Flood in Montana, March 23, 2018

Area Forecast Discussion...UPDATED
National Weather Service Glasgow MT
622 PM MDT Fri Mar 23 2018

.DISCUSSION...
Early evening update was to clear the winter wx headlines from the
northeast zones, since the winter storm has exited the region.
Also added fog to the grids due to its early forming already.
Added an update to the hydro discussion concerning minor flooding
along the Yellowstone River near Glendive.

SCT

Previous Discussion:
Afternoon Update (2pm MDT): The afternoon package was mostly just
tweaked from the blends to account for some of the deterministic
models, mostly in the wind and PoP/QPF forecast, as hydrology was
the main concern for the shift. With that said, the forecast was
in good shape, and the narrative for the weather expected over the
next week is basically unchanged. Bigelbach

PREVIOUS DISCUSSION: Radar returns nicely show an area of
precipitation presently tracking across northeast Montana early
this morning. Thermal profiles support mainly snow near the
Canadian border and especially into Sheridan County. This is where
2 to 4 inches of snow are expected, and a Winter Storm Warning
exists for Sheridan County for up to 7 or 8 inches of snow. Strong
winds will also allow for significant blowing and drifting of the
snow.

Closer to Highway 2 and locations south, thermal profiles are
warmer and precipitation has thus far been mainly rain and/or a
wintry mix. From about Malta to Glasgow to Sidney, as a reference,
SREF probability product indicates a change to mainly snow by
about 15Z just as steadiest precipitation lifts to the northeast.
Thus, will maintain 1 to 2 inches of slushy, wet accumulation at
the end of the event for these locations for now. However, should
more precipitation fall as rain/wintry mix as precipitation ends
later today, little snowfall would then be expected here. This
will remain a challenge over the next few hours, but will leave
headlines alone due to uncertainty. If anything, even with mainly
rain, with surface temperatures near freezing there may still be
some slick spots out there.

Latest 00z models have the Pacific trough maintaining southwest
flow aloft extending into the CWA through the weekend. As embedded
shortwaves track out ahead of the main trough, additional shower
activity may occur at times, though amounts look to be on the
lighter side. As the trough axis translates east, a bit of
northern stream energy may approach northeast Montana for the next
precipitation chances, mainly Tuesday or Tuesday night.

For the midweek and beyond, the forecast was mainly trended to
capture latest 00z model consensus guidance which captures nearly
seasonable temperatures along with occasional showers at times
when shortwaves track through the area. Details and timing are
hard to point out precisely at larger time scales, but confidence
should improve in the coming days for this period. Maliawco

&&

.AVIATION...

Expected Flight Category: Mostly IFR/MVFR conditions expected

Synopsis: As the low pressure system drifts out of eastern
Montana, ceilings under the remaining cloud deck across the
region should continue to stay at IFR to LIFR levels, but could
periodically lift into MVFR levels at GDV and GGW. However, all
sites could experience these continued IFR conditions through
tomorrow morning as the cloud deck slowly moves out of the region
and deteriorates.

Winds: West to northwest winds across most of the sites overnight
at 5-10 kts will flip back to the southeast tomorrow and come back
up to 10-15 kts, with gusts up to 25 kts mainly in the afternoon.

Bigelbach/SCT

&&

.HYDROLOGY...

Flood watches remain in effect for the Yellowstone and Musselshell
Rivers across northeast Montana for the potential for ice jam
flooding. With warming temperatures and some water loading due to
precipitation across the region, further rotting and breakup of
the river ice continues, and the reported ice jams along each
river continue to move downstream and jams along the tributaries
are beginning to spill into the main stem rivers.

In addition, a Flood Warning remains in effect today for the
Musselshell River from the Garfield and Petroleum county lines
north to Crooked Creek Recreation Area. Ice jamming is occurring
at the outlets of multiple tributaries along the length of the
Musselshell between Petroleum and Garfield Counties and could lead
to continued flooding issues along the River.

A small stream flood advisory has been issued for Petroleum
County, as many of the small streams and poor drainage areas are
beginning to fill up with water, mainly due to snowmelt issues.

A flood advisory was issued for adjacent areas along the
Yellowstone River from the Interstate 94 Bridge to Deer Creek for
minor flooding in low-lying fields due to ice jamming.

To monitor river stage readings, go to our Advanced Hydrologic
Prediction Service (AHPS) page at www.weather.gov/glasgow then
click on "Rivers and Lakes" then "River Observations". Data for
this page are provided by the USGS.

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Monday morning for Dawson...Garfield...
Petroleum...Prairie...Richland.

&&

weather.gov/glasgow

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
303 PM MDT FRI MAR 23 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0125 PM     SNOW             12 E WHITEWATER         48.76N 107.36W
03/23/2018  E2.0 INCH        PHILLIPS           MT   TRAINED SPOTTER

            SNOW STOPPED AROUND 10 AM

0128 PM     SNOW             14 SW HINSDALE          48.25N 107.30W
03/23/2018  E1.5 INCH        VALLEY             MT   TRAINED SPOTTER

            SNOW STOPPED AROUND 10 AM

0145 PM     SNOW             7 W LUSTRE              48.39N 106.03W
03/23/2018  E1.5 INCH        VALLEY             MT   TRAINED SPOTTER

            SNOW STOPPED AROUND 11 AM

0155 PM     SNOW             13 SE OPHEIM            48.72N 106.21W
03/23/2018  E4.0 INCH        VALLEY             MT   TRAINED SPOTTER

            SNOW STOPPED AROUND NOON

0200 PM     SNOW             1 E PEERLESS            48.78N 105.81W
03/23/2018  E5.0 INCH        DANIELS            MT   TRAINED SPOTTER

            SNOW STOPPED AROUND NOON

0210 PM     SNOW             PORT OF SCOBEY          49.00N 105.41W
03/23/2018  E4.0 INCH        DANIELS            MT   OTHER FEDERAL

            SNOW STOPPED A LITTLE AFTER NOON

0215 PM     SNOW             PLENTYWOOD              48.77N 104.56W
03/23/2018  M5.3 INCH        SHERIDAN           MT   CO-OP OBSERVER

            SNOWFALL TOTAL SINCE 5 AM. STILL A FEW FLURRIES FALLING.
            0.82 INCHES OF MOISTURE

0215 PM     SNOW             20 N POPLAR             48.40N 105.20W
03/23/2018  E2.0 INCH        ROOSEVELT          MT   CO-OP OBSERVER

0245 PM     NON-TSTM WND DMG 1 N CIRCLE              47.43N 105.60W
03/23/2018                   MCCONE             MT   UTILITY COMPANY

            FIVE POLES SNAPPED DUE TO WIND

&&

BB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
310 PM MDT FRI MAR 23 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0305 PM     SNOW             14 SSE CULBERTSON       47.94N 104.45W
03/23/2018  E4.0 INCH        RICHLAND           MT   TRAINED SPOTTER

            ESTIMATING ABOUT 4 INCHES OF SNOW. LOTS OF DRIFTING.

&&

BB