000
AXPZ20 KNHC 221554
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN FEB 22 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE...THE AXIS EXTENDS ALONG 
06N77W TO 02N104W TO 05N124W TO 03N140W. SCATTERED MODERATE 
CONVECTION IS NOTED WITHIN 180 NM OF 06N87W AND ALSO WITHIN 90N 
NM OF 09N128W. A SMALL MODERATE CLUSTER IS NOTED NEAR 06N134W.

...DISCUSSION...
A LONG WAVE TROUGH LIES OFF THE WESTERN UNITED STATES WITH 
SEVERAL EMBEDDED UPPER CYCLONES...THE FURTHEST S BEING AT 
32N140W AND ROTATING NE WITH TIME. A SERIES OF COLD FRONTS ARE 
ALSO ROTATING THROUGH THE PATTERN...BUT ARE BLOCKED BY A QUASI 
STATIONARY SURFACE RIDGE EXTENDING FROM SOUTHERN CALIFORNIA TO 
NEAR 20N134W. THE FRONTS WASH OUT OVER THE NW PORTION...BUT ARE 
ACCOMPANIED BY REINFORCING NW SWELLS TO ABOUT 11 FT. SHIFTING 
WINDS...BUT ONLY TO MAX OF 20 KT...ALSO ACCOMPANY THE FRONTS.

AN UPPER LEVEL TROUGH DISSECTS THE CENTRAL PORTION OF THE 
DISCUSSION AREA FROM SOUTHERN TEXAS TO NEAR 01N113W...WITH 
EMBEDDED CYCLONES AT 07N105W AND 02N112W. SOME CONVECTION IS 
ENHANCED NEAR 08N102W AND NEAR 04N117W. 

W OF THIS DISSECTING UPPER TROUGH...AN UPPER ANTICYCLONE HAS 
BECOME DOMINATE NEAR 05S145W...WITH A BROAD UPPER RIDGE 
EXTENDING NE TO WELL BEYOND 32N120W. DENSE UPPER DEBRIS MOISTURE 
IS SPREADING NE ALONG THE W PERIPHERY OF THIS UPPER RIDGE... 
BASICALLY COVERING THE UPPER LEVELS N OF 15N W OF 115W
SPILLING OVER MOST OF THE WESTERN N AMERICA. 

E OF THE DISSECTING AN UPPER LEVEL TROUGH...AN UPPER ANTICYCLONE 
IS OVER COLOMBIA NEAR 04N75W WITH A RIDGE NW TO 11N95W. ITCZ  
CONVECTION DESCRIBED ABOVE IS ENHANCED UNDER THE UPPER RIDGE 
WITH THE DEBRIS MOISTURE SPREADING NE ACROSS COSTA RICA. 
OTHERWISE THE UPPER LEVELS APPEAR VERY DRY E OF 112W.

CENTRAL AMERICAN GAPS...NORTHERLY WINDS 20 TO 30 KT HAVE BEGUN 
AS EXPECTED IN THE GULF OF TEHUANTEPEC PER A RECENT 1215 UTC 
QSCAT PASS. N WINDS EXPECTED INCREASE TO GALE FORCE BY THIS 
AFTERNOON AND TO FURTHER INCREASE TO MINIMUM STORM FORCE BY 
SUNRISE MON. MAINTAINED THE STORM WARNING A LITTLE LONGER THAN 
GUIDANCE TO COMPENSATE FOR LATE NIGHT DRAINAGE...FORECASTING A 
STRONG GALE TO 45 KT AT 1200 UTC TUE. NE TO E WINDS IN AND 
DOWNSTREAM OF THE GULF OF PAPAGAYO OF 20 TO 25 KNOTS WILL 
DIMINISH SOME THIS AFTERNOON...AND THEN INCREASE AGAIN MON 
SPREADING N OVER THE PACIFIC WATERS TO INCLUDE THE GULF OF 
FONSECA GAP AREA. 

$$
NELSON