Marine Weather and Tide Forecast for Granby, CO

DISCUSSION /Through Friday/
Issued at 1047 PM MDT Fri Apr 10 2026

SW flow aloft will remain over the area on Sat as a disturbance moves across WY. At the sfc, low pres will extend from ern WY into ern CO. Overall, low level moisture will mix out by aftn, except over the far nern plains where SBCAPE may be up to 1000 g/kg.
Further west, SBCAPE will be 500 j/kg or less and over the higher terrain. However, lapse rates will be decent along with quite a bit of mid level moisture. Thus will see higher based showers with a few tstms across the area. DCAPE over the plains will be around 1000 j/kg so a few of the stronger storms may produce marginal svr wind gusts. Highs will be warmer with readings in the 70's across the plains.

On Sun, drier air in SW flow aloft will spread across the area with little chc of pcpn. In addition, winds will increase over the higher terrain and portions of the plains. Highs across the plains will range from 75 to 80 degrees.

For Mon, an upper level trough will move in the Great Basin with increasing SW flow aloft as a sfc lee trough extends from ern WY into ern CO. Cross-sections show limited moisture embedded in the flow thru aftn with dry air in the lower levels. As a result, it will be warm and dry over the plains with just a slight chance of aftn showers over the higher terrain. Winds will remain gusty over the higher terrain and portions of the plains.

Looking ahead to Mon night into Tue, the upper level trough over the Great Basin will move across as a disorganized system with rather weak QG ascent. Best chc of precip will be in the mtns with just a chc of showers across the plains. Overall amounts with this system look to be on the light side at this time.

On Wed, the flow aloft will be zonal with latest cross-sections showing very little moisture in the flow. Thus it looks mainly dry with warmer temperatures as downslope low level flow develops.

On Thu, the flow aloft will become more SW as an upper level trough approaches from the Pacific NW. For now, Thu looks dry with above normal temperatures.

AVIATION /12Z TAFS through 12Z Sunday/
Issued at 534 AM MDT Sat Apr 11 2026

VFR conditions will persist through the period, but main concern today will be gusty outflow winds associated with high based showers and isolated storms.

Southwesterly winds will start this period, and should hold through most of the day today with a slight increase in speeds as we hit peak mixing by 18Z-20Z. However, those southwest winds will likely (60% chance) be interrupted by gusty and variable winds to 30-40 kts due to high based showers/isolated storms 20-24Z. Forecast soundings show the airmass reaching convective temps as early as 19-20Z, which means this could be an earlier day than normal for high based convection. At the same time, models sometimes mix too fast when high clouds are present. Therefore, we'll introduce gusty winds with passing showers starting 20Z at KAPA and KBJC, and 21Z and KDEN...and keep them til about 24Z.
DCAPE values reach near 1000 J/kg so gusts to 30-40 kts seem plausible and a low chance (10-20%) of gusts to 45 kts considering the stronger environmental flow also developing today (700 mb winds increasing to ~25 kts). Given MLCAPE is limited to 200 J/kg or less, the threat of thunder is relatively small (about 20%) so opted for TEMPO -SHRA vs -TSRA but impacts may be the same. Winds should settle down by 01-03Z with loss of heating and mixing, and most convection moving off to the east.
Eventually, normal S-SW winds will develop 03Z-06Z Sunday and hold through ~18Z Sunday.

FIRE WEATHER
Issued at 1047 PM MDT Fri Apr 10 2026

Have expanded watch for Sunday to include plains areas near the WY border and across South Park. Winds may end up being borderline in some areas but humidity levels will be low and precip has been minimal. At this time, best chc for stronger winds appears to be over South Park, southern Foothills, Palmer Divide and near the Wyoming border.

BOU WATCHES/WARNINGS/ADVISORIES
Fire Weather Watch from Sunday afternoon through Sunday evening for COZ214-216-238-239-241-242-246>251.