Next Storm/Next Snow Forecast Discussion from the Cherrywood Observatory – January 7, 2019

Est. Reading Time: 2 minutes
Figure 3: The forecast surface winds and isobar map from the GFS and for Colorado, for Monday noon.

Forecast Discussion:

The headline for today (and the reason I’m posting earlier than normal on Sunday PM):

High Wind Warning
Issued: 12:31 PM Jan. 6, 2019 – National Weather Service
 ** See Figure 2 below **
The National Weather Service in Denver has issued a High Wind
Warning, which is in effect from 8 AM to 10 PM MST Monday. The
High Wind Watch is no longer in effect.

* WINDS...West 30 to 45 mph with gusts up to 60 mph.

* TIMING...Monday morning through Monday evening.

* IMPACTS...High profile vehicles will be susceptible to
dangerous cross winds. Areas of blowing dust will be possible
with visibilities reduced to one mile or less. Possible power
outages caused by downed power lines.


A High Wind Warning means a hazardous high wind event is expected
or occurring. Strong winds may lead to property damage. Hazardous
driving conditions due to powerful cross winds will pose a
serious risk for drivers, especially for light weight and
high profile vehicles. Loose outdoor items should be brought
inside or secured properly.

Figure 1 shows the storm squeezing its water out on the Colorado western slopes – we get the energy (heating) from the precipitation formation linked to the powerful jet stream overhead to give us warming and (sometimes) violent down slope winds from later Sunday PM to Monday PM. Tie down any decorations you haven’t put away yet.

Figure 3 is the noon time sustained wind speeds. That is widespread strong steady winds!

Figure 1: The forecast surface map for Monday PM. From NCEP.
Figure 2: Extent of high wind warning for Sunday PM- Monday PM from the NWS.
Figure 3: The forecast surface winds and isobar map from the GFS and for Colorado, for Monday noon.

The longer range forecast:

We stay in the 50’s F (above normal temperatures) for the next 10 days. The GFS does not show Longmont getting any snow or rain during that time. That can change, but things are unlikely to be largely different from what you’ve seen later in December through today. Sorry, I wish I could make it snow.

Figure 4: The forecast accumulated snow map from the GFS and for Colorado, for the next 10 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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