000
AXPZ20 KNHC 170326
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU APR 17 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 
0300 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 02N78W 01N84W 07N115W 05N140W. 
NUMEROUS MODERATE/STRONG CONVECTION FROM 07N-13N BETWEEN 
105W-113W. SCATTERED MODERATE FROM 06N-12N BETWEEN 114W-135W.

...DISCUSSION...

W OF 110W...
A NEARLY STATIONARY CUT-OFF LOW REMAINS CENTERED NEAR 25N139W 
AND IS ONLY EXPECTED TO MOVE A GRAND TOTAL OF 325 NM TO THE E 
OVER THE NEXT 3 DAYS AS THE STRONGER MID-LATITUDE FLOW BYPASSES 
IT TO THE N. THE SUBTROPICAL JET BORDERS THE LOW TO ITS 
SE...EXTENDING FROM 10N140W TO 26N120W THEN MERGING WITH THE 
POLAR JET OVER THE SW UNITED STATES. MAXIMUM JET SPEEDS ARE NEAR 
60 KT WITHIN THE JET BETWEEN 128W-138W AND ABOUT 75 KT AS IT 
CROSSES THE BAJA PENINSULA AND NW MEXICO. AN AREA OF MODERATE 
SUBSIDENCE LIES ACROSS NW MEXICO AND OFFSHORE THE BAJA 
PENINSULA...WHICH IS FOSTERING FAIR SKIES AS FAR W AS 125W. A 
BROKEN STRATOCUMULUS FIELD LIES W OF 125W AROUND THE SUBTROPICAL 
RIDGE. FARTHER S...THE JET DIVERGES FROM ANOTHER AIR STREAM 
WHICH FLOWS SE AND CROSSES THE EQUATOR NEAR 136W...AND THE BROAD 
DOWNSTREAM DIFFLUENCE IS ENHANCING A LARGE AREA OF ITCZ 
CONVECTION BETWEEN 120W-134W. AN UPPER LEVEL SHORTWAVE TROUGH 
LIES FROM 15N115W TO 00N112W AND IT TOO IS PRODUCING DOWNSTREAM 
DIFFLUENCE WITH ENHANCED ITCZ CONVECTION BETWEEN 105W-113W.

E OF 110W...
AN UPPER LEVEL RIDGE AXIS LIES ACROSS THE ERN TROPICAL PACIFIC 
WATERS...ANCHORED BY A HIGH JUST OFF THE COSTA RICA COAST NEAR 
09N87W WITH AXIS EXTENDING WWD ALONG 10N. LARGE-SCALE SUBSIDENCE 
LIES E OF A LINE FROM THE GUATEMALA/MEXICO BORDER TO 00N110W AND 
IS SUPPRESSING DEEP CONVECTION ACROSS MOST OF THAT AREA...EXCEPT 
IMMEDIATELY NEAR THE ITCZ AXIS JUST N OF THE GALAPAGOS ISLANDS. 
HIGH LEVEL MOISTURE IS STREAMING INLAND ACROSS THE MEXICAN 
RIVIERA AS SOUTHWESTERLY FLOW ADVECTS OUTFLOW FROM CONVECTION IN 
THE DEEP TROPICS TO THE NE.

WINDS OVER THE GULF OF TEHUANTEPEC ARE BARELY REACHING 20 KT 
NOW...AND ARE EXPECTED TO DIMINISH BELOW THAT THRESHOLD BY THU 
AFTERNOON. WINDS ARE ALSO NEAR 20 KT OVER THE GULF OF PAPAGAYO 
BUT MAY BRIEFLY INCREASE TO 20-25 KT OVER THE NEXT 24 HRS...THEN 
DIMINISH BELOW 20 KT BY LATE SAT.

$$
BERG