000
AXPZ20 KNHC 170952
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED FEB 17 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...
AXIS WAS ANALYZED ALONG 06N77W TO 07N82W TO 06N91W TO 06N106W TO 
03N126W TO 03N140W. SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION WAS OCCURRING WITHIN 180 NM N OF AXIS BETWEEN 92W AND 
101W. SCATTERED MODERATE CONVECTION WAS OCCURRING WITHIN 120 NM 
S OF AXIS BETWEEN 102W AND 105W.

...DISCUSSION...
A POSITIVELY TILTED TROUGH N OF HAWAII...AND ASSOCIATED SURFACE 
COLD FRONT EXTENDING FROM OAHU NORTHEASTWARD TO 30N145W THEN TO 
LOW PRESSURE CENTERED NEAR 38N144W WILL CONTINUES SHIFT E. THIS 
IS HELPING TO WEAKEN THE SURFACE HIGH PRESSURE...AND MID TO 
UPPER LEVEL RIDGING WHICH HAS PREVAILED N OF 20N THE PAST 
SEVERAL NIGHTS AND CURRENTLY EXTENDING N-NE FROM 20N140W TO 
30N133W. TROUGHING PREVAILS E OF THIS UPPER LEVEL RIDGE. THE 
AXIS OF THIS TROUGH IS ALONG 120W S TO 13N...AND COMING INTO 
PHASE WITH THE TROUGH THAT EXTENDS TO THE EQUATOR S OF 13N. S OF 
17N UPPER LEVEL RIDGING PREVAILS OVER THE E PART OF THE AREA. 
THE SRN BRANCH OF THE JETSTREAM EXTENDS ACROSS THE AREA FROM 
10N140W AROUND THE BASE OF THE TROUGH NEAR 13N TO CENTRAL 
MEXICO. SATELLITE DERIVED WINDS DEPICTED 70-90 KT WINDS IN THE 
BASE OF THE TROUGH ACCELERATING TO 100-130 KT ACROSS THE 
SOUTHERN TIP OF BAJA AND ACROSS CENTRAL MEXICO. THIS BROAD JET 
WAS ADVECTING SHEARED CONVECTIVE DEBRIS FROM THE ITCZ...ACROSS 
MUCH OF MEXICO AND INTO THE GULF OF MEXICO. 

AS MENTIONED ABOVE...THE SURFACE HIGH PRESSURE HAS WEAKENED...TO 
1021 MB...CURRENTLY CENTERED NEAR 34N128W AS DEPICTED BY THE 
LATEST ASCAT PASS. AS A RESULT OF THE WEAKENED HIGH 
PRESSURE...THE COVERAGE OF FRESH TO STRONG TRADES HAS DECREASED. 
AS THE UPPER TROUGH AND ASSOCIATED COLD FRONT SHIFTS E...THE 
WEAK SURFACE HIGH PRESSURE WILL SHIFT SE. THIS WILL ENABLE THE 
SURFACE COLD FRONT TO SHIFT INTO THE NW PART OF THE AREA LATE 
TONIGHT...AND REACH FROM 30N129W TO 20N140W ON THU 
NIGHT...BEFORE STALLING AND DISSIPATING THROUGH SAT AS THE UPPER 
TROUGH PROVIDING THE ENERGY AND MOMENTUM TO THE COLD FRONT LIFTS 
OUT.  

SUBSIDING NW SWELL CONTINUES TO PREVAIL ACROSS THE FORECAST 
AREA...MIXING WITH NE SWELL IN REGIONS OF STRONGEST TRADES...AND 
GAP WINDS DISCUSSED BELOW. ANOTHER ROUND OF LONG PERIOD NW 
SWELLS GENERATED BEHIND THE COLD FRONT MENTIONED ABOVE WILL 
PROPAGATE S AND E ACROSS THE AREA. 

GAP WINDS
GALE FORCE WINDS CONTINUE IN THE GULF OF TEHUANTEPEC AS 
CONFIRMED BY THE LATEST ASCAT PASS. THESE CONDITIONS ARE 
EXPECTED TO CONTINUE THROUGH EARLY THU AFTERNOON BEFORE QUICKLY 
DIMINISHING BY LATE THU AFTERNOON/EARLY EVENING. 

THE COLD FRONT THAT MOVED ACROSS THE GULF OF MEXICO THAT HAS 
GENERATED THE GALE FORCE WINDS IN THE GULF OF TEHUANTEPEC HAS 
SHIFTED E AND IS NOW ALONG E HONDURAS. WINDS HAVE FUNNELED INTO 
THE GULF OF FONSECA AND 20 KT WINDS ARE CURRENTLY AFFECTING THE 
AREA. THESE WINDS WILL PULSE UP AND DOWN THROUGH THE OVERNIGHT 
HOURS WED INTO THU...AND WILL PEAK DURING THE OVERNIGHT HOURS 
WITH DRAINAGE FLOW CONTRIBUTING TO THE WINDS. WINDS OVER THE 
GULF OF FONSECA WILL DIMINISH BELOW 20 KT ON THU. 

NORTHEASTERLY WINDS OF 20 KT CONTINUE THROUGH THE GULF OF 
PAPAGAYO. THE COLD FRONT IN THE SW CARIBBEAN WILL S ALONG THE 
NICARAGUA COAST TODAY...AND WINDS FUNNELING INTO THE GULF OF 
PAPAGAYO WILL INCREASE TO 20 TO 30 KT.

FRESH TO STRONG TRADES N ALONG THE COLOMBIA COAST CONTINUE TO 
FUNNEL INTO THE GULF OF PANAMA...AND N TO NE WINDS OF 20 KT WILL 
CONTINUE THROUGH THE FORECAST PERIOD. 

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

$$
AL