000
AXPZ20 KNHC 082202
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE FEB 08 2011

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2045 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED ALONG AN AXIS 
FROM 07N78W TO 04N95W TO 08N120W TO 05N130W TO 05N140W. 
SCATTERED MODERATE FROM 09N TO 12N BETWEEN 115W AND 118W.

...DISCUSSION...
W OF 110W...A REX BLOCK PATTERN REMAINS ENTRENCHED AT THE MID 
AND UPPER LEVELS ACROSS THE AREA WITH AN UPPER RIDGE ANCHORED N 
OF THE AREA NEAR 35N129W AND TO THE N OF AN UPPER LOW COMPLEX 
GENERALLY CENTERED NEAR 23N132W...KEEPING A FRONTAL BOUNDARY 
STALLED WELL NW OF THE AREA OVER THE N CENTRAL PACIFIC. THIS 
PATTERN IS EXPECTED TO BREAK DOWN BY EARLY THU...AS THE UPPER 
RIDGE REORGANIZES TO THE WEST AND UPPER LOW COMPLEX OPENS UP 
INTO A TROUGH FROM CENTRAL CALIFORNIA TO 18N140W. A 1040 MB HIGH 
PRES ASSOCIATED WITH THE UPPER RIDGE IS CENTERED WELL N OF THE 
AREA NEAR 44N135W. 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 DISPLACED 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 FORECAST ISSUES REMAIN GAP WINDS IN THE 
GULFS OF TEHUANTEPEC AND PAPAGAYO. LAND-BASED OBSERVATIONS NEAR 
THE ISTHMUS OF TEHUANTEPEC STILL INDICATE WINDS OF GALE FORCE 
ARE STILL OCCURRING IN THE AREA. 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 THIS EVENING...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 30 
KT IN THE NORTHERN GULF WED MORNING BEFORE DIMINISHING TO 20 TO 
25 KT OVER THE NORTHERN AND CENTRAL GULF OF CALIFORNIA EARLY THU 
MORNING.

$$
COBB