000 AXNT20 KNHC 311812 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SUN DEC 31 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 1715 UTC. ...THE ITCZ... 6N8W 6N14W 2N30W 2N40W...CURVING TO THE EQUATOR AT 51W. ISOLATED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS FROM THE EQUATOR TO 6N BETWEEN THE PRIME MERIDIAN AND 53W IN BRAZIL AND FRENCH GUIANA. ...DISCUSSION... THE GULF OF MEXICO... A DEEP LAYER TROUGH CONTINUES FROM THE MIDWESTERN U.S.A...TO TEXAS AND NORTHERN MEXICO...AND TO THE EASTERN PACIFIC OCEAN ABOUT 150 NM SOUTH OF THE SOUTHERN TIP OF BAJA CALIFORNIA. AN UPPER LEVEL RIDGE IS ALONG 87W/88W FROM THE EASTERN PACIFIC OCEAN WATERS JUST WEST OF THE NICARAGUA COAST NEAR 12N BEYOND 30N. A COLD FRONT PASSES THROUGH EXTREME SOUTHWESTERN ALABAMA/ EXTREME SOUTHEASTERN MISSISSIPPI...TO THE CENTRAL GULF OF MEXICO TO A 1014 MB SOUTHWESTERN GULF OF MEXICO LOW PRESSURE CENTER NEAR 21N93W...AND CONTINUING TO THE NORTHERN ISTHMUS OF TEHUANTEPEC. WIDELY SCATTERED MODERATE SHOWERS TO LOCALLY STRONG THUNDERSTORMS ARE WITHIN 30 TO 45 NM ON EITHER SIDE OF 23N93W 27N90W 29N87W BEYOND 31N86W. THE CARIBBEAN SEA... BROAD UPPER LEVEL ANTICYCLONIC FLOW WITH THE 87W/88W RIDGE NOW IS LIMITED TO THE AREA WEST OF 80W. BROAD MIDDLE TO UPPER LEVEL CYCLONIC FLOW WITH A TROUGH COVERS THE REST OF THE AREA EAST OF 80W. A CYCLONIC CIRCULATION CENTER IS NEAR 16N67W. THIS TROUGH HAS BEEN DROPPING SOUTHWARD FROM THE ATLANTIC OCEAN TOWARD AND INTO THE CARIBBEAN SEA AT A STEADY RATE DURING THE LAST FEW DAYS. ISOLATED MODERATE SHOWERS FROM 17N TO 19N BETWEEN 59W AND 68W... AND FROM 11N TO 13N BETWEEN 60W AND 64W. MIDDLE TO UPPER LEVEL DRY AIR/SUBSIDENCE IS AT ITS GREATEST BETWEEN 70W AND 83W... WHICH MEANS THAT IT IS DOUBTFUL THAT THIS AREA WILL EXPERIENCE ANY DEEP CONVECTIVE PRECIPITATION. THE ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH PASSES THROUGH 32N59W TO 22N61W TO THE CARIBBEAN SEA 16N67W CYCLONIC CENTER. A 1007 MB LOW PRESSURE CENTER NEAR 38N58W IS FORECAST TO INTENSIFY RAPIDLY AND DEVELOP HURRICANE FORCE WINDS. THE 24 HOUR FORECAST POSITION FOR THIS 972 MB LOW IS 45N 45W. THE WIND FORECAST IS FOR 50 TO 70 KT AND SEAS FROM 24 TO 36 FT WITHIN 240 NM IN THE NORTHWESTERN QUADRANT...WITHIN 300 NM IN THE SOUTHWESTERN QUADRANT...AND WITHIN 180 NM IN THE SOUTHEASTERN QUADRANT. A SURFACE TROUGH IS ALONG 29N71W 28N73W 26N75W. SHOWERS ARE POSSIBLE NEAR THE TROUGH BUT IT IS NOT GOING TO BE DEEP CONVECTIVE PRECIPITATION WITH REALLY COLD CLOUD TOP TEMPERATURES. A CENTRAL ATLANTIC SURFACE STILL IS HANGING AROUND...AT THE END OF A COLD FRONT WHICH IS NORTH OF 31N...ALONG 31N37W 27N46W 25N50W 23N57W. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE IN ONE CLUSTER FROM 20N TO 22N BETWEEN 51W AND 53W...AND WITHIN A 15 TO 30 NM RADIUS OF 21N56W AND 27N52W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND DEBRIS CLOUDS FROM EARLIER CLOUD DEVELOPMENTS AND POSSIBLE PRECIPITATION ARE WITHIN 60 TO 90 NM ON EITHER SIDE OF 26N50W 22N55W BEYOND 31N43W. THIS IS THE AREA OF THE SOUTHWESTERLY JET STREAM/WIND MAXIMA ON TOP OF THE SURFACE TROUGH...WIND SPEEDS ARE AT LEAST 70 TO 80 KT ACCORDING TO THE 31/1500 UTC CIMSS SATELLITE DERIVED WIND DATA. A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 22N33W. CYCLONIC FLOW AROUND THIS CENTER COVERS THE ATLANTIC OCEAN WATERS FROM 10N TO 30N BETWEEN 25W AND 40W. BROAD UPPER LEVEL ANTICYCLONIC FLOW IS SOUTH OF 10N. A MIDDLE TO UPPER LEVEL TROUGH RUNS FROM A CYCLONIC CIRCULATION CENTER IN WEST CENTRAL ALGERIA TO SOUTHWESTERN MAURITANIA AND SENEGAL. UPPER LEVEL ANTICYCLONIC FLOW CONTINUES FROM 20N BEYOND 32N BETWEEN 10W AND 30W. $$ MT