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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1053 AM CST Thu Feb 22 2024 Valid 221700Z - 231200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/22/2024 .PREV DISCUSSION... /ISSUED 1245 AM CST Thu Feb 22 2024/ ...Synopsis... Fire weather concerns will be focused across southern/southwest TX this afternoon. 06 UTC surface observations show a very dry air mass in place across the southern High Plains as a surface low deepens over northern OK. Over the next 12-24 hours, this low is forecast to weaken as it migrates to the east/northeast, which will lead to a gradual reduction in gradient winds over the southern Plains. Although winds will be considerably weaker compared to yesterday/Wednesday, areas of 15-25 mph sustained winds are expected in the vicinity of a southward-moving cold front. Latest guidance places this front across southern TX by peak heating. The antecedent dry air mass should promote afternoon RH minimums near 10-20% - even behind the cold front, owing to fairly weak cold advection. Consequently, elevated fire weather conditions are expected across a swath of southern/southwest TX. Locally critical conditions are probable across the Big Bend region, generally along I-10 and southward to the Rio Grande where ensemble consensus shows a somewhat higher probability for sustained winds between 20-25 mph. After warm, dry, and windy conditions yesterday, fine fuels across the region should be receptive and will support the fire weather threat. ...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 1053 AM CST Thu Feb 22 2024 Valid 221700Z - 231200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/22/2024 .PREV DISCUSSION... /ISSUED 1245 AM CST Thu Feb 22 2024/ ...Synopsis... Fire weather concerns will be focused across southern/southwest TX this afternoon. 06 UTC surface observations show a very dry air mass in place across the southern High Plains as a surface low deepens over northern OK. Over the next 12-24 hours, this low is forecast to weaken as it migrates to the east/northeast, which will lead to a gradual reduction in gradient winds over the southern Plains. Although winds will be considerably weaker compared to yesterday/Wednesday, areas of 15-25 mph sustained winds are expected in the vicinity of a southward-moving cold front. Latest guidance places this front across southern TX by peak heating. The antecedent dry air mass should promote afternoon RH minimums near 10-20% - even behind the cold front, owing to fairly weak cold advection. Consequently, elevated fire weather conditions are expected across a swath of southern/southwest TX. Locally critical conditions are probable across the Big Bend region, generally along I-10 and southward to the Rio Grande where ensemble consensus shows a somewhat higher probability for sustained winds between 20-25 mph. After warm, dry, and windy conditions yesterday, fine fuels across the region should be receptive and will support the fire weather threat. ...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 1053 AM CST Thu Feb 22 2024 Valid 221700Z - 231200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/22/2024 .PREV DISCUSSION... /ISSUED 1245 AM CST Thu Feb 22 2024/ ...Synopsis... Fire weather concerns will be focused across southern/southwest TX this afternoon. 06 UTC surface observations show a very dry air mass in place across the southern High Plains as a surface low deepens over northern OK. Over the next 12-24 hours, this low is forecast to weaken as it migrates to the east/northeast, which will lead to a gradual reduction in gradient winds over the southern Plains. Although winds will be considerably weaker compared to yesterday/Wednesday, areas of 15-25 mph sustained winds are expected in the vicinity of a southward-moving cold front. Latest guidance places this front across southern TX by peak heating. The antecedent dry air mass should promote afternoon RH minimums near 10-20% - even behind the cold front, owing to fairly weak cold advection. Consequently, elevated fire weather conditions are expected across a swath of southern/southwest TX. Locally critical conditions are probable across the Big Bend region, generally along I-10 and southward to the Rio Grande where ensemble consensus shows a somewhat higher probability for sustained winds between 20-25 mph. After warm, dry, and windy conditions yesterday, fine fuels across the region should be receptive and will support the fire weather threat. ...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 1053 AM CST Thu Feb 22 2024 Valid 221700Z - 231200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/22/2024 .PREV DISCUSSION... /ISSUED 1245 AM CST Thu Feb 22 2024/ ...Synopsis... Fire weather concerns will be focused across southern/southwest TX this afternoon. 06 UTC surface observations show a very dry air mass in place across the southern High Plains as a surface low deepens over northern OK. Over the next 12-24 hours, this low is forecast to weaken as it migrates to the east/northeast, which will lead to a gradual reduction in gradient winds over the southern Plains. Although winds will be considerably weaker compared to yesterday/Wednesday, areas of 15-25 mph sustained winds are expected in the vicinity of a southward-moving cold front. Latest guidance places this front across southern TX by peak heating. The antecedent dry air mass should promote afternoon RH minimums near 10-20% - even behind the cold front, owing to fairly weak cold advection. Consequently, elevated fire weather conditions are expected across a swath of southern/southwest TX. Locally critical conditions are probable across the Big Bend region, generally along I-10 and southward to the Rio Grande where ensemble consensus shows a somewhat higher probability for sustained winds between 20-25 mph. After warm, dry, and windy conditions yesterday, fine fuels across the region should be receptive and will support the fire weather threat. ...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 1053 AM CST Thu Feb 22 2024 Valid 221700Z - 231200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/22/2024 .PREV DISCUSSION... /ISSUED 1245 AM CST Thu Feb 22 2024/ ...Synopsis... Fire weather concerns will be focused across southern/southwest TX this afternoon. 06 UTC surface observations show a very dry air mass in place across the southern High Plains as a surface low deepens over northern OK. Over the next 12-24 hours, this low is forecast to weaken as it migrates to the east/northeast, which will lead to a gradual reduction in gradient winds over the southern Plains. Although winds will be considerably weaker compared to yesterday/Wednesday, areas of 15-25 mph sustained winds are expected in the vicinity of a southward-moving cold front. Latest guidance places this front across southern TX by peak heating. The antecedent dry air mass should promote afternoon RH minimums near 10-20% - even behind the cold front, owing to fairly weak cold advection. Consequently, elevated fire weather conditions are expected across a swath of southern/southwest TX. Locally critical conditions are probable across the Big Bend region, generally along I-10 and southward to the Rio Grande where ensemble consensus shows a somewhat higher probability for sustained winds between 20-25 mph. After warm, dry, and windy conditions yesterday, fine fuels across the region should be receptive and will support the fire weather threat. ...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 1053 AM CST Thu Feb 22 2024 Valid 221700Z - 231200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/22/2024 .PREV DISCUSSION... /ISSUED 1245 AM CST Thu Feb 22 2024/ ...Synopsis... Fire weather concerns will be focused across southern/southwest TX this afternoon. 06 UTC surface observations show a very dry air mass in place across the southern High Plains as a surface low deepens over northern OK. Over the next 12-24 hours, this low is forecast to weaken as it migrates to the east/northeast, which will lead to a gradual reduction in gradient winds over the southern Plains. Although winds will be considerably weaker compared to yesterday/Wednesday, areas of 15-25 mph sustained winds are expected in the vicinity of a southward-moving cold front. Latest guidance places this front across southern TX by peak heating. The antecedent dry air mass should promote afternoon RH minimums near 10-20% - even behind the cold front, owing to fairly weak cold advection. Consequently, elevated fire weather conditions are expected across a swath of southern/southwest TX. Locally critical conditions are probable across the Big Bend region, generally along I-10 and southward to the Rio Grande where ensemble consensus shows a somewhat higher probability for sustained winds between 20-25 mph. After warm, dry, and windy conditions yesterday, fine fuels across the region should be receptive and will support the fire weather threat. ...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 1020 AM CST Thu Feb 22 2024 Valid 221630Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF SOUTHEASTERN ARKANSAS...NORTHERN MISSISSIPPI...AND ADJACENT SOUTHWESTERN TENNESSEE...NORTHWESTERN ALABAMA... ...SUMMARY... Strong thunderstorms may develop and overspread parts of the Mid South this evening, and perhaps pose some risk for damaging wind gusts and severe hail. ...Synopsis... A couple of short wave perturbations of Arctic origins (currently west of Hudson Bay) are forecast to continue to consolidate into a vigorous digging short wave trough to the southwest through south of Hudson Bay into the James Bay vicinity today through tonight. It still appears that this will contribute to larger-scale mid/upper trough amplification across the northern into mid-latitudes of eastern North America (and accompanied by a significant cold front crossing the Canadian/U.S. border into the northern Great Plains through upper Great Lakes region by late tonight). In phase with this regime, models indicate that the stronger westerlies across the southern mid- and subtropical latitudes will trend broadly cyclonic across the southern Great Plains through the Southeast, with one or two consolidating embedded lower amplitude perturbations digging from the central Great Plains/Ozark Plateau and lower Ohio Valley through the lower Mississippi/Tennessee Valleys and southern Appalachians by 12Z Friday. While there may be some further deepening of surface troughing shifting from the southern Great Plains through lower Ohio Valley into the Southeast through Mid Atlantic, models indicate that any embedded cyclogenesis will remain negligible, at least until it shifts offshore Friday through Friday night. In the wake of initially more amplified mid-level troughing now beginning to accelerate away from the Atlantic Seaboard, boundary-layer modification over the Gulf of Mexico has been slow. A limited moisture return is ongoing on moderately strong southerly return flow preceding the surface trough, but substantive further improvement still appears unlikely through this period. ...Mid South and Ohio/Tennessee Valleys... Observed and forecast soundings suggest that moistening supportive of thunderstorm development, with large-scale ascent, is generally occurring above a stable boundary, and beneath warm/dry capping layers aloft, with profiles supportive of only weak CAPE. It appears that this will remain the case as forcing for ascent begins to support increasing thunderstorm activity ahead of the digging mid-level troughing, southeast of the lower Ohio Valley through the Tennessee Valley and portions of the lower Mississippi Valley later today through tonight. However, at least some model output, perhaps most notably the High Resolution Rapid Refresh, suggests that a somewhat better moist (and potentially unstable) inflow to the southwestern flank of this forcing could enhance thunderstorm development this evening across parts of the Mid South into Gulf States. The HRRR depiction of convection includes an organizing cluster with 45+ kt rear inflow developing near or above the 850-800 mb layer. Even if this verifies, the potential efficiency of downward momentum transport to the surface remains unclear based on forecast soundings, but a few locally strong/damaging wind gusts might not be out of the question. ..Kerr/Squitieri.. 02/22/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1020 AM CST Thu Feb 22 2024 Valid 221630Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF SOUTHEASTERN ARKANSAS...NORTHERN MISSISSIPPI...AND ADJACENT SOUTHWESTERN TENNESSEE...NORTHWESTERN ALABAMA... ...SUMMARY... Strong thunderstorms may develop and overspread parts of the Mid South this evening, and perhaps pose some risk for damaging wind gusts and severe hail. ...Synopsis... A couple of short wave perturbations of Arctic origins (currently west of Hudson Bay) are forecast to continue to consolidate into a vigorous digging short wave trough to the southwest through south of Hudson Bay into the James Bay vicinity today through tonight. It still appears that this will contribute to larger-scale mid/upper trough amplification across the northern into mid-latitudes of eastern North America (and accompanied by a significant cold front crossing the Canadian/U.S. border into the northern Great Plains through upper Great Lakes region by late tonight). In phase with this regime, models indicate that the stronger westerlies across the southern mid- and subtropical latitudes will trend broadly cyclonic across the southern Great Plains through the Southeast, with one or two consolidating embedded lower amplitude perturbations digging from the central Great Plains/Ozark Plateau and lower Ohio Valley through the lower Mississippi/Tennessee Valleys and southern Appalachians by 12Z Friday. While there may be some further deepening of surface troughing shifting from the southern Great Plains through lower Ohio Valley into the Southeast through Mid Atlantic, models indicate that any embedded cyclogenesis will remain negligible, at least until it shifts offshore Friday through Friday night. In the wake of initially more amplified mid-level troughing now beginning to accelerate away from the Atlantic Seaboard, boundary-layer modification over the Gulf of Mexico has been slow. A limited moisture return is ongoing on moderately strong southerly return flow preceding the surface trough, but substantive further improvement still appears unlikely through this period. ...Mid South and Ohio/Tennessee Valleys... Observed and forecast soundings suggest that moistening supportive of thunderstorm development, with large-scale ascent, is generally occurring above a stable boundary, and beneath warm/dry capping layers aloft, with profiles supportive of only weak CAPE. It appears that this will remain the case as forcing for ascent begins to support increasing thunderstorm activity ahead of the digging mid-level troughing, southeast of the lower Ohio Valley through the Tennessee Valley and portions of the lower Mississippi Valley later today through tonight. However, at least some model output, perhaps most notably the High Resolution Rapid Refresh, suggests that a somewhat better moist (and potentially unstable) inflow to the southwestern flank of this forcing could enhance thunderstorm development this evening across parts of the Mid South into Gulf States. The HRRR depiction of convection includes an organizing cluster with 45+ kt rear inflow developing near or above the 850-800 mb layer. Even if this verifies, the potential efficiency of downward momentum transport to the surface remains unclear based on forecast soundings, but a few locally strong/damaging wind gusts might not be out of the question. ..Kerr/Squitieri.. 02/22/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1020 AM CST Thu Feb 22 2024 Valid 221630Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF SOUTHEASTERN ARKANSAS...NORTHERN MISSISSIPPI...AND ADJACENT SOUTHWESTERN TENNESSEE...NORTHWESTERN ALABAMA... ...SUMMARY... Strong thunderstorms may develop and overspread parts of the Mid South this evening, and perhaps pose some risk for damaging wind gusts and severe hail. ...Synopsis... A couple of short wave perturbations of Arctic origins (currently west of Hudson Bay) are forecast to continue to consolidate into a vigorous digging short wave trough to the southwest through south of Hudson Bay into the James Bay vicinity today through tonight. It still appears that this will contribute to larger-scale mid/upper trough amplification across the northern into mid-latitudes of eastern North America (and accompanied by a significant cold front crossing the Canadian/U.S. border into the northern Great Plains through upper Great Lakes region by late tonight). In phase with this regime, models indicate that the stronger westerlies across the southern mid- and subtropical latitudes will trend broadly cyclonic across the southern Great Plains through the Southeast, with one or two consolidating embedded lower amplitude perturbations digging from the central Great Plains/Ozark Plateau and lower Ohio Valley through the lower Mississippi/Tennessee Valleys and southern Appalachians by 12Z Friday. While there may be some further deepening of surface troughing shifting from the southern Great Plains through lower Ohio Valley into the Southeast through Mid Atlantic, models indicate that any embedded cyclogenesis will remain negligible, at least until it shifts offshore Friday through Friday night. In the wake of initially more amplified mid-level troughing now beginning to accelerate away from the Atlantic Seaboard, boundary-layer modification over the Gulf of Mexico has been slow. A limited moisture return is ongoing on moderately strong southerly return flow preceding the surface trough, but substantive further improvement still appears unlikely through this period. ...Mid South and Ohio/Tennessee Valleys... Observed and forecast soundings suggest that moistening supportive of thunderstorm development, with large-scale ascent, is generally occurring above a stable boundary, and beneath warm/dry capping layers aloft, with profiles supportive of only weak CAPE. It appears that this will remain the case as forcing for ascent begins to support increasing thunderstorm activity ahead of the digging mid-level troughing, southeast of the lower Ohio Valley through the Tennessee Valley and portions of the lower Mississippi Valley later today through tonight. However, at least some model output, perhaps most notably the High Resolution Rapid Refresh, suggests that a somewhat better moist (and potentially unstable) inflow to the southwestern flank of this forcing could enhance thunderstorm development this evening across parts of the Mid South into Gulf States. The HRRR depiction of convection includes an organizing cluster with 45+ kt rear inflow developing near or above the 850-800 mb layer. Even if this verifies, the potential efficiency of downward momentum transport to the surface remains unclear based on forecast soundings, but a few locally strong/damaging wind gusts might not be out of the question. ..Kerr/Squitieri.. 02/22/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1020 AM CST Thu Feb 22 2024 Valid 221630Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF SOUTHEASTERN ARKANSAS...NORTHERN MISSISSIPPI...AND ADJACENT SOUTHWESTERN TENNESSEE...NORTHWESTERN ALABAMA... ...SUMMARY... Strong thunderstorms may develop and overspread parts of the Mid South this evening, and perhaps pose some risk for damaging wind gusts and severe hail. ...Synopsis... A couple of short wave perturbations of Arctic origins (currently west of Hudson Bay) are forecast to continue to consolidate into a vigorous digging short wave trough to the southwest through south of Hudson Bay into the James Bay vicinity today through tonight. It still appears that this will contribute to larger-scale mid/upper trough amplification across the northern into mid-latitudes of eastern North America (and accompanied by a significant cold front crossing the Canadian/U.S. border into the northern Great Plains through upper Great Lakes region by late tonight). In phase with this regime, models indicate that the stronger westerlies across the southern mid- and subtropical latitudes will trend broadly cyclonic across the southern Great Plains through the Southeast, with one or two consolidating embedded lower amplitude perturbations digging from the central Great Plains/Ozark Plateau and lower Ohio Valley through the lower Mississippi/Tennessee Valleys and southern Appalachians by 12Z Friday. While there may be some further deepening of surface troughing shifting from the southern Great Plains through lower Ohio Valley into the Southeast through Mid Atlantic, models indicate that any embedded cyclogenesis will remain negligible, at least until it shifts offshore Friday through Friday night. In the wake of initially more amplified mid-level troughing now beginning to accelerate away from the Atlantic Seaboard, boundary-layer modification over the Gulf of Mexico has been slow. A limited moisture return is ongoing on moderately strong southerly return flow preceding the surface trough, but substantive further improvement still appears unlikely through this period. ...Mid South and Ohio/Tennessee Valleys... Observed and forecast soundings suggest that moistening supportive of thunderstorm development, with large-scale ascent, is generally occurring above a stable boundary, and beneath warm/dry capping layers aloft, with profiles supportive of only weak CAPE. It appears that this will remain the case as forcing for ascent begins to support increasing thunderstorm activity ahead of the digging mid-level troughing, southeast of the lower Ohio Valley through the Tennessee Valley and portions of the lower Mississippi Valley later today through tonight. However, at least some model output, perhaps most notably the High Resolution Rapid Refresh, suggests that a somewhat better moist (and potentially unstable) inflow to the southwestern flank of this forcing could enhance thunderstorm development this evening across parts of the Mid South into Gulf States. The HRRR depiction of convection includes an organizing cluster with 45+ kt rear inflow developing near or above the 850-800 mb layer. Even if this verifies, the potential efficiency of downward momentum transport to the surface remains unclear based on forecast soundings, but a few locally strong/damaging wind gusts might not be out of the question. ..Kerr/Squitieri.. 02/22/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1020 AM CST Thu Feb 22 2024 Valid 221630Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF SOUTHEASTERN ARKANSAS...NORTHERN MISSISSIPPI...AND ADJACENT SOUTHWESTERN TENNESSEE...NORTHWESTERN ALABAMA... ...SUMMARY... Strong thunderstorms may develop and overspread parts of the Mid South this evening, and perhaps pose some risk for damaging wind gusts and severe hail. ...Synopsis... A couple of short wave perturbations of Arctic origins (currently west of Hudson Bay) are forecast to continue to consolidate into a vigorous digging short wave trough to the southwest through south of Hudson Bay into the James Bay vicinity today through tonight. It still appears that this will contribute to larger-scale mid/upper trough amplification across the northern into mid-latitudes of eastern North America (and accompanied by a significant cold front crossing the Canadian/U.S. border into the northern Great Plains through upper Great Lakes region by late tonight). In phase with this regime, models indicate that the stronger westerlies across the southern mid- and subtropical latitudes will trend broadly cyclonic across the southern Great Plains through the Southeast, with one or two consolidating embedded lower amplitude perturbations digging from the central Great Plains/Ozark Plateau and lower Ohio Valley through the lower Mississippi/Tennessee Valleys and southern Appalachians by 12Z Friday. While there may be some further deepening of surface troughing shifting from the southern Great Plains through lower Ohio Valley into the Southeast through Mid Atlantic, models indicate that any embedded cyclogenesis will remain negligible, at least until it shifts offshore Friday through Friday night. In the wake of initially more amplified mid-level troughing now beginning to accelerate away from the Atlantic Seaboard, boundary-layer modification over the Gulf of Mexico has been slow. A limited moisture return is ongoing on moderately strong southerly return flow preceding the surface trough, but substantive further improvement still appears unlikely through this period. ...Mid South and Ohio/Tennessee Valleys... Observed and forecast soundings suggest that moistening supportive of thunderstorm development, with large-scale ascent, is generally occurring above a stable boundary, and beneath warm/dry capping layers aloft, with profiles supportive of only weak CAPE. It appears that this will remain the case as forcing for ascent begins to support increasing thunderstorm activity ahead of the digging mid-level troughing, southeast of the lower Ohio Valley through the Tennessee Valley and portions of the lower Mississippi Valley later today through tonight. However, at least some model output, perhaps most notably the High Resolution Rapid Refresh, suggests that a somewhat better moist (and potentially unstable) inflow to the southwestern flank of this forcing could enhance thunderstorm development this evening across parts of the Mid South into Gulf States. The HRRR depiction of convection includes an organizing cluster with 45+ kt rear inflow developing near or above the 850-800 mb layer. Even if this verifies, the potential efficiency of downward momentum transport to the surface remains unclear based on forecast soundings, but a few locally strong/damaging wind gusts might not be out of the question. ..Kerr/Squitieri.. 02/22/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1020 AM CST Thu Feb 22 2024 Valid 221630Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF SOUTHEASTERN ARKANSAS...NORTHERN MISSISSIPPI...AND ADJACENT SOUTHWESTERN TENNESSEE...NORTHWESTERN ALABAMA... ...SUMMARY... Strong thunderstorms may develop and overspread parts of the Mid South this evening, and perhaps pose some risk for damaging wind gusts and severe hail. ...Synopsis... A couple of short wave perturbations of Arctic origins (currently west of Hudson Bay) are forecast to continue to consolidate into a vigorous digging short wave trough to the southwest through south of Hudson Bay into the James Bay vicinity today through tonight. It still appears that this will contribute to larger-scale mid/upper trough amplification across the northern into mid-latitudes of eastern North America (and accompanied by a significant cold front crossing the Canadian/U.S. border into the northern Great Plains through upper Great Lakes region by late tonight). In phase with this regime, models indicate that the stronger westerlies across the southern mid- and subtropical latitudes will trend broadly cyclonic across the southern Great Plains through the Southeast, with one or two consolidating embedded lower amplitude perturbations digging from the central Great Plains/Ozark Plateau and lower Ohio Valley through the lower Mississippi/Tennessee Valleys and southern Appalachians by 12Z Friday. While there may be some further deepening of surface troughing shifting from the southern Great Plains through lower Ohio Valley into the Southeast through Mid Atlantic, models indicate that any embedded cyclogenesis will remain negligible, at least until it shifts offshore Friday through Friday night. In the wake of initially more amplified mid-level troughing now beginning to accelerate away from the Atlantic Seaboard, boundary-layer modification over the Gulf of Mexico has been slow. A limited moisture return is ongoing on moderately strong southerly return flow preceding the surface trough, but substantive further improvement still appears unlikely through this period. ...Mid South and Ohio/Tennessee Valleys... Observed and forecast soundings suggest that moistening supportive of thunderstorm development, with large-scale ascent, is generally occurring above a stable boundary, and beneath warm/dry capping layers aloft, with profiles supportive of only weak CAPE. It appears that this will remain the case as forcing for ascent begins to support increasing thunderstorm activity ahead of the digging mid-level troughing, southeast of the lower Ohio Valley through the Tennessee Valley and portions of the lower Mississippi Valley later today through tonight. However, at least some model output, perhaps most notably the High Resolution Rapid Refresh, suggests that a somewhat better moist (and potentially unstable) inflow to the southwestern flank of this forcing could enhance thunderstorm development this evening across parts of the Mid South into Gulf States. The HRRR depiction of convection includes an organizing cluster with 45+ kt rear inflow developing near or above the 850-800 mb layer. Even if this verifies, the potential efficiency of downward momentum transport to the surface remains unclear based on forecast soundings, but a few locally strong/damaging wind gusts might not be out of the question. ..Kerr/Squitieri.. 02/22/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0818 AM CST Thu Feb 22 2024 Valid 221300Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE MID-SOUTH REGION... CORRECTED FOR TYPO ...SUMMARY... Thunderstorms may produce marginally severe gusts or hail this afternoon and evening over parts of the Mid-South region. ...Synopsis... In the mean, mid/upper-level pattern amplification should begin again during this period, as ridging builds over NV, the Pacific Coast States and interior Northwest. Downstream, a series of shortwaves will contribute to substantial synoptic-scale height falls over much of the Mississippi and Ohio Valleys to the central Gulf Coast. None of those perturbations -- including some apparent in moisture-channel imagery over OK, northern KS/NE, and western CO -- are (or will become) particularly intense, but should contribute to at least weak large-scale destabilization aloft and maintenance or strengthening of cyclonic flow. At the surface, 11Z analysis showed a cold front extending from a low over southeastern ON across northern IN, through weak lows over central MO and near TUL, then across northwest TX to southern NM. The front should move eastward and southeastward today, to a 00Z position over eastern/southern OH, the lowest Ohio Valley, eastern/ southern AR, and northeast to south-central TX. By 12Z, the front should reach central NY, eastern PA, the southern Appalachians, central parts of MS/LA, and shelf waters of the northwestern Gulf. ...Mid-South region... Isolated to widely scattered thunderstorms are expected to develop by late this afternoon along/ahead of the cold front, over central/ eastern AR and perhaps western TN. Activity should strengthen and increase in coverage through evening as it encounters greater moisture across the Mississippi Valley and into northern portions of MS tonight. Some upscale organization into a short QLCS is possible from early multicell to supercell modes. Marginally severe hail and damaging gusts will be the main concerns. The outlook area will reside on the southwestern rim of a far larger swath of general thunderstorm potential, but with access to sustained, effectively surface-based and at least marginally moist inflow parcels beginning mid/late afternoon in AR and shifting east- southeastward with time. Progs that generate little substantial convection generally are too cool at the surface. Forecast max surface temperatures in the mid/upper 60s F over much of the area will support favorable low-level lapse rates, as well as some boundary-layer mixing, amidst potential for localized downward momentum transfer from stronger flow aloft, for gust support. Midlevel lapse rates are not expected to be very strong, limiting MLCAPE to around 250-750 J/kg, and likely keeping the hail potential isolated, marginal and conditional to supercell maturation. Sufficient deep shear will exist for that, however, with modified forecast soundings indicating around 40-45-kt effective-shear magnitudes and 150-250 J/kg effective SRH -- despite prefrontal veering with time of surface winds toward southwesterly. Greater diurnal boundary-layer mixing/drying, EML-related CINH and weaker CAPE will likely restrict severe potential around western parts of the outlook, while instability decreases northward, moisture decreases eastward, and lift weakens southward. ..Edwards.. 02/22/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0818 AM CST Thu Feb 22 2024 Valid 221300Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE MID-SOUTH REGION... CORRECTED FOR TYPO ...SUMMARY... Thunderstorms may produce marginally severe gusts or hail this afternoon and evening over parts of the Mid-South region. ...Synopsis... In the mean, mid/upper-level pattern amplification should begin again during this period, as ridging builds over NV, the Pacific Coast States and interior Northwest. Downstream, a series of shortwaves will contribute to substantial synoptic-scale height falls over much of the Mississippi and Ohio Valleys to the central Gulf Coast. None of those perturbations -- including some apparent in moisture-channel imagery over OK, northern KS/NE, and western CO -- are (or will become) particularly intense, but should contribute to at least weak large-scale destabilization aloft and maintenance or strengthening of cyclonic flow. At the surface, 11Z analysis showed a cold front extending from a low over southeastern ON across northern IN, through weak lows over central MO and near TUL, then across northwest TX to southern NM. The front should move eastward and southeastward today, to a 00Z position over eastern/southern OH, the lowest Ohio Valley, eastern/ southern AR, and northeast to south-central TX. By 12Z, the front should reach central NY, eastern PA, the southern Appalachians, central parts of MS/LA, and shelf waters of the northwestern Gulf. ...Mid-South region... Isolated to widely scattered thunderstorms are expected to develop by late this afternoon along/ahead of the cold front, over central/ eastern AR and perhaps western TN. Activity should strengthen and increase in coverage through evening as it encounters greater moisture across the Mississippi Valley and into northern portions of MS tonight. Some upscale organization into a short QLCS is possible from early multicell to supercell modes. Marginally severe hail and damaging gusts will be the main concerns. The outlook area will reside on the southwestern rim of a far larger swath of general thunderstorm potential, but with access to sustained, effectively surface-based and at least marginally moist inflow parcels beginning mid/late afternoon in AR and shifting east- southeastward with time. Progs that generate little substantial convection generally are too cool at the surface. Forecast max surface temperatures in the mid/upper 60s F over much of the area will support favorable low-level lapse rates, as well as some boundary-layer mixing, amidst potential for localized downward momentum transfer from stronger flow aloft, for gust support. Midlevel lapse rates are not expected to be very strong, limiting MLCAPE to around 250-750 J/kg, and likely keeping the hail potential isolated, marginal and conditional to supercell maturation. Sufficient deep shear will exist for that, however, with modified forecast soundings indicating around 40-45-kt effective-shear magnitudes and 150-250 J/kg effective SRH -- despite prefrontal veering with time of surface winds toward southwesterly. Greater diurnal boundary-layer mixing/drying, EML-related CINH and weaker CAPE will likely restrict severe potential around western parts of the outlook, while instability decreases northward, moisture decreases eastward, and lift weakens southward. ..Edwards.. 02/22/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0818 AM CST Thu Feb 22 2024 Valid 221300Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE MID-SOUTH REGION... CORRECTED FOR TYPO ...SUMMARY... Thunderstorms may produce marginally severe gusts or hail this afternoon and evening over parts of the Mid-South region. ...Synopsis... In the mean, mid/upper-level pattern amplification should begin again during this period, as ridging builds over NV, the Pacific Coast States and interior Northwest. Downstream, a series of shortwaves will contribute to substantial synoptic-scale height falls over much of the Mississippi and Ohio Valleys to the central Gulf Coast. None of those perturbations -- including some apparent in moisture-channel imagery over OK, northern KS/NE, and western CO -- are (or will become) particularly intense, but should contribute to at least weak large-scale destabilization aloft and maintenance or strengthening of cyclonic flow. At the surface, 11Z analysis showed a cold front extending from a low over southeastern ON across northern IN, through weak lows over central MO and near TUL, then across northwest TX to southern NM. The front should move eastward and southeastward today, to a 00Z position over eastern/southern OH, the lowest Ohio Valley, eastern/ southern AR, and northeast to south-central TX. By 12Z, the front should reach central NY, eastern PA, the southern Appalachians, central parts of MS/LA, and shelf waters of the northwestern Gulf. ...Mid-South region... Isolated to widely scattered thunderstorms are expected to develop by late this afternoon along/ahead of the cold front, over central/ eastern AR and perhaps western TN. Activity should strengthen and increase in coverage through evening as it encounters greater moisture across the Mississippi Valley and into northern portions of MS tonight. Some upscale organization into a short QLCS is possible from early multicell to supercell modes. Marginally severe hail and damaging gusts will be the main concerns. The outlook area will reside on the southwestern rim of a far larger swath of general thunderstorm potential, but with access to sustained, effectively surface-based and at least marginally moist inflow parcels beginning mid/late afternoon in AR and shifting east- southeastward with time. Progs that generate little substantial convection generally are too cool at the surface. Forecast max surface temperatures in the mid/upper 60s F over much of the area will support favorable low-level lapse rates, as well as some boundary-layer mixing, amidst potential for localized downward momentum transfer from stronger flow aloft, for gust support. Midlevel lapse rates are not expected to be very strong, limiting MLCAPE to around 250-750 J/kg, and likely keeping the hail potential isolated, marginal and conditional to supercell maturation. Sufficient deep shear will exist for that, however, with modified forecast soundings indicating around 40-45-kt effective-shear magnitudes and 150-250 J/kg effective SRH -- despite prefrontal veering with time of surface winds toward southwesterly. Greater diurnal boundary-layer mixing/drying, EML-related CINH and weaker CAPE will likely restrict severe potential around western parts of the outlook, while instability decreases northward, moisture decreases eastward, and lift weakens southward. ..Edwards.. 02/22/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0818 AM CST Thu Feb 22 2024 Valid 221300Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE MID-SOUTH REGION... CORRECTED FOR TYPO ...SUMMARY... Thunderstorms may produce marginally severe gusts or hail this afternoon and evening over parts of the Mid-South region. ...Synopsis... In the mean, mid/upper-level pattern amplification should begin again during this period, as ridging builds over NV, the Pacific Coast States and interior Northwest. Downstream, a series of shortwaves will contribute to substantial synoptic-scale height falls over much of the Mississippi and Ohio Valleys to the central Gulf Coast. None of those perturbations -- including some apparent in moisture-channel imagery over OK, northern KS/NE, and western CO -- are (or will become) particularly intense, but should contribute to at least weak large-scale destabilization aloft and maintenance or strengthening of cyclonic flow. At the surface, 11Z analysis showed a cold front extending from a low over southeastern ON across northern IN, through weak lows over central MO and near TUL, then across northwest TX to southern NM. The front should move eastward and southeastward today, to a 00Z position over eastern/southern OH, the lowest Ohio Valley, eastern/ southern AR, and northeast to south-central TX. By 12Z, the front should reach central NY, eastern PA, the southern Appalachians, central parts of MS/LA, and shelf waters of the northwestern Gulf. ...Mid-South region... Isolated to widely scattered thunderstorms are expected to develop by late this afternoon along/ahead of the cold front, over central/ eastern AR and perhaps western TN. Activity should strengthen and increase in coverage through evening as it encounters greater moisture across the Mississippi Valley and into northern portions of MS tonight. Some upscale organization into a short QLCS is possible from early multicell to supercell modes. Marginally severe hail and damaging gusts will be the main concerns. The outlook area will reside on the southwestern rim of a far larger swath of general thunderstorm potential, but with access to sustained, effectively surface-based and at least marginally moist inflow parcels beginning mid/late afternoon in AR and shifting east- southeastward with time. Progs that generate little substantial convection generally are too cool at the surface. Forecast max surface temperatures in the mid/upper 60s F over much of the area will support favorable low-level lapse rates, as well as some boundary-layer mixing, amidst potential for localized downward momentum transfer from stronger flow aloft, for gust support. Midlevel lapse rates are not expected to be very strong, limiting MLCAPE to around 250-750 J/kg, and likely keeping the hail potential isolated, marginal and conditional to supercell maturation. Sufficient deep shear will exist for that, however, with modified forecast soundings indicating around 40-45-kt effective-shear magnitudes and 150-250 J/kg effective SRH -- despite prefrontal veering with time of surface winds toward southwesterly. Greater diurnal boundary-layer mixing/drying, EML-related CINH and weaker CAPE will likely restrict severe potential around western parts of the outlook, while instability decreases northward, moisture decreases eastward, and lift weakens southward. ..Edwards.. 02/22/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0818 AM CST Thu Feb 22 2024 Valid 221300Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE MID-SOUTH REGION... CORRECTED FOR TYPO ...SUMMARY... Thunderstorms may produce marginally severe gusts or hail this afternoon and evening over parts of the Mid-South region. ...Synopsis... In the mean, mid/upper-level pattern amplification should begin again during this period, as ridging builds over NV, the Pacific Coast States and interior Northwest. Downstream, a series of shortwaves will contribute to substantial synoptic-scale height falls over much of the Mississippi and Ohio Valleys to the central Gulf Coast. None of those perturbations -- including some apparent in moisture-channel imagery over OK, northern KS/NE, and western CO -- are (or will become) particularly intense, but should contribute to at least weak large-scale destabilization aloft and maintenance or strengthening of cyclonic flow. At the surface, 11Z analysis showed a cold front extending from a low over southeastern ON across northern IN, through weak lows over central MO and near TUL, then across northwest TX to southern NM. The front should move eastward and southeastward today, to a 00Z position over eastern/southern OH, the lowest Ohio Valley, eastern/ southern AR, and northeast to south-central TX. By 12Z, the front should reach central NY, eastern PA, the southern Appalachians, central parts of MS/LA, and shelf waters of the northwestern Gulf. ...Mid-South region... Isolated to widely scattered thunderstorms are expected to develop by late this afternoon along/ahead of the cold front, over central/ eastern AR and perhaps western TN. Activity should strengthen and increase in coverage through evening as it encounters greater moisture across the Mississippi Valley and into northern portions of MS tonight. Some upscale organization into a short QLCS is possible from early multicell to supercell modes. Marginally severe hail and damaging gusts will be the main concerns. The outlook area will reside on the southwestern rim of a far larger swath of general thunderstorm potential, but with access to sustained, effectively surface-based and at least marginally moist inflow parcels beginning mid/late afternoon in AR and shifting east- southeastward with time. Progs that generate little substantial convection generally are too cool at the surface. Forecast max surface temperatures in the mid/upper 60s F over much of the area will support favorable low-level lapse rates, as well as some boundary-layer mixing, amidst potential for localized downward momentum transfer from stronger flow aloft, for gust support. Midlevel lapse rates are not expected to be very strong, limiting MLCAPE to around 250-750 J/kg, and likely keeping the hail potential isolated, marginal and conditional to supercell maturation. Sufficient deep shear will exist for that, however, with modified forecast soundings indicating around 40-45-kt effective-shear magnitudes and 150-250 J/kg effective SRH -- despite prefrontal veering with time of surface winds toward southwesterly. Greater diurnal boundary-layer mixing/drying, EML-related CINH and weaker CAPE will likely restrict severe potential around western parts of the outlook, while instability decreases northward, moisture decreases eastward, and lift weakens southward. ..Edwards.. 02/22/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0654 AM CST Thu Feb 22 2024 Valid 221300Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE MID-SOUTH REGION... ...SUMMARY... Thunderstorms may produce marginally severe gusts or hail this afternoon and evening over parts of the Mid-South region. ...Synopsis... In the mean, mid/upper-level pattern amplification should begin again during this period, as ridging builds over NV, the Pacific Coast States and interior Northwest. Downstream, a series of shortwaves will contribute to substantial synoptic-scale height falls over much of the Mississippi and Ohio Valleys to the central Gulf Coast. None of those perturbations -- including some apparent in moisture-channel imagery over OK, northern KS/NE, and western CO -- are (or will become) particularly intense, but should contribute to at least weak large-scale destabilization aloft and maintenance or strengthening of cyclonic flow. At the surface, 11Z analysis showed a cold front extending from a low over southeastern ON across northern IN, through weak lows over central MO and near TUL, then across northwest TX to southern NM. The front should move eastward and southeastward today, to a 00Z position over eastern/southern OH, the lowest Ohio Valley, eastern/ southern AR, and northeast to south-central TX. By 12Z, the front should reach central NY, eastern PA, the southern Appalachians, central parts of MS/LA, and shelf waters of the northwestern Gulf. ...Mid-South region... Isolated to widely scattered thunderstorms are expected to develop by late this afternoon along/ahead of the cold front, over central/ eastern AR and perhaps western TN. Activity should strengthen and increase in coverage through evening as it encounters greater moisture across the Mississippi Valley and into northern portions of MS tonight. Some upscale organization into a short QLCS is possible from early multicell to supercell modes. Marginally severe hail and damaging gusts will be the main concerns. The outlook area will reside on the southwestern rim of a far larger swath of general thunderstorm potential, but with access to sustained, effectively surface-based and at least marginally moist inflow parcels beginning mid/late afternoon in AR and shifting east- southeastward with time. Progs that generate little substantial convection generally are too cool at the surface. Forecast max surface temperatures in the mid/upper 60s F over much of the area will support favorable low-level lapse rates, as well as some boundary-layer mixing, amidst potential for localized downward momentum transfer from stronger flow aloft, for gust support. Midlevel lapse rates are not expected to be very strong, limiting MLCAPE to around 250-750 J/kg, and likely keeping the hail potential isolated, marginal and conditional to supercell maturation. Sufficient deep shear will exist for that, however, with modified forecast soundings indicating around 40-450-kt effective-shear magnitudes and 150-250 J/kg effective SRH -- despite prefrontal veering with time of surface winds toward southwesterly. Greater diurnal boundary-layer mixing/drying, EML-related CINH and weaker CAPE will likely restrict severe potential around western parts of the outlook, while instability decreases northward, moisture decreases eastward, and lift weakens southward. ..Edwards/Mosier.. 02/22/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0333 AM CST Thu Feb 22 2024 Valid 251200Z - 011200Z ...DISCUSSION... Medium-range models continue to show a powerful mid- to upper-level trough ejecting into the central U.S. by late Tuesday into Wednesday. A deep cyclone is currently progged by most ensemble members to move from the central Great Plains into the Great Lakes vicinity. Preceding this upper trough, an antecedent re-charging of steep lapse rates associated with an elevated mixed layer over the southern High Plains is forecast. A few days of airmass modification, both in terms of ambient temperature and moistening over the Gulf Basin, will occur in wake of frontal passage on Saturday. Northward moisture return beneath the aforementioned EML will probably result in a substantial warm sector by late afternoon Tuesday and into Wednesday farther east. Model run-to-run continuity is such that there is increased confidence in the introduction of 15-percent severe-risk highlights with the expected eastward progression of the trough. Will defer the possibility of an additional area farther east on Thursday until confidence in details related to earlier days becomes more focused. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0333 AM CST Thu Feb 22 2024 Valid 251200Z - 011200Z ...DISCUSSION... Medium-range models continue to show a powerful mid- to upper-level trough ejecting into the central U.S. by late Tuesday into Wednesday. A deep cyclone is currently progged by most ensemble members to move from the central Great Plains into the Great Lakes vicinity. Preceding this upper trough, an antecedent re-charging of steep lapse rates associated with an elevated mixed layer over the southern High Plains is forecast. A few days of airmass modification, both in terms of ambient temperature and moistening over the Gulf Basin, will occur in wake of frontal passage on Saturday. Northward moisture return beneath the aforementioned EML will probably result in a substantial warm sector by late afternoon Tuesday and into Wednesday farther east. Model run-to-run continuity is such that there is increased confidence in the introduction of 15-percent severe-risk highlights with the expected eastward progression of the trough. Will defer the possibility of an additional area farther east on Thursday until confidence in details related to earlier days becomes more focused. Read more