Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/24/20
Area Forecast Discussion
National Weather Service Great Falls MT
841 PM MDT Thu Apr 23 2020
.UPDATE...
This afternoon and evening, perturbations in the upper level flow
along with LI`s around -2 have favored more widespread thunderstorm
activity than originally anticipated, with thunderstorms building
and collapsing throughout most of the region for hours. Some of the
stronger thunderstorms have produced pea-sized hail. Have tweaked
almost all forecast grids, adjusting temperatures, RH, winds, sky
conditions, etc, as well as increasing POPs a bit. Ran some new snow
totals, and the most snow expected over the next 24 hours is 1 1/2
to 2 inches located over Kings Hill Pass, and West Yellowstone.
Roadways are expected to be slushy and slippery mostly in these
areas.
- Fogleman
&&
.SYNOPSIS...
Several weather disturbances moving east across the region will
maintain showery and somewhat cool conditions through Friday. A few
isolated weak thunderstorms are possible as well during this period.
snow is possible at times across higher elevations passes but
significant roadway accumulation is not expected. A return to dry
and milder conditions is expected Saturday.
&&
.DISCUSSION...
Tonight through Friday night...A series of weather disturbances
emebedded within a moist westerly flow from the Pacific will move
east across the Northern Rockies and MT, keeping showery and
unsettled conditions across the region through Friday evening.
Expect precipitation coverage to gradually decrease tonight with
increasing atmospheric stability, with a similar diminishing trend
in precipitation coverage likely on Friday as well. Temperatures
remain cool but close to seasonal averages for late April today
and Friday. Snow levels remain near to above pass level overnight
tonight which could bring some light snow to area passes, but
intermittent nature of precipitation and onset of daylight will
likely allow little or no snow accumulated on road surfaces. -TP
Saturday through next Thursday...An upper level ridge rebuilds
over MT on Saturday briefly, allowing for a quick rebound to dry
and warmer conditions for the early part of this weekend. The next
round of upper level energy from the eastern Pacific moves inland
Sunday through Monday, cooling temperatures again back to
seasonal averages and bringing another round of what looks to be
mainly showery precipitation and windy conditions. Longer range
models models continue to support a more pronounced period of
upper level ridging to build over the western US by the middle of
next week, resulting in potentially the warmest temperatures of
the season so far for north-central and southwest MT. Hoenisch
&&
.AVIATION...
Updated 627 PM MDT Thu Apr 23 2020 (24/00Z TAF Period)
KCTB and KHLN are expected to remain VFR throughout this TAF period,
with all other airfields falling into the MVFR range, at times, and
possible IFR conditions for KWYS. Mountain obscurations and aircraft
icing conditions are forecast. Areas of breezy winds will impact
light aircraft, especially when winds are funneled through mountain
passes. Expect the associated TURBC. This evening, confidence is low
for thunderstorms to occur over the airfields; however, it should be
noted that, as of the time of this TAF issuance, thunderstorms are
building and collapsing quickly throughout most of the region. Some
of these stronger storms are producing pea-sized hail. Expect all
aviation impacts that are assumed in and near thunderstorm.
Convective activity is expected to diminish as the atmosphere
settles, tonight.
- Fogleman
NOTE: Amendments not scheduled for Ennis (KEKS) due to
ongoing runway closure.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 37 59 34 66 / 30 30 0 0
CTB 35 59 34 62 / 30 10 0 0
HLN 37 60 34 67 / 30 20 0 0
BZN 33 58 32 64 / 60 30 10 0
WYS 23 49 23 51 / 50 30 10 0
DLN 32 56 31 61 / 40 10 0 0
HVR 38 61 36 67 / 30 20 0 0
LWT 34 54 33 62 / 40 40 10 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls