000
AXNT20 KNHC 202258
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SAT JAN 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2215 UTC.

...THE ITCZ...
ITCZ AXIS CENTERED ALONG 6N14W 4N25W 3N39W 2N45W CROSSING THE 
EQUATOR AT 48W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE 
WITHIN 60 NM OF THE AXIS FROM 19W-30W. 

...DISCUSSION...
GULF OF MEXICO...
AT 2100 UTC...A RAPIDLY DROPPING 1012 MB LOW IS ALONG THE COAST 
OF TEXAS JUST S OF GALVESTON WITH A COLD FRONT EXTENDING S ALONG 
THE COAST TO INLAND OVER MEXICO JUST N OF TAMPICO THEN 
CONTINUING N ALONG THE E SLOPES OF THE SIERRA MADRE MOUNTAINS 
AS A STATIONARY FRONT. ALSO FROM THE SURFACE LOW A WARM FRONT 
EXTENDS E TO 27N89W WHERE IT MERGES WITH A DISSIPATING 
STATIONARY FRONT THAT EXTENDS ACROSS S FLORIDA FROM THE W ATLC. 
THE LOW AND COLD/WARM FRONTS ARE ASSOCIATED WITH A DEEP LAYERED 
TROUGH CURRENTLY THAT EXTENDS FROM THE CENTRAL PLAIN STATES SW 
TO OVER NW MEXICO. UPPER LEVEL MOISTURE IS STREAMING ACROSS 
MEXICO FROM THE E PACIFIC REGION OVER TEXAS AND INTO THE LOWER 
MISSISSIPPI VALLEY FUELING SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS THAT ARE MAINLY INLAND AND ALONG THE COAST OF 
LOUISIANA AND TEXAS. THE GULF OF MEXICO IS DOMINATED BY AN UPPER 
RIDGE ANCHORED IN THE CARIBBEAN AND EXTENDS ACROSS FLORIDA INTO 
THE W ATLC. DRY UPPER AIR AND STRONG SUBSIDENCE COVERS MOST OF 
THE GULF EXCEPT IN THE FAR NW. LOW LEVEL CONVERGENCE IS 
GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE SE 
GULF S OF THE REMNANT FRONTAL BOUNDARY BETWEEN 80W-89W. 

CARIBBEAN SEA...
BROAD UPPER RIDGE COVERS THE CARIBBEAN ANCHORED BY AN UPPER 
HIGH LOCATED ALONG THE COAST OF CENTRAL AMERICA NEAR 15N83W AND 
EXTENDS INTO THE GULF OF MEXICO AND THE W ATLC. STRONG EASTERLY 
TRADE WINDS CONTINUE TO DOMINATE THE CARIBBEAN. DRY AIR AND 
STRONG SUBSIDENCE COVERS THE ENTIRE AREA WITH SOME LOW LEVEL 
CONVERGENCE GENERATING SCATTERED SHOWERS S OF 16N W OF 80W TO 
INLAND OVER CENTRAL AMERICA. 

ATLANTIC OCEAN...
BROAD UPPER RIDGE ANCHORED BY AN UPPER HIGH IN THE CARIBBEAN 
COVERS THE W AND CENTRAL ATLC W OF 50W. A DEEP LAYERED TROUGH IS 
OVER THE NW ATLC DRAPING A COLD FRONT INTO THE REGION NEAR 
32N56W EXTENDING W TO 27N74W WHERE IT CONTINUES INTO THE GULF OF 
MEXICO AS A DISSIPATING STATIONARY FRONT ACROSS S FLORIDA. AT 
THE SURFACE...A 1019 MB HIGH IS LOCATED NEAR 24N58W. AN UPPER 
TROUGH IS OVER THE E/CENTRAL ATLC EXTENDING THROUGH 32N40W S TO 
22N42W. AT THE SURFACE...A 1011 MB LOW IS CENTERED NEAR 27N43W 
WITH A SURFACE TROUGH EXTENDING SE ALONG 23N40W THEN SW TO 
17N49W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS 
ARE E OF THE SURFACE TROUGH N OF 21N BETWEEN 35W-40W. BROAD 
UPPER RIDGE COVERS THE REMAINDER OF THE ATLC ANCHORED DEEP IN 
THE TROPICS WITH A SURFACE RIDGE EXTENDING BETWEEN THE AZORES 
AND THE CANARY ISLANDS SW TO 17N35W. 

$$
PAW