347 FXUS63 KGLD 090107 AFDGLD Area Forecast Discussion National Weather Service Goodland KS 707 PM MDT Fri Aug 8 2025 .KEY MESSAGES... - Isolated to scattered thunderstorms are possible this afternoon and evening, a few of which could be strong to severe. Strong wind gusts are the main hazard, but large hail and a brief landspout tornado can`t be ruled out. - Temperatures trend cooler over the weekend, and additional storm chances exist during the afternoon and evening of both Saturday and Sunday, with the highest chances being in eastern Colorado. Strong to severe storms are possible. && .UPDATE... Issued at 705 PM MDT Fri Aug 8 2025 We have allowed the Heat Advisory to expire as scheduled. Temperatures are cooling across the area. Additionally, the severe weather threat is waning for this evening, but there is still some risk for severe storms until about 2 AM MT. && .SHORT TERM /THROUGH TONIGHT/... Issued at 1245 PM MDT Fri Aug 8 2025 A sfc trough is evident in 18z obs, roughly extending from near Hill City, KS, northward to Cherry County, NE, and minor sfc pressure falls (a millibar or two) have been noted over the last several hours. Much of the short-term forecast hinges on the dewpoints, and 18z obs show a gradient ranging from 40s east of a St. Francis to Leoti line to 55+ east of a Colby to Scott City line. Two areas of high clouds are present, one across southern CO and the other across NW CO. Across the drier air and cloud free parts of the CWA, temps have outpaced guidance, with Goodland reaching 100 degF at 10 AM MT, and Goodland and St. Francis at 105 and 102 degrees, respectively, as of 18z. With the dry air across eastern CO, there is still concern about periods of near-critical fire danger through this afternoon, but wind gusts should stay below 30 mph, and to this point observed wind gusts have been around 20 mph. There is a weak boundary evident on radar, with winds shifting from NW to NNW following it`s passage. Dewpoints are a bit higher behind this feature, and as its interacting with the considerably hotter air in place across Kit Carson, Cheyenne (KS) and Sherman counties, there has been an uptick in the vertical growth of the Cu field. This seems like the most likely area for t-storm development in our area between 1-3 PM MT. Elsewhere, there is agitated Cu beneath the high clouds across SE CO, and convective development is eventually expected to occur in this area and spread NE into the GLD CWA. Given the dry air across the western portions of the CWA, the main hazard will be gusty winds (with isolated gusts over 70 mph possible). If storms manage to persist farther east into the higher dewpoint air, the hail threat could increase. The landspout tornado threat is low, but not zero, especially if storms develop and remain in the vicinity of a boundary. The best window for severe storms will be between 1 PM and 6 PM MT. Several heat bursts were recorded in obs last night, including Goodland which rose 12 degF in an hour to 97 degF at 10 PM MT. While most of these did not register strong wind gusts at observation sites, we did receive a few public reports that locally strong winds were associated with some of the heat bursts. There could be additional heat bursts this evening after the sfc decouples and isolated/scattered convection persists into the late evening ahead of the cold front, but with the southward advance of the cold front overnight I do not anticipate the heat bursts to continue overnight. Models continue to show much higher moisture content behind the cold front. There is some concern that despite modest sustained winds behind the front, this increase in moisture could lead to fog and/or stratus, which is not currently captured by model guidance. Additionally, the northeast wind direction will result in an upslope component to the low-level flow. Satellite imagery and obs from across NE/SD this morning showed a stratus deck with ceilings between 1-3km AGL, and would not be surprised if a similar deck occurred in the post-frontal regime early Sat AM. MAV/MET guidance have had a better handle on some of the other recent fog/stratus events, and these guidance sources do have much higher cloud cover early Sat AM than other models, so trended the sky cover forecast higher (but still may not be high enough). && .LONG TERM /SATURDAY THROUGH FRIDAY/... Issued at 1247 PM MDT Fri Aug 8 2025 The expectation remains that the cold front will push south of the CWA for the daytime hours tomorrow, and the post-frontal regime will feature cooler temps with highs in the upper 80s/near 90F. It is expected to be more humid, however, as most models show a plume of higher dewpoints positioned across the CWA, ranging from the low 60s in east CO to near 70F in the eastern CWA. (Notably, some models have this swath of higher moisture shunted completely south of the CWA). While most of the area should stay dry through mid- afternoon, convection is expected to develop along the Front Range and moderate 500mb westerly winds (35-45 knots) within the base of the upper trough should help advect this activity eastward. Thanks to the expected higher dewpoints, these storms should move into an environment with greater instability than what has been present in recent days, with forecast MUCAPE values of 2000-3500 J/kg. With decent upper level flow, deep layer shear values approach 40 knots, and this parameter space will be conditionally supportive of severe storms. There are still a number of questions complicating Saturday`s severe storm forecast, including the potential influence of anvil shading from the initial convection along the Front Range and what impact it will have on the thermodynamics across our area. Forecast hodographs are straight, with the mean wind almost due east (tracking directly parallel to the anvil level winds), and bunkers motions for right/left movers are not sufficiently deviant to avoid their own anvil shading. NAM forecast soundings show a subtle warm nose (cap), so the loss of insolation could dramatically reduce the severe threat. For now, a marginal risk feels appropriate given the uncertainties, but if everything comes together favorably, the parameter space could support significant severe hazards (wind gusts over 70 mph and hail larger than 2"). CAMs do not agree on the storm timing, but do suggest that storms and associated severe risk could continue into late Sat night. Another round of storm development is expected along the Front Range Sunday, aided by a slow-moving upper wave. This will keep precip chances in the forecast for Sun afternoon-evening, increasing with westward extent. Once again, there is a conditional threat for strong to severe storms, although the latest guidance does suggest that instability values on Sun will be lower relative to Sat. Can`t rule out some lingering precip into the early parts of next week as a weak upper level trough slowly shifts east of the areal. Otherwise, next week is looking mostly dry with warming temperatures as upper level ridging builds over the Plains. High temps are forecast to rise from the low/mid 80s on Mon to mid/upper 90s Wed-Fri. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 355 PM MDT Fri Aug 8 2025 Some showers and storms may impact each terminal this evening but any threat currently appears to be done around 06-07Z. Winds are forecast to remain from the northeast which is climatologically favored for fog and stratus development with MVFR ceilings currently looking to be the main concern at this time. VFR conditions are then forecast to return around 14-15Z. Another round of storm potential may impact the GLD terminal just after the end of this TAF period as well with severe potential on the table. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None. && $$ UPDATE...CA SHORT TERM...Erwin LONG TERM...Erwin AVIATION...Trigg