000
AXPZ20 KNHC 210343
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU NOV 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...       
MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 09N74W TO 12N82W TO 
LOW PRES 1010 MB NEAR 08.5N88W TO LOW PRES 1020 MB NEAR 08N98W 
TO 07.5N110W WHERE IT TRANSITIONS TO ITCZ...AND CONTINUES TO 
06N125W TO BEYOND 06N140W. SCATTERED MODERATE CONVECTION NOTED 
WITHIN 210 NM S OF TROUGH BETWEEN 87W AND 102W. SCATTERED 
MODERATE TO STRONG CONVECTION NOTED WITHIN 210 NM N OF ITCZ 
BETWEEN 123W AND 137W.  


...DISCUSSION...                                              
RELATIVELY TRANQUIL WEATHER CONDITIONS PERSIST ACROSS THE 
DISCUSSION AREA THIS EVENING AS DRY AND SINKING AIR IN THE 
MIDDLE AND UPPER LEVELS DOMINATES MUCH OF THE DISCUSSION AREA. A 
LINGERING MIDDLE TO UPPER TROUGH SNAKES ACROSS N PORTIONS OF THE 
AREA FROM N CENTRAL MEXICO TO A TUTT LOW NEAR 17N133W...WITH 
BROAD TROFFING CONTINUING SW TO 11N148W. CONVECTION INDUCED 
SURROUNDING THE TUTT LOW YESTERDAY HAS ALL BUT DIED AS THIS 
CYCLONE CONTINUES TO WEAKEN. STRONG NW TO W FLOW PREVAILS N OF 
THIS TROUGH...WITH AN EMBEDDED SHORTWAVE TROUGH ALONG 118W 
MOVING INTO CALIFORNIA AND NEARING THE BAJA CALIFORNIA W COAST. 
BROAD UPPER RIDGING PREVAILS S AND SE OF THE TUTT LOW W OF 100W. 
WEAK AND DIFFLUENT FLOW ALOFT ACROSS THE TROPICS E OF 100W  WAS 
ALLOWING FOR DEEP CONVECTION NEAR THE MONSOON TROUGH TO PULSE 
AND PERSIST.
 
AT THE SURFACE...A WEAKENING 1019 MB HIGH WAS ANALYZED OVER THE 
NW PART OF THE AREA NEAR 27N139W WITH ASSOCIATED RIDGE EXTENDING 
SE TO NEAR 19N112W. AN OLD AND WEAK FRONTAL TROUGH HAS SUNK 
SOUTHWARD TO THE N BORDER OF THE AREA ALONG 30N...WITH STRONGER 
FRONT TO THE N ALONG ABOUT 35N EXPECTED TO MOVE S INTO THE ARE 
THU EVENING...BRINGING FRESH NLY WINDS AND INCREASING N 
SWELL...WHICH IS EXPECTED TO CAUSE SEAS TO PEAK AT 8 TO 11 FT N 
OF 25N BY FRIDAY EVENING. A RELATIVELY WEAK PRESSURE GRADIENT 
PERSISTS BETWEEN THE HIGH AND LOWER PRESSURE IN THE VICINITY OF 
THE ITCZ...AS WELL AS LOW PRESSURE ACROSS THE W SLOPES OF THE 
SIERRA MADRE OCCIDENTALES. WINDS OFFSHORE OF BAJA CALIFORNIA AND 
SW MEXICO WERE GENERALLY N TO NW AT 15 TO 20 KT N OF 25N THIS 
EVENING...WHILE NE TRADES BETWEEN THE ITCZ AND 10N WERE AROUND 
20 KT W OF 130W THIS EVENING...WITH SEAS THERE TO 8 FT. 

LOOKING AHEAD...A STRONG COLD FRONT IS EXPECTED TO MOVE ACROSS 
THE GULF OF MEXICO THIS WEEKEND. RESULTANT WINDS FUNNELING 
THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC WILL 
PRODUCE THE NEXT SIGNIFICANT GAP WINDS EVENT. NORTHERLY WINDS 
OVER THE GULF OF TEHUANTEPEC ARE EXPECTED TO REACH 20-25 KT BY 
SAT MORNING...AND THEN REACH GALE FORCE BY LATE SAT NIGHT INTO 
SUN. OTHERWISE...MODERATE TRADE WINDS AND DIMINISHING SEAS ARE 
EXPECTED THROUGH THE WEEKEND.

$$
STRIPLING