000 AXNT20 KNHC 240005 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT AUG 23 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION FOUR FORMED AT 1800 UTC NEAR TURKS AND CAICOS. AT 2100 UTC THE CENTER OF THE CYCLONE IS NEAR 21.8N 72.3W OR 220 NM ESE OF THE CENTRAL BAHAMAS...MOVING NORTHWEST AT 10 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WINDS ARE 30 KT WITH GUSTS TO 40 KT. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...AND THE DEPRESSION IS FORECAST TO BECOME A TROPICAL STORM BY SUNDAY. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 15N- 27N BETWEEN 65W-79W...INCLUDING PUERTO RICO AND HISPANIOLA. THE DEPRESSION IS EXPECTED TO PRODUCE RAINFALL TOTALS OF 4 TO 8 INCHES OVER THE SOUTHEASTERN BAHAMAS...THE TURKS AND CAICOS ISLANDS...AND THE CENTRAL BAHAMAS THROUGH TUESDAY...WITH ISOLATED AMOUNTS AROUND 12 INCHES POSSIBLE. STORM TOTAL RAINFALL AMOUNTS OF UP TO 12 INCHES ARE POSSIBLE IN PORTIONS OF HISPANIOLA... WHERE THESE RAINS COULD PRODUCE LIFE-THREATENING FLASH FLOODS AND MUDSLIDES...ESPECIALLY IN AREAS OF MOUNTAINOUS TERRAIN. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS WEST OF THE CAPE VERDE ISLANDS WITH AXIS EXTENDING FROM 20N25W TO 8N26W. THE WAVE IS EMBEDDED IN THE MONSOON TROUGH WHERE HIGH LOW-LEVEL MOISTURE IS NOTED IN THE TPW IMAGERY. THIS MOISTURE ALONG WITH UPPER-LEVEL DIVERGENCE IS SUPPORTING SCATTERED MODERATE CONVECTION WITHIN 320 NM WEST OF THE WAVE AXIS SOUTH OF 14N. ISOLATED SHOWERS ARE WITHIN 150 NM EAST OF THE AXIS SOUTH OF 14N. HOWEVER...THE NORTHERN PART OF THE WAVE IS BEING AFFECTED BY DRY SAHARAN AIR AND DUST...WHICH IS LIMITING THE CONVECTION IN THAT REGION. A TROPICAL WAVE IS ON THE CENTRAL ATLC WITH AXIS EXTENDING FROM 17N36W TO 9N36W...MOVING W AT 10 KT. NO DEEP CONVECTION IS ASSOCIATED WITH THE WAVE AS DRY SAHARAN AIR AND DUST IS IN ITS ENVIRONMENT. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE WEST AFRICAN COAST NEAR 13N16W AND CONTINUES ALONG 11N26W TO 10N38W. THE ITCZ BEGINS NEAR 9N38W AND CONTINUES TO 9N49W 9N60W. BESIDES THE CONVECTION ASSOCIATED WITH THE WAVES...NO OTHER AREAS OF SIGNIFICANT CONVECTION ARE NOTED. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL RIDGE IS ANCHORED BETWEEN THE TENNESSEE AND OHIO VALLEY COVERING MOST OF THE EASTERN CONUS AND EXTENDING SOUTH INTO THE GULF. THIS RIDGE ALOFT SUPPORT A SURFACE RIDGE ACROSS THE GULF BEING ANCHORED BY A 1015 MB HIGH ON THE COASTLINE OF LOUISIANA NEAR 29N92W...WHICH IS PROVIDING VARIABLE WINDS OF 5-10 KT. MODERATE LOW-LEVEL MOISTURE IS ACROSS THE BASIN WHICH IS ENHANCING ISOLATED SHOWERS S OF 25N W OF 90W AND OVER THE SE GULF. A SURFACE TROUGH IS ACROSS NORTHERN FLORIDA SUPPORTING SCATTERED HEAVY SHOWERS AND TSTMS EXTENDING OVER GULF WATERS N OF 27N E OF 85W. SURFACE RIDGING WILL CONTINUE ACROSS THE BASIN THROUGH MONDAY. MINIMAL CONVECTION IS EXPECTED THROUGH THAT TIME...EXCEPT FOR THE FAR EASTERN GULF DURING MONDAY EVENING/NIGHT WHERE A SURGE OF MOISTURE IS FORECAST TO SUPPORT RAINSHOWERS. CARIBBEAN SEA... A MIDDLE TO LOWER LEVEL CYCLONIC CIRCULATION ANCHORED NEAR THE INAGUA ISLANDS EXTENDS INTO THE CENTRAL CARIBBEAN SUPPORTING A SURFACE TROUGH ALONG 19N77W TO 10N80W WHICH IS ENHANCING SCATTERED SHOWERS AND TSTMS ON JAMAICA AND THE SW BASIN. THIS MIDDLE TO LOWER LEVEL CYCLONE ALSO SUPPORTS TROPICAL DEPRESSION FOUR ON THE SW N ATLC...WHICH RAINBANDS OF SCATTERED HEAVY SHOWERS AND TSTMS ARE AFFECTING HISPANIOLA...PUERTO RICO AND ADJACENT WATERS. THE DEPRESSION IS ALSO BRINGING SHOWERS AND TSTMS TO CENTRAL AND EASTERN CUBA. OTHERWISE...VARIABLE WINDS OF 10-15 KT ARE ACROSS THE BASIN. RAINSHOWERS WILL CONTINUE TO AFFECT PUERTO RICO THROUGH SUNDAY NIGHT WHILE RAINFALL FOR HISPANIOLA AND EASTERN CUBA COULD EXTEND BEYOND MONDAY. ...HISPANIOLA... THE RAINBANDS OF TROPICAL DEPRESSION FOUR CONTINUE TO AFFECT HISPANIOLA WITH SCATTERED HEAVY SHOWERS AND TSTMS WITH POTENTIAL OF CAUSING LOCALIZED FLOODING AND MUDSLIDES. RAINFALL ASSOCIATED WITH THE TROPICAL CYCLONE DESCRIBED IN SPECIAL FEATURES IS EXPECTED TO CONTINUE BEYOND MONDAY. ATLANTIC OCEAN... THE HIGHLIGHT ON THE BASIN IS ON THE SW N ATLC WHERE TROPICAL CYCLOGENESIS OCCURRED EARLIER TODAY. A MIDDLE TO LOWER LEVEL CYCLONE ANCHORED NEAR THE INAGUA ISLANDS IS ASSOCIATED WITH TROPICAL DEPRESSION. SEE THE SPECIAL FEATURES SECTION. OTHERWISE...BESIDES THE TROPICAL WAVES...SURFACE RIDGING AND FAIR WEATHER DOMINATE ELSEWHERE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR