Severe Storms

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1226 AM CDT Wed Jul 24 2024 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN MID-ATLANTIC VICINITY... ...SUMMARY... Isolated strong to severe thunderstorm may produce gusty/locally damaging winds on Thursday across parts of northern Mid-Atlantic vicinity. ...Northern Mid-Atlantic... An upper trough will progress eastward across the Northeast on Thursday. Ahead of this feature, southwesterly mid/upper level flow will increase to around 30-45 kt between 700 and 500 mb, supporting effective shear magnitudes around 30-40 kt. Cloudiness is expected across much of the Eastern Seaboard, and pockets of showers, especially across eastern VA/NC, are possible. This will likely inhibit stronger destabilization despite a very moist airmass. A narrow corridor of modest instability overlapping with favorable shear ahead of an eastward-advancing cold front may develop roughly along the I-95 corridor northern VA into southern NJ. Forecast soundings within this corridor suggest organized cells (perhaps marginal/transient supercells) will be possible, posing mainly a risk of locally strong/severe gusts during the afternoon/early evening. ...Northern Great Basin into Central MT... An upper shortwave trough will migrate east across the northern Rockies vicinity. A belt of moderate to strong mid/upper southwesterly flow will become oriented over portions of ID/MT into the Canadian Prairies. At the surface, boundary-layer moisture will be limited and strong heating/deep mixing will result in inverted-v sub-cloud layer thermodynamic profiles. Steep midlevel lapse rates however, will support around 500-750 J/kg MLCAPE. While southwesterly flow near/above 500 mb will increase through the afternoon, vertical shear is not forecast to be very strong. Isolated to scattered thunderstorms are expected over higher terrain during the afternoon. Generally modest vertical shear the deeply mixed boundary layer may limit organized convection, especially as storms try to track east into lower elevations ahead of a southeastward surging cold front during the evening. Inhibition is also expected to increase with eastward extent across MT. A few strong gusts are possible, but confidence in greater coverage of potentially severe thunderstorms is too low to include probabilities at this time. ..Leitman.. 07/24/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1226 AM CDT Wed Jul 24 2024 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN MID-ATLANTIC VICINITY... ...SUMMARY... Isolated strong to severe thunderstorm may produce gusty/locally damaging winds on Thursday across parts of northern Mid-Atlantic vicinity. ...Northern Mid-Atlantic... An upper trough will progress eastward across the Northeast on Thursday. Ahead of this feature, southwesterly mid/upper level flow will increase to around 30-45 kt between 700 and 500 mb, supporting effective shear magnitudes around 30-40 kt. Cloudiness is expected across much of the Eastern Seaboard, and pockets of showers, especially across eastern VA/NC, are possible. This will likely inhibit stronger destabilization despite a very moist airmass. A narrow corridor of modest instability overlapping with favorable shear ahead of an eastward-advancing cold front may develop roughly along the I-95 corridor northern VA into southern NJ. Forecast soundings within this corridor suggest organized cells (perhaps marginal/transient supercells) will be possible, posing mainly a risk of locally strong/severe gusts during the afternoon/early evening. ...Northern Great Basin into Central MT... An upper shortwave trough will migrate east across the northern Rockies vicinity. A belt of moderate to strong mid/upper southwesterly flow will become oriented over portions of ID/MT into the Canadian Prairies. At the surface, boundary-layer moisture will be limited and strong heating/deep mixing will result in inverted-v sub-cloud layer thermodynamic profiles. Steep midlevel lapse rates however, will support around 500-750 J/kg MLCAPE. While southwesterly flow near/above 500 mb will increase through the afternoon, vertical shear is not forecast to be very strong. Isolated to scattered thunderstorms are expected over higher terrain during the afternoon. Generally modest vertical shear the deeply mixed boundary layer may limit organized convection, especially as storms try to track east into lower elevations ahead of a southeastward surging cold front during the evening. Inhibition is also expected to increase with eastward extent across MT. A few strong gusts are possible, but confidence in greater coverage of potentially severe thunderstorms is too low to include probabilities at this time. ..Leitman.. 07/24/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1226 AM CDT Wed Jul 24 2024 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN MID-ATLANTIC VICINITY... ...SUMMARY... Isolated strong to severe thunderstorm may produce gusty/locally damaging winds on Thursday across parts of northern Mid-Atlantic vicinity. ...Northern Mid-Atlantic... An upper trough will progress eastward across the Northeast on Thursday. Ahead of this feature, southwesterly mid/upper level flow will increase to around 30-45 kt between 700 and 500 mb, supporting effective shear magnitudes around 30-40 kt. Cloudiness is expected across much of the Eastern Seaboard, and pockets of showers, especially across eastern VA/NC, are possible. This will likely inhibit stronger destabilization despite a very moist airmass. A narrow corridor of modest instability overlapping with favorable shear ahead of an eastward-advancing cold front may develop roughly along the I-95 corridor northern VA into southern NJ. Forecast soundings within this corridor suggest organized cells (perhaps marginal/transient supercells) will be possible, posing mainly a risk of locally strong/severe gusts during the afternoon/early evening. ...Northern Great Basin into Central MT... An upper shortwave trough will migrate east across the northern Rockies vicinity. A belt of moderate to strong mid/upper southwesterly flow will become oriented over portions of ID/MT into the Canadian Prairies. At the surface, boundary-layer moisture will be limited and strong heating/deep mixing will result in inverted-v sub-cloud layer thermodynamic profiles. Steep midlevel lapse rates however, will support around 500-750 J/kg MLCAPE. While southwesterly flow near/above 500 mb will increase through the afternoon, vertical shear is not forecast to be very strong. Isolated to scattered thunderstorms are expected over higher terrain during the afternoon. Generally modest vertical shear the deeply mixed boundary layer may limit organized convection, especially as storms try to track east into lower elevations ahead of a southeastward surging cold front during the evening. Inhibition is also expected to increase with eastward extent across MT. A few strong gusts are possible, but confidence in greater coverage of potentially severe thunderstorms is too low to include probabilities at this time. ..Leitman.. 07/24/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1211 AM CDT Wed Jul 24 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSISSIPPI AND OHIO VALLEYS...MID ATLANTIC REGION...ARIZONA...AND THE NORTHWEST STATES.... ...SUMMARY... Isolated strong to severe thunderstorms may produce damaging gusts from parts of Iowa/Illinois into Pennsylvania/New York. Other locally strong storms are possible in parts of the Northwest, northern Rockies, Southwest, and Mid Atlantic regions. ...IA/IL/IN... Large-scale troughing will amplify on Wednesday as a shortwave trough over MN digs into the western Great Lakes. A surface cold front will sag into the Mid MS an OH Valleys by afternoon, with very warm and humid conditions expected to the south of the front. All 00z model solutions agree on the development of afternoon storms along/ahead of the front from southeast IA into central IL/IN. Moderately strong westerly flow aloft, steep lapse rates, and degree of CAPE suggest a threat of a few strong/severe storms capable of damaging winds and some hail. ...PA/NY... As the aforementioned front sags into western NY, slightly enhanced southwesterly low-level winds will strengthen warm advection and lift over parts of eastern NY/PA. This will likely lead to scattered thunderstorms through the afternoon. Forecast soundings show MLCAPE values over 1000 J/kg and sufficient deep-layer shear for a few organized storm clusters capable of locally gusty/damaging winds. ...NC/VA... Deep west-southwesterly winds will strengthen by this afternoon along a corridor from the southern Appalachians into the Mid-Atlantic states. This enhanced flow/shear profile will aid in helping to organize scattered diurnal thunderstorm development from western NC into parts of southern/eastern VA. Mid-level lapse rates will be poor, but strong heating and high PWAT values will promote a risk of a few intense storm clusters capable of gusty/damaging winds. ...AZ... The upper ridge over the western states will remain centered over parts of NV/UT today, with 15-25 knots of northeasterly mid-level flow across central/eastern AZ. Meanwhile at the surface, considerable moisture is expected to spread northward from Baja CA into the lower deserts overnight, with dewpoints around 60s expected tomorrow. Most 00z CAM guidance suggests multiple clusters of thunderstorms will form along the eastern rim and mountains of eastern AZ, with steering flow helping to spread the storms westward into the moist air mass Wednesday evening. This may lead to a more active convective day over central/southern AZ, with damaging wind gusts possible. Will maintain only MRGL risk at this time, but trends will be monitored for possible upgrade to SLGT in later updates. ...Northwest... Relatively fast cyclonic flow aloft will remain over the Pacific Northwest states into the northern Great Basin. Water vapor imagery shows ample mid-level moisture in place from northern CA into southern OR, which should spread eastward and aid in afternoon thunderstorm development from OR into parts of ID/MT. Forecast soundings show weak CAPE, but a few of the stronger cells could produce locally gusty/damaging winds. ..Hart/Halbert/Lyons.. 07/24/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1211 AM CDT Wed Jul 24 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSISSIPPI AND OHIO VALLEYS...MID ATLANTIC REGION...ARIZONA...AND THE NORTHWEST STATES.... ...SUMMARY... Isolated strong to severe thunderstorms may produce damaging gusts from parts of Iowa/Illinois into Pennsylvania/New York. Other locally strong storms are possible in parts of the Northwest, northern Rockies, Southwest, and Mid Atlantic regions. ...IA/IL/IN... Large-scale troughing will amplify on Wednesday as a shortwave trough over MN digs into the western Great Lakes. A surface cold front will sag into the Mid MS an OH Valleys by afternoon, with very warm and humid conditions expected to the south of the front. All 00z model solutions agree on the development of afternoon storms along/ahead of the front from southeast IA into central IL/IN. Moderately strong westerly flow aloft, steep lapse rates, and degree of CAPE suggest a threat of a few strong/severe storms capable of damaging winds and some hail. ...PA/NY... As the aforementioned front sags into western NY, slightly enhanced southwesterly low-level winds will strengthen warm advection and lift over parts of eastern NY/PA. This will likely lead to scattered thunderstorms through the afternoon. Forecast soundings show MLCAPE values over 1000 J/kg and sufficient deep-layer shear for a few organized storm clusters capable of locally gusty/damaging winds. ...NC/VA... Deep west-southwesterly winds will strengthen by this afternoon along a corridor from the southern Appalachians into the Mid-Atlantic states. This enhanced flow/shear profile will aid in helping to organize scattered diurnal thunderstorm development from western NC into parts of southern/eastern VA. Mid-level lapse rates will be poor, but strong heating and high PWAT values will promote a risk of a few intense storm clusters capable of gusty/damaging winds. ...AZ... The upper ridge over the western states will remain centered over parts of NV/UT today, with 15-25 knots of northeasterly mid-level flow across central/eastern AZ. Meanwhile at the surface, considerable moisture is expected to spread northward from Baja CA into the lower deserts overnight, with dewpoints around 60s expected tomorrow. Most 00z CAM guidance suggests multiple clusters of thunderstorms will form along the eastern rim and mountains of eastern AZ, with steering flow helping to spread the storms westward into the moist air mass Wednesday evening. This may lead to a more active convective day over central/southern AZ, with damaging wind gusts possible. Will maintain only MRGL risk at this time, but trends will be monitored for possible upgrade to SLGT in later updates. ...Northwest... Relatively fast cyclonic flow aloft will remain over the Pacific Northwest states into the northern Great Basin. Water vapor imagery shows ample mid-level moisture in place from northern CA into southern OR, which should spread eastward and aid in afternoon thunderstorm development from OR into parts of ID/MT. Forecast soundings show weak CAPE, but a few of the stronger cells could produce locally gusty/damaging winds. ..Hart/Halbert/Lyons.. 07/24/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1211 AM CDT Wed Jul 24 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSISSIPPI AND OHIO VALLEYS...MID ATLANTIC REGION...ARIZONA...AND THE NORTHWEST STATES.... ...SUMMARY... Isolated strong to severe thunderstorms may produce damaging gusts from parts of Iowa/Illinois into Pennsylvania/New York. Other locally strong storms are possible in parts of the Northwest, northern Rockies, Southwest, and Mid Atlantic regions. ...IA/IL/IN... Large-scale troughing will amplify on Wednesday as a shortwave trough over MN digs into the western Great Lakes. A surface cold front will sag into the Mid MS an OH Valleys by afternoon, with very warm and humid conditions expected to the south of the front. All 00z model solutions agree on the development of afternoon storms along/ahead of the front from southeast IA into central IL/IN. Moderately strong westerly flow aloft, steep lapse rates, and degree of CAPE suggest a threat of a few strong/severe storms capable of damaging winds and some hail. ...PA/NY... As the aforementioned front sags into western NY, slightly enhanced southwesterly low-level winds will strengthen warm advection and lift over parts of eastern NY/PA. This will likely lead to scattered thunderstorms through the afternoon. Forecast soundings show MLCAPE values over 1000 J/kg and sufficient deep-layer shear for a few organized storm clusters capable of locally gusty/damaging winds. ...NC/VA... Deep west-southwesterly winds will strengthen by this afternoon along a corridor from the southern Appalachians into the Mid-Atlantic states. This enhanced flow/shear profile will aid in helping to organize scattered diurnal thunderstorm development from western NC into parts of southern/eastern VA. Mid-level lapse rates will be poor, but strong heating and high PWAT values will promote a risk of a few intense storm clusters capable of gusty/damaging winds. ...AZ... The upper ridge over the western states will remain centered over parts of NV/UT today, with 15-25 knots of northeasterly mid-level flow across central/eastern AZ. Meanwhile at the surface, considerable moisture is expected to spread northward from Baja CA into the lower deserts overnight, with dewpoints around 60s expected tomorrow. Most 00z CAM guidance suggests multiple clusters of thunderstorms will form along the eastern rim and mountains of eastern AZ, with steering flow helping to spread the storms westward into the moist air mass Wednesday evening. This may lead to a more active convective day over central/southern AZ, with damaging wind gusts possible. Will maintain only MRGL risk at this time, but trends will be monitored for possible upgrade to SLGT in later updates. ...Northwest... Relatively fast cyclonic flow aloft will remain over the Pacific Northwest states into the northern Great Basin. Water vapor imagery shows ample mid-level moisture in place from northern CA into southern OR, which should spread eastward and aid in afternoon thunderstorm development from OR into parts of ID/MT. Forecast soundings show weak CAPE, but a few of the stronger cells could produce locally gusty/damaging winds. ..Hart/Halbert/Lyons.. 07/24/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1211 AM CDT Wed Jul 24 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSISSIPPI AND OHIO VALLEYS...MID ATLANTIC REGION...ARIZONA...AND THE NORTHWEST STATES.... ...SUMMARY... Isolated strong to severe thunderstorms may produce damaging gusts from parts of Iowa/Illinois into Pennsylvania/New York. Other locally strong storms are possible in parts of the Northwest, northern Rockies, Southwest, and Mid Atlantic regions. ...IA/IL/IN... Large-scale troughing will amplify on Wednesday as a shortwave trough over MN digs into the western Great Lakes. A surface cold front will sag into the Mid MS an OH Valleys by afternoon, with very warm and humid conditions expected to the south of the front. All 00z model solutions agree on the development of afternoon storms along/ahead of the front from southeast IA into central IL/IN. Moderately strong westerly flow aloft, steep lapse rates, and degree of CAPE suggest a threat of a few strong/severe storms capable of damaging winds and some hail. ...PA/NY... As the aforementioned front sags into western NY, slightly enhanced southwesterly low-level winds will strengthen warm advection and lift over parts of eastern NY/PA. This will likely lead to scattered thunderstorms through the afternoon. Forecast soundings show MLCAPE values over 1000 J/kg and sufficient deep-layer shear for a few organized storm clusters capable of locally gusty/damaging winds. ...NC/VA... Deep west-southwesterly winds will strengthen by this afternoon along a corridor from the southern Appalachians into the Mid-Atlantic states. This enhanced flow/shear profile will aid in helping to organize scattered diurnal thunderstorm development from western NC into parts of southern/eastern VA. Mid-level lapse rates will be poor, but strong heating and high PWAT values will promote a risk of a few intense storm clusters capable of gusty/damaging winds. ...AZ... The upper ridge over the western states will remain centered over parts of NV/UT today, with 15-25 knots of northeasterly mid-level flow across central/eastern AZ. Meanwhile at the surface, considerable moisture is expected to spread northward from Baja CA into the lower deserts overnight, with dewpoints around 60s expected tomorrow. Most 00z CAM guidance suggests multiple clusters of thunderstorms will form along the eastern rim and mountains of eastern AZ, with steering flow helping to spread the storms westward into the moist air mass Wednesday evening. This may lead to a more active convective day over central/southern AZ, with damaging wind gusts possible. Will maintain only MRGL risk at this time, but trends will be monitored for possible upgrade to SLGT in later updates. ...Northwest... Relatively fast cyclonic flow aloft will remain over the Pacific Northwest states into the northern Great Basin. Water vapor imagery shows ample mid-level moisture in place from northern CA into southern OR, which should spread eastward and aid in afternoon thunderstorm development from OR into parts of ID/MT. Forecast soundings show weak CAPE, but a few of the stronger cells could produce locally gusty/damaging winds. ..Hart/Halbert/Lyons.. 07/24/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1211 AM CDT Wed Jul 24 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSISSIPPI AND OHIO VALLEYS...MID ATLANTIC REGION...ARIZONA...AND THE NORTHWEST STATES.... ...SUMMARY... Isolated strong to severe thunderstorms may produce damaging gusts from parts of Iowa/Illinois into Pennsylvania/New York. Other locally strong storms are possible in parts of the Northwest, northern Rockies, Southwest, and Mid Atlantic regions. ...IA/IL/IN... Large-scale troughing will amplify on Wednesday as a shortwave trough over MN digs into the western Great Lakes. A surface cold front will sag into the Mid MS an OH Valleys by afternoon, with very warm and humid conditions expected to the south of the front. All 00z model solutions agree on the development of afternoon storms along/ahead of the front from southeast IA into central IL/IN. Moderately strong westerly flow aloft, steep lapse rates, and degree of CAPE suggest a threat of a few strong/severe storms capable of damaging winds and some hail. ...PA/NY... As the aforementioned front sags into western NY, slightly enhanced southwesterly low-level winds will strengthen warm advection and lift over parts of eastern NY/PA. This will likely lead to scattered thunderstorms through the afternoon. Forecast soundings show MLCAPE values over 1000 J/kg and sufficient deep-layer shear for a few organized storm clusters capable of locally gusty/damaging winds. ...NC/VA... Deep west-southwesterly winds will strengthen by this afternoon along a corridor from the southern Appalachians into the Mid-Atlantic states. This enhanced flow/shear profile will aid in helping to organize scattered diurnal thunderstorm development from western NC into parts of southern/eastern VA. Mid-level lapse rates will be poor, but strong heating and high PWAT values will promote a risk of a few intense storm clusters capable of gusty/damaging winds. ...AZ... The upper ridge over the western states will remain centered over parts of NV/UT today, with 15-25 knots of northeasterly mid-level flow across central/eastern AZ. Meanwhile at the surface, considerable moisture is expected to spread northward from Baja CA into the lower deserts overnight, with dewpoints around 60s expected tomorrow. Most 00z CAM guidance suggests multiple clusters of thunderstorms will form along the eastern rim and mountains of eastern AZ, with steering flow helping to spread the storms westward into the moist air mass Wednesday evening. This may lead to a more active convective day over central/southern AZ, with damaging wind gusts possible. Will maintain only MRGL risk at this time, but trends will be monitored for possible upgrade to SLGT in later updates. ...Northwest... Relatively fast cyclonic flow aloft will remain over the Pacific Northwest states into the northern Great Basin. Water vapor imagery shows ample mid-level moisture in place from northern CA into southern OR, which should spread eastward and aid in afternoon thunderstorm development from OR into parts of ID/MT. Forecast soundings show weak CAPE, but a few of the stronger cells could produce locally gusty/damaging winds. ..Hart/Halbert/Lyons.. 07/24/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1211 AM CDT Wed Jul 24 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSISSIPPI AND OHIO VALLEYS...MID ATLANTIC REGION...ARIZONA...AND THE NORTHWEST STATES.... ...SUMMARY... Isolated strong to severe thunderstorms may produce damaging gusts from parts of Iowa/Illinois into Pennsylvania/New York. Other locally strong storms are possible in parts of the Northwest, northern Rockies, Southwest, and Mid Atlantic regions. ...IA/IL/IN... Large-scale troughing will amplify on Wednesday as a shortwave trough over MN digs into the western Great Lakes. A surface cold front will sag into the Mid MS an OH Valleys by afternoon, with very warm and humid conditions expected to the south of the front. All 00z model solutions agree on the development of afternoon storms along/ahead of the front from southeast IA into central IL/IN. Moderately strong westerly flow aloft, steep lapse rates, and degree of CAPE suggest a threat of a few strong/severe storms capable of damaging winds and some hail. ...PA/NY... As the aforementioned front sags into western NY, slightly enhanced southwesterly low-level winds will strengthen warm advection and lift over parts of eastern NY/PA. This will likely lead to scattered thunderstorms through the afternoon. Forecast soundings show MLCAPE values over 1000 J/kg and sufficient deep-layer shear for a few organized storm clusters capable of locally gusty/damaging winds. ...NC/VA... Deep west-southwesterly winds will strengthen by this afternoon along a corridor from the southern Appalachians into the Mid-Atlantic states. This enhanced flow/shear profile will aid in helping to organize scattered diurnal thunderstorm development from western NC into parts of southern/eastern VA. Mid-level lapse rates will be poor, but strong heating and high PWAT values will promote a risk of a few intense storm clusters capable of gusty/damaging winds. ...AZ... The upper ridge over the western states will remain centered over parts of NV/UT today, with 15-25 knots of northeasterly mid-level flow across central/eastern AZ. Meanwhile at the surface, considerable moisture is expected to spread northward from Baja CA into the lower deserts overnight, with dewpoints around 60s expected tomorrow. Most 00z CAM guidance suggests multiple clusters of thunderstorms will form along the eastern rim and mountains of eastern AZ, with steering flow helping to spread the storms westward into the moist air mass Wednesday evening. This may lead to a more active convective day over central/southern AZ, with damaging wind gusts possible. Will maintain only MRGL risk at this time, but trends will be monitored for possible upgrade to SLGT in later updates. ...Northwest... Relatively fast cyclonic flow aloft will remain over the Pacific Northwest states into the northern Great Basin. Water vapor imagery shows ample mid-level moisture in place from northern CA into southern OR, which should spread eastward and aid in afternoon thunderstorm development from OR into parts of ID/MT. Forecast soundings show weak CAPE, but a few of the stronger cells could produce locally gusty/damaging winds. ..Hart/Halbert/Lyons.. 07/24/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Tue Jul 23 2024 Valid 240100Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS EVENING OVER PORTIONS OF THE MID-ATLANTIC REGION...AND PARTS OF SOUTHEAST CALIFORNIA AND WESTERN ARIZONA.... ...SUMMARY... Isolated strong to severe storms are possible across parts of the Mid-Atlantic states and Desert Southwest this evening. ...VA/NC... Clusters of thunderstorms persist this evening across portions of central VA into central NC, in a moist and moderately unstable air mass. A localized strong/severe gust may still occur with these storms for another hour or two, before diurnal cooling stabilizes the environment. ...AZ/CA... Scattered thunderstorms have been affecting parts of southeast CA and western AZ this afternoon and early evening. Visible satellite imagery shows a region that remains mostly clear and ahead of a more organized MCS/outflow over western AZ. This region may still experience locally gusty/damaging wind gusts this evening. ..Hart.. 07/24/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Tue Jul 23 2024 Valid 240100Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS EVENING OVER PORTIONS OF THE MID-ATLANTIC REGION...AND PARTS OF SOUTHEAST CALIFORNIA AND WESTERN ARIZONA.... ...SUMMARY... Isolated strong to severe storms are possible across parts of the Mid-Atlantic states and Desert Southwest this evening. ...VA/NC... Clusters of thunderstorms persist this evening across portions of central VA into central NC, in a moist and moderately unstable air mass. A localized strong/severe gust may still occur with these storms for another hour or two, before diurnal cooling stabilizes the environment. ...AZ/CA... Scattered thunderstorms have been affecting parts of southeast CA and western AZ this afternoon and early evening. Visible satellite imagery shows a region that remains mostly clear and ahead of a more organized MCS/outflow over western AZ. This region may still experience locally gusty/damaging wind gusts this evening. ..Hart.. 07/24/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Tue Jul 23 2024 Valid 240100Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS EVENING OVER PORTIONS OF THE MID-ATLANTIC REGION...AND PARTS OF SOUTHEAST CALIFORNIA AND WESTERN ARIZONA.... ...SUMMARY... Isolated strong to severe storms are possible across parts of the Mid-Atlantic states and Desert Southwest this evening. ...VA/NC... Clusters of thunderstorms persist this evening across portions of central VA into central NC, in a moist and moderately unstable air mass. A localized strong/severe gust may still occur with these storms for another hour or two, before diurnal cooling stabilizes the environment. ...AZ/CA... Scattered thunderstorms have been affecting parts of southeast CA and western AZ this afternoon and early evening. Visible satellite imagery shows a region that remains mostly clear and ahead of a more organized MCS/outflow over western AZ. This region may still experience locally gusty/damaging wind gusts this evening. ..Hart.. 07/24/2024 Read more

No Mesoscale Discussions are in effect as of Tue Jul 23 22:46:02 UTC 2024.

No watches are valid as of Tue Jul 23 22:46:02 UTC 2024.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0446 PM CDT Tue Jul 23 2024 Valid 251200Z - 311200Z The upper-level ridge across much of the West for the past week will continue to break down early in the forecast period as a trough moves across southern Canada and the far northern United States. In the wake of this trough, guidance continues to indicate another trough, albeit much smaller, quickly moving north-northeast out of the Pacific, across the Great Basin, and rejoining the stronger mid-level flow across the Northern Rockies by late this weekend. By early next week the mid-level flow pattern across much of the West will turn zonal. ... Day 3/Thursday ... A multi-faceted fire-weather event should unfold across the interior Pacific Northwest, Northern Rockies, and northern High Plains. This region will experience the greatest impacts from the aforementioned trough moving across the U.S.-Canada border. Winds look to remain elevated across interior portions of Oregon and Washington as strong mid-level flow and a modest surface-pressure gradient remains in place. In addition to increased potential for rapid fire spread of new fires, existing fires from any potential new fire starts from Wednesday's dry thunderstorm event will also pose a threat for rapid spread. Farther east, a seasonably strong lee trough should develop across the northern High Plains in response to the approaching mid-level trough. Relative humidity will fall into at least the teens coincident with the increased low-level winds. Given extremely dry fuels, conditions appear to be coming together for at least locally critical fire conditions. In between the two regions of hot-dry-windy conditions, a plume of increased precipitable water will support isolated thunderstorm develop from southwest Idaho into central Montana. Given proximity to the mid-level jet associated with the trough, thunderstorms should move quickly enough to limit the potential for wetting rains. If confidence in the number of storms increases, a scattered dry thunderstorm area may be needed in subsequent forecasts. ... Day 4/Friday ... As the mid-level trough continues east across the northern United States, a period of downslope winds may develop across portions of northern Montana. This will result in elevated-to-locally critical fire weather conditions. These winds will also pose a threat of rapid fire spread for any fires that ignite over the previous several days of dry thunderstorms and hot-dry-windy conditions. Additionally, locally elevated-to-critical conditions will be possible in the northern High Plains, especially if the associated cold front is delayed in moving across the area. ... Days 5-8/Saturday-Tuesday ... The overall fire threat should lesson a bit during this time period as compared to this week as the mid-level ridge becomes established farther east across the southern Plains. Continued hot-dry conditions will exist, and a belt of increased mid-level moisture may work its way into the West and increase thunderstorm potential, but at this time, confidence in pinpointing the exact evolution of these smaller-scale features is too low to attempt to introduce highlights. ..Marsh.. 07/23/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0446 PM CDT Tue Jul 23 2024 Valid 251200Z - 311200Z The upper-level ridge across much of the West for the past week will continue to break down early in the forecast period as a trough moves across southern Canada and the far northern United States. In the wake of this trough, guidance continues to indicate another trough, albeit much smaller, quickly moving north-northeast out of the Pacific, across the Great Basin, and rejoining the stronger mid-level flow across the Northern Rockies by late this weekend. By early next week the mid-level flow pattern across much of the West will turn zonal. ... Day 3/Thursday ... A multi-faceted fire-weather event should unfold across the interior Pacific Northwest, Northern Rockies, and northern High Plains. This region will experience the greatest impacts from the aforementioned trough moving across the U.S.-Canada border. Winds look to remain elevated across interior portions of Oregon and Washington as strong mid-level flow and a modest surface-pressure gradient remains in place. In addition to increased potential for rapid fire spread of new fires, existing fires from any potential new fire starts from Wednesday's dry thunderstorm event will also pose a threat for rapid spread. Farther east, a seasonably strong lee trough should develop across the northern High Plains in response to the approaching mid-level trough. Relative humidity will fall into at least the teens coincident with the increased low-level winds. Given extremely dry fuels, conditions appear to be coming together for at least locally critical fire conditions. In between the two regions of hot-dry-windy conditions, a plume of increased precipitable water will support isolated thunderstorm develop from southwest Idaho into central Montana. Given proximity to the mid-level jet associated with the trough, thunderstorms should move quickly enough to limit the potential for wetting rains. If confidence in the number of storms increases, a scattered dry thunderstorm area may be needed in subsequent forecasts. ... Day 4/Friday ... As the mid-level trough continues east across the northern United States, a period of downslope winds may develop across portions of northern Montana. This will result in elevated-to-locally critical fire weather conditions. These winds will also pose a threat of rapid fire spread for any fires that ignite over the previous several days of dry thunderstorms and hot-dry-windy conditions. Additionally, locally elevated-to-critical conditions will be possible in the northern High Plains, especially if the associated cold front is delayed in moving across the area. ... Days 5-8/Saturday-Tuesday ... The overall fire threat should lesson a bit during this time period as compared to this week as the mid-level ridge becomes established farther east across the southern Plains. Continued hot-dry conditions will exist, and a belt of increased mid-level moisture may work its way into the West and increase thunderstorm potential, but at this time, confidence in pinpointing the exact evolution of these smaller-scale features is too low to attempt to introduce highlights. ..Marsh.. 07/23/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0446 PM CDT Tue Jul 23 2024 Valid 251200Z - 311200Z The upper-level ridge across much of the West for the past week will continue to break down early in the forecast period as a trough moves across southern Canada and the far northern United States. In the wake of this trough, guidance continues to indicate another trough, albeit much smaller, quickly moving north-northeast out of the Pacific, across the Great Basin, and rejoining the stronger mid-level flow across the Northern Rockies by late this weekend. By early next week the mid-level flow pattern across much of the West will turn zonal. ... Day 3/Thursday ... A multi-faceted fire-weather event should unfold across the interior Pacific Northwest, Northern Rockies, and northern High Plains. This region will experience the greatest impacts from the aforementioned trough moving across the U.S.-Canada border. Winds look to remain elevated across interior portions of Oregon and Washington as strong mid-level flow and a modest surface-pressure gradient remains in place. In addition to increased potential for rapid fire spread of new fires, existing fires from any potential new fire starts from Wednesday's dry thunderstorm event will also pose a threat for rapid spread. Farther east, a seasonably strong lee trough should develop across the northern High Plains in response to the approaching mid-level trough. Relative humidity will fall into at least the teens coincident with the increased low-level winds. Given extremely dry fuels, conditions appear to be coming together for at least locally critical fire conditions. In between the two regions of hot-dry-windy conditions, a plume of increased precipitable water will support isolated thunderstorm develop from southwest Idaho into central Montana. Given proximity to the mid-level jet associated with the trough, thunderstorms should move quickly enough to limit the potential for wetting rains. If confidence in the number of storms increases, a scattered dry thunderstorm area may be needed in subsequent forecasts. ... Day 4/Friday ... As the mid-level trough continues east across the northern United States, a period of downslope winds may develop across portions of northern Montana. This will result in elevated-to-locally critical fire weather conditions. These winds will also pose a threat of rapid fire spread for any fires that ignite over the previous several days of dry thunderstorms and hot-dry-windy conditions. Additionally, locally elevated-to-critical conditions will be possible in the northern High Plains, especially if the associated cold front is delayed in moving across the area. ... Days 5-8/Saturday-Tuesday ... The overall fire threat should lesson a bit during this time period as compared to this week as the mid-level ridge becomes established farther east across the southern Plains. Continued hot-dry conditions will exist, and a belt of increased mid-level moisture may work its way into the West and increase thunderstorm potential, but at this time, confidence in pinpointing the exact evolution of these smaller-scale features is too low to attempt to introduce highlights. ..Marsh.. 07/23/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0446 PM CDT Tue Jul 23 2024 Valid 251200Z - 311200Z The upper-level ridge across much of the West for the past week will continue to break down early in the forecast period as a trough moves across southern Canada and the far northern United States. In the wake of this trough, guidance continues to indicate another trough, albeit much smaller, quickly moving north-northeast out of the Pacific, across the Great Basin, and rejoining the stronger mid-level flow across the Northern Rockies by late this weekend. By early next week the mid-level flow pattern across much of the West will turn zonal. ... Day 3/Thursday ... A multi-faceted fire-weather event should unfold across the interior Pacific Northwest, Northern Rockies, and northern High Plains. This region will experience the greatest impacts from the aforementioned trough moving across the U.S.-Canada border. Winds look to remain elevated across interior portions of Oregon and Washington as strong mid-level flow and a modest surface-pressure gradient remains in place. In addition to increased potential for rapid fire spread of new fires, existing fires from any potential new fire starts from Wednesday's dry thunderstorm event will also pose a threat for rapid spread. Farther east, a seasonably strong lee trough should develop across the northern High Plains in response to the approaching mid-level trough. Relative humidity will fall into at least the teens coincident with the increased low-level winds. Given extremely dry fuels, conditions appear to be coming together for at least locally critical fire conditions. In between the two regions of hot-dry-windy conditions, a plume of increased precipitable water will support isolated thunderstorm develop from southwest Idaho into central Montana. Given proximity to the mid-level jet associated with the trough, thunderstorms should move quickly enough to limit the potential for wetting rains. If confidence in the number of storms increases, a scattered dry thunderstorm area may be needed in subsequent forecasts. ... Day 4/Friday ... As the mid-level trough continues east across the northern United States, a period of downslope winds may develop across portions of northern Montana. This will result in elevated-to-locally critical fire weather conditions. These winds will also pose a threat of rapid fire spread for any fires that ignite over the previous several days of dry thunderstorms and hot-dry-windy conditions. Additionally, locally elevated-to-critical conditions will be possible in the northern High Plains, especially if the associated cold front is delayed in moving across the area. ... Days 5-8/Saturday-Tuesday ... The overall fire threat should lesson a bit during this time period as compared to this week as the mid-level ridge becomes established farther east across the southern Plains. Continued hot-dry conditions will exist, and a belt of increased mid-level moisture may work its way into the West and increase thunderstorm potential, but at this time, confidence in pinpointing the exact evolution of these smaller-scale features is too low to attempt to introduce highlights. ..Marsh.. 07/23/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0446 PM CDT Tue Jul 23 2024 Valid 251200Z - 311200Z The upper-level ridge across much of the West for the past week will continue to break down early in the forecast period as a trough moves across southern Canada and the far northern United States. In the wake of this trough, guidance continues to indicate another trough, albeit much smaller, quickly moving north-northeast out of the Pacific, across the Great Basin, and rejoining the stronger mid-level flow across the Northern Rockies by late this weekend. By early next week the mid-level flow pattern across much of the West will turn zonal. ... Day 3/Thursday ... A multi-faceted fire-weather event should unfold across the interior Pacific Northwest, Northern Rockies, and northern High Plains. This region will experience the greatest impacts from the aforementioned trough moving across the U.S.-Canada border. Winds look to remain elevated across interior portions of Oregon and Washington as strong mid-level flow and a modest surface-pressure gradient remains in place. In addition to increased potential for rapid fire spread of new fires, existing fires from any potential new fire starts from Wednesday's dry thunderstorm event will also pose a threat for rapid spread. Farther east, a seasonably strong lee trough should develop across the northern High Plains in response to the approaching mid-level trough. Relative humidity will fall into at least the teens coincident with the increased low-level winds. Given extremely dry fuels, conditions appear to be coming together for at least locally critical fire conditions. In between the two regions of hot-dry-windy conditions, a plume of increased precipitable water will support isolated thunderstorm develop from southwest Idaho into central Montana. Given proximity to the mid-level jet associated with the trough, thunderstorms should move quickly enough to limit the potential for wetting rains. If confidence in the number of storms increases, a scattered dry thunderstorm area may be needed in subsequent forecasts. ... Day 4/Friday ... As the mid-level trough continues east across the northern United States, a period of downslope winds may develop across portions of northern Montana. This will result in elevated-to-locally critical fire weather conditions. These winds will also pose a threat of rapid fire spread for any fires that ignite over the previous several days of dry thunderstorms and hot-dry-windy conditions. Additionally, locally elevated-to-critical conditions will be possible in the northern High Plains, especially if the associated cold front is delayed in moving across the area. ... Days 5-8/Saturday-Tuesday ... The overall fire threat should lesson a bit during this time period as compared to this week as the mid-level ridge becomes established farther east across the southern Plains. Continued hot-dry conditions will exist, and a belt of increased mid-level moisture may work its way into the West and increase thunderstorm potential, but at this time, confidence in pinpointing the exact evolution of these smaller-scale features is too low to attempt to introduce highlights. ..Marsh.. 07/23/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1698 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR CENTRAL NORTH CAROLINA AND PORTIONS OF SOUTHERN AND SOUTHEASTERN VIRGINIA
Mesoscale Discussion 1698 NWS Storm Prediction Center Norman OK 0257 PM CDT Tue Jul 23 2024 Areas affected...Central North Carolina and portions of southern and southeastern Virginia Concerning...Severe potential...Watch unlikely Valid 231957Z - 232230Z Probability of Watch Issuance...20 percent SUMMARY...An increase in both thunderstorm coverage and intensity is expected across central NC and portions of southern VA over the next 2-3 hours. Localized damaging wind gusts up to 60 mph and hail around 0.75-1.25" will be possible with a few of the thunderstorms. DISCUSSION...Recent observational trends indicate an increase in deep moist convective coverage across central NC and southern VA. Substantial deep layer moisture remains in place across the Mid-Atlantic, with estimated PWATs near or exceeding daily climatological 90th percentiles. Subtly increasing ascent associated with at least one upstream mid-level perturbation within southwesterly flow aloft will continue to aid in scattered thunderstorm development through at least late this afternoon. Widespread updraft organization should remain limited across most this region due to modest deep layer effective shear. However, some stronger mid to upper flow over VA may continue to yield 30-35 kt of effective shear along and north of the VA/NC border, with the possibility of transient supercell structures capable of producing marginally severe hail. The overall severe threat with this activity will be the potential for damaging wind gusts up to 60 mph via precipitation loading/wet microbursts, especially with any merging linear clusters. Even with increasing thunderstorm coverage, the severe weather threat should remain relatively localized and a WW is not anticipated at this time. ..Barnes/Smith.. 07/23/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...LWX...RAH...RNK...CAE...GSP... LAT...LON 35638163 36268141 36718105 37317977 37687897 38177808 38227585 37857569 36977600 36297742 36177767 35807795 35457817 35207823 34827978 34858054 35308130 35638163 Read more