MikeCAdministrator
(Admin)
Sat Aug 20 2011 10:40 PM
Tropical Storm Irene To Cross Puerto Rico Tonight

11PM EDT Update 21 August 2011
They went closer to the TVCN and consensus with the 11PM track, but only marginally so. Irene may briefly hit hurricane force before landfall in Puerto Rico (at 70mph it's very close now). After that the official forecast takes it along the northern coast of the Dominican republic, and later through the Bahamas, with landfall near Cape Canaveral. The cone still is fairly uncertain at that range and may extend eastward or slightly westward. With a lean toward the east right now. Those in the Florida, Georgia, South Carolina, and North Carolina should continue to monitor Irene.

Hurricane watches are now up for the Central Bahamas.

8PM EDT Update 21 August 2011
Hurricane Warnings are up for Puerto Rico, Vieques, Culebra, and the entire coastline of the Dominican Republic.
Hurricane Watches are up for the US Virgin Islands

Tropical Storm Warnings are up for the US and British Virgin Islands, Haiti, St. Martin and St. Barthelemy, the Southeastern Bahamas and the Turks and Caicos Islands.
Tropical Storm watches are now up for the Central Bahamas as well.

Recon has found higher winds and lower pressure in Irene, 995 mb, after taking off from St. Croix while the center of circulation was over the island.

Most of Puerto Rico will be on the 'dirty' side of Irene as it passes over tonight, it will be an extremely rough evening there. Those in the area should be prepared.



After this, the forecast appears like there is no avoiding Hispaniola for Irene, and that it will at least cross over the Dominican Republic, probably as a hurricane. It is very likely Irene will become a hurricane tonight or early tomorrow as the system has a very healthy core, even though the southern outflow is lacking.

Beyond this is still speculation, but the current trends, with the notable exception of the GFDL, suggest it staying east of Florida and eventually impacting in south or North Carolina. The official forecast still takes it through Florida, which is very possible, this depends on exactly how far west Irene gets before feeling the weakness in the ridge. Based on radar imagery Irene may be in the process of slowing forward motion, which would extend the time affecting Peurto Rico.

Those in the Watch/Warning areas, Cone, and all along the US Southeast from all of Florida to North Carolina need to watch Irene very closely.

Tropical Depression Harvey is back over water in the Bay of Campeche and is expected to regain Tropical Storm Force before making a second landfall in Southern Mexico. Tropical Storm Warnings are up for the coast from Punta el Lagarto to Barra de Nautla.


Added radar recording of Puerto Rico long range radar here.

{{StormCarib}}

8:30AM Update 21 August 2011
Tropical Storm Irene has entered the Caribbean, it is now just west of the volcanic island of Montserrat, the center reformed a bit further north overnight closer to most of the convection, and on Leewards/Guadaloupe Radar the position is easily seen.

There is a strong subtropical ridge to the north of Irene which will curtain much movement to the north for the short term, but will still bring it uncomfortable close to Puerto Rico, with this forecast they will receive the dirty side of the storm. After that, the official forecast calls for Irene to become this year's first Atlantic hurricane as it approaches the Dominican Republic. Today and tomorrow will be very important days for the future track of the system.

For this reason there are now hurricane warnings up for the south coast of the Dominican Republic to haiti, as well as hurricane watches for the entirety of Puerto Rico, Vieques, and Culebra.



The ridge remains strong until about Wednesday, then it may have enough of a weakness to allow it to move more northward, and according to the official forecast that would take it over Haiti and Eastern Cuba, weakening the system, perhaps quite a bit. However, it main remain organized enough to recover somewhat after entering the Florida straights, and by then it will have slowed enough to give it a good day over the extremely warm Florida straits, and therefore the official forecast regenerates it into a hurricane and makes landfall in south Florida (South of Miami).

Most of the models are in fairly close agreement, but only diverge near closer to Florida, some taking it just west (which puts , and some taking it just east (Which would imply South or North Carolina as the ridge is expected to build back in quite solidly). The consensus is right up the spine of Florida, and unfortunately, there isn't much right now that would suggest otherwise that it will likely be some sort of threat to the Central Gulf, but more likely for Florida, Georgia, South Carolina, and North Carolina based on the current position . We'll look for good news in that regard. The best news would be for the system to have enough land interaction that it never recovers, but the official forecast still calls for a hurricane south Florida landfall Overnight Thursday into Friday. Those in the cone will need to watch Irene closely to see what happens with the track today and how much land interaction it has. And based on the official forecast, making sure your supplies are in order in case the cone verifies is probably a good idea, and watch to see what occurs with the track. Current indications are that if it were to change, it would be to the east. Still the odds of recurving before landfall in the US are very low.

Based on the latest satellites and radar, it looks like the center is getting drawn northward more into the convection, which is not so good for Puerto Rico, and lessens the impact from Hispaniola. Based on water vapor, I don't see this trend lasting much longer, the primarily western motion likely will kick in pretty soon.


Added radar recording of Puerto Rico long range radar here.

Leewards/Martinique Radar recording for Irene Approach

See the Forecast Lounge for more speculation on Irene.

Original Update
Tropical Storm Irene has formed East of the Leeward Islands from two recon reports in the area of the invest known as
97L.

Tropical Storm Warnings are up for: Puerto Rico and US Virgin Islands, Vieques, Culebra.

Curaco, St. Eustatius, St. Maartin. Dominica, Barbus, St. Kitts, Nevis, Antigua, Montserrat, Anguilla, British Virgin Islands.

Irene is a large system, the current official forecast track takes it through the Caribbean south of the islands until Hait, but the northern edges may still receive Tropical Storm force winds. It then clips through eastern Cuba, and the end of the forecast period puts it just south of Florida. There is greater than usual uncertainty about intensity, but track seems fairly solid in the Cone. Anyone in the cone should pay close attention to what happens with Irene over the next few days.

The good news is that the current forecast keeps it at Tropical Storm force after it crosses the islands, assuming that occurs, a much weaker system would be approaching Florida. It's also fairly disorganized right now for a Tropical Storm. The bad news, as this forecast goes with the large assumption that land interaction is fairly high after 3 days or so. If it were to avoid land (especially Hispaniola) it could be much stronger, and the National Hurricane Center indicates this as such. Therefore, it must be watched closely by the US Southeast, Florida, and North Central Gulf coasts.



Added radar recording of Puerto Rico long range radar here.

Leewards/Martinique Radar recording for Irene Approach

See the Forecast Lounge for more speculation on Irene.

{{StormCarib}}


{{StormLinks|Irene|09|9|2011|2|Irene}}

{{StormLinks|Harvey|08|8|2011|1|Harvey}}

{{StormLinks|98L|98|10|2011|3|98L}}




Flhurricane Radar Recording of Martinique Radar (93L Approach)

Long term Central Atantic wide area Water Vapor Satellite for Hurricane Season Peak flhurricane)

Long term West Atantic wide area Water Vapor Satellite for Hurricane Season Peak flhurricane)


Hugh
(Senior Storm Chaser)
Sat Aug 20 2011 11:08 PM
Re: Tropical Storm Irene Forms East of the Leeward Islands

Official track is out.... appears to take dead aim at Florida (the extreme southern tip of the peninsula)... although a recurve past day five wouldn't be shown in the oficial forecast.

Mike: The current forecast does not keep it at a tropical storm, actually. The 22/1800Z forecast is at 65kts, which is a Cat 1 hurricane in the Caribbean (before crossing Hispanola).


MikeCAdministrator
(Admin)
Sat Aug 20 2011 11:09 PM
Re: Tropical Storm Irene Forms East of the Leeward Islands

Tropical Storm Warnings are up for: Puerto Rico and US Virgin Islands, Vieques, Culebra.

Curaco, St. Eustatius, St. Maartin. Dominica, Barbus, St. Kitts, Nevis, Antigua, Montserrat, Anguilla, British Virgin Islands.


MikeCAdministrator
(Admin)
Sat Aug 20 2011 11:28 PM
Re: Tropical Storm Irene Forms East of the Leeward Islands

The official forecast is right along the model consensus (Well just slightly west of it), there is enough of a question factor toward the end to keep the entire cone (both west and east) into play, so it could shift into the Gulf.

The tricky thing is that intensity forecast, man, even 50 miles difference between Haiti or not would likely make a huge difference. The Hurricane Center is going conservative on the forecast, which is based on their own track and odds, so it's not too bad, but even they state in the discussion that it is highly uncertain. I'd keep watch of the trends over the week, if it were to affect South Florida it would likely be Friday.

For a graphic of actual probabilities, this is the best one:



Random Chaos
(Weather Analyst)
Sun Aug 21 2011 12:44 AM
Re: Tropical Storm Irene Forms East of the Leeward Islands

At present I would not obsess over the track taking it toward Florida.

First, this is 5 days out. In hurricane time, that is a very long period. Hurricanes are erratic and hard to predict past about two days.

Second, my rule of thumb on tropical cyclones: give 12 to 24 hours after a tropical storm is declared for model runs to do a good job with the tracks; give generally 12 hours after an significant strengthening of a cyclone to get updated model runs with the deeper storm. Based on this, it will be sometime tomorrow (Sunday) before we really get a good handle on the storm's track.

This is heavily due to the fact that model runs take time to run, with the GFS / NOGAPS outputting every 6 hours data ingested 6 hours earlier, and the GFDL / GFNL running every 6 hours base on the output of various global models. This means that the minimum time before the GFDL / GFNL shows a run that ingested the current storm data (specifically the hurricane hunter recon data) is at least 12 hours from now.

Third, if the storm does stick to that track, it will pass over the mountains on Hispanola. It will be substantially weakened by that.

Fourth, if the storm strengthens, and thus deepens, the track will likely shift toward the right, making it more likely to miss Florida (but not guaranteed), though that does open up other east coast targets.


LoisCane
(Veteran Storm Chaser)
Sun Aug 21 2011 12:53 AM
Re: Tropical Storm Irene Forms East of the Leeward Islands

Hard to ignore it, obsess is a funny word. Pay attention to it...

A worry I have is that each system this year has been small and not amounted to much. Because Hispanola was a good windbreak for the last one, does not mean it will work this time... as history has shown.

So, it's important to pay attention.

Yes, a stronger storm would pull more poleward and be affected by frontal boundaries... a weaker storm might go west but that depends on other factors... the strength of the high, etc.

If I lived in South Florida...which I basically do ... I would stock up on hurricane supplies this week (within reason money wise as everyone is very budget concous now as there are school snacks on sale this week that could be used for the kids or picnics later in the week if the storm pulls north.

Either way, she looks beautiful on sat imagery. Very classic Cape Verde looking storm pulling together here, well from a CV wave ..


CDMOrlando
(Weather Hobbyist)
Sun Aug 21 2011 03:33 AM
Re: Tropical Storm Irene Forms East of the Leeward Islands

The current run of the GFS shear map indicates upper level winds will remain very conducive for further development during the next 4-5 days.

There may have been a center reformation from the initial advisory, to the NW and just east of the convection, as she is now north of the forecast points.  Imagery also indicates more of a WNW motion at the moment, which may become more westerly (275-280)  briefly, based on current steering flow. http://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8dlm2.GIF

If this is a true deviation from course, then she could spend more time over water, which could be the worse case scenario, as a shift either way in track too much will allow more strengthening.


scottsvb
(Weather Master)
Sun Aug 21 2011 12:12 PM
Re: Tropical Storm Irene Forms East of the Leeward Islands

Not many postings going on here as in past years on systems... but sticking to Irene... the NHC has the position wrong. It's more like 16.8N and 62.3W.... it's obvious on Radar and Recon. Not sure if we need younger people to see cords at the NHC.

Edski
(Verified CFHC User)
Sun Aug 21 2011 12:26 PM
Re: Tropical Storm Irene Forms East of the Leeward Islands

It looks a little more to the north than I saw last night, and certainly in the eastern Hebert box. Most of Florida is in the 20-30% chance of TS force winds at 120 hours, which at this point seems a little troubling. As Lois Cane said, it's time to get prepared, not nervous. Getting nervous never helps.

scottsvb
(Weather Master)
Sun Aug 21 2011 12:32 PM
Re: Tropical Storm Irene Forms East of the Leeward Islands

People should already have the stuff they needed as of June 1st, but they can always go to the store or recheck items. For people living on the west coast of Florida.. I wouldnt make any plans until Tuesday morning if the models show a florida or GOM track by then.. Keys and S Florida Monday night. We still dont know forsure where this will go yet.

BayCoGator
(Weather Watcher)
Sun Aug 21 2011 12:33 PM
Re: Tropical Storm Irene Forms East of the Leeward Islands

Is that an eye beginning to form slightly N of 17 and about 62.5-ish W? Movement on latest vis frames seems to be generally westward, taking it south of PR.

scottsvb
(Weather Master)
Sun Aug 21 2011 12:37 PM
Re: Tropical Storm Irene Forms East of the Leeward Islands

No .. just dry slot.. which is normal.. pressure is too high for a eye ...

danielwAdministrator
(Moderator)
Sun Aug 21 2011 12:44 PM
Re: Tropical Storm Irene Forms East of the Leeward Islands

Definitely the Center of Circulation, or CoC.
Systems don't normally have an Eye until they area near 90 mph sustained winds and/ or pressure near 985mb.



Current location would place all of the Virgin Isles and Puerto Rico in the Right Quadrant with respect to motion/ heading. Hence the Watches and Warning for those areas.


danielwAdministrator
(Moderator)
Sun Aug 21 2011 12:48 PM
Re: Tropical Storm Irene Forms East of the Leeward Islands

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 21st day of the month at 12:28Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 300)
Storm Number & Year: 09L in 2011
Storm Name: Irene (flight in the North Atlantic basin)
Mission Number: 2
Observation Number: 02
A. Time of Center Fix: 21st day of the month at 12:08:00Z
B. Center Fix Coordinates: 16°46'N 62°22'W (16.7667N 62.3667W) (View map)
B. Center Fix Location: 10 miles (16 km) between the W and WNW (281°) from Salem, Montserrat.
C. Minimum Height at Standard Level: 1,477m (4,846ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 36kts (~ 41.4mph)
E. Location of the Estimated Maximum Surface Wind: 33 nautical miles (38 statute miles) to the WNW/NW (304°) of center fix
F. Maximum Flight Level Wind Inbound: From 43° at 43kts (From the NE at ~ 49.5mph)
G. Location of Maximum Flight Level Wind Inbound: 43 nautical miles (49 statute miles) to the NW (307°) of center fix
H. Minimum Sea Level Pressure: 1006mb (29.71 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 16°C (61°F) at a pressure alt. of 1,529m (5,016ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 17°C (63°F) at a pressure alt. of 1,524m (5,000ft)
K. Dewpoint Temp & 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, 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: 3 nautical miles
Remarks Section:
Maximum Flight Level Wind: 43kts (~ 49.5mph) in the northwest quadrant at 11:48:00Z


danielwAdministrator
(Moderator)
Sun Aug 21 2011 12:55 PM
Re: Tropical Storm Irene Forms East of the Leeward Islands

Center of Circulation can be seen here between Montserrat and St Kitts.



Loop may be viewed here:
http://www.ssd.noaa.gov/VAAC/DATA/rtgifs/souf/souf_ir4_loop_short.html


MikeCAdministrator
(Admin)
Sun Aug 21 2011 01:10 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Based on the latest satellites and radar, it looks like the center is getting drawn northward more into the convection, which is not so good for Puerto Rico, and lessens the impact from Hispaniola. Based on water vapor, I don't see this trend lasting much longer, the primarily western motion likely will kick in pretty soon. That and I put emily in the title earlier instead of Irene, which means I didn't get enough sleep.



BayCoGator
(Weather Watcher)
Sun Aug 21 2011 01:12 PM
Re: Tropical Storm Irene Forms East of the Leeward Islands

Thanks! Been a while since I've seen a TS sat image that wasn't lopsided with disjointed low and mid-level centers. This one is looking pretty healthy and symmetric this morning with good convection surrounding and close to the CoC.

javlin
(Weather Master)
Sun Aug 21 2011 01:44 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Quote:

Based on the latest satellites and radar, it looks like the center is getting drawn northward more into the convection, which is not so good for Puerto Rico, and lessens the impact from Hispaniola. Based on water vapor, I don't see this trend lasting much longer, the primarily western motion likely will kick in pretty soon. That and I put emily in the title earlier instead of Irene, which means I didn't get enough sleep.






I was just thinking that myself Mike just looked at a 24hr WV loop and one will notice Harvey,sm ULL and Irene all moving W and it has been that way for weeks.It appears now how strong does Irene get and how much lift does the trof provide as usual timing

http://mapcenter.hamweather.com/satellite/wv/24hr/crb.html?s=640x480


MikeCAdministrator
(Admin)
Sun Aug 21 2011 01:51 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

One of the bigger worries I have is that the steering currents aren't going to be a strong as some of the models are suggesting, meaning the storm will slow down more than indicated, so that the general turn north is less dramatic and more stretched out. Right now the storm is organizing itself and isn't really the best time to try to figure out the future path (I'm fairly sure it'll reform a bit north at the next advisory)

Very long term WV loop we've been running


scottsvb
(Weather Master)
Sun Aug 21 2011 01:54 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Well they blew the cords at the NHC at 8am adv... so they will move it more WNW... right now I see the LLC around 16.9N and 62.7W..beginning to turn more W compared to last night at around 275dg...probably stay that way for next 36-48hrs at least

danielwAdministrator
(Moderator)
Sun Aug 21 2011 01:59 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

While the CoC is technically in the Eastern Caribbean. The Main convection is slightly separated and over the Atlantic Ocean. The terrain doesn't appear to be influencing the system a whole lot. Based on the Eye dropsonde earlier. The drop did show SSW winds a the 4900 foot level. But that could be due to a lop-sided storm.

MikeCAdministrator
(Admin)
Sun Aug 21 2011 02:05 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Added radar recording of Puerto Rico long range radar here.

javlin
(Weather Master)
Sun Aug 21 2011 02:26 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

That almost sounds like Mike though it might miss the weakness?It remains to be seen.I have felt this season the models have had a definite affinity to want to move all system to the right no matter how weak they are even when the UL winds go W.

Thks for the loop <img src="http://image5.flhurricane.com/cyclone/images/graemlins/smile.gif" alt="" />


scottsvb
(Weather Master)
Sun Aug 21 2011 02:47 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Until the ECMWF and the GFS tilts more west into the GOM on days 4-5.. this will probably be along or east of Florida by Weds night or Thurs.

Hugh
(Senior Storm Chaser)
Sun Aug 21 2011 02:47 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Current San Juan radar does show that - for now, at least - Irene has resumed a due west track. Visible loop also confirms the due west motion. The dryness that I saw on the AVN loop a couple of hours ago has reduced somewhat, too... and outflow to the north is incredible right now. That would be disrupted if the LLC stays south of Hispanola, and really disrupted if it goes over the mountains of the D.R.

Update: 11am Advisory is out. Hurricane Warning issued for Puerto Rico.


javlin
(Weather Master)
Sun Aug 21 2011 02:59 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

I agree Scott but the models always seem to tilt right.The movement is definitly started to the due W ATTM and I am starting to think she's going to go S of the Islands which if this pans out is a concern?

http://www.ssd.noaa.gov/goes/flt/t2/flash-vis.html


danielwAdministrator
(Moderator)
Sun Aug 21 2011 03:40 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

A few of you may notice that I edited quite a few posts. I changed the top of the posts from
Tropical Storm Emily Enters the Northeastern Caribbean Sea;
To...

Tropical Storm Irene Enters the Northeastern Caribbean Sea

That's all I did. Thanks.


Hugh
(Senior Storm Chaser)
Sun Aug 21 2011 03:42 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Quote:

A few of you may notice that I edited quite a few posts. I changed the top of the posts from
Tropical Storm Emily Enters the Northeastern Caribbean Sea;
To...

Tropical Storm Irene Enters the Northeastern Caribbean Sea

That's all I did. Thanks.




ooops..... well, they're both women, right? LOL


danielwAdministrator
(Moderator)
Sun Aug 21 2011 04:25 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Wind speeds and temperatures from the NE Quadrant. From the latest dropsonde.
Just East-Northeast of Saint Eustatius Island.

Level Geo. Height Air Temp. Dew Point Wind Direction Wind Speed
1007mb (29.74 inHg) Sea Level (Surface) 25.4°C (77.7°F) 24.1°C (75.4°F) 120° (from the ESE) 44 knots (51 mph)
1000mb 64m (210 ft) 25.0°C (77.0°F) 24.1°C (75.4°F) 125° (from the SE) 42 knots (48 mph)
925mb 748m (2,454 ft) 21.6°C (70.9°F) 21.3°C (70.3°F) 125° (from the SE) 41 knots (47 mph)
850mb 1,480m (4,856 ft) 16.8°C (62.2°F) 14.5°C (58.1°F) 140° (from the SE) 51 knots (59 mph)

I wonder if Recon will recover to San Juan or St Croix. St Croix is just west of the Center and looks like it will pass over the Island. Turn on the instruments and measure from the ground.... Nah, never mind.


danielwAdministrator
(Moderator)
Sun Aug 21 2011 05:26 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1135 AM EDT SUN AUG 21 2011 (edited~danielw)

RELEASING EARLY TO UPDATE WARNINGS...

...N ATLC S OF 31N W OF 55W...CARIBBEAN SEA AND TROPICAL N ATLC S
OF 22N W OF 55W...

PER NHC GUIDANCE...TS IRENE OVER THE NE CARIBBEAN FORECAST TO
MOVE NW ACROSS THE NE CARIBBEAN TONIGHT INCREASING TO A MINIMAL
HURCN BEFORE REACHING HISPANIOLA MON MORNING...MAINTAIN TS
STRENGTH AS IT DISSECTS HISPANIOLA REACHING THE WINDWARD PASSAGE
TUE...MOVE ALONG THE NE COAST OF CUBA TUE NIGHT...THEN REGAIN
MINIMAL HURRICANE STRENGTH WED IN FL STRAITS BEFORE MOVING
INLAND S FL MIDDAY THU. UNCERTAINTY OF COURSE IS THE EXACT
TRACK AND DETERIORATION DUE TO LANDMASS ENCOUNTERS.

OTHERWISE A RIDGE WILL REMAIN IN PLACE FROM BERMUDA TO CENTRAL
FLORIDA THROUGH THE MIDDLE OF NEXT WEEK.


Hawkeyewx
(Weather Analyst)
Sun Aug 21 2011 05:40 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Recon just found another center jump northward(nearly half of a degree) as well as a pressure drop of 8 mb. There is no intense blob of convection firing over the center, but the core is organizing.

VORTEX DATA MESSAGE AL092011
A. 21/17:02:00Z
B. 17 deg 23 min N
063 deg 33 min W
C. 850 mb 1412 m
D. 43 kt
E. 251 deg 8 nm
F. 033 deg 40 kt
G. 301 deg 36 nm
H. 999 mb
I. 15 C / 1530 m
J. 21 C / 1519 m
K. NA / NA
L. NA
M. NA
N. 1345 / 8
O. 0.02 / 3 nm
P. AF300 0209A IRENE OB 17
MAX FL WIND 56 KT NE QUAD 15:44:20Z
MAX FL TEMP 21 C 194 / 6 NM FROM FL CNTR


MichaelA
(Weather Analyst)
Sun Aug 21 2011 05:46 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Looking at the sat loops, it appears that Irene is wobbling along a generally WNW track - Jog to the NW followed by a jog to the W, repeat. At any rate, the interactions with Puerto Rico, Hispaniola and potentially Cuba will likely keep the system weak. Depending on a turn to a more northerly direction - when and where - I don't see a chance for strengthening much unless Irene goes over the Bahamas and stays East of Florida.

MikeCAdministrator
(Admin)
Sun Aug 21 2011 05:46 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

The shift north is better news for Florida, as chances are going down for a landfall there, worse news for South Carolina/Georgia though. Still if the trends continue the recurve/not recurve chances approach 50/50 (Right now odds favor it not recurving, but that is dropping too.) The NHC's general cone is still good, however.

danielwAdministrator
(Moderator)
Sun Aug 21 2011 06:08 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

The shift was due Northwest of the last 1007mb Center fix. Or 0.46661691N and 0.4167W in 1 hour and 34 minutes.

My concern is with the Center temperatures. The vacuum is working, to a degree.
Inside eye/ center temperature is 6 degrees Celsius higher than outside the eye/ center.

I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 15°C (59°F) at a pressure alt. of 1,530m (5,020ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 21°C (70°F) at a pressure alt. of 1,519m (4,984ft)


Hugh
(Senior Storm Chaser)
Sun Aug 21 2011 06:22 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Looks like the recon took the "look out the window, guys" viewpoint.
While the last vortex fix showed a due northwest shift in the LLC... the radar appears to me to still show an almost due west motion of the apparently circulation. This could just be my eyes, but it could indicate that the radar is showing a MLC which is not well stacked with the LLC. The most recent visible image, however, appears to show an eye-like pinhole where I estimate that the LLC is (could be dry air - water vapor image shows dry air in the southern part of the circulation).
I think it's a bit early to tell much of anything from the possible short-term northward shift, though. It could shift back to the west in a few hours.


Joeyfl
(Weather Guru)
Sun Aug 21 2011 06:31 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

I think its much to soon to say whether or not its going further west into eastern Gulf, Up Floirda (NHC currently), or up Florida east coast. I think it will become more clear in next 24-48 hours. I agree with current NHC track for now. But I am a little more concerned about the intensity especially late in period but again we won't know how Irene will interact with mountains or stair step its way around the higher elevations. Time will tell...

MikeCAdministrator
(Admin)
Sun Aug 21 2011 07:26 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

The outflow on the northern side of the system has the look of a western Pacific storm, the south side, not so much, with the pressure drop the center may be on its way to stabilizing. But if it were to recenter again, it may be further northward to match the pattern. Still it is going to be a nasty evening in Puerto Rico.

If the poleward outflow takes over, it would tend to draw it north of Hispaniola, but with the ridge holding above it, it brings more risk toward the Carolinas vs Florida, abut at the same time the chance of a full recurve from the US goes up a bit (still unfortunately an outlier at this time since a trough that would be needed to kick it out just doesn't seem to be coming). There is still quite a bit up in the air with the system, but it appears the storm may trend toward the eastern/right side of the forecast cone. The track at 5PM likely won't change much since you would need a few runs of the models to keep a trend, especially with this system.


NewWatcher
(Storm Tracker)
Sun Aug 21 2011 07:33 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

I dunno I cant see much of a full recuve with the ridge building back in at the end of the period. Fla, GA, SC, NC all seem good bets at this point. In two days we will know significantly more.

WeatherNut
(Weather Master)
Sun Aug 21 2011 08:17 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Looks like Irene is forming an eyewall as we speak and it is showing up pretty good on SJU long range radar. The models have also seemed to move a little north with several only skimming the NE coast of the DMR.

Joeyfl
(Weather Guru)
Sun Aug 21 2011 08:47 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Irene's center getting ready to pass right over st Croix as we speak, lowest pressure 1003-1004 there right now and they are just west of the center with sustained northerly winds around 30mph at some of the northern coast personal weather stations. It looks as though Irene maybe getting bit stronger based on radar with center closing off some. It looks like a nasty night in Puerto Rico tonight as Irene's center looks to pass over the southern coast of that island. Side note models back to the east on latest runs, but I expect more of this for next 24-48 hours as I am still concerned that that trough does not look overly deep and not so sure about a hard turn north but time will tell FL to Carolina's need to watch closely.... http://tropic.ssec.wisc.edu/real-time/dl...zoom=&time=


Christiansted Harbor, Virgin Islands (CHSV3) has winds out of north at 29 gusts to 37mph with pressure down to 1002 mb. This station is located on northeast side of island of St Croix.


danielwAdministrator
(Moderator)
Sun Aug 21 2011 09:28 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Latest Harbor Cam photo from St Croix. I've been watching this web cam for about 6 hours and the conditions appear to be improving over the last couple of hours. At this location.
Based on the people sitting on the left bench.



3 hours ago. This was the scene. Notice the Catamaran Renegade is weathervaning with her bow into the NE wind. Camera faces toward the N and NE.



MikeCAdministrator
(Admin)
Sun Aug 21 2011 10:35 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Interesting that recon is currently based in St. Croix, and even without taking off they have a 999mb pressure reading (Since the center of Irene is crossing St. Croix right now).

WeatherNut
(Weather Master)
Sun Aug 21 2011 10:35 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

One of the buoys off St Croix (CHSV3) had a pressure reading 996Mb and is now reporting winds out of the SSW. LTBV3 has 997Mb and west wind yet the pressure is down slightly since the last reading

MikeCAdministrator
(Admin)
Sun Aug 21 2011 10:49 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Recon confirmed the 996mb reading too, and roughly 60MPH winds. It will likely be a rough night in Puerto Rico for those there. I think that's the first time recon has taken off from literally within the center of a tropical system. That will go down in their books for sure. It looks like the NHC's track at least the next two days is going to be spot on.

The system is looking very healthy on the PR radar.


Hugh
(Senior Storm Chaser)
Sun Aug 21 2011 10:55 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Quote:

Recon confirmed the 996mb reading too, and roughly 60MPH winds. It will likely be a rough night in Puerto Rico for those there. I think that's the first time recon has taken off from literally within the center of a tropical system. That will go down in their books for sure. It looks like the NHC's track at least the next two days is going to be spot on.

The system is looking very healthy on the PR radar.




Radar shows at least half of an eyewall has formed (on the east side of the LLC). If what I'm seeing in terms of motion on the radar continues, the entire island will be on the bad side of the storm. I'm frankly surprised that the recon was able to take off - did they go STRAIGHT UP to get above the storm? If not, they had to fly through some very nasty stuff indeed (not compared to a major hurricane, of course, but flying through the eye of a hurricane is one thing... flying up through the eyewall of a developing storm seems a bit more risky).



WeatherNut
(Weather Master)
Sun Aug 21 2011 11:07 PM
Attachment
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Thought I'd post this map of Hispaniola's topography and show why a northern clip of the island is not nearly as bad as from the south. Most of the highest peaks are on the Haitian side

typhoon_tip
(Meteorologist)
Sun Aug 21 2011 11:31 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea


Quick note: It is important to note that the exact center of the tropical cyclone, particularly one that is this anomalously large, is less important than knowing where you are in proximity to the large scale circulation over all.

Also, I wouldn't expect Irene to suffer the same impact from an interaction with the mountainous terrain of Hispaniola as Emily; the circulatory mass field of this cyclone is quite a bit larger and much more convincingly vertically integrated. Though a direct impact would have a significant detriment on Irene, the cyclone would have much better chance of regeneration - in other words, points farther west should not put their guard down should that happen.

The latest 3 hours worth of radar coverage are pointing out some interesting observations: The cyclone appears to have slowed substantial; it is currently - probably temporarily - wobbling S of due west at a very slow rate of speed.


Ed DunhamAdministrator
(Former Meteorologist & CFHC Forum Moderator (Ed Passed Away on May 14, 2017))
Sun Aug 21 2011 11:49 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Definately an average westerly movement for the past few hours - which will probably keep the storm south of Puerto Rico. The airport at St. Croix reported a pressure of 998MB and a peak wind gust of 40mph. The airport was on the south side of the center which helps to explain the weaker wind speeds. Land interaction with Hispaniola is now pretty much a guarantee and reduces the risk of a major storm later on (for the lawyers I said 'reduce', not 'eliminate').
ED


MikeCAdministrator
(Admin)
Sun Aug 21 2011 11:50 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Interesting to note Harvey is back over water and is forecast to become a Tropical Storm Before a second landfall in southern Mexico.

Hugh
(Senior Storm Chaser)
Mon Aug 22 2011 12:20 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Quote:

Definately an average westerly movement for the past few hours - which will probably keep the storm south of Puerto Rico. The airport at St. Croix reported a pressure of 998MB and a peak wind gust of 40mph. The airport was on the south side of the center which helps to explain the weaker wind speeds. Land interaction with Hispaniola is now pretty much a guarantee and reduces the risk of a major storm later on (for the lawyers I said 'reduce', not 'eliminate').
ED




Based upon the San Juan radar.... if Irene were moving due west (which, according to the NHC, it's not doing, since they say it's moving WNW)... at least part of the eyewall would move right over Puerto Rico. Granted, a radar isn't perfectly aligned, but I think it's a fair bet that Irene will cross right over Puerto Rico.

Edit: Recon vortex shows pressure down to 994 and winds inching up to near 65mph. Fix is almost due east of Caja de Muerto (a tiny island south of the main island of Puerto Rico).


danielwAdministrator
(Moderator)
Mon Aug 22 2011 12:45 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Note: NHC storm movements are based on averages.
If the storm takes a quick jog left or right it is usually an hour or more before the change in direction is notable. It can be 3 to 6 hours before a change in direction is mentioned. Depending on the next Advisory time, Proximity to land and other variables.

Remember Charley.


Robert
(Weather Analyst)
Mon Aug 22 2011 01:20 AM
observationsin tortola

my friend who lives in tortola, has been getting wind reading sustained at 45-50 mph with gust to 60mph. the last few hours.. no pressure readings

danielwAdministrator
(Moderator)
Mon Aug 22 2011 01:21 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

ICAO TISX
Station Name Christiansted
Country Virgin Islands (U.s.)
Location 17.70N 64.80W
Elevation 62
Time 22 / 01:10Z
Temperature 77.0
Dew Point 75.2
RH 94
Heat Index 77.9
Wind SSE (160) at 32, 47 gusts
Visibility 1.5
Pressure 1004.1
Weather Rain
Mist

Sky Condition Scattered clouds at 500ft
Broken clouds at 1200ft
Overcast at 1900ft

Remarks Hourly Precipitation Amount: 0.14 inch

METAR TISX 220110Z 16028G41KT 1 1/2SM RA BR SCT005 BKN012 OVC019 25/24 A2965 RMK AO2 PK WND 16041/0109 P0014

Peak Sustained Wind from 160 degrees at 41kts, 47mph. Occurred at 0109Z or 9:09 PM AST/ EDT.


javlin
(Weather Master)
Mon Aug 22 2011 01:23 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Quote:

Note: NHC storm movements are based on averages.
If the storm takes a quick jog left or right it is usually an hour or more before the change in direction is notable. It can be 3 to 6 hours before a change in direction is mentioned. Depending on the next Advisory time, Proximity to land and other variables.

Remember Charley.




Seems Dan when I was in school playing with numbers I use to get frustrated quite abit over there movement speed/directions I finally saw it was usually a 6hr average for the most part.In response to the movement it does look alittle S of W to me also but chucked it up to poor eyesight.I do Ed think she misses the next trop point to the S buy 1'.

That would be point @ 69.4W by 1'


Hugh
(Senior Storm Chaser)
Mon Aug 22 2011 01:47 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

A pinhole eye-like feature is now showing in the very latest radar image. Irene has definately ceased any obvious northward motion for the time being.

ftlaudbob
(Storm Chaser)
Mon Aug 22 2011 01:47 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

We will not know much until it crosses over the islands.That is the bottom line.This is true for the track as well as the intensity.It will be a very large system,so SE Florida should feel the affects of this.How bad it could get is still in question.

MikeCAdministrator
(Admin)
Mon Aug 22 2011 01:52 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

I cannot see the NHC changing the forecast track much if at all later tonight, with the model spread as it is now, the consensus is still at or just east of where the 5PM forecast track is offshore.

LoisCane
(Veteran Storm Chaser)
Mon Aug 22 2011 02:03 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Irene has changed dramatically tonight. She is pulling it together and pulling it together as she makes her way towards PR... her intensity and forward speed have changed. The five day track doesn't need to be changed as that has not changed yet, but this is a big storm that is going to only get bigger.

http://mkwc.ifa.hawaii.edu/satellite/sat...;animtype=flash

Funktop is equally as impressive.


javlin
(Weather Master)
Mon Aug 22 2011 02:04 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Yeah she is going to be a big girl and many will feel the effects.I have to wonder though do the models start changing to the W with a12-24 due W movement?if it should last that long.I only bring this up since everything in this region has moved E-W at 270'-280' for the last couple of weeks.Even Emily denied the models the WNW for the most part for what 24-36 hr maybe longer but had the desired result in the long run in relation to the models.It's what 3 weeks later and the synoptics over the CONUS has changed some so the trofs are not quite as sharp it's summer.I don't know watch and observe see how she looks in the morning and will she be S of Hispanola some.

MikeCAdministrator
(Admin)
Mon Aug 22 2011 02:12 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

There's a particularly nasty band just about to hit Vieques east of PR, some of the recon winds found may be putting it into hurricane category fairly soon. With it crossing Puerto Rico like it looks like it will, it will put most of the island on the stronger part of the storm, so any strengthening bursts as it crosses will be felt in parts around the island. Recon has indicated that the storm has moved due west over the past two hours.

The NHC is doing a good job keeping it conservative, I just don't see any reason to send out too many alarms yet for the US other than watch it closely, especially if this system crosses over Hispaniola. Although media hype may kick up once Irene gets called a hurricane. (Later tonight or early tomorrow AM) As far as Irene and Hispaniola it likely won't be destroyed like Emily, but it will still get weakened quite a bit. For those in PR, and the Dominican Republic, though, stay safe.


Hugh
(Senior Storm Chaser)
Mon Aug 22 2011 02:20 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

New vortex - pressure down another MB to 993. Fix is ALMOST due west of the previous fix (just slightly north of due west). Estimated SFC winds: 76mph. We could soon have the season's first hurricane, if the NHC confirms the recon info.

javlin
(Weather Master)
Mon Aug 22 2011 02:25 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Irene has definitly slowed down alot looking almost 10mph maybe.I would usually associate that with a turn coming up but the ridge is there maybe just consolidation.

Hugh that 2mins N and 18mins W basically due W


Hugh
(Senior Storm Chaser)
Mon Aug 22 2011 02:32 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

In the last several frames of the radar loop, an eye definately appears to be forming - and Irene definately appears to be hitting its breaks. It's going to be a LONG night for Puerto Rico.

danielwAdministrator
(Moderator)
Mon Aug 22 2011 02:32 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

H. Minimum Sea Level Pressure: 993mb (29.32 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 14°C (57°F) at a pressure alt. of 1,533m (5,030ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 22°C (72°F) at a pressure alt. of 1,522m (4,993ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 17°C (63°F)

8 degree Celsius spread between the Outside Eye temp and the Inside Eye temp. Vacuum is working better.

5 degree Celsius dewpoint spread inside the Eye/ Center. This means the air inside is drying out. Which is a precursor to the Eye clearing out vertically. The vacuum is working, but it is still not at 100 percent efficiency.


MikeCAdministrator
(Admin)
Mon Aug 22 2011 03:05 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

They went closer to the TVCN and consensus with the 11PM track, but only marginally so. Irene may briefly hit hurricane force before landfall in Puerto Rico (at 70mph it's very close now). After that the official forecast takes it along the northern coast of the Dominican republic, and later through the Bahamas, with landfall near Cape Canaveral. The cone still is fairly uncertain at that range and may extend eastward or slightly westward. With a lean toward the east right now. Those in the Florida, Georgia, South Carolina, and North Carolina should continue to monitor Irene.

danielwAdministrator
(Moderator)
Mon Aug 22 2011 03:16 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Notice the green semicircle. That's the highest cloud tops and they appear to be encircling the CDO. Or just inside the edge of the CDO.



A Near Perfect match of the Highest Cloud Tops to the strongest convection.



MikeCAdministrator
(Admin)
Mon Aug 22 2011 03:30 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Just a note: Puerto Rico's radar is out, not sure if it will be for the night or not. The island will probably have widespread power outages.

mwillis
(Weather Hobbyist)
Mon Aug 22 2011 04:28 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

in the water vaper imagery 03:45 UTC, you can see what looks like a blue comet, is that the eyewall forming?
http://www.ssd.noaa.gov/goes/flt/t2/wv-l.jpg


Joeyfl
(Weather Guru)
Mon Aug 22 2011 05:16 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

Seeing some sustained winds near 60 mph with higher gusts in islands just east of eastern Puerto Rico. Irene looks to be quite close to hurricane strength the higher elevations will likely see hurricane winds quite easily. Models not huge change GFS now going right along FL east coast as of 0z run slightly left from previous runs.

Random Chaos
(Weather Analyst)
Mon Aug 22 2011 10:47 AM
Re: Hurricane Irene Enters the Northeastern Caribbean Sea

Irene is upgraded to Hurricane. NHC is now saying that the storm will only graze Hispanola, and minimal land interaction will result in unlikely disruption of the storm. They are calling for the storm to become major at some point:

"GIVEN THE IMPRESSIVE UPPER-LEVEL FLOW PATTERN EXPECTED ACROSS IRENE...IT WOULD NOT SURPRISE ME IF THIS CYCLONE BECAME A MAJOR HURRICANE AT SOME TIME DURING ITS LIFETIME LIKE THE GFDL AND HWRF MODELS ARE FORECASTING."
(NHC Forecast Discussion)

Also, the 5:50 special update from NHC:

"PRELIMINARY REPORTS INDICATE THAT WIDESPREAD TREE AND POWERLINE DAMAGE HAS OCCURRED ON PUERTO RICO...AND MORE THAN 800 THOUSAND HOMES ARE WITHOUT POWER ON THE ISLAND.

ALSO...FAA DOPPLER WEATHER RADAR INDICATES WINDS TO NEAR MAJOR HURRICANE STRENGTH ARE NOW OCCURRING IN THE HIGHER ELEVATIONS OF THE INTERIOR MOUNTAINOUS REGIONS OF PUERTO RICO."

IR shows the storm slightly disrupted by Puerto Rico but still with overall good appearance, but with it reentering favorable water conditions, it should recover fairly quickly.


ralphfl
(Weather Master)
Mon Aug 22 2011 11:56 AM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

06 runs about the same with the GFS back a little more west and the gdfl has shifted back West a lot more then the 00 run.

The thing about the GFDL is over the years i have seen this from the model where it was way out of line with the gfs and other models but after awhile made its way back to the others.Those in Floirda and up the us easy coast should keep close watch as the track keep shifting more and more east


CFHCAdministrator
()
Mon Aug 22 2011 01:06 PM
Re: Tropical Storm Irene Enters the Northeastern Caribbean Sea

New Thread up.


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