TROPICAL LOW INVEST 94L FORECAST SYNOPSIS…ISSUED JUL. 29, 2015…11:10 A.M. EDT

SEVERE WEATHER THREAT: MARGINAL
TROPICAL STORM FORMATION:  LOW (20%)

ALL forecasts contained on this site,  are based on my analysis and knowledge of various forecast tools, including information contained in NHC products, and are not copies from any other entity.

*NOTE: In the TROPICAL STORM FORMATION line above, probabilities are for during the next 5 day period.  My personal probability will be listed as either NONE, MONITORING or PROBABLE.  This does not necessarily mean something will develop, but that certain forecast conditions are likely to be present, favoring development.  Once NHC products become available, then the appropriate probability and percentage will be used.

Please refer to the link for the Storm Prediction Center in the box at the top of the page, just below the Hurricane Hunter graphics.

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Current Storm Total for 2015:

TOTAL STORMS: 3
HURRICANES: 0
INTENSE HURRICANES: 0
U.S. LANDFALLS: 2

StormW Seasonal Forecast:

TOTAL STORMS:             8
HURRICANES:                   3
INTENSE HURRICANES: 1

Good day everyone!

Given that the current El Nino is rivaling the 1997 event, and that the vertical instability is well below normal in the Atlantic, along with the premise of continued shear over the Caribbean sea, I have decided to revise my seasonal forecast, which is noted above.

ENTER, INVEST 94L!

The Tropical Wave I began monitoring in the far eastern Atlantic, off the African coast, has been designated INVEST 94L.

Based on the 12Z ATCF FTP information, the following was available on INVEST 94L:

Location: 12.0°N 20.9°W
Moving: W at 15 mph
Min pressure: 1010 mb / 29.83 in
Max sustained: 25 mph

The NHC in Miami has designated a LOW (20%) probability of cyclone formation during the next 5 days in the 8:00 a.m. Graphical Tropical Weather Outlook (GTWO)

NHC 5 DAY GTWO
two_atl_5d0

Analysis of satellite imagery this morning, indicates this system is not as well organized as it was yesterday afternoon.

INVEST 94L FLOATER SATELLITE LOOP IMAGERY
avn0-lalo94L

rgb0-lalo94L

RAMSDIS METEOSAT FLOATER IMAGERY LOOP (CIRA)
tropical_met_4km_visir2_floater

Analysis of the current wind shear product from CIMSS indicates upper level winds to be marginal at the moment, with the 200 mb streamlines indicating a diffluent flow aloft, allowing for some slight upper divergence over INVEST 94L.  The current wind shear forecast from the GFS 06Z run indicates wind shear to remain marginally conducive over the next two and a half days, with shear values relaxing somewhat approximately 72 hours into the forecast period.  However, the streamline pattern tends to become less conducive thereafter.

CURRENT EATL WIND SHEAR PRODUCT FROM CIMSS
wm7shr

GFS 06Z WIND SHEAR FORECAST 78 HOURS
850200shear13
Analysis of the current SAL product indicates minimal dust.  However water vapor imagery at mid levels indicates limited moisture for this INVEST to work with, while moisture is a little more plentiful in the upper layers.

CURRENT SAL PRODUCT
truecol

WATER VAPOR (MID LEVEL)
wvmid

WATER VAPOR (UPPER)
wvhi

Looking closely at the SAL product, as well as the RAMSDIS floater, one can see that INVEST 94L is in a fairly stable environment, based on the surrounding Stratocumulus cloud deck (In simpler terms, the small, puffy cloud clusters around the INVEST).  These clouds indicate stable air surrounding the system.

Dynamic model track guidance had not posted as of my analysis, as it takes longer to run the dynamic models, vice the Statistical models.  However based on analysis of the current steering layers forecast, the graphic in the NHC Tropical Weather Outlook should be in order.  So, I expect this system to continue moving toward the west for at least the next 48- 72 hours, then more of a track toward the WNW.  Based on this forecast, as the system begins to reach 15N Latitude, it will loose it’s moisture support at the 500 mb level, which the GFS indicates to happen in about 60- 72 hours.  By day 5 in the current forecast period, it will enter an area where the Precipitable Water diminishes greatly.  Again, this is all based on the premise of the current forecast motion.

GFS 500 MB HUMIDITY FORECAST
gfs_atlantic_081_500_rh_ht

Putting it all together, I am calling for the INVEST to either remain status quo today, to possibly a slight chance of a little better organization this evening, followed by a decline as the more unfavorable conditions are met.  The preliminary intensity forecast indicates 2 of the 3 most accurate intensity models calling for a minimal tropical storm.  Based on forecast conditions, this seems a little bullish.

ATCF 12Z PRELIMINARY INTENSITY FORECAST
INVEST94L 12Z INTENSITY

I will continue to monitor this area for any significant changes during the next 48-72 hours.

I work the next 2 days, so I may not have another update until Saturday.

Elsewhere, Tropical Storm formation is not expected during the next 7 days.

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  

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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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2 Responses to TROPICAL LOW INVEST 94L FORECAST SYNOPSIS…ISSUED JUL. 29, 2015…11:10 A.M. EDT

  1. dellamom says:

    Thank you, Storm. Do I remember correctly that storms that enter drier areas tend to moisturize the environment for the next storm, but they also allow upwelling of cooler waters from deeper levels? So that would be an enhancing effect and an inhibiting effect, or is the upwelling just in shallower waters than the mid-Atlantic, such as the Gulf?

    • To answer the first…yes…if waves and disturbances can continue firing decent convection, it throws moisture into the atmosphere…however this sometimes takes 3-4 systems after another to accomplish this enough for dry air to be minimized. As far as upwelling, it generally takes a strong TS or above to bring up water from below the surface. It is more common in shallow depths, however a slow moving system will cause upwelling too.

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