Forecast Discussion:

Dry and cooler continues today. Figure 1 shows the departed cold front Monday PM.  Other than smoke, the skies are Colorado-clear. Speaking of smoke, the large fires in the south are pouring out copious amounts of smoke, but the haze around here Monday and today is actually coming from new fires in central Utah (Figure 2).

The upper air pattern for tonight shows the big ridge sitting to our west keeping us high and dry.

Figure 1: The forecast surface map for this afternoon. From NCEP.
Figure 2: The HRRR model forecast for smoke at all levels for midday Tuesday. From
Figure 3: The 500mb upper air forecast map for Tuesday PM from the GFS and Ridges are blue lines, troughs are red lines.

The longer range forecast:

The ridge is still in place tomorrow, but has slid across the state with its central axis just barely to our east (Figure 4).  From this , we see very little weather but rapidly warming temperatures through Thursday (Figure 5). Down in the bottom of figure 4 is an interesting feature – hurricane Bud (oh what a terrifying name).

Figure 5 is the NHC’s forecast of storm intensity and direction.  It currently has winds at 120mph making it a category 3 storm headed north-ish (Figure 6).  Figure 7 is the weather map for Friday PM and Bud is coming inland in northern Mexico.  Moisture is already streaming ahead of it into Colorado.  Figure 8 has a lee trough in NE Colorado and a lot of moisture from Bud nearby.  This could be interesting! Going back to Figure 5, afternoon heating will combine with Bud’s moisture for Friday afternoon storms.  Saturday and Sunday will see more moisture around.  After that, a stream of Gulf of Mexico moisture seems to get drawn into Colorado with rain showers for the beginning of next week.  Relief *may* be in sight!

Figure 4: The 500mb upper air forecast map for Wednesday PM from the GFS and Ridges are blue lines, troughs are red lines.
Figure 5: the total 10 days of the graphical forecast for Longmont, CO from
Figure 6: The National Hurricane center prediction for the future position and strength of hurricane Bud. From
Figure 7: The future weather map from the GFS and valid Friday PM.
Figure 8 The future weather map from the GFS and valid Saturday PM.
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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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