SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0138 PM CDT Tue Oct 01 2024 Valid 021200Z - 031200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN WYOMING... An Elevated risk area has been introduced to portions of the mid-Missouri River Valley into the upper Mississippi River Valley. Latest forecast guidance has come into better agreement regarding wind speeds and RH reductions ahead of the approaching cold front. Moisture return within the dry return pattern will be minimal and should allow RH reductions well into the 20-25% range. Sustained winds between 15-25 mph should be common and will support elevated fire weather concerns. An additional Elevated risk area was considered along the SD/ND border into eastern ND within the post-frontal regime. However, deterministic and ensemble guidance shows somewhat more spread/less certainty regarding the timing of the front and the degree of post-frontal RH reductions. Trends will continue to be monitored and additional highlights may be needed. ..Moore.. 10/01/2024 .PREV DISCUSSION... /ISSUED 0156 AM CDT Tue Oct 01 2024/ ...Synopsis... An elongated mid-level jet will extend along the US/Canada border on Wednesday. At the surface, a cold front will move through the Plains with a weak surface low developing in the central Plains Wednesday night. Ahead of this front, some dry and breezy conditions are expected from the Texas/Oklahoma Panhandle to the Upper Midwest. However, the majority of this region lacks dry fuels. Therefore, no Elevated area is justified in this region. An Elevated area has been drawn similar to the prior Day3 40% outlook across southern Wyoming where fuels are critically dry. Sustained winds of 25 to 30 mph are expected, as mid-level flow strengthens and a deeply-mixed airmass permits some of this stronger flow to reach the surface. Single-digit relative humidity is also expected across this region on Wednesday afternoon. Given the upper-end critical conditions expected, a Critical area has been added within the broader Elevated, where these conditions are expected to overlap the driest fuels across southeast Wyoming. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1144 AM CDT Tue Oct 01 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Discussion... Quasi-zonal flow aloft will prevail across most of the northern half of the U.S. Wednesday, while weak ridging affects the southern half of the country. A remnant cold front extending from the western Atlantic into the Gulf of Mexico will keep the moist/tropical airmass suppressed, with a dry airmass expected across the U.S. away from the Atlantic and Gulf Coast states. Thunderstorm potential will remain similarly suppressed, mainly near and south of the cold front across the Florida Peninsula. Very weak lower to middle tropospheric flow across this area precludes any appreciable severe risk. Elsewhere, thunderstorms are not anticipated. ..Goss.. 10/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Tue Oct 01 2024 Valid 011630Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. Scattered afternoon and evening thunderstorms will be possible over parts of the FL peninsula, and over eastern NC/southeast VA. Ample low-level moisture is present in these areas, along with strong daytime heating. However, poor mid-level lapse rates and weak wind fields below 4km will limit the intensity of storms, with no severe activity expected. Showers and a few thunderstorms will affect the central/eastern Great Lakes region today/tonight as a cold front sweeps across the area. Weak instability will preclude organized severe concerns. A few thunderstorms are expected later today over parts of southern AZ, western NM, and southern CO. While the strongest cells could produce gusty winds over southern AZ, no organized severe activity is expected. ..Hart/Weinman.. 10/01/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1022 AM CDT Tue Oct 01 2024 Valid 011700Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR FAR EASTERN MONTANA INTO WESTERN NORTH DAKOTA... The previous forecast remains on track with surface observations showing strengthening winds across central MT and parts of western ND as a surface low begins to deepen across southern SK. This trend will continue as the low deepens further across the southern Canadian Prairies this afternoon. Both the Elevated and Critical risk areas were expanded eastward with this update based on recent 12 UTC guidance, which suggests the axis of stronger 925-850 mb winds (and by extension the corridor with the strongest surface gusts) may be displaced slightly further east than previously anticipated and centered over the western to central Dakotas by peak heating. The 12 UTC GGW sounding sampled these stronger winds just above the nocturnal inversion; elevated to critical fire weather conditions should begin by around 18 UTC as this inversion is mixed out. See the previous discussion below for additional details. ..Moore.. 10/01/2024 .PREV DISCUSSION... /ISSUED 0153 AM CDT Tue Oct 01 2024/ ...Synopsis... A strong area of high pressure will initially dominate the pattern across the western 2/3rds of the CONUS for the first half of the day today. However, by midday lee troughing will start to strengthen across Alberta. This will tighten the pressure gradient across the northern Rockies and northern High Plains and result in gusty winds across Montana, the western Dakotas, and into the Nebraska Panhandle/northeast Colorado. The greatest confidence in 20+ mph sustained winds and low relative humidity, in the vicinity of dry fuels, is across eastern Montana and western North Dakota where the Critical delineation is present. Some strong winds are also possible across north-central Montana where relative humidity is expected to be in the low 20s. However, despite conditions that will likely meet Critical criteria, fuels are not that dry across this region and thus, an Elevated area is likely sufficient for the threat. An additional area of dry and breezy conditions is present across southern Wyoming, where winds of 15 to 20 mph are possible with single digit relative humidity. Finally, quite substantial dry and breezy conditions, meeting Critical criteria, are expected across southwest New Mexico and southeast Arizona. However, fuels in this region are not dry enough to support a significant fire threat. Therefore, no Elevated or Critical areas are warranted. ...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 1022 AM CDT Tue Oct 01 2024 Valid 011700Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR FAR EASTERN MONTANA INTO WESTERN NORTH DAKOTA... The previous forecast remains on track with surface observations showing strengthening winds across central MT and parts of western ND as a surface low begins to deepen across southern SK. This trend will continue as the low deepens further across the southern Canadian Prairies this afternoon. Both the Elevated and Critical risk areas were expanded eastward with this update based on recent 12 UTC guidance, which suggests the axis of stronger 925-850 mb winds (and by extension the corridor with the strongest surface gusts) may be displaced slightly further east than previously anticipated and centered over the western to central Dakotas by peak heating. The 12 UTC GGW sounding sampled these stronger winds just above the nocturnal inversion; elevated to critical fire weather conditions should begin by around 18 UTC as this inversion is mixed out. See the previous discussion below for additional details. ..Moore.. 10/01/2024 .PREV DISCUSSION... /ISSUED 0153 AM CDT Tue Oct 01 2024/ ...Synopsis... A strong area of high pressure will initially dominate the pattern across the western 2/3rds of the CONUS for the first half of the day today. However, by midday lee troughing will start to strengthen across Alberta. This will tighten the pressure gradient across the northern Rockies and northern High Plains and result in gusty winds across Montana, the western Dakotas, and into the Nebraska Panhandle/northeast Colorado. The greatest confidence in 20+ mph sustained winds and low relative humidity, in the vicinity of dry fuels, is across eastern Montana and western North Dakota where the Critical delineation is present. Some strong winds are also possible across north-central Montana where relative humidity is expected to be in the low 20s. However, despite conditions that will likely meet Critical criteria, fuels are not that dry across this region and thus, an Elevated area is likely sufficient for the threat. An additional area of dry and breezy conditions is present across southern Wyoming, where winds of 15 to 20 mph are possible with single digit relative humidity. Finally, quite substantial dry and breezy conditions, meeting Critical criteria, are expected across southwest New Mexico and southeast Arizona. However, fuels in this region are not dry enough to support a significant fire threat. Therefore, no Elevated or Critical areas are warranted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0725 AM CDT Tue Oct 01 2024 Valid 011300Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...Synopsis... In mid/upper levels, the main belt of westerlies is expected to remain near the Canadian border through the period, extending across more of the Great Lakes with time. That will occur as a synoptic- scale trough -- evident in moisture-channel imagery from a low over westernmost parts of Hudson Bay across northwestern ON to the upper Mississippi Valley -- ejects northeastward over northern ON, and James and Hudson Bays, through the period. This stronger flow will remain well poleward of thunder potential today near a weakening/ ejecting trough over the Tidewater region, south of a weak front over FL, and under or south of a weakening synoptic ridge over parts of CO/NM/AZ. Vertical shear and lapse rates aloft will be too weak in any of those areas to support organized severe potential. Locally strong gusts may accompany the high-based convection in AZ, with a deep/well-mixed subcloud layer, but only modest (5-15 kt) midlevel easterlies. A cold front sweeping across the Great Lakes, Ohio Valley, lower Mississippi Valley, and southern Plains, should encounter a marginally moist/unstable airmass for isolated thunder, within a band of convection over parts of the eastern Great Lakes. ..Edwards/Dean.. 10/01/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0725 AM CDT Tue Oct 01 2024 Valid 011300Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...Synopsis... In mid/upper levels, the main belt of westerlies is expected to remain near the Canadian border through the period, extending across more of the Great Lakes with time. That will occur as a synoptic- scale trough -- evident in moisture-channel imagery from a low over westernmost parts of Hudson Bay across northwestern ON to the upper Mississippi Valley -- ejects northeastward over northern ON, and James and Hudson Bays, through the period. This stronger flow will remain well poleward of thunder potential today near a weakening/ ejecting trough over the Tidewater region, south of a weak front over FL, and under or south of a weakening synoptic ridge over parts of CO/NM/AZ. Vertical shear and lapse rates aloft will be too weak in any of those areas to support organized severe potential. Locally strong gusts may accompany the high-based convection in AZ, with a deep/well-mixed subcloud layer, but only modest (5-15 kt) midlevel easterlies. A cold front sweeping across the Great Lakes, Ohio Valley, lower Mississippi Valley, and southern Plains, should encounter a marginally moist/unstable airmass for isolated thunder, within a band of convection over parts of the eastern Great Lakes. ..Edwards/Dean.. 10/01/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0319 AM CDT Tue Oct 01 2024 Valid 041200Z - 091200Z ...DISCUSSION... Recent model guidance has come into better agreement with regard to the upper-level pattern this weekend into early next week. As zonal flow begins to break down this Friday, an upper-level trough will dig southeastward and strengthen. Though conditional and uncertain, some severe threat could develop in association with this trough. After this trough exits the East Coast, ridging aloft and at the surface is expected to develop in its wake. On Saturday, a cold front will move through the Upper Midwest. Some moisture return is possible on the western flank of the surface ridge, but the quality of this moisture is highly uncertain. Wind fields would support organized storms in parts of the upper Mississippi Valley, but predictability remains quite low. For Sunday, the upper-level trough will continue southeastward with some intensification expected, especially towards Monday morning. A similar setup to Saturday will occur in parts of the upper Ohio Valley region. The strongest shear will likely be post-frontal, but some stronger storms could develop along the front during the afternoon. Moisture return ahead of the boundary remains a question and will be the key to severe potential. A strong mid-level jet will dig into the Mid-Atlantic Monday morning. Given the misaligned timing of the trough with diurnal heating, it is not clear that sufficient buoyancy will be present for an organized severe threat. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0319 AM CDT Tue Oct 01 2024 Valid 041200Z - 091200Z ...DISCUSSION... Recent model guidance has come into better agreement with regard to the upper-level pattern this weekend into early next week. As zonal flow begins to break down this Friday, an upper-level trough will dig southeastward and strengthen. Though conditional and uncertain, some severe threat could develop in association with this trough. After this trough exits the East Coast, ridging aloft and at the surface is expected to develop in its wake. On Saturday, a cold front will move through the Upper Midwest. Some moisture return is possible on the western flank of the surface ridge, but the quality of this moisture is highly uncertain. Wind fields would support organized storms in parts of the upper Mississippi Valley, but predictability remains quite low. For Sunday, the upper-level trough will continue southeastward with some intensification expected, especially towards Monday morning. A similar setup to Saturday will occur in parts of the upper Ohio Valley region. The strongest shear will likely be post-frontal, but some stronger storms could develop along the front during the afternoon. Moisture return ahead of the boundary remains a question and will be the key to severe potential. A strong mid-level jet will dig into the Mid-Atlantic Monday morning. Given the misaligned timing of the trough with diurnal heating, it is not clear that sufficient buoyancy will be present for an organized severe threat. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0208 AM CDT Tue Oct 01 2024 Valid 031200Z - 041200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...Synopsis... Generally zonal flow aloft is expected to continue across the northern CONUS. Upper-level ridging will remain in place across the central/southern CONUS. At the surface, a weakening cold front will be positioned along the Gulf Coast into northern Florida. A secondary, stronger cold front will move southward into the central Plains extending northeastward into the Midwest. Typical diurnally driven thunderstorms are expected in parts of the Florida Peninsula. Towards Friday morning, a very weak disturbance moving northward through the central Gulf may promote additional thunderstorms from southeastern Louisiana into the Florida Panhandle. Some elevated instability is possible near the cold front in northern Missouri as mid-level cooling and modest 850 mb moistening occurs. Given the weak low-level jet and limited moisture, convective development appears unlikely. ..Wendt.. 10/01/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Tue Oct 01 2024 Valid 021200Z - 031200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHEAST WYOMING... ...Synopsis... An elongated mid-level jet will extend along the US/Canada border on Wednesday. At the surface, a cold front will move through the Plains with a weak surface low developing in the central Plains Wednesday night. Ahead of this front, some dry and breezy conditions are expected from the Texas/Oklahoma Panhandle to the Upper Midwest. However, the majority of this region lacks dry fuels. Therefore, no Elevated area is justified in this region. An Elevated area has been drawn similar to the prior Day3 40% outlook across southern Wyoming where fuels are critically dry. Sustained winds of 25 to 30 mph are expected, as mid-level flow strengthens and a deeply-mixed airmass permits some of this stronger flow to reach the surface. Single-digit relative humidity is also expected across this region on Wednesday afternoon. Given the upper-end critical conditions expected, a Critical area has been added within the broader Elevated, where these conditions are expected to overlap the driest fuels across southeast Wyoming. ..Bentley.. 10/01/2024 ...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 0153 AM CDT Tue Oct 01 2024 Valid 011200Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHEAST MONTANA INTO WESTERN NORTH DAKOTA... ...Synopsis... A strong area of high pressure will initially dominate the pattern across the western 2/3rds of the CONUS for the first half of the day today. However, by midday lee troughing will start to strengthen across Alberta. This will tighten the pressure gradient across the northern Rockies and northern High Plains and result in gusty winds across Montana, the western Dakotas, and into the Nebraska Panhandle/northeast Colorado. The greatest confidence in 20+ mph sustained winds and low relative humidity, in the vicinity of dry fuels, is across eastern Montana and western North Dakota where the Critical delineation is present. Some strong winds are also possible across north-central Montana where relative humidity is expected to be in the low 20s. However, despite conditions that will likely meet Critical criteria, fuels are not that dry across this region and thus, an Elevated area is likely sufficient for the threat. An additional area of dry and breezy conditions is present across southern Wyoming, where winds of 15 to 20 mph are possible with single digit relative humidity. Finally, quite substantial dry and breezy conditions, meeting Critical criteria, are expected across southwest New Mexico and southeast Arizona. However, fuels in this region are not dry enough to support a significant fire threat. Therefore, no Elevated or Critical areas are warranted. ..Bentley.. 10/01/2024 ...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 1158 PM CDT Mon Sep 30 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Synopsis... Zonal flow aloft will develop across the northern CONUS while upper-level ridging will be present in the south on Wednesday. Thunderstorms are most likely to occur in the Florida Peninsula where daytime heating of a moist airmass and lift from sea breeze boundaries should promote widely scattered to scattered coverage. Weak convection could develop along the Blue Ridge, but increasing ridging aloft through the day should keep thunderstorm potential well below 10%. Additional very isolated activity could develop along parts of the Mogollon Rim, but coverage should remain below 10% here as well. ..Wendt.. 10/01/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1158 PM CDT Mon Sep 30 2024 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Synopsis... Zonal flow aloft will develop across the northern CONUS while upper-level ridging will be present in the south on Wednesday. Thunderstorms are most likely to occur in the Florida Peninsula where daytime heating of a moist airmass and lift from sea breeze boundaries should promote widely scattered to scattered coverage. Weak convection could develop along the Blue Ridge, but increasing ridging aloft through the day should keep thunderstorm potential well below 10%. Additional very isolated activity could develop along parts of the Mogollon Rim, but coverage should remain below 10% here as well. ..Wendt.. 10/01/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1155 PM CDT Mon Sep 30 2024 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...Synopsis and Discussion... An upper ridge will extend from CA across the Four Corners region and into the southern Plains today, as multiple strong troughs develop across Canada. One such lead trough will affect parts of the upper MS Valley and Great Lakes, eventually weakening the upper ridge over the Northeast. Behind this feature, a broad belt of strong westerlies will develop across the Canadian Rockies, sinking south across the US/CN border late. At the surface, high pressure will affect much of the intermountain West and Plains, with falling pressures across MT during the late afternoon. This developing surface trough will move into the Dakotas overnight, but will remain free of thunderstorms due to dry air. Dry air behind a cold front associated with the aforementioned surface high will push east across the Midwest and toward the lower MS Valley late, further stabilizing the air mass. Strong ascent moving across Lower MI and toward the lower Great Lakes may be sufficient for a few thunderstorms along the cold front, despite limited instability. Otherwise, the most favorable environment for general thunderstorms will be from FL into the eastern Carolinas where upper 60s F to 70s F dewpoints will remain. Shear will weaken over the Southeast throughout the day, but daytime heating as well as areas of weak surface convergence may support scattered thunderstorms over the interior FL Peninsula and near the coastal Carolinas. ..Jewell/Bentley.. 10/01/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1155 PM CDT Mon Sep 30 2024 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...Synopsis and Discussion... An upper ridge will extend from CA across the Four Corners region and into the southern Plains today, as multiple strong troughs develop across Canada. One such lead trough will affect parts of the upper MS Valley and Great Lakes, eventually weakening the upper ridge over the Northeast. Behind this feature, a broad belt of strong westerlies will develop across the Canadian Rockies, sinking south across the US/CN border late. At the surface, high pressure will affect much of the intermountain West and Plains, with falling pressures across MT during the late afternoon. This developing surface trough will move into the Dakotas overnight, but will remain free of thunderstorms due to dry air. Dry air behind a cold front associated with the aforementioned surface high will push east across the Midwest and toward the lower MS Valley late, further stabilizing the air mass. Strong ascent moving across Lower MI and toward the lower Great Lakes may be sufficient for a few thunderstorms along the cold front, despite limited instability. Otherwise, the most favorable environment for general thunderstorms will be from FL into the eastern Carolinas where upper 60s F to 70s F dewpoints will remain. Shear will weaken over the Southeast throughout the day, but daytime heating as well as areas of weak surface convergence may support scattered thunderstorms over the interior FL Peninsula and near the coastal Carolinas. ..Jewell/Bentley.. 10/01/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0748 PM CDT Mon Sep 30 2024 Valid 010100Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected for the remainder of the period. ...Discussion... Thunderstorm activity over parts of the CONUS will continue to dwindle through tonight due to loss of heating and weak lift. Scattered storms persist over parts of VA and eastern NC, within a weak surface trough. Much of the unstable air has been overturned from earlier storms, and the gradually cooling boundary layer should preclude any severe chances here. Scattered storms also persist over parts of FL this evening, and a general decrease is expected here as well. To the west, isolated thunderstorms may continue for a couple hours over northeast NM and into the far western OK/TX Panhandles within a weak instability plume and near a cold front. ..Jewell.. 10/01/2024 Read more

No watches are valid as of Mon Sep 30 22:41:02 UTC 2024.

No Mesoscale Discussions are in effect as of Mon Sep 30 22:41:02 UTC 2024.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0334 PM CDT Mon Sep 30 2024 Valid 021200Z - 081200Z Fire weather concerns will persist intermittently through the extended period across the western half of the CONUS. Long-range ensemble guidance continues to show a general ridging pattern over the southern half of the country, which will continue to favor stronger mid/upper-level flow along the U.S./Canadian border. This regime will favor seasonal to above-normal temperatures for the Plains into the West and mostly dry conditions. Consequently, dry fuels will likely be maintained and gradually expand in coverage for many locations. Fire weather concerns will emerge as shortwave troughs embedded within the mean zonal flow (and their attendant surface lows/fronts) propagate across the northern CONUS. ...D3/Wednesday - Southern Wyoming... Strong zonal flow is expected to persist across the northern CONUS through late D3/Wednesday. This will maintain a downslope flow regime into the WY Basin with afternoon RH values forecast to reach into the teens to low 20s. Deterministic and ensemble guidance show a signal for 15-25 mph winds, and with ERCs generally near the 90th percentile, elevated to critical fire weather conditions appear likely. ...D3/Wednesday - Coastal Southern CA... Upper ridging over the Great Basin combined with a weak coastal low will promote a modest offshore flow regime across southern CA. Unseasonably hot temperatures will continue to dry fuels and maintain very dry conditions. Localized elevated fire weather conditions are possible - mainly within the higher coastal terrain - late Wednesday into early Thursday morning. ...D5/Friday - northern Great Basin... Latest water-vapor imagery reveals a broad upper trough over the central Pacific, which is forecast to reach the West Coast by D5/Friday. Stronger flow overspreading the Pacific Northwest will promote downslope winds and surface pressure falls in the lee of the Cascades/northern Sierra Nevada. While run-to-run trends continue to show some variability regarding the strength of the winds, recent European solutions, which typically under-forecast winds, align with latest GEFS wind probabilities and suggests fire weather concerns may emerge during D5/Friday afternoon. ...D6/Saturday - northern Rockies/High Plains... The upper trough that is forecast to reach the Pacific Northwest on D5/Friday is expected to migrate into the northern Plains through D6/Saturday. As this occurs, lee cyclogenesis is probable and should support strengthening low-level pressure gradient winds both ahead of and behind the primary surface trough/cold front. While some uncertainty remains regarding the degree of RH reductions across the region, very dry fuels already in place (ERCs well above the 90th percentile) combined with a strong wind signal hint that a fire concern is possible. Further adjustments/expansions into the Plains are possible as guidance continues to come into better alignment. ..Moore.. 09/30/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more