Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 141121

Area Forecast Discussion
National Weather Service Denver/Boulder CO
421 AM MST Sun Jan 14 2018

.SHORT TERM...(Today and tonight)
Issued at 239 AM MST Sun Jan 14 2018

Scattered areas of light snow continue early this morning in
vicinity of an upper level jet in NW flow aloft. Expect this
activity to end by 12z.

For the rest of the day it will be dry as a sfc lee trough is in
place near the foothills.  This will allow for downslope low level
flow with warmer temps across nern CO.  Readings will range from the
mid 40s over the far nern plains with 55 to 60 closer to the

By tonight a cold front will move across the plains with upslope
component developing overnight. Meanwhile position of upper level
jet in NW flow aloft will eventually place portions of nern CO in
right exit region, so should see some light snow develop behind
the front. Not sure about overall timing but appears best chc of
light snow will be over the far nern plains by midnight and then
gradually spread into the front range urban corridor by 12z Mon.

.LONG TERM...(Monday through Saturday)
Issued at 417 AM MST Sun Jan 14 2018

A strong upper low/trough over the Great Lakes will bring a
shallow cold airmass and northerly upslope flow for the plains and
foothills of the CWA Monday and Monday evening. Weak northerly
flow aloft is progged on Tuesday and Tuesday night as a high
amplitude upper ridge slides east into Colorado. There is upward
synoptic scale energy over the CWA through mid Monday afternoon,
then downward motion is over the CWA Monday night into Tuesday
evening. Again, there is northerly upslope winds in the lower
levels on Monday and Monday evening, then more normal diurnal low
level wind patterns ensue Tuesday and Tuesday night. Moisture-
wise, there is some over the plains and foothills on Monday. It is
not very deep. It decreases Monday evening and it is confined to
the foothills and immediate plains. Moisture is very sparse later
Monday evening through Tuesday night for all areas. The QPF fields
show a small amount of measurable snow on Monday into the early
evening for the plains and foothills. Then there is nothing
through 12Z Wednesday. For pops will go with 40-70%s through the
day Monday, then "chance"s mainly for the Foothills and Palmer
Ridge Monday evening. No highlights at this time. For
temperatures, Monday`s highs are 14-20 C colder than today`s.
A pretty decent cool down for sure. Tuesday`s highs come up some
5-8 degrees C from Monday`s. For the later days, Wednesday
through Saturday, upper ridging will dominate Wednesday through
Thursday night. There is strong southwesterly flow aloft on
Friday, then and pa pretty strong upper trough comes across next
Saturday. We`ll see, night now it looks like alpine snow and wind
for the plains.


.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 239 AM MST Sun Jan 14 2018

VFR conditions expected today.  South winds this morning will become
more WNW by 18z thru the aftn hours.  By early evening winds will
become more SW.  By mid to late evening a cold front will move
across with winds becoming Northeast. Overnight into Mon morning
winds will be ENE.  Expect IFR conditions due to stratus to develop
by 09z with LIFR ceilings possible after 12z Mon.  Will see areas of
light snow mainly after 12z with visibilities in the 1 to 3 mile
range possible at times.




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