Drought in Montana, June 13 to 30, 2017

Area Forecast Discussion
National Weather Service Glasgow MT
820 PM MDT Mon Jun 12 2017

.SHORT TERM...for northeast Montana...tonight through Wed...
730PM UPDATE:
Changes to the forecast first focused on getting in the latest
hourly data sets for PoPs into the forecast to see when exactly
timing for rain is set for tonight. As of the current moment Bulk
of the rain looks to be coming between midnight and Noon tomorrow.
With between a tenth to a half of an inch expected depending on
location. Radar trends over northern Wyoming and southern Montana
showcase a variety of showers and thunderstorms along a curved
band rapping around a low pressure centered somewhere over
southeastern Idaho. This band is migrating north rapidly and
should be in southwestern corner of our CWA sometime after 10PM.
Another band has developed over a surface dewpoint density
discontinuity over the northern sections of the CWA and is also
migrating north however with how light echos are only a couple
hundredths can be expected there as it migrates north across the
International Border. GAH

PREVIOUS SHORT TERM DISCUSSION:
Tonight a vigorous low pressure system will push in from the
southwest, bringing an expansive area of showers and
thunderstorms as well as gusty east to southeast winds. Some
potential for stronger storms continues south of the Missouri
River, but the more organized severe threat is south of the
region. After midnight tonight continues to look like the wettest
period for northeast Montana. Recent model trends have
precipitation totals continuing to slowly taper downward, but all
in all the system should provide a much needed respite from
recent dry conditions.

By Tuesday morning, dry air will begin to wrap into the low
pressure system overhead, causing a decrease in precipitation
coverage. Winds will also taper off some as the surface trough
slides through. Afternoon convection could touch off in the dry
slot however, thus kept some pops in for the afternoon. Gilchrist

.LONG TERM...Wed night through Mon...

Made some changes only up through Day 4 of the forecast to try and
focus attention on this upcoming storm system. Blended the best
model consensus I could find regarding precip chances and amounts
from Tuesday evening through Wednesday. This period focused mainly
on the second round of showers and thunderstorms which seems to
simply linger near and north of the Missouri River. The dry slot
still seems to have a very significant effect on the expected
precip amounts coming out of the models. Low confidence on
rainfall totals. Wide range from 0.15 to 1.00 inch.

Mickelson

Previous long term discussion:
Upper low will be lifting from the Great Basin northeast across
Montana over the next few days. The low lifts across the northern
plains and into southern Manitoba Tuesday night and Wednesday with
precipitation tapering off from the southwest.

The rest of the week features nearly zonal flow across the
northwest corner of the country. Temperatures are expected to be
close to normal with a slight warming trend. Precipitation chances
are low, with the best possibility with a weak frontal system over
the weekend.

Ebert

&&

.AVIATION...

Flight category: VFR lowering to MVFR from south to north tonight.

Synopsis: A vigorous low pressure system is expected to bring
deteriorating aviation weather to northeast Montana tonight into
Tuesday. Showers and thunderstorms will begin pushing in from the
south by early evening, increasing in coverage and lowering cigs
through the overnight hours. Drier air will wrap in on Tuesday
decreasing shower and thunderstorm coverage by the afternoon.

Winds: Southeast 10-20G30kts, tapering off some by Tuesday
afternoon.

Gilchrist

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory until 6 AM MDT Tuesday For Fort Peck Lake for
Central and Southeast Phillips...Central and Southern Valley...
Garfield...McCone...Petroleum.

&&

weather.gov/glasgow

Hazardous Weather Outlook
National Weather Service Glasgow MT
249 PM MDT Mon Jun 12 2017

MTZ016>027-059>062-132100-
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-
249 PM MDT Mon Jun 12 2017

This Hazardous Weather Outlook is for portions of northeast
Montana.

.DAY ONE...This Afternoon and Tonight

Gusty east-southeast winds will impact boating on Fort Peck Lake
through tonight. A Lake Wind Advisory is in effect.

A large storm system will track across the area tonight through
Wednesday. Showers and thunderstorms will begin affecting
northeast Montana this evening and an isolated stronger
thunderstorm cannot be ruled out south of the Missouri River.
With that said, the best potential for severe weather is expected
to remain mostly to the south of the region.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.