000
AXNT20 KNHC 201742
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST TUE FEB 20 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N11W 5N20W 3N30W 2N40W CROSSING THE 
EQUATOR AT 46W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE 
WITHIN 120 NM OF THE AXIS BETWEEN 13W-23W. SCATTERED MODERATE IS 
WITHIN 120 NM N AND 60 NM S OF AXIS BETWEEN 26W-37W. 
 
...DISCUSSION...
GULF OF MEXICO...
WEST PORTION OF A 1028 MB SFC HIGH E OF FLORIDA IS EXTENDING 
INTO THE GULF...PRODUCING 10-20 KT SLY RETURN FLOW OVER THE 
BASIN. RIDGING DOMINATES THE UPPER LEVELS...EXTENDING N FROM ITS 
ORIGIN OVER GUATEMALA. DRY/STABLE MID TO UPPER AIR EXISTS S OF 
25N WITH MORE MOISTURE AVAILABLE TO THE N. UPPER DIFFLUENT ZONE 
BETWEEN THE UPPER HIGH AND THE UPPER TROUGH EXTENDING SW THROUGH 
THE SW U.S. IS SUPPORTING THE BAND OF UPPER MOISTURE WITH 
POSSIBLE LIGHT SHOWERS IN THE FAR NW GULF...SE TEXAS...AND 
LOUISIANA. HOWEVER...NOT SURE HOW MUCH OF THIS PRECIP IS 
REACHING THE GROUND. SCATTERED TO BROKEN LOW TO MID CLOUDS ARE 
IN THE GULF FROM 22N-27N...THOUGH MOSTLY FAIR WEATHER IS 
DOMINATING. RETURN FLOW WILL GRADUALLY RELAX THROUGH MIDWEEK AS 
THE SFC RIDGING WEAKENS ACROSS THE AREA. 
   
CARIBBEAN SEA...
WEAKENING STATIONARY FRONT ENTERS THE CARIBBEAN NEAR THE LEEWARD 
ISLANDS AT 18N64W AND CONTINUES WSW TO NEAR 15N76W. A TROUGH 
THEN CURVES FROM THAT POINT THROUGH 15N80W 10N79W...THOUGH 
SATELLITE IMAGERY AND SFC OBSERVATIONS SUGGEST THIS TROUGH HAS 
BECOME ITS OWN ENTITY...MOVING W FROM THE OLD STATIONARY FRONT. 
SCATTERED SHOWERS ANTICIPATED WITHIN 60 NM OF BOTH THE 
STATIONARY FRONT AND TROUGH...WITH THE ACTIVITY ASSOCIATED WITH 
THE TROUGH NOW MOVING INLAND OVER CENTRAL AMERICA. EXTREMELY 
DRY/STABLE MID TO UPPER AIR CONTINUES TO HOVER OVER THE 
CARIBBEAN...AROUND RIDGING EXTENDING E THROUGH THE BASIN FROM 
GUATEMALA. MODERATE TO STRONG TRADES WILL TAKE OVER MUCH OF THE 
BASIN THROUGH THE END OF THE WORKWEEK AS FRONT DISSIPATES AND 
HIGH PRESSURE BUILDS N OF THE AREA. 

ATLANTIC OCEAN...
A 1028 MB SFC HIGH IS LOCATED OFFSHORE FLORIDA NEAR 30N72W. THIS 
CONTINUES TO BUILD BEHIND THE COLD FRONT THAT ENTERS THE AREA AT 
32N42W TO 25N53W. FRONT IS THEN STATIONARY FROM THAT POINT TO 
THE LEEWARD ISLANDS. A THIN ROPE CLOUD IS STILL NOTED WITH THIS 
FRONT...WITH SCATTERED SHOWERS ANTICIPATED WITHIN 60 NM EITHER 
SIDE OF THE BOUNDARY. SCATTERED TO BROKEN COLD AIR STRATOCUMULUS 
CLOUDS EXISTS ELSEWHERE BEHIND THE FRONT E OF 77W. REMAINDER OF 
THE E AND CENTRAL ATLC SFC PATTERN DOMINATED BY THE SRN 
PERIPHERY OF A 1024 MB HIGH NW OF THE CANARY ISLANDS NEAR 
31N21W. ALOFT...UPPER RIDGING IS BUILDING INTO THE FAR WRN 
PORTION OF THE AREA BEHIND A WEAK UPPER TROUGH EXTENDING SW 
BETWEEN BERMUDA AND HISPANIOLA. MUCH OF THE REMAINDER OF THE 
AREA IS DOMINATED BY BROAD RIDGING...OUTSIDE OF A SHARP UPPER 
TROUGH EXTENDING S FROM SW EUROPE THROUGH NW AFRICA. FAIRLY DRY 
MID TO UPPER AIR ALSO DOMINATES BETWEEN 70W-30W. 

$$
WILLIS