000
AXPZ20 KNHC 310357
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC WED DEC 31 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
WWWW UTC. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM 8N78W TO 6N85W WHERE THE ITCZ 
BEGINS AND CONTINUES ALONG 5N92W 5N112W 6N132W TO 7N140W. 
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF ITCZ BETWEEN 
92W AND 95W. 

...DISCUSSION...                                                 
A NARROW NEGATIVELY TILTED MID TO UPPER LEVEL TROUGH PERSISTS 
FROM THE N CENTRAL PACIFIC N OF HAWAII SOUTHEASTWARD THROUGH A 
CLOSED UPPER LOW NEAR 27N132W TO 20N127W. AN ASSOCIATED 1014 MB 
SURFACE LOW IS CENTERED NEAR 25N137W WITH A SURFACE TROUGH 
EXTENDING ALONG 20N133W THEN W TO 15N140W. FRESH TO STRONG SE TO 
E FLOW IS NE OF THE LOW...BETWEEN THE LOW CENTER AND AN 
ELONGATED SURFACE RIDGE AXIS WHICH IS PARALLELING THE U.S. WEST 
COAST AND THE COAST OF BAJA CALIFORNIA. INSTABILITY BETWEEN THE 
UPPER TROUGH AND AN UPPER RIDGE TO THE E IS SUSTAINING AN AREA 
OF SHOWERS E OF THE SURFACE TROUGH. 

THIS UPPER TROUGH WILL WEAKEN AS IT SHIFTS EASTWARD OVER THE 
NEXT COUPLE OF DAYS TOWARD THE BAJA CALIFORNIA PENINSULA... 
EVENTUALLY COMING INTO PHASE WITH ANOTHER MID/UPPER IMPULSE 
MOVING SOUTHWARD DOWN THE WESTERN UNITED STATES. THE LOW PRES 
WILL OPEN INTO A TROUGH AND BECOME DIFFUSE LATE TONIGHT/EARLY 
WED...WITH WINDS MIGRATING NW. 

GULF OF CALIFORNIA...A COLD FRONT ASSOCIATED WITH THE MID/UPPER 
TROUGH MOVING SOUTHWARD ACROSS THE WESTERN UNITED STATES WILL 
MOVE INTO BAJA CALIFORNIA NORTE AND THE NORTHERN GULF OF 
CALIFORNIA OVERNIGHT...THEN BECOME DIFFUSE AS IT SHIFTS FURTHER 
SOUTHWARD DOWN THE PENINSULA. THERE MAY BE A BRIEF PERIOD OF 
FRESH TO STRONG SW WINDS OVER THE NORTHERN GULF OF CALIFORNIA 
TONIGHT...CONNECTED TO WEAK AND TRANSIENT LOW MOVING S OVER S 
CALIFORNIA TONIGHT. LOOKING AHEAD...HIGH PRES BUILDING OVER THE 
GREAT BASIN WILL SUPPORT DEVELOPMENT OF FRESH NW FLOW DOWN THE 
LENGTH OF THE GULF OF CALIFORNIA BY LATE THU/EARLY FRI.

SHORTER PERIOD NORTHERLY SWELL GENERATED BY STRONG NORTHERLY 
WINDS OFF THE COAST OF CALIFORNIA WITH COMBINED SEAS TO 8 FT 
WILL PROPAGATE SOUTH OF 30N WED...IMPACTING THE AREA N OF 29N 
BETWEEN 118W AND 126W BEFORE SUBSIDING BELOW 8 FT BY EARLY THU.

GAP WINDS...STRONG HIGH PRES OVER THE NORTHERN PLAINS WILL MOVE 
SOUTHWARD ALONG THE FRONT RANGE OF THE ROCKIES INTO THE SOUTHERN 
PLAINS THROUGH LATE WED. ALTHOUGH WELL REMOVED FROM THE EASTERN 
PACIFIC...THE STRENGTH OF THE HIGH PRES WILL INITIATE CONDITIONS 
FAVORABLE FOR STRONG GAP WINDS THROUGH THE GULFS OF TEHUANTEPEC 
AND PAPAGAYO STARTING TONIGHT.

FOR THE GULF OF TEHUANTEPEC...WINDS WILL REACH AT LEAST 30 KT 
OVERNIGHT WITH SEAS BUILDING AS HIGH AS 10 FT. THE HIGH PRES 
SHIFTS FARTHER SOUTH THROUGH LATE WED...ALLOWING GAP WINDS TO 
GALE FORCE THROUGH EARLY THU AND SEAS TO 12 FT. WINDS WEAKEN TO 
BELOW GALE FORCE AND SEAS DIMINISH 9 FT LATE THU AS THE HIGH 
PRES WEAKENS AND SHIFTS EAST.

GULF OF PAPAGAYO...GAP WINDS WILL PULSE TO 30 KT OVER THE NEXT 
COUPLE OF NIGHTS WITH SEAS BUILDING AS HIGH AS 9 TO 10 FT...WITH 
FURTHER EVENTS TO 25 KT INTO THE WEEKEND.

$$
PAW