000
AXPZ20 KNHC 270342
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU JAN 27 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 
0315 UTC.

...ITCZ...

AXIS IS CENTERED ALONG 4N78W 4N90W 5N106W 6N120W 8N130W 9N140W. 
SCATTERED MODERATE CONVECTION IS WITHIN 30 NM OF THE AXIS BETWEEN
131W-133W.

...DISCUSSION...

W OF 115W...A FAIRLY AMPLIFIED UPPER PATTERN REMAINS IN PLACE N 
OF 20N. AN UPPER TROUGH EXTENDS FROM NORTHERN BAJA SW TO AN
ELONGATED CYCLONIC CIRCULATION NEAR AT 23N124W...AND CONTINUES 
S TO 19N124W. ANOTHER UPPER TROUGH WITH AN ASSOCIATED COLD 
FRONT IS DIGGING EASTWARD THROUGH 145W N OF 20N...RESULTING IN A 
SHARPENING UPPER RIDGE BETWEEN THE TWO TROUGH STRETCHING FROM 
THE COAST OF WASHINGTON TO NEAR 21N137W. THE ASSOCIATED 1023 MB 
SURFACE HIGH IS ANALYZED N OF THE AREA AT 37N130W WITH A RIDGE 
SE TO NEAR 22N114W. THE HIGH IS FORECAST REMAIN NEARLY 
STATIONARY OVER THE NEXT 24 HOURS BLOCKING THE ADVANCE OF THE 
COLD FRONT WHICH IS FORECAST TO DISSIPATE NW OF THE AREA AS THE
UPPER SUPPORTING TROUGH LIFTS TO THE NE. MEANWHILE...THE 
SOUTHERN EXTENT OF THE UPPER TROUGH FROM NORTHERN BAJA TO 
12N142W BECOMES CUTOFF NEAR 13N145W ON THU. AN ASSOCIATED 
SURFACE TROUGH CURRENTLY W OF THE AREA ALONG 144W BECOMES MORE 
PRONOUNCED BY THU AS THE UPPER LOW CUTS OFF ALLOWING FOR THE
PRES GRADIENT TO TIGHTEN BETWEEN THE TROUGH AND RIDGING TO ITS
NE. SEAS ARE FORECAST TO BUILD TO 11 OR 12 FT IN MIXED NW AND NE 
SWELL OVER THE FAR WESTERN PORTION. NW SWELL PRODUCING SEAS OF 
ABOUT 10 FT ARE PROPAGATING SE THROUGH THE NW SECTION OF THE 
DISCUSSION AREA...REINFORCING AN EARLY GROUP OF NW SWELL OF 8 TO 
9 FT CURRENTLY MOVING ACROSS THE WHOLE AREA.

E OF 115W...BROAD SW UPPER LEVEL FLOW AHEAD OF THE ABOVE 
DESCRIBED TROUGH DOMINATES THIS PART OF THE AREA WITH A 
MID/UPPER LEVEL TROUGH EMBEDDED WITHIN THIS FLOW OVER THE 
FAR EASTERN PORTION OF THE AREA ALONG 16N98W TO 11N94W TO 5N88W. 
ABUNDANT UPPER LEVEL MOSITURE IS BEING ADVECTED BY THIS FLOW 
NORTHEASTWARD TO ACROSS NORTHERN AND CENTRAL MEXICO. PATCHES OF 
MODERATE SUBSIDENCE RESULTING IN RELATIVELY CLOUD FREE AREAS ARE 
NOTED TO THE E OF THE TROUGH...AND W OF THE TROUGH TO NEAR 105W. 
ONLY ISOLATED WEAK CONVECTION IS NOTED OVER THIS PORTION OF THE 
AREA MAINLY ALONG AND NEAR THE ITCZ.

GAP WINDS...
TIGHTENING PRES GRADIENT OVER SOUTHEASTERN MEXICO IN THE WAKE OF 
A COLD FRONT NOW OVER THE NW CARIBBEAN SEAS HAS PROMPTED A GALE 
WARNING FOR THE GULF OF TEHUANTEPEC AS A COLD AIR MASS SURGES 
SWD THROUGH THE CHIVELA PASS AS INDICATED BY SURFACE OBSERVATION 
REPORTS FROM STATION IXTEPEC ON THE SOUTH SIDE OF THE ISTHMUS 
WHERE N WINDS OVER THE PAST SEVERAL HOURS HAVE BEEN SUSTAINED AT 
30 KT WITH GUSTS TO 40 KT. THE HIGH WILL WEAKEN A LITTLE OVER 
THE NEXT 18 TO 24 HOURS ALLOWING FOR THE GALE WINDS TO 
TEMPORARILY DIMINISH...BUT IS EXPECTED TO BEGIN LATE FRI NIGHT 
AS THE NLY SURGE AGAIN BECOMES PRONOUNCED THROUGH THE CHIVELA 
PASS. SEAS IN THE GULF ARE EXPECTED TO BUILD UP POSSIBLY 10 FT 
PER LATEST WAVEWATCH GUIDANCE.

THE STRONG TEHUANTEPEC FLOW WILL GENERATE NE SWELL BY THU THAT 
WILL MIX WITH AN AREA OF NW SWELL GENERALLY S OF 14N BETWEEN 90W 
AND 118W...AND FROM 5N TO 12N BETWEEN 91W AND 106W AT WHICH
POINT THE LINGERING NW SWELL WILL BE DECAYING.

NE TO E 20 KT WINDS WILL BEGIN THROUGH THE GULF PAPAGAYO IN ABOUT
6 HOURS AND EXTENT WESTWARD TO NEAR 90W IN 18 HOURS...THEN 
DIMINISH IN 24 HOURS BEFORE STARTING UP AGAIN FROM 10N TO 12N
E OF 88W IN 48 HOURS.

GULF OF CALIFORNIA...HIGH PRES BUILDING OVER THE GREAT BASIN AND
INTERACTING WITH LOWER PRES OVER NW MEXICO HAS INDUCED NW WINDS 
OF 20 KT OVER THE FAR NORTHERN PORTION OF THE GULF. THESE WINDS
ARE FORECAST TO INCREASE TO 20 TO 25 KT IN 24 HOURS AS THEY 
EXTEND S TO 27N...THEN DIMINISH TO LESS THAN 20 KT IN 36 HOURS 
AS THE GRADIENT SLACKENS.

$$
AGUIRRE