• UTC: 2018-06-22 06:57

tornado/severe thunderstorm watches

  • SPC Day 2 Fire Weather Outlook
    on June 22, 2018 at 6:56 am

    SPC Day 2 Fire Weather Outlook Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 AM CDT Fri Jun 22 2018 Valid 231200Z - 241200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN INTO NORTHWEST ARIZONA... ...Synopsis... An upper-level trough will dig into the Great Basin on D2/Saturday. Strong mid-level flow will mix down to the surface as well-mixed boundary layers deepen over the course of the day. At the surface, a trough will develop in response the upper-level wave and enhance the surface winds further. A similar scenario will unfold in northern California, where strong northerly/northwesterly flow on the back side of the trough -- coupled with a surface trough -- will yield strong surface winds. Strong surface winds will overlap with critically low RH across the highlighted areas. ...Portions of the Great Basin into northwest Arizona... Strong mid-level flow will mix down to the surface in the afternoon with already enhanced surface due to a surface trough in the Great Basin. Surface winds will range from 20-25 mph with RH values dipping to 5-15%. Small southward extension of the critical area was made into Arizona on account of recent stronger wind guidance. Elsewhere, a surrounding area of elevated fire weather conditions will exist across much of New Mexico, western Colorado, and portions of Utah and Nevada. These locations will experience RH values 5-15%, however winds will not reach critical levels with their displacement from the stronger mid-level flow. ...Northern California... Elevated to locally critical fire weather conditions will exist in parts of the Sacramento Valley. Strong mid-level winds accompanied by a strong surface pressure gradient will yield winds in the 15-20 mph range. RH values will fall to 5-15% with the downsloping northerly/northwesterly flow. Critical winds will likely be too localized to warrant critical designation. ..Wendt.. 06/22/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read mor […]

  • SPC - No watches are valid as of Fri Jun 22 06:57:01 UTC 2018
    on June 22, 2018 at 6:56 am

    No watches are valid as of Fri Jun 22 06:57:01 UTC 2018. […]

  • SPC - No MDs are in effect as of Fri Jun 22 06:57:01 UTC 2018
    on June 22, 2018 at 6:56 am

    No Mesoscale Discussions are in effect as of Fri Jun 22 06:57:01 UTC 2018. […]

  • SPC Day 1 Fire Weather Outlook
    on June 22, 2018 at 6:55 am

    SPC Day 1 Fire Weather Outlook Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0152 AM CDT Fri Jun 22 2018 Valid 221200Z - 231200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN NEW MEXICO...SOUTH-CENTRAL COLORADO... ...Synopsis... A shortwave trough will progress across the Four Corners region today. Stout mid-level winds will mix down to the surface during peak afternoon heating. Strong surface winds will coincide with low RH values across portions of the southwestern CONUS and the Great Basin. ...Portions of northern New Mexico and south-central Colorado... The strongest mid-level winds will exist in this region. Deeply mixed boundary layers will yield surface winds of 20-25 mph, with stronger gusts, amidst RH values of 5-15%. Areas of northwest Colorado may see dry thunderstorms, however concerns over coverage do not warrant a 10% dry thunderstorm designation at this time. Elsewhere, elevated fire weather conditions will exist across parts of the southwestern CONUS, Great Basin, and southwest Colorado. RH values will also range from 5-15%, however winds will generally be lighter or be intermittently critical. Portions of southwest New Mexico may experience briefly critical conditions, but concerns over the duration of strong surface winds precluded critical designation. ..Wendt.. 06/22/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read mor […]

  • SPC Jun 22, 2018 0600 UTC Day 2 Convective Outlook
    on June 22, 2018 at 6:05 am

    SPC 0600Z Day 2 Outlook Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri Jun 22 2018 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM OKLAHOMA INTO SOUTHERN MISSOURI AND WESTERN ARKANSAS... ...SUMMARY... Scattered severe storms are expected from Oklahoma into southern Missouri and western Arkansas on Saturday, with isolated activity extending from northwest Texas toward the lower Ohio Valley. A few severe storms are also possible across the Mid Atlantic. ...Synopsis... A shortwave trough will move from the Mid Atlantic into the Northeast with a weak surface low across the lower Great Lakes. Ample low-level moisture will spread northward across eastern NC, VA, and the Delmarva ahead of a cold front, supporting a few strong storms. Moderate westerly flow aloft will extend westward into the central Plains where a very moist and unstable air mass will exist. Areas of storms will be ongoing throughout the day, with severe storms most likely from OK into MO and AR. ...From northwest TX into western KY and TN... Beneath zonal flow aloft, a front will stretch from northwest TX across central OK during the afternoon, with a potential outflow boundary across eastern OK into AR. South of these boundaries, a very moist and unstable air mass will exist with MUCAPE possibly approaching 4000 J/kg over OK. Some models suggest ongoing activity around eastern OK during the day, possibly regenerating on outflow. Others suggest more of a diurnal setup with storms near the front and outflow during the late afternoon. Deep-layer shear will favor supercells, and enhanced low-level shear near the front and/or outflow suggest a couple tornadoes will be possible as well as large hail and damaging wind. Predictability issues related to the possible early MCS and outflow currently preclude higher severe probabilities, but parts of the area may potentially be upgraded in later updates. ...Mid Atlantic... Early day rain driven by warm advection is expected to lift north across the area, followed by destabilization during the afternoon. Ample low-level moisture with 70s F dewpoints will counteract modest lapse rates aloft resulting in up to 2000 J/kg MUCAPE. Mean winds aloft will approach 30-40 kt, with minor turning with height in the low-levels possibly supporting rotation in some cells. A brief tornado or two will be possible along with marginal wind or hail. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Jewell.. 06/22/2018 Read mor […]

  • SPC Jun 22, 2018 0600 UTC Day 1 Convective Outlook
    on June 22, 2018 at 6:04 am

    SPC 1200Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Fri Jun 22 2018 Valid 221200Z - 231200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN CO INTO CENTRAL OK... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE LOWER MS VALLEY...SOUTHEAST...AND MID-ATLANTIC... ...SUMMARY... Scattered severe storms will be possible across parts of the central/southern Plains, Southeast and Mid-Atlantic States today. ...Southeast into the OH Valley and Mid-Atlantic... Upper low currently moving through the middle MS Valley is expected to gradually move northeastward through the OH Valley while devolving into an open wave. A series of vorticity maxima will rotate around this upper low, accompanied by anomalously strong mid-level flow, which is expected to spread across northern portions of the Southeast and into the Mid-Atlantic. Thunderstorms will likely be ongoing at the beginning of the period as one of the lobes of vorticity moves into the Lower MS Valley, providing the impetus for convection within the moist and low-inhibition airmass. Despite the unfavorable timing, the airmass will likely be moderately unstable with temperatures in the low 80s and dewpoints in the mid 70s helping support MLCAPE over 2000 J/kg. As previously mentioned, seasonally strong flow aloft will increase bulk shear and the potential for more robust, longer-lived updraft organization. Consequently, these early storms will likely pose a severe threat from northern LA/southern AR eastward across central MS and AL. Water-loaded downbursts and hail are the primary threats. A tornado or two cannot be ruled out, particularly on the western periphery of any convective line where enhanced storm-relative helicity from any southwestward progressing storms could contribute to locally higher tornado threat. Vorticity maximum responsible for these early day storms will continue eastward, likely reaching the Piedmont around or just after peak heating. Attendant forcing for ascent coupled with airmass destabilization will likely contribute to increased thunderstorm coverage in this region into the evening. Farther north, more subtle forcing may contribute to afternoon storms in the vicinity of the wedge front. While the overall bulk shear will be modest, easterly/southeasterly winds near the boundary could enhanced low-level shear while also increasing vertical vorticity along the boundary itself. As a result, a small area of relatively enhanced tornado probability exists across southeast VA. ...Southern/Central Plains... Fast-moving shortwave trough currently entering the western Great Basin will continue eastward, moving through the High Plains during the afternoon and through the Plains overnight. Strong lee cyclogenesis is anticipated ahead of this system across southeast CO with resulting southerly flow encouraging moisture return into the central Plains/High Plains. High 50s dewpoints, possibly low 60s, will likely arc into southeast CO along the northern periphery of the surface low. Steep mid-level lapse rates advected ahead of the approaching shortwave atop this at least moderately moist low-level airmass will result in moderate to strong instability during the afternoon. Additionally, increasing mid-level flow attendant to the approaching shortwave trough atop easterly/southeasterly results in strongly sheared environment. 0-6 km bulk shear over 50 kt is likely. All of these factors point to the potential for thunderstorms capable of hail over 2 inches in diameter and wind gusts over 60 kt across eastern CO. Tornadoes are also possible, particularly if storms are able to remain discrete. Strong cold pool generation coupled with the strong forcing for ascent and fast-moving shortwave trough all point to likelihood for quick upscale growth into what could be a significant mesoscale convective system. Steep mid-level lapse rates downstream into OK coupled with a strong low-level jet also point to the potential for a well-organized system capable of tracking much farther east than would normally be expected given the increased convective inhibition. ..Mosier/Wendt.. 06/22/2018 Read mor […]

Quakes.World