Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1248 PM CST Sun Dec 11 2022 Valid 121200Z - 131200Z Only minor adjustments were made based on ensemble guidance. The forecast otherwise remains on track. ..Wendt.. 12/11/2022 .PREV DISCUSSION... /ISSUED 0150 AM CST Sun Dec 11 2022/ ...Synopsis... As the deep upper trough over the western US continues to strengthen, southwesterly flow aloft will strengthen over the Rockies. At the surface a strong lee low is expected to develop across eastern CO and the central High Plains. With surface pressure falling below 1000 mb by early afternoon, low-level pressure gradients will intensify to the southwest of the surface low ahead of a cold front. In response, south/southwest winds will increase across the Foothills and central and southern High Plains. Widespread gusts of 25-35 mph will be possible through the afternoon. While winds will be strong, increasing moisture is expected to limit surface RH values through the day. A few hours of RH below 25% and overlap with the strong winds will be possible within dry fuels. Thus elevated fire-weather conditions are possible despite more marginal humidity values. Fire concerns will end quickly after sunset as snow and cooler air move over the southern and central Rockies. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Sun Dec 11 18:51:01 UTC 2022.

No Mesoscale Discussions are in effect as of Sun Dec 11 18:51:01 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CST Sun Dec 11 2022 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WESTERN/CENTRAL KS/OK INTO WESTERN NORTH TX... ...SUMMARY... Strong to isolated severe thunderstorms will be possible from western and central Kansas and Oklahoma into western north Texas, mainly during the nighttime hours. Hail, strong wind gusts, and a brief tornado will all be possible. ...Synopsis... A mid/upper-level cyclone and associated longwave trough are forecast to move eastward from the Intermountain West towards portions of the Great Plains by early Tuesday morning. A surface low is forecast to deepen over the central High Plains, as an attendant cold front begins moving through the southern High Plains late in the period. Meanwhile, an expansive surface ridge is forecast to remain in place over most of the eastern CONUS. ...Western/central KS/OK into western north TX... Despite modest low-level moisture return during the day on Monday, buoyancy is expected to remain very weak through late afternoon. Continued moistening near/above the surface and the arrival of steeper midlevel lapse rates associated with the approaching trough will support MUCAPE increasing to 500-1000 J/kg Monday night from northwest TX into western KS. Increasing large-scale ascent will support increasing thunderstorm coverage from mid/late evening into the overnight hours, with strengthening deep-layer flow/shear becoming favorable for organized convection. Uncertainty remains regarding the potential for near-surface-based development during the evening/overnight hours. Cool surface temperatures and late initiation will generally not be supportive of sustained surface-based storms. Low-level moisture return may become sufficient across parts of western north TX into southwest OK for storms to become rooted near the surface. Meanwhile, across parts of western KS, cold midlevel temperatures (500 mb temperatures at or below -20C) could support some increase in MLCAPE and decrease in MLCINH, despite temperatures generally remaining in the low 50s F. In these areas, relatively strong low-level shear/SRH may support a brief tornado threat with any sustained supercell or QLCS development. Otherwise, steep midlevel lapse rates and relatively cold temperatures aloft will support a conditional risk of hail with any stronger storms, though a tendency toward linear convective mode may temper this threat to some extent. Strong low-level flow will support some threat for locally severe gusts as well with any QLCS development, even if convection remains slightly elevated. ..Dean.. 12/11/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1011 AM CST Sun Dec 11 2022 Valid 111700Z - 121200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/11/2022 .PREV DISCUSSION... /ISSUED 0143 AM CST Sun Dec 11 2022/ ...Synopsis... Across the western CONUS, a mid-level trough is forecast to continue to amplify over the Great Basin as strong southwesterly flow begins to overspread the Rockies. As the trough deepens, a lee low is forecast to develop along the southern Rockies in response. Downslope winds are expected to increase through the day occasionally reaching 15-20 mph, especially through local terrain gaps near the Raton Mesa. With above average temperatures and downslope drying, afternoon RH values below 15% will be possible. The combination of dry surface conditions and locally gusty winds should support a few hours of low-end elevated fire weather conditions within dry fuels across portions of southeastern CO and northern NM. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1008 AM CST Sun Dec 11 2022 Valid 111630Z - 121200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected through tonight. ...Synopsis... Fast zonal flow is present today over most of the nation, while a large upper trough deepens over the western states. Scattered thunderstorms will continue to affect parts of the Gulf Coast states as a cold front sags into the region. Other isolated lightning flashes will be possible over parts of CA/NV beneath the cold upper trough. The severe threat in both areas appears low today. ..Hart/Bentley.. 12/11/2022 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1144 AM CST Sat Dec 10 2022 Valid 111200Z - 121200Z ...NO CRITICAL AREAS... No changes were made to the ongoing forecast. Some locally elevated conditions still appear possible within terrain-favored locations along the Front Range. ..Wendt.. 12/10/2022 .PREV DISCUSSION... /ISSUED 0157 AM CST Sat Dec 10 2022/ ...Synopsis... Zonal mid-level flow across the western CONUS is forecast to amplify as a large trough in the western US undergoes substantial deepening this weekend. Strong southerly flow will overspread the Rockies and Great Basin supporting the development of a surface pressure trough in the lee of the southern/central Rockies. The strongest winds are forecast to remain west of the Continental Divide, but some katabatic flow may allow for downslope winds to increase along the Front Range Sunday afternoon. Dry downslope flow (RH 15-20%) may occasionally reach 15-25 mph through terrain gaps and onto portions of the adjacent High Plains. Fuels remain modestly receptive to fire spread and some locally elevated fire-weather conditions will be possible in eastern CO and northern NM. However, the temporal and spatial overlap appears too low to introduce an Elevated area at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Sat Dec 10 17:46:01 UTC 2022.

No Mesoscale Discussions are in effect as of Sat Dec 10 17:46:01 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1103 AM CST Sat Dec 10 2022 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF EAST TEXAS ACROSS SOUTHERN LOUISIANA AND INTO SOUTHWEST MISSISSIPPI.... ...SUMMARY... A line of thunderstorms with locally damaging wind gusts is possible Saturday morning across portions of east Texas, across southern Louisiana and info southwest Mississippi. ...Synopsis... A dampening weak shortwave will move across Louisiana/Mississippi Sunday morning. The passage of this shortwave will help push a surface cold front southward across the region during the day. Farther west, a trough and associated strong mid-level jet will advance inland across the western CONUS with widespread thunderstorm activity associated with the cold air aloft. ...Portions of the east Texas across southern Louisiana and into southwest Mississippi... As a weak mid-level shortwave trough advances east across Texas today (Saturday), a cluster of strong to marginally severe storms is expected to develop. By Sunday morning, an MCS will likely be located somewhere in east Texas/western Louisiana. Despite the unfavorable diurnal timing, low-level moisture advection off the Gulf should sustain ample instability for some marginal severe threat to continue Sunday morning. However, by mid-day Sunday, the threat is expected to wane as low-level jet support weakens, and the storms move east of the best low-level moisture. A few locally damaging wind gusts will be the primary threat during the morning hour. A few storms may redevelop later in the day along the cold front, but are not expected to be strong enough to support any severe weather threat. ..Bentley.. 12/10/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1011 AM CST Sat Dec 10 2022 Valid 101630Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT OVER MUCH OF CENTRAL/EASTERN TEXAS AND WESTERN LOUISIANA... ...SUMMARY... Isolated severe thunderstorms are possible through tonight from central Texas to western Louisiana. ...TX/LA... Strong southwesterly flow aloft is present today from northern Mexico into the lower MS Valley. At the surface, a quasi-stationary boundary extends across the same area, extending from north-central TX into southern AR. Scattered showers and thunderstorms will continue to affect areas along this front throughout the forecast period, as the front sags slowly southward tonight. There is low risk of hail in the strongest storms this afternoon along or north of the front, but limited elevated CAPE should preclude a more organized risk. Later tonight, most CAM solutions show a few discrete cells forming in the open warm sector over southeast TX as a shortwave trough approaches. Sufficient moisture and CAPE will be present for rotating storms, but low-level flow/shear will be relatively weak, suggesting just a Marginal risk of a tornado or damaging wind gust. ..Hart/Dean.. 12/10/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0947 AM CST Sat Dec 10 2022 Valid 101700Z - 111200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/10/2022 .PREV DISCUSSION... /ISSUED 0155 AM CST Sat Dec 10 2022/ ...Synopsis... Zonal mid-level flow over the CONUS will remain in place today before a large trough deepens on the West Coast. Shortwave ridging over the central Rockies in the wake of a weak cold front will keep temperatures cool and winds light over much of the Rockies and High Plains through tonight. Surface high pressure over the higher terrain will limit surface winds, but weak downslope flow may occasionally gust to near 15 mph. However, poor overlap of dry and windy conditions should keep fire-weather concerns low. ...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 1227 PM CST Fri Dec 09 2022 Valid 101200Z - 111200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/09/2022 .PREV DISCUSSION... /ISSUED 0157 AM CST Fri Dec 09 2022/ ...Synopsis... In the mid levels, zonal flow is forecast to continue across the Rockies and southern High Plains D2/Sat. A shortwave trough will move eastward onto the Plains with shortwave ridging developing over the Rockies through the day. At the surface, a cold front will move out of the higher terrain bringing cooler conditions into eastern CO and western KS. Ahead of the front, weak downslope flow may occasionally gust upwards of 15 mph over modestly dry fuels. While localized fire concerns may exist for a few hours, confidence in sustained fire-weather conditions is too low to introduce highlights. Elsewhere, fire concerns are low. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Fri Dec 9 18:30:02 UTC 2022.

No Mesoscale Discussions are in effect as of Fri Dec 9 18:30:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CST Fri Dec 09 2022 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS... ...SUMMARY... Isolated severe thunderstorms are possible across portions of the southern Plains from Saturday morning into early Sunday morning. ...Synopsis... A southern-stream shortwave trough is expected to progress from northwest Mexico/southern AZ eastward through the southern High Plans and much of the southern Plains on Saturday. At the same time, an upper low is forecast to drop southward to the Pacific Northwest Coast as a series of shortwave troughs rotate through its western and southern periphery. An additional shortwave should move from the northern Plains eastward through the Upper Midwest and into the Upper Great Lakes region. At the surface, moisture return is anticipated across the southern Plains and Lower MS Valley ahead of the approaching southern-stream shortwave. A surface low will likely be centered over south-central OK early Saturday, before then pushing eastward across southeast OK and southern AR. As it does, an associated cold front is expected to progress gradually southeastward across TX. Resulting increasing buoyancy coupled with strengthening wind fields and lift will contribute to some severe risk across the southern Plains. Isolated lightning flashes are also possible from the southwest OR coast into central CA and west-central NV where cold mid-level temperatures and persistent large-scale forcing for ascent will align. ...Southern Plains... Showers and thunderstorms will likely be ongoing across central and eastern OK early Saturday, north of the low and attendant cold front. These showers and thunderstorms should gradually diminish as the low-level jet weakens, with additional activity expected to develop farther west in the vicinity of the front across southwest/south-central OK and north TX. Much of this activity will be elevated north of the front, but instability and shear are expected to be strong enough to support a low-probability hail threat. Isolated thunderstorm development within the warm sector is possible Saturday evening into Sunday morning as the shortwave moves closer and large-scale ascent strengthens. Southerly/southeasterly surface winds will result in curved low-level hodographs, but the overall magnitude will remain low due to modest low-level flow. Even so, a few more organized storms are possible, with an attendant threat of damaging gusts and/or a brief tornado. ..Mosier.. 12/09/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1016 AM CST Fri Dec 09 2022 Valid 091630Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through early Saturday. ...Synopsis... Several mid-level shortwave troughs are present amid a progressive mid-level pattern across the western two-thirds of the CONUS. A weakening mid-level trough will advance across the southern Great Lakes through the day today with a larger trough advancing across the Rockies in its wake. Additionally, another trough is approaching the West Coast which will bring moderate/heavy valley rain and mountain snow. As the mid-level trough over the Great Basin this morning advances into the Plains tonight, a low-level jet is expected to strengthen across the southern High Plains. As warm air advection strengthens and moisture increases, expect thunderstorms to develop across Oklahoma, mostly after 03Z and expand east-northeastward through the overnight period and into Saturday morning. Thunderstorm chances will increase along the northwest California/ southwest Oregon coast after 06Z as the trough advances east and colder air aloft overspreads relatively moist low level conditions. These thunderstorms may start to spread further inland closer to 12Z as the upper-level trough continues to advance east. ..Bentley.. 12/09/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0909 AM CST Fri Dec 09 2022 Valid 091700Z - 101200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/09/2022 .PREV DISCUSSION... /ISSUED 0155 AM CST Fri Dec 09 2022/ ...Synopsis... Across the CONUS, active mid-level flow is expected to remain in place today as a shortwave trough crosses the southern and central Rockies onto the High Plains. In response to increasing westerly flow aloft, downslope winds across proportions of southern CO and northern NM may occasionally reach 15-20 mph through the afternoon. While not overly warm, temperatures in the 40s and 50s F along with downslope drying and occasional stronger wind gusts may support a few hours of locally elevated fire weather potential from the Front Range into northern NM. However, relatively modest fuels and the limited overlap of gusty winds and dry surface conditions should limit the duration of any threat. Elsewhere across the CONUS, fire weather concerns are low. ...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 1243 PM CST Thu Dec 08 2022 Valid 091200Z - 101200Z ...NO CRITICAL AREAS... No changes are needed to the current D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 12/08/2022 .PREV DISCUSSION... /ISSUED 0108 AM CST Thu Dec 08 2022/ ...Synopsis... The potential for widespread fire weather concerns is low for Friday across the CONUS, but localized fire weather conditions may develop for parts of eastern Colorado. The upper disturbance currently approaching the Plains will quickly be followed by upper ridging across the central U.S. on Friday. Height falls across the Southwest will support increasing flow over the central Rockies with modest lee troughing in response. 15 mph southerly winds may occasionally gust up to 20-25 mph from northeast NM into eastern CO and far western KS where fine fuels remain dry. No appreciable moisture return will maintain dry conditions with afternoon RH values in the 15-25% range. Consequently, localized elevated fire weather conditions are probable where dry conditions can overlap with breezier winds. However, confidence in the spatial coverage and duration of elevated conditions remains too limited due to uncertainty in wind magnitudes, precluding highlights at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Thu Dec 8 18:45:02 UTC 2022.