SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1243 AM CDT Tue Oct 29 2024 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE PLAINS... ...SUMMARY... Thunderstorm development may begin late tonight from the Upper Mississippi Valley area south-southwestward across the Plains. Local/limited risk for hail/wind warrants continuation of Level 1/MRGL risk for the very end of the period. ...Plains... Seasonally strong upper trough, currently located just inland of the Pacific Coast, is forecast to shift across the Great Basin/lower CO River Valley this morning as strongest 500mb flow rotates across AZ into southern CO. This feature should advance into the Four Corners region by 30/12z with a corridor of strong high-level southwesterly winds expected to extend across NM into the upper Great Lakes. This flow regime warrants a strengthening lee trough, along with a plains-focused LLJ, through the end of the period. In response to the approaching upper system, lee trough should sharpen and get dislodged into southeastern NE-central KS-southern High Plains by sunrise Tuesday. Prior to large-scale forcing/approaching cold front, forecast soundings appear too capped/stable to warrant any appreciable risk for robust convection. However, sustained southerly low-level flow should result in a gradual increase in boundary-layer moisture during the latter half of the period, as 60F dew points could approach the KS border by 30/12z. If dew points are able to rise to near 60F then surface parcels will be negligibly inhibited, and SBCAPE would likely be adequate for robust updrafts, especially as dynamic support is spreading across this boundary by sunrise. Will maintain severe probabilities for very late in the period to account for some risk of robust convection developing along the cold front/dry line, primarily after 09z. Given the strength of the wind field, organized thunderstorms are possible, and this activity could generate wind/hail. Even so, greater risk appears to be later in the day2 period. ..Darrow/Lyons.. 10/29/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1243 AM CDT Tue Oct 29 2024 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE PLAINS... ...SUMMARY... Thunderstorm development may begin late tonight from the Upper Mississippi Valley area south-southwestward across the Plains. Local/limited risk for hail/wind warrants continuation of Level 1/MRGL risk for the very end of the period. ...Plains... Seasonally strong upper trough, currently located just inland of the Pacific Coast, is forecast to shift across the Great Basin/lower CO River Valley this morning as strongest 500mb flow rotates across AZ into southern CO. This feature should advance into the Four Corners region by 30/12z with a corridor of strong high-level southwesterly winds expected to extend across NM into the upper Great Lakes. This flow regime warrants a strengthening lee trough, along with a plains-focused LLJ, through the end of the period. In response to the approaching upper system, lee trough should sharpen and get dislodged into southeastern NE-central KS-southern High Plains by sunrise Tuesday. Prior to large-scale forcing/approaching cold front, forecast soundings appear too capped/stable to warrant any appreciable risk for robust convection. However, sustained southerly low-level flow should result in a gradual increase in boundary-layer moisture during the latter half of the period, as 60F dew points could approach the KS border by 30/12z. If dew points are able to rise to near 60F then surface parcels will be negligibly inhibited, and SBCAPE would likely be adequate for robust updrafts, especially as dynamic support is spreading across this boundary by sunrise. Will maintain severe probabilities for very late in the period to account for some risk of robust convection developing along the cold front/dry line, primarily after 09z. Given the strength of the wind field, organized thunderstorms are possible, and this activity could generate wind/hail. Even so, greater risk appears to be later in the day2 period. ..Darrow/Lyons.. 10/29/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 PM CDT Mon Oct 28 2024 Valid 290100Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected tonight. ...01z Update... Western CONUS upper trough is shifting east early this evening, and significant mid-level height falls are now spreading across the lower CO River Valley into the Great Basin. Leading edge of large-scale forcing appears to be partly responsible for weak frontal convection that currently extends across eastern NV-northern UT-central WY. Occasional flashes of lightning may persist with this frontal activity as the main wind shift sags southeast. Downstream, low-level warm advection is expected to increase and focus across the upper Great Lakes later this evening. Both GRB and MPX soundings exhibited modestly steep mid-level lapse rates, but profiles have yet to moisten sufficiently and buoyancy remains negligible. With time, elevated profiles should become more unstable, and lightning is expected with deeper convection. ..Darrow.. 10/29/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 PM CDT Mon Oct 28 2024 Valid 290100Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected tonight. ...01z Update... Western CONUS upper trough is shifting east early this evening, and significant mid-level height falls are now spreading across the lower CO River Valley into the Great Basin. Leading edge of large-scale forcing appears to be partly responsible for weak frontal convection that currently extends across eastern NV-northern UT-central WY. Occasional flashes of lightning may persist with this frontal activity as the main wind shift sags southeast. Downstream, low-level warm advection is expected to increase and focus across the upper Great Lakes later this evening. Both GRB and MPX soundings exhibited modestly steep mid-level lapse rates, but profiles have yet to moisten sufficiently and buoyancy remains negligible. With time, elevated profiles should become more unstable, and lightning is expected with deeper convection. ..Darrow.. 10/29/2024 Read more

No watches are valid as of Mon Oct 28 21:29:01 UTC 2024.

No Mesoscale Discussions are in effect as of Mon Oct 28 21:29:01 UTC 2024.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0349 PM CDT Mon Oct 28 2024 Valid 301200Z - 051200Z A progressive upper-level pattern is expected through the remainder of the week. An upper-level trough will eject into the Plains late this week and continue on into the Northeast. Farther west, another upper-level trough is expected to dig southward along the West Coast and gradually shift eastward this weekend into next week. Fire weather concerns will be focused on Wednesday. Thereafter, cool/wet conditions across much of the CONUS are expected to mitigate larger-scale fire weather concerns. Coincidentally, ensemble forecasts show low probability of critical fire weather through early next week. ...Southern High Plains... Dry and windy conditions are expected as westerly downslope winds increase behind a Pacific front on Wednesday. Strong mid-level winds and a surface low in the southern Plains will drive around 20 mph winds with near 15% RH. The duration of these conditions is the main uncertainty that precludes an increase in critical probabilities. Depending on the evolution of the upper-level pattern over the weekend into early next week, some increase in dry/windy conditions is possible. However, given expected precipitation in the region as well as uncertainty in the overall pattern, confidence in critical fire weather is low. ...Southern California... Offshore winds are possible from late Tuesday into Wednesday. While some locally elevated conditions could develop, potential for critical fire weather appears low given the precipitation that may accompany the upper-level trough. Models suggest another period of offshore winds may develop early next week. However, the degree of upper-level support differs quite markedly. Furthermore, additional precipitation is possible as the large-scale trough moves over the region during the weekend. Trends will be monitored, but critical fire weather potential also appears low early next week as well. ..Wendt.. 10/28/2024 ...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 0349 PM CDT Mon Oct 28 2024 Valid 301200Z - 051200Z A progressive upper-level pattern is expected through the remainder of the week. An upper-level trough will eject into the Plains late this week and continue on into the Northeast. Farther west, another upper-level trough is expected to dig southward along the West Coast and gradually shift eastward this weekend into next week. Fire weather concerns will be focused on Wednesday. Thereafter, cool/wet conditions across much of the CONUS are expected to mitigate larger-scale fire weather concerns. Coincidentally, ensemble forecasts show low probability of critical fire weather through early next week. ...Southern High Plains... Dry and windy conditions are expected as westerly downslope winds increase behind a Pacific front on Wednesday. Strong mid-level winds and a surface low in the southern Plains will drive around 20 mph winds with near 15% RH. The duration of these conditions is the main uncertainty that precludes an increase in critical probabilities. Depending on the evolution of the upper-level pattern over the weekend into early next week, some increase in dry/windy conditions is possible. However, given expected precipitation in the region as well as uncertainty in the overall pattern, confidence in critical fire weather is low. ...Southern California... Offshore winds are possible from late Tuesday into Wednesday. While some locally elevated conditions could develop, potential for critical fire weather appears low given the precipitation that may accompany the upper-level trough. Models suggest another period of offshore winds may develop early next week. However, the degree of upper-level support differs quite markedly. Furthermore, additional precipitation is possible as the large-scale trough moves over the region during the weekend. Trends will be monitored, but critical fire weather potential also appears low early next week as well. ..Wendt.. 10/28/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0326 PM CDT Mon Oct 28 2024 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI AND MIDDLE MISSOURI VALLEYS TO KANSAS/NORTHWESTERN OKLAHOMA... CORRECTED FOR THUNDER AREA REMOVAL IN THE NORTHEAST ...SUMMARY... Thunderstorm development may begin late in the period from the Upper Mississippi Valley area south-southwestward across the Plains. Local/limited risk for hail/wind warrants continuation of Level 1/MRGL risk for Tuesday night. ...Synopsis... A highly amplified flow field aloft will reside across the U.S. Tuesday, as a deep trough slowly crosses the Intermountain West through the period. By Wednesday morning, the trough should extend from the northern High Plains to the Four Corners area. Meanwhile, ridging will amplify in the eastern U.S., in response to the advance of the western trough. At the surface, a cold front will sweep across the Four Corners states through the first half of the period, ahead of the progressing upper system. A frontal wave should evolve over the central High Plains, and is expected to then shift north-northeastward across Nebraska, reaching the southern Minnesota vicinity by 12Z Tuesday morning. This will allow continued eastward advance of the trailing front, which should extend from the Mid Missouri Valley (western Iowa) vicinity south-southwestward to southern New Mexico/far West Texas by the end of the period. ...Upper Mississippi Valley south-southwestward to the northwestern Oklahoma vicinity... Ahead of the sharpening cold front becoming established across the Plains Tuesday/Tuesday night, a warm/modestly moist pre-frontal boundary layer is expected to evolve, beneath a fairly pronounced warm/capping layer aloft. Much of the large-scale ascent associated with the advancing upper system should remain to the cool side of the front, and thus expect the capping layer to be very slow to weaken/erode. Low-level warm advection ahead of the track of the surface low may support some primarily elevated convective development overnight, where modest elevated CAPE may be sufficient to permit a few stronger updrafts. Limited potential for hail nearing severe levels could accompany one or two of the strongest storms. A strong gust cannot be ruled out, should a less-elevated storm nearer the surface boundary evolve. Farther southwestward into the Plains, any potential storm development should be limited to the last 3 or 4 hours of the period, at the earliest -- due to the persistent capping. With that said, given gradually steepening lapse rates/increasing CAPE, and the presence of strong southwesterly flow aloft atop the frontal zone, low/conditional risk for a couple of storms capable of producing marginal hail/wind cannot be ruled out. A such, will retain an elongated Level 1/MRGL risk area across central portions of the country to reflect these potential convective scenarios that may evolve prior to the end of the period. ..Goss.. 10/28/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0326 PM CDT Mon Oct 28 2024 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI AND MIDDLE MISSOURI VALLEYS TO KANSAS/NORTHWESTERN OKLAHOMA... CORRECTED FOR THUNDER AREA REMOVAL IN THE NORTHEAST ...SUMMARY... Thunderstorm development may begin late in the period from the Upper Mississippi Valley area south-southwestward across the Plains. Local/limited risk for hail/wind warrants continuation of Level 1/MRGL risk for Tuesday night. ...Synopsis... A highly amplified flow field aloft will reside across the U.S. Tuesday, as a deep trough slowly crosses the Intermountain West through the period. By Wednesday morning, the trough should extend from the northern High Plains to the Four Corners area. Meanwhile, ridging will amplify in the eastern U.S., in response to the advance of the western trough. At the surface, a cold front will sweep across the Four Corners states through the first half of the period, ahead of the progressing upper system. A frontal wave should evolve over the central High Plains, and is expected to then shift north-northeastward across Nebraska, reaching the southern Minnesota vicinity by 12Z Tuesday morning. This will allow continued eastward advance of the trailing front, which should extend from the Mid Missouri Valley (western Iowa) vicinity south-southwestward to southern New Mexico/far West Texas by the end of the period. ...Upper Mississippi Valley south-southwestward to the northwestern Oklahoma vicinity... Ahead of the sharpening cold front becoming established across the Plains Tuesday/Tuesday night, a warm/modestly moist pre-frontal boundary layer is expected to evolve, beneath a fairly pronounced warm/capping layer aloft. Much of the large-scale ascent associated with the advancing upper system should remain to the cool side of the front, and thus expect the capping layer to be very slow to weaken/erode. Low-level warm advection ahead of the track of the surface low may support some primarily elevated convective development overnight, where modest elevated CAPE may be sufficient to permit a few stronger updrafts. Limited potential for hail nearing severe levels could accompany one or two of the strongest storms. A strong gust cannot be ruled out, should a less-elevated storm nearer the surface boundary evolve. Farther southwestward into the Plains, any potential storm development should be limited to the last 3 or 4 hours of the period, at the earliest -- due to the persistent capping. With that said, given gradually steepening lapse rates/increasing CAPE, and the presence of strong southwesterly flow aloft atop the frontal zone, low/conditional risk for a couple of storms capable of producing marginal hail/wind cannot be ruled out. A such, will retain an elongated Level 1/MRGL risk area across central portions of the country to reflect these potential convective scenarios that may evolve prior to the end of the period. ..Goss.. 10/28/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Mon Oct 28 2024 Valid 291200Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF CENTRAL HIGH PLAINS... Downslope warming and favorable timing of the mid-level jet across the central High Plains suggests Critical fire weather is probable in portions of the region. Strong sustained winds (and higher gusts) are still expected farther east. Uncertainty remains rather high in terms of how low RH will fall with continued moisture return northward. The Elevated area has been expanded east to account for some of this uncertainty and the potential for areas along the fringe of the moisture return to be drier than anticipated. Elevated conditions are possible in parts of central/northern Illinois. Models show a drier pocket of air moving over the region by afternoon. Current observations and forecast trajectories support this possibility. Fuels are quite dry and winds will be strong, but uncertainty remains quite large due to cirrus potentially impacting afternoon temperatures. ..Wendt.. 10/28/2024 .PREV DISCUSSION... /ISSUED 0210 AM CDT Mon Oct 28 2024/ ...Synopsis... As the upper trough deepens over the west, strong southwesterly flow aloft will remain over the Rockies and adjacent High Plains. A sub 1000 mb lee low and trailing surface trough will encourage gusty downslope winds of 20-30 mph across eastern CO/NM and parts of western KS, TX and OK. Elevated to near-critical fire-weather conditions are possible. ...High Plains... Surface winds are expected to intensify early in the day south of the lee low across portions of the central High Plains. Heating and downslope warming beneath scattered high clouds will support RH minimums of 15-25%. The overlap of strong winds and low RH will support several hours of elevated to near-critical fire-weather conditions. There remains some uncertainty on the exact areal extent of the fire-weather risk given the narrow corridor of the strongest winds are excepted to align with more limited RH from cloud cover and returning moisture, as well as fuels that are not as dry as farther east. While near-critical conditions are possible, forecast confidence remains too low to include a critical area. The most probable location for sustained critical conditions may be across parts of northeastern and eastern CO, where stronger winds and downslope drying could overlap with more receptive fuels. Farther east, strong southerly winds are likely over parts of central KS and OK. RH values are not expected to be overly low as southerly return flow advects moisture northward. However, pockets of drier air and gusts to 30+ mph could support sporadic locally elevated fire-weather conditions Tuesday afternoon given the exceptionally dry fuels. ...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 0254 PM CDT Mon Oct 28 2024 Valid 291200Z - 301200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF CENTRAL HIGH PLAINS... Downslope warming and favorable timing of the mid-level jet across the central High Plains suggests Critical fire weather is probable in portions of the region. Strong sustained winds (and higher gusts) are still expected farther east. Uncertainty remains rather high in terms of how low RH will fall with continued moisture return northward. The Elevated area has been expanded east to account for some of this uncertainty and the potential for areas along the fringe of the moisture return to be drier than anticipated. Elevated conditions are possible in parts of central/northern Illinois. Models show a drier pocket of air moving over the region by afternoon. Current observations and forecast trajectories support this possibility. Fuels are quite dry and winds will be strong, but uncertainty remains quite large due to cirrus potentially impacting afternoon temperatures. ..Wendt.. 10/28/2024 .PREV DISCUSSION... /ISSUED 0210 AM CDT Mon Oct 28 2024/ ...Synopsis... As the upper trough deepens over the west, strong southwesterly flow aloft will remain over the Rockies and adjacent High Plains. A sub 1000 mb lee low and trailing surface trough will encourage gusty downslope winds of 20-30 mph across eastern CO/NM and parts of western KS, TX and OK. Elevated to near-critical fire-weather conditions are possible. ...High Plains... Surface winds are expected to intensify early in the day south of the lee low across portions of the central High Plains. Heating and downslope warming beneath scattered high clouds will support RH minimums of 15-25%. The overlap of strong winds and low RH will support several hours of elevated to near-critical fire-weather conditions. There remains some uncertainty on the exact areal extent of the fire-weather risk given the narrow corridor of the strongest winds are excepted to align with more limited RH from cloud cover and returning moisture, as well as fuels that are not as dry as farther east. While near-critical conditions are possible, forecast confidence remains too low to include a critical area. The most probable location for sustained critical conditions may be across parts of northeastern and eastern CO, where stronger winds and downslope drying could overlap with more receptive fuels. Farther east, strong southerly winds are likely over parts of central KS and OK. RH values are not expected to be overly low as southerly return flow advects moisture northward. However, pockets of drier air and gusts to 30+ mph could support sporadic locally elevated fire-weather conditions Tuesday afternoon given the exceptionally dry fuels. ...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 0244 PM CDT Mon Oct 28 2024 Valid 282000Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today and tonight. ...20Z Update... The primary change to this outlook was to remove thunder probabilities over portions of the Pacific Northwest. Stronger forcing for ascent continues to drift eastward in tandem with the upper trough that is now shifting toward the Interior West. Otherwise, the previous forecast (see below) remains on track. ..Squitieri.. 10/28/2024 .PREV DISCUSSION... /ISSUED 1124 AM CDT Mon Oct 28 2024/ ...Synopsis and Discussion... An upper trough will amplify further today as it moves from the eastern Pacific across the western states. Low-topped showers across parts of coastal WA/OR may be capable of producing occasional lightning flashes, as mid-level temperatures beneath the upper trough remain rather cool, which is supporting weak MUCAPE. But, better forcing for ascent preceding the upper trough will overspread portions of the Great Basin and central Rockies through the period, where isolated thunderstorms may occur even though moisture will be quite limited. A separate area of isolated to scattered thunderstorm potential remains evident across parts of the Great Lakes tonight, as warm/moist advection increases in tandem with a strengthening low-level jet. Weak instability will limit the severe threat across all these regions, and severe thunderstorms are not forecast. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0219 PM CDT Mon Oct 28 2024 Valid 301200Z - 311200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN IOWA AND SOUTHEASTERN NEBRASKA SOUTHWESTWARD TO NORTH TEXAS... ...SUMMARY... Strong/locally severe thunderstorms, capable of producing severe wind gusts and large hail, are expected to develop Wednesday from the southern Plains north-northeastward to the Middle Mississippi Valley/Upper Midwest. ...Synopsis... An upper trough moving out of the interior West is forecast to eject northeastward across the central U.S. Wednesday, shunted from its prior, more eastward trajectory by stout ridging over the eastern CONUS. At the surface, steady eastward advance of a cold front across the central third of the country is expected. By the end of the period (early Thursday morning), the boundary should extend from the Upper Great Lakes region southwestward across the Mid Mississippi Valley and Ozarks region, to central Texas. ...Upper Midwest to Texas... Thunderstorm development is expected to occur -- potentially early in the period -- along the advancing cold front, as lapse rates gradually steepen atop a sufficiently moist/gradually warming boundary layer. The more substantial destabilization is expected to evolve from roughly Kansas southward, while the strongest/deepest forcing for ascent should occur from roughly Kansas northward. As such, initial convective development is expected in the vicinity of the Middle Missouri Valley during the morning, and spreading northeastward into the progressively weaker-CAPE environment into the upper Mississippi Valley/western Upper Great Lakes area. Despite the more limited CAPE, however, strong southwesterly flow aloft -- increasing with height -- will result in shear supporting at least isolated stronger/potentially severe storms. Hail and locally damaging wind gusts will be the primary risks, spreading eastward with time as the front advances. Threat should gradually diminish after dark, with the loss of heating/diminishing CAPE. Farther south, convective initiation should occur later, given weaker forcing for ascent, and residual capping. Storms that do initiate will occur in a thermodynamic and kinematic environment favoring rotating updrafts, and thus expect potential for large hail and locally damaging gusts with stronger storms. A tornado or two may also occur, though some upscale growth is expected to occur with time, potentially limiting this risk. While some severe potential may continue into the overnight hours, weakening CAPE should correspond to a gradual decrease in severe potential through 31/12Z. ..Goss.. 10/28/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Oct 28 2024 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI AND MIDDLE MISSOURI VALLEYS TO KANSAS/NORTHWESTERN OKLAHOMA... ...SUMMARY... Thunderstorm development may begin late in the period from the Upper Mississippi Valley area south-southwestward across the Plains. Local/limited risk for hail/wind warrants continuation of Level 1/MRGL risk for Tuesday night. ...Synopsis... A highly amplified flow field aloft will reside across the U.S. Tuesday, as a deep trough slowly crosses the Intermountain West through the period. By Wednesday morning, the trough should extend from the northern High Plains to the Four Corners area. Meanwhile, ridging will amplify in the eastern U.S., in response to the advance of the western trough. At the surface, a cold front will sweep across the Four Corners states through the first half of the period, ahead of the progressing upper system. A frontal wave should evolve over the central High Plains, and is expected to then shift north-northeastward across Nebraska, reaching the southern Minnesota vicinity by 12Z Tuesday morning. This will allow continued eastward advance of the trailing front, which should extend from the Mid Missouri Valley (western Iowa) vicinity south-southwestward to southern New Mexico/far West Texas by the end of the period. ...Upper Mississippi Valley south-southwestward to the northwestern Oklahoma vicinity... Ahead of the sharpening cold front becoming established across the Plains Tuesday/Tuesday night, a warm/modestly moist pre-frontal boundary layer is expected to evolve, beneath a fairly pronounced warm/capping layer aloft. Much of the large-scale ascent associated with the advancing upper system should remain to the cool side of the front, and thus expect the capping layer to be very slow to weaken/erode. Low-level warm advection ahead of the track of the surface low may support some primarily elevated convective development overnight, where modest elevated CAPE may be sufficient to permit a few stronger updrafts. Limited potential for hail nearing severe levels could accompany one or two of the strongest storms. A strong gust cannot be ruled out, should a less-elevated storm nearer the surface boundary evolve. Farther southwestward into the Plains, any potential storm development should be limited to the last 3 or 4 hours of the period, at the earliest -- due to the persistent capping. With that said, given gradually steepening lapse rates/increasing CAPE, and the presence of strong southwesterly flow aloft atop the frontal zone, low/conditional risk for a couple of storms capable of producing marginal hail/wind cannot be ruled out. A such, will retain an elongated Level 1/MRGL risk area across central portions of the country to reflect these potential convective scenarios that may evolve prior to the end of the period. ..Goss.. 10/28/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1152 AM CDT Mon Oct 28 2024 Valid 281700Z - 291200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE SOUTHERN PLAINS... High-level cloud cover is continuing to erode across the Texas Panhandle into western/central Oklahoma. Based on these and other observational trends, the Critical area has been adjusted to include more of those areas. Questions still remain how low RH will fall in central/eastern Oklahoma, but strong winds and very dry fuels will promote large fire potential nonetheless. ..Wendt.. 10/28/2024 .PREV DISCUSSION... /ISSUED 0208 AM CDT Mon Oct 28 2024/ ...Synopsis... An upper trough is forecast to deepen and shift eastward over the western US today and tonight. A strong lee low will deepen over eastern CO increasing southerly flow over much of the Plains. Well above normal temperatures and strong winds will overlap with abundant and near record dry fuels. The combination of abnormally high temperatures and strong winds will support widespread elevated to critical fire-weather conditions. ...Southern and central Plains... Strong flow aloft will overspread the southern Plains ahead of the deepening trough beginning early today. Southeast of a deepening lee low over eastern CO, south/southwest winds will quickly strengthen over parts of TX, OK and KS. By midday, winds of 20-30 mph and gusts as high as 40 mph, are likely over much of the southern Plains. The strong winds are expected to overlap with areas of lower relative humidity. A corridor of 15-20% RH appears likely to overlap with the strongest winds across the eastern TX Panhandle, western OK and southern KS. Critical fire-weather conditions are likely given extremely dry fuels. Farther east into central/eastern OK and KS, high cirrus and returning surface moisture could limit RH minimums. However, wind gusts of 30+ mph and critically dry fuels still appear likely to support widespread elevated to near-critical fire-weather conditions across the southern Plains. ...Southwest and Great Basin... Near the base of the upper trough, strong southwesterly flow is expected ahead of a cold front across the southern Great Basin and the Southwest. Downslope flow and warm temperatures will support RH values of 15-20% as surface winds increase to 15-20 mph. Elevated fire-weather conditions appear likely ahead of the front across the southern Great Basin and much of the Desert Southwest. ...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 1152 AM CDT Mon Oct 28 2024 Valid 281700Z - 291200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE SOUTHERN PLAINS... High-level cloud cover is continuing to erode across the Texas Panhandle into western/central Oklahoma. Based on these and other observational trends, the Critical area has been adjusted to include more of those areas. Questions still remain how low RH will fall in central/eastern Oklahoma, but strong winds and very dry fuels will promote large fire potential nonetheless. ..Wendt.. 10/28/2024 .PREV DISCUSSION... /ISSUED 0208 AM CDT Mon Oct 28 2024/ ...Synopsis... An upper trough is forecast to deepen and shift eastward over the western US today and tonight. A strong lee low will deepen over eastern CO increasing southerly flow over much of the Plains. Well above normal temperatures and strong winds will overlap with abundant and near record dry fuels. The combination of abnormally high temperatures and strong winds will support widespread elevated to critical fire-weather conditions. ...Southern and central Plains... Strong flow aloft will overspread the southern Plains ahead of the deepening trough beginning early today. Southeast of a deepening lee low over eastern CO, south/southwest winds will quickly strengthen over parts of TX, OK and KS. By midday, winds of 20-30 mph and gusts as high as 40 mph, are likely over much of the southern Plains. The strong winds are expected to overlap with areas of lower relative humidity. A corridor of 15-20% RH appears likely to overlap with the strongest winds across the eastern TX Panhandle, western OK and southern KS. Critical fire-weather conditions are likely given extremely dry fuels. Farther east into central/eastern OK and KS, high cirrus and returning surface moisture could limit RH minimums. However, wind gusts of 30+ mph and critically dry fuels still appear likely to support widespread elevated to near-critical fire-weather conditions across the southern Plains. ...Southwest and Great Basin... Near the base of the upper trough, strong southwesterly flow is expected ahead of a cold front across the southern Great Basin and the Southwest. Downslope flow and warm temperatures will support RH values of 15-20% as surface winds increase to 15-20 mph. Elevated fire-weather conditions appear likely ahead of the front across the southern Great Basin and much of the Desert Southwest. ...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 1124 AM CDT Mon Oct 28 2024 Valid 281630Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today and tonight. ...Synopsis and Discussion... An upper trough will amplify further today as it moves from the eastern Pacific across the western states. Low-topped showers across parts of coastal WA/OR may be capable of producing occasional lightning flashes, as mid-level temperatures beneath the upper trough remain rather cool, which is supporting weak MUCAPE. But, better forcing for ascent preceding the upper trough will overspread portions of the Great Basin and central Rockies through the period, where isolated thunderstorms may occur even though moisture will be quite limited. A separate area of isolated to scattered thunderstorm potential remains evident across parts of the Great Lakes tonight, as warm/moist advection increases in tandem with a strengthening low-level jet. Weak instability will limit the severe threat across all these regions, and severe thunderstorms are not forecast. ..Gleason/Moore.. 10/28/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0729 AM CDT Mon Oct 28 2024 Valid 281300Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...Discussion... Deep convective potential will remain limited today with severe storms not expected. This will be influenced by an amplifying large-scale pattern, highlights by strong height falls over the West, particularly across the Great Basin to central/southern Rockies. In this scenario, steep lapse rate profiles may support a few flashes of lightning with shallow convection near the Pacific Coast today. Increasing forcing for ascent and steepening lapse rates across the interior Great Basin/Four Corners may contribute to isolated convection, some of which may generate lightning later this afternoon into evening. Later tonight, primarily after 03Z, elevated thunderstorms are expected to develop and spread east-northeastward across the Upper Great Lakes. This will be a byproduct of a robustly strong southwesterly low-level jet and warm advection regime emanating from the central Plains toward the upper Mississippi Valley. ..Guyer/Leitman.. 10/28/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CDT Mon Oct 28 2024 Valid 311200Z - 051200Z ...DISCUSSION... ...Thursday/Day 4 to Saturday/Day 6... An upper-level trough is forecast to move eastward into the upper Mississippi Valley on Thursday, and into the Northeast on Friday. At the surface, a cold front is forecast to advance southeastward into the Gulf Coast states. Thunderstorm development will be likely near and ahead of the front Thursday afternoon and evening. Weak instability and limited large-scale ascent should keep any severe threat marginal. From Friday into Saturday, low-level moisture return is expected to take place further west into the southern Plains. Thunderstorms are forecast to develop on Friday over parts of eastern New Mexico and west Texas, with an isolated severe threat possible. On Saturday, moisture and instability is forecast to increase across the southern and central Plains, which could result in an expansion of severe threat coverage. However, the latest models suggest that instability will be relatively weak in most areas, helping to marginalize the severe threat. ...Sunday/Day 7 and Monday/Day 8... On Sunday and Monday, an upper-level system is forecast to move from near the southern California coast into northwestern Mexico. Ahead of the system, an anticyclonic and subtle southwesterly mid-level flow pattern is forecast in the south-central U.S, where a moist airmass should be located. Isolated to scattered thunderstorms are expected to develop on both Sunday and Monday afternoons with this airmass. The strongest instability is forecast to be near the western edge of the moist airmass, suggesting the greatest severe potential could be from west Texas extending north-northeastward into the central Plains. Forecast instability should be relatively weak, keeping any severe threat marginal. Read more