Home Weather Storm Tracker TROPICAL DEPRESSION FRED FORECAST SYNOPSIS…ISSUED AUG. 11, 2021…9:15 P.M. EDT

TROPICAL DEPRESSION FRED FORECAST SYNOPSIS…ISSUED AUG. 11, 2021…9:15 P.M. EDT

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TROPICAL DEPRESSION FRED FORECAST SYNOPSIS…ISSUED AUG. 11, 2021…9:15 P.M. EDT


Disclaimer:  This site is not affiliated with the National Hurricane Center, Hurricane Hunters, Storm Prediction Center, or National Weather Service.  ALL forecasts herein are the result of my analysis, and I am solely responsible for the content.  As ALWAYS, follow the National Hurricane Center, National Weather Service, and your local Emergency Management officials for emergency decisions.  In addition, this is strictly a FORECAST OFFICE.  I CANNOT make decisions regarding travel plans, etc.  My purpose, is to provide you the information, based solely on information I analyze, and the accuracy of the information at hand of the time of analysis, so you may make informed decisions.
(T. F. “Storm” Walsh)

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Please be aware, even though I do not post every night, rest assured I am continuously monitoring various areas for any significant weather.  I will be taking Sundays off (family time), unless we have active systems that may be posing a threat (i.e. Tropical, Winter Weather, Coastal Storms, etc.).
STORM WALSH PRE-SEASON FORECAST
TOTAL NAMED STORMS: 17 – 20
TOTAL HURRICANES :        7 – 9
MAJOR HURRICANES:       4 – 5

AVERAGE HURRICANE SEASON:
TOTAL NAMED STORMS: 14
TOTAL HURRICANES:         7
MAJOR HURRICANES:       3

2021 SEASON TOTALS:
TOTAL NAMED STORMS:  6
TOTAL HURRICANES:        1
MAJOR HURRICANES:      0

TOTAL U. S. LANDFALLS:  3

The following is the list of storm names for the 2021 Atlantic Hurricane Season:
Ana Bill Claudette Danny Elsa Fred Grace Henri Ida Julian Kate Larry
Mindy Nicholas Odette Peter Rose Sam Teresa Victor Wanda
As a storm becomes named, I will be marking it in bold red to keep track of the activity for this Atlantic season.

Please note..when we are dealing with multiple systems, they will be listed in order as to the greatest threat to land or the U. S. , to the least threat.

Good evening everyone,

As everyone probably knows by now, we had Tropical Storm FRED, which has recently been downgraded to a depression.  Current satellite images show FRED much less organized and somewhat ragged, as the storm has come ashore over the island of Hispaniola.  The following are satellite animations from WEATHERNERDS.
GOES 16 IR ANIMATION
11213813IR
GOES WATER VAPOR ANIMATION
11213813
As you can see, FRED is taking in some drier air on the southern periphery.  In the following full Atlantic animation, you’ll note INVEST 95L near 40W longitude.  I will not be updating on 95L, as FRED is the current main concern for land, and areas in the forecast path.  Since I should have more time this weekend, I will incorporate 95L into the synopsis.  Residents in the Lesser Antilles in the meantime should follow their local NWS entity regarding 95L.  It is noted however, that at 5:00 p.m. EDT, the NHC issued a 50% probability of development over the next 5 days.  95L should be approaching the Lesser Antilles in about 72 hours, where it should be approximately at 55W longitude, based on current guidance.
GOES 16 IR ATLANTIC VIEW
11213813ATL
AFRICA SATELLITE VIEW
sat_20210811_2230_animation
INVEST 95L GUIDANCE
aal95_2021081118_track_early
As of the 8:00 p.m. EDT intermediate advisory from the NHC, the following was available on FRED. 
8:00 PM AST Wed Aug 11
Location: 19.2°N 71.6°W
Moving: WNW at 15 mph
Min pressure: 1009 mb / 29.80
Max sustained: 35 mph
Based on analysis of satellite motion, and analysis of the current steering layer “mean”, Fred continues to move toward the WNW.  The NHC implies however, that the motion is an uncertain 290 deg. as erratic motion is expected as the center and storm interact with the mountains of Hispaniola.  Based on forecast steering however, FRED should continue on a WNW motion during the next 48 hours.  At around 72 hours in the forecast period, FRED will be feeling more of a weakness in the ridge, and should make a turn to the NW.  However, depending on how disrupted the center and LLC become, the COC could shift either way, and depending on where the actual COC exits into the water once more, will determine the forecast track.  In a nutshell, track guidance could shift either left or right.  It’s a wait and see, but based on forecast steering as I mentioned, a WNW should continue, with a NW turn thereafter, in which model guidance and the NHC forecast track indicate.  I will mention however, both the GFS and ECMWF MSLP anomaly forecast maps show FRED coming much closer to FL., with the ECMWF bring him ashore over south FL.  The latest guidance is from 00Z. The current official NHC track seems to favor the consensus models TVCA and TVCE
NHC FORECAST TRACK 
234805_5day_cone_with_line_and_wind
00Z ATCF TRACK GUIDANCE


ECMWF ENSEMBLE

Maximum sustained winds with FRED are now 35 mph.  Based on the last intensity forecast from the NHC which was at 5:00 p.m., they hold FRED at 35 mph as he crosses Hispaniola.  Based on my analysis of dry air intrusion, I believe he could weaken slighter before moving back over water.  The center is going to pretty much pass over the highest mountains of Hispaniola. 
HISPANIOLA TOPOGRAPHY1920px-Hispaniola_lrgAnalysis of the latest wind shear maps shows FRED pretty much remains in a lower shear environment.  NHC states that once back over water, moderate shear should affect him up to 60 hours in the period.  Albeit this is shown by the SHIPS diagnostic report, the GFS model seems to be a bit more forgiving with some lower shear values, as well does the ECMWF.  By 72 hours in the period, the GFS indicates shear lessens as FRED move close to FL., along with some anticyclonic motion noted.
GFS WIND SHEAR FORECASTgfs_dl_shear_carib_24gfs_dl_shear_carib_48gfs_dl_shear_carib_72
As far as re-intensification, this is going to depend on a few factors, such as how well does the COC remain in tact or not, actual wind shear over the system, where exactly does the center wind up exiting, and how much interaction it has with Cuba.  One other factor is, in about 48 hours based on the models, a large upper level anticyclone is forecast to develop near FRED.  Depending on how close this is to the center of the system, will make a difference on how strong the system becomes as it approaches and moves toward the Florida keys.  The close to the center, the better chance for intensification.  Analysis of the ECMWF indicates, along with the GFS, that the moisture at 500 mb improves once FRED is back over the water, based on analysis this evening of forecast 500 mb relative humidity values and the SHIPS diagnostic report.  The first sets of maps will show you where the models have FRED in the forecast, and then the 200 MB anticyclone relative to the system.
ECMWFecmwf-deterministic-caribbean-mslp_norm_anom-8856000
ecmwf-deterministic-caribbean-z200_speed-8856000
ecmwf-deterministic-caribbean-mslp_norm_anom-8942400
ecmwf-deterministic-caribbean-z200_speed-8942400
GFS




ECMWF 500 MB RELATIVE HUMIDITY FORECAST

Given the current uncertainty of exactly how the scenario will play out, but based on the more favorable environment in the 72 hour forecast, I agree right now with the NHC intensity forecast from 5:00 p.m. EDT. 
NHC INTENSITY FORECAST
INIT 11/2100Z 18.9N 71.0W 35 KT 40 MPH…INLAND
12H 12/0600Z 19.8N 72.7W 30 KT 35 MPH…INLAND
24H 12/1800Z 20.9N 75.0W 30 KT 35 MPH…OVER WATER
36H 13/0600Z 21.9N 77.1W 35 KT 40 MPH
48H 13/1800Z 22.9N 79.2W 35 KT 40 MPH
60H 14/0600Z 23.9N 80.6W 40 KT 45 MPH
72H 14/1800Z 25.3N 82.0W 40 KT 45 MPH
96H 15/1800Z 28.5N 84.0W 50 KT 60 MPH
120H 16/1800Z 31.0N 85.0W 45 KT 50 MPH…INLAND
Tropical Storm watches and warnings are still in effect, and the following information is from the NHC advisories:

I expect Tropical Storm watches to be issued for portions of the southern FL. peninsula sometime on Thursday.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Dominican Republic on the north coast from Cabo Frances Viejo 
to the Dominican Republic/Haiti border

A Tropical Storm Watch is in effect for...
* Haiti from the northern border with the Dominican Republic to
Gonaives
* Turks and Caicos Islands
* Southeastern Bahamas
* The Cuban provinces of Ciego de Avila, Camaguey, Las Tunas,
Holguin, Granma, Santiago de Cuba, and Guantanamo

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area, in this case within the
next 12 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area.

Interests elsewhere in Haiti, the Bahamas, Cuba, and the southern
Florida Peninsula and the Florida keys should monitor the progress
of Fred.

For storm information specific to your area, please monitor
products issued by your national meteorological service
HAZARDS AFFECTING LAND
RAINFALL: Tropical Depression Fred is expected to produce the 
following rainfall amounts:

Across the Dominican Republic...3 to 5 inches, with isolated maximum
totals of 8 inches. Heavy rainfall through Thursday morning could
lead to flash, urban, and small stream flooding, along with possible
rapid river rises and the potential for mudslides.

Over Haiti, the Turks and Caicos, the eastern Bahamas, and Cuba...1
to 3 inches with isolated maximum totals of 5 inches.

Across the western Bahamas...3 to 5 inches, with isolated maximum
totals of 8 inches.

Beginning Friday into next week, heavy rainfall associated with Fred
will impact Florida and parts of the Southeast. Through Monday, 3 to
5 inches of rain is anticipated across the Keys and the southern
Florida Peninsula, with isolated maximum totals of 8 inches. Heavy
rainfall could lead to areal, urban, and small stream flooding,
along with possible rapid river rises.

WIND:  Tropical storm conditions could occur in brief squalls over 
portions of the northwestern coast of the Dominican Republic for a 
few more hours.  Tropical storm conditions, mainly in brief 
squalls, will also be possible along the northern coast of Haiti, 
the Turks and Caicos, and the southeastern Bahamas beginning 
tonight. Tropical storm conditions are possible in Cuba beginning 
Thursday.

SURF:  Swells generated by Fred are expected to continue across the
U.S. Virgin Islands, Puerto Rico and Hispaniola tonight, where they
could cause life-threatening surf and rip current conditions.
Please consult products from your local weather office.


The following map will allow to to get information from your NWS office.
NWS WATCH / WARNING DISPLAY (LINKED…CLICK MAP, THEN YOUR AREA)

NWS SAN JUAN, PUERTO RICO LINK
https://www.weather.gov/sju/

WSI DOPPLER RADAR LOOP (LINKED, CLICK RADAR MAP)

RAP RADAR (CLICK IMAGE THEN RADAR SITE)
CARIBBEAN RADAR IMAGES (LINK)
https://www.barbadosweather.org/Composite/kidbuuComposite_Lionel_displayer2.php?Product=Reflectivity&Sector=fullView&Composite=Sabre&ANISP=700&MAPP=1&PlanetOfTheApes=11254

I will continue to monitor FRED for any significant changes to the forecast atmospheric parameters, and intend to update again tomorrow evening.

You may direct any questions by contacting me personally, ANYTIME, at: [email protected]

Have a blessed evening!

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

 

 



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