000 AXNT20 KNHC 151705 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON DEC 15 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH CROSSES THE AFRICAN COAST NEAR 07N12W AND CONTINUES OVER THE EASTERN ATLANTIC TO NEAR 05N17W. THE ITCZ BEGINS AT 05N17W AND CONTINUES ALONG 4N30W TO 4N40W. SCATTERED MODERATE CONVECTION IS FROM 3N TO 6N BETWEEN 19W AND 28W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH IS OVER THE NORTH CENTRAL GULF WHILE AN UPPER LEVEL RIDGE EXTENDS ACROSS FL AND THE EASTERN CONUS. AT THE SURFACE...HIGH PRESSURE CENTERED ACROSS THE SOUTHERN APPALACHIANS TO THE FL PANHANDLE HAS AN AXIS THAT ENTERS THE EASTERN GULF. THIS IS SUPPORTING LIGHT WINDS ACROSS THE EASTERN GULF...AND SOUTHERLY WINDS OF 10 TO 15 KT ACROSS THE WESTERN GULF. THE UPPER TROUGH SUPPORTS A COLD FRONT ACROSS EASTERN TX. SCATTERED SHOWERS ARE ACROSS THE NW GULF WELL AHEAD OF THE FRONT IN RETURN FLOW. THE REMAINDER OF THE GULF HAS FAIR WEATHER. OVER THE NEXT 24 HOURS THE COLD FRONT WILL ENTER THE NORTHERN GULF WITH SHOWERS POSSIBLE ACROSS THE NORTHERN BASIN. CARIBBEAN SEA... A SHEAR LINE EXTENDS FROM 17N77W TO 10N82W. NE WINDS OF 15 TO 20 KT ARE NW OF THE SHEAR LINE. NE WINDS OF 5 TO 10 KT ARE IMMEDIATELY SE OF THE SHEAR LINE. LOW LEVEL SPEED CONVERGENCE ALONG THIS LINE IS SUPPORTING WIDELY SCATTERED MODERATE CONVECTION WITHIN 75 NM OF EITHER SIDE OF THE SHEAR LINE AXIS. A 1010 MB SURFACE LOW IS CENTERED NEAR 12N76W. ISOLATED THUNDERSTORMS ARE WITHIN 75 NM OF THE LOW CENTER. AN UPPER TROUGH ALONG 60W SUPPORTS A COLD FRONT FROM THE CENTRAL ATLANTIC ACROSS THE VIRGIN ISLANDS AND ACROSS THE EASTERN CARIBBEAN TO 17N71W. THE PORTION OF THE COLD FRONT IN THE CARIBBEAN IS DISSIPATING. SCATTERED SHOWERS ARE WITHIN 125 NM OF EITHER SIDE OF THE FRONT INCLUDING THE VIRGIN ISLANDS AND PUERTO RICO. OVER THE NEXT 24 HOURS THE FRONT WILL DISSIPATE INTO A SURFACE TROUGH WHILE REMAINING IN THE VICINITY OF HISPANIOLA...PUERTO RICO...AND THE VIRGIN ISLANDS. CONVERGENCE ALONG THE REMNANT SHEAR LINE AND THE SURFACE TROUGH WILL SUPPORT SHOWER ACTIVITY THROUGH TUESDAY. HISPANIOLA... EXTENSIVE MOISTURE ON THE NORTH SIDE OF A DISSIPATING COLD FRONT IS PRODUCING SHOWER ACTIVITY ACROSS THE ISLAND TODAY. THE REMNANTS OF THE FRONT WILL REMAIN IN THE VICINITY OF THE ISLAND THROUGH TUESDAY NIGHT...WHICH WILL ENHANCE SHOWER ACTIVITY ACROSS THE ISLAND THROUGH THAT TIME. ATLANTIC OCEAN... AN UPPER TROUGH WITH AXIS ALONG 60W SUPPORTS A COLD FRONT THAT EXTENDS FROM A LOW OVER THE NW ATLANTIC TO 31N53W TO 23N58W TO 18N63W AND OVER THE EASTERN CARIBBEAN. SHOWERS ARE WITHIN 50NM NW OF THE FRONT AND 150 NM SE OF THE FRONT S OF 25N. SCATTERED MODERATE CONVECTION IS FROM 25N TO 31N BETWEEN 46W AND 55W. FARTHER EAST...AN UPPER LOW CENTERED NEAR 23N33W SUPPORTS A CLUSTER OF MODERATE CONVECTION FROM 23N TO 27N BETWEEN 34W AND 38W. A 1039 MB AREA OF HIGH PRESSURE CENTERED NEAR THE AZORES DOMINATES THE ATLANTIC E OF 35W. OVER THE NEXT 24 HOURS THE COLD FRONT WILL MOVE E TO NEAR 30N50W TO 22N55W WITH CONVECTION. THE PORTION OF THE COLD FRONT S OF 22N WILL BECOME STATIONARY AND DISSIPATE OVER THE NEXT 2 DAYS. ANOTHER COLD FRONT IS FORECAST TO ENTER THE WESTERN ATLANTIC ON WEDNESDAY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO