typhoon_tip
Meteorologist
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Quote:
if the Carribean system will go it will have to come together around 17n and 82w...that seems to be where a mid level circulation is for sure and possibly a LLC too.
System NW Caribbean: What's interesting in watching this area of disturbed weather over the last couple of days is that it keeps generating these llv vorticity maxims that summarily decay. I've seen 3 so far do this, where/when a tightly clustered region of cold cloud tops amid the greater area of convection decay, and in their wake there is a "tendency" in visible imagery for llv cloud rotation. These that I have witnessed have been on the order of a mere 50 nautical miles in diameter (est) and do not persist for too long before decaying them selves.... At which point, there is already another cluster of intense convection developing in a separate area, and the cycle seems to repeat. It really does appear that this region of the W and NW Caribbean is creating weak tropical lows as a response to convection "not quite" persisting in the same location long enough to make use of the time-dependency and corriolis forcing with air that is moving inward toward the upward moving air of these thunderstorm clusters. Moreover, if you look at the cirrus blow-off from Yucatan thunderstorms you note that they are moving E or ESE pretty clearly...This tells me that there is shear in the environment.. Not sure but do suspect this is partly why any given thunderstorm cluster isn't persisting, because the mechanics in the U/A are not quite right for difluent motion at this time... As HPC is pointing out however, these U/A conditions are expected to be more favorable sooner rather than later so it may just take off like all at once, once these U/A winds come around to a better anticyclonic impression.
We'll, see..
System S of Louisiana and near the mouth of the Mississippi: Frankly and surprisingly it appears like it has a better llv vis sat presentation than 99L. The upper U/A is a bit hostile however. What is interesting to me is that if this feature can persist beneath the mean steering field it would like avail of better U/A later on... Interesting prospect when you consider that we are likely better than 50% that a system will finally wrap up near 99L and the proximity of the two systems are close. If the system in the Gulf never does get deeper in the troposphere that is, it would likely just be asorbed in the circulation field of 99L.
System of the SE US Coast: That event (if occurs) is interesting... At first glance of the global based model I'm inclined to think it is primarily driven to existence by numerical instability of have a strong anticyclone moving off the NE US Coast, which in turn imparts a long fetch of modifying continental polar air over the still very warm Atlantic waters. This enhances baroclinicity in that region as a natural conclusion. Essentially, this configuration of having a trough developing in the Nations heart land, balanced against a anticyclone near 60W/45N (appr loc) teleconnects nicely to a weakness along the SE US Coast, and combined with said temperature gradients N/S in the west Atlantic Basic is actually quite often a precurser forecasters look for prior to Nor'easter/coastal cyclogenesis in the winter... Therefore, it is difficult to be totally certain that whatever forms there (if anything) wouldn't be more of a hybrid type subtropical low... In either event, there should certainly be an inverted trough in that location. Should the apparent developing gyre near 58W/21N assume a true warm core and attending structure, that would confuse this, because it is likely in my mind that an inverted trough/subtropical low could form off the SE US Coast without this feature currently moving WSW through said lat/lon. You could actually end up with an inverted trough that has a true tropical system approaching its lower axis from the ESE.
Definitely lots to consider!
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doug
Weather Analyst
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Clark: it looks like something is trying to get going at all three areas mentioned: near 21n; 19N and 17.5N
the area around 17.5 surely shows signs of a LLC but eroding convection; most convection is growing at 21N
One of these will have to assert itself or else it will remain a wave probably.
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doug
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Wingman51
Weather Guru
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Loc: Orlando, FL
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DATA FROM AN AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT
INVESTIGATING THE AREA OF DISTURBED WEATHER LOCATED BETWEEN THE
CAYMAN ISLANDS AND HONDURAS INDICATE THAT THE SYSTEM REMAINS
DISORGANIZED AND THAT A TROPICAL DEPRESSION HAS NOT FORMED. A LARGE
AREA OF LIGHT AND VARIABLE WINDS WITH A MINIMUM PRESSURE OF 1009 MB
...OR 29.80 INCHES... WAS DETECTED ABOUT 170 MILES SOUTHWEST OF
GRAND CAYMAN ISLAND. HOWEVER... THERE IS NO THUNDERSTORM ACTIVITY
COLLOCATED WITH THE AREA OF LOWEST PRESSURE.
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Margie
Senior Storm Chaser
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Loc: Twin Cities
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In some of the sat images it seems you can see a bit of the circ at that loc. It is skirting just north now of some of the warmest deep water in the Carribean, and is right in an area of warm SSTs, so since the low has moved north and shear is supposed to be low tomorrow, and the dry air that was east of the Yucatan has been pushed back, prolly tomorrow this thing will start start cooking.
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Katrina's Surge: http://www.wunderground.com/hurricane/Katrinas_surge_contents.asp
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damejune2
Storm Tracker
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Loc: Torrington, CT
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I am confused (no big surprise here) but for the last few days the wave in the NW Caribbean has been moving towards the WNW @ 10mph right? Why then does it seem like it's in the same place? I haven't checked the coordinates on it, but it doesn't seem to be getting any closer to the Yucatan Peninsula.
It hasn't really been moving that fast. Plus, even at 7mph, that's only about 170 miles per day...not that much movement. -Clark
Edited by Clark (Fri Sep 30 2005 03:28 AM)
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Tazmanian93
Weather Master
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Loc: Tampa
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It's def moving;
DATE/TIME LAT LON CLASSIFICATION
29/2332 UTC 18.7N 80.7W T1.0/1.0 99
29/1745 UTC 17.9N 82.0W T1.0/1.0 99
29/1145 UTC 16.2N 82.0W T1.0/1.0 99
28/2345 UTC 15.9N 80.8W T1.0/1.0 99
28/1745 UTC 15.9N 80.1W T1.0/1.0 99
27/2345 UTC 16.2N 77.7W TOO WEAK 99
27/1745 UTC 15.6N 77.1W TOO WEAK 99L
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Don't knock the weather; nine-tenths of the people couldn't start a conversation if it didn't change once in a while.
Go Bucs!!!!!!!!!
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Ed
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Tazmanian93
Weather Master
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Loc: Tampa
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Of course it's early, but I certainly do not care for 's future of 99. And def wanting to keep an eye on @ 132 hrs and UKM @ 120 hrs
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Don't knock the weather; nine-tenths of the people couldn't start a conversation if it didn't change once in a while.
Go Bucs!!!!!!!!!
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Ed
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HanKFranK
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Loc: Graniteville, SC
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notice those satellite positions for the system jump north and east at the end? that's just what they are... satellite guesses based on the convective pattern. hard to tell where the actual surface low is, but it has traditionally been displaced south and west of the convective area.. unless it finally got smart and redeveloped under the convection. friday could be nothing but a rehash of thursday, with the system meriting a recon but not having any real organization.
looked at the 00Z models that are available and they don't show anything that new/original... other than a weird hybrid system running due west at 25/30n from the canaries into the open atlantic. the old prognosticators for a system off the east coast are still seeing it, the camp that just sees an open trough advancing still sees just that. the future of our nw caribbean system is vague as several different models track a feature out of the area to anywhere from texas to southern mexico. none see a significant system. to restate with detail the idea that two systems will form and threaten the u.s. coast next week would be nailing jello to the wall... will just say that i'm not going to budge even though there may be cracks in the armor.
for now, stan is hiding in the bushes.
HF 0541z30september
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HURRICANELONNY
Weather Guru
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Loc: HOLLYWOOD,FL.
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That's funny. I"ve been thinking the same thing for days. For the last, lets say 3-4 days it's has been moving wnw-nw according to the . If that was true it would either been in the Gulf or hit Mexico. Sometimes I just think weather agencies don't put there heads together. Dr Lyons said stationary a couple of days ago while the discussion says wnw/nw around 10-15 mph. Go figure...... :?:
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SMOKE
Weather Watcher
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Loc: USA, Ga.
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RECON CNX. We'll see if it can get organized.
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Beaumont, TX
Storm Tracker
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Guys, how did ya'll think the did forecasting ? I have heard people complaining but I think they did a good job of forecasting. Watching the high move more east, I had a feeling she might come our way eventually. At the very least, we'd get high wind and rain if it had hit around Matagorda. Actually, we were very fortunate it went in a little east of Sabine Pass but we still we had extensive damage. Today we were allowed to return and check out homes so my husband, son, and brother-in-law are on their way to Beaumont. I know people who have already returned before today but we decided to wait until today. We are staying in Houston with my sister for now. I would like to be at home, of course, but at least I have a home to return to with what looks like little damage to the outside. One of the things I was wondering about is how many storms normally form in October? And are they ever the big ones or are they usually TS or cat 1 or 2's?
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stevie
Verified CFHC User
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Loc: Clear Lake, Texas
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Well, without much research, Opal (1996) and Jerry(1989) Floyd(1987), Irene(1999) were October storms. Usually fronts safe us here in Texas this time of year though. Jerry hit Halloween day on the east end of Galveston(100mph winds). Being the storm chaser that I am I met him in Kemah with some good winds.
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Thunderbird12
Meteorologist
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Loc: Oklahoma
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It appears that the system near 12N, 34W is now classified as 90L. That may turn out to be our next depression.
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HanKFranK
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i didn't think anything was going to form that far out this year. it waited until the last day of september, but that looks legit. it has a 1.5 on it, but all the forecast models take it more north than anything else.
99L has a 1.5 on it also... says pressures are falling and you can see the turning in the low-level wind field (because there isn't much convection/dry air intrustion on the west side). when they recon it later it's just as likely to be 'too broad' like it was earlier, but slowly and inevitably this thing is developing.
HF 1433z30september
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Thunderbird12
Meteorologist
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Loc: Oklahoma
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SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE THAT THE LARGE
LOW PRESSURE AREA LOCATED OVER THE NORTHWESTERN CARIBBEAN SEA HAS
BECOME BETTER ORGANIZED... EVEN THOUGH UPPER-LEVEL WINDS HAVE
BECOME LESS FAVORABLE. SHOWER AND THUNDERSTORM ACTIVITY HAS
INCREASED AND THIS SYSTEM STILL HAS THE POTENTIAL TO BECOME A
TROPICAL DEPRESSION DURING THE NEXT DAY OR SO AS IT MOVES SLOWLY
WEST-NORTHWESTWARD. THE RECONNAISSANCE FLIGHT SCHEDULED FOR THIS
AFTERNOON HAS BEEN CANCELED. HOWEVER... ANOTHER AIR FORCE RESERVE
AIRCRAFT IS SCHEDULED TO INVESTIGATE THE SYSTEM LATE TONIGHT OR
SATURDAY...IF NECESSARY. WHETHER OR NOT THIS SYSTEM BECOME A
TROPICAL CYCLONE... LOCALLY HEAVY RAINFALL WILL LIKELY AFFECT
JAMAICA... THE CAYMAN ISLANDS... PORTIONS OF CENTRAL AND WESTERN
CUBA... AND THE YUCATAN PENINSULA OVER THE NEXT COUPLE OF DAYS.
INTERESTS IN AND AROUND THE NORTHWESTERN CARIBBEAN SEA SHOULD
CLOSELY MONITOR THE PROGRESS OF THIS DISTURBANCE.
THE LOW PRESSURE CENTERED ABOUT 575 MILES WEST-SOUTHWEST OF THE
SOUTHWESTERNMOST CAPE VERDE ISLANDS HAS BECOME MUCH BETTER DEFINED.
THUNDERSTORM ACTIVITY HAS INCREASED AND BECOME BETTER ORGANIZED...
AND UPPER-LEVEL WINDS ARE FAVORABLE FOR A TROPICAL DEPRESSION TO
FORM LATER TODAY OR ON SATURDAY AS THE SYSTEM MOVES SLOWLY
NORTHWESTWARD OVER OPEN WATERS.
THE SMALL LOW PRESSURE AREA LOCATED OVER THE WESTERN GULF OF MEXICO
ABOUT 275 MILES EAST OF BROWNSVILLE TEXAS HAS WEAKNED AND BECOME
LESS ORGANIZED. SHOWER ACTIVITY REMAINS LIMITED AND UPPER-LEVEL
WINDS ARE UNFAVORABLE FOR DEVELOPMENT. THIS SYSTEM IS MOVING TOWARD
THE WEST-SOUTHWEST AT 10 TO 15 MPH AND SHOULD MOVE INLAND OVER
EXTREME NORTHEASTERN MEXICO OR EXTREME SOUTHERN TEXAS ON SATURDAY.
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typhoon_tip
Meteorologist
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Posts: 576
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Quote:
i didn't think anything was going to form that far out this year. it waited until the last day of september, but that looks legit. it has a 1.5 on it, but all the forecast models take it more north than anything else.
99L has a 1.5 on it also... says pressures are falling and you can see the turning in the low-level wind field (because there isn't much convection/dry air intrustion on the west side). when they recon it later it's just as likely to be 'too broad' like it was earlier, but slowly and inevitably this thing is developing.
HF 1433z30september
Ahhhh... Anytime a forecast is blown, or something surprises everyone and I hear that dreaded "...Climatology" word I always grin. Climatology can be beguiling often misleading tool there is available.
The following image illustrates a pervasive SST warm anomaly that encompasses virtually the entire Atlantic Basin S of (appr) 35N latitude, from the Bahamas to the Cape Verde Islands:
http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomnight.9.27.2005.gif
When knowing and understanding such that we do, that climatology is a time dependent long term statistical mean, it seems entirely reasonable to assume climate will not account for extremes that take place outside the mode on our graphs. Especially when considering that the Cape Verde season was not very prodigious during 2004 and particularly this year to date, therefore, cross-seasonal less than normal SST processing in those districts of the Atlantic Basin in question. I cannot atest for the actual depth of the thermocline...subsequently the actual upper oceanic heat content as an integrated value...but sufficed to say at least on the surface there appears to be higher SST than climatology.
In terms of pure observation I have noticed that last year and this year both have had a very peculiar middle and upper level tropospheric behavior from the Puerto Rico Archipelago east to the WNW of the Cape Verde Islands. In this region, despite having near neutral signals and/or slightly LaNina like conditions in the east Pacific there has still been heightened occurrences of unfavorable westerlies dipping fairly deeply into the tropical Atlantic. (For those of us who are unfamiliar with this, La"Nino" tends to excite stronger U/A west components in the means, effectively shearing the tops off any would be developments downwind in the Atlantic Basin...)
Much of the reason what the Cape Verde season tends to shut down in latter September so earnestly isn't just for SST, either. The activation of the westerlies in concert with season change definitely plays a pivotal role, because La Nino or not, you invariably will end up with trough incursions out there by the middle of October. This is just to point out that so long as we are running some pretty impressive cross-seasonal SST warm anomalies in the Atlantic Basin, approximately half of the "normal" reason why Cape Verde systems tend not to develop at this time of year is being compensated for by this unusual SST scenario.
Edited by typhoon_tip (Fri Sep 30 2005 04:01 PM)
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Thunderbird12
Meteorologist
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Loc: Oklahoma
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Looks like they are no longer calling for the upper-level winds to become more favorable for 99L, but it is certainly possible that a depression will form anyway. It certainly seems to be windier down there today... a few reporting stations are reporting sustained winds of around 15 knots. Yesterday, surface winds were lighter and the flight-level winds on the recon weren't getting above 15 knots.
Sounds like they are about ready to pull the trigger on 90L... if it maintains its current organization for another 6 hours, it could be named a depression on the next advisory.
I'm not sure how the little low in the Gulf could have become "less organized". Looks like it will merely remain a curiosity until it moves inland somewhere.
Based on the official forecast, it looks like Hurricane Otis could eventually have some impact on Baja California and the southwestern U.S. The 120-hr forecast has a weakening depression on the Arizona/Mexico border.
Edited by Thunderbird12 (Fri Sep 30 2005 03:54 PM)
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Margie
Senior Storm Chaser
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Posts: 1191
Loc: Twin Cities
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Post deleted by Margie
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Katrina's Surge: http://www.wunderground.com/hurricane/Katrinas_surge_contents.asp
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typhoon_tip
Meteorologist
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Posts: 576
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Quote:
Can you please get rid of the graphic in post #57509.
Already done...My apologies...wasn't aware that it would so significantly ulter everyone's GUI... Oops...still learning this forum's capabilities..
peace!
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Margie
Senior Storm Chaser
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Posts: 1191
Loc: Twin Cities
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Because it is finally into the warm deep water, I think that convection will get going right over the low (has, some already) and stick, in spite of the tremendous shear from winds going into that trof (very impressive looking!). As it moves west it is in the area of less shear.
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Katrina's Surge: http://www.wunderground.com/hurricane/Katrinas_surge_contents.asp
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