000 AXNT20 KNHC 252357 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU JUL 25 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURE... THE CENTER OF TROPICAL STORM DORIAN AT 25/2100 UTC IS NEAR 16.5N 37.8W. THE CENTER OF DORIAN IS ABOUT 1450 NM TO THE EAST OF THE NORTHERN LEEWARD ISLANDS. DORIAN IS MOVING WEST-NORTHWESTWARD 16 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 999 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 50 KNOTS WITH GUSTS TO 60 KNOTS. PLEASE READ THE FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/ WTNT34 KNHC FOR MORE DETAILS. CONVECTIVE PRECIPITATION... NUMEROUS STRONG FROM 16N TO 18N BETWEEN 36W AND 38W. ...TROPICAL WAVES... A CARIBBEAN SEA TROPICAL WAVE IS ALONG 87W/88W FROM THE YUCATAN PENINSULA NEAR 21N SOUTHWARD...MOVING WESTWARD 15 KNOTS. CONVECTIVE PRECIPITATION...SCATTERED STRONG IN THE NORTHERN HALF OF GUATEMALA. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH THE COASTAL BORDER AREAS OF SENEGAL AND GUINEA-BISSAU NEAR 12N16W...TO 10N18W AND 8N24W. THE ITCZ CONTINUES FROM 8N24W TO 7N26W AND 13N32W. THE ITCZ IS DISRUPTED BY THE WIND FLOW THAT IS MOVING AROUND TROPICAL STORM DORIAN. THE ITCZ CONTINUES FROM 12N38W TO 10N41W 8N50W AND 6N56W. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 8N TO 9N BETWEEN 18W AND 19W. SCATTERED MODERATE TO ISOLATED STRONG FROM 7N TO 9N BETWEEN 32W AND 34W. ISOLATED MODERATE ELSEWHERE FROM 5N TO 10N BETWEEN 12W AND 36W...FROM 4N TO 13N BETWEEN 38W AND 47W...AND TO THE SOUTH OF 10N TO THE WEST OF 51W. ...DISCUSSION... THE GULF OF MEXICO... MIDDLE LEVEL TO UPPER LEVEL NORTHEASTERLY WIND FLOW CROSSES INTO THE AREA FROM THE U.S.A. GULF COAST STATES...AND IT SPANS THE ENTIRE AREA. THE U.S.A. EAST COAST TROUGH HAS MOVED EASTWARD JUST ENOUGH NOT TO BE REACHING FLORIDA ANYMORE. THE TROUGH ENDS NEAR 29N78W IN THE WESTERN ATLANTIC OCEAN. A MIDDLE LEVEL TO UPPER LEVEL TROUGH IS ALONG 21N95W TO 16N94W...JUST INLAND OF THE GULF OF TEHUANTEPEC ON THE EASTERN PACIFIC OCEAN SIDE OF SOUTHERN MEXICO. A SURFACE RIDGE EXTENDS ALONG 24N73W...ACROSS THE BAHAMAS... THROUGH THE FLORIDA STRAITS...TO A CENTRAL GULF OF MEXICO 1020 MB HIGH PRESSURE CENTER THAT IS NEAR 25N91W. BROAD SURFACE ANTICYCLONIC WIND FLOW COVERS THE ENTIRE AREA. A HIGH LEVEL CEILING IS REPORTED AT THE NAVAL AIR STATION IN CORPUS CHRISTI. A LOW CLOUD CEILING IS OBSERVED AT ELLINGTON FIELD IN HOUSTON...IN TEXAS. A LOW CLOUD CEILING AND A MIDDLE LEVEL CLOUD CEILING ARE REPORTED IN LAKE CHARLES LOUISIANA. HIGH CLOUD CEILINGS ARE OBSERVED IN THE NEW ORLEANS LOUISIANA METROPOLITAN AREA. MULTILAYERED CLOUD CEILINGS AND NEARBY RAINSHOWERS ARE IN THE FLORIDA PANHANDLE FROM MARY ESTHER TO VALPARAISO TO DESTIN. LOW LEVEL TO MIDDLE LEVEL CLOUD CEILINGS ARE REPORTED FROM BROOKSVILLE TO THE TAMPA METROPOLITAN AREA. FAIR SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET ARE BEING REPORTED ELSEWHERE. FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE TO THE NORTH OF 27N TO THE WEST OF 88W... FAIR SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET ARE BEING REPORTED ACROSS THE AREA. THE CARIBBEAN SEA... MIDDLE LEVEL TO UPPER LEVEL EASTERLY WIND FLOW COVERS THE AREA TO THE NORTH OF 17N TO THE WEST OF THE WINDWARD PASSAGE. THIS WIND HAS MOVED FROM THE ATLANTIC OCEAN...BETWEEN THE 23N63W CYCLONIC CENTER AND FLORIDA...CROSSING CUBA...AND INTO THE NORTHWESTERN CORNER OF THE AREA. UPPER LEVEL SOUTHERLY TO SOUTHWESTERLY WIND FLOW COVERS THE AREA THAT IS TO THE SOUTH OF 17N81W 16N72W 18N64W. SOME OF THIS WIND FLOW MERGES WITH THE CYCLONIC WIND FLOW THAT IS MOVING AROUND THE 23N63W-TO-17N71W TROUGH. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 87W/88W FROM THE YUCATAN PENINSULA NEAR 21N SOUTHWARD...MOVING WESTWARD 15 KNOTS. CONVECTIVE PRECIPITATION...SCATTERED STRONG IN THE NORTHERN HALF OF GUATEMALA. THE MONSOON TROUGH IS ALONG 8N74W IN COLOMBIA...TO 9N79W IN PANAMA...BEYOND 9N84W IN COSTA RICA...INTO THE EASTERN PACIFIC OCEAN. CONVECTIVE PRECIPITATION...NUMEROUS STRONG IN COLOMBIA FROM 6N TO 7N BETWEEN 76W AND 77W AND FROM 10N TO 11N BETWEEN 74W AND 75W...IN PANAMA FROM 7N TO 9N BETWEEN 81W AND 82W. SCATTERED STRONG IN PANAMA AND COSTA RICA AND COASTAL WATERS FROM 10N TO 12N BETWEEN 82W AND 86W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT THE NORTHEAST TO EAST WINDS 25 TO 30 KNOTS AND 9 TO 11 FOOT SEA HEIGHTS FROM 11N TO 13N BETWEEN 72W AND 75W. EXPECT NORTHEAST TO EAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS TO 10 FEET ELSEWHERE FROM 11N TO 16N BETWEEN 71W AND 82W. HISPANIOLA... A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 23N63W CYCLONIC CIRCULATION CENTER...TO 20N68W...TO 17N71W IN THE CARIBBEAN SEA ABOUT 90 NM TO THE SOUTH OF HISPANIOLA. CONVECTIVE PRECIPITATION...WIDELY SCATTERED MODERATE TO ISOLATED STRONG IN HISPANIOLA TO THE SOUTH OF 19N TO THE EAST OF 72W IN HAITI. SCATTERED STRONG IN SOUTHERN CUBA TO THE WEST OF 80W...IN SOUTHEASTERN CUBA. THE GFS FORECAST FOR 700 MB AND FOR 500 MB SHOWS THAT A RIDGE WILL SPAN THE AREA FOR THE FIRST HALF OF THE FIRST 24 HOURS OR SO. THE RIDGE WILL SHIFT NORTHWESTWARD AND IT WILL BE REPLACED BY AN INVERTED TROUGH ACROSS THE AREA FOR MOST OF THE REST OF THE 48 HOUR PERIOD. THE INVERTED TROUGH EVENTUALLY WILL SHIFT WESTWARD ALSO...PUTTING HISPANIOLA ON THE EASTERN SIDE OF THE TROUGH. THE GFS FORECAST FOR 250 MB SHOWS THAT A TROUGH WITH A NORTHEAST-TO-SOUTHWEST ORIENTATION WILL SPAN THE AREA FOR THE NEXT 48 HOURS. NO TROPICAL WAVE IS APPARENT FOR AT LEAST THE NEXT FEW DAYS. THE ATLANTIC OCEAN... A WESTERN ATLANTIC OCEAN MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N77W TO 29N78W. THE TROUGH SUPPORTS A SURFACE FRONTAL BOUNDARY THAT IS ALONG 32N BETWEEN 78W AND GEORGIA IN THE SOUTHEASTERN U.S.A. BROAD SURFACE CYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN...FLORIDA... AND THE GULF OF MEXICO TO THE NORTH OF 26N BETWEEN 73W AND 88W. CYCLONIC WIND FLOW MOVES AWAY FROM THE TROUGH AND IT SHIFTS EASTWARD TOWARD THE 23N63W MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER AND TROUGH. CONVECTIVE PRECIPITATION...WIDELY SCATTERED MODERATE TO ISOLATED STRONG TO THE NORTH OF 26N BETWEEN 70W AND 80W. THE 24-HOUR RAINFALL TOTAL...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND RAINFALL TABLE...FOR THE TIME PERIOD ENDING AT 25/1200 UTC...WAS 0.42 INCHES FOR FREEPORT IN THE BAHAMAS. A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM 32N57W TO 28N60W TO A 23N63W CYCLONIC CIRCULATION CENTER...TO 20N68W...TO 17N71W IN THE CARIBBEAN SEA ABOUT 90 NM TO THE SOUTH OF HISPANIOLA. CONVECTIVE PRECIPITATION...WIDELY SCATTERED MODERATE TO ISOLATED STRONG IN HISPANIOLA TO THE SOUTH OF 19N TO THE EAST OF 72W IN HAITI. SCATTERED STRONG IN SOUTHERN CUBA TO THE WEST OF 80W...IN SOUTHEASTERN CUBA. SCATTERED MODERATE TO STRONG IN THE ATLANTIC OCEAN FROM 26N TO 30N BETWEEN 56W AND 60W. WIDELY SCATTERED TO SCATTERED MODERATE ELSEWHERE TO THE NORTH OF 20N BETWEEN 55W AND 69W. MIDDLE LEVEL TO UPPER LEVEL SOUTHWESTERLY WINDS...THAT ARE ON THE EASTERN SIDE OF THE 32N57W 23N63W 17N71W TROUGH... MEET AN AREA OF MIDDLE LEVEL SOUTHEASTERLY WIND FLOW... ROUGHLY IN THE AREA FROM 20N TO 30N ALONG 50W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE FROM 20N TO 31N BETWEEN 37W AND 51W. A MIDDLE LEVEL INVERTED TROUGH IS ALONG 20N48W 11N50W. IT IS SURROUNDED BY COMPARATIVELY DRIER AIR IN SUBSIDENCE IN WATER VAPOR IMAGERY. A SURFACE RIDGE EXTENDS FROM A 1033 MB HIGH PRESSURE CENTER THAT IS NEAR 40N45W TO 36N43W 29N32W AND 22N26W. A SECOND SURFACE RIDGE PASSES THROUGH 32N48W TO 24N60W. BROAD SURFACE ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN TO THE EAST OF 65W. A SURFACE RIDGE EXTENDS ALONG 24N73W...ACROSS THE BAHAMAS... THROUGH THE FLORIDA STRAITS...INTO THE CENTRAL GULF OF MEXICO. PLEASE READ THE FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC...THE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/WTNT34 KNHC...AND THE HIGH SEAS FORECAST... MIAHSFAT2...FOR MORE DETAILS ABOUT TROPICAL STORM DORIAN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT