Road & Weather Alert, 2019.10.01

Elk Peaks Consulting Group, Ltd. News

Road and Weather Alert | 2019.10.01

National Weather Service Grand Junction CO
522 AM MDT Tue Oct 1 2019

.SHORT TERM…(Today through Wednesday)
Issued at 333 AM MDT Tue Oct 1 2019

Early morning satellite data reveals an interesting phenomena over
far northwestern Colorado/northeast Utah. It is not often that the
low-level weather patterns of the Great Plains influence locations
west of the Continental Divide, however tonight is an exception.
Strong low-level upslope flow along the Continental Divide in
central Wyoming has pushed a shallow saturated layer up and over
into the Great Divide Basin along Interstate 80. It did not stop
there. Persistent low-level northeasterly flow forced this
saturated layer up and over the southwestern divide of this
basin…and it has now spilled downvalley into northern Moffat
county Colorado. The GOES east Night-Fog product has been
particularly useful in tracking this unusual phenomena, and as of
10z the low stratus clouds were on the doorstep of Daggett County,
Utah. Indeed it is uncommon to mention moist upslope flow from
the Great Plains affecting Utah…but here we are.

This low-level moist layer was surprisingly well forecast by all
available high-resolution guidance and current morning sky grids
reflect this confidence. Surface obs in southeast Wyoming
indicate that this layer remains elevated low stratus rather than
fog, and this will remain our forecast this morning up north.
While this moist layer will mix out by late morning, high-
resolution guidance indicates a similar event occurring tonight
into Wednesday morning. Sky grids may need adjusting to account
for low clouds up north once again.

Otherwise, the main story on Tuesday will be in the fire weather
world as strong winds mix to the surface by early afternoon. Low
humidity and dry fuels will complete the recipe for Red Flag
conditions today across much of eastern Utah and western Colorado.
For more information on the Red Flag Warnings, see the latest
RFWGJT product.

A shortwave trough will skirt across the far northern reaches of
Utah and Colorado on Wednesday. Forecast guidance is in generally
good agreement showing a mainly dry system, however some upslope
flow over the northern slopes of the Uintas as well as the Elkhead
and Park ranges may help squeeze out a shower or two. The best
opportunity for precipitation will come in the early afternoon
hours as this system will exit east of the divide by 6pm
Wednesday. Dry and breezy weather will continue across the rest of
eastern Utah and western Colorado on Wednesday with temperatures
running around 5 degrees below average for early October.

.LONG TERM…(Wednesday night through Monday)
Issued at 333 AM MDT Tue Oct 1 2019

A dry and benign weather pattern moves in from Wednesday night
onward over the western slope. The only opportunity for
precipitation in the long-term comes on Friday afternoon when
some moisture may try to sneak northward over the southwestern
Colorado high country. However, forecast guidance has backed off
on this idea considerably in the overnight model cycles. Therefore
we have dropped PoPs notably from national blend guidance in this
forecast package given the clear model trend. Afternoon highs
will run near to slightly above average for the remainder of the
long term with dry weather continuing through the weekend into
early next week.

.AVIATION…(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 500 AM MDT Tue Oct 1 2019

VFR conditions are expected at all terminals throughout the day
today. Strong southwest winds will mix to the surface by noon at
all terminals except for DRO. Winds could gust over 40 mph at
times especially in RIL, ASE, EGE, HDN, MTJ and GJT. Clear skies
are expected overnight into early Wednesday.

Issued at 233 AM MDT Tue Oct 1 2019

Strong jet-stream flow aloft will once again mix to the surface on
Tuesday afternoon. This will result in gusty winds over 30 mph at times.
Low relative humidity values will combine with the gusty winds and dry
fuels and will result in Red Flag conditions throughout much of
eastern Utah and western Colorado. Winds speeds will decrease on
Wednesday as the faster jet stream flow moves east. Red Flag
conditions could be possible again on Thursday in northern
Colorado as faster flow and dry air move in.

CO…Red Flag Warning from noon today to 7 PM MDT this evening for

UT…Red Flag Warning from noon today to 7 PM MDT this evening for

For the complete NWS forecast, visit: National Weather Service, Grand Junction, CO