466
fxus63 kiwx 310721
afdiwx
area forecast discussion
national weather service northern indiana
321 am edt tue mar 31 2026
.key messages...
- there is a slight risk for severe weather today (level 2 of 5).
- scattered strong to severe storms are likely to develop between 4-
8 pm edt, becoming more widespread after 8 pm edt.
- all hazards are possible today including damaging winds 60-70 mph,
1" diameter hail, and isolated tornadoes.
- near record warmth again today with highs in the mid 70s to near
80 degrees.
- much cooler wednesday with afternoon temperatures near 50.
- becoming mild again late in the week into the weekend with
additional chances for rain.
&&
.discussion...
issued at 320 am edt tue mar 31 2026
a very active week is ahead with mild temperatures and several
opportunties for rain and storms, including potential for
severe weather later today. our entire area is now under a
slight risk (level 2 of 5) for severe weather per the storm
prediction center. a developing low pressure system will lift
through the upper midwest today, with its trailing cold front
sweeping through our forecast area later this evening. the
system`s attendant warm front is well north of our area across
northern lower michigan currently. temperatures have remained
very mild overnight only dropping into the mid 60s. increased
low level mixing is ongoing with increasing southwesterly winds
over the past few hours. 850mb moisture transport ramps up today
as strong waa and southwesterly winds advect warm, moist air
from the gulf into the upper great lakes region. southerly low
level winds persist today with gusts to 30-35 mph, especially by
this afternoon and evening. with our area firmly in the warm
sector today, highs will be in the mid 70s to low 80s area-wide.
locations south of us 24 have the best chances of reaching 80
degrees or higher. dewpoints will be in low 60s by midday. amid
zonal flow aloft and aided by a 500mb shortwave lifting out of
eastern iowa/central illinois later this morning, scattered
convection may clip northwest indiana as it lifts from northern
illinois into lower michigan. this activity is expected to
produce an outflow boundary across northern. as the warm, moist
airmass destabilizes this afternoon, this outflow boundary
should be the focus of where storms develop this afternoon. hi-
res model guidance is all over the place and has yet to come to
a consensus on when and where exactly storms will develop this
afternoon. in an attempt to sift through all the potential
outcomes and determine what could happen today, i have medium
confidence in severe weather occuring but low confidence on the
exact onset. some models have storms developing as early as 2-4
pm edt while other don`t have storms developing until as late as
8 pm edt. with southwest surface flow and zonal winds aloft,
0-6km shear of 40-50 kts will exist all day today. models show
sbcape values of 1500-2000 j/kg this afternoon and evening; a
strong cap is in place now and should hold through the morning.
once the cap breaks and as the low level jet ramps up and we
continue to destabilize this afternoon, i think that convective
initiation should occur between 4-8 pm edt. scattered strong to
severe storms should get going ahead of the approaching cold
front, becoming more widespread after 8 pm edt. moderately steep
mid level lapse rates around 7 c/km will be supportive for
severe weather this afternoon and evening, but quickly diminish
after sunset. while we may start with discrete storms along the
outflow boundary this afternoon, as more storms pop up into the
evening ahead of the cold front, i`d expect a transition to more
of a linear setup with bowing segments/clusters. a mixed, messy
storm mode of both types may also occur as convection grows
upscale. low level vertical wind shear is evident in forecast
hodographs, which depict 0-1 km srh values of 200-300 m2/s2
across our forecast area throughout the evening. in line with
this, spc continues to have our entire area under a 2% tornado
risk with cig1 hatching. while the overall tornado threat is
rather low, it it not zero and if a tornado were to develop, it
could be strong (up to ef2 intensity). a strong tornado threat
would mainly exist if a storm were able to remain discrete this
afternoon/evening. an embedded brief, weak spin up or two is
also not out of the question within a linear/bowing segment.
main hazards though will be the damaging wind and hail threats.
wind gusts 6-70 mph and 1" diameter hail could occur within any
severe storm today.
the cold front will sweep though much of our forecast area from
northwest to southeast later this evening into early wednesday. the
frontal boundary may stall out over our southeast, somewhere in the
us 30 vicinity. while our entire area technically has a
marginal risk (level 1 of 4) for flooding today, winds along and
south of us 30 will still be southwesterly out ahead of the
front, so i have some concerns about a flooding threat
developing there late tonight into wednesday morning as those
surface winds will be parallel to the incoming cold/stationary
front. flooding will be possible given a saturated atmospheric
profile (low and mid level rh >80%), precipitable water values
of 1.25-1.5", and as aforementioned, strong moisture transport
at 850mb will be bringing in very warm and moisture air.
forecast soundings south of us 30 also show tall, skinny cape
profiles and a deep, warm cloud layer >10,000 ft. all of this
points towards potential flooding concerns developing along and
south of us 30, depending on the exact timing and forward speed
of the cold front. if the front is able to clear the area in a
relatively quick time span, the flooding threat will be lower.
temperatures crash on the backside of the front tonight, with
wednesday`s highs expected to occur at midnight. temperatures will
then be in the upper 40s to low 50s during the afternoon wednesday
with cyclonic northwest flow and caa on the backside of the front.
there may be some lingering rain and storms wednesday morning, but
then we end up in the dry slot of the next incoming system later in
the day. mild air then returns as temperatures quickly moderate back
into the 70s by thursday afternoon. the active weather pattern
continues with additional chances for rain on thursday as another
low pressure system lifts into the midwest and its attendant warm
front lifts across our area. more rain is possible next weekend too
as our active weather pattern looks to continue into early april.
&&
.aviation /06z tafs through 06z wednesday/...
issued at 219 am edt tue mar 31 2026
vfr conditions are expected at the terminals, with periods of
mvfr conditions possible later this afternoon into the overnight
hours as a cold front passes through. continued llws with warm
air advection/llj up to around 45-50 knots until morning.
southwest winds up to 25-30kts are expected through much of the
day, shifting west-northwest overnight and diminishing with
time. mvfr ceilings, potentially ifr, are possible as showers
and thunderstorms develop through the late afternoon/overnight
hours.
&&
.iwx watches/warnings/advisories...
in...none.
oh...none.
mi...none.
marine...small craft advisory until 2 pm edt wednesday for lmz043.
small craft advisory until 8 pm edt wednesday for lmz046.
&&
$$
update...fisher
discussion...johnson
aviation...mcd