Forecast discussion:

We were spared freezing drizzle and freezing fog for most locations around Longmont on Monday. Instead a very very light snow fell most of the morning and early afternoon.  It was not enough to coat the ground in most locations.

Now the winds switch to a westerly direction and down slope warms us up quickly.  Today’s high will be around 50F and Wednesday’s temperature will be 60F with much stronger winds. Figure 1 shows those down slope winds at their maximum tomorrow.  Wind speeds may hover around 20mph.  Good thing it is not trash day (well, for my neighborhood).  The mountains will see continued snow.  Estes Park will get 2-4″ + of snow Tuesday and Wednesday, for example.

Figure 1: The surface wind speeds midday Wednesday from the GFS and tropicaltidbits.com

The longer range forecast:

Looking off to Friday, small snow chances return on Thursday night in Longmont.  Snow totals look like a coating to an inch will build up in the Thursday ‘storm.’ We are on the edge of the no-snow zone (the GFS Figure 2).  The NAM looks similar (Figure 3).  Both put a foot or more snow in the higher elevations.  Bring it on!

What is interesting is the upper air pattern – for today (Figure 4) there is a trough over the western US and a ridge in the east.  Figure 5 is the pattern for next Monday – and it is very similar!  Having a trough to our west does mean more western Colorado and mountain snows.

Figure 2: The total snowfall between Monday PM and Thursday PM from the GFS and tropicaltidbits.com
Figure 3: The total snowfall between Monday PM and Thursday PM from the NAM and tropicaltidbits.com
Figure 4: The 500mb upper air forecast map for Tuesday morning from the GFS.
Figure 5: The 500mb upper air forecast map for Monday morning from the GFS.
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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.