In Brief:

Hold on, I’m looking something up… tedious, dull, monotonous, repetitious, unvaried, dry… OK those were synonyms for boring. Except for a slight chill and a couple of dry cold fronts, Longmont will see very little variation in the weather for the next week or more. That just means that exciting winter weather is building up for a big hit later this season! (I hope.)

Forecast Discussion:

Snow continues in the mountains with most to all ski resorts getting a daily addition of fresh powder (Figure 1). We’ll see warming down-slope flow here with some gusty windy conditions this afternoon (Monday). The upper air pattern this week is very “zonal” or flowing west to east. There is a gentle troughniess in the West with small short waves embedded in the flow. These troughs aren’t deep enough or slow enough to pull in moisture east of the Rockies (Figure 2). We remain dry.

The Longer Range Forecast:

We will see about 5-8 degrees of cool down from a dry cool front Wednesday afternoon and again Friday afternoon (Figure 3). The rest of the time we’ll rise to about 50F each afternoon. Those fronts do mean that the mountains will see a bit more enhanced snow fall rates (good for them!).

The first front is approaching Tuesday night (Figure 4). The upper air pattern rebounds to a shallow ridge heading into Thursday (Figure 5) – allowing us to quickly warm again to 50F (watch for down slop winds every ‘warm’ day). Over the next 10 days the mountains see a foot to a foot and a half in the higher mountains, but no snow occurs down on the Plains (Figure 6).

Figure 1: The forecast surface map for Monday noon from NCEP.
Figure 2: The 500mb forecast upper air analysis for early Monday PM. Pink dot is Longmont. Red lines are troughs, blue lines are ridges.
Figure 3: the graphical forecast for the next 10 days for Longmont, CO from weatherunderground.com
Figure 4: The forecast surface map for Tuesday night from NCEP.
Figure 5: The 500mb forecast upper air analysis for early Wednesday PM. Pink dot is Longmont. Red lines are troughs, blue lines are ridges.
Figure 6: 10:1 (snow to liquid) snowfall totals through the next 10 days from the GFS and tropicaltidbitscom for Colorado made Monday morning.
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John Ensworth works from Longmont as the Principle Investigator for the NASA Science Mission Directorate Earth and space science education product review through the IGES (The Institute for Global Environmental Strategies – www.strategies.org) . He is in his 14th year running this review. He is an astronomer (from the 2nd grade onward) and became a meteorologist (in the 5th grade) when a thunderstorm in Arizona rained on his telescope when the weather service had only forecasted a 10% chance of rain. He has college degrees in physics and astronomy and climatology and a graduate degree in meteorology and earth science. He lectures at the Little Thompson Observatory in Berthoud, the Estes Park Memorial Observatory in Estes Park, and for a number of online universities. He built and runs a backyard observatory near Pace and 17th in northeast Longmont where he has lived for 8 years with his wife, daughter, son, and two cats. Invitations to open house nights at this observatory, LTO, and EPMO will be posted with future discussions when they are scheduled. Forecasting severe weather and snow amounts via text lead to this column. He began texting friends about the weather right after the September 2013 flood. The readers of this column will, hopefully, keep him honest in what he ‘thought’ he had forecasted for ‘the most recent’ storm.

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