000 AXNT20 KNHC 211045 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT MON SEP 21 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 STORM IDA AT 21/0900 UTC IS NEAR 19.8N 47.3W. IDA IS MOVING TOWARD THE NORTH-NORTHWEST...OR 330 DEGREES...7 KNOTS. THE MINIMUM CENTRAL PRESSURE IS 1003 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 45 KNOTS WITH GUSTS TO 55 KNOTS. PUBLIC ADVISORIES ABOUT TROPICAL STORM IDA ARE BEING ISSUED UNDER THE WMO HEADER WTNT35 KNHC...AND UNDER THE AWIPS HEADER MIATCPAT5. FORECAST/ADVISORIES ABOUT TROPICAL STORM IDA ARE BEING ISSUED UNDER THE WMO HEADER WTNT25 KNHC...AND UNDER THE AWIPS HEADER MIATCMAT5. CONVECTIVE PRECIPITATION...NUMEROUS STRONG WITHIN A RADIUS OF 180 NM FROM THE CENTER IN THE EASTERN SEMICIRCLE. SCATTERED STRONG WITHIN A RADIUS OF 380 NM FROM THE CENTER IN THE EASTERN QUADRANT. ISOLATED MODERATE ELSEWHERE FROM 15N TO 24N BETWEEN 40W AND 51W. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 18W/19W FROM 17N SOUTHWARD...JUST EMERGING FROM THE COAST OF AFRICA. CONVECTIVE PRECIPITATION...SCATTERED STRONG WITHIN 30 NM ON EITHER SIDE OF 16N17W 14N19W 12N20W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL SECTIONS OF SENEGAL NEAR 15N17W TO 10N22W 06N28W 06N37W. NO ITCZ IS PRESENT AT THIS MOMENT. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM 04N TO 08N BETWEEN 10W AND 17W. ISOLATED MODERATE TO LOCALLY STRONG FROM 05N TO 08N BETWEEN 27W AND 40W. WIDELY SCATTERED MODERATE TO ISOLATED STRONG FROM 08N TO 12N BETWEEN 48W AND 52W. ...DISCUSSION... THE GULF OF MEXICO... BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE GULF OF MEXICO TO THE NORTH AND NORTHWEST OF THE ATLANTIC OCEAN-TO- STRAITS OF FLORIDA TROUGH...AND TO THE NORTH OF THE AREA OF CYCLONIC WIND FLOW THAT IS ASSOCIATED WITH THE EASTERN PACIFIC OCEAN 15N104W CYCLONIC CIRCULATION CENTER. COMPARATIVELY DRIER AIR IN SUBSIDENCE IS APPARENT IN WATER VAPOR IMAGERY IN THE AREA OF ANTICYCLONIC WIND FLOW. CLOUDS AND POSSIBLE RAINSHOWERS ARE TO THE SOUTH OF 25N82W 22N98W...AND TO THE NORTH OF 24N. A COLD FRONT/STATIONARY FRONT IS INLAND...BETWEEN GEORGIA AND EAST TEXAS. A SURFACE TROUGH IS ALONG THE FLORIDA WEST COAST. AN EASTERN PACIFIC OCEAN MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 15N104W. CYCLONIC WIND FLOW THAT IS MOVING AROUND THE CENTER COVERS MEXICO AND THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO FROM 23N SOUTHWARD...FROM 92W WESTWARD. A DIURNAL SURFACE TROUGH EXTENDS FROM THE WESTERN PART OF THE YUCATAN PENINSULA TO THE EASTERN PART OF THE ISTHMUS OF TEHUANTEPEC OF SOUTHERN MEXICO. CONVECTIVE PRECIPITATION... ISOLATED MODERATE TO LOCALLY STRONG IS INLAND BETWEEN 87W IN HONDURAS AND 97W IN THE ISTHMUS OF TEHUANTEPEC OF SOUTHERN MEXICO. THE CARIBBEAN SEA... AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 14N78W. CYCLONIC WIND FLOW THAT IS MOVING AROUND THE 14N78W CENTER COVERS THE CARIBBEAN SEA BETWEEN 70W AND 84W. CONVECTIVE PRECIPITATION...ISOLATED MODERATE TO LOCALLY STRONG FROM 16N SOUTHWARD BETWEEN 74W AND CENTRAL AMERICA. CONVECTIVE PRECIPITATION...WIDELY SCATTERED MODERATE TO ISOLATED STRONG COVERS THE NORTHWESTERN CORNER OF THE AREA...TO THE WEST AND NORTHWEST OF THE LINE THAT RUNS FROM 21N80W TO THE EASTERN COAST OF HONDURAS. UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE NORTHWESTERN CORNER OF THE AREA. AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 22N60W. CYCLONIC WIND FLOW THAT IS MOVING AROUND THE CENTER COVERS THE ATLANTIC OCEAN FROM 10N TO 32N BETWEEN 50W IN THE ATLANTIC OCEAN AND 70W IN THE CARIBBEAN SEA. THE 24-HOUR RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT 21/0000 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...ARE 0.11 IN TEGUCIGALPA IN HONDURAS...0.05 IN BERMUDA...AND 0.02 IN HAVANA CUBA. ...HISPANIOLA... UPPER LEVEL NORTHERLY WIND FLOW IS REACHING THE ISLAND...PARTLY WITH THE CYCLONIC FLOW THAT IS MOVING AROUND THE 22N60W ATLANTIC OCEAN CYCLONIC CIRCULATION CENTER. UPPER LEVEL SOUTHEASTERLY WIND FLOW ALSO IS REACHING THE ISLAND...WITH THE FLOW THAT IS MOVING AROUND THE 14N78W CYCLONIC CIRCULATION CENTER. CONVECTIVE PRECIPITATION...WARMING CLOUD TOP TEMPERATURES...DISSIPATING/ WEAKENING PRECIPITATION...AND CONVECTIVE DEBRIS CLOUDS ARE IN THE COASTAL WATERS OF WESTERN HAITI AND IN SOUTHERN HAITI. ISOLATED MODERATE WITHIN A 15 TO 30 NM RADIUS OF 18N72.5W IN SOUTHERN HAITI. CURRENT CONDITIONS...IN THE DOMINICAN REPUBLIC...FEW LOW LEVEL CLOUDS IN SANTO DOMINGO AND PUNTA CANA. SCATTERED LOW LEVEL CLOUDS ARE IN SANTIAGO AND PUERTO PLATA. THE GFS MODEL FORECAST FOR 250 MB SHOWS THAT THE EASTERN HALF OF THE ISLAND WILL RECEIVE NORTHERLY WIND FLOW AND THE WESTERN HALF WILL RECEIVE SOUTHERLY WIND FLOW...BECAUSE OF THE 22N60W CYCLONIC CENTER AND THE 14N78W CYCLONIC CENTER. ANTICYCLONIC WIND FLOW IS FORECAST TO BUILD FROM THE SOUTH AND A RIDGE WILL COVER HISPANIOLA FOR THE REST OF DAY ONE OF THE 48-HOUR FORECAST PERIOD. THE SAME RIDGE WILL CONTINUE ACROSS THE AREA FOR THE REST OF THE TIME. THE GFS MODEL FORECAST FOR 500 MB SHOWS THAT ANTICYCLONIC WIND FLOW WILL COVER THE AREA FOR FIRST 24 HOURS. NORTHERLY WIND FLOW WILL COVER HISPANIOLA FOR DAY TWO OF THE 48- HOUR FORECAST PERIOD. THE ATLANTIC OCEAN CYCLONIC CENTER IS FORECAST TO BE NEAR 23N65W. AN ANTICYCLONIC CIRCULATION CENTER IS FORECAST TO BE NEAR 22N75W. THE GFS MODEL FOR 700 MB STARTS WITH HISPANIOLA RECEIVING NORTHEAST-TO-EAST WIND FLOW...BEING ON THE WESTERN SIDE OF AN INVERTED TROUGH. THE WIND FLOW VARIES FROM EAST-SOUTHEAST...FROM THE NORTHEAST...AND FROM THE SOUTHEAST AGAIN...DURING DAY TWO...AS AN INVERTED TROUGH SPANS PUERTO RICO. THE ATLANTIC OCEAN... PLEASE REFER TO THE SPECIAL FEATURES SECTION FOR MORE DETAILS ABOUT TROPICAL STORM IDA. AN UPPER LEVEL TROUGH PASSES THROUGH 32N72W TO 29N73W...INTO THE STRAITS OF FLORIDA...TO WESTERN CUBA...TOWARD THE NORTHEASTERN COAST OF THE YUCATAN PENINSULA OF MEXICO. A SURFACE TROUGH EXTENDS FROM A 1007 MB LOW PRESSURE CENTER THAT IS NEAR 32N72W...TO 29N73W...TO THE NORTHERN BAHAMAS NEAR 25N78W. CONVECTIVE PRECIPITATION...WIDELY SCATTERED TO SCATTERED MODERATE AND ISOLATED STRONG FROM 26N NORTHWARD BETWEEN 66W AND 73W. ISOLATED MODERATE FROM 20N TO 26N BETWEEN 74W AND THE STRAITS OF FLORIDA...AND FROM 20N NORTHWARD BETWEEN 80W AND THE YUCATAN PENINSULA IN THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA. AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 22N60W. CYCLONIC WIND FLOW THAT IS MOVING AROUND THE CENTER COVERS THE ATLANTIC OCEAN FROM 10N TO 32N BETWEEN 50W IN THE ATLANTIC OCEAN AND 70W IN THE CARIBBEAN SEA. A 1010 MB LOW PRESSURE CENTER IS NEAR 19N54W. CONVECTIVE PRECIPITATION...SCATTERED STRONG WITHIN A 30 NM RADIUS OF 24N57W...AND FROM 26N TO 28N BETWEEN 50W AND 52W. ISOLATED MODERATE IS ELSEWHERE FROM 20N NORTHWARD BETWEEN 40W AND 67W. RAINSHOWERS ARE POSSIBLE ALSO FROM 14N NORTHWARD BETWEEN 60W AND 70W IN THE CARIBBEAN SEA. AN UPPER LEVEL TROUGH EXTENDS FROM A 32N18W CYCLONIC CIRCULATION CENTER...TOWARD THE CAPE VERDE ISLANDS. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG FROM 30N NORTHWARD BETWEEN 30W AND 34W. RAINSHOWERS ARE POSSIBLE IN SCATTERED TO BROKEN STRATIFORM CLOUDS THAT COVER THE AREA FROM 20N NORTHWARD BETWEEN 19W AND 40W. SURFACE ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN TO THE NORTH OF THE LINE THAT PASSES THROUGH 32N14W TO 2036W AND BEYOND 32N54W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT