000
AXPZ20 KNHC 172139
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON MAY 17 2010

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 85W FROM 03N TO 10N MOVING W AT 10 KT. 
SCATTERED MODERATE CONVECTION IS NOTED WITHIN 120 NM W OF THE 
WAVE AXIS FROM 05N TO 08N. THE WAVE IS UNDER FAVORABLE MOIST 
ANTICYCLONIC FLOW ALOFT WHICH SHOULD ALLOW FOR CONVECTIVE 
ENHANCEMENT HOWEVER THE WAVE IS LIKELY TO MOVE INTO A MORE 
ADVERSE ENVIRONMENT WITHIN NEXT 24-48 HRS.

TROPICAL WAVE IS ALONG 114W FROM 05N-14N WITH EMBEDDED LOW PRES 
1011 MB CENTERED NEAR 10N114W MOVING W AT 10 KT. NUMEROUS 
MODERATE AND SCATTERED STRONG CONVECTION IS NOTED WITHIN 240 NM 
OF THE LOW CENTER IN THE NE...SE AND SW QUADRANTS...AND WITHIN 
150 NM IN THE NW QUADRANT. THE LOW AND WAVE ARE UNDER SOUTHERLY 
ANTICYCLONIC FLOW WHICH WOULD BE FAVORABLE FOR DEVELOPMENT 
ALTHOUGH THE WAVE WILL LIKELY ENCOUNTER INCREASING WESTERLY 
SHEAR WITHIN THE NEXT 24-48 HOURS.

...ITCZ...

AXIS IS ALONG 08N78W TO 08N84W TO 09N93W TO 07N104W TO 09N112W 
TO 06N126W TO 06N137W. SCATTERED MODERATE CONVECTION IS WITHIN 
120 NM S OF THE AXIS BETWEEN 117W AND 121W...AND WITHIN 90 NM N 
OF THE AXIS BETWEEN 121W AND 124W.

...DISCUSSION...

AN UPPER LEVEL TROUGH EXTENDS FROM SOUTHERN ARIZONA NEAR 32N111W 
TO ACROSS FAR NW MEXICO AND SOUTHERN BAJA CALIFORNIA TO 24N112W 
TO 22N120W TO 19N139W. DRY AIR IS NOTED WITHIN 120 NM W OF THE 
TROUGH AXIS HOWEVER AN UPSTREAM ANTICYCLONE AT 23N140W 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 09N103W WITH A BROAD 
RIDGE AXIS EXTENDING ALONG 09-10N FROM 131W TO COSTA RICA. ITCZ 
CONVECTION IS BEING ENHANCED ON THE SOUTHERN PERIPHERY OF THE 
RIDGE W OF 109W AND ALSO E OF 92W. A JETSTREAM BRANCH WITH CORE 
WIND SPEEDS OF 70-85 KT EXTENDS FROM 12N140W TO 19N120W TO 
23N106W 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 24N136W TO 21N120W TO 19N106W. NE TRADES AT 20 
KT EXIST FROM 09N TO 14N W OF 126W 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 
32N129W TO 30N132W TO 27N140W. SW WINDS AT 20 KT N OF 29N AND E 
OF THE FRONT WILL DIMINISH DURING THE NEXT 24 HOURS AS THE FRONT 
DISSIPATES. AS THE SURFACE RIDGE STRENGTHENS THE PRES GRADIENT 
WILL TIGHTEN RESULTING IN NW-N WINDS AT 20 KT WITHIN 120 NM W OF 
BAJA CALIFORNIA N OF 24N FROM 24-48 HOURS.

CROSS EQUATORIAL LONG PERIOD SW SWELL UP TO 9 FT IS PROPAGATING 
INTO THE FAR SOUTHERN WATERS S OF 09N W OF 116W AND WILL EXPAND 
TO THE E DURING THE NEXT 24-48 HOURS.

$$
LEWITSKY