Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus65 kgjt 230856 

Area forecast discussion
National Weather Service Grand Junction Colorado
256 am MDT Mon Oct 23 2017

Short term...(today through tuesday)
issued at 246 am MDT Mon Oct 23 2017

As forecast, a weak shortwave is just starting to enter our
forecast area. Infrared imagery clearly shows this wave while upstream
observations report cloud ceilings around 6k feet though no reports
of precipitation...yet. As the wave gets closer, favorable
orographics looks to be able to squeeze out some precipitation,
maybe an inch at the highest elevations, and some flurries down to
8,500 feet for the northern mountains. Fortunately, this is a
quick moving wave and will have moved off to the east by noon, if
not a bit before. So expect some clouds, generally north of I-70,
this morning giving way to mostly sunny skies by this afternoon.
Temperatures look to be a few degrees warmer than seen yesterday.
All in all, not a bad start to the work week.

Tuesday, high pressure firmly builds in to the western half of the
United States bringing widespread sunshine and warm temperatures.

Long term...(tuesday night through sunday)
issued at 246 am MDT Mon Oct 23 2017

The ridge of high pressure will gradually begin to flatten late
Tuesday into Wednesday. As this occurs, a dry shortwave trough
will move through the region bringing a slight increase in high
and potentially mid- level clouds Wednesday afternoon. The
northwesterly wind gradient will tighten late Thursday as an upper
level jet moves overhead ahead of an approaching Pacific trough.
However, this is where extended models really begin to differ. The
Euro continues to be the slower and wetter solution, especially
at the upper levels, as it brings a +100kt jet right through our
County Warning Area on Thursday with showers accompanying the trough through
Thursday evening, though the higher terrain north of I-70 would be
favored for activity. The GFS, on the other hand, has an 80kt jet
just clipping our northeastern County Warning Area and focuses most, if not all,
of the energy and precipitation associated with this system east
of the Continental Divide with the Elkhead Mountains just seeing a
quick shot of snow. The one aspect of this storm that models do
seem to agree on is the nice shot of cold air that will accompany
the trough. The resulting northwest flow with allow temperatures
to drop back several degrees below seasonal norms and remain
there through the majority of the weekend.

As the previous forecaster mentioned models have been consistent in
re-establishing a strong ridge of high pressure over much of the
western Continental U.S. Friday and continuing into the new work week which
would see the return of mostly sunny skies and widespread dry


Aviation...(for the 12z tafs through 12z Tuesday morning)
issued at 246 am MDT Mon Oct 23 2017

No concerns for taf sites today. VFR continues.


Gjt watches/warnings/advisories...

National Weather Service Glossary of Abbreviations