Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 03/09/20
Area Forecast Discussion
National Weather Service Great Falls MT
800 PM MDT Sun Mar 8 2020
.UPDATE...
A trough passing through The Treasure State favors precipitation
across central Montana beginning overnight and continuing through
Monday morning. Up to an inch of snow accumulation is expected at
lower elevations with 1 to 3 inches expected in the mountains.
Inherited forecast continues accurate; therefore, no changes will be
made at this time.
- Fogleman
.SYNOPSIS...
Another weather disturbance will move into the region from the
west tonight with light snow or snow showers developing across
the mountains and much of central Montana late tonight into Monday
morning before shifting south into southwest Montana Monday
afternoon. Drier and milder conditions are likely to develop
through the middle of the work week along with increasing winds
before a colder and snowier weather pattern appears likely to
develop by next weekend.
&&
.DISCUSSION...
Sunday night through Tuesday...A broad upper level trough roughly
centered along the west coast today gradually shifts inland over the
next several days with mainly weak embedded shortwave energy moving
east across the region at times. Period of clearing this afternoon
will be followed by another increase in cloudiness this evening as
the next embedded wave moves in from the west. Not much moisture
initially with this feature but models continue to show a period of
favorable upper level jet positioning later tonight resulting in the
development of a frontogenic precipitation band across central MT
from late tonight into Monday morning before the band sags south and
weakens across SW MT Monday afternoon. Placement of the
precipitation band overnight into Monday morning looks to favor
areas from Helena to Lewistown where up to an inch of snowfall is
possible at lower elevations with 1-3 inches of snowfall possible
across the Little and Big Belt ranges. Surface winds will remain on
the light side through Monday and with snow accumulation mainly
light, we are not anticipating the need for any winter weather
highlights for the snow late tonight through Monday. Temperatures
remain fairly close to seasonal averages on Monday before warming
some on Tuesday as a period of drier conditions with increasing
winds develops under a west to northwesterly flow aloft. Hoenisch
Wednesday through next Sunday... The westerly flow aloft will keep
the forecast area mostly dry on Wednesday with breezy westerly
downslope winds and temperatures up to 10 degrees above normal. The
flow aloft will shift a bit more northwesterly on Thursday, which
will bring a chance of mainly mountain precipitation, along with
slightly cooler temperatures. Models are coming into better
agreement with bringing a fairly strong low pressure trough and
associated Canadian cold front southeast through Montana Friday into
Saturday, bringing widespread precipitation mainly for Friday night
into Saturday. At this time, the brunt of the cold air appears to
mostly impact North Central and Central Montana, as high
temperatures on Saturday there fall up to 20 degrees below normal.
This system is forecast to exit the area on Sunday, decreasing the
chance for precipitation and allowing temperatures to rebound
somewhat. However, there is some uncertainty with regard to this
system; it could deepen further through the weekend and linger over
the area, or it split and move more quickly through the area. Will
need to monitor this situation further over the next few days, but
winter weather highlights may be needed with this system. Coulston
&&
.AVIATION...
Updated 616 PM MDT Sun Mar 8 2020 (09/00Z TAF Period)
KWYS begins this TAF period under MVFR conditions; otherwise,
current obs at all other airfields show VFR conditions. Expect KCTB
and KHVR to remain VFR throughout this TAF period, with KBZN, KEKS,
KHLN, KGTF and KLWT becoming MVFR in snow, rain/snow and mist.
Conditions at KWYS are forecast to degrade into the IFR/LIFR range.
Mountain obscurations can be expected as well as aircraft icing
conditions. Initially, KCTB will experience some gusty winds to 25
kts, with winds gusting up to 19 kts for a period of time at KEKS.
Impacts are expected for light aircraft, particularly near mountains
and in passes. Expect the associated turbulence.
- Fogleman
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 25 44 24 48 / 30 30 0 0
CTB 19 41 21 45 / 10 10 0 0
HLN 30 45 24 48 / 50 60 10 0
BZN 31 43 24 46 / 20 40 50 10
WYS 21 37 16 37 / 20 30 70 10
DLN 29 44 26 44 / 10 20 30 0
HVR 13 41 22 48 / 0 10 0 0
LWT 21 37 22 43 / 50 70 20 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls