Severe Storms

No watches are valid as of Wed Feb 21 22:30:02 UTC 2024.

No Mesoscale Discussions are in effect as of Wed Feb 21 22:30:02 UTC 2024.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0350 PM CST Wed Feb 21 2024 Valid 231200Z - 291200Z An upper-level ridge will build in across the western US with downstream troughing across the east D3/Friday through D5/Sunday. Surface high pressure across the central US will keep winds generally light where the driest conditions are expected in the central and southern high Plains. As such, fire weather concerns will remain low through the weekend for much of the CONUS, though spotty elevated conditions in the lee of terrain features will be possible Sunday across the southern and central High Plains. Potential for Critical to Elevated fire weather conditions may return to the High Plains on D6/Monday. Late D5/Sunday into D6/Monday an upper-level low will begin to phase with the Polar jet stream with the western ridge drifting east and westerly flow aloft overspreading the Rockies. This pattern has become less amplified and progressive in recent runs, with the upper-level ridge lingering across the central US keeping lee trough development weaker. Indications are that the pattern will still favor a return of windy/dry westerly downslope flow into the central/southern Plains. Trends for this period will be monitored for inclusion of probabilities in subsequent updates. Late in the period D7/Tuesday into D8/Wednesday, a deeper trough may develop across the western US before moving eastward across the Rockies, with potential for development of a strong lee cyclone and subsequent strong flow across the central and southern Plains. This may bring the potential for widespread Elevated to Critical conditions. ..Thornton.. 02/21/2024 ...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 0350 PM CST Wed Feb 21 2024 Valid 231200Z - 291200Z An upper-level ridge will build in across the western US with downstream troughing across the east D3/Friday through D5/Sunday. Surface high pressure across the central US will keep winds generally light where the driest conditions are expected in the central and southern high Plains. As such, fire weather concerns will remain low through the weekend for much of the CONUS, though spotty elevated conditions in the lee of terrain features will be possible Sunday across the southern and central High Plains. Potential for Critical to Elevated fire weather conditions may return to the High Plains on D6/Monday. Late D5/Sunday into D6/Monday an upper-level low will begin to phase with the Polar jet stream with the western ridge drifting east and westerly flow aloft overspreading the Rockies. This pattern has become less amplified and progressive in recent runs, with the upper-level ridge lingering across the central US keeping lee trough development weaker. Indications are that the pattern will still favor a return of windy/dry westerly downslope flow into the central/southern Plains. Trends for this period will be monitored for inclusion of probabilities in subsequent updates. Late in the period D7/Tuesday into D8/Wednesday, a deeper trough may develop across the western US before moving eastward across the Rockies, with potential for development of a strong lee cyclone and subsequent strong flow across the central and southern Plains. This may bring the potential for widespread Elevated to Critical conditions. ..Thornton.. 02/21/2024 ...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 0350 PM CST Wed Feb 21 2024 Valid 231200Z - 291200Z An upper-level ridge will build in across the western US with downstream troughing across the east D3/Friday through D5/Sunday. Surface high pressure across the central US will keep winds generally light where the driest conditions are expected in the central and southern high Plains. As such, fire weather concerns will remain low through the weekend for much of the CONUS, though spotty elevated conditions in the lee of terrain features will be possible Sunday across the southern and central High Plains. Potential for Critical to Elevated fire weather conditions may return to the High Plains on D6/Monday. Late D5/Sunday into D6/Monday an upper-level low will begin to phase with the Polar jet stream with the western ridge drifting east and westerly flow aloft overspreading the Rockies. This pattern has become less amplified and progressive in recent runs, with the upper-level ridge lingering across the central US keeping lee trough development weaker. Indications are that the pattern will still favor a return of windy/dry westerly downslope flow into the central/southern Plains. Trends for this period will be monitored for inclusion of probabilities in subsequent updates. Late in the period D7/Tuesday into D8/Wednesday, a deeper trough may develop across the western US before moving eastward across the Rockies, with potential for development of a strong lee cyclone and subsequent strong flow across the central and southern Plains. This may bring the potential for widespread Elevated to Critical conditions. ..Thornton.. 02/21/2024 ...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 0154 PM CST Wed Feb 21 2024 Valid 212000Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS PARTS OF SOUTHEASTERN KANSAS INTO SOUTHWESTERN MISSOURI AND ACROSS PARTS OF CENTRAL ILLINOIS INTO NORTHWESTERN/CENTRAL INDIANA... ...SUMMARY... Isolated to widely scattered strong thunderstorm development is possible tonight across parts of the Ozark Plateau and lower Ohio Valley, perhaps accompanied by some risk for severe hail. ...20Z Update... In advance of a short wave trough which has emerged from the southern mid-latitude/subtropical eastern Pacific, a deep plume of warm/dry air continues to overspread much of the southern Great Plains toward the lower Mississippi Valley, coincident with large-scale mid-level ridging. Beneath this regime, surface dew points have only reach the mid/upper 50sF across much of the northwestern Gulf of Mexico, though they have risen into the lower/mid 60s near the coast of Mexico into parts of the Texas coastal plain. Even where surface dew points are highest, the boundary-layer moistening remains confined to a rather shallow layer based on morning observed and forecast soundings. Still, limited low-level level moistening appears underway on strengthening southerly return flow across southern/eastern Texas toward the Ozark Plateau and lower Ohio Valley, beneath the warm, capping air aloft. Latest model output continues to indicate that associated potential instability will contribute to at least low probabilities for thunderstorm development late this evening and overnight, generally focused along a couple zones of enhanced low/mid-level warm advection and/or weak frontogenetic forcing. Some machine learning forecast guidance continues to suggest low probabilities for severe hail may accompany stronger storms tonight. However, latest available forecast soundings from the NAM and Rapid Refresh do not appear overly supportive of this potential. ..Kerr.. 02/21/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Wed Feb 21 2024/ ...Southern MO... Morning water vapor loop shows a fast-moving shortwave trough over southern CA. This feature and its associated mid-level jet max will track across the southern Plains and into the mid MS valley by late tonight. Ahead of this system, strengthening southwesterly low-level winds will enhance warm/moist advection into parts of MO/IL, leading to a zone of modest instability after dark from southeast KS across much of southern MO. Forecast soundings from several 12z models indicate the boundary-layer remains capped, suggesting the prospects for robust thunderstorm development are rather low. However, a few morning CAM solutions do show a storm or two overnight, which given the steep mid-level lapse rates and strong shear would be capable of hail. Therefore, will maintain the ongoing MRGL risk area to denote the conditional risk. ...Northern IL/IN... A surface warm front is expected to become established from central MO into central IL later today. Low-level winds are expected to be rather weak in vicinity of the boundary, but flow into the mid-levels should result in elevated warm-advection and the initiation of a few thunderstorms after midnight. Forecast soundings suggest the potential for hail in the strongest cells, although the potential for severe-caliber hail appears marginal. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Wed Feb 21 2024 Valid 212000Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS PARTS OF SOUTHEASTERN KANSAS INTO SOUTHWESTERN MISSOURI AND ACROSS PARTS OF CENTRAL ILLINOIS INTO NORTHWESTERN/CENTRAL INDIANA... ...SUMMARY... Isolated to widely scattered strong thunderstorm development is possible tonight across parts of the Ozark Plateau and lower Ohio Valley, perhaps accompanied by some risk for severe hail. ...20Z Update... In advance of a short wave trough which has emerged from the southern mid-latitude/subtropical eastern Pacific, a deep plume of warm/dry air continues to overspread much of the southern Great Plains toward the lower Mississippi Valley, coincident with large-scale mid-level ridging. Beneath this regime, surface dew points have only reach the mid/upper 50sF across much of the northwestern Gulf of Mexico, though they have risen into the lower/mid 60s near the coast of Mexico into parts of the Texas coastal plain. Even where surface dew points are highest, the boundary-layer moistening remains confined to a rather shallow layer based on morning observed and forecast soundings. Still, limited low-level level moistening appears underway on strengthening southerly return flow across southern/eastern Texas toward the Ozark Plateau and lower Ohio Valley, beneath the warm, capping air aloft. Latest model output continues to indicate that associated potential instability will contribute to at least low probabilities for thunderstorm development late this evening and overnight, generally focused along a couple zones of enhanced low/mid-level warm advection and/or weak frontogenetic forcing. Some machine learning forecast guidance continues to suggest low probabilities for severe hail may accompany stronger storms tonight. However, latest available forecast soundings from the NAM and Rapid Refresh do not appear overly supportive of this potential. ..Kerr.. 02/21/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Wed Feb 21 2024/ ...Southern MO... Morning water vapor loop shows a fast-moving shortwave trough over southern CA. This feature and its associated mid-level jet max will track across the southern Plains and into the mid MS valley by late tonight. Ahead of this system, strengthening southwesterly low-level winds will enhance warm/moist advection into parts of MO/IL, leading to a zone of modest instability after dark from southeast KS across much of southern MO. Forecast soundings from several 12z models indicate the boundary-layer remains capped, suggesting the prospects for robust thunderstorm development are rather low. However, a few morning CAM solutions do show a storm or two overnight, which given the steep mid-level lapse rates and strong shear would be capable of hail. Therefore, will maintain the ongoing MRGL risk area to denote the conditional risk. ...Northern IL/IN... A surface warm front is expected to become established from central MO into central IL later today. Low-level winds are expected to be rather weak in vicinity of the boundary, but flow into the mid-levels should result in elevated warm-advection and the initiation of a few thunderstorms after midnight. Forecast soundings suggest the potential for hail in the strongest cells, although the potential for severe-caliber hail appears marginal. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Wed Feb 21 2024 Valid 212000Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS PARTS OF SOUTHEASTERN KANSAS INTO SOUTHWESTERN MISSOURI AND ACROSS PARTS OF CENTRAL ILLINOIS INTO NORTHWESTERN/CENTRAL INDIANA... ...SUMMARY... Isolated to widely scattered strong thunderstorm development is possible tonight across parts of the Ozark Plateau and lower Ohio Valley, perhaps accompanied by some risk for severe hail. ...20Z Update... In advance of a short wave trough which has emerged from the southern mid-latitude/subtropical eastern Pacific, a deep plume of warm/dry air continues to overspread much of the southern Great Plains toward the lower Mississippi Valley, coincident with large-scale mid-level ridging. Beneath this regime, surface dew points have only reach the mid/upper 50sF across much of the northwestern Gulf of Mexico, though they have risen into the lower/mid 60s near the coast of Mexico into parts of the Texas coastal plain. Even where surface dew points are highest, the boundary-layer moistening remains confined to a rather shallow layer based on morning observed and forecast soundings. Still, limited low-level level moistening appears underway on strengthening southerly return flow across southern/eastern Texas toward the Ozark Plateau and lower Ohio Valley, beneath the warm, capping air aloft. Latest model output continues to indicate that associated potential instability will contribute to at least low probabilities for thunderstorm development late this evening and overnight, generally focused along a couple zones of enhanced low/mid-level warm advection and/or weak frontogenetic forcing. Some machine learning forecast guidance continues to suggest low probabilities for severe hail may accompany stronger storms tonight. However, latest available forecast soundings from the NAM and Rapid Refresh do not appear overly supportive of this potential. ..Kerr.. 02/21/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Wed Feb 21 2024/ ...Southern MO... Morning water vapor loop shows a fast-moving shortwave trough over southern CA. This feature and its associated mid-level jet max will track across the southern Plains and into the mid MS valley by late tonight. Ahead of this system, strengthening southwesterly low-level winds will enhance warm/moist advection into parts of MO/IL, leading to a zone of modest instability after dark from southeast KS across much of southern MO. Forecast soundings from several 12z models indicate the boundary-layer remains capped, suggesting the prospects for robust thunderstorm development are rather low. However, a few morning CAM solutions do show a storm or two overnight, which given the steep mid-level lapse rates and strong shear would be capable of hail. Therefore, will maintain the ongoing MRGL risk area to denote the conditional risk. ...Northern IL/IN... A surface warm front is expected to become established from central MO into central IL later today. Low-level winds are expected to be rather weak in vicinity of the boundary, but flow into the mid-levels should result in elevated warm-advection and the initiation of a few thunderstorms after midnight. Forecast soundings suggest the potential for hail in the strongest cells, although the potential for severe-caliber hail appears marginal. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Wed Feb 21 2024 Valid 212000Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS PARTS OF SOUTHEASTERN KANSAS INTO SOUTHWESTERN MISSOURI AND ACROSS PARTS OF CENTRAL ILLINOIS INTO NORTHWESTERN/CENTRAL INDIANA... ...SUMMARY... Isolated to widely scattered strong thunderstorm development is possible tonight across parts of the Ozark Plateau and lower Ohio Valley, perhaps accompanied by some risk for severe hail. ...20Z Update... In advance of a short wave trough which has emerged from the southern mid-latitude/subtropical eastern Pacific, a deep plume of warm/dry air continues to overspread much of the southern Great Plains toward the lower Mississippi Valley, coincident with large-scale mid-level ridging. Beneath this regime, surface dew points have only reach the mid/upper 50sF across much of the northwestern Gulf of Mexico, though they have risen into the lower/mid 60s near the coast of Mexico into parts of the Texas coastal plain. Even where surface dew points are highest, the boundary-layer moistening remains confined to a rather shallow layer based on morning observed and forecast soundings. Still, limited low-level level moistening appears underway on strengthening southerly return flow across southern/eastern Texas toward the Ozark Plateau and lower Ohio Valley, beneath the warm, capping air aloft. Latest model output continues to indicate that associated potential instability will contribute to at least low probabilities for thunderstorm development late this evening and overnight, generally focused along a couple zones of enhanced low/mid-level warm advection and/or weak frontogenetic forcing. Some machine learning forecast guidance continues to suggest low probabilities for severe hail may accompany stronger storms tonight. However, latest available forecast soundings from the NAM and Rapid Refresh do not appear overly supportive of this potential. ..Kerr.. 02/21/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Wed Feb 21 2024/ ...Southern MO... Morning water vapor loop shows a fast-moving shortwave trough over southern CA. This feature and its associated mid-level jet max will track across the southern Plains and into the mid MS valley by late tonight. Ahead of this system, strengthening southwesterly low-level winds will enhance warm/moist advection into parts of MO/IL, leading to a zone of modest instability after dark from southeast KS across much of southern MO. Forecast soundings from several 12z models indicate the boundary-layer remains capped, suggesting the prospects for robust thunderstorm development are rather low. However, a few morning CAM solutions do show a storm or two overnight, which given the steep mid-level lapse rates and strong shear would be capable of hail. Therefore, will maintain the ongoing MRGL risk area to denote the conditional risk. ...Northern IL/IN... A surface warm front is expected to become established from central MO into central IL later today. Low-level winds are expected to be rather weak in vicinity of the boundary, but flow into the mid-levels should result in elevated warm-advection and the initiation of a few thunderstorms after midnight. Forecast soundings suggest the potential for hail in the strongest cells, although the potential for severe-caliber hail appears marginal. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Wed Feb 21 2024 Valid 221200Z - 231200Z No changes are needed for the D2 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/21/2024 .PREV DISCUSSION... /ISSUED 0147 AM CST Wed Feb 21 2024/ ...Synopsis... Elevated fire weather conditions are expected on Thursday across the greater Big Bend region of southern TX. A surface cyclone is currently forecast to strengthen tomorrow/Wednesday across the Plains, before weakening as it migrates northeast through the day Thursday. As this occurs, a weak, dry cold front will push southward across western/central TX, reaching the Rio Grande by Thursday afternoon. Dry conditions are anticipated both ahead of and immediately behind the front, with RH values in the teens to low 20s likely. The departure of the surface low to the northeast will result in weaker gradient winds along/behind the front compared to Wednesday, but widespread 15-20 mph winds appear probable across central to southwest TX based on a consensus of deterministic and ensemble solutions. As such, elevated (to locally critical) fire weather conditions are anticipated - primarily along and north of the Rio Grande where fuel ERCs are currently between the 50-75th percentile (with further drying expected today/Wednesday). ...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 0155 PM CST Wed Feb 21 2024 Valid 221200Z - 231200Z No changes are needed for the D2 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/21/2024 .PREV DISCUSSION... /ISSUED 0147 AM CST Wed Feb 21 2024/ ...Synopsis... Elevated fire weather conditions are expected on Thursday across the greater Big Bend region of southern TX. A surface cyclone is currently forecast to strengthen tomorrow/Wednesday across the Plains, before weakening as it migrates northeast through the day Thursday. As this occurs, a weak, dry cold front will push southward across western/central TX, reaching the Rio Grande by Thursday afternoon. Dry conditions are anticipated both ahead of and immediately behind the front, with RH values in the teens to low 20s likely. The departure of the surface low to the northeast will result in weaker gradient winds along/behind the front compared to Wednesday, but widespread 15-20 mph winds appear probable across central to southwest TX based on a consensus of deterministic and ensemble solutions. As such, elevated (to locally critical) fire weather conditions are anticipated - primarily along and north of the Rio Grande where fuel ERCs are currently between the 50-75th percentile (with further drying expected today/Wednesday). ...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 0155 PM CST Wed Feb 21 2024 Valid 221200Z - 231200Z No changes are needed for the D2 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/21/2024 .PREV DISCUSSION... /ISSUED 0147 AM CST Wed Feb 21 2024/ ...Synopsis... Elevated fire weather conditions are expected on Thursday across the greater Big Bend region of southern TX. A surface cyclone is currently forecast to strengthen tomorrow/Wednesday across the Plains, before weakening as it migrates northeast through the day Thursday. As this occurs, a weak, dry cold front will push southward across western/central TX, reaching the Rio Grande by Thursday afternoon. Dry conditions are anticipated both ahead of and immediately behind the front, with RH values in the teens to low 20s likely. The departure of the surface low to the northeast will result in weaker gradient winds along/behind the front compared to Wednesday, but widespread 15-20 mph winds appear probable across central to southwest TX based on a consensus of deterministic and ensemble solutions. As such, elevated (to locally critical) fire weather conditions are anticipated - primarily along and north of the Rio Grande where fuel ERCs are currently between the 50-75th percentile (with further drying expected today/Wednesday). ...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 0155 PM CST Wed Feb 21 2024 Valid 221200Z - 231200Z No changes are needed for the D2 Fire Weather Outlook. See previous discussion below. ..Thornton.. 02/21/2024 .PREV DISCUSSION... /ISSUED 0147 AM CST Wed Feb 21 2024/ ...Synopsis... Elevated fire weather conditions are expected on Thursday across the greater Big Bend region of southern TX. A surface cyclone is currently forecast to strengthen tomorrow/Wednesday across the Plains, before weakening as it migrates northeast through the day Thursday. As this occurs, a weak, dry cold front will push southward across western/central TX, reaching the Rio Grande by Thursday afternoon. Dry conditions are anticipated both ahead of and immediately behind the front, with RH values in the teens to low 20s likely. The departure of the surface low to the northeast will result in weaker gradient winds along/behind the front compared to Wednesday, but widespread 15-20 mph winds appear probable across central to southwest TX based on a consensus of deterministic and ensemble solutions. As such, elevated (to locally critical) fire weather conditions are anticipated - primarily along and north of the Rio Grande where fuel ERCs are currently between the 50-75th percentile (with further drying expected today/Wednesday). ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CST Wed Feb 21 2024 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of severe thunderstorms still appears negligible across the U.S. for Thursday through Thursday night. ...Synopsis... Within the northern mid-latitudes, consolidating short wave perturbations of Arctic origins are forecast to dig southwest through south of the Hudson Bay vicinity through this period. It appears that this will contribute to larger-scale mid-level trough amplification across much of eastern North America, and be accompanied by a significant cold front crossing the north central Canadian/U.S. border (from the Great Plains into the upper Great Lakes) by Thursday night. As an initially more zonal belt of westerlies across the southern mid- into subtropical latitudes trends broadly cyclonic east of the Rockies into the Southeast, one embedded short wave currently emerging from the Southwest, is forecast to gradually dig from the Ozark Plateau/lower Ohio Valley vicinity through the Tennessee Valley/southern Appalachians Thursday through Thursday night. Downstream, initially amplified mid-level troughing over the southwestern Atlantic will continue to progress away from the southern Atlantic Seaboard. Upstream, models indicate that a lower/mid-tropospheric cyclone may gradually redevelop southward across the mid- into subtropical latitudes of the eastern Pacific, preceded by building mid-level ridging across California into the Great Basin. Northerly flow and subsidence in the wake of the Atlantic mid-level trough has contributed to relatively dry conditions across much of the Gulf Basin and Caribbean. Although some modification has been occurring across parts of the western Gulf of Mexico, and supporting a limited ongoing return flow of moisture across south/southeast Texas toward the Ozark Plateau vicinity, boundary-layer moistening over the western Gulf remains rather modest and shallow, beneath warm/dry layers in the lower/mid-troposphere advecting east of the Rockies/Mexican Plateau. ...Ozark Plateau into Ohio and Tennessee Valleys... Model forecast soundings generally suggest only gradual further boundary-layer moistening and deepening across the northwestern Gulf of Mexico through Thursday night, and little substantive improvement of the low-level moist return flow across the lower Mississippi into Ohio and Tennessee Valleys. Beneath warm-layers farther aloft, forecast soundings suggest that this will yield only weak CAPE where larger-scale ascent is able to overcome mid-level inhibition. And it appears that stronger forcing for ascent supportive of thunderstorm initiation may tend to remain focused above moist adiabatic to more stable near-surface lapse rates throughout the period. Scattered initial thunderstorm development across the lower Ohio Valley will probably be supported by forcing for ascent aided by low-level warm advection preceding slowly deepening surface troughing, well in advance of the Arctic front. However, various model output, including some convection allowing guidance, suggests that a weak developing cold front within this surface troughing could become a focus for an organizing line of thunderstorms across the lower Ohio through Tennessee Valleys late Thursday afternoon into Thursday night. While it might not be out of the question that some of this activity could be accompanied by small hail and gusty winds, with surface cyclogenesis and lower/mid-tropospheric wind fields forecast to remain seasonably modest to weak, the potential for severe weather still appears negligible. ..Kerr.. 02/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CST Wed Feb 21 2024 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of severe thunderstorms still appears negligible across the U.S. for Thursday through Thursday night. ...Synopsis... Within the northern mid-latitudes, consolidating short wave perturbations of Arctic origins are forecast to dig southwest through south of the Hudson Bay vicinity through this period. It appears that this will contribute to larger-scale mid-level trough amplification across much of eastern North America, and be accompanied by a significant cold front crossing the north central Canadian/U.S. border (from the Great Plains into the upper Great Lakes) by Thursday night. As an initially more zonal belt of westerlies across the southern mid- into subtropical latitudes trends broadly cyclonic east of the Rockies into the Southeast, one embedded short wave currently emerging from the Southwest, is forecast to gradually dig from the Ozark Plateau/lower Ohio Valley vicinity through the Tennessee Valley/southern Appalachians Thursday through Thursday night. Downstream, initially amplified mid-level troughing over the southwestern Atlantic will continue to progress away from the southern Atlantic Seaboard. Upstream, models indicate that a lower/mid-tropospheric cyclone may gradually redevelop southward across the mid- into subtropical latitudes of the eastern Pacific, preceded by building mid-level ridging across California into the Great Basin. Northerly flow and subsidence in the wake of the Atlantic mid-level trough has contributed to relatively dry conditions across much of the Gulf Basin and Caribbean. Although some modification has been occurring across parts of the western Gulf of Mexico, and supporting a limited ongoing return flow of moisture across south/southeast Texas toward the Ozark Plateau vicinity, boundary-layer moistening over the western Gulf remains rather modest and shallow, beneath warm/dry layers in the lower/mid-troposphere advecting east of the Rockies/Mexican Plateau. ...Ozark Plateau into Ohio and Tennessee Valleys... Model forecast soundings generally suggest only gradual further boundary-layer moistening and deepening across the northwestern Gulf of Mexico through Thursday night, and little substantive improvement of the low-level moist return flow across the lower Mississippi into Ohio and Tennessee Valleys. Beneath warm-layers farther aloft, forecast soundings suggest that this will yield only weak CAPE where larger-scale ascent is able to overcome mid-level inhibition. And it appears that stronger forcing for ascent supportive of thunderstorm initiation may tend to remain focused above moist adiabatic to more stable near-surface lapse rates throughout the period. Scattered initial thunderstorm development across the lower Ohio Valley will probably be supported by forcing for ascent aided by low-level warm advection preceding slowly deepening surface troughing, well in advance of the Arctic front. However, various model output, including some convection allowing guidance, suggests that a weak developing cold front within this surface troughing could become a focus for an organizing line of thunderstorms across the lower Ohio through Tennessee Valleys late Thursday afternoon into Thursday night. While it might not be out of the question that some of this activity could be accompanied by small hail and gusty winds, with surface cyclogenesis and lower/mid-tropospheric wind fields forecast to remain seasonably modest to weak, the potential for severe weather still appears negligible. ..Kerr.. 02/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CST Wed Feb 21 2024 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of severe thunderstorms still appears negligible across the U.S. for Thursday through Thursday night. ...Synopsis... Within the northern mid-latitudes, consolidating short wave perturbations of Arctic origins are forecast to dig southwest through south of the Hudson Bay vicinity through this period. It appears that this will contribute to larger-scale mid-level trough amplification across much of eastern North America, and be accompanied by a significant cold front crossing the north central Canadian/U.S. border (from the Great Plains into the upper Great Lakes) by Thursday night. As an initially more zonal belt of westerlies across the southern mid- into subtropical latitudes trends broadly cyclonic east of the Rockies into the Southeast, one embedded short wave currently emerging from the Southwest, is forecast to gradually dig from the Ozark Plateau/lower Ohio Valley vicinity through the Tennessee Valley/southern Appalachians Thursday through Thursday night. Downstream, initially amplified mid-level troughing over the southwestern Atlantic will continue to progress away from the southern Atlantic Seaboard. Upstream, models indicate that a lower/mid-tropospheric cyclone may gradually redevelop southward across the mid- into subtropical latitudes of the eastern Pacific, preceded by building mid-level ridging across California into the Great Basin. Northerly flow and subsidence in the wake of the Atlantic mid-level trough has contributed to relatively dry conditions across much of the Gulf Basin and Caribbean. Although some modification has been occurring across parts of the western Gulf of Mexico, and supporting a limited ongoing return flow of moisture across south/southeast Texas toward the Ozark Plateau vicinity, boundary-layer moistening over the western Gulf remains rather modest and shallow, beneath warm/dry layers in the lower/mid-troposphere advecting east of the Rockies/Mexican Plateau. ...Ozark Plateau into Ohio and Tennessee Valleys... Model forecast soundings generally suggest only gradual further boundary-layer moistening and deepening across the northwestern Gulf of Mexico through Thursday night, and little substantive improvement of the low-level moist return flow across the lower Mississippi into Ohio and Tennessee Valleys. Beneath warm-layers farther aloft, forecast soundings suggest that this will yield only weak CAPE where larger-scale ascent is able to overcome mid-level inhibition. And it appears that stronger forcing for ascent supportive of thunderstorm initiation may tend to remain focused above moist adiabatic to more stable near-surface lapse rates throughout the period. Scattered initial thunderstorm development across the lower Ohio Valley will probably be supported by forcing for ascent aided by low-level warm advection preceding slowly deepening surface troughing, well in advance of the Arctic front. However, various model output, including some convection allowing guidance, suggests that a weak developing cold front within this surface troughing could become a focus for an organizing line of thunderstorms across the lower Ohio through Tennessee Valleys late Thursday afternoon into Thursday night. While it might not be out of the question that some of this activity could be accompanied by small hail and gusty winds, with surface cyclogenesis and lower/mid-tropospheric wind fields forecast to remain seasonably modest to weak, the potential for severe weather still appears negligible. ..Kerr.. 02/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CST Wed Feb 21 2024 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of severe thunderstorms still appears negligible across the U.S. for Thursday through Thursday night. ...Synopsis... Within the northern mid-latitudes, consolidating short wave perturbations of Arctic origins are forecast to dig southwest through south of the Hudson Bay vicinity through this period. It appears that this will contribute to larger-scale mid-level trough amplification across much of eastern North America, and be accompanied by a significant cold front crossing the north central Canadian/U.S. border (from the Great Plains into the upper Great Lakes) by Thursday night. As an initially more zonal belt of westerlies across the southern mid- into subtropical latitudes trends broadly cyclonic east of the Rockies into the Southeast, one embedded short wave currently emerging from the Southwest, is forecast to gradually dig from the Ozark Plateau/lower Ohio Valley vicinity through the Tennessee Valley/southern Appalachians Thursday through Thursday night. Downstream, initially amplified mid-level troughing over the southwestern Atlantic will continue to progress away from the southern Atlantic Seaboard. Upstream, models indicate that a lower/mid-tropospheric cyclone may gradually redevelop southward across the mid- into subtropical latitudes of the eastern Pacific, preceded by building mid-level ridging across California into the Great Basin. Northerly flow and subsidence in the wake of the Atlantic mid-level trough has contributed to relatively dry conditions across much of the Gulf Basin and Caribbean. Although some modification has been occurring across parts of the western Gulf of Mexico, and supporting a limited ongoing return flow of moisture across south/southeast Texas toward the Ozark Plateau vicinity, boundary-layer moistening over the western Gulf remains rather modest and shallow, beneath warm/dry layers in the lower/mid-troposphere advecting east of the Rockies/Mexican Plateau. ...Ozark Plateau into Ohio and Tennessee Valleys... Model forecast soundings generally suggest only gradual further boundary-layer moistening and deepening across the northwestern Gulf of Mexico through Thursday night, and little substantive improvement of the low-level moist return flow across the lower Mississippi into Ohio and Tennessee Valleys. Beneath warm-layers farther aloft, forecast soundings suggest that this will yield only weak CAPE where larger-scale ascent is able to overcome mid-level inhibition. And it appears that stronger forcing for ascent supportive of thunderstorm initiation may tend to remain focused above moist adiabatic to more stable near-surface lapse rates throughout the period. Scattered initial thunderstorm development across the lower Ohio Valley will probably be supported by forcing for ascent aided by low-level warm advection preceding slowly deepening surface troughing, well in advance of the Arctic front. However, various model output, including some convection allowing guidance, suggests that a weak developing cold front within this surface troughing could become a focus for an organizing line of thunderstorms across the lower Ohio through Tennessee Valleys late Thursday afternoon into Thursday night. While it might not be out of the question that some of this activity could be accompanied by small hail and gusty winds, with surface cyclogenesis and lower/mid-tropospheric wind fields forecast to remain seasonably modest to weak, the potential for severe weather still appears negligible. ..Kerr.. 02/21/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CST Wed Feb 21 2024 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk of severe thunderstorms still appears negligible across the U.S. for Thursday through Thursday night. ...Synopsis... Within the northern mid-latitudes, consolidating short wave perturbations of Arctic origins are forecast to dig southwest through south of the Hudson Bay vicinity through this period. It appears that this will contribute to larger-scale mid-level trough amplification across much of eastern North America, and be accompanied by a significant cold front crossing the north central Canadian/U.S. border (from the Great Plains into the upper Great Lakes) by Thursday night. As an initially more zonal belt of westerlies across the southern mid- into subtropical latitudes trends broadly cyclonic east of the Rockies into the Southeast, one embedded short wave currently emerging from the Southwest, is forecast to gradually dig from the Ozark Plateau/lower Ohio Valley vicinity through the Tennessee Valley/southern Appalachians Thursday through Thursday night. Downstream, initially amplified mid-level troughing over the southwestern Atlantic will continue to progress away from the southern Atlantic Seaboard. Upstream, models indicate that a lower/mid-tropospheric cyclone may gradually redevelop southward across the mid- into subtropical latitudes of the eastern Pacific, preceded by building mid-level ridging across California into the Great Basin. Northerly flow and subsidence in the wake of the Atlantic mid-level trough has contributed to relatively dry conditions across much of the Gulf Basin and Caribbean. Although some modification has been occurring across parts of the western Gulf of Mexico, and supporting a limited ongoing return flow of moisture across south/southeast Texas toward the Ozark Plateau vicinity, boundary-layer moistening over the western Gulf remains rather modest and shallow, beneath warm/dry layers in the lower/mid-troposphere advecting east of the Rockies/Mexican Plateau. ...Ozark Plateau into Ohio and Tennessee Valleys... Model forecast soundings generally suggest only gradual further boundary-layer moistening and deepening across the northwestern Gulf of Mexico through Thursday night, and little substantive improvement of the low-level moist return flow across the lower Mississippi into Ohio and Tennessee Valleys. Beneath warm-layers farther aloft, forecast soundings suggest that this will yield only weak CAPE where larger-scale ascent is able to overcome mid-level inhibition. And it appears that stronger forcing for ascent supportive of thunderstorm initiation may tend to remain focused above moist adiabatic to more stable near-surface lapse rates throughout the period. Scattered initial thunderstorm development across the lower Ohio Valley will probably be supported by forcing for ascent aided by low-level warm advection preceding slowly deepening surface troughing, well in advance of the Arctic front. However, various model output, including some convection allowing guidance, suggests that a weak developing cold front within this surface troughing could become a focus for an organizing line of thunderstorms across the lower Ohio through Tennessee Valleys late Thursday afternoon into Thursday night. While it might not be out of the question that some of this activity could be accompanied by small hail and gusty winds, with surface cyclogenesis and lower/mid-tropospheric wind fields forecast to remain seasonably modest to weak, the potential for severe weather still appears negligible. ..Kerr.. 02/21/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1055 AM CST Wed Feb 21 2024 Valid 211700Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN NEW MEXICO AND FAR WEST TEXAS... Critical fire weather conditions are expected across southeastern New Mexico into far western Texas this afternoon, with no major changes needed to the Elevated and Critical areas this morning. Morning satellite imagery shows mainly sunny skies with temperatures warming in to the low to mid 70s and mixing already occurring in surface observations. Gusts to 45 mph are being observed in the Sacramento Mountains, with gusts generally around 20-30 mph in the lee of the higher terrain. As daytime heating continues, expect wind speeds to increase amid deeper mixing, with potential for dangerous fire weather conditions through the afternoon. See previous discussion below for more information. ..Thornton.. 02/21/2024 .PREV DISCUSSION... /ISSUED 0100 AM CST Wed Feb 21 2024/ ...Synopsis... Elevated to critical fire weather conditions are expected today across the southern High Plains. Early-morning water-vapor imagery depicts a shortwave trough off the southern CA coast gradually traversing eastward. This feature is expected to gradually de-amplify through the day, resulting in acceleration of the wave as it approaches the southern Plains. 00 UTC soundings sampled an unseasonably warm and dry air mass across the southern High Plains, with a low-level thermal trough noted in recent analyses extending from southwest TX to southwest KS. This thermal ridge is hindering overnight RH recovery with RH values in the low to mid teens noted in 06 UTC surface observations across east NM and southwest TX. Heading into this afternoon, strengthening zonal flow over the southern Rockies associated with the approach of the upper wave and attendant jet max will promote continued downslope warming/drying. Scattered high-level cirrus may filter insolation to some degree, but diurnal warming coupled with deep boundary-layer mixing and the persistent downslope flow regime will support another day of RH values in the 5-10% range. Although a slight dry bias is noted in recent runs of the RAP/HRRR, the aforementioned observed trends and RH minimums observed yesterday lend credence to this RH forecast. 20-30 mph west/southwesterly gradient winds are expected based on strong consensus between high-res ensemble members, as a surface low deepens over southwest KS and a trailing surface trough/dryline pushes east. The onset of these winds is expected to occur as soon as a shallow nocturnal inversion is mixed out, which appears most likely around 18 UTC. Favorable phasing of the mid-level jet max with peak diurnal heating/boundary-layer mixing will foster efficient downward momentum transfer, manifesting as frequent 40-50 mph gusts by late afternoon. Consequently, widespread elevated to critical fire weather conditions are expected by early afternoon across a large swath of the southern High Plains. The primary limiting factor for a more robust fire weather threat continues to be fuel status. Although some fine-fuel drying did occur yesterday/Monday, most fuels across the TX/OK Panhandles and parts of southeast CO remain only modestly receptive with ERCs near the 50th percentile. As such, the Critical risk area remains confined to far west TX to southeast NM where fuels are drier and active burning was noted on ongoing fires this afternoon in GOES IR imagery. ...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 1055 AM CST Wed Feb 21 2024 Valid 211700Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEASTERN NEW MEXICO AND FAR WEST TEXAS... Critical fire weather conditions are expected across southeastern New Mexico into far western Texas this afternoon, with no major changes needed to the Elevated and Critical areas this morning. Morning satellite imagery shows mainly sunny skies with temperatures warming in to the low to mid 70s and mixing already occurring in surface observations. Gusts to 45 mph are being observed in the Sacramento Mountains, with gusts generally around 20-30 mph in the lee of the higher terrain. As daytime heating continues, expect wind speeds to increase amid deeper mixing, with potential for dangerous fire weather conditions through the afternoon. See previous discussion below for more information. ..Thornton.. 02/21/2024 .PREV DISCUSSION... /ISSUED 0100 AM CST Wed Feb 21 2024/ ...Synopsis... Elevated to critical fire weather conditions are expected today across the southern High Plains. Early-morning water-vapor imagery depicts a shortwave trough off the southern CA coast gradually traversing eastward. This feature is expected to gradually de-amplify through the day, resulting in acceleration of the wave as it approaches the southern Plains. 00 UTC soundings sampled an unseasonably warm and dry air mass across the southern High Plains, with a low-level thermal trough noted in recent analyses extending from southwest TX to southwest KS. This thermal ridge is hindering overnight RH recovery with RH values in the low to mid teens noted in 06 UTC surface observations across east NM and southwest TX. Heading into this afternoon, strengthening zonal flow over the southern Rockies associated with the approach of the upper wave and attendant jet max will promote continued downslope warming/drying. Scattered high-level cirrus may filter insolation to some degree, but diurnal warming coupled with deep boundary-layer mixing and the persistent downslope flow regime will support another day of RH values in the 5-10% range. Although a slight dry bias is noted in recent runs of the RAP/HRRR, the aforementioned observed trends and RH minimums observed yesterday lend credence to this RH forecast. 20-30 mph west/southwesterly gradient winds are expected based on strong consensus between high-res ensemble members, as a surface low deepens over southwest KS and a trailing surface trough/dryline pushes east. The onset of these winds is expected to occur as soon as a shallow nocturnal inversion is mixed out, which appears most likely around 18 UTC. Favorable phasing of the mid-level jet max with peak diurnal heating/boundary-layer mixing will foster efficient downward momentum transfer, manifesting as frequent 40-50 mph gusts by late afternoon. Consequently, widespread elevated to critical fire weather conditions are expected by early afternoon across a large swath of the southern High Plains. The primary limiting factor for a more robust fire weather threat continues to be fuel status. Although some fine-fuel drying did occur yesterday/Monday, most fuels across the TX/OK Panhandles and parts of southeast CO remain only modestly receptive with ERCs near the 50th percentile. As such, the Critical risk area remains confined to far west TX to southeast NM where fuels are drier and active burning was noted on ongoing fires this afternoon in GOES IR imagery. ...Please see www.spc.noaa.gov/fire for graphic product... Read more