000 AXNT20 KNHC 211804 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST FRI DEC 21 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC ...THE ITCZ... FROM CENTRAL COASTAL LIBERIA TO 5N20W 5N30W 3N40W...THROUGH THE EQUATOR AT 50W...INTO NORTHEASTERN BRAZIL NEAR 1S52W. SCATTERED STRONG SHOWERS/THUNDERSTORMS FROM 2N TO 6N BETWEEN 30W AND 42W. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE ELSEWHERE FROM THE EQUATOR TO 8N BETWEEN 20W AND 46W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH IS DIGGING INTO SOUTHERN CALIFORNIA/ARIZONA/NORTHERN BAJA CALIFORNIA. UPPER LEVEL MOISTURE FROM THE EASTERN PACIFIC OCEAN MOVES NORTHEASTWARD ACROSS MEXICO...AROUND AN UPPER LEVEL RIDGE THAT CUTS RIGHT THROUGH THE CENTER OF TEXAS AND OKLAHOMA AS FAR SOUTH AS SOUTHERN MEXICO. A DEEP LAYER TROUGH HAS DUG ITS WAY ACROSS THE U.S.A. GULF OF MEXICO COASTAL STATES...NOW FROM THE ATLANTIC OCEAN COAST OF NORTHERN GEORGIA TO SOUTHERN FLORIDA TO CUBA ALONG 80W. THE CYCLONIC FLOW AROUND THE TROUGH IS SPREADING OUT IN ORDER TO COVER THE BAHAMAS NORTH OF 26N AND THE ATLANTIC OCEAN WEST OF 74W. THE COLD FRONT WITH THIS TROUGH PASSES THROUGH 31N79W TO JUST NORTH OF LAKE OKEECHOBEE TO THE SOUTH CENTRAL GULF WATERS...CURVING INTO THE SOUTHWESTERN CORNER OF THE AREA. MIDDLE TO UPPER LEVEL DRY AIR/SUBSIDENCE COVER THE AREA. BROKEN LOW TO MIDDLE LEVEL CLOUDS AND POSSIBLE SHOWERS ARE WITHIN 90 NM TO 120 NM IN FRONT OF THE COLD FRONT. THE CARIBBEAN SEA... A LOW LEVEL TROUGH...AROUND 800 MB...STRETCHES FROM THE SOUTHEASTERN CORNER OF THE AREA TO NORTHERN SECTIONS/COASTAL PLAINS OF VENEZUELA AND COLOMBIA...AND ENDING IN THE EASTERN PACIFIC OCEAN JUST WEST OF COLOMBIA. ISOLATED MODERATE SHOWERS ARE IN THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA SOUTH OF 10N BETWEEN COASTAL COLOMBIA AND COASTAL PANAMA. MIDDLE TO UPPER LEVEL DRY AIR/SUBSIDENCE IS EVERYWHERE. A SURFACE TROUGH IS IN THE SOUTHEASTERN CORNER OF AREA FROM JUST SOUTHWEST OF GUADELOUPE TO 13N62.5W AND 10N62.5W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND ISOLATED MODERATE SHOWERS ARE FROM 9N TO 16N BETWEEN 59W AND 65W. BROAD UPPER LEVEL WESTERLY WIND FLOW COVERS THE AREA. THE ATLANTIC OCEAN... THE DEEP LAYER TROUGH WITH THE ATLANTIC OCEAN-TO-GULF OF MEXICO COLD FRONT IS MAKING ITS PRESENCE FELT IN THE ATLANTIC OCEAN WEST OF 74W. A CENTRAL ATLANTIC OCEAN MIDDLE TO UPPER LEVEL TROUGH SUPPORTS A SURFACE TROUGH FROM 33N50W TO 26N55W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND ISOLATED TO WIDELY SCATTERED MODERATE SHOWERS ARE WITHIN 60 NM TO 90 NM ON EITHER SIDE OF THE LINE THROUGH 32N45W 27N49W 24N54W 20N58W. LARGE SCALE UPPER LEVEL ANTICYCLONIC WIND FLOW IS NORTH OF 20N EAST OF THE 32N45W 20N58W TROUGH. MIDDLE TO UPPER LEVEL CYCLONIC FLOW IS FROM 14N TO 24N BETWEEN 27W AND 41W. NO CLEAR CYCLONIC CIRCULATION CENTER HAS DEVELOPED YET. A COLD FRONT REMAINS IN THE EASTERN ATLANTIC OCEAN FROM 32N19W TO 28N28W TO 29N34W. A STATIONARY FRONT CONTINUES FROM 29N34W TO 31N38W. A WARM FRONT CONTINUES NORTHWESTWARD FROM 31N38W. BROKEN LOW CLOUDS AND POSSIBLE SHOWERS ARE WITHIN 30 NM OR LESS ON EITHER SIDE OF 30N18W 28N23W 27N28W 30N36W. $$ MT