000
AXPZ20 KNHC 261520
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU APR 26 2007

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N77W 10N86W 7N105W 9N125W 5N140W. 
WIDELY SCATTERED MODERATE CONVECTION FROM 3N-7N BETWEEN 80W-85W. 
SCATTERED MODERATE/ISOLATED STRONG WITHIN 90 NM OF AXIS W OF 
110W.

...DISCUSSION...

SUBTROPICS...
A SHARP UPPER RIDGE LIES JUST OFF THE CALIFORNIA COAST ALONG 
133W AND HAS PRODUCED GENERALLY WEAK FLOW OVER THE SUBTROPICAL 
WATERS. AN UPPER TROUGH/MID-LEVEL LOW EXTENDS FROM SRN 
CALIFORNIA SW TO 20N130W AND CONFLUENCE INTO THIS FEATURE IS 
PRODUCING A SIGNIFICANT AREA OF MODERATE/STRONG SUBSIDENCE W OF 
A LINE FROM 20N124W 30N112W. A SURGE OF DRIER LOW-LEVEL AIR IS 
STREAMING DOWN THE CALIFORNIA COAST WITH ITS LEADING EDGE ALONG 
30N117W 26N122W 30N130W...MARKED BY AN EROSION OF THE NORMAL 
STRATOCUMULUS FIELD. E OF THE TROUGH...UPPER LEVEL MOISTURE 
DERIVED FROM THE TROPICS IS STREAMING NE ACROSS S/CENTRAL BAJA 
AND INTO NRN MEXICO. THE SURFACE RIDGE WHICH IS CURRENTLY IN 
PLACE IS EXPECTED TO BREAK DOWN WITHIN ABOUT 48 HRS...WHICH 
SHOULD LEAVE GENERALLY LIGHT FLOW W OF BAJA BY LATER IN THE 
WEEKEND.

TROPICS...
A SEGMENT OF THE UPPER TROUGH W OF BAJA REACHES DOWN INTO THE 
TROPICS ALONG 20N127W 10N133W AND IS INCREASING THE UPPER 
DIFFLUENCE OVER THE ITCZ. A WIDE SWATH OF CIRRUS IS EMANATING N 
OF THE ITCZ BETWEEN 110W-130W...OR BETWEEN THE TROUGH AND AN 
UPPER HIGH NEAR 11N106W...AND IS STREAMING NE TO THE MEXICAN 
COAST BETWEEN CENTRAL BAJA AND MANZANILLO. NLY UPPER FLOW 
CROSSING THE EQUATOR IS ALSO PRODUCING SOME DIFFLUENCE OVER THE 
ITCZ W OF 125W...MAKING THE ENTIRE AXIS FAIRLY CONVECTIVE W OF 
110W. FARTHER E...THE EXPANSIVE UPPER HIGH NEAR 12N106W IS 
PRODUCING FLOW WITH A NLY COMPONENT EWD TO 90W AND IS DRAWING 
DRIER AIR FROM MEXICO AND THE GULF OF MEXICO SWD OVER THE 
PACIFIC WATERS. THE UPPER FLOW E OF 90W IS MORE VARIABLE BUT 
ULTIMATELY BEGINS TO FLOW E WITH A MINIMAL JET EXTENDING FROM 
PANAMA TO THE CENTRAL CARIBBEAN. THIS IS HELPING TO INDUCE SOME 
TSTM DEVELOPMENT FROM PANAMA SWD A FEW HUNDRED NM.

$$
BERG