000
AXNT20 KNHC 210525
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST THU DEC 21 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...
CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...
NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC
OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N.
THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...
METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0445 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N7W 4N23W 3N40W 3N48W 2N53W. 
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE 
FROM 2N-7N BETWEEN 31W-52W. 

...DISCUSSION...
GULF OF MEXICO...
DEEP LAYERED TROUGH IS MOVING INTO THE NW GULF WITH A LARGE 
UPPER LOW OVER THE CENTRAL PLAIN STATES. THE ASSOCIATED COLD 
FRONT EXTENDS ALONG THE TEXAS COAST WITH A SQUALL LINE WELL TO 
THE E EXTENDING WITHIN 60/75 NM OF LINE FROM 28N92W ACROSS SE 
LOUISIANA TO OVER MISSISSIPPI AND ALABAMA. A VERY THIN LINE OF 
SCATTERED SHOWERS ARE ALONG THE FRONTAL BOUNDARY. UPPER RIDGE 
COVERS THE REMAINDER OF THE GULF WITH THE AXIS EXTENDING FROM 
THE W CARIBBEAN THROUGH THE YUCATAN CHANNEL ACROSS FLORIDA TO 
ALONG THE SE US COAST. TROPICAL MOISTURE CONTINUES TO STREAM 
ACROSS MEXICO FROM THE E PACIFIC REGION TO OVER THE GULF. 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS REMAIN OVER THE FAR SE 
GULF S OF 25N E OF 85W THROUGH THE STRAITS OF FLORIDA INCLUDING 
THE FLORIDA KEYS. 
 
CARIBBEAN SEA...
CUT-OFF UPPER LEVEL LOW IS OVER THE NW CARIBBEAN N OF 17N FROM 
75W-84W. THE REMAINDER OF THE CARIBBEAN IS DOMINATED BY AN UPPER 
RIDGE ANCHORED IN THE W TROPICAL ATLC. VERY DRY UPPER AIR AND 
MODERATE/STRONG SUBSIDENCE COVERS MOST OF THE AREA WITH THE 
EXCEPTION LOW LEVEL ISOLATED SHOWERS FROM 15N-20N BETWEEN 
73W-81W ENHANCED BY STRONG TRADE WINDS THAT ALSO DOMINATES THE 
CARIBBEAN. 

ATLANTIC OCEAN...
UPPER RIDGE COVERS THE FAR W ATLC W OF 70W WITH THE AXIS FROM 
ACROSS FLORIDA TO ALONG THE SE US COAST. DEEP LAYERED TROUGH IS 
OVER THE W ATLC N OF 23N FROM 52W-70W WITH THE ASSOCIATED COLD 
FRONT EXTENDING THROUGH 32N52W WSW ALONG 28N62W TO 28N74W WHERE 
IT BECOMES STATIONARY NW TO NEAR JACKSONVILLE FLORIDA. A REMNANT 
SURFACE TROUGH IS IN THE CENTRAL ATLC EXTENDING FROM 28N54W TO 
20N65W WITH ISOLATED SHOWERS WITHIN 180 NE E OF THE TROUGH. THE 
UPPER LOW IN THE NW CARIBBEAN GENERATING SCATTERED SHOWERS/ 
ISOLATED THUNDERSTORMS S OF 22N TO OVER HISPANIOLA AND E CUBA 
BETWEEN 68W-78W WHILE THE REMAINDER OF THE W ATLC REMAINS RATHER 
SHOWER FREE. NARROW UPPER RIDGE EXTENDS FROM THE TROPICS NEAR 
19N48W N ACROSS THE CENTRAL ATLC TO BEYOND 32N43W. BROAD UPPER 
TROUGH COVERS THE REMAINDER OF THE ATLC N OF 15N E OF 35W WITH 
AN UPPER LOW NEAR 28N19W AND A 1016 MB SURFACE LOW NEAR 27N27W. 
ISOLATED SHOWERS ARE E OF THE SURFACE LOW FROM 25N-30N BETWEEN 
17W-25W INCLUDING THE CANARY ISLANDS. 

$$
WALLACE