000
AXPZ20 KNHC 300347
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED JUL 30 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 
0230 UTC.

...TROPICAL WAVES... 
TROPICAL WAVE ALONG 97W N OF 04N MOVING W AT 15 KT.  THIS 
TROPICAL WAVE IS TRAILING A SURFACE LOW PRESSURE SYSTEM AT 
09N101W.  A WEAK UPPER LEVEL TROUGH FROM THE WRN CARIBBEAN TO 
THE S EDGE OF THE TROPICAL WAVE AXIS IS CARRYING DRY AIR THROUGH 
THE WAVE.  THIS DRY AIR COUPLED WITH A LACK OF DIFFLUENCE ALOFT 
IS LIMITING CONVECTION.  HOWEVER...SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION CAN BE FOUND TO THE NW OF THE LOW 
PRESSURE SYSTEM WITHIN 180 NM N OF THE ITCZ BETWEEN 101W AND 
107W.

TROPICAL WAVE ALONG 125W FROM 06N-18N MOVING W AT 15 KT. THIS 
TROPICAL WAVE IS EMBEDDED IN THE ITCZ WITH SCATTERED MODERATE 
CONVECTION WITHIN 210 NM N OF THE ITCZ BETWEEN 117W AND 121W AND 
ISOLATED MODERATE CONVECTION WITHIN 60 NM OF THE ITCZ BETWEEN 
122W AND 128W.  AN UPPER LEVEL LOW LIES TO THE NORTH OF THE WAVE 
AND A WEAK UPPER LEVEL ANTICYCLONE CAN BE FOUND TO THE E OF THE 
WAVE.  UPPER LEVEL DIFFLUENCE BETWEEN THESE TWO FEATURES COUPLED 
WITH DEEP TROPICAL MOISTURE ON THE SOUTHERN EDGE OF THE TROPICAL 
WAVE IS SUPPORTING THE CONVECTION AT THE MOMENT...BUT EXPECT THE 
CONVECTION TO WANE AS THE SYSTEM MOVES INTO A REGION OF LOWER 
SEA SURFACE TEMPERATURES AND AVAILABLE ATMOSPHERIC MOISTURE OVER 
THE NEXT FEW DAYS.

  
...ITCZ...
AXIS ALONG 06N79W TO 08N96W TO 07N106W TO 11N116W TO 10N139W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION CAN BE FOUND 
WITHIN 180 NM N OF THE ITCZ BETWEEN 101W AND 107W. SCATTERED 
MODERATE CONVECTION CAN ALSO BE FOUND WITHIN 210 NM N OF THE 
ITCZ BETWEEN 117W AND 121W. ISOLATED MODERATE CONVECTION LIES 
WITHIN 60 NM OF THE AXIS BETWEEN 122W AND 128W.



...DISCUSSION...
THE MID LEVEL RIDGE EXTENDING WEST-SOUTHWEST FROM THE DEEP 
ANTICYCLONE CENTERED OVER SOUTHERN ARIZONA/NEW MEXICO WILL BE 
WEAKENED BY THE INVERTED TROUGH SUPPORTING THE TROPICAL WAVE 
NEAR 125W PASSING ALONG ITS SE EDGE.  THE UPPER LEVEL HI CENTER 
IS ALSO EXPECTED TO RETREAT E TO THE SOUTHERN HIGH PLAINS BY 
THURSDAY.  THE INVERTED TROUGH SUPPORTING THE TROPICAL WAVE 
SHOULD MERGE TODAY WITH THE INVERTED TROUGH THAT HAS PERSISTED 
NEAR 135W THE LAST SEVERAL DAYS.  THE REMNANT OF GENEVIEVE NEAR 
18N134W IS ENCOUNTERING THIS WESTERN TROUGH AND IS WEAKENING AT 
THE MOMENT...WITH THE SYSTEM EXPECTED TO LOSE ITS CLOSED 
CIRCULATION AT THE SURFACE TODAY AS IT ENCOUNTERS INCREASING 
VERTICAL SHEAR.

A SLIGHT INCREASE IN THE AVAILABLE ATMOSPHERIC MOISTURE OVER 
MEXICO HELPED THE CAUSE FOR CONVECTION THIS EVENING. E STEERING 
FLOW ON THE S EDGE OF THE DEEP ANTICYCLONE IS PUSHING SOME OF 
THIS CONVECTION TO THE COAST.  CURRENTLY...SCATTERED MODERATE 
CONVECTION CAN BE FOUND E OF 103W AND N OF 16N TO THE COAST AS 
WELL AS E OF 107W BETWEEN 21N AND 24N TO THE COAST.

$$
SCHAUER CLARK