TROPICAL WEATHER FORECAST SYNOPSIS SPECIAL EDITION…DISTURBED WEATHER EASTERN CARIBBEAN…AUG. 12, 2013…ISSUED 7:55 P.M. EDT…PHFC

Good evening all!

Shower and thunderstorm activity located in the eastern and central Caribbean Sea have increased in coverage over the last few hours, and appear in the last few frames of satellite loop imagery, as if the area is trying to consolidate.

WATL SATELLITE LOOP IMAGERY

The area is associated with what the NHC is calling a tropical wave, but is depicted as a trof of low pressure on the surface analysis map, which is interacting with the Monsoon trof extending north and east of the Isthmus of Panama.  The NHC has assigned a 10% probability of this area becoming a tropical cyclone during the next 48 hours, and a 20% over the next 120 hours.

NHC GRAPHICAL TROPICAL WEATHER OUTLOOK

NHC 12Z SURFACE ANALYSIS 

The area in general is a rather large cyclonic gyre, however the particular area I am interested in is just to the south of Hispaniola.  here are two areas of vorticity well established at the 850 mb level, however based on current steering, the area closest to the Isthmus should move inland.

CIMSS 850 MB VORTICITY MAP

The current wind shear map from CIMSS indicates the upper level anticyclone I had mentioned in my morning synopsis, which the GFS wind shear forecast was showing, has begun to come to fruition, and we’ll have t monitor this to see if it persists.

CIMSS WIND SHEAR MAP

Analysis of the recent run of the forecast steering layers maps from the PSU e-WALL site indicate the area south of Hispaniola should move in a general westward motion over the next 12-18 hours, with a more north of west, to WNW motion thereafter.

The 18Z GFS run has dropped development of this area, however the 12Z CMC GGEM, and the FIM Experimental models still indicate development.  The CMC appears to develop a strong tropical storm, to possibly a weak Category One hurricane.  Both have been consistent thus far in closeness of landfall.  Based on forecast steering, I still prefer the FIM Experimental track.

CMC
12zggem500mbHGHTPMSLtropical126

FIM

Based on analysis of the current wind shear and zonal shear forecast from the GFS, should this area be steered as suggested, it will meet an environment more conducive for development in about 24-30 hours from now, as the current upper level anticyclone is forecast to move north, and then move in tandem with the area of disturbed weather.  Aiding this area at the moment, is an upper level low that is located over the southern GOMEX, which continues to move west.  This is allowing for some ventilation where the area of concern is located.

Based on these current and forecast conditions, should they hold true for the next 48-72 hours, I am calling for further slow organization over the next 24-36 hours, with the possibility of a little steadier organization thereafter, and I would not be surprised to see this become our next INVEST over the next 24-36 hours.  SHOULD this develop, I cannot at the moment rule out the probability of it making a run for CAT 1, should it just clip, or miss the Yucatan Peninsula, and slide through the uprights.  My concern here being, that if upper level winds remain favorable, this will traverse and area with some extremely high TCHP, which would allow for strengthening, and should conditions be optimal, Rapid Intensification.  TCHP values of 80+ will allow for R.I. if all others parameters are favorable.

TCHP MAPS

I will continue to monitor this area for any significant changes.

Have a great 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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8 Responses to TROPICAL WEATHER FORECAST SYNOPSIS SPECIAL EDITION…DISTURBED WEATHER EASTERN CARIBBEAN…AUG. 12, 2013…ISSUED 7:55 P.M. EDT…PHFC

  1. originallt says:

    Thanks Storm.

  2. Mike Doll says:

    Thanks Storm Ilwill be paying attention here in South Alabama. School starts on Monday could get intresting!!
    Mike

  3. Jerilyn (jerrob) says:

    Thanks for the late update 😄

  4. Elliot Lisak says:

    You might have an uninvited guest in your backyard soon. Stay safe and thank you for all your guidance,and insight. Are things really going to get as interesting as the foresight’s saying, TWC,
    WU, Levi’s, CW etc.

  5. stefanie says:

    Thanks for the update Storm. Rapid Intensification…two of my least favorite words.

  6. Monty says:

    Thanks Storm. This thing looks to be a threat…should it materialize. Ballpark guess…any threat to IAH?

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