Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 270414

Area Forecast Discussion
National Weather Service Bismarck ND
1114 PM CDT Mon Jun 26 2017

Issued at 1114 PM CDT Mon Jun 26 2017

Latest regional radar continues to show an area of showers and
thunderstorms approaching Glasgow, Montana. Wind gusts of 45 mph
and 50 mph have been reported within the precipitation area.
Latest Cam`s continue to weaken and push this convection east
towards Williston between 07z-08z. Scattered to broken mid/high
level clouds will be maintained across western and portions of
central ND overnight. Previous forecast had this handled well and
no changes needed.

UPDATE Issued at 933 PM CDT Mon Jun 26 2017

Little change from the previous update. Convection across
northeast Montana as of 0230 UTC sustained by the low level jet
and steep mid level lapse rates, despite limited moisture, is
expected to reach the North Dakota border around 07-08 UTC.
Additional isolated convection cannot be ruled out across the
southwest late tonight.

UPDATE Issued at 548 PM CDT Mon Jun 26 2017

Per CAM trends through the 21 UTC RAP/HRRR, increased the mention
for isolated elevated thunderstorms across western North Dakota
late tonight and central North Dakota tomorrow morning. At least
isolated storms seem plausible to survive from central Montana
early this evening into western and central North Dakota with the
low level jet. Given very weak instability/moisture, severe
weather is not expected.


.SHORT TERM...(This evening through Tuesday)
Issued at 309 PM CDT Mon Jun 26 2017

After several days of cool air associated with a surface high
pressure area, lee side low pressure will develop in Montana and
pull moisture into the region beginning late tonight but more so
on Tuesday. Superblend dewpoints begin to rise into the 50s to
around 60 across central North Dakota Tuesday afternoon along a
warm frontal boundary. An EML moves over southwest North Dakota
and this should help temperatures rise into the low to mid 90s and
at the same time provide a CAP to convection until late afternoon.
Will hold off on the mention of severe weather until Tuesday
evening when the cold front breaks the CAP.

.LONG TERM...(Tuesday night through Monday)
Issued at 309 PM CDT Mon Jun 26 2017

The early focus in the long term will be the marginal risk for
severe weather Tuesday night. Large hail and damaging winds appear
to be the main threat as the convection will likely be elevated.
NAM/GFS models do bring in a narrow band of significant CAPE
between 2 and three thousand along the cold front. Believe there
will be a short period of severe weather threat in central North
Dakota in the late afternoon and early evening shifting to the
James River Valley later in the evening. Large hail and damaging
winds appear to be the main threats.

Wednesday will be dry and cooler in a post cold frontal
environment. An upper low over western Canada will swing through
the region Thursday through Saturday bringing its instability
with scattered showers and thunderstorms. However there does not
appear to be good enough moisture to generate widespread rainfall
from these. Sunday and Monday should still see a lingering
influence from cyclonic flow aloft so cannot rule out widely
scattered thunderstorms. Temperatures will be cooling into the
60s and 70s by the end of the week recovering back into the 70s to
lower 80s by Sunday and Monday.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1114 PM CDT Mon Jun 26 2017

An area of showers and thunderstorms approaching Glasgow, Montana will
continue moving east towards KISN by 08z Tuesday. Have included a vcts
at KISN from 08z-12z Tuesday. Otherwise, sct/bkn mid and high level clouds
will continue through 00z Wednesday. Showers and thunderstorms will initiate
along a cold front between 00z-06z Wednesday. High confidence at this time
for showers/thunderstorms at KMOT/KBIS by 01z Wednesday, moving into KJMS
between 03z-06z Wednesday.




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