textproduct: Goodland

KEY MESSAGES

- Air temperatures nearing 100-105 are forecast through Tuesday. Heat indices may approach 105 along and east of Highway 83 in Kansas.

- Isolated storms with dry lightning and possibly wind gusts up to 60 mph are forecast to develop south of Interstate 70 this afternoon. Additional fire starts due to lightning is possible as humidity is forecast to be in the low to mid teens.

- Another round of strong to severe storms is forecast during the evening hours and may linger past midnight. Wind gusts up to 70 mph and hail around half dollar size are possible.

- Patchy fog in Red Willow County area overnight into Monday morning.

- Storm chances continue daily the next few days.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 1141 AM MDT Sun Aug 9 2026

Upper air analysis continues to show the ridge of high pressure centered over the Four Corners Region. The ridge is expanding slightly to the east, and should continue to do so through the day. Satellite imagery shows clouds and smoke moving around the ridge; area of fog was shrinking over Central/Eastern Nebraska. At the surface a cold front was slowly moving south through the middle forecast area. Further north another boundary was moving south through Southern Nebraska.

Unclear at this time how far south the weak cold front will move and how the other boundary moving south in Nebraska will affect the weather. Dew points are increasing behind it, so it may reinforce the higher dew points behind the cold front this afternoon. If it continues moving south through the morning it may push the cold front further south, which may also expand how far the better environment for hail would be.

This afternoon some models show a potential for isolated storms over the southeast part of the forecast area as a weak upper level trough axis moves through. The weak cold front is already in the southwest part of the forecast area, and clouds are increasing in coverage nearby the front. Confidence is 20% for storms to form along the stalled front due to almost no instability and very weak lift at best. There may also be some aid from the LLJ nose along the southeast border of the forecast area. Dry lightning and wind gusts up to 60 MPH will be the main risk for any storms that form there.

Regarding the heat potential, concur with prior shift that the heat index will be low enough to negate a heat advisory. In addition, the heat has been mentioned for a couple days in weather graphics and hazardous weather outlook so this is not a surprise heat wave.

The main round of storm activity will move in from the west around 6 PM MT ahead of the upper level short wave trough. Model guidance indicates the majority of the storm activity should remain north of I-70. Worst case for wind gusts would be 70 MPH. Most of the model data is in the 40-50 MPH range for wind gusts. The best time for any severe wind gusts will be 7-10 PM MT, with the window for wind gusts from thunderstorms ending around midnight.

Confidence is low (20%) for blowing dust to be much of an impact. As prior shift observed, mixing heights are quite high allowing dust to mix out, plus the most likely wind speeds will be under 60 MPH (dust storm conditions typically occur with wind gusts above 60 MPH).

There continues to be a potential for large hail up to half dollar size this evening. This threat will mainly be north of Highway 36 where the deep layer shear will be around 30 kts and the instability will be higher due to the higher dew points. The window for large hail will be 7 PM to midnight MT.

Given the same air mass as last night, heat busts may also occur with any storms that move through.

There will be moisture advection over the northeast part of the forecast area overnight through sunrise Monday. As such fog may form so included a mention of patchy fog.

Continue to be skeptical regarding receiving much rainfall with these storms. The cloud bases will be quite high, allowing evaporation to limit rainfall reaching the ground. However, wouldn't be surprised if the storm coverage ends up being higher than what the current forecast is suggesting. This is due to the role of the outflow boundaries potentially generating storms. If this happens storm coverage may be greater than forecast, but the storms will likely be moving rather quickly and not last long if the outflow boundaries are the main source for storm formation.

The upper level short wave trough will move east of the forecast area during the overnight hours bringing storm chances to an end.

Monday a similar weather pattern will continue. Highs will be similar to today. An upper level short wave trough will move into the forecast area from the west during the early evening. However the short wave trough looks to fill as it moves into the forecast area; this may be due to the ridge over the Southeast CONUS joining with the ridge over the Four Corners Region. Precipitation potential is much less than this evening, confined to East Central CO. Wind gusts should be of less magnitude than this evening. The storm/wind threat should end around 9 PM MT.

LONG TERM /TUESDAY THROUGH SUNDAY/

Issued at 239 PM MDT Sun Aug 9 2026

***Tuesday***

A flattened ridge at 500-mb is favored to be in place overhead Tuesday morning. A shortwave trough embedded in the ridge favors a low developing at the surface across the forecast area. Surface winds are expected to be light as the low only undergoes weak to modest deepening and centers itself over the County Warning Area (CWA). Hot conditions look to continue under this setup, with highs currently forecast in the upper 90s to mid 100s. Confidence in a Heat Advisory being needed Tuesday continues to rise, currently around 40%. Additionally, dry conditions are forecast as light westerly to southwesterly surface flow continues to bring in dry air, and temperatures rise through the afternoon. Relative humidities are forecast as low as the upper teens across Eastern Colorado Tuesday afternoon. However, the risk for critical fire weather conditions is low due to the weaker surface winds. Confidence in a Red Flag Warning being needed is less than 5%. However, it should be noted that there is a small chance (20% chance or less) for showers during the evening hours Tuesday, particularly in West-Central Kansas and East-Central Colorado. NAMNST model soundings for 00z Tuesday show inverted-V profiles up to around 3 km, which may suggest the potential for dry lightning with these storms. This could serve as an additional form of fire starts.

***Wednesday/Thursday***

GEFS and EC ensemble guidance are in support of upper-level ridging remaining overhead through Thursday, as troughing builds in across the Western United States. The surface low from Tuesday looks to remain approximately stationary over the area Wednesday and Thursday. Easterly/northeasterly surface flow in Southern Nebraska ahead of southerly flow from the Gulf of America would support moisture returning to the area, in addition to temperatures beginning to cool. Highs are forecast in the 90s on Wednesday, and the upper 70s to upper 80s on Thursday. Additionally, LREF guidance shows a 75% chance or higher both Wednesday and Thursday for dewpoints greater than 60 F, most particularly across portions of Red Willow County in Southwest Nebraska, and Decatur and Graham Counties in Northwest Kansas. Thunderstorm activity appears more probable across the area as well. NBM 24 hr precipitation guidance shows probabilities in the 60-80% range across Southwest Nebraska and Northern Yuma County in Colorado for greater than 0.1 inches of rain Wednesday. These probabilities extend into Northwest Kansas and East-Central Colorado on Thursday. LREF guidance also shows that this activity will be in association with a 30-50% chance for surface CAPE (a measure of atmospheric instability) greater than 1000 J/kg. Thunderstorms are in the forecast both days, but the risk of them becoming severe is low at this time, as GFS and EC model soundings show less than 30 kts of sfc-500mb vertical shear both days. However, it is important to note that hotter conditions on Wednesday may promote microburst conditions with thunderstorms, which could be associated with 60-70 mph winds. Even so, confidence in severe weather occurring is about 5% each Wednesday and Thursday.

***Friday-Sunday***

Deterministic guidance diverges a bit by Friday, though ensembles continue to show troughing off to the west alongside ridging overhead. As such, conditions similar to that of Wednesday and Thursday are forecast, though there is some uncertainty regarding whether storms will be severe or not. Still, NBM 24 hr precipitation guidance shows the highest probabilities for greater than 0.1 inches of rain across Eastern Colorado (60-75% through Saturday). As for temperatures, highs in the 70s and 80s are forecast to continue through the weekend.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1141 AM MDT Sun Aug 9 2026

VFR conditions forecast for the TAFs. Winds will be light and somewhat variable for both sites. However thunderstorm development will impact winds at both sites. Current model data indicates wind gusts of 30-40 kts with thunderstorms; worst case gusts would be 60 kts. At this time do not have enough confidence to place a mention in the TAFs aside from the VCTS. Best time for KGLD to be impacted by wind gusts would be 3-5z. KMCK may be far enough north to not be impacted by thunderstorm winds.

Otherwise there may be fog near KMCK overnight through 14z.

GLD WATCHES/WARNINGS/ADVISORIES

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