000
AXPZ20 KNHC 191608
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT APR 19 2008

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 1545 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 06N77W 04N85W 04N94W 95N105W
05N115W 04N126W 03N132W 03N140W. SCATTERED MODERATE TO NUMEROUS
STRONG CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 
82W-86.5W. SCATTERED STRONG CONVECTION IS WITHIN 60 NM S OF THE 
AXIS BETWEEN 114W-118W. SCATTERED MODERATE CONVECTION IS WITHIN 
60 NM N OF THE AXIS E OF 80W.

...DISCUSSION...

W OF 100W...

A MID/UPPER LEVEL TROUGH MOVING QUICKLY EWD ENTERS THE AREA 
THROUGH 32N125W...AND EXTENDS SW THROUGH 27N130W TO A MID/UPPER
LEVEL CYCLONIC CIRCULATION NEAR 22N138W...AND CONTINUES TO WELL
W OF THE REGION TO ANOTHER MID/UPPER LEVEL CYCLONIC CIRCULATION
JUST NE OF THE BIG ISLAND OF HAWAII. ANOTHER TROUGH EXTENDS FROM 
22N125W SE THROUGH 18N120W TO 12N113W...THEN SHARPENS SEWD TO
A SMALL MID/UPPER LEVEL CYCLONIC CIRCULATION NEAR 6N107W. THE
CYCLONIC CIRCULATION NEAR 22N138W WILL THEN BEGIN TO LIFT NE ON 
SUN ON STRONG SW FLOW. SATELLITE WATER VAPOR IMAGERY SHOWS 
MODERATE SUBSIDENCE NW OF A LINE FROM 32N118W TO 23N129W TO
18N140W. TO THE NE OF THE MID/UPPER LEVEL TROUGH...A RATHER 
STRONG SUBTROPICAL JET STREAM BRANCH EXTENDS FROM 17N132W TO 
23N125W...AND TO NE OF THE AREA TO ACROSS NRN BAJA CALIFORNIA. 
SATELLITE-DERIVED WINDS ARE INDICATED TO BE IN THE RANGE OF 
60-90 KT OVER THE NE PART OF THE AREA WHERE THE FLOW BECOMES 
CONFLUENT AROUND THE NRN PERIPHERY OF ANTICYCLONIC FLOW. THE 
ANTICYCLONIC FLOW NOTED HERE IS PART OF A HIGHLY AMPLIFIED AREA 
OF ANTICYCLONIC FLOW WITH A MEAN AXIS RUNNING ALONG THE WRN
SECTION OF MEXICO SE TO AN ELONGATED UPPER LEVEL ANTICYCLONE
NEAR 19N99W. EXTENSIVE UPPER LEVEL MOISTURE IN THE FORM OF HIGH 
CIRRUS CLOUDS IS BEING CHANNELED BY THE JET STREAM NEWD TOWARDS 
BAJA...NRN MEXICO AND THE SW UNITED STATES. SCATTERED SHOWERS
AND TSTMS ARE PRESENT N OF THE ITCZ WITHIN 30 NM EITHER SIDE A 
LINE FROM 9N103W TO 8N109W TO 7.5N114W...AND ALSO WITHIN 30 NM 
OF 10N125W.

AT THE SURFACE...HIGH PRES RIDGING ENTERS THE REGION THROUGH 
32N138W AND EXTENDS TO 25N126W AND TO 18N114W. HIGH PRES COVERS 
THE AREA N OF 15N W OF 115W. A SURFACE TROUGH MOVING W 15 KT IS 
ALONG 114W FROM 3N-10N...AND IS ENHANCING ITCZ CONVECTION WITHIN 
180 NM TO ITS E. A LOW TO MID-LEVEL CYCLONIC CIRCULATION IS NOTED
NEAR 5.5N114W PER OBSERVED CLOUD MOTION AND PARTIAL QUIKSCAT DAT
FROM JUST PAST 1400 UTC THIS MORNING. SCATTERED TO BROKEN LOW 
CLOUDS MOVING SW WITH ISOLATED SHOWERS IN NE FLOW ARE SEEN W OF 
130W.

E OF 100W...

MODERATE TO STRONG UPPER LEVEL WLY FLOW COVERS THE AREA N OF 24N 
AND E OF 111W. MODERATE SUBSIDENCE WITH DRY CONDITIONS ARE NOTED 
HERE...AND ALSO OVER JUST ABOUT THE ENTIRE AREA OUTSIDE THE 
ITCZ. A MID/UPPER LEVEL RIDGE RUNS FROM SE HONDURAS S THROUGH 
07.5N88W AND TO THE EQUATOR AT 88W. WEAK DIFFLUENCE ALOFT HAS 
AGAIN TRIGGERED SCATTERED TSTMS...SOME STRONG...OVER THE FAR ERN 
PART FROM ALONG COAST OF COLOMBIA FROM 4N-7N AND W TO 87W. ONLY 
ISOLATED SHOWERS AND TSTMS ARE NOTED ELSEWHERE S OF 8N AND E OF 
8N89W UNDER AS A WEAK PRES GRADIENT HAS TAKEN HOLD.

GAP WINDS...NE 20 KT WINDS ACROSS THE GULF OF PAPAGAYO ARE 
EXPECTED TO CONTINUE IN BRIEF SURGES THROUGH THE NEXT 48-72 HRS 
AT WHICH TIME STRONG TRADES IN THE SW CARIBBEAN WILL BE WEAK.

$$
AGUIRRE