Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 251135
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
535 AM MDT Tue Apr 25 2017

UPDATED AVIATION

.DISCUSSION...

Today through Wednesday...Mostly cloudy skies will persist across
the CWA and snow levels should continue to fluctuate between roughly
5000 and 6000 feet MSL. As one shortwave trough exits Southwest MT
to the south and east this morning, bands of steadier snow should
diminish over that area by late morning. The winter weather advisory
until noon today for southern Gallatin County was expanded to
include southern Madison and Beaverhead counties, including Raynolds
Pass and Monida Pass. Slick, snow-covered roadways should linger in
these areas this morning. Another shortwave trough will skirt the
international border and Hi-Line today as it also moves generally
southward and eastward. Accordingly, scattered showers are expected
with the passage of this disturbance, especially over North-Central
MT. In addition, isolated thunderstorms are possible late this
morning through early evening and may move slowly once again,
resulting in localized swaths of heavier rainfall. Subtle shortwave
high pressure ridging and boundary layer stabilization via nocturnal
cooling should result in drier weather later this evening into
Wednesday morning. Thereafter, the potential for scattered showers
and isolated thunderstorms will increase late Wednesday morning
through afternoon as another disturbance overspreads the CWA from
the west. Near-normal lows and slightly below-normal highs are
expected through Wednesday.
Jaszka

Wednesday night through Tuesday...An overall unsettled weather
pattern will reside over the region during the extended period.
Light rain from Wednesday afternoon will continue through Wednesday
night. The rain could change to snow by Thursday morning at lower
elevations. However, the latest models indicate some precipitation
to continue into the day on Thursday, but some breaks in the
precipitation are possible, especially along/west of I-15.
Scattered/likely areas of precipitation will then continue Thursday
night through Monday, with the lowest chance for precipitation being
Sat/Saturday night. By Tuesday of next week, the GFS model progs a
fairly deep upper level trof of low pressure to develop over the
region, resulting in a fairly good spring snowstorm over Central MT.
However, it is too early to feel confident in this storm at this
time. Otherwise cool afternoon temperatures on Thursday and Friday
will warm a touch over the weekend, only to cool a bit by next
Tuesday.
Brusda

&&

.AVIATION...
Updated 1135Z.

Abundant cloud cover will persist through the TAF period as multiple
disturbances cross the area. CIGS should tend VFR or MVFR, but lower
CIGS are possible at times. This includes KLWT, where IFR or lower
CIGS/VSBY in patchy fog are possible through about 15Z/Tue. In
addition, periods of rain showers, mountain snow showers, and
mountain obscuration are expected. Isolated thunderstorms are
possible this afternoon and early evening, but confidence in a storm
impacting any of the TAF sites is low.
Jaszka

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  49  33  54  36 /  50  40  40  60
CTB  44  31  51  35 /  80  60  50  60
HLN  53  35  55  36 /  50  40  40  70
BZN  48  31  53  34 /  80  40  50  90
WEY  38  21  40  27 /  70  30  60  90
DLN  49  33  51  32 /  50  30  50  80
HVR  48  32  54  36 /  30  30  40  50
LWT  45  30  50  33 /  40  50  60  70

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon MDT today Beaverhead...
Gallatin...Madison.

&&

$$

weather.gov/greatfalls


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