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TROPICAL DEPRESSION FRED / TROPICAL DEPRESSION SEVEN FORECAST SYNOPSIS…ISSUED AUG. 13, 2021…10:00 P.M. EDT

1 month ago 204
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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,
Tropical Depression FRED had taken a jog more toward the west during the day, and is currently moving toward the west, a little further inland over Cuba than was planned.  In my analysis of satellite loop imagery this evening, the center was extremely difficult to see, however it appears to seem a little more disorganized and somewhat elongated.  Convection is seen flaring up, however this may be due to oragraphic lift over the mountains of Cuba.
WEATHERNERDS GOES 16 SATELLITE ANIMATION IMAGES
52785046ir
VISIBLE ANIMATION
52785046vis
NOAA GOES 16 CLOUD TOP
06L_RBTOP
Activity continues to pick up as seen in the Atlantic full view loop, and African satellite loop imagery
WEATHERNERDS ATLANTIC ANIMATION
34608880ATL
AFRICA SATELLITE
sat_20210813_2230_animation
As of the 8:00 p.m. EDT intermediate advisory from the NHC, the following was available on FRED.
8:00 PM EDT Fri Aug 13
Location: 22.5°N 80.2°W
Moving: W at 12 mph
Min pressure: 1013 mb / 29.91 in
Max sustained: 35 mph
ABOUT 45 MI…70 KM W OF CAIBARIEN CUBA
ABOUT 175 MI…285 KM SE OF KEY WEST FLORIDA

FRED is moving west, and based on analysis of the current layer mean steering, and analysis of the forecast steering flow, I expect this motion to continue during tonight, and then FRED SHOULD turn toward the WNW.  NHC mentions he should make the turn this evening, however based on the satellite motion of the disorganized center, the westward motion was noted as of current.  It is possible for the forecast track to nudge slightly west, and given the disruption of the center more than thought, I cannot rule out a center reformation once FRED exits back into the water.  However, model guidance seems much better clustered, and save any center reformation, or unseen change in the forecast steering, I agree pretty much with the NHC forecast track.
NHC TRACKING MAP
234109_5day_cone_with_line_and_wind
NHC TRACKING MAP (LINKED TO THE NHC INTERACTIVE MAP…CLICK MAP)
234109_5day_cone_with_line_and_wind
00Z ATCF GUIDANCE
aal06_2021081400_track_early

ECMWF ENSEMBLE
ecmwf-bufr-fred06l-1628856000-8856000
Maximum sustained winds were still reported at 35 mph.  Analysis of the most recent wind shear map from CIMSS indicated FRED was still under 20 kts of westerly shear.  Based on analysis of forecast wind shear maps, wind shear is forecast to remain, during the next 24 – 30 hours. Upon FRED exiting toward the GOMEX, the shear forecast calls for wind shear to begin relaxing, and as time goes out in the period, the upper level could become favorable for a short time, until shear once again begins to increase between 48 – 60 hours, based on which global model is correct.  Based on analysis of this factor, and how long it may take FRED to recover after exiting Cuba, intensification rate and level remain somewhat uncertain.  Based on this, I agree with the NHC intensity forecast at this time.  Of note, the HMON hurricane model brings FRED to CAT 1 status right before landfall.  As of now, I don’t see this occurring, unless upper level conditions improve more than forecast, and FRED recovers very quickly.
NHC INTENSITY FORECAST
INIT 13/2100Z 22.3N 79.6W 30 KT 35 MPH…INLAND
12H 14/0600Z 23.0N 81.0W 30 KT 35 MPH…INLAND
24H 14/1800Z 24.2N 82.6W 35 KT 40 MPH…OVER WATER
36H 15/0600Z 25.4N 83.7W 35 KT 40 MPH
48H 15/1800Z 27.0N 84.8W 40 KT 45 MPH
60H 16/0600Z 28.8N 85.7W 45 KT 50 MPH
72H 16/1800Z 30.2N 86.2W 50 KT 60 MPH
96H 17/1800Z 33.5N 86.5W 25 KT 30 MPH…INLAND
120H 18/1800Z 37.0N 85.0W 20 KT 25 MPH…POST-TROP/INLAND
Tropical Storm watches and warnings are still in effect, and the following information is from the NHC advisories:
234109_current_wind_sm

SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * The Florida Keys west of Ocean Reef to the Dry Tortugas * Florida Bay A Tropical Storm Watch is in effect for... * The southwest coast of Florida from Englewood south and east to Ocean Reef A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area. Interests in the Bahamas, Cuba, and in the Florida peninsula and Florida Panhandle should monitor the progress of Fred. Additional watches and warnings could be required for portions of the west coast of Florida and the Florida panhandle tonight or Saturday. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service. HAZARDS AFFECTING LAND Key messages for Fred can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT1, WMO header WTNT41 KNHC and on the web at www.hurricanes.gov/graphics_at1.shtml?key_messages. RAINFALL: Fred is expected to produce the following rainfall amounts: Portions of Cuba...2 to 5 inches with isolated maximum totals of 8 inches. This rainfall may lead to scattered flash flooding. Across the Bahamas...1 to 3 inches, with isolated maximum totals of 5 inches. Today through Monday, 3 to 6 inches of rain is anticipated across the Keys, southern and central Florida north towards the Big Bend, with isolated maximum totals of 8 inches. Heavy rainfall could lead to areal, urban, and small stream flooding, and potentially worsen ongoing minor to isolated moderate river flooding over northern Florida. From Sunday onward, heavy rain and flood impacts could extend into inland portions of the Southeast and into the southern and central Appalachians and Piedmont as Fred interacts with a front in the area. WIND: Tropical storm conditions are expected in portions of the warning area across the Florida Keys on Saturday. Tropical storm conditions are possible in the watch area in Florida beginning Saturday. SURF: Swells generated by Fred are expected to spread across portions of the Bahamas and the northern coast of Cuba through tonight. These swells could reach the Florida Keys and southern Florida by early Saturday and increase along the west coast of Florida Saturday night and Sunday. Please consult products from your local weather office for more details. TORNADOES: There will be a risk of isolated tornadoes beginning Saturday afternoon over parts of central and south Florida.

234109_key_messages_sm

234109_spanish_key_messages_sm
NWS LOCAL PRODUCTS FOR FRED (CLICK LINK)
https://www.nhc.noaa.gov/text/refresh/index_hls1+shtml/122126.shtml?

The following are the current forecast precipitation totals for the U.S. from the WPC.
NCEP WPC TOTAL 7 DAY PRECIPITATION FORECAST
p168i
The following map will allow to to get information from your NWS office.

NWS WATCH / WARNING DISPLAY (LINKED…CLICK MAP, THEN YOUR AREA)

WSI DOPPLER RADAR LOOP (LINKED, CLICK RADAR MAP)

RAP RADAR (CLICK IMAGE THEN RADAR SITE)
TROPICAL DEPRESSION SEVEN
Tropical Depression SEVEN appeared better organized at the time of my analysis of the satellite animation earlier.  Based on satellite motion, and current steering, T. .D SEVEN was moving toward the west.  In fact, the current forward motion is rather quick.
TROPICAL DEPRESSION SEVEN SATELLITE ANIMATION FROM WEATHERNERDS
34608880
Analysis of water vapor imagery indicated the depression is surrounded by mid level dry air, however dry air intrusion, if any, appeared to be very minimal.  In fact, the moisture forecast based on RH values in the mid levels indicates improving conditions for both tropical systems.
WATER VAPOR ANIMATION
47923447
As of the 8:00 p.m. EDT intermediate advisory from the NHC, the following was available on T.D. SEVEN:
8:00 PM AST Fri Aug 13
Location: 15.6°N 53.1°W
Moving: W at 22 mph
Min pressure: 1010 mb / 29.83 in
Max sustained: 35 mph
ABOUT 580 MI…935 KM E OF THE LEEWARD ISLANDS

Based on the current steering layer mean, and analysis of the forecast steering flow, the depression should continue toward the W for approximately another 24 hours, prior to taking more of a WNW track.  Based on the 18Z track guidance, which was fairly clustered at the time, T. D. SEVEN could take a track somewhat similar to FRED.  However beginning at around 72 hours in the forecast period, the guidance becomes more spread.  Based on this analysis, and based on the amount of land interaction with Hispaniola, I have to agree with the current NHC forecast track.
NHC FORECAST TRACK MAP
234331_5day_cone_with_line_and_wind
NHC TRACKING MAP (LINKED TO THE NHC INTERACTIVE MAP…CLICK MAP)
234331_5day_cone_with_line_and_wind
00Z ATCF GUIDANCE
aal07_2021081400_track_early
Maximum sustained winds were reported at 35 mph.  Analysis of the most recent wind shear map from CIMSS indicated the depression was under 10 – 15 kts of shear.  During the next 48 hours, analysis of the 200 mb streamline forecast shows the system coming under the axis of an upper level ridge, and this should allow for shear to remain low.  Analysis of the wind shear forecast and current SHIPS diagnostic report indicates wind shear is forecast to increase in about 78 hours or so as the system nears Hispaniola.  Based on the forward speed and the forecast of shear.  IF the system can slow down, and the shear forecast materializes, I believe T.D. SEVEN could strengthen at a slightly better rate.  Until this occurs however, I agree with the NHC intensity forecast

NHC INTENSITY FORECAST
INIT 13/2100Z 15.4N 51.8W 30 KT 35 MPH

12H 14/0600Z 15.9N 54.7W 35 KT 40 MPH
24H 14/1800Z 16.4N 58.5W 35 KT 40 MPH
36H 15/0600Z 17.0N 61.9W 40 KT 45 MPH
48H 15/1800Z 17.7N 65.0W 45 KT 50 MPH
60H 16/0600Z 18.4N 67.7W 45 KT 50 MPH
72H 16/1800Z 19.0N 70.3W 40 KT 45 MPH…OVER HISPANIOLA
96H 17/1800Z 20.9N 74.7W 35 KT 40 MPH…OVER WATER
120H 18/1800Z 23.6N 79.1W 40 KT 45 MPH
Tropical Storm watches and warnings are in effect, and the following information is from the NHC advisories:
234331_current_wind_sm

SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Antigua and Barbuda, Anguilla, St. Kitts and Nevis, and Montserrat * Saba and Sint Eustatius * Sint Maarten * St. Martin and St. Barthelemy A Tropical Storm Watch is in effect for... * British Virgin Islands * U.S. Virgin Islands * Puerto Rico, including Vieques and Culebra A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. Interests elsewhere in the Leeward Islands, as well as the Dominican Republic, should monitor the progress of this system. Additional watches and warnings will likely be required for these areas tonight or on Saturday. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service. HAZARDS AFFECTING LAND Key messages for Tropical Depression Seven can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT2 and WMO header WTNT42 KNHC and on the web at www.hurricanes.gov/graphics_at2.shtml?key_messages. WIND: Tropical storm conditions are expected within the warning area over the Leeward Islands by Saturday night or early Sunday. Tropical storm conditions are possible over the Virgin Islands and Puerto Rico beginning on Sunday. RAINFALL: The depression is expected to produce the following rainfall amounts Saturday into Monday: Over the northern Leeward Islands and Virgin Islands...3 to 6 inches. This rainfall may produce scattered areas of flash and urban flooding. Over Puerto Rico...3 to 6 inches. Heavy rainfall could lead to flash, urban, and small stream flooding as well as potential mudslides.

234331_key_messages_sm

234331_spanish_key_messages_sm
NWS SAN JUAN, PUERTO RICO LINK
https://www.weather.gov/sju/

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

ECMWF AND GFS 5 DAY PRECIPITATION FORECAST
ecmwf-deterministic-caribbean-precip_120hr_inch-9288000

gfs-deterministic-caribbean-precip_120hr_inch-9309600
I will continue to monitor FRED and T. D. SEVEN for any significant changes to the forecast atmospheric parameters, and intend to update again tomorrow evening.  I will not be updating Saturday, as I have plenty of personal business to attend to.

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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