Aggregator

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...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 0304 PM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z No changes are need to the previous D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 07/14/2024 .PREV DISCUSSION... /ISSUED 0206 AM CDT Sun Jul 14 2024/ ...Synopsis... Isolated to widely scattered dry thunderstorms are expected again on Monday as a weak mid-level perturbation (currently off the CA coast) continues to translate to the north/northeast on the northwestern periphery of a de-amplifying upper ridge over the Four Corners. The diminishing ridge and weak nature of the offshore low will result in muted surface pressure gradients and generally benign winds away from convective outflows. A plume of 0.5 to 0.75 PWAT values is already in place across the Great Basin and central Rockies, and thunderstorms over the preceding days are not expected to appreciably moisten the lowest few kilometers or provide much wetting rainfall. This should maintain receptive fuels and favorable thermodynamic profiles for dry thunderstorms across a large swath of the Great Basin. Thunderstorm coverage may be higher across the central and northern Rockies, but higher PWAT values, lower LCLs, and higher MUCAPE values suggest the potential for wet thunderstorms should increase with eastward extent. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN PLAINS AND THE MIDWEST INTO THE OHIO VALLEY... ...SUMMARY... Strong to severe thunderstorms are still expected from the northern Plains into the Upper Midwest and Ohio Valley this afternoon through tonight. ...20Z Update... The primary changes made to this outlook were to adjust severe probabilities in the northern Plains to account for both the latest guidance consensus, and reflect recent trends in observations and re-analysis. Visible satellite and surface observations indicate a northwest-to-southeast oriented baroclinic boundary draped over extreme northeast MT/northwestern ND, down to central and eastern SD, extending to the MN border. Though MLCINH remains over the warm sector, and additional airmass modification is needed for appreciable airmass recovery after earlier storms, several hours of surface heating remain. Furthermore, this boundary may serve as a focal point for deep-moist convection to initiate and anchor on later this evening. Latest guidance consensus suggests that supercell structures with mainly a hail threat will materialize closer to the U.S./Canada by around 00Z (perhaps before). Thereafter, upscale growth into an MCS is possible along the baroclinic boundary. Should this occur, steep mid-level lapse rates, along with adequate vertical wind shear may promote a corridor of severe gusts, and a 75+ mph gust or two is possible, hence the addition of a hatched area within the Northern Plains Category 2/Slight Risk. The Slight Risk in the Midwest was also expanded a bit westward in IA to account for potential westward convective initiation. This convection may also form into an MCS and traverse the same areas impacted by an earlier MCS, hence why changes were not made farther east despite some convective overturning noted. Otherwise, the forecast remains on track across the west of the CONUS. ..Squitieri.. 07/14/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Sun Jul 14 2024/ ...Synopsis... West-northwesterly flow aloft is in place today across the northern Plains and Midwest, with several small-scale features noted in satellite imagery embedded in the flow. This will result in multiple MCSs from MT into the upper OH valley during this period. ...IN/OH this afternoon... A linear MCS is currently ongoing over portions of northwest IN and northeast IL. Strong heating ahead of the system across much of IN/OH, combined with surface dewpoints near 70F will yield a corridor of moderate CAPE, likely aiding intensification of storms. Given 20-25 knots of mid-level flow and relatively steep mid-level lapse rates, a few strong to severe storms are possible through the afternoon. Please refer to MCD #1612 for further details. ...Eastern IA/Southern WI/Northern IL/Northern IN... Strong heating is occurring in wake of aforementioned MCS across parts of eastern IA/southern WI/northern IL, where ample low-level moisture remains. A well-defined remnant MCV from the overnight severe MCS over SD is currently over northern IA, and will track into the destabilizing air mass. A consensus of morning CAM solutions suggest that thunderstorms will develop ahead of the MCV and track toward northern IL/IN this evening. Damaging winds and some hail would be the main threats. ...Northeast MT/Dakotas/Western MN... Water vapor imagery shows a strong upper trough digging southeastward across southern AB. Large scale lift ahead of this system will lead to scattered thunderstorm development by early evening across portions of northeast MT and western ND. Model solutions remain diverse in the details of how this convective scenario unfolds. However, it appears likely that one or more clusters of strong/severe storms will track across ND and into northeast SD/western MN during the night. Large hail and damaging winds will be possible with these storms. ...Mid Atlantic... Widely scattered afternoon thunderstorms are expected today from parts of eastern VA northeastward into eastern PA and NJ. Winds through the low/mid troposphere are rather weak and lapse rates are poor. Nevertheless, ample low-level moisture and rather high PWAT values may result in gusty winds near the strongest storms. ...AZ... Clear skies early today combined with dewpoints in the mid 60s will yield a hot and moderately unstable air mass this afternoon with MLCAPE values of 1000-1500 J/kg. Thunderstorms are expected to form over the higher terrain of western NM/eastern AZ and along the rim later today, with sufficient easterly mid-level flow to aid propagation off the mountains. Locally damaging wind gusts may accompany these storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN PLAINS AND THE MIDWEST INTO THE OHIO VALLEY... ...SUMMARY... Strong to severe thunderstorms are still expected from the northern Plains into the Upper Midwest and Ohio Valley this afternoon through tonight. ...20Z Update... The primary changes made to this outlook were to adjust severe probabilities in the northern Plains to account for both the latest guidance consensus, and reflect recent trends in observations and re-analysis. Visible satellite and surface observations indicate a northwest-to-southeast oriented baroclinic boundary draped over extreme northeast MT/northwestern ND, down to central and eastern SD, extending to the MN border. Though MLCINH remains over the warm sector, and additional airmass modification is needed for appreciable airmass recovery after earlier storms, several hours of surface heating remain. Furthermore, this boundary may serve as a focal point for deep-moist convection to initiate and anchor on later this evening. Latest guidance consensus suggests that supercell structures with mainly a hail threat will materialize closer to the U.S./Canada by around 00Z (perhaps before). Thereafter, upscale growth into an MCS is possible along the baroclinic boundary. Should this occur, steep mid-level lapse rates, along with adequate vertical wind shear may promote a corridor of severe gusts, and a 75+ mph gust or two is possible, hence the addition of a hatched area within the Northern Plains Category 2/Slight Risk. The Slight Risk in the Midwest was also expanded a bit westward in IA to account for potential westward convective initiation. This convection may also form into an MCS and traverse the same areas impacted by an earlier MCS, hence why changes were not made farther east despite some convective overturning noted. Otherwise, the forecast remains on track across the west of the CONUS. ..Squitieri.. 07/14/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Sun Jul 14 2024/ ...Synopsis... West-northwesterly flow aloft is in place today across the northern Plains and Midwest, with several small-scale features noted in satellite imagery embedded in the flow. This will result in multiple MCSs from MT into the upper OH valley during this period. ...IN/OH this afternoon... A linear MCS is currently ongoing over portions of northwest IN and northeast IL. Strong heating ahead of the system across much of IN/OH, combined with surface dewpoints near 70F will yield a corridor of moderate CAPE, likely aiding intensification of storms. Given 20-25 knots of mid-level flow and relatively steep mid-level lapse rates, a few strong to severe storms are possible through the afternoon. Please refer to MCD #1612 for further details. ...Eastern IA/Southern WI/Northern IL/Northern IN... Strong heating is occurring in wake of aforementioned MCS across parts of eastern IA/southern WI/northern IL, where ample low-level moisture remains. A well-defined remnant MCV from the overnight severe MCS over SD is currently over northern IA, and will track into the destabilizing air mass. A consensus of morning CAM solutions suggest that thunderstorms will develop ahead of the MCV and track toward northern IL/IN this evening. Damaging winds and some hail would be the main threats. ...Northeast MT/Dakotas/Western MN... Water vapor imagery shows a strong upper trough digging southeastward across southern AB. Large scale lift ahead of this system will lead to scattered thunderstorm development by early evening across portions of northeast MT and western ND. Model solutions remain diverse in the details of how this convective scenario unfolds. However, it appears likely that one or more clusters of strong/severe storms will track across ND and into northeast SD/western MN during the night. Large hail and damaging winds will be possible with these storms. ...Mid Atlantic... Widely scattered afternoon thunderstorms are expected today from parts of eastern VA northeastward into eastern PA and NJ. Winds through the low/mid troposphere are rather weak and lapse rates are poor. Nevertheless, ample low-level moisture and rather high PWAT values may result in gusty winds near the strongest storms. ...AZ... Clear skies early today combined with dewpoints in the mid 60s will yield a hot and moderately unstable air mass this afternoon with MLCAPE values of 1000-1500 J/kg. Thunderstorms are expected to form over the higher terrain of western NM/eastern AZ and along the rim later today, with sufficient easterly mid-level flow to aid propagation off the mountains. Locally damaging wind gusts may accompany these storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN PLAINS AND THE MIDWEST INTO THE OHIO VALLEY... ...SUMMARY... Strong to severe thunderstorms are still expected from the northern Plains into the Upper Midwest and Ohio Valley this afternoon through tonight. ...20Z Update... The primary changes made to this outlook were to adjust severe probabilities in the northern Plains to account for both the latest guidance consensus, and reflect recent trends in observations and re-analysis. Visible satellite and surface observations indicate a northwest-to-southeast oriented baroclinic boundary draped over extreme northeast MT/northwestern ND, down to central and eastern SD, extending to the MN border. Though MLCINH remains over the warm sector, and additional airmass modification is needed for appreciable airmass recovery after earlier storms, several hours of surface heating remain. Furthermore, this boundary may serve as a focal point for deep-moist convection to initiate and anchor on later this evening. Latest guidance consensus suggests that supercell structures with mainly a hail threat will materialize closer to the U.S./Canada by around 00Z (perhaps before). Thereafter, upscale growth into an MCS is possible along the baroclinic boundary. Should this occur, steep mid-level lapse rates, along with adequate vertical wind shear may promote a corridor of severe gusts, and a 75+ mph gust or two is possible, hence the addition of a hatched area within the Northern Plains Category 2/Slight Risk. The Slight Risk in the Midwest was also expanded a bit westward in IA to account for potential westward convective initiation. This convection may also form into an MCS and traverse the same areas impacted by an earlier MCS, hence why changes were not made farther east despite some convective overturning noted. Otherwise, the forecast remains on track across the west of the CONUS. ..Squitieri.. 07/14/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Sun Jul 14 2024/ ...Synopsis... West-northwesterly flow aloft is in place today across the northern Plains and Midwest, with several small-scale features noted in satellite imagery embedded in the flow. This will result in multiple MCSs from MT into the upper OH valley during this period. ...IN/OH this afternoon... A linear MCS is currently ongoing over portions of northwest IN and northeast IL. Strong heating ahead of the system across much of IN/OH, combined with surface dewpoints near 70F will yield a corridor of moderate CAPE, likely aiding intensification of storms. Given 20-25 knots of mid-level flow and relatively steep mid-level lapse rates, a few strong to severe storms are possible through the afternoon. Please refer to MCD #1612 for further details. ...Eastern IA/Southern WI/Northern IL/Northern IN... Strong heating is occurring in wake of aforementioned MCS across parts of eastern IA/southern WI/northern IL, where ample low-level moisture remains. A well-defined remnant MCV from the overnight severe MCS over SD is currently over northern IA, and will track into the destabilizing air mass. A consensus of morning CAM solutions suggest that thunderstorms will develop ahead of the MCV and track toward northern IL/IN this evening. Damaging winds and some hail would be the main threats. ...Northeast MT/Dakotas/Western MN... Water vapor imagery shows a strong upper trough digging southeastward across southern AB. Large scale lift ahead of this system will lead to scattered thunderstorm development by early evening across portions of northeast MT and western ND. Model solutions remain diverse in the details of how this convective scenario unfolds. However, it appears likely that one or more clusters of strong/severe storms will track across ND and into northeast SD/western MN during the night. Large hail and damaging winds will be possible with these storms. ...Mid Atlantic... Widely scattered afternoon thunderstorms are expected today from parts of eastern VA northeastward into eastern PA and NJ. Winds through the low/mid troposphere are rather weak and lapse rates are poor. Nevertheless, ample low-level moisture and rather high PWAT values may result in gusty winds near the strongest storms. ...AZ... Clear skies early today combined with dewpoints in the mid 60s will yield a hot and moderately unstable air mass this afternoon with MLCAPE values of 1000-1500 J/kg. Thunderstorms are expected to form over the higher terrain of western NM/eastern AZ and along the rim later today, with sufficient easterly mid-level flow to aid propagation off the mountains. Locally damaging wind gusts may accompany these storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN PLAINS AND THE MIDWEST INTO THE OHIO VALLEY... ...SUMMARY... Strong to severe thunderstorms are still expected from the northern Plains into the Upper Midwest and Ohio Valley this afternoon through tonight. ...20Z Update... The primary changes made to this outlook were to adjust severe probabilities in the northern Plains to account for both the latest guidance consensus, and reflect recent trends in observations and re-analysis. Visible satellite and surface observations indicate a northwest-to-southeast oriented baroclinic boundary draped over extreme northeast MT/northwestern ND, down to central and eastern SD, extending to the MN border. Though MLCINH remains over the warm sector, and additional airmass modification is needed for appreciable airmass recovery after earlier storms, several hours of surface heating remain. Furthermore, this boundary may serve as a focal point for deep-moist convection to initiate and anchor on later this evening. Latest guidance consensus suggests that supercell structures with mainly a hail threat will materialize closer to the U.S./Canada by around 00Z (perhaps before). Thereafter, upscale growth into an MCS is possible along the baroclinic boundary. Should this occur, steep mid-level lapse rates, along with adequate vertical wind shear may promote a corridor of severe gusts, and a 75+ mph gust or two is possible, hence the addition of a hatched area within the Northern Plains Category 2/Slight Risk. The Slight Risk in the Midwest was also expanded a bit westward in IA to account for potential westward convective initiation. This convection may also form into an MCS and traverse the same areas impacted by an earlier MCS, hence why changes were not made farther east despite some convective overturning noted. Otherwise, the forecast remains on track across the west of the CONUS. ..Squitieri.. 07/14/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Sun Jul 14 2024/ ...Synopsis... West-northwesterly flow aloft is in place today across the northern Plains and Midwest, with several small-scale features noted in satellite imagery embedded in the flow. This will result in multiple MCSs from MT into the upper OH valley during this period. ...IN/OH this afternoon... A linear MCS is currently ongoing over portions of northwest IN and northeast IL. Strong heating ahead of the system across much of IN/OH, combined with surface dewpoints near 70F will yield a corridor of moderate CAPE, likely aiding intensification of storms. Given 20-25 knots of mid-level flow and relatively steep mid-level lapse rates, a few strong to severe storms are possible through the afternoon. Please refer to MCD #1612 for further details. ...Eastern IA/Southern WI/Northern IL/Northern IN... Strong heating is occurring in wake of aforementioned MCS across parts of eastern IA/southern WI/northern IL, where ample low-level moisture remains. A well-defined remnant MCV from the overnight severe MCS over SD is currently over northern IA, and will track into the destabilizing air mass. A consensus of morning CAM solutions suggest that thunderstorms will develop ahead of the MCV and track toward northern IL/IN this evening. Damaging winds and some hail would be the main threats. ...Northeast MT/Dakotas/Western MN... Water vapor imagery shows a strong upper trough digging southeastward across southern AB. Large scale lift ahead of this system will lead to scattered thunderstorm development by early evening across portions of northeast MT and western ND. Model solutions remain diverse in the details of how this convective scenario unfolds. However, it appears likely that one or more clusters of strong/severe storms will track across ND and into northeast SD/western MN during the night. Large hail and damaging winds will be possible with these storms. ...Mid Atlantic... Widely scattered afternoon thunderstorms are expected today from parts of eastern VA northeastward into eastern PA and NJ. Winds through the low/mid troposphere are rather weak and lapse rates are poor. Nevertheless, ample low-level moisture and rather high PWAT values may result in gusty winds near the strongest storms. ...AZ... Clear skies early today combined with dewpoints in the mid 60s will yield a hot and moderately unstable air mass this afternoon with MLCAPE values of 1000-1500 J/kg. Thunderstorms are expected to form over the higher terrain of western NM/eastern AZ and along the rim later today, with sufficient easterly mid-level flow to aid propagation off the mountains. Locally damaging wind gusts may accompany these storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun Jul 14 2024 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN PLAINS AND THE MIDWEST INTO THE OHIO VALLEY... ...SUMMARY... Strong to severe thunderstorms are still expected from the northern Plains into the Upper Midwest and Ohio Valley this afternoon through tonight. ...20Z Update... The primary changes made to this outlook were to adjust severe probabilities in the northern Plains to account for both the latest guidance consensus, and reflect recent trends in observations and re-analysis. Visible satellite and surface observations indicate a northwest-to-southeast oriented baroclinic boundary draped over extreme northeast MT/northwestern ND, down to central and eastern SD, extending to the MN border. Though MLCINH remains over the warm sector, and additional airmass modification is needed for appreciable airmass recovery after earlier storms, several hours of surface heating remain. Furthermore, this boundary may serve as a focal point for deep-moist convection to initiate and anchor on later this evening. Latest guidance consensus suggests that supercell structures with mainly a hail threat will materialize closer to the U.S./Canada by around 00Z (perhaps before). Thereafter, upscale growth into an MCS is possible along the baroclinic boundary. Should this occur, steep mid-level lapse rates, along with adequate vertical wind shear may promote a corridor of severe gusts, and a 75+ mph gust or two is possible, hence the addition of a hatched area within the Northern Plains Category 2/Slight Risk. The Slight Risk in the Midwest was also expanded a bit westward in IA to account for potential westward convective initiation. This convection may also form into an MCS and traverse the same areas impacted by an earlier MCS, hence why changes were not made farther east despite some convective overturning noted. Otherwise, the forecast remains on track across the west of the CONUS. ..Squitieri.. 07/14/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Sun Jul 14 2024/ ...Synopsis... West-northwesterly flow aloft is in place today across the northern Plains and Midwest, with several small-scale features noted in satellite imagery embedded in the flow. This will result in multiple MCSs from MT into the upper OH valley during this period. ...IN/OH this afternoon... A linear MCS is currently ongoing over portions of northwest IN and northeast IL. Strong heating ahead of the system across much of IN/OH, combined with surface dewpoints near 70F will yield a corridor of moderate CAPE, likely aiding intensification of storms. Given 20-25 knots of mid-level flow and relatively steep mid-level lapse rates, a few strong to severe storms are possible through the afternoon. Please refer to MCD #1612 for further details. ...Eastern IA/Southern WI/Northern IL/Northern IN... Strong heating is occurring in wake of aforementioned MCS across parts of eastern IA/southern WI/northern IL, where ample low-level moisture remains. A well-defined remnant MCV from the overnight severe MCS over SD is currently over northern IA, and will track into the destabilizing air mass. A consensus of morning CAM solutions suggest that thunderstorms will develop ahead of the MCV and track toward northern IL/IN this evening. Damaging winds and some hail would be the main threats. ...Northeast MT/Dakotas/Western MN... Water vapor imagery shows a strong upper trough digging southeastward across southern AB. Large scale lift ahead of this system will lead to scattered thunderstorm development by early evening across portions of northeast MT and western ND. Model solutions remain diverse in the details of how this convective scenario unfolds. However, it appears likely that one or more clusters of strong/severe storms will track across ND and into northeast SD/western MN during the night. Large hail and damaging winds will be possible with these storms. ...Mid Atlantic... Widely scattered afternoon thunderstorms are expected today from parts of eastern VA northeastward into eastern PA and NJ. Winds through the low/mid troposphere are rather weak and lapse rates are poor. Nevertheless, ample low-level moisture and rather high PWAT values may result in gusty winds near the strongest storms. ...AZ... Clear skies early today combined with dewpoints in the mid 60s will yield a hot and moderately unstable air mass this afternoon with MLCAPE values of 1000-1500 J/kg. Thunderstorms are expected to form over the higher terrain of western NM/eastern AZ and along the rim later today, with sufficient easterly mid-level flow to aid propagation off the mountains. Locally damaging wind gusts may accompany these storms. Read more