Severe Thunderstorm Warning 86, NWS Glasgow, MT

Area Forecast Discussion
National Weather Service GLASGOW MT
850 AM MDT WED JUL 6 2016

.SHORT TERM...for northeast Montana...today through Fri...

Scattered showers are developing across central montana and will
continue moving into the central zones. Raised pops this morning
to account for this. Rest of forecast looked good. Of note,
stronger storms will be threatening the se zones through today.
TFJ

Previous discussion...
Upper low moving across the northern Rockies this morning
spreading mid to high level clouds over eastern Montana. This wave
will push a cold front across the state today. Modest instability
for thunderstorms but divergence aloft and good moisture feed
should produce a few wet storms this afternoon and overnight.

The upper low moves into the northern plains on Thursday with a
few lingering showers over the eastern zones. Upper ridge follows
with drier weather for Friday as the next low pressure system
begins to take shape off the Pacific Northwest.

Temperatures will be mainly in the 70s today and Thursday as the
low pressure moves over the region. Readings will rebound into the
80s with the ridge on Friday. Ebert

.LONG TERM...Fri night through Wed...

The upper flow pattern for Friday night places a ridge axis
slightly to our east and a closed low/storm system nudging up
against Vancouver Island. Therefore on Saturday upper flow will
back around to the southwest. The West Coast trough will be
picking up Pacific moisture from off the coast of California. This
will send moisture across the Divide.

Saturday evening and Sunday the trough begins to swing across the
Northwest, blowing through the region and Northeast Montana
Sunday night. Models are suggesting the storm becomes stacked and
cyclonic, with winds picking up. Prior to the cold front passing
through the area, models are suggesting an incursion of very warm
air pushing up through the area into Canada. The result could be
enhanced convective instability in place when the system moves
through. With the strength of this storm, and strong instability
in place, severe thunderstorms should be expected with the storm
front.

Although the models are closing together on this storm, there
still are timing and location differences that may make
difficulty in determining when strong storms may occur. But the
system is plenty wet, and once the front pushes through, much
cooler air follows.

Monday and beyond the storm does not appear to be ina hurry to
headeast, but remains in the general region - drifting north into
Canada, where it could produce wrap-around rain. Storm QPF totals
are hard to predict this far out, but this could produce
widespread wetting rains.

Model do show another trough moving into the Pacific Northwest by
mid-week.

Templer

&&

.AVIATION...

Today a low pressure trough/storm system drops out of British
Columbia and begins to swing across the Divide. The base of the
trough sends in moisture in the upper southwest flow that will
result in scattered showers with mostly general thunderstorms.
The area with the most unstable conditions will be around the
Yellowstone River valley, affecting mainly KGDV and KSDY with the
threat of strong storms. The period of TS for all sites will be
indicated by VCTS. Therefore be alert for amends for threatening
thunderstorms.

Winds increase to around 5-10kt this afternoon. Although the
clipper-like storm quickly moves across the region, a broad un-
focused surface low will limit surface winds. However, stronger
winds may be localized with any passing thunderstorm.

Templer

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

weather.gov/glasgow

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GLASGOW MT
327 AM MDT WED JUL 6 2016

MTZ016>027-059>062-070930-
CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY-
DANIELS-SHERIDAN-WESTERN ROOSEVELT-PETROLEUM-GARFIELD-MCCONE-
RICHLAND-DAWSON-PRAIRIE-WIBAUX-NORTHERN PHILLIPS-
SOUTHWEST PHILLIPS-NORTHERN VALLEY-EASTERN ROOSEVELT-
327 AM MDT WED JUL 6 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST
MONTANA.

.DAY ONE...TODAY AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER TODAY AND
TONIGHT IS LOW.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

A LARGE STORM SYSTEM AND COLD FRONT IS EXPECTED TO IMPACT
NORTHEAST MONTANA OVER THE WEEKEND. SEVERE STORMS ARE POSSIBLE
ON SUNDAY ALONG WITH HEAVY RAINFALL. ESTIMATED RAINFALL TOTALS
ARE UNCERTAIN AS WEATHER MODELS CONTINUE TO EVOLVE.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.