000
AXPZ20 KNHC 200921
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1005 UTC THU FEB 20 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.                              

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

THE MONSOON TROUGH EXTENDS FROM 09N84W TO 06N90W TO 04N105W. THE 
ITCZ CONTINUES FROM 04N105W TO BEYOND 06N140W. SCATTERED 
MODERATE CONVECTION IS NOTED WITHIN 240 NM N OF ITCZ AXIS 
BETWEEN 110W AND 128W.

...DISCUSSION...

THE MAIN FORECAST ISSUE FOR THE UPCOMING COUPLE OF DAYS WILL BE 
THE ONSET OF STRONG GAP FLOW THROUGH THE GULF OF TEHUANTEPEC 
LATE FRI NIGHT INTO EARLY SAT MORNING. A WEAK COLD FRONT WILL 
PUSH INTO THE GULF OF MEXICO AND STALL FROM THE NE GULF TO THE 
SW GULF...WITH STRONG WINDS FUNNELING SOUTHWARD ALONG THE COAST 
OF MEXICO. THESE WINDS WILL PUNCH THROUGH THE ISTHMUS OF 
TEHUANTEPEC INTO THE GULF OF TEHUANTEPEC LATE FRI EVENING. 
BECAUSE THE FRONT WILL STALL WITH THE HIGH PRES BEHIND THE FRONT 
SHIFTING EASTWARD RAPIDLY...THIS DOES NOT APPEAR TO BE VERY 
CONDUCIVE FOR A GALE EVENT. WINDS MAY BRIEFLY REACH 30 KT FRI 
NIGHT AND SAT MORNING BEFORE DIMINISHING QUICKLY THROUGH SAT. 
SEAS WILL BUILD AS HIGH AS 11 FT THROUGH EARLY SAT...THEN 
SUBSIDE BELOW 8 FT LATER IN THE DAY. OTHERWISE LIGHT TO MODERATE 
WINDS WILL PREVAIL IN THE TEHUANTEPEC AREA FROM NOW UNTIL LATE 
FRI.

FARTHER SOUTH...GAP WINDS OF 20 TO 25 KT WILL PULSE THROUGH BOTH 
THE GULF OF PAPAGAYO AND GULF OF PANAMA LATER THIS MORNING. 
STRONG EASTERLY TRADE WINDS IN THE SW CARIBBEAN WILL ALLOW A 
REPEAT OF THE STRONG GAP WINDS IN PAPAGAYO TONIGHT AND FRI NIGHT 
AS WELL.

AN UPPER LOW CENTERED NEAR 12N122W IS EXPECTED TO WEAKEN AND 
OPEN INTO A TROUGH AS IT DRIFTS EASTWARD THROUGH SAT. WEAK UPPER 
FORCING ALONG WITH LOW LEVEL TRADE WIND CONVERGENCE IS 
SUPPORTING AREAS OF SHOWERS OVER A LARGE AREA NORTH OF THE ITCZ 
BETWEEN 110W AND 125W...WITH A FEW THUNDERSTORMS POSSIBLE WITHIN 
60 NM N OF THE ITCZ BETWEEN 125W AND 128W. GLOBAL MODELS ARE IN 
DECENT AGREEMENT SHOWING A WEAK SURFACE LOW FORMING ALONG THE 
ITCZ NEAR 110W ASSOCIATED WITH THE UPPER FEATURE BY LATE 
FRI...THEN WEAKENING THROUGH SAT AS THE UPPER TROUGH DRIFTS 
EAST. GFS/WAVEWATCH GUIDANCE INDICATE AN AREA OF 20 KT WINDS 
WITH SEAS TO 8 FT ARE POSSIBLE ON THE NORTH SIDE OF THIS 
LOW LATE FRI...DIMINISHING THROUGH SAT AS THE SURFACE LOW FILLS.

A DEEP LAYER RIDGE IS BUILDING OVER THE WATERS WEST OF THE UPPER 
LOW...SUPPORTING A 1028 MB SURFACE HIGH CENTERED NEAR 
37N130W...WITH A SURFACE RIDGE EXTENDING SOUTHEASTWARD TO THE 
TIP OF THE BAJA PENINSULA. MODERATE TO FRESH TRADE WINDS ARE  
NOTED IN SCATTEROMETER DATA AND TOGA-TAO BUOY OBSERVATIONS 
ACROSS THE TROPICAL WATERS FROM THE ITCZ TO 20N W OF 120W. 
STRONG NORTHERLY WINDS PERSIST OFF THE COAST OF CALIFORNIA NORTH 
OF 32N...AS NOTED BY R/V MELVILLE ON STATION NEAR 32N122W. THIS 
HAS GENERATED A LARGE AREA OF NW TO N SWELL WITH HEIGHTS 8 TO 10 
FT OVER THE WATERS N OF 20N WEST OF 115W. THE LONGER PERIOD NW 
SWELL IS ALSO MIXING WITH FRESH TRADE WIND SWELL OVER THE WATERS 
FROM 10N TO 20N W OF 125W. A PAIR OF ALTIMETER PASSES OVER THE 
PAST SEVERAL HOURS DEPICT THESE AREAS OF HIGHER SEAS WELL. 
WAVEWATCH AND ECWAVE GLOBAL WAVE MODELS INDICATED THIS SWELL 
WILL PERSIST THROUGH FRI THEN GRADUALLY DECAY BELOW 8 FT THROUGH 
SAT. 

$$
CHRISTENSEN