905
fxus63 kiwx 170934
afdiwx
area forecast discussion
national weather service northern indiana
534 am edt sun may 17 2026
.key messages...
- mainly dry, warm, and humid today.
- strong to severe storms possible on monday and tuesday with a slight
risk on both days. locally heavy rainfall and damaging wind
gusts are possible, primarily during the afternoon and evening
hours.
- cooler with much more seasonable temperatures and dry midweek.
&&
.discussion...
issued at 307 am edt sun may 17 2026
satellite and radar imagery shows strong to severe thunderstorms
persisting across parts of missouri, iowa, and illinois early this
morning, with high level clouds on the eastern fringes of this
complex drifting into our forecast area. a warm, humid, and mainly
dry day is ahead. as a stalled boundary surges northward into lower
michigan, a stray shower or thunderstorm is possible. however, as
confidence increases that much of the activity will bypass us to the
north and northeast, i have decreased pops to be 14% or less
throughout the day. as an area of low pressure lifts into the upper
midwest, a tightening pressure gradient will develop, allowing for
south winds to gust as high as 25 mph this afternoon. breezy
southerly winds will allow for continued strong waa into the
forecast area, with highs climbing into the mid 80s today. moisture
also continued to get pulled northward today, with dewpoints well
into the mid 60s today.
an active weather pattern develops monday and tuesday with several
opportunties for severe weather. an upper level trough digs across
the four corners region on monday, sending even stronger surges of
moisture and warmth into the upper great lakes region as a
connection to the gulf deepens. our forecast area will be well into
the warm sector on monday with highs in the mid to upper 80s and
dewpoints in the upper 60s to near 70 degrees. activity to our west
sunday night into monday morning will have to be closely monitored,
as this will be the impetus for severe weather in our forecast area
monday afternoon and evening. a prefrontal trough and several 500mb
shortwaves will provide a source of lift. models diverge on exactly
where and how much convection will hold together, but if it does, it
will be moving into a incredibly unstable environment. sbcape of
1500-2000 j/kg will be present alongside steepening low level lapse
rates. shear may be the limiting factor monday as forecast soundings
depict a unidirectional vertical wind profile. spc maintains a
slight risk (level 2 of 5) for severe weather across our northwest
half of the forecast area, with the risk decreasing to marginal
(level 1 of 5) further southeast. a linear storm mode is most likely
with damaging winds as the main threat. with pwats around 1.5", even
if storms are not severe, they will likely be heavy rain producers
with rain rates in excess of 1"/hr.
our forecast area will be in a favorable region for severe weather
again on tuesday afternoon and evening ahead of an incoming cold
front. forecast soundings depict a very similar environment to
monday, with sbcape of 1500-2000 j/kg during peak heating hours.
highs will once again be in the mid to upper 80s with the gulf
connection fueling dewpoints well into the 60s. with the cold front
as the source of lift, forecast soundings depict slightly better
helicity up to 200 m2/s2. at this point, all hazards are possible,
but with a mostly unidirectional wind profile again, damaging winds
appear the most likely threat.
post frontal passage, drier and much more seasonable conditions
arrive midweek. high pressure builds in on wednesday and thursday
across the great lakes region. highs will be in the 60s; while
seasonable, it will feel much cooler than the previous stretch of
warm and humid days.
&&
.aviation /06z tafs through 06z monday/...
issued at 532 am edt sun may 17 2026
no changes needed for the 12z tafs. a dry day is ahead with
prevailing vfr ceilings. scattered high clouds are moving
through on the eastern fringes of ongoing convection across
missouri, iowa, and illinois. this convection should bypass the
area well to northeast this morning as it lifts northward along
a stalled boundary. today will be dry and breezy; southerly
winds are expected to gust as high as 20 to 25 kts during peak
diurnal heating this afternoon.
&&
.iwx watches/warnings/advisories...
in...none.
oh...none.
mi...none.
marine...none.
&&
$$
discussion...johnson
aviation...johnson