Forecast Discussion:

If Wednesday was nice weather to you, today will be even better with a warm afternoon in the mid-upper 70’s for a high temperature.  And dry. Figure 1 is the surface analysis for Thursday afternoon showing a dry front poised to enter the state (that will cool us a bit on Friday) – the best heating is often seen right before the front arrives with southwest winds and some downslope compression of the air. Friday will be nice and dry, breezy and a bit cooler.

Figure 1: The NCEP Thursday afternoon surface analysis map.

In the Longer Range:

The jet stream buckles over Colorado on Saturday with a sort-of split trough stretching from the eastern Pacific up into Montana.  But there is really very little moisture associated with this. Small troughs (red lines) and ridges (blue lines) are marked in the colored lines across the continent (Figure 2).

Again, from the weather5280.com folks, we have a new product for this column in Figure 3. You can see the rise and fall of daily temperatures for the next 10 days across the top graph. The bottom graph is a vertical stack of 20 GFS computer runs that don’t show rainfall until way out around the 19th to 21st. Saturday (purple line) looks dry – but it may be windy.

As a bonus, for Thursday (not the long term) – I’ve checked in on the HRRR smoke forecast to see if the California fires may darken our skies yet… and though it is forecasted to eventually make it into Colorado, Figure 4 shows it is not here by Thursday.

Figure 2: The GFS 500mb forecast map for Saturday midday.
Figure 3: The 10 day GFS Ensemble forecast (20 runs in the vertical on precipitation) from the GFS for Denver.
Figure 4: The HRRR smoke forecast for midday Thursday.
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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.