000
AXPZ20 KNHC 300944
TWDEP 

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

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

THE MONSOON TROUGH AXIS EXTENDS FROM COLOMBIA NEAR 09N75W TO 
10N81W TO 08.5N97W TO 11.5N107W TO LOW PRES 08N117W TO 
06N120W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO 
06N130W TO BEYOND 04N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION NOTED N OF 07N E OF 88W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION NOTED FROM 03.5N TO 07N BETWEEN 86W AND 112W. 


...DISCUSSION...

AN ELONGATED MIDDLE/UPPER LEVEL CYCLONIC CIRCULATION ENCOMPASSES 
NW PORTIONS OF THE DISCUSSION AREA...AND IS CENTERED NEAR 
26N142W. THE CIRCULATION IS FORECAST TO MOVE SW 10 TO 15 KT OVER 
THE NEXT 24 TO 48 HOURS...BECOME BETTER ORGANIZED...AND CUT OFF 
FROM THE MEAN FLOW NEAR 22N147W. STRONG SOUTHWESTERLY WINDS 
ALOFT ARE LOCATED ON THE SE SIDE OF THE CIRCULATION WITH A JET 
STREAM POSITIONED THROUGH 18N137W TO 24N133W THEN TURNING NE AND 
INTO NORTHERN BAJA CALIFORNIA. BROAD RIDGING ALOFT COVERS A VAST 
AREA FROM NEAR 10N TO 32N BETWEEN 100W AND 123W. E OF THE 
RIDGE...A WELL-DEFINED MIDDLE/UPPER LEVEL TROUGH HAS ITS AXIS 
EXTENDING FROM THE EASTERN BAY OF CAMPECHE TO 07N97W. DEEP 
LAYERED NLY FLOW BETWEEN THE RIDGE AND TROUGH IS YIELDING UPPER 
CONVERGENCE AND SUBSIDENCE FROM SE MEXICO S INTO THE EPAC TO 
10N. THIS FLOW IS ALSO FORCING THE MONSOON TROUGH AND ASSOCIATED 
CONVECTION S OF 07N/08N BETWEEN 97W AND 105W. WEAK TROUGHING 
EXTENDS DOWN TO THE SURFACE UNDERNEATH THE UPPER TROUGH...ACROSS 
MUCH OF THE YUCATAN PENINSULA. ABUNDANT MOISTURE CONVERGENCE E 
OF THE TROUGH TO 81W IN THE W CARIB IS INITIATING SCATTERED 
MODERATE TO STRONG CONVECTION ACROSS MUCH OF CENTRAL AMERICA 
BETWEEN PANAMA AND 90W...WITH ANTICYCLONIC AND DIFFLUENT UPPER 
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 EPAC SUBTROPICAL RIDGE REMAINS 
CENTERED NW OF THE AREA...ON A PAIR OF 1026 MB HIGHS LOCATED AT 
35N134W AND 31N153W. SUFFICIENT PRES GRADIENT CONTINUES E OF THE 
ASSOCIATED RIDGE TO PRODUCE FRESH NW TO N WINDS EXTENDING INTO 
NE PORTIONS OF THE AREA N OF 28N BETWEEN 118W AND 124W AND N OF 
26N WITHIN 90 NM OF W COAST OF BAJA CALIFORNIA. THE EASTERN-MOST 
HIGH WILL BECOME DOMINANT AND STRENGTHEN SLIGHTLY THROUGH THU TO 
EXPAND THIS AREA OF FRESH WINDS S TO 24N AND W TO NEAR 130W. 
FRESH NELY TRADEWINDS ARE ALSO FOUND S OF THE RIDGE N OF THE 
ITCZ...FROM 07N TO 20N W OF 132W AND FROM 07N TO 13N BETWEEN 
124W AND 132W. AS THE RIDGE SHIFTS SLIGHTLY NE DURING THE NEXT 
48 HOURS THIS AREA OF FRESH TRADES WILL DIMINISH IN AREAL 
COVERAGE.

A WAVE-LIKE FEATURE MOVING WWD THROUGH THE MONSOON TROUGH WAS 
ALONG ABOUT 121W...WITH A SURFACE LOW EVIDENT IN SATELLITE 
IMAGERY NEAR 08N117W. THIS PERTURBATION IS QUICKLY REACHING THE 
WRN PERIPHERY OF THE SUPPORTING UPPER RIDGE...AND THE MIDDLE 
LEVEL CIRCULATION APPEARS TO BE MOVING NW AND STRETCHING THE 
OVERALL CIRCULATION. CONVECTION HAS DIMINISHED DURING THE PAST 
12-24 HOURS...AND THIS TREND IS LIKELY TO CONTINUE AS THIS 
SYSTEM APPROACHES AN AREA OF UPPER CONVERGENCE AND UNFAVORABLE 
CONDITIONS. A SMALL ZONE OF 20 KT NE WINDS WAS LOCATED WITHIN 
240 NM NW OF THIS SURFACE LOW. THE LOW WILL DRIFT W REMAIN 
EMBEDDED WITHIN THE TROUGH...WITH WINDS WEAKENING TO LESS THAN 
20 KT BY 24 HOURS.

$$
STRIPLING