000
AXPZ20 KNHC 200346
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT FEB 20 2010

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 AXIS IS CENTERED ALONG 01N80W TO 06N97W TO 06N114W TO 
03N130W TO 06N139W. SCATTERED MODERATE AND ISOLATED STRONG 
CONVECTION WAS NOTED WITHIN 120 NM N OF THE AXIS BETWEEN 89W AND 
93W AND WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 103W AND 
116W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 180 NM N OF 
THE AXIS BETWEEN 123W AND 129W. 

...DISCUSSION...

AN UPPER LEVEL LOW IS CENTERED N OF THE AREA NEAR MONTERREY BAY 
CALIFORNIA WITH A WEAKENING/FLATTENING UPPER TROUGH EXTENDING 
FROM THE LOW TO 32N120W TO 27N120W. AN ATTENDANT SURFACE COLD 
FRONT ASSOCIATED WITH THIS FEATURE IS DISSIPATING AND CURRENTLY 
STRETCHES FROM 32N120W TO 21N135W. A SMALL AREA OF NW WINDS ARE 
OCCURRING BEHIND THE FRONT N OF 28N ALTHOUGH THE MAIN IMPACTS 
ASSOCIATED WITH THESE FEATURES ARE LONG PERIOD NW SWELL OF UP TO 
16 FT WHICH CONTINUES TO PROPAGATE THROUGH THE FAR N PORTION OF 
THE AREA. THE FRONT WILL DISSIPATE WITHIN 24 HOURS AS IT 
ENCOUNTERS THE MOUNTAINOUS TERRAIN OF BAJA CALIFORNIA ALTHOUGH 
NW WINDS WILL BECOME FUNNELED ALONG THE BAJA AND COAST OF OLD 
MEXICO N OF 20N AROUND A BUILDING RIDGE OF HIGH PRES THAT WILL 
ARRIVE BEHIND THE FRONT. 

AN UPPER LEVEL RIDGE IS W OF THIS TROUGH EXTENDING FROM 32N133W 
TO 27N134W WITH A DEEPER UPPER LEVEL TROUGH APPROACHING THE AREA 
EXTENDING FROM 32N140W TO THE BIG ISLAND OF HAWAII NEAR HILO. 
WATER VAPOR SATELLITE IMAGERY SHOWS AN AREA OF MODERATE 
SUBSIDENCE AND DRY AIR FROM 23N TO 30N E OF 133W. 

A WEAK SURFACE RIDGE IS ALSO IN PLACE S OF THE AFOREMENTIONED 
COLD FRONT FROM 10N TO 21N WITH ONLY A SMALL AREA OF 20 KT NE 
TRADES CONFINED TO THE FAR W PART OF THE DISCUSSION AREA FROM 
08N TO 14N W OF 133W. TRADES WILL EXPAND IN COVERAGE AND 
INCREASE TO 20 TO 25 KT DURING THE NEXT 48 HOURS AS HIGH PRES 
BECOMES ESTABLISHED OVER THE NW CORNER TIGHTENING THE PRES 
GRADIENT.

AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 06N122W WITH A 
RATHER FLAT UPPER LEVEL RIDGE AXIS EXTENDING TO 23N124W. MAINLY 
MID TO HIGH LEVEL MOISTURE IS BEING ADVECTED FROM THE TROPICS W 
OF 140W UP AND ALONG THE NORTHERN PERIPHERY OF THIS RIDGE TOWARD 
THE CENTRAL COAST OF MEXICO. ANOTHER MID TO UPPER LEVEL TROUGH 
EXTENDS FROM THE CENTRAL GULF OF MEXICO TO NEAR THE EQUATOR 
ALONG 96W. UPPER LEVEL DIFFLUENCE NEAR THE SOUTHERN PORTION OF 
THIS TROUGH IS ENHANCING CONVECTION WITHIN 120 NM N OF THE ITCZ 
AXIS BETWEEN 89W AND 93W AND WITHIN 120 NM EITHER SIDE OF AXIS 
BETWEEN 103W AND 116W. UPPER LEVEL DEBRIS MOISTURE FROM THIS 
ACTIVITY IS BEING ADVECTED NE ACROSS CENTRAL AMERICA AND INTO 
THE NW CARIBBEAN SEA.

A 1009 MB AREA OF LOW PRES IS EMBEDDED IN THE ITCZ CENTERED NEAR 
06N99W WITH A TROUGH EXTENDING FROM 13N96W TO 02N99W. AN EARLIER 
ASCAT PASS CAPTURED N TO NE WINDS OF 20 TO 25 KT WITHIN 210 NM 
EITHER SIDE OF THE TROUGH AXIS ALTHOUGH THERE HAVE BEEN NO 
ADDITIONAL RECENT SCATTEROMETER PASSES OR SURFACE OBSERVATIONS 
REPORTED IN THE PAST 6 HOURS. SCATTERED MODERATE AND ISOLATED 
STRONG CONVECTION IS OCCURRING WITHIN 330 NM E OF THE TROUGH 
AXIS AND WITHIN 120 NM W OF THE TROUGH AXIS. THESE FEATURES ARE 
EXPECTED TO DISSIPATE AS THEY CONTINUE TO PROPAGATE TO THE W 
AROUND 10 KT DURING THE NEXT 24 HOURS.

...GAP WINDS...
A STALLED OUT FRONTAL BOUNDARY REMAINS IN THE SW CARIBBEAN SEA 
WITH WINDS BEHIND IT BEING FUNNELED THROUGH THE NICARAGUA AND 
COSTA RICA PASSES INTO THE E PAC ACROSS AND DOWNWIND OF THE GULF 
OF PAPAGAYO. A 2316 UTC WINDSAT SCATTEROMETER PASS CAPTURED 20 
TO 25 KT NE TO E WINDS IN THAT AREA. WINDS WILL DIMINISH TO LESS 
THAN 20 KT IN 48 HOURS AS THE BOUNDARY IN THE CARIBBEAN SEA 
FINALLY DISSIPATES.

A 2316 UTC WINDSAT SCATTEROMETER PASS INDICATED THAT THE AREA OF 
20 TO 25 KT WINDS THAT WERE OCCURRING 6 HOURS EARLIER HAVE 
ALREADY DIMINISHED AND SHRUNK IN COVERAGE IN THE GULF OF PANAMA 
AND WINDS WILL CONTINUE TO DIMINISH TO LESS THAN 20 KT IN THE 
NEXT 12 HOURS...AS N TO NE TRADES N OF THE ISTHMUS OF PANAMA IN 
THE SW CARIBBEAN WEAKEN.

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

$$
LEWITSKY