In Brief:
The warm up begins.
Friday update:
The storm delivered! Longmont received over 2 inches of liquid and about 7-11 inches of snow in spots. Boulder saw 12-19 inches.
We warm up, melt off and dig out from here.


End Friday update.
Forecast Discussion:
Winter Storm Warning
Issued: 8:13 PM Mar. 12, 2024 – National Weather Service
...WINTER STORM WARNING IN EFFECT FROM 9 PM WEDNESDAY TO 6 AM MDT FRIDAY...
* WHAT...Heavy snow expected. Total snow accumulations between 9 and 18 inches. Winds gusting as high as 35 mph.
* WHERE...Boulder and the western suburbs of Denver, and Denver.
* WHEN...From 9 PM Wednesday to 6 AM MDT Friday.
* IMPACTS...Travel could be very difficult to impossible. The hazardous conditions could impact the Wednesday evening and Thursday morning commutes.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. The latest road conditions for
Colorado can be obtained by calling 5 1 1 or by going to www.cotrip.org.
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We have the warmth before the storm. Finally, it looks like a major winter storm is on its way. It should be the biggest of the year (channel 9 said the biggest in 3 years). We might hear some thunder early Wednesday morning, with a break in the action Wednesday morning with rain chances picking up again in the afternoon. Any rain that falls should change over to snow around 8pm (but could wait as long as the pre-dawn hours). If it does change to snow in the evening, then top snow totals are expected. (Figure 1)
It is looking more likely that most of I-25 south of Ft. Collins and especially the Denver Metro will get to or exceed a foot of snow. Snow tapers off early morning Friday.
The system is powered by a slow moving cut-off low that will roll by (Figure 2). The central mountains might pick up areas of 32-46 inches of snow (Figure 3). The pre-snow rain isn't looking very impressive, currently - maybe 0.1-0.25" of water (Figure 4) at the lower elevations. Matt Makens's map from weather5280 12-24" for Boulder and 6-12" for western Denver (Figure 5). Note: the trend in the models is for even more snow to fall forecast after forecast. I'll update as needed.
Snowfall roundup for Longmont:
Weather5280: 10.9"
The GFS: 14-16"
The NAM: 16-18"
The Canadian: 10-12"
Channel 9: 6-12"
Channel 7: 7"
My forecast: 7-14"





The Long Range Forecast:
For the weekend and beyond, we warm up and dig out.