Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 201826

Area Forecast Discussion
National Weather Service Bismarck ND
1226 PM CST Wed Feb 20 2019

Issued at 1215 PM CST Wed Feb 20 2019

Latest model data is trending further west with the precipitation
and making it more persistent over central North Dakota. Updated
the short term pops to keep snow in through this evening with a
chance of snow tonight. Recent observation at Bismarck 0.8 inches
of snow, with around 4 inches in southeast Dickey County. Expect
around 2 inches total snow central by the time the system wraps
up late tonight.

UPDATE Issued at 836 AM CST Wed Feb 20 2019

Surface obs and regional radars show widespread light snow
continues to move northwest as the upper low swings through teh
region. Weak TROWAL seen in the theta-e analysis supports this as
well. So increased POPs across teh northwest today, although teh
qpf will remain light.

UPDATE Issued at 546 AM CST Wed Feb 20 2019

Surface observations and webcams indicate light snow is falling
across all but far northwest North Dakota this morning. Expect
this trend to continue through at least the morning as an upper
level low spins over southeast Montana. Drastically increased
precipitation chances for this update.


.SHORT TERM...(Today and tonight)
Issued at 416 AM CST Wed Feb 20 2019

The main concern for the short term period is accumulating snow
across our southeast counties through this evening.

09Z upper air analysis shows a closed upper level low over
eastern MT/WY. A strong low-level jet centered over IA, along with
synoptic scale PVA and isentropic ascent, has already led to the
development of widespread snow across central into southeast ND.
Model guidance and observational trends suggest that the heaviest
snow will move over LaMoure and Dickey counties later this morning
and continue into the afternoon. Multiple iterations of the
HRRR/RAP paint 0.3 to 0.4" QPF over eastern parts of these
counties. Meanwhile, all other deterministic and ensemble guidance
is very consistent at 0.2". Model soundings show a very deep
saturated layer with temperatures colder than -10 C and ample lift
within the dendritic growth zone. Therefore, would expect snow-
to-liquid ratios approaching 20:1. Keeping QPF on the conservative
end of the spectrum results in a max snowfall forecast of around
4 inches for LaMoure and Dickey counties. A Winter Weather
Advisory has been issued for these two counties through this

The rest of western and central North Dakota will see mostly cloudy
skies and scattered to widespread light snow/flurries through the
day as the upper low meanders over the Dakotas. Snow will begin to
taper off from south to north this evening into tonight.

Given warm air-advection and warmer temperatures to start the day,
many locations will see their warmest day in awhile. But highs will
still be limited to the teens.

.LONG TERM...(Thursday through Tuesday)
Issued at 416 AM CST Wed Feb 20 2019

Weak PVA will keep a slight chance of light snow in the forecast
across northern ND on Thursday. A closed upper low over the Desert
Southwest will interact with a northern stream trough beginning
Thursday night. As these features pair up and move eastward, lift
out ahead of them will bring periods light snow to south central and
eastern ND on Friday.

The 00Z GFS and ECMWF are in agreement that another shortwave will
move across the Northern Plains over the weekend, bringing another
chance of light snow to the area. Behind this shortwave, another
bitterly cold Arctic air mass is poised to move into the Northern
Plains for early next week. This unfortunately means a return to
highs barely above zero and lows in the teens below.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1215 PM CST Wed Feb 20 2019

Updated the TAFs to indicate more persistent IFR conditions in
snow KMOT-KBIS-KJMS through this afternoon into the early evening
as a slow moving low pressure system exits the region tonight.
Otherwise conditions slowly improving to MVFR KMOT-KBIS-KJMS by
this evening, and remaining MVFR KISN-KDIK.


Winter Weather Advisory until 6 PM CST this evening for NDZ048-



LONG TERM...Hollan
AVIATION...WAA is the U.S. government's official web portal to all federal, state and local government web resources and services.