Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 190240

Area Forecast Discussion
National Weather Service Great Falls MT
840 PM MDT Wed Apr 18 2018

Updated Hydrology Discussion


Slightly warmer temperatures continue to build late this week,
with relatively dry conditions expected through the weekend. A
quick moving disturbance will send a cold front across the area on
Saturday with strong winds expected. The next chance of
precipitation will arrive with another quick moving storm system
to our south Sunday night through Monday followed by near normal
temperatures into next week.


Updated 0000Z.

VFR conditions will prevail through Thursday as a ridge of high
pressure moves across the region. Surface winds become light and
shift to easterly tonight at most terminals. Light winds and at
least partially clear skies tonight may lead to some patchy fog
development near the KCTB and KHVR terminals where despite dry
conditions, melting snowpack in the vicinity could lead to higher
low level moisture. Otherwise, a gradual increase in high level
cloud-cover can be expected tonight through Thursday morning.


Updated 840 PM Wednesday (4/18).

Flooding continues to affect northern and northeast portions of
north-central MT this evening with flood warnings for several
points along the Milk River and its tributaries in Hill and
Blaine counties as well as countywide for smaller creeks. Areal
flooding from creeks and snow-melt is also impacting areas further
west across Liberty, Toole and Pondera counties. Satellite
imagery this afternoon still shows a significant though dwindling
snowpack in portions of these counties with additional run-off
likely to continue to produce hydrological issues through the next
several days as temperatures gradully warm. New point flood
watches will be issued this evening for Lodge Creek in northeast
Hill county and The Missouri River at Landusky (near the Fred
Robinson Bridge) where river stage measurements are increasing and
may reach flood stage in the next 24 hrs. Hoenisch


/ISSUED 812 PM MDT Wed Apr 18 2018/
FXUS65 KTFX 190212

Area Forecast Discussion
National Weather Service Great Falls MT
812 PM MDT Wed Apr 18 2018


A fairly quiet evening from a meteorological standpoint (vs
hydrological) as an upper level ridge axis drifts across the
region for dry conditions. Surface pressure gradient has also
weakened allowing winds to become light, with a shift to easterly
winds occurring on the plains. Main change from previous forecast
was to reduce the coverage of patchy fog tonight through Thursday
morning as the airmass has dried significantly with most
locations now seeing dewpoints in the teens to around 20. Best
potential for patchy fog development tonight will likely be
limited to areas across the north-central MT plains that still
have snow-cover or standing water, mainly along the Hwy-2
corridor. Hoenisch

/ISSUED 552 PM MDT Wed Apr 18 2018/

Tonight through Friday...We stay in a relatively calm pattern
through the overnight hours. Looking aloft, a slow moving upper-
level trough will continue to press eastward onto the California
Coastline. With Montana residing on the downstream side of this
trough, Pacific moisture will increase from the south in the form
of increasing cloud cover. Additionally,some patchy areas of fog
may be possible across northern and central Montana through
daybreak but should refrain from being too widespread. Another
pleasant day is in store on Thursday as the aforementioned trough
passes to our south across the central Rockies. There may be just
enough moisture / associated lift for an isolated stray shower
across Beaverhead, Madison and Gallatin Counties but should
primarily be terrain driven and not deliver much in the way of
measurable QPF. This system will depart to the east Thursday
night with another chance of patchy fog through Friday morning
across north and central Montana. Friday will be just as beautiful
across the area with ample sunshine, and temperatures finally
cracking near to above normal, especially across the Plains. KLG

Friday Night through Wednesday...Forecast models are continuing
their consistent solutions. A fast-moving shortwave trough will
bring a good chance of showers to the mountains Saturday into
Saturday night. A Pacific cold front associated with this shortwave
will also sweep a narrow band of showers east across the area on
Saturday, then gusty west winds will follow the front Saturday
afternoon and evening. High winds are possible with this front, but
they do not appear to be likely at this time. Above normal
temperatures on Saturday will also cool back closer to normal on
Sunday. Another shortwave trough will move through the northwest
flow aloft in the wake of the earlier shortwave, which will move a
Canadian cold front south through Montana Sunday night, which will
keep temperatures near to slightly below normal for Monday. This
front will also bring another good chance of showers to the
mountains, as well as to much of central and southwest Montana
Sunday night into Monday. Models are in better agreement tonight
with keeping a weak high pressure ridge over the area for Tuesday
into Wednesday, which will keep the region dry as temperatures warm
back above normal. Coulston


GTF  28  56  32  63 /   0   0   0   0
CTB  27  51  29  61 /   0  10   0   0
HLN  30  58  33  64 /   0  10   0   0
BZN  27  55  30  60 /   0  10  10   0
WEY  20  47  23  51 /   0  20  20   0
DLN  27  53  29  57 /   0  10  10   0
HVR  29  51  31  56 /   0   0  10   0
LWT  31  56  31  59 /   0   0  10   0



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