Area Forecast Discussion
Issued by NWS North Platte, NE
Issued by NWS North Platte, NE
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146 FXUS63 KLBF 020015 AFDLBF Area Forecast Discussion National Weather Service North Platte NE 715 PM CDT Sat Jun 1 2024 .KEY MESSAGES... - Storms are anticipated to move into the area late this afternoon and evening, with potential for very large hail, damaging winds, and an isolated tornado. - Confidence in potential for a high impact event is increasing for late Sunday afternoon/evening, for a line of severe thunderstorms capable of producing widespread wind gusts at or above 70mph across central and western Nebraska. - Additional threats for thunderstorms exist Monday and Tuesday, though the threat for any severe weather remains uncertain. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 414 PM CDT Sat Jun 1 2024 Showers and thunderstorms that brought some large hail to portions of western Nebraska before daybreak have moved off to the east and dissipated. Visible satellite shows that an earlier well defined bubble high over central Nebraska and a lingering outflow boundary have started to erode under strong diurnal mixing, but anticipate hints of the boundary will linger for a bit. Further upstream thunderstorms have started to develop over the higher terrain in Wyoming and Colorado with a dry line extending from southeast WY down through eastern Colorado. Anticipate the dry line will push eastward and generate new convection that will grow upscale as it encounters more moisture and surface based CAPE values at or above 2500J/kg. The environment is well sheared with 0-6km bulk shear values at or above 40kt and long hodographs that develop better curvature as the convection moves into western and southwest Nebraska early this evening, along with lapse rates at least moderately steep surface and aloft. Initial mode of convection looks to be supercells that will build southeastward sliding along the ribbon of unstable air from the western sandhills through southwest Nebraska into northeastern Kansas. Initial storms closest to where the dry line moves into the axis of unstable air from about Hwy 61 westward will be capable of producing large to very large hail, damaging winds, and an isolated tornado. Later this evening into early tonight as storms move thorugh southwest/south central Nebraska generally along/south of I-80 there may be some clustering of storms into a loose MCS as outflows consolidate with primarily wind/hail threats before diminishing and moving off to the east before Midnight. With the expected slow movement of storms there will also be potential for locally heavy rainfall and flooding. Lingering elevated instability and an amplifying low level jet will maintain an opportunity to for isolated/widely scattered storms going overnight but with the axis of the jet shifting east any activity before sunrise may be confined to Hwy 183 eastward or possibly even Hwy 281 east. We get a break in convection Sunday morning but the break will be brief as a cold front approaching from the west. The airmass will rapidly destabilize ahead of the front with surface based CAPE values at or above 2500J/kg and steep lapse rates aloft. Some mid level drying and a small inverted-v evident in model soundings near the surface will boost DCAPE values to around 1500J/kg and present a good signal for potential of significant winds. Anticipate convection will develop ahead of the front entering the western sandhills mid to late afternoon, then rapidly grow upscale into a linear MCS that will cross the entire region through Sunday evening before exiting to the east before Midnight. The majority of mesoscale guidance is in good agreement depicting potential for a high impact event with potential for winds at or above 70mph over a fairly large area, along with large hail, late Sunday afternoon through Sunday evening. This bears close watching, especially for anyone traveling or with outdoor plans. && .LONG TERM /MONDAY THROUGH SATURDAY/... Issued at 414 PM CDT Sat Jun 1 2024 Progressive flow regime with a series of shallow trofs moving through the northern tier of states will keep active weather across central and western Nebraska into the first part of next week before a large ridge starts to build over the western US. Additional thunderstorm threats will persist into Monday and Tuesday, though confidence is not high with respect location and timing of best thunderstorm potential. Drier conditions are then expected into midweek as the western ridge builds. Differences in guidance locations of features creates uncertainty late week and beyond, but will have to watch for potential of thunderstorm development late next week in northwest flow aloft depending on exactly where the upper ridge becomes established. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 705 PM CDT Sat Jun 1 2024 Scattered thunderstorms are likely to impact western through central Nebraska tonight. Gusty winds and hail could accompany the strongest storms. Outside of any thunderstorm activity expect VFR conditions to prevail with south to southeast winds at 10-15 kts. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...MBS LONG TERM...MBS AVIATION...Taylor