000 AXPZ20 KNHC 030952 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON NOV 03 2014 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0830 UTC. ...SPECIAL FEATURES... AT 03/0900 UTC...VANCE WAS CENTERED NEAR 14.5N 110.3W OR ABOUT 440 NM...815 KM SW OF MANZANILLO MEXICO MOVING TOWARD THE NORTHWEST OR 320 DEGREES AT 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 971 MB. MAXIMUM SUSTAINED WINDS WERE 90 KT WITH GUSTS TO 110 KT. VANCE COULD STRENGTHEN A LITTLE MORE TODAY...BUT A WEAKENING TREND IS EXPECTED TO BEGIN TONIGHT...WITH STEADY TO RAPID WEAKENING FORECAST THEREAFTER. NUMEROUS MODERATE TO STRONG CONVECTION WAS WITHIN 90 NM OF CENTER WHILE NUMEROUS MODERATE WITH ISOLATED STRONG CONVECTION WAS ELSEWHERE WITHIN 300 NM OF CENTER...EXCEPT 0 NM SW QUADRANT. SWELLS GENERATED BY VANCE ARE EXPECTED TO BEGIN AFFECTING PORTIONS OF THE COAST OF SOUTHWESTERN MEXICO AND BAJA CALIFORNIA SUR IN A DAY OR TWO. THESE SWELLS ARE LIKELY TO CAUSE LIFE- THREATENING SURF AND RIP CURRENT CONDITIONS. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. THE SECOND GALE FORCE GAP WIND EVENT OF THE COLD SEASON 2014- 2015 HAS OCCURRED IN THE GULF OF TEHUANTEPEC AND WAS CONFIRMED BY SCATTEROMETER DATA. THE 0328 UTC ASCAT-A PASS CAPTURED AN AREA OF 30-40 KT NLY WINDS EXTENDING W-SW FROM THE GULF OF TEHUANTEPEC TO NEAR 13.5N96. A DEEP LAYER TROUGH MOVING INTO THE CENTRAL U.S. AND N CENTRAL MEXICO WILL BEGIN TO ERODE THE HIGH PRES OVER THE WESTERN GULF OF MEXICO TODAY AND DIMINISH THE TIGHT PRES GRADIENT CURRENTLY IN PLACE. THE GALE WARNING IS SCHEDULED TO EXPIRE AROUND MIDDAY TODAY...BUT WINDS WILL REMAIN 20-30 KT THROUGH TUE MORNING AND DIMINISH TO 20 KT OR LESS BY WED MORNING. BOTH THE 0328 UTC ASCAT-A PASS AND 0420 UTC ASCAT-B PASS SAW GALE FORCE WINDS IN THE N SEMICIRCLE OF A 1010 MB LOW PRES SYSTEM CENTERED NEAR 09N88W. A GALE WARNING HAS BEEN ISSUED. AS EXPLAINED ABOVE...THE HIGH PRES TO THE N OF THE SYSTEM OVER THE GULF OF MEXICO IS EXPECTED TO ERODE TODAY...DIMINISHING THE PRES GRADIENT N OF THIS LOW. THE GALE FORCE WINDS ARE FORECAST TO DIMINISH BY SUNSET TODAY. SCATTERED MODERATE TO STRONG CONVECTION WAS FOUND WITHIN 90 NM E SEMICIRCLE AND 210 NM W SEMICIRCLE OF THIS LOW WHICH IS TRAVELING W-NW AT 15-20 KT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 09N83W TO 07N91W TO LOW PRES NEAR 09N88W 1010 MB TO 11N103W...THEN CONTINUES FROM 12N116W TO LOW PRES NEAR 11N128W 1010 MB TO 09N133W. THE ITCZ AXIS WAS ANALYZED FROM 09N133W TO 09N140W. LOW PRES NEAR 09N88W HAD SCATTERED MODERATE TO STRONG CONVECTION WITHIN 90 NM E SEMICIRCLE AND 210 NM W SEMICIRCLE. LOW PRES NEAR 11N128W HAD SCATTERED MODERATE TO STRONG CONVECTION BETWEEN 90 NM AND 270 NM SW QUADRANT. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS N OF THE AXIS TO 18N BETWEEN 117W AND 125W. ...DISCUSSION... A 1010 MB LOW PRES CENTER LIES NEAR 11N128W ABOUT 1215 NM...2255 KM...SOUTHWEST OF THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA. THIS LOW APPEARS TO HAVE MOVED INTO AN AREA OF INCREASED NORTHERLY SHEAR. SCATTERED MODERATE TO STRONG CONVECTION HAS BEEN DISPLACES BETWEEN 90 NM AND 270 NM IN THE SW QUADRANT OF THE LOW. THIS LOW HAS A LOW CHANCE OF BECOMING A TROPICAL CYCLONE IN THE NEXT TWO DAYS. THE PRESSURE GRADIENT BETWEEN THE 1028 MB SUBTROPICAL HIGH CENTERED NEAR 34N135W AND THE MONSOON TROUGH AND ITCZ IS GENERATING A LARGE SWATH OF FRESH TO STRONG NE TRADE WINDS FROM 14N TO 21N W OF 122W AS SEEN IN THE ASCAT PASSES BETWEEN 0400- 0600 UTC. THE SUBTROPICAL HIGH IS FORECAST TO SHIFT NE AWAY FROM THE AREA...ALLOWING THE AREA OF FRESH TO STRONG TRADES TO SHRINK FROM EARLY TUE TO EARLY WED. THESE TRADES LIE IN A REGION OF NW SWELL OVER 8 FT AND WILL HELP TO PREVENT THE SEAS FROM SUBSIDING UNDER 8 FT HERE THROUGH EARLY WED. AN 0326 UTC ASCAT-A PASS NOTED A STRONG BREEZE IN THE GULF OF PAPAGAYO PRIOR TO THE PERIOD OF PEAK DRAINAGE FLOW. WINDS ARE NOW BELIEVED TO BE AS HIGH AS 30 KT. WINDS HERE SHOULD BEGIN TO GRADUALLY DIMINISH AFTER SUNRISE WHEN DRAINAGE FLOW STOPS AND ARE EXPECTED TO FALL BELOW A STRONG BREEZE BY MIDDAY TUE AS THE HIGH PRES TO THE N ERODES AS EXPLAINED IN THE GULF OF TEHUANTEPEC GALE PARAGRAPH ABOVE. HIGH PRES WILL BUILD OVER THE U.S. GREAT BASIN OVER THE NEXT FEW DAYS BEHIND THE AFOREMENTIONED DEEP LAYER TROUGH PASSING INTO THE CENTRAL U.S. THE PRES GRADIENT OVER THE NORTHERN GULF OF CALIFORNIA BETWEEN THIS HIGH AND LOWER PRES TO THE SE SHOULD BRING A FRESH TO STRONG NW TO N BREEZE TO THE GULF OF CALIFORNIA N OF 29N AROUND SUNRISE TUE. THESE WINDS ARE EXPECTED TO PERSIST THROUGH AT LEAST THE END OF THE PERIOD EARLY WED MORNING. $$ SCHAUER