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000
AXPZ20 KNHC 230300
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU MAY 23 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0230 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

MONSOON TROUGH AXIS EXTENDS FROM CENTRAL COSTA RICA TO 11N90W TO
LOW PRES NEAR 10N102W 1009 MB TO 09N114W TO 07N130W WHERE IT
TRANSITIONS TO ITCZ AXIS...AND CONTINUES TO 11N132W TO 05N140W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM S
OF THE AXIS BETWEEN 84W-87W...WITHIN 60 NM OF THE AXIS BETWEEN
127W-129W AND WITHIN 30 NM OF THE AXIS BETWEEN 103W-104W.
SCATTERED MODERATE CONVECTION IS WITHIN 90 NM S OF THE AXIS
BETWEEN 117W-121W.

...DISCUSSION...

A 1035 MB HIGH CENTER IS LOCATED WELL NW OF THE DISCUSSION AREA
AT 42N143W WITH A RIDGE EXTENDING SEWD INTO THE AREA THROUGH
32N135W TO 25N126W AND CONTINUING SE TO NEAR 21N121W. A TIGHT
PRES GRADIENT BETWEEN THE RIDGE AND LOW PRES OVER THE WESTERN
U.S. IS RESULTING IN GALE FORCE WINDS N OF THE AREA NEAR THE
CALIFORNIA COAST. ASSOCIATED NW-N WINDS OF 20-25 KT SEEP S INTO
THE AREA TO N OF 29N BETWEEN 119W-124W WHERE SEAS ARE IN THE 9-
11 FT RANGE. A WEAKENING SURFACE TROUGH...REMNANTS OF  ORMER
T.S. ALVIN ARE OVER THE SW PORTION OF THE AREA FROM NEAR 09N136W
TO 13N130W. THE PRES GRADIENT BETWEEN AFOREMENTIONED RIDGE AND
THIS TROUGH IS PRODUCING A SMALL AREA OF NE 20 KT WINDS FROM
ROUGHLY 12N TO 16N BETWEEN 130W-136W...WHERE SEAS ARE TO 9 FT.
OTHERWISE...MODERATE TO FRESH ANTICYCLONIC FLOW PREVAILS ACROSS
THE AREA W OF 120W...WITH SEAS GENERALLY 7 TO 8 FT IN MIXED
NORTHERLY AND SW CROSS EQUATORIAL SWELL. THE 1032 MB HIGH WILL
SLIDE W THROUGH FRI...HOWEVER THE TIGHT GRADIENT IS EXPECTED TO
REMAIN NE OF THE AREA. WINDS ARE FORECAST TO BE 20 KT OR LESS N
OF 13N W OF 117W BY EARLY FRI EVENING WITH SEAS TO 9 FT IN MIXED
N AND NE SWELL. THE REMNANT TROUGH OF ALVIN WILL MOVE TO JUST W
OF THE AREA FRI AFTERNOON WITH WINDS EXPECTED TO BE 20 KT OR
LESS AND SEAS LESS THAN 8 FT IN THE FAR SW PORTION OF THE AREA.

MONSOONAL FLOW HAS BECOME WELL ESTABLISHED ACROSS THE FAR
EASTERN PACIFIC E OF 110W...WITH MODERATE SW TO W WINDS
EXTENDING AS FAR N AS 11N BETWEEN 95W AND 110W. UPPER LEVEL
RIDGING PREVAILS ACROSS THE AREA E OF ABOUT 110W AND IS
PRODUCING A FAVORABLE ENVIRONMENT FOR SUSTAINED DEEP CONVECTION.

A BROAD LOW TO MIDDLE LEVEL CYCLONIC CIRCULATION IS FORECAST TO
DEVELOP OVER THE SE PORTION OF THE AREA THROUGH FRI WHILE
SHIFTING WWD. GLOBAL MODELS SUGGEST THAT EVENTUALLY A LOW PRES
SYSTEM MAY EVOLVE FROM THIS AREA. PRESENTLY...A WEAK 1009 MB LOW
IS ALONG THE MONSOON TROUGH AXIS NEAR 10N102W WITH PRES OF 1009
MB. SCATTERED MODERATE TO STRONG CONVECTION IS NOTED FROM 08N TO
12N BETWEEN 103W-108W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION CONVECTION IS WITHIN 45 NM OF A LINE FROM 08N101W TO
08N103W. THE LOW REMAINS UNDER UPPER EASTERLY SHEAR...BUT IT HAS
SOME POTENTIAL TO GRADUALLY DEVELOP OVER THE NEXT 48 HRS AS IT
TRACKS W TO NW DIRECTION.

NOTE...A GOES-E/GOES-13 ANOMALY OCCURRED LAST NIGHT PRIOR TO
0400 UTC AND HAS IMPACTED THE FULL SUITE OF IMAGERY AVAILABLE
FROM THIS SATELLITE...AND IS LIMITING CONFIDENCE IN SATELLITE
INTERPRETATION ACROSS THE REGION BETWEEN APPROXIMATELY 60W AND
100W. NESDIS ENGINEERS ARE WORKING ON RECOVERY EFFORTS AT THIS
TIME. GOES-14 IS BEING ACTIVATED AND THE FIRST IMAGES ARE
EXPECTED TO BECOME AVAILABLE AROUND 0500 UTC THU MAY 23.

$$
AGUIRRE