Area Forecast Discussion Issued by NWS Denver/Boulder, CO
000
FXUS65 KBOU 142344
AFDBOU
Area Forecast Discussion
National Weather Service Denver/Boulder CO
544 PM MDT Thu Mar 14 2024
.KEY MESSAGES...
- Don`t travel into the foothills! If you do, be prepared to be
stranded for an extended period of time. Expect slick roads
across the metros areas after 6 PM.
- Up to another foot for the Front Range mountains/foothills.
Additional 3 to 8 inches for the lower elevations and a few
inches for areas more north such as Fort Collins.
- Road closures will continue along with local power outages, and
impassable mountain highways and side streets.
- Conditions will gradually improve Friday morning but it will
take some time to dig out of this major winter storm. Except for
a small chance of light snow on Sunday, there will be a long
period of dry weather and warming temperatures.
&&
.SHORT TERM...(This evening through Friday)
Issued at 353 PM MDT Thu Mar 14 2024
Moderate to heavy snow continues this afternoon across the Front
Range, urban corridor, and Palmer Divide. Radar shows consistent
reflectivity spanning across these areas with pockets of moderate
snow rates now visible across the lower elevations now. CDOT
cameras show snow covered roads and low visibilities in the
foothills. As you head down in elevation to the adjacent plains,
roads are wet, potentially slushy from warmer roadways with the
high mid-March sun angle.
This storm will continue to impact the region this afternoon through
early tomorrow morning. Isentropic lift continues to provide an
ideal means for continued snowfall combined with anomalous moisture
and upslope flow. The shift to more favorable upslope direction
has been responsible for the uptick in snow this afternoon and
will continue to to help support healthy snowfall as it increases
to around 30 kts at around 700 mb late this afternoon into early
this evening. This will provide that last push of healthy upslope
snowfall across the Front Range mountains, foothills, and I-25
corridor. This will support periods of enhanced snowfall rates, up
to an inch an hour across the lower elevations and Palmer Divide
through the early evening hours. Model cross sections show upslope
flow transitioning southeast towards midnight. This will
gradually decrease the intensity of the snowfall with some only
lingering light showers around sunrise. Snow continues in the
Front Range mountains and foothills for the same timeframe, with
the peak rates 2"/hour slowly tapering off early tomorrow morning.
As for amounts, the first thing to keep in mind is that
temperatures and especially road temperatures will be cooler
tonight, so snow will be easier to accumulate after dark. The
Front Range mountains/foothills can see up to another foot of
snowfall through early tomorrow. Western Denver and Jefferson
counties around 4 to 8 inches and similar for the Palmer Divide.
Areas north of Denver like the Fort Collins metro area will tap
into the more favorable upslope for a little bit this evening
which will bring a few inches of snowfall by early Friday morning.
Expect gradually clearing skies later tomorrow morning through
the afternoon with highs in the 30s to low 40s in most areas. The
eastern plains will trend warmer with little to no snowpack with
highs in the mid to upper 40s.
.LONG TERM...(Friday night through Thursday)
Issued at 353 PM MDT Thu Mar 14 2024
The same cut off trough that is helping to bring us snow today, will
be lingering over Arizona on Saturday. Meanwhile, there will be a
trough that moves south out of Canada through the upper Midwest.
Colorado will be in-between these features under subsident flow.
This will lead to a period of dry weather on Friday night and
Saturday that will allow for some melting and people can dig out.
By Sunday, models show the cut off trough over Arizona creeping east-
northeastward towards the Four Corners. The majority of models keep
this trough far enough southwest that it does not produce snowfall
over our forecast area. However, there are a few ensemble members
that bring the trough much farther northeast and produce snow
mainly over the southern foothills. Therefore, there is a chance
of snow for the foothills and I-25 corridor but PoPs are in the
20-30% range. Temperatures may be a few degrees below normal on
Sunday but there will still be melting going on.
That same cut off trough becomes weaker on Monday and may even begin
to drift back westward. It will largely lose it`s forcing and
moisture so precipitation is not expected in our CWA. An upper level
ridge will become the more dominate feature on Tuesday and
Wednesday and temperatures will warm well above normal. Highs will
reach the 60s across the plains and the mid to upper 40s in the
foothills.
A jet stream will approach Colorado late on Thursday and this may
bring more active weather throughout the end of the week. The most
likely impact this will bring is mountain snowfall on the western
slopes.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 537 PM MDT Thu Mar 14 2024
Snow continues across all terminals through Friday morning
bringing LIFR conditions at least until 04-06Z. Winds are
decreasing across the region but should remain northeast between
7-10kts through 14Z. Snow should begin to lift as early as 12-14Z
thus leading to IFR conditions until 14Z. There is potential for
low clouds to linger until 18Z but models have indicated stronger
southerly flow by 18-20Z. If this occurs, expect cloud decks to
become SCT and visibilities increase near VFR conditions slightly
earlier near 16Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 6 AM MDT Friday for COZ033>037-
039>041.
Winter Weather Advisory until 6 AM MDT Friday for COZ038-043-045-
046.
&&
$$
SHORT TERM...Mensch
LONG TERM...Danielson
AVIATION...AD