November 28, 2020

Weather News – Road Conditions – weather forecast

HURRICANE EPSILON / INVEST 95L FORECAST SYNOPSIS…ISSUED OCT. 23, 2020…7:55 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: 10
MAJOR HURRICANES: 4

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!
Hurricane EPSILON has weakened considerably over the past 36 hours, and satellite loop imagery shows some structure degradation.  As of the  5:00 p.m. EDT advisory, the following was available on EPSILON:

5:00 PM AST Thu Oct 22
Location: 35.5°N 61.7°W
Moving: N at 12 mph
Min pressure: 968 mb
Max sustained: 85 mph

EPSILON SATELLITE LOOP IMAGERY (CLICK IMAGE)

EPSILON surprised both me and the NHC the evening of 21 Oct., having rapidly intensified from a 65 mph tropical storm on the 5:00 p.m. advisory on the 20th, to a MAJOR CAT 3 hurricane on the evening of 21 Oct. at 5:00 p.m. EDT, with maximum sustained winds of 115 mph, making EPSILON the 10th hurricane of the season, and fourth major hurricane.  This was not seen based on forecast conditions, and I for one, am still trying to figure out how EPSILON was able to go through R.I. and I’ll explain: 
1.) EPSILON was surrounded by drier mid level air which pretty much eroded one of the rain-bands east of the center.
2.)  Upper level outflow was not optimal to induce R.I., as outflow bean over the center of the storm, and only expanded north and NE of the center.  The flow on the southern portion of the hurricane was cyclonic, therefore no outflow channel was not created in the southern half of the storm.
3.)  OHC (Ocean Heat Content) ranged only from 0 kj/cm2 to 10 kj/cm2.  Generally 50 kj/cm2 is the threshold for allowing a storm to perform R.I. and maintain major hurricane strength
I am posting the OHC map from last night for a visual, (EPSILON performed R.I. where the blue OHC is seen and became a CAT 3 hurricane), and current upper level winds map, which resembles Oct. 21st evenings map.
CIMSS OHC

UPPER LEVEL WINDS

So in a nutshell, this has me perplexed, as this is only the second time in my years of forecasting I have seen a storm defy non optimal conditions for Rapid Intensification.  I am not sure how EPSILON pulled this off.  I will be researching this, however I’m not sure if an answer is readily available.

Based on analysis again of forecast steering maps, I agree with the tightly clustered ATCF track guidance, and the NHC forecast track map.
NHC FORECAST TRACK

ATCF 18Z GUIDANCE

The NHC expects some slight strengthening if the secondary eyewall can consolidate, as shear is expected to remain low.  Based on analysis, I have no problem with their intensity forecast:
INIT 23/2100Z 35.5N 61.7W 75 KT 85 MPH
12H 24/0600Z 37.0N 61.6W 80 KT 90 MPH
24H 24/1800Z 38.9N 59.0W 80 KT 90 MPH
36H 25/0600Z 41.9N 53.9W 75 KT 85 MPH
48H 25/1800Z 45.6N 45.6W 70 KT 80 MPH
60H 26/0600Z 50.0N 34.0W 65 KT 75 MPH…POST-TROP/EXTRATROP
72H 26/1800Z 54.0N 24.0W 65 KT 75 MPH…POST-TROP/EXTRATROP
96H 27/1800Z…DISSIPATED
Given that EPSILON will be recurving soon, this will be my final post on the storm

Now, to problems closer to home.
There has been a game changer regarding the W. Caribbean trof that we have been discussing over the past few days.  IF you recall from my last forecast, I had posted that I did not feel the area would develop, due to unfavorable conditions that would occur given the location at that time, and forecast movement.  However, the center has been relocated and  marked, down near the Cayman Islands, vice closer to the Yucatan Channel the other evening.  This shift in center location now places the area of lowest pressure in an area where upper level winds and OHC are favorable for further development.  I had analyzed this yesterday evening, and had intended to post, however when I went to add another graphic, my PC wiped out what I had already typed up, and it was too late to start all over.  I did note on very careful analysis of close up infrared satellite loop imagery (grayscale), a low level circulation was slowly beginning to come together.  Based on some further, slow organization, the area has now been designated INVEST 95L.
INVEST 95L CLOSEUP SATELLITE LOOP IMAGES (CLICK IMAGES)

As of 2:00 p.m. EDT, based on the ATCF BTK product, the following information was available:
2:00 PM EDT Thu Oct 23
Location: 19.4°N 81.9°W
Moving: NNW at 5 mph
Min pressure: 1007 mb /  29.74 in
Max sustained: 30 mph
INVEST 95L was moving toward the NW to NNW at around 5 mph.  As we know, having seen steering with storms this season, there sill most likely be shifts in forecast track as this becomes better organized over the next few days.  However based on my analysis of current forecast steering layers maps, I expect this NNW motion to continue during the next 24 – 48 hours, and INVEST 95L should cross the western tip of Cuba, or through the Yucatan Channel, just west of the tip of Cuba.  Thereafter, steering changes abruptly and for a brief period, as the ridge builds back for a very short period, sending the system on a short jog to the west.  Shortly after this, the steering flow is forecast to allow for a N to NNE tack motion.  Again, this will be watched closely as steering can change quickly.  This and strength of the system will determine the exact future path.  Based on analysis, I agree at the moment with the 18Z Guidance dynamic and consensus models which are the ones on the right most side and labeled TVCA / TVCE.
18Z TRACK GUIDANCE

https://i2.wp.com/hurricanes.ral.ucar.edu/realtime/plots/northatlantic/2020/al952020/track_early/aal95_2020102318_track_early.pngINVEST 95L as of the last update from CIMSS, indicates INVEST 95L is sitting in an area where conditions are currently favorable.  An upper level anticyclone is noted over the system in the wind shear map, and upper level outflow has become established based on the upper level wind map.  OHC is currently 150 kj/cm2.
INVEST 95L WIND SHEAR
UPPER LEVEL WINDS

OHC

Based on analysis this evening of forecast MSLP normalized anomaly maps, the ECMWF and GFS show an on and off development of a closed low, and at the moment, do not really develop this.  However, we’ve seen this before on initialization, and have seen some healthy systems develop.
GFS
ECMWF

Analysis of wind shear and 200 mb streamline maps from the GFS and ECMWF indicate the upper level environment is forecast to be favorable up to around 96 hours for further gradual development, with the upper level anticyclone remaining with the system, and upper level outflow seen in the 200 mb forecast maps. 
ECMWF AND GFS 200 MB WIND SPEED FORECAST MAPS

Once this enters the GOMEX, and right around the 96 hour period, upper level winds are forecast to begin to become non conducive for further development.  Based on this at the moment, I am calling for a tropical to depression to develop during the next 24 – 48 hours.  IF conditions pan out as forecast, INVEST 95L could become a tropical storm by 48 -60 hours, which is forecast by the more accurate intensity guidance models.   However, mid level dry air by 48 hours could be the only negating factor for strengthening.
ECMWF RH FORECAST

I will continue to monitor INVEST 95L for any (surprises) over the next 72 hours.

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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