Severe Storms

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0728 PM CDT Fri Oct 13 2023 Valid 140100Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe-storm risk has diminished in the Mid-Mississippi Valley area. Severe weather will remain unlikely through the rest of the period. ...Discussion... Convection ongoing across parts of Iowa and Illinois continues to weaken this evening, as nocturnal cooling continues to yield steadily decreasing instability. This has resulted in a cessation of appreciable severe potential. Occasional lightning will be possible across the Midwest/Ohio Valley as the storm system associated with the convective activity advances eastward. A few thunderstorms across Deep South Texas, and southern Florida, may persist through the evening and into the overnight, while a few storms may develop later over portions of eastern South Carolina and vicinity. However, severe weather is not expected. ..Goss.. 10/14/2023 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0447 PM CDT Fri Oct 13 2023 Valid 151200Z - 211200Z Surface high pressure will dominate the United States early next week as a cool, continental airmass is in place across much of the CONUS. Lee troughing may return by the middle of the week and bring some dry and breezy conditions to the Plains and vicinity. However, relative humidity is not expected to be that low, and these breezy conditions are anticipated where fuels are currently moist and should remain so. Therefore, fire weather concerns should remain minimal through next week. ..Bentley.. 10/13/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0748 PM CDT Thu Oct 12 2023 Valid 130100Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS MAINLY FROM EASTERN NEBRASKA AND KANSAS INTO WESTERN IOWA AND NORTHWEST MISSOURI... ...SUMMARY... A few severe storms remain possible this evening mainly over parts of eastern Nebraska. ...Central Plains... An upper low will continue to move slowly east across NE through tonight, with a 70-80 kt midlevel jet pushing east into IA and northern MO. At the surface, low pressure will fill as it moves east across the same areas. Storms have generally decreased in intensity this evening due to the cooling air mass, except for farther south into east-central KS in closer proximity to the surface warm plume. 00Z soundings downstream indicate minimal instability overall, with little additional destabilization expected as a cooling boundary layer counteracts any cooling aloft. Shear will remain strong over northern areas, but waning instability should limit the overall severe risk. As such, a Marginal Risk will remain over the area for sporadic hail in the stronger cells. ..Jewell.. 10/13/2023 Read more

No watches are valid as of Fri Oct 13 00:53:01 UTC 2023.

No Mesoscale Discussions are in effect as of Fri Oct 13 00:53:01 UTC 2023.

No watches are valid as of Thu Oct 12 01:53:02 UTC 2023.

MD 2239 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF NORTHERN AND CENTRAL NEBRASKA...SOUTHEASTERN SOUTH DAKOTA AND WEST CENTRAL IOWA
Mesoscale Discussion 2239 NWS Storm Prediction Center Norman OK 0850 PM CDT Wed Oct 11 2023 Areas affected...portions of northern and central Nebraska...southeastern South Dakota and west central Iowa Concerning...Severe potential...Watch unlikely Valid 120150Z - 120415Z Probability of Watch Issuance...20 percent SUMMARY...Increasing low-level warm advection may support additional thunderstorms capable of isolated hail this evening. Confidence in storm coverage and severity is low and a watch is not expected. DISCUSSION...As of 0140 UTC, regional IR satellite imagery showed cooling cloud tops along a band of convection across portions of the central Plains. Located along and north of a warm front emanating from a deepening lee low over eastern CO, convection is expected to continue to slowly deepen and increase in coverage near the frontal corridor through this evening and into the overnight hours. Area VADs and surface obs show low-level mass response ahead of the deepening low, along with a moderately strong low-level jet. Favored by the uptick in low and mid-level warm advection, forcing for ascent should continue to build this evening supporting additional storm development. While not overly robust, sufficient buoyancy (~500-1000 J/kg of MUCAPE) along the warm front should support a few stronger updrafts. Bolstered by a band of westerly mid-level flow associated with the deepening low, 30-40 kt effective shear may also support some organization of these updrafts into sustained multicells or transient supercell structures. Generally north of the surface warm front and with nocturnal cooling ongoing at the surface, storms should remain elevated with the main risk being isolated hail with the more sustained/robust updrafts. Hi-res guidance varies on the degree of storm coverage/intensity through this evening, casting uncertainty on how widespread any severe risk will be. However, current radar and observational trends do suggest a few stronger storms with hail potential may evolve over north-central NE and spread into portions of southern SD and western IA tonight. ..Lyons/Guyer.. 10/12/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DMX...FSD...OAX...GID...LBF...UNR... LAT...LON 41389491 41249657 41279934 41540048 41580061 42210136 43050101 43280048 43629845 43569762 43369652 43139586 42669435 42249336 41639310 41429388 41389491 Read more

No Mesoscale Discussions are in effect as of Thu Oct 12 00:52:01 UTC 2023.

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0744 PM CDT Wed Oct 11 2023 Valid 120100Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF CENTRAL AND WESTERN FLORIDA TOWARD THE COASTAL BEND... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes are possible this evening and tonight over the western Florida Peninsula/coastal-bend region. Strong to severe thunderstorms over the central Plains and Midwest may be capable of marginal hail through late tonight. ...Much of the western FL Peninsula to the coastal FL Panhandle... A front currently extends across north-central FL, with cool and relatively stable air to the north. The 00Z JAX sounding shows poor lapse rates and no instability within this air mass. The TLH exhibits similar characteristics, north of the boundary. South of these areas, and where winds have a southerly component, upper 70s F dewpoints are contributing to modest instability, ahead of the developing areas of storms over the Gulf of Mexico. Shear profiles are strengthening across the entire area in anticipation of the approaching convectively enhanced low, and a few supercells perhaps with tornado risk will conditionally be possible with any storms that move ashore. This appears most likely late tonight from the Coastal Bend southeastward toward the Tampa Bay area as stronger instability develops with time. ...From NE into northern IL... The 00Z LBF sounding shows nearly 1000 J/kg MLCAPE present, with steep lapse rates aloft. Meanwhile, showers and thunderstorms currently extend from the western Panhandle into northeast CO. As the surface low deepens and low-level theta-e advection persists with backed boundary-layer winds, conditions should remain favorable for scattered storms to develop, with some likely producing hail. Large-scale ascent will remain favorable, with increasing storm coverage likely later this evening. Effective shear appears to further favor cellular storm modes which will be favorable for hail. Isolated strong gusts may also occur in proximity to the warm surface air near the warm front. ..Jewell.. 10/12/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0744 PM CDT Wed Oct 11 2023 Valid 120100Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF CENTRAL AND WESTERN FLORIDA TOWARD THE COASTAL BEND... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes are possible this evening and tonight over the western Florida Peninsula/coastal-bend region. Strong to severe thunderstorms over the central Plains and Midwest may be capable of marginal hail through late tonight. ...Much of the western FL Peninsula to the coastal FL Panhandle... A front currently extends across north-central FL, with cool and relatively stable air to the north. The 00Z JAX sounding shows poor lapse rates and no instability within this air mass. The TLH exhibits similar characteristics, north of the boundary. South of these areas, and where winds have a southerly component, upper 70s F dewpoints are contributing to modest instability, ahead of the developing areas of storms over the Gulf of Mexico. Shear profiles are strengthening across the entire area in anticipation of the approaching convectively enhanced low, and a few supercells perhaps with tornado risk will conditionally be possible with any storms that move ashore. This appears most likely late tonight from the Coastal Bend southeastward toward the Tampa Bay area as stronger instability develops with time. ...From NE into northern IL... The 00Z LBF sounding shows nearly 1000 J/kg MLCAPE present, with steep lapse rates aloft. Meanwhile, showers and thunderstorms currently extend from the western Panhandle into northeast CO. As the surface low deepens and low-level theta-e advection persists with backed boundary-layer winds, conditions should remain favorable for scattered storms to develop, with some likely producing hail. Large-scale ascent will remain favorable, with increasing storm coverage likely later this evening. Effective shear appears to further favor cellular storm modes which will be favorable for hail. Isolated strong gusts may also occur in proximity to the warm surface air near the warm front. ..Jewell.. 10/12/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 PM CDT Tue Oct 10 2023 Valid 110100Z - 111200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. Scattered storms are expected to develop later tonight over parts of the middle and lower Missouri Valley. Non-severe, diurnally driven storms over western TX are expected to wane this evening as the boundary layer cools. To the northeast, a band of elevated convection is forecast after 06Z from southeast NE into MO, in association with increasing theta-e advection with southwest 850 mb flow to 40 kt. Forecast soundings show cool midlevel temperatures, but overall marginal instability to support any hail over 1.00" diameter. While initial development could exhibit robust updrafts, effective shear does not appear to support anything long-lived enough to produce severe weather. ..Jewell.. 10/11/2023 Read more

No watches are valid as of Wed Oct 11 00:59:01 UTC 2023.

No Mesoscale Discussions are in effect as of Wed Oct 11 00:59:01 UTC 2023.

No watches are valid as of Tue Oct 10 23:49:02 UTC 2023.

No Mesoscale Discussions are in effect as of Tue Oct 10 23:49:02 UTC 2023.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0307 PM CDT Tue Oct 10 2023 Valid 121200Z - 181200Z The period will begin with a mid-level trough ejecting from the Rockies and impinging on the Mississippi Valley late this week into the weekend, encouraging strong surface cyclone development across the central Plains. Trailing this cyclone will be a surface dryline and cold front, accompanied by dry and windy conditions across portions of the southern High Plains. 40 percent critical probabilities have been maintained across portions of the southern High Plains Day 3/Thursday, where confidence is highest in at least Elevated-equivalent dry and windy conditions occurring. High pressure building over the Interior West will encourage the strengthening of a surface pressure gradient over southern California on Thursday, supporting dry offshore flow, warranting the introduction of 40 percent Critical probabilities. For Friday into Saturday, the cold front and accompanying dry and breezy conditions will overspread portions of western Texas into the Lower Mississippi Valley. However, confidence in long-duration dry and windy conditions is low, with Critical probabilities withheld. After Saturday, surface high pressure and cooler surface temperatures will overspread much of the central and western CONUS, limiting significant wildfire-spread concerns. ..Squitieri.. 10/10/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0307 PM CDT Tue Oct 10 2023 Valid 121200Z - 181200Z The period will begin with a mid-level trough ejecting from the Rockies and impinging on the Mississippi Valley late this week into the weekend, encouraging strong surface cyclone development across the central Plains. Trailing this cyclone will be a surface dryline and cold front, accompanied by dry and windy conditions across portions of the southern High Plains. 40 percent critical probabilities have been maintained across portions of the southern High Plains Day 3/Thursday, where confidence is highest in at least Elevated-equivalent dry and windy conditions occurring. High pressure building over the Interior West will encourage the strengthening of a surface pressure gradient over southern California on Thursday, supporting dry offshore flow, warranting the introduction of 40 percent Critical probabilities. For Friday into Saturday, the cold front and accompanying dry and breezy conditions will overspread portions of western Texas into the Lower Mississippi Valley. However, confidence in long-duration dry and windy conditions is low, with Critical probabilities withheld. After Saturday, surface high pressure and cooler surface temperatures will overspread much of the central and western CONUS, limiting significant wildfire-spread concerns. ..Squitieri.. 10/10/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0307 PM CDT Tue Oct 10 2023 Valid 121200Z - 181200Z The period will begin with a mid-level trough ejecting from the Rockies and impinging on the Mississippi Valley late this week into the weekend, encouraging strong surface cyclone development across the central Plains. Trailing this cyclone will be a surface dryline and cold front, accompanied by dry and windy conditions across portions of the southern High Plains. 40 percent critical probabilities have been maintained across portions of the southern High Plains Day 3/Thursday, where confidence is highest in at least Elevated-equivalent dry and windy conditions occurring. High pressure building over the Interior West will encourage the strengthening of a surface pressure gradient over southern California on Thursday, supporting dry offshore flow, warranting the introduction of 40 percent Critical probabilities. For Friday into Saturday, the cold front and accompanying dry and breezy conditions will overspread portions of western Texas into the Lower Mississippi Valley. However, confidence in long-duration dry and windy conditions is low, with Critical probabilities withheld. After Saturday, surface high pressure and cooler surface temperatures will overspread much of the central and western CONUS, limiting significant wildfire-spread concerns. ..Squitieri.. 10/10/2023 ...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 0238 PM CDT Tue Oct 10 2023 Valid 102000Z - 111200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...20z Update... No changes have been made to the outlook with the 20z update, and severe storms are not expected through tonight. ..Leitman.. 10/10/2023 .PREV DISCUSSION... /ISSUED 1108 AM CDT Tue Oct 10 2023/ ...Synopsis... Thunderstorm potential today/tonight will be primarily influenced by the deepening of an upper wave (noted off the Pacific Northwest coast in morning satellite imagery) as it moves into the inter-mountain West over the next 24 hours. ...Pacific Northwest to the Southern High Plains... Across the Pacific Northwest and northern Rockies, cooling temperatures aloft combined with strong dynamic ascent within the left-exit region of the attendant upper jet will support widespread rainfall with embedded convection through tomorrow morning. Along the OR/WA coasts, latest satellite imagery depicts cooler/drier air aloft moving onshore, which should bolster low to mid-level buoyancy through the day. While some low-level shear is noted in coastal forecast soundings, hodograph structure through tonight is forecast to remain somewhat poor with 0-1 km SRH values sub-100 m2/s2. Combined with a transient convective signal in latest CAM guidance, the coastal tornado potential remains too limited to introduce probabilities. Steep mid-level lapse rates and residual mid-level moisture sampled by 12 UTC soundings from the northern Great Basin into the Southwest may support very isolated thunderstorms through the afternoon from southern WY to northern NM amid continued mid-level height falls. However, the broad-scale nature of the ascent combined with very low PWAT values suggests any convection should be fairly isolated and short lived. Additionally, a lack of a convective signal in any 12 UTC guidance limits confidence in thunder occurrence and coverage outside of southwest CO where a relatively stronger convective signal is noted in HREF thunder probabilities. Thunderstorm potential is higher across the southern High Plains where weak moisture return is coincident with steady surface pressure falls. ...Kansas/Missouri... A weak band of isentropic ascent in the 850-700 mb layer should continue to support occasional lighting flashes across central/eastern KS this afternoon. A strengthening low-level jet will bolster thunderstorm coverage and intensity across northern MO later tonight. Deep-layer shear values may approach 25-30 knots and could foster some storm organization. Small hail is possible with stronger cells across northwest MO, but storm interactions/clustering should limit the overall severe threat. ...South Texas/South Florida... Isolated thunderstorms are possible across the southern FL Panhandle within a stalled, frontolytic cold front, but limited buoyancy and weak forcing for ascent should preclude a severe threat. Likewise, marginal buoyancy profiles across south TX should support lightning as a tropical low deepens over the western Gulf of Mexico later tonight, but the severe potential remains low. Read more

No watches are valid as of Mon Oct 9 23:16:01 UTC 2023.