EX INVEST 94L Thread

[gatorcane]

The LLC is slowly moving NNW to NW on this visible -- and I agree with the NHC it is organizing...

Question is now how far north does this thing get?

http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

[Recurve]

I'll go with too soon, common sense maybe not meterological reasoning.
It hasn't developed, so we don't know where or what it is.
We're looking three to five days ahead, NAM and GFS not likely to be dead on.

Still... the apparent low is close to land, mets say it's drifting west and likely to die be stuck southward. Florida doesn't need to be on alert at all, keep one eye on it just cause it's down where Wilma, Charley , Floyd and Irene I think and Mitch ... can you imagine correctly forecasting Mitch's strike on Florida at this point in its life?

Minimal steering currents can make things way more...interesting

[cycloneye]

The Latest from Jeff Masters Blog:

A vigorous surface circulation has developed in association with a broad area of low pressure over the Western Caribbean (94L). A pass from the European ASCAT satellite at 11:02 am EDT showed that the surface circulation had gotten much less elongated, compared to this morning's QuikSCAT pass. Top winds were only about 10 mph in the 11 am ASCAT pass, but have no doubt increased since then. Satellite loops show a very large surface circulation covering the entire Western Caribbean, with a concentrated area of thunderstorms forming near the center of circulation. Surface pressures remain very low over the entire Western Caribbean. Wind shear is less than 10 knots, and is expected to remain less than 10 knots through Thursday. It is likely that this system will form into a tropical depression on Tuesday, despite the very large amount of atmosphere it is trying to spin up.

Steering currents are weak in the Western Caribbean, but most of the models show a slow motion to the west or northwest that will take 94L over Belize or Mexico's Yucatan Peninsula by Thursday. It is unlikely 94L will have time to become a hurricane before it moves over the Yucatan, and the main threat from the system will be heavy rain. These rains may cause significant flooding problems in Belize and Mexico's Yucatan. Heavy rains may also affect northeast Guatemala, but should not cause significant flooding.

There is a strong trough of low pressure forecast to swing across the U.S. this week, which could turn 94L northwards into Western Cuba, the Florida Keys, or Southwest Florida. However, this is unlikely, since none of the reliable computer models are forecasting such a turn.

It is likely that 94L will eventually emerge into the Gulf of Mexico or Western Caribbean after spending a few days over the Yucatan. When it does so, it will probably be intact enough to re-strengthen, since it is such a large system. Its long-term fate is highly uncertain, as the steering currents are weak and the storm's intensity will be controlled by interaction with land.
http://www.weatherunderground.com/blog/ ... amp=200710

[wxman57]

I'm not sure what data Dr. Masters is looking at to conclude that winds have increased since 11am. There are plenty of surface obs in the NW Caribbean and I still see no wind over 10-12 kts. Just a broad, weak low. Winds don't appear to have increased, though pressures are a bit lower than this morning. Looks much better on satellite loops than it does on the surface analysis. The stronger circulation is likely aloft in the mid levels, but not at the surface.

The low is about 100 miles offshore now. If it moves westward at 5-6 mph, then it'll be inland by around noon tomorrow. GFS has it inland by 7am CDT tomorrow. Not much time to become a depression, considering the very weak inflow and lack of deep convection. Not impossible, but I wouldn't call it likely.

Here's the latest plot with marine and land obs (21Z). Note that the buoy near 20N/85W just reported a SE wind at 15 kts and a slightly increasing pressure at 23Z:

[HURRICANELONNY]

How many times have you read the NHC/NWS forecasts and the next day a totally different forecast. It depends alot on the strength when the trough heads south into what direction it will go. Way to soon to say it will go south or even inland for that matter. It takes alot of time down there for something to get going. I think.

[Recurve]

Could hit SW Fla, the Keys or the entire east coast, he says...but that's "unlikely."

Interesting description of the environment, large area it's "trying to spin up."


Definetely getting more convective blobs and widespread storms hanging on. if the surface low was any more in the central caribbean, it'd be well positioned to intensify IMO.

[wxman57]

I put together a couple of charts to give you a better idea where 94L may go over the next 24 hours, and where it may track by Wednesday afternoon as the trof digs down across south Florida. The charts are mean 700-400mb (10,000-20,000 ft) wind streamlines and velocities. Note that high pressure to the north is steering it westward into the Yucatan tonight/tomorrow morning but by 4PM CDT Wednesday, the trof axis is just east of south FL and it's possible that what's left of 94L may track across Cuba but likely east of Florida:

[Recurve]

Thanks for the obs, Wxman and focusing on the facts. And the analysis to help everybody understand and learn.

Any way you can link to the obs full size, hard for me to read much beyond the barbs.

[cycloneye]

Thanks for the obs, Wxman and focusing on the facts. And the analysis to help everybody understand and learn.

Any way you can link to the obs full size, hard for me to read much beyond the barbs.

Click the bar at the upper left and you will get the closeup.

[cycloneye]

WHXX04 KWBC 082328
CHGQLM
ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

TROPICAL DEPRESSION INVEST 94L

INITIAL TIME 18Z OCT 8

DISCLAIMER ... THIS INFORMATION IS PROVIDED AS GUIDANCE. IT
REQUIRES INTERPRETATION BY HURRICANE SPECIALISTS AND SHOULD
NOT BE CONSIDERED AS A FINAL PRODUCT. PLEASE SEE THE TPC/NHC
OFFICIAL FORECAST.


FORECAST STORM POSITION

HOUR LATITUDE LONGITUDE HEADING/SPEED(KT)

0 18.2 86.0 275./ 6.0
6 18.3 85.9 30./ 1.9
12 19.2 86.2 339./ 8.9
18 19.6 86.6 317./ 5.1
24 19.8 87.3 293./ 6.9
30 20.0 87.9 286./ 6.8
36 20.1 89.2 272./11.5
42 19.7 90.3 251./11.8
48 19.0 90.8 212./ 7.3
54 18.4 91.2 214./ 7.2
60 18.1 91.2 187./ 3.1
66 17.4 91.1 168./ 7.2
72 17.1 90.1 107./ 9.6
78 17.1 89.9 109./ 1.7
84 16.7 89.7 148./ 3.9
90 16.2 89.4 152./ 5.4
96 16.3 89.1 84./ 3.8
102 16.0 89.0 164./ 2.6
108 16.1 88.5 84./ 4.9
114 16.2 88.3 54./ 2.5
120 16.6 88.2 9./ 3.2
126 16.6 88.0 66./ 1.9

18z GFDL

[Sanibel]

Bingo. Tropical formation off Yucatan north of Honduras.

[Sanibel]

There's a spin at Wxman's fix. How 2007 will affect it is yet to be seen.

NAM takes it east into eastern Cuba like Lenny (no way).

[cycloneye]

[cycloneye]

8:05 PM TWD:

...SPECIAL FEATURE...

A 1004 MB NORTHWESTERN CARIBBEAN SEA LOW PRESSURE CENTER IS NEAR
18N86W...ABOUT 120 NM EAST OF NORTHERN BELIZE. SURFACE PRESSURES
OVERALL REMAIN LOW IN THE AREA AND SATELLITE IMAGERY INDICATES
THAT THE LOW HAS BECOME A LITTLE BETTER DEFINED TODAY...WITH AN
INCREASE IN THUNDERSTORM ACTIVITY. ATMOSPHERIC CONDITIONS APPEAR
FAVORABLE FOR ADDITIONAL DEVELOPMENT OF THIS SYSTEM...AND IT MAY
BECOME A TROPICAL DEPRESSION DURING THE NEXT DAY OR TWO AS IT
MOVES SLOWLY WESTWARD OR NORTHWESTWARD. RESIDENTS IN THE
NORTHWESTERN CARIBBEAN SEA SHOULD MONITOR THE PROGRESS OF THIS
SYSTEM. AN AIR FORCE HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO
INVESTIGATE THIS LOW PRESSURE AREA ON TUESDAY IF NECESSARY.
STRONG SHOWERS AND THUNDERSTORMS ARE IN THE EASTERN COASTAL
PLAINS OF THE YUCATAN PENINSULA FROM 18N TO 21N BETWEEN 88W
AND 89W. OTHER STRONG SHOWERS AND THUNDERSTORMS STRETCH FROM
NORTHERN GUATEMALA TO THE NORTHWESTERN CORNER OF THE YUCATAN
PENINSULA BETWEEN 89W AND 91W. SHOWERS AND THUNDERSTORMS IN THE
CARIBBEAN SEA ARE FROM 16N TO 18N BETWEEN 85W AND 88W...AND
FROM 19N TO 21N BETWEEN 86W AND THE YUCATAN PENINSULA COAST.
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS
EAST OF 21N86W 15N83W TO 75W ARE IN AN AREA OF UPPER LEVEL
DIFFLUENT FLOW TO THE EAST OF THE SURFACE LOW PRESSURE CENTER.

http://www.storm2k.org/wx/modules.php?n ... ge&pid=109

[cycloneye]

WHXX01 KWBC 090036
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0036 UTC TUE OCT 9 2007

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

DISTURBANCE INVEST (AL942007) 20071009 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
071009 0000 071009 1200 071010 0000 071010 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 18.0N 86.3W 18.4N 87.1W 18.8N 88.3W 18.9N 89.6W
BAMD 18.0N 86.3W 18.4N 86.9W 18.6N 87.7W 18.8N 88.3W
BAMM 18.0N 86.3W 18.4N 87.0W 18.7N 87.9W 18.9N 88.8W
LBAR 18.0N 86.3W 18.5N 87.4W 19.5N 88.6W 20.8N 89.4W
SHIP 25KTS 31KTS 41KTS 49KTS
DSHP 25KTS 31KTS 32KTS 28KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
071011 0000 071012 0000 071013 0000 071014 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 18.8N 90.8W 17.8N 92.8W 16.2N 94.2W 15.0N 95.1W
BAMD 19.0N 88.9W 19.8N 89.2W 21.7N 86.5W 24.3N 80.3W
BAMM 19.0N 89.7W 19.1N 91.0W 18.5N 92.0W 17.4N 94.1W
LBAR 22.2N 89.6W 24.8N 86.8W 27.7N 79.6W 33.8N 66.1W
SHIP 58KTS 69KTS 71KTS 70KTS
DSHP 27KTS 30KTS 29KTS 27KTS

...INITIAL CONDITIONS...
LATCUR = 18.0N LONCUR = 86.3W DIRCUR = 270DEG SPDCUR = 4KT
LATM12 = 18.0N LONM12 = 85.6W DIRM12 = 270DEG SPDM12 = 4KT
LATM24 = 18.0N LONM24 = 84.8W
WNDCUR = 25KT RMAXWD = 40NM WNDM12 = 25KT
CENPRS = 1003MB OUTPRS = 1006MB OUTRAD = 180NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM


Continues to crawl westward.

[bawes]

If a storm forms out of this any chance it could follow a similar track to Opal?

http://weather.unisys.com/hurricane/atl ... /track.gif

[Tampa Bay Hurricane]

Good call Sanibel

[Sanibel]

Still a little weak. Lord knows I needed to finally get one right this year.

[Recurve]

I would only say at this point almost anything's possible (not trying to scare panhandle folks). The models haven't suggested that track, and it's hard to know if a trough is coming that could pull it north like that. Anybody know if Opal rounded a high or was steered by a trough?

This post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

[cycloneye]

10:30 PM TWO:

KNHC 090229
TWOAT

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1030 PM EDT MON OCT 8 2007

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

AN AREA OF LOW PRESSURE CENTERED OVER THE NORTHWESTERN CARIBBEAN
SEA ABOUT 125 MILES EAST OF CHETUMAL MEXICO IS MOVING SLOWLY
WEST-NORTHWESTWARD. SATELLITE IMAGERY INDICATES THAT THE
ASSOCIATED SHOWER ACTIVITY HAS DECREASED THIS EVENING.
HOWEVER...CONDITIONS APPEAR FAVORABLE FOR DEVELOPMENT AND THIS
SYSTEM COULD BECOME A TROPICAL DEPRESSION BEFORE REACHING THE
EAST COAST OF THE YUCATAN PENINSULA. INTERESTS IN BELIZE AND
THE YUCATAN PENINSULA SHOULD MONITOR THE PROGRESS OF THIS
SYSTEM. AN AIR FORCE HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO
INVESTIGATE THIS LOW PRESSURE AREA ON TUESDAY...IF NECESSARY.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$

FORECASTER BROWN