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No watches are valid as of Thu Sep 18 20:46:02 UTC 2025.

MD 2097 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF SOUTHEASTERN CALIFORNIA...SOUTHWESTERN ARIZONA...SOUTHERN NEVADA
Mesoscale Discussion 2097 NWS Storm Prediction Center Norman OK 0148 PM CDT Thu Sep 18 2025 Areas affected...portions of southeastern California...southwestern Arizona...southern Nevada Concerning...Severe potential...Watch unlikely Valid 181848Z - 182115Z Probability of Watch Issuance...20 percent SUMMARY...A few stronger thunderstorms may produce localized damaging wind and small hail this afternoon. DISCUSSION...An extremely unseasonably moist air mass is in place across portions of southern California into southern Arizona as the remnants of tropical cyclone Mario continue to move inland. Dew points are in the mid 60s to 70s across the California and Arizona low deserts (with a dew point of 76 F noted in the observation from Yuma, AZ). A morning band of convection continues northward across southern Nevada, with some increase in intensity over the last hour owing to daytime heating, with around 1000-1500 J/kg MLCAPE noted in surface objective analysis from the RAP. Additional activity has begun to develop south of this wave across the Mexico border and into southern Arizona/California. In addition to the unseasonably moist air mass, at least some weak shear for organization (25-30 kts) is present across the deserts. This will support potential for a few stronger storms and transient supercell structures with potential for damaging wind and small hail. Overall, this risk appears to be fairly localized and as such a watch is unlikely. ..Thornton/Guyer.. 09/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TWC...FGZ...PSR...VEF...SGX... LAT...LON 31871311 32831269 33521263 33841269 34081274 34441289 34701304 35361361 35411374 35541400 35591423 35581503 35521563 35451604 35301639 35071662 34841658 34481652 34301649 34081645 33841639 33561633 33331627 33151623 32851615 32641612 32541604 32501599 32501599 31871311 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Sep 18 2025 Valid 182000Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MISSOURI... ...SUMMARY... Isolated severe storms are possible mainly from late afternoon into tonight across Missouri into adjacent parts of the Lower Missouri Valley and southern Plains. Isolated strong to severe storms may also occur across southern California and the Lower Colorado River Valley. ...20z Update... The previous forecast remains on track. The primary adjustment was an eastward expansion of 5% wind/hail probabilities into northwest AR where pulse convection is developing within a very buoyant (though weakly sheared) environment. Similar thermodynamic/kinematic conditions have yielded sporadic wind/hail reports in recent days, so at least a low-end severe threat is anticipated through early evening (see MCD #2096 for additional details). Elsewhere, the forecast remains on track. Convection is beginning to deepen across northeast OK, far eastern KS, and far southwest MO, which is expected to increase in coverage and intensity within the Slight risk area through the evening based on recent environmental data and CAM solutions. Further west, consideration was given for removing risk probabilities across eastern TX into western OK; however, surface convergence along a diffuse front is gradually increasing with an attendant uptick in mid-level cumulus. Forecast soundings and a couple of recent HRRR/RRFS solutions hint that elevated convection along the boundary remains possible through mid-evening, and deep-layer wind shear is sufficient for organized convection. Across central OK, elevated thunderstorms developing late tonight within a modest warm advection regime may pose a threat for isolated large hail. See the previous discussion below and MCDs #2097 and #2098 for additional details. ..Moore.. 09/18/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/ ...Missouri and Lower Missouri Valley to southern Plains... Generally isolated severe storms will be possible today regionally ahead of the east/southeast-advancing front (and residual convection/outflows), but a somewhat greater/semi-focused corridor of severe potential, mostly in the form of damaging winds, appears to exist across portions of Missouri. This will be influenced by modestly stronger cyclonic flow aloft attendant to the mid/upper-level trough, with a favorably warm/moderately unstable boundary layer this afternoon. Bouts of damaging winds will be possible regionally, with some hail as well. ...Southern California/Lower Colorado River Valley.... An anomalously moist airmass associated with the remnants of tropical cyclone Mario continues to advect northward into and across southern portions of California/Arizona. 12Z NKX sounding sampled a 1.95 PW value, which is well above the 90th percentile based on daily SPC sounding climatology. Filtered heating is anticipated within this moist environment, resulting in moderate buoyancy across much of eastern southern California and southwest Arizona this afternoon. Moderate vertical shear is anticipated as well, particularly across southern California. Additional thunderstorm development is expected during the afternoon, with a predominantly multicellular mode. However, enough shear and instability are in place to support organization with any more persistent updrafts, and a few supercells capable of damaging gusts are possible. A very-low-probability tornado threat may exist as well, particularly in the Lower Colorado Valley vicinity where some guidance suggests surface winds stay more southeasterly. Even so, the low-level flow is weak and any tornado threat should be very localized. ...Eastern South Dakota/southeast North Dakota/western Minnesota... In proximity to the upper low over the Dakotas, a relatively moist environment, sufficient cloud breaks/heating, ample low-level CAPE, and ambient vorticity near a weak surface low and nearby front could be sufficient for some funnels this afternoon through around sunset. A brief non-supercell tornado cannot be conclusively ruled out near the boundary/surface low if stronger destabilization materializes, but the overall potential/likelihood should remain limited. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Sep 18 2025 Valid 182000Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MISSOURI... ...SUMMARY... Isolated severe storms are possible mainly from late afternoon into tonight across Missouri into adjacent parts of the Lower Missouri Valley and southern Plains. Isolated strong to severe storms may also occur across southern California and the Lower Colorado River Valley. ...20z Update... The previous forecast remains on track. The primary adjustment was an eastward expansion of 5% wind/hail probabilities into northwest AR where pulse convection is developing within a very buoyant (though weakly sheared) environment. Similar thermodynamic/kinematic conditions have yielded sporadic wind/hail reports in recent days, so at least a low-end severe threat is anticipated through early evening (see MCD #2096 for additional details). Elsewhere, the forecast remains on track. Convection is beginning to deepen across northeast OK, far eastern KS, and far southwest MO, which is expected to increase in coverage and intensity within the Slight risk area through the evening based on recent environmental data and CAM solutions. Further west, consideration was given for removing risk probabilities across eastern TX into western OK; however, surface convergence along a diffuse front is gradually increasing with an attendant uptick in mid-level cumulus. Forecast soundings and a couple of recent HRRR/RRFS solutions hint that elevated convection along the boundary remains possible through mid-evening, and deep-layer wind shear is sufficient for organized convection. Across central OK, elevated thunderstorms developing late tonight within a modest warm advection regime may pose a threat for isolated large hail. See the previous discussion below and MCDs #2097 and #2098 for additional details. ..Moore.. 09/18/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/ ...Missouri and Lower Missouri Valley to southern Plains... Generally isolated severe storms will be possible today regionally ahead of the east/southeast-advancing front (and residual convection/outflows), but a somewhat greater/semi-focused corridor of severe potential, mostly in the form of damaging winds, appears to exist across portions of Missouri. This will be influenced by modestly stronger cyclonic flow aloft attendant to the mid/upper-level trough, with a favorably warm/moderately unstable boundary layer this afternoon. Bouts of damaging winds will be possible regionally, with some hail as well. ...Southern California/Lower Colorado River Valley.... An anomalously moist airmass associated with the remnants of tropical cyclone Mario continues to advect northward into and across southern portions of California/Arizona. 12Z NKX sounding sampled a 1.95 PW value, which is well above the 90th percentile based on daily SPC sounding climatology. Filtered heating is anticipated within this moist environment, resulting in moderate buoyancy across much of eastern southern California and southwest Arizona this afternoon. Moderate vertical shear is anticipated as well, particularly across southern California. Additional thunderstorm development is expected during the afternoon, with a predominantly multicellular mode. However, enough shear and instability are in place to support organization with any more persistent updrafts, and a few supercells capable of damaging gusts are possible. A very-low-probability tornado threat may exist as well, particularly in the Lower Colorado Valley vicinity where some guidance suggests surface winds stay more southeasterly. Even so, the low-level flow is weak and any tornado threat should be very localized. ...Eastern South Dakota/southeast North Dakota/western Minnesota... In proximity to the upper low over the Dakotas, a relatively moist environment, sufficient cloud breaks/heating, ample low-level CAPE, and ambient vorticity near a weak surface low and nearby front could be sufficient for some funnels this afternoon through around sunset. A brief non-supercell tornado cannot be conclusively ruled out near the boundary/surface low if stronger destabilization materializes, but the overall potential/likelihood should remain limited. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Sep 18 2025 Valid 182000Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MISSOURI... ...SUMMARY... Isolated severe storms are possible mainly from late afternoon into tonight across Missouri into adjacent parts of the Lower Missouri Valley and southern Plains. Isolated strong to severe storms may also occur across southern California and the Lower Colorado River Valley. ...20z Update... The previous forecast remains on track. The primary adjustment was an eastward expansion of 5% wind/hail probabilities into northwest AR where pulse convection is developing within a very buoyant (though weakly sheared) environment. Similar thermodynamic/kinematic conditions have yielded sporadic wind/hail reports in recent days, so at least a low-end severe threat is anticipated through early evening (see MCD #2096 for additional details). Elsewhere, the forecast remains on track. Convection is beginning to deepen across northeast OK, far eastern KS, and far southwest MO, which is expected to increase in coverage and intensity within the Slight risk area through the evening based on recent environmental data and CAM solutions. Further west, consideration was given for removing risk probabilities across eastern TX into western OK; however, surface convergence along a diffuse front is gradually increasing with an attendant uptick in mid-level cumulus. Forecast soundings and a couple of recent HRRR/RRFS solutions hint that elevated convection along the boundary remains possible through mid-evening, and deep-layer wind shear is sufficient for organized convection. Across central OK, elevated thunderstorms developing late tonight within a modest warm advection regime may pose a threat for isolated large hail. See the previous discussion below and MCDs #2097 and #2098 for additional details. ..Moore.. 09/18/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/ ...Missouri and Lower Missouri Valley to southern Plains... Generally isolated severe storms will be possible today regionally ahead of the east/southeast-advancing front (and residual convection/outflows), but a somewhat greater/semi-focused corridor of severe potential, mostly in the form of damaging winds, appears to exist across portions of Missouri. This will be influenced by modestly stronger cyclonic flow aloft attendant to the mid/upper-level trough, with a favorably warm/moderately unstable boundary layer this afternoon. Bouts of damaging winds will be possible regionally, with some hail as well. ...Southern California/Lower Colorado River Valley.... An anomalously moist airmass associated with the remnants of tropical cyclone Mario continues to advect northward into and across southern portions of California/Arizona. 12Z NKX sounding sampled a 1.95 PW value, which is well above the 90th percentile based on daily SPC sounding climatology. Filtered heating is anticipated within this moist environment, resulting in moderate buoyancy across much of eastern southern California and southwest Arizona this afternoon. Moderate vertical shear is anticipated as well, particularly across southern California. Additional thunderstorm development is expected during the afternoon, with a predominantly multicellular mode. However, enough shear and instability are in place to support organization with any more persistent updrafts, and a few supercells capable of damaging gusts are possible. A very-low-probability tornado threat may exist as well, particularly in the Lower Colorado Valley vicinity where some guidance suggests surface winds stay more southeasterly. Even so, the low-level flow is weak and any tornado threat should be very localized. ...Eastern South Dakota/southeast North Dakota/western Minnesota... In proximity to the upper low over the Dakotas, a relatively moist environment, sufficient cloud breaks/heating, ample low-level CAPE, and ambient vorticity near a weak surface low and nearby front could be sufficient for some funnels this afternoon through around sunset. A brief non-supercell tornado cannot be conclusively ruled out near the boundary/surface low if stronger destabilization materializes, but the overall potential/likelihood should remain limited. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Sep 18 2025 Valid 182000Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MISSOURI... ...SUMMARY... Isolated severe storms are possible mainly from late afternoon into tonight across Missouri into adjacent parts of the Lower Missouri Valley and southern Plains. Isolated strong to severe storms may also occur across southern California and the Lower Colorado River Valley. ...20z Update... The previous forecast remains on track. The primary adjustment was an eastward expansion of 5% wind/hail probabilities into northwest AR where pulse convection is developing within a very buoyant (though weakly sheared) environment. Similar thermodynamic/kinematic conditions have yielded sporadic wind/hail reports in recent days, so at least a low-end severe threat is anticipated through early evening (see MCD #2096 for additional details). Elsewhere, the forecast remains on track. Convection is beginning to deepen across northeast OK, far eastern KS, and far southwest MO, which is expected to increase in coverage and intensity within the Slight risk area through the evening based on recent environmental data and CAM solutions. Further west, consideration was given for removing risk probabilities across eastern TX into western OK; however, surface convergence along a diffuse front is gradually increasing with an attendant uptick in mid-level cumulus. Forecast soundings and a couple of recent HRRR/RRFS solutions hint that elevated convection along the boundary remains possible through mid-evening, and deep-layer wind shear is sufficient for organized convection. Across central OK, elevated thunderstorms developing late tonight within a modest warm advection regime may pose a threat for isolated large hail. See the previous discussion below and MCDs #2097 and #2098 for additional details. ..Moore.. 09/18/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/ ...Missouri and Lower Missouri Valley to southern Plains... Generally isolated severe storms will be possible today regionally ahead of the east/southeast-advancing front (and residual convection/outflows), but a somewhat greater/semi-focused corridor of severe potential, mostly in the form of damaging winds, appears to exist across portions of Missouri. This will be influenced by modestly stronger cyclonic flow aloft attendant to the mid/upper-level trough, with a favorably warm/moderately unstable boundary layer this afternoon. Bouts of damaging winds will be possible regionally, with some hail as well. ...Southern California/Lower Colorado River Valley.... An anomalously moist airmass associated with the remnants of tropical cyclone Mario continues to advect northward into and across southern portions of California/Arizona. 12Z NKX sounding sampled a 1.95 PW value, which is well above the 90th percentile based on daily SPC sounding climatology. Filtered heating is anticipated within this moist environment, resulting in moderate buoyancy across much of eastern southern California and southwest Arizona this afternoon. Moderate vertical shear is anticipated as well, particularly across southern California. Additional thunderstorm development is expected during the afternoon, with a predominantly multicellular mode. However, enough shear and instability are in place to support organization with any more persistent updrafts, and a few supercells capable of damaging gusts are possible. A very-low-probability tornado threat may exist as well, particularly in the Lower Colorado Valley vicinity where some guidance suggests surface winds stay more southeasterly. Even so, the low-level flow is weak and any tornado threat should be very localized. ...Eastern South Dakota/southeast North Dakota/western Minnesota... In proximity to the upper low over the Dakotas, a relatively moist environment, sufficient cloud breaks/heating, ample low-level CAPE, and ambient vorticity near a weak surface low and nearby front could be sufficient for some funnels this afternoon through around sunset. A brief non-supercell tornado cannot be conclusively ruled out near the boundary/surface low if stronger destabilization materializes, but the overall potential/likelihood should remain limited. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Sep 18 2025 Valid 182000Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MISSOURI... ...SUMMARY... Isolated severe storms are possible mainly from late afternoon into tonight across Missouri into adjacent parts of the Lower Missouri Valley and southern Plains. Isolated strong to severe storms may also occur across southern California and the Lower Colorado River Valley. ...20z Update... The previous forecast remains on track. The primary adjustment was an eastward expansion of 5% wind/hail probabilities into northwest AR where pulse convection is developing within a very buoyant (though weakly sheared) environment. Similar thermodynamic/kinematic conditions have yielded sporadic wind/hail reports in recent days, so at least a low-end severe threat is anticipated through early evening (see MCD #2096 for additional details). Elsewhere, the forecast remains on track. Convection is beginning to deepen across northeast OK, far eastern KS, and far southwest MO, which is expected to increase in coverage and intensity within the Slight risk area through the evening based on recent environmental data and CAM solutions. Further west, consideration was given for removing risk probabilities across eastern TX into western OK; however, surface convergence along a diffuse front is gradually increasing with an attendant uptick in mid-level cumulus. Forecast soundings and a couple of recent HRRR/RRFS solutions hint that elevated convection along the boundary remains possible through mid-evening, and deep-layer wind shear is sufficient for organized convection. Across central OK, elevated thunderstorms developing late tonight within a modest warm advection regime may pose a threat for isolated large hail. See the previous discussion below and MCDs #2097 and #2098 for additional details. ..Moore.. 09/18/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/ ...Missouri and Lower Missouri Valley to southern Plains... Generally isolated severe storms will be possible today regionally ahead of the east/southeast-advancing front (and residual convection/outflows), but a somewhat greater/semi-focused corridor of severe potential, mostly in the form of damaging winds, appears to exist across portions of Missouri. This will be influenced by modestly stronger cyclonic flow aloft attendant to the mid/upper-level trough, with a favorably warm/moderately unstable boundary layer this afternoon. Bouts of damaging winds will be possible regionally, with some hail as well. ...Southern California/Lower Colorado River Valley.... An anomalously moist airmass associated with the remnants of tropical cyclone Mario continues to advect northward into and across southern portions of California/Arizona. 12Z NKX sounding sampled a 1.95 PW value, which is well above the 90th percentile based on daily SPC sounding climatology. Filtered heating is anticipated within this moist environment, resulting in moderate buoyancy across much of eastern southern California and southwest Arizona this afternoon. Moderate vertical shear is anticipated as well, particularly across southern California. Additional thunderstorm development is expected during the afternoon, with a predominantly multicellular mode. However, enough shear and instability are in place to support organization with any more persistent updrafts, and a few supercells capable of damaging gusts are possible. A very-low-probability tornado threat may exist as well, particularly in the Lower Colorado Valley vicinity where some guidance suggests surface winds stay more southeasterly. Even so, the low-level flow is weak and any tornado threat should be very localized. ...Eastern South Dakota/southeast North Dakota/western Minnesota... In proximity to the upper low over the Dakotas, a relatively moist environment, sufficient cloud breaks/heating, ample low-level CAPE, and ambient vorticity near a weak surface low and nearby front could be sufficient for some funnels this afternoon through around sunset. A brief non-supercell tornado cannot be conclusively ruled out near the boundary/surface low if stronger destabilization materializes, but the overall potential/likelihood should remain limited. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Sep 18 2025 Valid 182000Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MISSOURI... ...SUMMARY... Isolated severe storms are possible mainly from late afternoon into tonight across Missouri into adjacent parts of the Lower Missouri Valley and southern Plains. Isolated strong to severe storms may also occur across southern California and the Lower Colorado River Valley. ...20z Update... The previous forecast remains on track. The primary adjustment was an eastward expansion of 5% wind/hail probabilities into northwest AR where pulse convection is developing within a very buoyant (though weakly sheared) environment. Similar thermodynamic/kinematic conditions have yielded sporadic wind/hail reports in recent days, so at least a low-end severe threat is anticipated through early evening (see MCD #2096 for additional details). Elsewhere, the forecast remains on track. Convection is beginning to deepen across northeast OK, far eastern KS, and far southwest MO, which is expected to increase in coverage and intensity within the Slight risk area through the evening based on recent environmental data and CAM solutions. Further west, consideration was given for removing risk probabilities across eastern TX into western OK; however, surface convergence along a diffuse front is gradually increasing with an attendant uptick in mid-level cumulus. Forecast soundings and a couple of recent HRRR/RRFS solutions hint that elevated convection along the boundary remains possible through mid-evening, and deep-layer wind shear is sufficient for organized convection. Across central OK, elevated thunderstorms developing late tonight within a modest warm advection regime may pose a threat for isolated large hail. See the previous discussion below and MCDs #2097 and #2098 for additional details. ..Moore.. 09/18/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/ ...Missouri and Lower Missouri Valley to southern Plains... Generally isolated severe storms will be possible today regionally ahead of the east/southeast-advancing front (and residual convection/outflows), but a somewhat greater/semi-focused corridor of severe potential, mostly in the form of damaging winds, appears to exist across portions of Missouri. This will be influenced by modestly stronger cyclonic flow aloft attendant to the mid/upper-level trough, with a favorably warm/moderately unstable boundary layer this afternoon. Bouts of damaging winds will be possible regionally, with some hail as well. ...Southern California/Lower Colorado River Valley.... An anomalously moist airmass associated with the remnants of tropical cyclone Mario continues to advect northward into and across southern portions of California/Arizona. 12Z NKX sounding sampled a 1.95 PW value, which is well above the 90th percentile based on daily SPC sounding climatology. Filtered heating is anticipated within this moist environment, resulting in moderate buoyancy across much of eastern southern California and southwest Arizona this afternoon. Moderate vertical shear is anticipated as well, particularly across southern California. Additional thunderstorm development is expected during the afternoon, with a predominantly multicellular mode. However, enough shear and instability are in place to support organization with any more persistent updrafts, and a few supercells capable of damaging gusts are possible. A very-low-probability tornado threat may exist as well, particularly in the Lower Colorado Valley vicinity where some guidance suggests surface winds stay more southeasterly. Even so, the low-level flow is weak and any tornado threat should be very localized. ...Eastern South Dakota/southeast North Dakota/western Minnesota... In proximity to the upper low over the Dakotas, a relatively moist environment, sufficient cloud breaks/heating, ample low-level CAPE, and ambient vorticity near a weak surface low and nearby front could be sufficient for some funnels this afternoon through around sunset. A brief non-supercell tornado cannot be conclusively ruled out near the boundary/surface low if stronger destabilization materializes, but the overall potential/likelihood should remain limited. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Sep 18 2025 Valid 182000Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MISSOURI... ...SUMMARY... Isolated severe storms are possible mainly from late afternoon into tonight across Missouri into adjacent parts of the Lower Missouri Valley and southern Plains. Isolated strong to severe storms may also occur across southern California and the Lower Colorado River Valley. ...20z Update... The previous forecast remains on track. The primary adjustment was an eastward expansion of 5% wind/hail probabilities into northwest AR where pulse convection is developing within a very buoyant (though weakly sheared) environment. Similar thermodynamic/kinematic conditions have yielded sporadic wind/hail reports in recent days, so at least a low-end severe threat is anticipated through early evening (see MCD #2096 for additional details). Elsewhere, the forecast remains on track. Convection is beginning to deepen across northeast OK, far eastern KS, and far southwest MO, which is expected to increase in coverage and intensity within the Slight risk area through the evening based on recent environmental data and CAM solutions. Further west, consideration was given for removing risk probabilities across eastern TX into western OK; however, surface convergence along a diffuse front is gradually increasing with an attendant uptick in mid-level cumulus. Forecast soundings and a couple of recent HRRR/RRFS solutions hint that elevated convection along the boundary remains possible through mid-evening, and deep-layer wind shear is sufficient for organized convection. Across central OK, elevated thunderstorms developing late tonight within a modest warm advection regime may pose a threat for isolated large hail. See the previous discussion below and MCDs #2097 and #2098 for additional details. ..Moore.. 09/18/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/ ...Missouri and Lower Missouri Valley to southern Plains... Generally isolated severe storms will be possible today regionally ahead of the east/southeast-advancing front (and residual convection/outflows), but a somewhat greater/semi-focused corridor of severe potential, mostly in the form of damaging winds, appears to exist across portions of Missouri. This will be influenced by modestly stronger cyclonic flow aloft attendant to the mid/upper-level trough, with a favorably warm/moderately unstable boundary layer this afternoon. Bouts of damaging winds will be possible regionally, with some hail as well. ...Southern California/Lower Colorado River Valley.... An anomalously moist airmass associated with the remnants of tropical cyclone Mario continues to advect northward into and across southern portions of California/Arizona. 12Z NKX sounding sampled a 1.95 PW value, which is well above the 90th percentile based on daily SPC sounding climatology. Filtered heating is anticipated within this moist environment, resulting in moderate buoyancy across much of eastern southern California and southwest Arizona this afternoon. Moderate vertical shear is anticipated as well, particularly across southern California. Additional thunderstorm development is expected during the afternoon, with a predominantly multicellular mode. However, enough shear and instability are in place to support organization with any more persistent updrafts, and a few supercells capable of damaging gusts are possible. A very-low-probability tornado threat may exist as well, particularly in the Lower Colorado Valley vicinity where some guidance suggests surface winds stay more southeasterly. Even so, the low-level flow is weak and any tornado threat should be very localized. ...Eastern South Dakota/southeast North Dakota/western Minnesota... In proximity to the upper low over the Dakotas, a relatively moist environment, sufficient cloud breaks/heating, ample low-level CAPE, and ambient vorticity near a weak surface low and nearby front could be sufficient for some funnels this afternoon through around sunset. A brief non-supercell tornado cannot be conclusively ruled out near the boundary/surface low if stronger destabilization materializes, but the overall potential/likelihood should remain limited. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Sep 18 2025 Valid 182000Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MISSOURI... ...SUMMARY... Isolated severe storms are possible mainly from late afternoon into tonight across Missouri into adjacent parts of the Lower Missouri Valley and southern Plains. Isolated strong to severe storms may also occur across southern California and the Lower Colorado River Valley. ...20z Update... The previous forecast remains on track. The primary adjustment was an eastward expansion of 5% wind/hail probabilities into northwest AR where pulse convection is developing within a very buoyant (though weakly sheared) environment. Similar thermodynamic/kinematic conditions have yielded sporadic wind/hail reports in recent days, so at least a low-end severe threat is anticipated through early evening (see MCD #2096 for additional details). Elsewhere, the forecast remains on track. Convection is beginning to deepen across northeast OK, far eastern KS, and far southwest MO, which is expected to increase in coverage and intensity within the Slight risk area through the evening based on recent environmental data and CAM solutions. Further west, consideration was given for removing risk probabilities across eastern TX into western OK; however, surface convergence along a diffuse front is gradually increasing with an attendant uptick in mid-level cumulus. Forecast soundings and a couple of recent HRRR/RRFS solutions hint that elevated convection along the boundary remains possible through mid-evening, and deep-layer wind shear is sufficient for organized convection. Across central OK, elevated thunderstorms developing late tonight within a modest warm advection regime may pose a threat for isolated large hail. See the previous discussion below and MCDs #2097 and #2098 for additional details. ..Moore.. 09/18/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/ ...Missouri and Lower Missouri Valley to southern Plains... Generally isolated severe storms will be possible today regionally ahead of the east/southeast-advancing front (and residual convection/outflows), but a somewhat greater/semi-focused corridor of severe potential, mostly in the form of damaging winds, appears to exist across portions of Missouri. This will be influenced by modestly stronger cyclonic flow aloft attendant to the mid/upper-level trough, with a favorably warm/moderately unstable boundary layer this afternoon. Bouts of damaging winds will be possible regionally, with some hail as well. ...Southern California/Lower Colorado River Valley.... An anomalously moist airmass associated with the remnants of tropical cyclone Mario continues to advect northward into and across southern portions of California/Arizona. 12Z NKX sounding sampled a 1.95 PW value, which is well above the 90th percentile based on daily SPC sounding climatology. Filtered heating is anticipated within this moist environment, resulting in moderate buoyancy across much of eastern southern California and southwest Arizona this afternoon. Moderate vertical shear is anticipated as well, particularly across southern California. Additional thunderstorm development is expected during the afternoon, with a predominantly multicellular mode. However, enough shear and instability are in place to support organization with any more persistent updrafts, and a few supercells capable of damaging gusts are possible. A very-low-probability tornado threat may exist as well, particularly in the Lower Colorado Valley vicinity where some guidance suggests surface winds stay more southeasterly. Even so, the low-level flow is weak and any tornado threat should be very localized. ...Eastern South Dakota/southeast North Dakota/western Minnesota... In proximity to the upper low over the Dakotas, a relatively moist environment, sufficient cloud breaks/heating, ample low-level CAPE, and ambient vorticity near a weak surface low and nearby front could be sufficient for some funnels this afternoon through around sunset. A brief non-supercell tornado cannot be conclusively ruled out near the boundary/surface low if stronger destabilization materializes, but the overall potential/likelihood should remain limited. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Sep 18 2025 Valid 182000Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MISSOURI... ...SUMMARY... Isolated severe storms are possible mainly from late afternoon into tonight across Missouri into adjacent parts of the Lower Missouri Valley and southern Plains. Isolated strong to severe storms may also occur across southern California and the Lower Colorado River Valley. ...20z Update... The previous forecast remains on track. The primary adjustment was an eastward expansion of 5% wind/hail probabilities into northwest AR where pulse convection is developing within a very buoyant (though weakly sheared) environment. Similar thermodynamic/kinematic conditions have yielded sporadic wind/hail reports in recent days, so at least a low-end severe threat is anticipated through early evening (see MCD #2096 for additional details). Elsewhere, the forecast remains on track. Convection is beginning to deepen across northeast OK, far eastern KS, and far southwest MO, which is expected to increase in coverage and intensity within the Slight risk area through the evening based on recent environmental data and CAM solutions. Further west, consideration was given for removing risk probabilities across eastern TX into western OK; however, surface convergence along a diffuse front is gradually increasing with an attendant uptick in mid-level cumulus. Forecast soundings and a couple of recent HRRR/RRFS solutions hint that elevated convection along the boundary remains possible through mid-evening, and deep-layer wind shear is sufficient for organized convection. Across central OK, elevated thunderstorms developing late tonight within a modest warm advection regime may pose a threat for isolated large hail. See the previous discussion below and MCDs #2097 and #2098 for additional details. ..Moore.. 09/18/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/ ...Missouri and Lower Missouri Valley to southern Plains... Generally isolated severe storms will be possible today regionally ahead of the east/southeast-advancing front (and residual convection/outflows), but a somewhat greater/semi-focused corridor of severe potential, mostly in the form of damaging winds, appears to exist across portions of Missouri. This will be influenced by modestly stronger cyclonic flow aloft attendant to the mid/upper-level trough, with a favorably warm/moderately unstable boundary layer this afternoon. Bouts of damaging winds will be possible regionally, with some hail as well. ...Southern California/Lower Colorado River Valley.... An anomalously moist airmass associated with the remnants of tropical cyclone Mario continues to advect northward into and across southern portions of California/Arizona. 12Z NKX sounding sampled a 1.95 PW value, which is well above the 90th percentile based on daily SPC sounding climatology. Filtered heating is anticipated within this moist environment, resulting in moderate buoyancy across much of eastern southern California and southwest Arizona this afternoon. Moderate vertical shear is anticipated as well, particularly across southern California. Additional thunderstorm development is expected during the afternoon, with a predominantly multicellular mode. However, enough shear and instability are in place to support organization with any more persistent updrafts, and a few supercells capable of damaging gusts are possible. A very-low-probability tornado threat may exist as well, particularly in the Lower Colorado Valley vicinity where some guidance suggests surface winds stay more southeasterly. Even so, the low-level flow is weak and any tornado threat should be very localized. ...Eastern South Dakota/southeast North Dakota/western Minnesota... In proximity to the upper low over the Dakotas, a relatively moist environment, sufficient cloud breaks/heating, ample low-level CAPE, and ambient vorticity near a weak surface low and nearby front could be sufficient for some funnels this afternoon through around sunset. A brief non-supercell tornado cannot be conclusively ruled out near the boundary/surface low if stronger destabilization materializes, but the overall potential/likelihood should remain limited. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Sep 18 2025 Valid 182000Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MISSOURI... ...SUMMARY... Isolated severe storms are possible mainly from late afternoon into tonight across Missouri into adjacent parts of the Lower Missouri Valley and southern Plains. Isolated strong to severe storms may also occur across southern California and the Lower Colorado River Valley. ...20z Update... The previous forecast remains on track. The primary adjustment was an eastward expansion of 5% wind/hail probabilities into northwest AR where pulse convection is developing within a very buoyant (though weakly sheared) environment. Similar thermodynamic/kinematic conditions have yielded sporadic wind/hail reports in recent days, so at least a low-end severe threat is anticipated through early evening (see MCD #2096 for additional details). Elsewhere, the forecast remains on track. Convection is beginning to deepen across northeast OK, far eastern KS, and far southwest MO, which is expected to increase in coverage and intensity within the Slight risk area through the evening based on recent environmental data and CAM solutions. Further west, consideration was given for removing risk probabilities across eastern TX into western OK; however, surface convergence along a diffuse front is gradually increasing with an attendant uptick in mid-level cumulus. Forecast soundings and a couple of recent HRRR/RRFS solutions hint that elevated convection along the boundary remains possible through mid-evening, and deep-layer wind shear is sufficient for organized convection. Across central OK, elevated thunderstorms developing late tonight within a modest warm advection regime may pose a threat for isolated large hail. See the previous discussion below and MCDs #2097 and #2098 for additional details. ..Moore.. 09/18/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/ ...Missouri and Lower Missouri Valley to southern Plains... Generally isolated severe storms will be possible today regionally ahead of the east/southeast-advancing front (and residual convection/outflows), but a somewhat greater/semi-focused corridor of severe potential, mostly in the form of damaging winds, appears to exist across portions of Missouri. This will be influenced by modestly stronger cyclonic flow aloft attendant to the mid/upper-level trough, with a favorably warm/moderately unstable boundary layer this afternoon. Bouts of damaging winds will be possible regionally, with some hail as well. ...Southern California/Lower Colorado River Valley.... An anomalously moist airmass associated with the remnants of tropical cyclone Mario continues to advect northward into and across southern portions of California/Arizona. 12Z NKX sounding sampled a 1.95 PW value, which is well above the 90th percentile based on daily SPC sounding climatology. Filtered heating is anticipated within this moist environment, resulting in moderate buoyancy across much of eastern southern California and southwest Arizona this afternoon. Moderate vertical shear is anticipated as well, particularly across southern California. Additional thunderstorm development is expected during the afternoon, with a predominantly multicellular mode. However, enough shear and instability are in place to support organization with any more persistent updrafts, and a few supercells capable of damaging gusts are possible. A very-low-probability tornado threat may exist as well, particularly in the Lower Colorado Valley vicinity where some guidance suggests surface winds stay more southeasterly. Even so, the low-level flow is weak and any tornado threat should be very localized. ...Eastern South Dakota/southeast North Dakota/western Minnesota... In proximity to the upper low over the Dakotas, a relatively moist environment, sufficient cloud breaks/heating, ample low-level CAPE, and ambient vorticity near a weak surface low and nearby front could be sufficient for some funnels this afternoon through around sunset. A brief non-supercell tornado cannot be conclusively ruled out near the boundary/surface low if stronger destabilization materializes, but the overall potential/likelihood should remain limited. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Sep 18 2025 Valid 182000Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MISSOURI... ...SUMMARY... Isolated severe storms are possible mainly from late afternoon into tonight across Missouri into adjacent parts of the Lower Missouri Valley and southern Plains. Isolated strong to severe storms may also occur across southern California and the Lower Colorado River Valley. ...20z Update... The previous forecast remains on track. The primary adjustment was an eastward expansion of 5% wind/hail probabilities into northwest AR where pulse convection is developing within a very buoyant (though weakly sheared) environment. Similar thermodynamic/kinematic conditions have yielded sporadic wind/hail reports in recent days, so at least a low-end severe threat is anticipated through early evening (see MCD #2096 for additional details). Elsewhere, the forecast remains on track. Convection is beginning to deepen across northeast OK, far eastern KS, and far southwest MO, which is expected to increase in coverage and intensity within the Slight risk area through the evening based on recent environmental data and CAM solutions. Further west, consideration was given for removing risk probabilities across eastern TX into western OK; however, surface convergence along a diffuse front is gradually increasing with an attendant uptick in mid-level cumulus. Forecast soundings and a couple of recent HRRR/RRFS solutions hint that elevated convection along the boundary remains possible through mid-evening, and deep-layer wind shear is sufficient for organized convection. Across central OK, elevated thunderstorms developing late tonight within a modest warm advection regime may pose a threat for isolated large hail. See the previous discussion below and MCDs #2097 and #2098 for additional details. ..Moore.. 09/18/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/ ...Missouri and Lower Missouri Valley to southern Plains... Generally isolated severe storms will be possible today regionally ahead of the east/southeast-advancing front (and residual convection/outflows), but a somewhat greater/semi-focused corridor of severe potential, mostly in the form of damaging winds, appears to exist across portions of Missouri. This will be influenced by modestly stronger cyclonic flow aloft attendant to the mid/upper-level trough, with a favorably warm/moderately unstable boundary layer this afternoon. Bouts of damaging winds will be possible regionally, with some hail as well. ...Southern California/Lower Colorado River Valley.... An anomalously moist airmass associated with the remnants of tropical cyclone Mario continues to advect northward into and across southern portions of California/Arizona. 12Z NKX sounding sampled a 1.95 PW value, which is well above the 90th percentile based on daily SPC sounding climatology. Filtered heating is anticipated within this moist environment, resulting in moderate buoyancy across much of eastern southern California and southwest Arizona this afternoon. Moderate vertical shear is anticipated as well, particularly across southern California. Additional thunderstorm development is expected during the afternoon, with a predominantly multicellular mode. However, enough shear and instability are in place to support organization with any more persistent updrafts, and a few supercells capable of damaging gusts are possible. A very-low-probability tornado threat may exist as well, particularly in the Lower Colorado Valley vicinity where some guidance suggests surface winds stay more southeasterly. Even so, the low-level flow is weak and any tornado threat should be very localized. ...Eastern South Dakota/southeast North Dakota/western Minnesota... In proximity to the upper low over the Dakotas, a relatively moist environment, sufficient cloud breaks/heating, ample low-level CAPE, and ambient vorticity near a weak surface low and nearby front could be sufficient for some funnels this afternoon through around sunset. A brief non-supercell tornado cannot be conclusively ruled out near the boundary/surface low if stronger destabilization materializes, but the overall potential/likelihood should remain limited. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Thu Sep 18 2025 Valid 182000Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MISSOURI... ...SUMMARY... Isolated severe storms are possible mainly from late afternoon into tonight across Missouri into adjacent parts of the Lower Missouri Valley and southern Plains. Isolated strong to severe storms may also occur across southern California and the Lower Colorado River Valley. ...20z Update... The previous forecast remains on track. The primary adjustment was an eastward expansion of 5% wind/hail probabilities into northwest AR where pulse convection is developing within a very buoyant (though weakly sheared) environment. Similar thermodynamic/kinematic conditions have yielded sporadic wind/hail reports in recent days, so at least a low-end severe threat is anticipated through early evening (see MCD #2096 for additional details). Elsewhere, the forecast remains on track. Convection is beginning to deepen across northeast OK, far eastern KS, and far southwest MO, which is expected to increase in coverage and intensity within the Slight risk area through the evening based on recent environmental data and CAM solutions. Further west, consideration was given for removing risk probabilities across eastern TX into western OK; however, surface convergence along a diffuse front is gradually increasing with an attendant uptick in mid-level cumulus. Forecast soundings and a couple of recent HRRR/RRFS solutions hint that elevated convection along the boundary remains possible through mid-evening, and deep-layer wind shear is sufficient for organized convection. Across central OK, elevated thunderstorms developing late tonight within a modest warm advection regime may pose a threat for isolated large hail. See the previous discussion below and MCDs #2097 and #2098 for additional details. ..Moore.. 09/18/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/ ...Missouri and Lower Missouri Valley to southern Plains... Generally isolated severe storms will be possible today regionally ahead of the east/southeast-advancing front (and residual convection/outflows), but a somewhat greater/semi-focused corridor of severe potential, mostly in the form of damaging winds, appears to exist across portions of Missouri. This will be influenced by modestly stronger cyclonic flow aloft attendant to the mid/upper-level trough, with a favorably warm/moderately unstable boundary layer this afternoon. Bouts of damaging winds will be possible regionally, with some hail as well. ...Southern California/Lower Colorado River Valley.... An anomalously moist airmass associated with the remnants of tropical cyclone Mario continues to advect northward into and across southern portions of California/Arizona. 12Z NKX sounding sampled a 1.95 PW value, which is well above the 90th percentile based on daily SPC sounding climatology. Filtered heating is anticipated within this moist environment, resulting in moderate buoyancy across much of eastern southern California and southwest Arizona this afternoon. Moderate vertical shear is anticipated as well, particularly across southern California. Additional thunderstorm development is expected during the afternoon, with a predominantly multicellular mode. However, enough shear and instability are in place to support organization with any more persistent updrafts, and a few supercells capable of damaging gusts are possible. A very-low-probability tornado threat may exist as well, particularly in the Lower Colorado Valley vicinity where some guidance suggests surface winds stay more southeasterly. Even so, the low-level flow is weak and any tornado threat should be very localized. ...Eastern South Dakota/southeast North Dakota/western Minnesota... In proximity to the upper low over the Dakotas, a relatively moist environment, sufficient cloud breaks/heating, ample low-level CAPE, and ambient vorticity near a weak surface low and nearby front could be sufficient for some funnels this afternoon through around sunset. A brief non-supercell tornado cannot be conclusively ruled out near the boundary/surface low if stronger destabilization materializes, but the overall potential/likelihood should remain limited. Read more

MD 2096 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EASTERN OK...NORTHEAST TX...WESTERN AR...AND FAR SOUTHWEST MO
Mesoscale Discussion 2096 NWS Storm Prediction Center Norman OK 0141 PM CDT Thu Sep 18 2025 Areas affected...Parts of eastern OK...northeast TX...western AR...and far southwest MO Concerning...Severe potential...Watch unlikely Valid 181841Z - 182045Z Probability of Watch Issuance...5 percent SUMMARY...Isolated pulse-severe storms are possible through the afternoon. The stronger storms will be capable of producing locally damaging gusts and sporadic, marginally severe hail. DISCUSSION...Isolated to widely scattered thunderstorms are evolving within broadly confluent low-level flow extending from northwest AR across southeast OK, with a focus over higher terrain features. While this activity is generally displaced from the stronger midlevel southwesterlies attendant to a shortwave trough traversing KS, strong boundary-layer heating/mixing amid middle/upper 60s dewpoints is yielding a favorable environment for pulse-severe storms. Locally damaging gusts and sporadic, marginally severe hail will be possible with the stronger storms through the afternoon. Given the sporadic/mostly disorganized storm mode, a watch is not expected here. ..Weinman/Guyer.. 09/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...SGF...SHV...TSA...FWD...OUN... LAT...LON 34319702 34729658 36159475 36559402 36659351 36559270 36179240 35679233 34729302 33609409 33309472 33189537 33269625 33629697 34049716 34319702 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0236 PM CDT Thu Sep 18 2025 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Afternoon Update... Low potential for thunderstorms exists ahead of the mid-level moisture surge over portions of northern CA and southern OR Friday into Friday night. Should storms form, a primarily wet mode is expected with PWATS near or exceeding 1 inch at times, which should temper already limited fuels across the southern Cascades. Still, a low-end chance for lightning ignitions exists if storms develop over areas of drier fuels. Widespread concerns are not expected. ...New England... Breezy conditions (gusts 10-15 mph) are possible over parts of New England behind a departing cold front Friday afternoon and evening. As northwesterly flow aloft intensifies, vertical mixing and offshore flow will favor drying of the boundary layer with RH falling below 40%. While surface winds are not expected to be overly strong, ongoing drought is supporting drier than average fuel conditions over much of the Northeast. The increase in gusty winds and low humidity could allow for a modest increase in local elevated fire-weather conditions late Friday. ..Lyons.. 09/18/2025 .PREV DISCUSSION... /ISSUED 0149 AM CDT Thu Sep 18 2025/ ...Synopsis... A mid-level trough will traverse the Upper Mississippi Valley as a weak upper trough meanders along the West Coast tomorrow (Friday). A surface low over the Upper Mississippi Valley will encourage moist conditions across the Plains, while a benign surface pattern west of the Rockies will result in another quiescent day (fire weather wise) across the Interior West. Dry low-level conditions may persist over the Ohio Valley on Friday. However, like Day 1, the lack of a stronger surface wind field should limit the potential for wildfire spread. ...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 0236 PM CDT Thu Sep 18 2025 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Afternoon Update... Low potential for thunderstorms exists ahead of the mid-level moisture surge over portions of northern CA and southern OR Friday into Friday night. Should storms form, a primarily wet mode is expected with PWATS near or exceeding 1 inch at times, which should temper already limited fuels across the southern Cascades. Still, a low-end chance for lightning ignitions exists if storms develop over areas of drier fuels. Widespread concerns are not expected. ...New England... Breezy conditions (gusts 10-15 mph) are possible over parts of New England behind a departing cold front Friday afternoon and evening. As northwesterly flow aloft intensifies, vertical mixing and offshore flow will favor drying of the boundary layer with RH falling below 40%. While surface winds are not expected to be overly strong, ongoing drought is supporting drier than average fuel conditions over much of the Northeast. The increase in gusty winds and low humidity could allow for a modest increase in local elevated fire-weather conditions late Friday. ..Lyons.. 09/18/2025 .PREV DISCUSSION... /ISSUED 0149 AM CDT Thu Sep 18 2025/ ...Synopsis... A mid-level trough will traverse the Upper Mississippi Valley as a weak upper trough meanders along the West Coast tomorrow (Friday). A surface low over the Upper Mississippi Valley will encourage moist conditions across the Plains, while a benign surface pattern west of the Rockies will result in another quiescent day (fire weather wise) across the Interior West. Dry low-level conditions may persist over the Ohio Valley on Friday. However, like Day 1, the lack of a stronger surface wind field should limit the potential for wildfire spread. ...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 0236 PM CDT Thu Sep 18 2025 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Afternoon Update... Low potential for thunderstorms exists ahead of the mid-level moisture surge over portions of northern CA and southern OR Friday into Friday night. Should storms form, a primarily wet mode is expected with PWATS near or exceeding 1 inch at times, which should temper already limited fuels across the southern Cascades. Still, a low-end chance for lightning ignitions exists if storms develop over areas of drier fuels. Widespread concerns are not expected. ...New England... Breezy conditions (gusts 10-15 mph) are possible over parts of New England behind a departing cold front Friday afternoon and evening. As northwesterly flow aloft intensifies, vertical mixing and offshore flow will favor drying of the boundary layer with RH falling below 40%. While surface winds are not expected to be overly strong, ongoing drought is supporting drier than average fuel conditions over much of the Northeast. The increase in gusty winds and low humidity could allow for a modest increase in local elevated fire-weather conditions late Friday. ..Lyons.. 09/18/2025 .PREV DISCUSSION... /ISSUED 0149 AM CDT Thu Sep 18 2025/ ...Synopsis... A mid-level trough will traverse the Upper Mississippi Valley as a weak upper trough meanders along the West Coast tomorrow (Friday). A surface low over the Upper Mississippi Valley will encourage moist conditions across the Plains, while a benign surface pattern west of the Rockies will result in another quiescent day (fire weather wise) across the Interior West. Dry low-level conditions may persist over the Ohio Valley on Friday. However, like Day 1, the lack of a stronger surface wind field should limit the potential for wildfire spread. ...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 0236 PM CDT Thu Sep 18 2025 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Afternoon Update... Low potential for thunderstorms exists ahead of the mid-level moisture surge over portions of northern CA and southern OR Friday into Friday night. Should storms form, a primarily wet mode is expected with PWATS near or exceeding 1 inch at times, which should temper already limited fuels across the southern Cascades. Still, a low-end chance for lightning ignitions exists if storms develop over areas of drier fuels. Widespread concerns are not expected. ...New England... Breezy conditions (gusts 10-15 mph) are possible over parts of New England behind a departing cold front Friday afternoon and evening. As northwesterly flow aloft intensifies, vertical mixing and offshore flow will favor drying of the boundary layer with RH falling below 40%. While surface winds are not expected to be overly strong, ongoing drought is supporting drier than average fuel conditions over much of the Northeast. The increase in gusty winds and low humidity could allow for a modest increase in local elevated fire-weather conditions late Friday. ..Lyons.. 09/18/2025 .PREV DISCUSSION... /ISSUED 0149 AM CDT Thu Sep 18 2025/ ...Synopsis... A mid-level trough will traverse the Upper Mississippi Valley as a weak upper trough meanders along the West Coast tomorrow (Friday). A surface low over the Upper Mississippi Valley will encourage moist conditions across the Plains, while a benign surface pattern west of the Rockies will result in another quiescent day (fire weather wise) across the Interior West. Dry low-level conditions may persist over the Ohio Valley on Friday. However, like Day 1, the lack of a stronger surface wind field should limit the potential for wildfire spread. ...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 0236 PM CDT Thu Sep 18 2025 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Afternoon Update... Low potential for thunderstorms exists ahead of the mid-level moisture surge over portions of northern CA and southern OR Friday into Friday night. Should storms form, a primarily wet mode is expected with PWATS near or exceeding 1 inch at times, which should temper already limited fuels across the southern Cascades. Still, a low-end chance for lightning ignitions exists if storms develop over areas of drier fuels. Widespread concerns are not expected. ...New England... Breezy conditions (gusts 10-15 mph) are possible over parts of New England behind a departing cold front Friday afternoon and evening. As northwesterly flow aloft intensifies, vertical mixing and offshore flow will favor drying of the boundary layer with RH falling below 40%. While surface winds are not expected to be overly strong, ongoing drought is supporting drier than average fuel conditions over much of the Northeast. The increase in gusty winds and low humidity could allow for a modest increase in local elevated fire-weather conditions late Friday. ..Lyons.. 09/18/2025 .PREV DISCUSSION... /ISSUED 0149 AM CDT Thu Sep 18 2025/ ...Synopsis... A mid-level trough will traverse the Upper Mississippi Valley as a weak upper trough meanders along the West Coast tomorrow (Friday). A surface low over the Upper Mississippi Valley will encourage moist conditions across the Plains, while a benign surface pattern west of the Rockies will result in another quiescent day (fire weather wise) across the Interior West. Dry low-level conditions may persist over the Ohio Valley on Friday. However, like Day 1, the lack of a stronger surface wind field should limit the potential for wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more