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
2 %
87,618
7,843,829
Kansas City, MO...St. Louis, MO...Overland Park, KS...Kansas City, KS...Topeka, KS...
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.
Day 1 Wind Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
SIG SEVERE
62,029
5,636,107
Kansas City, MO...Overland Park, KS...Kansas City, KS...Topeka, KS...Springfield, IL...
30 %
61,307
7,356,667
Kansas City, MO...St. Louis, MO...Overland Park, KS...Kansas City, KS...Springfield, IL...
SPC AC 171637
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1137 AM CDT Sat Jun 17 2017
Valid 171630Z - 181200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER EASTERN
KANSAS ACROSS NORTHERN/CENTRAL MISSOURI INTO CENTRAL ILLINOIS...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM
CENTRAL/EASTERN KANSAS AND EASTERN OKLAHOMA ACROSS THE MIDDLE
MISSISSIPPI VALLEY INTO INDIANA AND SOUTHERN LOWER MICHIGAN...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
PLAINS TOWARD THE SOUTHERN GREAT LAKES...
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER THE EASTERN
DAKOTAS INTO MINNESOTA...
...SUMMARY...
Severe thunderstorms are expected late this afternoon into tonight,
mainly from the central Plains across the middle Mississippi Valley
into southern Lower Michigan, with damaging gusts and hail likely.
Isolated severe thunderstorms also are possible this afternoon over
parts of the Dakotas and Minnesota.
...Central Plains across the middle Mississippi Valley into southern
Lower Michigan...
Prior convection from yesterday/last night has modified the
environment across this region with slightly lower surface dew
points evident this morning. However, thinning clouds across much
of this corridor from Kansas into Illinois will promote stronger
diabatic heating to occur this afternoon, and some recovery of
low-level moisture with increasing surface dew points from Missouri
eastward is likely this afternoon. 12Z soundings over the Plains
maintain steep lapse rates that will spread eastward toward the
Mississippi Valley this afternoon, contributing to moderate/strong
instability with MLCAPE ranging from 3500-4000 J/kg over eastern
Kansas to 1500-2000 J/kg over in the Indiana/Michigan region. The
presence of the EML is also likely to delay convective initiation
from Kansas into Missouri until the late afternoon/evening.
As a short wave trough over the northern high plains moves
southeastward in response to stronger west-northwest winds in the
mid/upper levels, flow over the central plains and mid-Mississippi
Valley will strengthen enhancing deep layer shear over the region.
Model guidance is reasonably consistent indicating that storms are
likely to develop near an advancing cold front, initially over
southeast Iowa/northern Missouri, then gradually developing westward
along/near the front into parts of central/eastern Kansas late this
afternoon and evening. The strong instability coupled with 35-45 kt
deep layer shear will support development of multiple clusters/lines
of severe storms capable of producing large hail with significant
hail possible, especially during the early stages of storm
maturation, and damaging winds as activity moves eastward and
southeastward through the evening hours. There are indications that
some bowing line segment will develop which may promote significant
wind gusts mainly during the evening hours.
Farther west over the central High Plains, model consensus indicates
convective coverage will be more isolated with a few storms
developing from extreme northeast Colorado area moving southeastward
into parts of western Kansas. A deep mixed layer/steep lapse rates
will be favorable for strong/severe wind gusts and possible hail
late this afternoon and evening.
...Eastern Oklahoma into Eastern Texas and Southwest Louisiana...
A small complex of strong/severe storms continues to move southward
into southeast Oklahoma. The air mass in advance of the activity is
continuing to warm/destabilize, although a capping inversion on the
12Z SHV sounding associated within EML provides some uncertainty
regarding the persistence of the system into the afternoon. A low
probability of severe storms has been added into eastern Texas to
account for this scenario, with potential for additional strong
storms to develop as far south as southwest Louisiana.
...Eastern Dakotas, Minnesota...
Behind the surface cold front, widely scattered to scattered
thunderstorms are expected to develop this afternoon with the risk
for isolated severe hail and gusts. This potential will be
supported by the strengthening large-scale ascent and deep shear
associated with the approaching northern-stream trough in mid/upper
levels, overlying diabatically minimized afternoon MLCINH and weak
convergence near a surface trough. Though conditions will be
seasonally cool at the surface, with temps in the 60s and dew points
50s F, this still will support MLCAPE 500-1000 J/kg, with some areas
of effective-shear magnitudes reaching 30-35 kt. This threat should
abate quickly after dark as the boundary layer stabilizes, due to a
combination of cold advection and diabatic cooling.
..Weiss/Cohen.. 06/17/2017
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