000 AXNT20 KNHC 051804 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU SEP 05 2013 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL DEPRESSION GABRIELLE AT 05/1800 UTC IS NEAR 17.8N 68.4W. THIS POSITION ALSO IS ABOUT 49 NM TO THE SOUTH OF PUNTA CANA IN THE DOMINICAN REPUBLIC. GABRIELLE IS MOVINGRD 8 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1011 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 30 KNOTS WITH GUSTS TO 40 KNOTS. PUBLIC ADVISORIES ON GABRIELLE ARE ISSUED UNDER WMO HEADER WTNT32 KNHC AND UNDER AWIPS HEADER MIATCPAT2...AND FORECAST/ADVISORIES ARE ISSUED UNDER WMO HEADER WTNT22 KNHC AND UNDER AWIPS HEADER MIATCMAT2. A TROPICAL WAVE IS ABOUT 260 NM TO THE EAST OF GABRIELLE. THIS WAVE IS ALONG 62W/64W TO THE SOUTH OF 20N. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 19N TO 22N BETWEEN 61W AND 64W. NUMEROUS STRONG IS REACHING SOUTHERN COASTAL PUERTO RICO AND THE VIRGIN ISLANDS. NUMEROUS STRONG ALSO COVERS THE EASTERN CARIBBEAN SEA ISLANDS FROM GUADELOUPE TO DOMINICA TO MARTINIQUE. CLUSTERS OF RAINSHOWERS COVER THE REST OF THE CARIBBEAN SEA BETWEEN 60W AND 70W. THE 24-HOUR RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT 05/1200 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN...ARE 2.07 IN ST. THOMAS IN THE VIRGIN ISLANDS...AND 0.85 IN SAN JUAN PUERTO RICO. A 1010 MB LOW PRESSURE CENTER IS NEAR 21N94W IN THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO. A SURFACE TROUGH IS ALONG 25N95W...TO THE LOW CENTER...TO THE COAST OF MEXICO ALONG 93W... MORE INLAND TO 16N93W. UPPER LEVEL ANTICYCLONIC WIND FLOW WITH A RIDGE COVERS THE AREA OF THE SURFACE TROUGH AND 1010 MB LOW PRESSURE CENTER. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 21N TO 24N BETWEEN 92W AND 94W. SCATTERED MODERATE TO ISOLATED STRONG COVERS THE REST OF THE GULF OF MEXICO TO THE SOUTH OF 26N TO THE WEST OF 90W. THE 24-HOUR RAINFALL TOTAL IN INCHES FOR THE PERIOD ENDING AT 05/1200 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN...IS 0.63 IN MERIDA MEXICO. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS...AND A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 30W/32W TO THE SOUTH OF 19N...MOVING WESTWARD 15 TO 20 KNOTS. A 1012 MB LOW PRESSURE CENTER IS ALONG THE WAVE NEAR 14N. CONVECTIVE PRECIPITATION... SCATTERED MODERATE TO ISOLATED STRONG FROM 10N TO 19N BETWEEN 28W AND 35W. FURTHER DEVELOPMENT...IF ANY...IS EXPECTED TO BE LIMITED DUE TO DRY AIR. ENVIRONMENTAL CONDITIONS ARE FORECAST TO BECOME VERY UNFAVORABLE IN A COUPLE OF DAYS. THIS SYSTEM HAS A LOW CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS...AND A LOW CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS WHILE IT MOVES TO THE WEST-NORTHWEST ABOUT 9 KNOTS. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 22N53W 17N52W 12N51W... MOVING WESTWARD 15 TO 20 KNOTS. CONVECTIVE PRECIPITATION... SCATTERED MODERATE FROM 22N TO 25N BETWEEN 53W AND 55W. AN ATLANTIC OCEAN TROPICAL WAVE IS ABOUT 260 NM TO THE EAST OF T.D. GABRIELLE. THIS WAVE IS ALONG 62W/64W TO THE SOUTH OF 20N. THE WAVE IS MOVING WESTWARD 10 TO 15 KNOTS. A SURFACE TROUGH IS ALONG 26N59W 24N61W 21N63W. A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 29N60W. A TROUGH EXTENDS FROM THE CYCLONIC CENTER TO 26N63W AND 23N68W. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 19N TO 22N BETWEEN 61W AND 64W. NUMEROUS STRONG IS REACHING SOUTHERN COASTAL PUERTO RICO AND THE VIRGIN ISLANDS. NUMEROUS STRONG ALSO COVERS THE EASTERN CARIBBEAN SEA ISLANDS FROM GUADELOUPE TO DOMINICA TO MARTINIQUE. CLUSTERS OF RAINSHOWERS COVER THE REST OF THE CARIBBEAN SEA BETWEEN 60W AND 70W. THE 24-HOUR RAINFALL TOTAL IN INCHES FOR THE PERIOD ENDING AT 05/1200 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN...IS 0.17 IN GUADELOUPE. SCATTERED MODERATE TO ISOLATED STRONG FROM 28N TO 30N BETWEEN 52W AND 57W. SCATTERED MODERATE FROM 23N TO 28N BETWEEN 53W AND 60W. ANY DEVELOPMENT OF THIS SYSTEM IS EXPECTED TO BE SLOW DUE TO ITS PROXIMITY TO TROPICAL STORM GABRIELLE AND STRONG UPPER-LEVEL WINDS. THIS SYSTEM HAS A LOW CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES NORTHWESTWARD 9 TO 13N KNOTS. DEVELOPMENT IS NOT EXPECTED AFTER 48 HOURS...AND THIS SYSTEM HAS A LOW CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 80W/81W TO THE SOUTH OF 21N. THE WAVE IS MOVING WESTWARD 15 TO 20 KNOTS. THE WAVE IS MOVING THROUGH THE AREA OF A MIDDLE LEVEL TO UPPER LEVEL WESTERN CARIBBEAN SEA TROUGH. IT MAY NOT BE EASY TO FIND CONVECTIVE PRECIPITATION THAT IS RELATED SOLELY TO THE WAVE. CONVECTIVE PRECIPITATION...ISOLATED MODERATE TO THE NORTH OF 18N TO THE WEST OF 80W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL GUINEA-BISSAU NEAR 12N16W TO 14N31W AND 9N38W. THE ITCZ CONTINUES FROM 9N38W TO 7N44W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO STRONG FROM 8N TO 12N BETWEEN 16W AND 21W. SCATTERED MODERATE TO ISOLATED STRONG WITHIN A 30 NM TO 60 NM RADIUS OF 7N15W... ELSEWHERE FROM 16N TO 18N BETWEEN 18W AND 30W...FROM 7N TO 10N BETWEEN 29W AND 31W...AND WITHIN A 30 NM RADIUS OF 5N37W. ...DISCUSSION... FROM THE ATLANTIC OCEAN INTO THE GULF OF MEXICO... A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N74W IN THE ATLANTIC OCEAN...TO 29N75W...ACROSS FLORIDA NEAR 27N81W... TO 27N85W IN THE GULF OF MEXICO. A SHEAR AXIS CONTINUES FROM 27N85W TO 27N92W...ACROSS SOUTH TEXAS TO 27N103W IN MEXICO. CONVECTIVE PRECIPITATION...IN THE ATLANTIC OCEAN...SCATTERED MODERATE TO ISOLATED STRONG TO THE NORTH OF 30N BETWEEN 62W AND 80W. CONVECTIVE PRECIPITATION IN THE GULF OF MEXICO... SCATTERED STRONG FROM 24N TO 28N BETWEEN FLORIDA AND 90W. THE 24- HOUR RAINFALL TOTAL IN INCHES FOR THE PERIOD ENDING AT 05/1200 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN...IS 0.26 IN BERMUDA. THE REST OF THE GULF OF MEXICO... THE SURFACE PRESSURE GRADIENT IS COMPARATIVELY WEAK IN THE GULF OF MEXICO TO THE NORTHEAST AND EAST OF THE 1010 MB LOW PRESSURE CENTER AND SURFACE TROUGH...TO THE EAST OF 90W...AND TO THE NORTH OF 28N TO THE WEST OF 90W. FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE TO THE NORTH OF 27N TO THE WEST OF 88W... A LOW CLOUD CEILING IS AT THE ICAO STATION KGUL. VISIBILITIES OF ONE MILE OR LESS AND HAZE ARE BEING OBSERVED AT THE ICAO STATION KEMK. FAIR SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET ARE BEING REPORTED ELSEWHERE ACROSS THE AREA. MULTILAYERED CLOUD CEILINGS AND HEAVY RAIN ARE OBSERVED IN WESLACO IN THE DEEP SOUTH OF TEXAS. BROKEN MULTILAYERED CLOUDS COVER THE MIDDLE TEXAS GULF COASTAL PLAINS. BROKEN LOW CLOUDS COVER THE COASTAL PLAINS AND SLIGHTLY MORE INLAND FROM HOUSTON TO BEAUMONT-PORT ARTHUR AND FROM HOUSTON TOWARD THE MIDDLE TEXAS GULF COASTAL PLAINS. MULTILAYERED CLOUD CEILINGS AND RAIN ARE IN SOUTHERN COASTAL LOUISIANA...INCLUDING THE AREA AROUND LAKE PONTCHARTAIN. LOW LEVEL AND MIDDLE LEVEL CLOUD CEILINGS CONTINUE INTO SOUTHERN COASTAL MISSISSIPPI AND ALABAMA. LOW LEVEL AND MIDDLE LEVEL CLOUD CEILINGS COVER THE FLORIDA PANHANDLE FROM MARY ESTHER/DESTIN TO CRESTVIEW. FAIR SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET ARE BEING REPORTED ELSEWHERE IN THE COASTAL SECTIONS OF THE U.S.A. GULF COAST STATES. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT4...FOR MORE DETAILS ABOUT THE SURFACE TROUGH FROM 19.5N 93W TO 24N97W. 20 TO 25 KNOT WINDS AND SEA HEIGHTS LOWER THAN 8 FEET FROM 20N TO 24N WITHIN 120 NM TO THE NORTHEAST OF THE TROUGH. EXPECT SCATTERED THUNDERSTORMS WITHIN 180 NM TO THE EAST OF THE TROUGH FROM 20N TO 23.5N. THE REST OF THE CARIBBEAN SEA... A MIDDLE LEVEL TO UPPER LEVEL TROUGH IS ALONG 22N78W AT THE COAST OF CUBA...TO 19N80W IN THE CARIBBEAN SEA...TO NORTHEASTERN COASTAL NICARAGUA...SOUTHWESTWARD ACROSS NICARAGUA AND BEYOND... WEAKENING IN THE EASTERN PACIFIC OCEAN OFF THE COAST OF NICARAGUA. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG WITHIN 30 TO 60 NM ON EITHER SIDE OF 19N76W BETWEEN CUBA AND JAMAICA...17N80W...TO 14N83W IN NORTHEASTERN COASTAL NICARAGUA. WIDELY SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION IS ELSEWHERE BETWEEN 70W AND 80W...BETWEEN THE CIRCULATION THAT IS MOVING AROUND T.D. GABRIELLE AND THE CIRCULATION THAT IS MOVING AROUND THE 80W/81W TROPICAL WAVE. THE MONSOON TROUGH IS ALONG 9N BETWEEN 75W IN COLOMBIA BEYOND 84W IN SOUTHERN COSTA RICA. CONVECTIVE PRECIPITATION...WIDELY SCATTERED MODERATE TO ISOLATED STRONG TO THE SOUTH OF 11N TO THE WEST OF 78W IN THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA. PLEASE READ THE HIGHS SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT TROPICAL DEPRESSION GABRIELLE. HISPANIOLA... PLEASE READ THE NHC ADVISORIES AND LOCAL AND NATIONAL ADVISORIES FOR WATCH AND WARNING INFORMATION FOR THE DOMINICAN REPUBLIC... WITH RESPECT TO T.D. GABRIELLE. MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS HISPANIOLA. RAINSHOWERS THAT ARE AROUND THE PERIPHERY OF THE CIRCULATION OF T.D. GABRIELLE ARE REACHING THE EASTERN SECTIONS OF THE DOMINICAN REPUBLIC TO THE EAST OF 69W. THE GFS FORECAST FOR 700 MB AND FOR 500 MB SHOWS THAT A RIDGE WILL COVER THE AREA FOR THE FIRST 24 HOURS OF THE FORECAST... WHILE AN INVERTED TROUGH APPROACHES HISPANIOLA FROM THE EAST. THE INVERTED TROUGH WILL COVER THE AREA FOR THE REST OF THE 48 HOUR FORECAST PERIOD. THE GFS FORECAST FOR 250 MB SHOWS THAT AN EAST-TO-WEST ORIENTED RIDGE WILL COVER THE AREA FOR THE ENTIRE TIME. THE REST OF THE ATLANTIC OCEAN... BROAD SURFACE ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN TO THE NORTH OF 20N TO THE EAST OF 50W...AND TO THE NORTH OF 27N TO THE WEST OF 50W. A RIDGE EXTENDS FROM A 1026 MB HIGH PRESSURE CENTER THAT IS NEAR 34N32W TO A SECOND 1026 MB HIGH PRESSURE CENTER THAT IS NEAR 34N48W...TO 31N60W 29N73W...TO THE FLORIDA EAST COAST ALONG 28N. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...FOR MORE DETAILS ABOUT TROPICAL DEPRESSION GABRIELLE. EXPECT ALSO NORTHEAST TO EAST 20 TO 25 KNOT WINDS AND SEA HEIGHTS REACHING 9 FEET FROM 18N TO 23N TO THE EAST OF 40W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT