000 AXPZ20 KNHC 040300 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI MAY 04 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 08N97W TO LOW PRES NEAR 06N104W 1010 MB TO 05N110W TO 03N118W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N118W TO 00N135W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 03.5N TO 07.5N BETWEEN 104W AND 112W. IN ADDITION...ISOLATED TO SCATTERED MODERATE CONVECTION IS FROM 06N TO 08.5N BETWEEN 87W AND 95W. SIMILAR CONVECTION IS FROM 02N TO 03N BETWEEN 95W AND 101W. ...DISCUSSION... ALOFT...AN UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC CIRCULATION OVER NW OLD MEXICO NEAR 31N107W SW TO A DEVELOPING CYCLONIC CIRCULATION AT 21N116W AND CONTINUES SW TO NEAR 14N119W. IN ITS WAKE...DEEP LAYER RIDGING COVERS THE REMAINDER OF THE AREA WITH A MEAN RIDGE AXIS EXTENDING FROM SOUTHERN CALIFORNIA NEAR THE CHANNEL ISLANDS SW THROUGH 27N124W TO 16N140W. THE RIDGE IS MAINTAINING RATHER DRY AND STABLE ATMOSPHERIC CONDITIONS N OF THE TROPICS. THE TROUGH WILL QUICKLY LIFT NE TO WELL INLAND OVER THE CENTRAL U.S. DURING THE NEXT 18-24 HRS...WHILE THE CYCLONIC CIRCULATION AT 21N116W ALSO LIFTS NE TO ACROSS THE SOUTHERN BAJA CALIFORNIA PENINSULA IN ABOUT 24-30 HRS BEFORE BECOMING ABSORBED IN SOUTHWESTERLY FLOW OVER NW OLD MEXICO BY 48 HRS. AT THE SURFACE...A WEAK AND BROAD RIDGE EXTENDS INTO THE DISCUSSION AREA THROUGH 30N130W...AND CONTINUES SE TO NEAR 15N114W. WEAK 1010 MB LOW PRES HAS DEVELOPED IN THE MONSOON TROUGH NEAR 06N104W WITH AN ATTENDANT TROUGH FROM 09N103W THROUGH THE LOW TO 03N105W. ASSOCIATED CONVECTION IS AS IS DESCRIBED ABOVE. NO SIGNIFICANT DEVELOPMENT OF THIS LOW IS ANTICIPATED DURING THE NEXT 48 HOURS AS IT DRIFTS WESTWARD. AN AREA OF CROSS-EQUATORIAL SOUTHERLY SWELL IS S OF 06N BETWEEN 110W AND 127W AS PARTIALLY MEASURED BY A RECENT ALTIMETER PASS. THIS SWELL WILL GRADUALLY DECAY TO LESS THAN 8 FT BY 24 HOURS WHILE A DIFFERENT AREA OF MAINLY SOUTHERLY 8 FT SWELL BECOMES PREVALENT OVER THE FAR W CENTRAL WATERS. ELSEWHERE...EXPECT LIGHT TO MODERATE TRADE WINDS TO CONTINUE THROUGH THE NEXT 48 HRS WITH SEAS 7 FT OR LESS ACROSS THE ENTIRE TROPICAL NE PACIFIC REGION. THE ONLY EXCEPTION WILL BE ACROSS THE FAR NORTHERN DISCUSSION WATERS WHERE A COLD FRONT WILL BRUSH BY JUST N OF THE AREA TONIGHT THROUGH SAT. THE FRONT WILL WEAKEN IN RESPONSE TO A STRENGTHENING RIDGE WHICH WILL REDEVELOP OVER THAT REGION INTO THE WEEKEND. THIS PROCESS WILL USHER IN NE-E 20 KT WINDS ACROSS THE NW CORNER OF THE WATERS...WITH FRESH NW WINDS TO THE E ALONG THE COAST OF THE NORTHERN BAJA CALIFORNIA PENINSULA BY LATE FRI THROUGH SAT. $$ LEWITSKY