000
AXNT20 KNHC 221138
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI DEC 22 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1045 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 6N9W 4N16W 4N35W 5N46W 4N52W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM N 
OF THE AXIS FROM 40W-52W. CLUSTERS OF SCATTERED MODERATE 
CONVECTION ARE WITHIN 120 NM S OF THE AXIS FROM 38W-54W. 

...DISCUSSION...
GULF OF MEXICO...
DEEP LAYERED TROUGH COVERS THE NW GULF N OF 23N W OF 91W WITH A 
LARGE UPPER LOW OVER THE CENTRAL PLAIN STATES MOVING TOWARD THE 
UPPER MISSISSIPPI VALLEY. THE ASSOCIATED COLD FRONT EXTENDS FROM 
THE CENTRAL LOUISIANA TO A 1012 MB LOW ALONG THE TEXAS COAST 
NEAR 27N95W CONTINUING SW TO NE MEXICO. SCATTERED SHOWERS/ 
ISOLATED THUNDERSTORMS ARE NE OF A LINE FROM THE FLORIDA NEAR 
29N83W ALONG 26N90W TO MEXICO NEAR 22N98W. BROAD UPPER RIDGE 
COVERS THE REMAINDER OF THE GULF WITH THE AXIS EXTENDING FROM 
THE BAY OF CAMPECHE NE ACROSS FLORIDA TO ALONG THE E US COAST. 
TROPICAL MOISTURE CONTINUES TO STREAM ACROSS MEXICO FROM THE E 
PACIFIC REGION TO OVER THE GULF FUELING THE SHOWER ACTIVITY OVER 
MOST OF THE GULF. A LINE OF SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS ARE OVER THE FAR SE GULF FROM 26N83W SE ACROSS THE 
FLORIDA KEYS TO THE COAST OF CUBA NEAR 23N80W.  
 
CARIBBEAN SEA...
CUT-OFF UPPER LEVEL LOW IS OVER THE N CARIBBEAN CENTERED NEAR 
20N74W WITH THE UPPER TROUGH N OF 14N FROM 70W-83W. THE 
REMAINDER OF THE CARIBBEAN IS DOMINATED BY AN UPPER RIDGE 
ANCHORED IN THE W TROPICAL ATLC AND THE UPPER RIDGE OVER THE 
GULF OVER THE FAR W CARIBBEAN. VERY DRY UPPER AIR AND 
MODERATE/STRONG SUBSIDENCE COVERS MOST OF THE AREA WITH THE 
EXCEPTION OF THE SE CARIBBEAN WHERE TROPICAL MOISTURE IS BEING 
ADVECTED OVER THE WINDWARD ISLANDS WITH LITTLE SHOWER ACTIVITY. 
WIDELY ISOLATED LOW LEVEL SHOWERS ARE WITHIN 90/120 NM ALONG THE 
COAST OF PANAMA TO NICARAGUA DUE TO LOW LEVEL CONVERGENCE WITH 
THE STRONG TRADE WINDS THAT ALSO DOMINATES THE CARIBBEAN. 

ATLANTIC OCEAN...
UPPER RIDGE IS OVER THE W ATLC WITH THE AXIS EXTENDING FROM 
HISPANIOLA N TO BEYOND 32N72W. DIFFLUENCE FROM THE UPPER RIDGE 
AND THE UPPER LOW IN THE CARIBBEAN IS GENERATING SCATTERED 
SHOWERS/ISOLATED THUNDERSTORMS S OF 21N TO OVER HISPANIOLA 
BETWEEN 68W-73W. A SURFACE RIDGE COVERS THE W ATLC W OF THE 
FRONTAL BOUNDARY DESCRIBED BELOW WITH A 1029 MB HIGH JUST E OF 
BERMUDA. DEEP LAYERED TROUGH IS OVER THE W ATLC N OF 17N FROM 
40W-60W WITH THE ASSOCIATED COLD FRONT EXTENDING THROUGH 32N38W 
SW TO 25N49W WHERE A SURFACE TROUGH CONTINUES TO 21N62W. 
ISOLATED SHOWERS ARE WITHIN 120 NM OF THE FRONT. STRONG BROAD 
UPPER TROUGH COVERS THE E ATLC WITH THE AXIS EXTENDING THROUGH 
32N10W ALONG THE COAST OF AFRICA TO 17N22W AND A SMALL INDUCED 
UPPER HIGH IS JUST TO THE W NEAR 22N28W. A LOW LEVEL SURFACE 
TROUGH REMAINS ALONG 30W FROM 22N-31N. 

$$
WALLACE