000 AXNT20 KNHC 031803 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT AUG 03 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 1745 UTC. ...SPECIAL FEATURE... THE CENTER OF TROPICAL DEPRESSION DORIAN AT 03/1500 UTC IS NEAR 30.6N 78.4W. DORIAN IS ABOUT 173 NM TO THE EAST OF JACKSONVILLE FLORIDA. DORIAN IS MOVING NORTHEASTWARD 12 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1013 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 30 KNOTS WITH GUSTS TO 40 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...SCATTERED STRONG FROM 28N TO 29N BETWEEN 78W AND 80W...AND CUTTING ACROSS FLORIDA FROM NORTHEAST-TO-SOUTHWEST WITHIN 30 NM ON EITHER SIDE OF 28N80W 26N81W 25N82W. SCATTERED STRONG CONVECTIVE PRECIPITATION ALSO IS IN THE ATLANTIC OCEAN FROM 30N TO 33N BETWEEN 72W AND 74W...FROM 27N TO 30N BETWEEN 73W AND 76W...AND FROM 26N TO 28N BETWEEN 76W AND 77W. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 32W TO THE SOUTH OF 20N. THE WAVE IS MOVING WESTWARD 10 TO 15 KNOTS. THE WAVE STANDS OUT EASILY IN LONG-TERM SATELLITE IMAGERY. RAINSHOWERS ARE POSSIBLE FROM 15N TO 25N BETWEEN 28W AND 40W. AN ATLANTIC OCEAN TROUGH IS ALONG 39W/40W FROM 19N TO 24N...TO THE NORTHWEST OF THE TROPICAL WAVE. THIS FEATURE IS EMERGING OUT OF THE MID LATITUDES AHEAD OF THE 32W TROPICAL WAVE...AND IT WILL BECOME INDISTINGUISHABLE FROM THE TROPICAL WAVE DURING THE NEXT 24 HOURS AS THE FEATURES MERGE. THE MERGED TROUGH/TROPICAL WAVE WILL PROGRESS ACROSS THE ATLANTIC OCEAN...REACHING THE LEEWARD ISLANDS BY THE MIDDLE OF THE WEEK. A SOUTHWESTERN GULF OF MEXICO TROPICAL WAVE IS ALONG 96W TO THE SOUTH OF 21N. THE WAVE WAS DROPPED FROM THE 03/1500 UTC SURFACE MAP ANALYSIS BECAUSE IT IS APPARENT NOT ANY MORE. NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION IS ASSOCIATED WITH THIS WAVE. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH THE COASTAL SENEGAL NEAR 16N17W TO 13N26W 9N32W AND 8N37W. THE ITCZ CONTINUES FROM 8N37W TO 7N45W AND 5N50W. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 6N TO 10N BETWEEN 30W AND 37W...AND FROM 7N TO 9N BETWEEN 45W AND 48W. SCATTERED MODERATE TO ISOLATED STRONG ELSEWHERE FROM 10N TO 15N TO THE EAST OF 22W...FROM 9N TO 12N BETWEEN 23W AND 30W...AND FROM 7N TO 9N BETWEEN 42W AND 45W. ...DISCUSSION... THE GULF OF MEXICO... MIDDLE LEVEL TO UPPER LEVEL NORTHEASTERLY-TO-EASTERLY WIND FLOW CROSSES INTO THE AREA FROM THE U.S.A. GULF COAST STATES...AND IT SPANS THE ENTIRE AREA. AN ANTICYCLONIC CIRCULATION CENTER IS IN THE TEXAS PANHANDLE. A SURFACE RIDGE EXTENDS ALONG 26N74W IN THE ATLANTIC OCEAN... ACROSS SOUTH FLORIDA...INTO THE EAST CENTRAL GULF OF MEXICO... EVENTUALLY TO THE MIDDLE TEXAS GULF COAST. SCATTERED TO BROKEN LOW CLOUDS ARE IN THE MIDDLE TEXAS GULF COASTAL AREAS. SCATTERED TO BROKEN HIGH CLOUDS ARE IN THE HOUSTON METROPOLITAN AREA. BROKEN LOW CLOUDS COVER THE UPPER TEXAS GULF COASTAL AREAS INTO SOUTHWESTERN LOUISIANA. BROKEN TO OVERCAST LOW AND MIDDLE LEVEL CLOUDS WITH LIGHT RAIN ARE IN SOUTHEASTERN COASTAL LOUISIANA. BROKEN LOW AND HIGH LEVEL CLOUDS ARE OBSERVED IN THE NEW ORLEANS LOUISIANA METROPOLITAN AREA. SCATTERED LOW CLOUDS ARE ALONG THE COASTS OF MISSISSIPPI AND ALABAMA. MULTILAYERED CLOUD CEILINGS AND LIGHT RAIN/DRIZZLE ARE BEING REPORTED IN FLORIDA COASTAL AREAS FROM PERRY WESTWARD. BROKEN LOW AND MIDDLE LEVEL CLOUDS WITH POSSIBLE RAIN ARE FROM TAMPA TO ST. PETERSBURG/ CLEARWATER. BROKEN MIDDLE LEVEL AND HIGH LEVEL CLOUDS STRETCH FROM NAPLES TO THE KEY WEST NAVAL AIR STATION. 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... A LOW CLOUD CEILING IS BEING REPORTED AT THE ICAO STATION KVBS OFF THE SOUTHWESTERN COAST OF LOUISIANA. A VISIBILITY OF 5 MILES WITH HAZE IS BEING REPORTED AT THE ICAO STATION KCRH. FAIR SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET ARE BEING REPORTED ELSEWHERE ACROSS THE AREA. THE CARIBBEAN SEA... UPPER LEVEL ANTICYCLONIC WIND FLOW IS MOVING AROUND AN 11N75W 15N80W 18N86W RIDGE. AN ATLANTIC OCEAN MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 24N62W TO 17N67W. NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION IS APPARENT IN SATELLITE IMAGERY. MIDDLE LEVEL NORTHEASTERLY-TO-EASTERLY-TO SOUTHEASTERLY WIND FLOW COVERS THE ATLANTIC OCEAN AND THE CARIBBEAN SEA FROM 14N TO 21N BETWEEN 53W AND 67W. 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. THE MONSOON TROUGH IS ALONG 8N/9N BETWEEN 74W IN COLOMBIA... BEYOND 86W IN THE EASTERN PACIFIC OCEAN. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 10N TO 13N BETWEEN 81W AND 84W REACHING EASTERN NICARAGUA. ISOLATED STRONG IN THE COASTAL AREAS FROM 8N77W IN COLOMBIA...TO 10N80W TO 9N81W NEAR PANAMA. 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 10 TO 13 FOOT SEA HEIGHTS FROM 11N TO 13N BETWEEN 70W AND 78W. EXPECT NORTHEAST TO EAST WINDS 20 TO 25 KNOTS AND 8 TO 10 FOOT SEA HEIGHTS ELSEWHERE FROM 11N TO 16N BETWEEN 70W AND 82W. HISPANIOLA... UPPER LEVEL NORTHWESTERLY WIND FLOW IS MOVING ACROSS THE AREA. PART OF THIS WIND FLOW COMES FROM ANTICYCLONIC WIND FLOW THAT IS MOVING AROUND AN 11N75W 15N80W 18N86W UPPER LEVEL RIDGE. ANOTHER PART OF THE WIND FLOW COMES FROM NORTHERLY WIND FLOW THAT IS MOVING AROUND AN ATLANTIC OCEAN 32N48W 26N54W 24N62W 17N67W MIDDLE LEVEL TO UPPER LEVEL TROUGH. THE GFS FORECAST FOR 700 MB AND FOR 500 MB SHOWS THAT HISPANIOLA WILL BE ON THE SOUTHERN SIDE OF AN ANTICYCLONIC CIRCULATION CENTER FOR 48 HOURS. THE CENTER WILL START NEAR 23N63W IN THE ATLANTIC OCEAN...AND IT WILL END UP ON TOP OF CENTRAL CUBA. THE 500 MB GFS FORECAST IS SIMILAR TO THE 700 MB FORECAST. ONE DIFFERENCE IS THAT ONE ORGANIZED ANTICYCLONIC CIRCULATION CENTER IS NOT APPARENT. BROAD ANTICYCLONIC WIND FLOW WILL COVER THE AREA FOR 48 HOURS. THE WIND FLOW WILL START FROM EAST...AND IT WILL END UP BEING NORTHEASTERLY. THE 250 MB GFS FORECAST SHOWS THAT HISPANIOLA WILL BE COVERED BY CYCLONIC WIND FLOW FROM A NORTHEAST-TO-SOUTHWEST ORIENTED TROUGH...THAT GRADUALLY BECOMES MORE NORTH-TO-SOUTH BY THE END OF 48 HOURS. THE ATLANTIC OCEAN... A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 32N48W CYCLONIC CIRCULATION CENTER TO 26N54W...TO A 24N62W CYCLONIC CIRCULATION CENTER...TO 17N67W IN THE CARIBBEAN SEA. CONVECTIVE PRECIPITATION...SCATTERED STRONG IN THE ATLANTIC OCEAN FROM 29N TO 32N BETWEEN 54W AND 57W. ISOLATED MODERATE ELSEWHERE TO THE NORTH OF 25N BETWEEN 46W AND 70W. A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 17N42W. CYCLONIC WIND FLOW THAT IS MOVING AROUND THE CENTER COVERS THE ATLANTIC OCEAN FROM 13N TO 24N BETWEEN 38W AND 50W. A SURFACE RIDGE EXTENDS FROM A 1029 MB HIGH PRESSURE CENTER THAT IS NEAR 35N28W TO 32N40W 32N60W 26N74W...BEYOND SOUTH FLORIDA... INTO THE EAST 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 DEPRESSION DORIAN. A SECOND AREA OF INTEREST CONSISTS OF 20 KNOT WINDS OR LESS AND 8 FOOT SEA HEIGHTS FROM 21N TO 26N TO THE EAST OF 37W FOR THE NEXT 6 HOURS OR SO. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT