Area Forecast Discussion
Issued by NWS Glasgow, MT
FXUS65 KGGW 241430 AAA
Area Forecast Discussion...UPDATED
National Weather Service GLASGOW MT
830 AM MDT Fri Mar 24 2017
.SHORT TERM...for northeast Montana...today through Sun...
Sent an early update this morning as the visibility sensor in
Plentywood and the web-cam at the Comertown MT-5 Turn-Off DOT site
both indicated the need for a dense fog advisory. Temperatures
this morning turn it into a dense freezing fog. Issued that to
run until Noon today. Other nearby locations in a less-impactful
patchy fog or mist.
Previous short term discussion: The day begins with Northeast
Montana under an upper level ridge. Well to the south, positioned
over the Central Plains, is a cut- off stacked low that will not
affect our conditions. But off to the west is another Pacific
storm nudged up against SE Alaska, BC, Washington, Oregon and N.
California. This storm will affect us later.
Today with ridging we can expect another mild day with above
normal highs and a southerly breeze. But tonight, flow aloft
begins to back around to the southwest as the trough splits off,
sending a cold front into the Pac-NW. Another piece of the trough
swings across the Great Basin.
Saturday the trough brings the cold front into the local region,
but the northern portion of the Pac-NW trough heads into
Saskatchewan, taking the moisture with it. However, the southern
trough finally sends moisture along the front that clips the
southeast portion of the GGW CWA. These showers will linger
through Saturday night.
Sunday, a follow-on short-wave trekking east through southern
Saskatchewan sends a weak front into the area, possibly generating
a few showers. Through this process, temperatures will continue
.LONG TERM...Sun night through Fri...
Progressive pattern for next week with a series of shortwave trofs
moving through the regions. Strongest energy with these systems
expected to push through the desert southwest but with enough
connection to the north portion of the trof to bring some
potential for showers into eastern Montana.
Monday is expected to be dry and warm with trof digging into the
Great Basin. This system moves across the Rockies on Tuesday for
slight cooling of temperatures and some showers possible.
Pattern repeats with dry weather on Wednesday followed by trof and
showers on Thursday. Models intensify the southern portion of the
trof as it closes off over the SW states. This will keep the
cooler and potentially wet weather over eastern Montana into
Lingering fog over our NE zones this morning has brought IFR/MVFR
visibilities to KOLF and KSDY. Expect this to burn off by noon.
Other TAF sites in VFR and expected to remain there with a
tranquil and warm day today.
Light and variable winds early will increase from the south into
the 15 kt range by mid day, then turn more from the southeast
Dense Fog Advisory until noon MDT today for Sheridan.