000
AXNT20 KNHC 181752
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST MON FEB 18 2008

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1745 UTC

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N11W 0N34W 2S40W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS NOTED 120 NM OF 5N12W AND 
WITHIN 60 NM SE AND 300 NM NW OF THE ITCZ AXIS BETWEEN 21W AND 
37W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL TROUGH IS SWINGING E ACROSS THE NW GULF WHILE AN 
UPPER RIDGE EXTENDS NW OVER THE EXTREME SE PORTION. AT THE LOW 
LEVELS A BROAD FRONTAL ZONE IS ANALYZED FOR SIMPLICITY AS A 
SINGLE COLD FRONT FROM 31N83W TO 26N90W INTO A BROAD AREA OF LOW 
PRES OVER THE BAY OF CAMPECHE. BROKEN TO LOCALLY OVERCAST LOW 
AND MID LEVELS CLOUDS ARE WITHIN 120 NM OF THE ANALYZED FRONT. 
UPPER DIFFLUENCE...BETWEEN THE UPPER TROUGH AND RIDGE OVER THE 
NE GULF...IS ENHANCING TSTMS AHEAD OF THE SURFACE FRONT...WITH 
THE CONVECTIVE ACTIVITY DECREASING IN BOTH INTENSITY AND 
COVERAGE SINCE SUNRISE. THE RESULTANT DEBRIS MOISTURE IS 
SPREADING NE ACROSS FLORIDA FANNING OUT OVER THE ATLC W OF 
BERMUDA.
  
CARIBBEAN...
AN UPPER LEVEL RIDGE ORIGINATING OVER SOUTH AMERICA COVERS THE 
CARIBBEAN. DEBRIS MOISTURE IS SPREADING N OVER THE SW CARIBBEAN 
AND IS ALSO NOTED ALONG A BAND SPREADING E ACROSS THE RIDGE OVER 
THE NORTHERN PORTION. OTHERWISE THE UPPER LEVELS ARE DRY 
SUPPRESSING CONVECTION TO ONLY LIGHT TRADE WIND SHOWERS RACING W 
ACROSS THE NE ISLANDS.

ATLANTIC...
AN UPPER RIDGE EXTENDS N ACROSS THE CARIBBEAN OVER THE BAHAMAS 
TO A CREST JUST BEYOND 33N76W. A BROAD AND DEEP LAYERED TROUGH 
EXTENDS S INTO THE CENTRAL ATLC WITH AN EMBEDDED UPPER CYCLONE 
AT 22N55W. AN ASSOCIATED COLD FRONT ENTERS THE REGION NEAR 
32N42W EXTENDING WSW TO 28N52W ACCOMPANIED BY LOCALLY BROKEN LOW 
CLOUDS AND ISOLATED SHOWERS. A SURFACE RIDGE IS BUILDING S OVER 
THE AREA W OF THE FRONT INTO THE NW CARIBBEAN. AN UPPER RIDGE 
EXTENDS W OF THE AFRICAN COAST ENHANCING CONVECTION ALONG THE 
ITCZ E OF 45W RESULTING IN A LARGE MOISTURE PLUME SPREADING NE 
ACROSS W AFRICA TO THE S OF THE CANARIES. AT THE LOW LEVELS A 
LARGE AREA OF DUST AND SUBSIDENCE IS NOTED S OF 16N E OF 30W.

$$
NELSON