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170
FXUS63 KBIS 271340
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
840 AM CDT Tue Jun 27 2017

.UPDATE...
Issued at 835 AM CDT Tue Jun 27 2017

Previous forecast had scattered light rain showers across North
Central North Dakota this morning. Placed the showers further
west where radar shows some weak convection. Winds picking up in
the vicinity of the showers as mixing of the lower atmosphere
occurs across the northwest.

UPDATE Issued at 641 AM CDT Tue Jun 27 2017

Previous forecast remains in good shape. Only change needed was to
adjust wind speeds up a bit based on current observations.

&&

.SHORT TERM...(Today and tonight)
Issued at 305 AM CDT Tue Jun 27 2017

Main impacts today will be severe potential late afternoon and
evening. In the near term will monitor weakening convection over
eastern Mt to see if low pops warranted for the early am.
Otherwise, short wave crossing the northern rockies will continue
to propagate east into the region today. Associated surface
boundary over central MT will reach the western Dakotas at prime
heating. Main deterrent for convective development will be
respectable capping with convective temperatures in the lower 90s which
will likely limit any development until late afternoon at the
earliest. For this will limit any pops until late afternoon in
vcnty of boundary. Warm column in place and with breezy to windy
conditions will see temperatures recover through the 80s to
around 90. Could see some lower RH values however dewpoints should
be on the increase during the afternoon limiting fire weather
concerns however will need to monitor.

Model soundings erode capping this evening between 00-03z.
Although shear somewhat limited, instability and cape sufficient
so that a strong/severe storm possible mainly across the central
portion of the state. What convection does get going this evening
will continue to propagate eastward. Although drier air working in
behind boundary overnight mixing will hold temperatures up.

.LONG TERM...(Wednesday through Monday)
Issued at 305 AM CDT Tue Jun 27 2017

The cold front will have moved out to the east by Wednesday morning,
leaving cooler, drier weather for Wednesday. Highs will be more
comfortable in the 70s to lower 80s, but Wednesday will be quite
breezy with northwest winds at 10 to 20 mph sustained and low level
jet mixing down gusts to 40 mph at some locations. High pressure
rushes through Wednesday afternoon and evening, continuing to
reinforce drier air, but return flow will begin bringing some
low level moisture in behind the high pressure system.

By Thursday, the upper low over central Alberta matures and begins
to phase in with a surface low moving into western North Dakota from
the Canadian Rockies. As this system matures, it will remain in the
vicinity of the international border and will bring scattered
showers and thunderstorms on Thursday and Friday as this system
remains in the area. With a cold front passage Thursday and some
weak to moderate instability but weak bulk effective shear, there is
potential for a few strong thunderstorms to develop Thursday
afternoon and evening. Behind the front, Friday will be the coolest
day of the week with highs perhaps not even reaching the 70s north
of Interstate 94.

North central North Dakota may see some remaining wrap around
scattered showers and storms Saturday, but the latest model runs
suggest a drier period for most locations as trailing surface high
pressure moves through. Rain chances and temperatures begin to
increase Sunday again as the next disturbances moves through to the
south and a ridge begins to build in from the west.

Expect temperatures to cool from Wednesday to Friday, with highs
only reaching the 60s and 70s Thursday through Saturday, but
recovering back into the 70s to lower 80s by Sunday and Monday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 641 AM CDT Tue Jun 27 2017

Gusty southerly winds today switching northwest later in the day
into the overnight as a cold front pushes through. Scattered
thunderstorms possible late day and overnight. Areas of MVFR cigs
expected late tonight over the James River Valley, otherwise VFR
conditions expected.


&&

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

$$

UPDATE...WAA
SHORT TERM...Voelker
LONG TERM...BP
AVIATION...JJS