000
AXPZ20 KNHC 040829
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1005 UTC SAT JAN 04 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURE...                                         
GULF OF TEHUANTEPEC GALE WARNING...COOL DENSE AIR CONTINUES TO 
FUNNEL THROUGH THE CHIVELA PASS FROM THE GULF OF MEXICO AND INTO 
THE GULF OF TEHUANTEPEC. ALTHOUGH THERE HAVE BEEN NO RECENT SHIP 
OBSERVATIONS OR SCATTEROMETER PASSES OVER THE AREA...A 10 MB IN 
MSLP DIFFERENCE ACROSS THE TEHUANTEPEC ISTHMUS IS NOTED IN 
RECENT OBSERVATIONS. ALONG WITH THE COOLER AIR TO THE 
NORTH...GALE FORCE WINDS ARE LIKELY CONTINUING ACROSS THE GULF 
OF TEHUANTEPEC THIS MORNING. WINDS WILL GRADUALLY DIMINISH TO 
BELOW GALE FORCE LATER TODAY AS THE COLD AIR ADVECTION AND 
PRESSURE GRADIENT ACROSS SOUTHERN MEXICO WEAKENS. LOOKING 
AHEAD...ANOTHER SIMILAR STRONG GALE WIND EVENT WITH PEAK WINDS 
TO 45-50 KT IS EXPECTED TO BEGIN MON MORNING.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              
MONSOON TROUGH EXTENDS FROM 07N78W TO 08N84W TO 06N90W...THEN 
ITCZ AXIS TO 08N120W TO 08N140W. SCATTERED MODERATE CONVECTION 
IS NOTED WITHIN 120 NM N OF ITCZ AXIS BETWEEN 120W AND 125W. 

...DISCUSSION...                                               

THE LARGE SCALE UPPER PATTERN REMAINS FAIRLY AMPLIFIED WITH THE 
AXIS OF A PROGRESSIVE BROAD UPPER RIDGE SHIFT EAST THROUGH 115W 
AHEAD OF A STILL FAIRLY SHARP BUT WEAKENING UPPER TROUGH MOVING 
THROUGH 130W. UPPER DIVERGENCE BETWEEN THESE FEATURES IS 
SUPPORTING SCATTERED SHOWERS N OF THE ITCZ BETWEEN 120 AND 125W. 

A NEGATIVELY TILTED UPPER TROUGH NE OF HAWAII IS MOVING INTO 
TOWARD THE DISCUSSION AREA. AN ASSOCIATED COLD FRONT WILL MOVE 
INTO THE AREA TONIGHT AND START TO STALL FROM 30N135W TO 22N145W 
MON INTO TUE AS THE UPPER SUPPORT LIFTS OUT TO THE NE. STRONG 
SOUTHERLY WINDS WITHIN 90 NM AHEAD OF THE FRONT N OF 28N TONIGHT 
AND SUNDAY. THE WINDS DIMINISH SUNDAY INTO MONDAY AS THE FRONT 
WEAKENS...BUT ASSOCIATED NW SWELL IN EXCESS OF 8 FT WILL COVER 
MOST OF THE AREA N OF 13N W OF 135W BY MONDAY...BEFORE DECAYING 
BELOW 8 FT THROUGH TUESDAY.
 
AN ASCAT PASS FROM 04 UTC ALONG WITH A CONCURRENT OBSERVATION 
FROM RESEARCH VESSEL KAQP NEAR 10N104W INDICATED AN AREA OF 
WINDS TO 25 KT IN THE DOWNWIND PLUME FROM THE TEHUANTEPEC GAP 
EVENT. WHILE THESE WINDS ARE LIKELY TO TAPER OFF TO 20 KT OR 
LESS OVER THE NEXT SEVERAL HOURS...THE PLUME OF SHORT PERIOD N 
TO NE SWELL IN EXCESS OF 8 FT GENERATED BY THE GAP EVENT WILL 
PERSIST OVER MUCH OF THE AREA FROM 02N TO 13N BETWEEN 93W AND 
100W THROUGH TONIGHT. THIS AREA OF SWELL WILL SHRINK 
CONSIDERABLY THROUGH SUNDAY AS THE SWELL DECAYS BELOW 8 FT AND 
SHIFTS W OF 100W.

GULF OF PAPAGAYO...WINDS TO AT LEAST 20 KT WERE NOTED PULSING 
THROUGH THE GULF OF PAPAGAYO IN A 03 UTC ASCAT PASS. THIS IS THE 
RESULT OF STRONG TRADE WIND FLOW OVER THE SW CARIBBEAN AND LOCAL 
DRAINAGE EFFECTS THAT WILL INTENSIFY IN THE EARLY MORNING HOURS. 
WAVE MODEL GUIDANCE IS INDICATING THAT SUCCESSIVE PULSES OF 
STRONG WINDS THROUGH PAPAGAYO WILL ALLOW SEAS TO BUILD TO 8 FT 
DOWNSTREAM LATER TODAY...EVENTUALLY MERGING WITH THE N TO NE 
SWELL FROM TEHUANTEPEC. ANOTHER PULSE OF 20 TO 25 KT WINDS IS 
POSSIBLE LATE TONIGHT AND EARLY SUNDAY THROUGH PAPAGAYO.

GULF OF CALIFORNIA...HIGH PRES IS EXPECTED TO BUILD N OF THE 
AREA OVER THE GREAT BASIN THROUGH SUNDAY...ALLOWING STRONG NW TO 
N FLOW ACROSS THE NORTHERN GULF OF CALIFORNIA BY SUNDAY NIGHT 
INTO MONDAY. LOOKING AHEAD...THE RIDGE BREAKS DOWN AND SHIFTS 
EAST MONDAY INTO TUESDAY AHEAD OF A TROUGH DIGGING INTO THE NW 
STATES...ALLOWING WINDS IN THE GULF OF CALIFORNIA TO DIMINISH 
MONDAY INTO TUESDAY ACCORDINGLY.

$$
CHRISTENSEN