000 AXPZ20 KNHC 121512 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN AUG 12 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1330 UTC. ...SPECIAL FEATURE... TROPICAL STORM HECTOR WAS CENTERED NEAR 18.3N 110.0W AT 1500 UTC AND WAS MOVING W OR 270 DEG AT 9 KT. MAXIMUM SUSTAINED WINDS WERE 40 KT WITH GUSTS TO 50 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE WAS 997 MB. HECTOR IS ENCOUNTERING STRONG EASTERLY SHEAR WITH NUMEROUS STRONG CONVECTION SKEWED WITHIN 120 NM SW QUADRANT AND SCATTERED MODERATE TO STRONG CONVECTION FOUND ELSEWHERE WITHIN 360 NM W SEMICIRCLE. THE SHEAR OVER HECTOR SHOULD GRADUALLY DECREASE OVER THE NEXT TWO DAYS...AND HECTOR IS EXPECTED TO GRADUALLY STRENGTHEN AS A RESULT. HECTOR WILL CONTINUE MOVING WESTWARD ON THE SOUTH SIDE OF A STEERING MID-LEVEL RIDGE FOUND OVER THE SW UNITED STATES. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 12N87W TO 15N102W THEN CONTINUES FROM 15N121W TO 11N126W TO 11N132W TO 08N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN 180 NM S AND N OF THE AXIS TO THE COAST BETWEEN 91W AND 102W. SCATTERED MODERATE CONVECTION ALSO WAS FROM 15N TO 19N BETWEEN 102W AND 108W IN THE REGION BETWEEN THE MONSOON TROUGH AND TROPICAL STORM HECTOR. ...DISCUSSION... A RIDGE ALOFT EXTENDS OVER THE FORECAST AREA FROM AN ANTICYCLONE NEAR 28N129W TO 21N140W. WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE UNDER THIS RIDGE N OF 16N W OF 130W. A SECOND UPPER ANTICYCLONE LIES NEAR 26N112W AND EXTENDS RIDGES SW TO 20N130W AND SE TO 18N102W. A WEAK UPPER TROUGH ALONG 130W FROM 10N TO 20N LIES NEAR THE TERMINUS OF THE WESTERN RIDGE. A WEAK SURFACE REFLECTION OF THIS TROUGH HAS MANIFESTED ITSELF AS A WIGGLE IN THE MONSOON TROUGH NEAR 130W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION CAN BE FOUND FROM 08N TO 12N BETWEEN 113W AND 120W...WHERE SPEED DIFFLUENCE IN THE REAR RIGHT QUADRANT OF A 40 KT EAST-NORTHEASTERLY UPPER JET ALONG THE EQUATOR AND S OF THE UPPER TROUGH IS LIFTING THE LOW LEVEL MOSITURE POOLED NEAR THE MONSOON TROUGH AND ENHANCING CONVECTION. TROPICAL STORM HECTOR LIES BETWEEN THE TWO UPPER RIDGE AXES STEMMING FROM THE ANTICYCLONE NEAR 26N112W. HECTOR IS IN AN AREA OF WEAKLY DIFFLUENT 20-30 KT EASTERLY UPPER FLOW. THE CONVECTION NEAR HECTOR IS DESCRIBED IN THE SPECIAL FEATURES SECTION ABOVE. WINDS ALOFT ARE WEAKER AND MORE DIFFLUENT NEAR THE RIDGE AXIS ALONG THE MEXICAN COAST WHERE CONVECTION IS BEING ENHANCED CLOSE TO THE MONSOON TROUGH AXIS. THIS CONVECTION IS DESCRIBED IN THE SECTION ABOVE. THE CENTER OF THE ELONGATED 1024 MB SUBTROPICAL HIGH WAS ANALYZED NW OF THE FORECAST AREA NEAR 35N144W. THE HIGH IS FORECAST TO CONSOLIDATE AND STRENGTHEN SLIGHTLY OVER THE NEXT FEW DAYS BUT REMAIN NEARLY STATIONARY. NORTHERLY WINDS BETWEEN THE SUBTROPICAL HIGH AND TROUGHING OVER CALIFORNIA ARE PRODUCING FRESH N TO NE WINDS OVER WATERS N OF 27N W OF 130W ACCORDING TO THE 0534 UTC ASCAT PASS AND NORTHERLY SWELL TO 9 FT CONTINUES TO PROPAGATE INTO THE FORECAST AREA. THE AREA OF FRESH TO STRONG WINDS N OF THE FORECAST AREA WILL SHRINK AS THE SUBTROPICAL HIGH CONSOLIDATES AND SWELL SHOULD SUBSIDE BELOW 8 FT BY EARLY MON. THE REMNANTS OF GILMA WERE ANALYZED NEAR 21.5N121W AT 1006 MB. THE 0532 UTC ASCAT PASS SHOWED WINDS WERE STILL 20-25 KT WITHIN 60 NM S QUADRANT OF THE LOW CENTER...WITH THE PASS ONLY CLIPPING THE REMAINDER OF THE EASTERN SEMICIRCLE. WINDS WITH THE REMNANTS OF GILMA SHOULD WEAKEN TO A FRESH BREEZE OR LESS BY MON MORNING. THESE IS NO DEEP CONVECTION ASSOCIATED WITH THE SYSTEM. GAP WINDS...FRESH TO STRONG NE TO E WINDS ARE EXPECTED TO SURGE INTO AND JUST DOWNSTREAM OF THE GULF OF PAPAGAYO LATE TONIGHT AND CONTINUE THROUGH MON NIGHT BEFORE DIMINISHING. $$ SCHAUER