000
AXPZ20 KNHC 280915
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1005 UTC SAT DEC 28 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

THE MONSOON TROUGH EXTENDS FROM 06N77W TO 03N80W TO 
03N84W...WHERE IT TRANSITIONS TO AN ITCZ EXTENDING TO 09N120W TO 
BEYOND 08N140W. SCATTERED MODERATE CONVECTION NOTED 90 NM N OF 
AXIS BETWEEN 105W AND 113W...AND WITHIN 60 NM N OF AXIS BETWEEN 
130W AND 133W.

...DISCUSSION... 

E OF 110W... 
A CUT OFF MID/UPPER LEVEL LOW REMAINS CENTERED OVER 
W TEXAS/SE NEW MEXICO WITH A TROUGH EXTENDING SW THROUGH 
SOUTHERN BAJA...SUPPORTING CLUSTER OF SHOWERS AND THUNDERSTORMS 
OFF THE COAST OF W CENTRAL MEXICO. 

GULF OF TEHUANTEPEC...THE UPPER PATTERN IS SUPPORTING WEAK 1016 
MB SURFACE LOW PRES OVER THE SW GULF OF MEXICO. A TIGHT PRES 
GRADIENT REMAINS IN PLACE BETWEEN THE LOW PRES AND 1028 MB HIGH 
PRES OVER S CENTRAL TEXAS/NE MEXICO...RESULTING IN GALE FORCE 
WINDS ALONG THE FAR SW GULF OF MEXICO...THEN FUNNELING INTO THE 
GULF OF TEHUANTEPEC AT NEAR GALE FORCE. THE PATTERN WILL CHANGE 
STARTING THIS MORNING AS THE CLOSED MID/UPPER LOW PRES OPENS UP 
AND LIFTS NE AHEAD OF A SHARP TROUGH DIGGING EASTWARD ACROSS THE 
ROCKIES. THE SURFACE LOW OVER THE SW GULF WILL LIFT NE AS 
WELL...ALLOWING FOR WINDS OVER THE GULF OF TEHUANTEPEC TO 
DIMINISH. LOOKING AHEAD...WINDS A STRONG COLD FRONT ASSOCIATED 
WITH THE TROUGH DIGGING THROUGH THE ROCKIES WILL PUSH THROUGH 
THE WESTERN GULF OF MEXICO...FOLLOWED BY GALE FORCE WINDS INTO 
THE GULF OF TEHUANTEPEC BY TUE MORNING WITH SUBSEQUENT PULSES TO 
GALE FORCE LASTING INTO EARLY WED.

GULF OF PAPAGAYO...AN ASCAT PASS FROM 0338 UTC INDICATED WINDS 
AROUND 20 KT IN THE GULF OF PAPAGAYO. A CONCURRENT ALTIMETER 
PASS SHOWED MAXIMUM SEAS TO 7 FT. THESE WINDS ARE IN PART DUE TO 
STRONG TRADE WINDS OVER THE SW CARIBBEAN...AND WILL DIMINISH 
THROUGH MON AS THE TRADES RELAX SLIGHTLY...RESURGING BY TUE 
MORNING.

GULF OF PANAMA...EARLIER OSCAT DATA AND SHIP OBSERVATIONS 
INDICATED FRESH NORTHERLY FLOW ACROSS THE ISTHMUS INTO THE GULF 
OF PANAMA PUSHING THE MONSOON TROUGH WELL TO THE SOUTH. THESE 
WINDS WILL DIMINISH THROUGH TONIGHT.

GULF OF CALIFORNIA...HIGH PRES OVER THE GREAT BASIN HAS 
DISSIPATED AS THE STRONG TROUGH MOVES ACROSS THE 
ROCKIES...ALLOWING WINDS TO DIMINISH OVER THE GULF OF CALIFORNIA 
SINCE YESTERDAY. WINDS WILL PULSE TO 20 KT PERIODICALLY OVER THE 
NEXT SEVERAL DAYS AS HIGH PRES BUILDS AND WEAKENS N OF THE AREA 
IN RESPONSE TO SERIES OF WEAK UPPER TROUGHS IN THE NW FLOW ALOFT.

W OF 110W...A SHARP NEGATIVELY TILTED UPPER TROUGH REMAINS IN 
PLACE FROM 25N145W TO 17N137W. THIS IS SUPPORTING SHOWERS AND A 
FEW THUNDERSTORMS N OF THE ITCZ TO 20N W OF 130W. THE UPPER 
TROUGH HAD BEEN SUPPORTING A WEAK SURFACE TROUGH ALONG THE 
ITCZ...WHICH IN TURN WAS MAINTAINING FRESH TRADE WIND FLOW FROM 
15N TO 20N W OF 135W. THERE SEEMS TO BE SCANT EVIDENCE RECENTLY 
OF THIS SURFACE TROUGH...AND A RECENT SHIP OBSERVATION SHOWS 
WINDS HAVE DIMINISHED. GLOBAL MODELS ARE GOOD AGREEMENT SHOWING 
THE UPPER TROUGH WEAKENING AND LIFTING NE OVER THE NEXT COUPLE 
OF DAYS WITH LIMITED IMPACT AT THE SURFACE.

NW SWELL WITH HEIGHTS TO 8 FT PERSIST N OF 07N W OF 130W THIS 
MORNING. MWW3 AND ECWAVE GUIDANCE INDICATE THE SWELL WILL 
GRADUALLY SUBSIDE BELOW 8 FT THROUGH EARLY SUN...FOLLOWED BY 
ANOTHER PUSH OF NW SWELL IN EXCESS OF 8 FT N OF 18N W OF 130W 
LATE SUN THROUGH MON.
 
$$
CHRISTENSEN