Area Forecast Discussion
Issued by NWS Great Falls, MT

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815
FXUS65 KTFX 221129
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
530 AM MDT Thu Sep 22 2016

AVIATION SECTION UPDATED

.DISCUSSION...

Today through Saturday...A low pressure trof over the West Coast
will move southeast over Nevada by late afternoon. The nose of an
upper level jet will be approaching the southwest zones this morning
and another surge of widespread rain will move across the zones
today. Central and northern portions of the CWA will be very moist
as good east to southeast flow at low levels continues. These
central and northern portions of the zones will begin to dry from
the west Friday morning. However, the upper level low will be over
the Idaho/Utah/Wyoming border Friday morning moving towards
Northwest Wyoming. This will cause good synoptic lift over Southwest
Montana Friday. Temperatures aloft will not get too cold although
snow levels will be dropping to near 8000 feet Friday. The low
pressure trof will move east of the zones Saturday although rain
showers over the eastern zones will continue through the day.
Zelzer

Saturday Night through Thursday...Once a few lingering showers
depart by early Sunday, fair and dry weather prevails through the
remainder of the extended period. A high-amplitude flow over CONUS
is anchored by a broad anomalous ridge centered offshore the Pacific
coast. Northern portions of this ridge amplify further while the
ridge axis drifts across the Northern Rockies and into central MT by
Tuesday afternoon. While NCEP WPC has struggled with widely varying
ensemble solutions over the southern and eastern CONUS, the PAC NW
consistently remains under the influence of the west coast ridge.
Lee troughing could produce breezy conditions on Tuesday and
Wednesday as shortwave disturbances move through western Canada and
begin to flatten the ridge. Have introduced slight-chance POPs over
the northern Rockies Wednesday night as the longwave ridge is
finally flattened into a more active west or southwest flow pattern.
Temperatures will begin the period slightly below average, then
gradually warm to slightly above average through mid week. Overall,
a pleasant period of early Fall weather. PN

&&

.AVIATION...Updated 1128Z.

An upper level low pressure trof will continue to bring widespread
precipitation across Central and Southwest Montana. Also, widespread
IFR/MVFR conditions and mountain obscuration will continue into
Friday morning. Conditions will improve across the Northern Rockies
early Friday but IFR/MVFR conditions and precipitation will continue
eastward and across Southwest Montana.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  51  43  53  47 / 100  80  80  40
CTB  46  40  56  44 / 100  80  60  20
HLN  56  42  55  44 /  70  70  70  50
BZN  58  43  49  42 /  90  80  70  80
WEY  56  35  47  34 /  80  70  80  60
DLN  55  41  49  40 /  80  80  80  60
HVR  50  43  53  46 / 100  90  80  40
LWT  50  41  50  44 / 100  90  70  60

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

weather.gov/greatfalls



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