Tropical Storm John Public Advisory Number 8A

9 months 4 weeks ago
Issued at 600 AM CST Tue Sep 24 2024 000 WTPZ35 KNHC 241146 TCPEP5 BULLETIN Tropical Storm John Intermediate Advisory Number 8A NWS National Hurricane Center Miami FL EP102024 600 AM CST Tue Sep 24 2024 ...LIFE-THREATENING FLASH FLOODING POSSIBLE ACROSS PORTIONS OF SOUTHERN MEXICO DURING THE NEXT FEW DAYS... SUMMARY OF 600 AM CST...1200 UTC...INFORMATION ---------------------------------------------- LOCATION...17.7N 100.3W ABOUT 60 MI...100 KM NNW OF ACAPULCO MEXICO MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...NW OR 305 DEGREES AT 8 MPH...13 KM/H MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Mexico has adjusted the Tropical Storm Warning westward from Punta Maldonado to Zihuatanejo. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Punta Maldonado to Zihuatanejo A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case over the next few hours. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 600 AM CST (1200 UTC), the center of Tropical Storm John was located near latitude 17.7 North, longitude 100.3 West. John is moving toward the northwest near 8 mph (13 km/h). A slow westward motion is expected during the next few days. Maximum sustained winds are near 50 mph (85 km/h) with higher gusts. Continued rapid weakening is anticipated, and John is expected to become a tropical depression later today. Tropical-storm-force winds extend outward up to 45 miles (75 km) from the center. The estimated minimum central pressure is 999 mb (29.50 inches). HAZARDS AFFECTING LAND ---------------------- Key Messages for John can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP5 and WMO header WTPZ45 KNHC and on the web at hurricanes.gov/text/MIATCDEP5.shtml RAINFALL: Through Thursday, Tropical Storm John is expected to produce 6 to 12 inches of rain with isolated totals around 15 inches across the coastal areas of Chiapas. In areas along and near the Oaxaca coast to southeast Guerrero, between 10 and 20 inches of rain with isolated totals near 30 inches can be expected through Thursday. For a complete depiction of forecast rainfall associated with Tropical Storm John, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_ep5.shtml?rainqpf WIND: Tropical storm conditions are ongoing within portions of the tropical storm warning area and should continue for the next few hours. Wind speeds atop and on the windward sides of hills and mountains are often up to 30 percent stronger than the near-surface winds indicated in this advisory, and in some elevated locations could be even greater. SURF: Swells associated with John are forecast to continue affecting the coast of southern Mexico during the next day or so, with the potential for dangerous surf and rip currents. Please see local statements for more information. NEXT ADVISORY ------------- Next complete advisory at 900 AM CST. $$ Forecaster Cangialosi
NHC Webmaster

Tropical Storm John Forecast Discussion Number 8

9 months 4 weeks ago
Issued at 300 AM CST Tue Sep 24 2024 523 WTPZ45 KNHC 240852 TCDEP5 Tropical Storm John Discussion Number 8 NWS National Hurricane Center Miami FL EP102024 300 AM CST Tue Sep 24 2024 John moved inland at around 0315 UTC as a 105 kt Category 3 Hurricane. Since that time, the the storm has apparently turned more leftward and remains just inland, skirting the southern coast of Mexico. While surface observations have been sparse, my best guess is that the storm recently passed just to the north of Acapulco, where the airport earlier reported tropical-storm-force wind gusts and west winds as the pressure dropped to 998 mb. Assuming the small core has continued to quickly weaken, John is being downgraded to a tropical storm, and the initial intensity is 60 kt this advisory. Following fixes from earlier microwave and more recent geostationary satellite imagery, John now appears to be moving northwestward at 310/7 kt. The track forecast, which has been problematic with John from the start, is just as difficult now. John has continued to deviate westward of the previous forecast track and is now moving roughly parallel to the coast of Mexico. To make matters worse, a decent chunk of the of the global models guidance (ECMWF, UKMET) and hurricane regional models (HWRF, HMON) suggest the circulation could continue turning westward and attempt to re-emerge over the Eastern Pacific. Even the GFS and CMC solutions, which appear to dissipate the surface circulation inland over Mexico, show the mid-level circulation persisting and drifting back offshore, leading to the development of a new low-level circulation. Because it is becoming distinctly possible that John does not move far enough inland to dissipate entirely, and the aforementioned continued leftward trends, the latest NHC track forecast is altered quite a bit form the prior forecast, and now shows the possibility that John, albeit as a tropical depression, moving back offshore as it becomes tangled in the larger monsoonal flow. By 72 h, most of the track guidance shows the system moving back inland. The updated track forecast is roughly in between the HCCA and ECMWF trackers, and is of very low confidence given John's track history. It also remains possible the system could dissipate later today if it moves further inland. Intensity-wise, John should continue to rapidly weaken as long as it remains onshore, and the NHC intensity forecast shows the tropical cyclone weakening to a tropical depression later today. However, the new NHC forecast now maintains the system as a depression and does not show dissipation beyond 24 h given the latest track forecast taking the system along the coast of Mexico and not far enough inland to completely dissipate. Some of the models (notably the ECMWF) attempt to also re-intensify John as it gets far enough back offshore, but given the large changes made on this forecast cycle, the NHC intensity will not show that solution quite yet. Even if John remains inland, larger-scale moist monsoonal southeasterly flow will persist along the southern coast of Mexico, likely contributing to catastrophic rainfall both along the coast and inland over the up-slope portion of the mountainous terrain. This is a very dangerous life-threatening flooding scenario. KEY MESSAGES: 1. Tropical Storm John could still producing tropical storm conditions for the next few hours in the tropical storm warning area. 2. Slow-moving John will bring very heavy rainfall to coastal portions of southwest Mexico through the upcoming week. This heavy rainfall will likely cause significant and possibly catastrophic, life-threatening flash flooding and mudslides to the Mexican States of Chiapas, Oaxaca, and southeast Guerrero, particularly in areas near the coast and along the up-slope portion of areas of higher terrain. FORECAST POSITIONS AND MAX WINDS INIT 24/0900Z 17.3N 100.0W 60 KT 70 MPH...INLAND 12H 24/1800Z 17.4N 100.8W 30 KT 35 MPH...INLAND 24H 25/0600Z 17.0N 101.0W 30 KT 35 MPH...OVER WATER 36H 25/1800Z 16.7N 100.9W 30 KT 35 MPH 48H 26/0600Z 16.9N 100.6W 30 KT 35 MPH 60H 26/1800Z 17.4N 100.7W 25 KT 30 MPH...INLAND 72H 27/0600Z 18.1N 101.3W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 28/0600Z...DISSIPATED $$ Forecaster Papin
NHC Webmaster

Tropical Storm John Wind Speed Probabilities Number 8

9 months 4 weeks ago
Issued at 0900 UTC TUE SEP 24 2024 000 FOPZ15 KNHC 240850 PWSEP5 TROPICAL STORM JOHN WIND SPEED PROBABILITIES NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102024 0900 UTC TUE SEP 24 2024 AT 0900Z THE CENTER OF TROPICAL STORM JOHN WAS LOCATED NEAR LATITUDE 17.3 NORTH...LONGITUDE 100.0 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 60 KTS...70 MPH...110 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 06Z TUE 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 TUE 18Z TUE 06Z WED 18Z WED 06Z THU 06Z FRI 06Z SAT PERIODS TO TO TO TO TO TO TO 18Z TUE 06Z WED 18Z WED 06Z THU 06Z FRI 06Z SAT 06Z SUN FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT ZIHUATANEJO 34 1 2( 3) 1( 4) 1( 5) 1( 6) X( 6) X( 6) ACAPULCO 34 99 X(99) X(99) X(99) X(99) X(99) X(99) ACAPULCO 50 66 X(66) X(66) 1(67) X(67) X(67) X(67) $$ FORECASTER PAPIN
NHC Webmaster

Summary for Tropical Storm John (EP5/EP102024)

9 months 4 weeks ago
...JOHN NOW A TROPICAL STORM AND MOVING NORTHWESTWARD... ...LIFE-THREATENING FLASH FLOODING TO CONTINUE ALONG SOUTHERN MEXICAN COAST FOR THE NEXT FEW DAYS... As of 3:00 AM CST Tue Sep 24 the center of John was located near 17.3, -100.0 with movement NW at 8 mph. The minimum central pressure was 990 mb with maximum sustained winds of about 70 mph.
NHC Webmaster

Tropical Storm John Public Advisory Number 8

9 months 4 weeks ago
Issued at 300 AM CST Tue Sep 24 2024 000 WTPZ35 KNHC 240850 TCPEP5 BULLETIN Tropical Storm John Advisory Number 8 NWS National Hurricane Center Miami FL EP102024 300 AM CST Tue Sep 24 2024 ...JOHN NOW A TROPICAL STORM AND MOVING NORTHWESTWARD... ...LIFE-THREATENING FLASH FLOODING TO CONTINUE ALONG SOUTHERN MEXICAN COAST FOR THE NEXT FEW DAYS... SUMMARY OF 300 AM CST...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...17.3N 100.0W ABOUT 115 MI...185 KM NW OF PUNTA MALDONADO MEXICO ABOUT 30 MI...45 KM NNW OF ACAPULCO MEXICO MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 8 MPH...13 KM/H MINIMUM CENTRAL PRESSURE...990 MB...29.24 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Mexico has changed the the Hurricane Warning from east of Acapulco to Lagunas de Chacahua to a Tropical Storm Warning. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * East of Acapulco to Lagunas de Chacahua A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case over the next few hours. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 300 AM CST (0900 UTC), the center of Tropical Storm John was located near latitude 17.3 North, longitude 100.0 West. John is moving toward the northwest near 8 mph (13 km/h). A very slow motion westward followed by very little motion is forecasted over the next several days. Maximum sustained winds are near 70 mph (110 km/h) with higher gusts. Additional rapid weakening is anticipated, and John is expected to become a tropical depression later today. Tropical-storm-force winds extend outward up to 45 miles (75 km) from the center. The estimated minimum central pressure is 990 mb (29.24 inches). HAZARDS AFFECTING LAND ---------------------- Key Messages for John can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP5 and WMO header WTPZ45 KNHC and on the web at hurricanes.gov/text/MIATCDEP5.shtml RAINFALL: Through Thursday, Hurricane John is expected to produce 6 to 12 inches of rain with isolated totals around 15 inches across the coastal areas of Chiapas. In areas along and near the Oaxaca coast to southeast Guerrero, between 10 and 20 inches of rain with isolated totals near 30 inches can be expected through Thursday. For a complete depiction of forecast rainfall associated with Hurricane John, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_ep5.shtml?rainqpf WIND: Tropical Storm conditions are ongoing within portions of the tropical storm warning area and should continue for the next few hours. Wind speeds atop and on the windward sides of hills and mountains are often up to 30 percent stronger than the near-surface winds indicated in this advisory, and in some elevated locations could be even greater. SURF: Swells associated with John are forecast to continue affecting the coast of southern Mexico during the next couple of days, with the potential for dangerous surf and rip currents much of the week. Please see local statements for more information. NEXT ADVISORY ------------- Next intermediate advisory at 600 AM CST. Next complete advisory at 900 AM CST. $$ Forecaster Papin
NHC Webmaster

Tropical Storm John Forecast Advisory Number 8

9 months 4 weeks ago
Issued at 0900 UTC TUE SEP 24 2024 000 WTPZ25 KNHC 240849 TCMEP5 TROPICAL STORM JOHN FORECAST/ADVISORY NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102024 0900 UTC TUE SEP 24 2024 TROPICAL STORM CENTER LOCATED NEAR 17.3N 100.0W AT 24/0900Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 310 DEGREES AT 7 KT ESTIMATED MINIMUM CENTRAL PRESSURE 990 MB MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT. 50 KT....... 0NE 20SE 20SW 0NW. 34 KT....... 30NE 40SE 40SW 30NW. 12 FT SEAS.. 10NE 90SE 60SW 10NW. 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 17.3N 100.0W AT 24/0900Z AT 24/0600Z CENTER WAS LOCATED NEAR 16.9N 99.3W FORECAST VALID 24/1800Z 17.4N 100.8W...INLAND MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 25/0600Z 17.0N 101.0W...OVER WATER MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 25/1800Z 16.7N 100.9W MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 26/0600Z 16.9N 100.6W MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 26/1800Z 17.4N 100.7W...INLAND MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 27/0600Z 18.1N 101.3W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 100 NM ON DAY 4 AND 125 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 28/0600Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 17.3N 100.0W INTERMEDIATE PUBLIC ADVISORY...WTNT35 KNHC/MIATCPEP5...AT 24/1200Z NEXT ADVISORY AT 24/1500Z $$ FORECASTER PAPIN
NHC Webmaster

SPC Sep 24, 2024 Day 4-8 Severe Weather Outlook

9 months 4 weeks ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0250 AM CDT Tue Sep 24 2024 Valid 271200Z - 021200Z ...DISCUSSION... A low-end tropical cyclone related tornado risk may continue into Day 4/Fri from parts of the Southeast toward the central Appalachian vicinity. However, spread among medium range guidance is quite large at this time frame regarding the position of the remnant tropical cyclone. Beyond Day 4/Fri, medium range guidance generally maintains an closed upper cyclone across the broader Mid-South and Ohio Valley vicinity through Day 6/Sun before this feature weakens and an open wave trough evolves and progresses east toward the Atlantic coast through early next week. Meanwhile, upper ridging will persist across much of the western half of the CONUS. Overall, severe potential beyond Day 4/Fri appears low given areas of widespread precipitation and cloudiness, along with limited instability and weakening deep-layer flow with time. Read more

SPC Sep 24, 2024 Day 4-8 Severe Weather Outlook

9 months 4 weeks ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0250 AM CDT Tue Sep 24 2024 Valid 271200Z - 021200Z ...DISCUSSION... A low-end tropical cyclone related tornado risk may continue into Day 4/Fri from parts of the Southeast toward the central Appalachian vicinity. However, spread among medium range guidance is quite large at this time frame regarding the position of the remnant tropical cyclone. Beyond Day 4/Fri, medium range guidance generally maintains an closed upper cyclone across the broader Mid-South and Ohio Valley vicinity through Day 6/Sun before this feature weakens and an open wave trough evolves and progresses east toward the Atlantic coast through early next week. Meanwhile, upper ridging will persist across much of the western half of the CONUS. Overall, severe potential beyond Day 4/Fri appears low given areas of widespread precipitation and cloudiness, along with limited instability and weakening deep-layer flow with time. Read more

SPC Sep 24, 2024 Day 4-8 Severe Weather Outlook

9 months 4 weeks ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0250 AM CDT Tue Sep 24 2024 Valid 271200Z - 021200Z ...DISCUSSION... A low-end tropical cyclone related tornado risk may continue into Day 4/Fri from parts of the Southeast toward the central Appalachian vicinity. However, spread among medium range guidance is quite large at this time frame regarding the position of the remnant tropical cyclone. Beyond Day 4/Fri, medium range guidance generally maintains an closed upper cyclone across the broader Mid-South and Ohio Valley vicinity through Day 6/Sun before this feature weakens and an open wave trough evolves and progresses east toward the Atlantic coast through early next week. Meanwhile, upper ridging will persist across much of the western half of the CONUS. Overall, severe potential beyond Day 4/Fri appears low given areas of widespread precipitation and cloudiness, along with limited instability and weakening deep-layer flow with time. Read more

SPC Sep 24, 2024 Day 4-8 Severe Weather Outlook

9 months 4 weeks ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0250 AM CDT Tue Sep 24 2024 Valid 271200Z - 021200Z ...DISCUSSION... A low-end tropical cyclone related tornado risk may continue into Day 4/Fri from parts of the Southeast toward the central Appalachian vicinity. However, spread among medium range guidance is quite large at this time frame regarding the position of the remnant tropical cyclone. Beyond Day 4/Fri, medium range guidance generally maintains an closed upper cyclone across the broader Mid-South and Ohio Valley vicinity through Day 6/Sun before this feature weakens and an open wave trough evolves and progresses east toward the Atlantic coast through early next week. Meanwhile, upper ridging will persist across much of the western half of the CONUS. Overall, severe potential beyond Day 4/Fri appears low given areas of widespread precipitation and cloudiness, along with limited instability and weakening deep-layer flow with time. Read more

SPC Sep 24, 2024 Day 4-8 Severe Weather Outlook

9 months 4 weeks ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0250 AM CDT Tue Sep 24 2024 Valid 271200Z - 021200Z ...DISCUSSION... A low-end tropical cyclone related tornado risk may continue into Day 4/Fri from parts of the Southeast toward the central Appalachian vicinity. However, spread among medium range guidance is quite large at this time frame regarding the position of the remnant tropical cyclone. Beyond Day 4/Fri, medium range guidance generally maintains an closed upper cyclone across the broader Mid-South and Ohio Valley vicinity through Day 6/Sun before this feature weakens and an open wave trough evolves and progresses east toward the Atlantic coast through early next week. Meanwhile, upper ridging will persist across much of the western half of the CONUS. Overall, severe potential beyond Day 4/Fri appears low given areas of widespread precipitation and cloudiness, along with limited instability and weakening deep-layer flow with time. Read more

SPC Sep 24, 2024 Day 4-8 Severe Weather Outlook

9 months 4 weeks ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0250 AM CDT Tue Sep 24 2024 Valid 271200Z - 021200Z ...DISCUSSION... A low-end tropical cyclone related tornado risk may continue into Day 4/Fri from parts of the Southeast toward the central Appalachian vicinity. However, spread among medium range guidance is quite large at this time frame regarding the position of the remnant tropical cyclone. Beyond Day 4/Fri, medium range guidance generally maintains an closed upper cyclone across the broader Mid-South and Ohio Valley vicinity through Day 6/Sun before this feature weakens and an open wave trough evolves and progresses east toward the Atlantic coast through early next week. Meanwhile, upper ridging will persist across much of the western half of the CONUS. Overall, severe potential beyond Day 4/Fri appears low given areas of widespread precipitation and cloudiness, along with limited instability and weakening deep-layer flow with time. Read more

SPC MD 2099

9 months 4 weeks ago
MD 2099 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR KENTUCKY...FAR SOUTHEAST ILLINOIS...FAR SOUTHERN INDIANA
Mesoscale Discussion 2099 NWS Storm Prediction Center Norman OK 1256 AM CDT Tue Sep 24 2024 Areas affected...Kentucky...Far Southeast Illinois...Far Southern Indiana Concerning...Severe potential...Watch unlikely Valid 240556Z - 240830Z Probability of Watch Issuance...5 percent SUMMARY...An isolated severe threat will continue across the Ohio Valley over the next several hours. A severe wind gust, or a brief tornado will be possible. The severe threat is expected to remain marginal, and watch issuance appears unlikely. DISCUSSION...The latest water vapor imagery shows a mid-level shortwave trough moving into the Ozarks. A distinct vorticity max is evident on mosaic radar as an MCV in far southeast Missouri. Thunderstorms are ongoing from near the MCV extending northeastward into southern Illinois and southern Indiana, near a maximum in warm air advection. Surface dewpoints in the lower Ohio Valley are in the upper 60s F, and the RAP has MLCAPE up to 750 J/kg in the vicinity of Evansville, Indiana. The WSR-88D VWP at Louisville has 0-6 km shear around 45 knots, with 0-3 km storm-relative helicity around 175 m2/s2. Directional shear is confined mostly to the lowest 1 kilometer. This wind profile should be enough for transient supercell structure. Any tornado that forms would likely be brief. An isolated severe gust will also be possible, especially if any of the cells can obtain a bowing structure. ..Broyles/Smith.. 09/24/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILN...LMK...IND...PAH... LAT...LON 38588746 37968858 37498899 37138902 36918858 36898743 36918552 37288477 38038439 38578496 38708635 38588746 Read more

SPC Sep 24, 2024 0730 UTC Day 3 Severe Thunderstorm Outlook

9 months 4 weeks ago
SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0207 AM CDT Tue Sep 24 2024 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NORTHERN FLORIDA INTO GEORGIA... ...SUMMARY... A tropical cyclone is forecast to move inland across northern Florida and Georgia on Thursday. A risk for tropical cyclone related tornadoes will accompany convection within the outer bands. ...FL/GA vicinity... A broad Marginal risk (level 1 of 5) has been delineated for parts of northern FL into GA as a tropical cyclone is forecast by the National Hurricane Center to move inland Thursday evening into early Friday. Southeasterly flow will increase over the region in response to the northerly moving hurricane. While exact track, size, and intensity of the storm is still somewhat uncertain, the favored eastern semi-circle of the storm should bring some risk for tornadoes to portions of the area. Forecast soundings indicated low to mid 70s F dewpoints amid strong low-level shear and sufficient instability to support rotation within low-top supercells associated with the outer bands of the tropical system. The outlook area may need to be refined in subsequent forecasts as storm track and evolution of convective bands becomes more certain, but inclusion of low-end probabilities appears prudent based on trends the past few model cycles. Reference the National Hurricane Center forecast for further details related to this potential tropical cyclone. ..Leitman.. 09/24/2024 Read more

SPC Sep 24, 2024 0730 UTC Day 3 Severe Thunderstorm Outlook

9 months 4 weeks ago
SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0207 AM CDT Tue Sep 24 2024 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NORTHERN FLORIDA INTO GEORGIA... ...SUMMARY... A tropical cyclone is forecast to move inland across northern Florida and Georgia on Thursday. A risk for tropical cyclone related tornadoes will accompany convection within the outer bands. ...FL/GA vicinity... A broad Marginal risk (level 1 of 5) has been delineated for parts of northern FL into GA as a tropical cyclone is forecast by the National Hurricane Center to move inland Thursday evening into early Friday. Southeasterly flow will increase over the region in response to the northerly moving hurricane. While exact track, size, and intensity of the storm is still somewhat uncertain, the favored eastern semi-circle of the storm should bring some risk for tornadoes to portions of the area. Forecast soundings indicated low to mid 70s F dewpoints amid strong low-level shear and sufficient instability to support rotation within low-top supercells associated with the outer bands of the tropical system. The outlook area may need to be refined in subsequent forecasts as storm track and evolution of convective bands becomes more certain, but inclusion of low-end probabilities appears prudent based on trends the past few model cycles. Reference the National Hurricane Center forecast for further details related to this potential tropical cyclone. ..Leitman.. 09/24/2024 Read more

SPC Sep 24, 2024 0730 UTC Day 3 Severe Thunderstorm Outlook

9 months 4 weeks ago
SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0207 AM CDT Tue Sep 24 2024 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NORTHERN FLORIDA INTO GEORGIA... ...SUMMARY... A tropical cyclone is forecast to move inland across northern Florida and Georgia on Thursday. A risk for tropical cyclone related tornadoes will accompany convection within the outer bands. ...FL/GA vicinity... A broad Marginal risk (level 1 of 5) has been delineated for parts of northern FL into GA as a tropical cyclone is forecast by the National Hurricane Center to move inland Thursday evening into early Friday. Southeasterly flow will increase over the region in response to the northerly moving hurricane. While exact track, size, and intensity of the storm is still somewhat uncertain, the favored eastern semi-circle of the storm should bring some risk for tornadoes to portions of the area. Forecast soundings indicated low to mid 70s F dewpoints amid strong low-level shear and sufficient instability to support rotation within low-top supercells associated with the outer bands of the tropical system. The outlook area may need to be refined in subsequent forecasts as storm track and evolution of convective bands becomes more certain, but inclusion of low-end probabilities appears prudent based on trends the past few model cycles. Reference the National Hurricane Center forecast for further details related to this potential tropical cyclone. ..Leitman.. 09/24/2024 Read more

SPC Sep 24, 2024 0730 UTC Day 3 Severe Thunderstorm Outlook

9 months 4 weeks ago
SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0207 AM CDT Tue Sep 24 2024 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NORTHERN FLORIDA INTO GEORGIA... ...SUMMARY... A tropical cyclone is forecast to move inland across northern Florida and Georgia on Thursday. A risk for tropical cyclone related tornadoes will accompany convection within the outer bands. ...FL/GA vicinity... A broad Marginal risk (level 1 of 5) has been delineated for parts of northern FL into GA as a tropical cyclone is forecast by the National Hurricane Center to move inland Thursday evening into early Friday. Southeasterly flow will increase over the region in response to the northerly moving hurricane. While exact track, size, and intensity of the storm is still somewhat uncertain, the favored eastern semi-circle of the storm should bring some risk for tornadoes to portions of the area. Forecast soundings indicated low to mid 70s F dewpoints amid strong low-level shear and sufficient instability to support rotation within low-top supercells associated with the outer bands of the tropical system. The outlook area may need to be refined in subsequent forecasts as storm track and evolution of convective bands becomes more certain, but inclusion of low-end probabilities appears prudent based on trends the past few model cycles. Reference the National Hurricane Center forecast for further details related to this potential tropical cyclone. ..Leitman.. 09/24/2024 Read more