000 AXPZ20 KNHC 040949 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 0815 UTC. ...SPECIAL FEATURES... HURRICANE VANCE WAS CENTERED NEAR 18.4N 110.0W OR ABOUT 60 NM... 115 KM E-SE OF SOCORRO ISLAND OR ABOUT 350 NM...650 KM SW OF MAZATLAN MEXICO AT 04/0900 UTC MOVING TOWARD THE NORTH-NORTHEAST OR 25 DEGREES AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 970 MB. MAXIMUM SUSTAINED WINDS ARE 90 KT WITH GUSTS TO 110 KT. NUMEROUS MODERATE TO STRONG CONVECTION WAS WITHIN 180 NM NE QUADRANT...120 NM SE QUADRANT AND 60 NM W SEMICIRCLE WITH SCATTERED MODERATE CONVECTION ELSEWHERE WITHIN 390 NM N QUADRANT. RAINFALL TOTALS OF 4 TO 8 INCHES WITH ISOLATED AMOUNTS NEAR 12 INCHES ARE EXPECTED THROUGH WEDNESDAY OVER THE STATES OF SINALOA...NAYARIT....AND DURANGO IN WESTERN MEXICO. THESE RAINS ARE LIKELY TO PRODUCE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES...ESPECIALLY IN AREAS OF MOUNTAINOUS TERRAIN. STEADY TO RAPID WEAKENING IS FORECAST DURING THE NEXT DAY OR SO...AND VANCE COULD WEAKEN TO A TROPICAL DEPRESSION BY THE TIME IT REACHES THE COAST OF MEXICO. HOWEVER...A TROPICAL STORM WATCH IS IN EFFECT FROM MAZATLAN NORTHWARD TO TOPOLOBAMPO MEXICO. SWELLS GENERATED BY VANCE ARE EXPECTED TO BEGIN AFFECTING PORTIONS OF THE COAST OF SOUTHWESTERN MEXICO AND BAJA CALIFORNIA SUR TODAY AND TONIGHT. 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 0400 UTC ASCAT-B PASS SHOWED GALE FORCE WINDS PERSISTING IN THE GULF OF TEHUANTEPEC. A DEEP LAYER TROUGH MOVING INTO THE CENTRAL U.S. AND N CENTRAL MEXICO HAS BEGUN TO ERODE THE HIGH PRES OVER THE WESTERN GULF OF MEXICO AND WEAKEN THE PRES GRADIENT ACROSS THE ISTHMUS OF TEHUANTEPEC. THE GALE WARNING IS EXPECTED TO EXPIRE AFTER THE PERIOD OF MAXIMUM NOCTURNAL DRAINAGE FLOW IS COMPLETE TODAY. WINDS ARE EXPECTED TO DIMINISH BELOW A FRESH TO STRONG BREEZE BY MIDDAY WED. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 07N77W TO 09N84W TO 07N94W TO LOW PRES NEAR 11.5N105W 1008 MB...THEN CONTINUES FROM 13N115W TO 19N119W TO LOW PRES NEAR 11N129W 1008 MB TO 10N132W. ITCZ AXIS FROM 10N132W TO 09N140W. SCATTERED MODERATE TO STRONG CONVECTION WAS FROM 02N TO 7.5N E OF 84W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS FROM 05N TO 09N BETWEEN 93W AND 99W. NUMEROUS MODERATE TO STRONG CONVECTION WAS WITHIN 210 NM N AND NW QUADRANTS OF LOW PRES NEAR 11.5N105W WITH SCATTERED MODERATE CONVECTION ELSEWHERE WITHIN 240 NM S SEMICIRCLE. SCATTERED MODERATE TO STRONG CONVECTION WAS WITHIN 270 NM E QUADRANT OF LOW PRES NEAR 11N129W. ...DISCUSSION... AN ASCAT-A PASS FROM 0628 UTC SHOWED GALE FORCE WINDS E OF THE 1008 MB LOW PRES CENTER NEAR 11N129W. THIS AREA OF THE PASS COINCIDED WITH THE SCATTERED MODERATE TO STRONG CONVECTION WITHIN 270 NM E QUADRANT OF THE LOW AND APPEARS TO BE RAIN CONTAMINATED. FARTHER N OF THE LOW...RELIABLE OBSERVATIONS OF 30 KT WINDS WERE FOUND EMBEDDED IN THE LARGER TRADE WIND FLOW. THE TIGHT PRESSURE GRADIENT BETWEEN THE 1027 MB SUBTROPICAL HIGH NEAR 33N132W AND THE MONSOON TROUGH/ITCZ HAS YIELDED A WIDE SWATH OF FRESH TO STRONG TRADES PRIMARILY FROM 10N TO 20N W OF 120W. THE SUBTROPICAL HIGH IS FORECAST TO SHIFT NE AWAY FROM THE AREA...ALLOWING THE AREA OF FRESH TO STRONG TRADES TO SHRINK TODAY THROUGH EARLY THU. THESE TRADES LIE IN A REGION OF NW SWELL OVER 8 FT AND WILL HELP TO PREVENT THE SEAS FROM SUBSIDING UNDER 8 FT OVER MUCH OF THE AREA THROUGH WED. THE 0400 UTC ASCAT-B PASS SAW WINDS TO 30 KT IN THE NE QUADRANT OF A 1008 MB LOW PRES SYSTEM CENTERED NEAR 11.5N105W. NUMEROUS MODERATE TO STRONG CONVECTION WAS WITHIN 210 NM N AND NE QUADRANTS OF THE LOW PRES SYSTEM WITH SCATTERED MODERATE CONVECTION ELSEWHERE WITHIN 240 NM S SEMICIRCLE. THIS LOW IS EXPECTED TO GRADUALLY BECOME OVER POWERED BY THE CIRCULATION AROUND VANCE TO THE N OVER THE NEXT TWO DAYS. A PULSE OF NEAR GALE FORCE WINDS FROM THE GULF OF PAPAGAYO YESTERDAY HELPED SPUR A WEAK LOW THAN HAS DIMINISHED TO A PERTURBATION ALONG THE MONSOON TROUGH NEAR 95W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS FROM 05N TO 09N BETWEEN 93W AND 99W. THE 0358 UTC ASCAT PASS SHOWED A VERY SMALL AREA OF 25 KT WINDS WHICH LIKELY DIMINISHED BY 0600 UTC. HOWEVER...AN AREA OF 8 FT NE SWELL CONTINUED TO PROPAGATE W WITH THE SYSTEM. THIS SWELL WILL MERGE WITH THE SWELL FROM THE GULF OF TEHUANTEPEC GALE EVENT LATER TODAY. WITHIN THE GULF OF PAPAGAYO ARE E OF 89W...WINDS ARE BELIEVED TO HAVE REACHED A FRESH TO STRONG BREEZE THIS MORNING. THE ARE EXPECTED TO DIMINISH BY THE AFTERNOON AFTER THE PERIOD OF PEAK DRAINAGE FLOW. A SHARP UPPER TROUGH LIES FROM THE U.S. FOUR CORNERS TO NEAR 10N130W AND IS SENDING A COLD FRONT THROUGH THE S CENTRAL U.S. TOWARD NORTHERN MEXICO. A STRONG UPPER JET ON THE EASTERN SIDE OF THE TROUGH IS CARRYING MID AND UPPER LEVEL MOISTURE FROM THE LOW PRES SYSTEM NEAR 11N128W AND FROM HURRICANE VANCE NORTHEASTWARD INTO BAJA CALIFORNIA SUR AND NW MEXICO. AT THE SURFACE...STRONG HIGH PRES OVER THE U.S. GREAT BASIN BEHIND THE ASSOCIATED COLD FRONT WILL PERSIST THE NEXT FEW DAYS. THE PRES GRADIENT OVER THE NORTHERN GULF OF CALIFORNIA BETWEEN THIS HIGH AND LOWER PRES TO THE SE HAS BROUGHT A FRESH TO STRONG NW TO N BREEZE TO THE GULF OF CALIFORNIA N OF 29N THAT IS EXPECTED TO INCREASE TO NEAR GALE FORCE LATER TODAY. WINDS ABOVE THE ADVISORY CRITERIA OF 20-25 KT ARE EXPECTED TO PERSIST OVER THE NORTHERN GULF OF CALIFORNIA THROUGH AT LEAST THE END OF THE PERIOD EARLY THU MORNING. $$ SCHAUER