Severe Storms

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0728 PM CDT Sun Oct 29 2023 Valid 300100Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Minimal thunderstorm activity is expected through tonight. ...Synopsis... A large, positive-tile upper trough will continue to push eastward across the upper MS Valley and Great Lakes, trailing southwestward into the central Plains. At the surface, a sprawling area of high pressure will support cool air moving southward across the remainder of southern TX this evening and across the lower MS, OH and TN Valley through Monday morning. Weak elevated instability continues to support embedded thunder within patches of precipitation, mainly over northwest into west-central TX in closer proximity to better moisture and with a few hundred J/kg MUCAPE. With time, the deepening cool air should shunt thunderstorm potential farther south, from central TX toward the middle Rio Grande Valley. Lack of appreciable instability and weak lapse rates aloft will preclude any severe hail risk. ..Jewell.. 10/30/2023 Read more

No Mesoscale Discussions are in effect as of Sun Oct 29 03:05:02 UTC 2023.

No watches are valid as of Sun Oct 29 03:05:02 UTC 2023.

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0752 PM CDT Sat Oct 28 2023 Valid 290100Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER FAR SOUTHWEST TEXAS AND EXTREME SOUTHEAST NEW MEXICO... ...SUMMARY... A few strong to marginally severe storm remain possible this evening and into the early morning hours over a small part of west Texas and extreme southeastern New Mexico. ...Southwest TX... A cold front currently extends from central TX into southeast NM, with a gradual southward motion. The 00Z MAF sounding shows a capping inversion with around 1100 J/kg MLCAPE, and moderate mid to high level flow. Ongoing small cells exist to the southwest, but remain quite disorganized. Sporadic cells may persist in the relatively warmer air, prior to frontal passage. Despite the likelihood of elevated parcels north of the front, sufficient instability may still support a marginal hail threat as the deepening post-frontal air mass aids cap removal for elevated parcels. Moderate southwest flow aloft with the positive-tilt trough may enhance deep-layer shear somewhat tonight, possibly supporting isolated cells producing marginal hail. ..Jewell.. 10/29/2023 Read more

No watches are valid as of Sat Oct 28 03:11:01 UTC 2023.

No Mesoscale Discussions are in effect as of Sat Oct 28 03:11:01 UTC 2023.

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0748 PM CDT Fri Oct 27 2023 Valid 280100Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Synopsis... A mean mid-level trough will reside over the West and an anticyclone will remain centered over FL. Water-vapor imagery this evening shows a weak disturbance moving east-northeast across the IA/WI vicinity. This mid to upper-level feature will continue into MI tonight and into southeast Canada by early Saturday morning. In the low levels, a cold front over Lower MI extends south-southwest into eastern IL and into central TX. The northern portion of the front will continue sweeping east across the central Great Lakes and parts of the OH Valley. A few thunderstorms will remain possible near the front over the Midwest. Weak buoyancy from the Mid South northward into the Great Lakes (i.e., reference 00z area raobs) will likely limit both storm coverage/intensity through the early morning. ..Smith.. 10/28/2023 Read more

No watches are valid as of Fri Oct 27 03:24:02 UTC 2023.

MD 2264 CONCERNING HEAVY SNOW FOR PORTIONS OF EASTERN NORTH DAKOTA INTO EXTREME NORTHWESTERN MINNESOTA
Mesoscale Discussion 2264 NWS Storm Prediction Center Norman OK 1021 PM CDT Thu Oct 26 2023 Areas affected...portions of eastern North Dakota into extreme northwestern Minnesota Concerning...Heavy snow Valid 270321Z - 270915Z SUMMARY...Occasional instances of heavy snow, including 1-1.5 inch/hour snowfall rates, are possible tonight across portions of eastern North Dakota into extreme northwestern Minnesota. DISCUSSION...A pronounced mid-level trough, located over western SD, is poised to overspread the eastern Dakotas over the next few hours, increasing deep-layer ascent and supporting higher precipitation rates across eastern portions of the Northern Plains tonight. At the same time, modest northeasterly 850 mb warm-air advection (to the northwest of a surface low) over the Upper MS Valley will continue to increase low-level lift and moisture ahead of an ongoing snow band across central ND and northern SD. Given near saturation at 700 mb (which is also in proximity to the dendritic growth zone), increased deep-layer ascent tonight will promote moderate to heavy snow. Some of the latest CAM guidance (i.e. deterministic HRRR and HREF- ensemble probabilities) suggests that the best chance for 1-1.5 inch/hour snowfall rates will be across northeast ND into extreme northwest MN in the 05-09Z (Midnight - 4 AM CDT) time frame. ..Squitieri.. 10/27/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...BIS... LAT...LON 45980148 47280106 48260061 48640015 48939928 49049847 49039807 49049703 48759676 48229670 47649706 46719865 46239972 45980045 45980148 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 PM CDT Thu Oct 26 2023 Valid 270100Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast through tonight. ...Synopsis... Water-vapor imagery this evening shows a mid-level anticyclone centered over the GA with large-scale troughing over the Rockies. A lead mid-level shortwave trough over the mid MS Valley this evening will continue northeastward to the southern Great Lakes overnight. A potent disturbance over WY this evening will move into the Dakotas and Upper Midwest tonight. Primary area of limited convective concern this evening is located over southeast TX within a very moist airmass (dewpoints in the mid 70s) in association with a thunderstorm cluster. However, only modest flow will temper overall storm intensity as temperatures slowly cool through the evening. Elsewhere, a cold front will sweep southeast across a large part of the Midwest/central Great Plains tonight. Widely spaced and very isolated, weak thunderstorms are possible over a large part of the Midwest tonight. ..Smith.. 10/27/2023 Read more

No watches are valid as of Thu Oct 26 01:39:02 UTC 2023.

No Mesoscale Discussions are in effect as of Thu Oct 26 01:39:02 UTC 2023.

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 PM CDT Wed Oct 25 2023 Valid 260100Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF CENTRAL INTO NORTH TEXAS... ...SUMMARY... Very isolated potential for damaging gusts and/or a brief tornado may continue until the mid evening across parts of central into north Texas. ...Synopsis... Water-vapor imagery early this evening shows the mid- to upper-level trough over the southern High Plains, and it will continue east-northeast into the central/southern Plains later tonight. A moist/warm conveyor belt will continue to extend from TX north-northeast into the mid MS Valley through tonight. A north-northeast to south-southwest oriented band of convection will slowly shift east across eastern OK and the I-35 corridor in TX tonight. A moist/adequately unstable airmass will support thunderstorm development through the evening despite gradually waning instability. It seems some lingering potential for a damaging gust/brief tornado may continue into the mid evening, mainly across central into north TX, before storm intensity diminishes by late evening. ..Smith.. 10/26/2023 Read more

No watches are valid as of Wed Oct 25 03:14:02 UTC 2023.

MD 2261 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR WEST TEXAS
Mesoscale Discussion 2261 NWS Storm Prediction Center Norman OK 1011 PM CDT Tue Oct 24 2023 Areas affected...west Texas Concerning...Severe potential...Watch unlikely Valid 250311Z - 250545Z Probability of Watch Issuance...20 percent SUMMARY...Some hail and locally strong wind gusts may accompany an evolving squall line spreading east of the New Mexico/Texas state border, and northeast/east of the Pecos valley through 1-2 AM CDT. It still appears that a severe weather watch will not be needed, but trends will continue to be monitored. DISCUSSION...Convection has gradually grown upscale into an evolving squall line, generally focused on the leading edge of lower/mid-tropospheric cooling slowly advancing toward the Texas South Plains/Pecos Valley vicinity. Modest strengthening of ambient southerly low-level flow (including to 30+ kt around 850 mb) is contributing to strengthening easterly/southeasterly inflow of more moist air advecting into the high plains. Beneath a remnant plume of steeper lapse rates, associated instability probably will maintain, or perhaps support some further intensification of, the squall line late this evening into the overnight hours. As this occurs, it is possible that channels of strengthening rear inflow may continue to develop, accompanied by potential for occasional locally strong wind gusts reaching the surface. However, based on the output convection allowing guidance, including the HRRR, and latest RAP/NAM forecast soundings, it still appears that peak gusts will remain mostly below severe limits. ..Kerr/Hart.. 10/25/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LUB...MAF... LAT...LON 34510238 34290074 32200141 30800300 31540341 32930273 34510238 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0732 PM CDT Tue Oct 24 2023 Valid 250100Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN HIGH PLAINS... ...SUMMARY... Thunderstorms, associated with marginally severe wind gusts and hail, will continue to be possible this evening over parts of the southern High Plains. ...Southern High Plains... Latest water vapor imagery shows a mid-level low over northwestern Mexico with a plume of mid-level moisture located in southwesterly flow over the southern Rockies. Thunderstorms are ongoing within this plume from eastern Arizona eastward into west Texas, where surface dewpoints are in the lower to mid 60s F. The RAP is analyzing MLCAPE in the 1000 to 1500 J/kg range across much of west-central Texas. As the storms continue to interact with the northwestern edge of the moderately unstable airmass, the instability combined with moderate to strong deep-layer shear, will be likely be sufficient for an isolated severe threat. Hail, along with a few marginally severe wind gusts, will be possible with the stronger cores over the next few hours. ..Broyles.. 10/25/2023 Read more

No watches are valid as of Tue Oct 24 02:32:02 UTC 2023.

MD 2256 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHERN IOWA AND SOUTHERN MINNESOTA
Mesoscale Discussion 2256 NWS Storm Prediction Center Norman OK 0927 PM CDT Mon Oct 23 2023 Areas affected...Northern Iowa and southern Minnesota Concerning...Severe potential...Watch possible Valid 240227Z - 240530Z Probability of Watch Issuance...40 percent SUMMARY...Elevated supercells may develop in the next 2-3 hours. These storms will be capable of large hail (1.5-2 in.). A watch is possible. DISCUSSION...Subtle signs of lift are evident in parts of west-central/northwest Iowa on IR satellite imagery. The KOAX VAD is showing the low-level jet at around 40 kts already this evening. This is expected to increase into the overnight. Lift along a warm front will eventually support potentially scattered elevated thunderstorm development within the next 2-3 hours. The 00Z observed OAX sounding showed very steep mid-level lapse rates. Though more muted, these lapse rates also extend into Iowa/Minnesota per this evenings DVN/MPX soundings. Mid/upper-level winds are strong enough to support long hodographs and 35-40 kt of effective shear. The strongest storms will be supercellular and capable of large hail (1.5-2 in.). Convective trends will continue to be monitored and a watch is possible this evening. ..Wendt.. 10/24/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ARX...MPX...DMX...FSD...OAX... LAT...LON 44049223 43919483 43719570 43149635 42389651 41989635 41909551 42159468 42589272 43019151 43539134 43859145 44049223 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0812 PM CDT Mon Oct 23 2023 Valid 240100Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN IOWA AND FAR SOUTHERN MINNESOTA... ...SUMMARY... Isolated to scattered large hail will be possible late this evening into the overnight across northern Iowa, southern Minnesota, and eastward into Wisconsin. ...Synopsis... A split flow upper-air pattern is forecast tonight over the western half of the Lower 48 states. Water-vapor imagery early this evening shows a large-scale trough rotating across southern CA and Baja California. In the low levels, a warm front will advance north across portions of the Midwest as an elongated warm air conveyor belt extends from the southern Great Plains arcing north-northeast into the Great Lakes. ...IA/MN/WI... Latest surface observations show the northern periphery of richer moisture has moved into western IA/eastern NE. The 00z Omaha raob featured 8 deg C/km 700-500 mb lapse rates and moderate buoyancy. The LLJ is forecast to intensify this evening and focus large-scale ascent mainly in the form of isentropic ascent/warm-air advection in the vicinity of the warm front. Recent time-lagged HRRR model runs indicate isolated to scattered storms developing farther west and near the MO River by late this evening. This activity seems to favor a west-east corridor across northern IA and perhaps far southern MN. Given the favorable lapse rates and deep-layer shear profiles supporting the potential for updraft rotation, have introduced a small 15-percent hail probability (Slight Risk). ...Rio Grande/western part of the Edwards Plateau... The 00z Del Rio raob showed relatively weak lapse rates above the boundary layer, indicative of moisture via decayed TC remnants. Despite the lack of lightning and weak updraft development through early evening, a low probability for a strong updraft could materialize later tonight across this region as southerly 850-mb flow strengthens. However, it seems the risk for severe will be limited by overall weak buoyancy/lapse rates. ..Smith.. 10/24/2023 Read more

No watches are valid as of Mon Oct 23 02:47:02 UTC 2023.