Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/30/20
Area Forecast Discussion
National Weather Service Great Falls MT
807 PM MDT Wed Apr 29 2020
.UPDATE...
The previous shift forecast is playing out nicely. The only
adjustment I made during this evening`s forecast update was to
slightly increase POPs along our border with the Glasgow Weather
Forecast Office. Our co-workers, there, increased their POPs, which
actually ended-up bringing them more in line with our forecast; so,
just a bit of a tweak to those POPs was all that was needed on my
end. Aside from that, no other changes will be made, at this time.
- Fogleman
.SYNOPSIS...
With an upper level disturbance moving into the region tonight,
expect a mild night, with mostly cloudy skies along with a few
showers or thunderstorms along the divide and across Southwest MT.
On Thursday, showers and thunderstorms will affect much of
Southwest and Central MT, with some storms on the strong side. It
turns drier, but remains mild to start the weekend, but rain and a
few storms move back into the region by Sunday.
&&
.DISCUSSION...
Tonight thru Thursday night...An upper level disturbance will
approach the region tonight. Expect some showers/isolated
thunderstorms along the divide and across Southwest MT tonight.
Otherwise, cloud cover will generally keep overnight lows on the
mild side tonight. On Thursday, a stronger upper level disturbance
will move from southwest to northeast through the region. Expect
another round of storms to start in Southwest MT by early afternoon,
then move northeastward up into Central MT by evening. There is
enough instability that a marginal risk has been extended northward
to just south of Great Falls/Stanford line. The main threat from the
stronger cells will be severe wind gusts, but an isolated large hail
cell can not be ruled out either. Afternoon temperatures will
generally be a touch cooler than today, with the warmest
temperatures in the Havre area, as precipitation will not make it
into that region until evening.
Friday through Monday...Overall, the forecast models are going
drier, with slightly above normal temperatures for Friday/Saturday.
Again, the GFS tries to bring a weak cold front southward into the
Hi-line area on Friday, but the EC/NAM/NBM are drier, thus kept pops
mostly dry for now. For Saturday night into Monday, a cold front
moves from west to east across the region. Expect
showers/thunderstorms as this front moves through the region.
Overall, no heavy/significant storms are expected at this time.
Tuesday and Wednesday...Both the GFS/EC differ on solutions by the
middle portion of next week. The GFS tries to dig an upper level
trof over the region, while the EC tries to build an upper level
ridge. Overall confidence is low during this time period, thus the
NBM blend of low pops and seasonable temperatures looks on track.
Brusda
&&
.AVIATION...
Updated 625 PM MDT Wed Apr 29 2020 (30/00Z TAF Period)
VFR conditions will prevail throughout this TAF period at our North
Central Montana airfields. All other airfields will begin VFR, and
fall into the MVFR range in -SHRA BR. Additionally, periods of -TSRA
can be expected at KLWT and throughout Southwest Montana beginning
after 30/16Z in the Southwest and moving Northeastward. Expect all
hazards assumed in and near TS. Areas of VIRGA are forecast. Sudden
downdrafts should be expected in and near VIRGA. LLWS is forecast at
KCTB from 30/12Z - 30/15Z. There is no low level ICG forecast for
this period; however, from 30/06Z through the end of the TAF period,
upper level ICG FL130 and above is forecast. Please see,
aviationweather.gov/icing for details. Outside of TS, gusty winds
are forecast at KCTB, KHVR, KHLN and KEKS. These winds will impact
light aircraft, especially near mountains and in passes. Please see,
aviationweather.gov/turbulence, for aircraft weight specific TURBC
forecast.
- Fogleman
NOTE: Amendments not scheduled for Ennis (KEKS) due to
ongoing runway closure.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 53 73 41 64 / 30 30 40 0
CTB 51 67 40 61 / 40 10 10 10
HLN 51 72 39 65 / 30 50 40 10
BZN 48 73 40 65 / 40 70 70 20
WYS 37 60 31 57 / 50 80 50 20
DLN 48 70 39 63 / 50 70 30 10
HVR 53 78 45 65 / 20 10 40 10
LWT 50 69 40 60 / 10 70 80 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls