Aggregator

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0252 AM CDT Sat Sep 21 2024 Valid 241200Z - 291200Z ...DISCUSSION... Forecast confidence is low during the Day 4-8 period as large spread is evident across medium range forecast guidance. Some low-end severe potential (sub-15 percent) may continue into Day 4/Tuesday over parts of the OH/TN Valleys and adjacent Appalachians as a surface cold front continue to progress east amid modest mid/upper level southwesterly flow. Thereafter, guidance suggests a cut-off upper low will develop over some part of the central section of the CONUS, though confidence is the evolution of this feature is low. Despite this uncertainty, severe potential appears low beyond Day 4/Tuesday given prior cold frontal passage and limited Gulf return flow. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0158 AM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... No fire weather concerns are expected on Sunday. A cool post-frontal air mass is expected across the Plains with potential for widespread precipitation. Dry conditions will continue across the southwestern US. As the upper low moves eastward across the Rockies, winds will also decrease with cooler temperatures expected across the region which will aid in keeping fire weather concerns low. ..Thornton.. 09/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0158 AM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... No fire weather concerns are expected on Sunday. A cool post-frontal air mass is expected across the Plains with potential for widespread precipitation. Dry conditions will continue across the southwestern US. As the upper low moves eastward across the Rockies, winds will also decrease with cooler temperatures expected across the region which will aid in keeping fire weather concerns low. ..Thornton.. 09/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0158 AM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... No fire weather concerns are expected on Sunday. A cool post-frontal air mass is expected across the Plains with potential for widespread precipitation. Dry conditions will continue across the southwestern US. As the upper low moves eastward across the Rockies, winds will also decrease with cooler temperatures expected across the region which will aid in keeping fire weather concerns low. ..Thornton.. 09/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0158 AM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... No fire weather concerns are expected on Sunday. A cool post-frontal air mass is expected across the Plains with potential for widespread precipitation. Dry conditions will continue across the southwestern US. As the upper low moves eastward across the Rockies, winds will also decrease with cooler temperatures expected across the region which will aid in keeping fire weather concerns low. ..Thornton.. 09/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0158 AM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... No fire weather concerns are expected on Sunday. A cool post-frontal air mass is expected across the Plains with potential for widespread precipitation. Dry conditions will continue across the southwestern US. As the upper low moves eastward across the Rockies, winds will also decrease with cooler temperatures expected across the region which will aid in keeping fire weather concerns low. ..Thornton.. 09/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Sat Sep 21 2024 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Fire weather concerns will remain low across the CONUS today as a cold front brings cooler temperatures and increasing precipitation chances across much of the central/northern Plains. Brief periods of Elevated fire weather concerns will be possible across portions of New Mexico as enhanced mid-level flow rounds the western US upper low. In this region, relative humidity reductions to 15-20 percent will briefly overlap winds around 15-20 mph. Fuels across this region remain unsupportive of large-fire spread at this time with potential for additional rainfall from thunderstorm activity on Saturday. As such, no areas were included with this outlook. ..Thornton.. 09/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Sat Sep 21 2024 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Fire weather concerns will remain low across the CONUS today as a cold front brings cooler temperatures and increasing precipitation chances across much of the central/northern Plains. Brief periods of Elevated fire weather concerns will be possible across portions of New Mexico as enhanced mid-level flow rounds the western US upper low. In this region, relative humidity reductions to 15-20 percent will briefly overlap winds around 15-20 mph. Fuels across this region remain unsupportive of large-fire spread at this time with potential for additional rainfall from thunderstorm activity on Saturday. As such, no areas were included with this outlook. ..Thornton.. 09/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Sat Sep 21 2024 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Fire weather concerns will remain low across the CONUS today as a cold front brings cooler temperatures and increasing precipitation chances across much of the central/northern Plains. Brief periods of Elevated fire weather concerns will be possible across portions of New Mexico as enhanced mid-level flow rounds the western US upper low. In this region, relative humidity reductions to 15-20 percent will briefly overlap winds around 15-20 mph. Fuels across this region remain unsupportive of large-fire spread at this time with potential for additional rainfall from thunderstorm activity on Saturday. As such, no areas were included with this outlook. ..Thornton.. 09/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Sat Sep 21 2024 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Fire weather concerns will remain low across the CONUS today as a cold front brings cooler temperatures and increasing precipitation chances across much of the central/northern Plains. Brief periods of Elevated fire weather concerns will be possible across portions of New Mexico as enhanced mid-level flow rounds the western US upper low. In this region, relative humidity reductions to 15-20 percent will briefly overlap winds around 15-20 mph. Fuels across this region remain unsupportive of large-fire spread at this time with potential for additional rainfall from thunderstorm activity on Saturday. As such, no areas were included with this outlook. ..Thornton.. 09/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Sat Sep 21 2024 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Fire weather concerns will remain low across the CONUS today as a cold front brings cooler temperatures and increasing precipitation chances across much of the central/northern Plains. Brief periods of Elevated fire weather concerns will be possible across portions of New Mexico as enhanced mid-level flow rounds the western US upper low. In this region, relative humidity reductions to 15-20 percent will briefly overlap winds around 15-20 mph. Fuels across this region remain unsupportive of large-fire spread at this time with potential for additional rainfall from thunderstorm activity on Saturday. As such, no areas were included with this outlook. ..Thornton.. 09/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0149 AM CDT Sat Sep 21 2024 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE OHIO VALLEY AND MID-SOUTH... ...SUMMARY... Isolated strong to severe thunderstorms are possible across the Ohio Valley and Mid-South region on Monday. ...Ohio Valley and Mid-South vicinity... An upper shortwave trough over the Mid-MS Valley will become absorbed within a larger-scale trough shifting east across the Plains on Monday. A belt of enhanced mid/upper level southwesterly flow will overspread the Ohio Valley/Mid-South vicinity through much of the period. At the surface, a cold front will develop south and east across the Ohio and the Mid/Lower MS Valley area. A seasonally moist airmass characterized by 60s F dewpoints will be in place ahead of the front. Areas of precipitation and cloud cover are likely from MO through the Ohio Valley early in the period, resulting in forecast uncertainty. Nevertheless, enhanced midlevel flow overspreading a moist airmass ahead of a cold front should support some risk for severe thunderstorms where greater destabilization occurs. Locally damaging gusts and hail appear to be the most likely concerns with the strongest convection Monday afternoon into the evening. ..Leitman.. 09/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0149 AM CDT Sat Sep 21 2024 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE OHIO VALLEY AND MID-SOUTH... ...SUMMARY... Isolated strong to severe thunderstorms are possible across the Ohio Valley and Mid-South region on Monday. ...Ohio Valley and Mid-South vicinity... An upper shortwave trough over the Mid-MS Valley will become absorbed within a larger-scale trough shifting east across the Plains on Monday. A belt of enhanced mid/upper level southwesterly flow will overspread the Ohio Valley/Mid-South vicinity through much of the period. At the surface, a cold front will develop south and east across the Ohio and the Mid/Lower MS Valley area. A seasonally moist airmass characterized by 60s F dewpoints will be in place ahead of the front. Areas of precipitation and cloud cover are likely from MO through the Ohio Valley early in the period, resulting in forecast uncertainty. Nevertheless, enhanced midlevel flow overspreading a moist airmass ahead of a cold front should support some risk for severe thunderstorms where greater destabilization occurs. Locally damaging gusts and hail appear to be the most likely concerns with the strongest convection Monday afternoon into the evening. ..Leitman.. 09/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0149 AM CDT Sat Sep 21 2024 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE OHIO VALLEY AND MID-SOUTH... ...SUMMARY... Isolated strong to severe thunderstorms are possible across the Ohio Valley and Mid-South region on Monday. ...Ohio Valley and Mid-South vicinity... An upper shortwave trough over the Mid-MS Valley will become absorbed within a larger-scale trough shifting east across the Plains on Monday. A belt of enhanced mid/upper level southwesterly flow will overspread the Ohio Valley/Mid-South vicinity through much of the period. At the surface, a cold front will develop south and east across the Ohio and the Mid/Lower MS Valley area. A seasonally moist airmass characterized by 60s F dewpoints will be in place ahead of the front. Areas of precipitation and cloud cover are likely from MO through the Ohio Valley early in the period, resulting in forecast uncertainty. Nevertheless, enhanced midlevel flow overspreading a moist airmass ahead of a cold front should support some risk for severe thunderstorms where greater destabilization occurs. Locally damaging gusts and hail appear to be the most likely concerns with the strongest convection Monday afternoon into the evening. ..Leitman.. 09/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0149 AM CDT Sat Sep 21 2024 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE OHIO VALLEY AND MID-SOUTH... ...SUMMARY... Isolated strong to severe thunderstorms are possible across the Ohio Valley and Mid-South region on Monday. ...Ohio Valley and Mid-South vicinity... An upper shortwave trough over the Mid-MS Valley will become absorbed within a larger-scale trough shifting east across the Plains on Monday. A belt of enhanced mid/upper level southwesterly flow will overspread the Ohio Valley/Mid-South vicinity through much of the period. At the surface, a cold front will develop south and east across the Ohio and the Mid/Lower MS Valley area. A seasonally moist airmass characterized by 60s F dewpoints will be in place ahead of the front. Areas of precipitation and cloud cover are likely from MO through the Ohio Valley early in the period, resulting in forecast uncertainty. Nevertheless, enhanced midlevel flow overspreading a moist airmass ahead of a cold front should support some risk for severe thunderstorms where greater destabilization occurs. Locally damaging gusts and hail appear to be the most likely concerns with the strongest convection Monday afternoon into the evening. ..Leitman.. 09/21/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 AM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO CENTRAL/SOUTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central/southern Missouri. ...Southern Plains to Mid-MS Valley... Forecast guidance has trended somewhat southward with severe potential on Sunday, and the Marginal risk (level 1 of 5) has been adjusted to reflect latest model trends. An upper shortwave trough over the central/southern Rockies Sunday morning will eject east to the mid-MS Valley by Monday morning. This will bring a belt of 40-50 kt mid/upper southwesterly flow over the region. At the surface, a cold front will develop southeast from near Lake Michigan to northwest Texas at midday to the Ohio Valley and central Texas by 12z Monday. A seasonally moist airmass will be in place ahead of the front, with surface dewpoints in the mid to upper 60s F forecast. Some uncertainty remains in where the corridor of greater strong/severe storm potential will develop, mainly driven by ongoing convection across parts of the region Sunday morning. Nevertheless, where pockets of greater heating occur, favorable vertical shear and increasing forcing from both the surface front and the ejecting midlevel wave, will support organized storm development. Damaging gusts will be the main hazard with thunderstorm clusters and line segments. However, vertical shear may be suitable for a few supercells, especially across west Texas. Isolated large hail will be possible with any more discrete cells that develop and can be maintained ahead of the front. ..Leitman.. 09/21/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 AM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO CENTRAL/SOUTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central/southern Missouri. ...Southern Plains to Mid-MS Valley... Forecast guidance has trended somewhat southward with severe potential on Sunday, and the Marginal risk (level 1 of 5) has been adjusted to reflect latest model trends. An upper shortwave trough over the central/southern Rockies Sunday morning will eject east to the mid-MS Valley by Monday morning. This will bring a belt of 40-50 kt mid/upper southwesterly flow over the region. At the surface, a cold front will develop southeast from near Lake Michigan to northwest Texas at midday to the Ohio Valley and central Texas by 12z Monday. A seasonally moist airmass will be in place ahead of the front, with surface dewpoints in the mid to upper 60s F forecast. Some uncertainty remains in where the corridor of greater strong/severe storm potential will develop, mainly driven by ongoing convection across parts of the region Sunday morning. Nevertheless, where pockets of greater heating occur, favorable vertical shear and increasing forcing from both the surface front and the ejecting midlevel wave, will support organized storm development. Damaging gusts will be the main hazard with thunderstorm clusters and line segments. However, vertical shear may be suitable for a few supercells, especially across west Texas. Isolated large hail will be possible with any more discrete cells that develop and can be maintained ahead of the front. ..Leitman.. 09/21/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1213 AM CDT Sat Sep 21 2024 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WEST TEXAS INTO CENTRAL/SOUTHERN MISSOURI... ...SUMMARY... Isolated severe thunderstorms are possible on Sunday from west Texas to central/southern Missouri. ...Southern Plains to Mid-MS Valley... Forecast guidance has trended somewhat southward with severe potential on Sunday, and the Marginal risk (level 1 of 5) has been adjusted to reflect latest model trends. An upper shortwave trough over the central/southern Rockies Sunday morning will eject east to the mid-MS Valley by Monday morning. This will bring a belt of 40-50 kt mid/upper southwesterly flow over the region. At the surface, a cold front will develop southeast from near Lake Michigan to northwest Texas at midday to the Ohio Valley and central Texas by 12z Monday. A seasonally moist airmass will be in place ahead of the front, with surface dewpoints in the mid to upper 60s F forecast. Some uncertainty remains in where the corridor of greater strong/severe storm potential will develop, mainly driven by ongoing convection across parts of the region Sunday morning. Nevertheless, where pockets of greater heating occur, favorable vertical shear and increasing forcing from both the surface front and the ejecting midlevel wave, will support organized storm development. Damaging gusts will be the main hazard with thunderstorm clusters and line segments. However, vertical shear may be suitable for a few supercells, especially across west Texas. Isolated large hail will be possible with any more discrete cells that develop and can be maintained ahead of the front. ..Leitman.. 09/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Sat Sep 21 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HIGH PLAINS... ...SUMMARY... Scattered severe storms are expected this afternoon and evening across the southern High Plains. Isolated strong to severe thunderstorms are also possible from the mid Missouri Valley to the Upper Midwest, and also from western Pennsylvania into northern/central Virginia. ...Southern High Plains... Notable upper trough has advanced into the lower CO River Valley early this morning. Strong 500mb speed max will soon round the base of the trough and eject across southern AZ into southern NM by late afternoon. This feature will greatly influence convective development/intensity across the southern High Plains by peak heating. Northern-stream short-wave trough will shift east today which will allow a sharp surface cold front to surge south across the High Plains into eastern CO by early afternoon, likely arcing across the northern TX Panhandle into northeast NM by 22/00z. Strong boundary-layer heating is expected across southern NM with more modest warming forecast within southeasterly upslope flow from the TX/NM border into the Sangre de Cristo range, just southwest of the cold front. Forecast soundings suggest convective temperatures will be breached fairly early, aided in part by frontal/orographic influences. Scattered convection will easily develop ahead of the short wave, and this activity will be strongly sheared as the speed max approaches. Supercells are expected to evolve within this environment as 0-6km shear will be on the order of 50kt, along with veering winds with height. Large hail should develop with this activity along with some risk for a few tornadoes. ...Upper Midwest to Mid MO Valley... Northern-stream short-wave trough is progressing across SK/eastern MT into the northern Plains, in line with latest model guidance. This feature is forecast to suppress the height field immediately downstream across eastern ND into northern MN, though the strongest falls will remain north of the international border. Even so, notable surface front will advance into MN-western IA-southern NE by 18z, then steadily surge east into the early evening hours. This boundary will serve as the focus for potential convective development during the late afternoon, though surface heating is not expected to be particularly strong ahead of the wind shift. With the strongest forcing expected to spread across northwest ON, convection may be more isolated along the front trailing across the Upper Midwest. Even so, some hail/wind threat will exist with this activity which should peak in intensity during the early evening. ...Western PA into western VA... Weak short-wave trough will dig southeast across the upper OH Valley later this afternoon with modest mid-level northwesterly flow expected to extend across western PA/VA. This feature will encourage scattered convection later this afternoon along a frontal zone that will be draped across the Delmarva-western PA into western NY. Convection that evolves near this wind shift will move southeast with an attendant risk for gusty winds and some hail. ..Darrow/Thornton.. 09/21/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Sat Sep 21 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HIGH PLAINS... ...SUMMARY... Scattered severe storms are expected this afternoon and evening across the southern High Plains. Isolated strong to severe thunderstorms are also possible from the mid Missouri Valley to the Upper Midwest, and also from western Pennsylvania into northern/central Virginia. ...Southern High Plains... Notable upper trough has advanced into the lower CO River Valley early this morning. Strong 500mb speed max will soon round the base of the trough and eject across southern AZ into southern NM by late afternoon. This feature will greatly influence convective development/intensity across the southern High Plains by peak heating. Northern-stream short-wave trough will shift east today which will allow a sharp surface cold front to surge south across the High Plains into eastern CO by early afternoon, likely arcing across the northern TX Panhandle into northeast NM by 22/00z. Strong boundary-layer heating is expected across southern NM with more modest warming forecast within southeasterly upslope flow from the TX/NM border into the Sangre de Cristo range, just southwest of the cold front. Forecast soundings suggest convective temperatures will be breached fairly early, aided in part by frontal/orographic influences. Scattered convection will easily develop ahead of the short wave, and this activity will be strongly sheared as the speed max approaches. Supercells are expected to evolve within this environment as 0-6km shear will be on the order of 50kt, along with veering winds with height. Large hail should develop with this activity along with some risk for a few tornadoes. ...Upper Midwest to Mid MO Valley... Northern-stream short-wave trough is progressing across SK/eastern MT into the northern Plains, in line with latest model guidance. This feature is forecast to suppress the height field immediately downstream across eastern ND into northern MN, though the strongest falls will remain north of the international border. Even so, notable surface front will advance into MN-western IA-southern NE by 18z, then steadily surge east into the early evening hours. This boundary will serve as the focus for potential convective development during the late afternoon, though surface heating is not expected to be particularly strong ahead of the wind shift. With the strongest forcing expected to spread across northwest ON, convection may be more isolated along the front trailing across the Upper Midwest. Even so, some hail/wind threat will exist with this activity which should peak in intensity during the early evening. ...Western PA into western VA... Weak short-wave trough will dig southeast across the upper OH Valley later this afternoon with modest mid-level northwesterly flow expected to extend across western PA/VA. This feature will encourage scattered convection later this afternoon along a frontal zone that will be draped across the Delmarva-western PA into western NY. Convection that evolves near this wind shift will move southeast with an attendant risk for gusty winds and some hail. ..Darrow/Thornton.. 09/21/2024 Read more