000 AXNT20 KNHC 241154 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST MON DEC 24 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 1115 UTC ...THE ITCZ... FROM THE SIERRA LEONE/LIBERIA BORDER TO 7N27W 5N40W INTO EXTREME NORTHEASTERN BRAZIL NEAR 3N52W. ISOLATED MODERATE SHOWERS ARE SOUTH OF 8N IN THE ATLANTIC OCEAN FROM THE PRIME MERIDIAN AND SOUTH AMERICA. ...DISCUSSION... THE GULF OF MEXICO... MIDDLE TO UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE AREA THANKS TO THE RIDGE THAT EXTENDS FROM THE WEST CENTRAL CARIBBEAN SEA NORTHEASTWARD ACROSS CUBA AND THE BAHAMAS INTO THE ATLANTIC OCEAN ALONG THE U.S.A. EAST COAST. MIDDLE TO UPPER LEVEL DRY AIR/ SUBSIDENCE COVER THE SOUTHEASTERN HALF OF THE AREA. MIDDLE TO UPPER LEVEL MOISTURE ON THE WESTERN SIDE OF THE RIDGE COVERS THE NORTHWESTERN HALF OF THE AREA. UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS MEXICO NORTH OF 28N WEST OF 108W. A MIDDLE TO UPPER LEVEL TROUGH HAS MOVED FROM SOUTHEASTERN NEW MEXICO INTO CENTRAL TEXAS. THE REST OF TEXAS TO THE EAST OF THE TROUGH FINDS ITSELF ON THE WESTERN SIDE OF THE MIDDLE TO UPPER LEVEL CARIBBEAN SEA-TO-WESTERN ATLANTIC OCEAN RIDGE. A COLD FRONT CONTINUES THROUGH 32N77W IN THE ATLANTIC OCEAN TO FLORIDA ABOUT 30 NM NORTHWEST OF LAKE OKEECHOBEE TO THE SOUTHEASTERN GULF OF MEXICO. THE FRONT BECOMES STATIONARY IN THE SOUTHEASTERN CORNER OF THE AREA...CURVING TOWARD THE SOUTHWESTERN CORNER OF THE AREA AND INTO THE ISTHMUS OF TEHUANTEPEC...AND THEN CURVING NORTHWESTWARD FROM JUST WEST OF THE ISTHMUS OF TEHUANTEPEC TO 22N99W. MODEL GUIDANCE SUGGESTS THAT THE FRONT WILL WEAKEN AND SLOW DOWN IN ITS EASTWARD MOVEMENT. IT MAY STALL OVER SOUTH FLORIDA AND THE SOUTHEASTERN GULF OF MEXICO DURING THE NEXT 24 HOURS AS THE FRONT LOSES ITS MIDDLE TO UPPER LEVEL SUPPORT. BROKEN LOW CLOUDS AND POSSIBLE SHOWERS ACCOMPANY THE FRONT. THE CARIBBEAN SEA... A MIDDLE TO UPPER LEVEL RIDGE EXTENDS FROM THE AREA OF EASTERN HONDURAS/NORTHEASTERN NICARAGUA NORTHEASTWARD ACROSS CUBA AND THE BAHAMAS INTO THE ATLANTIC OCEAN ALONG THE U.S.A. EAST COAST. THIS RIDGE ENHANCES DRY AIR/SUBSIDENCE. A SEPARATE AREA OF UPPER LEVEL ANTICYCLONIC FLOW ORIGINATES OVER NORTHERN SOUTH AMERICA AND COVERS THE AREA EAST OF A SOUTHEASTERN CUBA-TO- NORTHEASTERN NICARAGUA LINE. A DEEP LAYER TROUGH SUPERIMPOSES ITSELF ON TOP OF THE NORTHEASTERN CORNER OF THE AREA PASSING THROUGH 27N52W IN THE ATLANTIC OCEAN TO PUERTO RICO. ALL THE PRECIPITATION WITH THIS TROUGH IS NORTH OF 18N AND EAST OF 57W. BROAD SURFACE-TO-LOW LEVEL CYCLONIC FLOW AND UPPER LEVEL ANTICYCLONIC OUTFLOW ARE ON TOP OF THE SOUTHWESTERN CORNER OF THE AREA. NUMEROUS STRONG SHOWERS/THUNDERSTORMS ARE IN THE GULF OF URABA OF NORTHWESTERN COLOMBIA. SCATTERED MODERATE TO STRONG SHOWERS/THUNDERSTORMS ARE ALONG THE PANAMA COAST WITHIN A 20 NM RADIUS OF 10N78.5W...AND FROM 9N TO 10N BETWEEN 80W AND 81W...ALSO NORTH OF PANAMA. THE ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL RIDGE FROM THE WEST CENTRAL CARIBBEAN SEA CROSSES CUBA AND THE BAHAMAS AND CONTINUES NORTHEASTWARD BEYOND 32N70W. ONE SURFACE TROUGH STANDS ALONE ALONG 73W/74W FROM GREAT INAGUA TO 28N. POSSIBLE SHOWERS ARE WITH THIS TROUGH. MOSTLY LOW CLOUDS ARE ROTATING CYCLONICALLY AROUND THIS FEATURE. A DEEP LAYER TROUGH PASSES THROUGH 35N44W TO 27N52W INTO THE NORTHEASTERN CORNER OF THE CARIBBEAN SEA NEAR PUERTO RICO. THIS TROUGH SUPPORTS THE COLD FRONT THAT PASSES THROUGH 32N35W TO 28N47W. A TROUGH CONTINUES FROM 28N47W TO A 1015 MB LOW PRESSURE CENTER NEAR 23N57W TO 20N63W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND ISOLATED MODERATE SHOWERS ARE FROM 18N TO 26N BETWEEN 45W AND 57W...AND WITHIN 120 NM TO 180 NM ON EITHER SIDE OF THE LINE THAT PASSES THROUGH 26N50W 29N45W BEYOND 32N41W. BROAD UPPER LEVEL WESTERLY-TO-SOUTHWESTERLY WIND FLOW COVERS THE ATLANTIC WATERS SOUTH OF 17N/18N FROM THE EASTERN CARIBBEAN SEA TO AFRICA. BROAD EASTERLY SURFACE WIND FLOW SOUTH OF 20N EAST OF 60W. A MIDDLE TO UPPER LEVEL TROUGH PASSES THROUGH THE NORTHERN HALF OF MOROCCO TO THE CANARY ISLANDS TO 24N31W. A SURFACE RIDGE IS UNDER THIS TROUGH...FROM A 1028 MB HIGH PRESSURE CENTER NEAR 33N20W TO 30N29W 26N36W 23N41W TO 17N55W. $$ MT