textproduct: Goodland

KEY MESSAGES

- A Severe Thunderstorm Watch has been issued for eastern Colorado until 1 AM MT. Severe storms are possible this afternoon into the overnight hours may hail up to 3 inches in diameter, 80 mph wind gusts, and a tornado or two..

- Additional potential for strong to severe storms and flooding overnight and into the morning Wednesday.

- Locations that received heavy rain during the past several days are more prone to experience flash flooding through the next 24-48 hours. Flood Watch has been expanded to account for this.

- Severe weather chances continue through at least Thursday.

UPDATE

Issued at 441 PM MDT Tue Jun 23 2026

A Severe Thunderstorm Watch has been issued for eastern Colorado until 1 AM MT. Severe storms are possible this afternoon into the overnight hours may hail up to 3 inches in diameter, 80 mph wind gusts, and a tornado or two. Convection is starting to form in central Colorado and is expected to expand to the east. This could be a threat that extending into early morning Wednesday.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 1205 PM MDT Tue Jun 23 2026

NW flow is forecast to continue through the day with embedded shortwaves. These shortwaves are forecast to continue to lead to developing showers and storms through the morning. Main focus in the next few hours is the potential for a developing MCS and additional flooding concerns as the northwest flow remains parallel with the overall mean flow and continues with the flooding threat. Efficient rain producers have already been observed across Dundy and Hitchcock this morning with 1-2 inch per hour rainfall rates being observed which is further exacerbating the flooding threat from the heavy rain that was observed over the weekend. This along with the potential for more overnight heavy rain (which I will get into here later) have opted to extend the Flood Watch through 15Z Wednesday.

As mentioned concern is increasing for a potential MCS currently originating in western Nebraska and moving through favoring locations along and east of Highway 25. Wind gusts up to 60 mph may be possible with this MCS as it moves through along isolated instances of severe hail with any stronger updraft. 12Z RAP data does have a more favorable environment for severe winds to the west of Highway 25 so if the MCS could track a little further west then the severe threat would increase. With this MCS, flooding remains a concern with 1-2 inch per hour rainfall rates expected in the heavier cores. Radar from storms earlier this morning estimates 1-2 inches of new rainfall across far east Dundy and norther/western Hitchcock county so will need to closely watch this area as the MCS moves through. 12Z data is further supporting the potential for higher rainfall rates as well with this MCS as it moves across already saturated portions of the CWA so have opted to expand the Flood Watch into Red Willow, Norton, Sheridan, Graham and Gove counties.

Now to this afternoon, evening and tonight. HREF and REFS paint balls suggest that there is around 10% chance of a discrete supercell developing across eastern Colorado between 22-02Z which would be capable of all hazards. The big question for the day is how long will the cloud cover hold across Colorado and will the daytime showers and storms stabilize the environment. Subtle shortwaves through the afternoon and evening look to be main driver should any discrete cells develop. The next main form of forcing is overnight after 06Z as 500mb shortwave moves through the center part of the area and correlates with the nose of a 700mb jet. Showers and storms are forecast to develop along this nose leading to the potential for more heavy to torrential rainfall potential. Along the 700mb jet nose CAPE is forecast to increase further which looks to be where our severe potential may lie. Large hail would be the main hazard along with the potential for very large hail if we could get a sustained supercell.

On top of the showers and storms a fairly strong signal for fog is forecast across most of the area as well. Surface to 1km mixing ratio differences around 3-4 g/kg which suggests that some dense fog may be possible but at this time am not anticipating widespread dense fog. Showers and storms overnight however may disrupt the fog, so will maintain the patchy fog wording in the forecast from the previous shift.

Rainfall is forecast to continue through at least mid morning Wednesday but may last longer. Very little change in the overall synoptic pattern is seen with a surface high in place across the southern Plains. More robust shortwaves are forecast to move off of the Rockies during the afternoon and into the evening. Additional showers and storms are forecast to develop and move to the east into the area. Initially discrete supercells may be possible with all hazards before clustering together into another MCS as the evening and night goes as the area becomes in the in the left exit region of a developing 500mb jet which will further help increase coverage of showers and storms. Large to very large hail and damaging winds are forecast to be the primary hazards. If a bowing segment can occur initially then wind gusts may exceed 80 mph. A tornado or two may be possible as well as the low level jet increases during the evening.

Flooding is forecast again to become an issue Wednesday night into Thursday morning especially across the areas that have seen the heaviest rainfall over the past several days. The signal is there for the potential for several more inches of rainfall to occur.

LONG TERM /THURSDAY THROUGH TUESDAY/

Issued at 130 PM MDT Tue Jun 23 2026

Chances for showers and thunderstorms continue Thursday for the county warning area (CWA). Our region is forecast to be in a mostly zonal flow with multiple shortwaves traversing through the area. Severe weather is possible for the CWA with Probability of Precipitation (PoPs) of 60-90% Thursday. Instability has decreased since yesterday's model runs, but the environment is still supportive of a wind and hail risk with CAPE around 1000 J/kg and around 20 knots of deep-layer shear. Model soundings show a skinny CAPE profile. This, combined with recent substantial rainfall across the CWA, raises flooding concerns.

Friday, we transition to more of a weak ridging pattern with an incoming trough west of the Rocky Mountains. Expect sunny skies and high temperatures forecast in the 80s. Saturday through the end of the forecast period continues to warm with high temperatures forecast in the 90s to low 100s for the CWA. Saturday onward will also be fairly windy with afternoon gusts around 35 mph possible for our Colorado counties.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 333 PM MDT Tue Jun 23 2026

VFR conditions are forecast to start this TAF period but an increase in stratus is forecast to return around 04Z for each terminal. Showers and storms are forecast to develop this evening and overnight with higher confidence at GLD. Patchy fog is also a concern where rainfall isn't. Stratus and patchy fog potential is forecast to continue through around mid to late morning before waning. Towards the latter part of the period another round of storms may be possible for GLD.

HYDROLOGY

Issued at 1205 PM MDT Tue Jun 23 2026

MCS moving across the area this morning has moved over locations that has seen the heaviest rainfall from the past several days. These have been very efficient rainfall producers with 1.5-2.5 per hour rainfall rates. A report of 3+ inches has been received from northern Hitchcock county since midnight. The Flood Watch was expanded earlier today to account for this round of heavy rain along with the potential for additional heavy rain tonight.

The favored area for tonight is mainly for Sheridan, Graham and Gove counties as the nose of a 700mb jet sets up over those counties. High PWATS are forecast to continue as well leading to the potential for flooding as this mornings heavy rain may have exacerbated already saturated soils from the weekend. There is the potential for the heavy rains to continue into at least the mid morning hours as well.

Assuming everything can remain on par with the current forecast, additional, perhaps even more impactful flooding may occur Wednesday night as storms merge into an MCS from discrete cells from Colorado. Very high PWATS around 1.5 inches are forecast to remain but the more concerning feature I'm seeing with current guidance is slower corfidi vectors which may lead to more of a backbuilding and training threat. Very strong agreement within ensemble qpf amounts as well of inches of rainfall occurring. I contemplated expanding and further extending the Flood Watch to account for this signal but wanted to hold off and ensure any showers and storms Wednesday morning don't disrupt the atmosphere from the potential for heavy rain Wednesday night and into Thursday morning.

GLD WATCHES/WARNINGS/ADVISORIES

KS...Flood Watch through Wednesday morning for KSZ001>004-015-016- 029. CO...None. NE...Flood Watch through Wednesday morning for NEZ079>081.