000
AXPZ20 KNHC 210341
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU FEB 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

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

THE MONSOON TROUGH IS ALONG 02N79W TO 02N84W. THE INTERTROPICAL 
CONVERGENCE ZONE AXIS EXTENDS FROM 02N84W TO 04N90W TO 02N100W 
TO 05N120W TO 07N140W. SCATTERED MODERATE CONVECTION IS FROM 03N 
TO 09N BETWEEN 130W AND 133W. SIMILAR CONVECTION IS FROM 08N TO 
10N BETWEEN 119W AND 123W.

...DISCUSSION...

A RATHER VIGOROUS UPPER LEVEL LOW ON THE THE SOUTHERN PORTION OF 
A LARGE UPPER TROUGH OVER THE WESTERN CONUS IS MOVING SE FROM 
SOUTHERN ARIZONA TO SOUTHERN NEW MEXICO. THIS FEATURE SUPPORTS A 
WEAKENING SURFACE COLD FRONT THAT EXTENDS FROM SOUTHERN NEW 
MEXICO TO ACROSS THE CENTRAL GULF OF CALIFORNIA WITH A TERMINUS 
OVER THE SOUTHERN BAJA CALIFORNIA PENINSULA NEAR 27N113W. THE 
WESTERN PORTION OF THE FRONT PREVIOUSLY EXTENDING W OF THE 
PENINSULA BUT IT HAS SINCE DISSIPATED DURING THE PAST 6 HOURS. 

RESIDUAL NW-N 20-30 KT WINDS ARE W OF THE NORTHERN BAJA 
CALIFORNIA WHERE THE PRES GRADIENT REMAINS PINCHED...ALTHOUGH 
THESE WINDS WILL DIMINISH TO 20 KT OR LESS BY FRI. LARGE NW 
SWELL OF 11-16 FT ARE ALSO PRESENT ACROSS THE SAME AREA. THESE 
SWELLS WILL DECAY TO 9-12 FT BY THU EVENING...AND TO 8-9 FT BY 
FRI EVENING. 

HIGHLY AMPLIFIED DEEP LEVEL RIDGING TO THE W OF THE LOW IS 
REFLECTED AS A NEARLY STATIONARY STRONG 1036 MB SURFACE HIGH 
CENTER NW OF THE AREA AT 36N147W WITH AN ASSOCIATED RIDGE 
STRETCHING SE THROUGH 32N137W TO 24N120W TO 12N95W. A VERY TIGHT 
PRES GRADIENT IS SW OF THE RIDGE WITH FRESH TO STRONG WINDS FROM 
09N TO 28N W OF 130W...AND FROM 12N TO 25N BETWEEN 120W AND 130W 
AS SUGGESTED BY EARLIER SCATTEROMETER PASSES. SEAS OF 9-13 FT 
ARE COINCIDENT WITH THESE WINDS WITH A SURROUNDING AREA OF 8-11 
FT NW SWELL. THESE FRESH TO STRONG WINDS WILL NOT VARY MUCH IN 
STRENGTH OR COVERAGE DURING THE NEXT 24-48 HOURS AS THE RIDGE 
HOLDS RELATIVELY IN PLACE.

FRESH TO STRONG SW TO W WINDS WILL PRECEDE THE FRONT OVER THE 
NORTHERN PORTION OF THE GULF OF CALIFORNIA FROM 27N TO 30.5N... 
HOWEVER THESE WINDS WILL DIMINISH TO 20 KT OR LESS BY LATE 
TONIGHT AS THE FRONT WEAKENS.
 
GAP WINDS...
FRESH TO STRONG WINDS WILL CONTINUE TO PULSE IN THE GULF OF 
PAPAGAYO...WITH THE STRONGEST WINDS OCCURRING DURING THE 
OVERNIGHT AND EARLY MORNING HOURS WITH ENHANCEMENT BY NOCTURNAL 
DRAINAGE FLOW. ASSOCIATED SIGNIFICANT WAVE HEIGHTS WILL PEAK TO 
AROUND 9 FT. THE AREAL COVERAGE OF THESE WINDS WILL SHRINK TO E 
OF 88W BY FRI AFTERNOON...AND LIKELY TO MODERATE TO FRESH LEVELS 
OVERALL THIS WEEKEND AS CONDITIONS BECOME LESS FAVORABLE.

$$
LEWITSKY