Area Forecast Discussion


047 
FXUS65 KTFX 161800
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1200 AM MDT Wed Oct 16 2013
UPDATED AVIATION DISCUSSION
.UPDATE...
Canadian cold front continues to push southward through the region
this morning. A band of light rain is accompanying the frontal
passage. Generally most areas will see less than a tenth of an
inch of precip today. Snow will generally fall above 7000 feet
with some light snow accumulations. Temperatures look on
track...with high temperatures likely occurring this morning over
North Central MT just ahead of the front. Other than a small
adjustment to pops...all else is on track for today. Brusda
&&
.AVIATION...
UPDATED 1800Z.
An upper level trough and surface cold front will continue to track 
SE through North Central and SW MT today, exiting the region this 
evening. Good coverage of rain showers follows behind the front/wind 
shift to the north, which will spread farther south in the 
KLWT-KBZN-KHLN areas this afternoon, though coverage will likely be 
lesser in these areas. Occasional MVFR and isolated IFR possible in 
showers through this afternoon with widespread VFR tonight as skies 
clear behind the system. Hoenisch
&&
.PREV DISCUSSION...
/ISSUED 600 AM MDT Wed Oct 16 2013/
Wednesday through Friday...A quick moving cold front associated
with a shortwave trough will move across the area this morning.The
cold front is expected to move across the hi-line around 6 am
local time. Forecasts generally keep the frontal boundary a few
hours ahead of the precipitation as it moves south out of Canada.
The main area of precipitation will likely last less than 6 hours
as it moves quickly southward. Precipitation totals should be
limited to around one tenth of an inch due to the fast moving
nature of this system. However...locally higher amounts especially
over the mountainous terrain is possible. The largest amounts of
snowfall accumulations should be limited to the mountains along
the Northern Rocky Mountain Front including Glacier National Park.
However totals are still expected to remain below advisory
criteria. Central Montana can expected to see the wind shift from
the front around noon local time. The front will move across
Southwest Montana around sunset...with a more scattered
precipitation shield trailing over the region...widespread
precipitation is not expected over Southwest Montana. After the
system passes on Wednesday...the general flow remains out of the
northwest with the boundary between cyclonic flow...from the
large scale trough over the Great Lakes...and the the
anticyclonic flow...from the large scale ridge off the Pacific
Coast...overhead. This will lead to some lack of confidence over
temperatures and precipitation forecasts. The current forecast
ensemble keeps us under the building high pressure associated
with upper level ridge which will lead to warmer temperatures and
dry conditions aloft. However if the boundary sets up to our
east...as suggested by the ECMWF...we will be under cooler more
unsettled conditions. Have gone with the warmer drier conditions
as suggested by the consensus suite for remainder of the work
week. Suk
Friday night through Wednesday...The long term period will remain 
under general northwest flow resulting from a ridge of high pressure 
over the west coast. Models differ on its strength and position 
which may result in some unsettled periods. Models indicate that 
there will be some disturbances in the flow aloft over Montana but 
continue to keep most of the energy and moisture over eastern 
Montana. As a result, a dry forecast is in order into Sunday before 
the chance of showers increases over terrain through Wednesday. Any 
precipitation that does occur looks to be light overall. Forecast 
confidence is fairly weak after Sunday with models disagreeing on 
how much the ridge to the west influences the region. No significant 
systems look to be moving towards the region throughout the period 
though. Models continue to remain relatively warm through the long 
term with highs nearing 60 in the lower elevations some days.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF  46  30  48  33 /  70  50  10  10 
CTB  44  28  49  31 /  80  20   0  10 
HLN  51  30  50  31 /  50  30  10  10 
BZN  48  28  44  27 /  20  30  10  10 
WEY  42  23  39  21 /  10  20  10  10 
DLN  50  27  47  26 /  10  10  10  10 
HVR  48  29  51  31 /  80  20  10  10 
LWT  46  27  42  29 /  60  70  10  10 
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls