Scientific Forecaster Discussion
fxus65 kbou 281037
Area forecast discussion
National Weather Service Denver/Boulder Colorado
337 am MST Tue Feb 28 2017
Short term...(today and tonight)
issued at 152 am MST Tue Feb 28 2017
Jet Max along the Colorado/Wyoming border this morning shifting to the east
with a some decrease in snow showers across znes 31 and 33. Latest
radar mosaic this morning however showing snow with heavier
enhanced bands along I-70 west of Vail. Main concern for snowfall
today will be associated with this band as the main trough axis
moves across the state. The stronger jet by later this morning
will be over southern and eastern Colorado. The bands are progged to
translate eastward into the cwa ahead of the main trough axis
later this morning and afternoon. Some concern the bands will
extend a little further north this morning as possibly spread into
zn33 briefly so have extended the Winter Weather Advisory there
until until 11 am. Best instability will occur along the
Interstate 70 corridor in closer proximity to the banded
snowfall. Will keep the Winter Weather Advisory for zn34 in
effect through 5 PM the aftn. The hrrr mdl still generating some
decent qpf in the Denver area around 00z. Nam12 forecast sounding
show a brief period of good instability in a saturated airmass
this afternoon. As a result, some concern for a quick burst of
snow around 00z. Will keep the mention of an inch of snow in the
grids for Denver and for areas south and east as well. Also added
isolated thunder the grids at that time. By early this evening,
increasing mid level subsidence develops strong northwest winds
developing in the mountains, foothills and adjacent plains after
03z this evening. No highlights, but areas in and near the
foothills could see some gusts in the 50-60 mph range. Snow will
decrease but could still get 1-3 inches along the higher north and
west facing slopes with areas of blowing snow along and east of
the Continental Divide.
Long term...(wednesday through monday) issued at 152 am MST Tue
Feb 28 2017
An upper level ridge building along the West Coast will produce a
northwest flow aloft across the central rockies. A few snow showers
will be possible over the mountains, otherwise it will be dry.
Temperatures are expected to be cool under this pattern with highs
in the upper 30s to lower 40s.
Thursday and Friday will be dry under westerly flow aloft.
Temperatures will begin to warm. Highs on Thursday should be near
normal. By Friday, high temperatures are expected to be above normal
with mid to upper 50s expected across northeast Colorado.
For the weekend, westerly flow aloft will turn to the southwest
Sunday as an upper level trough moves over the Pacific northwest.
Temperatures will be very mild this weekend with 60s expected over
northeast Colorado. Can't rule out a few 70s on Sunday. As the upper
level trough moves across the northern rockies Sunday and Monday, it
could bring light snow to the northern mountains. Will have low pops
for this on Sunday. A cold front behind the trough is expected to
slide across eastern Colorado Monday. This will bring cooler
temperatures, however readings should remain above normal. No
precipitation is expected with this front.
Aviation...(for the 06z tafs through 06z Tuesday night)
issued at 152 am MST Tue Feb 28 2017
Will keep generally southeast winds at kden/kapa through mid aftn.
The northeast winds around 22z transitioning to gusty northwest
winds overnight. VFR conditions through until 18-19z then could
see ils restrictions with bkn-ovc cigs 040-060 kft agl developing
by 21z. Snow showers will move off the foothills after 21z and
could see IFR cigs/vsbys develops in the 23-01z time frame. Will
mention isolated thunder as well in the public zone but keep it
out of the terminal forecast at this time. Good instability with
the passage of the trough so possibility of a quick inch of snow
around 00z. Strong subsidence by early evening with gusty
northwest winds developing, could see some gusts to 40 kts at kbjc
after 08z tonight. Cigs should improve fairly quickly after 03z
with increasing subsidence developing.
Winter Weather Advisory until 5 PM MST this afternoon for coz034.
Winter Weather Advisory until 11 am MST this morning for coz033.
Winter Weather Advisory until 5 am MST this morning for coz031.