000
AXPZ20 KNHC 020355
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU APR 02 2009

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0330 UTC.

...ITCZ...
ITCZ AXIS EXTENDS FROM 08N83W TO 01N110W TO 02N125W TO 03N140W. 
ISOLATED MODERATE CONVECTION IS WITHIN 100 NM N OF AXIS BETWEEN 
90W-92W.  SIMILAR CONVECTION FROM 22N TO 6N W OF 130W.  

...DISCUSSION...
ALOFT...MID TO UPPER-LEVEL TROUGH EXTENDS ACROSS SW CONUS THEN 
CONTINUES SW TO OVER NORTHERN BAJA PENINSULA TO NEAR 28N120W. 
90-110 KT SUBTROPICAL JETSTREAM JUST S OF TROUGH FROM 26N121W TO 
26N107W WHERE WIND INCREASE TO 120-130 KT.  JET CROSSES NORTHERN 
MEXICO AND SE TEXAS.  DEEP UPPER-LEVEL HIGH CENTERED AT 11N108W 
DOMINATES AREA S OF TROUGH BETWEEN 90W AND 125W.  MODERATE TO 
STRONG SUBSIDENCE WITH DRY STABLE AIR ASSOCIATED WITH THIS 
ANTICYCLONIC CIRCULATION S AND E OF THE HIGH CENTER.  FEATURE 
PERSIST OVER AREA THE NEXT DAY OR SO...AS INTENSITY REMAINS 
FAIRLY CONSTANT.  WATER VAPOR IMAGERY INDICATES DRY AIR FROM 24N 
TO 30N...AND INCREASING MOISTURE S OF 24N DUE TO THE PRESENCE OF 
UPPER JET.  BROKEN TO OVERCAST STRATOCUMULUS CLOUDS EMBEDDED 
WITHIN MOIST AIR FROM 15N-24N.

AT THE SURFACE...1037 MB SURFACE HIGH CURRENTLY NW OF DISCUSSION 
AREA NEAR 36N150W WITH RIDGE EXTENDING THROUGH AREA FROM 30N140W 
TO 16N108W.  PRES GRADIENT BETWEEN RIDGE AND ITCZ SUPPORTING 
MODERATE TO FRESH TRADE WINDS W OF 130W.  THESE WINDS EXPECTED 
TO DIMINISH IN 36 TO 48 HOURS AS HIGH PRES NW OF AREA WEAKENS. 
IN ADDITION...HIGH PRES GRADIENT BETWEEN ABOVE MENTIONED SFC 
HIGH AND LOWER PRES OVER SW U.S. SUPPORTING GALE FORCE WINDS 
JUST N OF THE FORECAST AREA NEAR THE COAST OF CALIFORNIA.  WINDS 
ARE EXPECTED TO SLIGHTLY INCREASE N OF 23N BETWEEN 115W AND 130W 
IN ABOUT 48 HOURS DUE TO A WEAK COLD SURGE FROM THE NORTH. 

$$
GR