Aggregator

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0324 PM CDT Sat Sep 07 2024 Valid 091200Z - 151200Z A seasonably strong trough will move into the Northwest early next week. This feature will dig into the Great Basin mid/late next week before lifting northeastward by the weekend. Fire weather concerns will be greatest within parts of the Great Basin beginning next week. Additional concerns are possible in the Plains depending on trends in model guidance and fuel receptiveness. ...Great Basin... Fire weather concerns will increase across the Great Basin on Tuesday as upper-level winds begin to increase across the Sierra. The spatial extent of stronger surface winds on Tuesday is a bit uncertain given the initially weak surface pressure pattern. Potential for critical fire weather will increase on Wednesday as the trough digs farther south and east and a deeper surface trough develops in the central/eastern Basin. Very dry conditions are possible along with winds that could exceed 20 mph, especially in southern Nevada into western Utah. ...Northwest... A few hours of elevated to near-critical conditions are possible in the lee of the Cascades as winds increase ahead of the surface front on Monday. RH may be on the marginal side, particularly with northward extent, as the influence of marine air will be on the increase. However, recent active fire behavior and ignitions from recent lightning suggest some fire weather concerns will be present with the modest increase in westerly surface winds. ...Central and Northern High Plains/Plains... As the strong trough moves into the Great Basin and eventually lifts northeastward mid/late next week, southerly winds across these regions will increase as a surface low and lee trough deepens. The typically drier GFS would suggest at least elevated fire weather conditions are possible, but there is low confidence in ensemble guidance as well as the ECMWF as to where and for how long near-critical/critical conditions may occur. Furthermore, fuels are not equally dry across all areas. In general, initial return flow cases tend to verify drier than expected and with the added potential for a tropical system to impact the central Gulf Coast into the Mid South late next week, this may further stunt moisture return northward. Trends in model guidance and fuel dryness will continue to be monitored. ...Western/central Montana... As a surface low deepens in Alberta/Saskatchewan and a lee trough extends into the central High Plains, surface winds will increase in the lee of the terrain and into parts of central Montana. Downslope winds will lead to dry afternoon conditions on Monday. Upper-level winds over the area will be only modest and fuels are only moderately dry, however. Potential for critical fire weather appears too low for highlights, though at least a few hours of elevated conditions are possible. ..Wendt.. 09/07/2024 ...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 0238 PM CDT Sat Sep 07 2024 Valid 072000Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast today, though a few strong gusts could accompany the more robust storms. ...20Z Update... The forecast remains on track, and only minor changes were made to the outlook with this update. In particular, the General Thunder line was trimmed behind the frontal rain band and associated wind shift in the Northeast, where cool post-frontal conditions have generally depleted instability. Updrafts within this band have remained too shallow/weak for an appreciable lightning risk thus far. However, an isolated strike still cannot be ruled out, especially over portions of eastern NJ and far southeastern NY/Long Island -- where filtered boundary-layer heating has occurred amid middle 60s dewpoints. Isolated/embedded strong gusts also remain possible (earlier 44 mph gust in eastern PA), though the weak/shallow updrafts (and associated downdrafts) should continue to limit the severe risk. Elsewhere, severe potential still appears too localized and/or marginal for severe probabilities. See the previous discussion below for details. ..Weinman.. 09/07/2024 .PREV DISCUSSION... /ISSUED 1131 AM CDT Sat Sep 07 2024/ ...Northeast... A cold front will move steadily east across the northeast today, accompanied by showers and thunderstorms. Extensive cloud cover in advance of the front will tend to limit heating/destabilization, however modest MLCAPE (on the order of 250-500 J/kg) may develop from the northern Delmarva Peninsula north into southeast NY this afternoon. Ascent with an upper-level trough will continue to move east in tandem with the front, and scattered thunderstorms may develop this afternoon with some potential for locally gusty winds. Weak instability and poor low-level lapse rates should limit severe potential. ...Central High Plains... Low-level moisture will be generally modest east of a surface trough that will extend north-south across eastern portions of WY/CO this afternoon. Still, lower 50s surface dew points and steep mid-level lapse rates should contribute to MLCAPE of 750-locally near 1000 J/kg. Isolated thunderstorms may form and move southeast within a northwest mid-level flow environment late this afternoon/evening, and a deep/well-mixed boundary layer suggests some potential for localized strong wind gusts. Thunderstorm potential may extend eastward into western portions of NE/KS this evening as a low-level jet strengthens. The overall coverage of any severe potential remains too low to introduce severe probabilities. ...Interior Northwest... The potential for isolated thunderstorms, already ongoing this morning over south-central OR, will continue today as modest large-scale ascent associated with a mid-level trough overspreads inland areas of the Pacific Northwest. These storms may produce limited rainfall, exacerbating fire weather concerns. ...Lower Colorado River Valley and Vicinity... Strong heating will contribute to scattered thunderstorm development this afternoon, and 12z hi-res guidance suggests that a couple of stronger storms or small clusters may have the potential for gusty outflow winds within a hot/well-mixed boundary layer. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Sat Sep 07 2024 Valid 072000Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast today, though a few strong gusts could accompany the more robust storms. ...20Z Update... The forecast remains on track, and only minor changes were made to the outlook with this update. In particular, the General Thunder line was trimmed behind the frontal rain band and associated wind shift in the Northeast, where cool post-frontal conditions have generally depleted instability. Updrafts within this band have remained too shallow/weak for an appreciable lightning risk thus far. However, an isolated strike still cannot be ruled out, especially over portions of eastern NJ and far southeastern NY/Long Island -- where filtered boundary-layer heating has occurred amid middle 60s dewpoints. Isolated/embedded strong gusts also remain possible (earlier 44 mph gust in eastern PA), though the weak/shallow updrafts (and associated downdrafts) should continue to limit the severe risk. Elsewhere, severe potential still appears too localized and/or marginal for severe probabilities. See the previous discussion below for details. ..Weinman.. 09/07/2024 .PREV DISCUSSION... /ISSUED 1131 AM CDT Sat Sep 07 2024/ ...Northeast... A cold front will move steadily east across the northeast today, accompanied by showers and thunderstorms. Extensive cloud cover in advance of the front will tend to limit heating/destabilization, however modest MLCAPE (on the order of 250-500 J/kg) may develop from the northern Delmarva Peninsula north into southeast NY this afternoon. Ascent with an upper-level trough will continue to move east in tandem with the front, and scattered thunderstorms may develop this afternoon with some potential for locally gusty winds. Weak instability and poor low-level lapse rates should limit severe potential. ...Central High Plains... Low-level moisture will be generally modest east of a surface trough that will extend north-south across eastern portions of WY/CO this afternoon. Still, lower 50s surface dew points and steep mid-level lapse rates should contribute to MLCAPE of 750-locally near 1000 J/kg. Isolated thunderstorms may form and move southeast within a northwest mid-level flow environment late this afternoon/evening, and a deep/well-mixed boundary layer suggests some potential for localized strong wind gusts. Thunderstorm potential may extend eastward into western portions of NE/KS this evening as a low-level jet strengthens. The overall coverage of any severe potential remains too low to introduce severe probabilities. ...Interior Northwest... The potential for isolated thunderstorms, already ongoing this morning over south-central OR, will continue today as modest large-scale ascent associated with a mid-level trough overspreads inland areas of the Pacific Northwest. These storms may produce limited rainfall, exacerbating fire weather concerns. ...Lower Colorado River Valley and Vicinity... Strong heating will contribute to scattered thunderstorm development this afternoon, and 12z hi-res guidance suggests that a couple of stronger storms or small clusters may have the potential for gusty outflow winds within a hot/well-mixed boundary layer. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Sat Sep 07 2024 Valid 072000Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast today, though a few strong gusts could accompany the more robust storms. ...20Z Update... The forecast remains on track, and only minor changes were made to the outlook with this update. In particular, the General Thunder line was trimmed behind the frontal rain band and associated wind shift in the Northeast, where cool post-frontal conditions have generally depleted instability. Updrafts within this band have remained too shallow/weak for an appreciable lightning risk thus far. However, an isolated strike still cannot be ruled out, especially over portions of eastern NJ and far southeastern NY/Long Island -- where filtered boundary-layer heating has occurred amid middle 60s dewpoints. Isolated/embedded strong gusts also remain possible (earlier 44 mph gust in eastern PA), though the weak/shallow updrafts (and associated downdrafts) should continue to limit the severe risk. Elsewhere, severe potential still appears too localized and/or marginal for severe probabilities. See the previous discussion below for details. ..Weinman.. 09/07/2024 .PREV DISCUSSION... /ISSUED 1131 AM CDT Sat Sep 07 2024/ ...Northeast... A cold front will move steadily east across the northeast today, accompanied by showers and thunderstorms. Extensive cloud cover in advance of the front will tend to limit heating/destabilization, however modest MLCAPE (on the order of 250-500 J/kg) may develop from the northern Delmarva Peninsula north into southeast NY this afternoon. Ascent with an upper-level trough will continue to move east in tandem with the front, and scattered thunderstorms may develop this afternoon with some potential for locally gusty winds. Weak instability and poor low-level lapse rates should limit severe potential. ...Central High Plains... Low-level moisture will be generally modest east of a surface trough that will extend north-south across eastern portions of WY/CO this afternoon. Still, lower 50s surface dew points and steep mid-level lapse rates should contribute to MLCAPE of 750-locally near 1000 J/kg. Isolated thunderstorms may form and move southeast within a northwest mid-level flow environment late this afternoon/evening, and a deep/well-mixed boundary layer suggests some potential for localized strong wind gusts. Thunderstorm potential may extend eastward into western portions of NE/KS this evening as a low-level jet strengthens. The overall coverage of any severe potential remains too low to introduce severe probabilities. ...Interior Northwest... The potential for isolated thunderstorms, already ongoing this morning over south-central OR, will continue today as modest large-scale ascent associated with a mid-level trough overspreads inland areas of the Pacific Northwest. These storms may produce limited rainfall, exacerbating fire weather concerns. ...Lower Colorado River Valley and Vicinity... Strong heating will contribute to scattered thunderstorm development this afternoon, and 12z hi-res guidance suggests that a couple of stronger storms or small clusters may have the potential for gusty outflow winds within a hot/well-mixed boundary layer. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Sat Sep 07 2024 Valid 072000Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast today, though a few strong gusts could accompany the more robust storms. ...20Z Update... The forecast remains on track, and only minor changes were made to the outlook with this update. In particular, the General Thunder line was trimmed behind the frontal rain band and associated wind shift in the Northeast, where cool post-frontal conditions have generally depleted instability. Updrafts within this band have remained too shallow/weak for an appreciable lightning risk thus far. However, an isolated strike still cannot be ruled out, especially over portions of eastern NJ and far southeastern NY/Long Island -- where filtered boundary-layer heating has occurred amid middle 60s dewpoints. Isolated/embedded strong gusts also remain possible (earlier 44 mph gust in eastern PA), though the weak/shallow updrafts (and associated downdrafts) should continue to limit the severe risk. Elsewhere, severe potential still appears too localized and/or marginal for severe probabilities. See the previous discussion below for details. ..Weinman.. 09/07/2024 .PREV DISCUSSION... /ISSUED 1131 AM CDT Sat Sep 07 2024/ ...Northeast... A cold front will move steadily east across the northeast today, accompanied by showers and thunderstorms. Extensive cloud cover in advance of the front will tend to limit heating/destabilization, however modest MLCAPE (on the order of 250-500 J/kg) may develop from the northern Delmarva Peninsula north into southeast NY this afternoon. Ascent with an upper-level trough will continue to move east in tandem with the front, and scattered thunderstorms may develop this afternoon with some potential for locally gusty winds. Weak instability and poor low-level lapse rates should limit severe potential. ...Central High Plains... Low-level moisture will be generally modest east of a surface trough that will extend north-south across eastern portions of WY/CO this afternoon. Still, lower 50s surface dew points and steep mid-level lapse rates should contribute to MLCAPE of 750-locally near 1000 J/kg. Isolated thunderstorms may form and move southeast within a northwest mid-level flow environment late this afternoon/evening, and a deep/well-mixed boundary layer suggests some potential for localized strong wind gusts. Thunderstorm potential may extend eastward into western portions of NE/KS this evening as a low-level jet strengthens. The overall coverage of any severe potential remains too low to introduce severe probabilities. ...Interior Northwest... The potential for isolated thunderstorms, already ongoing this morning over south-central OR, will continue today as modest large-scale ascent associated with a mid-level trough overspreads inland areas of the Pacific Northwest. These storms may produce limited rainfall, exacerbating fire weather concerns. ...Lower Colorado River Valley and Vicinity... Strong heating will contribute to scattered thunderstorm development this afternoon, and 12z hi-res guidance suggests that a couple of stronger storms or small clusters may have the potential for gusty outflow winds within a hot/well-mixed boundary layer. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Sat Sep 07 2024 Valid 072000Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast today, though a few strong gusts could accompany the more robust storms. ...20Z Update... The forecast remains on track, and only minor changes were made to the outlook with this update. In particular, the General Thunder line was trimmed behind the frontal rain band and associated wind shift in the Northeast, where cool post-frontal conditions have generally depleted instability. Updrafts within this band have remained too shallow/weak for an appreciable lightning risk thus far. However, an isolated strike still cannot be ruled out, especially over portions of eastern NJ and far southeastern NY/Long Island -- where filtered boundary-layer heating has occurred amid middle 60s dewpoints. Isolated/embedded strong gusts also remain possible (earlier 44 mph gust in eastern PA), though the weak/shallow updrafts (and associated downdrafts) should continue to limit the severe risk. Elsewhere, severe potential still appears too localized and/or marginal for severe probabilities. See the previous discussion below for details. ..Weinman.. 09/07/2024 .PREV DISCUSSION... /ISSUED 1131 AM CDT Sat Sep 07 2024/ ...Northeast... A cold front will move steadily east across the northeast today, accompanied by showers and thunderstorms. Extensive cloud cover in advance of the front will tend to limit heating/destabilization, however modest MLCAPE (on the order of 250-500 J/kg) may develop from the northern Delmarva Peninsula north into southeast NY this afternoon. Ascent with an upper-level trough will continue to move east in tandem with the front, and scattered thunderstorms may develop this afternoon with some potential for locally gusty winds. Weak instability and poor low-level lapse rates should limit severe potential. ...Central High Plains... Low-level moisture will be generally modest east of a surface trough that will extend north-south across eastern portions of WY/CO this afternoon. Still, lower 50s surface dew points and steep mid-level lapse rates should contribute to MLCAPE of 750-locally near 1000 J/kg. Isolated thunderstorms may form and move southeast within a northwest mid-level flow environment late this afternoon/evening, and a deep/well-mixed boundary layer suggests some potential for localized strong wind gusts. Thunderstorm potential may extend eastward into western portions of NE/KS this evening as a low-level jet strengthens. The overall coverage of any severe potential remains too low to introduce severe probabilities. ...Interior Northwest... The potential for isolated thunderstorms, already ongoing this morning over south-central OR, will continue today as modest large-scale ascent associated with a mid-level trough overspreads inland areas of the Pacific Northwest. These storms may produce limited rainfall, exacerbating fire weather concerns. ...Lower Colorado River Valley and Vicinity... Strong heating will contribute to scattered thunderstorm development this afternoon, and 12z hi-res guidance suggests that a couple of stronger storms or small clusters may have the potential for gusty outflow winds within a hot/well-mixed boundary layer. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Sat Sep 07 2024 Valid 072000Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast today, though a few strong gusts could accompany the more robust storms. ...20Z Update... The forecast remains on track, and only minor changes were made to the outlook with this update. In particular, the General Thunder line was trimmed behind the frontal rain band and associated wind shift in the Northeast, where cool post-frontal conditions have generally depleted instability. Updrafts within this band have remained too shallow/weak for an appreciable lightning risk thus far. However, an isolated strike still cannot be ruled out, especially over portions of eastern NJ and far southeastern NY/Long Island -- where filtered boundary-layer heating has occurred amid middle 60s dewpoints. Isolated/embedded strong gusts also remain possible (earlier 44 mph gust in eastern PA), though the weak/shallow updrafts (and associated downdrafts) should continue to limit the severe risk. Elsewhere, severe potential still appears too localized and/or marginal for severe probabilities. See the previous discussion below for details. ..Weinman.. 09/07/2024 .PREV DISCUSSION... /ISSUED 1131 AM CDT Sat Sep 07 2024/ ...Northeast... A cold front will move steadily east across the northeast today, accompanied by showers and thunderstorms. Extensive cloud cover in advance of the front will tend to limit heating/destabilization, however modest MLCAPE (on the order of 250-500 J/kg) may develop from the northern Delmarva Peninsula north into southeast NY this afternoon. Ascent with an upper-level trough will continue to move east in tandem with the front, and scattered thunderstorms may develop this afternoon with some potential for locally gusty winds. Weak instability and poor low-level lapse rates should limit severe potential. ...Central High Plains... Low-level moisture will be generally modest east of a surface trough that will extend north-south across eastern portions of WY/CO this afternoon. Still, lower 50s surface dew points and steep mid-level lapse rates should contribute to MLCAPE of 750-locally near 1000 J/kg. Isolated thunderstorms may form and move southeast within a northwest mid-level flow environment late this afternoon/evening, and a deep/well-mixed boundary layer suggests some potential for localized strong wind gusts. Thunderstorm potential may extend eastward into western portions of NE/KS this evening as a low-level jet strengthens. The overall coverage of any severe potential remains too low to introduce severe probabilities. ...Interior Northwest... The potential for isolated thunderstorms, already ongoing this morning over south-central OR, will continue today as modest large-scale ascent associated with a mid-level trough overspreads inland areas of the Pacific Northwest. These storms may produce limited rainfall, exacerbating fire weather concerns. ...Lower Colorado River Valley and Vicinity... Strong heating will contribute to scattered thunderstorm development this afternoon, and 12z hi-res guidance suggests that a couple of stronger storms or small clusters may have the potential for gusty outflow winds within a hot/well-mixed boundary layer. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Sat Sep 07 2024 Valid 072000Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast today, though a few strong gusts could accompany the more robust storms. ...20Z Update... The forecast remains on track, and only minor changes were made to the outlook with this update. In particular, the General Thunder line was trimmed behind the frontal rain band and associated wind shift in the Northeast, where cool post-frontal conditions have generally depleted instability. Updrafts within this band have remained too shallow/weak for an appreciable lightning risk thus far. However, an isolated strike still cannot be ruled out, especially over portions of eastern NJ and far southeastern NY/Long Island -- where filtered boundary-layer heating has occurred amid middle 60s dewpoints. Isolated/embedded strong gusts also remain possible (earlier 44 mph gust in eastern PA), though the weak/shallow updrafts (and associated downdrafts) should continue to limit the severe risk. Elsewhere, severe potential still appears too localized and/or marginal for severe probabilities. See the previous discussion below for details. ..Weinman.. 09/07/2024 .PREV DISCUSSION... /ISSUED 1131 AM CDT Sat Sep 07 2024/ ...Northeast... A cold front will move steadily east across the northeast today, accompanied by showers and thunderstorms. Extensive cloud cover in advance of the front will tend to limit heating/destabilization, however modest MLCAPE (on the order of 250-500 J/kg) may develop from the northern Delmarva Peninsula north into southeast NY this afternoon. Ascent with an upper-level trough will continue to move east in tandem with the front, and scattered thunderstorms may develop this afternoon with some potential for locally gusty winds. Weak instability and poor low-level lapse rates should limit severe potential. ...Central High Plains... Low-level moisture will be generally modest east of a surface trough that will extend north-south across eastern portions of WY/CO this afternoon. Still, lower 50s surface dew points and steep mid-level lapse rates should contribute to MLCAPE of 750-locally near 1000 J/kg. Isolated thunderstorms may form and move southeast within a northwest mid-level flow environment late this afternoon/evening, and a deep/well-mixed boundary layer suggests some potential for localized strong wind gusts. Thunderstorm potential may extend eastward into western portions of NE/KS this evening as a low-level jet strengthens. The overall coverage of any severe potential remains too low to introduce severe probabilities. ...Interior Northwest... The potential for isolated thunderstorms, already ongoing this morning over south-central OR, will continue today as modest large-scale ascent associated with a mid-level trough overspreads inland areas of the Pacific Northwest. These storms may produce limited rainfall, exacerbating fire weather concerns. ...Lower Colorado River Valley and Vicinity... Strong heating will contribute to scattered thunderstorm development this afternoon, and 12z hi-res guidance suggests that a couple of stronger storms or small clusters may have the potential for gusty outflow winds within a hot/well-mixed boundary layer. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Sep 07 2024 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe-thunderstorm potential currently appears low on Monday. ...Synopsis... A deep mid/upper-level trough is forecast to move gradually eastward across the northeast CONUS on Monday. An embedded shortwave is expected to move through the base of the trough across the lower Great Lakes region into the Mid Atlantic/Northeast. A midlevel shortwave trough is forecast to move across the northern Rockies/High Plains, with a weaker shortwave potentially moving from the central Plains into the upper Midwest. An area of low pressure initially over the Bay of Campeche may evolve into a tropical cyclone. Isolated to scattered thunderstorms will be possible across parts of the lower Great Lakes, Intermountain West, and potentially into parts of the High Plains, though low-level moisture is expected to remain rather limited. Nocturnal elevated convection may be possible from the northern Plains into the upper Midwest, though this potential remains quite uncertain. ...Lower Great Lakes vicinity... Ascent and cooling temperatures aloft in association with the digging shortwave trough will support diurnal thunderstorm potential from the lower Great Lakes into central/northern NY. Most guidance suggests that buoyancy will remain quite limited, though gusty winds and small hail could accompany any deeper convection. The 07/12Z NAM is notably stronger with both the digging shortwave and destabilization, suggesting a threat for more-organized convection. Confidence in this more aggressive scenario is too low for probabilities at this time. ...Deep South Texas... See NHC forecasts and advisories for more information regarding possible tropical cyclone development in the Bay of Campeche. Uncertainty remains high regarding the details, but guidance generally suggests that the favored northeast quadrant of any developing cyclone will remain offshore of south TX into Tuesday morning, which would limit inland severe potential through the end of the period. ..Dean.. 09/07/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Sep 07 2024 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe-thunderstorm potential currently appears low on Monday. ...Synopsis... A deep mid/upper-level trough is forecast to move gradually eastward across the northeast CONUS on Monday. An embedded shortwave is expected to move through the base of the trough across the lower Great Lakes region into the Mid Atlantic/Northeast. A midlevel shortwave trough is forecast to move across the northern Rockies/High Plains, with a weaker shortwave potentially moving from the central Plains into the upper Midwest. An area of low pressure initially over the Bay of Campeche may evolve into a tropical cyclone. Isolated to scattered thunderstorms will be possible across parts of the lower Great Lakes, Intermountain West, and potentially into parts of the High Plains, though low-level moisture is expected to remain rather limited. Nocturnal elevated convection may be possible from the northern Plains into the upper Midwest, though this potential remains quite uncertain. ...Lower Great Lakes vicinity... Ascent and cooling temperatures aloft in association with the digging shortwave trough will support diurnal thunderstorm potential from the lower Great Lakes into central/northern NY. Most guidance suggests that buoyancy will remain quite limited, though gusty winds and small hail could accompany any deeper convection. The 07/12Z NAM is notably stronger with both the digging shortwave and destabilization, suggesting a threat for more-organized convection. Confidence in this more aggressive scenario is too low for probabilities at this time. ...Deep South Texas... See NHC forecasts and advisories for more information regarding possible tropical cyclone development in the Bay of Campeche. Uncertainty remains high regarding the details, but guidance generally suggests that the favored northeast quadrant of any developing cyclone will remain offshore of south TX into Tuesday morning, which would limit inland severe potential through the end of the period. ..Dean.. 09/07/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Sep 07 2024 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe-thunderstorm potential currently appears low on Monday. ...Synopsis... A deep mid/upper-level trough is forecast to move gradually eastward across the northeast CONUS on Monday. An embedded shortwave is expected to move through the base of the trough across the lower Great Lakes region into the Mid Atlantic/Northeast. A midlevel shortwave trough is forecast to move across the northern Rockies/High Plains, with a weaker shortwave potentially moving from the central Plains into the upper Midwest. An area of low pressure initially over the Bay of Campeche may evolve into a tropical cyclone. Isolated to scattered thunderstorms will be possible across parts of the lower Great Lakes, Intermountain West, and potentially into parts of the High Plains, though low-level moisture is expected to remain rather limited. Nocturnal elevated convection may be possible from the northern Plains into the upper Midwest, though this potential remains quite uncertain. ...Lower Great Lakes vicinity... Ascent and cooling temperatures aloft in association with the digging shortwave trough will support diurnal thunderstorm potential from the lower Great Lakes into central/northern NY. Most guidance suggests that buoyancy will remain quite limited, though gusty winds and small hail could accompany any deeper convection. The 07/12Z NAM is notably stronger with both the digging shortwave and destabilization, suggesting a threat for more-organized convection. Confidence in this more aggressive scenario is too low for probabilities at this time. ...Deep South Texas... See NHC forecasts and advisories for more information regarding possible tropical cyclone development in the Bay of Campeche. Uncertainty remains high regarding the details, but guidance generally suggests that the favored northeast quadrant of any developing cyclone will remain offshore of south TX into Tuesday morning, which would limit inland severe potential through the end of the period. ..Dean.. 09/07/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Sep 07 2024 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe-thunderstorm potential currently appears low on Monday. ...Synopsis... A deep mid/upper-level trough is forecast to move gradually eastward across the northeast CONUS on Monday. An embedded shortwave is expected to move through the base of the trough across the lower Great Lakes region into the Mid Atlantic/Northeast. A midlevel shortwave trough is forecast to move across the northern Rockies/High Plains, with a weaker shortwave potentially moving from the central Plains into the upper Midwest. An area of low pressure initially over the Bay of Campeche may evolve into a tropical cyclone. Isolated to scattered thunderstorms will be possible across parts of the lower Great Lakes, Intermountain West, and potentially into parts of the High Plains, though low-level moisture is expected to remain rather limited. Nocturnal elevated convection may be possible from the northern Plains into the upper Midwest, though this potential remains quite uncertain. ...Lower Great Lakes vicinity... Ascent and cooling temperatures aloft in association with the digging shortwave trough will support diurnal thunderstorm potential from the lower Great Lakes into central/northern NY. Most guidance suggests that buoyancy will remain quite limited, though gusty winds and small hail could accompany any deeper convection. The 07/12Z NAM is notably stronger with both the digging shortwave and destabilization, suggesting a threat for more-organized convection. Confidence in this more aggressive scenario is too low for probabilities at this time. ...Deep South Texas... See NHC forecasts and advisories for more information regarding possible tropical cyclone development in the Bay of Campeche. Uncertainty remains high regarding the details, but guidance generally suggests that the favored northeast quadrant of any developing cyclone will remain offshore of south TX into Tuesday morning, which would limit inland severe potential through the end of the period. ..Dean.. 09/07/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Sep 07 2024 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe-thunderstorm potential currently appears low on Monday. ...Synopsis... A deep mid/upper-level trough is forecast to move gradually eastward across the northeast CONUS on Monday. An embedded shortwave is expected to move through the base of the trough across the lower Great Lakes region into the Mid Atlantic/Northeast. A midlevel shortwave trough is forecast to move across the northern Rockies/High Plains, with a weaker shortwave potentially moving from the central Plains into the upper Midwest. An area of low pressure initially over the Bay of Campeche may evolve into a tropical cyclone. Isolated to scattered thunderstorms will be possible across parts of the lower Great Lakes, Intermountain West, and potentially into parts of the High Plains, though low-level moisture is expected to remain rather limited. Nocturnal elevated convection may be possible from the northern Plains into the upper Midwest, though this potential remains quite uncertain. ...Lower Great Lakes vicinity... Ascent and cooling temperatures aloft in association with the digging shortwave trough will support diurnal thunderstorm potential from the lower Great Lakes into central/northern NY. Most guidance suggests that buoyancy will remain quite limited, though gusty winds and small hail could accompany any deeper convection. The 07/12Z NAM is notably stronger with both the digging shortwave and destabilization, suggesting a threat for more-organized convection. Confidence in this more aggressive scenario is too low for probabilities at this time. ...Deep South Texas... See NHC forecasts and advisories for more information regarding possible tropical cyclone development in the Bay of Campeche. Uncertainty remains high regarding the details, but guidance generally suggests that the favored northeast quadrant of any developing cyclone will remain offshore of south TX into Tuesday morning, which would limit inland severe potential through the end of the period. ..Dean.. 09/07/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Sep 07 2024 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe-thunderstorm potential currently appears low on Monday. ...Synopsis... A deep mid/upper-level trough is forecast to move gradually eastward across the northeast CONUS on Monday. An embedded shortwave is expected to move through the base of the trough across the lower Great Lakes region into the Mid Atlantic/Northeast. A midlevel shortwave trough is forecast to move across the northern Rockies/High Plains, with a weaker shortwave potentially moving from the central Plains into the upper Midwest. An area of low pressure initially over the Bay of Campeche may evolve into a tropical cyclone. Isolated to scattered thunderstorms will be possible across parts of the lower Great Lakes, Intermountain West, and potentially into parts of the High Plains, though low-level moisture is expected to remain rather limited. Nocturnal elevated convection may be possible from the northern Plains into the upper Midwest, though this potential remains quite uncertain. ...Lower Great Lakes vicinity... Ascent and cooling temperatures aloft in association with the digging shortwave trough will support diurnal thunderstorm potential from the lower Great Lakes into central/northern NY. Most guidance suggests that buoyancy will remain quite limited, though gusty winds and small hail could accompany any deeper convection. The 07/12Z NAM is notably stronger with both the digging shortwave and destabilization, suggesting a threat for more-organized convection. Confidence in this more aggressive scenario is too low for probabilities at this time. ...Deep South Texas... See NHC forecasts and advisories for more information regarding possible tropical cyclone development in the Bay of Campeche. Uncertainty remains high regarding the details, but guidance generally suggests that the favored northeast quadrant of any developing cyclone will remain offshore of south TX into Tuesday morning, which would limit inland severe potential through the end of the period. ..Dean.. 09/07/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Sep 07 2024 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe-thunderstorm potential currently appears low on Monday. ...Synopsis... A deep mid/upper-level trough is forecast to move gradually eastward across the northeast CONUS on Monday. An embedded shortwave is expected to move through the base of the trough across the lower Great Lakes region into the Mid Atlantic/Northeast. A midlevel shortwave trough is forecast to move across the northern Rockies/High Plains, with a weaker shortwave potentially moving from the central Plains into the upper Midwest. An area of low pressure initially over the Bay of Campeche may evolve into a tropical cyclone. Isolated to scattered thunderstorms will be possible across parts of the lower Great Lakes, Intermountain West, and potentially into parts of the High Plains, though low-level moisture is expected to remain rather limited. Nocturnal elevated convection may be possible from the northern Plains into the upper Midwest, though this potential remains quite uncertain. ...Lower Great Lakes vicinity... Ascent and cooling temperatures aloft in association with the digging shortwave trough will support diurnal thunderstorm potential from the lower Great Lakes into central/northern NY. Most guidance suggests that buoyancy will remain quite limited, though gusty winds and small hail could accompany any deeper convection. The 07/12Z NAM is notably stronger with both the digging shortwave and destabilization, suggesting a threat for more-organized convection. Confidence in this more aggressive scenario is too low for probabilities at this time. ...Deep South Texas... See NHC forecasts and advisories for more information regarding possible tropical cyclone development in the Bay of Campeche. Uncertainty remains high regarding the details, but guidance generally suggests that the favored northeast quadrant of any developing cyclone will remain offshore of south TX into Tuesday morning, which would limit inland severe potential through the end of the period. ..Dean.. 09/07/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 PM CDT Sat Sep 07 2024 Valid 081200Z - 091200Z Minor changes were made to the ongoing dry thunderstorm area in the Northwest based on recent guidance. See the previous discussion for more details. ..Wendt.. 09/07/2024 .PREV DISCUSSION... /ISSUED 0207 AM CDT Sat Sep 07 2024/ ...Synopsis... The upper trough on the Pacific Coast is forecast to move inland Sunday while the mid-level ridge over much of the West is expected to continue retreating. A belt of stronger mid-level flow associated with the trough will gradually overspread portions of the Northwest and northern Great Basin, supporting an increase in surface winds to 15-25 mph. Aided by the increased mixing, and residual warm temperatures beneath the weakening ridge, diurnal minimum RH values below 15% are likely. Widespread elevated to near-critical fire-weather conditions are possible across the northern Sierra and Great Basin, where the dry and breezy conditions will overlap with areas of dry fuels. Farther north in the lee of the Cascades, gusty downslope and gap winds may also support brief elevated fire-weather potential as stronger flow aloft develops. However, some humidity recovery will eventually occur as marine influence will increase with time, potentially limiting the coverage and duration of fire-weather concerns. ...Dry Thunderstorms... Isolated to widely scattered thunderstorms are likely to be ongoing early in the period as the cold core of the upper trough moves inland over the Northwest. As lift from the upper trough and mid-level moisture move inland, additional storms may develop into the afternoon atop warm and dry low levels. Forecast soundings suggest mid/high-level cloud cover and some potential for smoke to limit heating and diurnal storm coverage. Still, isolated storm potential, along with dry low levels and storm motions greater than 20 kt will likely support a risk for dry thunderstorms atop receptive fuels. Confidence in dry thunderstorm coverage is greatest across portions of the northern and central Cascades, into eastern ID and far southwestern MT. Scattered thunderstorms are also possible farther across the southern Great Basin and southern CA. Displaced from the stronger flow aloft, and with access to more robust monsoon moisture, slower storm speeds and a wetter storm mode are expected. Still, a few drier lightning strikes will remain possible atop mostly receptive fuel beds. ...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 0156 PM CDT Sat Sep 07 2024 Valid 081200Z - 091200Z Minor changes were made to the ongoing dry thunderstorm area in the Northwest based on recent guidance. See the previous discussion for more details. ..Wendt.. 09/07/2024 .PREV DISCUSSION... /ISSUED 0207 AM CDT Sat Sep 07 2024/ ...Synopsis... The upper trough on the Pacific Coast is forecast to move inland Sunday while the mid-level ridge over much of the West is expected to continue retreating. A belt of stronger mid-level flow associated with the trough will gradually overspread portions of the Northwest and northern Great Basin, supporting an increase in surface winds to 15-25 mph. Aided by the increased mixing, and residual warm temperatures beneath the weakening ridge, diurnal minimum RH values below 15% are likely. Widespread elevated to near-critical fire-weather conditions are possible across the northern Sierra and Great Basin, where the dry and breezy conditions will overlap with areas of dry fuels. Farther north in the lee of the Cascades, gusty downslope and gap winds may also support brief elevated fire-weather potential as stronger flow aloft develops. However, some humidity recovery will eventually occur as marine influence will increase with time, potentially limiting the coverage and duration of fire-weather concerns. ...Dry Thunderstorms... Isolated to widely scattered thunderstorms are likely to be ongoing early in the period as the cold core of the upper trough moves inland over the Northwest. As lift from the upper trough and mid-level moisture move inland, additional storms may develop into the afternoon atop warm and dry low levels. Forecast soundings suggest mid/high-level cloud cover and some potential for smoke to limit heating and diurnal storm coverage. Still, isolated storm potential, along with dry low levels and storm motions greater than 20 kt will likely support a risk for dry thunderstorms atop receptive fuels. Confidence in dry thunderstorm coverage is greatest across portions of the northern and central Cascades, into eastern ID and far southwestern MT. Scattered thunderstorms are also possible farther across the southern Great Basin and southern CA. Displaced from the stronger flow aloft, and with access to more robust monsoon moisture, slower storm speeds and a wetter storm mode are expected. Still, a few drier lightning strikes will remain possible atop mostly receptive fuel beds. ...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 0156 PM CDT Sat Sep 07 2024 Valid 081200Z - 091200Z Minor changes were made to the ongoing dry thunderstorm area in the Northwest based on recent guidance. See the previous discussion for more details. ..Wendt.. 09/07/2024 .PREV DISCUSSION... /ISSUED 0207 AM CDT Sat Sep 07 2024/ ...Synopsis... The upper trough on the Pacific Coast is forecast to move inland Sunday while the mid-level ridge over much of the West is expected to continue retreating. A belt of stronger mid-level flow associated with the trough will gradually overspread portions of the Northwest and northern Great Basin, supporting an increase in surface winds to 15-25 mph. Aided by the increased mixing, and residual warm temperatures beneath the weakening ridge, diurnal minimum RH values below 15% are likely. Widespread elevated to near-critical fire-weather conditions are possible across the northern Sierra and Great Basin, where the dry and breezy conditions will overlap with areas of dry fuels. Farther north in the lee of the Cascades, gusty downslope and gap winds may also support brief elevated fire-weather potential as stronger flow aloft develops. However, some humidity recovery will eventually occur as marine influence will increase with time, potentially limiting the coverage and duration of fire-weather concerns. ...Dry Thunderstorms... Isolated to widely scattered thunderstorms are likely to be ongoing early in the period as the cold core of the upper trough moves inland over the Northwest. As lift from the upper trough and mid-level moisture move inland, additional storms may develop into the afternoon atop warm and dry low levels. Forecast soundings suggest mid/high-level cloud cover and some potential for smoke to limit heating and diurnal storm coverage. Still, isolated storm potential, along with dry low levels and storm motions greater than 20 kt will likely support a risk for dry thunderstorms atop receptive fuels. Confidence in dry thunderstorm coverage is greatest across portions of the northern and central Cascades, into eastern ID and far southwestern MT. Scattered thunderstorms are also possible farther across the southern Great Basin and southern CA. Displaced from the stronger flow aloft, and with access to more robust monsoon moisture, slower storm speeds and a wetter storm mode are expected. Still, a few drier lightning strikes will remain possible atop mostly receptive fuel beds. ...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 0156 PM CDT Sat Sep 07 2024 Valid 081200Z - 091200Z Minor changes were made to the ongoing dry thunderstorm area in the Northwest based on recent guidance. See the previous discussion for more details. ..Wendt.. 09/07/2024 .PREV DISCUSSION... /ISSUED 0207 AM CDT Sat Sep 07 2024/ ...Synopsis... The upper trough on the Pacific Coast is forecast to move inland Sunday while the mid-level ridge over much of the West is expected to continue retreating. A belt of stronger mid-level flow associated with the trough will gradually overspread portions of the Northwest and northern Great Basin, supporting an increase in surface winds to 15-25 mph. Aided by the increased mixing, and residual warm temperatures beneath the weakening ridge, diurnal minimum RH values below 15% are likely. Widespread elevated to near-critical fire-weather conditions are possible across the northern Sierra and Great Basin, where the dry and breezy conditions will overlap with areas of dry fuels. Farther north in the lee of the Cascades, gusty downslope and gap winds may also support brief elevated fire-weather potential as stronger flow aloft develops. However, some humidity recovery will eventually occur as marine influence will increase with time, potentially limiting the coverage and duration of fire-weather concerns. ...Dry Thunderstorms... Isolated to widely scattered thunderstorms are likely to be ongoing early in the period as the cold core of the upper trough moves inland over the Northwest. As lift from the upper trough and mid-level moisture move inland, additional storms may develop into the afternoon atop warm and dry low levels. Forecast soundings suggest mid/high-level cloud cover and some potential for smoke to limit heating and diurnal storm coverage. Still, isolated storm potential, along with dry low levels and storm motions greater than 20 kt will likely support a risk for dry thunderstorms atop receptive fuels. Confidence in dry thunderstorm coverage is greatest across portions of the northern and central Cascades, into eastern ID and far southwestern MT. Scattered thunderstorms are also possible farther across the southern Great Basin and southern CA. Displaced from the stronger flow aloft, and with access to more robust monsoon moisture, slower storm speeds and a wetter storm mode are expected. Still, a few drier lightning strikes will remain possible atop mostly receptive fuel beds. ...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 0156 PM CDT Sat Sep 07 2024 Valid 081200Z - 091200Z Minor changes were made to the ongoing dry thunderstorm area in the Northwest based on recent guidance. See the previous discussion for more details. ..Wendt.. 09/07/2024 .PREV DISCUSSION... /ISSUED 0207 AM CDT Sat Sep 07 2024/ ...Synopsis... The upper trough on the Pacific Coast is forecast to move inland Sunday while the mid-level ridge over much of the West is expected to continue retreating. A belt of stronger mid-level flow associated with the trough will gradually overspread portions of the Northwest and northern Great Basin, supporting an increase in surface winds to 15-25 mph. Aided by the increased mixing, and residual warm temperatures beneath the weakening ridge, diurnal minimum RH values below 15% are likely. Widespread elevated to near-critical fire-weather conditions are possible across the northern Sierra and Great Basin, where the dry and breezy conditions will overlap with areas of dry fuels. Farther north in the lee of the Cascades, gusty downslope and gap winds may also support brief elevated fire-weather potential as stronger flow aloft develops. However, some humidity recovery will eventually occur as marine influence will increase with time, potentially limiting the coverage and duration of fire-weather concerns. ...Dry Thunderstorms... Isolated to widely scattered thunderstorms are likely to be ongoing early in the period as the cold core of the upper trough moves inland over the Northwest. As lift from the upper trough and mid-level moisture move inland, additional storms may develop into the afternoon atop warm and dry low levels. Forecast soundings suggest mid/high-level cloud cover and some potential for smoke to limit heating and diurnal storm coverage. Still, isolated storm potential, along with dry low levels and storm motions greater than 20 kt will likely support a risk for dry thunderstorms atop receptive fuels. Confidence in dry thunderstorm coverage is greatest across portions of the northern and central Cascades, into eastern ID and far southwestern MT. Scattered thunderstorms are also possible farther across the southern Great Basin and southern CA. Displaced from the stronger flow aloft, and with access to more robust monsoon moisture, slower storm speeds and a wetter storm mode are expected. Still, a few drier lightning strikes will remain possible atop mostly receptive fuel beds. ...Please see www.spc.noaa.gov/fire for graphic product... Read more