000
AXPZ20 KNHC 130342
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED OCT 13 2010

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.

...THE ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 8N80W 6N90W
6N100W TO A 1011 MB LOW NEAR 8N110W TO ANOTHER 1011 MB LOW NEAR
12N125W TO 8N131W TO 9N140W. SCATTERED MODERATE CONVECTION IS 
WITHIN 120 NM N OF THE AXIS BETWEEN 131W-134W.

...DISCUSSION...

AN UPPER TROUGH EXTENDS FROM THE CENTRAL U.S SW TO ACROSS 
SOUTHERN CALIFORNIA AND W TO 34N125W. AN ELONGATED MID/UPPER 
LEVEL CYCLONIC CIRCULATION MOVING E IS OVER THE FAR NE PORTION 
OF THE AREA NEAR 27N118W WITH A NEGATIVELY TILTED NARROW TROUGH 
EXTENDING SE TO MEXICO NEAR 19N105W...THEN CONTINUES S TO A 
SMALL UPPER LEVEL CYCLONIC CIRCULATION NEAR 12N105W. SATELLITE 
WATER VAPOR IMAGERY SHOWS MODERATE SUBSIDENCE WITH VERY STABLE 
ATMOSPHERIC CONDITIONS WITHIN 90 NM EITHER SIDE OF THE CYCLONIC 
CIRCULATION NEAR 27N118W...E OF THE TROUGH AND W OF THE TROUGH 
TO NEAR 110W. A VERY PRONOUNCED JET STREAM BRANCH ENTERS THE 
REGION THROUGH 22N140W...AND CONTINUES NE TO 25N128W AND SE TO 
ACROSS THE NARROW TROUGH AT 23N108W THEN TURNS SHARPLY NE TO 
OVER NW MEXICO. MAXIMUM JET CORE WINDS ARE IN THE RANGE OF 
60-100 KT.

S OF THE JET STREAM BRANCH...BROAD ANTICYCLONIC FLOW COVERS THE 
AREA W OF 110W WITH A MEAN ANTICYCLONE CENTER NEAR 12N126W. THE
JET IS ADVECTING AMPLE DEEP TROPICAL CENTRAL PACIFIC UPPER
MOSITURE IN THE FORM OF BROKEN CIRRUS CLOUDS FROM 18N TO 25N
EASTWARD TO NEAR 110W WHERE THEY DISSIPATE IN THE MODERATE 
SUBSIDENCE AREA. THE SURFACE LOW NEAR 12N125W HAS SCATTERED 
STRONG CONVECTION WITHIN 120 NM IN THE NE QUADRANT WHICH IS 
BEING SUPPORTED BY THE UPPER ANTICYCLONE NEAR 12N126W. THE 
ANTICYCLONIC ALOFT IS ALSO HELPING TO SUPPORT ITCZ CONVECTION W 
OF 120W.

A BROAD AREA OF MID/UPPER LEVEL RIDGING COVERS THE EASTERN 
PORTION OF THE REGION N OF 10N E OF 100W...AND ALONG AND E OF
THE REMAINDER OF CENTRAL AMERICA E TO WELL OVER THE CARIBBEAN
SEA. SCATTERED TSTMS ACTIVITY FROM ALONG THE COAST OF COSTA RICA
SOUTHEASTWARD TO THE GULF OF PANAMA IS WEAKENING WHILE THE 
UPPER LEVEL DEBRIS CLOUDINESS IS BEING DRIVEN WNW UNDER THE 
RIDGE.

ELSEWHERE AT THE SURFACE...A RIDGE EXTENDS FROM 32N137W TO 
22N119W. HIGH PRES COVERS THE AREA N OF 20N W OF 117W. THE PRES 
GRADIENT S OF THE RIDGE AND N OF THE ITCZ IS SUPPORTING NE TO E 
TRADES OF 20 KT IN AN AREA FROM 12N TO 18N W OF 129W WITH SEAS
TO 9 FT. THE RIDGE IS FORECAST TO REMAIN RATHER WEAK THROUGH THE 
NEXT 48 HOURS ALLOWING FOR THIS AREA OF WINDS TO DIMINISH TO
LESS THAN 20 KT FROM 12N TO 20N W OF 121W WITH SEAS TO 8 FT IN 
N TO NE SWELL.

GAP WINDS...N WINDS OF 20 TO 25 KT THROUGH THE ISTHMUS OF 
TEHUANTEPEC ARE EXPECTED TO INCREASE TO 25 TO 35 KT BY WED 
MORNING...AND TO 35 TO 45 KT IN 24 HOURS INTO 48 HOURS AS HIGH 
PRES SURGES SE ACROSS SOUTHEASTERN MEXICO RESULTING IN A TIGHT 
PRES GRADIENT. SEAS SHOULD BUILD UP TO 15 FT DURING THE PERIOD.
HIGH WINDS JUST ABOVE THE SURFACE COULD POSSIBLY MIX DOWN GIVEN
A COLDER AIR MASS SURGING THROUGH THE GULF.

$$
AGUIRRE