000 AXPZ20 KNHC 191517 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN MAY 19 2013 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1345 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE REMNANTS OF ALVIN ARE MANIFESTED AS A TROUGH FROM 15N119W TO 07N120W WITH WEAK 1008 MB LOW PRES EMBEDDED WITHIN THE TROUGH NEAR 12N120W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN 150 NM E OF THE TROUGH. THE MONSOON TROUGH AXIS WAS ANALYZED FROM 08N78W TO 08N83W TO 10N88W TO 06N106W. THE AXIS IS INTERRUPTED BY THE REMNANTS OF ALVIN. THEN...THE ITCZ AXIS WAS ANALYZED FROM 10N122W TO 08N130W TO 06N140W. SCATTERED MODERATE CONVECTION WAS FROM 05N TO 08N E OF 89W. SCATTERED MODERATE CONVECTION WAS WITHIN 150 NM EITHER SIDE OF LINE FROM 11N105W TO 05N95W. SCATTERED MODERATE CONVECTION WAS WITHIN 120 NM N OF THE AXIS BETWEEN 122W AND 130W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN 180 NM N OF AXIS W OF 130W. ...DISCUSSION... THE 0726 UTC OSCAT AND 0536 UTC ASCAT PASSES SHOW AN ELONGATED WIND FIELD ASSOCIATED WITH THE REMNANTS OF ALVIN. THE REMAINING TROUGH LIES FROM 15N119W TO 07N120W WITH WEAK 1008 MB LOW PRES EMBEDDED WITHIN THE TROUGH NEAR 12N120W. WINDS TO 30 KT WERE STILL OBSERVED IN THE NE QUADRANT OF THE WEAK LOW. CONVECTION WAS SKEWED TO THE E OF THE TROUGH WHICH LIES UNDER 25-40 KT OF SW SHEAR. THIS SHEAR WILL CONTINUE TO TAKE ITS TOLL ON THE LINGERING SURFACE SYSTEM AS IT MOVES W AROUND 10 KT TODAY. WINDS ARE EXPECTED TO DROP BELOW ADVISORY CRITERIA WITH THE WEAKENING SYSTEM BY EARLY TUE. 1034 MB HIGH PRESSURE WAS ANALYZED NEAR 46N135W WITH A RIDGE EXTENDING S THROUGH 37N135W THEN SE TO 13N106W. A MODERATE TO FRESH NW BREEZE LIES E OF THE RIDGE AXIS ALONG THE COAST OF BAJA CALIFORNIA ACCORDING TO THE 0730 UTC OSCAT PASS. TO THE N...WINDS ARE INCREASING OFF THE CALIFORNIA COAST AS A COLD FRONT SWEEPS THROUGH THE OFFSHORE WATERS AND INTO THE WESTERN UNITED STATES. WINDS ARE EXPECTED TO REACH GALE FORCE THERE BY MON MORNING. NW SWELL IS ALREADY TRAVELING S OF 32N AND WILL EXPAND TO WATERS N OF 27N BETWEEN 118W-127W BY MON MORNING BEFORE BEGINNING TO RETREAT AS THE GALE FORCE WINDS TO THE N DIMINISH. MODERATE TO FRESH TRADE WINDS WERE OBSERVED BY THE 0630 UTC ASCAT AND 0906 UTC OSCAT PASSES IN THE AREA N OF THE ITCZ TO ABOUT 15N. SEAS TO 9 FT WERE OBSERVED BY EARLIER JASON ALTIMETER PASSES GENERALLY IN THE AREA FROM 08N-13N W OF 132W. WINDS WILL REMAIN BELOW ADVISORY CRITERIA HERE THROUGH THE FORECAST PERIOD AND SEAS GENERATED BY TRADE WIND FLOW WILL SHIFT W OF THE AREA BY EARLY MON. THE AREA WITH THE HIGHEST PRECIPITABLE WATER VALUES OUTSIDE OF THE REMNANTS OF ALVIN WITHIN THE FORECAST AREA LIES OVER WESTERN WATERS ALONG THE ITCZ. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS NOTED WITHIN 180 NM N OF THE ITCZ AXIS W OF 130W. WESTERLY FLOW ALOFT HERE IS BEING DIVERTED AROUND A WEAK UPPER ANTICYCLONE NEAR 09N133W...ENHANCING THE CONVECTION. AN AREA OF SCATTERED MODERATE TO STRONG CONVECTION FROM 05N-08N E OF 89W TO THE COAST OF PANAMA AND COLOMBIA IS BEING ENHANCED BY UPPER LEVEL DIVERGENCE BETWEEN 20 KT NORTH-NORTHEASTERLIES TO THE S AND 5-10 KT EASTERLIES WINDS TO THE N. POOLED LOW- TO MID- LEVEL MOISTURE IS EVIDENT HERE IN PRECIPITABLE WATER IMAGERY ALONG THE MONSOON TROUGH. THE POOL EXTENDS AS FAR W AS 100W. ANOTHER AREA OF SCATTERED MODERATE CONVECTION WAS NOTED IN THIS REGION WITHIN 150 NM EITHER SIDE OF A LINE FROM 11N105W TO 05N95W WHERE UPPER LEVEL DIVERGENCE BETWEEN ANTICYCLONE OVER THE GULF OF TEHUANTEPEC AND ANOTHER JUST SE OF THE GALAPAGOS ISLANDS IS ENHANCING CONVECTION. CONDITIONS WILL REMAIN FAVORABLE FOR CONVECTION ALONG THE EASTERN PORTION OF THE MONSOON TROUGH INTO EARLY TUE. $$ SCHAUER