000
AXPZ20 KNHC 041538
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI APR 04 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 1515 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N86W 4N95W 2N107W 4N124W 3N140W. 
SCATTERED MODERATE TO ISOLATED STRONG 50 NM EITHER SIDE OF AXIS 
BETWEEN 91W AND 93W.

...DISCUSSION...
W OF 130W...A VIGOROUS CUT-OFF LOW HAS BEEN DRIFTING SOUTHWARD 
DURING THE PAST 24 HOURS AND IS SITUATED JUST W OF THE 
DISCUSSION AREA NEAR 26N148W. LARGE SCALE MODELS INDICATE THAT 
THE LOW SHOULD BEGIN TO WEAKEN AND MOVE OVER THE NORTHWEST 
PORTION OF THE AREA ON SUN. NEXT APPROACHING STRONG MID TO UPPER 
PULSE OVER THE NW PACIFIC IS EXPECTED TO TRIGGER THE LOWS 
NORTHEASTWARD TRACK. A RELATIVELY STRONG SUBTROPICAL JETLET 
ENTERING THE AREA NEAR 19N140W CONTINUES NORTHEASTWARD TO 
27N130W. BOTH FEATURES ARE PRODUCING MULTI-LAYERED CLOUDS N OF 
12N...WITH A FEW SHOWERS OVER THE EXTREME NW AREA. A RIDGE AXIS 
EXTENDS OVER THE SOUTHWEST REGION...S OF 10N. DIFFLUENT 
EASTERLIES S OF THE AXIS ARE SUPPORTING SCATTERED SHOWERS AND 
THUNDERSTORMS ALONG THE ITCZ. AT THE SURFACE...A WEAKENING 
FRONTAL BOUNDARY IS ASSOCIATED WITH THE AFOREMENTIONED UPPER LOW 
AND ALONG 140W N OF 20N. SELY FLOW DOWNSTREAM OF THE FRONT TO 
135W IS IN THE 15-20 KT RANGE WITH A NW SWELL NEAR 8 FT. 
ELSEWHERE...TRADES 20 KT OR LESS LIE N OF 10N S OF 20N...WITH 
SEAS BELOW 8 FT. EXPECT THE THE NE-E WINDS AND SEAS TO INCREASE 
SLIGHTLY...N OF 9N EARLY SAT MORNING AND INTO SUN AS THE 
STRENGTHENING SUBTROPICAL HIGH INTERACTS WITH THE WEAKENING 
FRONT. HOWEVER...WAVE MODELS SUGGEST THAT THE SEAS WILL NOT BE 
HIGHER THAN 9 FT FOR THIS TIME PERIOD. 

E OF 130W...THE EARLIER MENTIONED SUBTROPICAL JET BECOMES MORE 
ZONAL E OF 27N130W...AS IT PROPAGATES EASTWARD ALONG 27N OVER 
SOUTHERN BAJA CALIFORNIA AND INTO NORTHERN MX. A PLUME OF MID TO 
UPPER TROPOSPHERIC MOISTURE ASSOCIATED WITH THE JET SPREADS OVER 
THE DISCUSSION AREA N OF 21N. A QUASI-STATIONARY MID-LEVEL 
ANTICYCLONE DOMINATES THE CENTRAL PORTION...ALONG 15N...AND IS 
GENERATING MODERATE SUBSIDENCE DRIER CONDITIONS FROM 7N TO 21N. 
AT THE SURFACE...FRESH NORTHERLY WINDS TO 20 KT CONTINUE TO 
INFLUENCE THE W COAST AND ADJACENT WATERS OF BAJA 
CALIFORNIA...AND THE SOUTHERN PORTION OF THE GULF OF CALIFORNIA. 
LITTLE CHANGE OVER THIS REGION IS EXPECTED THROUGH THE WEEKEND 
AS THE SUBTROPICAL HIGH TO THE NW OF THE AREA MAINTAINS 
STRENGTH. EXPECT SEAS TO GRADUALLY BUILD TO 9 FT IN A GENERALLY 
NW SWELL N OF 27N E OF 122W ON SUN.


$$
ROBERTS