000 AXNT20 KNHC 121726 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON DEC 12 2006 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1615 UTC. ...THE ITCZ... 7N11W 4N20W 4N30W 3N40W 2N50W INTO NORTHEASTERN BRAZIL NEAR 2N52W. WIDELY SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS FROM 2N TO 6N BETWEEN 15W AND 22W. SHOWERS ARE POSSIBLE IN LOW CLOUDS FROM 1N TO 5N BETWEEN 32W AND 52W. ...DISCUSSION... THE GULF OF MEXICO... UPPER LEVEL SOUTHWESTERLY TO WESTERLY WIND FLOW MOVES FROM THE EASTERN PACIFIC OCEAN ACROSS MEXICO NORTH OF 20N...TO THE BASE OF A DEEP LAYER TROUGH NEAR 26N95W. THIS TROUGH STARTS OUT IN THE CENTRAL U.S.A. AND REACHES THE NORTHWESTERN GULF WATERS. A SURFACE TROUGH IS ALONG 31N93W TO 27N94W. A COLD FRONT IS IN THE TEXAS GULF COAST PLAINS SET TO ENTER THE NORTHWESTERN GULF OF MEXICO WATERS DURING THE NEXT SIX HOURS OR LESS. MIDDLE TO UPPER LEVEL DRY AIR IS EVERYWHERE IN TEXAS TO THE NORTHWEST OF THE FRONT. A BAND OF UPPER LEVEL MOISTURE RIDING ALONG THE ACCOMPANYING WIND MAXIMA/JET STREAM IS WITHIN 90 NM ON EITHER SIDE OF 22N107W 26N94W BEYOND 31N86W. A MIDDLE TO UPPER LEVEL RIDGE IS ALONG 80W FROM 20N NORTHWARD OVER CUBA AND FLORIDA TOWARD SOUTH CAROLINA. BROKEN TO OVERCAST MULTILAYERED CLOUDINESS AND SHOWERS ARE UNDER THIS RIDGE...FROM 20N TO 26N BETWEEN 80W AND 85W. SURFACE TO LOW LEVEL CYCLONIC FLOW EXTENDS FROM THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA...THROUGH THE YUCATAN CHANNEL...INTO THE EAST CENTRAL GULF OF MEXICO. BROKEN TO OVERCAST LOW TO MIDDLE LEVEL CLOUDS AND POSSIBLE SHOWERS HAVE BEEN IN THE GULF WATERS EAST OF 90W FOR THE LAST FEW DAYS. SIMILAR CLOUDS AND PRECIPITATION ARE SOUTH OF 24N BETWEEN 90W AND THE MEXICO COAST. THE CARIBBEAN SEA... SURFACE TO LOW LEVEL CYCLONIC FLOW EXTENDS FROM THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA...THROUGH THE YUCATAN CHANNEL...INTO THE EAST CENTRAL GULF OF MEXICO. A TROUGH...POSSIBLY THE REMNANT OF AN OLD FRONTAL BOUNDARY...REMAINS EITHER FROM THE NORTHWESTERN WATERS INTO THE YUCATAN PENINSULA AND/OR NORTHWARD THROUGH THE YUCATAN CHANNEL INTO THE SOUTHEASTERN GULF OF MEXICO. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE NORTH OF THE HONDURAS COAST TO CUBA AND THE YUCATAN CHANNEL WEST OF 80W. BROAD SURFACE TO LOW LEVEL CYCLONIC FLOW IN THE CLOUD FIELD ON VISIBLE SATELLITE IMAGERY COVERS THE AREA FROM THE CENTRAL CARIBBEAN SEA INTO THE WEST-CENTRAL SECTIONS IN TRADE WIND FLOW. SHOWERS ARE POSSIBLE FROM THE CENTRAL WATERS TO THE WEST-CENTRAL WATERS. UPPER LEVEL SOUTHERLY WINDS ARE BLOWING FROM THE EQUATOR OVER SOUTH AMERICA NORTHWARD...HAVING LITTLE TO NO INFLUENCE OVER THE CARIBBEAN SEA. MIDDLE LEVEL FLOW IS NORTHEASTERLY TO EASTERLY...ACCORDING TO SATELLITE IMAGERY AND THE 12/1200 UTC CIMSS SATELLITE DERIVED WIND DATA. MIDDLE TO UPPER LEVEL DRY AIR STILL REMAINS SOUTH OF 20N EAST OF CENTRAL AMERICA. THE ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH PASSES THROUGH 34N52W TO 28N55W TO THE NORTHEASTERN CARIBBEAN SEA NEAR 18N63W. THIS TROUGH IS SUPPORTING THE COLD FRONT THROUGH 31N45W TO 26N50W TO 22N58W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE WITHIN 30 TO 60 NM ON EITHER SIDE OF THE LINE THROUGH 32N43W TO 29N44W TO 25N46W. AN UPPER LEVEL RIDGE IS BEING SQUEEZED IN BETWEEN THE APPROACHING TROUGH AND THE CYCLONIC FLOW AROUND A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER NEAR 24N31W. CYCLONIC FLOW AROUND THIS CENTER ROUGHLY COVERS THE ATLANTIC WATERS FROM 14N TO 30N BETWEEN 20W AND 40W. AN UPPER LEVEL RIDGE GOES FROM 25N20W BEYOND 32N27W. A SURFACE TROUGH IS ALONG 19N41W 16N44W 12N47W. SHOWERS ARE WITHIN 30 TO 60 NM ON EITHER SIDE OF THE TROUGH. THE ATLANTIC WATERS FROM 10N TO 20N BETWEEN 45W AND 60W ARE IN A SEPARATE AREA OF MIDDLE LEVEL CYCLONIC FLOW. THE UPPER LEVEL SOUTHERLY FLOW TO THE SOUTH OF THIS AREA IS MOVING TOWARD IT AND POSSIBLY OVER THE TOP OF IT...BUT ALSO THE SOUTHERLY FLOW SIMPLY IS MOVING AROUND IT AND/OR TO THE SIDE OF IT. $$ MT