Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 290243

Area Forecast Discussion
National Weather Service Bismarck ND
943 PM CDT SAT MAY 28 2016

Issued at 939 PM CDT Sat May 28 2016

As sunset approaches the convection is quickly subsiding. Updated
the pops to end the precipiation shortly after midnight. Kept the
mention of patchy fog where rain fell this afternoon and evening,
which is mainly northwest through portions of the south central.

UPDATE Issued at 607 PM CDT Sat May 28 2016

This update will refine the chances for thunderstorms along a
line in central north dakota moving east Saturday evening. Severe
weather is not expected with this line however abundant lightning
and brief heavy rain is expected.

added some fog across the northwest and portions of the south
central after midnight as the CONSShort guidance suggested this.


.SHORT TERM...(This evening through Sunday)
Issued at 345 PM CDT Sat May 28 2016 upper level low was over British Columbia with a
trough extending southeastward into Montana...and a leading vort
energy impulse moving east across western North Dakota. A line of
showers and thunderstorms associated with this feature is forecast
to continue moving east across the state tonight. Meanwhile another
weaker upper level low was over the Red River Valley from Sioux
Falls to near Fargo...with a line of instability with higher CAPE
farther west from near Devils Lake south across the James River
Valley. A line of scattered showers and thunderstorms was associated
with this feature, which was moving westward very slowly or was
stationary as the upper low lifts north/northeastward tonight.

Chances of showers and thunderstorms should end from west to east
across our area tonight...and a mid level ridge moves east across
North Dakota through Sunday. A mild and dry day Sunday with mostly
sunny skies is in store for us.

.LONG TERM...(Sunday night through Saturday)
Issued at 345 PM CDT Sat May 28 2016

Main highlight is the severe thunderstorm potential Monday, mainly
over far southwest into portions of south central North Dakota.
SPC continues to advertise a slight risk in this area.

Sunday night an upper level closed low that is currently over
British Columbia develops into a longwave trough as it moves east
into the Canadian and US Rockies. As this occurs a low level jet
develops over the plains along with a southerly return flow as
surface low pressure develops over the Rockies...bringing a return
to higher dewpoints in the 50s/60s to North Dakota on Monday. A few
leading upper level impulses...with increasing instability aided by
the developing low level jet...will warrant keeping a chance of
showers and thunderstorms developing Sunday night mainly in the west
and south central portions of North Dakota.

Monday the upper level closed low/trough moves southeast across
Montana, and a leading shortwave moves east/northeastward across
North Dakota...providing support aloft for widespread showers and
thunderstorms - along with increasing CAPE and bulk shear. This
environment gives us fairly high confidence for severe weather -
especially in the southwest and south central parts of North Dakota.

Both the GFS and ECMWF depict the upper low moving east across North
Dakota Tuesday into Wednesday morning, then lifting northeast into
western Ontario Wednesday afternoon. This will keep a chance of
showers and thunderstorms across our area Tuesday and Tuesday night,
then mainly a chance in central North Dakota on Wednesday.

Wednesday night through Saturday should be dry with a northwest flow
over North Dakota as an upper level ridge builds over the west coast
and Rockies.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 607 PM CDT Sat May 28 2016

Main hazards to aviation will be thunderstorms moving through
central North Dakota Saturday evening impacting KBIS-KJMS
primarily between 00-05z. After 06z some fog will be expected to
form over the northwest impacting KISN between 08-14z with vsbys
3br. Otherwise vfr.


.BIS Watches/Warnings/Advisories...


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