000
AXPZ20 KNHC 192121
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT APR 19 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 03N77W 06N85W 08N107W 03N130W 
03N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 
03N-07N BETWEEN 79W-88W. ISOLATED MODERATE/STRONG WITHIN 75 NM 
OF AXIS BETWEEN 88W-95W. SCATTERED MODERATE/ISOLATED STRONG 
WITHIN 180 NM OF AXIS BETWEEN 103W-120W.

...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 120W AND ALONG WITH THE UPPER LOW...IS 
PRODUCING MODERATE/STRONG SUBSIDENCE NW OF A LINE FROM 30N117W 
TO 18N140W. THE SUBSIDENCE IS PRODUCING AN INVERSION WITH A BASE 
OF 3000-4000 FT AND MAINTAINING A BROKEN STRATOCUMULUS FIELD N 
OF 23N W OF 116W. 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 19N114W TO 06N117W AND THE ASSOCIATED DOWNSTREAM DIFFLUENCE 
IS FOSTERING A SURFACE TROUGH NEAR 115W AND WIDESPREAD 
CONVECTIVE DEVELOPMENT ALONG THE ITCZ BETWEEN 104W-120W.

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 SRN 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.

NORTHERLY FLOW OVER THE BAY OF CAMPECHE HAS INITIATED A MODEST 
TEHUANTEPEC EVENT WITH THE MORNING QUIKSCAT PASS INDICATING 
WINDS 20-25 KT. THE EVENT WILL BE SHORT-LIVED AND GRADUALLY 
SUBSIDE...DIMINISHING 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