EPAC: ALVIN - Post-Tropical

[Meow]

The first East Pacific disturbance in 2013.

[lester]

BEGIN
NHC_ATCF
invest_ep902013.invest
FSTDA
R
U
040
010
0000
201305131832
NONE
NOTIFY=ATRP
END
INVEST, EP, E, , , , , 90, 2013, DB, O, 2013051318, 9999999999, , , , , , METWATCH, , EP902013
EP, 90, 2013051218, , BEST, 0, 65N, 916W, 20, 1009, DB, 0, , 0, 0, 0, 0,
EP, 90, 2013051300, , BEST, 0, 65N, 925W, 20, 1009, DB, 0, , 0, 0, 0, 0,
EP, 90, 2013051306, , BEST, 0, 65N, 933W, 20, 1009, DB, 0, , 0, 0, 0, 0,
EP, 90, 2013051312, , BEST, 0, 65N, 941W, 20, 1009, DB, 0, , 0, 0, 0, 0,
EP, 90, 2013051318, , BEST, 0, 65N, 950W, 20, 1009, DB, 34, NEQ, 0, 0, 0, 0, 1010, 200, 0, 0, 0, E, 0, , 0, 0, INVEST, S,

[Kingarabian]

Annnnnd weerreeeee baacckk!

[TropicalAnalystwx13]

This was a huge win for the CMC. It began showing development well over a week ago.

The GFS has finally caught on as well. Shows 90E peaking as a mid-grade tropical storm (~50 knots) with a pressure of 993 millibars.

[cycloneye]

[TropicalAnalystwx13]

The first runs of the dynamical/statistical models (above) are always bullish. I have doubts about it becoming as intense as a cyclone as shown, but it may become a healthy tropical storm.

The bullish SHIPS brings it up to 80 knots in 96 hours.

V (KT) NO LAND 20 23 25 28 32 40 48 57 67 73 76 80 80

The environment is characterized with less than 10 knots of wind shear, SSTs above 29C, and relative humidity values above 69% through 120 hours. Definitely favorable.

SHEAR (KT) 1 6 1 2 4 5 5 3 2 4 10 6 9
SST (C) 29.4 29.3 29.3 29.2 29.1 29.1 29.0 29.0 29.1 29.3 29.5 29.6 29.3
700-500 MB RH 71 72 70 70 69 73 69 69 71 73 72 67 66
HEAT CONTENT 30 32 28 22 16 15 20 29 38 53 51 38 39

[Kingarabian]

Any trough to pull this close to Mexico or will it be a fish?

[TropicalAnalystwx13]

Any trough to pull this close to Mexico or will it be a fish?

A trough is forecast over the West Coast in 4–5 days...this might induce a west-northwest motion. After that, however, expansive ridging is forecast to the north of what is expected to be a tropical cyclone, forcing it westward. Fish.

[Yellow Evan]

Any chance this will beat the May 15 deadline?

[mrbagyo]

It's consolidating
Eastern Pacific is back

[Hurricane Jed]

Pity this will be a fish. I'd take the rain

[SouthDadeFish]

Definitely a lot of convergence going on. OSCAT got a hit around 18Z:



Some strong winds in those rain contaminated readings...

37 GHz color from a recent TRMM pass shows a lot of rain too:

[cycloneye]

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON MAY 13 2013

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2100 UTC.

LOW PRESSURE NEAR 07N93W IS EMBEDDED WITHIN THE MONSOON TROUGH.
THE LOW HAS STRENGTHENED OVER THE PAST 24 HOURS WITH THE HELP OF
SHEAR VORTICITY ASSOCIATED WITH GAP WINDS FROM THE GULFS OF
TEHUANTEPEC AND PAPAGAYO...AND CONVECTION REMAINS ACTIVE
ASSOCIATED WITH THE LOW PRESSURE CENTER AS MENTIONED ABOVE. THE
LOW IS WITHIN A BAROTROPICALLY UNSTABLE ENVIRONMENT WHICH IS
FAVORABLE FOR THE CONTINUED GROWTH OF THIS FEATURE...AND THE
EVENTUAL BREAKDOWN OF THE MONSOON TROUGH. MODEL GUIDANCE IS
DEPICTING A BREAKDOWN OF THE MONSOON TROUGH THE MIDDLE OF THE
WEEK. THE BREAKDOWN OF THE MONSOON TROUGH ASSOCIATED WITH A
WESTWARD PROPAGATING DISTURBANCE...IN THIS CASE A CARIBBEAN WAVE
THAT PROPAGATED INTO THE EASTERN NORTH PACIFIC...HAS BEEN
ASSOCIATED WITH TROPICAL CYCLOGENESIS. IT STILL REMAINS TO BE
SEEN WHETHER THE MONSOON TROUGH WILL BREAK DOWN...AND IF WE WILL
SEE TROPICAL CYCLOGENESIS IN THIS CASE...BUT IT WILL BE
INTERESTING TO WATCH OVER THE NEXT SEVERAL DAYS.

[TropicalAnalystwx13]

Latest GFS run shows this becoming a minimal hurricane at peak intensity, similar to the SHIPS, LGEM, and others. I have doubts about whether or not it gets that strong, specifically due to a dry environment which is not atypical during May anyways. We'll have to see though.

[Hurricane Jed]

I think it all hinges on how fast it develops. If it RI's then we could see a minimal hurricane.

[TropicalAnalystwx13]

00z ATCF update drops 90E's pressure to 1007 mb; winds up to 30 mph; changed from "DB" (disturbance) to "LO" (low) again.

EP, 90, 2013051400, , BEST, 0, 69N, 956W, 25, 1007, LO,

[Yellow Evan]

I really want to see this form. Since this is at sea, we can rout for RI without it hurting anyone. Some trivia notes:
If forms within next 18 hours, becomes fourth off-season storm east of 140W since 1949, and eight overall since 1949.
If this is named by May 21, it becomes the fourth earliest storm east of 1940W since 1949, and eight overall since 1949
If this becomes a hurricane before May 22, it becomes 2nd earliest storm east of 140W and third overall.
If this becomes a major hurricane before May 24, it becomes 2nd earliest major hurricane overall, and first east of 140W.

[RL3AO]

The EPac really seems like it just throws on a switch come May 15. Fun to watch.

[cycloneye]

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE MAY 14 2013

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1500 UTC.


LOW PRES EMBEDDED IN MONSOON TROUGH NEAR 7N98W HAS STRENGTHENED.
ACTIVE CONVECTION REMAINS S AND W OF THE LOW. THE LOW IS WITHIN
A FAVORABLE ENVIRONMENT FOR CONTINUED GROWTH. AS THE LOW MOVES W
GLOBAL MODELS ARE BULLISH ON THIS DISTURBANCE BECOMING A
TROPICAL CYCLONE SOMEWHERE BETWEEN 105W AND 110W WITHIN THE NEXT
2-3 DAYS.

[Hurricane Jed]

It looks pretty terrible right now.



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