000 AXNT20 KNHC 091105 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED SEP 09 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL DEPRESSION GRACE AT 09/0900 UTC IS NEAR 14.3N 47.2W. GRACE IS MOVING TOWARD THE WEST...OR 270 DEGREES... 15 KNOTS. THE MINIMUM CENTRAL PRESSURE IS 1007 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 25 KNOTS WITH GUSTS TO 35 KNOTS. PUBLIC ADVISORIES ABOUT TROPICAL DEPRESSION GRACE ARE BEING ISSUED UNDER THE WMO HEADER WTNT32 KNHC...AND UNDER THE AWIPS HEADER MIATCPAT2. FORECAST/ADVISORIES ABOUT TROPICAL DEPRESSION GRACE ARE BEING ISSUED UNDER THE WMO HEADER WTNT22 KNHC...AND UNDER THE AWIPS HEADER MIATCMAT2. CONVECTIVE PRECIPITATION... WIDELY SCATTERED MODERATE TO ISOLATED STRONG FROM 13N TO 15N BETWEEN 45W AND 49W. THE CENTER OF TROPICAL DEPRESSION EIGHT AT 09/0900 UTC IS NEAR 30.9N 61.4W...OR ABOUT 190 NM TO THE EAST-SOUTHEAST OF BERMUDA. THE TROPICAL DEPRESSION IS STATIONARY FOR THE MOMENT. THE MINIMUM CENTRAL PRESSURE IS 1011 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 30 KNOTS WITH GUSTS TO 40 KNOTS. PUBLIC ADVISORIES ABOUT TROPICAL DEPRESSION EIGHT ARE BEING ISSUED UNDER THE WMO HEADER WTNT33 KNHC...AND UNDER THE AWIPS HEADER MIATCPAT3. FORECAST/ADVISORIES ABOUT TROPICAL DEPRESSION GRACE ARE BEING ISSUED UNDER THE WMO HEADER WTNT23 KNHC...AND UNDER THE AWIPS HEADER MIATCMAT3. CONVECTIVE PRECIPITATION...SCATTERED TO NUMEROUS STRONG FROM 29.5N TO 32.5N BETWEEN 57W AND 60W. ISOLATED MODERATE ELSEWHERE FROM 25N TO 30N BETWEEN 55W AND 74W. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 24W/25W FROM 21N SOUTHWARD...MOVING WESTWARD 10 TO 15 KNOTS...ACROSS THE CAPE VERDE ISLANDS. THIS POSITION IS A MEAN POSITION THAT IS BASED ON SATELLITE IMAGERY AND THE 700 MB WIND FIELD. CONVECTIVE PRECIPITATION...WIDELY SCATTERED TO SCATTERED MODERATE AND ISOLATED STRONG FROM 13N TO 16N BETWEEN 24W AND 29W. BROKEN MULTILAYERED CLOUD AND RAINSHOWERS ARE POSSIBLE ELSEWHERE FROM 10N TO 26N BETWEEN AFRICA AND 36W. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 56W/57W FROM 17N SOUTHWARD...MOVING WESTWARD 15 KNOTS. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 10N TO 11.5N BETWEEN 59W AND 61W. WARMING CLOUD TOP TEMPERATURES AND WEAKENING BUT POSSIBLY STILL LINGERING PRECIPITATION ELSEWHERE FROM 11N TO 13N BETWEEN 55W AND 60W. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 69W FROM 17N SOUTHWARD... MOVING WESTWARD 15 KNOTS. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM 14N TO 15N BETWEEN 70W AND 72W. RAINSHOWERS ARE POSSIBLE ELSEWHERE FROM 16N SOUTHWARD TO VENEZUELA AND COLOMBIA BETWEEN 66W AND 72W. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 84W/85W FROM 20N SOUTHWARD...THROUGH EASTERN HONDURAS AND CENTRAL NICARAGUA...TO COSTA RICA. THE WAVE IS MOVING WESTWARD 10 TO 15 KNOTS. CONVECTIVE PRECIPITATION...ISOLATED STRONG IN INDIVIDUAL CLUSTERS FROM THE GULF OF URABA OF COLOMBIA TO THE PANAMA COAST ALONG 80W AND ALONG 81W...TO THE COASTAL WATERS OF COSTA RICA AND NICARAGUA FROM 10N TO 11.5N BETWEEN 82W AND 83W. ISOLATED MODERATE IN NORTHEASTERN NICARAGUA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL SECTIONS OF SENEGAL NEAR 15N17W TO THE 24W/25W TROPICAL WAVE ALONG 12N...TO 10N30W AND 10N41W. NO ITCZ IS PRESENT AT THIS MOMENT. THE ITCZ IS BEING BROKEN UP BY TROPICAL DEPRESSION GRACE AND THE 56W/57W TROPICAL WAVE. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM 02N TO 07N BETWEEN 09W AND 183W. ISOLATED MODERATE ELSEWHERE FROM 08N TO 11N BETWEEN 20W AND 53W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 27N92W. CYCLONIC WIND FLOW COVERS THE GULF OF MEXICO. CONVECTIVE PRECIPITATION...RAINSHOWERS ARE POSSIBLE TO THE EAST OF THE LINE THAT RUNS FROM 18N94W 20N93W 26N96W 29N91W. SCATTERED TO NUMEROUS STRONG IS IN THE ATLANTIC OCEAN FROM 29N TO 32N BETWEEN 78W AND 80W IN THE COASTAL WATERS FROM FLORIDA TO SOUTH CAROLINA. THE SURFACE PRESSURE GRADIENT IN THE GULF OF MEXICO IS COMPARATIVELY WEAK. A WEAK RIDGE EXTENDS FROM A 1018 MB HIGH PRESSURE CENTER THAT IS NEAR 30N72W...ACROSS CENTRAL FLORIDA... TO THE MEXICO GULF COAST NEAR 23N98W. THE CARIBBEAN SEA... AN INVERTED TROUGH IS ALONG 70W FROM 16N SOUTHWARD TO THE COAST OF NORTHWESTERN VENEZUELA. THIS TROUGH IS CLOSE TO THE AREA OF THE 69W TROPICAL WAVE. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM 14N TO 15N BETWEEN 70W AND 72W. RAINSHOWERS ARE POSSIBLE ELSEWHERE FROM 16N SOUTHWARD TO VENEZUELA AND COLOMBIA BETWEEN 66W AND 72W. UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE AREA FROM 72W WESTWARD. BROKEN TO OVERCAST MULTILAYERED CLOUDS COVER THE CARIBBEAN SEA FROM 77W WESTWARD. A RIDGE EXTENDS FROM THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA...NORTHWESTWARD...TO THE YUCATAN CHANNEL AND WESTERN CUBA. MIDDLE LEVEL TO UPPER LEVEL SOUTHEASTERLY WIND FLOW COVERS THE CARIBBEAN SEA FROM 80W EASTWARD...WITH COMPARATIVELY DRIER AIR IN SUBSIDENCE. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM 16N NORTHWARD FROM 84W WESTWARD. THE MONSOON TROUGH IS ALONG 08N/09N BETWEEN 73W IN COLOMBIA AND 83W NEAR COSTA RICA AND PANAMA. CONVECTIVE PRECIPITATION... ISOLATED STRONG IN INDIVIDUAL CLUSTERS FROM THE GULF OF URABA OF COLOMBIA TO THE PANAMA COAST ALONG 80W AND ALONG 81W...TO THE COASTAL WATERS OF COSTA RICA AND NICARAGUA FROM 10N TO 11.5N BETWEEN 82W AND 83W. THE 24-HOUR RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT 09/0000 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...ARE 0.12 IN CURACAO. ...HISPANIOLA... AN UPPER LEVEL TROUGH PASSES THROUGH THE ATLANTIC OCEAN NEAR 26N63W...REACHING THE EASTERN SECTIONS OF THE DOMINICAN REPUBLIC NEAR 19N70W. UPPER LEVEL NORTHWESTERLY WIND FLOW REACHES MUCH OF HISPANIOLA. ONLY THE EASTERNMOST PART OF THE ISLAND IS OBSERVING UPPER LEVEL WESTERLY WIND FLOW. 600 MB-TO-800 MB LEVEL EASTERLY WIND FLOW ALSO IS MOVING ACROSS HISPANIOLA. CONVECTIVE PRECIPITATION...SCATTERED STRONG FROM 17N TO 19N BETWEEN 73W AND 75W IN SOUTHWESTERN HAITI AND SURROUNDING COASTAL WATERS. CURRENT CONDITIONS...IN THE DOMINICAN REPUBLIC...FEW LOW LEVEL CLOUDS ARE IN SANTO DOMINGO...PUNTA CANA...AND IN SANTIAGO. FEW LOW LEVEL CLOUDS AND SCATTERED HIGH LEVEL CLOUDS ARE IN PUERTO PLATA. THE GFS MODEL FORECAST FOR 250 MB SHOWS THAT THE CURRENT TROUGH THAT IS IN THE EASTERN SECTIONS OF HISPANIOLA REMAINS ACROSS THE EASTERN SECTIONS OF THE ISLAND FOR THE WHOLE 48 HOUR FORECAST PERIOD. THAT MEANS MOSTLY NORTHERLY WIND FLOW ON THE WESTERN SIDE OF THE TROUGH...AND SOUTHWESTERLY WIND FLOW ON THE EASTERN SIDE OF THE TROUGH. THE GFS MODEL FORECAST FOR 500 MB SHOWS THAT AN ANTICYCLONIC CIRCULATION CENTER WILL BE BETWEEN ANDROS ISLAND IN THE BAHAMAS AND SOUTH FLORIDA. A RIDGE WILL EXTEND FROM THE ANTICYCLONIC CIRCULATION CENTER TO HISPANIOLA FOR THE FIRST 24 HOURS OF THE 48-HOUR FORECAST PERIOD. THE RIDGE WILL MOVE WESTWARD...BRINGING NORTHEASTERLY WIND FLOW ACROSS THE AREA FOR THE REST OF THE FORECAST TIME. THE GFS MODEL FOR 700 MB SHOWS THAT NORTHEAST-TO-EAST WIND FLOW WILL PASS ACROSS THE AREA FOR THE FIRST 12 TO 18 HOURS...FOLLOWED BY TIME PERIODS OF EAST-TO- SOUTHEAST WIND FLOW. THE ATLANTIC OCEAN... PLEASE REFER TO THE SPECIAL FEATURES SECTION FOR MORE DETAILS ABOUT TROPICAL DEPRESSION GRACE AND TROPICAL DEPRESSION EIGHT. A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N44W TO A 24N52W CYCLONIC CIRCULATION CENTER...TO 19N54W. A STATIONARY FRONT PASSES THROUGH 32N29W TO 31N34W...TO 31N41W 28N47W...AND TO 29N54W. CONVECTIVE PRECIPITATION...WIDELY SCATTERED MODERATE TO ISOLATED STRONG WITHIN 360 NM TO THE NORTH OF THE LINE THAT PASSES THROUGH 32N26W 27N32W 21N51W. A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N23W TO 24N30W TO 20N34W. COMPARATIVELY DRIER AIR IN SUBSIDENCE IS WITHIN 150 NM ON EITHER SIDE OF THE TROUGH. A SURFACE RIDGE PASSES THROUGH THE MADEIRA ARCHIPELAGO TO A 1019 MB HIGH PRESSURE CENTER THAT IS NEAR 27N30W TO 26N50W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT