000
AXPZ20 KNHC 282203
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT MAR 28 2009

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 1500 UTC.

...ITCZ...
AXIS WAS ALONG 08N83W TO 04N92W TO 02N103W TO 02N112W TO 05N129W 
TO 06N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS 
WITHIN 120 NM OF AXIS BETWEEN 81W AND 95W. ISOLATED MODERATE 
CONVECTION WITHIN 180 NM N OF AXIS W OF 130W.

...DISCUSSION...
FEW SYNOPTIC FEATURES ON THE MAP TODAY...OTHER THAN A 1035 MB 
HIGH CENTERED AT 37N 143W...AND NW OF THE FORECAST AREA...WHICH 
IS HELPING TO INDUCE A N TO NE SURFACE FLOW UP TO 20 KT IN THE 
PACIFIC WEST OF BAJA...AND 120W. SEAS ACROSS THIS AREA ARE 
RUNNING 6 TO 9 FT IN MIXED WIND WAVES AND BUILDING NW SWELL. NLY 
FLOW OF 20-25 KT OFF OF THE NRN CALIFORNIA COAST EXTENDS S INTO 
N PORTIONS OF THE FORECAST AREA...AND WELL OFF SHORE OF NRN 
BAJA...WHERE N TO NW WIND SWELL WAS MAINTAINING SEAS AT 8 TO 10 
FT N OF 24N. A WEAK AND NON-CONVECTIVE CYCLONIC SWIRL OBSERVED 
EARLIER TODAY JUST WEST OF LAS TRES MARIAS ISLANDS...AND SE OF 
THE GULF OF CALIFORNIA...WAS SLOWLY SPINNING DOWN AND BECOMING 
ILL DEFINED. THE ITCZ REMAINS NONDESCRIPT AND ILL-DEFINED WITH 
THE ONLY SIGNIFICANT CONVECTION FOUND ACROSS THE FAR E AND FAR W 
PORTIONS...NEAR 92W AND W OF 130W.  NO GALES ARE ANTICIPATED IN 
THE NEXT FEW DAYS IN OUR AREA OF RESPONSIBILITY.  ONE ITEM WORTH 
WATCHING IS WHETHER THE CURRENT 45 KT GALE OVER THE WESTERN GULF 
OF MEXICO BEHIND A COLD FRONT WILL INDUCE A GAP WIND EVENT IN 
THE GULF OF TEHUANTEPEC. NONE OF THE MODELS ARE INDICATING A 
SIGNIFICANT TEHUANTEPECER...BUT A BRIEF 20 KT...POSSIBLY 20-25 
KT EVENT HAS BEEN INCLUDED IN THE HIGH SEAS FORECAST TO OCCUR 
OVERNIGHT THROUGH SUNDAY AFTERNOON. 

OF NOTE JUST SOUTH OF OUR REGION...THERE IS A PROMINENT ITCZ IN 
THE SOUTH PACIFIC STRETCHING ROUGHLY FROM 5S85W TO 3S135W WITH A 
SIZABLE FLAREUP OF CONVECTION NEAR 120W.  INDEED...THE TOTAL 
PRECIPITABLE WATER IMAGERY SHOWS MUCH MORE MOISTURE ASSOCIATED 
WITH THE SOUTHERN HEMISPHERE ITCZ THAN ITS COUNTERPART NORTH OF 
THE EQUATOR.  WHILE NOT UNCOMMON TO HAVE A SOUTH PACIFIC ITCZ 
THIS TIME OF YEAR...FURTHER TROPICAL DEVELOPMENT ALONG THIS 
SOUTHERN HEMISPHERE ITCZ IS NOT LIKELY.

IN THE UPPER LEVELS...A STRONG CUT-OFF LOW WAS OBSERVED NEAR 
23N142W...AND IS SHOWING SIGNS OF SLOWLY ELONGATING ENE TO WSW.  
A MODERATE UPPER LEVEL JET OF 85-100 KT OUT OF THE WEST WAS 
OCCURRING SOUTHEAST OF THE LOW...FROM 17N-20N WEST OF 130W. 
ISOLATED TO SCATTERED MID TO UPPER LEVEL CLOUDINESS OCCURS WEST 
OF 120W INDUCED BY THE FLOW AROUND THE UPPER LOW AS WELL AS 
OUTFLOW FROM THE ITCZ NEAR AND WEST OF 140W.  IN GENERAL...LARGE 
SCALE DESCENT IS DOMINATING THE REGION AS IT TYPICALLY DOES THIS 
TIME OF YEAR.     

$$
STRIPLING