000
FXUS63 KBIS 152011
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
311 PM CDT Tue Aug 15 2017

.SHORT TERM...(This evening through Wednesday)
Issued at 311 PM CDT Tue Aug 15 2017

Showers, and maybe an embedded thunderstorm spread across the area
this afternoon and tonight, then we dry out on Wednesday.

Latest surface analysis shows low pressure extending from the
western portions of the central plains northward into the western
Dakotas. Upper level analysis shows a broad upper trough over
western U.S and Canada with circulations over Saskatchewan and the
Desert southwest, with another digging shortwave trough dropping
down the Pacific west coast. Closer to home, a broad southwest
flow remains from the central high plains into the northern
plains. Numerous impulses tracking through the flow are producing
showers and thunderstorms, with the strongest activity over
Nebraska and western Iowa.

In western and central ND, widespread showers extend from western
Grant and Sioux counties, north northeast to southern Ward
county, with another smaller area from central SD to around Linton
in south central ND, tracking east northeast. The highest rain
totals are expected to track from just west of Bismarck Mandan,
into the Turtle Mountains and the Devils lake Basin. High PWATs
(1.50-1.75in) advect from central ND into the James River Valley
during the late afternoon and evening. With limited CAPE it
remains to be seen if we develop any thunder over the southern
JRV, where we had heavy rain this past weekend. HPC continues a
marginal risk of excessive rain over southeast ND, including the
JRV. Convection allowing models are mixed in their solutions of
convection over the JRV through the evening and point toward
areas south of the ND border to having the best risk of Thunder.
Will continue to monitor but at this time will not add any
additional wording for heavy rain.

One additional area for possible thunder late this afternoon or
early evening would be the far northwest. with drier air moving
in, the threat of severe storms here seems minimal. NAM/HRRR
Bufkit soundings do indicate a few hours of weak CAPE with around
20 knots of bulk shear this evening.

Showers taper over western and central ND this evening, and
lingers over the far southern JRV into Wednesday morning.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 311 PM CDT Tue Aug 15 2017

Warmer and drier weather in the long term period

An upper level ridge is expected to push in by the end of the week.
Generally, Wednesday and Thursday appear dry. A shortwave trough
drops through the area on Thursday night and Friday bringing a
small chance of showers and thunderstorms northwest to southeast
across the area. Then another slight chance of storms Sunday.
After highs in the 70s Wednesday, daytime highs are expected to be
mainly in the low to mid 80s Thursday through Tuesday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 311 PM CDT Tue Aug 15 2017

Main impacts to aviation will continue to be widespread MVFR and
IFR ceilings associated with showers and isolated thunderstorms
this afternoon and evening. Stratus will linger and expand to
cover much of North Dakota overnight impacting possibly all
terminals, especially KBIS-KMOT-KJMS. KDIK-KISN will be on the
western fringes of the stratus deck.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...TWH
LONG TERM...TWH
AVIATION...NH