Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus63 kbis 280539 

Area forecast discussion
National Weather Service Bismarck ND
1239 am CDT Mon may 28 2018

issued at 1231 am CDT Mon may 28 2018

Attempted to time the arrival of showers and scattered
thunderstorms across southern North Dakota based on current radars
and the high res models. Made some minor adjustments otherwise
current forecast looks OK.

Update issued at 851 PM CDT sun may 27 2018

Delayed precipitation entering southern North Dakota and limited
the chance for thunderstorms to far southern North Dakota for this
update. Latest radar trends and short-term models indicate storms
in South Dakota won't make it across the border until after
midnight. Due to this delay, less instability and shear will be
available than originally forecast. This should limit severe
storms to a very small, isolated chance in a brief window late
tonight across far southern North Dakota. Also, thunderstorm
chances tomorrow look to be a bit further south than earlier
indications. The latest guidances suggests showers/thunderstorm
chances will be confined to southwest and south central North
Dakota tomorrow.

Update issued at 537 PM CDT sun may 27 2018

A few minor tweaks were made to the precipitation forecast for
tonight. Thunderstorms aren't expected for several hours. The main
focus for thunderstorm development will be across LaMoure,
McIntosh and Dickey counties late this evening as this is the area
of greatest instability coupled with an area of strengthening
low/mid level frontogenesis.


Short term...(this evening through monday)
issued at 154 PM CDT sun may 27 2018

Latest visible imagery shows a mix of sun and cloud across
western/central North Dakota. Cumulus field evident across
northwest and north central, and some cumulus along with high
clouds elsewhere. Pressure falls continue to push into eastern
North Dakota ahead of a cold front, with 3hr pressure rises
across the west and central. Adjusted high temperatures into the
upper 70s north, with upper 80s south central to the lower 90s far
southern James River Valley.

Water vapor imagery shows our next mid level shortwave slowly
moving north from Colorado, which will promote the development of
showers and thunderstorms into southern South Dakota between 00z
and 03z. Some of the cam's show an area of showers/thunderstorms
extending near and south of Ellendale by 03z, and have added this
area into the forecast grids this evening. Otherwise, the trend
is for the ongoing convection in South Dakota to lift into
southern North Dakota 06z-12z Monday, mainly along and south of
Interstate 94. This convection will be moving into an area of
weakening cape/shear. Thus at this time most of the thunderstorms
should remain non-severe.

For Monday, greater instability begins to initiate in the afternoon
with another chance for showers and thunderstorms. Think the south
has the best opportunity for severe weather chances as the highest
cape/shear again resides along and south of Interstate 94.

Long term...(monday night through sunday)
issued at 154 PM CDT sun may 27 2018

Scattered showers and thunderstorms will continue Monday night
through Tuesday night, then taper off from west to east during
the day Wednesday. This is in response to a slow moving upper low
which shifts from Wyoming into central and eastern North Dakota.
A brief break Wednesday night into most of Thursday, then periodic
showers/thunderstorms return via a southwest flow aloft through


Aviation...(for the 06z tafs through 06z Monday night)
issued at 1231 am CDT Mon may 28 2018

High pressure across southern prairie provinces of Canada and the
northern plains will keep flying conditions VFR. A nearly
stationary frontal boundary across northern South Dakota will be
the focus for widely scattered thunderstorms across southern North
Dakota, kbis-kdik.


Bis watches/warnings/advisories...


National Weather Service Glossary of Abbreviations