Forecast Discussion:

8am Update:

The high wind warnings have been expanded today.  Peak winds will occur between 11am and 4pm.  Channel 4 news predicted up to 100mph winds in the Foothills in wind prone areas.

Figure 1 update: current state weather warnings and advisories fro

End 8am Update.

Super nice decoration-removing weather keeps on going.  I almost started on the front yard lights yesterday. There is a lee trough and some moisture moving in, leading to cloudy skies later in the day on Saturday (Figure 1).  There is a lot of rainfall and snowfall hitting the western U.S. and desert southwest.

Later today, the trough creating all that unsettled weather moves towards us (red line in Figure 2 over Colorado), but the Rockies will wring out the moisture and we’ll see nothing to nearly nothing but warm down slope flow.  A flurry or sprinkle might be possible to I-25 north of Denver tonight and tomorrow AM.  Don’t count on it being much (Figure 3).

Figure 1: The current surface map from Saturday PM and the Weather Channel.
Figure 2: The 500mb forecast upper air analysis for Sunday PM. Pink dot is Longmont. Red lines are troughs, blue lines are ridges.
Figure 3: The forecast surface map for Sunday PM. From NCEP.

The longer range forecast:

The snowfall for the next 5 days from the GFS shows up to a foot in places in the higher mountains (what a season it has been on THAT side of the Divide!!) – Figure 4. Even over the next 10 days, we’ll be lucky to see an inch (according to this model – Figure 5). is still asserting its Winter forecast.  Figure 6 shows us just a bit below normal in temperatures. Figure 7 has us a bit above normal in snowfall.  A lot of catch-up needs to occur for this forecast to still come true.  We’ll watch it here!

Figure 4: The forecast accumulated snow map from the GFS and for Colorado, for the next 5 days.
Figure 5: The forecast accumulated snow map from the GFS and for Colorado, for the next 10 days.
Figure 6: The Nov – March temperature forecast departure from normal from publicly released data from WeatherBell
Figure 7: The Nov – March snowfall forecast departure from normal from publicly released data from WeatherBell
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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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