May 12, 2021

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TROPICAL STORM EPSILON / CARIBBEAN TROUGH FORECAST SYNOPSIS…ISSUED OCT. 20, 2020…8:20 P.M. EDT

7 min read


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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Greetings to everyone!
Please be aware, even though I do not post every night, rest assured I am continuously monitoring the tropics.  I will be taking Sundays off (family time), unless we have active systems that may be posing a threat, or development of new systems (i.e. INVESTS).

The following are the storm names for the 2020 hurricane season.  The names in bold red have already formed this season:
Arthur Bertha  Cristobal  Dolly  Edouard  Fay  Gonzalo  Hanna  Isaias Josephine Kyle Laura Marco Nana  Omar  Paulette  Rene  Sally  Teddy
Vicky Wilfred

We are now into the Greek alphabet as far as storm names.  The following names in bold red have been used so far:
Alpha Beta Gamma Delta Epsilon Zeta Eta Theta Iota Kappa Lambda

STORMW’s SEASONAL FORECAST
TOTAL NAMED STORMS: 18 – 21
TOTAL HURRICANES :        7 – 10
MAJOR HURRICANES:        4 – 6

AVERAGE HURRICANE SEASON:
TOTAL NAMED STORMS: 12
TOTAL HURRICANES:         6
MAJOR HURRICANES:        2

2020 SEASON TOTAL:
NAMED STORMS: 26
HURRICANES: 9
MAJOR HURRICANES: 3

U.S. LANDFALLS: 10
I’ve given thought to this, due to the time it takes to ACCURATELY analyze the global and hurricane models and the various parameters that need to be analyzed, collecting important graphics, then having to type the synopsis, I will continue to post links from the NHC and other sites as necessary, with the information you need as far as surge, storm information, watches and warnings, local NWS forecast conditions and statements, actions to be implemented, etc. if a storm is threatening.  IF YOU SEE A LINK, PLEASE CLICK IT, as there is VALUABLE information to help you prepare and stay abreast, and could save your life.  This is less time consuming and contains ALL the information you’ll need to prepare for a tropical storm or hurricane should it be forecast to affect your area.

Good evening!
EPSILON has increased in strength during the past 24 hours, and has become more symmetric since last night, appearing more tropical.  Yesterday evening, based on the criteria for a tropical system, in my opinion, EPSILON was more sub-tropical.  Analysis this evening however, supports EPSILON being a bona fide tropical storm.  As of the 5:00 p.m. EDT advisory, the following information was available from the NHC:

5:00 PM AST Tue Oct 20
Location: 27.9°N 55.8°W
Moving: NW at 13 mph
Min pressure: 992 mb / 29.29 in
Max sustained: 65 mph
GOES 16 EPSILON SATELLITE LOOP (CLICK IMAGES)

EPSILON was moving to the NW, and based on analysis of the current forecast steering layers maps, I expect this motion to continue up until around Thursday, when I expect a more NNW motion beginning as EPSILON begins to make a northward transition as it moves through a break in the ridge.  Sometime early on Saturday, and approaching deep layer trof is forecast to turn EPSILON toward the NE.  Based on this analysis, and current ATCF track guidance which is tightly clustered, I agree with the NHC forecast track, re-curving EPSILON:
NHC FORECAST TRACK

ATCF 18Z TRACK GUIDANCE

EPSILON’S sustained winds were reported to be 65 mph. EPSILON is currently under moderate wind shear of around 20 – 25 kts, and is almost completely surrounded by mid level dry air.  There is a dry slot noted east of the center in water vapor loop imagery.  However despite this, EPSILON has strengthened.  Upper level outflow has begun somewhat early, with an outflow channel now apparent north and flowing east of the center.  Albeit not an optimal setup, upper level air is being evacuated from the center.  It is noted in the above satellite loop imagery, that an eye or eye feature may be trying to develop.
EPSILON WATER VAPOR LOOP (CLICK IMAGE)

CIMSS UPPER LEVEL WINDS

Even though the storm is under moderate shear, AMSU data does indicate it is warm core which is a plus, and further AMSU data indicates EPSILON is currently a shallow warm core symmetric system.  The plus behind this is, being a shallow to mid level system right now, mid level wind shear is around 10 kts or less, so deep layer shear is most likley not affecting the system as much.
AMSU HWRF MODEL


Based on wind shear analysis and current SHIPS diagnostic information, upper level winds are forecast to improve, and EPSILON is forecast to become a hurricane within the next 24 – 36 hours.  I am a little skeptical of this, however with the possible developing eye and premise of upper level winds becoming more favorable, I cannot rule this out.  What raised a question with me on hurricane status was, dry air begins to intrude in the circulation.  However, based on analysis of RH forecast values from the ECMWF, the drier air does not appear to enter the core of the storm, hence the forecast for attaining hurricane status.  IF dry air does not enter the core, I pretty much agree with the NHC intensity forecast.  Should dry air begin to entrain into the core, the convection would begin to collapse. 
ECMWF 500 MB RH FORECAST



Right now, I did not detect this in the grayscale IR satellite loop due to lack of arc clouds flowing outward at the surface.  As EPSILON begins moving into lower OHC, any further strengthening should cease and intensity remain steady.  By Saturday or very early Sunday, Epsilon should begin its extra-tropical transition.  As this occurs, the storm should begin to expand in diameter.
NHC INTENSITY FORECAST
INIT 20/2100Z 27.9N 55.8W 55 KT 65 MPH
12H 21/0600Z 28.8N 57.8W 65 KT 75 MPH
24H 21/1800Z 29.3N 59.6W 70 KT 80 MPH
36H 22/0600Z 30.3N 60.5W 75 KT 85 MPH
48H 22/1800Z 31.6N 61.2W 75 KT 85 MPH
60H 23/0600Z 33.0N 61.6W 75 KT 85 MPH
72H 23/1800Z 34.0N 61.8W 75 KT 85 MPH
96H 24/1800Z 36.7N 60.7W 75 KT 85 MPH
120H 25/1800Z 42.0N 51.0W 70 KT 80 MPH
CIMSS OHC MAP

I will continue to monitor EPSILON for any significant changes.

Elsewhere, the trough of low pressure in the W. Caribbean is pretty ill defined in satellite analysis:
GOES 16 W. CARIBBEAN LOOP (CLICK IMAGE)

Based on analysis of current shear from CIMSS, there is an upper level anticyclone in the W. Caribbean, however it is centered SSE of the circled area in the satellite loop map.  This is creating wind shear over the area, and is why you note the upper level clouds being blown eastward.  Analysis of the global models still show the area not developing a closed low.  In analysis of forecast wind shear maps and 200 mb streamline maps, it currently appears that the upper level anticyclone remains in tact during the next few days.  However, it meanders around in a anticyclonic gyre, and never really centers of the area of lower pressure.  IF this does not change, and with the lower pressures moving NW over the Yucatan Peninsula, and eventually into the GOMEX, wind shear will increase over the area.  In addition, dry air is currently affecting the area, and is pretty much forecast to remain an issue.  IF there is not any improvement to the forecast surrounding environmental conditions, I don’t see development occurring.
W. CARIBBEAN WATER VAPOR LOOP (CLICK IMAGE)
ECMWF 500 MB RH FORECAST

I will continue to monitor the W. Caribbean for any significant changes.

You may direct any questions by contacting me personally, ANYTIME, at: twalsh22000@yahoo.com

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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