000
AXPZ20 KNHC 212155
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE MAR 21 2006

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...ITCZ...
ITCZ AXIS ALONG 3N78W 5N90W 4N100W 5N110W 
1N140W. NO SIGNIFICANT CONVECTION.

...DISCUSSION...
W OF 100W...
BROAD LONGWAVE TROUGH DOMINATES THE AREA N OF 18N WITH MEAN AXIS 
ALONG 115-120W. TROUGH WAS ACCOMPANIED BY MODERATE TO STRONG MID 
TO UPPER LEVEL SUBSIDENCE. SHORTWAVE TROUGH MOVING THROUGH THE 
MAIN TROUGH EXTENDS FROM A CYCLONIC CIRCULATION OVER SRN NEVADA 
SWWD THROUGH 32N116W TO 24N124W. FURTHER W...MID/UPPER LEVEL 
RIDGE WAS MOVING INTO THE FAR W PORTION OF THE DISCUSSION 
AREA...GENERALLY N OF 20N W OF 130W. GENERALLY ZONAL FLOW 
CHARACTERIZED THE TROPICS WITH A WEAK UPPER LEVEL TROUGH S OF 
12N ALONG 134W MOVING EWD 15 KT. DRY AIR IN THE REGION WAS 
SUPPRESSING CONVECTION ALONG THE ITCZ. AT THE SURFACE...
COLD FRONT EXTENDED FROM NW BAJA CALIFORNIA TO 25N126W. 
OTHER THAN AN INCREASE IN NWLY WINDS BEHIND THE FRONT VERY 
LITTLE WEATHER IS ASSOCIATED WITH THE FRONT.

E OF 100W...
BROAD MID TO UPPER LEVEL RIDGE WITH MEAN AXIS ALONG 80W 
DOMINATED VIRTUALLY THE ENTIRE AREA. STRONG SUBSIDENCE COVERS 
SOUTHERN MEXICO...CENTRAL AMERICA...THE CARIBBEAN AND THE 
PACIFIC S OF 15N E OF 105W. THIS DRY AIR WAS ALSO SUPPRESSING 
CONVECTION ALONG THE ITCZ. 

$$
COBB