000
AXPZ20 KNHC 040920
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN MAY 04 2008

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 05N77W TO 07N89W TO 04N104W TO 
05N112W TO 03N130W TO 02N140W. SCATTERED MODERATE CONVECTION IS 
WITHIN 180 NM EITHER SIDE OF THE AXIS BETWEEN 91W AND 103W. 
SCATTERED MODERATE CONVECTION IS WITHIN 60 NM S OF THE AXIS 
BETWEEN 83W AND 87W ALSO FROM 6N TO 9N BETWEEN 110W AND 123W.

...DISCUSSION...

W OF 110W...
A SLOW MOVING MID TO UPPER TROUGH EXTENDS FROM CENTRAL 
CALIFORNIA THROUGH 30N123W TO 20N140W. UPPER CONFLUENCE ALONG 
AND TO THE W OF THE AXIS...INFLUENCED BY AN UPPER HIGH NEAR 
32N142W...IS PRODUCING WIDESPREAD DRY STABLE AIR CAPPING THE 
LOW-LEVEL STRATUS/STRATOCUMULUS CLOUDS. AN 80-100 KT JET BRANCH 
ORIGINATES E OF THE TROUGH AXIS AND EXTENDS INTO THE S CENTRAL 
UNITED STATES TRANSPORTING A PLUME OF MOISTURE...MAINLY IN THE 
FORM OF DENSE MID-HIGH LEVEL CLOUDS...WITHIN 600 NM SE OF A LINE 
FROM 9N132W TO CENTRAL N BAJA NEAR 29N114W. GLOBAL MODELS ARE IN 
AGREEMENT IN DEPICTING A SMALL UPPER LOW OVER WASHINGTON STATE 
DIVING S LEADING TO THE DEVELOPMENT OF A LARGE CUT OFF LOW IN 
THE VICINITY OF S CALIFORNIA LATER TODAY AND MON. THE CUT OFF 
WILL THEN WEAKEN AND PUSH E ON TUE.

AT THE SFC...HIGH PRES CENTERED WELL N OF THE REGION IS 
PRODUCING AN AREA OF 20 KT NE TRADES ON ITS S PERIPHERY ROUGHLY 
FROM 07N TO 22N W OF 128W WITH SEAS RUNNING IN THE 8-9 FT RANGE 
MAINLY IN NW SWELL. NW SWELL IS ALSO KEEPING SEAS 8-9 FT OFF THE 
N COAST OF BAJA. SEAS OFF THE COAST OF N BAJA WILL SUBSIDE BELOW 
8 FT LATER TODAY BUT INCREASE AGAIN LATE MON OVER THE FAR N 
WATERS BETWEEN 120W-130W AS N SWELL SPREADS S FROM GALE FORCE 
WINDS OFF THE N CALIFORNIA COAST. 

E OF 110W...
A QUASI-STATIONARY MID TO UPPER RIDGE AXIS STRETCHES FROM 
COLOMBIA NW ACROSS CENTRAL AMERICA AND SOUTHERN MEXICO ALLOWING 
MOIST SLY UPPER FLOW TO LIE OVER MUCH OF THIS REGION. IN THE 
LOWER LEVELS...A BROAD TROUGH OF LOW PRES IS EMBEDDED WITHIN THE 
ITCZ CENTERED IN THE VICINITY OF 94W. A 00Z QSCAT PASS CONFIRMS 
THAT THE E-W ELONGATED CYCLONIC TURNING EVIDENT ON SHORTWAVE IR 
IMAGES IS AT THE SFC...HOWEVER ASSOCIATED WINDS ARE LIGHT. 
CONVECTION HAS EXPANDED AND DEEPENED OVER THE PAST COUPLE OF 
HOURS BUT REMAINS DISORGANIZED. SCATTERED MODERATE IS FROM 
9N-12N BETWEEN 92W-95W AND STRETCHED WITHIN THE ITCZ (OUTLINED 
ABOVE). MANY OF THE NWP MODELS HAVE THIS WEAK FEATURE 
INITIALIZED AND TRACK IT WEST-NORTHWEST AS A WEAK LOW OR OPEN 
TROUGH ON THE S PERIPHERY OF A BUILDING LOW-MID LEVEL 
RIDGE...AND THIS SCENARIO SEEMS REASONABLE. OTHERWISE...LITTLE 
TO MENTION IN TERMS OF WINDS AND SEAS AS SW SWELL IS SUBSIDING 
AND WINDS REMAIN BELOW HIGH SEAS CRITERIA OVER THE NEXT COUPLE 
OF DAYS.

$$
CANGIALOSI