000
AXPZ20 KNHC 081519
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE FEB 08 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED ALONG AN AXIS 
FROM 06N77W TO 04N95W TO 08N120W TO 05N130W TO 05N140W. 
SCATTERED MODERATE CONVECTION FROM 08N TO 11N BETWEEN 115W AND 
125W.

...DISCUSSION...
W OF 110W...A REX BLOCK PATTERN REMAINS IN PLACE ACROSS THE 
UPPER LEVELS WITH AN UPPER RIDGE ANCHORED N OF THE AREA NEAR 
35N128W AND TO THE N OF AN UPPER LOW COMPLEX GENERALLY CENTERED 
NEAR 22N132W...KEEPING A FRONTAL BOUNDARY STALLED NW OF THE AREA 
OVER THE N CENTRAL PACIFIC. THIS PATTERN IS EXPECTED TO 
GRADUALLY BREAK DOWN THROUGH EARLY THU...AS THE UPPER RIDGE 
REORGANIZES TO THE WEST AND UPPER LOW COMPLEX OPENS UP INTO A 
TROUGH FROM CENTRAL CALIFORNIA TO 08N140W. A 1041 MB HIGH PRES 
ASSOCIATED WITH THE UPPER RIDGE IS CENTERED WELL N OF THE AREA 
NEAR 45N135W. A TIGHT PRESSURE GRADIENT BETWEEN THIS HIGH AND A 
TROUGH ALONG THE CALIFORNIA COAST IS RESULTING IN A PERSISTENT 
LONG FETCH OF 20 TO 25 KT NE WINDS FROM CENTRAL CALIFORNIA TO 
NEAR 25N140W...ACCOMPANIED BY FRESH NE SWELL. ASIDE FROM THESE 
WINDS...TRADES TO THE SOUTH REMAIN FAIRLY MODEST IN STRENGTH AND 
AREAL COVERAGE DUE TO THE SURFACE HIGH PRES POSITION WELL TO THE 
NORTH. SCATTERED MODERATE CONVECTION CONTINUES N OF THE 
ITCZ...AIDED BY WEAK TRADE WIND FLOW AT THE SURFACE AND DECENT 
DIVERGENT FLOW ALOFT ON THE SE SIDE OF THE UPPER LOW COMPLEX. 
MEANWHILE LONG PERIOD NW SWELL CONTINUES TO SHIFT SE THROUGH 
THE  AREA. 

E OF 110W...THE MAIN ISSUE REMAINS GAP WINDS IN THE GULFS OF 
TEHUANTEPEC AND PAPAGAYO. LAND-BASED OBSERVATIONS THROUGH THE 
ISTHMUS OF TEHUANTEPEC HINT THAT WINDS ARE LIKELY WELL BELOW 
STORM FORCE BY NOW...ALTHOUGH THERE IS NO RECENT DATA OVER WATER 
IN OR NEAR THE GULF OF TEHUANTEPEC. MODEL CONSENSUS SUGGESTS 
THIS AS WELL...SHOWING WINDS RAPIDLY DIMINISHING THROUGH THIS 
AFTERNOON AS THE COOLER DRIER AND DENSER AIR ASSOCIATED WITH THE 
HIGH PRES OVER THE SW GULF OF MEXICO MODIFIES AND SHIFTS E. 
WINDS WILL DIMINISH BELOW GALE FORCE BY THIS EVENING IF NOT 
SOONER...AND BE BELOW 20 KT OVERNIGHT. RESIDUAL NE SWELL OF 8 TO 
10 FT WILL PERSIST IN THE AREA ABOUT 300 NM SW OF TEHUANTEPEC 
THROUGH TUE. FURTHER SOUTH...FRESH TO STRONG GAP FLOW THROUGH 
PAPAGAYO WILL DIMINISH LATER TODAY. EXPECT THE WINDS TO PULSE 
AGAIN OVERNIGHT...BUT SHOULD BE MUCH WEAKER THAN CURRENTLY AS 
THE PRESSURE GRADIENT OVER THE SW CARIBBEAN REMAINS WEAK. 

GULF OF CALIFORNIA...A COLD FRONT WILL APPROACH THE NORTHERN 
GULF OF CALIFORNIA LATE TUE NIGHT AND INCREASE WINDS TO 20 TO 25 
KT IN THE NORTHERN GULF WED MORNING BEFORE DIMINISHING TO 20 KT 
OVER THE NORTHERN AND CENTRAL GULF OF CALIFORNIA EARLY THU 
MORNING.

$$
CHRISTENSEN