000
AXPZ20 KNHC 110335
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON OCT 11 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 9N85W TO
8N82W TO LOW NEAR 11N137W 1010 MB TO 8N113W TO 8N121W TO LOW 
NEAR 11N137W 1010 MB TO 8N140W. SCATTERED MODERATE/ISOLATED 
STRONG CONVECTION IS WITHIN 60 NM N OF THE AXIS BETWEEN 
137W-139W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM S OF 
THE AXIS BETWEEN 115W-117W.

...DISCUSSION...

AN UPPER TROUGH EXTENDS FROM A WELL DEFINED CYCLONIC CIRCULATION 
OVER NEBRASKA SW TO ACROSS NW MEXICO AND CENTRAL BAJA CALIFORNIA
TO 27N116W WHERE IT BECOMES A NARROW SHEAR AXIS TO 26N118W TO
25N131W AND SW TO AN UPPER LEVEL CYCLONE W OF THE AREA NEAR
21N143W. SMALL CYCLONIC CIRCULATIONS ARE EMBEDDED WITHIN THE 
TROUGH NEAR 26N119W AND 24N132W. SATELLITE WATER VAPOR IMAGERY
SHOWS MODERATE SUBSIDENCE WITH VERY STABLE ATMOSPHERIC CONDITIONS
WITHIN 150 NM EITHER SIDE OF THE TROUGH/SHEAR AXIS. AN UPPER 
ANTICYCLONE WAS N OF THE AREA JUST ABOUT TO THE CROSS THE 
SOUTHERN CALIFORNIA COAST WITH A RIDGE EXTENDING SW TO A COL 
REGION NEAR 30N135W. DEEP ATMOSPHERIC RIDGING IS BUILDING 
EASTWARD TO THE W OF THE COL WHILE THE TAIL END OF A LARGE UPPER 
TROUGH IS FAST APPROACHING THE FAR NW CORNER OF THE AREA.

OVER THE TROPICAL ZONE...BROAD ANTICYCLONIC FLOW COVERS THE AREA 
S OF 20N W OF 120W...WHILE A MID/UPPER TROUGH EXTENDS FROM 
21N121W SE TO 14N114W TO NEAR 8N106W. UPPER DIFFLUENCE BETWEEN
THE TROUGH AND THE EASTERN PERIPHERY OF THE ANTICYCLONIC FLOW
AREA IS HELPING TO SUPPORT CONVECTION ALONG THE ITCZ BETWEEN
115W-117W. DIFFLUENCE ON THE BACK SIDE OF THE ANTICYCLONIC
AREA IS AIDING ITCZ CONVECTION BETWEEN 137W-139W. AN UPPER 
ANTICYCLONE OVER THE CARIBBEAN NEAR PUERTO RICO HAS A RIDGE AXIS 
EXTENDING W ACROSS CENTRAL AMERICA...THEN NW ACROSS THE ISTHMUS 
OF TEHUANTEPEC AND TO A CREST NEAR 22N114W. A LARGE PLUME OF
UPPER LEVEL MOISTURE IS RIDING OVER THE BROAD ANTICYCLONIC AREA
FROM 10N TO 20N E OF 140W TO 118W WHERE IT DISSOLVES IN VERY 
DRY AIR ALOFT THE COVERS JUST ABOUT THE ENTIRE EASTERN PACIFIC
...WITH THE EXCEPTION OF THE PORTION S OF COSTA RICA AND PANAMA
WHERE UPPER LEVEL DEBRIS MOISTURE CONVECTION OVER S AMERICA AND
S OF THE ITCZ IS BEING CHANNELED WESTWARD IN UPPER LEVEL EASTERLY
FLOW.

AT THE SURFACE...A RIDGE IS BUILDING SE THROUGH 32N137W TO 
25N130W TO 22N123W. A WEAKENING STATIONARY FRONTAL BOUNDARY
EXTENDS FROM 32N137W TO W OF THE REGION ALONG 31N. THE PRES 
GRADIENT S OF THE RIDGE AND N OF THE ITCZ IS SUPPORTING NE TO E 
TRADES OF 20 TO 25 KT IN AN AREA FROM 11N TO 21N W OF 127W WHERE 
SEAS ARE IN THE RANGE OF 8 TO 11 FT IN NE WIND WAVES AND IN A SW
SWELL. THE RIDGE IS FORECAST WEAKEN THROUGH THE NEXT 48 HOURS
ALLOWING FOR THE AREA OF TRADES TO DIMINISH WITH WINDS LESSENING
TO 20 KT FROM 12N TO 18N W OF 135W.

GAP WINDS...N TO NE WINDS OF 20 TO 25 KT THROUGH THE GULF OF 
TEHUANTEPEC ARE EXPECTED TO PULSE TO 20 KT IN DIURNALLY INDUCED 
DRAINAGE FLOW EARLY MON MORNING BEFORE DIMINISHING TO 10 TO 15 
KT EARLY MON EVENING. WINDS INCREASE ONCE AGAIN LATE TUE NIGHT
...POSSIBLY REACHING GALE FORCE BEGINNING WED NIGHT AS HIGH PRES
SURGES SE ACROSS SOUTHEASTERN MEXICO.

$$
AGUIRRE