000
AXPZ20 KNHC 200934
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT FEB 20 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 
0900 UTC.

...ITCZ...

THE AXIS IS CENTERED ALONG 04N77W TO 05N90W TO 05N110W TO 
05N130W TO 03N140W. OUTSIDE OF THE CONVECTION ASSOCIATED WITH 
THE LOW PRES...SCATTERED MODERATE CONVECTION IS NOTED WITHIN 90 
NM EITHER SIDE OF AXIS FROM 94W TO 98W. SIMILAR CONVECTION IS 
FROM 04N TO 07N BETWEEN 110W AND 113W.  

...DISCUSSION...

AN UPPER LEVEL LOW IS SPINNING NEAR LOS ANGELES CALIFORNIA WITH 
A WEAKENING/FLATTENING UPPER TROUGH EXTENDING FROM THE LOW TO  
NEAR 27N120W. THE ASSOCIATED COLD FRONT IS MOVING ACROSS THE N 
WATERS AND EXTENDS FROM 30N121W TO 21N135W. A RECENT ASCAT PASS 
SHOWED SW WINDS OF 20 KT JUST AHEAD OF THE FRONT AND N OF 28N AS 
WELL AS NW WINDS OF 20 KT BEHIND THE FRONT TO 128W PARTICULARLY 
N OF 27N. THE FRONT IS FORECAST TO DISSIPATE IN ABOUT 24 HOURS. 
LONG PERIOD NW SWELLS FOLLOW THIS FRONTAL SYSTEM RAISING SEAS UP 
TO 15 FT. ANOTHER UPPER LEVEL TROUGH IS JUST APPROACHING THE NW 
CORNER OF THE FORECAST REGION. STRONG ZONAL FLOW DOMINATES THE 
AREA BETWEEN 12N AND 27N. THESE WINDS ARE TRANSPORTING ABUNDANT 
MID/UPPER LEVEL MOISTURE FROM THE EPAC INTO SOUTH-CENTRAL 
MEXICO.  

A 1023 MB HIGH IS ANALYZED NEAR 26N140W. THIS HIGH WILL MOVE EWD 
ACROSS THE N WATERS DURING THE NEXT 48 HOURS. AS A RESULT...THE 
AREA OF TRADE WINDS IS FORECAST TO EXPAND EASTWARD REACHING NEAR 
110W IN 48 HOURS.  

A 1009 MB AREA OF LOW PRES IS EMBEDDED IN THE ITCZ CENTERED NEAR 
06N107W WITH A TROUGH EXTENDING FROM 10N106W TO 03N107W. AN 
EARLIER WINDSAT PASS CAPTURED N TO NE WINDS OF 20 WITHIN 120 NM 
NW QUADRANT OF LOW...WHILE THE GFS COMPUTER MODEL SHOWS SE TO S 
WINDS OF 20 KT WITHIN 90 NM SE QUADRANT OF LOW. AN AREA OF 
MODERATE TO STRONG CONVECTION HAS DEVELOPED E OF LOW CENTER 
COVERING FROM 03N TO 07N BETWEEN 103W AND 107W. A DIFFLUENT 
PATTERN ALOFT IS HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. THE 
LOW PRES IS FORECAST TO SLOWLY MOVE WWD BETWEEN NOW AND 48 HOURS 
BUT ACCORDING TO THE MARINE GUIDANCE WINDS WILL REMAIN BELOW 20 
KT NEAR THE LOW CENTER.  

...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 MUCH EARLIER 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.

WINDS ACROSS THE GULF OF PANAMA 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

$$
GR