000
AXPZ20 KNHC 262149
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED OCT 26 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1530 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS E TO W FROM 09N80W TO 11N87W TO 
09N96W WHERE LOW LEVEL WINDS INDICATE THE ITCZ AXIS BEGINS AND 
CONTINUES WNW TO AN EMBEDDED LOW PRES AT 13N132W...WITH THE ITCZ 
THEN CONTINUING SW TO BEYOND 09N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED WITHIN 150 NM OF THE LOW 
PRES CENTER AT 13N132W AND ALSO FROM 09N TO 11N BETWEEN 122W AND 
128W.

...DISCUSSION...

AN UPPER LEVEL TROUGH DISSECTS NORTH AMERICA AND CONTINUES SW 
INTO THE DISCUSSION AREA FROM 32N120W TO 24N132W THEN THROUGH AN 
UPPER CYCLONE AT 20N137W...THEN THE TROUGH CONTINUES S TO BASE 
OVER THE DEEP TROPICAL PACIFIC AT 08N134W. AN UPPER ANTICYCLONE 
IS OVER OLD MEXICO AT 20N97W WITH AN UPPER RIDGE EXTENDING W TO 
A CREST AT 11N127W. UPPER DIFFLUENCE E OF THE UPPER TROUGH AXIS 
IS ENHANCING CONVECTION NEAR THE SURFACE LOW AT 13N132W AND 
ALONG THE ITCZ AS PREVIOUSLY DESCRIBED. THE DEBRIS MOISTURE IS 
ADVECTED NE ALONG THE NW PERIPHERY OF THE RIDGE...ROUGHLY WITHIN
270 NM EITHER SIDE OF A LINE FROM 09N131W TO 22N124W THEN THE 
MOISTURE PLUME NARROWS AS IT CONTINUES NW ACROSS EXTREME 
NORTHERN OLD MEXICO AND SOUTHERN ARIZONA. VERY DRY UPPER AIR IS 
SPREADING SE THROUGH THE UPPER TROUGH ACROSS SOUTHERN 
CALIFORNIA. DRY UPPER AIR IS ALSO NOTED S OF 23N E OF 113W.

ELSEWHERE AT THE SURFACE...A RIDGE EXTENDS FROM 32N140W TO 
17N107W. 
 
GAP WINDS...NORTHERLY WINDS AT 15 TO 20 KT CONTINUE OVER AND 
JUST DOWNSTREAM OF GULF OF TEHUANTEPEC WITH ACCOMPANYING SEAS OF 
8 FT. THESE NORTHERLY WINDS WILL DIMINISH BELOW 20 KT IN A FEW 
HOURS. A STRONG COLD FRONT WILL MOVE THROUGH THE SW GULF OF 
MEXICO ON FRI RESULTING IN A STRONG SURGE OF NORTHERLY WINDS TO 
FUNNEL THROUGH THE CHIVELA PASS LATE FRI AFTERNOON.
THESE WINDS WILL LIKELY INCREASE TO GALE FORCE LATE FRI NIGHT.
 
GULF OF CALIFORNIA...NW WINDS AT 15 TO 20 KT WILL CONTINUE 
THROUGH FRI.

$$
NELSON