000
AXPZ20 KNHC 171540
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE DEC 17 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURE...
 
GULF OF TEHUANTEPEC...GALE CONDITIONS OF 30-40 KT ARE EXPECTED 
TO PERSIST THROUGH MID-MORNING TODAY THEN DIMINISH TO MINIMAL 
GALE FORCE OF 30-35 KT THIS AFTERNOON THROUGH EARLY WED NIGHT. 
THE MAXIMUM DRAINAGE WINDS SHOULD REACH 30 KT LATE WED NIGHT 
THROUGH SUNRISE THU...THEN DIMINISH TO 10-15 KT LATE THU NIGHT. 
16 FT MAXIMUM SEAS DOWNSTREAM FROM THE GULF OF TEHUANTEPEC WILL 
GRADUALLY SUBSIDE TO LESS THAN 8 FT BY THU AFTERNOON. RESULTANT 
PLUME OF NE SWELL CONTINUES TO MIX WITH CROSS-EQUATORIAL SW AND 
LONG PERIOD NW SWELL...WITH COMBINED SEAS TO 8 FT REACHING ALONG 
05N BETWEEN 93-108W.  

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

THE MONSOON TROUGH EXTENDS W FROM THE COLOMBIAN COAST AT 08N78W 
ACROSS CENTRAL PANAMA TO 09N85W TO 07N100W. THE ITCZ EXTENDS 
FROM 07N100W TO 08N130W TO 07N140W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS WITHIN 90 NM N AND 30 NM S OF ITCZ AXIS W 
OF 112W.
   
...DISCUSSION... 

A SURFACE RIDGE ANCHORED BY 1027 MB HIGH PRES CENTERED NEAR 38N 
140W EXTENDS SE TO 21N112W. SCATTEROMETER DATA SHOWS FRESH NE 
TRADES S OF THE RIDGE AND N OF THE ITCZ W OF 120W. LONG PERIOD 
NW SWELL IS MIXING WITH THE NE TRADE WIND SWELL AND LONG PERIOD 
CROSS-EQUATORIAL SOUTHERLY SWELL...RESULTING IN COMBINED SEAS OF 
7-10 FT WITHIN THE AREA OF ENHANCED TRADES. NW SWELL WILL SLOWLY 
SUBSIDE TODAY...AND THE AFFECTED AREA OF 8 FT OR GREATER SEAS 
WILL SHRINK TO 08-15N BETWEEN 117-140W BY TONIGHT. THE GRADIENT 
WILL TIGHTEN A LITTLE WED WITH FRESH TRADES EXPECTED FROM 08-25N 
W OF 126W AND SEAS 6-9 FT BY WED NIGHT. 

A HIGH AMPLITUDE SHORT WAVE WILL SWEEP SOUTH THU THROUGH FRI... 
AND REACH 20N ALONG 105W BY SAT AFTERNOON. THE SHORT WAVE WILL 
INTENSIFY COLD AIR ADVECTION ALONG THE WEST COAST AND DRAG A DRY 
COLD FRONT FAR INTO THE TROPICAL EAST PACIFIC THU THROUGH FRI 
NIGHT. THE FRONT WILL REACH FROM SOUTHERN CALIFORNIA TO 30N128W 
THU...FROM SOUTHERN ARIZONA TO 25N125W THU NIGHT...AND FROM WEST 
TEXAS ACROSS NORTHERN MEXICO TO 18N124W FRI THEN BECOME DIFFUSE 
S OF THE BAJA PENINSULA FRI NIGHT AND SAT. STRONG HIGH PRES 
BEHIND THE COLD FRONT WILL INDUCE GALE FORCE N WINDS ALONG THE 
COAST OF CENTRAL AND SOUTHERN CALIFORNIA THU AND FRI...PRODUCING 
LARGE SEAS TO 20-22 FT N OF THE FORECAST AREA ALONG 125W THU 
NIGHT. 15-18 FT SWELL WILL SPREAD S OF 30N BETWEEN 120-130W FRI. 

GULF OF PAPAGAYO...NE-E WINDS WILL PULSE AT 20-25 KT DURING MAX 
NOCTURNAL DRAINAGE PERIOD TONIGHT THROUGH THU NIGHT...THEN MAX 
AT 15-20 KT ON FRI NIGHT. NE SWELL PROPAGATING SW FROM THE GULF 
OF PAPAGAYO WILL MIX WITH NW SWELL FROM THE GULF OF TEHUANTEPEC 
EVENT AND CROSS-EQUATORIAL S SWELL...RESULTING IN COMBINED SEAS 
OF 6-9 FT AS FAR W AS 09N92W.

GULF OF CALIFORNIA...MODERATE TO FRESH NW WINDS WILL DIMINISH TO 
5-10 KT WED AND BECOME SOUTHERLY WED NIGHT. WINDS WILL INCREASE 
TO 20-25 KT OVER THE NORTHERN GULF EARLY THU AHEAD OF THE COLD 
FRONT EXPECTED TO ARRIVE THU AFTERNOON. THE FRONT WILL PUSH 
SOUTH OF THE BAJA PENINSULA THROUGH FRI EVENING ACCOMPANIED BY A 
SHIFT IN WINDS FROM SW THROUGH W TO NW FROM HIGH PRES BUILDING 
BEHIND THE FRONT. 
 

$$
MUNDELL