The SPC is forecasting ...Severe thunderstorms expected over parts of the central Plains this afternoon and tonight....
the latest public statement about this event. View What is a Watch? clip.
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.
Day 1 Wind Risk
Area (sq. mi.)
Some Larger Population Centers in Risk Area
Omaha, NE...Lincoln, NE...Bellevue, NE...Grand Island, NE...Kearney, NE...
Omaha, NE...Lincoln, NE...Sioux City, IA...Council Bluffs, IA...Bellevue, NE...
Charlotte, NC...Kansas City, MO...Atlanta, GA...Raleigh, NC...Greensboro, NC...
SPC AC 011950
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0250 PM CDT Fri Jun 01 2018
Valid 012000Z - 021200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS LATE THIS
AFTERNOON AND EVENING ACROSS PARTS OF CENTRAL/EASTERN NEBRASKA...
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS
SURROUNDING AREAS OF THE CENTRAL PLAINS...AND ACROSS PARTS OF THE
WESTERN/CENTRAL NORTH DAKOTA...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE EASTERN GULF COAST STATES...
Large hail, damaging winds, and a few tornadoes are likely from the
northern and central Plains into the middle Missouri Valley late
this afternoon into tonight. Severe winds and some hail are also
possible across parts of the Southeast.
...20Z Outlook Update...
Adjustments to the 10 percent probability of thunder (categorical
thunder) line and severe categorical and probabilistic lines (mainly
across parts of the southern high Plains and Southeast) have been
made. This is mostly in at attempt to better account for current
trends concerning destabilization and the influence of ongoing and
Areal coverage suggested in the vicinity of the dryline across the
southern high Plains, near/beneath the center of prominent
subtropical ridging, may still be a bit generous. Aside from the
higher terrain of southwest Texas, forcing to support convective
development is generally weak/unclear, but convection allowing model
output suggests the initiation of storms is at least possible.
Primary severe weather potential will remain focused across parts of
the northern and central Plains late this afternoon and evening,
supported by large-scale forcing associated with the short wave
trough now progressing across/east of the northern Rockies. For
more detailed information concerning ongoing or imminent severe
weather potential across this and other areas, please refer to the
latest SPC mesoscale discussions and watches.
.PREV DISCUSSION... /ISSUED 1145 AM CDT Fri Jun 01 2018/
Water vapor imagery late this morning features a notable late-spring
shortwave trough spreading northeastward from the northern Rockies
toward the northern High Plains, with appreciable height falls
expected as far east as the middle Missouri Valley and Upper Midwest
by tonight. A belt of strengthening (and backing) mid-level winds
will precede this trough, while surface cyclogenesis occurs across
the Dakotas today, and secondary cyclogenesis occurs across the
central Plains tonight.
It appears that an initial increase in severe thunderstorms will
occur relatively early this afternoon across northern Wyoming and
southeast Montana with a few supercells capable of large hail.
Another focus for potentially intense storm development will be in
and around west-central/south-central North Dakota near a surface
triple point. Persistent regenerative convection at midday poses
some uncertainty, but abating cloud cover should allow for rapid
destabilization by mid/late afternoon. Deep-layer/low-level shear
will be more than adequate for supercells capable of large hail and
a few tornadoes especially across west-central/south-central North
Dakota where low-level SRH is likely to be maximized.
Farther south, additional at least isolated to widely scattered late
afternoon/early evening development is expected southward across
South Dakota and into central Nebraska initially in vicinity of a
surface trough, with more extensive upscale-evolving development
likely this evening as an upstream cold front overtakes the surface
trough. A very unstable environment will exist along and
south/southwest of a warm front, with deep-layer/low-level shear
maximized near/just north of the warm front. Supercells capable of
very large hail and some tornado risk can be expected initially,
with the scenario likely to result in mature MCS development by late
evening. Aided by a strengthening (50+ kt) low-level jet, an MCS is
likely to spread southeastward with damaging wind potential across
the Missouri Valley this evening and possibly into the overnight.
Although the severe-weather potential may not be as widespread as
previously thought, multiple outflow/differential-heating related
boundaries will help focus an increase in coverage/intensity of
thunderstorms this afternoon within a moist and increasingly
unstable environment. Damaging winds will be the most common impact,
although some hail is possible as well.
...Southern High Plains...
Widely scattered thunderstorms are forecast to develop this
afternoon near the dryline, from northwestern OK and the eastern TX
Panhandle southwestward across the lower Caprock region to the lower
Pecos River area around FST. Isolated severe gusts and/or hail
appear possible for a few hours before nocturnal cooling stabilizes
the air mass in the evening and convective coverage/intensity
By mid-afternoon, intense insolation will contribute to surface
temps above 100 F and very deep/well-mixed boundary layers -- even
on the moist side of the dryline -- beneath midlevel lapse rates
exceeding 8 deg C/km. Even where moist-sector dew points mix down
into the 50s F, heating and weak mass convergence readily should
remove MLCINH and contribute to MLCAPE exceeding 2000 J/kg in much
of the outlook corridor. DCAPE of 1000-2000 J/kg should be common,
supporting maintenance of hail and acceleration of downdrafts to
surface. Vertical shear is forecast to be modest by most measures
under or near the upper ridge, as low-level flow is expected to
weaken with southward extent, yielding small boundary-layer
hodographs. As such, the primary convective mode should be
multicellular, though some supercell structures are possible over
the Panhandle/western OK area where mid/upper winds and cloud-layer
shear will be more favorable.
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z