000
AXPZ20 KNHC 200321
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN APR 20 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 03N77W 06N85W 08N107W 03N130W 
03N140W. SCATTERED MODERATE/STRONG CONVECTION WITHIN 45 NM OF 
THE COAST OF COLOMBIA S OF 06N. SCATTERED MODERATE/STRONG FROM 
02N-06N BETWEEN 80W-88W. ISOLATED SHOWERS/TSTMS FROM 02N-09N 
BETWEEN 91W-97W. SCATTERED MODERATE/ISOLATED STRONG FROM 03N-10N 
BETWEEN 111W-121W.

...DISCUSSION...

W OF 110W...
A SPLIT FLOW REGIME CONTINUES TO DOMINATE THE AREA OF THE 
PACIFIC BETWEEN FROM 120W TO WELL W OF THE HAWAIIAN ISLANDS AND 
AS SUCH A MID/UPPER LOW HAS BEEN STUCK IN LIGHT STEERING FLOW 
NEAR 22N138W FOR THE PAST FEW DAYS. THE SUBTROPICAL JET LIES S 
AND E OF THE LOW...EXTENDING FROM 14N140W NE TOWARDS NW MEXICO 
WHERE IT MERGES WITH THE POLAR JET DIVING DOWN THE CALIFORNIA 
COAST. THE POLAR JET IS ASSOCIATED WITH A PROGRESSIVE SHORTWAVE 
TROUGH WHICH LIES NEAR 118W...AND ALONG WITH THE UPPER LOW IS 
PRODUCING MODERATE/STRONG SUBSIDENCE NW OF A LINE FROM 30N116W 
TO 18N140W. THE SUBSIDENCE IS PRODUCING AN INVERSION BASE AT 
3000-4000 FT AND IS MAINTAINING A BROKEN STRATOCUMULUS FIELD N 
OF 23N W OF 115W. A BROAD PLUME OF TROPICAL MOISTURE LIES SE OF 
THE LINE WITH PATCHES OF BROKEN CIRRUS FLOWING NE TOWARDS BAJA 
CALIFORNIA AND NW MEXICO. ELSEWHERE...A SHORTWAVE TROUGH EXTENDS 
FROM 20N110W TO 08N118W AND THE ASSOCIATED DOWNSTREAM DIFFLUENCE 
IS FOSTERING A SURFACE TROUGH NEAR 115W AND WIDESPREAD 
CONVECTIVE DEVELOPMENT ALONG THE ITCZ BETWEEN 110W-121W.

E OF 110W...
MUCH OF THE EASTERN PART OF THE TROPICAL PACIFIC IS DOMINATED BY 
STRONG MID/UPPER LEVEL RIDGING...ANCHORED BY A HIGH CENTERED 
OVER SE MEXICO. THE HIGH IS FORCING THE SUBTROPICAL JET TO FLOW 
NE ACROSS NW MEXICO INTO NEW MEXICO AND TEXAS WHERE INCREASED 
MOISTURE IS CAUSING THE DEVELOPMENT OF MID/HIGH LEVEL 
CLOUDINESS. MODERATE/STRONG SUBSIDENCE COVERS THE AREA N OF 10N 
E OF 104W AND IS PRODUCING MAINLY FAIR SKIES BETWEEN THE COAST 
AND THE ITCZ. WEAK AND CHAOTIC UPPER LEVEL FLOW E OF 95W IS 
PRODUCING UPPER LEVEL DIFFLUENCE AND ENHANCING CONVECTION SW OF 
PANAMA AND COSTA RICA ALONG THE ITCZ AS WELL AS ALONG THE 
COLOMBIAN COAST.

A WEAK TEHUANTEPEC EVENT CONTINUES WITH WINDS TO 20 KT IN A 
NARROW ZONE EXTENDING UP TO 120 NM OFF THE COAST...BUT SHOULD 
DIMINISH LESS THAN 20 KT BY SUN AFTERNOON.  WINDS OVER THE GULF 
OF PAPAGAYO WILL OCCASIONALLY REACH 20 KT OVER THE NEXT 48 HRS 
DUE TO INCREASED TRADES OVER THE CARIBBEAN WATERS.

$$
BERG