Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 150243

Area Forecast Discussion
National Weather Service Bismarck ND
943 PM CDT Thu Sep 14 2017

Issued at 930 PM CDT Thu Sep 14 2017

Added showers to the southwest of Bismarck and spread them into
the central tonight. Otherwise, a well defined series of
shortwaves from the northwest CONUS to central CA into UT/WY on
the water vapor channel. This lines up very well with the global
models. Have confidence that we will see increasing chances for
showers tonight then widespread showers spreading across west and
central North Dakota on Friday.

UPDATE Issued at 617 PM CDT Thu Sep 14 2017

Broad southwest flow aloft continues this evening with a shortwave
moving through Wyoming and Colorado. This will lift into the
northern plains Friday bringing increasing chances for showers
late tonight and especially Friday. The threat of thunderstorms
across the southeast resumes Friday with primarily elevated
thunderstorms southeast. Current forecast looks good.


.SHORT TERM...(This evening through Friday)
Issued at 312 PM CDT Thu Sep 14 2017

Rain developing west tonight and continuing area wide Friday
highlight the short term forecast.

The 12 UTC global suites are in good agreement on widespread
rainfall developing across the west tonight, into the far north
central late with the leading impulses ahead of the long wave
western CONUS trough. The trend is for a slower start to the
widespread steady rain across central North Dakota on Friday
morning, favored closer towards midday or even the early
afternoon with the arrival of the more potent shortwave.
Thereafter, rain is expected to continue for most of the area
through Friday night. It should be noted the threat for elevated
thunderstorms, possibly strong to perhaps even marginally severe
across the far south central and James River Valley on Friday.
Steep mid level lapse rates above the inversion extending around
800mb and strong speed shear support a low end severe hail threat
in a high shear/low CAPE environment.

.LONG TERM...(Friday night through Thursday)
Issued at 312 PM CDT Thu Sep 14 2017

Continued rainfall chances Saturday and possible frost Sunday
morning highlight the extended forecast.

Again following the 12 UTC suite, a brief lull in precipitation is
possible late Friday night into early Saturday morning until the
arrival of the strong shortwave extending southeast of the upper
low across Saskatchewan and Alberta. Precipitation is favored to
be most widespread Saturday across the west into the north central
with some hints of drier air across the south central. Storm
total rainfall amounts of 1.50 to 2.50 inches, with locally higher
amounts, are favored along an axis from southwest through north
central North Dakota.

As cool high pressure builds in Saturday night into Sunday,
widespread lows in the 30s and frost are possible especially
across the west Sunday morning.


.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 617 PM CDT Thu Sep 14 2017

The main hazard to aviation this forecast period will be
deteriorating conditions from VFR/MVFR to widespread IFR
conditions in low ceilings late tonight and Friday. Visibilities
may fall into the IFR criteria KDIK- KBIS where heavier rain is
expected by Friday afternoon.




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