000
AXPZ20 KNHC 070406
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON FEB 07 2011

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED ALONG AN AXIS 
FROM 01N80W TO 05N100W TO LOW PRES NEAR 08N111W...05N125W TO 
03N140W. SCATTERED MODERATE CONVECTION WITHIN 60-90 NM OF THE 
AXIS BETWEEN 110W AND 118W. SCATTERED MODERATE WITHIN 75 NM OF 
12N105W.

...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 
37N131W...N OF AN UPPER LOW COMPLEX GENERALLY CENTERED NEAR 
17N133W. THIS OVERALL PATTERN WILL CONTINUE TO BLOCK THE 
EASTWARD ADVANCE OF FRONTAL FEATURES OVER THE N CENTRAL PACIFIC 
FOR AT LEAST THE NEXT 48 TO 72 HOURS. AT THE SURFACE A 1035 MB 
HIGH PRES AREA ASSOCIATED WITH THE UPPER RIDGE HAS SHIFTED NW 
AND MERGED WITH ANOTHER HIGH CENTER AND IS NOW CENTERED NEAR 
45N143W. THIS WILL ALLOW FRESH TRADE WIND FLOW FROM 09N 
TO 28N W OF 120W TO DIMINISH THROUGH 48 HOURS. NE WINDS BETWEEN 
THE HIGH PRES TO THE NORTH AND TROUGHING ALONG THE CALIFORNIA 
COAST ARE REACHING SW FROM CALIFORNIA TO THE AREA N OF 27N W OF 
125W. THIS FLOW IS ALSO BEING ENHANCED BY A WEAK 1016 MB SURFACE 
LOW SHIFTING S FROM THE SOUTHERN CALIFORNIA COAST. THIS LOW IS 
FORECAST TO OPEN INTO A TROUGH ALONG 125W FROM 22N TO 30N MON 
MORNING BEFORE DISSIPATING TUE. FRESH NE SWELL GENERATED BY THIS 
FLOW WILL PROPAGATE SW...MIXING WITH LONG PERIOD NW SWELL N OF 
25N W OF 130W THROUGH TUE. NE SWELL IN THE AREA OF FRESH TRADES 
IS CURRENTLY ESTIMATED TO AS HIGH AS 12 FT FROM 10N TO 25N W OF 
130W...BUT THIS WILL SUBSIDE AND SHIFT W OF 140W THROUGH TUE. 
MIXING WITH THIS...NW SWELL WITH SEAS TO 8 FT WILL COVER MOST OF 
THE AREA W OF 120W OVER THE NEXT 48 HOURS. 

E OF 110W...FRESH GAP WIND FLOW THROUGH THE GULF OF PAPAGAYO HAS 
DROPPED BELOW 20 KT THIS EVENING. THESE WINDS ARE FORECAST TO 
PULSE TO 20 KT MAINLY DURING OVERNIGHT AND EARLY MORNING HOURS
DURING PEAK DRAINAGE FLOW THROUGH THE PASSES. NORTHERLY WINDS 
THROUGH THE ISTHMUS OF PANAMA ARE FORECAST TO DROP BELOW 
20 KT EARLY MON AS FLOW OVER THE SW CARIBBEAN VEERS MORE TO THE 
NE TO E. 

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 HAVE TRENDED STRONGER THIS EVENING
WITH STORM FORCE WINDS NOW FORECAST FOR A BRIEF PERIOD OVERNIGHT 
MON NIGHT WITH 50 KT WINDS AND SEAS TO 16 FT EXPECTED. WINDS 
WILL DROP BELOW GALE FORCE LATE TUE. ELSEWHERE A 1011 MB SURFACE 
LOW ANALYZED NEAR 08N112W IS EXPECTED TO DISSIPATE IN THE NEXT 
12 TO 18 HOURS.

$$
COBB