Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0153 AM CDT Tue Jul 08 2025 Valid 091200Z - 101200Z ...Synopsis... A compact midlevel trough will track eastward across the Northwest during the day -- in tandem with a robust midlevel trough/low moving eastward from British Columbia into Alberta. Large-scale ascent preceding the midlevel trough moving across the Northwest will promote another day of isolated high-based thunderstorms -- with a focus over southeastern OR into southwestern ID. Deep inverted-V soundings and PW around 0.7 inches will favor dry thunderstorms capable of producing lightning-induced ignitions and strong/erratic outflow winds. Similar to Day 1/Tuesday, a belt of strong deep-layer westerly flow (peripheral to the midlevel trough) across the Cascades will lead to breezy/gusty westerly surface winds in the Columbia Basin. While increasing boundary-layer moisture will limit RH reductions compared to Day 1/Tuesday, stronger surface winds will offset this and still yield elevated fire-weather conditions. Over the Great Basin, moderate midlevel southwesterly winds accompanying the compact midlevel trough will overspread the Great Basin during the day. Deep boundary-layer mixing into this strengthening flow aloft will support another day of elevated to locally critical fire-weather conditions, given increasingly dry/receptive fuels. ..Weinman.. 07/08/2025 ...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 0152 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...Synopsis... Along the northwestern periphery of an expansive midlevel ridge over the Southwest, a midlevel low will approach the northern CA coast as it gradually phases with a robust midlevel trough moving across British Columbia. Large-scale ascent preceding the midlevel low will promote isolated dry/high-based thunderstorms over the higher terrain of OR into far southeastern WA. Given dry/receptive fuels and limited rainfall with these storms, lightning-induced ignitions will be possible, along with strong convective outflow. Additionally, strong deep-layer westerly flow in the base of the midlevel trough moving across British Columbia will overspread the Cascades, resulting in dry/breezy downslope flow and elevated fire-weather conditions in the Columbia Basin. Farther south, a belt of enhanced midlevel southwesterly flow will overspread the Great Basin between the large-scale ridge and midlevel low. Deep boundary-layer mixing into this enhanced flow aloft will favor dry/breezy conditions over central NV into western UT, and given dry fuels, elevated fire-weather conditions are expected. ..Weinman.. 07/08/2025 ...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 0152 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...Synopsis... Along the northwestern periphery of an expansive midlevel ridge over the Southwest, a midlevel low will approach the northern CA coast as it gradually phases with a robust midlevel trough moving across British Columbia. Large-scale ascent preceding the midlevel low will promote isolated dry/high-based thunderstorms over the higher terrain of OR into far southeastern WA. Given dry/receptive fuels and limited rainfall with these storms, lightning-induced ignitions will be possible, along with strong convective outflow. Additionally, strong deep-layer westerly flow in the base of the midlevel trough moving across British Columbia will overspread the Cascades, resulting in dry/breezy downslope flow and elevated fire-weather conditions in the Columbia Basin. Farther south, a belt of enhanced midlevel southwesterly flow will overspread the Great Basin between the large-scale ridge and midlevel low. Deep boundary-layer mixing into this enhanced flow aloft will favor dry/breezy conditions over central NV into western UT, and given dry fuels, elevated fire-weather conditions are expected. ..Weinman.. 07/08/2025 ...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 0152 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...Synopsis... Along the northwestern periphery of an expansive midlevel ridge over the Southwest, a midlevel low will approach the northern CA coast as it gradually phases with a robust midlevel trough moving across British Columbia. Large-scale ascent preceding the midlevel low will promote isolated dry/high-based thunderstorms over the higher terrain of OR into far southeastern WA. Given dry/receptive fuels and limited rainfall with these storms, lightning-induced ignitions will be possible, along with strong convective outflow. Additionally, strong deep-layer westerly flow in the base of the midlevel trough moving across British Columbia will overspread the Cascades, resulting in dry/breezy downslope flow and elevated fire-weather conditions in the Columbia Basin. Farther south, a belt of enhanced midlevel southwesterly flow will overspread the Great Basin between the large-scale ridge and midlevel low. Deep boundary-layer mixing into this enhanced flow aloft will favor dry/breezy conditions over central NV into western UT, and given dry fuels, elevated fire-weather conditions are expected. ..Weinman.. 07/08/2025 ...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 0152 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...Synopsis... Along the northwestern periphery of an expansive midlevel ridge over the Southwest, a midlevel low will approach the northern CA coast as it gradually phases with a robust midlevel trough moving across British Columbia. Large-scale ascent preceding the midlevel low will promote isolated dry/high-based thunderstorms over the higher terrain of OR into far southeastern WA. Given dry/receptive fuels and limited rainfall with these storms, lightning-induced ignitions will be possible, along with strong convective outflow. Additionally, strong deep-layer westerly flow in the base of the midlevel trough moving across British Columbia will overspread the Cascades, resulting in dry/breezy downslope flow and elevated fire-weather conditions in the Columbia Basin. Farther south, a belt of enhanced midlevel southwesterly flow will overspread the Great Basin between the large-scale ridge and midlevel low. Deep boundary-layer mixing into this enhanced flow aloft will favor dry/breezy conditions over central NV into western UT, and given dry fuels, elevated fire-weather conditions are expected. ..Weinman.. 07/08/2025 ...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 0152 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...Synopsis... Along the northwestern periphery of an expansive midlevel ridge over the Southwest, a midlevel low will approach the northern CA coast as it gradually phases with a robust midlevel trough moving across British Columbia. Large-scale ascent preceding the midlevel low will promote isolated dry/high-based thunderstorms over the higher terrain of OR into far southeastern WA. Given dry/receptive fuels and limited rainfall with these storms, lightning-induced ignitions will be possible, along with strong convective outflow. Additionally, strong deep-layer westerly flow in the base of the midlevel trough moving across British Columbia will overspread the Cascades, resulting in dry/breezy downslope flow and elevated fire-weather conditions in the Columbia Basin. Farther south, a belt of enhanced midlevel southwesterly flow will overspread the Great Basin between the large-scale ridge and midlevel low. Deep boundary-layer mixing into this enhanced flow aloft will favor dry/breezy conditions over central NV into western UT, and given dry fuels, elevated fire-weather conditions are expected. ..Weinman.. 07/08/2025 ...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 0152 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...Synopsis... Along the northwestern periphery of an expansive midlevel ridge over the Southwest, a midlevel low will approach the northern CA coast as it gradually phases with a robust midlevel trough moving across British Columbia. Large-scale ascent preceding the midlevel low will promote isolated dry/high-based thunderstorms over the higher terrain of OR into far southeastern WA. Given dry/receptive fuels and limited rainfall with these storms, lightning-induced ignitions will be possible, along with strong convective outflow. Additionally, strong deep-layer westerly flow in the base of the midlevel trough moving across British Columbia will overspread the Cascades, resulting in dry/breezy downslope flow and elevated fire-weather conditions in the Columbia Basin. Farther south, a belt of enhanced midlevel southwesterly flow will overspread the Great Basin between the large-scale ridge and midlevel low. Deep boundary-layer mixing into this enhanced flow aloft will favor dry/breezy conditions over central NV into western UT, and given dry fuels, elevated fire-weather conditions are expected. ..Weinman.. 07/08/2025 ...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 0152 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...Synopsis... Along the northwestern periphery of an expansive midlevel ridge over the Southwest, a midlevel low will approach the northern CA coast as it gradually phases with a robust midlevel trough moving across British Columbia. Large-scale ascent preceding the midlevel low will promote isolated dry/high-based thunderstorms over the higher terrain of OR into far southeastern WA. Given dry/receptive fuels and limited rainfall with these storms, lightning-induced ignitions will be possible, along with strong convective outflow. Additionally, strong deep-layer westerly flow in the base of the midlevel trough moving across British Columbia will overspread the Cascades, resulting in dry/breezy downslope flow and elevated fire-weather conditions in the Columbia Basin. Farther south, a belt of enhanced midlevel southwesterly flow will overspread the Great Basin between the large-scale ridge and midlevel low. Deep boundary-layer mixing into this enhanced flow aloft will favor dry/breezy conditions over central NV into western UT, and given dry fuels, elevated fire-weather conditions are expected. ..Weinman.. 07/08/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0495 Status Updates
STATUS REPORT ON WW 495 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 E BUB TO 30 W OLU TO 15 ENE LNK TO 20 S SDA TO 40 WNW LWD TO 30 W DSM TO 25 SE FOD. ..DEAN..07/08/25 ATTN...WFO...DMX...OAX...GID...LBF... STATUS REPORT FOR WS 495 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC039-049-053-121-153-159-175-181-080740- IA . IOWA COUNTIES INCLUDED ARE CLARKE DALLAS DECATUR MADISON POLK RINGGOLD UNION WARREN NEC035-059-067-077-079-081-093-095-097-109-121-125-129-131-143- 151-159-163-169-175-185-080740- NE . NEBRASKA COUNTIES INCLUDED ARE CLAY FILLMORE GAGE GREELEY HALL HAMILTON HOWARD JEFFERSON JOHNSON LANCASTER MERRICK NANCE NUCKOLLS OTOE POLK SALINE SEWARD SHERMAN THAYER VALLEY YORK Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0109 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC... CORRECTED FOR REGIONAL HEADER ...SUMMARY... Scattered severe thunderstorms are expected across the Mid Atlantic. More isolated activity is expected across portions of the Plains into the Mid Mississippi Valley. ...Middle Atlantic... Early-morning water-vapor imagery depicts a notable short-wave trough over the upper MS Valley, shifting east in line with latest model guidance. This feature is forecast to advance into the central Great Lakes region by the end of the period. As the short wave advances east, a corridor of higher PW (currently extending from AR into the upper OH Valley) will be shunted downstream as a low-amplitude disturbance ejects toward the Mid Atlantic. While some suppression of the height field can be expected late, it appears the weak disturbance should be the primary mechanism for encouraging somewhat stronger southwesterly flow which would extend as far south as central VA. Even so, 0-6km bulk shear is only expected to be on the order of 20-25kt, but favorably oriented for clusters and short line segments. Forecast soundings exhibit poor lapse rates, but high-water content suggests damaging downbursts are likely, especially with any organized clusters. Convective temperatures will be breached by 17-18z as readings climb into the mid 80s, and scattered thunderstorms should readily develop from central PA into central VA. This activity will then propagate toward the Mid Atlantic Coast with an attendant risk for damaging winds. ...Plains... Upper ridge is forecast to hold across the southwestern U.S. through the day1 period; although, northwesterly flow is expected to increase a bit along the eastern periphery of this feature over the High Plains. As a result, high-level diffluent flow will be noted across the southern Plains into southern MO. At the surface, low-level boundaries/convergence will prove weak, and left-over convective debris will likely prove influential in late-afternoon development. Early this morning, an MCS was propagating south across eastern NE/southwest IA. This complex will likely advance into southeast KS/southwest MO by sunrise. It's not entirely clear how organized this cluster will be at the start of the period, but convective outflow will likely contribute to additional development later in the day. Strong boundary-layer heating will also aid isolated thunderstorm development across the High Plains of eastern WY/CO/NM. This activity will spread southeast during the evening with a risk for hail/wind. ..Darrow/Weinman.. 07/08/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0109 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC... CORRECTED FOR REGIONAL HEADER ...SUMMARY... Scattered severe thunderstorms are expected across the Mid Atlantic. More isolated activity is expected across portions of the Plains into the Mid Mississippi Valley. ...Middle Atlantic... Early-morning water-vapor imagery depicts a notable short-wave trough over the upper MS Valley, shifting east in line with latest model guidance. This feature is forecast to advance into the central Great Lakes region by the end of the period. As the short wave advances east, a corridor of higher PW (currently extending from AR into the upper OH Valley) will be shunted downstream as a low-amplitude disturbance ejects toward the Mid Atlantic. While some suppression of the height field can be expected late, it appears the weak disturbance should be the primary mechanism for encouraging somewhat stronger southwesterly flow which would extend as far south as central VA. Even so, 0-6km bulk shear is only expected to be on the order of 20-25kt, but favorably oriented for clusters and short line segments. Forecast soundings exhibit poor lapse rates, but high-water content suggests damaging downbursts are likely, especially with any organized clusters. Convective temperatures will be breached by 17-18z as readings climb into the mid 80s, and scattered thunderstorms should readily develop from central PA into central VA. This activity will then propagate toward the Mid Atlantic Coast with an attendant risk for damaging winds. ...Plains... Upper ridge is forecast to hold across the southwestern U.S. through the day1 period; although, northwesterly flow is expected to increase a bit along the eastern periphery of this feature over the High Plains. As a result, high-level diffluent flow will be noted across the southern Plains into southern MO. At the surface, low-level boundaries/convergence will prove weak, and left-over convective debris will likely prove influential in late-afternoon development. Early this morning, an MCS was propagating south across eastern NE/southwest IA. This complex will likely advance into southeast KS/southwest MO by sunrise. It's not entirely clear how organized this cluster will be at the start of the period, but convective outflow will likely contribute to additional development later in the day. Strong boundary-layer heating will also aid isolated thunderstorm development across the High Plains of eastern WY/CO/NM. This activity will spread southeast during the evening with a risk for hail/wind. ..Darrow/Weinman.. 07/08/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0109 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC... CORRECTED FOR REGIONAL HEADER ...SUMMARY... Scattered severe thunderstorms are expected across the Mid Atlantic. More isolated activity is expected across portions of the Plains into the Mid Mississippi Valley. ...Middle Atlantic... Early-morning water-vapor imagery depicts a notable short-wave trough over the upper MS Valley, shifting east in line with latest model guidance. This feature is forecast to advance into the central Great Lakes region by the end of the period. As the short wave advances east, a corridor of higher PW (currently extending from AR into the upper OH Valley) will be shunted downstream as a low-amplitude disturbance ejects toward the Mid Atlantic. While some suppression of the height field can be expected late, it appears the weak disturbance should be the primary mechanism for encouraging somewhat stronger southwesterly flow which would extend as far south as central VA. Even so, 0-6km bulk shear is only expected to be on the order of 20-25kt, but favorably oriented for clusters and short line segments. Forecast soundings exhibit poor lapse rates, but high-water content suggests damaging downbursts are likely, especially with any organized clusters. Convective temperatures will be breached by 17-18z as readings climb into the mid 80s, and scattered thunderstorms should readily develop from central PA into central VA. This activity will then propagate toward the Mid Atlantic Coast with an attendant risk for damaging winds. ...Plains... Upper ridge is forecast to hold across the southwestern U.S. through the day1 period; although, northwesterly flow is expected to increase a bit along the eastern periphery of this feature over the High Plains. As a result, high-level diffluent flow will be noted across the southern Plains into southern MO. At the surface, low-level boundaries/convergence will prove weak, and left-over convective debris will likely prove influential in late-afternoon development. Early this morning, an MCS was propagating south across eastern NE/southwest IA. This complex will likely advance into southeast KS/southwest MO by sunrise. It's not entirely clear how organized this cluster will be at the start of the period, but convective outflow will likely contribute to additional development later in the day. Strong boundary-layer heating will also aid isolated thunderstorm development across the High Plains of eastern WY/CO/NM. This activity will spread southeast during the evening with a risk for hail/wind. ..Darrow/Weinman.. 07/08/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0109 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC... CORRECTED FOR REGIONAL HEADER ...SUMMARY... Scattered severe thunderstorms are expected across the Mid Atlantic. More isolated activity is expected across portions of the Plains into the Mid Mississippi Valley. ...Middle Atlantic... Early-morning water-vapor imagery depicts a notable short-wave trough over the upper MS Valley, shifting east in line with latest model guidance. This feature is forecast to advance into the central Great Lakes region by the end of the period. As the short wave advances east, a corridor of higher PW (currently extending from AR into the upper OH Valley) will be shunted downstream as a low-amplitude disturbance ejects toward the Mid Atlantic. While some suppression of the height field can be expected late, it appears the weak disturbance should be the primary mechanism for encouraging somewhat stronger southwesterly flow which would extend as far south as central VA. Even so, 0-6km bulk shear is only expected to be on the order of 20-25kt, but favorably oriented for clusters and short line segments. Forecast soundings exhibit poor lapse rates, but high-water content suggests damaging downbursts are likely, especially with any organized clusters. Convective temperatures will be breached by 17-18z as readings climb into the mid 80s, and scattered thunderstorms should readily develop from central PA into central VA. This activity will then propagate toward the Mid Atlantic Coast with an attendant risk for damaging winds. ...Plains... Upper ridge is forecast to hold across the southwestern U.S. through the day1 period; although, northwesterly flow is expected to increase a bit along the eastern periphery of this feature over the High Plains. As a result, high-level diffluent flow will be noted across the southern Plains into southern MO. At the surface, low-level boundaries/convergence will prove weak, and left-over convective debris will likely prove influential in late-afternoon development. Early this morning, an MCS was propagating south across eastern NE/southwest IA. This complex will likely advance into southeast KS/southwest MO by sunrise. It's not entirely clear how organized this cluster will be at the start of the period, but convective outflow will likely contribute to additional development later in the day. Strong boundary-layer heating will also aid isolated thunderstorm development across the High Plains of eastern WY/CO/NM. This activity will spread southeast during the evening with a risk for hail/wind. ..Darrow/Weinman.. 07/08/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0109 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC... CORRECTED FOR REGIONAL HEADER ...SUMMARY... Scattered severe thunderstorms are expected across the Mid Atlantic. More isolated activity is expected across portions of the Plains into the Mid Mississippi Valley. ...Middle Atlantic... Early-morning water-vapor imagery depicts a notable short-wave trough over the upper MS Valley, shifting east in line with latest model guidance. This feature is forecast to advance into the central Great Lakes region by the end of the period. As the short wave advances east, a corridor of higher PW (currently extending from AR into the upper OH Valley) will be shunted downstream as a low-amplitude disturbance ejects toward the Mid Atlantic. While some suppression of the height field can be expected late, it appears the weak disturbance should be the primary mechanism for encouraging somewhat stronger southwesterly flow which would extend as far south as central VA. Even so, 0-6km bulk shear is only expected to be on the order of 20-25kt, but favorably oriented for clusters and short line segments. Forecast soundings exhibit poor lapse rates, but high-water content suggests damaging downbursts are likely, especially with any organized clusters. Convective temperatures will be breached by 17-18z as readings climb into the mid 80s, and scattered thunderstorms should readily develop from central PA into central VA. This activity will then propagate toward the Mid Atlantic Coast with an attendant risk for damaging winds. ...Plains... Upper ridge is forecast to hold across the southwestern U.S. through the day1 period; although, northwesterly flow is expected to increase a bit along the eastern periphery of this feature over the High Plains. As a result, high-level diffluent flow will be noted across the southern Plains into southern MO. At the surface, low-level boundaries/convergence will prove weak, and left-over convective debris will likely prove influential in late-afternoon development. Early this morning, an MCS was propagating south across eastern NE/southwest IA. This complex will likely advance into southeast KS/southwest MO by sunrise. It's not entirely clear how organized this cluster will be at the start of the period, but convective outflow will likely contribute to additional development later in the day. Strong boundary-layer heating will also aid isolated thunderstorm development across the High Plains of eastern WY/CO/NM. This activity will spread southeast during the evening with a risk for hail/wind. ..Darrow/Weinman.. 07/08/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0109 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC... CORRECTED FOR REGIONAL HEADER ...SUMMARY... Scattered severe thunderstorms are expected across the Mid Atlantic. More isolated activity is expected across portions of the Plains into the Mid Mississippi Valley. ...Middle Atlantic... Early-morning water-vapor imagery depicts a notable short-wave trough over the upper MS Valley, shifting east in line with latest model guidance. This feature is forecast to advance into the central Great Lakes region by the end of the period. As the short wave advances east, a corridor of higher PW (currently extending from AR into the upper OH Valley) will be shunted downstream as a low-amplitude disturbance ejects toward the Mid Atlantic. While some suppression of the height field can be expected late, it appears the weak disturbance should be the primary mechanism for encouraging somewhat stronger southwesterly flow which would extend as far south as central VA. Even so, 0-6km bulk shear is only expected to be on the order of 20-25kt, but favorably oriented for clusters and short line segments. Forecast soundings exhibit poor lapse rates, but high-water content suggests damaging downbursts are likely, especially with any organized clusters. Convective temperatures will be breached by 17-18z as readings climb into the mid 80s, and scattered thunderstorms should readily develop from central PA into central VA. This activity will then propagate toward the Mid Atlantic Coast with an attendant risk for damaging winds. ...Plains... Upper ridge is forecast to hold across the southwestern U.S. through the day1 period; although, northwesterly flow is expected to increase a bit along the eastern periphery of this feature over the High Plains. As a result, high-level diffluent flow will be noted across the southern Plains into southern MO. At the surface, low-level boundaries/convergence will prove weak, and left-over convective debris will likely prove influential in late-afternoon development. Early this morning, an MCS was propagating south across eastern NE/southwest IA. This complex will likely advance into southeast KS/southwest MO by sunrise. It's not entirely clear how organized this cluster will be at the start of the period, but convective outflow will likely contribute to additional development later in the day. Strong boundary-layer heating will also aid isolated thunderstorm development across the High Plains of eastern WY/CO/NM. This activity will spread southeast during the evening with a risk for hail/wind. ..Darrow/Weinman.. 07/08/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0109 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC... CORRECTED FOR REGIONAL HEADER ...SUMMARY... Scattered severe thunderstorms are expected across the Mid Atlantic. More isolated activity is expected across portions of the Plains into the Mid Mississippi Valley. ...Middle Atlantic... Early-morning water-vapor imagery depicts a notable short-wave trough over the upper MS Valley, shifting east in line with latest model guidance. This feature is forecast to advance into the central Great Lakes region by the end of the period. As the short wave advances east, a corridor of higher PW (currently extending from AR into the upper OH Valley) will be shunted downstream as a low-amplitude disturbance ejects toward the Mid Atlantic. While some suppression of the height field can be expected late, it appears the weak disturbance should be the primary mechanism for encouraging somewhat stronger southwesterly flow which would extend as far south as central VA. Even so, 0-6km bulk shear is only expected to be on the order of 20-25kt, but favorably oriented for clusters and short line segments. Forecast soundings exhibit poor lapse rates, but high-water content suggests damaging downbursts are likely, especially with any organized clusters. Convective temperatures will be breached by 17-18z as readings climb into the mid 80s, and scattered thunderstorms should readily develop from central PA into central VA. This activity will then propagate toward the Mid Atlantic Coast with an attendant risk for damaging winds. ...Plains... Upper ridge is forecast to hold across the southwestern U.S. through the day1 period; although, northwesterly flow is expected to increase a bit along the eastern periphery of this feature over the High Plains. As a result, high-level diffluent flow will be noted across the southern Plains into southern MO. At the surface, low-level boundaries/convergence will prove weak, and left-over convective debris will likely prove influential in late-afternoon development. Early this morning, an MCS was propagating south across eastern NE/southwest IA. This complex will likely advance into southeast KS/southwest MO by sunrise. It's not entirely clear how organized this cluster will be at the start of the period, but convective outflow will likely contribute to additional development later in the day. Strong boundary-layer heating will also aid isolated thunderstorm development across the High Plains of eastern WY/CO/NM. This activity will spread southeast during the evening with a risk for hail/wind. ..Darrow/Weinman.. 07/08/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0109 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC... CORRECTED FOR REGIONAL HEADER ...SUMMARY... Scattered severe thunderstorms are expected across the Mid Atlantic. More isolated activity is expected across portions of the Plains into the Mid Mississippi Valley. ...Middle Atlantic... Early-morning water-vapor imagery depicts a notable short-wave trough over the upper MS Valley, shifting east in line with latest model guidance. This feature is forecast to advance into the central Great Lakes region by the end of the period. As the short wave advances east, a corridor of higher PW (currently extending from AR into the upper OH Valley) will be shunted downstream as a low-amplitude disturbance ejects toward the Mid Atlantic. While some suppression of the height field can be expected late, it appears the weak disturbance should be the primary mechanism for encouraging somewhat stronger southwesterly flow which would extend as far south as central VA. Even so, 0-6km bulk shear is only expected to be on the order of 20-25kt, but favorably oriented for clusters and short line segments. Forecast soundings exhibit poor lapse rates, but high-water content suggests damaging downbursts are likely, especially with any organized clusters. Convective temperatures will be breached by 17-18z as readings climb into the mid 80s, and scattered thunderstorms should readily develop from central PA into central VA. This activity will then propagate toward the Mid Atlantic Coast with an attendant risk for damaging winds. ...Plains... Upper ridge is forecast to hold across the southwestern U.S. through the day1 period; although, northwesterly flow is expected to increase a bit along the eastern periphery of this feature over the High Plains. As a result, high-level diffluent flow will be noted across the southern Plains into southern MO. At the surface, low-level boundaries/convergence will prove weak, and left-over convective debris will likely prove influential in late-afternoon development. Early this morning, an MCS was propagating south across eastern NE/southwest IA. This complex will likely advance into southeast KS/southwest MO by sunrise. It's not entirely clear how organized this cluster will be at the start of the period, but convective outflow will likely contribute to additional development later in the day. Strong boundary-layer heating will also aid isolated thunderstorm development across the High Plains of eastern WY/CO/NM. This activity will spread southeast during the evening with a risk for hail/wind. ..Darrow/Weinman.. 07/08/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0109 AM CDT Tue Jul 08 2025 Valid 081200Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC... CORRECTED FOR REGIONAL HEADER ...SUMMARY... Scattered severe thunderstorms are expected across the Mid Atlantic. More isolated activity is expected across portions of the Plains into the Mid Mississippi Valley. ...Middle Atlantic... Early-morning water-vapor imagery depicts a notable short-wave trough over the upper MS Valley, shifting east in line with latest model guidance. This feature is forecast to advance into the central Great Lakes region by the end of the period. As the short wave advances east, a corridor of higher PW (currently extending from AR into the upper OH Valley) will be shunted downstream as a low-amplitude disturbance ejects toward the Mid Atlantic. While some suppression of the height field can be expected late, it appears the weak disturbance should be the primary mechanism for encouraging somewhat stronger southwesterly flow which would extend as far south as central VA. Even so, 0-6km bulk shear is only expected to be on the order of 20-25kt, but favorably oriented for clusters and short line segments. Forecast soundings exhibit poor lapse rates, but high-water content suggests damaging downbursts are likely, especially with any organized clusters. Convective temperatures will be breached by 17-18z as readings climb into the mid 80s, and scattered thunderstorms should readily develop from central PA into central VA. This activity will then propagate toward the Mid Atlantic Coast with an attendant risk for damaging winds. ...Plains... Upper ridge is forecast to hold across the southwestern U.S. through the day1 period; although, northwesterly flow is expected to increase a bit along the eastern periphery of this feature over the High Plains. As a result, high-level diffluent flow will be noted across the southern Plains into southern MO. At the surface, low-level boundaries/convergence will prove weak, and left-over convective debris will likely prove influential in late-afternoon development. Early this morning, an MCS was propagating south across eastern NE/southwest IA. This complex will likely advance into southeast KS/southwest MO by sunrise. It's not entirely clear how organized this cluster will be at the start of the period, but convective outflow will likely contribute to additional development later in the day. Strong boundary-layer heating will also aid isolated thunderstorm development across the High Plains of eastern WY/CO/NM. This activity will spread southeast during the evening with a risk for hail/wind. ..Darrow/Weinman.. 07/08/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Tue Jul 08 2025 Valid 091200Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN PLAINS AS WELL AS PORTIONS OF THE SOUTHEAST INTO SOUTHERN NEW ENGLAND... ...SUMMARY... At least isolated severe storms are possible in the northern Plains on Wednesday, with locally large hail and areas of severe gusts. Isolated damaging gusts are also possible across parts of the eastern U.S. ... Synopsis ... A midlevel ridge centered over the four corners will begin to break down on Wednesday as a low-amplitude shortwave trough quickly moves from off the northern California coast into the Great Basin. Additionally, a larger amplitude trough will move across southern Canada. Elsewhere, broad mid-level troughing will persist across the eastern US. Surface lee toughing will exist across the northern Plains in response to westerly downslope flow. This westerly flow will help maintain steep mid-level lapse rates into the northern Plains atop a moist boundary layer supported by southerly surface winds on the east side of the northern Plains lee trough. ... Northern Plains ... Strong diurnal heating should allow temperatures to warm into the mid-to-perhaps-upper 90Fs across much of the Dakotas by mid afternoon. This heating, coupled with surface dewpoint temperatures in the 60Fs, will support surface-based CAPE in excess of 2500-3000 J/kg with little to no convective inhibition. Additionally, modest northwest mid-to-upper-level flow on the northeast periphery of the four corners ridge will support somewhat elongated hodographs and effective-layer shear around 30 knots. Despite the region being displaced from the stronger large-scale ascent associated with the aforementioned shortwave troughs, isolated thunderstorms are still expected to develop by late afternoon. The overall thermodynamic and kinematic environment should support multicell clusters to transient supercell structures capable of producing large hail -- perhaps in excess of 2 inches in diameter. By early evening any thunderstorm clusters persisting will pose an increasing damaging wind threat. A categorical upgrade to Level 2/Slight Risk was considered with this forecast. However, given the nebulous forcing mechanisms for initiating thunderstorms, uncertainty remains as to the coverage of severe thunderstorms. As such a Level 1/Marginal Risk was maintained, even though a potential for significant hail exists. ... Southeast US to Southern New England ... Scattered to widespread thunderstorms will develop during the late morning into the afternoon within a moist, unstable, and weakly capped airmass. Precipitable water values around 2" will support water loading of updrafts and a resulting potential for strong thunderstorm winds capable of scattered wind damage. ..Marsh.. 07/08/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Tue Jul 08 2025 Valid 091200Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN PLAINS AS WELL AS PORTIONS OF THE SOUTHEAST INTO SOUTHERN NEW ENGLAND... ...SUMMARY... At least isolated severe storms are possible in the northern Plains on Wednesday, with locally large hail and areas of severe gusts. Isolated damaging gusts are also possible across parts of the eastern U.S. ... Synopsis ... A midlevel ridge centered over the four corners will begin to break down on Wednesday as a low-amplitude shortwave trough quickly moves from off the northern California coast into the Great Basin. Additionally, a larger amplitude trough will move across southern Canada. Elsewhere, broad mid-level troughing will persist across the eastern US. Surface lee toughing will exist across the northern Plains in response to westerly downslope flow. This westerly flow will help maintain steep mid-level lapse rates into the northern Plains atop a moist boundary layer supported by southerly surface winds on the east side of the northern Plains lee trough. ... Northern Plains ... Strong diurnal heating should allow temperatures to warm into the mid-to-perhaps-upper 90Fs across much of the Dakotas by mid afternoon. This heating, coupled with surface dewpoint temperatures in the 60Fs, will support surface-based CAPE in excess of 2500-3000 J/kg with little to no convective inhibition. Additionally, modest northwest mid-to-upper-level flow on the northeast periphery of the four corners ridge will support somewhat elongated hodographs and effective-layer shear around 30 knots. Despite the region being displaced from the stronger large-scale ascent associated with the aforementioned shortwave troughs, isolated thunderstorms are still expected to develop by late afternoon. The overall thermodynamic and kinematic environment should support multicell clusters to transient supercell structures capable of producing large hail -- perhaps in excess of 2 inches in diameter. By early evening any thunderstorm clusters persisting will pose an increasing damaging wind threat. A categorical upgrade to Level 2/Slight Risk was considered with this forecast. However, given the nebulous forcing mechanisms for initiating thunderstorms, uncertainty remains as to the coverage of severe thunderstorms. As such a Level 1/Marginal Risk was maintained, even though a potential for significant hail exists. ... Southeast US to Southern New England ... Scattered to widespread thunderstorms will develop during the late morning into the afternoon within a moist, unstable, and weakly capped airmass. Precipitable water values around 2" will support water loading of updrafts and a resulting potential for strong thunderstorm winds capable of scattered wind damage. ..Marsh.. 07/08/2025 Read more