000
AXPZ20 KNHC 021558
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI JAN 02 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1530 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...06N77W TO 
04N85W TO 10N123W TO 07N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION FROM 09N TO 14N BETWEEN 116W AND 127W. 

...DISCUSSION...

MID TO UPPER LEVEL TROUGH/SHEAR AXIS EXTENDS FROM A CYCLONIC 
CIRCULATION OVER THE EXTREME NORTHERN GULF OF CALIFORNIA NEAR 
31N114W WSWWD THROUGH 26N130W TO ANOTHER WEAK CIRCULATION NEAR 
22N138W. MODERATE TO STRONG SUBSIDENCE WAS NOTED WITHIN 120-180 
NM EITHER SIDE OF THE TROUGH AXIS AND NEAR THE CIRCULATION 
CENTERS. A SHARPENING MID/UPPER LEVEL TROUGH WELL NW OF THE AREA
IS FCST TO DIG SWD INTO THE NE PORTION OF THE AREA AND DRIVE A 
COLD FRONT INTO THE REGION LATE SAT WITH FRESHENING NW WINDS OF 
20 KT BEHIND THE FRONT SAT NIGHT AND SUN. AT THE SURFACE...
1028 MB HIGH PRES NW OF THE AREA NEAR 32N144W WITH ASSOCIATED 
SFC RIDGE EXTENDING SE THROUGH 27N130W TO 18N110W. PRES GRADIENT 
S OF THE RIDGE IS MAINTAINING AN AREA OF MODERATE TO FRESH 
TRADES FROM 12N TO 22N W OF 125W. TRADES MAY INCREASE SLIGHTLY 
TO NEAR 30 KT ALONG 140W BY SUN AS THE PRES GRADIENT 
TIGHTENS.     

A SERIES OF UPPER LEVEL TROUGHS AND RIDGES DOMINATE THE PATTERN 
OVER THE DEEP TROPICS. DIFLUENT ANTICYCLONIC FLOW AT THE UPPER 
LEVELS FROM 08N TO 20N BETWEEN 115W AND 130W IS AIDING IN 
MAINTAINING DEEP CONVECTION IN THE VICINITY OF A SURFACE TROUGH 
WHICH EXTENDS FROM 14N122W TO 6N126W. STRONG UPPER LEVEL WSW 
WINDS ARE ADVECTING MID AND HIGH LEVEL MOISTURE FROM THIS REGION 
NE ACROSS SRN BAJA CALIFORNIA AND OVER MOST OF MEXICO.   

GAP WINDS...
QUIKSCAT DATA IS NOW AVAILABLE WITH THE HIGH RESOLUTION DATA 
FROM 1240 UTC INDICATING NLY WINDS OF 20-25 KT IN THE GULF OF 
TEHUANTEPEC. MWP MODEL GUIDANCE SUGGESTS WINDS WILL DROP BELOW 
20 KT WITHIN THE NEXT 12 HOURS. ELSEWHERE IN THE GAP WIND 
REGION...ALTHOUGH SCATTEROMETER DATA MISSED THE GULF OF PAPAGAYO 
WINDS IN THE AREA REMAIN IN THE 20-25 KT RANGE. THESE WINDS ARE 
EXPECTED TO PERSIST THROUGH THE NEXT 48 HOURS.  

$$
COBB