Area Forecast Discussion
Issued by NWS Glasgow, MT

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FXUS65 KGGW 121650

Area Forecast Discussion
National Weather Service Glasgow MT
950 AM MST Tue Dec 12 2017


Signs were showing that temps and winds could be higher than
forecast with also lower humidity. A Red Flag Warning was issued.
See Fire Weather Forecast below for more details.

Otherwise, winds line up well in direction and they increase today
with peak mid-level winds coming this evening. Speeds increase to
50-55 kts but Lapse Rates and timing do not look ideal for a High
Wind Warning. If this changes, warnings may be issued this
afternoon or evening. TFJ

Previous Discussion...
Upper ridge that covers the western US and Canada will get flatten
somewhat today by a shortwave trough that moves through British
Columbia and Alberta. Northeast Montana will see warmer air ahead
of this wave today with continued dry weather. This wave will dive
southeast across eastern Montana tonight with a dry cold front.
The cold front will be a few hours ahead of the wave and move
through the forecast area in the late afternoon and early evening.
Gusty NW winds are expected with this system and will continue for
most of tonight.

The ridge axis will be pushed back to the Pacific Coast on
Wednesday with Montana in NW flow aloft and a somewhat cooler air
mass over the region.

The next wave on NW flow aloft drops SE across the region
Wednesday Night with another cold front

Another wave comes through late Wednesday night. Again windy
conditions are possible over eastern Montana, and some spotty
precipitation. The system may have enough moisture for a chance of
rain and/or snow depending on temperatures. That system moves to
the southeast Thursday morning. Thursday will be mainly dry and
cooler with highs in the 30s in most areas.

The upper ridge builds back into Montana Thursday and Thursday
Night which will bring warmer air to the forecast area on Friday.
However, a shortwave trough will flatten the ridge on Friday and
move through the state Friday Night and Saturday with a cold
front Friday Night. Models differ at this point on where to track
the moisture with this system. Could see a chance of rain and
snow depending on temperatures Friday Night and Saturday morning.

Models are pointing towards a shortwave ridge on Sunday with dry
weather and continued above normal temperatures for mid December.

NW flow aloft prevails Monday and Tuesday. A cold front is
expected Sunday Night or Monday. Then, the models differ on
whether to keep the front to the south of the forecast area on
Tuesday or bring it back east as a warm front. Could see a chance
of rain or snow at times. Forrester



VFR. Either clear skies and some high clouds will prevail most of today.
A cold front late this afternoon and this evening will bring mid
level clouds through the area with gusty NW winds. Look for west
to southwest winds 5 to 10 knots this morning, becoming west 10 to
20 knots this afternoon and northwest 15 to 25 knots this evening
and continuing overnight.



A very warm and dry airmass will be in place across the area while
winds increase this afternoon. Winds will be strong into the
evening hours and with unusually low humidities (to 10 percent), a
Red Flag Warning was issued. TFJ


Red Flag Warning until 10 PM MST this evening for MTZ135>137.


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