000
AXPZ20 KNHC 301520
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED MAY 30 2012

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 
1430 UTC.

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

THE MONSOON TROUGH IS ALONG 09N85W TO 09N97W TO 11N107W TO 
08N117W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 
08N117W TO 04N140W. SCATTERED STRONG CONVECTION IS FROM 04N TO 
07N E OF 79W. SCATTERED MODERATE CONVECTION IS FROM 03N TO 08N 
BETWEEN 85W AND 90W...FROM 05N TO 08N BETWEEN 92W AND 96W...AND 
FROM 10N TO 12N BETWEEN 111W AND 116W. WIDELY SCATTERED MODERATE 
CONVECTION IS FROM 04N TO 08N BETWEEN 99W AND 114W.

...DISCUSSION...

AN ELONGATED MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION 
ENCOMPASSES NW PORTIONS OF THE DISCUSSION AREA...AND IS CENTERED 
NEAR 24N143W. THE CIRCULATION IS FORECAST TO MOVE SW AT 10 TO 15 
KT OVER THE NEXT 24 TO 48 HOURS...BECOME BETTER ORGANIZED...AND 
CUT OFF FROM THE MEAN FLOW NEAR 22N146W BY EARLY FRIDAY. STRONG 
SOUTHWESTERLY WINDS ALOFT ARE LOCATED ON THE SE PERIPHERY OF THE 
CIRCULATION WITH A JET STREAM POSITIONED THROUGH 18N139W TO 
28N131W THEN TURNING NE INTO EXTREME NORTHERN BAJA CALIFORNIA. 
BROAD RIDGING ALOFT COVERS A LARGE AREA FROM NEAR 05N TO 32N 
BETWEEN 98W AND 125W. E OF THE RIDGE...A WELL-DEFINED MIDDLE TO 
UPPER LEVEL TROUGH EXTENDS AN AXIS FROM SOUTHERN MEXICO NEAR 
17N93W TO 03N103W. DEEP LAYERED NORTHERLY FLOW BETWEEN THE RIDGE 
AND TROUGH IS YIELDING UPPER LEVEL CONVERGENCE AND SUBSIDENCE 
FROM SE MEXICO SOUTHWARD INTO THE E PACIFIC WATERS TO 08N. 
ANOTHER RESULT OF THIS FLOW IS FORCING THE MONSOON TROUGH AND 
ASSOCIATED CONVECTION S OF 08N BETWEEN 98W AND 107W. WEAK 
TROUGHING EXTENDS DOWN TO THE SURFACE UNDERNEATH THE UPPER LEVEL 
TROUGH...ACROSS MUCH OF THE YUCATAN PENINSULA. ABUNDANT MOISTURE 
CONVERGENCE EAST OF THE TROUGH TO 74W IN THE WESTERN CARIBBEAN 
SEA AND NORTHERN COLOMBIA IS GENERATING WIDELY SCATTERED 
MODERATE TO STRONG CONVECTION ACROSS FORECAST WATERS NEARBY TO 
COSTA RICA AND PANAMA...WITH ANTICYCLONIC AND DIFFLUENT UPPER 
LEVEL FLOW AIDING IN SUSTAINING THIS CONVECTION. LITTLE MOVEMENT 
OF THIS TROUGH IS EXPECTED OVER THE NEXT TWO DAYS...WITH ACTIVE 
CONVECTION EXPECTED TO CONTINUE TO PULSE ACROSS THIS PORTION OF 
CENTRAL AMERICA.

ELSEWHERE AT THE SURFACE...THE E PACIFIC SUBTROPICAL RIDGE 
REMAINS ANCHORED NW OF THE AREA...WITH A 1026 MB HIGH CENTERED 
NEAR 35N134W AND A 1025 HIGH CENTERED NEAR 31N154W. A SUFFICIENT 
PRESSURE GRADIENT EXISTS ON THE SOUTHEASTERN PERIPHERY OF THE 
ASSOCIATED RIDGE TO PRODUCE FRESH NW TO N WINDS EXTENDING INTO 
NE PORTIONS OF THE AREA N OF 27N E OF 125W. THE EASTERN-MOST 
HIGH IS FORECAST TO BECOME DOMINANT AND STRENGTHEN SLIGHTLY 
THROUGH THURSDAY EXPANDING THE AREA OF FRESH WINDS SOUTHWARD TO 
23N AND W TO NEAR 124W. A SMALL SLIVER OF FRESH NORTHEASTERLY 
TRADEWINDS ARE ALSO FOUND S OF THE RIDGE N OF THE ITCZ...FROM 
05N TO 18N W OF 137W. AS THE RIDGE SHIFTS SLIGHTLY NE DURING THE 
NEXT 48 HOURS THIS AREA OF FRESH TRADES WILL DIMINISH IN AREAL 
COVERAGE.

FINALLY...A WEAK 1011 MB LOW IS CENTERED NEAR 08N117W NEAR THE 
INTERSECTION OF THE MONSOON TROUGH AND ITCZ. SATELLITE IMAGERY 
INDICATES THE BROAD SURFACE CIRCULATION REMAINS...HOWEVER EAST 
TO SOUTHEAST MIDDLE TO UPPER LEVEL WINDS HAVE DECOUPLED 
CONVECTION THAT WAS OCCURRING OVERNIGHT AND THE LOW APPEARS TO 
LOCATED BENEATH AN AREA OF UPPER LEVEL CONVERGENCE AND 
UNFAVORABLE CONDITIONS.

$$
HUFFMAN