Forecast Discussion:

We received up to an inch of snow over the last couple of days and now are on our way to a warm up. Spring won’t be held back for long in mid-April. We are mostly dry (with just a bit of moisture coming off the mountains on northwest flow (Figure 1)) Sunday afternoon. We’ll see mid 60’sF Monday and mid 70’sF Tuesday (Figure 2).

The longer range forecast:

Still in Figure 2, we can see that the next system is moving in midday Tuesday with increasing shower chances and cooling temperatures. This unsettled period will last 48 hours – to Thursday late morning. This is caused by a (mostly) open upper air wave that is slowly crossing our part of the nation (Figure 3 – red dash in the northern and southern branch of the jet stream).

Over the next 3.75 days (covering this period) the GFS gives us a bit of snow in places across town at night (Figure 4) and up to 1/4th inch of water (Figure 5). Nothing really notable.

More unsettled weather returns next weekend with a mostly dry and not too cold sunrise on Easter. More on that later.

Figure 1: the current surface weather map from Sunday afternoon.
Figure 2: the graphical forecast for the next 10 days for Longmont, CO from
Figure 3: The 500mb forecast upper air analysis for Wednesday morning next week. Pink dot is Longmont. Red lines are troughs, blue lines are ridges.
Figure 4: the forecast accumulated snowfall map from the GFS and for Colorado, over the next almost 4 days.
Figure 5: the forecast accumulated precipitation map from the GFS and for Colorado, over the next almost 4 days.
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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.

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