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000
AXPZ20 KNHC 250923
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT MAY 25 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS EXTENDS FROM 10N86W TO LOW PRES NEAR 09N88W
1009 MB TO LOW PRES NEAR 10N97W 1010 MB TO LOW PRES NEAR 11N107W
1009 MB TO 08N122W. ITCZ AXIS EXTENDS FROM 08N122W TO 08N140W.
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 120 NM S
OF AXIS BETWEEN 90W AND 94W...FROM 08N TO 10N BETWEEN 108W AND
114W...AND FROM 08N TO 10N BETWEEN 119W AND 123W.

...DISCUSSION...

ALOFT...AN UPPER LEVEL TROUGH CROSSES NEAR 30N140W. STRONG SW
FLOW AHEAD OF THE TROUGH IS TRANSPORTING ABUNDANT MID TO UPPER
LEVEL MOISTURE ACROSS THE NW PART OF THE FORECAST AREA. A CUT-
OFF LOW IS FORECAST TO DEVELOP ALONG THE TROUGH AXIS AND WILL
MOVE ACROSS THE NW PART THROUGH EARLY SUN. ANOTHER UPPER TROUGH
EXTENDS FROM NW MEXICO ALONG SOUTHERN BAJA CALIFORNIA TO NEAR
13N110W. BETWEEN THESE UPPER LEVEL TROUGHS...BROAD ANTICYCLONIC
FLOW IS NOTED. ANOTHER ANTICYCLONE DOMINATES THE WATERS E OF
105W...INCLUDING SE MEXICO AND NORTHERN CENTRAL AMERICA. THIS
SYSTEM CONTINUES TO PROVIDE A FAVORABLE UPPER LEVEL ENVIRONMENT
FOR CONVECTION ALONG AND NEAR THE MONSOON TROUGH.

THERE ARE THREE LOW PRES SYSTEMS EMBEDDED IN THE MONSOON TROUGH.
THEY ARE LOCATED NEAR 09N88W...10N97W AND 11N107W. THESE LOWS
ARE PRODUCING DISORGANIZED CLOUDINESS AND SHOWERS AND NONE OF
THEM ARE SHOWING SIGNS OF ORGANIZATION AT THIS MOMENT.
SCATTEROMETER DATA SHOW MAINLY GENTLE TO MODERATE WINDS IN
ASSOCIATION WITH THESE LOWS. ENVIRONMENTAL CONDITIONS APPEAR
FAVORABLE FOR SOME GRADUAL DEVELOPMENT OF THE LOW PRES LOCATED
NEAR 09N88W AS IT DRIFTS WESTWARD. DEVELOPMENT OF THE LOW PRES
LOCATED NEAR 11N107W SHOULD BE SLOW TO OCCUR AS IT MOVES LITTLE
DURING THE NEXT COUPLE OF DAYS. SOME TROPICAL DEVELOPMENT IS
SEEN IN MOST OF THE GLOBAL MODELS. THE GFS IS THE MOST
AGGRESSIVE INDICATING GENESIS AND INTENSIFICATION OF TWO LOW
PRES. IT WILL BE INTERESTING TO CONTINUE WATCHING THESE AREAS
OVER THE NEXT FEW DAYS. SEE LATEST TROPICAL WEATHER OUTLOOKS FOR
PROBABILITY CONDITIONS RELATING TO THESE LOW PRES FEATURES.

AT THE SURFACE...A 1030 MB HIGH IS ANALYZED NW OF THE AREA AT
35N144W WITH A RIDGE EXTENDING SEWD TO NEAR 21N116W. THE TIGHT
PRES GRADIENT BETWEEN THE RIDGE AND LOW PRES OVER THE WRN U.S.
CONTINUES TO RESULT IN STRONG NW-N WINDS JUST N OF THE FORECAST
WATERS WITH SEAS THERE UP TO AROUND 11 FT. AN ALTIMETER PASS
PROVIDED OBSERVATIONS OF SEA HEIGHTS OF AROUND 9 FT ACROSS THE N
WATERS WHILE A COUPLE OF SHIPS REPORTED SEAS OF 9-10 FT ALONG
30N. THE MOST RECENT SCATTEROMETER DATA REVEALED NE TRADES OF 15-
20 KT OVER THE WEST-CENTRAL WATERS FROM N OF THE ITCZ TO NEAR
20N AND W OF 120W WITH SEAS TO 9 FT IN MIXED NE AND NW SWELL.
THESE MARINE CONDITIONS WILL PERSIT OVER THE NEXT COUPLE OF
DAYS...WITH SEAS SUBSIDING TO 8 FT IN THE REGION OF THE TRADE
WINDS.

STRENGTHENING HIGH PRES ACROSS THE GULF OF MEXICO WILL PRODUCE A
BRIEF GAP WIND EVENT LASTING ONLY ABOUT 6-9 HOURS ACROSS THE
GULF OF TEHUANTEPEC EARLY ON SUN WITH N WINDS OF 20-25 KT AND
SEAS TO 8 FT. NE-E WINDS ARE ALSO EXPECTED TO BRIEFLY INCREASE
TO THE RANGE OF 20-25 KT ACROSS THE GULF OF PAPAGAYO...MOST
PROBABLY ATTRIBUTED TO THE AFOREMENTIONED DEVELOPING LOW PRES
OVER THE FAR ERN PART OF THE FORECAST AREA ALONG THE MONSOON
TROUGH.

LONG PERIOD CROSS EQUATORIAL SW SWELLS AT 16-18 SECONDS DOMINATE
MOST OF THE FORECAST WATERS E OF 115W...WHILE LONG PERIOD NW
SWELLS ARE SPREADING ACROSS THE NRN PORTION. THESE SWELL EVENTS
ARE FORECAST TO MERGE LATER TODAY.

$$
GR