000
AXPZ20 KNHC 012126
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED APR 01 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 
2130 UTC.

...ITCZ...
THE ITCZ AXIS EXTENDS FROM 08N83W TO 01N110W TO 04N133W TO 
03N140W. ISOLATED MODERATE CONVECTION IS WITHIN 60 NM EITHER 
SIDE OF AXIS E OF 92W. SCATTERED MODERATE CONVECTION IS WITHIN 
180 NM N OF AXIS BETWEEN 132W AND 138W. 

...DISCUSSION...
ALOFT...A MID TO UPPER-LEVEL TROUGH EXTENDS ACROSS THE SW CONUS 
THEN CONTINUES SW FROM NW MEXICO TO OVER THE NORTHERN BAJA 
PENINSULA NEAR 28N TO AN UPPER-LEVEL LOW THAT HAS DEVELOPED 
ALONG THE TROUGH AXIS NEAR 28N137W. A 90-110 KT SUBTROPICAL 
JETSTREAM IS JUST S OF THE TROUGH FROM 25N122W TO 28N104W WHERE 
WINDS INCREASE TO 120-130 KT. THE JET CROSSES NORTHERN MEXICO 
INTO SOUTH-CENTRAL TEXAS. A DEEP UPPER-LEVEL HIGH CENTERED NEAR 
11N108W DOMINATES THE AREA S OF THE TROUGH BETWEEN 90W AND 125W. 
MODERATE TO STRONG SUBSIDENCE WITH DRY STABLE AIR IS ASSOCIATED 
WITH THIS ANTICYCLONIC CIRCULATION MAINLY S AND E OF THE HIGH 
CENTER. THIS FEATURE WILL PERSIST OVER THE AREA OVER THE NEXT 
DAY OR SO...AS THE INTENSITY REMAINS FAIRLY CONSTANT. WATER 
VAPOR IMAGERY INDICATES DRY AIR FROM 25N TO 30N...AND INCREASING 
MOISTURE S OF 25N COINCIDENT WITH THE UPPER JET. A BAND OF  
BROKEN TO OVERCAST STRATOCUMULUS CLOUDS ARE EMBEDDED WITHIN THE 
MOIST AIR FROM 15N TO 25N.

AT THE SURFACE...A 1038 MB SURFACE HIGH IS CURRENTLY LOCATED NW 
OF THE DISCUSSION AREA NEAR 36N149W...WITH A RIDGE EXTENDING 
THROUGH THE AREA FROM 30N140W TO 12N108W. THE PRES GRADIENT 
BETWEEN THE RIDGE AND THE ITCZ IS SUPPORTING MODERATE TO STRONG 
TRADES IN THE 20-25 KT RANGE W OF 130W. THIGH PRES GRADIENT 
BETWEEN THIS HIGH AND LOWER PRES OVER THE SW U.S. IS ALSO 
SUPPORTING GALE FORCE WINDS JUST N OF THE FORECAST AREA NEAR THE 
COAST OF CALIFORNIA. WINDS ARE EXPECTED TO SLIGHTLY INCREASE N 
OF 28N BETWEEN 115W AND 130W DUE TO A WEAK COLD SURGE FROM THE 
NORTH. 

$$
GR