Marine Weather and Tide Forecast for Granby, CO

DISCUSSION /Through Monday/
Issued at 206 PM MDT Mon May 12 2025

Current satellite imagery shows some cumulus have formed over the foothills and eastern plains this afternoon. Moisture is sparse across the majority of the forecast area, with some heightened moisture in place over the far eastern plains where the cumulus reside. There is enough instability in place coinciding with the aforementioned moisture to allow for an isolated shower or weak storm to form, mainly for Lincoln and Washington Counties through the afternoon. With the dry lower levels in place, there is a small chance that we see a dry microburst or two under these showers, with gusts between 35-45 mph possible.

The forecast remains largely unchanged from yesterday's. Tomorrow is still expected to be another warm and dry day ahead of Wednesday's pattern shift due to the approaching trough that has officially pushed ashore the Pacific Northwest today. There will be increased fire weather concerns for the next few days as winds begin to increase, especially over the mountain valleys on Tuesday. However, with our recent fuel status update showing all zones to be under critical thresholds, no highlights are expected at this time. With a tightening pressure gradient expected as well as increased southwesterly flow aloft on Wednesday, winds are expected to increase further, bringing fire weather concerns to portions of the plains. We will monitor fuels through tomorrow's warm and dry conditions to determine if any highlights will be needed for Wednesday.

As the trough passes over the Rockies on Wednesday, an associated cold front at the surface is progged to slide south across the forecast area Wednesday afternoon/evening. Depending on exact timing, there could be some slight impacts on the afternoon high temperatures, but either way, temperatures are expected to see about a 10 degree cool down from Tuesday. We will see increasing PoPs from Wednesday afternoon into the evening, with a chance for some showers and thunderstorms as the trough axis passes and the front drops south.

Temperatures will moderate towards normal through the weekend behind the front. A shortwave looks to pass through on the back side of the passing trough on Thursday that will bring a chance for afternoon showers and storms to the mountains and adjacent plains. The more active pattern looks to continue for the second half of the week with Sunday looking like the best potential for widespread precipitation across the forecast area.

AVIATION /00Z TAFS through 00Z Wednesday/
Issued at 630 PM MDT Mon May 12 2025

VFR through the TAF period. Winds will generally be drainage tonight. During the day tomorrow, wind direction will be difficult to forecast and the winds will likely end up being quite variable.
No showers or thunderstorms are expected.

BOU WATCHES/WARNINGS/ADVISORIES
None.