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Area forecast discussion 
National Weather Service Bismarck ND
1000 am CDT Tuesday Jun 2 2015

issued at 953 am CDT Tuesday Jun 2 2015

Surface low pressure is situated over north central South Dakota.
Scattered thunderstorms have moved east of the James River Valley
into southeast North Dakota. More widespread showers with embedded
thunderstorms remain across northwest North Dakota along a frontal
boundary. For the morning update...kept high chance to likely probability of precipitation
across the north...and lowered probability of precipitation across the southern half of
the state through the morning...then bumped up chances this
afternoon. Made some minor updates to clouds based on latest
satellite pictures.

Update issued at 637 am CDT Tuesday Jun 2 2015

Remnants on the overnight convection moving into the James River
Valley. GFS/NAM continue to show a regeneration of thunderstorms
across North Dakota Tuesday afternoon. Until then trended the
probability of precipitation down this morning.


Short term...(today and tonight)
issued at 520 am CDT Tuesday Jun 2 2015

High resolution models last evening and overnight underperformed
with their output. About the best verifying model is the nam12
which excellently depicted the thunderstorms from southeast
Montana and western South Dakota moving into North Dakota and
weakening to a large area of rain. The NAM even had the
orientation and placement of the rain...and timing...well depicted
based on reality. Followed the NAM for this short term forecast

The large area of rain this morning...oriented west to east
through central North Dakota...will continue to push north and
east through the morning with drier air working into the south to
cut off precipitation. Redevelopment of thunderstorms is forecast
for the afternoon. With increasing instability and speed shear...
storms should refire and lean...allowing the updraft to separate
from the downdraft and storms to intensify across the south. The
Storm Prediction Center has the area basically south if Highway 2
and east of Highway 85 in the slight risk for this afternoon into
tonight. Aiding daytime heating south will be the next middle level
short wave pushing northeast through the area later today. This
energy is more diffuse...less focused...than that of Monday and
Monday night.

Storms overnight were slow moving...and based on radar rain
estimates that are likely hail contaminated...produced heavy rain.
Slow movers tonight will need to be closely monitored for possible
flooding of low lying and poor drainage areas...along with
smaller creeks and streams.

Long term...(wednesday through monday)
issued at 520 am CDT Tuesday Jun 2 2015

The extended period looks active with an h500 trough over the
West Coast sending shortwave energy northeast into the northern
plains this week. This pattern holds through Friday...then a
northern stream flow will bring shortwave energy from western
Canada into the northern plains for the weekend. Either way it
will be an active weather period with a reasonable chance of
getting an inch of rain through the weekend.

Temperatures will be cool on Wednesday but will moderate toward
more normal readings by the weekend.


Aviation...(for the 12z tafs through 12z Wednesday morning)
issued at 637 am CDT Tuesday Jun 2 2015

A large area of -shra oriented west to east through central North
Dakota will continue to move northeast through 02/16z. Expect
mainly VFR weather but pockets of MVFR ceilings and visibilities in
heavier rain showers. By 02/19z scattered -tsra are forecast to
redevelop...especially over southern taf sites from kdik-kbis-
kjms. After 02/21z some storms could become severe with large hail
and damaging winds. IFR/MVFR ceilings and visibilities are likely
in storms with heavy rain from 02/21z to 03/03z.


Bis watches/warnings/advisories...


short term...jpm
long term...warm air advection
aviation...warm air advection

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