000
AXPZ20 KNHC 010349
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE APR 01 2008

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 0315 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG AXIS 07N81W 03N102W 07N123W 
04N140W.  WIDELY SCATTERED MODERATE WITHIN 90 NM EITHER SIDE OF 
AXIS BETWEEN 82W AND 108W AND AND WITHIN 300 NM S OF AXIS 
BETWEEN 116W AND 122W.

...DISCUSSION...
A SHARP MID TO UPPER SHORTWAVE TROUGH HAS MOVED EASTWARD ALONG 
137W SUPPORTING A COLD FRONT THAT IS ALONG THE NW PORTION OF THE 
DISCUSSION AREA FROM 30N136W TO 28N140W. ALL OF THE ASSOCIATED 
CONVECTION LIES N OF THE REGION...WHERE THE GREATEST LIFT AND 
DIVERGENCE ALOFT EXISTS. A LARGE UPPER HIGH IS SITUATED IN THE 
TROPICAL EPAC NEAR 15N102W AND A WEAKER HIGH IS LOCATED NEAR 
5N133W. STRONG SW FLOW ALOFT...REACHING 100 KT AT BAJA 
CALIFORNIA...BETWEEN THE HIGHS AND THE TROUGH IS ADVECTING A 
PLUME OF MOISTURE...MAINLY IN THE FORM OF MID-HIGH LEVEL 
CLOUDS...ACROSS SOUTHERN BAJA CALIFORNIA AND INTO NORTHWESTERN 
MAINLAND MEXICO.  SUBSIDENCE PREVAILS ELSEWHERE...ESPECIALLY N 
OF 10N E OF 110W DUE TO UPPER CONVERGENCE.  THIS CORRESPONDS 
WITH THE RATHER ANEMIC CONVECTION WITH THE ITCZ THROUGHOUT MOST 
OF THE REGION EXCEPT BETWEEN 110 AND 122W. 

AT THE SURFACE...A MODEST 1022 MB SUBTROPICAL RIDGE IS OBSERVED 
NEAR 32N125W.  THE WEAKENING OF THE HIGH IS DUE TO A 
SOUTHEASTWARD MOVING 1010 MB LOW NEAR 37N137W. THIS HAS ALLOWED 
NE/E TRADES TO SLACKEN ACROSS THE REGION WITH 20 KT WINDS MAINLY 
CONFINED FROM 7N-17N W OF 122W AND IMMEDIATELY ADJACENT TO THE 
WEST COAST OF BAJA CALIFORNIA.  THE MAIN WIND EVENT IN THE AREA 
DURING THE NEXT DAY AND A HALF WILL BE ASSOCIATED WITH THE 
AFOREMENTIONED COLD FRONT. AS THE FRONT PUSHES FARTHER INTO THE 
REGION...WINDS AROUND 20 TO POSSIBLY 25 KT ARE EXPECTED ON 
EITHER SIDE OF THE FRONT N OF 25N. NW SWELLS WILL BUILD IN 
BEHIND THE FRONT LATE ON TUESDAY UP TO ABOUT 9 FT.  IN TWO DAYS 
AS THE FRONT BEGINS DISSIPATING...IT IS POSSIBLE THAT THERE WILL 
BE NO AREAS OF 20 KT SURFACE WINDS ANYWHERE IN THE REGION.  IN 
THREE DAYS TIME...A NEW COLD FRONT WILL BE ENTERING THE NW 
CORNER OF THE AREA.  AT THE SAME TIME...THE PRESSURE GRADIENT 
NEAR BAJA CALIFORNIA WILL TIGHTEN.  BOTH LOCATIONS SHOULD SEE A 
RESUMPTION OF 20-25 KT WINDS AT THAT TIME.  IT IS NOTED THAT THE 
ECMWF IS CONSIDERABLE SLOWER IN BRINGING IN THE FORMER FEATURE 
INTO OUR AREA COMPARED WITH THE GFS.

$$
LANDSEA