000 AXPZ20 KNHC 240341 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC WED OCT 24 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 0315 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM 12N87W TO 13N90W TO 1006 MB LOW PRES AT 11N95W TO 12N111W TO 07.5N127W WHERE IT TRANSITIONS TO THE ITCZ TO 07N140W. SCATTERED MODERATE TO STRONG CONVECTION EXISTS FROM 10N TO 14N BETWEEN 96W AND 101W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE MONSOON TROUGH BETWEEN 103W AND 109W ...AND WITHIN 60 NM S OF THE MONSOON TROUGH BETWEEN 102W AND 105W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM OF THE MONSOON TROUGH BETWEEN 111W AND 119W. ...DISCUSSION... ALOFT... MID/UPPER LEVEL ANTICYCLONIC FLOW ANCHORED BY AN ANTICYCLONE AT 21N108W COVERS THE AREA N OF 10N E OF ABOUT 130W. DIFFLUENT FLOW ON THE SOUTHERN PERIPHERY OF THE ANTICYCLONE IS ENHANCING CONVECTION ALONG AND NEAR THE MONSOON TROUGH AS MENTIONED ABOVE. TO THE NW OF THE ANTICYCLONIC FLOW...A LONGWAVE TROUGH STRETCHES NE TO SW FROM 31N132W TO 22N139W AND SSW TO 10N141W. SCATTERED TO BROKEN HIGH CLOUDS STREAMING NE ARE SEEN BETWEEN THE ANTICYCLONE AND NE EDGE OF THE TROUGH. THE ANTICYCLONE AND ASSOCIATED MID/UPPER LEVEL RIDGING WILL REMAIN THROUGH THU...BUT WILL BECOME SOMEWHAT FLATTEN AS THE TROUGH PULLS AWAY TO INLAND THE WESTERN U.S. AS MOSTLY MID LEVEL RIDGING MOVES INTO THE NW PORTION. SURFACE... AN AREA OF STRENGTHENING HIGH PRES IS BUILDING ESE OVER THE NORTHERN AND CENTRAL WATERS. THIS AREA OF HIGH PRES IS FORECAST TO SHIFT EASTWARD ALONG 31N THROUGH THU...WHICH WILL COMBINE WITH LOW PRES TROUGHING OVER FAR NW MEXICO AND BAJA CALIFORNIA TO TIGHTEN THE PRES GRADIENT OVER THE NE PORTION...BRINGING INCREASING N-NW WINDS ALONG AND OFFSHORE THE WEST COAST OF THE BAJA PENINSULA. EXPECT NW WINDS OF 20-25 KT TO BEGIN N OF 27N E OF 117W BY LATE TONIGHT...AND GRADUALLY EXPAND SWD TO NEAR 25N BY THU BETWEEN 115W AND 123W. SEAS WILL BUILD TO 10 FT WITHIN THIS AREA OF WINDS. INTENSIFYING CIRCULATION ASSOCIATED WITH LARGE TROPICAL STORM SANDY IN THE SW CARIBBEAN IS ACTING TO STRENGTHEN W-SW WIND FLOW S OF THE MONSOON TROUGH WHICH EXTENDS ACROSS NICARAGUA INTO THE CARIBBEAN. EXPECT MOIST CONVERGENT MONSOONAL FLOW TO PRODUCE WIDESPREAD AREAS OF RAIN WITH EMBEDDED SQUALLS AND OCCASIONAL MODERATE TO HEAVY TSTMS ACROSS PANAMA AND COSTA RICA. THIS WEATHER WILL GRADUALLY SHIFT NORTHWARD INTO NICARAGUA THROUGH THU...WITH STRONG GUSTY WINDS POSSIBLE IN HEAVIER DOWNPOURS. BOTH ASCAT AND OSCAT PASSES FROM YESTERDAY SHOWED LIGHT TO MODERATE WINDS ACROSS MOST OF THE DISCUSSION AREA EXCEPT FOR MODERATE TO FRESH W-SW WINDS JUST S OF THE MONSOON TROUGH E OF ABOUT 110W. NE WINDS IN THE BAY OF CAMPECHE ENHANCED BY THE CIRCULATION OF TROPICAL STORM SANDY LOCATED E OF THE DISCUSSION AREA IN THE SW CARIBBEAN ARE FILTERING INTO THE GULF OF TEHUANTEPEC AS N-NE WINDS OF 20-25 KT AS HIGHLIGHTED BY THE ASCAT PASS FROM YESTERDAY AND ALSO BY THE OSCAT PASS FROM YESTERDAY AFTERNOON. THE CYCLONIC FLOW AROUND SANDY IN COMBINATION WITH A WEAK RIDGE THAT NOSES SOUTHWEST ACROSS THE SE MEXICO WILL BE SUFFICIENT TO ALLOW FOR THE N-E WINDS OF 20-25 KT TO INCREASE TO 20-30 KT WED...THEN DIMINISH 20 KT OR LESS ON THU AS THE GRADIENT SIGNIFICANTLY SLACKENS. THE DOWNSTREAM EFFECTS OF THIS ONGOING GAP WIND EVENT IS HELPING TO MAINTAIN A DISORGANIZED OF CONVECTION N OF THE MONSOON TROUGH BETWEEN 96W AND 101W AS DESCRIBED ABOVE UNDER ITCZ/MONSOON TROUGH. GLOBAL MODELS CONTINUE TO SUGGEST THAT LOW PRES WILL FORM DOWNSTREAM OF THE GULF IN THE NEAR FUTURE...BUT IT APPEARS THAT IT WILL NOT BE AS SIGNIFICANT AS WHAT THE GFS WAS DEPICTING DURING THE PAST FEW DAYS. $$ AGUIRRE