000
AXPZ20 KNHC 232130
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT FEB 23 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

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

THE MONSOON TROUGH IS ALONG 04N77W TO 08N87W TO 06N92W. THE 
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N92W TO 
04N100W TO 07N126W THEN RESUMES FROM 06N129W TO 05N140W. 
SCATTERED MODERATE CONVECTION IS FROM 08N TO 13N BETWEEN 130W 
AND 135W. ADDITIONAL SCATTERED MODERATE CONVECTION IS WITHIN 240 
NM N OF A LINE FROM 17N123W TO 12N140W.

...DISCUSSION...

1039 MB SURFACE HIGH PRES IS POSITIONED NW OF THE DISCUSSION 
WATERS NEAR 37N139W. A RIDGE EXTENDS SE FROM THE HIGH THROUGH 
32N134W TO 22N115W TO 13N98W. A TIGHT PRES GRADIENT IS SW OF THE 
RIDGE AND N OF THE ITCZ RESULTING IN FRESH TO STRONG NE TO E 
TRADES N OF 15N W OF 130W...AND ALSO FROM 09N TO 15N W OF 120W. 
SEAS OF 8 TO 11 FT IN MIXED NE AND NW SWELL ARE COINCIDENT WITH 
THESE WINDS. A SURROUNDING AREA OF 8 TO 10 FT PRIMARILY NW SWELL 
COVERS THE MAJORITY OF THE REMAINDER OF THE NW HALF OF THE 
WATERS. THE HIGH AND RIDGE WILL WEAKEN SLIGHTLY WHILE DRIFTING E 
DURING THE NEXT 24 TO 48 HOURS...ALLOWING FOR THE AREA OF TRADES 
TO SHRINK FROM 09N TO 17N W OF 128W BY MON AFTERNOON.

A DISSIPATING COLD FRONT STRETCHES FROM SOUTHERN CALIFORNIA NEAR 
THE CHANNEL ISLANDS THROUGH 32N126W BACK TO THE W TO NW TO 
35N133W. GALE FORCE WINDS ARE N OF THIS FRONT AND THESE WINDS 
ARE GENERATING SEAS OF UP TO 16 TO 18 FT N OF 32N. THESE SEAS 
WILL SPREAD INTO THE N CENTRAL WATERS AS NW SWELL EARLY SUN 
ALONG WITH FRESH TO STRONG NORTHERLY WINDS BEHIND THE DECAYING 
FRONTAL BOUNDARY. THE SWELL WILL SUBSIDE TO 9 TO 11 FT OVER THE 
N CENTRAL WATERS BY MON AFTERNOON.

A WEAK SURFACE TROUGH IS EMBEDDED IN THE ITCZ EXTENDING FROM 
10N125W TO 05N125W. ONLY ISOLATED CONVECTION IS PRESENT NEAR THE 
NORTHERN TIP OF THE TROUGH WITH STRONG UPPER LEVEL WESTERLY 
WINDS PRESENT. THE TROUGH IS FORECAST TO MOVE WESTWARD... 
APPROACHING 140W BY MON.

HIGH PRES WILL DEVELOP OVER THE U.S. GREAT BASIN REGION BY EARLY 
SUN. THIS HIGH COMBINED WITH ELONGATED TROUGHING ALONG THE 
WESTERN COAST OF MEXICO/EAST GULF OF CALIFORNIA WILL RESULT IN A 
TIGHT PRES GRADIENT OVER THE NW MEXICO REGION SUPPORTING FRESH 
TO NEAR GALE FORCE NORTHERLY WINDS. THESE WINDS WILL COMMENCE IN 
THE NORTHERN GULF OF CALIFORNIA SUN MORNING... SPREADING 
SOUTHWARD ACROSS THE ENTIRE GULF BY LATE SUN NIGHT...THEN 
DIMINISHING EARLY NEXT WEEK. EXPECT SEAS TO BUILD TO UP 10 FT AT 
THE TAIL END OF THE FETCH REGION.

GAP WINDS...                                                
MODEL GUIDANCE NOW ONLY FORECASTS MAINLY FRESH WINDS AT MOST IN 
THE GULF OF PAPAGAYO TONIGHT THROUGH THE NEXT 48 HOURS. THE 
OTHER GAPS AND CORRESPONDING GULFS WILL REMAIN BELOW ADVISORY 
CRITERIA THROUGH EARLY NEXT WEEK.

$$
LEWITSKY