000
AXPZ20 KNHC 231555
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 
05N77W TO 07N85W TO 03N105W TO 03N125W TO 05N140W. ISOLATED 
MODERATE AND STRONG CONVECTION IS NOTED FROM 04N TO 06N E OF 95W 
AND ALSO WITHIN 30 NM EITHER SIDE OF LINE FROM 11N128W TO 
08N137W.

...DISCUSSION...
A LONG WAVE TROUGH LIES OFF THE WESTERN UNITED STATES WITH AN 
EMBEDDED UPPER CYCLONE NEAR 44N133W. DRY UPPER AIR IS NOTED NW 
OF LINE 32N125W TO 21N140W. A SERIES OF SURFACE COLD FRONTS ARE 
ALSO ROTATING THROUGH THE PATTERN INTO THE NW PORTION PORTION OF 
THE DISCUSSION AREA...BUT ARE IMMEDIATELY BLOCKED BY A QUASI 
STATIONARY SURFACE HIGH NEAR 28N120W 1021 MB. ALTHOUGH THE 
FRONTS WASH OUT OVER THE NW PORTION...REINFORCING NW SWELLS TO 
11 FT CONTINUE TO PROPAGATE SE INTO THE AREA. BRIEF SHIFTING 
WINDS...BUT ONLY TO MAX OF 20 KT...ALSO ACCOMPANY THE FRONTS.

A LONG WAVE UPPER TROUGH OVER THE EASTERN UNITED STATES EXTENDS 
SW ACROSS THE GULF OF MEXICO AND DISSECTS THE CENTRAL PORTION OF 
THE DISCUSSION AREA FROM SOUTHERN TEXAS TO EQUATOR AT 118W. 
EMBEDDED UPPER CYCLONES AT NOTED NEAR 18N101W AND 10N114W WHERE 
THE ASSOCIATED UPPER DIFFLUENCE IS ENHANCING ISOLATED TSTMS NEAR 
04N114W.

W OF THIS DISSECTING UPPER TROUGH...AN UPPER ANTICYCLONE NEAR 
04N151W HAS A RIDGE EXTENDING NE INTO THE DISCUSSION AREA ALONG 
19N140W TO BEYOND THE EQUATOR AT 126W. UPPER DIFFLUENCE IS 
ENHANCING CONVECTION UNDER THE RIDGE NEAR 08N135W WITH THE 
DEBRIS MOISTURE ADVECTED SE TO THE EQUATOR. ANOTHER UPPER 
ANTICYCLONE HAS FORMED OVER THE SOUTHERN TIP OF THE BAJA 
PENINSULA WITH A LONGWAVE RIDGE EXTENDING NNE ACROSS CENTRAL N 
AMERICA. DENSE UPPER DEBRIS MOISTURE IS SPREADING NE ALONG THE W 
PERIPHERY OF THIS LONGWAVE UPPER RIDGE...BASICALLY COVERING THE 
UPPER LEVELS N OF 20N BETWEEN 125W AND 110W AND EVENTUALLY 
SPILLING OVER MOST OF CENTRAL N AMERICA. 

E OF THE DISSECTING AN UPPER LEVEL TROUGH...AN UPPER ANTICYCLONE 
IS OVER COLOMBIA NEAR 07N75W HAS A RIDGE EXTENDING NW TO 14N90W. 
UPPER DIFFLUENCE IS ENHANCING ITCZ CONVECTION...DESCRIBED 
ABOVE...WITH THE DEBRIS MOISTURE SPREADING NE BUT EVAPORATING 
BEFORE REACHING CENTRAL AMERICA. OTHERWISE THE UPPER LEVELS 
APPEAR VERY DRY E OF 112W.

CENTRAL AMERICAN GAPS...A STORM WARNING IS IN EFFECT FOR THE 
GULF OF TEHUANTEPEC AND IS EXPECTED TO WEAKEN TO A STRONG GALE 
AROUND SUNRISE TUE...AND FURTHER WEAKEN BELOW GALE FORCE LATE 
TUE NIGHT. NE TO E WINDS IN AND DOWNSTREAM OF THE GULF OF 
PAPAGAYO OF 20 TO 25 KNOTS WILL SPREAD N OVER THE PACIFIC WATERS 
E OF 94W TONIGHT. NORTHERLY WINDS WILL INCREASE TO 20 KT 
DOWNSTREAM OF THE GULF PANAMA TUE AND WED. 

$$
NELSON