000
AXPZ20 KNHC 200902
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED NOV 20 2013

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 
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
THE MONSOON TROUGH EXTENDS FROM 09N84W TO 07N112W WHERE LOW 
LEVEL WINDS SUGGEST A TRANSITION TO ITCZ WHICH EXTENDS TO 
07N124W TO 04.5N130W TO BEYOND 06N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WAS NOTED WITHIN 240 NM S OF TROUGH 
BETWEEN 83W AND 88W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WAS NOTED WITHIN 120 NM S OF TROUGH BETWEEN 88W AND 
97W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS NOTED 
WITHIN 90 NM N AND 30 NM S OF TROUGH BETWEEN 97W AND 100W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS NOTED WITHIN 
90 NM N OF ITCZ BETWEEN 120W AND 127W.

...DISCUSSION...                                                
RELATIVELY TRANQUIL WEATHER CONDITIONS PERSIST ACROSS THE 
DISCUSSION AREA DURING THE OVERNIGHT HOURS. A WEAKENING 1020 MB 
HIGH PRESSURE CENTER WAS ANALYZED OVER THE N PART OF THE AREA 
NEAR 27N133W WITH ASSOCIATED RIDGE EXTENDING SE TO NEAR 17N110W. 
DUE TO THE RELATIVE WEAK HIGH PRESSURE CENTER...THE PRESSURE 
GRADIENT BETWEEN THIS FEATURE AND LOWER PRESSURE IN THE VICINITY 
OF THE ITCZ...AS WELL AS LOW PRESSURE ACROSS THE W SLOPES OF THE 
SIERRA MADRE OCCIDENTALES...REMAINS WEAK. WINDS OFFSHORE OF BAJA 
CALIFORNIA AND SW MEXICO WERE GENERALLY N TO NW AT AROUND 15 TO 
20 KT DURING THE OVERNIGHT HOURS AS DEPICTED BY THE LATEST 0512 
UTC ASCAT PASS...WITH 15 TO 20 KT TRADE WINDS N OF THE ITCZ. THE 
HIGH PRESSURE CENTER WILL WEAKEN AND COLLAPSE AS IT SHIFTS 
WESTWARD OVER THE NEXT 24 HOURS. STRONG HIGH PRESSURE WELL N OF 
THE AREA WILL BUILD SOUTHWARD OVER THE NEXT 24 HOURS. THE 
PRESSURE GRADIENT BETWEEN THIS STRONGER HIGH PRESSURE CENTER AND 
LOW PRESSURE OVER THE WESTERN UNITED STATES WILL PRODUCE GALE 
FORCE WINDS N OF THE AREA WHICH WILL GENERATE A LARGE N SWELL 
THAT WILL PROPAGATE INTO THE AREA LATE THU INTO FRI. 

LOOKING AHEAD...A STRONG COLD FRONT IS EXPECTED TO MOVE ACROSS 
THE GULF OF MEXICO THIS WEEKEND. RESULTANT WINDS FUNNELING 
THOUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC WILL 
PRODUCE THE NEXT SIGNIFICANT GAP WINDS EVENT. WINDS OVER THE 
GULF OF TEHUANTEPEC ARE EXPECTED TO REACH GALE FORCE BY LATE SAT 
INTO SUN. 

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AL