SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1152 AM CDT Thu Sep 05 2024 Valid 051700Z - 061200Z ...NO CRITICAL AREAS... No changes are needed to the current D1 Fire Weather Outlook. See previous discussion for more information. ..Thornton.. 09/05/2024 .PREV DISCUSSION... /ISSUED 1212 AM CDT Thu Sep 05 2024/ ...Synopsis... Fire weather concerns will be limited for today across the country. 05 UTC surface observations show a cold front slowly migrating south across the Plains and the upper MS River Valley. This front is expected to reach the southern Plains by evening as surface high pressure builds across the northern CONUS. Breezy conditions are expected behind the front, but an influx of cooler air combined with cloud cover and isolated to scattered showers and thunderstorms limits fire weather concerns. Across the West, an upper ridge currently over the region will linger through the next 24 hours. This will promote mostly clear skies and dry conditions for the afternoon with RH values in the teens and low 20s common. Surface winds will remain relatively benign with the exception of mountainous areas of southern CA, the northern Cascades, and parts of central to southern UT. Any fire weather concerns across these regions should remain sufficiently localized to preclude the need for highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1152 AM CDT Thu Sep 05 2024 Valid 051700Z - 061200Z ...NO CRITICAL AREAS... No changes are needed to the current D1 Fire Weather Outlook. See previous discussion for more information. ..Thornton.. 09/05/2024 .PREV DISCUSSION... /ISSUED 1212 AM CDT Thu Sep 05 2024/ ...Synopsis... Fire weather concerns will be limited for today across the country. 05 UTC surface observations show a cold front slowly migrating south across the Plains and the upper MS River Valley. This front is expected to reach the southern Plains by evening as surface high pressure builds across the northern CONUS. Breezy conditions are expected behind the front, but an influx of cooler air combined with cloud cover and isolated to scattered showers and thunderstorms limits fire weather concerns. Across the West, an upper ridge currently over the region will linger through the next 24 hours. This will promote mostly clear skies and dry conditions for the afternoon with RH values in the teens and low 20s common. Surface winds will remain relatively benign with the exception of mountainous areas of southern CA, the northern Cascades, and parts of central to southern UT. Any fire weather concerns across these regions should remain sufficiently localized to preclude the need for highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Thu Sep 05 2024 Valid 051630Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTH-CENTRAL COLORADO INTO NORTHERN/CENTRAL NEW MEXICO... ...SUMMARY... Thunderstorms capable of producing isolated severe wind gusts and hail will be possible today across parts of far south-central Colorado into northern/central New Mexico. ...Synopsis... Satellite imagery shows a shortwave trough moving southeastward through the central Rockies, between the upper ridging in place over the western Great Basin and the broad upper troughing across central Canadian and northern Plains/Upper MS Valley. Another shortwave trough exists over the Upper MS Valley. This shortwave trough is forecast to continue progressing eastward through the base broad central Canada/northern Plains trough, moving across the Upper Great Lakes and into eastern Ontario. Recent surface analysis places a surface low associated with this shortwave over Lake Superior, with a cold front extending southwestward from this low through KS and into northeast NM. This front is forecast to progress southward/southeastward as its parent surface low lifts northeastward. Isolated thunderstorms are possible along this frontal boundary, but overall severity should be mitigated by modest buoyancy and vertical shear. Greater thunderstorm coverage and severity is anticipated over the southern Rockies as the previously mentioned central Rockies shortwave trough continues southeastward and promotes thunderstorm development. Lastly, a tropical wave just off the TX Coast is contributing to abundant moisture across much of Gulf Coast, with low 70s dewpoints reaching into much of east TX and northern LA, and upper 70s across FL. Precipitable water values over 2" cover much of this region as well. Heavy rain is the primary threat (as indicated by the latest Day 1 Excessive Rainfall Outlook from WPC), but a few water-loaded downbursts capable of damaging gusts are possible from southeast TX and southern/central LA eastward along the Gulf Coast and over the Florida Peninsula. Coverage of these gusts is expected to be sparse and too low to delineate a 5% wind probability area. ...Southern Rockies/southern High Plains... Moderate low-level moisture is anticipated within the post-frontal airmass across the southern Rockies and adjacent southern High Plains this afternoon, characterized by dewpoints in the low to mid 50s across the High Plains and upper 40s across the higher terrain. Even with this modest moisture, the airmass is expected to destabilize, fostered by deep boundary-layer mixing and cool temperatures aloft (i.e. around -10 deg C at 500 mb). Surface easterlies/northeasterlies beneath modest westerlies aloft will contribute to effective bulk shear around 35 kt, which is strong enough for some updraft organization. Isolated hail is possible across the higher terrain with the initially more cellular development. Damaging gusts are expected to be the primary risk thereafter as storms trend towards a more clustered mode and move eastward into the more mixed southern High Plains. ..Mosier/Squitieri.. 09/05/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Thu Sep 05 2024 Valid 051630Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTH-CENTRAL COLORADO INTO NORTHERN/CENTRAL NEW MEXICO... ...SUMMARY... Thunderstorms capable of producing isolated severe wind gusts and hail will be possible today across parts of far south-central Colorado into northern/central New Mexico. ...Synopsis... Satellite imagery shows a shortwave trough moving southeastward through the central Rockies, between the upper ridging in place over the western Great Basin and the broad upper troughing across central Canadian and northern Plains/Upper MS Valley. Another shortwave trough exists over the Upper MS Valley. This shortwave trough is forecast to continue progressing eastward through the base broad central Canada/northern Plains trough, moving across the Upper Great Lakes and into eastern Ontario. Recent surface analysis places a surface low associated with this shortwave over Lake Superior, with a cold front extending southwestward from this low through KS and into northeast NM. This front is forecast to progress southward/southeastward as its parent surface low lifts northeastward. Isolated thunderstorms are possible along this frontal boundary, but overall severity should be mitigated by modest buoyancy and vertical shear. Greater thunderstorm coverage and severity is anticipated over the southern Rockies as the previously mentioned central Rockies shortwave trough continues southeastward and promotes thunderstorm development. Lastly, a tropical wave just off the TX Coast is contributing to abundant moisture across much of Gulf Coast, with low 70s dewpoints reaching into much of east TX and northern LA, and upper 70s across FL. Precipitable water values over 2" cover much of this region as well. Heavy rain is the primary threat (as indicated by the latest Day 1 Excessive Rainfall Outlook from WPC), but a few water-loaded downbursts capable of damaging gusts are possible from southeast TX and southern/central LA eastward along the Gulf Coast and over the Florida Peninsula. Coverage of these gusts is expected to be sparse and too low to delineate a 5% wind probability area. ...Southern Rockies/southern High Plains... Moderate low-level moisture is anticipated within the post-frontal airmass across the southern Rockies and adjacent southern High Plains this afternoon, characterized by dewpoints in the low to mid 50s across the High Plains and upper 40s across the higher terrain. Even with this modest moisture, the airmass is expected to destabilize, fostered by deep boundary-layer mixing and cool temperatures aloft (i.e. around -10 deg C at 500 mb). Surface easterlies/northeasterlies beneath modest westerlies aloft will contribute to effective bulk shear around 35 kt, which is strong enough for some updraft organization. Isolated hail is possible across the higher terrain with the initially more cellular development. Damaging gusts are expected to be the primary risk thereafter as storms trend towards a more clustered mode and move eastward into the more mixed southern High Plains. ..Mosier/Squitieri.. 09/05/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 AM CDT Thu Sep 05 2024 Valid 051300Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTH-CENTRAL COLORADO INTO NORTHERN/CENTRAL NEW MEXICO... ...SUMMARY... Thunderstorms capable of producing isolated severe wind gusts and hail will be possible today across parts of far south-central Colorado into northern/central New Mexico. ...Central/Southern Rockies into the Southern High Plains... On the southwest fringe of large-scale upper troughing over Canada and the northern Plains/Upper Midwest, a mid-level shortwave trough over the central Rockies this morning will move generally southward across NM and vicinity through the day. Even though low-level moisture remains fairly modest across the southern Rockies and adjacent High Plains along/near of a cold front, cool mid-level temperatures and somewhat steepened lapse rates aloft will likely contribute to the development of around 500-750 J/kg of MLCAPE by early afternoon as daytime heating occurs. Initial development of robust convection by around 18-19Z will likely be tied to the higher terrain as weak large-scale ascent associated with the shortwave trough overspreads the south-central Rockies in a low-level post-frontal regime. This activity should then spread generally south-southeastward across parts of northern/central NM through the late afternoon and into the evening. While low-level easterly flow ahead of the front is forecast to remain weak, veering winds with height through mid/upper levels should still support around 25-35 kt of effective bulk shear and some updraft organization. The strongest cores that can develop may be capable of producing severe hail. Otherwise, the threat for isolated strong to severe wind gusts should spread southward in tandem with any small clusters that can form. ...Great Lakes/Midwest to the Central Plains... Generally elevated convection is ongoing this morning across parts of the Upper Midwest along and near a surface cold front, and ahead of a large-scale upper trough moving generally southeastward. Instability across this region is expected to remain weak (MUCAPE 500 J/kg or less), which should tend to limit the overall severe threat. Still, some of the stronger cores could produce small hail or gusty winds in the short term. Other thunderstorms may eventually develop this afternoon along/near the front across parts of the Midwest and/or central Plains. Regardless, the overall severe threat across these regions currently appears too limited to introduce low severe probabilities. ..Gleason/Leitman.. 09/05/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 AM CDT Thu Sep 05 2024 Valid 051300Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTH-CENTRAL COLORADO INTO NORTHERN/CENTRAL NEW MEXICO... ...SUMMARY... Thunderstorms capable of producing isolated severe wind gusts and hail will be possible today across parts of far south-central Colorado into northern/central New Mexico. ...Central/Southern Rockies into the Southern High Plains... On the southwest fringe of large-scale upper troughing over Canada and the northern Plains/Upper Midwest, a mid-level shortwave trough over the central Rockies this morning will move generally southward across NM and vicinity through the day. Even though low-level moisture remains fairly modest across the southern Rockies and adjacent High Plains along/near of a cold front, cool mid-level temperatures and somewhat steepened lapse rates aloft will likely contribute to the development of around 500-750 J/kg of MLCAPE by early afternoon as daytime heating occurs. Initial development of robust convection by around 18-19Z will likely be tied to the higher terrain as weak large-scale ascent associated with the shortwave trough overspreads the south-central Rockies in a low-level post-frontal regime. This activity should then spread generally south-southeastward across parts of northern/central NM through the late afternoon and into the evening. While low-level easterly flow ahead of the front is forecast to remain weak, veering winds with height through mid/upper levels should still support around 25-35 kt of effective bulk shear and some updraft organization. The strongest cores that can develop may be capable of producing severe hail. Otherwise, the threat for isolated strong to severe wind gusts should spread southward in tandem with any small clusters that can form. ...Great Lakes/Midwest to the Central Plains... Generally elevated convection is ongoing this morning across parts of the Upper Midwest along and near a surface cold front, and ahead of a large-scale upper trough moving generally southeastward. Instability across this region is expected to remain weak (MUCAPE 500 J/kg or less), which should tend to limit the overall severe threat. Still, some of the stronger cores could produce small hail or gusty winds in the short term. Other thunderstorms may eventually develop this afternoon along/near the front across parts of the Midwest and/or central Plains. Regardless, the overall severe threat across these regions currently appears too limited to introduce low severe probabilities. ..Gleason/Leitman.. 09/05/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0313 AM CDT Thu Sep 05 2024 Valid 081200Z - 131200Z ...DISCUSSION... A deep upper-level trough initially over the eastern CONUS on D4/Sunday is forecast to move offshore early next week. In the wake of this trough and its attendant cold front, a surface ridge is expected to persist over much of the eastern CONUS through mid week. This ridge will likely prevent the northward return of richer low-level moisture for most of the extended-range period, which should tend to limit organized severe-thunderstorm potential across much of the CONUS. There is some potential for the influence of the eastern surface ridge to wane by D7/Wednesday into D8/Thursday, while some guidance suggests a mid/upper-level trough will approach the central/northern High Plains during this time frame. Should this occur, there could be some increase in severe potential, though predictability remains rather low at this forecast range. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Thu Sep 05 2024 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong storms are possible across parts of the Northeast and Mid Atlantic on Saturday. ...Synopsis... A deep trough is forecast to take on more of a neutral or negative tilt on Saturday, as an embedded mid/upper-level cyclone moves slowly eastward across parts of ON/QC. A surface low initially near the lower Great Lakes may gradually deepen as it moves northeastward, while a trailing cold front will move through parts of the Northeast and Mid Atlantic through the day and into the evening. Farther south, a gradually deepening frontal wave is forecast to move near the Carolina coast through the day, and then move offshore by evening. To the west, an upper-level ridge is forecast to remain in place across the Southwest, while an upper-level trough moves slowly eastward across northern CA and the Pacific Northwest. ...Parts of the Northeast/Mid Atlantic... Some modest low-level moisture return is possible along/ahead of the front across the Mid Atlantic and Northeast, though buoyancy will likely remain meager due to weak midlevel lapse rates, and timing of the front remains somewhat uncertain. If adequate destabilization can occur along/ahead of the front, then increasing low/midlevel flow and large-scale ascent would support potential for somewhat organized convection during the day across parts of the Northeast and Mid Atlantic, which could pose some damaging-wind potential. Severe probabilities may eventually be needed for parts of the region, if confidence increases regarding frontal timing and development of sufficient instability. ...Central/southern High Plains vicinity... Modest low-level moisture return (dewpoints generally in the low 50s F) beneath relatively steep midlevel lapse rates will support moderate destabilization across parts of the central/southern High Plains. Deep-layer shear will become at least marginally supportive of organized storms within a modest northwesterly flow regime. Storm development and coverage (if any) across the High Plains remains uncertain, with large-scale ascent likely to remain subtle at best. Diurnal storm development will also be possible across the higher terrain of the southern/central Rockies, though buoyancy and deep-layer shear will tend to be somewhat weaker compared to areas farther east. ...Coastal NC... Depending on the track of the frontal wave that is forecast to develop Friday night near the coastal Carolinas, rich low-level moisture may spread slightly inland during the morning/afternoon, before the low moves offshore. While some increase in low-level flow is expected as the wave gradually deepens, buoyancy will likely remain quite weak. Any severe potential with the system may be rather limited, unless low-level mass response ends up being stronger than currently forecast. ..Dean.. 09/05/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CDT Thu Sep 05 2024 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR MUCH OF OHIO INTO ADJACENT PARTS OF THE GREAT LAKES AND OHIO VALLEY... ...SUMMARY... Strong to locally severe storms are possible on Friday across much of Ohio and adjacent portions of the Great Lakes and Ohio Valley. ...Synopsis... An upper-level trough is forecast to amplify as it digs southeastward across the Great Lakes and Ohio Valley regions on Friday. A mid/upper-level cyclone is forecast to develop with time, as a strong embedded shortwave moves southeastward into the base of the trough by Friday evening. A cold front will move through parts of the Great Lakes, Ohio Valley, Midwest, and southern Plains. Farther south, a weak surface wave may develop along a front near the Gulf Coast and move northeastward along or just offshore of the Carolina coast late Friday night into early Saturday morning. To the west, an upper ridge will remain in place across the Southwest, while a shortwave trough begins to move inland across northern CA into the Pacific Northwest. ...Ohio and adjacent parts of the Great Lakes/Ohio Valley... Thunderstorms are expected to develop near the cold front Friday afternoon across parts of Ohio and vicinity, as the amplifying upper-level trough begins to impinge upon the region. Low-level moisture will likely remain rather limited ahead of the front, though relatively strong heating/mixing will steepen low-level lapse rates. Somewhat more favorable moisture and buoyancy will reside near and immediately behind the front, with MLCAPE potentially approaching or exceeding 1000 J/kg. Low-level flow will likely remain rather weak, but gradually increasing effective shear (generally into the 25-35 kt range) could support a few stronger storms capable of at least isolated damaging winds during the afternoon and perhaps into the evening. Isolated hail also cannot be ruled out with any stronger discrete cells. ...Gulf Coast to the Carolina Coast... Some increase in low-level flow is possible in the vicinity of the frontal wave that may develop near the Gulf Coast and move toward the coastal Carolinas overnight. While this could be accompanied by some increase in low-level shear/SRH, buoyancy is currently expected to remain quite weak, so potential for organized convection inland appears relatively uncertain/limited at this time. ..Dean.. 09/05/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CDT Thu Sep 05 2024 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR MUCH OF OHIO INTO ADJACENT PARTS OF THE GREAT LAKES AND OHIO VALLEY... ...SUMMARY... Strong to locally severe storms are possible on Friday across much of Ohio and adjacent portions of the Great Lakes and Ohio Valley. ...Synopsis... An upper-level trough is forecast to amplify as it digs southeastward across the Great Lakes and Ohio Valley regions on Friday. A mid/upper-level cyclone is forecast to develop with time, as a strong embedded shortwave moves southeastward into the base of the trough by Friday evening. A cold front will move through parts of the Great Lakes, Ohio Valley, Midwest, and southern Plains. Farther south, a weak surface wave may develop along a front near the Gulf Coast and move northeastward along or just offshore of the Carolina coast late Friday night into early Saturday morning. To the west, an upper ridge will remain in place across the Southwest, while a shortwave trough begins to move inland across northern CA into the Pacific Northwest. ...Ohio and adjacent parts of the Great Lakes/Ohio Valley... Thunderstorms are expected to develop near the cold front Friday afternoon across parts of Ohio and vicinity, as the amplifying upper-level trough begins to impinge upon the region. Low-level moisture will likely remain rather limited ahead of the front, though relatively strong heating/mixing will steepen low-level lapse rates. Somewhat more favorable moisture and buoyancy will reside near and immediately behind the front, with MLCAPE potentially approaching or exceeding 1000 J/kg. Low-level flow will likely remain rather weak, but gradually increasing effective shear (generally into the 25-35 kt range) could support a few stronger storms capable of at least isolated damaging winds during the afternoon and perhaps into the evening. Isolated hail also cannot be ruled out with any stronger discrete cells. ...Gulf Coast to the Carolina Coast... Some increase in low-level flow is possible in the vicinity of the frontal wave that may develop near the Gulf Coast and move toward the coastal Carolinas overnight. While this could be accompanied by some increase in low-level shear/SRH, buoyancy is currently expected to remain quite weak, so potential for organized convection inland appears relatively uncertain/limited at this time. ..Dean.. 09/05/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Thu Sep 05 2024 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHEASTERN NEW MEXICO... ...SUMMARY... Thunderstorms capable of severe wind gusts will be possible today across part of northeastern New Mexico. ...Northeastern New Mexico... A shortwave trough will move southward across the central Rockies today. At the surface, a cold front will move southward into the southern High Plains, as a lee trough develops and deepens across northeastern New Mexico. As surface temperatures warm today near the surface trough, a cluster of thunderstorms is expected to develop ahead of a band of large-scale ascent. This cluster of storms is expected to expand in size across southern Colorado and move southward into northeastern New Mexico this afternoon. Ahead of the cluster, surface dewpoints in the 50s F will contribute to weak destabilization. MLCAPE is expected to peak in the 500 to 750 J/kg range by mid afternoon. RAP forecast soundings at 21Z in northeastern New Mexico have 0-6 shear in the 25 to 30 knot range, with 0-3 km lapse rates peaking in the 8.5 to 9 C/km range. This should be sufficient for isolated severe wind gusts associated with the stronger multicells. Hail will also be possible within the stronger cores. The wind and hail threat should persist throughout much of the afternoon as the storms gradually move southward from northeastern New Mexico into east-central New Mexico. ..Broyles/Moore.. 09/05/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Thu Sep 05 2024 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHEASTERN NEW MEXICO... ...SUMMARY... Thunderstorms capable of severe wind gusts will be possible today across part of northeastern New Mexico. ...Northeastern New Mexico... A shortwave trough will move southward across the central Rockies today. At the surface, a cold front will move southward into the southern High Plains, as a lee trough develops and deepens across northeastern New Mexico. As surface temperatures warm today near the surface trough, a cluster of thunderstorms is expected to develop ahead of a band of large-scale ascent. This cluster of storms is expected to expand in size across southern Colorado and move southward into northeastern New Mexico this afternoon. Ahead of the cluster, surface dewpoints in the 50s F will contribute to weak destabilization. MLCAPE is expected to peak in the 500 to 750 J/kg range by mid afternoon. RAP forecast soundings at 21Z in northeastern New Mexico have 0-6 shear in the 25 to 30 knot range, with 0-3 km lapse rates peaking in the 8.5 to 9 C/km range. This should be sufficient for isolated severe wind gusts associated with the stronger multicells. Hail will also be possible within the stronger cores. The wind and hail threat should persist throughout much of the afternoon as the storms gradually move southward from northeastern New Mexico into east-central New Mexico. ..Broyles/Moore.. 09/05/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1213 AM CDT Thu Sep 05 2024 Valid 061200Z - 071200Z ...Synopsis... Isolated dry thunderstorms will be the primary fire weather concern for Friday across parts of the northern Sierra Nevada into southwest OR. Recent water-vapor imagery reveals a weak upper disturbance over the eastern Pacific on the fringe of the upper ridge over the western U.S. This feature is expected to drift east/northeast over the next 48 hours, reaching northern CA/southern OR by late afternoon/evening Friday. As this occurs, a modest influx of mid-level moisture and ascent-driven mid-level cooling over the northern Sierra Nevada and southern Cascades should support adequate buoyancy for isolated thunderstorms. Recent forecast soundings suggest that boundary layer conditions will be sufficiently dry for dry lightning strikes, which will pose a fire weather concern given the dry fuels over the region (ERCs generally at or above the 80th percentile). Thunderstorms will be most likely along and to the lee side of the northern Sierra Nevada and southern Cascades where orographic ascent will aid in convective initiation. Additionally, strengthening southwesterly mid-level flow should enhance downslope winds across northern CA into northwest NV. Areas of elevated fire weather conditions are possible (and will most likely occur within the dry-thunderstorm risk area, but ensemble confidence in the coverage and duration of these conditions is somewhat limited (around 30-40% probability for sustained elevated conditions based on latest ensemble guidance). ..Moore.. 09/05/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1213 AM CDT Thu Sep 05 2024 Valid 061200Z - 071200Z ...Synopsis... Isolated dry thunderstorms will be the primary fire weather concern for Friday across parts of the northern Sierra Nevada into southwest OR. Recent water-vapor imagery reveals a weak upper disturbance over the eastern Pacific on the fringe of the upper ridge over the western U.S. This feature is expected to drift east/northeast over the next 48 hours, reaching northern CA/southern OR by late afternoon/evening Friday. As this occurs, a modest influx of mid-level moisture and ascent-driven mid-level cooling over the northern Sierra Nevada and southern Cascades should support adequate buoyancy for isolated thunderstorms. Recent forecast soundings suggest that boundary layer conditions will be sufficiently dry for dry lightning strikes, which will pose a fire weather concern given the dry fuels over the region (ERCs generally at or above the 80th percentile). Thunderstorms will be most likely along and to the lee side of the northern Sierra Nevada and southern Cascades where orographic ascent will aid in convective initiation. Additionally, strengthening southwesterly mid-level flow should enhance downslope winds across northern CA into northwest NV. Areas of elevated fire weather conditions are possible (and will most likely occur within the dry-thunderstorm risk area, but ensemble confidence in the coverage and duration of these conditions is somewhat limited (around 30-40% probability for sustained elevated conditions based on latest ensemble guidance). ..Moore.. 09/05/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1212 AM CDT Thu Sep 05 2024 Valid 051200Z - 061200Z ...NO CRITICAL AREAS... ...Synopsis... Fire weather concerns will be limited for today across the country. 05 UTC surface observations show a cold front slowly migrating south across the Plains and the upper MS River Valley. This front is expected to reach the southern Plains by evening as surface high pressure builds across the northern CONUS. Breezy conditions are expected behind the front, but an influx of cooler air combined with cloud cover and isolated to scattered showers and thunderstorms limits fire weather concerns. Across the West, an upper ridge currently over the region will linger through the next 24 hours. This will promote mostly clear skies and dry conditions for the afternoon with RH values in the teens and low 20s common. Surface winds will remain relatively benign with the exception of mountainous areas of southern CA, the northern Cascades, and parts of central to southern UT. Any fire weather concerns across these regions should remain sufficiently localized to preclude the need for highlights. ..Moore.. 09/05/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1212 AM CDT Thu Sep 05 2024 Valid 051200Z - 061200Z ...NO CRITICAL AREAS... ...Synopsis... Fire weather concerns will be limited for today across the country. 05 UTC surface observations show a cold front slowly migrating south across the Plains and the upper MS River Valley. This front is expected to reach the southern Plains by evening as surface high pressure builds across the northern CONUS. Breezy conditions are expected behind the front, but an influx of cooler air combined with cloud cover and isolated to scattered showers and thunderstorms limits fire weather concerns. Across the West, an upper ridge currently over the region will linger through the next 24 hours. This will promote mostly clear skies and dry conditions for the afternoon with RH values in the teens and low 20s common. Surface winds will remain relatively benign with the exception of mountainous areas of southern CA, the northern Cascades, and parts of central to southern UT. Any fire weather concerns across these regions should remain sufficiently localized to preclude the need for highlights. ..Moore.. 09/05/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0758 PM CDT Wed Sep 04 2024 Valid 050100Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PART OF THE CENTRAL HIGH PLAINS NORTHEASTWARD INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Isolated severe storms capable of damaging wind gusts and hail will be possible this evening from parts of the central Rockies northeastward into the upper Mississippi Valley. ...Central Rockies/Central Plains/Upper Mississippi Valley... The latest water vapor imagery shows a positively-tilted upper-level trough over the north-central Rockies, with west-southwesterly mid-level flow over the northern Plains and upper Mississippi Valley. At the surface, a cold front is located from eastern Colorado northeastward into southwest Minnesota. Scattered thunderstorms are ongoing behind the front from Colorado and Wyoming eastward into the central High Plains. RAP analysis has weak instability in place across the central High Plains and central Rockies, with MLCAPE generally in the 250 to 500 J/kg range. Forecast soundings across this weakly unstable airmass this evening have 0-3 km shear mostly between 25 and 35 knots, with 850-500 mb lapse rates near 7 C/km. This environment should be enough to continue a marginal severe threat for a few more hours this evening. Hail and isolated severe gusts will be the primary threats. As the upper-level trough moves eastward this evening, large-scale ascent will overspread parts of the northern Plains and upper Mississippi Valley. Thunderstorms are expected to develop within and near a pocket of moderate instability over eastern South Dakota, northeastern Nebraska and southwest Minnesota. These storms could also be associated with a potential for marginally severe wind gusts and hail. The greatest threat should be with cells that develop near the front late this evening, where instability is expected to be the strongest. ..Broyles.. 09/05/2024 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0456 PM CDT Wed Sep 04 2024 Valid 061200Z - 121200Z High pressure will continue to build in across the western US D3/Friday through D4/Saturday, with a warming and drying trend. Thunderstorm activity will be minimal across the Southwest as Monsoonal moisture has gradually shifted southward. Temperatures across the west will climb to above normal, but winds will remain mostly light where fuels are the driest in the west. The aforementioned hot, dry, unstable conditions will lead to some increase in fire behavior. A return of isolated dry thunderstorm activity is expected beginning late D3/Friday and D4/Saturday across northern California into the Pacific Northwest as a trough approaches from the Pacific and precipitable water values steadily increase. Isolated dry thunder probabilities were included on D3/Friday across the Sierra into western Nevada and into south-central Oregon and northward into the Cascade Range in Oregon and Washington on D4/Saturday, where signal for thunderstorms is highest in multiple deterministic runs. Monsoonal moisture will slowly begin to return northward across the Southwest by D5/Sunday-D8/Wednesday. A few areas of isolated dry thunderstorms will be possible across northern Arizona into southern Utah. Fuels within this region remain seasonably wet with recent rainfall and as such no areas have been included at this time. Further warming and drying is expected through the early extended and status of fuels will be reevaluated for future outlooks. The Pacific trough will deepen and move inland by D6/Monday-D8 /Wednesday, bringing enhanced westerly flow across northern California, the Pacific Northwest, and into the Great Basin. This will lead to potential Elevated to Critical conditions, particularly on D7/Tuesday and D8/Wednesday. For now, confidence remains too low to include areas based on model agreement, fuels, and potential rainfall. ..Thornton.. 09/04/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Wed Sep 4 21:29:02 UTC 2024.

No Mesoscale Discussions are in effect as of Wed Sep 4 21:29:02 UTC 2024.