textproduct: Goodland

KEY MESSAGES

- Heat Advisory in effect today for southwest NE and portions of northwest KS, where hot temps and high humidity will drastically increase the potential for heat related illnesses.

- Late afternoon-evening storm chances return by mid-week.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 340 PM MDT Mon Jul 20 2026

Through Tonight: No change from prior forecast; Heat Advisory remains in effect for southwest Nebraska and portions of northwest Kansas (east and north of Colby), where air temperatures and/or heat indices ranging from 100 to 105F are likely. As of 1:15 pm MDT, multiple ASOS/AWOS sites (KMCK, KNRN, KOIN, KSYF) have reported air temperatures in the triple digits, hottest in Norton (KNRN) where the temperature was 102F and heat index was 103F.

Tue: An inverted surface ridge, the southernmost extent of surface pressure rises and low-level cold advection in the wake of a modest mid-latitude cyclone (progressing east across southern Ontario and the Upper Great Lakes tonight) will extend southward into the Goodland county warning area by sunrise Tue, manifesting as a NE or ENE wind shift and modest effective cold frontal passage. Relatively breezy (15-25 mph) ENE to E winds will prevail through the majority of the day. In contrast to previous days, horizontal thermal advection (weak low-level cold advection in the wake of the front) will be the deciding variable w/regard to high temperatures. Guidance suggests highs ranging from 91-94F (north) to 94-98F (south). While low-level convergence along the southward progressing effective front could potentially serve as a focus for convection over southwest KS during the late afternoon, a profoundly suppressive (and thermodynamically hostile) environment beneath the core of the upper level ridge will significantly hamper, or altogether preclude, in-situ convective development.

Tue night: Southeasterly low-level flow /moisture advection/ beneath a pronounced elevated mixed layer will foster marginal to moderate nocturnal destabilization (500-1500 J/kg MUCAPE) over the Tri-State Area during the late evening and overnight. Convection allowing guidance suggests that low-level upslope flow may assist in the development of diurnal convection along portions of the Cheyenne Ridge and CO Front Range (I-25 corridor) during the late afternoon (~6-9p MDT).. and that light (10-15 mph) W to SW steering flow could allow said activity to slowly/gradually propagate east into portions of far northeast CO and southwest NE during the late evening and overnight hours. If convection emanating from the the Rockies/Cheyenne Ridge is sufficiently deep/long-lived (e.g. persistent enough to produce an MCV), this is certainly possible, though, even then.. W to SW steering flow would likely keep the majority of activity north of the Goodland county warning area. Simulated reflectivity forecasts via 18Z runs of the HRRR and NAM NEST are consistent with this line of thinking. Bottom line, expect a low (~30%) chance for thunderstorms along/north of Highway 36 Tue eve- night.

Wed-Wed night: A pronounced upper level ridge will persist over the region, though.. the core of the ridge will shift southward over the Southern Plains (TX-OK). Guidance suggests that surface high pressure anchored over the Upper Midwest will help maintain breezy ESE-SE low-level flow over the Tri-State Area. Expect sensible weather conditions analogous to Tue, i.e. highs in the lower-mid 90's (north) to mid-upper 90's (south) and a similar potential for evening/overnight convection, mainly in northern portions of the Goodland CWA. Given that a weak W to SW steering flow regime will persist over the region, and that environmental conditions could be modified by early morning convection, there is very low confidence in convective coverage and evolution.

LONG TERM /THURSDAY THROUGH MONDAY/

Issued at 232 PM MDT Mon Jul 20 2026

Ensemble guidance remains in good agreement on the synoptic evolution through late week and into next weekend, featuring a late summer Southern High Plains/Central Rockies ridge of high pressure pattern. The Tri-State Area will sit on the northern periphery of the mid level ridge axis, maintaining generally zonal flow aloft with subtle shortwave trough impulses ejecting out of Colorado on Thursday and Friday afternoons.

High confidence exists regarding near to above normal warmth. The NBM 25th to 75th percentile range for daily maximum temperatures remains exceptionally tight (spread of only 3-5 degrees) for Saturday and Sunday with temps nearing 100, indicating strong ensemble consensus for above normal temperatures this weekend. Model spread is higher (i.e. higher uncertainty) for maximum temperatures for Thursday and Friday on the order of 6-10 degrees ranging from the upper 80s to the lower 90s depending on cloud cover and precipitation coverage. As the 500 mb ridge amplifies slightly over the Southern Plains Friday into Sunday, warm 850 mb thermal ridges (30-33 C) build into the Plains. Median NBM highs push into the upper 90s for most of the CWA, with the eastern third (e.g., Hill City, Norton, McCook areas) seeing a 40-60% probability of temperatures topping 100 degrees on Saturday and 60-80% on Sunday for much of the area. Maximum afternoon heat index values across eastern locations may approach between 100 and 105 on Saturday and Sunday afternoons as low level moisture lingers east of the dryline.

Thursday Afternoon PoPs peak in the 20-40% range west of KS Hwy 27 and across eastern Colorado (Cheyenne/Kit Carson counties) where terrain forced lift and low-level convergence are greatest. Later in the evening model forecasts indicate higher probabilities heading into Thursday night with increasing chances of at least some precipitation with model averages between 0.15 and 0.25, locally higher amounts possible (as high as 40% chance of exceeding 0.30). Ensemble SBCAPE probabilities exceed 40% for > 1000 J/kg east of the dryline each afternoon. However, deep-layer shear remains modest (20-25 kts), keeping storms mostly somewhat unorganized at this time. High inverted-V low levels (DCAPE > 1200 J/kg) suggest localized strong downburst winds (40-60 mph) will be the primary threats with collapsing cells.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 340 PM MDT Mon Jul 20 2026

VFR conditions will rule through the 18Z TAF period at both terminals. Light (~5-10 knot) SE or variable winds will prevail this afternoon and evening. A few sporadic gusts to 15-20 knots are possible during peak heating/mixing this afternoon, similar to yesterday. Winds will shift to the NE or ENE and increase to 10-15 knots during a modest cold frontal passage late tonight (~07-10Z Tue). An hour or two after the initial wind shift, by sunrise, winds will further increase to 14-18 knots w/gusts to 20-25 knots. Relatively breezy NE to ENE winds are expected to persist through the remainder of the 00Z TAF period.

GLD WATCHES/WARNINGS/ADVISORIES

KS...Heat Advisory until 1 AM CDT Tuesday for KSZ001>004-014>016. CO...None. NE...Heat Advisory until midnight MDT /1 AM CDT/ tonight for NEZ079>081.