000 AXPZ20 KNHC 040344 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0300 UTC. ...SPECIAL FEATURES... HURRICANE VANCE IS CENTERED NEAR 17.4N 110.6W OR ABOUT 85 NM... 160 KM SSE OF SOCORRO ISLAND OR ABOUT 420 NM...780 KM SW OF MAZATLAN MEXICO AT 04/0300 UTC MOVING TOWARD THE NORTH-NORTHEAST OR 20 DEGREES AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 965 MB. MAXIMUM SUSTAINED WINDS ARE 95 KT WITH GUSTS TO 115 KT. WEAKENING IS FORECAST TO BEGIN BY TUESDAY MORNING...AND STEADY TO RAPID WEAKENING IS EXPECTED THEREAFTER. ON THE FORECAST TRACK...VANCE IS EXPECTED TO PASS JUST EAST OF SOCORRO ISLAND TONIGHT AND EARLY TUESDAY MORNING...AND BE NEAR THE SOUTHWESTERN COAST OF MEXICO BY LATE WEDNESDAY. A TROPICAL STORM WATCH IS NOW IN EFFECT FROM MAZATLAN NORTHWARD TO TOPOLOBAMPO MEXICO. NUMEROUS MODERATE TO STRONG CONVECTION IS WITHIN 90 NM OF CENTER. VANCE AND MOISTURE SPREADING NORTHWARD AHEAD OF THE SYSTEM IS EXPECTED TO PRODUCE RAINFALL TOTALS OF 4 TO 8 INCHES WITH ISOLATED AMOUNTS NEAR 12 INCHES THROUGH WEDNESDAY OVER THE STATES OF SINALOA...NAYARIT...AND DURANGO IN WESTERN MEXICO. THESE RAINS ARE LIKELY TO PRODUCE LIFE-THREATENING FLASH FLOODS AND MUDSLIDES...ESPECIALLY IN AREAS OF MOUNTAINOUS TERRAIN. SWELLS GENERATED BY VANCE ARE EXPECTED TO BEGIN AFFECTING PORTIONS OF THE COAST OF SOUTHWESTERN MEXICO AND BAJA CALIFORNIA SUR TONIGHT AND TUESDAY. 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. AGAIN...MARINE GUIDANCE SUGGESTS MINIMAL GALE FORCE WINDS ACROSS THE GULF OF TEHUANTEPEC DURING THE OVERNIGHT AND EARLY MORNING HOURS LIKELY WITH THE AID OF THE NOCTURNAL DRAINAGE FLOW. SO THE DECISION WAS MADE TO ISSUE A GALE WARNING FOR THIS REGION THROUGH LATE TUE MORNING. 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 TONIGHT AND WEAKEN THE PRES GRADIENT ACROSS THE ISTHMUS OF TEHUANTEPEC. WINDS WILL REMAIN IN THE 20-25 KT RANGE THROUGH LATE TUE AND DIMINISH TO 20 KT OR LESS BY WED MORNING. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS ACROSS THE GULF OF PANAMA TO 09N84W TO 08N94W TO LOW PRES NEAR 11N105W 1008 MB...THEN RESUMES FROM 12N112W TO LOW PRES NEAR 11N128W 1008 MB TO 09N135W. ITCZ AXIS CONTINUES FROM 09N135W TO 09N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 120 NM S OF TROUGH BETWEEN 94W AND 97W. ...DISCUSSION... A 1008 MB LOW PRES IS EMBEDDED WITHIN THE MONSOON TROUGH NEAR 11N105W. GALE FORCE WINDS WERE NOTED PER SCATTEROMETER DATA WITHIN 120 NM NE QUADRANT OF THE LOW CENTER ON MON. CURRENTLY...MARINE GUIDANCE SUGGESTS WINDS OF 20-25 KT IN ASSOCIATION WITH THIS LOS PRES...PARTICULRLY TO THE NE QUADRANT. THIS SYSTEM IS PRODUCING DISORGANIZED SHOWER AND TSTM ACTIVITY. SATELLITE IMAGES SHOW NUMEROUS MODERATE TO STRONG CONVECTION WITHIN 90 NM W AND 75 NM E SEMICIRCLES. SCATTERED MODERATE TO STRONG CONVECTION IS SEEN ELSEWHERE FROM 10N TO 16N BETWEEN 103W AND 110W. DEVELOPMENT OF THIS SYSTEM WILL BE SLOW TO OCCUR DURING THE NEXT DAY OR TWO WHILE IT MOVES W-NW OR NW AT ABOUT 12 KT. AFTER THAT TIME...DEVELOPMENT IS NOT EXPECTED DUE TO STRONG UPPER-LEVEL WINDS. ANOTHER 1008 MB LOW PRES REMAINS NEAR 11N128W. CONVECTION HAS INCREASED AGAIN JUST E OF THE LOW CENTER WHERE A CLUSTER OF MODERATE TO STRONG CONVECTION IS OBSERVED FROM 10N TO 13N BETWEEN 125W AND 128W. THIS SYSTEM WILL CONTINUE TO DRIFT WWD. A 1026 MB HIGH PRES LOCATED NEAR 32N134W EXTENDS A RIDGE ACROSS THE N WATERS MAINLY N OF 18N W OF 115W. THE PRESSURE GRADIENT BETWEEN THE HIGH AND LOWER PRES IN THE VICINITY OF THE MONSOON TROUGH/ITCZ IS GENERATING A LARGE SWATH OF FRESH TO STRONG NE TRADE WINDS FROM 12N TO 23N W OF 120W WITH SEAS OF 8-11 FT. THE HIGH IS FORECAST TO SHIFT NE AWAY FROM THE AREA...ALLOWING THE AREA OF FRESH TO STRONG TRADES TO DECREASE LATE TUE INTO WED. THE PRES GRADIENT REMAINS TIGHT ENOUGH ACROSS THE CARIBBEAN SEA TO MAINTAIN A GAP WIND EVENT ACROSS THE GULF OF PAPAGAYO. EXPECT NE WINDS OF 20-25 KT AND SEAS OF 8-10 FT WITHIN 45 NM EITHER SIDE OF A LINE FROM 11N86W TO 09N93W...INCLUDING THE GULF OF PAPAGAYO. WINDS HERE SHOULD BEGIN TO GRADUALLY DIMINISH LATE TUE MORNING AS THE HIGH PRES TO THE N WEAKENS. THE PRES GRADIENT OVER THE NORTHERN GULF OF CALIFORNIA BETWEEN THE AFOREMENTIONED HIGH PRES TO THE N AND LOWER PRES TO THE SE SHOULD BRING A FRESH TO STRONG NW TO N BREEZE TO THE GULF OF CALIFORNIA N OF 25N BY LATE TUE. SEAS ARE EXPECTED TO BUILD TO NEAR 9 FT BY EARLY WED. WINDS WILL ALSO INCREASE TO 20-25 KT JUST W OF THE BAJA CALIFORNIA PENINSULA BY LATE TUE. THE WINDS ARE EXPECTED TO DECREASE TO 20 KT OR LESS BY WED NIGHT. $$ GR