000
AXPZ20 KNHC 282210 CCA
TWDEP 

TROPICAL WEATHER DISCUSSION...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE SEP 28 2010

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 
2145 UTC.

...ITCZ...

AXIS CENTERED ALONG 12N88W 8N98W 10N110W TO A WEAK 1010 MB LOW
AT 11N121W TO 10N127W TO 12N131W TO 11N140W. SCATTERED MODERATE
CONVECTION WAS WITHIN 60 NM OF THE AXIS W OF 136W.

...DISCUSSION...

W OF 125W...

A MID/UPPER LEVEL ANTICYLONE WAS NEAR 20N135W WHILE A RATHER
VIGOROUS SHORTWAVE TROUGH APPROACHES THE FAR NW CORNER OF THE
AREA. THE ASSOCIATED SURFACE COLD FRONT WAS ABOUT 130 NM NW OF 
32N140W. SW UPPER LEVEL FLOW WAS INCREASING AHEAD OF THE TROUGH 
IN A VERY PRONOUNCED JET STREAM WITH WINDS OF 35-55 KT. SATELLITE
WATER VAPOR IMAGERY DEPICTED MODERATE SUBSIDENCE OVER THIS 
PORTION OF THE REGION RESULTING IN STABLE ENVIRONMENTAL 
CONDITIONS WITH SCATTERED TO BROKEN STRATOCUMULUS CLOUDS NOTED N 
OF 19N...AND LIMITING MOISTURE IN THE TROPICAL ZONE. ITCZ 
CONVECTION WAS BEING AIDED BY DIFFLUENT FLOW ON THE SW PERIPHERY 
OF THE ANTICYCLONE.

E OF 125W...

A MID/UPPER LEVEL CYCLONIC CIRCULATION WAS OVER THE FAR NE PART 
W OF NORTHERN BAJA CALIFORNIA NEAR 30.5N119W MOVING SLOWLY N. A
TROUGH EXTEND S FROM THE CIRCULATION TO NEAR 24N122W...THEN SW
TO A COL REGION AT 23N126W. THE SURFACE REFLECTION OF THE 
CYCLONIC CIRCULATION WAS ANALYZED AS A TROUGH FROM 24N114W TO
N OF 32N AT 120W. THE CIRCULATION AND ITS ASSOCIATED TROUGH WERE 
BEING SQUEEZED IN BETWEEN THE ANTICYCLONE NEAR 20N135W...AND A 
MUCH LARGER ANTICYCLONE ANCHORED OVER THE WESTERN U.S. THE 
ANTICYCLONIC FLOW ON THE SOUTHERN PERIPHERY OF THE LARGE 
ANTICYCLONE WAS COMBINING WITH THAT ON THE NE SEMICIRCLE
OF THE CYCLONIC CIRCULATION TO ADVECT AMPLE MID/UPPER LEVEL 
MOISTURE FROM NW MEXICO N AND NW ACROSS MUCH OF SOUTHERN 
CALIFORNIA AND TO AS FAR W AS 123W N OF 27N. THIS MOISTURE 
SHOULD CONTINUE TO RESULT IN PERIODS OF LOW CLOUD OVERCAST TO 
THE THIS AND CALIFORNIA COAST OVER THE NEXT COUPLE OF DAYS...
AND PERHAPS LONGER.

A MID/UPPER LEVEL ANTICYCLONE WAS CENTERED ALONG THE COAST OF 
MEXICO NEAR 21N106W WITH A RIDGE W TO 20N120W AND NW TO 23N126W.
ANOTHER RIDGE EXTENDED FROM THE ANTICYCLONE ESE ACROSS 
SOUTHEASTERN MEXICO AND THE FAR WESTERN CARIBBEAN SEA. THE 
ANTICYCLONE WAS SUPPORTING CONVECTION THAT HAD DEVELOPED 
ASSOCIATED WITH A SURFACE 1008 MB LOW NEAR 19N107W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION WAS WITHIN 90 NM OF THE
LOW IN THE SW QUADRANT AND 120 NM IN THE NW QUADRANT.

OF MARINE RELATED ISSUES...SW TO W WINDS OF 20 TO 25 KT PRESENT 
FROM 8N TO 13N E OF 100W WERE SERVING AS INFLOW INTO THE LARGE
MONSOON GYRE COVERING THE FAR EASTERN PORTION OF THE AREA THAT
HAS BECOME ESTABLISHED TO THE N OF 7N AND E OF 102W AND INTO
THE NW CARIBBEAN SEA. THIS SAME WINDS CONTINUED AS INFLOW INTO
TROPICAL DEPRESSION SIXTEEN IN THE NORTHWESTERN CARIBBEAN SEA.
WITH THE DEPRESSION FORECAST TO LIFT NNE OVER THE NEXT 48 
HOURS...THESE WINDS WILL DIMINISH SOME IN COVERAGE BUT EXPECT
A SW SWELL TRAIN TO RESULT IN 8 TO 11 FT SEAS OVER THE AREA
CONFINED FROM 5N TO 13N E OF 97W.

WITH A GULF OF MEXICO COLD FRONT NOW HAVING CLEARED THE BAY OF
CAMPECHE AS IT MOVES ACROSS THE YUCATAN PENINSULA AND A 1006 MB
LOW LOCATED S OF THE GULF OF TEHUANTEPEC NEAR 15N93W WITH A 
TROUGH WNW TO 15N98W...THE FLOW IN THE WAKE OF THE FRONT 
COMBINED WITH THAT AROUND THE LOW HAS INDUCED NW TO N 20 KT 
WINDS THROUGH THE THE ISTHMUS OF TEHUANTEPEC AS NOTED IN ASCAT 
PASS FROM NEAR 1600 UTC THIS MORNING. THE LOW WAS ASSOCIATED 
WITH A BROAD AREA OF LOW PRES SITUATED A COUPLE OF HUNDRED MILES 
W OF MANZANILLO. THIS AREA LIES UNDER ONLY MARGINALLY FAVORABLE 
UPPER LEVEL WINDS...SO THE CHANCE IS LOW FOR IT TO BECOME A 
TROPICAL CYCLONE OVER THE NEXT 48 HOURS AS IT DRIFTS IN A 
GENERAL SE MOTION.

ELSEWHERE...15-17 SEC LONG PERIOD SWELL TRAIN CONTINUED TO 
PROPAGATE E FROM THE N CENTRAL PACIFIC IN TO THE DISCUSSION 
AREA. WAVEWATCH MODEL GUIDANCE SHOWED SEAS SUBSIDING FROM A MAX 
OF 13 FT OVER NW WATERS FROM THIS SWELL TRAIN. THIS INITIAL 
SWELL TRAIN WILL CONTINUE TO SPREAD SE ACROSS NW HALF OF THE 
BASIN AND GRADUALLY SUBSIDE. HOWEVER BEYOND 48 HOURS...
A LARGE BATCH OF LONG PERIOD NW SWELLS WITH SEAS OF UP TO 14 FT 
IS FORECAST TO APPROACH THE FAR NW CORNER OF THE AREA BY THE 
WEEKEND.

$$
AGUIRRE