000
AXPZ20 KNHC 040253
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN OCT 04 2009

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 
0245 UTC.

...SPECIAL FEATURE...

TROPICAL DEPRESSION OLAF HAS DEGENERATED INTO A REMNANT LOW. THE 
LOW IS CENTERED NEAR 24.1N 112.3W AT 04/0300 UTC OR ABOUT 45 
NM...80 KM SOUTH OF CABO SAN LAZARO MEXICO MOVING E OR 085 
DEGREES AT 12 KT. MAXIMUM SUSTAINED WIND SPEED ARE DOWN TO 25 KT 
WITH GUSTS TO 35 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 
MB. WESTERLY SHEAR ALOFT HAS SHEARED ALL DEEP CONVECTION LEAVING 
OLAF NOTHING MORE THAN A SWIRL OF LOW CLOUDS. THE NEAREST AREA 
OF DEEP CONVECTION WAS OVER THE SOUTHERN GULF OF CALIFORNIA  
LOCATED MORE THAN 200 NM AWAY FROM THE CENTER OF OLAF. OLAF IS 
EXPECTED TO DISSIPATE ON SUNDAY. SEE LATEST NHC  
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC 
FOR MORE DETAILS.

...ITCZ...

AXIS WAS CENTERED ALONG 08N78W TO 10N95W TO 08N110W TO 13N128W 
TO 09N140W. SCATTERED MODERATE WITHIN 60-90 NM EITHER SIDE OF 
THE AXIS BETWEEN 88W AND 92W...AND BETWEEN 104 AND 108W. 

...DISCUSSION...

A WELL-DEFINED MIDDLE/UPPER LEVEL TROUGH IS LOCATED OVER THE NW 
PART OF THE DISCUSSION AREA AND WAS IN THE PROCESS OF BECOMING 
PINCHED OFF WITH THE AXIS EXTENDING THROUGH 32N130W TO BEYOND 
20N140W. A FAIRLY LARGE CYCLONIC CIRCULATION WAS INDICATED 
WITHIN THE TROUGH NEAR 26N140W. A LARGE AREA OF MODERATE TO 
STRONG SUBSIDENCE WAS NOTED WITHIN THE TROUGH AND CYCLONIC 
CIRCULATION. AXIS OF SUBTROPICAL JETSTREAM EXTENDS FROM NEAR THE 
BASE OF THE TROUGH AT 19N140W TO 26N130W AND INTO NORTHERN BAJA 
CALIFORNIA INTO AN AREA OF GENERALLY CONFLUENT FLOW OVER THE SW 
CONUS. SATELLITE CLOUD DRIFT WINDS INDICATED CORE SPEEDS OF
75-85 KT ALONG 130W...INCREASING TO 100-110 KT OVER THE SW 
CONUS. 

AN EXPANSIVE MIDDLE/UPPER LEVEL ANTICYCLONIC CIRCULATION IS 
CENTERED OVER CENTRAL MEXICO NEAR 21N98W WITH AN ASSOCIATED 
RIDGE AXIS EXTENDING WESTWARD ALONG 21N TO 115W. A BROAD AREA OF 
STRONG SOUTHWESTERLY FLOW ALOFT ON THE N SIDE OF THE ANTICYCLONE
EXTENDED NORTHWARD ACROSS NORTHERN MEXICO TO THE JET AXIS NOTED 
ABOVE. TROPICAL DEPRESSION OLAF HAS ENCOUNTERED THIS AREA OF 
STRONG WINDS AND HAS DEGENERATED INTO A REMNANT LOW. SEE SPECIAL 
FEATURES SECTION FOR ADDITIONAL INFORMATION. 

EASTERLY WINDS DOMINATED THE TROPICAL EAST PACIFIC SOUTH OF THE 
ANTICYCLONE ABOVE GENERALLY IN THE AREA BETWEEN 90W AND 105W. 

AT THE SURFACE...A RIDGE EXTENDS FROM A 1032 MB HIGH CENTERED 
NEAR 39N147W THROUGH 32N137W TO 22N125W. NW OF LINE FROM 30N118W 
TO 20N120W TO 15N140W WINDS ARE FROM THE N TO NE AT 20 TO 
LOCALLY 25 KT WITH SEAS 8 TO 12 FT IN N TO NE SWELL. MODERATE 
EASTERLY WINDS ALOFT ARE LOCATED OVER THE TROPICS BETWEEN 105W 
AND 120W BECOMING MORE NORTHEASTERLY BETWEEN 120W AND 140W. A 
SURFACE TROUGH IS LOCATED FROM 15N133W TO 10N135W.  

$$
COBB