Aggregator

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0350 AM CDT Thu Jul 11 2024 Valid 141200Z - 191200Z ...DISCUSSION... An upper-level ridge will remain in place over much of the western and central CONUS through at least early next week. Multiple mid-level impulses are expected to traverse the anticyclonic flow over the northern CONUS through at least Days 4-5 (Sunday-Monday). These impulses may be accompanied by multiple rounds of strong to severe thunderstorms given continued low-level WAA/moisture advection along the eastern periphery of a regenerating EML. By days 6-7 (Tuesday-Wednesday), a mid-level trough will amplify over the Great Lakes, with a surface cold front expected to sweep southward across the northern Plains into the Northeast, promoting showers and thunderstorms (perhaps strong to severe), but also clearing out the low-level moisture, EML, and associated buoyancy in the process. ...Days 4-5 (Sunday-Monday)... Medium-range guidance consensus shows a mid-level impulse approaching the Great Lakes region from the northern Plains on Sunday (albeit later than earlier model runs). While both the latest ECMWF and GFS agree on the mid-level impulse overspreading the nose of the WAA (and associated 3000-4000 J/kg MUCAPE) over the Upper MS Valley on Sunday, the later arrival of the mid-level impulse past peak afternoon heating results in a complex forecast. The GFS depicts potential convection over the northern Great Lakes by late afternoon/early evening while the ECMWF develops precipitation over central/southern MN that rapidly progress to the WI/IL border. While it is unclear which scenario will unfold, both regimes involve organized convection traversing an axis of strong to extreme instability amid adequate deep-layer shear to support a severe threat. This includes the possibility of a severe-wind producing MCS, warranting a broad 15 percent area. Substantial modifications may be needed to this highlight in later outlooks as mesoscale details and associated placement of key baroclinic boundaries becomes evident. The latest ECMWF and GFS depicts a more pronounced mid-level trough traversing the Upper MS Valley by afternoon peak heating on Day 5 (Monday). Continued low-level moisture advection from the south, beneath a regenerating plume of steep mid-level lapse rates from the west, will support another day of strong to extreme instability overspreading the Upper Midwest. This time, stronger deep-layer shear with the better-timed mid-level impulse will coincide with the instability axis, fostering an environment favorable for severe storms. Given impacts from Day 4 (Sunday) convection, it is unclear how and where mesoscale low-level boundaries will become established over the Midwest, and these will be key to supporting a severe threat (including the possibility of severe wind-producing bow-echo MCSs). 15 percent highlights have been added over the general area where both the GFS and ECMWF agree on precipitation occurring with overlapping favorable vertical wind shear and strong/extreme instability. Like Sunday though, the highlights provided for Monday will likely need substantial modification based on later-known placement of important mesoscale meteorological features. ...Days 6-7 (Tuesday-Wednesday)... ECMWF and GFS are in general agreement in thunderstorms initiating along and ahead of a surface cold front, anywhere from the northern Plains to the Northeast states in the Days 6-7 (Tuesday-Wednesday) time frame. These storms would traverse a buoyancy axis, possibly becoming strong or even severe in the process. However, great uncertainty exists on precisely where and when the greatest severe threat would materialize, since there is more disagreement among medium-range guidance members compared to earlier days. Furthermore, details on severe placement and timing still hinge on the evolution of earlier thunderstorm events (i.e. where baroclinic boundaries are left behind). When taking into account both model disagreements and uncertainties of preceding convective influences, severe probabilities have been withheld this outlook. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0350 AM CDT Thu Jul 11 2024 Valid 141200Z - 191200Z ...DISCUSSION... An upper-level ridge will remain in place over much of the western and central CONUS through at least early next week. Multiple mid-level impulses are expected to traverse the anticyclonic flow over the northern CONUS through at least Days 4-5 (Sunday-Monday). These impulses may be accompanied by multiple rounds of strong to severe thunderstorms given continued low-level WAA/moisture advection along the eastern periphery of a regenerating EML. By days 6-7 (Tuesday-Wednesday), a mid-level trough will amplify over the Great Lakes, with a surface cold front expected to sweep southward across the northern Plains into the Northeast, promoting showers and thunderstorms (perhaps strong to severe), but also clearing out the low-level moisture, EML, and associated buoyancy in the process. ...Days 4-5 (Sunday-Monday)... Medium-range guidance consensus shows a mid-level impulse approaching the Great Lakes region from the northern Plains on Sunday (albeit later than earlier model runs). While both the latest ECMWF and GFS agree on the mid-level impulse overspreading the nose of the WAA (and associated 3000-4000 J/kg MUCAPE) over the Upper MS Valley on Sunday, the later arrival of the mid-level impulse past peak afternoon heating results in a complex forecast. The GFS depicts potential convection over the northern Great Lakes by late afternoon/early evening while the ECMWF develops precipitation over central/southern MN that rapidly progress to the WI/IL border. While it is unclear which scenario will unfold, both regimes involve organized convection traversing an axis of strong to extreme instability amid adequate deep-layer shear to support a severe threat. This includes the possibility of a severe-wind producing MCS, warranting a broad 15 percent area. Substantial modifications may be needed to this highlight in later outlooks as mesoscale details and associated placement of key baroclinic boundaries becomes evident. The latest ECMWF and GFS depicts a more pronounced mid-level trough traversing the Upper MS Valley by afternoon peak heating on Day 5 (Monday). Continued low-level moisture advection from the south, beneath a regenerating plume of steep mid-level lapse rates from the west, will support another day of strong to extreme instability overspreading the Upper Midwest. This time, stronger deep-layer shear with the better-timed mid-level impulse will coincide with the instability axis, fostering an environment favorable for severe storms. Given impacts from Day 4 (Sunday) convection, it is unclear how and where mesoscale low-level boundaries will become established over the Midwest, and these will be key to supporting a severe threat (including the possibility of severe wind-producing bow-echo MCSs). 15 percent highlights have been added over the general area where both the GFS and ECMWF agree on precipitation occurring with overlapping favorable vertical wind shear and strong/extreme instability. Like Sunday though, the highlights provided for Monday will likely need substantial modification based on later-known placement of important mesoscale meteorological features. ...Days 6-7 (Tuesday-Wednesday)... ECMWF and GFS are in general agreement in thunderstorms initiating along and ahead of a surface cold front, anywhere from the northern Plains to the Northeast states in the Days 6-7 (Tuesday-Wednesday) time frame. These storms would traverse a buoyancy axis, possibly becoming strong or even severe in the process. However, great uncertainty exists on precisely where and when the greatest severe threat would materialize, since there is more disagreement among medium-range guidance members compared to earlier days. Furthermore, details on severe placement and timing still hinge on the evolution of earlier thunderstorm events (i.e. where baroclinic boundaries are left behind). When taking into account both model disagreements and uncertainties of preceding convective influences, severe probabilities have been withheld this outlook. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 AM CDT Thu Jul 11 2024 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Multiple clusters of strong to severe thunderstorms are possible across portions of the Northern Plains into the Upper Mississippi Valley on Saturday. ...Synopsis... A mid-level anticylone, centered over the central Rockies, will promote upper ridging from the Interior West to the MS Valley on Saturday. The first in a series of pronounced mid-level impulses is poised to pivot around the anticyclone and rapidly traverse the northern Plains and Upper MS Valley through the period. Rich low-level moisture, aided by widespread WAA beneath an EML, will precede the arrival of the mid-level impulse, resulting in strong to extreme buoyancy becoming established over the northern Plains and Upper MS Valley. The capping inversion associated with the EML makes it difficult to pinpoint precisely where and when the greatest severe threat will be. Nonetheless, at least a few clusters of strong to severe storms should evolve across the north-central CONUS on Saturday. ...Northern Plains into the Upper MS Valley... Surface lee troughing over the Plains will continue to foster low-level WAA, ushering in mid to upper 70s F surface dewpoints beneath an eastward-advecting plume of 7-8 C/km mid-level lapse rates from the EML. This thermodynamic regime will support 3000-5000 J/kg of MUCAPE from the Dakotas eastward to the MS River. However, accompanying this strong to locally extreme instability is an appreciable amount of MLCINH, which is typical for EML plumes pivoting around a synoptic scale anticyclone. The aforementioned approaching mid-level impulse cresting the upper ridge is expected to reach the MT/ND border by around 00Z and reach the MS River by 12Z. The point where the mid-level impulse overspreads the rich low-level moisture, along with the east-northeastern terminus of the low-level WAA regime, appear to be the most likely regions for convective initiation. Peak afternoon heating, along with low-level convergence at the WAA terminus, may support the initiation of multicellular clusters over parts of eastern IA into IL sometime during the mid-afternoon to early evening time frame. Given modest vertical wind shear, cold-pool mergers could support upscale growth into one or more MCSs that will approach Lake Michigan, accompanied by at least isolated severe wind or hail. Around sunset, additional storms may develop across northern and eastern MN into western WI, perhaps driven by isentropic lift. Since these storms will traverse the periphery of greater instability amid modest vertical wind shear, it is unclear how severe these storms will become, though at least isolated severe hail and/or wind is plausible. Finally, thunderstorms may initiate as far west as the MT/ND border or even adjacent parts of Canada by early evening. This severe threat is the most conditional of all scenarios. Should capping be overcome, the storms will initiate west of an elongated axis of strong to extreme instability, amid at least 30 kts of effective bulk shear. The storms will be initially displaced west of the richer low-level moisture, hence they would be high-based in nature, accompanied by primarily a severe gust threat. Though less likely, if these storms can congeal into an organized MCS, the MCS could become longer-lived and pose a threat for a more focused corridor of severe gusts. ..Squitieri.. 07/11/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 AM CDT Thu Jul 11 2024 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Multiple clusters of strong to severe thunderstorms are possible across portions of the Northern Plains into the Upper Mississippi Valley on Saturday. ...Synopsis... A mid-level anticylone, centered over the central Rockies, will promote upper ridging from the Interior West to the MS Valley on Saturday. The first in a series of pronounced mid-level impulses is poised to pivot around the anticyclone and rapidly traverse the northern Plains and Upper MS Valley through the period. Rich low-level moisture, aided by widespread WAA beneath an EML, will precede the arrival of the mid-level impulse, resulting in strong to extreme buoyancy becoming established over the northern Plains and Upper MS Valley. The capping inversion associated with the EML makes it difficult to pinpoint precisely where and when the greatest severe threat will be. Nonetheless, at least a few clusters of strong to severe storms should evolve across the north-central CONUS on Saturday. ...Northern Plains into the Upper MS Valley... Surface lee troughing over the Plains will continue to foster low-level WAA, ushering in mid to upper 70s F surface dewpoints beneath an eastward-advecting plume of 7-8 C/km mid-level lapse rates from the EML. This thermodynamic regime will support 3000-5000 J/kg of MUCAPE from the Dakotas eastward to the MS River. However, accompanying this strong to locally extreme instability is an appreciable amount of MLCINH, which is typical for EML plumes pivoting around a synoptic scale anticyclone. The aforementioned approaching mid-level impulse cresting the upper ridge is expected to reach the MT/ND border by around 00Z and reach the MS River by 12Z. The point where the mid-level impulse overspreads the rich low-level moisture, along with the east-northeastern terminus of the low-level WAA regime, appear to be the most likely regions for convective initiation. Peak afternoon heating, along with low-level convergence at the WAA terminus, may support the initiation of multicellular clusters over parts of eastern IA into IL sometime during the mid-afternoon to early evening time frame. Given modest vertical wind shear, cold-pool mergers could support upscale growth into one or more MCSs that will approach Lake Michigan, accompanied by at least isolated severe wind or hail. Around sunset, additional storms may develop across northern and eastern MN into western WI, perhaps driven by isentropic lift. Since these storms will traverse the periphery of greater instability amid modest vertical wind shear, it is unclear how severe these storms will become, though at least isolated severe hail and/or wind is plausible. Finally, thunderstorms may initiate as far west as the MT/ND border or even adjacent parts of Canada by early evening. This severe threat is the most conditional of all scenarios. Should capping be overcome, the storms will initiate west of an elongated axis of strong to extreme instability, amid at least 30 kts of effective bulk shear. The storms will be initially displaced west of the richer low-level moisture, hence they would be high-based in nature, accompanied by primarily a severe gust threat. Though less likely, if these storms can congeal into an organized MCS, the MCS could become longer-lived and pose a threat for a more focused corridor of severe gusts. ..Squitieri.. 07/11/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 AM CDT Thu Jul 11 2024 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Multiple clusters of strong to severe thunderstorms are possible across portions of the Northern Plains into the Upper Mississippi Valley on Saturday. ...Synopsis... A mid-level anticylone, centered over the central Rockies, will promote upper ridging from the Interior West to the MS Valley on Saturday. The first in a series of pronounced mid-level impulses is poised to pivot around the anticyclone and rapidly traverse the northern Plains and Upper MS Valley through the period. Rich low-level moisture, aided by widespread WAA beneath an EML, will precede the arrival of the mid-level impulse, resulting in strong to extreme buoyancy becoming established over the northern Plains and Upper MS Valley. The capping inversion associated with the EML makes it difficult to pinpoint precisely where and when the greatest severe threat will be. Nonetheless, at least a few clusters of strong to severe storms should evolve across the north-central CONUS on Saturday. ...Northern Plains into the Upper MS Valley... Surface lee troughing over the Plains will continue to foster low-level WAA, ushering in mid to upper 70s F surface dewpoints beneath an eastward-advecting plume of 7-8 C/km mid-level lapse rates from the EML. This thermodynamic regime will support 3000-5000 J/kg of MUCAPE from the Dakotas eastward to the MS River. However, accompanying this strong to locally extreme instability is an appreciable amount of MLCINH, which is typical for EML plumes pivoting around a synoptic scale anticyclone. The aforementioned approaching mid-level impulse cresting the upper ridge is expected to reach the MT/ND border by around 00Z and reach the MS River by 12Z. The point where the mid-level impulse overspreads the rich low-level moisture, along with the east-northeastern terminus of the low-level WAA regime, appear to be the most likely regions for convective initiation. Peak afternoon heating, along with low-level convergence at the WAA terminus, may support the initiation of multicellular clusters over parts of eastern IA into IL sometime during the mid-afternoon to early evening time frame. Given modest vertical wind shear, cold-pool mergers could support upscale growth into one or more MCSs that will approach Lake Michigan, accompanied by at least isolated severe wind or hail. Around sunset, additional storms may develop across northern and eastern MN into western WI, perhaps driven by isentropic lift. Since these storms will traverse the periphery of greater instability amid modest vertical wind shear, it is unclear how severe these storms will become, though at least isolated severe hail and/or wind is plausible. Finally, thunderstorms may initiate as far west as the MT/ND border or even adjacent parts of Canada by early evening. This severe threat is the most conditional of all scenarios. Should capping be overcome, the storms will initiate west of an elongated axis of strong to extreme instability, amid at least 30 kts of effective bulk shear. The storms will be initially displaced west of the richer low-level moisture, hence they would be high-based in nature, accompanied by primarily a severe gust threat. Though less likely, if these storms can congeal into an organized MCS, the MCS could become longer-lived and pose a threat for a more focused corridor of severe gusts. ..Squitieri.. 07/11/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 AM CDT Thu Jul 11 2024 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Multiple clusters of strong to severe thunderstorms are possible across portions of the Northern Plains into the Upper Mississippi Valley on Saturday. ...Synopsis... A mid-level anticylone, centered over the central Rockies, will promote upper ridging from the Interior West to the MS Valley on Saturday. The first in a series of pronounced mid-level impulses is poised to pivot around the anticyclone and rapidly traverse the northern Plains and Upper MS Valley through the period. Rich low-level moisture, aided by widespread WAA beneath an EML, will precede the arrival of the mid-level impulse, resulting in strong to extreme buoyancy becoming established over the northern Plains and Upper MS Valley. The capping inversion associated with the EML makes it difficult to pinpoint precisely where and when the greatest severe threat will be. Nonetheless, at least a few clusters of strong to severe storms should evolve across the north-central CONUS on Saturday. ...Northern Plains into the Upper MS Valley... Surface lee troughing over the Plains will continue to foster low-level WAA, ushering in mid to upper 70s F surface dewpoints beneath an eastward-advecting plume of 7-8 C/km mid-level lapse rates from the EML. This thermodynamic regime will support 3000-5000 J/kg of MUCAPE from the Dakotas eastward to the MS River. However, accompanying this strong to locally extreme instability is an appreciable amount of MLCINH, which is typical for EML plumes pivoting around a synoptic scale anticyclone. The aforementioned approaching mid-level impulse cresting the upper ridge is expected to reach the MT/ND border by around 00Z and reach the MS River by 12Z. The point where the mid-level impulse overspreads the rich low-level moisture, along with the east-northeastern terminus of the low-level WAA regime, appear to be the most likely regions for convective initiation. Peak afternoon heating, along with low-level convergence at the WAA terminus, may support the initiation of multicellular clusters over parts of eastern IA into IL sometime during the mid-afternoon to early evening time frame. Given modest vertical wind shear, cold-pool mergers could support upscale growth into one or more MCSs that will approach Lake Michigan, accompanied by at least isolated severe wind or hail. Around sunset, additional storms may develop across northern and eastern MN into western WI, perhaps driven by isentropic lift. Since these storms will traverse the periphery of greater instability amid modest vertical wind shear, it is unclear how severe these storms will become, though at least isolated severe hail and/or wind is plausible. Finally, thunderstorms may initiate as far west as the MT/ND border or even adjacent parts of Canada by early evening. This severe threat is the most conditional of all scenarios. Should capping be overcome, the storms will initiate west of an elongated axis of strong to extreme instability, amid at least 30 kts of effective bulk shear. The storms will be initially displaced west of the richer low-level moisture, hence they would be high-based in nature, accompanied by primarily a severe gust threat. Though less likely, if these storms can congeal into an organized MCS, the MCS could become longer-lived and pose a threat for a more focused corridor of severe gusts. ..Squitieri.. 07/11/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0231 AM CDT Thu Jul 11 2024 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Multiple clusters of strong to severe thunderstorms are possible across portions of the Northern Plains into the Upper Mississippi Valley on Saturday. ...Synopsis... A mid-level anticylone, centered over the central Rockies, will promote upper ridging from the Interior West to the MS Valley on Saturday. The first in a series of pronounced mid-level impulses is poised to pivot around the anticyclone and rapidly traverse the northern Plains and Upper MS Valley through the period. Rich low-level moisture, aided by widespread WAA beneath an EML, will precede the arrival of the mid-level impulse, resulting in strong to extreme buoyancy becoming established over the northern Plains and Upper MS Valley. The capping inversion associated with the EML makes it difficult to pinpoint precisely where and when the greatest severe threat will be. Nonetheless, at least a few clusters of strong to severe storms should evolve across the north-central CONUS on Saturday. ...Northern Plains into the Upper MS Valley... Surface lee troughing over the Plains will continue to foster low-level WAA, ushering in mid to upper 70s F surface dewpoints beneath an eastward-advecting plume of 7-8 C/km mid-level lapse rates from the EML. This thermodynamic regime will support 3000-5000 J/kg of MUCAPE from the Dakotas eastward to the MS River. However, accompanying this strong to locally extreme instability is an appreciable amount of MLCINH, which is typical for EML plumes pivoting around a synoptic scale anticyclone. The aforementioned approaching mid-level impulse cresting the upper ridge is expected to reach the MT/ND border by around 00Z and reach the MS River by 12Z. The point where the mid-level impulse overspreads the rich low-level moisture, along with the east-northeastern terminus of the low-level WAA regime, appear to be the most likely regions for convective initiation. Peak afternoon heating, along with low-level convergence at the WAA terminus, may support the initiation of multicellular clusters over parts of eastern IA into IL sometime during the mid-afternoon to early evening time frame. Given modest vertical wind shear, cold-pool mergers could support upscale growth into one or more MCSs that will approach Lake Michigan, accompanied by at least isolated severe wind or hail. Around sunset, additional storms may develop across northern and eastern MN into western WI, perhaps driven by isentropic lift. Since these storms will traverse the periphery of greater instability amid modest vertical wind shear, it is unclear how severe these storms will become, though at least isolated severe hail and/or wind is plausible. Finally, thunderstorms may initiate as far west as the MT/ND border or even adjacent parts of Canada by early evening. This severe threat is the most conditional of all scenarios. Should capping be overcome, the storms will initiate west of an elongated axis of strong to extreme instability, amid at least 30 kts of effective bulk shear. The storms will be initially displaced west of the richer low-level moisture, hence they would be high-based in nature, accompanied by primarily a severe gust threat. Though less likely, if these storms can congeal into an organized MCS, the MCS could become longer-lived and pose a threat for a more focused corridor of severe gusts. ..Squitieri.. 07/11/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0201 AM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ..Dean.. 07/11/2024 ...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 0201 AM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ..Dean.. 07/11/2024 ...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 0201 AM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ..Dean.. 07/11/2024 ...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 0201 AM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ..Dean.. 07/11/2024 ...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 0201 AM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...Synopsis... Hot and dry conditions will persist across much of the West on Friday, due to a persistent mid/upper-level ridge covering much of the Great Basin into the Southwest and southern Rockies. A belt of modestly enhanced low/midlevel flow along the western/northern periphery of the ridge will continue to support potential for elevated to locally critical fire-weather conditions across parts of the interior Northwest. ...Parts of south-central/southeast OR into northeast CA/northwest NV... Guidance continues to vary somewhat regarding the strength of low-level flow across parts of OR into northeast CA/northwest NV on Friday. In general, west-southwesterly winds are expected to increase to 15-20 mph (with higher gusts) during the afternoon, as RH values drop near/below 10 percent, resulting in elevated to locally critical fire-weather conditions. ...Snake River Plain vicinity... A similar regime to D1/Thursday is expected on Friday across the Snake River Plain and vicinity, with elevated to locally critical fire-weather conditions likely during the afternoon and early evening. Relatively hot and dry conditions are again expected, with RH potentially dropping to near or below 10 percent during the afternoon. Guidance generally suggests that flow will be similar or perhaps slightly weaker compared to D1/Thursday, but still sufficiently strong to support sustained winds of 15-20 mph with higher gusts. ...Parts of the Sierra Nevada... Most guidance suggests a modest increase in moisture across parts of the Sierra Nevada on Friday, along the western periphery of the mid/upper-level ridge. Confidence is currently low regarding whether instability will become sufficient to support thunderstorm development, but some dry-thunderstorm potential cannot be ruled out during the afternoon/evening, and this area will continue to be monitored for potential inclusion of an isolated dry-thunderstorm area. ..Dean.. 07/11/2024 ...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 0200 AM CDT Thu Jul 11 2024 Valid 111200Z - 121200Z ...Synopsis... A mid/upper-level ridge will remain anchored over the Great Basin today, resulting in a continuation of very hot and dry conditions over much of the West. Multiple low-amplitude shortwave troughs will move along the western and northern periphery of the ridge, with a modest increase in low/midlevel flow expected from northern parts of the Great Basin into the interior Northwest. ...Snake River Plain of ID and vicinity... As flow gradually increases within a persistently hot and dry environment, several hours of elevated to locally critical conditions are expected across parts of the Snake River Plain and vicinity this afternoon into the early evening. Sustained winds are forecast to increase into the 15-20 mph range (with higher gusts), as RH potentially drops to near or below 10 percent. ...Northeast CA into northwest NV... A modest increase in low-level flow is also expected along the northwest periphery of the ridge, from parts of northeast CA into northwest NV. Sustained winds of 15-20 mph (with higher gusts) combined with hot and dry conditions (with RH falling below 10 percent) will result in elevated fire-weather conditions during the afternoon and early evening. ..Dean.. 07/11/2024 ...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 0200 AM CDT Thu Jul 11 2024 Valid 111200Z - 121200Z ...Synopsis... A mid/upper-level ridge will remain anchored over the Great Basin today, resulting in a continuation of very hot and dry conditions over much of the West. Multiple low-amplitude shortwave troughs will move along the western and northern periphery of the ridge, with a modest increase in low/midlevel flow expected from northern parts of the Great Basin into the interior Northwest. ...Snake River Plain of ID and vicinity... As flow gradually increases within a persistently hot and dry environment, several hours of elevated to locally critical conditions are expected across parts of the Snake River Plain and vicinity this afternoon into the early evening. Sustained winds are forecast to increase into the 15-20 mph range (with higher gusts), as RH potentially drops to near or below 10 percent. ...Northeast CA into northwest NV... A modest increase in low-level flow is also expected along the northwest periphery of the ridge, from parts of northeast CA into northwest NV. Sustained winds of 15-20 mph (with higher gusts) combined with hot and dry conditions (with RH falling below 10 percent) will result in elevated fire-weather conditions during the afternoon and early evening. ..Dean.. 07/11/2024 ...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 0200 AM CDT Thu Jul 11 2024 Valid 111200Z - 121200Z ...Synopsis... A mid/upper-level ridge will remain anchored over the Great Basin today, resulting in a continuation of very hot and dry conditions over much of the West. Multiple low-amplitude shortwave troughs will move along the western and northern periphery of the ridge, with a modest increase in low/midlevel flow expected from northern parts of the Great Basin into the interior Northwest. ...Snake River Plain of ID and vicinity... As flow gradually increases within a persistently hot and dry environment, several hours of elevated to locally critical conditions are expected across parts of the Snake River Plain and vicinity this afternoon into the early evening. Sustained winds are forecast to increase into the 15-20 mph range (with higher gusts), as RH potentially drops to near or below 10 percent. ...Northeast CA into northwest NV... A modest increase in low-level flow is also expected along the northwest periphery of the ridge, from parts of northeast CA into northwest NV. Sustained winds of 15-20 mph (with higher gusts) combined with hot and dry conditions (with RH falling below 10 percent) will result in elevated fire-weather conditions during the afternoon and early evening. ..Dean.. 07/11/2024 ...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 0200 AM CDT Thu Jul 11 2024 Valid 111200Z - 121200Z ...Synopsis... A mid/upper-level ridge will remain anchored over the Great Basin today, resulting in a continuation of very hot and dry conditions over much of the West. Multiple low-amplitude shortwave troughs will move along the western and northern periphery of the ridge, with a modest increase in low/midlevel flow expected from northern parts of the Great Basin into the interior Northwest. ...Snake River Plain of ID and vicinity... As flow gradually increases within a persistently hot and dry environment, several hours of elevated to locally critical conditions are expected across parts of the Snake River Plain and vicinity this afternoon into the early evening. Sustained winds are forecast to increase into the 15-20 mph range (with higher gusts), as RH potentially drops to near or below 10 percent. ...Northeast CA into northwest NV... A modest increase in low-level flow is also expected along the northwest periphery of the ridge, from parts of northeast CA into northwest NV. Sustained winds of 15-20 mph (with higher gusts) combined with hot and dry conditions (with RH falling below 10 percent) will result in elevated fire-weather conditions during the afternoon and early evening. ..Dean.. 07/11/2024 ...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 0200 AM CDT Thu Jul 11 2024 Valid 111200Z - 121200Z ...Synopsis... A mid/upper-level ridge will remain anchored over the Great Basin today, resulting in a continuation of very hot and dry conditions over much of the West. Multiple low-amplitude shortwave troughs will move along the western and northern periphery of the ridge, with a modest increase in low/midlevel flow expected from northern parts of the Great Basin into the interior Northwest. ...Snake River Plain of ID and vicinity... As flow gradually increases within a persistently hot and dry environment, several hours of elevated to locally critical conditions are expected across parts of the Snake River Plain and vicinity this afternoon into the early evening. Sustained winds are forecast to increase into the 15-20 mph range (with higher gusts), as RH potentially drops to near or below 10 percent. ...Northeast CA into northwest NV... A modest increase in low-level flow is also expected along the northwest periphery of the ridge, from parts of northeast CA into northwest NV. Sustained winds of 15-20 mph (with higher gusts) combined with hot and dry conditions (with RH falling below 10 percent) will result in elevated fire-weather conditions during the afternoon and early evening. ..Dean.. 07/11/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... A couple instances of severe gusts and perhaps hail are possible across the northern High Plains tomorrow (Friday). ...Synopsis... Multiple impulses embedded in deamplifying cyclonic flow will traverse the OH Valley into the Northeast as an upper-level anticyclone dominates the Interior West and begins to impinge on the Plains States tomorrow (Friday). While surface high pressure should remain in place across much of the Intermountain West tomorrow, surface lee troughing over the Plains will encourage a broad fetch of rich low-level moisture across the MS Valley, which will continue to advect northward through the period. By afternoon, thunderstorms should develop over the northern High Plains. Given the increased low-level moisture and modest deep-layer shear, a few thunderstorms may become strong to severe. ...Northern High Plains... By afternoon peak heating, a warm, well-mixed boundary layer will become established across the northern High Plains, that in tandem with the passing of a weak mid-level impulse pivoting around the anticyclone, will support convective initiation. Forecast soundings show the mixed boundary layer (and corresponding 9+ C/km lapse rates) extending above 700 mb, suggesting that these storms should be high-based in nature. Stronger flow aloft pivoting around the anticyclone with the mid-level impulse should result in elongated hodographs and subsequent potential for organized multicells capable of a few severe gusts. An instance or two of hail may also accompany the stronger storms cores in ND, where mid-level flow best coincides with richer low-level moisture. Strong WAA should continue across the northern Plains overnight, potentially supporting the initiation of additional thunderstorms over central ND. Some of the latest guidance suggests that a southward-propagating MCS could develop. However, nocturnal static stability should also be settling in, so it is unclear how prevalent severe gusts could become. An east-southeastward expansion of severe probabilities may be needed in future outlooks if the risk of a more organized MCS becomes apparent. ..Squitieri.. 07/11/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... A couple instances of severe gusts and perhaps hail are possible across the northern High Plains tomorrow (Friday). ...Synopsis... Multiple impulses embedded in deamplifying cyclonic flow will traverse the OH Valley into the Northeast as an upper-level anticyclone dominates the Interior West and begins to impinge on the Plains States tomorrow (Friday). While surface high pressure should remain in place across much of the Intermountain West tomorrow, surface lee troughing over the Plains will encourage a broad fetch of rich low-level moisture across the MS Valley, which will continue to advect northward through the period. By afternoon, thunderstorms should develop over the northern High Plains. Given the increased low-level moisture and modest deep-layer shear, a few thunderstorms may become strong to severe. ...Northern High Plains... By afternoon peak heating, a warm, well-mixed boundary layer will become established across the northern High Plains, that in tandem with the passing of a weak mid-level impulse pivoting around the anticyclone, will support convective initiation. Forecast soundings show the mixed boundary layer (and corresponding 9+ C/km lapse rates) extending above 700 mb, suggesting that these storms should be high-based in nature. Stronger flow aloft pivoting around the anticyclone with the mid-level impulse should result in elongated hodographs and subsequent potential for organized multicells capable of a few severe gusts. An instance or two of hail may also accompany the stronger storms cores in ND, where mid-level flow best coincides with richer low-level moisture. Strong WAA should continue across the northern Plains overnight, potentially supporting the initiation of additional thunderstorms over central ND. Some of the latest guidance suggests that a southward-propagating MCS could develop. However, nocturnal static stability should also be settling in, so it is unclear how prevalent severe gusts could become. An east-southeastward expansion of severe probabilities may be needed in future outlooks if the risk of a more organized MCS becomes apparent. ..Squitieri.. 07/11/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Thu Jul 11 2024 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... A couple instances of severe gusts and perhaps hail are possible across the northern High Plains tomorrow (Friday). ...Synopsis... Multiple impulses embedded in deamplifying cyclonic flow will traverse the OH Valley into the Northeast as an upper-level anticyclone dominates the Interior West and begins to impinge on the Plains States tomorrow (Friday). While surface high pressure should remain in place across much of the Intermountain West tomorrow, surface lee troughing over the Plains will encourage a broad fetch of rich low-level moisture across the MS Valley, which will continue to advect northward through the period. By afternoon, thunderstorms should develop over the northern High Plains. Given the increased low-level moisture and modest deep-layer shear, a few thunderstorms may become strong to severe. ...Northern High Plains... By afternoon peak heating, a warm, well-mixed boundary layer will become established across the northern High Plains, that in tandem with the passing of a weak mid-level impulse pivoting around the anticyclone, will support convective initiation. Forecast soundings show the mixed boundary layer (and corresponding 9+ C/km lapse rates) extending above 700 mb, suggesting that these storms should be high-based in nature. Stronger flow aloft pivoting around the anticyclone with the mid-level impulse should result in elongated hodographs and subsequent potential for organized multicells capable of a few severe gusts. An instance or two of hail may also accompany the stronger storms cores in ND, where mid-level flow best coincides with richer low-level moisture. Strong WAA should continue across the northern Plains overnight, potentially supporting the initiation of additional thunderstorms over central ND. Some of the latest guidance suggests that a southward-propagating MCS could develop. However, nocturnal static stability should also be settling in, so it is unclear how prevalent severe gusts could become. An east-southeastward expansion of severe probabilities may be needed in future outlooks if the risk of a more organized MCS becomes apparent. ..Squitieri.. 07/11/2024 Read more