000
AXPZ20 KNHC 120301
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE APR 12 2011

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...

THE INTERTROPICAL CONVERGENCE ZONE AXIS WAS ANALYZED FROM 08N78W 
TO 09N95W WITH A BREAK AND CONTINUING AGAIN FROM 06N104W TO 
04N117W TO 05N128W WITH A BREAK AND CONTINUING AGAIN FROM 
02N132W TO EQUATOR AT 135W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WITHIN 120 NM S OF AXIS BETWEEN 83W AND 88W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 180 NM OF 
AXIS BETWEEN 104W AND 110W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WITHIN 180 NM N OF AXIS BETWEEN 118W AND 123W. 

...DISCUSSION...

SURFACE FEATURES...
A 1034 MB SURFACE HIGH AT 37N138W NORTH OF OUR AREA IS HELPING 
TO PRODUCE WINDS OF 20 KT THROUGHOUT MUCH OF THE REGION N OF 09N 
AND W OF 117W.  WEST OF BAJA CALIFORNIA 20 KT NNW WINDS WERE 
OBSERVED BY SHIP DNER.  20 KT NE TRADEWINDS S OF 22N W OF 115W 
ARE ALSO RESULTING FROM THE GRADIENT PRODUCED BY THE SURFACE 
HIGH.  AS THE SYNOPTIC PATTERN CHANGES LITTLE DURING THE NEXT 
FEW DAYS...THIS WINDS SHOULD CONTINUE. THE ONLY NOTEWORTHY 
CHANGE IS THAT THE SURFACE WINDS WEST OF BAJA MAY GO UP TO 25-30 
KT IN ABOUT TWO DAYS.  SIGNIFICANT WAVE HEIGHTS CURRENTLY 
ACCOMPANYING THESE WINDS ARE UP TO 11 FT IN THE TRADEWIND BELT.

SURFACE WINDS HAVE ALSO BEEN ENHANCED IN THE GULF OF CALIFORNIA 
TODAY WITH PEAK NW WINDS INDICATED BY THE 1634Z ASCAT PASS OF 20 
TO 25 KT NORTH OF 25N.  THESE WINDS SHOULD DROP BELOW THE 20 KT 
THRESHOLD BY EARLY AFTERNOON TUESDAY.

A 1012 MB LOW IS LOCATED NEAR 08N101W.  WHILE THIS HAS A 
SUBSTANTIAL CIRCULATION ASSOCIATED WITH IT...THERE IS CURRENTLY 
NO DEEP CONVECTION NEARBY AND IT IS LIKELY TO DISSIPATE WITHIN 
THE NEXT DAY.  A SECOND SURFACE LOW HAS FORMED NEAR 04N131W WITH 
SCATTERED MODERATE CONVECTION WITHIN 180 NM N SEMICIRCLE.  
HOWEVER...THIS SYSTEM IS NOT LIKELY TO BECOME A PRE-SEASON 
TROPICAL CYCLONE DUE TO THE STRONG VERTICAL SHEAR CURRENTLY 
SCOURING THE TROPICAL NE PACIFIC WEST OF 120W.

A BRIEF WEAK NW SWELL EVENT WITH PEAK SIGNIFICANT WAVE HEIGHTS 
OF 8 TO 9 FT SHOULD REACH OUR NW CORNER BY EARLY AFTERNOON 
TUESDAY AND JUST LAST THROUGH WEDNESDAY.

GAP WIND EVENTS...
A MODERATE...N 20 TO 25 KT...GULF OF TEHUANTEPEC WIND EVENT 
SHOULD COMMENCE IN ABOUT 18 HOURS...AND BOTH THE GFS AND ECMWF 
RUNS NOW AGREE WITH THIS TIMING.  THIS IS UNLIKELY TO REACH GALE 
FORCE CONDITIONS AND SHOULD DROP BELOW THE 20 KT THRESHOLD LATE 
ON WEDNESDAY.

A WEAK...NE 20 KT...GULF OF PAPAGAYO WIND EVENT HAD PREVIOUSLY 
BEEN INDICATED IN THE HIGH SEAS FORECAST.  HOWEVER...THIS EVENT 
IS TOO WEAK AND EPISODIC WITH 20 KT ONLY FOR A FEW HOURS IN THE 
MORNINGS TO CONTINUE ITS MENTION IN THIS PRODUCT.

UPPER LEVELS...
A SHORT WAVE TROUGH IN THE MID AND UPPER LEVELS IS MOVING 
EASTWARD THROUGH 128W N OF 25N...SUPPORTING A WEAKENING SURFACE 
COLD FRONT EXTENDING FROM NORTHERN CALIFORNIA TO 31N140W. THE 
UPPER SHORT WAVE TROUGH WILL FLATTEN OUT DURING THE NEXT DAY AS 
UPPER LEVEL JET ENERGY DIGS A NEW SHORT WAVE TROUGH TO THE WEST 
ALONG 140W N OF 20N.

$$
LANDSEA