000 AXPZ20 KNHC 112225 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC FRI MAY 11 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2130 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM 08N78W TO 06N86W TO 11N99W TO LOW PRES AT 09N105.5W TO 10N111W TO LOW PRES AT 08.5N114W TO 06N123W THEN ITCZ TO BEYOND 03N140W. SCATTERED MODERATE TO STRONG S OF TROUGH TO 03N E OF 90W AND S OF TROUGH TO 04.5N BETWEEN 90W AND 102W. SCATTERED MODERATE TO STRONG WITHIN 90 NM OF LOW PRES AT 09N105.5W. SCATTERED MODERATE ISOLATED STRONG WITHIN 180 NM OF LOW PRES AT 08.5N114W09N105.5W. EXCEPT 310 NM SW QUADRANT. ALOFT... MID TO UPPER CYCLONE SPINNING NEAR 28N141W HAS BEGUN TO LIFT NE LATE THIS MORNING AND AFTERNOON AS FORECAST...AND IS CLIPPING FAR NW CORNER OF BASIN. ASSOCIATED MID TO UPPER TROUGH EXTENDING SW TO S OF THE HAWAIIAN ISLANDS. SECOND VIGOROUS CYCLONE OVER N CENTRAL TEXAS CONTINUES TO MOVE SLOWLY E. MID TO UPPER SHORTWAVE TROUGH TO THE SW...EXTENDING FROM NW MEXICO TO 17N113W AND MOVING SOMEWHAT IN TANDEM WITH CYCLONE...BUT HAS YET TO COME IN PHASE WITH IT. DRY AIR AND SUBSIDENCE WITHIN SOUTHERN END OF TROUGH BEGINNING TO IMPINGE UPON NW PORTIONS OF ACTIVE CONVECTION IN MONSOON TROUGH...AND SECOND LOW ALONG MONSOON TROUGH DESCRIBED ABOVE. BROAD RIDGE BETWEEN CYCLONES SHIFTING SLOWLY EWD BETWEEN 20N-30N...BEHIND SHORTWAVE TROUGH...AND CURRENTLY ALONG 123W THERE. S OF THESE FEATURES LIES TWO TROPICAL RIDGES...ONE CENTERED ON MID LEVEL ANTICYCLONE NEAR 07N128W AND EXTENDING N-NE...AND MERGING WITH RIDGE DESCRIBED ABOVE...AND A SECOND BROAD RIDGE CENTERED ON UPPER ANTICYCLONE NEAR 12N91W EXTENDING N ACROSS MUCH OF THE GULF OF MEXICO...AND SPANNING BETWEEN 70W AND 114W. DEEP CONVECTION PULSING S OF THE MONSOONAL TROUGH CONTINUES TO INDUCE DIVERGENT FLOW ALONG THE S SIDE OF RIDGE BETWEEN 05N-10N AND IS AIDING IN MAINTAINING THIS PERSISTENT RIDGING ALOFT. AT LOWER LEVELS...TWO AREAS OF ACTIVE CONVECTION HAVE EVOLVED IN THE PAST 24 HOURS...WITH LOW TO MID LEVEL CYCLONIC TURNING INDICATED IN SATELLITE IMAGERY...ONE NEAR 09N105.5W AND A SECOND NEAR 09N105.5W. COMPUTER MODEL GUIDANCE HAS NOT BEEN IN AGREEMENT THAT PAST SEVERAL RUNS ON THE EVOLUTION OF THESE TWO AREAS OF LOW PRESSURE. RECENTLY...THE WESTERN-MOST LOW HAS MAINTAINED WIDESPREAD CONVECTION AND SOME SHORT BANDS...BUT CONVECTION HAS DIMINISHED SIGNIFICANTLY IN THE PAST FEW HOURS...AND DRIER LOW TO MID LEVEL AIR IS SLOWLY REACHING NEAR THIS FEATURE FROM THE NW. MEANWHILE...THE MORE EASTERN LOW DOES NOT APPEAR AS WELL ORGANIZED IN SATELLITE IMAGERY...AND A PARTIAL 1646 UTC ASCAT PASS DID NOT SUGGEST A WELL DEFINED CENTER WITH SIGNIFICANT WINDS. GLOBAL MODELS SUGGEST SOME POTENTIAL FOR THIS LOW TO STRENGTHEN AS IT LIFTS N DURING THE NEXT 48 HOURS...AND THE GFS HAS BEEN VERY INSISTENT DURING THE PAST SEVERAL RUNS THIS THIS LOW WILL INTENSIFY. THIS SYSTEM IS BEING MONITORED FOR POTENTIAL TROPICAL CYCLONE DEVELOPMENT...AS IT PRESENTLY COVERED IN OUR OUR HIGH SEAS FORECAST UNDER AWIPS HEADER MIAHSFEP2. ELSEWHERE AT THE LOWER LEVELS... A WEAK 1019 MB HIGH PRES CENTER HAS DEVELOP JUST NW OF THE AREA NEAR 23N129W AND EXTENDS RIDGE SE TO NEAR 16N104W. DUE TO WEAK PRES GRADIENT ACROSS W PORTIONS OF THE BASIN...NE TRADEWINDS REMAIN BELOW 20 KT N OF THE ITCZ BUT ARE EXPECTED TO INCREASE TO 20 KT ACROSS FAR W PORTIONS W OF 137W BY 24 HOURS. THE HIGH WILL SINK SLIGHTLY SE AND STRENGTHEN TO 1022 MB OVER THE WEEKEND AND INDUCE GRADIENT WINDS TO 20 KT ALONG THE W COAST OF BAJA CALIFORNIA. LONG PERIOD SWELLS UP TO 11 FT PRODUCED BY PREVIOUS GALE EVENT WELL N OF BASIN PRESENTLY AFFECT WATERS N OF 23N W OF 118W WITH SEAS EXPECTED TO SUBSIDE BELOW 8 FT BY SAT NIGHT. WEAK TROUGH MOVING THROUGH BAY OF CAMPECHE EXPECTED TO FORCE N WINDS ACROSS ISTHMUS INTO GULF OF TEHUANTEPEC BY THE END OF FORECAST PERIOD SUN. $$ STRIPLING