Severe Storms

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 PM CDT Mon Sep 02 2024 Valid 030100Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF NORTHEASTERN OREGON...SOUTHEASTERN WASHINGTON...CENTRAL IDAHO AND ADJACENT SOUTHWESTERN MONTANA... ...SUMMARY... Widely scattered strong to severe wind gusts remain possible near lingering thunderstorm activity across parts of the northern Intermountain Region through this evening. ...01Z Update... Lower/mid-tropospheric subsidence and drying are probably tending to suppress ongoing scattered thunderstorm development across the Great Basin into adjacent northern Intermountain Region. However, widely scattered stronger thunderstorm development remains possible into this evening, within favorable large-scale forcing for ascent in the exit region of a vigorous upper jet streak (including 70+ kt around 300 mb) nosing north-northeastward through eastern Oregon, and in the downstream lower/mid-level warm advection regime overspreading central Idaho. Even within this regime, higher precipitable water on the order of .7-.8 inches appears to be supporting only weak CAPE (e.g. little more than 100 J/kg of mixed-layer CAPE in the 03/00Z sounding from Boise, ID), and this is limiting the strength of the updrafts and associated precipitation, which in turn is limiting the strength of downdraft potential despite being rooted above a warm and deeply mixed boundary layer. The potential for stronger gusts, aided by downward mixing of higher momentum from aloft, seems likely to remain generally focused across the higher elevations of north central and northeastern Oregon into the mountains of central Idaho, before convection weakens later this evening. ..Kerr.. 09/03/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 PM CDT Mon Sep 02 2024 Valid 030100Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF NORTHEASTERN OREGON...SOUTHEASTERN WASHINGTON...CENTRAL IDAHO AND ADJACENT SOUTHWESTERN MONTANA... ...SUMMARY... Widely scattered strong to severe wind gusts remain possible near lingering thunderstorm activity across parts of the northern Intermountain Region through this evening. ...01Z Update... Lower/mid-tropospheric subsidence and drying are probably tending to suppress ongoing scattered thunderstorm development across the Great Basin into adjacent northern Intermountain Region. However, widely scattered stronger thunderstorm development remains possible into this evening, within favorable large-scale forcing for ascent in the exit region of a vigorous upper jet streak (including 70+ kt around 300 mb) nosing north-northeastward through eastern Oregon, and in the downstream lower/mid-level warm advection regime overspreading central Idaho. Even within this regime, higher precipitable water on the order of .7-.8 inches appears to be supporting only weak CAPE (e.g. little more than 100 J/kg of mixed-layer CAPE in the 03/00Z sounding from Boise, ID), and this is limiting the strength of the updrafts and associated precipitation, which in turn is limiting the strength of downdraft potential despite being rooted above a warm and deeply mixed boundary layer. The potential for stronger gusts, aided by downward mixing of higher momentum from aloft, seems likely to remain generally focused across the higher elevations of north central and northeastern Oregon into the mountains of central Idaho, before convection weakens later this evening. ..Kerr.. 09/03/2024 Read more

No watches are valid as of Mon Sep 2 22:32:01 UTC 2024.

No Mesoscale Discussions are in effect as of Mon Sep 2 22:32:01 UTC 2024.

MD 2043 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF EASTERN OREGON INTO NORTHEAST NEVADA AND WESTERN INTO CENTRAL IDAHO
Mesoscale Discussion 2043 NWS Storm Prediction Center Norman OK 0356 PM CDT Mon Sep 02 2024 Areas affected...portions of eastern Oregon into northeast Nevada and western into central Idaho Concerning...Severe potential...Watch unlikely Valid 022056Z - 022230Z Probability of Watch Issuance...5 percent SUMMARY...A couple of strong to severe gusts may accompany the deeper storm cores that manage to develop. Any severe threat that materializes should be sparse, and a WW issuance is not expected. DISCUSSION...A pronounced 500 mb vort max is currently traversing the CA/OR border, aiding in the ascent of marginally buoyant boundary-layer based parcels. MRMS mosaic radar imagery shows convective initiation underway from the lee of the Cascades toward eastern ID. These storms are developing atop a very dry boundary layer (evident via 50-60 F surface temperature/dewpoint spreads), with RAP forecast soundings showing inverted-v soundings extending up to 500 mb. As such, these storms will be high-based in nature. Strong mid-level flow is overspreading portions of the Interior West ahead of the approaching trough, contributing to 30+ kts of effective bulk shear. As such, a few storms may become marginally organized, capable producing strong to potentially severe gusts. However, severe potential is highly dependent on how vertically deep storm cores can become. The severe gust threat is expected to be sparse, and a WW issuance is not anticipated. ..Squitieri/Smith.. 09/02/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TFX...SLC...PIH...MSO...BOI...LKN...OTX...PDT... MFR... LAT...LON 44142133 44812118 45552062 46051987 46361816 45771419 44861296 43951263 41821330 40791411 40221486 40001533 40001577 40221636 40551693 41031717 41781741 42351781 42831848 43191920 43472024 43572053 44142133 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0454 PM CDT Mon Sep 02 2024 Valid 041200Z - 101200Z Fire concerns will remain low in the extended. High pressure will build in across the western US D3/Wednesday through D6/Saturday, with a warming and drying trend. As this occurs, monsoonal moisture will gradually shift southward with drying conditions extending into the desert Southwest through D5/Friday. Winds will remain mostly light where fuels are dry, keeping fire weather concerns low. Moisture will slowly begin to return northward by D7/Sun-D8/Mon. Across the High Plains, southerly flow will slowly bring moisture northward, with several disturbances will bringing occasional chances for rain and thunderstorm activity. This should bring some relief to very dry conditions and help improve status of fuels. Occasional post-frontal northwesterly breezes will be possible, but relative humidity looks to remain above critical thresholds. ..Thornton.. 09/02/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0454 PM CDT Mon Sep 02 2024 Valid 041200Z - 101200Z Fire concerns will remain low in the extended. High pressure will build in across the western US D3/Wednesday through D6/Saturday, with a warming and drying trend. As this occurs, monsoonal moisture will gradually shift southward with drying conditions extending into the desert Southwest through D5/Friday. Winds will remain mostly light where fuels are dry, keeping fire weather concerns low. Moisture will slowly begin to return northward by D7/Sun-D8/Mon. Across the High Plains, southerly flow will slowly bring moisture northward, with several disturbances will bringing occasional chances for rain and thunderstorm activity. This should bring some relief to very dry conditions and help improve status of fuels. Occasional post-frontal northwesterly breezes will be possible, but relative humidity looks to remain above critical thresholds. ..Thornton.. 09/02/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0454 PM CDT Mon Sep 02 2024 Valid 041200Z - 101200Z Fire concerns will remain low in the extended. High pressure will build in across the western US D3/Wednesday through D6/Saturday, with a warming and drying trend. As this occurs, monsoonal moisture will gradually shift southward with drying conditions extending into the desert Southwest through D5/Friday. Winds will remain mostly light where fuels are dry, keeping fire weather concerns low. Moisture will slowly begin to return northward by D7/Sun-D8/Mon. Across the High Plains, southerly flow will slowly bring moisture northward, with several disturbances will bringing occasional chances for rain and thunderstorm activity. This should bring some relief to very dry conditions and help improve status of fuels. Occasional post-frontal northwesterly breezes will be possible, but relative humidity looks to remain above critical thresholds. ..Thornton.. 09/02/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0454 PM CDT Mon Sep 02 2024 Valid 041200Z - 101200Z Fire concerns will remain low in the extended. High pressure will build in across the western US D3/Wednesday through D6/Saturday, with a warming and drying trend. As this occurs, monsoonal moisture will gradually shift southward with drying conditions extending into the desert Southwest through D5/Friday. Winds will remain mostly light where fuels are dry, keeping fire weather concerns low. Moisture will slowly begin to return northward by D7/Sun-D8/Mon. Across the High Plains, southerly flow will slowly bring moisture northward, with several disturbances will bringing occasional chances for rain and thunderstorm activity. This should bring some relief to very dry conditions and help improve status of fuels. Occasional post-frontal northwesterly breezes will be possible, but relative humidity looks to remain above critical thresholds. ..Thornton.. 09/02/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0454 PM CDT Mon Sep 02 2024 Valid 041200Z - 101200Z Fire concerns will remain low in the extended. High pressure will build in across the western US D3/Wednesday through D6/Saturday, with a warming and drying trend. As this occurs, monsoonal moisture will gradually shift southward with drying conditions extending into the desert Southwest through D5/Friday. Winds will remain mostly light where fuels are dry, keeping fire weather concerns low. Moisture will slowly begin to return northward by D7/Sun-D8/Mon. Across the High Plains, southerly flow will slowly bring moisture northward, with several disturbances will bringing occasional chances for rain and thunderstorm activity. This should bring some relief to very dry conditions and help improve status of fuels. Occasional post-frontal northwesterly breezes will be possible, but relative humidity looks to remain above critical thresholds. ..Thornton.. 09/02/2024 ...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 0250 PM CDT Mon Sep 02 2024 Valid 022000Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN GREAT BASIN AND THE NORTHWEST... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the interior Pacific Northwest may be capable of occasional strong to severe wind gusts this afternoon and evening. ...20Z Update... Minor adjustments were made to the general thunderstorm area to account for current observed trends. The remainder of the forecast is unchanged. See the previous discussion for additional details. ..Wendt.. 09/02/2024 .PREV DISCUSSION... /ISSUED 1118 AM CDT Mon Sep 02 2024/ ...Interior Pacific Northwest into the Northern Great Basin/Rockies... Water-vapor imagery this morning shows a closed low near the northern CA/southern OR coast. This upper feature will move east through OR and be situated along the OR/ID border by daybreak Tuesday. A belt of stronger flow (30-50 kt 500-mb winds) will move through the base of the larger-scale mid-level trough and overspread northern NV into southwestern ID and eastern OR this afternoon into the early evening. Large-scale ascent associated with the upper disturbance and the development of weak buoyancy (mainly via heating), will facilitate the development of isolated to scattered high-based thunderstorms beginning later this afternoon and persisting into the evening. Forecast soundings show large surface temperature-dewpoint spreads (50 degrees F) with 9+ degrees C lapse rates into the mid levels and a dry sub-cloud layer. Evaporative cooling of the more intense downdrafts will probably yield a risk for isolated 60-70 mph gusts before weakening later this evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 02 2024 Valid 022000Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN GREAT BASIN AND THE NORTHWEST... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the interior Pacific Northwest may be capable of occasional strong to severe wind gusts this afternoon and evening. ...20Z Update... Minor adjustments were made to the general thunderstorm area to account for current observed trends. The remainder of the forecast is unchanged. See the previous discussion for additional details. ..Wendt.. 09/02/2024 .PREV DISCUSSION... /ISSUED 1118 AM CDT Mon Sep 02 2024/ ...Interior Pacific Northwest into the Northern Great Basin/Rockies... Water-vapor imagery this morning shows a closed low near the northern CA/southern OR coast. This upper feature will move east through OR and be situated along the OR/ID border by daybreak Tuesday. A belt of stronger flow (30-50 kt 500-mb winds) will move through the base of the larger-scale mid-level trough and overspread northern NV into southwestern ID and eastern OR this afternoon into the early evening. Large-scale ascent associated with the upper disturbance and the development of weak buoyancy (mainly via heating), will facilitate the development of isolated to scattered high-based thunderstorms beginning later this afternoon and persisting into the evening. Forecast soundings show large surface temperature-dewpoint spreads (50 degrees F) with 9+ degrees C lapse rates into the mid levels and a dry sub-cloud layer. Evaporative cooling of the more intense downdrafts will probably yield a risk for isolated 60-70 mph gusts before weakening later this evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 02 2024 Valid 022000Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN GREAT BASIN AND THE NORTHWEST... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the interior Pacific Northwest may be capable of occasional strong to severe wind gusts this afternoon and evening. ...20Z Update... Minor adjustments were made to the general thunderstorm area to account for current observed trends. The remainder of the forecast is unchanged. See the previous discussion for additional details. ..Wendt.. 09/02/2024 .PREV DISCUSSION... /ISSUED 1118 AM CDT Mon Sep 02 2024/ ...Interior Pacific Northwest into the Northern Great Basin/Rockies... Water-vapor imagery this morning shows a closed low near the northern CA/southern OR coast. This upper feature will move east through OR and be situated along the OR/ID border by daybreak Tuesday. A belt of stronger flow (30-50 kt 500-mb winds) will move through the base of the larger-scale mid-level trough and overspread northern NV into southwestern ID and eastern OR this afternoon into the early evening. Large-scale ascent associated with the upper disturbance and the development of weak buoyancy (mainly via heating), will facilitate the development of isolated to scattered high-based thunderstorms beginning later this afternoon and persisting into the evening. Forecast soundings show large surface temperature-dewpoint spreads (50 degrees F) with 9+ degrees C lapse rates into the mid levels and a dry sub-cloud layer. Evaporative cooling of the more intense downdrafts will probably yield a risk for isolated 60-70 mph gusts before weakening later this evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 02 2024 Valid 022000Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN GREAT BASIN AND THE NORTHWEST... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the interior Pacific Northwest may be capable of occasional strong to severe wind gusts this afternoon and evening. ...20Z Update... Minor adjustments were made to the general thunderstorm area to account for current observed trends. The remainder of the forecast is unchanged. See the previous discussion for additional details. ..Wendt.. 09/02/2024 .PREV DISCUSSION... /ISSUED 1118 AM CDT Mon Sep 02 2024/ ...Interior Pacific Northwest into the Northern Great Basin/Rockies... Water-vapor imagery this morning shows a closed low near the northern CA/southern OR coast. This upper feature will move east through OR and be situated along the OR/ID border by daybreak Tuesday. A belt of stronger flow (30-50 kt 500-mb winds) will move through the base of the larger-scale mid-level trough and overspread northern NV into southwestern ID and eastern OR this afternoon into the early evening. Large-scale ascent associated with the upper disturbance and the development of weak buoyancy (mainly via heating), will facilitate the development of isolated to scattered high-based thunderstorms beginning later this afternoon and persisting into the evening. Forecast soundings show large surface temperature-dewpoint spreads (50 degrees F) with 9+ degrees C lapse rates into the mid levels and a dry sub-cloud layer. Evaporative cooling of the more intense downdrafts will probably yield a risk for isolated 60-70 mph gusts before weakening later this evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 02 2024 Valid 022000Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN GREAT BASIN AND THE NORTHWEST... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the interior Pacific Northwest may be capable of occasional strong to severe wind gusts this afternoon and evening. ...20Z Update... Minor adjustments were made to the general thunderstorm area to account for current observed trends. The remainder of the forecast is unchanged. See the previous discussion for additional details. ..Wendt.. 09/02/2024 .PREV DISCUSSION... /ISSUED 1118 AM CDT Mon Sep 02 2024/ ...Interior Pacific Northwest into the Northern Great Basin/Rockies... Water-vapor imagery this morning shows a closed low near the northern CA/southern OR coast. This upper feature will move east through OR and be situated along the OR/ID border by daybreak Tuesday. A belt of stronger flow (30-50 kt 500-mb winds) will move through the base of the larger-scale mid-level trough and overspread northern NV into southwestern ID and eastern OR this afternoon into the early evening. Large-scale ascent associated with the upper disturbance and the development of weak buoyancy (mainly via heating), will facilitate the development of isolated to scattered high-based thunderstorms beginning later this afternoon and persisting into the evening. Forecast soundings show large surface temperature-dewpoint spreads (50 degrees F) with 9+ degrees C lapse rates into the mid levels and a dry sub-cloud layer. Evaporative cooling of the more intense downdrafts will probably yield a risk for isolated 60-70 mph gusts before weakening later this evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 02 2024 Valid 022000Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN GREAT BASIN AND THE NORTHWEST... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the interior Pacific Northwest may be capable of occasional strong to severe wind gusts this afternoon and evening. ...20Z Update... Minor adjustments were made to the general thunderstorm area to account for current observed trends. The remainder of the forecast is unchanged. See the previous discussion for additional details. ..Wendt.. 09/02/2024 .PREV DISCUSSION... /ISSUED 1118 AM CDT Mon Sep 02 2024/ ...Interior Pacific Northwest into the Northern Great Basin/Rockies... Water-vapor imagery this morning shows a closed low near the northern CA/southern OR coast. This upper feature will move east through OR and be situated along the OR/ID border by daybreak Tuesday. A belt of stronger flow (30-50 kt 500-mb winds) will move through the base of the larger-scale mid-level trough and overspread northern NV into southwestern ID and eastern OR this afternoon into the early evening. Large-scale ascent associated with the upper disturbance and the development of weak buoyancy (mainly via heating), will facilitate the development of isolated to scattered high-based thunderstorms beginning later this afternoon and persisting into the evening. Forecast soundings show large surface temperature-dewpoint spreads (50 degrees F) with 9+ degrees C lapse rates into the mid levels and a dry sub-cloud layer. Evaporative cooling of the more intense downdrafts will probably yield a risk for isolated 60-70 mph gusts before weakening later this evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 02 2024 Valid 022000Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN GREAT BASIN AND THE NORTHWEST... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the interior Pacific Northwest may be capable of occasional strong to severe wind gusts this afternoon and evening. ...20Z Update... Minor adjustments were made to the general thunderstorm area to account for current observed trends. The remainder of the forecast is unchanged. See the previous discussion for additional details. ..Wendt.. 09/02/2024 .PREV DISCUSSION... /ISSUED 1118 AM CDT Mon Sep 02 2024/ ...Interior Pacific Northwest into the Northern Great Basin/Rockies... Water-vapor imagery this morning shows a closed low near the northern CA/southern OR coast. This upper feature will move east through OR and be situated along the OR/ID border by daybreak Tuesday. A belt of stronger flow (30-50 kt 500-mb winds) will move through the base of the larger-scale mid-level trough and overspread northern NV into southwestern ID and eastern OR this afternoon into the early evening. Large-scale ascent associated with the upper disturbance and the development of weak buoyancy (mainly via heating), will facilitate the development of isolated to scattered high-based thunderstorms beginning later this afternoon and persisting into the evening. Forecast soundings show large surface temperature-dewpoint spreads (50 degrees F) with 9+ degrees C lapse rates into the mid levels and a dry sub-cloud layer. Evaporative cooling of the more intense downdrafts will probably yield a risk for isolated 60-70 mph gusts before weakening later this evening. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/02/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Mon Sep 02 2024/ ...Synopsis... Fire weather concerns will continue into Tuesday as an upper wave (currently moving onshore along the northern CA coast) translates east across the northern Rockies. However, fire weather conditions are not expected to be as intense or widespread as compared to Monday across on either side of the continental divide. ...Nevada into Idaho... Portions of northeast NV and central ID are forecast to remain within the dry slot of the maturing upper-level low. This will maintain clear skies/warm conditions across the region, but will also support broad scale subsidence/drying and windy conditions across the region. Regional orographic influences - namely the Snake River Plain in eastern ID as well as the Independence and Ruby mountains of northeast NV, will augment the dry/windy conditions and should support several hours of elevated fire weather conditions. Isolated to scattered thunderstorms are also anticipated across northern ID, MT, and WY by late afternoon as the low shifts east. While a few dry thunderstorms are possible based on forecast thermal profiles, recent ensemble guidance shows a stronger signal for wetting rainfall compared to Monday, limiting confidence in the dry-lightning threat. ...Central/Northern Plains... A lee trough is expected to become established over the next 24 hours, but will see more substantial deepening through Tuesday afternoon amid increasing synoptic-scale ascent ahead of the approaching upper wave. This will result in not only strengthening westerly downslope flow across eastern WY, but will also bolster pressure gradient winds across central NE into SD. Recent ensemble guidance shows reasonably high confidence in maintaining at least a few hours of elevated fire weather conditions for both regions with 15-20 mph winds and RH reductions into the teens and low 20s. Persistent southerly flow overnight Monday into Tuesday will support some degree of moisture return into the Plains, which is expected to limit the spatial coverage of elevated fire weather conditions. That said, guidance typically struggles to accurately capture boundary-layer mixing/RH reductions in such return flow regimes, and fire weather conditions may be more widespread across NE/SD than currently depicted. ...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 0243 PM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/02/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Mon Sep 02 2024/ ...Synopsis... Fire weather concerns will continue into Tuesday as an upper wave (currently moving onshore along the northern CA coast) translates east across the northern Rockies. However, fire weather conditions are not expected to be as intense or widespread as compared to Monday across on either side of the continental divide. ...Nevada into Idaho... Portions of northeast NV and central ID are forecast to remain within the dry slot of the maturing upper-level low. This will maintain clear skies/warm conditions across the region, but will also support broad scale subsidence/drying and windy conditions across the region. Regional orographic influences - namely the Snake River Plain in eastern ID as well as the Independence and Ruby mountains of northeast NV, will augment the dry/windy conditions and should support several hours of elevated fire weather conditions. Isolated to scattered thunderstorms are also anticipated across northern ID, MT, and WY by late afternoon as the low shifts east. While a few dry thunderstorms are possible based on forecast thermal profiles, recent ensemble guidance shows a stronger signal for wetting rainfall compared to Monday, limiting confidence in the dry-lightning threat. ...Central/Northern Plains... A lee trough is expected to become established over the next 24 hours, but will see more substantial deepening through Tuesday afternoon amid increasing synoptic-scale ascent ahead of the approaching upper wave. This will result in not only strengthening westerly downslope flow across eastern WY, but will also bolster pressure gradient winds across central NE into SD. Recent ensemble guidance shows reasonably high confidence in maintaining at least a few hours of elevated fire weather conditions for both regions with 15-20 mph winds and RH reductions into the teens and low 20s. Persistent southerly flow overnight Monday into Tuesday will support some degree of moisture return into the Plains, which is expected to limit the spatial coverage of elevated fire weather conditions. That said, guidance typically struggles to accurately capture boundary-layer mixing/RH reductions in such return flow regimes, and fire weather conditions may be more widespread across NE/SD than currently depicted. ...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 0243 PM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/02/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Mon Sep 02 2024/ ...Synopsis... Fire weather concerns will continue into Tuesday as an upper wave (currently moving onshore along the northern CA coast) translates east across the northern Rockies. However, fire weather conditions are not expected to be as intense or widespread as compared to Monday across on either side of the continental divide. ...Nevada into Idaho... Portions of northeast NV and central ID are forecast to remain within the dry slot of the maturing upper-level low. This will maintain clear skies/warm conditions across the region, but will also support broad scale subsidence/drying and windy conditions across the region. Regional orographic influences - namely the Snake River Plain in eastern ID as well as the Independence and Ruby mountains of northeast NV, will augment the dry/windy conditions and should support several hours of elevated fire weather conditions. Isolated to scattered thunderstorms are also anticipated across northern ID, MT, and WY by late afternoon as the low shifts east. While a few dry thunderstorms are possible based on forecast thermal profiles, recent ensemble guidance shows a stronger signal for wetting rainfall compared to Monday, limiting confidence in the dry-lightning threat. ...Central/Northern Plains... A lee trough is expected to become established over the next 24 hours, but will see more substantial deepening through Tuesday afternoon amid increasing synoptic-scale ascent ahead of the approaching upper wave. This will result in not only strengthening westerly downslope flow across eastern WY, but will also bolster pressure gradient winds across central NE into SD. Recent ensemble guidance shows reasonably high confidence in maintaining at least a few hours of elevated fire weather conditions for both regions with 15-20 mph winds and RH reductions into the teens and low 20s. Persistent southerly flow overnight Monday into Tuesday will support some degree of moisture return into the Plains, which is expected to limit the spatial coverage of elevated fire weather conditions. That said, guidance typically struggles to accurately capture boundary-layer mixing/RH reductions in such return flow regimes, and fire weather conditions may be more widespread across NE/SD than currently depicted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more