000
AXPZ20 KNHC 200251
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI JUL 20 2007

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 
0300 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 94W N OF 2N MOVING W 10 KT. SCATTERED 
MODERATE CONVECTION FROM 5N TO 8N BETWEEN 100W AND 104W. LOW 
PRES 1010 MB CENTERED ALONG THE WAVE WHERE IT INTERSECTS THE 
ITCZ AT 9N94W. SUBSIDENT NELY FLOW ALOFT WILL CONTINUE TO IMPACT 
THE WAVE AND LOW CENTER... RESULTING IN UNFAVORABLE CONDITIONS 
FOR SIGNIFICANT DEVELOPMENT AS IT SLOWLY MOVES W. 
  
TROPICAL WAVE ALONG 116W FROM 4N TO 18N MOVING W 15 KT. EARLIER 
QUIKSCAT DATA SHOWED STRONG LOW LEVEL CONVERGENCE OF SW AND NW 
FLOW ALONG THE ITCZ...INTERSECTING THE WAVE NEAR 12N116W. NO 
SIGNIFICANT CONVECTION IS NOTED WITH THIS WAVE AT THIS TIME. 
DESPITE SOME WEAK DIVERGENCE ALOFT SUPPORTING THE LOW LEVEL 
CONVERGENCE...THE WAVE IS MOVING INTO SLIGHTLY DRIER AIR...AND 
FURTHER SIGNIFICANT CONVECTIVE DEVELOPMENT IS NOT EXPECTED.

TROPICAL WAVE ALONG 133W FROM 2N TO 17N MOVING W 15 KT. NO 
SIGNIFICANT CONVECTION ASSOCIATED WITH THIS WAVE AS IT IS IN AN 
AREA OF SUBSIDENCE UNFAVORABLE FOR CONVECTIVE DEVELOPMENT.

...ITCZ...
AXIS 10N86W 10N99W 17N106W 9N125W 12N133W 10N140W. SCATTERED 
MODERATE FROM 6N TO 8N BETWEEN 93W AND 96W. 

...DISCUSSION...
E OF 100W...WEAK SURFACE LOW 1009 MB CENTERED NEAR 9N94W IS 
EXPECTED TO CONTINUE WNW ALONG A TROPICAL WAVE. MODEL CONSENSUS 
IS THAT THIS LOW WILL MAINTAIN ITSELF AS IT MOVES W ALONG 9N 
THROUGH THE WEEKEND...BUT WILL NOT DEEPEN SIGNIFICANTLY. ANOTHER 
TROPICAL WAVE WILL PANAMANIAN WATERS THIS WEEKEND.

W OF 100W...QUIKSCAT DATA SHOW THAT SWLY FLOW CONTINUES INTO THE 
ITCZ E OF 115W. AN UPPER TROUGH EXTENDS FROM NW MEXICO TO 
19N115W TO AN UPPER LOW NEAR 15N122W. UPPER DIVERGENCE SE OF 
THIS TROUGH IS COUPLED WITH THE LOW LEVEL SWLY CONVERGENCE TO 
ENHANCE CONVECTION ALONG THE ITCZ...AS DEPICTED ON SATELLITE 
IMAGERY BY A LARGE CONVERGENT LINE FROM 7N125W. GENERALLY DRY 
MID AND UPPER LEVELS PREVAIL ALONG AND NW OF THE UPPER TROUGH. 
AT THE SURFACE...FRESH NWLY WINDS REMAIN OFF THE BAJA 
COAST...ALTHOUGH THIS HAS BEEN RAPIDLY WEAKENING SINCE A WEAK 
SURFACE TROUGH PUSHED INTO THE AREA. THE SWLY CONVERGENCE WILL 
DIMINISH BY THE WEEKEND AHEAD OF THE LOW MOVING W ALONG 9N. 
WINDS WILL INCREASE MODESTLY TO 20 KT AROUND THE LOW BY 48 HOURS.

$$
CHRISTENSEN