000
AXNT20 KNHC 171121
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST WED JAN 17 2007

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 3N3W 5N14W 3N31W 4N48W 3N52W. 
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE 
WITHIN 150 NM OF THE AXIS FROM 33W-46W AND WITHIN 120/150 NM N 
OF THE AXIS FROM 15W-19W.

...DISCUSSION...
GULF OF MEXICO...
THE COLD FRONT CONTINUES TO MOVE EASTWARD ACROSS THE N GULF 
WHILE THE S PORTION IS BACKING WESTWARD AS A WARM FRONT. THE 
FRONT EXTENDS FROM THE W ATLC ACROSS CENTRAL FLORIDA JUST S OF 
DAYTONA BEACH TO OVER SARASOTA ALONG 24N91W TO THE BAY OF 
CAMPECHE AND S MEXICO NEAR 18N94W. STRONG NORTHERLY SURFACE 
WINDS ARE W OF THE FRONT WITH GALE FORCE WINDS S OF 25N W OF THE 
FRONT. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N AND W OF 
THE FRONT TO INLAND OVER THE N GULF COAST STATES AS WELL AS 
MEXICO. THE UPPER LEVEL SUPPORT FOR THIS SYSTEM REMAINS INLAND 
EXTENDING FROM THE W ATLC ACROSS NEW ENGLAND TO THE UPPER 
MID-WEST STATES THEN SW OVER THE DESERT SW. THE GULF REMAINS 
ALONG THE WESTERN EDGE OF A BROAD UPPER RIDGE ANCHORED BY AN 
UPPER HIGH LOCATED OVER THE STRAITS OF FLORIDA JUST N OF CENTRAL 
CUBA. TROPICAL MOISTURE FROM THE E PACIFIC REGION CONTINUES TO 
STREAM ACROSS MEXICO AND TEXAS FUELING THE PRECIPITATION 
ASSOCIATED WITH THE FRONTAL BOUNDARY. THE BROAD SURFACE RIDGE 
OVER THE US EXTENDS S OVER MEXICO AND THE GULF OF MEXICO BEHIND 
THE FRONTAL BOUNDARY WITH A 1037 MB HIGH OVER SW TEXAS AND A 
STRONG 1042 MB HIGH OVER E MISSOURI. LOW LEVEL CONVERGENCE IS 
GENERATING SOME SCATTERED SHOWERS S OF THE FRONT OVER THE SE 
GULF TO OVER CUBA BETWEEN 81W-85W. 

CARIBBEAN SEA...
BROAD UPPER RIDGE ANCHORED IN THE STRAITS OF FLORIDA JUST N OF 
CENTRAL CUBA COVERS THE W CARIBBEAN NE OF A LINE FROM THE VIRGIN 
ISLANDS ALONG 15N73W THE COSTA RICA/NICARAGUA BORDER. AN UPPER 
RIDGE OVER THE TROPICS COVERS THE REMAINDER OF THE SE CARIBBEAN. 
A SURGE OF STRONG SUBSIDENCE AND VERY DRY AIR CONTINUES TO 
DOMINATE THE REGION SUPPRESSING ANY SHOWERS. STRONG TRADE WINDS 
CONTINUE ACROSS THE REGION AS HIGH SURFACE PRESSURE REMAINS IN 
CONTROL OF THE ATLC. THE WINDS ARE NOW BELOW GALE FORCE WINDS 
OFF THE N COAST OF COLOMBIA.  

ATLANTIC OCEAN...
THE COLD FRONT EXTENDS THROUGH THE W ATLC ALONG 32N72W INTO THE 
GULF OF MEXICO JUST S OF DAYTONA BEACH FLORIDA. SCATTERED 
SHOWERS/ISOLATED THUNDERSTORMS ARE NW OF THE FRONT TO INLAND 
OVER THE SE US. BROAD UPPER RIDGE THAT COVERS THE GULF OF MEXICO 
AND THE CARIBBEAN IS ANCHORED IN THE W ATLC IN THE STRAITS OF 
FLORIDA NEAR 24N79W AND COVERS THE ATLC W OF 60W. DRY AIR AND 
STRONG SUBSIDENCE DOMINATE THE AREA LIMITING SHOWER ACTIVITY 
OVER THE REMAINDER OF THE W ATLC. CUT-OFF UPPER LOW IS IN THE 
S/CENTRAL ATLC NEAR 22N54W WITH THE UPPER TROUGH DIPPING SW OVER 
THE W TROPICAL ATLC JUST E OF THE LEEWARD ISLANDS. WEAK SURFACE 
TROUGH EXTENDS FROM 13N54W TO 27N52W WITH SCATTERED SHOWERS AND 
POSSIBLE ISOLATED THUNDERSTORMS FROM 18N-25N BETWEEN 44W-54W. 
SURFACE RIDGE REMAINS IN CONTROL OF THE ATLC WITH THE AXIS 
EXTENDING FROM THE NE ATLC BETWEEN THE CANARY ISLANDS AND THE 
AZORES THROUGH A 1028 MB HIGH NEAR 32N40W TO A WEAKER 1027 MB 
HIGH SW OF BERMUDA NEAR 28N68W. AN UPPER TROUGH IS DROPPING S 
OVER THE NE ATLC EXTENDING ALONG 32N17W SW THROUGH A DEVELOPING 
UPPER LOW NEAR 26N78W TO 22N32W WITH NO SURFACE FEATURES AND NO 
SHOWER ACTIVITY. BROAD UPPER RIDGE DOMINATES THE REMAINDER OF 
THE ATLC ANCHORED DEEP IN THE TROPICAL ATLC INCLUDING THE SE 
CARIBBEAN. 
  
$$
WALLACE