000 AXNT20 KNHC 171747 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SAT JAN 17 2015 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 1745 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 6N11W ALONG 5N13W TO 4N17W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 4N30W TO 3N40W. ISOLATED MODERATE CONVECTION ARE WITHIN 100 NM OF THE ITCZ/MONSOON TROUGH AXIS BETWEEN 13W AND 30W. ...DISCUSSION... GULF OF MEXICO... SURFACE HIGH PRESSURE EXTENDS ACROSS THE EASTERN US AND INTO THE GULF PROVIDING LIGHT ANTICYCLONIC FLOW MAINLY BETWEEN 5 AND 10 KT ACROSS THE BASIN. A WEAKNESS IN THE RIDGE IN THE FORM OF A SURFACE TROUGH IS OVER THE CENTRAL GULF FROM 27N90W TO 22N88W. SCATTERED SHOWERS ARE WITHIN 120 NM OF EITHER SIDE OF THE TROUGH AXIS. OTHERWISE...FAIR WEATHER DOMINATES THE BASIN. IN THE UPPER LEVELS...GENERALLY ZONAL FLOW IS OCCURRING ACROSS THE BASIN. OVER THE NEXT 24 HOURS A TROUGH WILL MOVE ACROSS THE SE US AND THE EXTREME NE GULF OF MEXICO. THIS WILL SUPPORT A COLD FRONT THAT IS FORECAST TO MOVE ACROSS NORTHERN FL AND POSSIBLY PORTIONS OF THE NE GULF. THE TROUGH OVER THE CENTRAL GULF IS FORECAST TO REMAIN NEARLY STATIONARY WITH SHOWERS. CARIBBEAN SEA... BROAD UPPER RIDGING CONTINUES TO COVER THE CARIBBEAN ANCHORED OVER SOUTH AMERICA AND EXTENDS INTO THE W ATLC. THIS RIDGE IS INHIBITING ANY DEEP CONVECTION ACROSS THE BASIN. A TROUGH ACROSS THE NW ATLANTIC ALONG 63W SUPPORTS A COLD FRONT THAT EXTENDS ACROSS THE WESTERN ATLANTIC AND WESTERN CUBA WHERE IT TRANSITIONS TO A STATIONARY FRONT THAT EXTENDS FROM 21N78W TO A 1016 MB SURFACE LOW NEAR 20N86W. SCATTERED SHOWERS ARE WITHIN 100 NM OF EITHER SIDE OF THE FRONT. ELSEWHERE ACROSS THE CARIBBEAN...CLOUDY CONDITIONS AND ISOLATED SHOWERS ARE OVER HISPANIOLA AND PUERTO RICO WELL AHEAD OF THE ATLANTIC COLD FRONT. OVER THE NEXT 24 HOURS THE SURFACE LOW AND STATIONARY FRONT OVER THE NW CARIBBEAN IS FORECAST TO DISSIPATE. MAINLY FAIR WEATHER IS EXPECTED TO CONTINUE ACROSS THE BASIN THROUGH SUNDAY. ...HISPANIOLA... ISOLATED TO SCATTERED SHOWERS ARE OCCURRING ACROSS THE ISLAND AHEAD OF AN APPROACHING COLD FRONT IN THE WESTERN ATLANTIC. THE TAIL END OF THIS COLD FRONT IS EXPECTED TO MOVE ACROSS THE NORTHERN PORTIONS OF THE ISLAND TONIGHT AND WILL BE EAST OF THE ISLAND BY SUNDAY AFTERNOON. AN ENHANCEMENT IN SHOWER ACTIVITY CAN BE EXPECTED THROUGH TONIGHT WITH A DECREASE DURING THE DAY SUNDAY BEHIND THE FRONT. ATLANTIC OCEAN... AN UPPER TROUGH ALONG 63W SUPPORTS A COLD FRONT THAT EXTENDS FROM A NW ATLANTIC LOW PRESSURE SYSTEM TO 31N57W TO 22N70W TO WESTERN CUBA NEAR 21N75W. SCATTERED SHOWERS ARE WITHIN 50 NM AHEAD OF THE FRONT S OF 24N. WIDELY SCATTERED MODERATE CONVECTION IS FROM 24N TO 31N BETWEEN 50W AND 60W. UPPER LEVEL DIFFLUENCE AROUND THE BASE OF AN UPPER TROUGH ALONG 48W IS SUPPORTING ISOLATED MODERATE CONVECTION FROM 4N TO 9N BETWEEN 42W AND 51W. ELSEWHERE...A 1036 MB SURFACE HIGH PRESSURE SYSTEM CENTERED NEAR 34N27W DOMINATES THE CENTRAL AND EASTERN BASIN WITH ANTICYCLONIC FLOW AND FAIR WEATHER. OVER THE NEXT 24 HOURS A COLD FRONT WILL EXIT THE SE US. THE COLD FRONT CURRENTLY IN THE WESTERN ATLANTIC WILL MOVE INTO THE CENTRAL ATLANTIC NEAR 30N50W TO THE VIRGIN ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO