000
AXPZ20 KNHC 040916
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU FEB 04 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 06N77W 
TO 06N90W TO 09N106W TO 04N125W TO 04N140W. NO SIGNIFICANT DEEP 
CONVECTION IS SEEN ALONG THE ITCZ AT THIS TIME.     

...DISCUSSION...

A DEEP LAYER LOW IN THE SW U.S. NEAR THE FOUR CORNER WITH A 
TROUGH EXTENDING S OVER WESTERN MEXICO AND INTO THE TROPICAL 
PACIFIC DOMINATES THE WEATHER PATTERN OVER MUCH OF THE REGION W 
OF 120W. ALOFT...A 130-150 KT SUBTROPICAL UPPER JET BRANCH LIES 
OVER N WATERS ON THE W SIDE OF THE TROUGH...WITH CORE WINDS OF 
80-100 KT ROUNDING THE BASE OF THE TROUGH AND TURNING NE OVER 
MEXICO AND INCREASING TO A 120-150 KT SOUTHERLY JET INTO THE 
U.S. SOUTHERN PLAINS. UPPER LEVEL DIFFLUENCE BETWEEN THIS TROUGH 
AND AN UPPER RIDGE AXIS OVER THE CENTRAL GULF OF MEXICO IS 
SUPPORTING WIDESPREAD CLOUDINESS AND AREAS OF PRECIPITATION 
PRIMARILY E OF THE TROUGH AXIS OVER MAINLAND MEXICO. UPPER 
DIFFLUENCE AHEAD OF THE TROUGH AXIS IS ALSO HELPING TO INDUCE   
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION FROM 10N TO 16N 
BETWEEN 100W AND 102W. THIS CONVECTIVE ACTIVITY LIES ON THE 
EASTERN SIDE OF A SURFACE TROUGH EXTENDING FROM 17N103W TO 
07N110W. AN ASCAT PASS AT 0424 UTC PROVIDED OBSERVATIONS OF 20 
TO 25 KT NEAR THE NORTHERN END OF THE TROUGH AND HELPED TO 
ADJUST THE POSITION OF IT. THE TROUGH IS EXPECTED TO SHIFT 
EASTWARD WITH THE DEEP LAYER TROUGH AND WILL DISSIPATE IN ABOUT 
24 HOURS. MODERATE TO STRONG SUBSIDENCE DOMINATES THE REGION 
FROM 10N TO 25N W OF 110W DUE TO THE PRESENCE OF AN UPPER LEVEL
RIDGE. SIMILAR CONDITIONS CAN BE FOUND E OF 92W INCLUDING 
CENTRAL AMERICA. 

A 1016 MB WEAK HIGH PRES NEAR 27N123W WILL MOVE EWD ACROSS THE N 
WATERS TODAY AHEAD OF A STRONG COLD FRONT CURRENTLY STRETCHING 
OVER THE NW PORTION OF THE FORECAST AREA. 20 KT NE TRADE WINDS 
LIE S OF THIS HIGH FROM 06N TO 18N W OF 120W ACCORDING TO THE 
ASCAT PASS FROM 0604 UTC AND SOME SHIP REPORTS. THE TRADES ARE 
EXPECTED TO INCREASE AGAIN BY SAT AS A RIDGE BUILDS EWD OVER THE 
N WATERS. THE AFOREMENTIONED COLD FRONT EXTENDS FROM 30N138W TO 
26N140W. A GALE WARNING IS IN EFFECT N OF 28N W OF 133W FOR THE 
S-SW WINDS IN ADVANCE OF THE FRONT. A RECENT ASCAT PASS MISSED 
THE AREA OF POSSIBLE GALE FORCE WINDS BUT SHOWED W TO NW WINDS 
OF 20 TO 30 KT BEHIND THE FRONT AS WELL AS S TO SW WINDS OF 20 
TO 25 KT WITHIN 150 NM E OF FRONT S OF 27N. IN ADDITION...SHIP 
WBWK REPORTED 30 KT SW WINDS NEAR 30N136W AT 06000 UTC. A 
REINFORCING COLD FRONT WILL CLIP THE FAR N WATERS ON FRI. THIS 
SYSTEM WILL BRING A NEW SURGE OF NW SWELL INTO THE REGION...WITH 
SEAS EXPECTED TO REACH 21 FT IN FAR NW WATERS FRI AFTERNOON. 

GAP WINDS...
ASCAT DATA FROM 0242 UTC REVEALS THAT STRONG NE TO E WINDS OF 20 
TO 25 KT CONTINUE TO BLOW THROUGH THE GULF OF PAPAGAYO...WITH 
WINDS EXPECTED TO BE STRONGEST DURING THE OVERNIGHT AND EARLY 
MORNING HOURS WITH THE AID OF DRAINAGE FLOW. WINDS HERE ARE 
EXPECTED TO DIMINISH TO 20 KT BY FRI AFTERNOON. SIMILARLY...THE 
20 KT WINDS CURRENTLY IN THE GULF OF PANAMA ARE EXPECTED TO 
DIMINISH BY LATE FRI NIGHT WHEN THE PRES GRADIENT BETWEEN LOW 
PRES IN COLOMBIA AND HIGH PRES TO THE NORTH WEAKENS AS A COLD 
FRONT ENTERS THE FAR NW CARIBBEAN. THE NEXT TEHUANTEPEC EVENT 
WILL LIKELY BEGIN SATURDAY...BUT IT DOES NOT APPEAR THAT IT WILL 
BECOME STRONG ENOUGH TO REQUIRE A WARNING.

ELSEWHERE...FORECAST WATERS ARE DOMINATED BY NW SWELL AND 
GENERALLY LIGHT WINDS. 

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

$$
GR