000
AXPZ20 KNHC 072205
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI JAN 07 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 
2115 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS CENTERED FROM LOW PRES
NEAR 5N79W 1011 MB TO ANOTHER LOW NEAR 9N105W TO 6N113W TO 
7N128W TO 6N135W TO 8N140W. NO SIGNIFICANT CONVECTION IS NOTED.

...DISCUSSION...

AN ILL-DEFINED SURFACE TROUGH EXTENDS FROM 24N123W TO 19N127W. 
SATELLITE WATER VAPOR IMAGERY SHOWS A MID/UPPER LEVEL TROUGH
EXTENDING FROM AN UPPER LEVEL LOW MOVING INLAND SOUTHERN CALIFORNIA
SSW TO 21N124W. A SURFACE RIDGE EXTENDS FROM A 1026 MB HIGH 
CENTERED N OF THE AREA NEAR 38N130W SW TO JUST W OF THE AREA 
NEAR 20N142W...AND ANOTHER RIDGE SE TO 19N113W. TO THE NW OF 
THE AREA A 995 MB LOW IS CENTERED NEAR 36N150W WITH ITS ASSOCIATED
COLD FRONT EXTENDING SSE TO 29N142W AND THEN SW AS A STATIONARY
FRONT TO JUST PASSED THE HAWAIIAN ISLANDS. WINDS AHEAD OF THIS SYSTEM
ARE AFFECTING THE FAR WESTERN PORTION OF THE AREA NW OF A LINE FROM
23N140W TO 32N135W WHERE WINDS ARE 20-25 KT ARE NOTED. THESE WINDS
ARE EXPECTED TO CONTINUE THROUGH THE NEXT 48 HOURS WITH SEAS OF 
8 TO 11 FT IN LARGE NW SWELLS.

ELSEWHERE A RELATIVELY PRES GRADIENT EXISTS THROUGHOUT...WITH 
THE EXCEPTION OF THE CENTRAL PORTION OF THE REGION FROM 15N TO 
21N BETWEEN 110W AND 117W WHERE THE GRADIENT SUPPORTS N TO NE
WINDS OF 20 KT WITH SEAS THERE UP TO 8 FT. NE TO E WINDS OF
20 KT ARE ALSO OCCURRING WITHIN AN AREA BOUNDED BY 7N123W TO 
17N112W TO 20N116W TO 11N127W TO 7N123W.

SATELLITE IMAGERY SHOWS EXTENSIVE MID/UPPER LEVEL MOISTURE 
ADVECTING NORTHEASTWARD ACROSS THE TROUGH BETWEEN THE MID/UPPER 
TROUGH MENTIONED ABOVE AND AN UPPER LEVEL ANTICYLONE ANCHORED 
NEAR 13N105W. MODERATE SW FLOW ASSOCIATED WITH BROAD 
ANTICYCLONIC SE OF THE MID/UPPER LEVEL TROUGH IS PUSHING THIS 
MOISTURE NE TO WELL INLAND THE MEXICO AND THE SW U.S. POSSIBLE 
AREAS OF RAIN ALONG WITH EMBEDDED SCATTERED SHOWERS ARE WITHIN 
THE AREA OF CLOUDINESS.

DURING THE NEXT 24 HOURS...MODELS FORECAST SURFACE RIDGING TO 
BUILD OVER THE EASTERN PART OF THE AREA N OF 20N AND STRENGTHEN. 
THIS WILL MAINATIAN NW-N WINDS OF 20-25 KT OVER THE AREA N OF
20N E OF 110W INCLUDING THE GULF OF CALIFORNIA...BUT THEN
DIMINISH TO LESS THAN 20 KT IN ABOUT 30 HOURS.

A RATHER WEAK STATIONARY 1007 MB LOW IS OVER THE FAR EASTERN 
PORTION OF THE AREA CENTERED NEAR 5N80W. THE LOW IS HELPING TO 
PULL IN LIGHT NLY FLOW FROM ACROSS PANAMA SOUTHWARD TO 4N 
BETWEEN 78W AND 80W. ANOTHER LOW...WITH A BETTER DEFINED 
CIRCULATION...IS ALONG THE ITCZ AXIS NEAR 8N102W WITH A PRES OF 
1008 MB. THE LOW IS VOID OF DEEP CONVECTION WITH ONLY ISOLATED 
SHOWERS NOTED WITHIN 120 NM IN THE N SEMICIRCLE. IT IS FORECAST 
BY THE GLOBAL MODELS TO MOVE IN A WNW MOTION OVER THE NEXT 48 
HOURS WITH NO SIGNIFICANT WINDS.

GAP WINDS...
HIGH PRES BUILDING SE ACROSS MEXICO IS USHERING IN A DENSER AIR 
MASS ACROSS THIS AREA. THIS HAS BEGUN TO FILTER THROUGH THE 
CHIVELA PASS AND INTO THE GULF OF TEHUANTEPEC...RESULTING IN N 
WINDS OF 20-25 KT WITH SEAS OF 8-10 FT AS REPORTED BY SHIP 
OBSERVATIONS IN THAT AREA. A RATHER PROGRESSIVE UPPER LEVEL 
LEVEL PATTERN WILL QUICKLY SHIFT THE DENSER AIR MASS EASTWARD 
AND INTO THE CENTRAL GULF OF MEXICO BY 24 HOURS. THIS WILL 
RESULT IN SE RETURN FLOW DEVELOPING OVER THE WESTERN GULF OF 
MEXICO...AND DIMINISH THE WINDS FUNNELING THROUGH THE CHIVELA 
PASS. WINDS ARE EXPECTED TO DIMINISH TO BELOW 20 KT BY 12HOURS 
WITH SEAS DROPPING TO BELOW 8 FT.

$$
AGUIRRE