Marine Weather and Tide Forecast for Granby, CO

DISCUSSION /Through Sunday/
Issued at 208 AM MDT Mon May 25 2026

The flow aloft will be light SSW today with sfc based capes in the 500-800 j/kg range by aftn. Slightly higher values up to 1000 j/kjg will be over the far northeastern plains. DCAPE is fcst to be in the 1000-1500 j/kg range. Overall, expect sct higher based showers and tstms this aftn into the early evening hours. Some areas will see gusty winds associated with the showers and storms.
Higs across the plains will be in the 85 to 90 degree range.

Looking ahead to Tue, the flow aloft will become more southerly as an upper level low develops over the wrn US. Meanwhile, a disturbance embedded in the flow will affect the mtns by aftn. Sfc based capes are fcst to be around 500 j/kg. Overall, it appears the best chc of showers and storms will focus over the higher terrain Tue aftn with lower chances across the plains. Highs over nern CO will be in the upper 70's to mid 80's.

By Wed, a blocking pattern begins to develop as an upper level high forms over the nrn high plains while an upper level low is over the wrn US. This leaves the area in rather light S to SSW flow aloft.
Meanwhile, low level moisture will continue to increase over the plains with SSE winds. Sfc based capes by aftn will be in the 700-1000 j/kg range. Latest blended solutions have rather high pops over much of the area Wed aftn. At this point, not sure where the best chances will be. With weak flow aloft, it appears storms that do form will be slow moving with some potential for heavier rainfall in some areas. Highs on Wed, will range from the mid 70's to lower 80's across the plains.

The blocking pattern will stay intact for Thu as weak S to SSW flow aloft will continue. Sfc based capes will stay in the 700-1000 j/kg range as well. Once again there will be a chance of slow moving tstms in the aftn and early evening hours due to the weak flow aloft. Highs on Thu will remain in the mid 70's to lower 80's across the plains.

By Fri, the blocking high will shift eastward as the upper level low moves into the Great Basin. At the sfc, a lee trough will develop east of the mtns. The flow aloft will begin to increase some from the SSW with sfc based capes increasing to the 1000-1500 j/kg range. As a result, may see a slightly better chc for svr storms by Fri aftn across portions of the plains.

Looking ahead to Sat, the upper level low over the Great Basin will begin to move northeast into the nrn Rockies. This will allow for increasing SW flow aloft across the area. Sfc based capes will be in the 1000-1500 j/kg range over the plains with a better shear profile, so the threat of a few svr storms should increase on Sat.

AVIATION /12Z TAFS through 12Z Tuesday/
Issued at 512 AM MDT Mon May 25 2026

Light drainage winds will continue this morning. Sct showers and a few tstms will be possible between 20z and 00Z. Most of this activity will be high based and may produce brief wind gusts from 40 to 50 mph as they move across. Winds will be erratic this aftn due to outflow boundaries from the showers and storms. By 00Z the tstm threat will diminish with just a slight chc of high based showers thru 02z. Winds may just stay south this evening, except at BJC where NW winds may occur for a few hours. By 06Z south winds may gust up to 25 mph at APA and DIA thru 12z Tue.
BJC will have a SSW wind overnight.

BOU WATCHES/WARNINGS/ADVISORIES
None.