Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

FXUS65 KTFX 222110

Area Forecast Discussion
National Weather Service Great Falls MT
306 PM MDT Tue Oct 22 2019

Windy conditions continue this afternoon, then diminish somewhat as 
colder air moves into the region tonight, changing rain to snow in 
many areas. After a cool day on Wednesday, expect warmer and windy 
conditions to redevelop by Friday. However, it turns sharply colder 
next weekend, with another round of snow for some areas.


Tonight through Wednesday...Gusty winds developed as expected this
afternoon as a front pushed across the CWA. The highest gust
reported so far was 81mph at Two Medicine Bridge in East Glacier,
but multiple wind gusts over warning criteria of 58mph have been
reported along and west of I-15 north of Great Falls. As the
mid/high level clouds cleared out early this afternoon, convective
showers have developed along the Hi-Line east of I-15, with some
lightning reported over parts of Hill and Blaine counties so far.
Some of these showers could bring down strong wind gusts.

Winds should drop off gradually during the evening hours, though
remain gusty overnight as strong pressure rises occur. Rain and 
snow showers will continue into tomorrow morning as well owing to
N-NW'ly flow and a shortwave tracking SE across the area. The best
precipitation is likely over the central mountains, where 4 to 8 
inches of snow are possible in the Little Belts and Snowys, with
little or no accumulating snow expected at lower elevations. Gusty
NW'ly winds are expected over the central and northern parts of
the CWA, but not expected to approach high wind warning criteria.
Precip and winds should both abate Wed night. -Kredensor

Thursday through Friday...Shortwave ridging will quickly build
over the region for Thursday into Friday. Thus expect much warmer
air to move into the region by Friday, thus afternoon 
temperatures could be a touch higher than currently forecasted.
Expect another potential for strong winds. The strong winds on 
Friday could be a bit more widespread over North Central MT, and 
high wind highlights might be needed once again.

Saturday through Tuesday...The 1st of two strong cold fronts will 
move southward through the region early on Saturday.
Generally expect falling temperatures over much of the region
during the day on Saturday, with accumulating snowfall likely in
the favored upslope areas of North Central MT. Overall snow
amounts look to be around 6 inches in the mountains and an inch or
two at lower elevations at this time. It remains cool on Sunday,
with the 2nd cold front moving southward through the region Sunday
night into Monday. Again, another round of light snowfall is
expected with the 2nd cold front, along with colder air moving 
into the region. It is possible that temperatures on Monday could 
be quite a bit colder than currently forecasted should this front 
pan out. Temperatures slowly rebound on Tuesday, as drier air 
moves back into the region. Brusda/PAN


Updated 1155 AM MDT Tue Oct 22 2019 (18Z TAF Period) 

Strong W-WNW'ly winds will remain the main concern this afternoon
into the early evening hours, especially for central and northern
areas. Wind gusts over 40kts have been common at KCTB and have 
approached those levels at KGTF, with those winds likely to 
continue through most of the afternoon. Localized gusts over 50
knots will be possible across north-central Montana through 07z or
so. Turbulence and mountain waves may cause some flying concerns,
with periods of low level wind shear likely as well. Scattered 
rain/snow showers and isolated thunderstorms will develop this 
afternoon and evening, especially where some clearing is allowing
surface heating, as a front moves eastward through the region. 
Overall, much of the area will have mid/high clouds through this 
afternoon, with lowering ceilings this evening. Brusda/Kredensor


GTF  34  42  26  51 /  40  40   0   0 
CTB  30  42  24  50 /  40  40   0   0 
HLN  33  45  24  52 /  20  40  10   0 
BZN  29  44  19  50 /  30  40  10   0 
WEY  21  33   6  37 /  30  20   0   0 
DLN  30  42  21  48 /  10  10   0   0 
HVR  32  43  24  52 /  30  30   0   0 
LWT  32  37  23  48 /  60  50  10   0 


High Wind Warning until 7 PM MDT this evening Eastern Glacier...
Eastern Pondera...Eastern Teton...Northern Rocky Mountain 
Front...Southern Rocky Mountain Front.

High Wind Warning until 7 PM MDT this evening Cascade...Central 
and Southern Lewis and Clark...Judith Basin...Meagher.

Winter Weather Advisory from 9 PM this evening to noon MDT 
Wednesday Cascade...Judith Basin...Meagher.

National Weather Service Glossary of Abbreviations