000
AXPZ20 KNHC 050355
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC TUE NOV 04 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 
0215 UTC.                       

...SPECIAL FEATURES...                                          

TROPICAL STORM VANCE WAS CENTERED NEAR 21.5N 108.0W OR ABOUT 135 
NM...250 KM...SW OF MAZATLAN MEXICO AT 05/0300 UTC MOVING TOWARD 
THE N-NE OR 030 DEGREES AT 13 KT. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 992 MB. MAXIMUM SUSTAINED WINDS CONTINUE TO 
DIMINISHED AND WERE 45 KT WITH GUSTS TO 55 KT. VANCE CONTINUES 
TO WEAKEN THIS EVENING DUE TO STRONG SW VERTICAL WIND 
SHEAR...WHICH HAS DISPLACED THE MID LEVEL CENTER AND MOST OF THE 
CONVECTION OFF TO THE NE...WHERE SCATTERED MODERATE TO STRONG 
CONVECTION WAS OCCURRING WITHIN 360 NM ACROSS THE E SEMICIRCLE. 
RAINFALL TOTALS OF 4 TO 8 INCHES WITH ISOLATED AMOUNTS NEAR 12 
INCHES ARE STILL EXPECTED TONIGHT THROUGH WED 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. LARGE 
SWELLS GENERATED BY VANCE ARE AFFECTING PORTIONS OF THE COAST OF 
SOUTHWESTERN MEXICO AND BAJA CALIFORNIA SUR THIS EVENING AND 
WILL CONTINUE INTO MIDDAY WED BEFORE SUBSIDING QUICKLY. THESE 
SWELLS WILL LIKELY TO CAUSE VERY LARGE AND DANGEROUS SURF 
CONDITIONS LEADING TO LIFE-THREATENING RIP CURRENT CONDITIONS. 
THE RAPID WEAKENING TREND IS EXPECTED TO CONTINUE TONIGHT WITH 
VANCE WEAKENING TO A TROPICAL DEPRESSION BY THE TIME IT REACHES 
THE COAST OF MEXICO WITHIN THE NEXT 18 HOURS. HOWEVER...A 
TROPICAL STORM WATCH REMAINS IN EFFECT FROM MAZATLAN NORTHWARD 
TO TOPOLOBAMPO MEXICO. SEE THE LATEST NHC FORECAST/ ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS.
 
...TROPICAL LOWS...

THE LOW PRES CENTER SUGGESTED BY VISIBLE SATELLITE IMAGERY NEAR 
14.5N105W LATE THIS AFTERNOON APPEARS TO HAVE BECOME ELONGATED 
AND PULLED TO THE NORTH...EMBEDDED IN THE BROADER SOUTHERLY FLOW 
OCCURRING SE OF VANCE. AN ELONGATED AREA OF S TO SE WINDS 20 TO 
25 KT AND SEAS 9 TO 11 FT WAS OCCURRING HERE FROM 15N TO 18N 
BETWEEN 103W AND 106W. LOOK FOR THIS AREA OF WINDS AND SEAS TO 
SHIFT NORTHWARD IN UNISON WITH VANCE AND SLOWLY IMPROVE DURING 
THE NEXT 12 TO 24 HOURS AS VANCE MOVES INLAND AND DISSIPATES.

A 1008 MB LOW PRES CENTER CAN BE SEEN IN SATELLITE IMAGERY NEAR 
10.5N133.5W MOVING W ALONG THE MONSOON TROUGH. THIS LOW HAS 
MOVED INTO AN AREA OF STRONG MIDDLE TO UPPER LEVEL SUBSIDENCE 
AND REMAINS VOID OF CONVECTION. HIGH PRES TO THE N OF THE AREA 
IS CREATING A STRONG PRES GRADIENT N OF THE LOW AND THE MONSOON 
TROUGH AND ITCZ ACROSS THIS AREA...PRODUCING AN LARGE AREA OF 
FRESH TO STRONG TRADEWINDS. NE TO W WINDS 20 TO 30 KT WERE 
OCCURRING WITHIN 240 NM ACROSS THE N SEMICIRCLE OF THIS LOW 
WHERE SEAS WERE 8 TO 12 FT. THE FRESH TO STRONG TRADES EXTENDED 
ELSEWHERE FROM 14N TO 20N W OF 124W. ACROSS THE REMAINDER OF 
THIS TRADE WIND BELT...FROM 09N TO 26N W OF 114W NE TRADES WERE 
15 TO 20 KT WITH SEAS 8 TO 11 FT IN MIXED NW AND NE SWELL. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

MONSOON TROUGH AXIS EXTENDS FROM 06N73W TO 09N854 TO 07N94W TO 
14N105W...WHERE IT HAS FRACTURED FROM VANCE...THEN RESUMES FROM 
13.5N112W TO LOW PRES 10.5N133.5W...THEN ITCZ TO 08N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 270 
NM S OF TROUGH E OF 86W. SCATTERED MODERATE TO STRONG CONVECTION 
NOTED WITHIN 150 NM N AND 90 NM S OF TROUGH BETWEEN 90W AND 
101W. SCATTERED MODERATE TO STRONG CONVECTION NOTED FROM 12N TO 
14N BETWEEN 113W AND 118W. SCATTERED STRONG CONVECTION NOTED 
FROM 05.5N TO 09.5N W OF 137W. 

...DISCUSSION...  

GULF OF TEHUANTEPEC...THE GALE CONDITIONS HAVE ENDED ACROSS THE 
GULF THIS AFTERNOON AS THE ASSOCIATED HIGH PRESSURE OVER THE 
GULF OF MEXICO HAS BEGUN TO SHIFT E OF THE GULF OF MEXICO BASIN. 
WINDS HAVE DECREASED LATE THIS AFTERNOON AND EVENING TO AROUND 
20 KT...BUT EXPECT TONIGHTS NORTHERLY DRAINAGE TO SUPPORT A 
MAXIMUM OF 25 KT OVERNIGHT BEFORE DECREASING AGAIN DURING THE 
DAY WED. COMPUTER MODEL GUIDANCE IS SUGGESTING THE NORTHERLY 
FLOW WILL INCREASE TO 20-25 KT BY LATE THU...AND GRADUALLY 
INCREASE TO 20-30 KT BY SUNRISE FRI WITH SEAS BUILDING TO 11 FT. 

GULF OF PAPAGAYO....NE WINDS NEAR 20 KT WITH SEAS OF 5-7 FT WERE 
OBSERVED DOWNSTREAM OF PAPAGAYO TO 88W THIS EVENING. 
HOWEVER...DRAINAGE FLOW ACROSS THE GULF OF PAPAGAYO IS EXPECTED 
TO INCREASE WINDS TO 20-25 KT OVERNIGHT THROUGH LATE WED MORNING 
BEFORE SUBSIDING BELOW 20 KT LATE WED AFTERNOON. NOCTURNAL WINDS 
MAY PULSE AGAIN TO NEAR 20 KT WED NIGHT...BUT THE STRONG NELY 
FLOW ACROSS THE CARIBBEAN AND CENTRAL AMERICA WILL DIMINISH 
DURING THE NEXT 24-36 HOURS AND END THIS CURRENT GAP WIND EVENT. 
 
.GULF OF CALIFORNIA...NW WINDS OF 20-25 KT WITH SEAS OF 5-9 FT 
ARE ASSUMED TO HAVE SPREAD SOUTHWARD THROUGH THE NORTHERN GULF 
TO THE TIBURON BASIN...AND WILL FUNNEL THROUGH THE ISLANDS 
OVERNIGHT BEFORE RETREATING NORTHWARD OF 28N WED MORNING. THESE 
NOCTURNAL WINDS TONIGHT ARE EXPECTED TO INCREASE TO 20 TO 30 KT 
WITH SEAS BUILDING 6 TO 10 FT. WINDS AND SEAS ARE THEN EXPECTED 
TO GRADUALLY DIMINISH WED AFTERNOON THROUGH THU AS VANCE MOVERS 
INLAND AND DISSIPATES AND THE REGIONAL PRES GRADIENT DECREASES.  
 
$$
STRIPLING