National Weather Service Forecast Discussion

000
FXUS65 KBOU 030143
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
743 PM MDT Sun Oct 2 2022

.UPDATE...
Issued at 742 PM MDT Sun Oct 2 2022

Updated to decrease PoPs across the Front Range. Did leave
isolated PoPs in the forecast though. A couple weak showers/storms
have formed. They may continue for a couple hours yet. Increased
PoPs over the mountains for this evening. Scattered showers have
already tracked across the northern mountains. There is also a
large area of showers and storms moving east across western
Colorado. It will weaken as it tracks east, but a little should
make it into the central mountains. Not expecting it to survive
onto the Front Range, though did leave low PoPs in through
midnight. May see a couple showers linger past midnight in the
mountains, but overall it should be dry through early Monday
afternoon before the next round of showers and storms develop.

&&

.SHORT TERM...(This evening through Monday)
Issued at 327 PM MDT Sun Oct 2 2022

An upper level low continues to spin across Montana this
afternoon, with southwesterly flow aloft bringing widely scattered
showers and storms to the region. Sound familiar?

After several straight days of a similar pattern.... we still
won`t see much change over the next 24 hours. At least one storm
has managed to develop so far this afternoon near Agate, and some
high resolution guidance is insistent on a few thunderstorms
developing over the lower foothills into the I-25 corridor later
this afternoon. I remain a bit skeptical of this but satellite
does show at least a few cumulus trying to bubble up. There isn`t
as much instability available compared to yesterday, but any
storms that do form would be capable of producing small hail and
gusty winds. There is also the potential for a strong storm or two
in our far western areas (Jackson/Grand counties), but the better
instability axis looks to be just outside our CWA.

At least a few showers will linger into the overnight hours,
especially across the high country. Overnight lows will fall in
the upper 20s to 30s over the higher terrain, with 40s expected
across the plains.

It`ll be close to a copy and paste forecast for tomorrow. The
upper level low to our north won`t budge much, and we`ll still be
embedded in an area of above normal moisture. There should be a
little more coverage of showers and storms tomorrow afternoon over
the higher terrain, with a showers and a few thunderstorms
spreading into the plains by the late afternoon hours.
Temperatures should be very similar to today.

.LONG TERM...(Monday night through Sunday)
Issued at 327 PM MDT Sun Oct 2 2022

There should be a pretty good batch of showers and storms moving
from the mountains across the plains Monday night, tapering from
northwest to southeast overnight. With limited lift, instability,
and available moisture, amounts don`t look tremendous but it
should be another round of wetting rain showers for most places.
There`s just a little cooling so the snow level should remain
fairly high, but seeing a little snow down into the higher
mountain valleys in places like Breckenridge is a possibility. It
shouldn`t be enough to have much travel impact beyond brief slush
over the pass summits as the ground remains fairly warm.

On Tuesday drier air aloft will be moving in, though there`s still
some low level moisture and a little instability. The showers and
a few storms should be mainly over the mountains, though there is
still a chance on the plains. Temperatures will likely be a couple
degrees cooler in the wake of the Monday night trough.

Wednesday looks like the driest and possibly the warmest day as
light northerly flow aloft continues to filter drier air into
northern Colorado. There may still be a few showers/storms in the
central mountains.

There`s pretty good agreement on a trough dropping from northern
Canada south across the plains by Friday. This will push a cold
front down the plains that will probably run out ahead of the mid
level trough and pass through northeastern Colorado sometime on
Thursday. The air behind it isn`t that cold, will be moderating as
it moves south, and the coldest air looks to stay further
northeast, but it will drop our temperatures a few degrees. This
looks like it will only have a little lift along/behind the
boundary for late Thursday or Thursday night, and will likely
stabilize the plains for Friday. The NBM gives a chance of showers
to the northeast corner Thursday night and keeps the low level of
convection going over the mountains Thursday and Friday without
much elsewhere and this looks alright. The biggest question of
this forecast is the highs on Friday, with the model spread
ranging through the 50s and 60s depending on how strong the push
of colder air into the area is and how much cloud cover. No
quarrels with the NBM just dropping highs 5 to 10 degrees though
it could be colder if there`s enough moisture to keep it cloudy
much of the day.

For next weekend, we get back into light westerly flow aloft with
light surface winds. Some moderation of daytime temperatures may
be offset by cooler nights depending on whether there`s any mid
level moisture coming back in the weak flow aloft. Models disagree
on this, but there shouldn`t be much of a temperature change.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 530 PM MDT Sun Oct 2 2022

Showers and thunderstorms across northern and western Colorado
are not expected to make it east of the Front Range Mountains this
evening. The few updrafts that formed east of the mountains
quickly collapsed. Expect scattered mid and high clouds through
tonight and Monday morning. Rain showers are expected late Monday
afternoon and into Monday evening. Just a slight chance for a
thunderstorm with this due to limited instability. Southerly winds
are expected for tonight and Monday. A slight chance for an
outflow boundary from the north yet this evening from the dying
convection over the northern mountains.

&&

.HYDROLOGY...
Issued at 327 PM MDT Sun Oct 2 2022

Scattered showers and a few thunderstorms will be possible yet
again on Monday. While there is well above normal moisture for
this time of year, storm motions will be quick and instability is
forecast to be meager. Can`t rule out some brief heavy downpours,
but the overall threat is slowly diminishing compared to the past
few days.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

UPDATE...Meier
SHORT TERM...Hiris
LONG TERM...Gimmestad
AVIATION...Meier
HYDROLOGY...Hiris

NWS BOU Office Area Forecast Discussion