RSS Mesoscale Discussions from Storm Prediction Center
Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1137 AM CDT WED JUN 17 2026
...Severe thunderstorms expected over parts of the Midwest this
afternoon and tonight...
* LOCATIONS...
Central Illinois
Central Indiana
* HAZARDS...
Several tornadoes, a couple intense
Scattered damaging winds, some hurricane force
Scattered large hail, some baseball size
* SUMMARY...
Numerous severe thunderstorms are expected this afternoon into
tonight, with the peak threat centered over Illinois and
Indiana. Intense tornadoes, swaths of damaging gusts over 75 mph
and damaging wind-driven large hail will all be possible.
Preparedness actions...
Review your severe weather safety procedures for the possibility
of dangerous weather today. Stay tuned to NOAA Weather Radio,
weather.gov, or other media for watches and warnings. A tornado
watch means that conditions are favorable for tornadoes to form
during the next several hours. If a tornado warning is issued for
your area, move to a place of safety, ideally in a basement or
interior room on the lowest floor of a sturdy building.
&&
..Hart.. 06/17/2026
$$
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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1128 AM CDT Wed Jun 17 2026
Valid 171630Z - 181200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
ILLINOIS AND INDIANA...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT OVER
SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI...
...SUMMARY...
Numerous severe thunderstorms are expected this afternoon into
tonight, with the peak threat centered over Illinois and Indiana.
Intense tornadoes, swaths of damaging gusts over 75 mph and damaging
wind-driven large hail will all be possible.
...MO/IL/IN...
An intense and fast-moving shortwave trough continues to approach
the Midwest today, with an associated 90+ knot mid level jet
streaking across the region. A very strong southerly low-level jet
precedes this trough, and has resulted in widespread thunderstorms
over central IL. The effects of this early convection will be
important to the mesoscale details of where the main risk of severe
storms will develop later today.
The primary outflow boundary from ongoing storms currently extends
from extreme northeast MO into south-central IL, and continues to
sag southward. Strong heating is occurring to the south of the
boundary, and given the intense low-level flow, some northward
return is expected. However, it appears unlikely to substantially
destabilize as far north as earlier forecasts. The zone in vicinity
of the boundary will become very unstable by mid-late afternoon,
with forecast soundings continuing to show impressive shear values
and hodograph structures suggestive of tornadic supercell potential.
Very large hail and damaging winds will also be possible with this
activity as it tracks quickly eastward into central IN. Strong
tornadoes are possible.
By mid-evening, a line of severe storms will likely extend from
central MO into southern IN, with damaging winds becoming the
primary threat.
...Southeast MN...
A small area of heating/destabilization has developed near the
surface low over southern MN. Cold temperatures aloft and strong
deep-layer shear suggests a threat of a few severe storms capable of
hail and gusty/damaging winds this afternoon.
...LA/MS...
Tropical Storm Arthur will track northward and affect LA and
southern MS tonight. A zone of strong southerly low-level winds to
the east of the circulation will result in some concern for
overnight and pre-dawn tornadoes across southeast LA into far
southern MS.
...Southern AZ/NM...
Scattered afternoon and evening thunderstorms are expected across
southeast AZ and southwest NM. Strong heating and ample instability
will pose a risk of damaging wind gusts in the strongest cells.
..Hart/Chalmers.. 06/17/2026
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1223 PM CDT Wed Jun 17 2026
Valid 181200Z - 191200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL
KENTUCKY INTO THE MID-ATLANTIC AND PORTIONS OF NEW ENGLAND...
...SUMMARY...
Isolated to scattered severe thunderstorms will be possible from
Kentucky to the Mid-Atlantic, and across parts of the Northeast.
Damaging wind gusts will be the main hazard with this activity.
...Synopsis...
A potent upper trough and associated mid-level jet streak will move
into the northern Mid-Atlantic/New England Thursday morning. A deep
surface low moving through southern Ontario/Quebec will drive a
surface cold front through the regions. This front will extend
southwestward into the Ohio Valley/southern Appalachians and parts
of the central/southern Plains. The remnants of what is now Tropical
Storm Arthur will continue through parts of the Southeast.
...New England/Mid-Atlantic...
Convection will likely be ongoing ahead of the upper trough during
the morning, particularly from eastern New York into New England.
While this activity is likely to inhibit afternoon destabilization,
strong wind fields will still promote some risk for damaging winds
and perhaps a brief tornado. The strongest activity will develop by
early afternoon along the cold front and progress eastward. Bowing
segments and marginal supercell structures will be possible. The
strong low-level jet will be shifting eastward during the day, but
portions of New England will still have strong 850 mb winds during
the early/mid afternoon. If sufficient heating occurs, this is where
the tornado risk will be marginally greater.
...Kentucky/West Virginia/Virginia...
Stronger instability is expected south of the surface front on
account of richer low-level moisture. Scattered storms are expected
to form along the front by mid afternoon. Though the low-level jet
will weaken much quicker in these areas, deep-layer shear near the
front will remain sufficient for organized cells and linear
segments. These storms will move eastward through the afternoon and
pose a risk of damaging wind gusts.
...Southern Plains into Ozarks...
Elevated convection may be ongoing early in the period near and
north of the cold front in southern Kansas/southwest Missouri. These
storms could produce large hail. With time, the front will sag
southward. Strong heating of a 70+ F dewpoint airmass will
potentially promote afternoon thunderstorms capable of marginally
severe hail and isolated severe gusts. During the evening,
additional thunderstorms may develop as a modest increase in the
low-level jet occurs. Some guidance suggests this activity may
cluster into a small MCS within western Oklahoma/northwest Texas.
Where and if this occurs is not certain. Some risk for severe gusts
could extent into the evening if this occurs.
...Southeast...
The remnants of Tropical Storm Arthur will move through a very moist
(70+ F dewpoints) airmass. Local shear magnitudes will be modestly
enhanced by the remnant circulation. Scattered convection will be
capable of wind damage and perhaps a tornado or two. Portions of
Georgia may see greater surface heating ahead of the circulation. A
few stronger storms are possible here. Even so, poor mid-level lapse
rates and deep-layer shear (especially away from the circulation
center) will limit the overall severe threat.
..Wendt.. 06/17/2026
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