000 AXPZ20 KNHC 140254 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN MAY 13 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 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH ANALYZED FROM 10N74W TO LOW PRES NEAR 09N81W 1008 MB TO 07N87W TO 09N92W TO LOW PRES AT 10N105W 1008 MB TO LOW PRES AT 07.5N119W 1010 MB...THEN ITCZ FROM 06N121.5W TO 04N126W TO BEYOND 02.5N140W. SCATTERED TO NUMEROUS MODERATE TO STRONG CONVECTION S OF TROUGH TO 04N BETWEEN 80W AND 85W. SCATTERED MODERATE TO STRONG CONVECTION WITHIN 60 NM N OF TROUGH AND S OF TROUGH TO 02N BETWEEN 85W AND 96W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 150 NM N AND 90 NM S OF ITCZ FROM 126W TO 132W. SCATTERED MODERATE ISOLATED STRONG WITHIN 210 NM OF LOW PRES CENTER AT 09.5N104.5W EXCEPT 60 NM SW QUADRANT. SCATTERED MODERATE ISOLATED STRONG WITHIN 210 NM W SEMICIRCLE OF LOW PRES CENTER AT 07.5N119W. ...DISCUSSION... ALOFT...WELL-DEFINED DEEP LAYER CYCLONE AT 37N126W MOVING NE AWAY FROM FORECAST AREA AND IS DRAGGING A MIDDLE TO UPPER LEVEL TROUGH SW TO 23N141W. VERY DRY SUBSIDING AIR MASS W OF TROUGH AXIS. HARP HIGH AMPLITUDE RIDGE IS SQUEEZED ALONG 116W N OF AREA...BETWEEN CYCLONE AND DEVELOPING CYCLONE OVER DESERT SW OF THE U.S. SOUTH OF THESE FEATURES A BROAD RIDGE EXTENDS FROM 16N120W TO 31N123W. WEAK MIDDLE LEVEL CYCLONIC TURNING NOTED IN WATER VAPOR IMAGERY DRIFTING W OFF W COAST OF MEXICO AND S OF THE BAJA PENINSULA. CONVERGENCE AND SUBSIDENCE WITHIN THIS TROUGHING PRODUCING VERY DRY STABLE CONDITIONS AND HELPS TO EXPLAIN NEARLY CLOUD FREE SKIES ACROSS MUCH OF THE AREA E OF 123W N OF THE MONSOON TROUGH. VERY SHALLOW MOISTURE IN THE MARINE LAYER PRODUCING STRATOCUMULUS W OF THE BAJA PENINSULA UNDERNEATH THIS SUBSIDENCE. TROPICAL RIDGE HAS SHIFTED EWD PAST 24-48 HOURS...IN TANDEM WITH MAJORITY OF CONVECTION...AND IS NOW CENTERED ON UPPER ANTICYCLONE NEAR 13N91W EXTENDING NE ACROSS GULF OF MEXICO. SCATTERED DEEP CONVECTION CONTINUES TO PULSE AND FLARE ON BOTH SIDES OF THE MONSOON TROUGH AND UNDERNEATH THIS UPPER RIDGE...WITH LIGHT ANTICYCLONIC SHEAR ALLOWING FOR DEEP CONVECTIVE GROWTH. AT LOWER LEVELS...TWO LOW PRES CENTERS EMBEDDED IN THE MONSOON TROUGH DESCRIBED ABOVE HAVE BEEN INDUCING SCATTERED TO MODERATE DEEP CONVECTION ENHANCED BY WARM SST AND FAVORABLE UPPER LEVEL SUPPORT TODAY...BUT CONVECTION ASSOCIATED WITH THE WESTERN-MOST LOW ALONG 118W HAS DIMINISHED SIGNIFICANTLY IN THE PAST FEW 12 HOURS. SOME OF THE GLOBAL MODELS HAVE BEEN QUITE BULLISH IN INTENSIFYING THE EASTERN-MOST LOW ALONG 105W IN RECENT DAYS... BUT HAVE SINCE MODERATED THEIR INTENSIFICATION. THIS LOW DOES HOWEVER APPEAR BETTER ORGANIZED THAN 24 HOURS AGO AND HAS A MODERATE POTENTIAL TO INTENSIFY INTO A TROPICAL CYCLONE. DRY LOW AND MID LEVEL AIR LIES TO THE NW OF THIS SYSTEM AND COMBINED WITH A MODEST INCREASE IN WIND SHEAR FORECAST IN A FEW DAYS MAY LIKELY LIMIT THE WINDOW OF OPPORTUNITY FOR INTENSIFICATION TO OCCUR DURING THE NEXT 36-48 HOURS. ...ELSEWHERE AT THE LOWER LEVELS... 1021 MB HIGH PRES CENTER NEAR 29N127W HAS SHIFTED SUFFICIENTLY E PAST 24 HOURS TO INDUCE STRONG PRES GRADIENT ALONG THE W COAST OF EXTREME SRN CALIFORNIA S THROUGH CENTRAL BAJA CALIFORNIA... BRINGING FRESH TO STRONG NW BREEZE. A 2032 UTC OSCAT PASS SURPRISINGLY REVEALED NW WINDS 25-30 KT ACROSS PORTIONS OF BAHIA DE SEBASTIAN VIZCAINO ALONG THE W COAST OF BAJA CALIFORNIA NORTE. THIS HIGH WILL REMAIN NEARLY STATIONARY FOR THE NEXT 24 HOURS THEN STRAIGHTEN SLIGHTLY AND DRIFT NW...AND MAINTAIN THESE STRONG NW WINDS ALONG AND OFFSHORE OF MUCH OF THE BAJA PENINSULA. LOOK FOR SEAS TO BUILD 8-10 FT THERE BY TUE MORNING. WEAK TROUGH OVER BAY OF CAMPECHE HAS FORCED N WINDS ACROSS CHIVELA PASS AND THROUGH THE GULF OF TEHUANTEPEC YIELDING NARROW PLUME OF 20-25 KT WINDS. WINDS ARE EXPECTED TO REACH 20 TO 30 KT LATE TONIGHT THROUGH MON MORNING BEFORE DIMINISHING LATE TUE. FRESH ELY WINDS OVER GULF OF PAPAGAYO EXPECTED TO DIMINISH MON AS WEAK LOW PRES JUST W OF GULF SHIFT W AWAY FROM THE AREA. A LARGE CONVECTIVE OUTBREAK THIS AFTERNOON OVER THE FAR EPAC BETWEEN 87W AND THE PACIFIC W COAST OF COLOMBIA MAY VERY WELL HAVE BEEN INITIATED FRESH MONSOONAL WESTERLY WINDS CONVERGING WITH A VERY WEAK EARLY SEASON TROPICAL WAVE EXITING COLOMBIA. WINDS ACROSS THIS AREA HAVE ALREADY BEGUN TO BACK SW THIS EVENING AND THE ASSOCIATED CONVECTION IN NOW LINING UP MORE SW TONE. LOOK FOR THIS AREA OF DISTURBED WEATHER TO SHIFT W THE NEXT FEW DAYS AND BE CENTERED NEAR 96W BY TUE. ASSOCIATED TSTMS WITH HEAVY RAINFALL WILL AFFECT PANAMA...COSTA RICA...AND PORTIONS OF NICARAGUA AND THEIR ADJACENT WATERS DURING THIS TIME. $$ STRIPLING