WW 338 SEVERE TSTM IL IN MI OH LM 162010Z - 170300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 338
NWS Storm Prediction Center Norman OK
410 PM EDT Tue Jun 16 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
East Central Illinois
Northern and Central Indiana
Southern Lower Michigan
Northwest Ohio
Lake Michigan
* Effective this Tuesday afternoon and evening from 410 PM until
1100 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Scattered large hail events to 1.5 inches in diameter possible
A tornado or two possible
SUMMARY...Thunderstorms will form this afternoon along a cold front
and sweep eastward across the watch area. The strongest storms will
be capable of damaging winds and large hail. A tornado or two is
also possible.
The severe thunderstorm watch area is approximately along and 55
statute miles east and west of a line from 30 miles south of Terre
Haute IN to 30 miles east northeast of Grand Rapids MI. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU8).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
24030.
...Hart
WW 0338 Status Updates
STATUS REPORT ON WW 338
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 SW MTO TO
40 ENE LAF TO 10 NNE MIE TO 10 SSE FWA TO 35 ESE SBN TO 35 WSW
MBS.
..WEINMAN..06/17/26
ATTN...WFO...ILX...IWX...IND...LOT...GRR...
STATUS REPORT FOR WS 338
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
ILC023-025-033-035-045-049-079-101-159-170140-
IL
. ILLINOIS COUNTIES INCLUDED ARE
CLARK CLAY CRAWFORD
CUMBERLAND EDGAR EFFINGHAM
JASPER LAWRENCE RICHLAND
INC003-005-011-013-021-023-033-035-055-057-059-063-065-081-087-
095-097-105-107-109-113-119-121-133-135-145-151-153-159-165-167-
170140-
IN
. INDIANA COUNTIES INCLUDED ARE
ALLEN BARTHOLOMEW BOONE
BROWN CLAY CLINTON
DE KALB DELAWARE GREENE
HAMILTON HANCOCK HENDRICKS
HENRY JOHNSON LAGRANGE
MADISON MARION MONROE
MONTGOMERY MORGAN NOBLE
No Mesoscale Discussions are in effect as of Wed Jun 17 01:04:11 UTC 2026.SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0800 PM CDT Tue Jun 16 2026
Valid 170100Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF IOWA
AND OVER A SMALL PART OF CENTRAL INDIANA...
...SUMMARY...
Severe storms producing hail remain possible from southern Kansas
into northwest Oklahoma this evening. Isolated severe hail or wind
will persist across the northern Plains and into Iowa by Wednesday
morning. Isolated severe storms may persist from Indiana into
western Ohio this evening.
...IN/OH/MI...
00Z DTX and ILN soundings show modest instability but favorable
shear profiles to sustain cellular storm mode this evening. However,
storms across this region are beginning to decrease in coverage and
intensity, though isolated strong to severe storms may persist with
marginal hail or brief tornado risk before the upper trough moves
out of the area and the air mass stabilizes.
...KS/OK/TX Panhandle...
A mixed boundary layer, increasing low-level jet and northwest flow
aloft is aiding a few cells over southwest KS into northwest OK.
Periodic large damaging hail remain possible, and a cell or two may
persist this evening, perhaps toward the eastern TX Panhandle as
moisture returns northwestward. However, the cooling boundary layer
will eventually result in decreasing coverage.
...From MT to IA...
Scattered storms exist from MT into ND, beneath cool temperatures
aloft with the developing upper trough. Locally severe gusts may
occur with any of this activity as a relatively dry/mixed sub cloud
layer exists on 00Z soundings.
Later tonight, as the low-level jet increases into the central
Plains, a plume of mid 60s F dewpoints will reach eastern NE into
IA, and may fuel cells initially producing hail following a possible
MCS.
..Jewell.. 06/17/2026
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0450 PM CDT Tue Jun 16 2026
Valid 181200Z - 241200Z
...Synopsis...
On Day 3/Thursday, an upper low will slowly slide eastward over
southern Quebec as a belt of strong mid-level flow expands across
the Ohio Valley into the Northeast. Simultaneously, an upper ridge
will break down across the West owing to an approaching upper
trough. Some isolated dry thunderstorm potential alongside dry and
breezy conditions with above normal temperatures (and resultant dry
fuels) will support expansive fire concerns through Day 5/Saturday.
The trough will lose its amplitude as it traverses the Great Plains,
transitioning western CONUS to temporary zonal flow aloft. While
predictability is low, extended guidance exhibits increasing
potential for ridging to build back across the Pacific Northwest,
bringing warm and dry conditions back into the region early next
week.
...Day 3-5/Thursday-Saturday - Parts of the Pacific Northwest and
Great Basin...
As upper-level troughing moves onshore the West Coast, surging
mid-level moisture and synoptic scale lift will bring increasing
chances for thunderstorms. Given preceding days of warm and dry
conditions and coincident curing fuels, the isolated nature of
thunderstorm development could pose a threat for lightning ignitions
across a very dry environment -- possibly as early as Day 3/Thursday
evening. The potential for thunderstorm development on Day
3/Thursday will be reevaluated on the approaching Day 2 outlook
cycle as higher resolution guidance becomes available. Fast storm
motions, high cloud bases, and locally breezy conditions support 10%
Dry Thunderstorm probabilities on Day 4/Friday, and again on Day
5/Saturday as the trough shifts eastward. Spatial extent of the
aforementioned risk areas may fluctuate as guidance is better
resolved in future outlook cycles.
Increasing southerly to westerly flow across the Southwest will
transport very dry air and breezy conditions amid recently receptive
fuels, promoting continued fire concerns in the Great Basin through
the weekend. 40% Critical probabilities have been maintained on Days
4-5/Friday-Saturday to account for this threat.
..Elizalde-Garcia.. 06/16/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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