TROPICAL DISTURBANCE 92L / TROPICAL LOW 93L FORECAST SYNOPSIS…SPECIAL EDITION…AUG. 13, 2013…ISSUED 10:00 P.M. EDT…PHFC

Good evening everyone!

The area of disturbed weather located in the central Caribbean Sea continues to slowly organize this evening, and appears to have become slightly better consolidate since this morning.  Based on satellite loop imagery, and the current ATCF FTP data, the disturbance was centered near Latitude 16.2N…Longitude 81.4W.  Current estimated winds were near 25 mph, and estimated pressure was 1009 mb / 29.80 in.  The NHC in Miami has upgraded the probability for this becoming a tropical cyclone over the next 48 hours to 30% (MEDIUM).

NHC GRAPHICAL TROPICAL WEATHER OUTLOOK

WATL SATELLITE LOOP IMAGERY

SATELLITE STILL INDICATING CENTER OF DISTURBANCE 92L
ir92-l (1)

Based on the current run of the forecast steering layers maps from the PSU e-WALL site, valid 00Z tonight, I expect the slow westward motion to continue for about another 12 hours.  Thereafter, forecast steering indicates the steering flow to become more of a flow to the WNW.  By late Wed. / Early Thu., more of a NW track should begin to take place.   Right now, model guidance as far as forecast track was not available at the time of analysis.  However, based on the steering forecast, and track of the GFS, CMC, and FIM Experimental Model, we may either have a tropical depression, or mid grade tropical storm making landfall on the Gulf Coast between the AL/MS border, to the western FL. Panhandle area.  Given the lack of a model guidance suite at the moment, I am still partial to the FIM Experimental model forecast solution track.

GFS
18zgfs500mbHGHTPMSLtropical090

CMC
12zggem500mbHGHTPMSLtropical108

FIM EXPERIMENTAL

Strength is going to be questionable at best right now, until we get a closed LLC, and then see what lies ahead of the system.  However, the GFS wind shear forecast has been fairly consistent on the last 3 runs, of showing pretty much favorable upper level conditions over the disturbance for the next 96 hours.  Albeit about 6 hours late, the current wind shear map from CIMSS shows an upper level anticyclone almost directly over where the system is centered based on the ATCF information.  This was forecast to occur by the GFS wind shear forecast maps.  During the next 72 – 96 hours, the recent run of the shear maps indicate an upper level anticyclone to remain over, or in close proximity of the disturbance, or tropical storm should it attain that strength.  Based on these forecast parameters, save any possible time over the Yucatan Peninsula, I am inclined to go with the FIM forecast of a 50-60 mph tropical storm.  Again, this is a best guess estimate until this system organizes and closes off a LLC.

CURRENT WIND SHEAR MAP FROM CIMSS

GFS WIND SHEAR / ZONAL SHEAR FORECAST

I will continue to monitor this system for any significant changes, and should have an update in the morning.

Tropical Low 93L

Based on ATCF FTP information, this area is already a closed low of 1010 mb, or 29.83 in.  Winds were estimated at 25 mph.  This low is moving slowly westward, and I expect this motion to continue for the next 12-24 hours.  A slight weakness in the ridge in the EATL is forecast, and this will allow 93L to pull more toward the WNW.  Based on information from the NHC Tropical Weather Outlook, and projected path of the the only dynamic model, this low could run into some drier air if it gets too far north in latitude, as well as cooler sst’s.  Should any change in steering keep it below 15N Latitude, it would remain in fairly conducive conditions for further slow development.  I will continue to monitor this low for any significant changes.

EATL / EUMETSAT SATELLITE IMAGERY AND LOOP

WATER VAPOR IMAGERY

93L 00Z DYNAMIC MODEL GUIDANCE
00zatcfearlyinvest1best.gif93L

Have a blessed evening!

T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST
MEMBER WEST CENTRAL FL AMS
CERTIFIED SKYWARN OFFICIAL STORM SPOTTER (advanced)
CoCoRaHS OBSERVER

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About palmharborforecastcenter

I am a Tropical Forecast meteorologist, providing hurricane forecasts during the Atlantic Hurricane Season. I retired from the U.S. Coast Guard in July of 2001. Meteorology became my passion in high school, and I have continued my educational background in meteorology since 1996, when I undertook the study of Tropical Meteorology. While working toward my degree, I had to unexpectedly withdraw from college due to my oldest sons medical reasons. I do however, meet the educational criteria of the AMS to be recognized as a meteorologist. Studies include, but are not limited to the Navy Aerographers Mate course, Naval METOC meteorology course, Meteorology 2010 Sophomore level course while attending St. Petersburg College, Clearwater, FL., Basic Forecasting course for operational meteorologists from Rapid WX, meteorology institute, a four month meteorological internship, and extensive research on numerous meteorological topics such as the MJO, NAO, satellite imagery interpretation, etc. I have been forecasting Tropical Weather (Tropical Storms and Hurricanes) since 1996, with my main client being three different Coast Guard Commands.
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7 Responses to TROPICAL DISTURBANCE 92L / TROPICAL LOW 93L FORECAST SYNOPSIS…SPECIAL EDITION…AUG. 13, 2013…ISSUED 10:00 P.M. EDT…PHFC

  1. Mike Doll says:

    Thanks Storm appreciate the time your putting in. Tghe local mets here in Mobile are saying most likly west no concerns for us. I say BULLY on them. Many of my friends are looking at me funny when I say a tropical system will most likly visit us this weekend . I say anything from a depression to a storm or a hurricane . They think I’m smoking crack LOL

    Mike

  2. greg goodman says:

    Thanks mr storm i will be tuned in.

  3. Monty says:

    Thanks Storm. I remember Allison…back in ’01 or ’02 I think…dumped as much as 20″ of rain in and around IAH…so a tropical storm in that region can’t be taken lightly…right?? How good is the FIM experimental Operational Forecast Model? You seem to be putting some confidence in it. So…it must have some pretty good credibility Senior Chief!! Thanks always buddy!!

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