Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 191931

Area Forecast Discussion
National Weather Service Bismarck ND
231 PM CDT Tue Sep 19 2017

.SHORT TERM...(This evening through Wednesday)
Issued at 146 PM CDT Tue Sep 19 2017

Convection continues to track east across central ND this
afternoon. Greatest risk of severe storms looks to be along and
east of a line from around Harvey to Linton. Most mesoscale models
show rapid intensification near the current line of convection in
the next 1-2 hours as remaining cap dissipates. With a very strong
synoptic system, all threats remain: Large hail, Damaging winds
and even tornadoes. The severe threat will exit the eastern CWA
during the evening hours. Clearing from west to east tonight with
overnight lows dropping into the mid 30s possibly over the
southwest. Areal extent appears small for areas of frost. Will
mention some frost but advisory not anticipated at this time.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 146 PM CDT Tue Sep 19 2017

Cooler and much drier on Wednesday. Our main concern will be
possible fire weather issues in the southwest during the
afternoon. Minimum humidities are in the 20 to 25 percent range
with sustained winds around 20 mph. As was mentioned on the mid
shift, it still looks like marginal fire weather conditions may
exist for a brief period. With uncertainty in duration with only
marginal winds, we will not issue a fire weather watch at this
time. Overnight shift can re-evaluate. If we mix out more than
anticipated, fire weather hazards may still be needed.

Relatively dry period Wednesday and Thursday as the first upper
low lifts into Canada. The next round of active weather picks up
Thursday night and continues through the weekend as another upper
low deepens over the western U.S. keeping a southwest upper flow
over the northern plains. However, we also begin to cool down and
the thunder risk beyond today and tonight looks to be minimal
through the weekend. Highs mainly in the 60s and 70s Wednesday and
Thursday. A transition on Friday to cooler highs mainly in the 50s
over the weekend.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 146 PM CDT Tue Sep 19 2017

The main hazard to aviation this afternoon and evening will be
thunderstorms. For this used VCTS for KBIS-KJMS due to timing
uncertainty. But conditions favor a line of thunderstorms with
gusty winds, possibly impacting KJMS around 21Z-24Z today. VFR
conditions expected behind the cold front that moves through KJMS
this evening.




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