SPC Day 3-8 Fire Weather Outlook
2024-06-25
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0348 PM CDT Mon Jun 24 2024 Valid 261200Z - 021200Z Confidence in critical fire weather conditions remains limited through the second half of the work week and into the upcoming weekend. However, at least low-end fire concerns are expected to persist across parts of the Great Basin. ...D3/Wednesday to D4/Thursday - northern Great Basin... Recent GOES water-vapor imagery reveals a upper low over the northern Pacific that is gradually approaching the Pacific Northwest. Concurrently, mid-level moisture is slowly streaming northward through central/southern CA. A combination of increasing moisture and ascent ahead of the wave should promote isolated to scattered showers and thunderstorms across the Pacific Northwest and parts of the Great Basin beginning early D3/Wed. Increasing low-level winds within the dry slot of the maturing low will promote dry/windy conditions in the lee of the northern Sierra Nevada. Recent ensemble guidance continues to show a signal for elevated to critical fire weather conditions across northwest NV and adjacent portions of OR; however, the extent of the fire weather threat may be conditional on morning rainfall amounts and sufficient clearing in the wake of morning showers/thunderstorms. The mid-level jet max is forecast to pass over the northern Great Basin/northern Rockies around peak heating on D4/Thur. The westerly downslope flow regime across much of NV and southern ID should continue to promote dry conditions, especially across areas that receive little rainfall in the preceding 24 hours. Ensemble solutions show a strong signal for 15+ mph winds, and drier solutions - notably the deterministic GFS as well as a few GEFS members - suggest winds may reach 20-30 mph as strong mid-level flow mixes to the surface. Consequently, elevated to critical fire weather conditions appear possible. ...D6/Saturday to D7/Sunday - Great Basin... Long-range ensembles and cluster analyses continue to suggest that a second, perhaps more amplified, upper wave will approach the Pacific Northwest/northern Great Basin during the D6/Sat to D7/Sun period. While spread in guidance is noted (and expected at this range), the overall synoptic regime implies increasing rain chances for the Pacific Northwest with fire weather potential across central NV into UT where drier/windier conditions are probable. Trends in this system will be monitored for potential fire concerns heading into the upcoming weekend. ..Moore.. 06/24/2024 ...Please see www.spc.noaa.gov/fire for graphic product...
SPC Jun 25, 2024 0100 UTC Day 1 Convective Outlook
2024-06-25
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0758 PM CDT Mon Jun 24 2024 Valid 250100Z - 251200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE UPPER MISSISSIPPI RIVER VALLEY... ...SUMMARY... Scattered severe thunderstorms are expected over parts of the Upper Midwest this evening and overnight. A corridor of potentially widespread destructive wind gusts could develop over parts of Minnesota into Wisconsin. ...01z Update Upper Midwest... Much of the previous forecast remains unchanged with only minor modifications. Several areas of scattered thunderstorms are ongoing over the northern Red River Valley and upper Midwest. Scattered supercells ahead of the occluded front over northern MN should continue eastward with a risk for damaging gusts and hail this evening before slowly weakening as they encounter decreasing buoyancy near Lake Superior. Farther south, complexities surrounding the isolated ongoing convection in southern WI and additional convective initiation of elevated storms near and north of the effective warm front remain substantial. Storms over southern WI appear likely to continue southeast on the fringes of the better ascent and buoyancy with a risk for damaging gusts and hail this evening. Observational data shows increasing low-level warm-air advection and upper-level ascent could support additional storm development this evening over portions of west-central MN with the potential for rapid upscale growth into a bowing MCS. Substantial spatial uncertainty is also evident in late afternoon CAM guidance, but most guidance now does indicate some form of relatively intense MCS forming along the front in the 02-04z time frame. With 5000-6000 J/kg MUCAPE and moderate effective shear in place, a swath of significant damaging winds remains possible over parts of eastern MN, and much of central/southern WI, though with substantial uncertainty. Will maintain level-3 Enhanced wind probabilities as is with minor adjustments to the level-2 Slight over lower MI where storms may persist through the end of the convective period. ...Carolinas... The cold front over the eastern US is slowly moving offshore this evening. Remaining storms have undergone a gradual decrease in coverage and intensity this evening with the cessation of diurnal heating and the weakening of broader-scale forcing for ascent. An isolated damaging gust could occur with the stronger storms centered near the NC/SC border, but the broader severe risk should continue to decrease below MRGL criteria after sunset. ..Lyons.. 06/25/2024
SPC Day 3-8 Fire Weather Outlook
2024-06-24
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0348 PM CDT Mon Jun 24 2024 Valid 261200Z - 021200Z Confidence in critical fire weather conditions remains limited through the second half of the work week and into the upcoming weekend. However, at least low-end fire concerns are expected to persist across parts of the Great Basin. ...D3/Wednesday to D4/Thursday - northern Great Basin... Recent GOES water-vapor imagery reveals a upper low over the northern Pacific that is gradually approaching the Pacific Northwest. Concurrently, mid-level moisture is slowly streaming northward through central/southern CA. A combination of increasing moisture and ascent ahead of the wave should promote isolated to scattered showers and thunderstorms across the Pacific Northwest and parts of the Great Basin beginning early D3/Wed. Increasing low-level winds within the dry slot of the maturing low will promote dry/windy conditions in the lee of the northern Sierra Nevada. Recent ensemble guidance continues to show a signal for elevated to critical fire weather conditions across northwest NV and adjacent portions of OR; however, the extent of the fire weather threat may be conditional on morning rainfall amounts and sufficient clearing in the wake of morning showers/thunderstorms. The mid-level jet max is forecast to pass over the northern Great Basin/northern Rockies around peak heating on D4/Thur. The westerly downslope flow regime across much of NV and southern ID should continue to promote dry conditions, especially across areas that receive little rainfall in the preceding 24 hours. Ensemble solutions show a strong signal for 15+ mph winds, and drier solutions - notably the deterministic GFS as well as a few GEFS members - suggest winds may reach 20-30 mph as strong mid-level flow mixes to the surface. Consequently, elevated to critical fire weather conditions appear possible. ...D6/Saturday to D7/Sunday - Great Basin... Long-range ensembles and cluster analyses continue to suggest that a second, perhaps more amplified, upper wave will approach the Pacific Northwest/northern Great Basin during the D6/Sat to D7/Sun period. While spread in guidance is noted (and expected at this range), the overall synoptic regime implies increasing rain chances for the Pacific Northwest with fire weather potential across central NV into UT where drier/windier conditions are probable. Trends in this system will be monitored for potential fire concerns heading into the upcoming weekend. ..Moore.. 06/24/2024 ...Please see www.spc.noaa.gov/fire for graphic product...
SPC Jun 24, 2024 2000 UTC Day 1 Convective Outlook
2024-06-24
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Mon Jun 24 2024 Valid 242000Z - 251200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN THE UPPER MS VALLEY ACROSS SOUTH WI... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SEPARATELY IN EAST NC... ...SUMMARY... Scattered severe thunderstorms are expected over parts of the Upper Midwest late this afternoon into tonight. A corridor of potentially widespread destructive wind gusts could develop over parts of Minnesota into Wisconsin. ...20Z Update... Overall forecast scenario remains valid with potential for an intense, bowing MCS this evening into tonight. With continued spatiotemporal differences among recent guidance for initial supercell development, confidence is below-average for further increases in severe probabilities along the north-northwest to south-southeast oriented MLCAPE gradient over the Upper MS Valley. In addition, the likely orientation of the MCS with respect to the instability gradient suggest the significant severe wind threat may be relatively confined owing to abundant warm-moist sector MLCIN to the west and diminishing instability to the east. The corridor previously highlighted, that is centered on a portion of the Upper MS Valley into south WI, remains the most probable zone for potentially destructive wind gusts. ..Grams.. 06/24/2024 .PREV DISCUSSION... /ISSUED 1131 AM CDT Mon Jun 24 2024/ ...Upper Midwest... A weakening MCS continues to track eastward across central MN, associated with a shortwave trough over southern Canada. Extreme instability will develop along the southern fringe of this MCS and accompanying cloud shield, with hot/humid conditions leading to MLCAPE values over 4500 J/kg by late afternoon across southwest MN. Very warm temperatures aloft will likely suppress convective development in this volatile air mass, but strengthening southwesterly low-level winds by early evening will enhance warm advection and likely lead to thunderstorms over central MN. Initial storms will be supercellular, with forecast soundings showing ample low level and deep-layer shear to support a risk of very large hail, damaging winds, and a few tornadoes. As the evening progresses, most morning CAM solutions indicate that the cluster of supercells will grow upscale into a fast moving bowing MCS. However, there is considerable diversity regarding the track of the most intense storms. Given the very warm temperatures aloft, it seems likely the storms will track southeastward along the thermal gradient - across central/southern WI and into northern IL. The potential exists for a corridor of widespread and occasionally significant (exceeding 65 kt) wind damage, so have upgraded to ENH. The low-level air mass will become increasingly less unstable as the storms move across Lake Michigan and into northern IN by early Tue morning, suggesting a weakening trend. ...Central High Plains... Scattered high-based showers and thunderstorms are expected to develop over the central Rockies and Black Hills today and spread eastward into parts of SD/NE/KS. Hot surface temperatures and inverted-v profiles will support a risk of gusty/damaging winds with this activity for a few hours early this evening. ...Eastern NC/SC... A surface front is sagging southeastward across NC today, with a very moist and moderately unstable air mass in place ahead of the front. Thunderstorms are expected to form in this environment, with sufficient westerly flow aloft to help organize the storms and promote a risk of damaging wind gusts. Given the amount of heating that is occurring in eastern NC, and morning guidance showing substantial coverage of storms, have added a SLGT risk for parts of this area.
SPC Day 1 Fire Weather Outlook
2024-06-24
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1041 AM CDT Mon Jun 24 2024 Valid 241700Z - 251200Z The previous forecast remains on track with only minor adjustments needed. Latest surface observations are in line with morning model solutions, which depict dry conditions but slightly weaker winds compared to yesterday (which yielded predominantly elevated fire weather conditions). See the previous discussion below for additional details. ..Moore.. 06/24/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Mon Jun 24 2024/ ...Synopsis... An upper-level trough will continue eastward into the Northern Plains today. Upper-level winds across the Northwest into the northern Great Basin will remain modestly strong into the afternoon. Similarly, a modestly strong surface pressure gradient will remain across these areas before weakening overnight. ...OR/CA/NV into Snake River Plain... Though surface winds will be slightly weaker than on Sunday, 15-20 mph winds can generally be expected given the lingering presence of the synoptic features described earlier. Stronger winds do appear probable in the Snake River Plain due to terrain effects and favorable orientation of the mid-level winds. RH of 15-20% will be common by the afternoon. Elevated fire weather is expected with the greatest potential for locally critical conditions in the Snake River Plain. ...Please see www.spc.noaa.gov/fire for graphic product...
SPC Day 2 Fire Weather Outlook
2024-06-24
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0218 PM CDT Mon Jun 24 2024 Valid 251200Z - 261200Z ...NO CRITICAL AREAS... The previous forecast remains on track. Recent high-res ensemble guidance continues to suggest the potential for elevated fire weather conditions across northwest NV into southern/southeast OR; however, increasing mid/high-level cloud cover should modulate diurnal RH reductions across this region. Thunderstorm development remains probable across the western to central Great Basin late Tuesday into early Wednesday as a plume of 1.0+ inch PWAT values (already noted in GOES imagery over southern CA) migrates northward ahead of an approaching mid-level wave. While some dilution of this moisture is expected over the next 24 hours, model solutions and forecast soundings suggest that most thunderstorms should produce wetting rainfall. Consequently, confidence in the dry lightning threat remains limited. ..Moore.. 06/24/2024 .PREV DISCUSSION... /ISSUED 0137 AM CDT Mon Jun 24 2024/ ...Synopsis... An upper-level ridge will build into the Great Basin and extend into the Northwest on Tuesday. Overall, mid-level winds will be weaker across these areas than on previous days. There is some potential for subtle shortwave troughs within the flow to enhance winds in parts of northwest Nevada and southeast Oregon. An upper-level trough will approach the Northwest late in the period. The surface pressure pattern will be rather nebulous for much of the day. A surface low will deepen within the Columbia Basin vicinity, but this will primarily occur during the evening/overnight. At this time, only locally elevated fire weather conditions are expected from parts of northern Nevada into southeast Oregon and southern Idaho. A plume of mid-level moisture will push farther north and west as well. A weak shortwave trough is expected to promote thunderstorms along the Sierra Front in Nevada. The areas where confidence in storm coverage is highest will see an increase in PWAT values to near/over an inch. Drier storms could occur farther east in an area where mid-level moisture is less, but confidence in coverage is also much lower. ...Please see www.spc.noaa.gov/fire for graphic product...