000
AXPZ20 KNHC 010938
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON MAR 01 2010

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0800 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG AN AXIS 
FROM 05N77W TO 02N100W TO 06N125W TO 04N132W TO 04N140W. 
SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS FOUND 
WITHIN 150 NM S OF THE ITCZ AXIS E OF 79W AND WITHIN 150 NM N OF 
THE ITCZ AXIS W OF 139W. A TROUGH IS EMBEDDED IN THE ITCZ WITH 
SCATTERED MODERATE CONVECTION FOUND WITHIN 90 NM W AND 30 NM E 
OF ITS AXIS FROM 08N104W TO 00N107W.

...DISCUSSION...

SPLIT FLOW IS FOUND ALOFT OVER THE FORECAST AREA WITH THE 
SOUTHERN STREAM JET EXTENDING W FROM CENTRAL MEXICO ALONG 20N TO 
THE LEADING EDGE OF A WEAKENING UPPER TROUGH WITH AN AXIS FROM 
22N128W TO 04N135W. A BAND OF CIRRUS CLOUDS DENOTES THE AREA OF 
TROPICAL MOISTURE TRANSPORT ALOFT NORTHEASTWARD INTO MEXICO FROM 
THE ITCZ ALONG THE JET AXIS. THIS SOUTHERN STREAM TROUGH WILL 
CONTINUE TO WEAKEN AND SHIFT EASTWARD AS THE PROGRESSIVE 
NORTHERN STREAM BRINGS THE DEEP-LAYERED TROUGH CURRENTLY OVER NW 
WATERS EASTWARD. THE ASCAT PASS FROM 0552 UTC SHOWED NW WINDS TO 
30 KT BEHIND THE ASSOCIATED COLD FRONT. THIS FRONT WILL WEAKEN 
THROUGH THE DAY TODAY AS THE BULK OF THE SHORTWAVE ENERGY 
ASSOCIATED WITH THIS SYSTEM PUSHES NORTHEASTWARD OUT OF THE 
FORECAST AREA...WITH THE WESTERN PORTION OF THE FRONT EXCEPTED 
TO DISSIPATE BY TUE MORNING AND THE REMAINDER OVER FORECAST 
WATERS DISSIPATING AS THE NORTHERN PORTION OF THE FRONT MOVES 
INTO CALIFORNIA WED MORNING. 1019 MB HIGH PRES CURRENTLY AHEAD 
OF THIS FRONT NEAR 29N126W HAS BEEN WEAKENED AND SHOVED EASTWARD 
AS THIS COLD FRONT ADVANCED OVER THE LAST 24 HOURS. LOOK FOR 
THIS HIGH TO MERGE WITH STRONGER HIGH PRES W OF THE FRONT TUE. 
THE 0546 UTC ASCAT AND 0322 UTC WINDSAT PASSES SHOW FRESH TRADES 
IN PLACE OVER WESTERN WATERS FROM 06N TO 13N W OF 130W. LOOK FOR 
THE AREA OF TRADES TO EXPAND NORTHEASTWARD TUE INTO WED AS HIGH 
PRES BUILDS AND THE PRES GRADIENT BETWEEN IT AND THE ITCZ 
INCREASES. MEANWHILE...NW SWELL BEHIND THE COLD FRONT WILL RAISE 
SIGNIFICANT WAVE HEIGHTS TO 20 FT OVER FORECAST WATERS BY TUE 
MORNING. CURRENTLY...NW SWELL TO 15 FT RESIDES OVER THE NW HALF 
OF THE FORECAST AREA ASSOCIATED WITH THE DEEP-LAYERED NORTHERN 
STREAM TROUGH OVER THE SOUTHERN U.S. PLAINS AND NORTHERN MEXICO. 
THIS SWELL WILL DAMPEN AS IT SPREADS SOUTHEASTWARD...BUT WILL 
QUICKLY BE REPLACED BY THE NEW LONGER PERIOD BATCH OF NW SWELL 
BEHIND THE COLD FRONT.

GAP WINDS...
LIGHT AND VARIABLE WINDS WERE REPORTED IN THE GULF OF 
TEHUANTEPEC BY THE 0406 UTC ASCAT PASS. IN THE WESTERN GULF OF 
MEXICO...WINDS HAVE TURNED SOUTHERLY IN ADVANCE OF THE DEEP 
LAYER TROUGH CURRENTLY PASSING THROUGH U.S. SOUTHERN PLAINS AND 
NORTHERN MEXICO. THE COLD FRONT ASSOCIATED WITH THIS DEEP LAYER 
TROUGH WILL PASS THROUGH THE WESTERN GULF AND USHER NORTHERLY 
WINDS THROUGH THE ISTHMUS OF TEHUANTEPEC BEGINNING TUE 
AFTERNOON. WINDS WILL QUICKLY RISE TO GALE FORCE.

THE COLD FRONT THAT INDUCED THE GALE YESTERDAY IN THE GULF OF 
TEHUANTEPEC HAS PUSHED SOUTHWARD THROUGH CENTRAL AMERICA AND HAS 
WEAKENED OVER THE SW CARIBBEAN. NEAR GALE FORCE WINDS 
ARE CURRENTLY FOUND IN THE GULF OF PAPAGAYO BEHIND THE COLD 
FRONT WITH N WINDS TO 25 KT IN THE GULF OF PANAMA ACCORDING TO 
THE 0222 UTC ASCAT PASS. WINDS ARE EXPECTED TO DIMINISH BELOW 20 
KT IN BOTH LOCATIONS OVERNIGHT TONIGHT AS THE FRONTAL BOUNDARY 
FINALLY DISSIPATES.

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

$$
SCHAUER