000
AXNT20 KNHC 180512
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SUN FEB 18 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0445 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N10W 4N16W 2N34W CROSSING THE 
EQUATOR NEAR 40W TO SOUTH AMERICA NEAR 3S44W. CLUSTERS OF 
SCATTERED MODERATE CONVECTION ARE WITHIN 225 NM OF THE AXIS FROM 
7W-48W. 
 
...DISCUSSION...
GULF OF MEXICO...
SHORTWAVE UPPER TROUGH IS DIGGING S OVER THE SE US AND N GULF OF 
MEXICO THROUGH SE LOUISIANA TO 26N92W EMBEDDED WITHIN A VERY 
BROAD UPPER TROUGH THAT EXTENDS FROM THE W ATLC TO THE CENTRAL 
PLAIN STATES SETTING UP WESTERLY UPPER FLOW ACROSS THE GULF. AT 
18/0300 UTC...THE FAST MOVING COLD FRONT ASSOCIATED WITH THIS 
SHORTWAVE EXTENDS FROM A 1014 MB LOW OVER THE FLORIDA PANHANDLE 
NEAR 31N85W SW ALONG 25N90W TO MEXICO NEAR 23N98W. THIS FRONT 
WILL CLEAR THE GULF LATER THIS MORNING. THE GULF IS EMBEDDED 
WITHIN SOME VERY DRY AIR BUT SOME SCATTERED SHOWERS ARE AHEAD OF 
THE FRONT OVER THE NE GULF N OF 27N. SUBTROPICAL JET REMAINS 
CENTERED ACROSS THE N GULF WITH WINDS OF 90 TO 150 KT COVERING 
THE GULF N OF 23N. OVERCAST LOW CLOUDS REMAIN OVER THE BAY OF 
CAMPECHE. 
   
CARIBBEAN SEA...
REMNANT FRONTAL BOUNDARY REMAINS OVER THE W CARIBBEAN FROM THE W 
ATLC ACROSS CUBA NEAR 20N75W TO NE NICARAGUA. PATCHES OF 
BROKEN/OVERCAST LOW/MID LEVEL CLOUDS WITH POSSIBLE ISOLATED 
SHOWERS ARE W OF THE FRONTAL BOUNDARY. MODERATE/STRONG EASTERLY 
TRADE WINDS DOMINATES THE ENTIRE CARIBBEAN WITH AN UPPER LEVEL 
RIDGE DOMINATING THE AREA ANCHORED IN THE SW CARIBBEAN NEAR 
12N80W WITH THE RIDGE AXIS EXTENDING NE ACROSS HISPANIOLA/PUERTO 
RICO INTO THE W/CENTRAL ATLC. STRONG SUBSIDENCE AND DRY AIR AT 
ALL LEVELS E OF THE REMNANT FRONTAL BOUNDARY. 

ATLANTIC OCEAN...
THE SURFACE RIDGE ANCHORED IN THE CENTRAL GULF OF MEXICO IS NOW 
SEPARATED BY A WEAK SURFACE TROUGH WITH A 1017 MB HIGH ANCHORED 
OVER BERMUDA. A SLOW MOVING COLD FRONT ENTERS THE W/CENTRAL ATLC 
NEAR 32N50W CONTINUING SW ALONG 26N60W TO THE TURKS AND CAICOS 
WHERE IT BEGINS TO DISSIPATE INTO THE CARIBBEAN NEAR 20N75W. 
OVERCAST LOW/MID CLOUDS AND ISOLATED SHOWERS ARE WITHIN 200/250 
NM W OF THE FRONT. THE ASSOCIATED UPPER LEVEL TROUGH DIPS S OVER 
THE FAR W ATLC AND OVER THE E US WITH MOST OF THE UPPER LEVEL 
ENERGY N OF THE REGION. A SUBTROPICAL JET WITH WINDS OF 90 TO 
130 KT THAT COVERS THE GULF EXTENDS INTO THE W ATLC ACROSS N 
FLORIDA THEN NE TO BEYOND 32N75W. UPPER RIDGE ANCHORED IN THE 
CARIBBEAN EXTENDS AN AXIS NE ACROSS HISPANIOLA/PUERTO RICO TO 
BEYOND 32N40W. AN UPPER TROUGH IS OVER THE E ATLC EXTENDING 
THROUGH 32N14W SW INTO THE TROPICS NEAR 12N38W. THE E ATLC IS 
ALSO DOMINATED BY A SURFACE RIDGE THAT EXTENDS FROM A 1028 MB 
HIGH BETWEEN THE AZORES AND THE MADEIRA ISLANDS TO JUST NE OF 
THE LEEWARD ISLANDS NEAR 20N58W SUPPLYING MOSTLY FAIR WEATHER 
AND MODERATE TRADES ACROSS A GOOD PORTION OF THE REGION. 

$$
WALLACE