000
AXPZ20 KNHC 070938
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON FEB 07 2011

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0715 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED ALONG AN AXIS 
FROM 00N81W TO 03N91W TO 07N140W TO 07N118W TO 02N140W. 
SCATTERED MODERATE CONVECTION LIES WITHIN 45 NM EITHER SIDE OF 
THE ITCZ AXIS BETWEEN 105W AND 107W...WITHIN 150 NM N OF THE 
ITCZ AXIS BETWEEN 115W AND 117W...AND WITHIN 60 NM EITHER SIDE 
OF THE ITCZ AXIS BETWEEN 120W AND 122W.

...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 
37N138W AND TO THE N OF AN UPPER LOW COMPLEX GENERALLY CENTERED 
NEAR 18N137W. THIS OVERALL PATTERN WILL CONTINUE TO BLOCK THE 
EASTWARD ADVANCE OF FRONTAL FEATURES OVER THE N CENTRAL PACIFIC 
FOR THE NEXT FEW DAYS. AT THE SURFACE...HIGH PRES HAS 
REORGANIZED WELL N OF THE FORECAST AREA. A 1039 MB HIGH PRES 
CENTER NOW LIES NEAR 45N138W. THIS HIGH WILL MIGRATE EVEN 
FURTHER NORTH TODAY BEFORE WEAKENING SLIGHTLY AND RETURNING TO 
JUST E OF ITS CURRENT POSITION IN ABOUT 48 HOURS. FRESH TRADE 
WIND FLOW GENERALLY FOUND FROM 08N TO 22N W OF 120W WILL 
DIMINISH THROUGH 48 HOURS AS A RESULT. NE WINDS BETWEEN THE HIGH 
PRES TO THE NORTH AND TROUGHING ALONG THE CALIFORNIA COAST AS 
WELL AS NEAR A SURFACE TROUGH FROM 30N122W TO 26N123W ARE 
REACHING TO THE AREA N OF 27N W OF 125W. THE TROUGH OVER THE 
FORECAST AREA IS EXPECTED TO SHIFT WEST-SOUTHWESTWARD BEFORE 
DISSIPATING TUE MORNING ALONG 130W N OF 20N. FRESH NE SWELL 
GENERATED BY THIS FLOW WILL PROPAGATE SW...MIXING WITH LONG 
PERIOD NW SWELL OVER NW WATERS THROUGH TUE. THIS SWELL TRAIN 
WILL MOVE INTO THE REGION OF NE SWELL IN THE AREA OF FRESH 
TRADES AND WILL YIELD SEAS OF 8 TO 10 FT OVER MOST OF THE AREA W 
OF 130W THROUGH TUE MORNING. 

E OF 110W...THE 2326Z WINDSAT PASS SHOWS A SMALL AREA OF 20 KT 
WINDS DOWNSTREAM OF THE GULF OF PAPAGAYO. THE FORECAST CONTINUES 
TO CALL FOR THESE WINDS TO PULSE TO 20 KT MAINLY DURING 
OVERNIGHT AND EARLY MORNING HOURS AT THE TIME OF PEAK DRAINAGE 
FLOW. NORTHERLY WINDS TO 20 KT IN THE GULF OF PANAMA N OF 07N 
WERE CONFIRMED BY THE 0224Z ASCAT PASS BUT ARE FORECAST TO DROP 
BELOW 20 KT LATER THIS MORNING AS FLOW OVER THE SW CARIBBEAN 
VEERS MORE TO THE NE TO E. 

THE MAIN FORECAST ISSUE BY MON EVENING WILL BE THE ONSET OF GALE 
FORCE WINDS THROUGH THE GULF OF TEHUANTEPEC AS DENSER COLD AND 
DRY AIR PUSHES S OVER THE WESTERN GULF OF MEXICO AND INTO THE 
CHIVELA PASS. NUMERICAL MODELS CONTINUE TO HINT AT STORM FORCE 
WINDS FOR A BRIEF PERIOD OVERNIGHT MON NIGHT WITH 50 KT WINDS 
AND SEAS TO 16 FT EXPECTED. WINDS WILL QUICKLY DROP BELOW GALE 
FORCE TUE AFTERNOON AS THE PROGRESSIVE FRONT QUICKLY MOVES E OF 
THE AREA. THE SAME COLD FRONT THAT IS EXPECTED TO BRING STORM 
CONDITIONS TO THE GULF OF TEHUANTEPEC IS CURRENTLY GENERATING NW 
TO N WINDS TO 20 KT IN THE CENTRAL GULF OF CALIFORNIA. LOOK FOR 
THESE WINDS TO DIP BELOW 20 KT OVERNIGHT MON NIGHT. A SECOND 
COLD FRONT WILL APPROACH THE NORTHERN GULF OF CALIFORNIA LATE 
TUE NIGHT AND INCREASE WINDS TO 20 KT IN THE NORTHERN GULF BY 
EARLY WED MORNING.

$$
SCHAUER/COBB