Marine Weather and Tide Forecast for Denver, CO

UPDATE
Issued at 827 PM MDT Mon Apr 28 2025

Cold front has pushed to the Palmer Divide as of 830 PM, with much cooler air settling across the forecast area. A few showers continue north of Denver, mainly from Fort Collins area to Fort Morgan. However, these should end in the next couple hours as the airmass continues to stabilize. We will fill in with areas of stratus across the plains with sufficient cold/moist advection.
Overall the forecast is on track with only minor adjustments made for current conditions and short term trends. A chilly night in store for sure with lows in the 30s across the plains, and 20s mountains.

SHORT TERM /Through Tuesday/
Issued at 216 PM MDT Mon Apr 28 2025

The forecast this afternoon is still largely on track. Some shallow convection has developed across northern Weld into Morgan/Logan counties, where SPC mesoanalysis shows an axis of meager (MUCAPE of 100-250 J/kg) instability. This is slowly drifting south-southeastward. It's unclear if this will make it down to the I-70 corridor, but given the dry sub-cloud layer airmass shown by recent ACARS soundings, any impacts across the metro would be minimal... with just a few sprinkles and some briefly gusty winds.

Meanwhile, a cold front is advancing across southeastern Wyoming/southwestern Nebraska. Guidance is a little too dry behind the front, and recent obs from Torrington and Scottsbluff have dew points near 40F. This front should be a little more diffuse than some of the stronger cold fronts we're known for here... but we should generally see the main wind shift/moisture gradient reach the CO border by about 3-4pm, and should make it into the Denver area by about 6pm this evening. Some low cloud cover is expected to develop in the moist post-frontal airmass overnight, with stratus quickly burning off tomorrow morning.

A fairly typical spring day is in store for tomorrow. Today's broad trough axis stretching from Utah into the Dakotas will likely split, with a piece of the trough closing off and drifting into northern Arizona tomorrow afternoon. Broad, moist, south- southeasterly flow should allow for some modest instability to develop across the Front Range into the adjacent plains. Most HRRR members, along with at least a few of the members of the UCAR/NCAR MPAS ensemble, develop a cluster of showers/storms across the I-70 foothills, which would eventually drift east into the metro by the late afternoon or early evening. Temperatures should be near normal again with highs in the mid 60s likely.

LONG TERM /Tuesday night through Monday/
Issued at 216 PM MDT Mon Apr 28 2025

The chance for weak showers and storms will linger into the evening hours Tuesday before ending by midnight as the airmass stabilizes. Weak ridging will be over the area late Tuesday night and early Wednesday. This will be short-lived as an upper level trough approaches from the northwest. Scattered showers move into northern Colorado late Wednesday afternoon and increase as they spread southward during the evening. Precipitation becomes more stratiform Wednesday night north of I-76 with widespread rain expected with snow above 7000-8000 feet MSL. The rain and snow slowly spreads south across the rest of the area late Wednesday night and Thursday morning. Heaviest precipitation will be west of I-25. With the cloud cover and precipitation over the area, it will be cooler Thursday with highs in the 50s over most of northeast Colorado. It will be warmest across northern Colorado where skies start to clear during the afternoon hours. By early Thursday evening, the precipitation is expected to be south of the area.

Upper level ridge builds over the Central and Southern Rockies Friday. Warmer temperatures return to the area with highs reaching the upper 60s to lower 70s across northeast Colorado. Other than isolated to widely scattered showers/storms over the mountains, dry conditions are expected across the area. The ridge axis slides east of Colorado for Saturday with flow aloft becoming southwesterly. A shortwave trough embedded in the southwest flow aloft lifts across Colorado Saturday. Timing of the trough passage is still somewhat unclear. If the best lift from the trough pushes overhead during the afternoon hours, during peak heating and best instability, scattered showers/storms will be possible.
If the trough passes overhead too early in the day, would expect fewer showers/storms.

A large/strong upper level low moves across southern California Sunday and into the Desert Southwest/Four Corners area Monday.
Over Colorado, southwest flow aloft is expected to prevail Sunday.
This is expected to bringing warmer temperatures and limited chances for showers and thunderstorms. For early next week, the upper level low slowly progresses eastward. There's still a large spread between the models on the strength and track of the upper level low. Chances for precipitation will increase as the low nears, though if it takes a northerly track, mostly dry conditions could prevail. Temperatures will remain mild ahead of the low Monday with highs expected to be in the 70s over northeast Colorado.

AVIATION /00Z TAFS through 00Z Wednesday/
Issued at 601 PM MDT Mon Apr 28 2025

Isolated showers are diminishing, but variable winds associated with those will have some impacts til 01Z-02Z. A cold front is on track to reach KDEN by 0130Z, and KAPA by 0230Z with a period of gusty north/northeast winds to 30 kts. Behind that front, the main concern shifts to stratus. Upstream obs still have widespread stratus, so despite the latest guidance still being bearish on this potential we'll have MVFR ceilings forecast 06Z-15Z.

Any stratus Tuesday morning should quickly burn off, with southeasterly winds gradually increasing from the late morning into the early afternoon hours. Gusts to 20-25 knots expected.
Other concern will be scattered showers and storms. We think it'll be a late day occurrence mainly after 22Z and at least enough for a Prob30 -TSRA with gusty winds.

BOU WATCHES/WARNINGS/ADVISORIES
None.