Area Forecast Discussion
Issued by NWS Great Falls, MT

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KTFX 250445
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1045 PM MDT Mon Apr 24 2017

.UPDATED AVIATION...

.UPDATE...
Slow-moving showers and isolated thunderstorms are producing
persistent moderate to heavy rains over localized areas. Have
issued an SPS to cover ponding issues for impacted areas. For grid
updates, made minor changes to PoPs/QPF based on afternoon model
runs and current observed trends. No major changes otherwise.
Cassell

&&

.AVIATION...
Updated 0600Z.

Scattered showers will continue to be found across portions of
northern and central MT tonight...while rain and snow push into
southern portions. Some snow could even be found across lower
elevation sites briefly Tuesday morning...mainly from KCTB to
KGTF. MVFR to brief IFR conditions are expected under any rain or
snow shower tonight through Tuesday morning. Tuesday afternoon
will see shower activity become more scattered...with lower
elevation snow ending...and some thunderstorms possible across
much of the area. VFR to MVFR conditions can be expected Tuesday
afternoon. Shower activity then looks to diminish Tuesday
evening...with widespread VFR expected by the end of the period.
Mountain obscuration is possible through Tuesday morning...breaking
up Tuesday afternoon. Anglin

&&

.PREV DISCUSSION...
/ISSUED 547 PM MDT Mon Apr 24 2017/

Tonight through Wednesday...Mostly sunny skies today across
North-central Montana has produced weak instability. Weak surface
convergence along a stationary front will help spawn additional
rain showers and isolated thunderstorms this evening.
Precipitation coverage  more widespread overnight due to upslope
low level flow and enhanced divergence aloft. This activity
extends into southwest Montana as a shortwave trough moves from
west to east broadly along I90. A winter weather advisory remains
in effect for southern Gallatin county where up to 3 inches of
snow are expected at lower elevations, with higher amounts in the
mountains. Precipitation continues through mid-day Tuesday before
tapering from west to east. A dry period follow Tuesday night with
subsidence following the departing shortwave. The next, more
significant push of moisture advances into the area on Wednesday,
with widespread rain and mountain snow developing from west to
east. PN

Wednesday night through Monday...An unsettled weather pattern
will continue to reside over the region into early next week. The
precipitation is likely to become more widespread by late
Wednesday through Friday. Total precipitation amounts for later
this week are still expected to average between 0.30 and 0.60
inches for many areas, with some isolated higher amounts. The main
concern will be during the overnight hours as snow levels lower
to around 3500/4000 feet or so. Thus some snow is possible in the
bigger cities at lower elevations later in the week. At this time
most snow accumulations at lower elevations will be on grassy
areas, but a few inches of snow are likely in the mountains each
day. Afternoon temperatures will be below normal through the
entire period, with Thursday/Friday being the coolest days. Brusda

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  35  49  33  54 /  80  70  40  50
CTB  35  47  32  51 /  90  70  50  50
HLN  37  55  36  56 /  80  60  30  40
BZN  35  51  32  54 / 100  90  50  50
WEY  29  42  25  42 /  80  60  30  80
DLN  34  52  33  52 /  90  40  30  60
HVR  34  47  33  55 /  40  50  50  40
LWT  32  44  31  51 /  50  60  60  50

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon MDT Tuesday Gallatin.

&&

$$

weather.gov/greatfalls



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.