TROPICAL DISTURBANCE INVEST 92L / TROPICAL STORM ERIN FORECAST SYNOPSIS…AUG. 15, 2013…ISSUED 7:40 P.M. EDT…PHFC

Good evening everyone!

Tropical Disturbance INVEST 92L  remains over the Yucatan Peninsula this evening.  However, based on careful analysis of RGB and Shortwave IR2 satellite loop imagery, I am relocating the center of the disturbance a little further north and west of the 18Z ATCF FTP information, which placed the center near 19.3N…88.3W.  I hold it near 20.7N…89.2W, which is kind of supported by the 925 mb vorticity map

INVEST 92L SATELLITE LOOP IMAGERY

925 MB VORTICITY MAP

The disturbance is moving to the WNW, and I expect this motion to continue tonight, with a turn more to the NW tomorrow.  Currently, the NHC has a 50% (medium) probability of this becoming a tropical cyclone during the next 48 hours, and a 60% (high) chance in the next 5 days.

At the moment, the area is under 15-20 knots of shear, as the upper level anticyclone is just west of the circulation.  Based on the possible relocation of the LLC, and current run of the GFS wind shear forecast products, INVEST 92L may encounter a little more favorable environment than forecast earlier today, with a weak upper level anticyclone forecast over the central GOMEX in about 18 hours.  This is now forecast to remain right before whatever may become of the disturbance, makes it ashore on the Gulf Coast.  The GFS and FIM models still show an open wave, while the CMC has a depression coming ashore.  Given the possible center relocation, I expect the center to be over the water again in about 12 hours or less…so if these conditions do materialize, there is the  slim chance the CMC may be correct.

Based on current and forecast steering, I’m to the right of the 18Z Dynamic Model guidance TVCN track.  I do prefer the track of the FIM model, in that any center will still be over E. LA, however with the weather to the right of track.  Regardless of development or not, winds of 35 to possibly 40 mph may be experienced along the AL/FL Panhandle border in about 48-50 hours.  Residents in these areas may experience flooding due to accumulated rainfall totals 120 hours into the forecast period.

18Z DYNAMIC MODEL GUIDANCE
18zatcfearlyinvest2best.92L

FIM MODEL PRODUCTS

I will continue to monitor INVEST 92L for any significant changes.

Tropical Storm Erin continues to move toward a weakness in the ridge.  As of the 5:00 p.m. EDT advisory from the NHC, the following was available:

5:00 PM AST Thu Aug 15
Location: 15.0°N 27.5°W
Moving: WNW at 14 mph
Min pressure: 1006 mb/29.71 in
Max sustained: 40 mph

HURREVAC TRACKING MAPS
ERIN 72

ERIN 120 FCST

Satellite loop imagery shows almost a NW motion, and convection was just SW of the LLC.

ERIN SATELLITE LOOP IMAGERY

Erin is currently under favorable upper level winds,and should remain in favorable conditions for the next 72 hours, based on the wind shear forecast.  However, the NHC forecast still calls for her to move into a more stable environment, which would preclude strengthening.  Based on current and forecast steering maps, and satellite loop imagery, I prefer the southern portion of the guidance package, however I am somewhat north of the NHC official track.

I will continue to monitor Erin as she approaches just north of the Lesser Antilles, to see if any significant environmental changes occur.

I will have another update in the a.m.

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

Advertisements

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.
This entry was posted in Tropical Synopsis. Bookmark the permalink.

7 Responses to TROPICAL DISTURBANCE INVEST 92L / TROPICAL STORM ERIN FORECAST SYNOPSIS…AUG. 15, 2013…ISSUED 7:40 P.M. EDT…PHFC

  1. James says:

    What do you think of that big blob of African goodness just about to exit the coast? looks impressive.

  2. originallt says:

    The Weather Channel, Jim Cantore to be precise, said at the 11pm briefing, that the models have shifted to the South and West, and any storm that might develop from Invest 92L would go into Tx or Mexico. Well I guess we’ll see. Tx could use the rain.

  3. Monty says:

    Thanks Storm…looks like we have two interesting systems. Think Erin can stay together if she veers North?

  4. Alicia Lindsey says:

    Thanks for keeping us updated.
    Alicia

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s