ATL: ERIN - Post-Tropical - Discussion

[galaxy401]

Has a TCFA been issued on this one yet?

Not yet. I assume one will be issued later today if it continues the organization process is going thru.

Kind of strange considering this invest has a higher % chance of developing than 92L (though both are about the same). Most likely because this invest isn't a threat to land.

[otowntiger]

Dr. Jeff Masters' WunderBlog

Posted by: Dr. Jeff Masters, 12:40 GMT le 14 août 2013

http://www.wunderground.com/blog/JeffMa ... rynum=2489

New African Tropical Wave 93L Organizing
A tropical wave that pushed off the coast of Africa on Tuesday (93L) is showing a modest amount of heavy thunderstorm activity and spin on satellite loops as it heads west-northwest at 10 mph. The wave is over warm waters of 28°C and is under a moderate 10 - 15 knots of wind shear, which should allow continued development today and Thursday. The 00Z SHIPS model forecast predicts that wind shear will be low to moderate for the next five days, which favors development. However, the waters beneath 93L will steadily cool to a marginal 26°C by Friday, and the atmosphere will steadily get drier, as 93L encounters the Saharan Air Layer (SAL), discouraging development. In their 8 am EDT Wednesday Tropical Weather Outlook, NHC gave the system a 60% of developing by Monday, and a 60% chance of developing by Friday. [b]The expected west-northwest track of 93L over the next five days will carry it into a region of ocean where it is uncommon for tropical cyclones located there to eventually impact any land areas except Bermuda.[/b]

Sounding fishy!

[CrazyC83]

Has a TCFA been issued on this one yet?

Not yet. I assume one will be issued later today if it continues the organization process is going thru.

Kind of strange considering this invest has a higher % chance of developing than 92L (though both are about the same). Most likely because this invest isn't a threat to land.

That likely plays a role. If a closed LLC is found in 92L, advisories would need to begin immediately as warnings would be required. For 93L, they can wait for persistence and don't have to rush things.

[cycloneye]

TCFA Issued

Here it is.

SUBJ/TROPICAL CYCLONE FORMATION ALERT//
REF/A/FLEWEACEN NORFOLK VA/141200Z AUG 13//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTNT21 KNGU 141200)//
RMKS/1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE
WITHIN 100 NM EITHER SIDE OF A LINE FROM 13.0N 20.9W TO 13.0N 24.7W
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 20 TO 25 KNOTS. METSAT
IMAGERY AT 141200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 12.9N 20.8W. THE SYSTEM IS MOVING WESTWARD AT 07 KNOTS.
2. REMARKS: SATELLITE IMAGERY INDICATES CONVECTION ASSOCIATED WITH
AN AREA OF LOW PRESSURE LOCATED 279 MILES SOUTH-SOUTHEAST OF THE
CAPE VERDE ISLANDS HAS BECOME BETTER ORGANIZED WITHIN THE LAST 6
TO 12 HOURS. DESPITE DRY AIR ENTRAINMENT DUE TO THE SAHARAN AIR
LAYER TO THE NORTH, FAVORABLE WIND SHEAR VALUES OF 5 TO 10 KNOTS
AND WARM SEA SURFACE TEMPERATURES WILL AID IN THE FURTHER
DEVELOPMENT OF THIS SYSTEM.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED
BY 151300Z.

[Yellow Evan]

CLOUDINESS AND SHOWERS ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED
A COUPLE OF HUNDRED MILES SOUTHEAST OF THE CAPE VERDE ISLANDS
REMAIN WELL ORGANIZED...AND A TROPICAL DEPRESSION COULD FORM LATER
TODAY OR ON THURSDAY. THIS SYSTEM HAS A HIGH CHANCE...70
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
AFTER THAT...THE LOW WILL BE MOVING INTO A LESS FAVORABLE
ENVIRONMENT FOR DEVELOPMENT. THIS SYSTEM HAS A HIGH CHANCE...80
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS.
REGARDLESS OF ADDITIONAL DEVELOPMENT...THIS SYSTEM WILL LIKELY
BRING SHOWERS AND GUSTY WINDS TO THE SOUTHERN CAPE VERDE ISLANDS
LATER TODAY AND THURSDAY AS IT MOVES WESTWARD AT 10 TO 15 MPH.
INTERESTS IN THESE ISLANDS SHOULD MONITOR THE PROGRESS OF THIS
SYSTEM.

[Gustywind]

2 PM Discussion.



...SPECIAL FEATURES...
TROPICAL WAVE EXTENDS FROM 13N21W TO 18N20W MOVING W AT 10-15
KT. THE WAVE REMAINS EMBEDDED WITHIN THE MONSOON TROUGH WITH A
LOW-LEVEL CYCLONIC CIRCULATION FOCUSED ON A 1009 MB LOW CENTERED
NEAR 13N21W. AN EARLY MORNING ASCAT PASS AROUND 14/1122 UTC
INDICATED THE PRESENCE OF THE LOW-LEVEL CIRCULATION AND THE WAVE
AXIS WITH 20-30 KT SOUTH-SOUTHWESTERLY WINDS WITHIN 210 NM OF
THE SE SEMICIRCLE OF THE LOW CENTER. SCATTERED MODERATE
CONVECTION IS FROM 09N-14N BETWEEN 18W-30W.

[Gustywind]

CLOUDINESS AND SHOWERS ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED
A COUPLE OF HUNDRED MILES SOUTHEAST OF THE CAPE VERDE ISLANDS
REMAIN WELL ORGANIZED...AND A TROPICAL DEPRESSION COULD FORM LATER
TODAY OR ON THURSDAY. THIS SYSTEM HAS A HIGH CHANCE...70
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
AFTER THAT...THE LOW WILL BE MOVING INTO A LESS FAVORABLE
ENVIRONMENT FOR DEVELOPMENT. THIS SYSTEM HAS A HIGH CHANCE...80
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS.
REGARDLESS OF ADDITIONAL DEVELOPMENT...THIS SYSTEM WILL LIKELY
BRING SHOWERS AND GUSTY WINDS TO THE SOUTHERN CAPE VERDE ISLANDS
LATER TODAY AND THURSDAY AS IT MOVES WESTWARD AT 10 TO 15 MPH.
INTERESTS IN THESE ISLANDS SHOULD MONITOR THE PROGRESS OF THIS
SYSTEM.

So % are up to 70%. Given the latest from the NHC something could form today or tommorow, maybe a TD is cooking . Let's wait and see.

[Gustywind]

From accuweather.com

http://www.accuweather.com/en/weather-n ... i/16575404


A weak low pressure developed near the Cape Verde Islands Tuesday morning that may strengthen through the end of the week. The current track sends the system west-northwest in a direction that will keep it away from land for the next several days.

Conditions are quickly becoming more favorable in the Atlantic for development, which is typical for mid- to late August.

Over the past week, the strong, opposing wind shear has weakened across the tropics. Furthermore, the dry, Saharan air off the African coast has begun to dissipate.

The disintegration of these factors will lead to an uptick of storms in the Atlantic Basin in the coming weeks.

[Gustywind]

Cycloneye could we have the latest pics and loop for 93L? Thanks.

[CrazyC83]

Would warnings be needed for the Cape Verde islands?

[cycloneye]

Cycloneye could we have the latest pics and loop for 93L? Thanks.

Here you go.

[Gustywind]

Latest from SSD... increasing numbers for 93L.


DATE/TIME LAT LON CLASSIFICATION STORM
14/1745 UTC 13.1N 21.8W T1.0/1.0 93L
14/1200 UTC 12.5N 20.8W TOO WEAK 93L

[Jimsot]

Gusty

So is 93L going to be a girl or a boy? ERIN, or FERNAND?

[Gustywind]

Gusty

So is 93L going to be a girl or a boy? ERIN, or FERNAND?

a boy and a girl : TDINVEST93L

[TheStormExpert]

I think this is more likely to become Erin than Invest 92L at the moment.

[TheStormExpert]

I don't see SST's being any more of an issue than they were for Dorian.

Current Atlantic SST's:



Current Atlantic SST Anomalies:

[Jimsot]

I think this is more likely to become Erin than Invest 92L at the moment.

A few days ago the 'season' was over, now two Invests battle over the 'E' and 'F' designations. I too think 93L will be Erin, but its only an opinion and NOT a forecast.

[Extratropical94]

18Z Best track:

AL, 93, 2013081418, , BEST, 0, 131N, 218W, 25, 1008, LO,

[cycloneye]

On it's way to TD or TS status tonight if trends continue.

[CalmBeforeStorm]

On it's way to TD or TS status tonight if trends continue.

http://oi42.tinypic.com/wwgppi.jpg

I think this is the deepest convection we've seen in the MDR this season.