textproduct: Goodland

KEY MESSAGES

- Occasional shower chances through the rest of the week.

- Marginal severe risk Thursday afternoon and evening, primarily in Colorado, but could see that into northwest Kansas through the evening hours.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 255 AM MDT Wed May 20 2026

Through Mid-Afternoon: Guidance continues to indicate that low- level moisture return assoc/w modest SE to SSE low-level flow will be a slow/gradual affair that's confined to eastern Colorado, mainly western portions of Kit Carson/Cheyenne counties where 850 mb dewpoints around -1 to -3C (this morning) are progged to increase to 2 to 7C during the late afternoon (21-00Z). Mid-level (700-500 mb) warm advection in advance of an upper level wave.. a modest 250-350 mb trough / shear-axis progressing slowly east across the central Rockies.. may foster the development of light showers over portions of the area later this morning, mainly west and north of Goodland between ~12-18Z (6a-12p) when/where mid-level warm advection -may- be strong enough to capitalize on/utilize a very meager amount of elevated instability (50-100 J/kg MUCAPE). Expect broken/overcast cloud cover over most or all of the area and 10 to 20 mph SE winds with highs in the upper 50's to mid 60's.

Late Afternoon-Toninght: A modest (1013-1015 mb) lee cyclone will develop in southeast CO this late this afternoon into tonight as the aforementioned upper wave emerges from the Rockies and progresses east across the High Plains. Guidance suggests that increasing low-level moisture will foster marginal diurnal destabilization (~250 J/kg mlcape) along/west of a line from Akron-Limon-Lamar this afternoon, when/where low-level convergence in vicinity of the developing lee cyclone will aid in the development of scattered showers/storms that progress downstream/east toward the CO-KS border by sunset (00-02Z), at which point low-mid level (850-600 mb) warm advection on the E and NE periphery of the developing lee cyclone and modest DPVA attendant the upper wave may assist in the development of additional showers/storms over northwest KS this evening. While recent (06Z 05/20) runs of the HRRR and NAM NEST broadly agree that convection will develop in CO late this aft and progress east across northwest KS this evening and overnight, they vary considerably w/regard to convective coverage.. the NAM NEST being the least-agressive solution. While gusty winds may accompany any storms, severe weather is not anticipated. Expect lows in the lower-mid 40's. -Vincent

Thursday will see a somewhat similar scenario, but shifted northward as the northern Rockies upper low strengthens and a stronger shortwave trough moves across eastern Colorado at the time of peak heating. The instability axis will shift further east and the REFS has a corridor of 1000-1500 j/kg from Limon to Fort Morgan along with 35kts of deep layer shear. While the surface-based instability will rapidly weaken after 00Z, MUCAPE of at least 500 j/kg as well as deep layer shear of 40kts are forecast as the showers and thunderstorms move in from Colorado Thursday night. The parameters suggest a marginally severe storm or two will be possible with some pockets of MUCAPE up to 1000 j/kg forecast by the NAM through about 06z before weakening. NBM has rain amounts of up to 1" in eastern Colorado Thursday evening with the stronger storms, then around 0.25-0.50" in the rest of the area overnight with rain and isolated storms.

The upper trough axis and associated surface cold front will be slowly moving through the area Friday morning with showers and isolated thunderstorms continuing. This morning activity should limit the afternoon instability, though it is possible some clearing could occur on the western and southern edges of the forecast area. Also will need to see where the front ends up in the afternoon as new convection could develop along it. However, both the GFS and ECMWF currently have the front well to the south, entering Oklahoma, while the NAM is slower and has the front in the southern part of the area. Since this is still a few days out and there will be multiple days of convection which may impact the ultimate timing and location of the front, confidence is low in the details and any potential severe hazards on Friday.

Temperatures through the period show little variation with highs in the 60s and lows in the 30s and 40s.

LONG TERM /SATURDAY THROUGH TUESDAY/

Issued at 110 PM MDT Tue May 19 2026

Saturday, our region is forecast to be under a weak southwest flow with a weak trough along the Rocky Mountains. Expect mostly sunny skies and a slight warming trend through the beginning of the work week. High temperatures are forecast in the 70s for Saturday and the 80s for Sunday and Monday. Saturday will have a 25-35% chance for showers and thunderstorms across the county warning area (CWA) from weak shortwave passages.

After Sunday, we transition to more of a ridge pattern, so expect primarily sunny skies and gusts up to 30 mph in the afternoons for our Colorado counties Sunday and Monday. Warm temperatures continue Tuesday with highs forecast in the 80s. Wind gusts up to 40 mph are possible Tuesday for the western CWA. With relative humidity (RH) values overall trending down and forecast in the low 20s for Tuesday, fire weather potential will need to be monitored through the week.

Models are in disagreement on the track and evolution of a surface low off the coast of Baja California that starts to develop late Sunday. If this surface low ends up tracking toward our region, we have potential for an active pattern and severe weather potential late next week.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1145 PM MDT Tue May 19 2026

GLD: VFR conditions are anticipated to prevail through the TAF period, with ceilings at or above ~6,000 ft AGL. SE winds at 7-12 knots will increase to 12-15 knots w/gusts to ~20 knots a few hours after sunrise and persist through the afternoon. Winds will back to the ESE-E and decrease to 10-12 knots after sunset, near the end of the 06Z TAF period.

MCK: VFR conditions are anticipated to prevail through the TAF period, with ceilings at or above ~5,000 ft AGL. There is low probability (~30%) for MVFR conditions associated with showers after sunrise, mainly between ~12-16Z. SE winds at 5-10 knots will modestly increase to 10-13 knots a few hours after sunrise and persist through the afternoon. Winds will back to the ESE-E after sunset, near the end of the 06Z TAF period.

GLD WATCHES/WARNINGS/ADVISORIES

KS...None. CO...None. NE...None.