Forecast Discussion:

We had some clouds and mild temperatures Saturday – today will be very much the same. A real change is coming with another fast moving clipper roaring down on northwest flow (see yesterday’s discussion). Figure 1 shows the mild temperatures Sunday midday. After midnight, the first push of cold air is heading in. We should have Monday’s warmest temperatures around here (Figure 2) before dawn. Much colder air coming in Monday morning will drop temperatures in the lower 30’sF down to around 20F by the afternoon drive time.  Take more coat with you than you need in the morning! Figure 3 shows the Tuesday AM upper teen temperatures for Longmont.

What about snow?  A shallow but moist up-slope flow will begin after midnight tonight through much of Monday.  We should see periods of light snow showers now and then.

Figure 4 is the GFS’s take – it gives us nothing to 1″  (sorry, the pink dot is missing this time!).

Figure 5 is the NAM’s take – We get around 1″.  The two models are consistent.  Consistently low on snow.

My call is that Longmont should see a coating to locally 2″ if things come together for some neighborhoods.

Figure 1: The surface temperatures forecasted for Sunday midday from the GFS and
Figure 2: The surface temperatures forecasted for Monday pre-dawn from the GFS and
Figure 3: The surface temperatures forecasted for Tuesday pre-dawn from the GFS and
Figure 4: total snowfall between Saturday PM and Tuesday AM from the GFS and
Figure 5: total snowfall between Saturday PM and Tuesday AM from the NAM and

The longer range forecast:

We slowly warm and dry out again beyond this storm. Our next small-ish storm seems to be slated for Saturday.  Have a great Martin Luther King day today all!

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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 – . 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.