Fergus Falls, MN...Bemidji, MN...Williston, ND...Wahpeton, ND...Sidney, MT...
Probabilistic Tornado Graphic
Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
5 %
16,990
129,461
Minot, ND...Devils Lake, ND...
2 %
24,272
300,169
Bismarck, ND...Grand Forks, ND...Mandan, ND...Jamestown, ND...Valley City, ND...
Probabilistic Damaging Wind Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Mandan, ND...Fergus Falls, MN...Bemidji, MN...Wahpeton, ND...
SPC AC 091249
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0749 AM CDT Fri Jun 09 2017
Valid 091300Z - 101200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
INTO TONIGHT FOR PARTS OF THE NORTHERN PLAINS...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
SLIGHT RISK AREA...FROM SOUTHEASTERN MONTANA TO NORTHWESTERN
MINNESOTA...
...SUMMARY...
Strong to severe thunderstorms, capable of large hail, damaging
winds, and perhaps a couple tornadoes, will be possible across the
northern Plains today through tonight.
...Northern Plains through tonight...
Within a belt of cyclonic mid-upper flow over the northwestern
CONUS, embedded speed maxima will eject east-northeastward from the
northern Rockies/Great Basin to the northern Plains by Saturday
morning. An associated surface cyclone will develop slowly eastward
across ND, as boundary-layer dewpoints in the 60s are drawn
northward across the Dakotas (and augmented by evapotranspiration)
beneath steep midlevel lapse rates. The elevated mixed layer plume
will act to cap the boundary layer until mid-late afternoon, when
convective initiation becomes probable across central ND in
association with deeper surface mixing and low-level ascent along a
surface trough.
Moderate-strong buoyancy (MLCAPE ranging from 1500-3000 J/kg from
north to south across central ND)and effective bulk shear in excess
of 40 kt will support a risk for supercells late this
afternoon/evening. Somewhat large temperature-dewpoint spreads
suggest that large hail/damaging winds will be the main risks.
However, substantial low-level shear/hodograph curvature and
somewhat lower spreads along the north edge of the warm sector in
north central ND could support a couple of tornadoes. Some of the
afternoon convection could persist into early tonight and spread as
far east as northwest MN with an associated hail/wind threat.
A few clusters/bands of thunderstorms may also form by early tonight
near and just northeast of the higher terrain in southern
MT/northern WY, and spread northeastward to ND overnight. Isolated
damaging winds and/or large hail could occur with the strongest
storms along and on the immediate cool side of a surface cold front.
..Thompson.. 06/09/2017
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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