000
AXPZ20 KNHC 190954
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN MAR 19 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...ITCZ...
ITCZ AXIS IS ALONG 2N78W 1N86W 7N105W 4N120W 1N140W. ISOLATED 
MODERATE WITHIN 180 NM N OF AXIS BETWEEN 88W AND 100W. 

...DISCUSSION...
A MID TO UPPER LEVEL LONGWAVE TROUGH DOMINATES WESTERN N AMERICA 
WITH AN EMBEDDED DEEP LAYERED CYCLONE CENTERED OVER SE NEVADA 
TRAILING A TROUGH S INTO THE DISCUSSION AREA FROM 32N115W 
TO BROAD BASE IN THE TROPICAL N PACIFIC WITH AXIS NEAR 6N122W. 
AN EMBEDDED SHORTWAVE TROUGH IS ROTATING THROUGH THE LARGER 
PATTERN WITH AXIS ROUGHLY ALONG 32N120W 22N140W. AN UPSTREAM 
LONGWAVE RIDGE HAS AMPLIFIED NE FROM THE TROPICAL PACIFIC TO 
CANADA NEAR 53N130W AND IS BECOMING UNSTABLE AND COLLAPSING SE 
AND WILL LIKELY SHIFT SE INTO THE NW PORTION OF THIS DISCUSSION 
AREA WITHIN 12 HOURS.  

A BAND OF UPPER DRY AIR...AND SUBSIDENCE...IS INDICATED WITH 120 
NM EITHER SIDE OF LINE 32N112W 26N130W THEN THE BAND WIDENS TO 
240 NM EITHER SIDE OF POINTS 27N137W 37N136W. AN AREA OF UPPER 
MOISTURE IS SPILLING S ACROSS THE UPPER RIDGE COVERING THE AREA 
N OF 29N BETWEEN 120W AND 133W. ANOTHER BAND OF UPPER 
MOISTURE...ORIGINATING FROM CONVECTION UNDER THE UPSTREAM RIDGE 
NEAR 23N158W...AND FROM ITCZ CONVECTION BETWEEN 150W AND 
163W...IS NOTED WITHIN 240 NM EITHER SIDE OF LINE 15N140W 
20N120W TO 25N107W AND CONTINUES NE ACROSS NW OLD MEXICO FANNING 
OUT OVER THE SE CONUS AND PARTIALLY CONTRIBUTING TO CONVECTION 
OVER CENTRAL TEXAS ATTM.     

AN BROAD UPPER ANTICYCLONE IS ESTIMATED NEAR 6N97W WITH A RIDGE 
EXTENDING N TO BEYOND 32N94W. THE RESULTANT UPPER FLOW IS ZONAL  
OVER THE DISCUSSION AREA E OF 110W. UPPER DIFFLUENCE IS 
ENHANCING ONLY ISOLATED ITCZ CONVECTION W OF 120W AND BETWEEN 
108W AND 85W. ANOTHER AREA OF CONVECTION IS JUST N OF THE UPPER 
RIDGE NEAR 13N112W. RESULTANT DEBRIS MOISTURE EVAPORATES QUICKLY 
IS THE SAME AREAS. OTHERWISE...DRY UPPER AIR AND SUBSIDENCE THAT 
IS SUPPRESSING CONVECTION...IS NOTED E OF LINE 5N140W 15N115W 
25N95W. LOW LEVEL STRATOCUMULUS COVERS THE AREA N OF 10N W OF 
110W.

A SSMI PASS INDICATES THAT NE WINDS CONTINUE IN THE GULF OF 
PAPAGAYO AND EXTENDS SW TO NEAR 8N93W. MODELS DECREASE THE 
GRADIENT IN THE W CARIBBEAN IN ABOUT 36 HOURS. NLY WINDS TO 20 
KT EXPECTED FOR ABOUT 30 HOURS IN THE GULF OF PANAMA. 

$$
NELSON