000
AXPZ20 KNHC 071542
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED APR 07 2010

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 
1500 UTC.

...ITCZ...

AXIS WAS CENTERED ALONG ALONG 02.5N78W TO 06N93W TO 04N107W TO 
04.5N120W TO 03N126W TO 03N140W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION WITHIN 180 NM N OF AXIS AND 60 NM S OF AXIS E 
OF 92W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 180 
NM S OF AXIS BETWEEN 92W AND 100W. ISOLATED MODERATE TO STRONG 
CONVECTION WITHIN 180 NM N OF AXIS AND 250 NM S OF AXIS BETWEEN 
100W AND 110W. NUMEROUS MODERATE SCATTERED STRONG CONVECTION 
WITHIN 180 NM EITHER SIDE OF AXIS BETWEEN 110W AND 117W. 
ISOLATED MODERATE TO STRONG CONVECTION WITHIN 90 NM N OF AXIS 
AND 210 NM S OF AXIS BETWEEN 117W AND 126W. SCATTERED MODERATE 
TO STRONG CONVECTION WITHIN 180 NM EITHER SIDE OF AXIS W OF 
126W. 

...DISCUSSION...

THE TAIL END OF A LONG WAVE TROUGH EXTENDED SW FROM THE SW U.S. 
INTO THE AREA TO NEAR 27N117W. A SHORT WAVE RIDGE LIES JUST TO 
THE WEST OF THIS BROAD TROUGH WITH ANOTHER TROUGH OVER THE 
WESTERN PART OF THE AREA. IN THE DEEP TROPICS...ACTIVE 
CONVECTION ALONG THE ITCZ WAS MAINTAINING UPPER LEVEL RIDGING 
ALIGNED ROUGHLY ALONG 7N. 

AT THE SURFACE...WEAKENING SURFACE HIGH PRESSURE NORTH OF THE 
AREA IS STILL STRONG ENOUGH TO MAINTAIN A TIGHT PRESSURE 
GRADIENT BETWEEN THIS FEATURE AND THE ITCZ. FRESH TO STRONG 
WINDS CONTINUE FROM 05N TO 22N W OF 120W. AS AN UPPER LEVEL 
TROUGH AND ASSOCIATED COLD FRONT MOVE N OF THE AREA THIS 
AFTERNOON INTO TONIGHT WILL CAUSE THE THE ABOVE HIGH CENTER TO 
DISSIPATE...THEN BE REPLACED BY A STRONGER HIGH IN THE WAKE OF 
THE COLD FRONT ON THU. THE RESULTANT TIGHTENING PRES GRADIENT 
WILL PRODUCE A LARGE AREA OF TRADES OVER JUST ABOUT THE ENTIRE 
WESTERN HALF OF THE AREA N OF THE ITCZ. 

A TIGHT PRES GRADIENT BETWEEN THE AFOREMENTIONED HIGH PRES AND 
TROUGHING OVER THE SIERRA MADRE OCCIDENTAL CONTINUES TO RESULT 
IN NW TO N WINDS OF 20-25 KT N OF 22N E OF 123W. THIS GRADIENT 
IS ALSO RESPONSIBLE FOR NW WINDS OF 20 TO 25 KT THROUGH THE GULF 
OF CALIFORNIA N OF 25N. 

FRESH TO STRONG TRADES OVER THE CARIBBEAN WATERS CONTINUES TO 
FUNNEL THROUGH INTO THE GULF OF PAPAGAYO RESULTING IN WINDS TO 
20 KT. THE WINDS WILL PULSE OVER THE FORECAST PERIOD WITH THE 
STRONGEST WINDS IN THE EARLY MORNING HOURS IN RESPONSE TO 
ENHANCED NOCTURNAL DRAINAGE FLOW.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
AL