Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 270240
AFDBIS

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

.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 00Z TAFS through 00Z Tuesday evening)
Issued at 933 PM CDT Mon Jun 26 2017

Isolated thunderstorms may enter western North Dakota late tonight
and into central North Dakota Tuesday morning. Additional
scattered, potentially severe thunderstorms may develop across
much of the area early Tuesday evening into the early overnight.
Low level wind shear is possible tonight for much of the area with
strong winds just off the surface. VFR conditions are expected
outside of thunderstorms.

&&

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

$$

UPDATE...PA
SHORT TERM...WAA
LONG TERM...WAA
AVIATION...PA


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