000
AXPZ20 KNHC 211531
TWDEP
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE MAY 21 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.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS W FROM A LOW PRES NEAR 10N80W TO
12N89W TO 10N96W TO 10N108W TO 08N117W TO 12N126W TO 07N135W...
THEN TRANSITIONS TO THE ITCZ W OF 07N135W TO 05N140W. SCATTERED
MODERATE ISOLATED STRONG CONVECTION IS WITHIN 120 NM S OF THE
AXIS E OF 87W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM S
OF THE AXIS BETWEEN 96W AND 104W...AND WITHIN 75 NM OF THE AXIS
BETWEEN 111W AND 120W.
...DISCUSSION...
A SURFACE RIDGE EXTENDS SE TO AROUND 20N110W. MODERATE TO FRESH
NORTHERLY WINDS CONTINUE ACROSS NORTH-CENTRAL WATERS WITH SEAS
TO 7-8 FT IN N SWELL MIXING WITH LONG PERIOD CROSS-EQUATORIAL SW
SWELL. A REINFORCING SURGE N OF 30N LATER TODAY WILL SPREAD S
ACROSS WATERS N OF 20N BETWEEN 115W-140W THROUGH THU NIGHT WITH
SEAS BUILDING 8 TO 13 FT IN LONG PERIOD N SWELL WED THROUGH THU
NEAR 30N120W. WINDS AND SEAS WILL BEGIN TO SUBSIDE ON FRI WITH
WINDS 15 KT AND SEAS 5-7 FT ACROSS THE SUBTROPICAL WATERS BY SAT.
A TROPICAL LOW CROSSING THE ISTHMUS OF PANAMA NEAR 10N80W IS
ASSOCIATED WITH A TROPICAL WAVE IN THE EASTERN CARIBBEAN. IT IS
EXPECTED TO REACH THE SW CARIBBEAN WED. MODEL GUIDANCE SUGGESTS
A SURFACE LOW WILL FORM ALONG THE MONSOON TROUGH AS THE TROPICAL
WAVE MOVES INTO THE EASTERN PACIFIC. A SECOND WEAKER LOW IS ALSO
EXPECTED TO DEVELOP ALONG THE MONSOON TROUGH NEAR 10N86W EARLY
THU...WITH THE LOW MEANDERING IN THAT AREA THIS WEEKEND.
THE REMNANTS OF ALVIN CONTINUE TO WEAKEN... AND ARE DEPICTED AS
A SW-NE ORIENTED TROUGH THAT EXTENDS FROM 09N129W TO 14N127W.
NE TO E WINDS AT 20-25 KT AND SEAS 7-10 FT ARE NOTED WITHIN 300
NM NW OF THE TROUGH. EXPECT THE TROUGH TO DRIFT W AND WEAKEN AS
A BREAK IN THE CONVERGENCE ZONE. NE TRADES W OF THE TROUGH WILL
DIMINISH TO 15-20 KT TONIGHT...WHILE SEAS SUBSIDING TO LESS THAN
8 FT ON WED.
GFS MODEL SHOWS NORTHERLY DRAINAGE FLOW WILL INCREASE TO 20 KT
IN THE GULF OF TEHUANTEPEC ON FRI NIGHT THEN GRADUALLY INCREASE
TO 20-25 KT SAT NIGHT AND SUN MORNING.
$$
MUNDELL
