204 
FXUS65 KTFX 052316
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
516 PM MDT Sat Oct 5 2013

...UPDATE TO AVIATION...
Updated for 00z TAF.

VFR conditions will prevail at all terminals for the effective
period as a ridge of high pressure continues to build across the region.
Gusty west/southwest winds will subside this evening with
scattered mid/upper level clouds drifting southeastward. Winds
will become gusty once again late Sunday morning, especially at
GTF and CTB where gusts of around 25 kts are expected. A few mid/upper
level clouds will continue to drift across the area through
tomorrow afternoon. Foltz


&&

.PREV DISCUSSION...
/ISSUED 330 PM MDT Sat Oct 5 2013/

Tonight through Monday...An upper level ridge will continue to
build over the Northern Rocky Mountains tonight and Sunday. High
level clouds streaming over the forecast area today will gradually
shift north and east as the ridge noses into the region tonight.
As a result, mostly clear skies and above seasonal temperatures
are expected on Sunday and Sunday night. Breezy to windy conditions
will also prevail over North Central Montana during this time. In
Southwest Montana conditions should also remain generally dry but
there continues to be a possibility for localized clouds and
patchy fog in the West Yellowstone Valley. On Monday, the upper
ridge progresses eastward as a strong jet and upper level wave
move inland over the Pacific Northwest. Winds are expected to
increase, especially along the Rocky Mountain Front, but at this
time it appears they should remain below high wind warning
criteria. Cloud cover will also increase as Pacific moisture
starts to stream into the forecast area. However, only scattered
showers are expected over the Northern Rocky Mountain Front while
the remainder of the forecast area should remain dry. mpj

Monday Night through Saturday...An unsettled weather pattern will 
develop early next week with increasing precipitation chances and 
cooler temperatures. Pacific moisture will increase on Monday night 
as a broad upper-level trough and a series of embedded shortwaves 
pushes into the Northern Rockies. Both the ECMWF and GFS show 
differences regarding precipitation amounts, timing and amplitude of 
this trough.  Given those uncertainties, have kept a slight chance 
of precipitation over the plains with chance-to-likely pops in the 
mountains. For now, the best chance of precipitation will be Tuesday 
night into Wednesday as a surface cold front moves over the Treasure 
State. This front will bring cooler temperatures of 10 to 15 degrees 
below seasonal averages on Wednesday. As the trough deepens into the 
Great Basin, a closed area of low pressure may develop there and 
then track north into Wyoming. This scenario would keep a cool 
northerly airmass over north-central Montana through the end of next 
week with the possibility for light upslope precipitation. If the 
low tracks farther south, then drier conditions with temperatures 5 
to 10 degrees below seasonal averages would prevail. Have trended 
towards the cooler and wetter solution for late next week into early 
next weekend with the best precipitation chances in the mountains. 
MLV

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  42  71  45  69 /   0   0   0  10 
CTB  41  70  41  65 /   0   0   0  10 
HLN  37  68  39  65 /   0   0   0   0 
BZN  32  64  35  66 /   0   0   0   0 
WEY  25  53  29  56 /   0   0   0   0 
DLN  32  63  35  63 /   0   0   0   0 
HVR  38  72  40  71 /   0   0   0   0 
LWT  37  68  41  70 /   0   0   0   0 

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$


weather.gov/greatfalls