Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0246 PM CDT Wed Sep 20 2023 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER SOUTHEAST OKLAHOMA INTO NORTHEAST TEXAS...AND OVER PARTS OF THE NORTHERN GREAT BASIN... ...SUMMARY... Strong storms capable of hail and gusty winds are possible across parts of southeastern Oklahoma and northeast Texas through this evening. Gusty winds may also accompany a few storms over the northern Great Basin. ...OK/TX... A very conditional risk for a strong/severe storm through early evening continues across parts of southeast OK into northeast TX. The Marginal (level 1 of 5) risk area has been trimmed from portions of eastern OK into western AR and far northeast TX. Persistent clouds and showers/thunderstorms have limited heating much of the day. Southwestern portions of the Marginal risk area have largely cleared out this afternoon and allowed temperatures to warm into the upper 70s to mid 80s. However, quite a bit of inhibition remains. Furthermore, HRRR and RRFS guidance shows little convective development this afternoon/evening. Some cumulus development is noted closer to the I-35 corridor amid stronger instability and weaker inhibition. Nebulous large-scale ascent may be insufficient to overcome this inhibition. However, if a storm can develop near the western edge of the Marginal risk and track southeast along residual outflow, a risk for hail and strong gusts could occur for a few hours. ...NV/UT/ID/WY... No changes have been made with the 20z update. See previous discussion below for more details. ..Leitman.. 09/20/2023 .PREV DISCUSSION... /ISSUED 1109 AM CDT Wed Sep 20 2023/ ...OK/AR/TX/LA... A persistent nocturnal MCS is weakening over western AR, with clearing skies over eastern OK in its wake. Strong heating will help yield a moderately unstable air mass by late afternoon across southeastern OK, where there will be some chance of a thunderstorm or two. Effective shear values of 40-50 knots and steep mid-level lapse rates will support a risk of large hail and damaging winds in any persistent storm that develops. However, weakening large scale support and a residual cap suggest the risk of initiation is rather low in the primary instability region. ...NV/UT/ID/WY... A rather dynamic upper trough is digging quickly southeastward today across the Pacific Northwest region. This will allow large scale ascent to overspread much of the northern Great Basin by this afternoon. A corridor of mid-level moisture ahead of the trough extends from northern NV into northwest WY, and should be favorable for the development of scattered high-based showers and thunderstorms later today. Skies are currently clear in this region, allowing steep low-level lapse rates to develop. As winds aloft strengthen this afternoon, the potential will exist for gusty/damaging wind gusts in a few of the fast-moving storms. Read more

MD 2164 CONCERNING SEVERE THUNDERSTORM WATCH 686... FOR NORTHWEST TEXAS AND WESTERN OKLAHOMA.
Mesoscale Discussion 2164 NWS Storm Prediction Center Norman OK 0555 PM CDT Tue Sep 19 2023 Areas affected...Northwest Texas and western Oklahoma. Concerning...Severe Thunderstorm Watch 686... Valid 192255Z - 200030Z The severe weather threat for Severe Thunderstorm Watch 686 continues. SUMMARY...Increasing coverage and intensity of severe thunderstorms is expected through the evening. DISCUSSION...Showers which developed across the Texas Panhandle have intensified into supercells over the last hour as they moved into increasing instability (1500 J/kg MLCAPE). Effective shear of 40 to 45 knots per FDR VWP will continue to maintain the supercell threat through the evening. The long, relatively straight hodographs supports splitting supercells, the first of which has already occurred along the Texas/Oklahoma border east of Childress. Given moderate instability to the north of these ongoing storms, there may sufficient instability to support longer lived left-moving supercells capable of large to very large hail, particularly across southwest Oklahoma. ..Bentley.. 09/19/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD...OUN...SJT...LUB...AMA...MAF... LAT...LON 32900070 33680061 34800021 35779936 36029885 36059816 35919752 34969739 33669768 32809812 32579908 32900070 Read more

WW 0686 Status Updates
STATUS REPORT ON WW 686 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..KERR..09/19/23 ATTN...WFO...OUN...LUB...AMA...SJT...FWD... STATUS REPORT FOR WS 686 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS OKC009-011-015-017-031-033-039-043-051-055-057-065-067-073-075- 137-141-149-192340- OK . OKLAHOMA COUNTIES INCLUDED ARE BECKHAM BLAINE CADDO CANADIAN COMANCHE COTTON CUSTER DEWEY GRADY GREER HARMON JACKSON JEFFERSON KINGFISHER KIOWA STEPHENS TILLMAN WASHITA TXC009-023-075-077-087-101-125-151-155-191-197-207-237-253-263- 269-275-337-345-417-429-433-447-485-487-503-192340- TX . TEXAS COUNTIES INCLUDED ARE ARCHER BAYLOR CHILDRESS CLAY COLLINGSWORTH COTTLE DICKENS FISHER FOARD HALL HARDEMAN HASKELL JACK JONES KENT KING KNOX MONTAGUE Read more

WW 686 SEVERE TSTM OK TX 192145Z - 200400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 686 NWS Storm Prediction Center Norman OK 445 PM CDT Tue Sep 19 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Oklahoma Northwest Texas * Effective this Tuesday afternoon and evening from 445 PM until 1100 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Isolated severe thunderstorms are expected to develop through early evening and move southeast. Very large hail, possibly up to baseball size, and damaging winds will be possible. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 110 miles southwest of Wichita Falls TX to 60 miles north northeast of Clinton OK. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 28030. ...Bunting Read more

MD 2163 CONCERNING SEVERE THUNDERSTORM WATCH 686... FOR NORTH-CENTRAL TEXAS.
Mesoscale Discussion 2163 NWS Storm Prediction Center Norman OK 0520 PM CDT Tue Sep 19 2023 Areas affected...north-central Texas. Concerning...Severe Thunderstorm Watch 686... Valid 192220Z - 192345Z The severe weather threat for Severe Thunderstorm Watch 686 continues. SUMMARY...A supercell across north-central Texas could pose a large hail threat this evening. DISCUSSION...A supercell formed on the western periphery of mid-day elevated convection which moved east across north-central Texas. Given only weak CINH near this storm and its radar depiction over the last hour, this storm has likely rooted and is surface based in a region with around 1000 J/kg MLCAPE. 40+ knots of mid-level northwesterly flow (per FWD VWP) has yielded near 50 knots of effective shear. This environment will support supercells capable of large hail (potentially 2+ inches). If this storm continues to turn right, which it has started to do over the last 15 to 30 minutes, portions of at least the northern DFW metro area may be impacted by large to very large hail this evening. If this storm continues to maintain its current intensity or strengthen, an expansion of watch 686 may be needed. ..Bentley/Bunting.. 09/19/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD... LAT...LON 33649755 33609688 33189611 32739589 32469641 32599703 32869743 33099767 33269770 33649755 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0358 PM CDT Tue Sep 19 2023 Valid 211200Z - 271200Z On the backside of a midlevel cut-off low centered over portions of Oregon, a substantial mid/upper-level jet streak will overspread the West Coast on Day 3/Thursday. In the northern Sacramento Valley, boundary-layer mixing into the strong flow aloft, coupled with a tightening surface pressure gradient, will favor breezy/gusty surface winds and 10-15 percent RH on Day 3/Thursday. While this may yield elevated fire-weather conditions, confidence in the development of critical conditions is too low for probabilities at this time. Along the southeastern periphery of the midlevel low, strong deep-layer southwesterly flow will be in place across much of the Southwest into the central/southern Rockies on Days 3-5/Thursday-Saturday. A deeply mixed boundary layer across these areas will support 20+ mph sustained southwesterly surface winds and 15-20 percent RH. These meteorological conditions would typically warrant Critical probabilities, though ample rainfall and generally unreceptive fuels should limit the overall fire-weather threat. Beyond Day 5/Saturday, strong midlevel flow accompanying a mid/upper-level trough will overspread the northwestern CONUS, favoring strengthening surface winds across the region. While this may lead to an increase in fire-weather concerns, rainfall preceding this system and continued model disagreement limits confidence in the fire-weather threat. ..Weinman.. 09/19/2023 ...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 0358 PM CDT Tue Sep 19 2023 Valid 211200Z - 271200Z On the backside of a midlevel cut-off low centered over portions of Oregon, a substantial mid/upper-level jet streak will overspread the West Coast on Day 3/Thursday. In the northern Sacramento Valley, boundary-layer mixing into the strong flow aloft, coupled with a tightening surface pressure gradient, will favor breezy/gusty surface winds and 10-15 percent RH on Day 3/Thursday. While this may yield elevated fire-weather conditions, confidence in the development of critical conditions is too low for probabilities at this time. Along the southeastern periphery of the midlevel low, strong deep-layer southwesterly flow will be in place across much of the Southwest into the central/southern Rockies on Days 3-5/Thursday-Saturday. A deeply mixed boundary layer across these areas will support 20+ mph sustained southwesterly surface winds and 15-20 percent RH. These meteorological conditions would typically warrant Critical probabilities, though ample rainfall and generally unreceptive fuels should limit the overall fire-weather threat. Beyond Day 5/Saturday, strong midlevel flow accompanying a mid/upper-level trough will overspread the northwestern CONUS, favoring strengthening surface winds across the region. While this may lead to an increase in fire-weather concerns, rainfall preceding this system and continued model disagreement limits confidence in the fire-weather threat. ..Weinman.. 09/19/2023 ...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 0358 PM CDT Tue Sep 19 2023 Valid 211200Z - 271200Z On the backside of a midlevel cut-off low centered over portions of Oregon, a substantial mid/upper-level jet streak will overspread the West Coast on Day 3/Thursday. In the northern Sacramento Valley, boundary-layer mixing into the strong flow aloft, coupled with a tightening surface pressure gradient, will favor breezy/gusty surface winds and 10-15 percent RH on Day 3/Thursday. While this may yield elevated fire-weather conditions, confidence in the development of critical conditions is too low for probabilities at this time. Along the southeastern periphery of the midlevel low, strong deep-layer southwesterly flow will be in place across much of the Southwest into the central/southern Rockies on Days 3-5/Thursday-Saturday. A deeply mixed boundary layer across these areas will support 20+ mph sustained southwesterly surface winds and 15-20 percent RH. These meteorological conditions would typically warrant Critical probabilities, though ample rainfall and generally unreceptive fuels should limit the overall fire-weather threat. Beyond Day 5/Saturday, strong midlevel flow accompanying a mid/upper-level trough will overspread the northwestern CONUS, favoring strengthening surface winds across the region. While this may lead to an increase in fire-weather concerns, rainfall preceding this system and continued model disagreement limits confidence in the fire-weather threat. ..Weinman.. 09/19/2023 ...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 0358 PM CDT Tue Sep 19 2023 Valid 211200Z - 271200Z On the backside of a midlevel cut-off low centered over portions of Oregon, a substantial mid/upper-level jet streak will overspread the West Coast on Day 3/Thursday. In the northern Sacramento Valley, boundary-layer mixing into the strong flow aloft, coupled with a tightening surface pressure gradient, will favor breezy/gusty surface winds and 10-15 percent RH on Day 3/Thursday. While this may yield elevated fire-weather conditions, confidence in the development of critical conditions is too low for probabilities at this time. Along the southeastern periphery of the midlevel low, strong deep-layer southwesterly flow will be in place across much of the Southwest into the central/southern Rockies on Days 3-5/Thursday-Saturday. A deeply mixed boundary layer across these areas will support 20+ mph sustained southwesterly surface winds and 15-20 percent RH. These meteorological conditions would typically warrant Critical probabilities, though ample rainfall and generally unreceptive fuels should limit the overall fire-weather threat. Beyond Day 5/Saturday, strong midlevel flow accompanying a mid/upper-level trough will overspread the northwestern CONUS, favoring strengthening surface winds across the region. While this may lead to an increase in fire-weather concerns, rainfall preceding this system and continued model disagreement limits confidence in the fire-weather threat. ..Weinman.. 09/19/2023 ...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 Tue Sep 19 2023 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF OKLAHOMA...THE TEXAS BIG COUNTRY...AND NORTH-CENTRAL TEXAS... ...SUMMARY... Severe thunderstorms capable of large to very hail and damaging gusts are possible today and tonight across portions of Oklahoma and the Texas Big Country into north-central Texas. ...20Z Update... ...Much of OK into TX Big Country and North TX... Warm-air advection showers and thunderstorms continue in an arc from north-central OK into north-central TX. Temperatures immediately west of the this arc are in the low 80s, increasing into the upper 80s and low 90s farther west across western OK and adjacent portions of the TX Panhandle. This warming is expected to continue, fostering further destabilization ahead a subtle shortwave moving across the TX/OK Panhandles. Consequently, as outlined in the previous forecast, re-development is still anticipated across western OK and northwest TX later this afternoon/evening. These storms will then track eastward/northeastward into more of central OK and north-central TX. Moderate northwesterly flow aloft will contribute to 45-50 kt of effective shear, supporting the potential for organized updrafts capable of large to very large hail. Damaging gusts are possible with this activity as well, particularly if upscale growth into a forward-propagating line occurs. ..Mosier.. 09/19/2023 .PREV DISCUSSION... /ISSUED 1110 AM CDT Tue Sep 19 2023/ ...OK/North TX... Morning water vapor imagery loop shows multiple subtle mid-level vorticity maxima moving across the central Plains. The primary system is currently over southwest/south-central KS, and aided in rather widespread convection overnight across OK/KS. The back edge of stronger forcing associated with this feature is over western OK, with clear skies and southerly low-level winds back in place. By mid/late afternoon, strong heating will lead to a corridor of moderate CAPE across western OK into western North TX. A consensus of CAMS develop scattered thunderstorms along this axis, with storms persisting for a few hours and tracking into central OK and north-central TX. Forecast soundings show steep mid-level lapse rates and 40-50 knots of effective shear. This will support supercells capable of very large hail and damaging wind gusts. An isolated tornado or two is also possible. Model guidance is also consistent in developing storms in north-central OK this afternoon, just ahead of the upper system over KS. This area will see less heating/destabilization than farther south, but could also see a cluster of intense storms that move across northeast OK. Damaging winds and hail would be the main threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Tue Sep 19 2023 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF OKLAHOMA...THE TEXAS BIG COUNTRY...AND NORTH-CENTRAL TEXAS... ...SUMMARY... Severe thunderstorms capable of large to very hail and damaging gusts are possible today and tonight across portions of Oklahoma and the Texas Big Country into north-central Texas. ...20Z Update... ...Much of OK into TX Big Country and North TX... Warm-air advection showers and thunderstorms continue in an arc from north-central OK into north-central TX. Temperatures immediately west of the this arc are in the low 80s, increasing into the upper 80s and low 90s farther west across western OK and adjacent portions of the TX Panhandle. This warming is expected to continue, fostering further destabilization ahead a subtle shortwave moving across the TX/OK Panhandles. Consequently, as outlined in the previous forecast, re-development is still anticipated across western OK and northwest TX later this afternoon/evening. These storms will then track eastward/northeastward into more of central OK and north-central TX. Moderate northwesterly flow aloft will contribute to 45-50 kt of effective shear, supporting the potential for organized updrafts capable of large to very large hail. Damaging gusts are possible with this activity as well, particularly if upscale growth into a forward-propagating line occurs. ..Mosier.. 09/19/2023 .PREV DISCUSSION... /ISSUED 1110 AM CDT Tue Sep 19 2023/ ...OK/North TX... Morning water vapor imagery loop shows multiple subtle mid-level vorticity maxima moving across the central Plains. The primary system is currently over southwest/south-central KS, and aided in rather widespread convection overnight across OK/KS. The back edge of stronger forcing associated with this feature is over western OK, with clear skies and southerly low-level winds back in place. By mid/late afternoon, strong heating will lead to a corridor of moderate CAPE across western OK into western North TX. A consensus of CAMS develop scattered thunderstorms along this axis, with storms persisting for a few hours and tracking into central OK and north-central TX. Forecast soundings show steep mid-level lapse rates and 40-50 knots of effective shear. This will support supercells capable of very large hail and damaging wind gusts. An isolated tornado or two is also possible. Model guidance is also consistent in developing storms in north-central OK this afternoon, just ahead of the upper system over KS. This area will see less heating/destabilization than farther south, but could also see a cluster of intense storms that move across northeast OK. Damaging winds and hail would be the main threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Tue Sep 19 2023 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF OKLAHOMA...THE TEXAS BIG COUNTRY...AND NORTH-CENTRAL TEXAS... ...SUMMARY... Severe thunderstorms capable of large to very hail and damaging gusts are possible today and tonight across portions of Oklahoma and the Texas Big Country into north-central Texas. ...20Z Update... ...Much of OK into TX Big Country and North TX... Warm-air advection showers and thunderstorms continue in an arc from north-central OK into north-central TX. Temperatures immediately west of the this arc are in the low 80s, increasing into the upper 80s and low 90s farther west across western OK and adjacent portions of the TX Panhandle. This warming is expected to continue, fostering further destabilization ahead a subtle shortwave moving across the TX/OK Panhandles. Consequently, as outlined in the previous forecast, re-development is still anticipated across western OK and northwest TX later this afternoon/evening. These storms will then track eastward/northeastward into more of central OK and north-central TX. Moderate northwesterly flow aloft will contribute to 45-50 kt of effective shear, supporting the potential for organized updrafts capable of large to very large hail. Damaging gusts are possible with this activity as well, particularly if upscale growth into a forward-propagating line occurs. ..Mosier.. 09/19/2023 .PREV DISCUSSION... /ISSUED 1110 AM CDT Tue Sep 19 2023/ ...OK/North TX... Morning water vapor imagery loop shows multiple subtle mid-level vorticity maxima moving across the central Plains. The primary system is currently over southwest/south-central KS, and aided in rather widespread convection overnight across OK/KS. The back edge of stronger forcing associated with this feature is over western OK, with clear skies and southerly low-level winds back in place. By mid/late afternoon, strong heating will lead to a corridor of moderate CAPE across western OK into western North TX. A consensus of CAMS develop scattered thunderstorms along this axis, with storms persisting for a few hours and tracking into central OK and north-central TX. Forecast soundings show steep mid-level lapse rates and 40-50 knots of effective shear. This will support supercells capable of very large hail and damaging wind gusts. An isolated tornado or two is also possible. Model guidance is also consistent in developing storms in north-central OK this afternoon, just ahead of the upper system over KS. This area will see less heating/destabilization than farther south, but could also see a cluster of intense storms that move across northeast OK. Damaging winds and hail would be the main threat. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0153 PM CDT Tue Sep 19 2023 Valid 201200Z - 211200Z An Elevated area was added for portions of northern CA (including the northern/northwestern Sacramento Valley), far south-central OR, and far northwest NV. The latest high-resolution guidance and CANSAC WRF runs have come into reasonably good agreement, depicting the development of around 15 mph sustained northerly surface winds (with gusts upwards of 25 mph) and 15-25 percent RH during the afternoon/evening hours -- along the southern periphery of the cooler conditions to the north. For the northern/northwestern Sacramento Valley, the best overlap of breezy winds and reduced RH is expected from the evening into the overnight hours, with some uncertainty regarding RH reductions during this time frame. Given modestly receptive fuels across the area and possibly a few holdover fires from recent lightning activity, elevated fire-weather conditions are expected. ..Weinman.. 09/19/2023 .PREV DISCUSSION... /ISSUED 0117 AM CDT Tue Sep 19 2023/ ...Synopsis... Fire weather concerns are expected to be minimal on Wednesday. A mid-level trough will amplify across the Northwest and bring cool and moist conditions to much of this region. Farther south, dry and breezy conditions are expected across the Great Basin and Southwest as mid-level flow strengthens in the well-mixed environment. However fuels remain green in this region, which should preclude the potential for new large fires. ...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 0153 PM CDT Tue Sep 19 2023 Valid 201200Z - 211200Z An Elevated area was added for portions of northern CA (including the northern/northwestern Sacramento Valley), far south-central OR, and far northwest NV. The latest high-resolution guidance and CANSAC WRF runs have come into reasonably good agreement, depicting the development of around 15 mph sustained northerly surface winds (with gusts upwards of 25 mph) and 15-25 percent RH during the afternoon/evening hours -- along the southern periphery of the cooler conditions to the north. For the northern/northwestern Sacramento Valley, the best overlap of breezy winds and reduced RH is expected from the evening into the overnight hours, with some uncertainty regarding RH reductions during this time frame. Given modestly receptive fuels across the area and possibly a few holdover fires from recent lightning activity, elevated fire-weather conditions are expected. ..Weinman.. 09/19/2023 .PREV DISCUSSION... /ISSUED 0117 AM CDT Tue Sep 19 2023/ ...Synopsis... Fire weather concerns are expected to be minimal on Wednesday. A mid-level trough will amplify across the Northwest and bring cool and moist conditions to much of this region. Farther south, dry and breezy conditions are expected across the Great Basin and Southwest as mid-level flow strengthens in the well-mixed environment. However fuels remain green in this region, which should preclude the potential for new large fires. ...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 0153 PM CDT Tue Sep 19 2023 Valid 201200Z - 211200Z An Elevated area was added for portions of northern CA (including the northern/northwestern Sacramento Valley), far south-central OR, and far northwest NV. The latest high-resolution guidance and CANSAC WRF runs have come into reasonably good agreement, depicting the development of around 15 mph sustained northerly surface winds (with gusts upwards of 25 mph) and 15-25 percent RH during the afternoon/evening hours -- along the southern periphery of the cooler conditions to the north. For the northern/northwestern Sacramento Valley, the best overlap of breezy winds and reduced RH is expected from the evening into the overnight hours, with some uncertainty regarding RH reductions during this time frame. Given modestly receptive fuels across the area and possibly a few holdover fires from recent lightning activity, elevated fire-weather conditions are expected. ..Weinman.. 09/19/2023 .PREV DISCUSSION... /ISSUED 0117 AM CDT Tue Sep 19 2023/ ...Synopsis... Fire weather concerns are expected to be minimal on Wednesday. A mid-level trough will amplify across the Northwest and bring cool and moist conditions to much of this region. Farther south, dry and breezy conditions are expected across the Great Basin and Southwest as mid-level flow strengthens in the well-mixed environment. However fuels remain green in this region, which should preclude the potential for new large fires. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Mon Sep 18 22:31:02 UTC 2023.

No Mesoscale Discussions are in effect as of Mon Sep 18 22:31:02 UTC 2023.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0352 PM CDT Mon Sep 18 2023 Valid 201200Z - 261200Z A midlevel cut-off low will evolve southward from the Pacific Northwest into parts of the Great Basin on Days 3-4/ Wednesday-Thursday, as a substantial mid/upper-level jet streak advances southward along the Pacific Northwest coast. On the backside of the midlevel low, breezy northerly surface winds will develop over portions of OR, northern CA, and northwest NV on Day 3/Wednesday (and to a lesser extent on Day 4/Thursday). While the strengthening winds may influence any ongoing fires across the region, cool surface temperatures and limited RH reductions should generally limit the fire-weather threat. Along the southern and eastern peripheries of the midlevel low, strong deep-layer southwesterly flow will overspread parts of the Great Basin, the Southwest, the central/southern Rockies, and the central High Plains on Days 3-5/Wednesday-Friday. Deep boundary-layer mixing into the strong flow aloft will yield dry/breezy conditions across these areas. While these meteorological conditions would typically warrant Critical probabilities, above-average rainfall and generally unreceptive fuels cast uncertainty on the overall fire-weather risk. ..Weinman.. 09/18/2023 ...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 0251 PM CDT Mon Sep 18 2023 Valid 182000Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE TEXAS PANHANDLE AND SOUTH PLAINS...AND ADJACENT PORTIONS OF SOUTHEASTERN NEW MEXICO AND WESTERN OKLAHOMA... ...SUMMARY... Isolated, marginal severe wind and hail will be possible across the Texas Panhandle vicinity from about 5 to 9 PM CDT. ...Discussion... Aside from minor line adjustments, the reasoning regarding, and the areal extent of, the potential/isolated severe-weather threat for this afternoon and early evening across the Texas Panhandle/South Plains and vicinity remains consistent with prior outlooks. Thus, no major changes appear necessary at this time. ..Goss.. 09/18/2023 .PREV DISCUSSION... /ISSUED 1059 AM CDT Mon Sep 18 2023/ ...TX Panhandle... Clear skies are currently present across the TX Panhandle and western OK, where dewpoints are in the 50s to lower 60s and afternoon temperatures will approach 90F. The result will be a deeply mixed boundary layer with steep low-level lapse rates. A weak surface boundary will stretch across the region by late afternoon. Roughly half of the morning CAM solutions suggest widely scattered high-based thunderstorms will form along this boundary. Winds aloft are rather weak, so those cells that form will likely be rather disorganized and transient in intensity. However, the strongest cells could produce locally gusty winds and hail for a few hours early this evening. ...Elsewhere... Elsewhere, another mesoscale area of modest concern for strong storms would be over parts of eastern NE. If a storm or two can form in this area, gusty winds might be possible for a couple of hours. Finally, scattered high-based showers and thunderstorms may occur across much of the intermountain west today from MT/UT into the Four Corners region. Any cell in this area could produce a locally intense wind gust, but the overall coverage is expected to be low. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0201 PM CDT Mon Sep 18 2023 Valid 191200Z - 201200Z Minor adjustments were made to the northern Plains Elevated highlights based on the latest guidance consensus. Farther west, locally elevated conditions are possible across portions of southeast Oregon, the northern Cascade gaps, and the Columbia Basin. However, the overlap of breezy winds and low RH is generally limited for these areas -- precluding highlights. For additional details, see the previous discussion below. ..Weinman.. 09/18/2023 .PREV DISCUSSION... /ISSUED 0151 AM CDT Mon Sep 18 2023/ ...Synopsis... Some elevated fire weather concerns are possible on Tuesday across northeast Montana and northwest North Dakota. The mid-level shortwave trough, currently over the northeast Pacific which will traverse the Pacific Northwest today, will move into the northern Plains on Tuesday. As this occurs, the surface front/low-pressure center will start to accelerate east. As it departs, some strong westerly/northwesterly winds are expected to the west of the surface low. There is still considerable spread within guidance regarding how dry/breezy conditions will be in this region. RH ranges from 15 percent to 40 percent and winds range from 10 to 15 mph all the way to 25 to 30 mph. An Elevated delineation should cover this threat and its associated uncertainties for the time being with additional refinement likely needed in later outlooks as the forecast evolution becomes more clear. Elsewhere, no significant fire weather concerns are anticipated on Tuesday. ...Please see www.spc.noaa.gov/fire for graphic product... Read more