000 AXNT20 KNHC 110005 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST MON DEC 10 2012 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL GUINEA NEAR 10N14W TO 06N19W. THE ITCZ CONTINUES FROM 06N19W TO 02N50W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE FROM 02N TO 07N EAST OF 18W. ...DISCUSSION... THE GULF OF MEXICO... AT 2100 UTC...A FAST MOVING COLD FRONT EXTENDS FROM COASTAL ALABAMA SOUTHWESTWARD TO NORTHEAST MEXICO. A 1634 UTC ASCAT SCATTEROMETER PASS ALONG WITH NUMEROUS SHIPS AND BUOYS INDICATED N WINDS 25-35 KT IN THE NORTHWESTERN GULF OF MEXICO NORTH OF THE FRONT. SOUTH OF THE FRONT...SW WINDS WERE SUBSTANTIALLY WEAKER WITH PEAK WINDS ONLY 15-20 KT. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OCCURRING AHEAD OF THE FRONT IN THE EASTERN GULF OF MEXICO AND OVER CENTRAL FLORIDA. THIS CONVECTION IS IN THE FORM OF UNORGANIZED...YET QUITE VIGOROUS THUNDERSTORM ACTIVITY...AS IT DOES NOT HAVE THE LINEAR APPEARANCE OF A SQUALL LINE. AT THIS TIME...THERE DOES NOT APPEAR TO BE ANY COHERENT SURFACE FEATURE ASSOCIATED WITH THE CONVECTIVE ACTIVITY. THE FRONT IS BEING AIDED BY A LARGE SHORT-WAVE TROUGH THAT IS CURRENTLY CENTERED OVER THE SOUTHWESTERN UNITED STATES AND NORTHWESTERN MEXICO. FORCING FOR THE COLD FRONT SHOULD BE SHORT-LIVED...HOWEVER...AND THE GALE FORCE WINDS SHOULD WEAKEN SHORTLY AND THE FRONT SHOULD WASH OUT BEFORE REACHING SOUTH FLORIDA. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT4...FOR MORE DETAILS ABOUT 30 TO 35 KT WINDS AND SEAS TO 11 FEET TO THE NORTHWEST OF THE COLD FRONT. THE CARIBBEAN SEA... WHILE THERE ARE NO SYNOPTIC FEATURES IN THE CARIBBEAN...THE STRONG PRESSURE GRADIENT FROM THE BERMUDA HIGH TO LOW PRESSURES OVER SOUTH AMERICA ARE CAUSING ENHANCED TRADEWINDS. A SURFACE RIDGE PASSES OVER THE NORTHWESTERN BAHAMAS...INTO THE FLORIDA STRAITS...TO THE NORTHWESTERN CARIBBEAN. THE 1456 UTC ASCAT SCATTEROMETER PASS INDICATED 20-30 KT E WINDS IN THE CENTRAL CARIBBEAN. NO SIGNIFICANT CONVECTION IS CURRENTLY OCCURRING OVER THE CARIBBEAN. HOWEVER...SOME LOW-TOPPED SHOWERS ARE LIKELY OCCURRING NEAR TRINIDAD AND BARBADOS ALONG THE WESTERN END OF A SHEAR LINE. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT THE 20 TO 25 KNOT WINDS AND SEAS TO 11 FEET IN THE CENTRAL CARIBBEAN. THE ATLANTIC OCEAN... A DEEP LAYER TROUGH PASSES THROUGH 32N30W TO 25N31W 22N43W... TO 16N53W AND 14N58W. THE TROUGH SUPPORTS A DISSIPATING STATIONARY FRONT THAT STARTS NEAR 31N27W TO 26N30W AND 22N32W. A SHEAR AXIS CONTINUES FROM 22N32W TO 18N40W 15N46W 13N54W AND 12N59W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION WITHIN 200 NM TO 300 NM TO THE EAST-SOUTHEAST OF THE FRONTAL BOUNDARY/SHEAR AXIS. A SURFACE TROUGH IS ALONG 14N52W 11N55W 8N57W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG FROM 10N TO 16N BETWEEN 47W AND 62W...AND FROM 5N TO 9N BETWEEN 51W AND 55W. A SURFACE RIDGE EXTENDS FROM A 1028 MB HIGH PRESSURE CENTER THAT IS NEAR 32N46W TO 30N64W 29N72W...ACROSS ANDROS ISLAND IN THE BAHAMAS...INTO THE FLORIDA STRAITS...TO 24N91W IN THE GULF OF MEXICO. A SURFACE RIDGE PASSES THROUGH 32N15W...ABOUT 95 NM TO THE EAST-SOUTHEAST OF THE MADEIRA ARCHIPELAGO...ACROSS THE CANARY ISLANDS AND THE CAPE VERDE ISLANDS...TO 6N26W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...FOR MORE DETAILS ABOUT 20 TO 25 KNOT WINDS AND SEAS TO 13 FEET. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ CL/MT