000
AXPZ20 KNHC 180324
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE MAY 18 2010

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.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 86W FROM 03N TO 10N MOVING W AT 10 KT. NO 
SIGNIFICANT CONVECTION IS NOTED NEAR THE WAVE. THE WAVE IS UNDER 
FAVORABLE MOIST ANTICYCLONIC FLOW ALOFT WHICH SHOULD ALLOW FOR 
SOME NEAR TERM CONVECTIVE ENHANCEMENT...HOWEVER THE WAVE IS 
LIKELY TO MOVE INTO A MORE ADVERSE ENVIRONMENT WITHIN NEXT 24-48 
HOURS.

TROPICAL WAVE IS FROM 05N114W TO 14N1114W WITH EMBEDDED 1010 MB 
LOW PRES NEAR 09.5N113.5W DRIFTING W AROUND 5 KT. SCATTERED 
MODERATE TO STRONG CONVECTION IS NOTED WITHIN 180 NM OF THE LOW 
CENTER IN THE NE AND E QUADRANTS...AND SCATTERED MODERATE 
CONVECTION IS WITHIN 90 NM OF THE LOW CENTER IN THE W SEMICIRCLE.
THE LOW AND WAVE ARE UNDER SOUTHERLY ANTICYCLONIC FLOW WHICH 
WOULD BE FAVORABLE FOR SOME DEVELOPMENT ALTHOUGH THESE FEATURES 
WILL LIKELY ENCOUNTER INCREASING WESTERLY SHEAR WITHIN THE NEXT 
24-48 HOURS.

...ITCZ...

AXIS IS ALONG 07N78W TO 08N87W TO 09N92W TO 06N103W TO 09N112W 
TO 06N128W TO 06N140W. SCATTERED MODERATE CONVECTION IS NOTED 
WITHIN 75 NM EITHER SIDE OF THE AXIS BETWEEN 108W AND 110W. 
NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS NOTED 
WITHIN 150 NM N OF THE AXIS AND 45 NM S OF THE AXIS BETWEEN 116W 
AND 121W.

...DISCUSSION...

AN UPPER LEVEL TROUGH EXTENDS FROM NEAR THE NEW MEXICO/MEXICO 
BORDER NEAR 32N108W TO THE GULF OF CALIFORNIA NEAR 25N111W TO 
21N126W TO 19N132W. DRY AIR IS NOTED WITHIN 90 NM W OF THE 
TROUGH AXIS HOWEVER AN UPSTREAM ANTICYCLONE AT 22N138W IS 
BRINGING PLENTIFUL MOISTURE OVER ITS CREST AND INTO THE E 
PACIFIC ELSEWHERE NW-N OF THE TROUGH AXIS TO 32N.

AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 10N102W WITH A BROAD 
RIDGE AXIS EXTENDING ALONG 09-10N FROM 135W TO COSTA RICA. ITCZ 
CONVECTION IS BEING ENHANCED ON THE SOUTHERN PERIPHERY OF THE 
RIDGE W OF 108W AND ALSO E OF 90W. A JETSTREAM BRANCH WITH CORE 
WIND SPEEDS OF 70-85 KT EXTENDS FROM 17N140W TO 19N121W TO 
22N106W AND IS ADVECTING CONVECTIVE DEBRIS FROM THE ITCZ TO THE 
NE OVER CENTRAL MEXICO.

AT THE SURFACE...A BROAD AND WEAKENING RIDGE OF HIGH PRES 
EXTENDS FROM NEAR 24N140W TO 20N120W TO 17N110W. NE TRADES AT 20 
KT EXIST FROM 08N TO 13N W OF 128W AND WILL DIMINISH SLIGHTLY IN 
AERIAL COVERAGE DURING THE NEXT 24 HOURS THEN WILL EXPAND AGAIN 
FROM 48-72 HOURS AS THE RIDGE REBUILDS AND STRENGTHENS.

A VERY WEAK COLD FRONT EXTENDS OVER THE NORTHERN WATERS FROM 
32N125W TO 30N128W TO 27N140W. SW WINDS TO 20 KT N OF 29N AND E 
OF THE FRONT WILL DIMINISH TO 10-15 KT DURING THE NEXT 12 HOURS 
AS THE FRONT DISSIPATES. AS THE SURFACE RIDGE STRENGTHENS THE 
PRES GRADIENT WILL TIGHTEN RESULTING IN NW-N WINDS AT 20-25 KT 
WITHIN 90-180 NM W OF BAJA CALIFORNIA N OF 23N FROM 18-48 HOURS.

CROSS EQUATORIAL LONG PERIOD SW SWELL UP TO 9 FT IS PROPAGATING 
INTO THE FAR SOUTHERN WATERS S OF 10N W OF 116W...AND S OF 05N 
BETWEEN 107W AND 116W AND WILL EXPAND TO THE E DURING THE NEXT
24-48 HOURS.

$$
LEWITSKY