Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 241126
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
530 AM MDT Tue Apr 24 2018

Aviation Section Updated.

.SYNOPSIS...

Enjoy mostly clear skies and mild temperatures through the rest of
the week. A few showers are possible Wednesday afternoon. Lowland
floodwater is gradually receding. However, mid-slope snow melt
will lead to further rises on streams and creeks originating in
the mountains.

&&

.DISCUSSION...

Subsidence associated with a building ridge aloft will provide
clear skies and mild temperatures today. Patchy fog is possible
early this morning, particularly near Lewistown and Bozeman.
Breezy southwest winds will develop later today due to surface
pressure falls over Alberta. A shortwave crosses the state on
Wednesday, with an attendant cold front that will shift winds to
northerly. A few light showers are possible with this passing
shortwave system. A high amplitude ridge returns on Thursday and
Friday. Temperatures on Friday are forecast to reach the upper 70s
to near 80 degrees. Strong sun and mild temperatures will
continue to increase the snowmelt rates, as outlined below in the
hydrology section.

By the weekend, a moist, SW flow aloft may develop as another large
upper level low shifts inland off the Pacific. This setup appears
favorable for at least some increase in the risk of showers/storms,
some of which could be strong. As this upper low moves inland, a
more unsettled, and potentially cooler, pattern may develop.

&&

.AVIATION...
Updated 1130Z.

VFR conditions prevail through the period. Breezy southwest winds
develop this afternoon across North-central MT.

&&

.HYDROLOGY...

River flooding continues along the Milk River Valley. Flooding
concerns may increase across SW MT and areas adjacent to the Rocky
Mountain Front through the week.

Rivers in our forecast area are cresting now, or have crested,
along the Milk River Valley. This trend continues this week. It
must be stressed, though, that fields, yards, pastures, etc will
remain water logged for some time, even after the rivers/creeks
fall. In some cases, the water could remain around for a couple of
weeks.

With increasing temperatures this week, attention will then turn
towards increasing snowmelt coming out of the Rockies and how that
will impact not only mainstem rivers, but also creeks/streams
coming out of the mountains (as has already been an issue in parts
of Madison County). Please continue to monitor river forecasts in
this area as well as any ongoing or future flood products through
the week.
MARTIN

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  63  38  64  34 /   0   0  10  10
CTB  66  34  57  31 /   0   0  10  10
HLN  60  33  66  35 /   0   0  10  20
BZN  54  29  65  33 /   0   0  10  20
WEY  48  21  53  26 /   0   0   0  10
DLN  54  29  65  31 /   0   0   0  10
HVR  66  36  65  32 /   0   0   0  10
LWT  55  33  65  32 /   0   0   0  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...

Flood highlights continue for portions of North-Central and
Southwest MT.

&&

$$

http://www.weather.gov/greatfalls


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