Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 23 2019 Valid 232000Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE HIGH PLAINS REGION...AS WELL AS PARTS OF SOUTHERN VIRGINIA AND NORTHEAST NORTH CAROLINA... ...SUMMARY... Severe thunderstorm risk continues this afternoon into early tonight for portions of North Carolina and Virginia, as well as the central High Plains. ...Discussion... Evolution of ongoing convection remains largely in line with the most recent outlook reasoning and areal outlines. Storms are increasing across parts of southern Virginia, within the SLGT risk area, and where newly issued WW #612 is in effect. Farther west, convection remains thus far subdued over the high Plains, but should increase over the next couple of hours. For additional short-term information across this area, please refer to recently issued MCD #1839. ..Goss.. 08/23/2019 .PREV DISCUSSION... /ISSUED 1125 AM CDT Fri Aug 23 2019/ ...VA/NC this afternoon/evening... A surface cold front will continue to move slowly southward across VA this afternoon into NC overnight, in the wake of a midlevel trough crossing New England. The southern fringe of the westerlies extends south to near the VA/NC border, where a series of subtle speed maxima/embedded MCVs will translate eastward this afternoon. Low-level convergence/ascent along the front and an accompanying differential heating zone should support thunderstorm development by early afternoon across central VA, and storms will spread east-southeastward through the remainder of the afternoon/evening. Though midlevel lapse rates will be rather modest, surface heating will steepen low-level lapse rates and boost afternoon MLCAPE to near 1500 J/kg. Given effective bulk shear in the 25-35 kt range, and mix of organized multicell clusters and some low-end supercells can be expected in a broken band along the front this afternoon. Damaging winds should be the main severe threat. ...Central High Plains this afternoon into tonight... A midlevel shortwave trough is moving slowly eastward over the northern Rockies, as other subtle embedded waves progress eastward over the central Rockies. Steep midlevel lapse rates, daytime heating, and low-level upslope flow will promote an environment favorable for afternoon thunderstorm development east of the Front Range from northeast NM northward into eastern WY. Deep-layer vertical shear will not be particularly strong over most of the High Plains. The corridors of the somewhat stronger vertical shear will be immediately east of the midlevel trough in WY, and in the vicinity of southeast CO where low-level east-southeast flow will reside beneath the more westerly flow aloft, contributing to effective bulk shear of 30-35 kt. Thus, expect a mix of multicell clusters and some low-end supercells capable of producing damaging winds and large hail. A few clusters will likely persist into tonight in association with warm advection and a modest low-level jet. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0228 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SNAKE RIVER VALLEY INTO SOUTHERN WYOMING... The previous forecast remains on track, with the exception of a minor expansion made to the elevated area over portions of central Utah. Winds in the Wasatch Range should be sustained in the 15-20 mph range during the afternoon/evening to go along with RH values in the 10-15% range and receptive fuels. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 0156 AM CDT Fri Aug 23 2019/ ...Synopsis... On D2/Saturday, a strong mid-level jet will overspread the Pacific Northwest with the nose of the jet impinging upon the northern Great Basin/central Rockies. Critical fire weather will be most likely for portions of the Snake River Valley and southern Wyoming. In these locations, terrain-enhanced downslope flow will promote 20-25 mph winds with 10-15% afternoon RH. Upper and potentially mid-level clouds will again be a factor in stunting afternoon heating/boundary-layer mixing, which will likely limit the spatial extent of the critical fire weather threat. Surrounding portions of the northern Great Basin and central Rockies will see elevated fire weather conditions, with similar afternoon RH but winds generally in the 15-20 mph range. ...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 0228 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SNAKE RIVER VALLEY INTO SOUTHERN WYOMING... The previous forecast remains on track, with the exception of a minor expansion made to the elevated area over portions of central Utah. Winds in the Wasatch Range should be sustained in the 15-20 mph range during the afternoon/evening to go along with RH values in the 10-15% range and receptive fuels. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 0156 AM CDT Fri Aug 23 2019/ ...Synopsis... On D2/Saturday, a strong mid-level jet will overspread the Pacific Northwest with the nose of the jet impinging upon the northern Great Basin/central Rockies. Critical fire weather will be most likely for portions of the Snake River Valley and southern Wyoming. In these locations, terrain-enhanced downslope flow will promote 20-25 mph winds with 10-15% afternoon RH. Upper and potentially mid-level clouds will again be a factor in stunting afternoon heating/boundary-layer mixing, which will likely limit the spatial extent of the critical fire weather threat. Surrounding portions of the northern Great Basin and central Rockies will see elevated fire weather conditions, with similar afternoon RH but winds generally in the 15-20 mph range. ...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 0228 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SNAKE RIVER VALLEY INTO SOUTHERN WYOMING... The previous forecast remains on track, with the exception of a minor expansion made to the elevated area over portions of central Utah. Winds in the Wasatch Range should be sustained in the 15-20 mph range during the afternoon/evening to go along with RH values in the 10-15% range and receptive fuels. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 0156 AM CDT Fri Aug 23 2019/ ...Synopsis... On D2/Saturday, a strong mid-level jet will overspread the Pacific Northwest with the nose of the jet impinging upon the northern Great Basin/central Rockies. Critical fire weather will be most likely for portions of the Snake River Valley and southern Wyoming. In these locations, terrain-enhanced downslope flow will promote 20-25 mph winds with 10-15% afternoon RH. Upper and potentially mid-level clouds will again be a factor in stunting afternoon heating/boundary-layer mixing, which will likely limit the spatial extent of the critical fire weather threat. Surrounding portions of the northern Great Basin and central Rockies will see elevated fire weather conditions, with similar afternoon RH but winds generally in the 15-20 mph range. ...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 0228 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SNAKE RIVER VALLEY INTO SOUTHERN WYOMING... The previous forecast remains on track, with the exception of a minor expansion made to the elevated area over portions of central Utah. Winds in the Wasatch Range should be sustained in the 15-20 mph range during the afternoon/evening to go along with RH values in the 10-15% range and receptive fuels. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 0156 AM CDT Fri Aug 23 2019/ ...Synopsis... On D2/Saturday, a strong mid-level jet will overspread the Pacific Northwest with the nose of the jet impinging upon the northern Great Basin/central Rockies. Critical fire weather will be most likely for portions of the Snake River Valley and southern Wyoming. In these locations, terrain-enhanced downslope flow will promote 20-25 mph winds with 10-15% afternoon RH. Upper and potentially mid-level clouds will again be a factor in stunting afternoon heating/boundary-layer mixing, which will likely limit the spatial extent of the critical fire weather threat. Surrounding portions of the northern Great Basin and central Rockies will see elevated fire weather conditions, with similar afternoon RH but winds generally in the 15-20 mph range. ...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 0228 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SNAKE RIVER VALLEY INTO SOUTHERN WYOMING... The previous forecast remains on track, with the exception of a minor expansion made to the elevated area over portions of central Utah. Winds in the Wasatch Range should be sustained in the 15-20 mph range during the afternoon/evening to go along with RH values in the 10-15% range and receptive fuels. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 0156 AM CDT Fri Aug 23 2019/ ...Synopsis... On D2/Saturday, a strong mid-level jet will overspread the Pacific Northwest with the nose of the jet impinging upon the northern Great Basin/central Rockies. Critical fire weather will be most likely for portions of the Snake River Valley and southern Wyoming. In these locations, terrain-enhanced downslope flow will promote 20-25 mph winds with 10-15% afternoon RH. Upper and potentially mid-level clouds will again be a factor in stunting afternoon heating/boundary-layer mixing, which will likely limit the spatial extent of the critical fire weather threat. Surrounding portions of the northern Great Basin and central Rockies will see elevated fire weather conditions, with similar afternoon RH but winds generally in the 15-20 mph range. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Fri Aug 23 18:16:03 UTC 2019.

MD 1838 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF SOUTHERN VIRGINIA AND NORTHEASTERN NORTH CAROLINA
Mesoscale Discussion 1838 NWS Storm Prediction Center Norman OK 0114 PM CDT Fri Aug 23 2019 Areas affected...Parts of southern Virginia and northeastern North Carolina Concerning...Severe potential...Watch possible Valid 231814Z - 232015Z Probability of Watch Issuance...40 percent SUMMARY...Increasing thunderstorm development is expected within the next few hours, which may gradually organize and pose an increasing risk for potentially damaging wind gusts by 4-6 PM EDT. Trends are being monitored for the possibility of a severe weather watch. DISCUSSION...A gradual destabilization of the seasonably moist boundary layer within pre-frontal surface troughing is ongoing. Largest mixed-layer CAPE (up to 2000 J/kg), is still confined to portions of the North Carolina piedmont and coastal plain, perhaps into the Hampton Roads area of southeast Virginia, where temperatures have reached or are approaching 90F. However, CAPE appears to be in excess of 1000 J/kg ahead of the southward advancing cold front, across much of the remainder of central/southern Virginia, with insolation likely to contribute to further destabilization during the next few hours. Areas of deepening convective development are now underway, within the the surface troughing (including around the Southern Pines NC vicinity and southeast of Richmond VA, as well as near the southward advancing cold front, across the higher terrain of western Virginia (east/southeast of Hot Springs VA) eastward toward the southern Delmarva Peninsula. It appears that the front may provide the primary focus for increasing thunderstorm development through 20-22Z, perhaps aided by forcing for ascent associated with a low-amplitude mid-level wave progressing east of the central Appalachians. A belt of 30-40 kt westerly mid-level flow (in the 700-500 mb layer) is contributing to modest deep layer shear along this corridor, which could promote the the gradual upscale growth of an organizing cluster of storms posing increasing risk for potentially damaging wind gusts. ..Kerr/Thompson.. 08/23/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...LWX...RAH...RNK... LAT...LON 37777943 37807796 37877650 37897537 37117557 36207543 35507602 35477686 35317859 35447942 35737950 36137907 36597948 37018038 37777943 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS...AND ACROSS THE KANSAS/OKLAHOMA VICINITY... ...SUMMARY... Isolated severe storms are possible over parts of the northern Plains, and across the Kansas/Oklahoma area on Saturday. ...Synopsis... While large-scale upper troughing expands across western Canada and the adjacent northwestern portions of the U.S., a smaller, short-wave disturbance on the larger trough's southern fringe will shift across the Plains states Saturday. This feature will be the primary influencer of convective/limited severe risk across the country for this forecast period. At the surface, high pressure will prevail across the eastern half of the country, while a cold front sags southeastward across the northwestern U.S./northern Intermountain region. Elsewhere, a lee trough will remain across the high Plains, while a remnant front lingers east-to-west from the Carolinas to Oklahoma. ...Kansas/Oklahoma vicinity... Remnant showers and thunderstorms will likely be ongoing over portions of the MRGL risk area at the start of the period, with various/complex convective outflows resulting from the convection. Where afternoon heating can occur, new storm development is expected during the afternoon, focused near the aforementioned outflows, and possibly differential heating boundaries. During the evening, as a strong southerly low-level jet develops, upscale growth into an MCS is expected, which should spread southeastward with time across Oklahoma and vicinity. With slightly enhanced west-northwesterly flow aloft expected to spread across the region atop low-level southerlies, shear may be sufficient for evolution of a few strong/severe storms initially. Wind risk could continue through the evening and into the overnight hours, depending upon the degree of organization within any southeastward-moving MCS. ...Portions of the Dakotas into the northern High Plains... As a cold front advances southeastward across Montana Saturday, a zone of heating/destabilization ahead of the front should support mid to late afternoon development of scattered to isolated thunderstorms -- mainly over western North Dakota and possibly into parts of northern South Dakota. With stronger mid-level westerlies to remain generally west of the convective initiation zone, shear should remain modest -- though some enhancement due to evening low-level jet development is expected. As such, a few stronger/locally severe storms should emerge, with accompanying risk for locally gusty/damaging winds and hail. Threat should continue through much of the evening, but begin to diminish overnight as the boundary layer cools/stabilizes diurnally. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 08/23/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS...AND ACROSS THE KANSAS/OKLAHOMA VICINITY... ...SUMMARY... Isolated severe storms are possible over parts of the northern Plains, and across the Kansas/Oklahoma area on Saturday. ...Synopsis... While large-scale upper troughing expands across western Canada and the adjacent northwestern portions of the U.S., a smaller, short-wave disturbance on the larger trough's southern fringe will shift across the Plains states Saturday. This feature will be the primary influencer of convective/limited severe risk across the country for this forecast period. At the surface, high pressure will prevail across the eastern half of the country, while a cold front sags southeastward across the northwestern U.S./northern Intermountain region. Elsewhere, a lee trough will remain across the high Plains, while a remnant front lingers east-to-west from the Carolinas to Oklahoma. ...Kansas/Oklahoma vicinity... Remnant showers and thunderstorms will likely be ongoing over portions of the MRGL risk area at the start of the period, with various/complex convective outflows resulting from the convection. Where afternoon heating can occur, new storm development is expected during the afternoon, focused near the aforementioned outflows, and possibly differential heating boundaries. During the evening, as a strong southerly low-level jet develops, upscale growth into an MCS is expected, which should spread southeastward with time across Oklahoma and vicinity. With slightly enhanced west-northwesterly flow aloft expected to spread across the region atop low-level southerlies, shear may be sufficient for evolution of a few strong/severe storms initially. Wind risk could continue through the evening and into the overnight hours, depending upon the degree of organization within any southeastward-moving MCS. ...Portions of the Dakotas into the northern High Plains... As a cold front advances southeastward across Montana Saturday, a zone of heating/destabilization ahead of the front should support mid to late afternoon development of scattered to isolated thunderstorms -- mainly over western North Dakota and possibly into parts of northern South Dakota. With stronger mid-level westerlies to remain generally west of the convective initiation zone, shear should remain modest -- though some enhancement due to evening low-level jet development is expected. As such, a few stronger/locally severe storms should emerge, with accompanying risk for locally gusty/damaging winds and hail. Threat should continue through much of the evening, but begin to diminish overnight as the boundary layer cools/stabilizes diurnally. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 08/23/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS...AND ACROSS THE KANSAS/OKLAHOMA VICINITY... ...SUMMARY... Isolated severe storms are possible over parts of the northern Plains, and across the Kansas/Oklahoma area on Saturday. ...Synopsis... While large-scale upper troughing expands across western Canada and the adjacent northwestern portions of the U.S., a smaller, short-wave disturbance on the larger trough's southern fringe will shift across the Plains states Saturday. This feature will be the primary influencer of convective/limited severe risk across the country for this forecast period. At the surface, high pressure will prevail across the eastern half of the country, while a cold front sags southeastward across the northwestern U.S./northern Intermountain region. Elsewhere, a lee trough will remain across the high Plains, while a remnant front lingers east-to-west from the Carolinas to Oklahoma. ...Kansas/Oklahoma vicinity... Remnant showers and thunderstorms will likely be ongoing over portions of the MRGL risk area at the start of the period, with various/complex convective outflows resulting from the convection. Where afternoon heating can occur, new storm development is expected during the afternoon, focused near the aforementioned outflows, and possibly differential heating boundaries. During the evening, as a strong southerly low-level jet develops, upscale growth into an MCS is expected, which should spread southeastward with time across Oklahoma and vicinity. With slightly enhanced west-northwesterly flow aloft expected to spread across the region atop low-level southerlies, shear may be sufficient for evolution of a few strong/severe storms initially. Wind risk could continue through the evening and into the overnight hours, depending upon the degree of organization within any southeastward-moving MCS. ...Portions of the Dakotas into the northern High Plains... As a cold front advances southeastward across Montana Saturday, a zone of heating/destabilization ahead of the front should support mid to late afternoon development of scattered to isolated thunderstorms -- mainly over western North Dakota and possibly into parts of northern South Dakota. With stronger mid-level westerlies to remain generally west of the convective initiation zone, shear should remain modest -- though some enhancement due to evening low-level jet development is expected. As such, a few stronger/locally severe storms should emerge, with accompanying risk for locally gusty/damaging winds and hail. Threat should continue through much of the evening, but begin to diminish overnight as the boundary layer cools/stabilizes diurnally. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 08/23/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Fri Aug 23 2019 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS...AND ACROSS THE KANSAS/OKLAHOMA VICINITY... ...SUMMARY... Isolated severe storms are possible over parts of the northern Plains, and across the Kansas/Oklahoma area on Saturday. ...Synopsis... While large-scale upper troughing expands across western Canada and the adjacent northwestern portions of the U.S., a smaller, short-wave disturbance on the larger trough's southern fringe will shift across the Plains states Saturday. This feature will be the primary influencer of convective/limited severe risk across the country for this forecast period. At the surface, high pressure will prevail across the eastern half of the country, while a cold front sags southeastward across the northwestern U.S./northern Intermountain region. Elsewhere, a lee trough will remain across the high Plains, while a remnant front lingers east-to-west from the Carolinas to Oklahoma. ...Kansas/Oklahoma vicinity... Remnant showers and thunderstorms will likely be ongoing over portions of the MRGL risk area at the start of the period, with various/complex convective outflows resulting from the convection. Where afternoon heating can occur, new storm development is expected during the afternoon, focused near the aforementioned outflows, and possibly differential heating boundaries. During the evening, as a strong southerly low-level jet develops, upscale growth into an MCS is expected, which should spread southeastward with time across Oklahoma and vicinity. With slightly enhanced west-northwesterly flow aloft expected to spread across the region atop low-level southerlies, shear may be sufficient for evolution of a few strong/severe storms initially. Wind risk could continue through the evening and into the overnight hours, depending upon the degree of organization within any southeastward-moving MCS. ...Portions of the Dakotas into the northern High Plains... As a cold front advances southeastward across Montana Saturday, a zone of heating/destabilization ahead of the front should support mid to late afternoon development of scattered to isolated thunderstorms -- mainly over western North Dakota and possibly into parts of northern South Dakota. With stronger mid-level westerlies to remain generally west of the convective initiation zone, shear should remain modest -- though some enhancement due to evening low-level jet development is expected. As such, a few stronger/locally severe storms should emerge, with accompanying risk for locally gusty/damaging winds and hail. Threat should continue through much of the evening, but begin to diminish overnight as the boundary layer cools/stabilizes diurnally. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 08/23/2019 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Fri Aug 23 2019 Valid 231700Z - 241200Z The previous forecast generally remains on track. The ongoing elevated area has been expanded slightly across portions of south-central Nevada and into northeast Arizona, based on the potential for wind/RH conditions (coinciding with receptive fuels) as depicted in the latest high resolution guidance. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Fri Aug 23 2019/ ...Synopsis... A mid-level trough currently positioned over the southwest Montana vicinity will progress eastward into the central High Plains today. On the back side of this trough, enhanced mid-level flow will be present over parts of southwestern Wyoming into Utah and eastern Nevada. Potential for elevated fire weather conditions will exist from the Great Divide Basin, western Colorado, and portions of the southern Great Basin. In these locations, 15-20 mph surface winds and 5-20% afternoon RH are probable. Two factors introduce some uncertainty to how widespread these elevated conditions will be: 1) a weakening surface pressure gradient throughout the day and 2) potential for mid/upper-level clouds over portions of Utah/Nevada during the afternoon. Current position of dry air aloft on water vapor satellite imagery would indicate that it may only overlap portions of western Colorado during the afternoon, which is also supported by model forecast soundings. Nonetheless, several areas will see at least briefly elevated conditions with potential for locally critical conditions in terrain-favored locations. ...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 1132 AM CDT Fri Aug 23 2019 Valid 231700Z - 241200Z The previous forecast generally remains on track. The ongoing elevated area has been expanded slightly across portions of south-central Nevada and into northeast Arizona, based on the potential for wind/RH conditions (coinciding with receptive fuels) as depicted in the latest high resolution guidance. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Fri Aug 23 2019/ ...Synopsis... A mid-level trough currently positioned over the southwest Montana vicinity will progress eastward into the central High Plains today. On the back side of this trough, enhanced mid-level flow will be present over parts of southwestern Wyoming into Utah and eastern Nevada. Potential for elevated fire weather conditions will exist from the Great Divide Basin, western Colorado, and portions of the southern Great Basin. In these locations, 15-20 mph surface winds and 5-20% afternoon RH are probable. Two factors introduce some uncertainty to how widespread these elevated conditions will be: 1) a weakening surface pressure gradient throughout the day and 2) potential for mid/upper-level clouds over portions of Utah/Nevada during the afternoon. Current position of dry air aloft on water vapor satellite imagery would indicate that it may only overlap portions of western Colorado during the afternoon, which is also supported by model forecast soundings. Nonetheless, several areas will see at least briefly elevated conditions with potential for locally critical conditions in terrain-favored locations. ...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 1132 AM CDT Fri Aug 23 2019 Valid 231700Z - 241200Z The previous forecast generally remains on track. The ongoing elevated area has been expanded slightly across portions of south-central Nevada and into northeast Arizona, based on the potential for wind/RH conditions (coinciding with receptive fuels) as depicted in the latest high resolution guidance. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Fri Aug 23 2019/ ...Synopsis... A mid-level trough currently positioned over the southwest Montana vicinity will progress eastward into the central High Plains today. On the back side of this trough, enhanced mid-level flow will be present over parts of southwestern Wyoming into Utah and eastern Nevada. Potential for elevated fire weather conditions will exist from the Great Divide Basin, western Colorado, and portions of the southern Great Basin. In these locations, 15-20 mph surface winds and 5-20% afternoon RH are probable. Two factors introduce some uncertainty to how widespread these elevated conditions will be: 1) a weakening surface pressure gradient throughout the day and 2) potential for mid/upper-level clouds over portions of Utah/Nevada during the afternoon. Current position of dry air aloft on water vapor satellite imagery would indicate that it may only overlap portions of western Colorado during the afternoon, which is also supported by model forecast soundings. Nonetheless, several areas will see at least briefly elevated conditions with potential for locally critical conditions in terrain-favored locations. ...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 1132 AM CDT Fri Aug 23 2019 Valid 231700Z - 241200Z The previous forecast generally remains on track. The ongoing elevated area has been expanded slightly across portions of south-central Nevada and into northeast Arizona, based on the potential for wind/RH conditions (coinciding with receptive fuels) as depicted in the latest high resolution guidance. Otherwise, see the previous discussion for additional details. ..Karstens.. 08/23/2019 .PREV DISCUSSION... /ISSUED 1259 AM CDT Fri Aug 23 2019/ ...Synopsis... A mid-level trough currently positioned over the southwest Montana vicinity will progress eastward into the central High Plains today. On the back side of this trough, enhanced mid-level flow will be present over parts of southwestern Wyoming into Utah and eastern Nevada. Potential for elevated fire weather conditions will exist from the Great Divide Basin, western Colorado, and portions of the southern Great Basin. In these locations, 15-20 mph surface winds and 5-20% afternoon RH are probable. Two factors introduce some uncertainty to how widespread these elevated conditions will be: 1) a weakening surface pressure gradient throughout the day and 2) potential for mid/upper-level clouds over portions of Utah/Nevada during the afternoon. Current position of dry air aloft on water vapor satellite imagery would indicate that it may only overlap portions of western Colorado during the afternoon, which is also supported by model forecast soundings. Nonetheless, several areas will see at least briefly elevated conditions with potential for locally critical conditions in terrain-favored locations. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Fri Aug 23 16:35:01 UTC 2019.

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Fri Aug 23 2019 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS PARTS OF VA/NC AND THE HIGH PLAINS... ...SUMMARY... Severe thunderstorms appear most probable this afternoon into early tonight for portions of North Carolina and Virginia, as well as the central High Plains. ...VA/NC this afternoon/evening... A surface cold front will continue to move slowly southward across VA this afternoon into NC overnight, in the wake of a midlevel trough crossing New England. The southern fringe of the westerlies extends south to near the VA/NC border, where a series of subtle speed maxima/embedded MCVs will translate eastward this afternoon. Low-level convergence/ascent along the front and an accompanying differential heating zone should support thunderstorm development by early afternoon across central VA, and storms will spread east-southeastward through the remainder of the afternoon/evening. Though midlevel lapse rates will be rather modest, surface heating will steepen low-level lapse rates and boost afternoon MLCAPE to near 1500 J/kg. Given effective bulk shear in the 25-35 kt range, and mix of organized multicell clusters and some low-end supercells can be expected in a broken band along the front this afternoon. Damaging winds should be the main severe threat. ...Central High Plains this afternoon into tonight... A midlevel shortwave trough is moving slowly eastward over the northern Rockies, as other subtle embedded waves progress eastward over the central Rockies. Steep midlevel lapse rates, daytime heating, and low-level upslope flow will promote an environment favorable for afternoon thunderstorm development east of the Front Range from northeast NM northward into eastern WY. Deep-layer vertical shear will not be particularly strong over most of the High Plains. The corridors of the somewhat stronger vertical shear will be immediately east of the midlevel trough in WY, and in the vicinity of southeast CO where low-level east-southeast flow will reside beneath the more westerly flow aloft, contributing to effective bulk shear of 30-35 kt. Thus, expect a mix of multicell clusters and some low-end supercells capable of producing damaging winds and large hail. A few clusters will likely persist into tonight in association with warm advection and a modest low-level jet. ..Thompson/Cook.. 08/23/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Fri Aug 23 2019 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS PARTS OF VA/NC AND THE HIGH PLAINS... ...SUMMARY... Severe thunderstorms appear most probable this afternoon into early tonight for portions of North Carolina and Virginia, as well as the central High Plains. ...VA/NC this afternoon/evening... A surface cold front will continue to move slowly southward across VA this afternoon into NC overnight, in the wake of a midlevel trough crossing New England. The southern fringe of the westerlies extends south to near the VA/NC border, where a series of subtle speed maxima/embedded MCVs will translate eastward this afternoon. Low-level convergence/ascent along the front and an accompanying differential heating zone should support thunderstorm development by early afternoon across central VA, and storms will spread east-southeastward through the remainder of the afternoon/evening. Though midlevel lapse rates will be rather modest, surface heating will steepen low-level lapse rates and boost afternoon MLCAPE to near 1500 J/kg. Given effective bulk shear in the 25-35 kt range, and mix of organized multicell clusters and some low-end supercells can be expected in a broken band along the front this afternoon. Damaging winds should be the main severe threat. ...Central High Plains this afternoon into tonight... A midlevel shortwave trough is moving slowly eastward over the northern Rockies, as other subtle embedded waves progress eastward over the central Rockies. Steep midlevel lapse rates, daytime heating, and low-level upslope flow will promote an environment favorable for afternoon thunderstorm development east of the Front Range from northeast NM northward into eastern WY. Deep-layer vertical shear will not be particularly strong over most of the High Plains. The corridors of the somewhat stronger vertical shear will be immediately east of the midlevel trough in WY, and in the vicinity of southeast CO where low-level east-southeast flow will reside beneath the more westerly flow aloft, contributing to effective bulk shear of 30-35 kt. Thus, expect a mix of multicell clusters and some low-end supercells capable of producing damaging winds and large hail. A few clusters will likely persist into tonight in association with warm advection and a modest low-level jet. ..Thompson/Cook.. 08/23/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Fri Aug 23 2019 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EARLY TONIGHT ACROSS PARTS OF VA/NC AND THE HIGH PLAINS... ...SUMMARY... Severe thunderstorms appear most probable this afternoon into early tonight for portions of North Carolina and Virginia, as well as the central High Plains. ...VA/NC this afternoon/evening... A surface cold front will continue to move slowly southward across VA this afternoon into NC overnight, in the wake of a midlevel trough crossing New England. The southern fringe of the westerlies extends south to near the VA/NC border, where a series of subtle speed maxima/embedded MCVs will translate eastward this afternoon. Low-level convergence/ascent along the front and an accompanying differential heating zone should support thunderstorm development by early afternoon across central VA, and storms will spread east-southeastward through the remainder of the afternoon/evening. Though midlevel lapse rates will be rather modest, surface heating will steepen low-level lapse rates and boost afternoon MLCAPE to near 1500 J/kg. Given effective bulk shear in the 25-35 kt range, and mix of organized multicell clusters and some low-end supercells can be expected in a broken band along the front this afternoon. Damaging winds should be the main severe threat. ...Central High Plains this afternoon into tonight... A midlevel shortwave trough is moving slowly eastward over the northern Rockies, as other subtle embedded waves progress eastward over the central Rockies. Steep midlevel lapse rates, daytime heating, and low-level upslope flow will promote an environment favorable for afternoon thunderstorm development east of the Front Range from northeast NM northward into eastern WY. Deep-layer vertical shear will not be particularly strong over most of the High Plains. The corridors of the somewhat stronger vertical shear will be immediately east of the midlevel trough in WY, and in the vicinity of southeast CO where low-level east-southeast flow will reside beneath the more westerly flow aloft, contributing to effective bulk shear of 30-35 kt. Thus, expect a mix of multicell clusters and some low-end supercells capable of producing damaging winds and large hail. A few clusters will likely persist into tonight in association with warm advection and a modest low-level jet. ..Thompson/Cook.. 08/23/2019 Read more