000
AXPZ20 KNHC 122127
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON APR 12 2010

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 
2130 UTC.

...ITCZ...

AXIS EXTENDS ALONG 05N77W TO 08N88W TO 05N115W...THEN CONTINUES 
FROM 04N120W TO 06N130W TO 03N140W. SCATTERED MODERATE TO STRONG 
WITHIN 90-120 NM OF THE AXIS BETWEEN 85W AND 90W. SCATTERED 
MODERATE ISOLATED STRONG WITHIN 120 NM S OF THE AXIS E OF 
85W...FROM THE EQUATOR TO 07N BETWEEN 98W AND 111W. SCATTERED 
MODERATE WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 111W AND 
140W. 

...DISCUSSION...

A DEEP LAYERED CYCLONE IS CENTERED OVER WESTERN OREGON AND IS 
BEGINNING TO LIFT NWD. AN ASSOCIATED NEGATIVELY TILTED SHORTWAVE 
MID TO UPPER TROUGH EXTENDS SSE FROM THE CYCLONE TO 28N112W. 
THE TROUGH IS GRAZING THE NE PORTION OF THE AREA AND IS NOT
EXPECTED TO HAVE MUCH OF AN IMPACT ON THE AREA BEYOND 24 HOURS.  
FURTHER SOUTH...AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 
12N121W WITH A RIDGE EXTENDING W TO BEYOND 11N140W...AND A RIDGE 
EXTENDING E TO 10N92W. 

UPPER DIFFLUENT FLOW S AND SE OF THE ANTICYCLONE IS ENHANCING 
CONVECTION ALONG THE ITCZ BETWEEN 105W AND 130W. THE RESULTANT 
CONVECTIVE DEBRIS IS FANNING OUT WITHIN THE RIDGE OVER THE 
DISCUSSION AREA S OF 15N BETWEEN 110W AND 135W...WITH SOME 
MOISTURE SWEEPING NE OVER CENTRAL MEXICO. AXIS OF A BRANCH OF 
THE SUBTROPICAL JET CUTS ACROSS 26N140W TO 29N130W THEN DIVES
SE THROUGH 26N120W TO THE BASE OF AN AMPLIFYING SHORTWAVE TROUGH 
OVER OLD MEXICO NEAR 21N105W. SATELLITE DERIVED WINDS INDICATED 
CORE SPEEDS OF 110-130 KT. THIS JET CAPS AN EXPANDING AREA OF 
MID TO UPPER LEVEL MOISTURE ORIGINATING FROM ITCZ CONVECTION W 
OF AREA BETWEEN 150W AND 165W. 

AN UPPER SHORTWAVE TROUGH OVER THE SE UNITED STATES EXTENDS SW 
ACROSS THE GULF OF MEXICO AND THE YUCATAN PENINSULA TO A BASE 
OVER THE E PACIFIC NEAR THE COAST OF GUATEMALA. THIS TROUGH IS 
SUPPRESSING AN UPPER RIDGE WHICH EXTENDS W FROM COLOMBIA TO A 
SHARP CREST AT 08N88W AND WAS SEPARATED FROM THE EAST-CENTRAL 
PACIFIC RIDGE BY A COL. UPPER LEVEL DIFFLUENT FLOW OVER THE W 
PORTION OF THE RIDGE IS ENHANCING CONVECTION ALONG THE ITCZ 
BETWEEN COLOMBIA AND 105W...WITH SOME OF THE DEBRIS MOISTURE 
NOW ADVECTED NE ALONG THE PERIPHERY OF THIS TROPICAL RIDGE OVER 
THE SOUTHERN CARIBBEAN. OTHERWISE...THE UPPER LEVELS ARE DRY 
OVER THE TROPICAL PACIFIC FROM 08N TO 18N E OF 105W.

AT THE SURFACE...A COLD FRONT IS BEGINNING TO WEAKEN FROM 
EXTREME NE BAJA CALIFORNIA NEAR 31N116W TO 23N130W AND IS 
EXPECTED TO CONTINUE EAST AND DISSIPATE OVERNIGHT. A RIDGE WILL 
BUILD SE ACROSS THE AREA IN THE WAKE OF THE FRONT. NE TRADES AT 
15 TO 20 KT GENERALLY COVER THE AREA FROM 08N TO 15N W OF 130W. 
ASSOCIATED NE SWELL IS MIXING WITH SW SWELL THAT HAS BEEN 
PROPAGATING NE OVER THE AREA E OF 130W...AND NOTED AS FAR N AS 
SOUTHERN CALIFORNIA. 

GAP WINDS...

GULF OF PAPAGAYO...PERSISTENT NE TRADES TRADES OVER THE W  
CARIBBEAN SEA WILL CONTINUE TO FUNNEL THROUGH THE GULF OF 
PAPAGAYO AT 20 TO 25 KT THROUGH TONIGHT THEN DIMINISH BELOW 20 
KT LATE TUE.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
COBB