TROPICAL STORM DOLLY / TROPICAL WEATHER FORECAST SYNOPSIS…ISSUED SEP. 02, 2014…9:05 A.M. EDT…WEST CENTRAL FLORIDA HURRICANE AND SEVERE WEATHER FORECAST CENTER

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Good morning everyone!

Tropical Depression FIVE becomes Tropical Storm DOLLY.  Based on the 8:00 A.M. EDT Intermediate Advisory from the NHC, the following information was available regarding Tropical Depression FIVE:

LOCATED: 23.0N…95.7 W
MOTION: WNW 13 MPH
MAX SUSTAINED: 50 MPH
PRESSURE: 1005 MB / 29.68 IN.

HURREVAC TRACKING GRAPHICS
HURREVAC TD 5

12Z DYNAMIC MODEL GUIDANCE
99L dynamic

TROPICAL STORM DOLLY SATELLITE FLOATER LOOP IMAGES

GOMEX SATELLITE LOOP IMAGES

INTELLICAST DOPPLER RADAR LOOP (BROWNSVILLE TX)

Dolly continues to move the WNW at around 13 mph.  I expect this motion to continue through the next 24 hours, prior to a slight bend left in track, based on current and forecast steering layers maps.  However, given the past motion has been more o the NW up to around 8:00 a.m. EDT, I believe the center of Dolly will make land fall near 24.3N…97.9W.  Albeit slim, I cannot rule out 100% of Dolly possibly slowing prior to land fall, and taking a small jog northward.  My uncertainty at the moment comes from analysis of water loop imagery, in which a small ridge has developed to the west of the storm over Mexico…this COULD allow her to slow down briefly, and shunt her just slightly further NW.  You can notice the ridging in satellite loop imagery. 

Information in the 5:00 a.m. Forecast discussion from the NHC, did verify my forecast of the center reforming further north:

The initial motion estimate is northwestward or 305/12 kt, which is based on a blend of passive microwave, scatterometer, and conventional satellite fix data. Other than the northward relocation of the center position, the forecast track reasoning remains unchanged from the previous advisories.

CURRENT LAYER MEAN STEERING


WATER VAPOR IMAGE (CLICK TO LOOP)
SAT_wv_east

There has been no change in my forecast thinking on strength of Dolly prior to landfall.  Tropical Storm Dolly has now entered an area where vertical wind shear values are only about 5-10 knots based on the wind shear tendency map, albeit upper level winds are forecast within the next 12-18 hours to become marginal.  Satellite loop imagery, especially shortwave IR2 indicates Dolly was previously a sheared system.  However if you look closely at the satellite loop images posted, you can see the convection now beginning to build over the center.

Based on this analysis, I agree with the NHC Intensity Forecast:

FORECAST POSITIONS AND MAX WINDS
INIT 02/0900Z 22.6N 94.8W 40 KT 45 MPH
12H 02/1800Z 23.1N 95.9W 45 KT 50 MPH
24H 03/0600Z 23.7N 97.5W 45 KT 50 MPH
36H 03/1800Z 24.1N 98.9W 35 KT 40 MPH…INLAND
48H 04/0600Z…DISSIPATED INLAND

From the NHC Intermediate advisory:

SUMMARY OF WATCHES AND WARNINGS IN EFFECT…

A TROPICAL STORM WARNING IS IN EFFECT FOR… * TUXPAN TO BARRA EL MEZQUITAL MEXICO

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA…IN THIS CASE WITHIN THE NEXT 24 HOURS.

HAZARDS AFFECTING LAND ———————-

RAINFALL…DOLLY IS EXPECTED TO PRODUCE RAINFALL AMOUNTS OF 3 TO 6 INCHES WITH ISOLATED MAXIMUM AMOUNTS OF 10 INCHES ACROSS SOUTHERN TAMAULIPAS…NORTHERN VERACRUZ…AND EASTERN SAN LUIS POTOSI MEXICO THROUGH WEDNESDAY EVENING. THIS RAINFALL COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES IN AREAS OF MOUNTAINOUS TERRAIN.

WIND…TROPICAL STORM CONDITIONS ARE EXPECTED WITHIN THE WARNING AREA BY TONIGHT.

NHC WATCH/WARNING DISPLAY

Residents within the warned areas should monitor their local Weather Service office statements and advisories regarding these hazards.

Elsewhere, the NHC has interest in a tropical wave that will be moving off the African Continent near the end of this week.  Actually, there are 2 areas to be monitored.  Other than this wave just mentioned, another is getting ready to exit the African coast in about 24 hours.  Based on some of the Global models that develop this one, and the forecast steering maps valid for 12Z this morning, this wave could recurve near 40W in a few days.

EUMETSAT LOOP IMAGE (CLICK TO ANIMATE)
EUMETSAT_MSG_IR108-all

The second wave, which has Global model support for development, including the ECMWF, is forecast at the moment to travel further west.  Depending on which model is initializing the location correctly when it exits into the Atlantic, it could either recurve as well, or if lower in latitude as per the ECMWF, could track further west, but also appears to begin to lift shortly thereafter.  This will all remain to be seen, as the steering pattern is subject to change over the next 7 – 10 days.  This wave will probably stand the better probability of development, and upper level winds over the far eastern Atlantic do not become more conducive for development until around 84 – 96 hours as of 06Z this morning.

I will be monitoring these areas closely over the next 7 days.

The GFS is also suggesting we may not be finished with activity in the W. Caribbean / BOC area over the next 2 weeks.

I will not have another update until tomorrow a.m.

Have a blessed day!

T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST / SEVERE WEATHER SPECIALIST
MEMBER WEST CENTRAL FLORIDA AMS
CoCoRAHS OBSERVER
OFFICIAL SKYWARN SPOTTER (ADVANCED)

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