Areal Flood Warning 2, NWS Great Falls, MT

Area Forecast Discussion
National Weather Service Great Falls MT
535 PM MDT Mon Mar 20 2017

Updated Aviation Discussion.

.DISCUSSION...

Tonight through Wednesday...

Rain and snow showers over the central and southwestern Montana
counties will diminish tonight through early Tuesday morning as
upper ridging builds overhead and the mid-level frontal energy
splits apart. After mostly quiet weather across the region Tuesday
morning into early afternoon, a disturbance pushes north through
the area Tuesday afternoon through evening, bringing another
round of showers north over the southwest and central MT mountain
region, with some light rain or potentially even freezing rain
moving out onto the plains Tuesday evening into early Wednesday
morning. Any freezing precipitation will be short-lived, however,
as the ensuing warm frontal passage will cause temperatures to
quickly warm Wednesday morning through afternooon with increasing
west-southwest winds, especially across the plains. Cassell

Wednesday night through Sunday...It will be an unsettled weather
pattern during the extended period...with Friday looking to be the
one nice day though. A warm front will have moved through the
region by Wednesday night, with showers on the decrease through
Thursday. By Friday, an upper level ridge will be over the region,
resulting in mostly dry/mild conditions. However, the next upper
level trof moves into the region by Saturday afternoon, resulting
in a chance for precipitation over Southwest MT. The precip could
spread northward into North Central MT Saturday night into Sunday.
The GFS progs about 0.50 inches with this system, while the EC is
half that. Showers decrease on Sunday, but with a cool
northwesterly flow aloft developing by Monday, a few scattered
showers will once again be possible. Overall, Friday afternoon
temperatures look to be the warmest, with highs in the 60s,
otherwise seasonable temperatures in the 50s are expected most
other days during the extended. Brusda

&&

.AVIATION...
Updated 2335Z.

Westerly flow aloft will begin to back toward southwesterly during
the TAF period as a weather disturbance nears SW MT around 06Z/Tue
and then North-Central MT around 12Z to 18Z/Tue. Simultaneously, a
stationary front is expected to persist across Southwest MT, in
vicinity of KBTM, KEKS, and KBZN. Periods of precipitation and
occasional MVFR VSBY/MVFR or lower CIGS are expected at KBZN and
KEKS, and possibly KHLN. Also expect periods of mountain obscuration
in SW MT during the period. Farther north over the plains, VFR cigs
and vsby should prevail but with easterly/southeasterly upslope flow
can't rule out MVFR cigs at times.  Jaszka/Cassell

&&

.HYDROLOGY...
300 PM Update.

The Flood Warnings for Battle and Lodge Creeks have been extended.
Battle creek is seeing improvement with river levels expected to
dip below flood stage today...however...another rise in river
levels is expected later today through early Tuesday
morning...hence the extension through the day Tuesday. Lodge Creek
continues to see flooding impacts and remains at minor flood
stage. Latest forecast shows a slow decline through the day
Tuesday...with some flooding concerns possibly continuing into
Wednesday morning. This flood warning has been extended until
around Noon Wednesday to cover these fluctuations. In
addition...rising rivers have been found across areas of Blaine
County mainly along Highway 2 from Chinook to Harlem. And Areal
Flood advisory has been issued to cover this.

For the remainder of the CWA. Cooler temps today should slow day
any additional snowmelt flooding. With the cooler temps there are
chances ice jams may form and bring additional flooding. Please
report any flooding when safely to do so and never drive across
flooded roads. Anglin

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  30  52  37  64 /  20  20  30  20
CTB  25  46  31  55 /  20  20  20  20
HLN  29  54  37  62 /  60  20  40  20
BZN  30  52  35  59 /  40  20  30  30
WEY  30  48  32  45 /  50  20  40  30
DLN  33  57  36  58 /  40  30  40  10
HVR  28  46  30  58 /  10  20  20  40
LWT  28  43  32  60 /  30  20  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...

Flood Warning for Lodge and Battle creeks until further notice.

Flood Advisory for portions of Blaine County through this evening.

&&

weather.gov/greatfalls