000
AXPZ20 KNHC 080920
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC THU JAN 8 2015

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. 

...SPECIAL FEATURES...

GULF OF TEHUANTEPEC GALE WARNING...STRONG HIGH PRES EXTENDING 
SOUTHWARD FROM THE CENTRAL U.S. TO SOUTHERN MEXICO CONTINUES TO 
MAINTAIN A TIGHT GRADIENT ACROSS THE ISTHMUS OF TEHUANTEPEC. 
THIS IS SUPPORTING GALE FORCE WINDS OF 30-40 KT THROUGH THE GULF 
OF TEHUANTEPEC. ASCAT SCATTEROMETER PASS AT 0400 UTC SHOWED AREA 
OF 40 KT WINDS N OF 15N CLOSE TO 95W. VERY COLD TEMPS ACROSS 
MOST OF THE E AND CENTRAL U.S. WILL REINFORCE THE PRES GRADIENT 
IN SE MEXICO TO MAINTAIN THE GAP WIND EVENT THROUGH FRI MORNING 
WITH WINDS EXPECTED TO FLUCTUATE AT AND JUST BELOW MINIMAL GALE 
FORCE THROUGH THE UPCOMING WEEKEND. NE TO E SWELL ASSOCIATED 
WITH THIS EVENT COMBINED WITH A GALE WIND EVENT OVER THE GULF OF 
PAPAGAYO IS PRODUCING A VERY LARGE AREA OF SEAS 8 FT OR GREATER 
THAT EXTENDS SW TO BEYOND 110W. BY THU EVENING...8-11 FT SEAS 
WILL COVER MUCH OF THE AREA S OF 14N BETWEEN 92W AND 125W.

GULF OF PAPAGAYO GALE WARNING...THE STRONG PRESSURE GRADIENT IS 
COMBINING WITH STRONG TRADE WINDS IN THE WESTERN CARIBBEAN TO 
SUPPORT AN UNUSUALLY STRONG GAP WIND EVENT ACROSS THE GULF OF 
PAPAGAYO...WITH WINDS 30-35 KT EXTENDING SW AND DOWNWIND TO 92W. 
WINDS ARE EXPECTED TO DIMINISH TO 25-30 KT THIS AFTERNOON...AND 
THEN PULSE AGAIN TO NEAR GALE FORCE EACH NIGHT THROUGH SAT AS 
HIGH PRESSURE N OF THE AREA WEAKENS SLIGHTLY. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
             
THE MONSOON TROUGH EXTENDS FROM 04N77W TO 03N85W. ITCZ EXTENDS 
FROM 03N85W TO 05N104W TO 05N116W TO 08N123W TO 08N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 75 NM N 
OF THE AXIS BETWEEN 105W AND 112W...AND WITHIN 60 NM EITHER 
SIDE OF THE AXIS BETWEEN 118W AND 126W. 
 
...DISCUSSION...                                                 

HIGH PRESSURE OVER THE WESTERN U.S. EXTENDS A RIDGE SW OVER NE 
WATERS TO NEAR 18N132W. A COLD FRONT OVER NW WATERS EXTENDS FROM 
30N131W TO 18N140W...WITH SCATTERED MODERATE CONVECTION WITHIN 
60 NM E OF THE FRONT. THE PRES GRADIENT BETWEEN THESE FEATURES 
IS SUPPORTING 20-25 KT S WINDS AHEAD OF THE FRONT. ALSO...THE 
PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER PRESSURE ALONG THE 
ITCZ IS MAINTAINING LARGE AREA OF FRESH TO LOCALLY STRONG WINDS 
N OF THE ITCZ W OF 110W. TRADE WIND CONVERGENCE IS PRODUCING 
MODERATE TO ISOLATED STRONG CONVECTION AS MENTIONED ABOVE. THE 
COLD FRONT WILL SHIFT EASTWARD AND GRADUALLY WEAKEN THROUGH 
SAT...WITH WINDS DIMINISHING BELOW 20 KT TODAY. LONG PERIOD NW 
SWELL ASSOCIATED WITH THE FRONT WILL PROPAGATE E-SE WITH MAX 
SEAS TO 14-15 FT AT PRESENT SUBSIDING TO 11-12 FT.

FRESH TO LOCALLY STRONG N WINDS ARE FUNNELING INTO THE GULF OF 
PANAMA FROM THE CARIBBEAN. WINDS WILL PULSE TO 25 KT DURING LATE 
NIGHT AND EARLY MORNING HOURS TONIGHT AND THU NIGHT AND DIMINISH 
TO 20 KT OR LESS DURING THE AFTERNOON AND EARLY EVENING HOURS. 

$$ 
MUNDELL