000
AXPZ20 KNHC 310905
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE MAY 31 2011

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.
 
...ITCZ...
ITCZ IS ANALYZED FROM 10N84W TO 10N93W TO 12N99W TO LOW PRES 
1009 MB NEAR 10N107W TO 07N120W TO 07N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION FROM 08N TO 12N BETWEEN 95W AND 102W.

...DISCUSSION...
WEAKENING COLD FRONT BRUSHING PAST NORTHERN PORTION EXTENDS FROM 
32N128W TO 30N132W TO 30N140W. THE COLD FRONT IS DISRUPTING THE 
HIGH PRES RIDGE ALONG 30N AND WEAKENING THE PRES GRADIENT NEAR 
THE COAST OF NORTHERN BAJA CALIFORNIA. AS A RESULT...NW WINDS 
ALONG THE COAST AS DEPICTED BY 0515 UTC ASCAT PASS ARE GENERALLY 
LESS THAN 20 KT. EXPECT THE COLD FRONT TO WEAKEN FURTHER TODAY 
THEN DISSIPATE LATE TONIGHT. HIGH PRES BUILDS AGAIN BEHIND THE
FRONT ALLOWING FRESH NW WINDS TO REDEVELOP W OF BAJA CALIFORNIA 
WED AND THU. GFS MODEL GUIDANCE SHOWS TRADE WINDS GENERALLY LESS 
THAN 20 KT THROUGH THU NIGHT.

BROADLY DIFFLUENT FLOW ALOFT IS ASSOCIATED WITH AN UPPER LEVEL 
RIDGE EXTENDING W ALONG 10-11N FROM AROUND 90W TO 120W. THIS IS 
ENHANCING ITCZ CONVECTION BETWEEN 90W AND 105W. DEEP CONVECTION 
ASSOCIATED WITH A 1009 MB LOW NEAR 10N107W APPEARS TO BE GOING 
THROUGH A DIURNAL MINIMUM PHASE. IR AND WATER VAPOR IMAGERY SHOW 
CIRRUS OUTFLOW NEAR THE LOW IS ANTICYCLONIC AND THUS FAVORABLE 
FOR ACTIVE CONVECTION TO REAPPEAR NEAR THE LOW WITHIN THE NEXT 6 
TO 12 HOURS. LATEST GFS AND EUROPEAN MODEL FORECASTS INDICATE THE
AREA IN THE ITCZ BETWEEN 100W AND 110W WILL BECOME FAVORABLE FOR 
CYCLONIC CIRCULATIONS TO DEVELOP AND INTENSIFY OVER THE NEXT 48 
TO 72 HOURS. GFS MODEL SHOWS S-SW MONSOON WINDS INCREASING TO 20 
KT BETWEEN 5N AND 10N E OF 110W WITH A TROPICAL LOW INDICATED IN 
THE MODEL NEAR 11N105W IN ABOUT 48 HOURS. FURTHER DEVELOPMENT OF 
THIS LOW IS DEPICTED IN THE LONG RANGE 3-5 DAY FORECAST. 

LARGE LONG PERIOD S SWELLS WITH SEAS OF 8-12 FT ARE PROPAGATING 
ACROSS THE ENTIRE BASIN. SEAS WILL SLOWLY SUBSIDE BY MID-WEEK. 
UNUSUALLY HIGH BREAKERS AND HEAVY SURF ARE EXPECTED ALONG THE 
ENTIRE PACIFIC COAST OF CENTRAL AMERICA TODAY THROUGH WED.

A SURFACE TROUGH IN THE WESTERN CARIBBEAN WILL SHIFT W AND START 
TO FUNNEL THROUGH THE CHIVELAS PASS INTO THE GULF OF TEHUANTEPEC 
TONIGHT. AS A RESULT...STRONG N WINDS ARE EXPECTED IN THE GULF OF
TEHUANTEPEC LATER TONIGHT AND CONTINUE THROUGH EARLY THU. 25-30 
KT WINDS ARE EXPECTED...AND BRIEF GALE FORCE WINDS ARE POSSIBLE.

$$
MUNDELL