000
AXPZ20 KNHC 180341
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI JAN 18 2008

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 
0300 UTC.
 
...ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N78W 7N120W 5N140W. SCATTERED MODERATE 
CONVECTION WITHIN 45 NM OF 4N84.5W.

...DISCUSSION...
A PRONOUNCED LONGWAVE TROUGH EXTENDS SW FROM THE SOUTHWEST CONUS 
ACROSS NORTHERN BAJA CALIFORNIA TO 25N123W. AN EMBEDDED SHORTWAVE 
TROUGH IS SWINGING S ACROSS BAJA CALIFORNIA TO 23N115W. BROAD MID 
LEVEL RIDGING W OF THE TROUGH ALONG 130W. THE TROUGH WILL GRADUALLY 
SHIFT EWD OVER THE NEXT FEW DAYS AND FLATTEN AS THE BROAD SCALE FLOW 
BECOMES WLY OVER THE REGION. LITTLE DEEP CONVECTION IS OBSERVED OVER 
THE FAR ERN PART OF THE PACIFIC IN THE VICINITY OF THE TROUGH DUE TO 
SUBSIDENCE N OF 21N E OF 120W. ITCZ CONVECTION IS EXPECTED TO REMAIN 
SUBDUED UNDER DRY AIR THAT COVERS NEARLY THE ENTIRE AREA ESE OF THE 
TROUGH. LIMITED ITCZ CONVECTION BETWEEN 81W-86W DUE TO WEAK LOW LEVEL
CONVERGENCE SUPPORTED BY ANTICYCLONIC FLOW ALOFT.

STRONG HIGH PRES CENTERED OVER THE WESTERN CONUS IN COMBINATION WITH 
LOW PRES OVER NORTHWEST MEXICO HAD PROMPTED A GALE WARNING FOR THE 
GULF OF CALIFORNIA EARLIER TODAY...BUT WINDS ARE EXPECTED TO BE BELOW
GALE TONIGHT. GULF OF CALIFORNIA WINDS WILL BE NW 20-25 KT...DROPPING
BELOW 20 KT IN ABOUT 24 HRS.

SFC RIDGE EXTENDS FROM 32N133W SE TO 22N121W. HIGH PRES COVERS THE 
AREA N OF 20N AND W OF 110W. A WEAK SLOW MOVING SFC TROUGH S OF 10N 
ALONG 128W IS PRODUCING BROKEN LOW CLOUDS AND ISOLATED SHOWERS.

GULF OF PAPAGAYO GAP WINDS FLUCTUATING DIURNALLY AROUND 20 KT WILL 
LAST INTO EARLY NEXT WEEK. THE NEXT GALE EVENT IS EXPECTED TO BEGIN 
IN THE GULF OF TEHUANTEPEC IN ABOUT 48 HOURS LATE SAT DUE TO STRONG 
HIGH PRES BUILDING S OVER CENTRAL AND SOUTHEASTERN MEXICO...AND 
PERSIST THROUGH SUN.

$$
MUNDELL