Marine Weather and Tide Forecast for Nunn, CO

UPDATE
Issued at 820 PM MDT Fri Apr 25 2025

A Denver Cyclone has allowed for some interesting weather across the forecast area this evening. NNE winds along its northern edge have kept persistent drizzle across the northern plains and urban corridor due to its upslope component. Fog has started to thicken in the past hour or so and is expected to spread across portions of the plains throughout tonight. We have gone ahead and issued a Dense Fog Advisory for the eastern plains and areas along the northern border until 10 AM Saturday morning, and increased PoPs in areas where drizzle has persisted for this evening update.

SHORT TERM /Through Saturday/
Issued at 212 PM MDT Fri Apr 25 2025

Stratus remains firmly in place this afternoon across the lower elevations, keeping temperatures cool and in the 40's outside of areas of partial clearing around the Palmer Divide and southern metro where they've climbed into the 50's as anticipated. Modest instability should fuel a few afternoon showers generally over the Continental Divide, but any weak cells will lose steam as they attempt roll off the higher terrain and enter a more stable environment through this evening. Thus, main potential east of the Front Range is for some decaying rain showers. Tonight, patchy fog may redevelop on the backside of a surface cyclone.

A Denver cyclone setup Saturday will bring enhanced southerly flow across most of the plains, with better clearing of low-level stratus through the morning. This will allow for warmer temperatures and some destabilization by the afternoon, with showers and a few weak thunderstorms developing mostly east of the I-25 corridor. That said, the eastern plains will remain capped through a good portion of the day, limiting downstream convective growth.

LONG TERM /Saturday night through Friday/
Issued at 212 PM MDT Fri Apr 25 2025

Strong pre-frontal southerly flow will develop on Sunday in advance of an approaching upper-level trough. Robust warm advection will push temperatures into the upper 70's to low 80's east of the Rockies, and a dry airmass west of a dryline near the Kansas/Nebraska state line will keep humidity near and below 15% for most of the lower elevations in the afternoon. Critical fire weather conditions are thus expected to develop, with fire danger largely dictated by fuel susceptibility, which is currently quite variable over the plains. Nonetheless, wind gusts in excess of 30-40 mph will be widespread for the plains and Park County, so a Fire Weather Watch has been issued. As for the aforementioned dryline, there's potential for it to extend as far west as Sedgwick/Phillips Counties and allow for some afternoon thunderstorms in our northeast corner later in the day.

A more moist airmass will be in place Monday following the front, with higher chances for precipitation region-wide, moderately cooler temperatures, and breezy northerly winds.

We look to remain within a slightly cooler pattern through much of the week, with oscillations between largely zonal flow aloft and a few potential dipping waves. Ensembles indicate plenty of model divergence still, so the forecast maintains near daily chances for some afternoon convection, especially for the high country, with Wednesday currently appearing to be the most favorable for more widespread precipitation.

AVIATION /00Z TAFS through 00Z Sunday/
Issued at 609 PM MDT Fri Apr 25 2025

A cyclone is currently causing variable winds at KDEN and low ceilings and vis at all Denver TAF sites this evening.
North/northeasterly winds on the back end of the cyclone are creating persistent low stratus and mist/FG that is keeping lower visibilities in place. Gusty southeasterly winds on the front end of the cyclone are slowly inching northward and into the airfield at KDEN. If the cyclone continues to move northward, southeasterly winds could take over at KDEN, which would bring some downsloping compressional warming off the Palmer, providing a slight improvement to the current conditions. The most likely scenario is that the cyclone continues to evolve, bringing NNE to NNW winds to all TAF locations, with FG and VIS down to 1/2SM over the next few hours. Depending on how the cyclone progresses, FG may develop over KDEN sooner than what is in the current TAF, with hi-res guidance showing potential for 1/2SM VIS between 2 to 5Z, but with the current position of the cyclone keeping the SE winds over portions of the field, confidence was too low to put in the current TAF. With the winds making an anticipated turn to the NNW around 10Z, another round of FG is expected to develop over KDEN and KBJC through the early morning hours 13-15Z, before stronger southerly winds are expected to aid in clearing out the fog and lifting ceilings.

Southerly winds are expected to increase throughout the morning at all TAF sites, with gusts to 30-35kts possible by 18/20Z. Thunderstorms are expected to develop near the TAF sites between 22Z to 02Z.

BOU WATCHES/WARNINGS/ADVISORIES
Fire Weather Watch from Sunday morning through Sunday evening for COZ214-240>247-249.

Dense Fog Advisory until 10 AM MDT Saturday for COZ038-042- 046>051.