Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus65 kgjt 222334 

Area forecast discussion
National Weather Service Grand Junction Colorado
434 PM MST Fri Nov 22 2019

Short term...(tonight through Saturday night)
issued at 356 PM MST Fri Nov 22 2019

The center of the storm which has impacted eastern Utah and
western Colorado since Monday night has moved to the western
Kansas border area this afternoon. Though not in close proximity
to the forecast area moisture wrapping around the low continued to
generate light snow over the Colorado mountains. A funneling
effect up the Uncompahgre basin has favored snowfall across
Ridgway, Ouray and Telluride as well as high east-west oriented

Models in good agreement tonight, moving the storm center farther
onto the Central Plains. As the system shifts eastward, dry
northwest flow will erode moisture across the area during the
night. Before that drying is realized however, scattered snow
showers will persist along the Continental Divide this evening,
though additional accumulations will be light and localized. By
midnight snow will be ending with clouds decreasing across the
area. Low level stratus and areas of fog are possible in the
higher valleys late tonight and early Saturday morning.

Light and dry northwest flow will continue across the forecast
area Saturday and Saturday night. Weak warm advection and fewer
clouds are expected to yield near normal temperatures on Saturday
though lows will be running cold tonight and again Saturday night.

Long term...(sunday through friday)
issued at 356 PM MST Fri Nov 22 2019

Dry and seasonal conditions are expected to continue regionwide on
Sunday before conditions take a turn Sunday night. A shallow
mid-level short-wave trough is expected to push rapidly across the
northwest driving a cold front to the northern border of the
forecast area by 12z Monday. Scattered showers develop over the
Elkhead and park mountains ahead of the front late Sunday night.
Snow becomes more widespread Monday as the mid-level trough drives
the cold front to the southern border late in the afternoon.
Negative div-q at mid-levels and a divergent jet couplet aloft
provide plenty of dynamic lift to add to blustery wind derived
orographic lift into Monday evening. However, moisture associated
with this cold system appears far less impressive than our last
storm which should limit snowfall accumulations. As of this
writing it appears this storm will generate advisory level snow
for most Colorado mountains and possibly the eastern uintas and
high valleys of western Colorado. As would be expected,
temperatures become much cooler behind the front on Tuesday.

On Tuesday night, a closed low digs southward along the West Coast
with overrunning moisture generating light showers over the area
during the night. Models continue to struggle with this system in
days 5 through 7 with GFS quicker to move the low inland and more
aggressive with quantitative precipitation forecast output. Canadian and European model (ecmwf) more similar. What
all models share is the idea that this will be protracted event
with the potential of yielding heavy snow in the mountains from
Thursday through Friday and beyond which could very well impact
travel before, during and after the Thanksgiving Holiday. Until
models come into better agreement, hesitate to get into the
details, but urge those reading this to be prepared for
challenging, and possibly hazardous winter driving conditions.


Aviation...(for the 00z tafs through 00z Saturday evening)
issued at 421 PM MST Fri Nov 22 2019

A few snow showers will linger for the next few hours at ktex,
kase, kege. MVFR cigs will probably continue longer than some of
the guidance is suggesting therefore the clearing times have been
extended especially at the Central Mountain sites.


Gjt watches/warnings/advisories...

National Weather Service Glossary of Abbreviations