Area Forecast Discussion
Issued by NWS Great Falls, MT

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KTFX 152340
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
535 PM MDT Mon Sep 15 2014

AVIATION SECTION UPDATED

.DISCUSSION...
Tonight through Wednesday...An upper ridge of high pressure from
the Pacific Northwest will move to western Montana Tuesday and
then to central Montana Wednesday. This will continue the warming
trend. High- level moisture will spread over the forecast Tuesday
and continue through Wednesday. For Tuesday afternoon weak
instability could develop over southwest Montana and will add a
mention of thunderstorms to the forecast for that area. Then for
Wednesday afternoon instability is forecast to increase but
guidance differs on how much. Do not see any weather disturbances
aloft to help in the development of showers/thunderstorms but
models indicate a weak trough of low pressure near the surface
over the east slopes. Due to this trough and also terrain effects
have expanded the mention of thunderstorms from southwest Montana
to the Rocky Mountain Front and east slopes of the Rocky
Mountains. Any precipitation that falls from the showers and
thunderstorms should be light. Blank

Wednesday night through Monday...An upper level low pressure trof
will move over the West Coast early Thursday and into the Pacific
Northwest by afternoon. This will begin to knock down the high
pressure ridge over Central Montana and bring moist, unsettled,
southwest flow aloft over the zones. The increase in moisture and
lowering of heights aloft will bring continued instability to the
region, especially over the southwest zones. A chance of showers
or thunderstorms will be greatest in this area. The trof will move
across Central Montana Friday, the air mass will cool and, with
the passage of the trof, a chance of showers will continue. With
the trof moving east, high pressure will build aloft again
Saturday. This ridge will continue to build through Sunday. A
shortwave will move into the ridge Monday but the air mass will
remain quite dry precipitation isn`t expected. Temperatures will
remain well above normals through the period. Zelzer

&&

.AVIATION...
UPDATED 2335Z.
High pressure ridge continues to dominate the regional weather
pattern, bringing dry conditions, mostly clear skies and light
winds. Expect those conditions to continue this evening and Tues,
with just some SCT-BKN high clouds moving in from the
west/southwest tomorrow aftn/eve.
Waranauskas

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  45  82  52  85 /   0   0  10  20
CTB  40  80  45  81 /   0   0   0  10
HLN  48  85  52  88 /   0   0  10  10
BZN  43  82  47  84 /   0   0  10  10
WEY  34  72  37  74 /   0  10  20  20
DLN  46  81  49  84 /   0  10  10  10
HVR  42  80  47  85 /   0   0   0  10
LWT  46  82  51  85 /   0   0  10  10

&&

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

$$

weather.gov/greatfalls
www.twitter.com/NWSGreatFalls
www.facebook.com/NWSGreatFalls






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.