000 AXNT20 KNHC 060534 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST SAT DEC 06 2014 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 12N17W TO 11N19W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N24W TO 2N39W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 150 NM EITHER SIDE OF THE ITCZ BETWEEN 19W- 30W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 60 NM OF THE COAST OF LIBERIA BETWEEN THE IVORY COAST BORDER AND 10W. ...DISCUSSION... GULF OF MEXICO... A NARROW UPPER TROUGH IS MOVING ACROSS THE LOWER MISSISSIPPI VALLEY FROM SE MISSOURI TO SE LOUISIANA THEN SW TO THE S TIP OF TEXAS SUPPORTING A FRONTAL BOUNDARY THAT REMAINS INLAND OVER THE SE CONUS. THIS IS AMPLIFYING THE UPPER RIDGE TO THE E THAT EXTENDS FROM THE YUCATAN CHANNEL ACROSS FLORIDA AND INTO THE W ATLC. A SMALL UPPER LOW IS OVER S MEXICO NEAR 17N93W AND EXTENDS TO OVER THE BAY OF CAMPECHE. A SURFACE RIDGE EXTENDS FROM A 1030 MB HIGH OVER NORTH CAROLINA SW OVER THE GULF TO NEAR TUXPAN MEXICO WITH SKIES REMAINING RATHER CLEAR TONIGHT. SOME ISOLATED LOW LEVEL SHOWERS ARE MOVING ACROSS FLORIDA INTO THE E GULF S OF 27N E OF 85W INCLUDING THE STRAITS OF FLORIDA. THE SURFACE RIDGE WILL WEAKEN AS A WEAK COLD FRONT MOVES INTO THE NW GULF LATE SAT AND WILL EXTEND FROM FORT MYERS FLORIDA TO NE MEXICO LATE SUN THEN DISSIPATING ACROSS MUCH OF THE GULF BY LATE MON. CARIBBEAN SEA... A BROAD UPPER RIDGE DOMINATES THE CARIBBEAN WITH AN UPPER RIDGE AXIS EXTENDING FROM COLOMBIA TO THE YUCATAN CHANNEL. A WEAK SURFACE TROUGH EXTENDS FROM NEAR 15N79W TO 10N80W. THE MONSOON TROUGH EXTENDS ALONG 10N FROM COLOMBIA TO COSTA RICA GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 12N E OF 82W AND FROM 10N-14N W OF 82W TO THE COAST OF NICARAGUA. A SURFACE TROUGH IN THE CENTRAL ATLC EXTENDS TO OVER THE LEEWARD ISLANDS. LINGERING MOISTURE WITH SCATTERED SHOWERS ARE FROM 14N- 18N BETWEEN 60W-63W WITH ISOLATED SHOWERS WITHIN 75 NM OF LINE FROM 15N63W TO 14N70W. STRONG SUBSIDENCE AND DRY STABLE AIR COVER THE CARIBBEAN N OF 17N LEAVING THIS PORTION OF THE CARIBBEAN WITH CLEAR SKIES TONIGHT. THE W ATLC SURFACE RIDGE IS BRINGING FRESH TO OCCASIONALLY STRONG NE WINDS TO ACROSS NW AND N CENTRAL PORTIONS OF THE CARIBBEAN THROUGH SAT NIGHT WITH WEAKER PRESSURE GRADIENT ELSEWHERE. HISPANIOLA... SKIES OVER HISPANIOLA REMAIN RATHER CLEAR TONIGHT. EASTERLY FLOW ALOFT AND THE NE SURFACE FLOW WILL KEEP THE ISLAND FROM SEEING ANY SIGNIFICANT THUNDERSTORMS THROUGH MON. HOWEVER...ISOLATED LOW LEVEL FAST MOVING SHOWERS ARE ALWAYS A POSSIBILITY WITH THE NE TRADE WINDS. ATLANTIC OCEAN... THE UPPER RIDGE EXTENDS FROM THE YUCATAN CHANNEL ACROSS FLORIDA INTO THE W ATLC NEAR CAPE CANAVERAL TO BEYOND 32N76W COVERING THE AREA W OF 70W. A SURFACE RIDGE COVERS THE W ATLC ANCHORED BY A 1030 MB HIGH OVER NORTH CAROLINA AND EXTENDING A RIDGE AXIS INTO THE GULF OF MEXICO. AN UPPER TROUGH COVERS THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC N OF 20N BETWEEN 55W-70W SUPPORTING A 1011 MB LOW NEAR 27N61W AND A SURFACE TROUGH EXTENDING N TO BEYOND 32N58W AND A SECOND SURFACE TROUGH EXTENDING S ALONG 23N61W TO OVER THE LEEWARD ISLANDS NEAR 17N62W. A SECOND UPPER RIDGE IS TO THE E PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS N OF 25N BETWEEN 50W-62W AND WITHIN 150/200 NM OF LINE FROM 25N52W TO OVER THE LESSER ANTILLES NEAR 17N62W. A SURFACE RIDGE COVERS THE CENTRAL INTO THE E ATLC ANCHORED BY A 1046 MB HIGH OVER 300 NM N OF THE AZORES. ALSO IN THE E ATLC IS ANOTHER UPPER TROUGH EXTENDING ALONG 33W S INTO THE TROPICS NEAR 8N SUPPORTING A LARGE OCCLUDED FRONTAL SYSTEM N OF THE AREA WITH A COLD FRONT THAT ENTERS THE REGION NEAR 32N12W AND EXTENDS TO 29N21W. NEAR GALE FORCE WINDS ARE EXPECTED N OF 30N FROM 20W-35W. PLEASE SEE METEO FRANCE FORECAST UNDER WMO HEADER FQNT50 LFPW FOR MORE INFORMATION. THE W ATLC SURFACE RIDGE WILL SHIFT NE AHEAD OF A COLD FRONT THAT WILL MOVE INTO W ATLC SAT NIGHT INTO SUN AND EXTEND FROM 32N73W TO MELBOURNE FLORIDA SUN NIGHT AND WEAKEN FROM 32N70W TO THE STRAITS OF FLORIDA MON NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW