000 AXNT20 KNHC 190005 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON MAY 18 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLANTIC NEAR 09N13W CONTINUING TO 05N21W. THE ITCZ BEGINS NEAR 05N21W AND CONTINUES ALONG 03N40W TO THE NORTHERN COAST OF BRAZIL NEAR 01N50W. SCATTERED MODERATE CONVECTION IS FROM 01N TO 12N E OF 25W AND FROM 01N TO 05N BETWEEN 33W AND 43W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE EXTENDS FROM THE NORTHERN PLAINS SE TO THE SE CONUS INTO THE N-NE GULF AND THE SW N ATLC WATERS. IN THE GULF THE RIDGE IS BEING ANCHORED BY A 1021 MB HIGH NEAR 29N84W AND PROVIDES E-SE WIND FLOW OF 10 TO 15 KT...EXCEPT IN THE VICINITY OF THE HIGH PRESSURE CENTER WHERE WINDS ARE LESS THAN 10 KT AND VARIABLE. MIDDLE TO UPPER LEVEL RIDGING DOMINATES ACROSS THE BASIN ALONG WITH DRY AIR...THUS SUPPORTING FAIR WEATHER. ISOLATED SHOWERS ARE OVER THE SOUTH-CENTRAL...SOUTHWEST FLORIDA AND ADJACENT WATERS BEING ENHANCED BY SHALLOW MOISTURE AND SURFACE TROUGHING. FOG IS BEING REPORTED OVER THE NW BASIN N OF 27N W OF 93W COINCIDING WITH MEDIUM PROBABILITIES OF FOG IN THE GOES-13 IFR IMAGERY. SURFACE RIDGING AND FAIR WEATHER CONDITIONS WILL CONTINUE DURING THE NEXT THREE DAYS. CARIBBEAN SEA... SOUTHWESTERLY TO WESTERLY FLOW DOMINATES ALOFT AND ADVECTS MOISTURE FROM AREAS OF LOW PRESSURE OVER THE EPAC WATERS...COLOMBIA AND VENEZUELA. SSMI TPW IMAGERY SHOW MOISTURE DOMINATING ALSO AT THE LOWER LEVELS...WHICH ENHANCES ISOLATED SHOWERS AND TSTMS OVER EASTERN CUBA...HISPANIOLA...JAMAICA...PUERTO RICO AND THE SW CARIBBEAN. SIMILAR CONVECTION IS OBSERVED OVER THE YUCATAN CHANNEL. MIDDLE- LEVEL TROUGHING MOVING EASTWARD ALONG WITH LOW LEVEL MOISTURE WILL CONTINUE TO ENHANCE SHOWERS FOR THE SAME REGIONS DURING THE NEXT TWO DAYS. ...HISPANIOLA... LINGERING MOISTURE ASSOCIATED WITH THE PASSAGE OF A STATIONARY FRONT N OF THE ISLAND ALONG WITH MIDDLE-LEVEL TROUGHING SUPPORT SCATTERED SHOWERS AND TSTMS OVER THE CENTRAL ISLAND AND ISOLATED SHOWERS ELSEWHERE. THIS SHOWER ACTIVITY IS FORECAST TO PERSIST DURING THE NEXT TWO DAYS. ATLANTIC OCEAN... A SURFACE RIDGE EXTENDS FROM THE NORTHERN PLAINS SE TO THE SE CONUS INTO THE N-NE GULF AND THE SW N ATLC WATERS. IN THE SW N ATLC THE RIDGE IS BEING ANCHORED BY A 1022 MB HIGH NEAR 30N75W. A WEAKNESS IN THE RIDGE IS BEING ANALYZED AS A SURFACE TROUGH ALONG THE NORTHERN BAHAMAS...ENHANCING SHOWERS THERE AND IN ADJACENT WATERS. A MIDDLE TO UPPER LEVEL LOW OVER THE NORTH- CENTRAL ATLC EXTENDS A TROUGH SOUTHWARD THAT CONTINUES TO SUPPORT A COLD FRONT N OF 30N AND A STATIONARY FRONT ALONG 30N44W SW TO 22N57W TO 19N66W. ISOLATED SHOWERS ARE WITHIN 100 NM EITHER SIDE OF THE BOUNDARY. ELSEWHERE...RIDGING AND FAIR WEATHER DOMINATES. THE FRONT WILL WEAKEN TUESDAY MORNING LEAVING AN ELONGATED AREA OF LOW PRESSURE OVER THE CENTRAL ATLC. A NEW COLD FRONT ENTERS THE NORTHERN-CENTRAL BASIN WEDNESDAY MORNING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR