000
AXNT20 KNHC 181810 CCA
TWDAT 

TROPICAL WEATHER DISCUSSION...COR
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST TUE DEC 18 2007

COR FOR ITCZ SECTION AND TYPOGRAPHICAL MISTAKES

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 1715 UTC

...THE ITCZ...
FROM SOUTHERN SIERRA LEONE NEAR 7N12W 3N30W 1N40W TO THE EQUATOR
AT 50W INTO NORTHEASTERN BRAZIL ALONG THE EQUATOR AT 56W.
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS
FROM 2N TO 3N BETWEEN 7W AND 8W. ISOLATED MODERATE SHOWERS
WITHIN 120 NM ON EITHER SIDE OF 7N11W 5N22W 3N40W 2N53W...
INCLUDING FROM 1S TO 5N IN THE COASTAL PLAINS FROM NORTHEASTERN 
BRAZIL INTO FRENCH GUIANA. ISOLATED MODERATE SHOWERS ARE 
ELSEWHERE SOUTH OF 11N BETWEEN 43W AND 60W IN THE ATLANTIC OCEAN.

...DISCUSSION...

THE GULF OF MEXICO...
UPPER LEVEL SOUTHWESTERLY FLOW FROM THE EASTERN PACIFIC OCEAN
JUST WEST OF MEXICO EVENTUALLY BECOMES PREDOMINANTLY WESTERLY 
FLOW AS IT CROSSES MEXICO AND THE GULF OF MEXICO TO FLORIDA AND 
BEYOND INTO THE ATLANTIC OCEAN. A NORTHEAST-TO-SOUTHWEST ORIENTED
SURFACE RIDGE COVERS THE AREA AFTER THE COLD FRONT OF THE WEEKEND
OF A FEW DAYS AGO. NO DEEP CONVECTIVE PRECIPITATION.

THE CARIBBEAN SEA...
BROAD UPPER LEVEL ANTICYCLONIC FLOW AND MIDDLE TO UPPER LEVEL 
DRY AIR/SUBSIDENCE ARE WEST OF THE LINE FROM HAITI TO THE 
COLOMBIA/PANAMA BORDER. A MIDDLE LEVEL CYCLONIC CIRCULATION 
CENTER APPEARS TO BE FORMING NEAR 16N68W. UPPER LEVEL 
SOUTHWESTERLY WIND FLOW MOVES FROM NORTHEASTERN VENEZUELA
ACROSS THE SOUTHEASTERN CARIBBEAN SEA ISLANDS INTO THE ATLANTIC 
OCEAN. THE ATLANTIC OCEAN COLD FRONT THAT PASSED THROUGH THE 
GULF OF MEXICO DURING SATURDAY 15 DECEMBER AND SUNDAY
16 DECEMBER PASSES OVER EXTREME EASTERN CUBA AND REACHES
EASTERN HONDURAS.
 
THE ATLANTIC OCEAN...
THE DEEP LAYERED TROUGH THAT SUPPORTS THE LATEST COLD FRONT TO 
PASS THROUGH THE GULF OF MEXICO ON SATURDAY 15 DEC AND SUNDAY
16 DEC PASSES JUST EAST OF BERMUDA TO 28N65W 25N65W TO JUST 
SOUTHEAST OF THE TURKS ISLANDS. MIDDLE TO UPPER LEVEL DRY AIR/
SUBSIDENCE IS WITHIN AT LEAST 500 NM WEST OF THE TROUGH. THE 
COLD FRONT PASSES THROUGH 32N58W TO 24N70W TO 17N82W.
A STATIONARY FRONT CONTINUES FROM 17N82W TO EASTERN HONDURAS
TO 14N86W IN SOUTH CENTRAL HONDURAS. BROKEN LOW CLOUDS ARE
WITHIN 150 NM TO 200 NM NORTHWEST OF THE FRONT. BROKEN LOW
AND HIGH CLOUDS ARE NORTHWEST OF THE FRONT IN THE CARIBBEAN SEA. 
POSSIBLE SHOWERS ARE NORTH OF 26N BETWEEN 56W AND 63W. AN UPPER 
LEVEL ANTICYCLONIC CIRCULATION CENTER IS NEAR 30N44W. 
ANTICYCLONIC FLOW COVERS THE AREA NORTH OF 17N BETWEEN 33W
AND THE DEEP LAYER TROUGH. UPPER LEVEL WESTERLY FLOW EXITS 
NORTHEASTERN VENEZUELA AND THE SOUTHEASTERN CARIBBEAN SEA AND 
ENTERS THE ATLANTIC OCEAN. THE FLOW BECOMES 30W ALONG AND SOUTH 
OF 16N...THEN BECOMING SOUTHWESTERLY FLOW WITH A SHORT WAVE 
TROUGH INTO MAURITANIA. A DEEP LAYER CYCLONIC CIRCULATION CENTER 
IS ABOUT 120 NM SOUTHEAST OF SAO MIGUEL OF THE AZORES. BROAD
CYCLONIC FLOW COVERS THE ATLANTIC OCEAN NORTH OF 16N EAST OF 
33W. THE TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 32N14W 
TO 25N20W TO 22N30W TO 21N39W. A DISSIPATING COLD FRONT 
CONTINUES FROM 21N39W TO 23N45W AND 26N50W. BROKEN TO OVERCAST 
LOW TO MIDDLE LEVEL CLOUDS ARE WITHIN 60 NM ON EITHER SIDE OF 
21N30W 25N20W BEYOND 31N13W. SHOWERS ARE POSSIBLE NORTH OF THE 
CANARY ISLANDS ON EITHER SIDE OF THE FRONT/TROUGH.

$$
MT