127
fxus63 kiwx 182350
afdiwx
area forecast discussion
national weather service northern indiana
650 pm est wed feb 18 2026
.key messages...
- highs in the 60s on thursday are within 5 degrees of record
levels.
- thunderstorms will be possible on thursday. a marginal risk
for severe weather exists mainly during the later afternoon on
into the evening with gusty winds, hail, and a tornado as the
main threats.
- cooler air arrives friday with snow becoming more likely,
especially by sunday morning.
&&
.discussion...
issued at 228 pm est wed feb 18 2026
within this -pna pattern of a trough in the west and a ridge in the
east, the sensible weather is warmer temps along with waves ejecting
at some trajectory towards the upper mississippi valley and lower
great lakes area. after the morning rain, the column looks to dry
out with big changes coming as 50 degree dew points this morning
drop to the 30s this evening. as this happens, gradient weakens this
afternoon and the mixing height struggles to get much higher than
850 mb and this keeps breezy gusts below 30 kts. this is still
enough to dry out grasses above the ground and potentially get to
leaves on ground. as such, cannot completely rule out a grassy fire
scenario, but snowmelt and the morning rain may be able to keep the
ground somewhat wet yet.
as an upper low moves into the upper mississippi valley and northern
plains/northern great lakes area tonight, another surface low ejects
out of the rockies and into the central plains tomorrow morning and
reaches central il by thursday evening. at the same time, a slow
eastward meandering cold front looks to stall around the us-24 area
this evening. as that surface low approaches, it may be able to
shove the boundary northward thursday am. an initial wave pushes
northward through the area thursday morning, and initially, it
looked like this may be what initiates convection as it moves north
and east with the front. however, it now appears like a second wave
moving into the area during the afternoon/evening may be the main
forcing for the event and could set off some thunderstorms at that
point. instability appears to be the limiting factor for this setup
as morning convection could leave behind debris clouds and push any
outflow boundaries south, stunting low level instability generation.
the cold front waits until thursday night to move through so shower
and thunderstorm generation are still possible, but by this
point, instability would likely be worked over. thursday`s
highs look to be in the 50s and 60s, but would trend downward
for friday, with highs in the 40s more likely by then. rain
would be finishing up north of us-6 as the main shortwave
associated with the deepening low pressure system finally moves
into the eastern great lakes by friday afternoon/evening.
between friday and saturday, the aforementioned trough over the
western conus translates eastward and upper trajectories take a more
southward storm track allowing cold air to come in on the backside
of the eastward-moving trough. this allows for negative 850 mb
temperatures to arrive in the area, making it more conducive for the
arrival of snow. there could be some lake enhancement with this, but
it appears to be forced mainly by a trough coming down on the
western side of an upper low east of the great lakes without a
vigorous shortwave in the vicinity of lake mi, limiting snow
output. temperatures also look to be in the low to potentially
mid 30s, which causes wet snow ratios. even still, models do
have time periods where lake enhanced inversion creep up to 5
to 6 kft, which may allow for an area of advisory level snow.
lake enhancement lets up later monday/monday night as high
pressure and mid level ridging finally works its way into the
area. temperatures look to creep back up by midweek next week
as waa takes over. next system arrives during the tue/wed time
frame.
&&
.aviation /00z tafs through 00z friday/...
issued at 650 pm est wed feb 18 2026
low level moisture surge ahead of the next system arriving late
thursday will likely bring a period of fog, rain, and low
stratus thursday morning. confidence is not high (especially
further north at ksbn) given a high degree of spread in the
guidance but increasing moisture over cold ground conceptually
supports the idea of fog/stratus development. held conservative
for now with worst conditions tied to prob30 mention of light
rain but this may need to be adjusted if confidence in fog
increases later this evening. more rain (and possibly
thunderstorms) then expected late thursday but best chances
arrive right at 00z so held off mentioning with this forecast.
&&
.iwx watches/warnings/advisories...
in...none.
oh...none.
mi...none.
marine...none.
&&
$$
discussion...roller
aviation...agd