000
AXNT20 KNHC 011058
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SAT DEC 01 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 
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 
1015 UTC.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 7N11W 6N24W 3N42W 2N52W. 
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE 
WITHIN 120 NM OF THE ITCZ AXIS E OF 32W TO THE COAST OF W AFRICA 
AND WITHIN 60 NM OF LINE FROM 7N33W TO 10N43W.  

DISCUSSION...

GULF OF MEXICO...
A SURFACE RIDGE DOMINATES THE E HALF OF THE US EXTENDING S OVER 
THE ENTIRE GULF OF MEXICO. AN UPPER RIDGE EXTENDS FROM AN UPPER 
HIGH IN THE E PACIFIC REGION OVER MEXICO INTO THE CENTRAL PLAIN 
STATES COVERING THE W GULF W OF 90W. A UPPER SHORTWAVE TROUGH 
EXTENDS FROM THE W ATLC ACROSS THE FLORIDA PENINSULA TO THE NE 
YUCATAN PENINSULA. MOSTLY DRY STABLE AIR DOMINATES THE GULF. 
HOWEVER...SOME SCATTERED LOW LEVEL SHOWERS DOT THE SE GULF S OF 
25N W OF 88W. 

CARIBBEAN SEA...
A BROAD UPPER RIDGE COVERS THE W CARIBBEAN WITH THE AXIS 
EXTENDING FROM COLOMBIA TO THE S COAST OF CUBA COVERING THE AREA 
W OF 70W. A BROAD UPPER LOW IN THE S/CENTRAL ATLC COVERS THE E 
CARIBBEAN E OF 70W WITH DRY STABLE AIR DOMINATING THE ENTIRE 
REGION. MODERATE/STRONG NE TRADE WINDS DOMINATE THE CARIBBEAN 
USHERING IN SOME ISOLATED LOW LEVEL AND FAST MOVING SHOWERS S OF 
15N FROM 70W-76W AND E OF 70W. 

ATLANTIC OCEAN...
A UPPER SHORTWAVE TROUGH EXTENDS THROUGH 32N68W ACROSS THE 
FLORIDA PENINSULA NEAR FORT LAUDERDALE INTO THE E GULF OF MEXICO 
WITH A WEAK 1020 MB LOW NEAR 32N73W AND A SURFACE TROUGH 
EXTENDING SW TO LAKE OKEECHOBEE FLORIDA. SCATTERED SHOWERS ARE 
WITHIN 90 NM OF THE SURFACE TROUGH. THE UPPER RIDGE EXTENDS 
ACROSS THE W ATLC FROM CENTRAL CUBA TO 31N65W. BROAD UPPER LOW 
IS CENTERED IN THE S/CENTRAL ATLC NEAR 23N55W COVERING THE AREA 
FROM 50W-70W INCLUDING THE E CARIBBEAN. A SURFACE TROUGH EXTENDS 
FROM 29N52W ALONG 24N55W TO 17N60W WITH SCATTERED SHOWERS/ 
ISOLATED THUNDERSTORMS FROM 21N-28N BETWEEN 48W-61W. SMALL WEAK 
UPPER LOW IS IN THE E ATLC NEAR 29N37W WITH AN UPPER TROUGH OVER 
THE FAR E ATLC N OF 19N E OF 24W AND NO SURFACE REFLECTIONS 
ASSOCIATED WITH EITHER OF THESE UPPER LEVEL FEATURES. UPPER 
RIDGE COVERS MUCH OF THE TROPICS S OF 20N E OF 50W TO INLAND 
OVER AFRICA PROVIDING UPPER LEVEL DIFFLUENCE TO GENERATE 
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 200 
NM OF LINE FROM 7N52W TO 20N45W. A JET STREAM WITH WINDS 
ESTIMATED TO BE 80 TO 110 KT EXTENDS AROUND THE N BOUNDARY OF 
THIS UPPER RIDGE WITH THE STRONGEST WINDS E OF 25W. AT THE 
SURFACE...A BROAD SURFACE RIDGE COVERS THE ATLC WITH A WEAKNESS 
ALONG THE SURFACE TROUGH.    

$$
WALLACE