102 WTNT43 KNHC 180855 TCDAT3 Potential Tropical Cyclone Three Discussion Number 3 NWS National Hurricane Center Miami FL AL032021 400 AM CDT Fri Jun 18 2021 The system became a little better organized overnight at the northern end of its associated broad surface trough over the central Gulf of Mexico. Satellite images show increasing deep convection along with more curvature to the low clouds, suggesting that the ill-defined center of this system is trying to re-form farther to the north. Since it still lacks a well-defined center, the system remains a potential tropical cyclone. Recent scatterometer data indicate that winds have increased to at least 30 kt and have grown over a larger area on the east side of the circulation. The initial motion is a highly uncertain 360/12. There is fair agreement that this northward motion, with some re-formation of the center, will continue as the system remains steered by a subtropical ridge to the southeast. The low should then turn northeastward and move across the southeastern U.S. No significant changes were made to the previous track forecast and the guidance is in fairly good agreement. It should also be noted that model "spaghetti" plots are not doing a good job tracking the center of this system, and could give a very misleading impression on the forecast track if used by themselves. There is still a lot of shear over the Gulf of Mexico and that should continue through landfall. However, the system is somewhat hybrid in nature and the shear shouldn't prevent its intensification to a tropical storm later today (possibly with subtropical characteristics). Model guidance is consistent with slow strengthening until landfall, and the new forecast is close to the previous one. After landfall, most of the global models show a strong band of heavy rain and tropical-storm-force winds persisting on the southeastern side. The expected large distance from the center necessitates extending the Tropical Storm Warning into the northwestern Florida panhandle. The system will likely dissipate in about 3 days over the southeastern United States. Given the current and anticipated structure of this system, users should not focus on the exact track of the center, as rainfall and wind hazards are likely to extend well east of the center and arrive well in advance of landfall. Key Messages: 1. The system is expected to produce heavy rainfall, considerable flash, urban and small stream flooding beginning today and continuing through the weekend along the Central Gulf coast with flood impacts spreading northeastward into the Southern Appalachians. 2. Tropical storm conditions are expected to begin today in areas near and well to the east of the center along portions of the central Gulf Coast from Intracoastal City, Louisiana, to the Okaloosa/Walton County line, Florida, including New Orleans. FORECAST POSITIONS AND MAX WINDS INIT 18/0900Z 25.2N 91.5W 30 KT 35 MPH...POTENTIAL TROP CYCLONE 12H 18/1800Z 27.0N 91.5W 35 KT 40 MPH...TROPICAL CYCLONE 24H 19/0600Z 29.2N 91.2W 40 KT 45 MPH 36H 19/1800Z 31.0N 89.5W 35 KT 40 MPH...INLAND 48H 20/0600Z 32.6N 87.6W 25 KT 30 MPH...INLAND 60H 20/1800Z 34.5N 85.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 21/0600Z...DISSIPATED $$ Forecaster Blake
000 FONT13 KNHC 180855 PWSAT3 POTENTIAL TROPICAL CYCLONE THREE WIND SPEED PROBABILITIES NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL AL032021 0900 UTC FRI JUN 18 2021 AT 0900Z THE CENTER OF POTENTIAL TROPICAL CYCLONE THREE WAS LOCATED NEAR LATITUDE 25.2 NORTH...LONGITUDE 91.5 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 30 KTS...35 MPH...55 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME EASTERN DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME CENTRAL DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 06Z FRI AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 06Z FRI 18Z FRI 06Z SAT 18Z SAT 06Z SUN 06Z MON 06Z TUE PERIODS TO TO TO TO TO TO TO 18Z FRI 06Z SAT 18Z SAT 06Z SUN 06Z MON 06Z TUE 06Z WED FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT ATLANTA GA 34 X X( X) X( X) 1( 1) 2( 3) X( 3) X( 3) PANAMA CITY FL 34 X X( X) 2( 2) 1( 3) X( 3) X( 3) X( 3) DESTIN EXEC AP 34 X X( X) 4( 4) 1( 5) 1( 6) X( 6) X( 6) COLUMBUS GA 34 X X( X) 1( 1) 1( 2) 2( 4) X( 4) X( 4) BIRMINGHAM AL 34 X X( X) 2( 2) 3( 5) 3( 8) X( 8) X( 8) MONTGOMERY AL 34 X X( X) 3( 3) 5( 8) 2(10) X(10) X(10) WHITING FLD FL 34 X X( X) 6( 6) 4(10) X(10) X(10) X(10) PENSACOLA FL 34 X X( X) 7( 7) 3(10) X(10) X(10) X(10) GFMX 290N 870W 34 X 1( 1) 3( 4) 1( 5) X( 5) X( 5) X( 5) MOBILE AL 34 X 1( 1) 17(18) 4(22) X(22) X(22) X(22) MOBILE AL 50 X X( X) 2( 2) 1( 3) X( 3) X( 3) X( 3) GULFPORT MS 34 X 1( 1) 26(27) 2(29) X(29) X(29) X(29) GULFPORT MS 50 X X( X) 3( 3) 1( 4) X( 4) X( 4) X( 4) STENNIS MS 34 X 3( 3) 29(32) 1(33) X(33) X(33) X(33) STENNIS MS 50 X X( X) 4( 4) 1( 5) X( 5) X( 5) X( 5) BURAS LA 34 X 6( 6) 20(26) X(26) X(26) X(26) X(26) BURAS LA 50 X X( X) 2( 2) 1( 3) X( 3) X( 3) X( 3) GFMX 280N 890W 34 1 4( 5) 3( 8) X( 8) X( 8) X( 8) X( 8) JACKSON MS 34 X X( X) 5( 5) 1( 6) X( 6) X( 6) X( 6) NEW ORLEANS LA 34 X 10(10) 27(37) X(37) X(37) X(37) X(37) NEW ORLEANS LA 50 X X( X) 5( 5) X( 5) X( 5) X( 5) X( 5) GFMX 280N 910W 34 9 35(44) 1(45) X(45) X(45) X(45) X(45) GFMX 280N 910W 50 X 5( 5) X( 5) X( 5) X( 5) X( 5) X( 5) BATON ROUGE LA 34 X 5( 5) 15(20) X(20) X(20) X(20) X(20) MORGAN CITY LA 34 X 13(13) 16(29) X(29) X(29) X(29) X(29) MORGAN CITY LA 50 X 1( 1) 2( 3) X( 3) X( 3) X( 3) X( 3) LAFAYETTE LA 34 X 3( 3) 5( 8) X( 8) X( 8) X( 8) X( 8) NEW IBERIA LA 34 X 6( 6) 7(13) X(13) X(13) X(13) X(13) GFMX 280N 930W 34 1 3( 4) 1( 5) X( 5) X( 5) X( 5) X( 5) CAMERON LA 34 X 2( 2) 1( 3) X( 3) X( 3) X( 3) X( 3) $$ FORECASTER BLAKE
000 WTNT23 KNHC 180853 TCMAT3 POTENTIAL TROPICAL CYCLONE THREE FORECAST/ADVISORY NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL AL032021 0900 UTC FRI JUN 18 2021 CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY... THE TROPICAL STORM WARNING HAS BEEN EXTENDED EASTWARD FOR THE FLORIDA PANHANDLE FROM THE ALABAMA/FLORIDA BORDER TO THE OKALOOSA/WALTON COUNTY LINE. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A TROPICAL STORM WARNING IS IN EFFECT FOR... * INTRACOASTAL CITY LOUISIANA TO THE OKALOOSA/WALTON COUNTY LINE. * LAKE PONTCHARTRAIN...LAKE MAUREPAS...AND METROPOLITAN NEW ORLEANS A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA...IN THIS CASE WITHIN 12 TO 24 HOURS. INTERESTS ELSEWHERE ALONG THE NORTHERN GULF COAST SHOULD MONITOR THE PROGRESS OF THIS SYSTEM. POTENTIAL TROP CYCLONE CENTER LOCATED NEAR 25.2N 91.5W AT 18/0900Z POSITION ACCURATE WITHIN 60 NM PRESENT MOVEMENT TOWARD THE NORTH OR 360 DEGREES AT 12 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1007 MB MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 25.2N 91.5W AT 18/0900Z AT 18/0600Z CENTER WAS LOCATED NEAR 24.5N 91.5W FORECAST VALID 18/1800Z 27.0N 91.5W...TROPICAL CYCLONE MAX WIND 35 KT...GUSTS 45 KT. 34 KT...180NE 180SE 0SW 0NW. FORECAST VALID 19/0600Z 29.2N 91.2W MAX WIND 40 KT...GUSTS 50 KT. 34 KT...180NE 180SE 0SW 0NW. FORECAST VALID 19/1800Z 31.0N 89.5W...INLAND MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 0NE 150SE 0SW 0NW. FORECAST VALID 20/0600Z 32.6N 87.6W...INLAND MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 20/1800Z 34.5N 85.0W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 21/0600Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 25.2N 91.5W INTERMEDIATE PUBLIC ADVISORY...WTNT33 KNHC/MIATCPAT3...AT 18/1200Z NEXT ADVISORY AT 18/1500Z $$ FORECASTER BLAKE
This graphic shows an approximate representation of coastal areas under a hurricane warning (red), hurricane watch (pink), tropical storm warning (blue) and tropical storm watch (yellow). The orange circle indicates the current position of the center of the tropical cyclone. The black line, when selected, and dots show the National Hurricane Center (NHC) forecast track of the center at the times indicated. The dot indicating the forecast center location will be black if the cyclone is forecast to be tropical and will be white with a black outline if the cyclone is forecast to be extratropical. If only an L is displayed, then the system is forecast to be a remnant low. The letter inside the dot indicates the NHC’s forecast intensity for that time:
D: Tropical Depression – wind speed less than 39 MPH S: Tropical Storm – wind speed between 39 MPH and 73 MPH H: Hurricane – wind speed between 74 MPH and 110 MPH M: Major Hurricane – wind speed greater than 110 MPH
NHC tropical cyclone forecast tracks can be in error. This forecast uncertainty is conveyed by the track forecast “cone”, the solid white and stippled white areas in the graphic. The solid white area depicts the track forecast uncertainty for days 1-3 of the forecast, while the stippled area depicts the uncertainty on days 4-5. Historical data indicate that the entire 5-day path of the center of the tropical cyclone will remain within the cone about 60-70% of the time. To form the cone, a set of imaginary circles are placed along the forecast track at the 12, 24, 36, 48, 72, 96, and 120 h positions, where the size of each circle is set so that it encloses 67% of the previous five years official forecast errors. The cone is then formed by smoothly connecting the area swept out by the set of circles.
It is also important to realize that a tropical cyclone is not a point. Their effects can span many hundreds of miles from the center. The area experiencing hurricane force (one-minute average wind speeds of at least 74 mph) and tropical storm force (one-minute average wind speeds of 39-73 mph) winds can extend well beyond the white areas shown enclosing the most likely track area of the center. The distribution of hurricane and tropical storm force winds in this tropical cyclone can be seen in the Wind History graphic linked above.
Considering the combined forecast uncertainties in track, intensity, and size, the chances that any particular location will experience winds of 34 kt (tropical storm force), 50 kt, or 64 kt (hurricane force) from this tropical cyclone are presented in tabular form for selected locations and forecast positions. This information is also presented in graphical form for the 34 kt, 50 kt, and 64 kt thresholds.
000 WTNT33 KNHC 180540 TCPAT3 BULLETIN Potential Tropical Cyclone Three Intermediate Advisory Number 2A NWS National Hurricane Center Miami FL AL032021 100 AM CDT Fri Jun 18 2021 ...POTENTIAL TROPICAL CYCLONE THREE FORECAST TO BRING HEAVY RAINFALL AND FLOODING TO THE NORTHERN GULF COAST... SUMMARY OF 100 AM CDT...0600 UTC...INFORMATION ---------------------------------------------- LOCATION...24.0N 92.0W ABOUT 390 MI...630 KM S OF MORGAN CITY LOUISIANA MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Intracoastal City Louisiana to the Alabama/Florida border * Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case within 12 to 24 hours. Interests elsewhere along the northern Gulf Coast should monitor the progress of this system. For storm information specific to your area, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. DISCUSSION AND OUTLOOK ---------------------- At 100 AM CDT (0600 UTC), the poorly defined disturbance was centered near latitude 24.0 North, longitude 92.0 West. The system is moving toward the north near 9 mph (15 km/h), and this motion with some increase in forward speed is expected for the next day or so. On the forecast track, the system will approach the north-central Gulf Coast late Friday or early Saturday. A northeastward motion across the southeastern United States is likely after landfall. Satellite-derived wind data indicate that the maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Some strengthening is forecast, and a subtropical or tropical storm is likely to form over the west-central or northwestern Gulf of Mexico later today. * Formation chance through 48 hours...high...90 percent. * Formation chance through 5 days...high...90 percent. The estimated minimum central pressure is 1007 mb (29.74 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Potential Tropical Cyclone Three can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC. RAINFALL: The potential tropical cyclone is expected to produce total rainfall of 3 to 6 inches with isolated amounts of 8 inches across the Yucatan Peninsula of Mexico. Rainfall totals of 4 to 8 inches with isolated maximum amounts of 12 inches are possible beginning today and continuing through the weekend from along the Central Gulf coast, northeastward into the southern Appalachians. This will likely produce areas of flash, urban and small stream flooding as well as minor to isolated moderate river flooding with new and renewed rises on already elevated rivers. STORM SURGE: The combination of storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... Intracoastal City, LA to MS/AL Border...2-3 ft Vermilion Bay and Lake Borgne...2-3 ft Lake Pontchartrain and Lake Maurepas...1-2 ft MS/AL border to AL/FL border including Mobile Bay...1-3 ft Cameron, LA to Intracoastal City, LA...1-2 ft Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office. WIND: Tropical storm conditions are expected to first reach the coast within the warning area later today, making outside preparations difficult or dangerous. TORNADOES: The threat for a couple of tornadoes is expected to begin this afternoon across coastal Louisiana. This threat should expand northward across southern portions of Louisiana and Mississippi, and southwest Alabama Friday night into Saturday. NEXT ADVISORY ------------- Next complete advisory at 400 AM CDT. $$ Forecaster Blake
000 WTNT43 KNHC 180238 TCDAT3 Potential Tropical Cyclone Three Discussion Number 2 NWS National Hurricane Center Miami FL AL032021 1000 PM CDT Thu Jun 17 2021 Satellite imagery and data from an Air Force Reserve Hurricane Hunter aircraft indicate that the low pressure area over the southwestern Gulf of Mexico has changed little in organization during the past several hours, and the associated convection lies well to the east of the broad and poorly defined center. The initial intensity will be held at 25 kt based partially on ship reports from the northeastern and northern parts of the system. Due to the poorly defined center, the initial motion is a highly uncertain 360/8. The system should move generally northward for the next 24-36 h to a position near the coast of Louisiana, followed by a motion toward the northeast across the southeastern United States as it moves through a weakness in the subtropical ridge caused by an upper-level trough over Texas, northern Mexico, and the adjacent Gulf of Mexico. The forecast track is basically an update of the previous forecast. It should be noted that the latest GFS run continues to forecast a re-formation of the center to the north sometime on Friday, and the forecast forward motion tries to account for this possibility. The aforementioned upper-level trough is causing shear over the system, and present indications are that some shear will persist through landfall and hinder development. The intensity forecast calls for the low to become a tropical cyclone in about 12 h, followed by some modest strengthening to tropical storm strength at 24-36 h. This would be followed by weakening over land, with the system dissipating over the southeastern United States between 72- 96 h. There is a chance that, due to the interaction with the upper-level trough, the system may take on subtropical cyclone characteristics instead of tropical cyclone characteristics. The new intensity forecast is similar to the previous forecast, and it lies at the upper edge of the intensity guidance envelope. Given the current and anticipated structure of this system, users should not focus on the exact track of the center, as rainfall and wind hazards are likely to extend well east of the center and arrive well in advance of landfall. Key Messages: 1. The system is expected to produce heavy rainfall, considerable flash, urban and small stream flooding beginning Friday and continuing through the weekend along the Central Gulf coast, spreading northeastward into the Southern Appalachians. 2. Tropical storm conditions are expected to begin Friday in areas near and well to the east of the center along portions of the central Gulf Coast from Intracoastal City, Louisiana, to the Alabama/Florida border, including New Orleans. FORECAST POSITIONS AND MAX WINDS INIT 18/0300Z 23.5N 92.2W 25 KT 30 MPH...POTENTIAL TROP CYCLONE 12H 18/1200Z 25.0N 92.4W 30 KT 35 MPH...TROPICAL CYCLONE 24H 19/0000Z 27.2N 92.4W 35 KT 40 MPH 36H 19/1200Z 29.8N 91.1W 40 KT 45 MPH...INLAND 48H 20/0000Z 32.0N 88.8W 30 KT 35 MPH...INLAND 60H 20/1200Z 34.1N 86.1W 25 KT 30 MPH...POST-TROP/INLAND 72H 21/0000Z 35.6N 83.0W 20 KT 25 MPH...POST-TROP/INLAND 96H 22/0000Z...DISSIPATED $$ Forecaster Beven
This graphic shows an approximate representation of coastal areas under a hurricane warning (red), hurricane watch (pink), tropical storm warning (blue) and tropical storm watch (yellow). The orange circle indicates the current position of the center of the tropical cyclone. The black line, when selected, and dots show the National Hurricane Center (NHC) forecast track of the center at the times indicated. The dot indicating the forecast center location will be black if the cyclone is forecast to be tropical and will be white with a black outline if the cyclone is forecast to be extratropical. If only an L is displayed, then the system is forecast to be a remnant low. The letter inside the dot indicates the NHC’s forecast intensity for that time:
D: Tropical Depression – wind speed less than 39 MPH S: Tropical Storm – wind speed between 39 MPH and 73 MPH H: Hurricane – wind speed between 74 MPH and 110 MPH M: Major Hurricane – wind speed greater than 110 MPH
NHC tropical cyclone forecast tracks can be in error. This forecast uncertainty is conveyed by the track forecast “cone”, the solid white and stippled white areas in the graphic. The solid white area depicts the track forecast uncertainty for days 1-3 of the forecast, while the stippled area depicts the uncertainty on days 4-5. Historical data indicate that the entire 5-day path of the center of the tropical cyclone will remain within the cone about 60-70% of the time. To form the cone, a set of imaginary circles are placed along the forecast track at the 12, 24, 36, 48, 72, 96, and 120 h positions, where the size of each circle is set so that it encloses 67% of the previous five years official forecast errors. The cone is then formed by smoothly connecting the area swept out by the set of circles.
It is also important to realize that a tropical cyclone is not a point. Their effects can span many hundreds of miles from the center. The area experiencing hurricane force (one-minute average wind speeds of at least 74 mph) and tropical storm force (one-minute average wind speeds of 39-73 mph) winds can extend well beyond the white areas shown enclosing the most likely track area of the center. The distribution of hurricane and tropical storm force winds in this tropical cyclone can be seen in the Wind History graphic linked above.
Considering the combined forecast uncertainties in track, intensity, and size, the chances that any particular location will experience winds of 34 kt (tropical storm force), 50 kt, or 64 kt (hurricane force) from this tropical cyclone are presented in tabular form for selected locations and forecast positions. This information is also presented in graphical form for the 34 kt, 50 kt, and 64 kt thresholds.
000 FONT13 KNHC 180238 PWSAT3 POTENTIAL TROPICAL CYCLONE THREE WIND SPEED PROBABILITIES NUMBER 2 NWS NATIONAL HURRICANE CENTER MIAMI FL AL032021 0300 UTC FRI JUN 18 2021 AT 0300Z THE CENTER OF POTENTIAL TROPICAL CYCLONE THREE WAS LOCATED NEAR LATITUDE 23.5 NORTH...LONGITUDE 92.2 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 25 KTS...30 MPH...45 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME EASTERN DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME CENTRAL DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 00Z FRI AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 00Z FRI 12Z FRI 00Z SAT 12Z SAT 00Z SUN 00Z MON 00Z TUE PERIODS TO TO TO TO TO TO TO 12Z FRI 00Z SAT 12Z SAT 00Z SUN 00Z MON 00Z TUE 00Z WED FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT ATLANTA GA 34 X X( X) X( X) 1( 1) 4( 5) X( 5) X( 5) DESTIN EXEC AP 34 X X( X) 1( 1) 2( 3) X( 3) X( 3) X( 3) COLUMBUS GA 34 X X( X) X( X) 1( 1) 3( 4) X( 4) X( 4) BIRMINGHAM AL 34 X X( X) X( X) 4( 4) 7(11) X(11) X(11) MONTGOMERY AL 34 X X( X) 1( 1) 3( 4) 5( 9) X( 9) X( 9) WHITING FLD FL 34 X X( X) 2( 2) 3( 5) X( 5) X( 5) X( 5) PENSACOLA FL 34 X X( X) 2( 2) 3( 5) X( 5) X( 5) X( 5) MOBILE AL 34 X X( X) 5( 5) 10(15) 1(16) X(16) X(16) GULFPORT MS 34 X X( X) 11(11) 13(24) X(24) X(24) X(24) STENNIS MS 34 X X( X) 18(18) 13(31) 1(32) X(32) X(32) STENNIS MS 50 X X( X) 2( 2) 2( 4) X( 4) X( 4) X( 4) BURAS LA 34 X X( X) 18(18) 4(22) 1(23) X(23) X(23) GFMX 280N 890W 34 X 2( 2) 5( 7) X( 7) X( 7) X( 7) X( 7) JACKSON MS 34 X X( X) 3( 3) 6( 9) 1(10) X(10) X(10) NEW ORLEANS LA 34 X X( X) 30(30) 6(36) X(36) X(36) X(36) NEW ORLEANS LA 50 X X( X) 5( 5) 1( 6) X( 6) X( 6) X( 6) GFMX 280N 910W 34 X 10(10) 22(32) X(32) X(32) X(32) X(32) GFMX 280N 910W 50 X 1( 1) 2( 3) X( 3) X( 3) X( 3) X( 3) BATON ROUGE LA 34 X X( X) 23(23) 5(28) X(28) X(28) X(28) BATON ROUGE LA 50 X X( X) 4( 4) 1( 5) X( 5) X( 5) X( 5) MORGAN CITY LA 34 X X( X) 28(28) 6(34) X(34) X(34) X(34) MORGAN CITY LA 50 X X( X) 4( 4) 2( 6) X( 6) X( 6) X( 6) ALEXANDRIA LA 34 X X( X) 3( 3) 1( 4) X( 4) X( 4) X( 4) LAFAYETTE LA 34 X X( X) 14(14) 2(16) X(16) X(16) X(16) NEW IBERIA LA 34 X X( X) 17(17) 3(20) X(20) X(20) X(20) NEW IBERIA LA 50 X X( X) 3( 3) X( 3) X( 3) X( 3) X( 3) GFMX 280N 930W 34 X 13(13) 4(17) X(17) X(17) X(17) X(17) LAKE CHARLES 34 X X( X) 3( 3) X( 3) X( 3) X( 3) X( 3) CAMERON LA 34 X 1( 1) 3( 4) X( 4) X( 4) X( 4) X( 4) $$ FORECASTER BEVEN
567 WTNT23 KNHC 180237 TCMAT3 POTENTIAL TROPICAL CYCLONE THREE FORECAST/ADVISORY NUMBER 2 NWS NATIONAL HURRICANE CENTER MIAMI FL AL032021 0300 UTC FRI JUN 18 2021 CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY... NONE. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A TROPICAL STORM WARNING IS IN EFFECT FOR... * INTRACOASTAL CITY LOUISIANA TO THE ALABAMA/FLORIDA BORDER * LAKE PONTCHARTRAIN...LAKE MAUREPAS...AND METROPOLITAN NEW ORLEANS A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS. INTERESTS ELSEWHERE ALONG THE NORTHERN GULF COAST SHOULD MONITOR THE PROGRESS OF THIS SYSTEM. POTENTIAL TROP CYCLONE CENTER LOCATED NEAR 23.5N 92.2W AT 18/0300Z POSITION ACCURATE WITHIN 60 NM PRESENT MOVEMENT TOWARD THE NORTH OR 360 DEGREES AT 8 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1007 MB MAX SUSTAINED WINDS 25 KT WITH GUSTS TO 35 KT. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 23.5N 92.2W AT 18/0300Z AT 18/0000Z CENTER WAS LOCATED NEAR 23.1N 92.2W FORECAST VALID 18/1200Z 25.0N 92.4W...TROPICAL CYCLONE MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 19/0000Z 27.2N 92.4W MAX WIND 35 KT...GUSTS 45 KT. 34 KT...150NE 150SE 0SW 0NW. FORECAST VALID 19/1200Z 29.8N 91.1W...INLAND MAX WIND 40 KT...GUSTS 50 KT. 34 KT...180NE 180SE 0SW 0NW. FORECAST VALID 20/0000Z 32.0N 88.8W...INLAND MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 20/1200Z 34.1N 86.1W...POST-TROP/INLAND MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 21/0000Z 35.6N 83.0W...POST-TROP/INLAND MAX WIND 20 KT...GUSTS 30 KT. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 22/0000Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 23.5N 92.2W INTERMEDIATE PUBLIC ADVISORY...WTNT33 KNHC/MIATCPAT3...AT 18/0600Z NEXT ADVISORY AT 18/0900Z $$ FORECASTER BEVEN
566 WTNT33 KNHC 180237 TCPAT3 BULLETIN Potential Tropical Cyclone Three Advisory Number 2 NWS National Hurricane Center Miami FL AL032021 1000 PM CDT Thu Jun 17 2021 ...THE POTENTIAL TROPICAL CYCLONE REMAINS POORLY ORGANIZED AS IT MOVES OVER THE SOUTHWESTERN GULF OF MEXICO... ...EXPECTED TO BRING HEAVY RAINFALL AND FLOODING TO THE NORTHERN GULF COAST... SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...23.5N 92.2W ABOUT 435 MI...695 KM S OF MORGAN CITY LOUISIANA MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Intracoastal City Louisiana to the Alabama/Florida border * Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. Interests elsewhere along the northern Gulf Coast should monitor the progress of this system. For storm information specific to your area, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. DISCUSSION AND OUTLOOK ---------------------- At 1000 PM CDT (0300 UTC), the disturbance was centered near latitude 23.5 North, longitude 92.2 West. The system is moving toward the north near 9 mph (15 km/h) and this motion with some increase in forward speed is expected for the next day or so. On the forecast track, the system will approach the north-central Gulf Coast late Friday or early Saturday. A northeastward motion across the southeastern United States is likely after landfall. Maximum sustained winds are near 30 mph (45 km/h) with higher gusts. Some strengthening is forecast Friday and Friday night. A subtropical or tropical depression or storm is likely to form over the west-central or northwestern Gulf of Mexico on Friday. * Formation chance through 48 hours...high...90 percent. * Formation chance through 5 days...high...90 percent. The estimated minimum central pressure is 1007 mb (29.74 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Potential Tropical Cyclone Three can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC. RAINFALL: The potential tropical cyclone is expected to produce total rainfall of 3 to 6 inches with isolated amounts of 8 inches across the Yucatan Peninsula of Mexico. Rainfall totals of 4 to 8 inches with isolated maximum amounts of 12 inches are possible beginning Friday and continuing through the weekend from along the Central Gulf coast, northeastward into the southern Appalachians. This will likely produce areas of flash, urban and small stream flooding as well as minor to isolated moderate river flooding with new and renewed rises on already elevated rivers. STORM SURGE: The combination of storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... Intracoastal City, LA to MS/AL Border...2-3 ft Vermilion Bay and Lake Borgne...2-3 ft Lake Pontchartrain and Lake Maurepas...1-2 ft MS/AL border to AL/FL border including Mobile Bay...1-3 ft Cameron, LA to Intracoastal City, LA...1-2 ft Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office. WIND: Tropical storm conditions are expected to first reach the coast within the warning area on Friday, making outside preparations difficult or dangerous. TORNADOES: The threat for a couple of tornadoes is expected to begin Friday afternoon across coastal Louisiana. This threat should expand northward across southern portions of Louisiana and Mississippi, and southwest Alabama Friday night into Saturday. NEXT ADVISORY ------------- Next intermediate advisory at 100 AM CDT. Next complete advisory at 400 AM CDT. $$ Forecaster Beven
