Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 01/03/21

Area Forecast Discussion

National Weather Service Glasgow MT

 1048 AM MST Sat Jan 2 2021

.DISCUSSION...

1030AM UPDATE:
Rain has exited Valley county allowing the advisory to be
cancelled. However, reports from Roosevelt county indicated that
rain is forming ice on roads and warming trends for ground
temperatures do not appear to be rising fast enough. Therefore,
the advisory has been extended for an additional 2 hours to try to
capture the remaining impacts on the backend of this event. GAH


930AM UPDATE:
A Winter Weather Advisory for freezing rain has been issued across
the hi-line. With radar trends intensifying and frozen ground
across the east have placed it out till Noon. Wind gusts in
southwest Phillips are also up indicated that winds aloft are very
strong behind the front. GAH


MORNING DISCUSSION:
A weak disturbance is moving across Montana this morning. Radar
echos to the west indicate showers are already moving into the
area but observations are hinting that it is too dry for
precipitation to reach the surface. As showers persist over the
next several hours, precipitation may eventually reach the ground
and where some locations may still be near freezing, roads could
have patches of black ice until at least after the sun has been
up and downsloping winds kick the temperatures up an extra notch.
QPF spread in the models remain, keeping confidence low but with
a dry boundary layer to begin with, QPF is expecting to be light,
around a trace to a couple hundredths. Showers should end by the
evening.

Temperatures were busted yesterday as brief compressional heating
in the late afternoon boosted the high in Glasgow to the mid 40s.
Warm westerly winds and downsloping is expected to be stronger
this weekend, so using a blend of the warmest temperature models,
highs are expected to be in the 40s to lower 50s across the area.
Current observations in the west are already quite warm and the
sounding this morning has temperatures in the mid to upper 40s
aloft. That being said, it will be possible for efficient mixing
and another temperature bust each day this weekend. Glasgow
Airport could even break the previous record of 50 on Sunday.

Another cold front on the heels of the first disturbance will
bring stronger winds through Central and Eastern Montana Sunday
afternoon. Most models have wind speeds at 850mb at 50 to 60 kts
in areas where lapse rates are around 7-8 C/km, particularly
along the western zones and higher terrain such as the Little
Rockies. A High Wind Warning has been issued for southwest
Phillips county. While confidence is high for gusty winds
throughout the area, the magnitude is too marginal to expand the
warning at this time.

A progressive weather pattern for next week with a series of
ridges and troughs is expected. It will resemble recent activity
where each trough is fairly dry and unseasonably warm temperatures
prevail, although not as warm as what is expected this weekend.
Northeastern Montana is roughly 15 to 30 degrees above normal and
relatively dry for this time of year. Looking into the extended,
warm and dry weather is expecting to hang around for another
couple weeks.

Roxy


&&

.AVIATION...
LAST UPDATED: 1730Z

FLIGHT CAT: VFR

DISCUSSION: A cold front will move through the area this morning.

ICE: Light, scattered precipitation will be possible and with the
ground near freezing, any rain that reaches the surface could
freeze on contact causing increased breaking distance on landing.
Temperatures will warm enough in the afternoon for the FREEZING
RAIN threat to diminish. This hazard could impact KOLF, KSDY, and
KGDV.

LLWS: Low level wind shear will become a problem as the cold
front passes through the area. Strong winds above may not be able
to reach the surface initially. This will create a strong speed
shear difference for aircraft approaches. This threat will last
through the whole of the cycle.

WIND: West to southwest at 5 to 15 kts this morning. Veering west
and increasing to 10 to 20 kts with gusts up to 25 this afternoon.
Backing to the southwest and decreasing 15 kts or less overnight.


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
High Wind Warning from 11 AM to 11 PM MST Sunday for Southwest
Phillips.

Winter Weather Advisory until 2 PM MST this afternoon for
Daniels...Eastern Roosevelt...Sheridan...Western Roosevelt.


&&

$$

weather.gov/glasgow