Grover, Colorado Weather Forecast Discussion

621
FXUS65 KBOU 232334
AFDBOU
Area Forecast Discussion
National Weather Service Denver/Boulder CO
534 PM MDT Tue Sep 23 2025
.KEY MESSAGES...
- The wet weather system will come to an end this evening. The
  main concern will be slick and icy roads above 9,000 feet
  tonight as temperatures fall below freezing. Rainfall totals may
  exceed 2" across the eastern plains.
- Turning warmer and drier again for the rest of the week ahead.
- The next system will be a weak wave that could bring light
  precipitation late Sunday through Tuesday.
&&
.DISCUSSION /Through Tuesday/...
Issued at 235 PM MDT Tue Sep 23 2025
Water vapor imagery shows a closed trough becoming more of an open
wave across southern Colorado this afternoon. The imagery shows a
classic upslope, over-running event for north-central and
northeast Colorado given the track of the low through southern
Colorado. The VAD wind profile shows 35 knot east-northeasterly
winds from 24,000-30,000 feet which is helping to push abundant
moisture into northern Colorado. Warm air advection within the
700-500 mb layer is also adding to the forcing for this event.
Radar shows a pocket of heavier rain from Greeley to Fort Collins
and southward to Boulder. Rainfall totals in those areas have
mostly eclipsed 1" with another 0.25-0.5" of additional rain
expected. There is another pocket of heavier rainfall near Fort
Morgan, Akron, and Sterling. Some rain gauges have already picked
up more than 2" there and an additional inch of rain could occur.
As the system will be moving east-southeastward, that area will
be the last to see the rainfall come to an end. Rain has been
lighter across the Denver metro this afternoon but the morning
rainfall along with last night`s rain has added up to more than
an inch near downtown Denver.
As for snowfall, we have seen consistent snowfall throughout the
day mainly above 10,000 feet. Webcams show that roads are mostly
just wet below 11,000 feet so travel impacts are generally low.
Some of the ski area webcams show up to 5" of snow has
accumulated.
Heading into this evening, the trough will become weaker and as it
departs our area to the east, it will bring one last wave of
precipitation from north to south ending around 7-8pm for most of
the area. There is some concern that mountain passes will become
icy and slick due to temperatures dipping below freezing after
sunset considering there is plenty of moisture on the roads. Low
temperatures will be in the mid 40s across the plains and the
mountains and mountain valleys will likely see lows in the upper
20s.
An upper level ridge will develop over Idaho and influence the
weather in Colorado through the end of the week. Each day through
Friday will have warmer temperatures with highs across the plains
in the low to mid 80s on Friday. There will be plenty of sunshine
and generally light winds.
A weak cold front will move through Friday night resulting in
highs being 5-10 degrees cooler on Saturday than on Friday. Most
models agree that there will be a weak upper level trough that
moves towards Colorado late Sunday through Tuesday. The forcing
will be minimal with this trough and only light precipitation is
possible.
&&
.AVIATION /00Z TAFS through 00Z Thursday/...
Issued at 532 PM MDT Tue Sep 23 2025
MVFR to IFR conditions expected through tonight. Widespread
showers will persist for all TAF sites through this evening. Short
range guidance indicates weakening winds past 00Z this evening
under continued W/NW flow.
Showers should end late this evening, but there could be some
lingering precipitation through 06Z (07Z for APA). After that, the
stratus deck will slowly erode early Wednesday morning, with
generally light W/NW winds.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 PM MDT this evening for COZ033-
034.
&&
$$
DISCUSSION...Danielson
AVIATION...Rodriguez

NWS BOU Office Area Forecast Discussion