000
AXPZ20 KNHC 262132
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN APR 26 2009

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...
THE ITCZ AXIS IS CENTERED ALONG 03N78W TO 06N100W TO 04N120W TO 
05N132W TO 04N140W. SCATTERED MODERATE ISOLATED STRONG FROM 03N 
TO 07N BETWEEN 119W TO 130W. 


...DISCUSSION...
A TROUGH/RIDGE/TROUGH PATTERN COVERS MOST OF THE REGION WITH THE 
RIDGE AXIS ALONG 125W. A TROUGH OVER THE ERN PORTION OF THE AREA 
EXTENDS ALONG NW MEXICO AND THE BAJA CALIFORNIA PENINSULA. THE 
BASE OF THIS TROUGH REACHES 20N. SWLY FLOW AHEAD OF A SHORT-WAVE 
TROUGH OVER THE BAY OF CAMPECHE AND SE MEXICO IS TRANSPORTING 
HIGH DEBRIS CLOUDINESS FROM THE ITCZ CONVECTION TOWARDS CENTRAL 
AMERICA. A STRONG SHORT-WAVE TROUGH REMAINS W OF THE REGION. A 
DIFFLUENT PATTERN AHEAD OF THIS UPPER-LEVEL FEATURE IS ENHANCING 
SOME SHOWER ACTIVITY FROM 14N TO 19N BETWEEN 132W AND 137W. A 
RIDGE DOMINATES THE SW CORNER OF THE AREA...AND IS HELPING TO 
INDUCE MODERATE TO ISOLATED STRONG CONVECTION ALONG THE ITCZ 
AXIS WEST OF 115W. A SFC TROUGH IS ANALYZED ALONG 135W S OF 11N. 
A CLUSTER OF MODERATE/ISOLATED STRONG CONVECTION IS JUST AHEAD 
OF THE TROUGH AXIS FROM 06N TO 08N BETWEEN 135W AND 140W.

SURFACE LOW PRES ASSOCIATED WITH THE TROUGH W OF THE AREA IS
FORECAST TO TRACK N OVER THE NEXT 48 HRS AS THE SHORTWAVE TROUGH 
LIFTS NE. HOWEVER...SE WINDS OF ABOUT 20 KT ON THE EAST SIDE OF 
THE SFC LOW WILL CONTINUE TO IMPACT THE FAR NW CORNER OF THE 
REGION TONIGHT AND MON. 

HIGH PRES RIDGING EXTENDS SE INTO THE AREA FROM 31N128W TO 
17N115W. PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES OVER THE 
SW CONUS WILL KEEP NW 20-25 KT OVER THE NE WATERS N OF 21N E OF 
122W TO THE COAST OF BAJA CALIFORNIA COAST...BUT ARE EXPECTED TO 
GRADUALLY WEAKEN IN ABOUT 24 TO 36 HOURS. A QSCAT PASS FROM THIS 
MORNING CONFIRMED THESE WINDS.

TRADE WINDS IN THE 20 TO 25 KT RANGE COVER A LARGE PORTION OF 
THE AREA N OF THE ITCZ W OF ABOUT 115W. AN EARLIER QSCAT PASS 
ALSO CONFIRMED THESE WIND SPEEDS. COMPUTER MODEL ANTICIPATES A 
GRADUAL DECLINE IN THE TRADE WINDS AS STRONG HIGH PRES LOCATED 
WELL N OF AREA WEAKENS.

MOSTLY FAIR WEATHER PREVAILS ALONG THE MEXICAN COAST AND THE 
BAJA CALIFORNIA PENINSULA. VIS SATELLITE IMAGERY ALSO SHOWS 
PATCHES OF SCATTERED TO BROKEN STRATOCUMULUS CLOUDS N OF 19N W 
OF 115W. 

GAP WINDS...
NE-E WINDS OF 20 KT IN THE GULF OF PAPAGAYO ARE FORECAST TO 
PERSIST OVER THE NEXT 48 HRS WITH SEAS UP TO 8 FT.

$$
GR