Aggregator

Issued at 1500 UTC FRI SEP 27 2024 000 WTPZ25 KNHC 271432 TCMEP5 TROPICAL STORM JOHN FORECAST/ADVISORY NUMBER 19 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102024 1500 UTC FRI SEP 27 2024 TROPICAL STORM CENTER LOCATED NEAR 18.1N 103.0W AT 27/1500Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE NORTH-NORTHWEST OR 330 DEGREES AT 3 KT ESTIMATED MINIMUM CENTRAL PRESSURE 993 MB MAX SUSTAINED WINDS 50 KT WITH GUSTS TO 60 KT. 50 KT....... 20NE 30SE 25SW 20NW. 34 KT....... 40NE 140SE 60SW 40NW. 12 FT SEAS.. 0NE 330SE 330SW 0NW. 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 18.1N 103.0W AT 27/1500Z AT 27/1200Z CENTER WAS LOCATED NEAR 18.0N 102.9W FORECAST VALID 28/0000Z 18.8N 103.8W...INLAND MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 10NE 80SE 20SW 20NW. FORECAST VALID 28/1200Z 19.4N 105.1W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 29/0000Z 19.9N 106.5W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 29/1200Z 20.4N 108.3W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 30/0000Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 18.1N 103.0W INTERMEDIATE PUBLIC ADVISORY...WTNT35 KNHC/MIATCPEP5...AT 27/1800Z NEXT ADVISORY AT 27/2100Z $$ FORECASTER KELLY

Issued at 1500 UTC FRI SEP 27 2024 ZCZC MIAPWSEP5 ALL TTAA00 KNHC DDHHMM TROPICAL STORM JOHN WIND SPEED PROBABILITIES NUMBER 19 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102024 1500 UTC FRI SEP 27 2024 AT 1500Z THE CENTER OF TROPICAL STORM JOHN WAS LOCATED NEAR LATITUDE 18.1 NORTH...LONGITUDE 103.0 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 50 KTS...60 MPH...95 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) PACIFIC DAYLIGHT TIME (PDT)...SUBTRACT 7 HOURS FROM Z TIME HAWAIIAN STANDARD TIME (HST)...SUBTRACT 10 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 12Z 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 12Z FRI 00Z SAT 12Z SAT 00Z SUN 12Z SUN 12Z MON 12Z TUE PERIODS TO TO TO TO TO TO TO 00Z SAT 12Z SAT 00Z SUN 12Z SUN 12Z MON 12Z TUE 12Z WED FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT BARRA NAVIDAD 34 1 8( 9) 2(11) X(11) X(11) X(11) X(11) MANZANILLO 34 21 16(37) X(37) X(37) X(37) X(37) X(37) MANZANILLO 50 1 2( 3) X( 3) X( 3) X( 3) X( 3) X( 3) L CARDENAS 34 99 X(99) X(99) X(99) X(99) X(99) X(99) ZIHUATANEJO 34 99 X(99) X(99) X(99) X(99) X(99) X(99) $$ FORECASTER KELLY NNNN

Issued at 900 AM CST Fri Sep 27 2024 ZCZC MIATCPEP5 ALL TTAA00 KNHC DDHHMM BULLETIN Tropical Storm John Advisory Number 19 NWS National Hurricane Center Miami FL EP102024 900 AM CST Fri Sep 27 2024 ...JOHN ABUTTING THE COAST... ...CATASTROPHIC FLASH FLOODING AND MUDSLIDES CONTINUE OVER PORTIONS OF SOUTHERN AND SOUTHWESTERN MEXICO... SUMMARY OF 900 AM CST...1500 UTC...INFORMATION ---------------------------------------------- LOCATION...18.1N 103.0W ABOUT 55 MI...85 KM W OF LAZARO CARDENAS MEXICO ABOUT 105 MI...170 KM SE OF MANZANILLO MEXICO MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H PRESENT MOVEMENT...NNW OR 330 DEGREES AT 3 MPH...6 KM/H MINIMUM CENTRAL PRESSURE...993 MB...29.33 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Punta Maldonado to Manzanillo A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case within the next 12 hours. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 900 AM CST (1500 UTC), the center of Tropical Storm John was located near latitude 18.1 North, longitude 103.0 West. John is moving toward the north-northwest near 3 mph (6 km/h) and this motion is expected to continue through today. On the forecast track, the center of John is forecast to move along the coast or just inland of southwestern Mexico later today and tonight. Maximum sustained winds have decreased to near 60 mph (95 km/h) with higher gusts. Gradual weakening is expected today, with a faster rate of weakening forecast by tonight while the center begins to interact with the higher terrain of southwestern Mexico. Tropical-storm-force winds extend outward up to 160 miles (260 km) from the center. The estimated minimum central pressure is 993 mb (29.33 inches). HAZARDS AFFECTING LAND ---------------------- RAINFALL: Through Saturday, Tropical Storm John is expected to produce additional rainfall amounts of 4 to 8 inches with locally over 10 inches across portions of the Mexican States of Guerrero and Michoacán. Additional rainfall of 2 to 4 inches with locally over 6 inches are expected today across the Mexican States of Colima and western Oaxaca.the Sierra Madre Del Sur mountains For a complete depiction of forecast rainfall associated with John, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_ep5.shtml?rainqpf STORM SURGE: Storm surge is likely to produce coastal flooding near and to the east of where the center makes landfall. Near the coast, the surge will be accompanied by large waves. WIND: Tropical storm conditions are expected to continue across coastal portions of the Tropical Storm Warning area through today. SURF: Swells associated with John are forecast to continue to affect the coast of southern and southwestern Mexico through tonight into Saturday, with the potential for dangerous surf and rip currents. Please see local statements for more information. NEXT ADVISORY ------------- Next intermediate advisory at 1200 PM CST. Next complete advisory at 300 PM CST. $$ Forecaster Kelly NNNN

WW 0688 Status Updates
STATUS REPORT ON WW 688 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 ENE CHS TO 15 WNW FAY TO 20 NNW GSO. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2124. ..GRAMS..09/27/24 ATTN...WFO...RAH...MHX...AKQ...ILM...GSP...RNK...CAE... STATUS REPORT FOR WT 688 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC001-013-015-017-019-029-031-033-037-041-047-049-051-053-055- 061-063-065-069-073-077-079-081-083-085-091-095-101-103-105-107- 117-127-129-131-133-135-137-139-141-143-145-147-155-157-163-169- 177-181-183-185-187-191-195-271540- NC . NORTH CAROLINA COUNTIES INCLUDED ARE ALAMANCE BEAUFORT BERTIE BLADEN BRUNSWICK CAMDEN CARTERET CASWELL CHATHAM CHOWAN COLUMBUS CRAVEN CUMBERLAND CURRITUCK DARE DUPLIN DURHAM EDGECOMBE FRANKLIN GATES GRANVILLE GREENE GUILFORD HALIFAX HARNETT HERTFORD HYDE JOHNSTON JONES LEE LENOIR MARTIN NASH NEW HANOVER NORTHAMPTON ONSLOW ORANGE PAMLICO PASQUOTANK PENDER PERQUIMANS PERSON PITT ROBESON ROCKINGHAM Read more

WW 0688 Status Updates
STATUS REPORT ON WW 688 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 ENE CHS TO 25 WSW SOP TO 5 NE CLT. ..GRAMS..09/27/24 ATTN...WFO...RAH...MHX...AKQ...ILM...GSP...RNK...CAE... STATUS REPORT FOR WT 688 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC001-013-015-017-019-025-029-031-033-037-041-047-049-051-053- 055-057-059-061-063-065-067-069-073-077-079-081-083-085-091-093- 095-101-103-105-107-117-119-123-125-127-129-131-133-135-137-139- 141-143-145-147-151-153-155-157-159-163-165-167-169-171-177-181- 183-185-187-191-195-197-271440- NC . NORTH CAROLINA COUNTIES INCLUDED ARE ALAMANCE BEAUFORT BERTIE BLADEN BRUNSWICK CABARRUS CAMDEN CARTERET CASWELL CHATHAM CHOWAN COLUMBUS CRAVEN CUMBERLAND CURRITUCK DARE DAVIDSON DAVIE DUPLIN DURHAM EDGECOMBE FORSYTH FRANKLIN GATES GRANVILLE GREENE GUILFORD HALIFAX HARNETT HERTFORD HOKE HYDE JOHNSTON JONES LEE LENOIR MARTIN MECKLENBURG MONTGOMERY MOORE NASH NEW HANOVER NORTHAMPTON ONSLOW ORANGE PAMLICO PASQUOTANK PENDER Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Fri Sep 27 2024 Valid 271300Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERNMOST SOUTH CAROLINA OVER PORTIONS OF SOUTHERN/EASTERN NORTH CAROLINA... ...SUMMARY... Tornadoes will be most likely through midday and remain possible into afternoon across parts of the Carolinas and Virginia. ...Synopsis... In mid/upper levels, a zonal to west-southwesterly belt of flow will persist from the northwestern CONUS and western Canada into central Canada, well-removed from a cut-off, cold-core low now evident in moisture-channel imagery over northern MS. This low is expected to pivot slowly northeastward into middle TN by 00Z, then wobble erratically over that area and/or south-central KY through the night as it absorbs the remnant vorticity max from what is now Tropical Storm Helene. ...SC/NC/VA... The path of center of Tropical Storm Helene finally has turned northward. See SPC Tornado watch 688 and associated mesoscale discussions for near-term coverage of the tornado threat over the region. Refer to NHC advisories for the latest track/intensity guidance on Helene. The NHC forecast shows that the center should bend northwestward across southwestern NC, eastern TN and into southern KY through tonight, weakening greatly and becoming more closely conjoined with the mid/upper cyclone. For several more hours, into at least midday, a broad area of strong low-level flow above the surface, and related large low-level shear/hodographs, should extend well east and northeast of center across the outlook area, superimposed over: 1. Relatively maximized low-level convergence, in an arc initially located over eastern SC into southern NC, preceded by well-backed surface winds, and forecast to shift northward to northeastward today; 2. A richly moist, high-theta-e and weak-MLCINH boundary layer advecting inland from the Atlantic and characterized by surface dewpoints commonly in the 70s F. These conditions will yield a favorable environment for tornadoes from any supercells that can cross it, whether within or ahead of the main spiral/convergence band. The most probable area for several supercells to interact with this favorable airmass is over the 10%/"enhanced" tornado-risk area, with potential decreasing westward and northward from there due to weaker instability. Although the supportive low-level airmass will continue to shift northeastward over eastern NC and south-central/southeastern VA this afternoon, tornado potential will diminish with time from midafternoon into early evening. This will occur as convection decreases in coverage and intensity across the area due to a combination of weakening lift and shear, as the remnants of Helene decay rapidly and back well westward away from the area. This process will decouple the remaining stronger low-level flow and isallobaric forcing away from the most-favorable boundary layer near the coast, where hodographs should shrink by the hour this afternoon into evening. ..Edwards/Broyles.. 09/27/2024 Read more

WW 0688 Status Updates
STATUS REPORT ON WW 688 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..BROYLES..09/27/24 ATTN...WFO...RAH...MHX...AKQ...ILM...GSP...RNK...CAE... STATUS REPORT FOR WT 688 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC001-007-013-015-017-019-025-029-031-033-037-041-047-049-051- 053-055-057-059-061-063-065-067-069-073-077-079-081-083-085-091- 093-095-101-103-105-107-117-119-123-125-127-129-131-133-135-137- 139-141-143-145-147-151-153-155-157-159-163-165-167-169-171-177- 179-181-183-185-187-191-195-197-271340- NC . NORTH CAROLINA COUNTIES INCLUDED ARE ALAMANCE ANSON BEAUFORT BERTIE BLADEN BRUNSWICK CABARRUS CAMDEN CARTERET CASWELL CHATHAM CHOWAN COLUMBUS CRAVEN CUMBERLAND CURRITUCK DARE DAVIDSON DAVIE DUPLIN DURHAM EDGECOMBE FORSYTH FRANKLIN GATES GRANVILLE GREENE GUILFORD HALIFAX HARNETT HERTFORD HOKE HYDE JOHNSTON JONES LEE LENOIR MARTIN MECKLENBURG MONTGOMERY MOORE NASH NEW HANOVER NORTHAMPTON ONSLOW ORANGE PAMLICO PASQUOTANK PENDER PERQUIMANS PERSON Read more

No watches are valid as of Fri Sep 27 12:02:02 UTC 2024.