000
AXPZ20 KNHC 161557
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU MAR 16 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...ITCZ...
ITCZ AXIS ALONG AXIS 3N77W 5N88W 7N106W 3N130W 5N140W. SCATTERED 
MODERATE CONVECTION WITHIN 30 NM EITHER SIDE OF LINE 6N85W 6N94W.

...DISCUSSION...
A LONGWAVE TROUGH IS ANCHORED OVER NE PACIFIC AND ALONG THE 
WESTERN N AMERICA WITH SEVERAL EMBEDDED CYCLONES. ONE DEEP 
LAYERED...VERTICALLY STACKED...CYCLONE IS CENTERED NEAR 45N129W. 
AN UPPER SHORTWAVE TROUGH IS ROTATING AROUND THE CYCLONE AND 
EXTENDS S INTO THE DISCUSSION AREA ALONG 32N130W 12N123W TO A 
BASE THE EQUATOR AT 120W. AN ILL-DEFINED AND SMALL UPPER CYCLONE 
IS NOTED ALONG THE TROUGH AXIS NEAR 11N118W AND IS SHIFTING 
E WITH TIME. A BAND OF UPPER DRY AIR IS INDICATED ON WATER VAPOR 
IMAGERY WITHIN 120 NM EITHER SIDE OF LINE 32N106W TO 15N124W 
WHERE IT MERGES WITH A LARGER AREA OF DRY AIR THEN DOMINATES THE 
TROPICS W OF THE UPPER TROUGH...ROUGHLY S OF 14N BETWEEN 120W 
AND 144W. ASSOCIATED SUBSIDENCE HAS COMPLETELY SUPPRESSED ITCZ 
CONVECTION W OF 110W. A SECONDARY UPPER SHORTWAVE LIES ALONG 
37N130W TO BEYOND 32145W. AN ASSOCIATED COLD FRONT WILL MOVE SE 
INTO THE DISCUSSION AREA TONIGHT AND SHIFT E THROUGH THE 
N-CENTRAL WATERS FRI BLOCKED TO THE N OF 27N BY A LOW LEVEL 
QUASI-STATIONARY RIDGE THAT SPLITS THE DISCUSSION AREA FROM NW 
TO SE.   

AN UPPER TROPICAL RIDGE OVER EQUATORIAL N ATLC EXTENDS WNW 
ACROSS VENEZUELA...THE NW CARIBBEAN...THE WESTERN GULF OF MEXICO 
AND EVENTUALLY MERGES WITH A LONGWAVE RIDGE THAT DOMINATES ALL 
OF CENTRAL N AMERICA. A MOSTLY MID LEVEL RIDGE CRESTS OVER OLD 
MEXICO AND S CENTRAL CONUS ALONG 24N110W 32N101W AND IS SPILLING 
SE OVER THE CAROLINAS NEAR 36N78W ATTM. AN UPPER MOISTURE 
PLUME...THAT ORIGINATED FROM CONVECTION W OF THE AREA A COUPLE 
OF DAYS AGO AND FROM PREVIOUSLY ENHANCED ITCZ CONVECTION BETWEEN 
128W AND 113W YESTERDAY...IS NOW INDICATED WITHIN 120 NM EITHER 
SIDE OF LINE FROM 10N118W TO 25N103W WHERE THE PLUME FANS 
COVERING THE SE CONUS AND MOST OF THE W AND NE GULF OF MEXICO. 
THIS MOISTURE PLUME WILL LIKELY PLAY A PART IN AN INCREASE IN 
CONVECTION ALONG A RETURN FLOW TROUGH IN NE TEXAS AND SW 
LOUISIANA THIS AFTERNOON. NOTE THAT THE SUBTROPICAL SW JET OVER 
OLD MEXICO IS DIFFLUENT OVER THE RIO GRANDE AREA OF TEXAS AND A 
SHORTWAVE TROUGH OVER NW TEXAS IS ERODING THE NW PERIPHERY OF 
THE ABOVE MENTIONED SHORTWAVE RIDGE AND COULD BE THE NECESSARY 
LIFTING MECHANISM.
    
OTHERWISE DRY UPPER AIR AND SUBSIDENCE IS INDICATED S OF 18N E 
OF 108W WITH SCATTERED CONVECTION ENHANCED ALONG THE ITCZ NEAR 
5N88W.  THE RESULTANT DEBRIS MOISTURE IS EVAPORATING ROUGHLY IN 
THE SAME AREA.  

NLY WINDS 20-25 KT...INDICATED IN THE GULF OF PAPAGAYO AND 
EXPECTED TO CONTINUE THROUGH 48 HOURS AS GRADIENT CONTINUES IN W 
CARIBBEAN. NLY WINDS 20 KT DETECTED BY QUICK SCAT IN GULF OF 
TEHUANTEPEC THIS MORNING WILL DECREASE LATER TODAY. MODELS 
INDICATE GRADIENT IN SW CARIBBEAN WILL SPILL SW INTO GULF OF 
PANAMA AND CONTINUE FOR 48 HOURS.

$$
NELSON