000
AXPZ20 KNHC 202152
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC THU NOV 20 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2045 UTC.                       

...SPECIAL FEATURES...                                          
THE GULF OF TEHUANTEPEC GALE WARNING HAS BEEN DISCONTINUED. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

THE MONSOON TROUGH EXTENDS FROM 10N84W ALONG 7N96W 4N104W TO A 
1010 MB NEAR 13N113W. THE ITCZ BEGINS W OF THE LOW NEAR 10N117W 
AND EXTENDS ALONG 10N126W TO 7N140W. SCATTERED MODERATE TO 
STRONG CONVECTION IS WITHIN 150 NM N AND 200 NM S OF MONSOON 
TROUGH BETWEEN 89W AND 98W. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION IS WITHIN 120 NM OF THE 1010 LOW WITHIN THE NE 
QUADRANT...WITHIN 150 NM OF MONSOON TROUGH BETWEEN 98W-105W... 
WITHIN 120 NM OF ITCZ BETWEEN 116W-130W...AND WITHIN 90 NM OF 
ITCZ W OF 135W. SCATTERED MODERATE CONVECTION IS FROM 5N-7N 
BETWEEN 82W-86W.

...DISCUSSION...                                                 
ALTHOUGH THE GULF OF TEHUANTEPEC IS NO LONGER EXPERIENCING GALE 
FORCE WINDS...STRONG N TO NE WINDS REMAIN WITH SEAS TO 11 FT. 
THESE WINDS WILL GRADUALLY DIMINISH OVER THE NEXT 12 TO 24 HOURS 
WITH SEAS SUBSIDING BELOW 8 FT BY FRI AFTERNOON. 

A BROAD UPPER TROUGH COVERS THE AREA N OF 27N W OF BAJA 
CALIFORNIA SUPPORTING A COLD FRONT THAT EXTENDS THROUGH 32N130W 
TO 31N135W. STRONG SUBSIDENCE COVERS THE AREA FROM 17N-27N E OF 
120W AND FROM 20N-30N W OF 120W. THIS FRONT IS FORECAST TO STAY 
N OF 30N AS IT QUICKLY MOVES EASTWARD OVER THE NEXT 24 HRS 
BEFORE MOVING INLAND. 

OTHERWISE...A BROAD SURFACE RIDGE DOMINATES THE AREA N OF 15N W 
OF 118W ANCHORED BY A 1027 MB HIGH JUST W OF THE AREA NEAR 
29N143W. THE PRESSURE GRADIENT BETWEEN THE SURFACE RIDGE AND THE 
LOWER PRESSURE OF THE TROPICS IS INDUCING AN AREA OF FRESH TO 
STRONG EASTERLY TRADE WINDS WITH SEAS TO 10 FT. THESE WINDS WILL 
EXPAND NORTHWARD AND RETREAT WESTWARD OVER THE NEXT 24 HRS THEN 
PERSIST THROUGH 48 HRS. SEAS WILL REMAIN IN THE RANGE OF 8 TO 9 
FT. 

IN THE TROPICS...THE AREA S OF THE STRONG SUBSIDENCE IS MOISTURE 
LADEN AND THUS ACTIVE MONSOON TROUGH/ITCZ. SEE ABOVE. AN 
ELONGATED 1010 MB LOW IS EMBEDDED WITHIN THE MONSOON TROUGH/ITCZ 
CENTERED NEAR 13N113W DRIFTING W. THE LOW IS FORECAST TO WEAKEN 
AND BECOME A TROUGH LATER TONIGHT WHILE LIFTING THE MONSOON 
TROUGH/ITCZ NORTHWARD. THIS WILL INCREASE THE SEAS TO 8 FT THAT 
WILL SHIFT W OVER THE NEXT COUPLE OF DAYS. 

WAVEWATCH GUIDANCE SUGGESTS THAT A NEW SET OF NW SWELLS...IN THE 
WAKE OF THE CURRENT COLD FRONT THAT PASSES JUST N OF 30N WILL 
PROPAGATE SE ACROSS THE FAR NW AND N/CENTRAL WATERS WITH SEAS TO 
9 FT STARTING TONIGHT. ANOTHER ROUND OF NW SWELLS WILL MOVE 
INTO THE NW CORNER ON SAT. 

$$
PAW