SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 AM CDT Wed Sep 18 2024 Valid 181300Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSOURI VALLEY NORTHWARD INTO EASTERN SOUTH DAKOTA AND WESTERN MINNESOTA... ...SUMMARY... Thunderstorms capable of severe wind gusts and isolated large hail are possible today across parts of the eastern Dakotas and Minnesota southward in the mid Missouri Valley. A marginal severe threat will also be possible in parts of the central and southern Plains. ...Northern Plains/Upper Mississippi Valley/Mid Missouri Valley... Water-vapor imagery depicts a mid-level low over southeast MT this morning and this feature will continue northeastward during the period and reach southeastern SK by early Thursday morning. A mid-level ridge extending northward from the northwest Gulf Coast into the upper MS Valley will slowly shift eastward into the Upper Great Lakes. A ribbon of stronger southwesterly mid-level flow will extend from southern CA through the central High Plains and wrapping cyclonically through the eastern Dakotas and into southern Canada. In the low levels, a surface trough will be the primary feature of interest with a plume of 60s deg F dewpoints extending northward to the east of the boundary from the southern Great Plains into the Upper Midwest. In wake of early day dissipating shower/thunderstorm activity (e.g., eastern Dakotas, southern KS), heating of an adequately moist boundary layer will result in moderate destabilization by mid afternoon (1500-2500 J/kg SBCAPE). Isolated to scattered thunderstorms are forecast within a zone of 25-40 kt 0-6 km shear. Some model guidance varies on storm coverage across the Slight Risk (isolated vs. scattered) but forecast sounding profiles indicate a risk for organized storms mainly in the form of organized multicells and supercells. Hail/wind may accompany the stronger storms during the late afternoon through the early evening before this activity begins to weaken. Further south into the southern and central Plains, low-levels are forecast to be drier near the surface trough, with dewpoints expected to be mostly in the upper 50s and lower 60s F. Warmer mid-level temperatures and limited large-scale ascent than farther north will likely contribute to tempering the overall intensity of the updrafts and resultant severe intensity/coverage. Models suggest perhaps locally higher storm coverage and resulting severe-wind threat from the TX Panhandle north-northeast into far southern KS during the late afternoon/early evening. ..Smith/Mosier.. 09/18/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 AM CDT Wed Sep 18 2024 Valid 181300Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSOURI VALLEY NORTHWARD INTO EASTERN SOUTH DAKOTA AND WESTERN MINNESOTA... ...SUMMARY... Thunderstorms capable of severe wind gusts and isolated large hail are possible today across parts of the eastern Dakotas and Minnesota southward in the mid Missouri Valley. A marginal severe threat will also be possible in parts of the central and southern Plains. ...Northern Plains/Upper Mississippi Valley/Mid Missouri Valley... Water-vapor imagery depicts a mid-level low over southeast MT this morning and this feature will continue northeastward during the period and reach southeastern SK by early Thursday morning. A mid-level ridge extending northward from the northwest Gulf Coast into the upper MS Valley will slowly shift eastward into the Upper Great Lakes. A ribbon of stronger southwesterly mid-level flow will extend from southern CA through the central High Plains and wrapping cyclonically through the eastern Dakotas and into southern Canada. In the low levels, a surface trough will be the primary feature of interest with a plume of 60s deg F dewpoints extending northward to the east of the boundary from the southern Great Plains into the Upper Midwest. In wake of early day dissipating shower/thunderstorm activity (e.g., eastern Dakotas, southern KS), heating of an adequately moist boundary layer will result in moderate destabilization by mid afternoon (1500-2500 J/kg SBCAPE). Isolated to scattered thunderstorms are forecast within a zone of 25-40 kt 0-6 km shear. Some model guidance varies on storm coverage across the Slight Risk (isolated vs. scattered) but forecast sounding profiles indicate a risk for organized storms mainly in the form of organized multicells and supercells. Hail/wind may accompany the stronger storms during the late afternoon through the early evening before this activity begins to weaken. Further south into the southern and central Plains, low-levels are forecast to be drier near the surface trough, with dewpoints expected to be mostly in the upper 50s and lower 60s F. Warmer mid-level temperatures and limited large-scale ascent than farther north will likely contribute to tempering the overall intensity of the updrafts and resultant severe intensity/coverage. Models suggest perhaps locally higher storm coverage and resulting severe-wind threat from the TX Panhandle north-northeast into far southern KS during the late afternoon/early evening. ..Smith/Mosier.. 09/18/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Wed Sep 18 2024 Valid 211200Z - 261200Z ...DISCUSSION... Lower-end severe potential should return on D4/Saturday in advance of a southern-stream shortwave trough over the Southwest. A mid-level jetlet, with 500-mb winds from 50-60 kts, is progged to eject across NM as the shortwave trough reaches the Four Corners area. A mesoscale corridor of severe storms might develop Saturday afternoon across a part of eastern NM or Far West TX. The expected buoyancy plume should be modest in amplitude and rather confined spatially owing to mid-level temperatures warmer than -3 C at 500 mb across much of TX. This shortwave trough may weaken slightly as it progresses towards the central Great Plains on D5/Sunday. But moderate mid-level southwesterlies may overspread a plume of rich low-level moisture arcing to the west-northwest from the Mid/Lower MS Valley. A mesoscale corridor of focused severe potential could develop in parts of KS/NE to western MO. Predictability for each scenario on D4-5 remains too low to confidently delineate a 15 percent area at these spatiotemporal scales. Larger-scale pattern predictability becomes too low into early next week. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Wed Sep 18 2024 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Friday. ...Discussion... A quiet pattern for severe potential is expected on Friday. A stout mid-level anticyclone will be anchored over the Lower Rio Grande Valley, with a ridge extending northeast to a separate anticyclone over QC. A surface cold front should slowly weaken and stall over the Upper Great Lakes to the Ozarks. In the wake of this front, low-level moisture will be limited downstream of an amplifying northern-stream shortwave trough across the Canadian Rockies into the southern Prairie Provinces. Mainly overnight elevated thunder potential is expected in the northern Great Plains. In the southern stream, a shortwave trough should slowly progress east across southern CA into AZ. Scant to meager buoyancy will preclude appreciable severe potential in the Southwest. But locally strong gusts will be possible with isolated high-based, low-topped thunderstorms around peak heating. ..Grams.. 09/18/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Wed Sep 18 2024 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Friday. ...Discussion... A quiet pattern for severe potential is expected on Friday. A stout mid-level anticyclone will be anchored over the Lower Rio Grande Valley, with a ridge extending northeast to a separate anticyclone over QC. A surface cold front should slowly weaken and stall over the Upper Great Lakes to the Ozarks. In the wake of this front, low-level moisture will be limited downstream of an amplifying northern-stream shortwave trough across the Canadian Rockies into the southern Prairie Provinces. Mainly overnight elevated thunder potential is expected in the northern Great Plains. In the southern stream, a shortwave trough should slowly progress east across southern CA into AZ. Scant to meager buoyancy will preclude appreciable severe potential in the Southwest. But locally strong gusts will be possible with isolated high-based, low-topped thunderstorms around peak heating. ..Grams.. 09/18/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 AM CDT Wed Sep 18 2024 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... In the wake of a midlevel low moving northeastward from the northern Plains into Canada, an expansive surface high will develop across much of the West. At the same time, a deep midlevel low and strong deep-layer southwesterly flow will overspread southern CA and the Lower CO River Valley. Overall, this pattern will limit the overlap of strong surface winds and warm/dry boundary-layer conditions atop dry fuels. ..Weinman.. 09/18/2024 ...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 0154 AM CDT Wed Sep 18 2024 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... In the wake of a midlevel low moving northeastward from the northern Plains into Canada, an expansive surface high will develop across much of the West. At the same time, a deep midlevel low and strong deep-layer southwesterly flow will overspread southern CA and the Lower CO River Valley. Overall, this pattern will limit the overlap of strong surface winds and warm/dry boundary-layer conditions atop dry fuels. ..Weinman.. 09/18/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 AM CDT Wed Sep 18 2024 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Synopsis... A deep low-pressure system will move slowly east-northeastward over the northern High Plains through the period. On the backside of this system, a tight pressure gradient, and boundary-layer mixing into a belt of strong flow aloft, will yield strong post-frontal surface winds and 15-20 percent RH from eastern WY into the central Dakotas. While this would ordinarily support fire-weather concerns, precipitation over the past 24 hours should limit fuel receptiveness and the overall fire-weather threat. ..Weinman.. 09/18/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 AM CDT Wed Sep 18 2024 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Synopsis... A deep low-pressure system will move slowly east-northeastward over the northern High Plains through the period. On the backside of this system, a tight pressure gradient, and boundary-layer mixing into a belt of strong flow aloft, will yield strong post-frontal surface winds and 15-20 percent RH from eastern WY into the central Dakotas. While this would ordinarily support fire-weather concerns, precipitation over the past 24 hours should limit fuel receptiveness and the overall fire-weather threat. ..Weinman.. 09/18/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Wed Sep 18 2024 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN A PART OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms are possible from mid-afternoon to mid-evening on Thursday across central/eastern Minnesota, northern Iowa, and western Wisconsin. A few tornadoes, isolated very large hail, and damaging winds may occur. ...Upper Midwest... A vertically stacked cyclone near the ND/SK/MB border area on Thursday morning will advance northeast across MB through the period. Mid-level west-southwesterlies will remain enhanced (35-50 kt from 700-500 mb) through the afternoon to the south-southeast of this cyclone, before the system as a whole weakens and progresses farther away from the Upper Midwest. At the surface, a cold front will arc south, and progress east over MN/IA. Ahead of the front, a confined plume of mid to upper 60s surface dew points will be maintained, but will decrease within a drier boundary layer deeper into WI and IL. The aforementioned flow regime will yield initially steep mid-level lapse rates from 7-8 C/km through early afternoon. Coupled with the rich buoyancy plume, moderate to large MLCAPE of 2000-3000 J/kg appears plausible, northeast of the Mid-MO Valley. Guidance spread does exist with the timing and related spatial placement of initial thunderstorm development along the front. Some models suggest scattered convection should form during the early to mid afternoon, while others are delayed until the late afternoon. This may be related to the strength of the elevated mixed layer and timing of weakened MLCIN. This uncertainty within a limited longitudinal extent of greater threat, precludes a level 3-ENH risk. The conditional large to very large hail threat appears favorable amid a vertically veering wind profile with height that will support initial supercells. While some clustering is possible owing to frontal convergence, the bulk of severe convection may remain tied to semi-discrete supercells given the nearly perpendicular mid-level wind profile to the front and moderately enlarged low-level hodograph. This should support potential for a few tornadoes as well. Clustering should become more prominent after sunset, but the severe threat is expected to diminish soon after dusk as activity outpaces the nocturnally shrinking buoyancy plume. ..Grams.. 09/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Wed Sep 18 2024 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN A PART OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms are possible from mid-afternoon to mid-evening on Thursday across central/eastern Minnesota, northern Iowa, and western Wisconsin. A few tornadoes, isolated very large hail, and damaging winds may occur. ...Upper Midwest... A vertically stacked cyclone near the ND/SK/MB border area on Thursday morning will advance northeast across MB through the period. Mid-level west-southwesterlies will remain enhanced (35-50 kt from 700-500 mb) through the afternoon to the south-southeast of this cyclone, before the system as a whole weakens and progresses farther away from the Upper Midwest. At the surface, a cold front will arc south, and progress east over MN/IA. Ahead of the front, a confined plume of mid to upper 60s surface dew points will be maintained, but will decrease within a drier boundary layer deeper into WI and IL. The aforementioned flow regime will yield initially steep mid-level lapse rates from 7-8 C/km through early afternoon. Coupled with the rich buoyancy plume, moderate to large MLCAPE of 2000-3000 J/kg appears plausible, northeast of the Mid-MO Valley. Guidance spread does exist with the timing and related spatial placement of initial thunderstorm development along the front. Some models suggest scattered convection should form during the early to mid afternoon, while others are delayed until the late afternoon. This may be related to the strength of the elevated mixed layer and timing of weakened MLCIN. This uncertainty within a limited longitudinal extent of greater threat, precludes a level 3-ENH risk. The conditional large to very large hail threat appears favorable amid a vertically veering wind profile with height that will support initial supercells. While some clustering is possible owing to frontal convergence, the bulk of severe convection may remain tied to semi-discrete supercells given the nearly perpendicular mid-level wind profile to the front and moderately enlarged low-level hodograph. This should support potential for a few tornadoes as well. Clustering should become more prominent after sunset, but the severe threat is expected to diminish soon after dusk as activity outpaces the nocturnally shrinking buoyancy plume. ..Grams.. 09/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Wed Sep 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSOURI VALLEY NORTHWARD INTO EASTERN SOUTH DAKOTA AND WESTERN MINNESOTA... ...SUMMARY... Thunderstorms capable of severe wind gusts and isolated large hail are possible today across parts of the eastern Dakotas and Minnesota southward in the mid Missouri Valley. A marginal severe threat will also be possible in parts of the central and southern Plains. ...Northern Plains/Upper Mississippi Valley/Mid Missouri Valley... An upper-level low will move northeastward through the northern High Plains today, as an associated mid-level speed max translates northeastward through the northern Plains. At the surface, a low will move through northeastern Montana, with a trough extending southward across the High Plains. To the east of the trough in the mid Missouri Valley and northern Plains, surface dewpoints will generally be in the lower to mid 60s F. As surface temperatures warm today, moderate instability will develop within a narrow corridor from eastern Nebraska northward into the eastern Dakotas. Isolated to scattered thunderstorms are expected to form to the east of the surface trough near the instability axis during the afternoon. These storms will move northeastward across the eastern portion of the central and northern Plains during the late afternoon and evening. RAP forecast soundings at 00Z/Thu near the instability axis at Sioux Falls, South Dakota have 0-6 km shear in the 30 to 35 knot range. Some speed shear is evident in lowest 3 km, and low-level lapse rates are forecast to be steep, peaking in the 7.5 to 8 C/km range. This environment should support supercell development during the late afternoon and early evening. Supercells will likely be capable of producing severe wind gusts and isolated large hail. Further south into the southern and central Plains, low-levels are forecast to be drier near the surface trough, with dewpoints expected to be mostly in the upper 50s and lower 60s F. For this reason, instability is expected to remain relative weak today. This, combined with limited large-scale ascent will likely keep any severe threat isolated and marginal. ..Broyles/Weinman.. 09/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Wed Sep 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSOURI VALLEY NORTHWARD INTO EASTERN SOUTH DAKOTA AND WESTERN MINNESOTA... ...SUMMARY... Thunderstorms capable of severe wind gusts and isolated large hail are possible today across parts of the eastern Dakotas and Minnesota southward in the mid Missouri Valley. A marginal severe threat will also be possible in parts of the central and southern Plains. ...Northern Plains/Upper Mississippi Valley/Mid Missouri Valley... An upper-level low will move northeastward through the northern High Plains today, as an associated mid-level speed max translates northeastward through the northern Plains. At the surface, a low will move through northeastern Montana, with a trough extending southward across the High Plains. To the east of the trough in the mid Missouri Valley and northern Plains, surface dewpoints will generally be in the lower to mid 60s F. As surface temperatures warm today, moderate instability will develop within a narrow corridor from eastern Nebraska northward into the eastern Dakotas. Isolated to scattered thunderstorms are expected to form to the east of the surface trough near the instability axis during the afternoon. These storms will move northeastward across the eastern portion of the central and northern Plains during the late afternoon and evening. RAP forecast soundings at 00Z/Thu near the instability axis at Sioux Falls, South Dakota have 0-6 km shear in the 30 to 35 knot range. Some speed shear is evident in lowest 3 km, and low-level lapse rates are forecast to be steep, peaking in the 7.5 to 8 C/km range. This environment should support supercell development during the late afternoon and early evening. Supercells will likely be capable of producing severe wind gusts and isolated large hail. Further south into the southern and central Plains, low-levels are forecast to be drier near the surface trough, with dewpoints expected to be mostly in the upper 50s and lower 60s F. For this reason, instability is expected to remain relative weak today. This, combined with limited large-scale ascent will likely keep any severe threat isolated and marginal. ..Broyles/Weinman.. 09/18/2024 Read more

MD 2081 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF EASTERN MONTANA...WESTERN NORTH DAKOTA...AND NORTHWESTERN SOUTH DAKOTA
Mesoscale Discussion 2081 NWS Storm Prediction Center Norman OK 0625 PM CDT Tue Sep 17 2024 Areas affected...Portions of eastern Montana...western North Dakota...and northwestern South Dakota Concerning...Severe potential...Watch possible Valid 172325Z - 180200Z Probability of Watch Issuance...60 percent SUMMARY...The risk of severe wind gusts and large hail should gradually increase over the next few hours. The area is being monitored for a possible watch, though timing is still uncertain. DISCUSSION...A few strong to severe storms have developed along a north/south-oriented confluence zone across eastern MT. These storms are evolving in an environment characterized by around 40 kt of deep-layer shear (per regional VWP) and moderate surface-based instability -- supportive of organized clusters and supercell structures. Isolated large hail and severe wind gusts could accompany this activity. During the next few hours, large-scale ascent preceding an approaching midlevel trough may encourage an uptick in convection from northeastern MT into western ND and northwestern SD. Sufficient deep-layer shear/mostly straight hodographs and steep deep-layer lapse rates should favor organized clusters and supercells capable of severe wind gusts and large hail. The overall timing and coverage of the severe threat still remains somewhat uncertain, and convective trends are being monitored for a possible watch for parts of the area. ..Weinman/Hart.. 09/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BIS...UNR...BYZ...GGW...TFX... LAT...LON 44600402 46000472 46820548 47140652 47420795 47610861 48260896 48790884 49020819 49010575 48900484 48720435 48260376 46750285 45540234 44960227 44600266 44430348 44600402 Read more

MD 2082 CONCERNING SEVERE THUNDERSTORM WATCH 674...675... FOR CENTRAL HIGH PLAINS
Mesoscale Discussion 2082 NWS Storm Prediction Center Norman OK 0641 PM CDT Tue Sep 17 2024 Areas affected...Central High Plains Concerning...Severe Thunderstorm Watch 674...675... Valid 172341Z - 180145Z The severe weather threat for Severe Thunderstorm Watch 674, 675 continues. SUMMARY...Strong winds are the primary risk along the leading edge of a squall line as it propagates across the central High Plains. DISCUSSION...Early-evening water-vapor imagery suggests mid-level short-wave trough is located over southeast CO, ejecting northeast into the central High Plains. Organized convection has evolved ahead of this feature, primarily expressed as a squall line which extends from southwest Yuma County CO-Baca County CO. Strong winds are likely associated with this squall line, and this is the primary risk as the squall line advances into western KS/southwest NE over the next 1-2 hours. ..Darrow.. 09/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...DDC...GLD...PUB...BOU... LAT...LON 37460250 39190230 40240282 40790133 39720082 37380154 37460250 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 PM CDT Tue Sep 17 2024 Valid 180100Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE HIGH PLAINS... ...SUMMARY... Thunderstorms capable of producing scattered to numerous severe wind gusts and hail will continue to develop across the High Plains this evening. Some of the wind gusts may be significant (75+ mph). ...Southern and Central High Plains... A mid-level low is evident on water vapor imagery over the northern Rockies, with cyclonic southwesterly flow located from the Four Corners into the central and northern Plains. Ahead of the trough, a band of strong large-scale ascent appears to be spreading into the central High Plains, where a large plume of mid-level moisture is located. Thunderstorms are ongoing ahead of this band of ascent, and are moving into a moderately unstable airmass where MLCAPE is estimated to be in the 1000 to 2000 J/kg range. Concerning the shear environment, regional WSR-88D VWPs in east-central Colorado have 0-6 km shear from 40 to 50 knots, with some directional shear in the lowest 3 km. In addition, the RAP has a strengthening low-level jet analyzed from far eastern Colorado and western Kansas northward into southeastern South Dakota. As the low-level jet continues to strengthen, the lift, shear and instability will continue to support severe thunderstorm development over the southern and central High Plains this evening. In response, an organized line segment will continue to move eastward across western Nebraska, western Kansas and the Texas Panhandle, where scattered severe wind gusts are expected. Wind gusts above 70 knots will be possible along the more organized parts of the line. The threat should persist into the mid to late evening. ...Northern High Plains... Water vapor imagery shows an upper-level low over eastern Idaho, with divergent mid-level from the south and south-southeast across much of the northern High Plains. An axis moderate instability is analyzed from central North Dakota into northeastern Montana, where MLCAPE is estimated in the 2000 to 3000 J/kg range. Thunderstorms are ongoing near the instability axis in northeastern Montana. Additional storms have developed further south near the South Dakota-Wyoming state line. The latest WSR-88D VWP at Glasgow, Montana has easterly flow at the surface, with a sharply veering wind profile in the low-levels. 0-6 km shear is estimated to be near 40 knots. This environment, along with steep low to mid-level lapse rates should continue to support a severe threat for several more hours. A potential for severe wind gusts and isolated large hail will exist with the stronger storms. ..Broyles.. 09/18/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 PM CDT Tue Sep 17 2024 Valid 180100Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE HIGH PLAINS... ...SUMMARY... Thunderstorms capable of producing scattered to numerous severe wind gusts and hail will continue to develop across the High Plains this evening. Some of the wind gusts may be significant (75+ mph). ...Southern and Central High Plains... A mid-level low is evident on water vapor imagery over the northern Rockies, with cyclonic southwesterly flow located from the Four Corners into the central and northern Plains. Ahead of the trough, a band of strong large-scale ascent appears to be spreading into the central High Plains, where a large plume of mid-level moisture is located. Thunderstorms are ongoing ahead of this band of ascent, and are moving into a moderately unstable airmass where MLCAPE is estimated to be in the 1000 to 2000 J/kg range. Concerning the shear environment, regional WSR-88D VWPs in east-central Colorado have 0-6 km shear from 40 to 50 knots, with some directional shear in the lowest 3 km. In addition, the RAP has a strengthening low-level jet analyzed from far eastern Colorado and western Kansas northward into southeastern South Dakota. As the low-level jet continues to strengthen, the lift, shear and instability will continue to support severe thunderstorm development over the southern and central High Plains this evening. In response, an organized line segment will continue to move eastward across western Nebraska, western Kansas and the Texas Panhandle, where scattered severe wind gusts are expected. Wind gusts above 70 knots will be possible along the more organized parts of the line. The threat should persist into the mid to late evening. ...Northern High Plains... Water vapor imagery shows an upper-level low over eastern Idaho, with divergent mid-level from the south and south-southeast across much of the northern High Plains. An axis moderate instability is analyzed from central North Dakota into northeastern Montana, where MLCAPE is estimated in the 2000 to 3000 J/kg range. Thunderstorms are ongoing near the instability axis in northeastern Montana. Additional storms have developed further south near the South Dakota-Wyoming state line. The latest WSR-88D VWP at Glasgow, Montana has easterly flow at the surface, with a sharply veering wind profile in the low-levels. 0-6 km shear is estimated to be near 40 knots. This environment, along with steep low to mid-level lapse rates should continue to support a severe threat for several more hours. A potential for severe wind gusts and isolated large hail will exist with the stronger storms. ..Broyles.. 09/18/2024 Read more

WW 0675 Status Updates
STATUS REPORT ON WW 675 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SSW ITR TO 35 NNW ITR TO 30 NNE AKO TO 30 WNW SNY TO 10 ENE BFF TO 35 W CDR. ..SPC..09/18/24 ATTN...WFO...BOU...GLD...LBF...CYS... STATUS REPORT FOR WS 675 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC017-063-075-095-115-125-180140- CO . COLORADO COUNTIES INCLUDED ARE CHEYENNE KIT CARSON LOGAN PHILLIPS SEDGWICK YUMA KSC023-071-109-153-181-193-199-203-180140- KS . KANSAS COUNTIES INCLUDED ARE CHEYENNE GREELEY LOGAN RAWLINS SHERMAN THOMAS WALLACE WICHITA NEC005-007-013-029-033-045-049-057-069-075-085-087-091-101-105- 111-117-123-135-157-161-165-180140- NE . NEBRASKA COUNTIES INCLUDED ARE Read more

WW 675 SEVERE TSTM CO KS NE WY 172055Z - 180300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 675 NWS Storm Prediction Center Norman OK 255 PM MDT Tue Sep 17 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast and East-Central Colorado Northwest Kansas Western Nebraska Eastern Wyoming * Effective this Tuesday afternoon and evening from 255 PM until 900 PM MDT. * Primary threats include... Widespread damaging winds likely with isolated significant gusts to 80 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...High-based convection should gradually increase in coverage and intensity as it spreads northeastward across the central High Plains this afternoon and evening. Numerous strong to severe wind gusts should be the main threat with this activity, with the highest gusts potentially reaching up to 70-80 mph. The severe thunderstorm watch area is approximately along and 80 statute miles east and west of a line from 35 miles south southwest of Burlington CO to 60 miles north northeast of Torrington WY. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 674... AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24040. ...Gleason Read more

WW 0676 Status Updates
STATUS FOR WATCH 0676 HAS NOT BEEN ISSUED YET Read more