MikeC
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| (Admin) |
| Sun Aug 26 2012 05:10 PM |
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Isaac Still Trying to get Organized
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6:00 AM EDT 27 August 2012 Update
Tropical Storm Isaac is now solidly in the Gulf of Mexico this morning, and the center has relocated closer to the central dense overcast., but the center still remains south of most of the weather. So strengthening for the next 12 hours or so would be slow, but there are signs that an actual eye (possibly tilted) is trying form, and Isaac's in the best position it's been since formation to strengthen this afternoon and evening.
The NOAA aircraft twitter states "Radar suggests an eye is forming in #Isaac.It is elliptical with major axis WNW-ESE and diameter 30 nm. In major bands to west."
But there are factors that will keep it from strengthening too quickly, such as the dry air and upper level low to the south of it, and the inability to keep the mid and low level centers aligned..
The eastern part of the storm is still moving through the Florida peninsula but should be out by the end of the day, this morning the heaviest bands are moving through central Florida, the bands train for a very long distance, so certain parts of Florida will likely see extended periods of rain, some of which could be rough or spawn tornadoes.
Those in the northern Gulf coast warning area should take preparations today. The storm moved more north than forecast last night (because of re-locations) and the forecast track briefly moved a bit east. Still because of center relocation, the exact track is in question.
New Tropical storm warnings are now up form Intracoastal City, AL to Morgan City, LA and new hurricane watches are up as well for the same area. the hurricane warning remains up east of there to Destin, FL.
2:00 AM EDT 27 August 2012 Update
Recon appears to be finding that Isaac is attempting to recenter itself much closer to its mid-level center, which had been impressive on radar all day Sunday. Tonight this center is nestled within explosive, deep convection, and it would seem that this MLC has probably drilled down to the surface, and if so, will try to leave the old low-level center to float and sputter in its wake.
We will be keeping an eye on this development closely, and should have a better handle on what the outcome of these, yet again competing centers, is by daybreak.
Ciel
Recon found that Isaac's strength has not changed much today, and the center passed just south of Key West.
The Hurricane Warning for the Keys, Dry Tortugas, Florida West coast and Florida Bay was changed to a Tropical Storm Warning.
And the tropical storm watch north of Sebastian cancelled.
However, the hurricane watch for a good portion of the gulf, is now a hurricane warning. This stretches from Morgan City, LA eastward to Destin, Fl and includes New Orleans and Lake Pontchartrain. This is a very large area to be under a hurricane warning, and it's basically because of the great deal of uncertainty in with the track (larger than the cone), because of the model spread.
Timing for landfall would be early morning on Wednesday based on the official track.
Those in the hurricane warning area need to be preparing now and watching the progress of the storm closely.
Please listen to local officials and media for recommendation for your area.
Early reports from the Keys indicate it wasn't too bad, thankfully Isaac did not strengthen rapidly today.
Let everyone know about Isaac related conditions in your area
Discussion on Isaac has been lively in the Forecast Lounge .
Special Storm Related Links
Florida Power & Light Power Outage Map
Progress Energy Power Outage Map
Florida Road Conditions
Florida Emergency Management (Floridadisaster.org)
Florida Keys/Monroe County, FL Emergency Information
Long Term RBTOP Satellite Float of Isaac (2012) -- Alternate style
Full Florida Radar Recording of Isaac Approach - Alternate animation
Noaa Hurricane Research Division Flight twitter
Flowing Wind Map
One minute Satellite Imagery of Isaac (Special GOES-14)
Storm Surge Probabilities for Isaac
Webcams and Streaming Video
Follow-along map/video of HurricaneTrack's Mark Sudduth (Joined by Mike Watkins later). GPS map, Radar, sat, and streaming video Please see hurricanetrack.com.
Mark and Mike are in Mississippi.
Jim Williams from Hurricane City is taking to the road for Isaac
]"Cyclone Oz" from Crazymother and his brother are also crazy and following Isaac with two vehicles .
Note: Webcams tend to get overloaded and die during events like these, if power outages don't get to them first.
Ocean Key Resort Live Stream cams (3 on one page)
Florida Keys Webcams
Beach Cam Key West (Controllable) South Street Key West Cam (Controllable)
Duval Street Key West streaming cam (w/ Audio)
Bahia Honda Key Cam Recording (Alt)
Florida Keys traffic cameras
Southernmost House Key West Cam RecordingAlt)
{{LAInfo}}
{{EastFloridaRadar}}
{{NortheastGulfRadar}}
{{NorthGulfRadar}}
{{StormLinks|Isaac|09|9|2012|09|Issac}}
{{StormLinks|97L|97|10|2012|97|97L}} WWL AM 870 in New Orleans streaming. Storm information online
| Colleen A. |
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| Sun Aug 26 2012 05:42 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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I'm very curious...if the track is so far away from Tampa, why didn't they drop the TS Warnings for our area? Or is because of the uncertainty they discussed in the 5pm discussion?
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MikeC
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| (Admin) |
| Sun Aug 26 2012 05:59 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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Quote:
I'm very curious...if the track is so far away from Tampa, why didn't they drop the TS Warnings for our area? Or is because of the uncertainty they discussed in the 5pm discussion?
The large wind field will be enough to bring tropical storm force winds across it, also Isaac seems to have slowed down quite a bit recently.
| Colleen A. |
| (Moderator) |
| Sun Aug 26 2012 06:07 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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Thank you, Mike. I thought I noticed that; but wasn't sure if I was the only one. I'm not entirely sure/confident that this current track will verify. Just a gut feeling. Thanks for your feedback.
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MikeC
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| (Admin) |
| Sun Aug 26 2012 06:17 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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In what seems to be a trend for Isaac, there are multiple mobile live trackers this year..
including...
Follow-along map/video of HurricaneTrack's Mark Sudduth (Joined by Mike Watkins later). GPS map, Radar, sat, and streaming video Please see [url=http://www.hurricanetrack.com]hurricanetrack.com[//url].
Jim Williams from Hurricane City is taking to the road for Isaac
]"Cyclone Oz" from Crazymother and his brother are also crazy and following Isaac with two vehicles .
If anyone else is out and about with a stream, let us know. Although I think this is a dangerous trend.
| typhoon_tip |
| (Meteorologist) |
| Sun Aug 26 2012 06:59 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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This is interesting ... According to the last 1 hour of rad animation, Isaac hasn't apparently moved, or is doing so very slowly. This from the Key West vantage.
| WesnWylie |
| (Weather Guru) |
| Sun Aug 26 2012 07:01 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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Not quiet sure what Isaac is doing at this time. Looking at the radar, he is just inching along now. There's the big flare-up near/N of the LLC but pressure has remained pretty steady.
| Thunderbird12 |
| (Meteorologist) |
| Sun Aug 26 2012 07:05 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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With the center moving somewhat further west than expected yesterday and the lack of significant strengthening, the tornado threat over Florida has thus far been rather low and the earlier Tornado Watch has expired. There is still a threat for isolated tornadoes and I'm sure that SPC will reissue a watch if it looks like the threat is ramping up.
Isaac's radar presentation is a bit odd right now, with radar elements at different levels moving in opposite directions in the intense convective mass northwest of the center. I'm not exactly sure how to interpret that, but it may be that Isaac is no longer vertically stacked and is trying to reorganize. The low-level center that was visible on radar earlier has disappeared under the southern edge of the convective mass and doesn't seem to be very well defined any more.
| Hawkeyewx |
| (Weather Analyst) |
| Sun Aug 26 2012 08:15 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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Isaac continues to really struggle with the dry air entrainment into its southern half. If anything, the convection and the surface center have become even more detached this evening. The last few recon fixes have actually shown the surface center moving mostly westward. Until this comes together there will be no strengthening. I like what the GFDL is doing with the strength. It only drops the pressure another 3 mb by tomorrow morning due to the poor organization. Then later tomorrow it shows a steady strengthening phase commencing.
| DaViking |
| (Verified CFHC User) |
| Sun Aug 26 2012 08:38 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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Looking at Doppler from Key West, It looks to me that a fairly defined "eye like feature" has formed and it appears to be drifting slowly North.
I'm using the Base reflectivity and did a quick check with velocity. Or, could this be a decoupling of the storm?
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MikeC
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| (Admin) |
| Sun Aug 26 2012 08:51 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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From what I can tell, that is the mid level circulation. Recon (Af300) just did a center fix a bit south of there, so yes it's decoupled a bit. The center can either reform under the mlc, or the current one will struggle on. But that hasn't happened yet, either way that pretty much halts any real strengthening for the short term at least. The upper level low and dry air to the southwest is impacting the storm too. The mid levels are unusually warm too, which is probably another facto.r.
So yeah, it's going to be another day of struggling isaac. (I hope it stays this way through the entire Gulf, honestly)
| BayCoGator |
| (Verified CFHC User) |
| Sun Aug 26 2012 09:00 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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Quote:
Looking at Doppler from Key West, It looks to me that a fairly defined "eye like feature" has formed and it appears to be drifting slowly North.
I'm using the Base reflectivity and did a quick check with velocity. Or, could this be a decoupling of the storm?
It does appear as though the LLC did undercut the convection and might be drifting NNW. It almost appears to be nearly due W of Key West. Hard to tell if this is another manifestation of Isaac's organization problems or if it's a legitimate move. Sure seems like he slowed up a bit, though...forecasting headache!
Edit - thanks, Mike. Wasn't sure if that was the LLC or mid-level. Decent presentation on radar, though.
| Hawkeyewx |
| (Weather Analyst) |
| Sun Aug 26 2012 09:26 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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This water vapor loop shows very well what is going on. The upper low to the west is too close and it is pumping a boatload of dry air northward and totally undercutting the storm.
Water Vapor
Frankly, the latest radar loop suggests Isaac is in some trouble. You can see a couple low level spiral bands moving wnw while the mid level CDO feature is now drifting away to the north... becoming increasingly decoupled. Recon has the pressure up 2 mb per the latest pass-through.
| Joeyfl |
| (Weather Guru) |
| Sun Aug 26 2012 09:43 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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Just when things were looking more clear Issac has taken a turn for the worse at least for now or not depending on the way you look at it. Issac low level center is hard to find and while recon is finding pressure 992mb south of the Dry Tortugas the mid level low is now moving northerly past the Tortugas. This will stop any further possible intensification and could throw a really monkey wrench in the future of Issac....The 11pm discussion should be interesting to say the least
| BayCoGator |
| (Verified CFHC User) |
| Sun Aug 26 2012 09:44 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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Quote:
This water vapor loop shows very well what is going on. The upper low to the west is too close and it is pumping a boatload of dry air northward and totally undercutting the storm.
Water Vapor
No question there's ample dry air SW, however, it also looks like Isaac has plenty of moisture SE that he's pulling in. Last few frames on the WV loop indicate Isaac is breathing pretty well, too. Best outflow the storm's had in a while.
| Thunderbird12 |
| (Meteorologist) |
| Sun Aug 26 2012 09:53 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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There is a pretty well-defined mid-level circulation evident on the higher tilts of the Key West base velocity data (starting at the 1.3 degree tilt at roughly 10,000 feet AGL) at around 24.6N, 82.7W. That is well north of the last recon fix (about an hour ago) at 24.1N, 82.6W. The northern center may try to take over at some point. The current LLC (based on recon) has essentially no radar signature whatsoever.
There have been a couple of tornado warnings issued in the past hour for south Florida, with one currently in effect for parts of south-central Broward and northeastern Miami-Dade county, just northeast of Miami. While the tornado threat isn't really high, some threat will persist through the night.
| upsman |
| (Registered User) |
| Sun Aug 26 2012 09:54 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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anyone else here see a slight north turn in this????? http://radar.weather.gov/ridge/radar.php?rid=byx&product=N0R&overlay=11101111&loop=yes
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MikeC
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| (Admin) |
| Sun Aug 26 2012 10:13 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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That's the mid level circulation, although there is some signs the center may be trying to reform closer to my (maybe just around the Dry Tortugas/Ft. Jefferson)
Also looks like a bad band going through near Ft. Lauderdale now.
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danielw
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| (Moderator) |
| Sun Aug 26 2012 10:16 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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24.1N 82.7W rough average fix
Air Force Vortex 18 minutes ago:
Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 27th day of the month at 01:50Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 300)
Storm Number & Year: 09L in 2012
Storm Name: Isaac (flight in the North Atlantic basin)
Mission Number: 24
Observation Number: 08
A. Time of Center Fix: 27th day of the month at 1:13:10Z
B. Center Fix Coordinates: 24°10'N 82°34'W (24.1667N 82.5667W)
B. Center Fix Location: 56 miles (91 km) to the WSW (241°) from Key West, FL, USA.
C. Minimum Height at Standard Level: 1,377m (4,518ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 38kts (~ 43.7mph)
E. Location of the Estimated Maximum Surface Wind: 69 nautical miles (79 statute miles) to the NE (40°) of center fix
F. Maximum Flight Level Wind Inbound: From 122° at 47kts (From the ESE at ~ 54.1mph)
G. Location of Maximum Flight Level Wind Inbound: 37 nautical miles (43 statute miles) to the NNE (32°) of center fix
H. Minimum Sea Level Pressure: 994mb (29.35 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 18°C (64°F) at a pressure alt. of 1,516m (4,974ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 21°C (70°F) at a pressure alt. of 1,525m (5,003ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 19°C (66°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Level: 850mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 0.5 nautical miles
Remarks Section:
Maximum Flight Level Wind: 60kts (~ 69.0mph) in the northwest quadrant at 23:17:30Z
Sea Level Pressure Extrapolation From: 850mb
NOAA Vortex, 8 minutes ago:
Product: NOAA Vortex Message (URNT12 KWBC)
Transmitted: 27th day of the month at 01:47Z
Aircraft: Lockheed WP-3D Orion (Reg. Num. N42RF)
Storm Number & Year: 09L in 2012
Storm Name: Isaac (flight in the North Atlantic basin)
Mission Number: 23
Observation Number: 31
A. Time of Center Fix: 27th day of the month at 1:05:38Z
B. Center Fix Coordinates: 24°06'N 82°48'W (24.1N 82.8W)
B. Center Fix Location: 71 miles (115 km) to the WSW (244°) from Key West, FL, USA.
C. Minimum Height at Standard Level: Not Available
D. Estimated (by SFMR or visually) Maximum Surface Wind: 28kts (~ 32.2mph)
E. Location of the Estimated Maximum Surface Wind: 3 nautical miles (3 statute miles) to the SE (137°) of center fix
F. Maximum Flight Level Wind Inbound: From 246° at 23kts (From the WSW at ~ 26.5mph)
G. Location of Maximum Flight Level Wind Inbound: 24 nautical miles (28 statute miles) to the SSE (158°) of center fix
H. Minimum Sea Level Pressure: 993mb (29.32 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 18°C (64°F) at a pressure alt. of 2,443m (8,015ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 20°C (68°F) at a pressure alt. of 2,444m (8,018ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 11°C (52°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind and Pressure
N. Fix Level: Other - Not surface, 1500ft, 925mb (if vortex is newer than about mid 90's; see note for more), 850mb, 700mb, 500mb, 400mb, 300mb or 200mb
O. Fix Determined By / Fix Level (Undecoded): 1 / 1 nm
Remarks Section - Remarks That Were Decoded...
Maximum Flight Level Wind: 45kts (~ 51.8mph) in the northeast quadrant at 23:30:00Z
Maximum Flight Level Wind Outbound: 44kts (~ 50.6mph) in the north quadrant at 1:22:49Z
Remarks Section - Additional Remarks...
SLP EXTRAP FROM 8K FT
| Thunderbird12 |
| (Meteorologist) |
| Sun Aug 26 2012 10:33 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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Looks like the mid-level center at around 24.7N, 82.9W has descended to the point where it can be picked up on the lowest radar tilt out of Key West. That is still around 7000 feet AGL, so it has a ways to go before it reaches the surface. The wind field has been slowly intensifying to the northeast of the mid-level circulation.
The system as a whole does look like it has started to move to the northwest again, after moving very little earlier this evening.
| ralphfl |
| (Weather Master) |
| Sun Aug 26 2012 10:34 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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I still see wnw and believe that is the 11pm direction also
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Ed Dunham
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| (Meteorologist & CFHC Forum Moderator) |
| Sun Aug 26 2012 11:14 PM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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Convective blooming makes it difficult to get a good fix on the movement from satellite, but it sure did slow down. Radar and Recon would suggest a decoupled system but it can certainly recover if the convective increase continues. Currently in this area there is not much in the way of a hint regarding the mid level steering for a decoupled system but in this case an old trick provides a clue. Water vapor loop shows the dry air moving up from the SSW under the influence of an upper level low over the Yucatan Peninsula.
Don't rely on the latest forecast bulletin to determine current movement because some of the content is made up early and the movement in the bulletin is usually a 12-hour average - a method that can sometimes get you in trouble. Using the 00Z and 03Z positions from the Forecast bulletin, Isaac has moved about 25 miles - which is a near-term speed of about 7 knots (over 3 hours) and not the 12 knots that is stated in the bulletin. This is why in meteorology the image is always better than the words. Check out the position fix at 06Z and you'll get a better feel for the short term movement.
Cheers,
ED
| sara33 |
| (Weather Guru) |
| Mon Aug 27 2012 12:35 AM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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Ed, Can you post the link to the 06Z please that you are referring to. Thanks!!
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Ed Dunham
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| (Meteorologist & CFHC Forum Moderator) |
| Mon Aug 27 2012 12:48 AM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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I guess that I should have clarified the NHC position location in the 2am (06Z) Intermediate bulletin.
Cheers,
ED
| dolfinatic |
| (Weather Guru) |
| Mon Aug 27 2012 01:48 AM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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I only see a more northerly component to the movement mainly NW at this time and considerably slower as well. Radar shows the northerly movement cant argue with that. Curious to see the 5 am disco. But probably wont change much. NHC like to keep continuity.
| Bloodstar |
| (Moderator) |
| Mon Aug 27 2012 01:50 AM |
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Re: Isaac Passes Just South of Key West, Hurricane Warnings now Up for Parts of the Gulf Coast
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Quote:
I guess that I should have clarified the NHC position location in the 2am (06Z) Intermediate bulletin.
Cheers,
ED
Well, it looks like the latest fix from Dropsonde into the eye is 24.93N 83.52W Which seems to indicate the center has relocated significantly north. (50 miles?)
I'm not sure what 50 miles would do to the model runs, but I hope outside of Louisiana and Mississippi are still paying close attention, because Tomorrow morning might be a shock.
The Hurricane hunters are also picking up a significant swath of 50 - 60 Knot winds aloft in the northeast quadrant. But so far those winds don't appear to be reflected down at the base.
Satellite shows the center fix is right smack in the middle of the most intense convection.
This could be a problem.
| cieldumort |
| (Moderator) |
| Mon Aug 27 2012 02:14 AM |
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Re: Isaac Attempting to Reorganize Under Explosive Central Convection Overnight.
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Here is a snapshot of Mission 24 into Isaac clearly showing the center reformation noted above by Bloodstar.
Tropical Storm Isaac has always been dogged by multiple centers, but it is likely that a core has so far not been able to establish not only because of competing vortices existing since its inception, but also because deep, central convection was never quite that persistent, pervasive and pronounced, having been held in check by repeated injections of dry air from its west and south, land interruptions, and bouts of modest shear.
These inhibiting factors are lessening overnight tonight, and should Isaac finally create a stable core, and provided he remains over water, rapid intensification will become very possible at times during the next 72 hours, likely starting as soon as the present.
| cieldumort |
| (Moderator) |
| Mon Aug 27 2012 02:31 AM |
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Re: Isaac Attempting to Reorganize Under Explosive Central Convection Overnight.
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Pretty conclusive Vortex Message coming out of the new center:
A. Time of Center Fix: 27th day of the month at 5:12:00Z
B. Center Fix Coordinates: 24°55'N 83°31'W (24.9167N 83.5167W)
B. Center Fix Location: 112 miles (180 km) to the WNW (283°) from Key West, FL, USA.
C. Minimum Height at Standard Level: 1,351m (4,432ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 34kts (~ 39.1mph)
E. Location of the Estimated Maximum Surface Wind: 89 nautical miles (102 statute miles) to the SW (217°) of center fix
F. Maximum Flight Level Wind Inbound: From 356° at 31kts (From the N at ~ 35.7mph)
G. Location of Maximum Flight Level Wind Inbound: 99 nautical miles (114 statute miles) to the SW (221°) of center fix
H. Minimum Sea Level Pressure: 990mb (29.23 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 16°C (61°F) at a pressure alt. of 1,527m (5,010ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 25°C (77°F) at a pressure alt. of 1,512m (4,961ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 17°C (63°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Level: 850mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 2 nautical miles
Remarks Section:
Maximum Flight Level Wind: 62kts (~ 71.3mph) in the northeast quadrant at 5:24:00Z
| BabyCat |
| (Weather Guru) |
| Mon Aug 27 2012 02:34 AM |
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Re: Isaac Attempting to Reorganize Under Explosive Central Convection Overnight.
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When will there be an updated model run?
If we're lucky, we will see this new information reflected in 12z model runs (later this morning).
Ciel
| ftlaudbob |
| (Storm Chaser) |
| Mon Aug 27 2012 02:54 AM |
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Re: Isaac Attempting to Reorganize Under Explosive Central Convection Overnight.
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Quote:
When will there be an updated model run?
The different models all run at different times.
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MikeC
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| (Admin) |
| Mon Aug 27 2012 06:50 AM |
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Re: Isaac Attempting to Reorganize Under Explosive Central Convection Overnight.
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There is an eye (albeit elliptical) forming in Isaac now, so it may get to hurricane strength today.
NOAA 2 recon is finding this as well (see https://twitter.com/HRD_AOML_NOAA )
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MikeC
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| (Admin) |
| Mon Aug 27 2012 07:03 AM |
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Re: Isaac Attempting to Reorganize Under Explosive Central Convection Overnight.
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Also in Florida, beware, there are still a few nasty bands over the state. One will likely come up from Okeechobee into Central Florida, and Cape Canaveral/Volusia is about to get a bad band as well, another one will near Jacksonville soon too.
| Hawkeyewx |
| (Weather Analyst) |
| Mon Aug 27 2012 09:13 AM |
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Re: Isaac Attempting to Reorganize Under Explosive Central Convection Overnight.
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Satellite shows increasing banding surrounding the center this morning, as opposed to just a fuzzy blob like late yesterday, which definitely indicates the surface and mid-level centers have finally made the connection and slow intensification has commenced. Landfall should be tomorrow, though, so there isn't a ton of time for any ridiculous strengthening. Gulf coast residents are fortunate Isaac's organization phase was delayed so long.
| WesnWylie |
| (Weather Guru) |
| Mon Aug 27 2012 09:37 AM |
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Re: Isaac Still Trying to get Organized
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After going more NW earlier this AM, Isaac seems to be heading W/NW once again over the last 45 minutes. Unfortunately, the circulation will be out of range of the Tampa radar in a few hours. It does look like it is still trying to organize, though.
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MikeC
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| (Admin) |
| Mon Aug 27 2012 09:53 AM |
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Re: Isaac Still Trying to get Organized
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Recon still showing it moving northwest, at this time I'd take that until a visual eye actually shows. I'm not sure if the northwest trend will continue or not, but it has for the past few hours.
| Thunderbird12 |
| (Meteorologist) |
| Mon Aug 27 2012 10:45 AM |
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Re: Isaac Still Trying to get Organized
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Isaac is finally starting to look like something that could become a hurricane, with at least a partial eyewall evident in the long-range radar and confirmed by recon. Outflow seems to be improving as well. The crucial time for intensification looks like it will be tonight, which is when several model solutions (such as the ECMWF) have been implying that most of the strengthening (if any) will occur. It still looks like the environment will become quite favorable, but large storms with ill-defined inner cores like Isaac typically do not undergo rapid intensification, so steady intensification seems like the best bet.
If Isaac can significantly tighten up its circulation in the next 6-12 hours, then something more than steady intensification would be possible. Odds are against it.
| Hawkeyewx |
| (Weather Analyst) |
| Mon Aug 27 2012 11:00 AM |
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Re: Isaac Still Trying to get Organized
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Despite the increasing organization, Isaac is still not doing much. The latest recon report shows no increase in wind and a pressure still stuck a bit below 990 mb. We may have to wait until tonight to see steady strengthening. Heck, it may never strengthen much.
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MikeC
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| (Admin) |
| Mon Aug 27 2012 11:07 AM |
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Re: Isaac Still Trying to get Organized
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Central Florida is getting a few very nasty bands coming through, Tornado in Christmas/Chuluota area crossing into Seminole now.
The 11AM advisory has WNW in one spot, and NW in another, movement in the movement section is 305, which is barely considered northwest, but it's splitting hairs.
| Rasvar |
| (Weather Master) |
| Mon Aug 27 2012 11:24 AM |
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Re: Isaac Still Trying to get Organized
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Quote:
The 11AM advisory has WNW in one spot, and NW in another, movement in the movement section is 305, which is barely considered northwest, but it's splitting hairs.
I guess that's what happens when you are trying to figure out where the real center is. Isaac really does seem to have the same level of ability to organize his core that I have to organize my desk - not much.
| WesnWylie |
| (Weather Guru) |
| Mon Aug 27 2012 11:29 AM |
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Re: Isaac Still Trying to get Organized
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NHC: "THE LACK OF STRENGTHENING APPEARS TO TO BE DUE TO THE
LARGER-THAN-AVERAGE WIND RADII...WHICH HAVE YET TO CONTRACT
INWARD...ALONG WITH THE PERIODIC ENTRAINMENT OF DRY MID-LEVEL AIR
FROM THE EASTERN SEMICIRCLE INTO THE INNER-CORE REGION. UNTIL THE
DRY AIR MIXES OUT...EROSION OF THE INNER-CORE CONVECTION WILL
LIKELY CONTINUE UNTIL ISAAC APPROACHES THE NORTH-CENTRAL GULF COAST
IN ABOUT 24 HOURS."
This system reminds me of Hurricane Alex back in 2010, regarding the issue with the strengthening wind field (or lack thereof). It also had trouble getting above a Tropical Storm until closer to landfall. It made it to a Cat. 2 with winds of 105mph; however, it's pressure was 946mb - that of a Major Hurricane.
Added at 10:34 AM CDT : Here's a good summary of Alex by the NWS in Corpus Christi: http://www.srh.noaa.gov/crp/?n=hurricanealex
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MikeC
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| (Admin) |
| Mon Aug 27 2012 11:36 AM |
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Re: Isaac Still Trying to get Organized
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Hurricane Hunters just found an 80MPH wind with the SMFR, A sign Isaac may becoming a hurricane now.
| BayCoGator |
| (Verified CFHC User) |
| Mon Aug 27 2012 12:33 PM |
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Re: Isaac Still Trying to get Organized
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Quote:
Hurricane Hunters just found an 80MPH wind with the SMFR, A sign Isaac may becoming a hurricane now.
And appears to be moving more W than N, too...
| WeatherNut |
| (Weather Master) |
| Mon Aug 27 2012 01:37 PM |
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Re: Isaac Still Trying to get Organized
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At 12:38est buoy 42003 recorded a pressure of 986.3mb (and falling rapidly) and winds of 37kts gust 47kts out of the south...so I think we are going to see lower pressures this time with recon
(as a side note...does anyone know why the aircraft are not reporting surface pressures?)
| Bloodstar |
| (Moderator) |
| Mon Aug 27 2012 02:11 PM |
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Re: Isaac Still Trying to get Organized
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Quote:
Hurricane Hunters just found an 80MPH wind with the SMFR, A sign Isaac may becoming a hurricane now.
The good news is the center relocation didn't advance the organization of the storm faster, So while Isaac may be near or at Hurricane status now, the 12 hour delay could be really important in keeping Isaac from becoming an even more dangerous storm.
| hogrunr |
| (Weather Guru) |
| Mon Aug 27 2012 02:18 PM |
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Re: Isaac Still Trying to get Organized
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Also to note about Isaac's track and center relocations. According to one of NOAA's twitter pages, the center is rotating trochoidal around the storm.
https://twitter.com/HRD_AOML_NOAA
http://en.wikipedia.org/wiki/Trochoid
So this makes a visible center location/system movement hard to determine.
| BayCoGator |
| (Verified CFHC User) |
| Mon Aug 27 2012 02:54 PM |
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Re: Isaac Still Trying to get Organized
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Quote:
Also to note about Isaac's track and center relocations. According to one of NOAA's twitter pages, the center is rotating trochoidal around the storm.
https://twitter.com/HRD_AOML_NOAA
http://en.wikipedia.org/wiki/Trochoid
So this makes a visible center location/system movement hard to determine.
Very interesting phenomenon considering the storms healthy satellite appearance. You'd think a storm with such an unsettled organizational foundation wouldn't present so well.
| Bloodstar |
| (Moderator) |
| Mon Aug 27 2012 02:59 PM |
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Re: Isaac Still Trying to get Organized
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Quote:Quote:
Also to note about Isaac's track and center relocations. According to one of NOAA's twitter pages, the center is rotating trochoidal around the storm.
https://twitter.com/HRD_AOML_NOAA
http://en.wikipedia.org/wiki/Trochoid
So this makes a visible center location/system movement hard to determine.
Very interesting phenomenon considering the storms healthy satellite appearance. You'd think a storm with such an unsettled organizational foundation wouldn't present so well.
IIRC - Trochoid movement is common with storm, it leads to the classic wobble along the mean motion. so I don't think trochoidal movement indicates an unhealthy storm specifically.
| hogrunr |
| (Weather Guru) |
| Mon Aug 27 2012 03:00 PM |
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Re: Isaac Still Trying to get Organized
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Quote:Quote:
Also to note about Isaac's track and center relocations. According to one of NOAA's twitter pages, the center is rotating trochoidal around the storm.
https://twitter.com/HRD_AOML_NOAA
http://en.wikipedia.org/wiki/Trochoid
So this makes a visible center location/system movement hard to determine.
Very interesting phenomenon considering the storms healthy satellite appearance. You'd think a storm with such an unsettled organizational foundation wouldn't present so well.
That being said...it does seem like there is definitely a more western component to the movement in the last couple of satellite frames. Looking at the satellite overlayed with the forecast points seems to point towards this movement as well.
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danielw
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| (Moderator) |
| Mon Aug 27 2012 03:14 PM |
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Re: Isaac Still Trying to get Organized
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Trochoid or Fujiwhara. The models predicted this rotation about a moving center point several days ago.
However, the rotation is forecast to consolidate before landfall.
Two main points of concern at this time are the storm surge and the prolonged hours of tropical storm force winds over the area. Issac is forecast to slow down to a crawl at landfall and this could mean a 24 to 36 hour period of winds higher than 45 mph. Copius amounts of rainfall can be produced in a slow moving tropical cyclone.
I saw a local NWS model forecast here of up to 8 inches of rainfall from Issac with wind gusts to 80 mph. Those amounts have decreased for some reason but they are still prolonged.
I'm 60 miles inland.
Make sure that you are finished with or nearly finished with storm preps before Sunset tonight or about 8 PM.
| mikethewreck |
| (Weather Watcher) |
| Mon Aug 27 2012 09:12 PM |
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Re: Isaac Still Trying to get Organized
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Is the band that was on the east coast of Florida today with significant energy (several tornadoes in the Treasure Coast area including one that audibly went by our house at 11 AM) which is now pulling off to the north by east another rotational center in this vortically challenged storm?
My wife went through Andrew in Leisure City (Ground Zero for that Cat 5 monster) and was scared today by the intense storm band and tornado. She was also thankful her paranoid husband put up all the shutters and storm panels Saturday morning.
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danielw
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| (Moderator) |
| Mon Aug 27 2012 11:21 PM |
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Re: Isaac Still Trying to get Organized
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Product: NOAA Vortex Message (URNT12 KWBC)
Transmitted: 28th day of the month at 02:54Z
Aircraft: Lockheed WP-3D Orion (Reg. Num. N42RF)
Storm Number & Year: 09L in 2012
Storm Name: Isaac (flight in the North Atlantic basin)
Mission Number: 28
Observation Number: 46
A. Time of Center Fix: 28th day of the month at 2:11:18Z
B. Center Fix Coordinates: 27°04'N 86°57'W (27.0667N 86.95W)
B. Center Fix Location: 229 miles (368 km) to the SSW (200°) from Panama City, FL, USA.
C. Minimum Height at Standard Level: 2,979m (9,774ft) at 700mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 52kts (~ 59.8mph)
E. Location of the Estimated Maximum Surface Wind: 17 nautical miles (20 statute miles) to the SE (145°) of center fix
F. Maximum Flight Level Wind Inbound: From 254° at 49kts (From the WSW at ~ 56.4mph)
G. Location of Maximum Flight Level Wind Inbound: 74 nautical miles (85 statute miles) to the S (173°) of center fix
H. Minimum Sea Level Pressure: 980mb (28.94 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 12°C (54°F) at a pressure alt. of 3,070m (10,072ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 15°C (59°F) at a pressure alt. of 3,054m (10,020ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 12°C (54°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Poorly Defined
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind, Pressure and Temperature
N. Fix Level: 700mb
O. Fix Determined By / Fix Level (Undecoded): 1 / 1 nm
Remarks Section:
Maximum Flight Level Wind: 70kts (~ 80.6mph) in the southeast quadrant at 22:34:49Z
Maximum Flight Level Wind Outbound: 62kts (~ 71.3mph) in the northeast quadrant at 2:24:20Z
Sea Level Pressure Extrapolation From: 700mb
Maximum Flight Level Temp: 16°C (61°F) which was observed 6 nautical miles to the SE (127°) from the flight level center
Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 28th day of the month at 03:06Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 309)
Storm Number & Year: 09L in 2012
Storm Name: Isaac (flight in the North Atlantic basin)
Mission Number: 29
Observation Number: 06
A. Time of Center Fix: 28th day of the month at 2:31:00Z
B. Center Fix Coordinates: 27°07'N 87°00'W (27.1167N 87.W)
B. Center Fix Location: 227 miles (365 km) to the SSW (201°) from Panama City, FL, USA.
C. Minimum Height at Standard Level: 1,251m (4,104ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 50kts (~ 57.5mph)
E. Location of the Estimated Maximum Surface Wind: 62 nautical miles (71 statute miles) to the NW (307°) of center fix
F. Maximum Flight Level Wind Inbound: From 43° at 65kts (From the NE at ~ 74.8mph)
G. Location of Maximum Flight Level Wind Inbound: 73 nautical miles (84 statute miles) to the NW (308°) of center fix
H. Minimum Sea Level Pressure: 979mb (28.91 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 16°C (61°F) at a pressure alt. of 1,521m (4,990ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 22°C (72°F) at a pressure alt. of 1,466m (4,810ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 17°C (63°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Open in the south
M. Eye Shape & Diameter: Circular with a diameter of 28 nautical miles (32 statute miles)
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Levels (sfc and flt lvl centers are within 5nm of each other): Surface and 850mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1 nautical mile
Remarks Section:
Maximum Flight Level Wind: 65kts (~ 74.8mph) in the northwest quadrant at 2:07:30Z
Maximum Flight Level Wind Outbound: 68kts (~ 78.3mph) in the southeast quadrant at 2:54:00Z
| OrlandoDan |
| (Storm Tracker) |
| Tue Aug 28 2012 06:24 AM |
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Re: Isaac Still Trying to get Organized
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Does anyone else see a fairly defined eye form on various Floater loops of 0945 UTC?
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danielw
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| (Moderator) |
| Tue Aug 28 2012 07:59 AM |
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Re: Isaac Still Trying to get Organized
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I see two consecutive Vortex messages with max. flight level winds that should equal 75 mph at the surface.
The pressure/ wind relationship should equal a maximum wind speed of 98 mph IF Issac were a fully formed storm.
That's my two cents.
Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 28th day of the month at 09:25Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 309)
Storm Number & Year: 09L in 2012
Storm Name: Isaac (flight in the North Atlantic basin)
Mission Number: 29
Observation Number: 22
A. Time of Center Fix: 28th day of the month at 8:43:20Z
B. Center Fix Coordinates: 27°26'N 87°58'W (27.4333N 87.9667W) (View map)
B. Center Fix Location: 213 miles (342 km) to the SSW (192°) from Pensacola, FL, USA.
C. Minimum Height at Standard Level: 1,239m (4,065ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 50kts (~ 57.5mph)
E. Location of the Estimated Maximum Surface Wind: 78 nautical miles (90 statute miles) to the NE (45°) of center fix
F. Maximum Flight Level Wind Inbound: From 143° at 71kts (From the SE at ~ 81.7mph)
G. Location of Maximum Flight Level Wind Inbound: 83 nautical miles (96 statute miles) to the NE (46°) of center fix
H. Minimum Sea Level Pressure: 977mb (28.85 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 18°C (64°F) at a pressure alt. of 1,526m (5,007ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 21°C (70°F) at a pressure alt. of 1,525m (5,003ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 21°C (70°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Open in the southwest
M. Eye Shape & Diameter: Circular with a diameter of 32 nautical miles (37 statute miles)
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Levels (sfc and flt lvl centers are within 5nm of each other): Surface and 850mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 2 nautical miles
Remarks Section:
Maximum Flight Level Wind: 78kts (~ 89.8mph) in the east quadrant at 7:52:00Z
Product: NOAA Vortex Message (URNT12 KWBC)
Transmitted: 28th day of the month at 11:37Z
Aircraft: Lockheed WP-3D Orion (Reg. Num. N42RF)
Storm Number & Year: 09L in 2012
Storm Name: Isaac (flight in the North Atlantic basin)
Mission Number: 30
Observation Number: 13
A. Time of Center Fix: 28th day of the month at 11:03:52Z
B. Center Fix Coordinates: 27°47'N 88°08'W (27.7833N 88.1333W) (View map)
B. Center Fix Location: 190 miles (306 km) to the SSE (163°) from Gulfport, MS, USA.
C. Minimum Height at Standard Level (Undecoded): NA NA
D. Estimated (by SFMR or visually) Maximum Surface Wind: 59kts (~ 67.9mph)
E. Location of the Estimated Maximum Surface Wind: 79 nautical miles (91 statute miles) to the S (174°) of center fix
F. Maximum Flight Level Wind Inbound: From 257° at 69kts (From the WSW at ~ 79.4mph)
G. Location of Maximum Flight Level Wind Inbound: 74 nautical miles (85 statute miles) to the S (174°) of center fix
H. Minimum Sea Level Pressure: 981mb (28.97 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 14°C (57°F) at a pressure alt. of 2,425m (7,956ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 18°C (64°F) at a pressure alt. of 2,437m (7,995ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 15°C (59°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Poorly Defined
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Level: Other - Not surface, 1500ft, 925mb (if vortex is newer than about mid 90's; see note for more), 850mb, 700mb, 500mb, 400mb, 300mb or 200mb
Remarks Section - Remarks That Were Decoded...
Maximum Flight Level Wind: 75kts (~ 86.3mph) in the east quadrant at 9:14:32Z
Maximum Flight Level Wind Outbound: 63kts (~ 72.5mph) in the north quadrant at 11:24:40Z
Remarks Section - Additional Remarks...
SEC MAX FL WIND 66 KT BRNG:175 deg RNG:103 nm
SLP EXTRAP FROM 8K FT
| JoshuaK |
| (Weather Guru) |
| Tue Aug 28 2012 08:31 AM |
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Re: Isaac Still Trying to get Organized
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Look at this here;
000
URNT12 KNHC 281222
VORTEX DATA MESSAGE AL092012
A. 28/11:38:20Z
B. 27 deg 51 min N
088 deg 13 min W
C. 850 mb 1224 m
D. 45 kt
E. 303 deg 69 nm
F. 042 deg 58 kt
G. 304 deg 78 nm
H. 977 mb
I. 17 C / 1527 m
J. 21 C / 1527 m
K. 20 C / NA
L. OPEN SSW - NNE
M. C50
N. 12345 / 8
O. 0.02 / 1 nm
P. AF306 3109A ISAAC OB 04
MAX OUTBOUND FL WIND 86 KT SE QUAD 11:57:30Z
Pressure remains low while 86 knot winds, which would normally translate to 85 mph surface winds, but in this storm's case they seem to be going at about a 15mph reduction rate instead of a normal 10, so perhaps 80mph surface winds? Still a hurricane, or should be, at the 11AM advisory, since the intermediate has already come out.
EDIT: Oh and yes, looks like an eye is forming on the last few frames on Visible, AVN, and Water Vapor, centered at about 27.7N and 88.5W as of the 11:45 UTC image.