000
AXPZ20 KNHC 070341
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE APR 07 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...
THE INTERTROPICAL CONVERGENCE ZONE LIES ALONG A LINE FROM 04N77W 
TO 07N90W TO 01N106W... THEN FROM 02N127W TO 06N140W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS FROM 02N TO 05N BETWEEN 
96W AND 104W.

...DISCUSSION...
GAP WINDS...
ATTENTION REMAINS FOCUSED ON A LATE SEASON GULF OF TEHAUNTEPEC 
GAP WIND EVENT. TUXTLA GUTIERREZ...LOCATED IN SE MEXICO ALONG 
THE ISTHMUS OF TEHUANTEPEC...HAS REPORTED GALE FORCE WINDS OF 38 
KT DURING THE PAST 2 HOURS. THESE WINDS ARE ASSOCIATED WITH A  
STRONG SURFACE RIDGE IN THE WAKE OF A COLD FRONT CURRENTLY 
MOVING ACROSS THE YUCATAN PENINSULA. WINDS ARE FORECAST TO REACH 
STORM FORCE OVERNIGHT TONIGHT INTO EARLY TUE...THOUGH WOULD NOT 
BE SURPRISED TO LOCALLY HIGHER WINDS GIVEN THE EXPECTED STEEP 
LOW LEVEL LAPSE RATES IN THIS REGION. THESE WINDS ARE FORECAST 
TO SUBSIDE TO GALE FORCE BY LATE TUE BEFORE DIMINISHING EARLY 
WED. THE STRONGEST WINDS ARE EXPECTED BETWEEN TONIGHT AND 
07/1200 UTC. GIVEN THE STRONG WINDS...SEAS WILL BUILD UP TO 
17-18 FT BASED ON WAVEWATCH GUIDANCE. THE SAME SURFACE RIDGE 
WILL CONTINUE RESULTING IN NW TO N WINDS UP TO 20 KT ACROSS THE 
GULF OF CALIFORNIA DURING THE NEXT 12 HOURS OR SO. HOWEVER... 
WINDS WILL INCREASE AGAIN ACROSS THIS REGION EARLY WED. 
ALSO...THE INCREASING TRADE WINDS OVER THE CARIBBEAN REGION ARE 
FORECAST TO EXTEND INTO THE GULF OF PAPAGAYO BY TUE NIGHT/EARLY 
WED...WHEN SURFACE WINDS ARE EXPECTED TO REACH 20 TO 25 KT.

ELSEWHERE...
A SFC TROUGH...REMNANTS OF A FRONTAL BOUNDARY...CURRENTLY 
EXTENDS FROM 30N126W TO 22N134W. NW WINDS OF 20 FT AND SEAS UP 
TO 15 FT ARE FOUND IN THE WAKE OF THIS TROUGH WHICH IS BEING 
SUPPORTED BY A CLOSED UPPER LOW CENTERED NEAR 35N130W. A JET 
STREAM BRANCH WITH CORE WINDS OF 90-110 KT AROUND THE BASE OF 
THIS UPPER-LEVEL LOW CLIPS THE N WATERS PARTICULARLY BETWEEN 
125W AND 135W. COMPUTER MODEL GUIDANCE SUGGESTS THAT THIS LOW 
WILL MOVE NEWD REACHING THE COAST OF CALIFORNIA EARLY WED. THE 
NORTHWESTERLY SWELL BEHIND THE TROUGH WILL PROPAGATE ACROSS A 
LARGE PART OF THE DISCUSSION AREA THROUGH MIDWEEK. 

FARTHER TO THE S...THE AXIS OF THE SUBTROPICAL JET STREAM 
STRETCHES ALONG A LINE FROM 22N140W TO 25N120W TO CENTRAL BAJA 
CALIFORNIA INTO N MEXICO AND TEXAS...WHERE A MAIN CORE OF 130 KT 
IS NOTED. THIS JET IS ADVECTING ABUNDANT MID TO UPPER LEVEL 
MOISTURE EASTWARD ACROSS THE DISCUSSION AREA. SE OF THIS 
JET...ATMOSPHERIC STABILITY AND DEEP LAYERED DRY AIR IN THE 
VICINITY OF AN UPPER HIGH NEAR 11N100W IS SUPPORTING FAIR 
WEATHER ACROSS MUCH OF THE SE PORTION OF THE DISCUSSION AREA. 

$$
GR