Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0122 PM CDT Fri May 05 2023 Valid 061200Z - 071200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS NEW MEXICO INTO FAR SOUTHEAST COLORADO... No changes. See previous discussion below. ..Bentley.. 05/05/2023 .PREV DISCUSSION... /ISSUED 0146 AM CDT Fri May 05 2023/ ...Synopsis... In the mid-levels, the broad trough over the western US is forecast to weaken as it shifts north and east through the start of the weekend. Strong southwesterly flow aloft will slacken over portions of the Southwest and High Plains. However, enough lingering flow will likely exist behind a lee trough/dryline to support gusty winds through Saturday afternoon. A few hours of elevated and critical fire-weather conditions are possible. ...New Mexico into portions of far southeastern Colorado... As large-scale ascent weakens with the broadening of the upper trough, the surface lee low over the central Plains is also expected to slowly fill through the day. While weaker than the day before, gusty southwest flow of 15-20 mph and higher gusts are still expected over portions of NM and CO Saturday. Dry downslope flow and warm temperatures behind the lee trough should still support RH values below 15%. A few hours of elevated and critical fire-weather conditions appear likely given dry fuels. The most likely corridor for sustained critical conditions is over portions of central and eastern NM where the strongest winds and lowest RH overlap through much of the afternoon. ...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 0122 PM CDT Fri May 05 2023 Valid 061200Z - 071200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS NEW MEXICO INTO FAR SOUTHEAST COLORADO... No changes. See previous discussion below. ..Bentley.. 05/05/2023 .PREV DISCUSSION... /ISSUED 0146 AM CDT Fri May 05 2023/ ...Synopsis... In the mid-levels, the broad trough over the western US is forecast to weaken as it shifts north and east through the start of the weekend. Strong southwesterly flow aloft will slacken over portions of the Southwest and High Plains. However, enough lingering flow will likely exist behind a lee trough/dryline to support gusty winds through Saturday afternoon. A few hours of elevated and critical fire-weather conditions are possible. ...New Mexico into portions of far southeastern Colorado... As large-scale ascent weakens with the broadening of the upper trough, the surface lee low over the central Plains is also expected to slowly fill through the day. While weaker than the day before, gusty southwest flow of 15-20 mph and higher gusts are still expected over portions of NM and CO Saturday. Dry downslope flow and warm temperatures behind the lee trough should still support RH values below 15%. A few hours of elevated and critical fire-weather conditions appear likely given dry fuels. The most likely corridor for sustained critical conditions is over portions of central and eastern NM where the strongest winds and lowest RH overlap through much of the afternoon. ...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 0122 PM CDT Fri May 05 2023 Valid 061200Z - 071200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS NEW MEXICO INTO FAR SOUTHEAST COLORADO... No changes. See previous discussion below. ..Bentley.. 05/05/2023 .PREV DISCUSSION... /ISSUED 0146 AM CDT Fri May 05 2023/ ...Synopsis... In the mid-levels, the broad trough over the western US is forecast to weaken as it shifts north and east through the start of the weekend. Strong southwesterly flow aloft will slacken over portions of the Southwest and High Plains. However, enough lingering flow will likely exist behind a lee trough/dryline to support gusty winds through Saturday afternoon. A few hours of elevated and critical fire-weather conditions are possible. ...New Mexico into portions of far southeastern Colorado... As large-scale ascent weakens with the broadening of the upper trough, the surface lee low over the central Plains is also expected to slowly fill through the day. While weaker than the day before, gusty southwest flow of 15-20 mph and higher gusts are still expected over portions of NM and CO Saturday. Dry downslope flow and warm temperatures behind the lee trough should still support RH values below 15%. A few hours of elevated and critical fire-weather conditions appear likely given dry fuels. The most likely corridor for sustained critical conditions is over portions of central and eastern NM where the strongest winds and lowest RH overlap through much of the afternoon. ...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 1230 PM CDT Fri May 05 2023 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID-MISSISSIPPI VALLEY AND FROM SOUTHERN OKLAHOMA INTO CENTRAL TEXAS... ...SUMMARY... Isolated severe thunderstorms producing hail and damaging gusts are possible across parts of the Mid-Mississippi Valley Saturday morning and afternoon. Additional severe thunderstorms capable of very large hail and damaging gusts are possible from southern Oklahoma into central Texas Saturday afternoon into early evening. A more limited risk for strong gusts and hail is possible across southern Mississippi and southeast Louisiana through Saturday afternoon. ...Synopsis... A low-amplitude mid/upper shortwave trough will shift northeast across the central Plains to the Upper Midwest on Saturday. This will bring a belt of enhanced southwesterly flow over the region. A more subtle shortwave impulse is forecast to migrates northeast across TX/OK during the afternoon/evening. Another impulse, likely associated with Day 1 convection over TX is forecast to spread east beneath an upper ridge over the Lower MS Valley. These features will focus thunderstorm potential on Saturday from the Upper Midwest through the MS Valley and across OK/TX. ...OK/TX... A surface dryline is forecast to extend south/southwest from southeast KS into central OK and west-central TX. Midlevel capping will likely suppress thunderstorm develop across northern OK into far eastern KS and western MO as this area will remain between the influence of wave ejecting further north toward the Upper Midwest, and the subtle wave migrating across TX. Strong heating along the dryline amid upper 60s to low 70s F surface dewpoints and very steep midlevel lapse rates will contribute to strong destabilization (3000+ J/kg MLCAPE) during the afternoon. Increasing midlevel moisture and subtle forcing from the midlevel shortwave impulse and from the dryline circulation should be sufficient to erode capping by peak heating. Isolated to scatter thunderstorms are expected by late afternoon. Deep-layer flow will remain somewhat modest, but vertically veering profiles will result in around 40 kt effective shear magnitudes, supporting initial supercells. Elongated hodographs above 2-3 km and lapse rates around 8-9 C/km suggest large to very large hail (greater than 2 inches) will be possible. Steep low-level lapse rates may also support strong outflow winds. The eastward extent of the threat will be limited by strengthening inhibition after loss of daytime heating given a lack of stronger ascent and warmer temperatures aloft. ...Mid-MS Valley vicinity... Large-scale ascent will be focused across eastern NE/SD into MN/WI by afternoon/evening as the shortwave trough migrates northeast. This influence of this shortwave will be limited with southward extent across the Mid-MS Valley. Capping will likely suppress thunderstorm activity west of the MS River. Nevertheless, southerly low-level flow will transport rich Gulf moisture northward into southeast IA and much of IL. Some elevated morning convection posing a risk for marginally severe hail is possible in this warm advection regime in the vicinity of east-central MO/west-central IL. This activity could persist along the moisture/instability gradient into western KY during the afternoon. Some wind/hail risk could accompany this activity though uncertainty in this scenario remains high. Additional thunderstorm development during the afternoon from southeast IA southward along the MS River appears more conditional given strong capping and nebulous large-scale ascent. If isolated convection develops and can become sustained, large hail and damaging gusts will be possible. ...Upper Midwest vicinity... Further north into eastern SD and the Upper Midwest, convection is likely to develop near a surface low over central/eastern SD and eastward along the warm front extending across southern MN into southwest WI. Cooler temperatures and more modest boundary-layer moisture this far north will limit instability. However, steep midlevel lapse rates greater than 7.5 C/km will aid in weak destabilization by late afternoon into the evening. Clusters of storms, potentially elevated with storm motion to the cool side of the warm front, may pose a risk for marginally severe hail and gusty winds. ...Lower MS Valley... Residual outflow from Day 1 convection and at least modest ascent associated with and eastward progressing impulse will provide support for thunderstorms on Saturday. Surface dewpoints in the low 70s F and warming into the 80s beneath steep midlevel lapse rates will support moderate instability. Capping above 850 mb will result in a somewhat uncertain/conditional risk, but most forecast guidance suggests at least a few storm will develop during the afternoon. Modest shear and rather weak deep-layer flow will likely limit longevity of intense/well-organized convection. Nevertheless, some risk of strong gusts and marginal hail could accompany this activity. ..Leitman.. 05/05/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri May 05 2023 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID-MISSISSIPPI VALLEY AND FROM SOUTHERN OKLAHOMA INTO CENTRAL TEXAS... ...SUMMARY... Isolated severe thunderstorms producing hail and damaging gusts are possible across parts of the Mid-Mississippi Valley Saturday morning and afternoon. Additional severe thunderstorms capable of very large hail and damaging gusts are possible from southern Oklahoma into central Texas Saturday afternoon into early evening. A more limited risk for strong gusts and hail is possible across southern Mississippi and southeast Louisiana through Saturday afternoon. ...Synopsis... A low-amplitude mid/upper shortwave trough will shift northeast across the central Plains to the Upper Midwest on Saturday. This will bring a belt of enhanced southwesterly flow over the region. A more subtle shortwave impulse is forecast to migrates northeast across TX/OK during the afternoon/evening. Another impulse, likely associated with Day 1 convection over TX is forecast to spread east beneath an upper ridge over the Lower MS Valley. These features will focus thunderstorm potential on Saturday from the Upper Midwest through the MS Valley and across OK/TX. ...OK/TX... A surface dryline is forecast to extend south/southwest from southeast KS into central OK and west-central TX. Midlevel capping will likely suppress thunderstorm develop across northern OK into far eastern KS and western MO as this area will remain between the influence of wave ejecting further north toward the Upper Midwest, and the subtle wave migrating across TX. Strong heating along the dryline amid upper 60s to low 70s F surface dewpoints and very steep midlevel lapse rates will contribute to strong destabilization (3000+ J/kg MLCAPE) during the afternoon. Increasing midlevel moisture and subtle forcing from the midlevel shortwave impulse and from the dryline circulation should be sufficient to erode capping by peak heating. Isolated to scatter thunderstorms are expected by late afternoon. Deep-layer flow will remain somewhat modest, but vertically veering profiles will result in around 40 kt effective shear magnitudes, supporting initial supercells. Elongated hodographs above 2-3 km and lapse rates around 8-9 C/km suggest large to very large hail (greater than 2 inches) will be possible. Steep low-level lapse rates may also support strong outflow winds. The eastward extent of the threat will be limited by strengthening inhibition after loss of daytime heating given a lack of stronger ascent and warmer temperatures aloft. ...Mid-MS Valley vicinity... Large-scale ascent will be focused across eastern NE/SD into MN/WI by afternoon/evening as the shortwave trough migrates northeast. This influence of this shortwave will be limited with southward extent across the Mid-MS Valley. Capping will likely suppress thunderstorm activity west of the MS River. Nevertheless, southerly low-level flow will transport rich Gulf moisture northward into southeast IA and much of IL. Some elevated morning convection posing a risk for marginally severe hail is possible in this warm advection regime in the vicinity of east-central MO/west-central IL. This activity could persist along the moisture/instability gradient into western KY during the afternoon. Some wind/hail risk could accompany this activity though uncertainty in this scenario remains high. Additional thunderstorm development during the afternoon from southeast IA southward along the MS River appears more conditional given strong capping and nebulous large-scale ascent. If isolated convection develops and can become sustained, large hail and damaging gusts will be possible. ...Upper Midwest vicinity... Further north into eastern SD and the Upper Midwest, convection is likely to develop near a surface low over central/eastern SD and eastward along the warm front extending across southern MN into southwest WI. Cooler temperatures and more modest boundary-layer moisture this far north will limit instability. However, steep midlevel lapse rates greater than 7.5 C/km will aid in weak destabilization by late afternoon into the evening. Clusters of storms, potentially elevated with storm motion to the cool side of the warm front, may pose a risk for marginally severe hail and gusty winds. ...Lower MS Valley... Residual outflow from Day 1 convection and at least modest ascent associated with and eastward progressing impulse will provide support for thunderstorms on Saturday. Surface dewpoints in the low 70s F and warming into the 80s beneath steep midlevel lapse rates will support moderate instability. Capping above 850 mb will result in a somewhat uncertain/conditional risk, but most forecast guidance suggests at least a few storm will develop during the afternoon. Modest shear and rather weak deep-layer flow will likely limit longevity of intense/well-organized convection. Nevertheless, some risk of strong gusts and marginal hail could accompany this activity. ..Leitman.. 05/05/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri May 05 2023 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID-MISSISSIPPI VALLEY AND FROM SOUTHERN OKLAHOMA INTO CENTRAL TEXAS... ...SUMMARY... Isolated severe thunderstorms producing hail and damaging gusts are possible across parts of the Mid-Mississippi Valley Saturday morning and afternoon. Additional severe thunderstorms capable of very large hail and damaging gusts are possible from southern Oklahoma into central Texas Saturday afternoon into early evening. A more limited risk for strong gusts and hail is possible across southern Mississippi and southeast Louisiana through Saturday afternoon. ...Synopsis... A low-amplitude mid/upper shortwave trough will shift northeast across the central Plains to the Upper Midwest on Saturday. This will bring a belt of enhanced southwesterly flow over the region. A more subtle shortwave impulse is forecast to migrates northeast across TX/OK during the afternoon/evening. Another impulse, likely associated with Day 1 convection over TX is forecast to spread east beneath an upper ridge over the Lower MS Valley. These features will focus thunderstorm potential on Saturday from the Upper Midwest through the MS Valley and across OK/TX. ...OK/TX... A surface dryline is forecast to extend south/southwest from southeast KS into central OK and west-central TX. Midlevel capping will likely suppress thunderstorm develop across northern OK into far eastern KS and western MO as this area will remain between the influence of wave ejecting further north toward the Upper Midwest, and the subtle wave migrating across TX. Strong heating along the dryline amid upper 60s to low 70s F surface dewpoints and very steep midlevel lapse rates will contribute to strong destabilization (3000+ J/kg MLCAPE) during the afternoon. Increasing midlevel moisture and subtle forcing from the midlevel shortwave impulse and from the dryline circulation should be sufficient to erode capping by peak heating. Isolated to scatter thunderstorms are expected by late afternoon. Deep-layer flow will remain somewhat modest, but vertically veering profiles will result in around 40 kt effective shear magnitudes, supporting initial supercells. Elongated hodographs above 2-3 km and lapse rates around 8-9 C/km suggest large to very large hail (greater than 2 inches) will be possible. Steep low-level lapse rates may also support strong outflow winds. The eastward extent of the threat will be limited by strengthening inhibition after loss of daytime heating given a lack of stronger ascent and warmer temperatures aloft. ...Mid-MS Valley vicinity... Large-scale ascent will be focused across eastern NE/SD into MN/WI by afternoon/evening as the shortwave trough migrates northeast. This influence of this shortwave will be limited with southward extent across the Mid-MS Valley. Capping will likely suppress thunderstorm activity west of the MS River. Nevertheless, southerly low-level flow will transport rich Gulf moisture northward into southeast IA and much of IL. Some elevated morning convection posing a risk for marginally severe hail is possible in this warm advection regime in the vicinity of east-central MO/west-central IL. This activity could persist along the moisture/instability gradient into western KY during the afternoon. Some wind/hail risk could accompany this activity though uncertainty in this scenario remains high. Additional thunderstorm development during the afternoon from southeast IA southward along the MS River appears more conditional given strong capping and nebulous large-scale ascent. If isolated convection develops and can become sustained, large hail and damaging gusts will be possible. ...Upper Midwest vicinity... Further north into eastern SD and the Upper Midwest, convection is likely to develop near a surface low over central/eastern SD and eastward along the warm front extending across southern MN into southwest WI. Cooler temperatures and more modest boundary-layer moisture this far north will limit instability. However, steep midlevel lapse rates greater than 7.5 C/km will aid in weak destabilization by late afternoon into the evening. Clusters of storms, potentially elevated with storm motion to the cool side of the warm front, may pose a risk for marginally severe hail and gusty winds. ...Lower MS Valley... Residual outflow from Day 1 convection and at least modest ascent associated with and eastward progressing impulse will provide support for thunderstorms on Saturday. Surface dewpoints in the low 70s F and warming into the 80s beneath steep midlevel lapse rates will support moderate instability. Capping above 850 mb will result in a somewhat uncertain/conditional risk, but most forecast guidance suggests at least a few storm will develop during the afternoon. Modest shear and rather weak deep-layer flow will likely limit longevity of intense/well-organized convection. Nevertheless, some risk of strong gusts and marginal hail could accompany this activity. ..Leitman.. 05/05/2023 Read more

WW 0185 Status Updates
STATUS REPORT ON WW 185 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..LYONS..05/04/23 ATTN...WFO...OUN...LUB...FWD... STATUS REPORT FOR WT 185 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS OKC019-033-057-065-067-085-137-141-042240- OK . OKLAHOMA COUNTIES INCLUDED ARE CARTER COTTON HARMON JACKSON JEFFERSON LOVE STEPHENS TILLMAN TXC009-023-075-077-097-101-155-197-269-275-337-485-487-042240- TX . TEXAS COUNTIES INCLUDED ARE ARCHER BAYLOR CHILDRESS CLAY COOKE COTTLE FOARD HARDEMAN KING KNOX MONTAGUE WICHITA WILBARGER THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 185 TORNADO OK TX 041955Z - 050200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 185 NWS Storm Prediction Center Norman OK 255 PM CDT Thu May 4 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southwest and south central Oklahoma Northwest into north central Texas * Effective this Thursday afternoon and evening from 255 PM until 900 PM CDT. * Primary threats include... A couple tornadoes possible Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Isolated damaging wind gusts to 70 mph possible SUMMARY...A couple of supercells are expected to develop this afternoon and move eastward near the Red River through this evening. The storm environment will favor large hail of 2 to 2.5 inches in diameter as the primary threat, though a couple of tornadoes will also be possible. The tornado watch area is approximately along and 40 statute miles north and south of a line from 30 miles south of Childress TX to 25 miles south of Ardmore OK. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && AVIATION...Tornadoes and 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 27025. ...Thompson Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu May 04 2023 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHWEST OKLAHOMA INTO CENTRAL TEXAS... ...SUMMARY... Isolated large hail, damaging gusts, and a couple of tornadoes will be possible this through this evening from southwest Oklahoma into northwest and central Texas. ...Synopsis... Only minor adjustments have been made to the Slight risk (Level 2 of 5) area across northwest TX/southwest OK. These changes are based on current position of the dryline and an outflow boundary, and trends in visible satellite/surface observations. Overall forecast thinking remains unchanged from the previous outlook. For short term severe potential across northwest TX and far southwest OK, see MCD 673 and Tornado Watch 185. For short term severe potential further south along the dryline across west-central TX, see MCD 674. ..Leitman.. 05/04/2023 .PREV DISCUSSION... /ISSUED 1125 AM CDT Thu May 04 2023/ ...TX/OK area this afternoon/evening... Within the subtropical jet, embedded perturbations will eject east-northeastward from northern Mexico to the southern Plains through tonight. The strength and orientation of the midlevel flow supports modest lee cyclogenesis across extreme southeast CO, and resultant southerly low-level flow and moisture advection (mid-upper 60s dewpoints) across TX. A broad swath of mid-high clouds covers much of TX/OK this morning, with embedded/elevated convection ongoing in small clusters from the TX South Plains to southern/central OK. The cloud plume will slow surface heating in central/north TX, while the morning rainfall will tend to reinforce the baroclinic zone near the Red River through this afternoon. The stronger surface heating/mixing will occur with clearing of the mid-high clouds from the west by mid afternoon across west central into northwest TX. Low-level moisture advection will be rather modest (low 60s dewpoints) into the zone of stronger surface heating, with somewhat modest buoyancy expected by May standards in the southern Plains (MLCAPE around 1500 J/kg). Supercells will be most probable late this afternoon/evening where the warmer temperatures and steeper low-level lapse rates impinge on the northwest edge of the somewhat richer low-level moisture, near and east of the dryline/warm front intersection. Large hail (some of which be 2 inch diameter or a little larger) will be the main concern, though the stronger storms could produce isolated damaging winds. If a supercell can move along the baroclinic zone near or just south of the Red River this evening, the somewhat enhanced low-level shear and moisture will support the potential for a couple of tornadoes. Farther south, a few supercells will be possible from the Del Burros northeastward into the Edwards Plateau along the sharpening dryline by late afternoon. Relatively straight hodographs and MLCAPE near 2500 J/kg will favor large hail as the primary severe threat, some of which could be larger than 2 inches in diameter. ...Northern Rockies/Great Basin this afternoon/evening... Pockets of surface heating, and a band of ascent around the northeast periphery of the Great Basin midlevel low, will support scattered thunderstorms across the northern Rockies this afternoon/evening. Buoyancy and southeasterly deep-layer shear could be sufficient for a isolated storms with strong/damaging outflow gusts and marginally severe hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu May 04 2023 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHWEST OKLAHOMA INTO CENTRAL TEXAS... ...SUMMARY... Isolated large hail, damaging gusts, and a couple of tornadoes will be possible this through this evening from southwest Oklahoma into northwest and central Texas. ...Synopsis... Only minor adjustments have been made to the Slight risk (Level 2 of 5) area across northwest TX/southwest OK. These changes are based on current position of the dryline and an outflow boundary, and trends in visible satellite/surface observations. Overall forecast thinking remains unchanged from the previous outlook. For short term severe potential across northwest TX and far southwest OK, see MCD 673 and Tornado Watch 185. For short term severe potential further south along the dryline across west-central TX, see MCD 674. ..Leitman.. 05/04/2023 .PREV DISCUSSION... /ISSUED 1125 AM CDT Thu May 04 2023/ ...TX/OK area this afternoon/evening... Within the subtropical jet, embedded perturbations will eject east-northeastward from northern Mexico to the southern Plains through tonight. The strength and orientation of the midlevel flow supports modest lee cyclogenesis across extreme southeast CO, and resultant southerly low-level flow and moisture advection (mid-upper 60s dewpoints) across TX. A broad swath of mid-high clouds covers much of TX/OK this morning, with embedded/elevated convection ongoing in small clusters from the TX South Plains to southern/central OK. The cloud plume will slow surface heating in central/north TX, while the morning rainfall will tend to reinforce the baroclinic zone near the Red River through this afternoon. The stronger surface heating/mixing will occur with clearing of the mid-high clouds from the west by mid afternoon across west central into northwest TX. Low-level moisture advection will be rather modest (low 60s dewpoints) into the zone of stronger surface heating, with somewhat modest buoyancy expected by May standards in the southern Plains (MLCAPE around 1500 J/kg). Supercells will be most probable late this afternoon/evening where the warmer temperatures and steeper low-level lapse rates impinge on the northwest edge of the somewhat richer low-level moisture, near and east of the dryline/warm front intersection. Large hail (some of which be 2 inch diameter or a little larger) will be the main concern, though the stronger storms could produce isolated damaging winds. If a supercell can move along the baroclinic zone near or just south of the Red River this evening, the somewhat enhanced low-level shear and moisture will support the potential for a couple of tornadoes. Farther south, a few supercells will be possible from the Del Burros northeastward into the Edwards Plateau along the sharpening dryline by late afternoon. Relatively straight hodographs and MLCAPE near 2500 J/kg will favor large hail as the primary severe threat, some of which could be larger than 2 inches in diameter. ...Northern Rockies/Great Basin this afternoon/evening... Pockets of surface heating, and a band of ascent around the northeast periphery of the Great Basin midlevel low, will support scattered thunderstorms across the northern Rockies this afternoon/evening. Buoyancy and southeasterly deep-layer shear could be sufficient for a isolated storms with strong/damaging outflow gusts and marginally severe hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Thu May 04 2023 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHWEST OKLAHOMA INTO CENTRAL TEXAS... ...SUMMARY... Isolated large hail, damaging gusts, and a couple of tornadoes will be possible this through this evening from southwest Oklahoma into northwest and central Texas. ...Synopsis... Only minor adjustments have been made to the Slight risk (Level 2 of 5) area across northwest TX/southwest OK. These changes are based on current position of the dryline and an outflow boundary, and trends in visible satellite/surface observations. Overall forecast thinking remains unchanged from the previous outlook. For short term severe potential across northwest TX and far southwest OK, see MCD 673 and Tornado Watch 185. For short term severe potential further south along the dryline across west-central TX, see MCD 674. ..Leitman.. 05/04/2023 .PREV DISCUSSION... /ISSUED 1125 AM CDT Thu May 04 2023/ ...TX/OK area this afternoon/evening... Within the subtropical jet, embedded perturbations will eject east-northeastward from northern Mexico to the southern Plains through tonight. The strength and orientation of the midlevel flow supports modest lee cyclogenesis across extreme southeast CO, and resultant southerly low-level flow and moisture advection (mid-upper 60s dewpoints) across TX. A broad swath of mid-high clouds covers much of TX/OK this morning, with embedded/elevated convection ongoing in small clusters from the TX South Plains to southern/central OK. The cloud plume will slow surface heating in central/north TX, while the morning rainfall will tend to reinforce the baroclinic zone near the Red River through this afternoon. The stronger surface heating/mixing will occur with clearing of the mid-high clouds from the west by mid afternoon across west central into northwest TX. Low-level moisture advection will be rather modest (low 60s dewpoints) into the zone of stronger surface heating, with somewhat modest buoyancy expected by May standards in the southern Plains (MLCAPE around 1500 J/kg). Supercells will be most probable late this afternoon/evening where the warmer temperatures and steeper low-level lapse rates impinge on the northwest edge of the somewhat richer low-level moisture, near and east of the dryline/warm front intersection. Large hail (some of which be 2 inch diameter or a little larger) will be the main concern, though the stronger storms could produce isolated damaging winds. If a supercell can move along the baroclinic zone near or just south of the Red River this evening, the somewhat enhanced low-level shear and moisture will support the potential for a couple of tornadoes. Farther south, a few supercells will be possible from the Del Burros northeastward into the Edwards Plateau along the sharpening dryline by late afternoon. Relatively straight hodographs and MLCAPE near 2500 J/kg will favor large hail as the primary severe threat, some of which could be larger than 2 inches in diameter. ...Northern Rockies/Great Basin this afternoon/evening... Pockets of surface heating, and a band of ascent around the northeast periphery of the Great Basin midlevel low, will support scattered thunderstorms across the northern Rockies this afternoon/evening. Buoyancy and southeasterly deep-layer shear could be sufficient for a isolated storms with strong/damaging outflow gusts and marginally severe hail. Read more

MD 0674 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF WEST-CENTRAL TEXAS TO THE MIDDLE RIO GRANDE VALLEY
Mesoscale Discussion 0674 NWS Storm Prediction Center Norman OK 0248 PM CDT Thu May 04 2023 Areas affected...parts of west-central Texas to the middle Rio Grande Valley Concerning...Severe potential...Watch possible Valid 041948Z - 042215Z Probability of Watch Issuance...60 percent SUMMARY...At least isolated severe storms producing large hail will be possible from late this afternoon into the evening. DISCUSSION...Visible imagery shows a CU field near a dryline extending from northwest TX southwestward toward the Rio Grande. Winds have veered to west/southwest behind the dryline, with temperatures currently into the mid 80s F. East of the dryline, cirrus has generally thinned, with areas of heating in the moist air mass. A moisture gradient does exist from central into southwest TX, and is not expected to move much in the near term. Continued heating as well as deepening of the moist boundary layer ahead of the dryline may yield several storms by late afternoon, perhaps aided by a weak midlevel feature moving across southwestern TX. Little else will be present to support a more organized severe threat, but trends will be monitored for signs of increasing severe storm coverage through early evening. Modest instability and favorably long hodographs should favor mainly hail. ..Jewell/Thompson.. 05/04/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...EWX...SJT...MAF... LAT...LON 29690251 30640192 31520135 32160107 32710093 32910055 32959967 32399919 31679921 30779949 29760017 29140079 29470120 29700143 29780223 29690251 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0130 PM CDT Thu May 04 2023 Valid 051200Z - 061200Z Minor adjustments were made to include a larger portion of southeastern Colorado within the Elevated in alignment with recent trends. Otherwise, the forecast remains on track with no further updates needed. See previous discussion below for more information. ..Thornton.. 05/04/2023 .PREV DISCUSSION... /ISSUED 0155 AM CDT Thu May 04 2023/ ...Synopsis... Critical fire weather conditions are expected Friday afternoon across far southeast AZ into much of NM. The meandering upper-level low over the West Coast is forecast to begin translating east towards the Rockies during the day Friday. Despite weak lee troughing over the High Plains, strong mid-level flow will overspread much of the Southwest. Deep boundary-layer mixing and broad subsidence will allow for efficient downward transport of 25-35 mph winds and promote RH reductions into the single digits to low teens. Sustained critical conditions appears most likely from far southeast AZ into northeast NM where boundary-layer winds are currently expected to be strongest. Elevated fire conditions may extend well into the TX Panhandle and possibly as far east as western OK. Fuels are currently unreceptive across this region after recent rainfall, which precludes an eastward expansion of the risk area. However, rapid drying of fine grasses may support local fire concerns. Similarly, elevated conditions may spread further north into southeast CO than currently depicted, but this potential appears to be conditional on the strength of the lee cyclone over east-central CO. This area may be a candidate for highlight expansion if guidance comes into better agreement regarding the evolution of the surface low. ...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 0130 PM CDT Thu May 04 2023 Valid 051200Z - 061200Z Minor adjustments were made to include a larger portion of southeastern Colorado within the Elevated in alignment with recent trends. Otherwise, the forecast remains on track with no further updates needed. See previous discussion below for more information. ..Thornton.. 05/04/2023 .PREV DISCUSSION... /ISSUED 0155 AM CDT Thu May 04 2023/ ...Synopsis... Critical fire weather conditions are expected Friday afternoon across far southeast AZ into much of NM. The meandering upper-level low over the West Coast is forecast to begin translating east towards the Rockies during the day Friday. Despite weak lee troughing over the High Plains, strong mid-level flow will overspread much of the Southwest. Deep boundary-layer mixing and broad subsidence will allow for efficient downward transport of 25-35 mph winds and promote RH reductions into the single digits to low teens. Sustained critical conditions appears most likely from far southeast AZ into northeast NM where boundary-layer winds are currently expected to be strongest. Elevated fire conditions may extend well into the TX Panhandle and possibly as far east as western OK. Fuels are currently unreceptive across this region after recent rainfall, which precludes an eastward expansion of the risk area. However, rapid drying of fine grasses may support local fire concerns. Similarly, elevated conditions may spread further north into southeast CO than currently depicted, but this potential appears to be conditional on the strength of the lee cyclone over east-central CO. This area may be a candidate for highlight expansion if guidance comes into better agreement regarding the evolution of the surface low. ...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 0130 PM CDT Thu May 04 2023 Valid 051200Z - 061200Z Minor adjustments were made to include a larger portion of southeastern Colorado within the Elevated in alignment with recent trends. Otherwise, the forecast remains on track with no further updates needed. See previous discussion below for more information. ..Thornton.. 05/04/2023 .PREV DISCUSSION... /ISSUED 0155 AM CDT Thu May 04 2023/ ...Synopsis... Critical fire weather conditions are expected Friday afternoon across far southeast AZ into much of NM. The meandering upper-level low over the West Coast is forecast to begin translating east towards the Rockies during the day Friday. Despite weak lee troughing over the High Plains, strong mid-level flow will overspread much of the Southwest. Deep boundary-layer mixing and broad subsidence will allow for efficient downward transport of 25-35 mph winds and promote RH reductions into the single digits to low teens. Sustained critical conditions appears most likely from far southeast AZ into northeast NM where boundary-layer winds are currently expected to be strongest. Elevated fire conditions may extend well into the TX Panhandle and possibly as far east as western OK. Fuels are currently unreceptive across this region after recent rainfall, which precludes an eastward expansion of the risk area. However, rapid drying of fine grasses may support local fire concerns. Similarly, elevated conditions may spread further north into southeast CO than currently depicted, but this potential appears to be conditional on the strength of the lee cyclone over east-central CO. This area may be a candidate for highlight expansion if guidance comes into better agreement regarding the evolution of the surface low. ...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 1229 PM CDT Thu May 04 2023 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TEXAS... ...SUMMARY... Severe thunderstorms will be possible across parts of central Texas Friday afternoon and evening, with large hail and damaging winds expected to be the primary threats. Isolated strong storms are also possible across portions of the Tennessee Valley to the central Gulf Coast, and across parts of Nebraska. ...Synopsis... An upper ridge will spread east from the south-central U.S. toward the Midwest/Southeast vicinity on Friday. As this occurs, an upper trough over the western U.S. will pivot northeast toward the northern/central Plains. Several shortwave impulses embedded within the upper ridge, as well as the ejecting western trough, will focus severe potential across portions of the southern Plains, the South and the central Plains. ...TX/far southeast OK... Central/eastern TX will remain well south/east of the influence for the ejecting western upper trough. However, forecast guidance depicts a favorably timed shortwave trough ejecting from Mexico toward the ArkLaTex during the afternoon. Moderate to strong destabilization is expected amid a seasonally moist airmass to the east of a dryline. Deep-layer flow will remain somewhat weak, but vertically veering profiles will contribute to 40+ kt effective shear magnitudes. Very steep midlevel lapse rates and elongated hodographs suggest potential for supercells capable of very large hail (some greater than 2+ inches). Steep low-level lapse rates and some midlevel dryness could also support strong downdrafts and severe outflow winds. ...MS/AL vicinity... A somewhat complicated/low-confidence forecast scenario is expected across parts of the Mid-South to the TN Valley/central Gulf Coast vicinity. An MCS may be ongoing at the beginning of the period somewhere in the vicinity of AR near the Mississippi River. Low-level moisture will be increasing through the morning and into the afternoon across the Lower MS Valley into parts of western/southern AL. The MCS may develop east/southeast along the moisture/instability gradient, or new development along outflow also could develop and track southeast during the afternoon. While convective evolution is uncertain, moderate vertical shear and at least weak instability will support strong gusts and hail. A secondary shortwave impulse is forecast to move across the TN Valley late in the period. This could aid in the development of elevated thunderstorms overnight into early Saturday morning across parts of the TN Valley. This activity would mainly pose a risk of marginally severe hail. ...Central Plains... Modest low-level moistening to the north/northeast of a surface low across the central High Plains will result in weak to locally moderate destabilization across much of NE during the afternoon/evening. A shortwave trough moving northeastward from the southern Rockies will provide forcing for ascent and thunderstorm development is expected by mid to late afternoon. Some upscale growth is possible by evening as a southerly low-level jet strengthens across the region. Isolated severe hail/wind will be possible with the strongest storms. ..Leitman.. 05/04/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu May 04 2023 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TEXAS... ...SUMMARY... Severe thunderstorms will be possible across parts of central Texas Friday afternoon and evening, with large hail and damaging winds expected to be the primary threats. Isolated strong storms are also possible across portions of the Tennessee Valley to the central Gulf Coast, and across parts of Nebraska. ...Synopsis... An upper ridge will spread east from the south-central U.S. toward the Midwest/Southeast vicinity on Friday. As this occurs, an upper trough over the western U.S. will pivot northeast toward the northern/central Plains. Several shortwave impulses embedded within the upper ridge, as well as the ejecting western trough, will focus severe potential across portions of the southern Plains, the South and the central Plains. ...TX/far southeast OK... Central/eastern TX will remain well south/east of the influence for the ejecting western upper trough. However, forecast guidance depicts a favorably timed shortwave trough ejecting from Mexico toward the ArkLaTex during the afternoon. Moderate to strong destabilization is expected amid a seasonally moist airmass to the east of a dryline. Deep-layer flow will remain somewhat weak, but vertically veering profiles will contribute to 40+ kt effective shear magnitudes. Very steep midlevel lapse rates and elongated hodographs suggest potential for supercells capable of very large hail (some greater than 2+ inches). Steep low-level lapse rates and some midlevel dryness could also support strong downdrafts and severe outflow winds. ...MS/AL vicinity... A somewhat complicated/low-confidence forecast scenario is expected across parts of the Mid-South to the TN Valley/central Gulf Coast vicinity. An MCS may be ongoing at the beginning of the period somewhere in the vicinity of AR near the Mississippi River. Low-level moisture will be increasing through the morning and into the afternoon across the Lower MS Valley into parts of western/southern AL. The MCS may develop east/southeast along the moisture/instability gradient, or new development along outflow also could develop and track southeast during the afternoon. While convective evolution is uncertain, moderate vertical shear and at least weak instability will support strong gusts and hail. A secondary shortwave impulse is forecast to move across the TN Valley late in the period. This could aid in the development of elevated thunderstorms overnight into early Saturday morning across parts of the TN Valley. This activity would mainly pose a risk of marginally severe hail. ...Central Plains... Modest low-level moistening to the north/northeast of a surface low across the central High Plains will result in weak to locally moderate destabilization across much of NE during the afternoon/evening. A shortwave trough moving northeastward from the southern Rockies will provide forcing for ascent and thunderstorm development is expected by mid to late afternoon. Some upscale growth is possible by evening as a southerly low-level jet strengthens across the region. Isolated severe hail/wind will be possible with the strongest storms. ..Leitman.. 05/04/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu May 04 2023 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TEXAS... ...SUMMARY... Severe thunderstorms will be possible across parts of central Texas Friday afternoon and evening, with large hail and damaging winds expected to be the primary threats. Isolated strong storms are also possible across portions of the Tennessee Valley to the central Gulf Coast, and across parts of Nebraska. ...Synopsis... An upper ridge will spread east from the south-central U.S. toward the Midwest/Southeast vicinity on Friday. As this occurs, an upper trough over the western U.S. will pivot northeast toward the northern/central Plains. Several shortwave impulses embedded within the upper ridge, as well as the ejecting western trough, will focus severe potential across portions of the southern Plains, the South and the central Plains. ...TX/far southeast OK... Central/eastern TX will remain well south/east of the influence for the ejecting western upper trough. However, forecast guidance depicts a favorably timed shortwave trough ejecting from Mexico toward the ArkLaTex during the afternoon. Moderate to strong destabilization is expected amid a seasonally moist airmass to the east of a dryline. Deep-layer flow will remain somewhat weak, but vertically veering profiles will contribute to 40+ kt effective shear magnitudes. Very steep midlevel lapse rates and elongated hodographs suggest potential for supercells capable of very large hail (some greater than 2+ inches). Steep low-level lapse rates and some midlevel dryness could also support strong downdrafts and severe outflow winds. ...MS/AL vicinity... A somewhat complicated/low-confidence forecast scenario is expected across parts of the Mid-South to the TN Valley/central Gulf Coast vicinity. An MCS may be ongoing at the beginning of the period somewhere in the vicinity of AR near the Mississippi River. Low-level moisture will be increasing through the morning and into the afternoon across the Lower MS Valley into parts of western/southern AL. The MCS may develop east/southeast along the moisture/instability gradient, or new development along outflow also could develop and track southeast during the afternoon. While convective evolution is uncertain, moderate vertical shear and at least weak instability will support strong gusts and hail. A secondary shortwave impulse is forecast to move across the TN Valley late in the period. This could aid in the development of elevated thunderstorms overnight into early Saturday morning across parts of the TN Valley. This activity would mainly pose a risk of marginally severe hail. ...Central Plains... Modest low-level moistening to the north/northeast of a surface low across the central High Plains will result in weak to locally moderate destabilization across much of NE during the afternoon/evening. A shortwave trough moving northeastward from the southern Rockies will provide forcing for ascent and thunderstorm development is expected by mid to late afternoon. Some upscale growth is possible by evening as a southerly low-level jet strengthens across the region. Isolated severe hail/wind will be possible with the strongest storms. ..Leitman.. 05/04/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu May 04 2023 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TEXAS... ...SUMMARY... Severe thunderstorms will be possible across parts of central Texas Friday afternoon and evening, with large hail and damaging winds expected to be the primary threats. Isolated strong storms are also possible across portions of the Tennessee Valley to the central Gulf Coast, and across parts of Nebraska. ...Synopsis... An upper ridge will spread east from the south-central U.S. toward the Midwest/Southeast vicinity on Friday. As this occurs, an upper trough over the western U.S. will pivot northeast toward the northern/central Plains. Several shortwave impulses embedded within the upper ridge, as well as the ejecting western trough, will focus severe potential across portions of the southern Plains, the South and the central Plains. ...TX/far southeast OK... Central/eastern TX will remain well south/east of the influence for the ejecting western upper trough. However, forecast guidance depicts a favorably timed shortwave trough ejecting from Mexico toward the ArkLaTex during the afternoon. Moderate to strong destabilization is expected amid a seasonally moist airmass to the east of a dryline. Deep-layer flow will remain somewhat weak, but vertically veering profiles will contribute to 40+ kt effective shear magnitudes. Very steep midlevel lapse rates and elongated hodographs suggest potential for supercells capable of very large hail (some greater than 2+ inches). Steep low-level lapse rates and some midlevel dryness could also support strong downdrafts and severe outflow winds. ...MS/AL vicinity... A somewhat complicated/low-confidence forecast scenario is expected across parts of the Mid-South to the TN Valley/central Gulf Coast vicinity. An MCS may be ongoing at the beginning of the period somewhere in the vicinity of AR near the Mississippi River. Low-level moisture will be increasing through the morning and into the afternoon across the Lower MS Valley into parts of western/southern AL. The MCS may develop east/southeast along the moisture/instability gradient, or new development along outflow also could develop and track southeast during the afternoon. While convective evolution is uncertain, moderate vertical shear and at least weak instability will support strong gusts and hail. A secondary shortwave impulse is forecast to move across the TN Valley late in the period. This could aid in the development of elevated thunderstorms overnight into early Saturday morning across parts of the TN Valley. This activity would mainly pose a risk of marginally severe hail. ...Central Plains... Modest low-level moistening to the north/northeast of a surface low across the central High Plains will result in weak to locally moderate destabilization across much of NE during the afternoon/evening. A shortwave trough moving northeastward from the southern Rockies will provide forcing for ascent and thunderstorm development is expected by mid to late afternoon. Some upscale growth is possible by evening as a southerly low-level jet strengthens across the region. Isolated severe hail/wind will be possible with the strongest storms. ..Leitman.. 05/04/2023 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1137 AM CDT Thu May 04 2023 Valid 041700Z - 051200Z Slight modifications were made to extend the current Elevated region into portions of western Texas from the Permian Basin to Trans-Pecos. Much of the region from the Texas Panhandle to Cap Rock and the Rolling Plains has seen rainfall in the last 24-48 hours, which has mitigated the fire potential as mentioned below. Less rainfall was received with south and westward extent. Status of fuels (in coordination with local partners) and ensemble guidance indications of around 80 percent probability of at least Elevated conditions further supports this change. See previous discussion for more information. ..Thornton.. 05/04/2023 .PREV DISCUSSION... /ISSUED 0128 AM CDT Thu May 04 2023/ ...Synopsis... Elevated fire weather conditions are expected this afternoon across the Southwest into the southern High Plains. Subsidence in the wake of a sub-tropical shortwave trough will overspread southeast AZ and NM this afternoon. Poor overnight RH recovery is noted at a few surface stations across this region, and 00 UTC soundings from TUS, ABQ, and EPZ sampled very dry boundary layers. With additional drying/warming expected this afternoon, RH reductions into the low to mid teens appear likely. Weak lee cyclogenesis across the TX Panhandle into northwest OK will result in a modest low-level mass response across the Southwest. Sustained winds near 15 mph are expected, but should frequently gust between 20-30 mph. The previous Elevated risk area has been expanded to include portions of southeast NM. Although this area has recently received spotty rainfall, local reports noted that dry lightning over the past 48 hours has resulted in a few fire starts. This not only indicates that fuels are generally receptive (outside of pockets of heavier rainfall), but also implies that holdover fires are possible and may spread amid the hot, dry, and windy conditions expected today. ...Please see www.spc.noaa.gov/fire for graphic product... Read more