000
AXPZ20 KNHC 251518
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT APR 25 2009

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 
1500 UTC.

...ITCZ...
AXIS IS ALONG 6N77W 7N90W 3N120W 6N140W. SCATTERED STRONG 
CONVECTION FROM 05N-07N E OF 79W. SCATTERED MODERATE TO STRONG 
CONVECTION WITHIN 120 NM N OF AXIS FROM 110W-116W AND WITHIN 200 
NM N OF AXIS FROM 134W-137W.

...DISCUSSION...
A LARGE UPPER LEVEL CYCLONIC CIRCULATION AND TROUGH IS NW OF THE 
AREA WITH MOIST SW FLOW E OF THE TROUGH WITH BROKEN/OVERCAST 
CLOUDS W OF 135W. THIS MOISTURE IS FLOWING THROUGH AN UPPER 
LEVEL RIDGE THAT IS OVER THE W PORTION OF THE DISCUSSION AREA W 
OF AROUND 125W. A 90 KT JET STREAM EXTENDS FROM 25N140W TO 
29N133W WHERE WINDS DECREASE. THE TAIL END OF A SHORTWAVE 
THROUGH MOVING THROUGH SOUTHERN CALIFORNIA AND NEVADA SEPARATES 
THIS RIDGE WITH AN UPPER LEVEL RIDGE FROM NORTHERN MEXICO NEAR 
THE BIG BEND OF TEXAS SW TO 16N110W.

A SHARP UPPER LEVEL TROUGH EXTENDS FROM THE WESTERN BAY OF 
CAMPECHE ACROSS MEXICO TO 5N103W. SW FLOW E OF THE TROUGH IS 
ADVECTING MID/UPPER LEVEL MOISTURE NE FROM SOUTHERN MEXICO TO 
COSTA RICA FROM CONVECTION OVER THE ITCZ. STRONG SUBSIDENCE WITH 
DRY STABLE AIR IS BETWEEN THE TROUGH AND ABOVE MENTIONED RIDGE.

COLD FRONT IS OVER NW MEXICO FROM THE ARIZONA/MEXICO BORDER NEAR
32N114W ACROSS THE FAR NW GULF OF CALIFORNIA TO THE W COAST OF 
BAJA CALIFORNIA NEAR 29N116W. NO SIGNIFICANT WEATHER IS 
ASSOCIATED WITH THE FRONT. OTHERWISE SURFACE RIDGE COVERS THE 
AREA N OF 12N W OF 105W. BROKEN/OVERCAST STRATOCUMULUS CLOUDS 
BLANKETS THE AREA N OF 18N W OF 115W. STRONG ELY WINDS CONTINUE 
TO BLOW THROUGH THE GULF OF PAPAGAYO REGION WILL CONTINUE 
THROUGH THE NEXT COUPLE OF DAYS BEFORE DIMINISHING SLOWLY EARLY 
NEXT WEEK.

$$
DGS