Forecast Update: Memorial Day weekend will be SOGGY!

The weather for Memorial Day Weekend will not be pleasant across the Front Range unfortunately. A cold front is set to arrive early Saturday paving the way for a relatively cold and gloomy holiday weekend. Will the weekend be a total washout? How much rain can the area expect? When and where will a little snow mix in? Read on to find out!

Key Highlights from This Post:

A slew of ingredients will come together facilitating a soggy Memorial Day Weekend ahead for the Front Range
Saturday will begin quiet, but scattered storms will be possible by afternoon and evening
Sunday and Monday will be very chilly with widespread rain and low clouds. Outdoor plans may be ruined!
Some snow is in the cards, but only above 11000 feet in the Mountains along the Divide
Rainfall totals of 0.75″ to 1.5″ are expected through Monday for the entire area
A drying and warming trend begins on Tuesday. Go figure!

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appy Friday! We’ve got an update on the forecast for the holiday weekend ahead, which will be a rather rainy and chilly affair for the Front Range. This shouldn’t be a surprise based on how things were looking earlier this week! As of early Friday morning, we’re in between storm systems with a potent low across the Midwest and yet another skirting eastward along the Canadian border. A shortwave ridge axis is directly over Denver.

Here’s the view from space showing the two storm systems as well as the pleasant and sunny weather across most of Colorado this morning.

As you can see in the animation below which runs through Tuesday, a secondary system will come ashore into California on Saturday. This southern storm system will help to ramp up moisture levels in eastern Colorado and will ultimately keep the gloomy weather around for us through Monday.

Unfortunately, most of our long holiday weekend ahead will be plagued by soggy weather as a stalled cold front will be draped across the Front Range area. As is normal for late May, the storm track is retreating further north. Remember the parent low pressure for this cold front is in southern Canada. The result is very minimal forcing to move this front away from our area. It will more or less linger for three full days.

The near-surface temperature forecast below is for sunrise Saturday. The cold front is projected to be along the Wyoming border at this time but will be dropping southward quickly towards Denver. Early Saturday morning will be mild in the 60’s to even the lower 70’s. However, temperatures will fall a little behind the front back into the 60’s.

The added moisture and weak upslope behind the front will fuel afternoon and evening showers and storms across the entire Front Range area. Saturday won’t be a complete washout, but there will be an elevated risk of late-day wet weather. Plan any outdoor activities being mindful of somewhat deteriorating conditions as the day wears on. There will be a slight threat of severe weather across southeast Colorado on Saturday (see below), but for our immediate area the cold front should keep things stable enough for just weak thunderstorms.

Sunday the stakes get upped significantly as high pressure kicks out into eastern Montana. Broad clockwise flow around this high will strengthen and turn winds due easterly into the Front Range. This is efficient upslope and will favor widespread stratiform rainfall much of the day Sunday for our entire area, continuing into Sunday night. Expect rain to begin sometime in the morning or by mid-day and continue persistently into the evening and overnight. Sunday will be quite cold with highs in the 50’s. This is about 20 degrees below normal for late May.

In case you are wondering, yes it will be cold enough this weekend for some snow in the Mountains, but only above 11000 feet or so. The cold front isn’t terribly deep, so the cold air will barely (if at all) make it over the Continental Divide. Still, the eastern peaks of the Front Range can expect several inches of slushy snow by sunrise Monday, around 3-7″ above treeline along the Divide. When traveling, watch out for a little snow on some of the higher passes, like Eisenhower Tunnel, Sunday afternoon trough Sunday night. No major impacts are expected though. No snow is in the pipeline where people actually live, though if models trend a few degrees colder we could see a rain/snow mix along the higher portions of Peak-to-Peak Highway.

Widespread showers will continue into Memorial Day as well, though there is some indication in the models that the latter part of the day might dry out, BUT we’re not overly optimistic. Though it probably won’t be as intense or wet as Sunday, Monday could be another candidate for a washout as well. Expect highs in the 50’s to lower 60’s at best with light rain ongoing. The aforementioned southern-track storm will be controlling our weather on Monday, and that one is still way out over the Pacific Ocean as of writing, so confidence is lower on the outcome for Monday. However, most signs are pointing to continued gloomy weather for Boulder and Denver.

All in all, this Memorial Day weekend will be very wet for the Front Range. With persistent upslope-forced precipitation expected Sunday into Monday, it’s no surprise that more than 1″ of rain is predicted through the weekend by nearly every single model. The latest European and GFS model precipitation forecasts are shown below. The Euro is clearly positioning the bullseye further northward, owing to a slightly more southeasterly component to the upslope which favors the northern Front Range. The GFS is more squarely targeting the Denver Metro area with due easterly upslope. Either way, here comes the moisture!

The GFS ensemble precipitation forecast is shown below. This confirms some variability in the location of the heaviest rainfall, but also highlights the fact that the Front Range will do well in most outcomes. In our opinion, a reasonable range for weekend rain totals will be 0.75″ to 1.5″. If the weekend weather is going to be crappy, we might as well get decent moisture out of it!

One final note, as has been the case for the last several months, eastern Colorado will greatly benefit from rainfall this weekend, while the Western Slope will miss out yet again. Drought has been nearly eradicated east of the Continental Divide, but the situation remains dire to the west. This time of year, the only hope for precipitation west of the Divide is the upcoming monsoon season. As we discussed in our recent summer outlook, that very well could be a disappointment this year. Western Colorado truly is in trouble this summer, along with much of the western United States.

Looking into our crystal ball for next week, a drier, warmer and more “summer-like” pattern is expected with low chances for late-day thunderstorms and highs largely in the 80’s (maybe even getting near 90?). That’s all for now. Enjoy the long and wet weekend ahead!