000
AXPZ20 KNHC 030929
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED FEB 03 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 INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED ALONG 05N77W 
TO  05N90W TO 08N108W TO 06N125W TO 05N140W. NO SIGNIFICANT DEEP 
CONVECTION.  

...DISCUSSION...

A MID/UPPER LEVEL TROUGH ALONG THE W COAST OF U.S. EXTENDS INTO 
THE DISCUSSION AREA TO A LOW NEAR 28N114W AND ALONG A NEGATIVELY 
TILTED AXIS TO 17N107W. A 130-150 KT SUBTROPICAL UPPER JET 
BRANCH LIES ON THE W SIDE OF THE TROUGH...WITH CORE WINDS OF 
80-100 KT ROUNDING THE BASE OF THE TROUGH TURNING NE ACROSS 
NORTHERN MEXICO INTO THE GULF OF MEXICO. A DIFFLUENT PATTERN 
ALOFT BETWEEN THIS TROUGH AND AN UPPER RIDGE AXIS OVER THE 
WESTERN GULF OF MEXICO IS SUPPORTING WIDESPREAD CLOUDINESS AND 
AREAS OF PRECIPITATION OVER MEXICO N OF 17N. A CLUSTER OF 
MODERATE TO ISOLATED STRONG CONVECTION IS FROM 16N TO 18N E OF 
105W TO THE COAST OF MEXICO. THIS ACTIVITY LIES ON THE EASTERN 
SIDE OF A SURFACE TROUGH EXTENDING FROM 21N107W TO 15N108W. AN 
ASCAT PASS FROM AROUND 0445 UTC REVEALS THE TROUGH POSITION AND 
SHOWS FEW OF UNCONTAMINATED 20 TO 25 KT WIND BARBS BETWEEN THE 
TROUGH AXIS AND THE COAST OF MEXICO. THE TROUGH IS FORECAST TO 
MOVE EWD WITH AN AREA OF SE TO S WINDS OF 20 KT. MODERATE TO 
STRONG SUBSIDENCE DOMINATES THE REGION W OF 120W AND S OF 25N. 
SIMILAR CONDITIONS ARE NOTED S OF 12N AND E OF 100W.  

THE NEXT COLD FRONT IS FORECAST TO ENTER THE FAR NW PORTION OF 
THE DISCUSSION AREA TONIGHT. THE GFS AND ECMWF MODELS SHOW WINDS 
REACHING GALE FORCE IN THE SOUTHERLY FLOW OUT AHEAD OF THE FRONT 
BY THIS AFTERNOON. THE FNMOC EFS GALE PROBABILITY INDICATES NEAR 
A 30 PERCENT CHANCE OF GALE FORCE WINDS IN FORECAST WATERS. 
BASED ON ALL OF THIS...A GALE WARNING IS ALREADY IN EFFECT OVER 
THE NW WATERS N OF 28N W OF 136W BEGINNING AT 04/0000 UTC. LARGE 
AND LONG PERIOD  

A 1016 MB WEAK HIGH PRES NEAR 27N135W WILL MOVE EWD ACROSS THE N 
WATERS DURING THE NEXT COUPLE OF DAYS. ACCORDING TO A RECENT 
ASCAT PASS...NE TRADE WINDS IN THE 20 TO 25 KT RANGE CURRENTLY 
LIE S OF THIS HIGH FROM 07N TO 16N W OF 127W. EXPECT TRADES TO 
WEAKEN TO 20 KT DURING THE NEXT 24 HOURS. 

REGIONAL SEAS CONTINUE TO BE DOMINATED BY NWLY SWELL...AND ARE 
RUNNING IN THE 8 TO 10 FOOT RANGE N OF 15N W OF 120W. A NEW SET 
OF NW SWELL WILL PROPAGATE ACROSS THE AREA IN THE WAKE OF THE 
AFOREMENTIONED COLD FRONT. 

GAP WINDS...
BASED ON THE NAM MODEL...WILL KEEP WINDS THROUGH THE GULF OF 
TEHUANTEPEC IN THE 20 TO 25 KT RANGE FOR THE NEXT 12 HOURS 
TAKING IN ACCOUNT THAT GAP WINDS TEND TO PEAK DIURNALLY AT 1400 
UTC DUE TO MAXIMIZED DRAINAGE FLOW IN THE EARLY MORNING HOURS. 

NE TO E WINDS OF 20 TO 25 KT WILL CONTINUE TO BLOW ACROSS THE 
GULF OF PAPAGAYO DURING THE NEXT 24 HOURS...WITH WINDS EXPECTED 
TO BE STRONGEST DURING THE OVERNIGHT AND EARLY MORNING HOURS 
WITH THE AID OF DRAINAGE FLOW. HOWEVER...WINDS WILL DIMINISH TO 
20 KT THU AS THE PRES GRADIENT BETWEEN LOW PRES IN COLOMBIA AND 
HIGH PRES TO THE NORTH WEAKENS AS A LOW PRES SYSTEM DEVELOPS 
OVER THE WESTERN GULF OF MEXICO. 

NLY WINDS OF 20 KT ARE ALSO EXPECTED THROUGH THE GULF OF PANAMA 
THROUGH EARLY FRI. 

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

$$
GR