000 AXNT20 KNHC 180005 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE MAR 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 06N11W TO 03N14W TO 03N19W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 03N30W TO THE COAST OF NORTHERN NEAR 01S49W. SCATTERED MODERATE CONVECTION IS FROM 01S-04N BETWEEN 07W AND 19W...AND FROM 02S TO 02N W OF 41W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL RIDGE WITH AXIS NEAR 87W EXTENDS FROM THE YUCATAN PENINSULA NORTHWARD ACROSS THE GULF...THE SOUTH AND SOUTHEAST U.S. THUS SUPPORTING A SURFACE RIDGE ANCHORED ON THE NW GULF BY A 1019 MB HIGH NEAR 27N93W. MAINLY FAIR WEATHER AND CLEAR SKIES ARE ACROSS THE BASIN BEING SUPPORTED BY DRY SUBSIDENCE FROM ALOFT. WINDS ARE VARIABLE RANGING FROM 5 TO 10 KT. A FRONTAL SYSTEM MOVING ACROSS THE MIDDLE ATLC AND CENTRAL STATES WILL ENTER THE NE GULF AND FLORIDA PENINSULA WED MORNING WHILE SURFACE RIDGING WILL DOMINATE ELSEWHERE. THE TAIL OF THE FRONT IS FORECAST TO STALL ACROSS THE CENTRAL FLORIDA THU MORNING DEVELOPING A LOW PRESSURE CENTER NEAR CAPE CORAL FLORIDA. CARIBBEAN SEA... AN ELONGATED UPPER LEVEL TROUGH WITH AXIS OVER THE CENTRAL ATLC EXTENDING SW TO A BASE OVER HISPANIOLA SUPPORTS A COLD FRONT WITH DISSIPATING TAIL BEING NEAR 150 NM AWAY FROM THE NE DOMINICAN REPUBLIC. MOISTURE ASSOCIATED WITH THE PASSAGE OF THIS FRONT ALONG WITH FORCING FROM THE UPPER LEVEL TROUGH SUPPORT CLOUDINESS AND POSSIBLE SCATTERED TO ISOLATED SHOWERS OVER HISPANIOLA AND ADJACENT NORTHERN WATERS. SSMI TPW IMAGERY SHOW A TONGUE OF LOW LEVEL MOISTURE MOVING ACROSS THE NORTHERN-CENTRAL CARIBBEAN...THUS ENHANCING SIMILAR SHOWER ACTIVITY OVER SOUTHERN ADJACENT WATERS OF HISPANIOLA. A PRE-FRONTAL TROUGH IS ANALYZED MOVING ACROSS THE LEEWARD ISLANDS WITH AXIS EXTENDING FROM 19N61W TO 14N62W WITH POSSIBLE ISOLATED SHOWERS WITHIN 100 NM EITHER SIDE OF ITS AXIS. ELSEWHERE...FAIR WEATHER CONTINUES TO BE FAVORED BY SUBSIDENCE OF DRY AIR FROM THE MIDDLE AND UPPER LEVELS. TRADES OF 10 KT DOMINATES OVER THE BASIN...EXCEPT OVER THE SW CARIBBEAN CLOSE TO THE COAST OF COLOMBIA WHERE WINDS INCREASES UP TO 20 KT. LITTLE CHANGE IS EXPECTED ACROSS THE BASIN OVER THE NEXT 48 HOURS. HISPANIOLA... LINGERING MOISTURE ASSOCIATED WITH THE PASSAGE OF A COLD FRONT N OF THE ISLAND ALONG WITH FORCING FROM THE UPPER LEVEL TROUGH SUPPORTING THE FRONT SUPPORT CLOUDINESS AND POSSIBLE SCATTERED TO ISOLATED SHOWERS OVER HISPANIOLA AND ADJACENT NORTHERN WATERS. A TONGUE OF LOW LEVEL MOISTURE MOVES ACROSS THE NORTHERN- CENTRAL CARIBBEAN...THUS ENHANCING SIMILAR SHOWER ACTIVITY OVER SOUTHERN ADJACENT WATERS OF HISPANIOLA. SHOWERS ARE EXPECTED TO CONTINUE THROUGH THURSDAY. ATLANTIC OCEAN... MIDDLE TO UPPER LEVEL RIDGING ACROSS THE SW N ATLC SUPPORT A SURFACE RIDGE ANCHORED BY A 1017 MB HIGH NEAR 25N68W THAT FAVORS FAIR WEATHER IN THIS REGION OF THE BASIN. FARTHER EAST...AN ELONGATED UPPER LEVEL TROUGH WITH AXIS NEAR 52W EXTENDING SW TO A BASE OVER HISPANIOLA IN THE CARIBBEAN SUPPORT A COLD FRONT ANALYZED FROM 30N48W SW TO 24N