883 FXUS63 KGLD 182317 AFDGLDArea Forecast Discussion National Weather Service Goodland KS 517 PM MDT Thu Sep 18 2025
.KEY MESSAGES...
- Conditional potential for isolated thunderstorm development along/east of Hwy 83 late Friday aft-eve (~5-10 pm MDT). A severe storm capable of producing large hail is possible, should storms develop.
- Above average temperatures will return over the weekend, with highs in the mid 80`s on Sat-Sun.
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.SHORT TERM /THROUGH FRIDAY/... Issued at 250 PM MDT Thu Sep 18 2025
Overview: A broad, complex upper level low over the Northern Plains will slowly shift east toward the Upper Midwest tonight and Friday.
Today: Shortwave energy over central KS at 18 UTC (per SPC Mesoanalysis 400-250 mb Pot Vort) will progress E-ENE into east- northeast KS this afternoon and evening. While cyclonic flow aloft will remain in place over the region, subsidence in the wake of the aforementioned shortwave will likely be sufficient to suppress convective development Additionally.. a cool, convectively overturned airmass will significantly hamper diurnal destabilization this afternoon.. limiting instability/MLCAPE to ~250 J/kg at peak heating. Expect little, if any, potential for convection in the Goodland CWA.
Tonight: A compact upper low/wave in eastern MT at 18 UTC.. situated on the northwest periphery of the broader, complex upper low over the Northern Plains.. will dig SSE into western- southern SD by ~12 UTC Friday morning. Focused upper forcing /DPVA/ with this feature may well aid in the development of nocturnal convection ~06-12Z Friday morning -- over northeast WY and southwest SD (150-200 miles N of the Goodland CWA). Expect dry conditions and near average lows in the upper 40`s to lower 50`s.
Friday: The aforementioned upper wave in SD will dig SSE through central and southeast Nebraska during the late morning and early afternoon. Guidance suggests that low-level convergence within.. and strengthening southerly flow on the eastern periphery of.. a broad lee cyclone/trough in western KS may aid in isolated convective development along and east of Highway 83 during the late afternoon and early evening (~23-04 UTC, 5-10 pm MDT). Morning convection accompanying the upper wave in central Nebraska may alter/influence environmental conditions over southwest NE and northwest KS during the afternoon.. lending a fair amount of uncertainty with regard to whether or not (and if so, to what extent) convection may develop. Output from current and recent runs of the HRRR and NAM NEST suggest a conditional potential for an isolated supercell capable of producing large hail.
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.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... Issued at 250 PM MDT Thu Sep 18 2025
Sat-Sun: Guidance suggests that a complex, disjointed synoptic pattern characterized by (1) a sinuous, speedy northern stream jet at higher latitudes in Canada and (2) a speedy, increasingly sinuous southern stream jet along the southern Pacific Coast, Desert Southwest and 4-Corners.. will prevail over North America this weekend. While the Tri-State area will be in closest proximity to (and more likely to be influenced by) the southern stream jet.. a fractured branch of the northern stream jet (manifesting as slow moving/nearly-stalled waves over the Northern Plains) will no doubt introduce additional complexity/ uncertainty to the evolution of the upper level pattern (and sensible weather conditions) over the Central Plains. Expect increasing upper level cloud cover.. orographic cirrus, in particular.. which may temper highs over western portions of the area. Considerable uncertainty with regard to precipitation chances.
Mon-Wed: Long range guidance suggests that a closed low will develop over the central-northern Rockies or High Plains early next week. If this is the case.. one would expect active/ dynamic weather. Below average confidence in forecast specifics. Forecast confidence typically decreases with range. Below average, in this context, is intended to communicate a further reduction in confidence associated with /inherent-to/ increased pattern complexity, e.g. patterns characterized by cut-off waves and multi-branched jet/wave interactions, among other factors.
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.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 516 PM MDT Thu Sep 18 2025
The few stratocumulus clouds remaining around FL050 should dissipate with the loss of diurnal heating over the next couple hours, leaving mostly clear skies overnight. While winds will generally switch around to a southerly direction tonight into early Friday morning, there may be a period of sufficiently light winds at MCK that patchy dense fog develops. While the probability is low, with HREF chances running around 10-20%, GLAMP guidance suggests brief visibilities as low as 1/4 mile around sunrise. Given this low probability but potentially high impact outcome, made mention of IFR visibilities in a tempo group at MCK from 09z-13z (4-8am CDT).
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.GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None.
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SHORT TERM...Vincent LONG TERM...Vincent AVIATION...Bumgardner
NWS GLD Office Area Forecast Discussion