000
AXNT20 KNHC 061026
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI APR 06 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 
0945 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N9W 4N17W 2N37W INTO SOUTH AMERICA 
NEAR 2N52W. NUMEROUS STRONG CONVECTION IS ALONG THE COAST OF 
AFRICA WITHIN 90/120 NM OF THE AXIS E OF 12W. CLUSTERS OF 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION S OF THE ITCZ AXIS 
W OF 40W. 

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER TROUGH COVERS THE E HALF OF THE US WITH A BROADENING 
SHORTWAVE TROUGH EXTENDING FROM LOUISIANA TO THE E BAY OF 
CAMPECHE. THE ASSOCIATED SURFACE FEATURES CONSIST OF A 1010 MB 
LOW CENTERED NEAR 24N87W WITH A COLD FRONT EXTENDING S OVER THE 
E COAST OF THE YUCATAN PENINSULA TO NEAR 15N91W ENTERING THE NW 
CARIBBEAN. THIS LOW IS ALSO ATTACHED TO A SLOW MOVING COLD FRONT 
THAT EXTENDS FROM THE W ATLC ACROSS S FLORIDA NEAR MIAMI. HEAVY 
SHOWERS/THUNDERSTORMS OVER THE SE GULF S OF 27N E OF 88W WITH 
THE STRONGEST ACTIVITY OVER THE STRAITS OF FLORIDA. STRONG 
SUBSIDENCE AND DRY AIR ARE FOLLOWING THE FRONTAL SYSTEM OVER THE 
N AND W GULF WITH DEW POINTS DROPPING INTO THE 40S OVER THE GULF 
WATERS AND CLEARING SKIES. STRONG NORTHERLY WINDS COVER THE SAME 
AREA BEHIND THE FRONT. THE FRONT SHOULD CLEAR THE GULF BY SAT 
MORNING. 

CARIBBEAN SEA...
THE COLD FRONT INLAND OVER THE YUCATAN PENINSULA IS GENERATING 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS IN THE FAR W CARIBBEAN 
WITHIN 75 NM OF LINE FROM THE GULF OF HONDURAS NEAR 16N87W TO 
OVER THE YUCATAN CHANNEL/W CUBA NEAR 22N84W INTO THE GULF OF 
MEXICO AND W ATLC. A BROAD UPPER RIDGE EXTENDS FROM OVER 
VENEZUELA NEAR 10N66W ACROSS PUERTO RICO INTO THE W ATLC 
COVERING THE REMAINDER CARIBBEAN WITH SW WIND TRANSPORTING UPPER 
LEVEL MOISTURE FROM THE E PACIFIC ACROSS CENTRAL AMERICA INTO 
THE SW CARIBBEAN GENERATING SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS S OF 11N FROM 80W-83W. THE FAR E CARIBBEAN IS 
UNDER STRONG SUBSIDENCE AND DRY AIR WITH ONLY HIGH DEBRIS 
CLOUDS. LIGHT EASTERLY TRADE WINDS CONTINUE ACROSS THE 
CARIBBEAN. 

ATLANTIC OCEAN...
ALTHOUGH THE UPPER RIDGE/TROUGH/RIDGE PATTERN CONTINUES TO 
DOMINATE THE FORECAST AREA ANOTHER UPPER TROUGH IS MOVING ACROSS 
THE NW ATLC DRAPING A SLOW MOVING COLD FRONT INTO THE AREA 
THROUGH 32N68W ACROSS S FLORIDA NEAR MIAMI. SCATTERED SHOWERS/ 
ISOLATED THUNDERSTORMS ARE WITHIN 125 NM EITHER SIDE OF THE 
FRONTAL BOUNDARY W OF 73W AND WITHIN 90 NM EITHER SIDE OF THE 
FRONT E OF 73W. THE BROAD UPPER RIDGE EXTENDS FROM THE CARIBBEAN 
INTO THE W ATLC ACROSS PUERTO RICO TO BEYOND 32N59W. WEAK 1019 
MB HIGH IS SHIFTING EASTWARD NE OF THE VIRGIN/LEEWARD ISLANDS 
NEAR 25N53W. A DEEP LAYERED TROUGH IS IN THE CENTRAL ATLC N OF 
15N FROM 30W-53W WITH THE A SERIES OF UPPER LOWS REMAINING N OF 
THE REGION. THE ASSOCIATED WEAKENING COLD FRONT EXTENDS INTO THE 
REGION NEAR 32N31W SW TO 26N40W THEN DISSIPATING TO 25N45W. 
MODERATE SUBSIDENCE AND DRY UPPER AIR COVERS THE BULK OF THE 
ATLC E OF E OF 60W...THUS LIMITING ANY SHOWER ACTIVITY 
ASSOCIATED WITH THE COLD FRONT IN THE CENTRAL ATLC. UPPER RIDGE 
OVER THE E ATLC EXTENDS FROM A UPPER HIGH S OF THE CAPE VERDE 
ISLANDS NEAR 8N18W COVERING THE AREA E OF 30W AND CONTINUING TO 
SUPPRESS THE ITCZ AXIS CONVECTION. E/W UPPER RIDGE COVERS THE 
TROPICAL ATLC EXTENDING FROM THE SAME UPPER HIGH ACROSS THE ATLC 
TO NEAR 38W. 

$$
WALLACE