835
fxus63 kiwx 141825
afdiwx
area forecast discussion
national weather service northern indiana
225 pm edt thu may 14 2026
.key messages...
- periodic chances for showers and thunderstorms starts friday
and continues into tuesday or wednesday of next week.
- greatest chance for severe weather appears to be on monday
(slight risk), but we also already have a marginal risk of
severe weather for saturday.
- increasing warmth and humidity is forecast for between
saturday and tuesday. a 40% chance for highs of at least 80
degrees exists for areas south of us-30 on saturday and a high
chance (at least 80%) for 80 degree high temperatures exists
along and south of us-24 on tuesday. a majority of the area
surpasses 80 degrees on sunday and monday.
&&
.discussion...
issued at 216 pm edt thu may 14 2026
lower theta-e airmass pushes through the area today as surface high
pressure slides eastward. we were able to dip down into the mid to
upper 30s last night with the light winds and mostly clear skies.
850 mb temperatures warm from 0c this morning to 7c friday morning
and we have high clouds knocking on the door during the overnight,
which should allow a bit of a floor for temperatures above 40
degrees.
then, mid level ridging on the high`s tail and weak height falls
paired with low level moisture advection signify an attempt to
produce rain friday morning. the modest shortwave paired with this
activity is quickly through the area though and that rain should be
through the area by midday or the early afternoon.
a theta-e plume pushes into the area friday night and early saturday
morning and a shortwave arrives in the flow later friday night to
saturday morning with the potential to produce rain again. the nam
appears to be stronger with available shear for saturday morning
with 25 to 35 kts whereas the ecmwf and gfs appear to be closer to
20 to 30 kts. instability and moisture content increase during the
morning with dew points reaching 60f and mucape surpassing 1000
j/kg. there will also be pockets of better moisture in the low to
mid levels of the atmospheric column allowing for a heavy rain
potential. there is lift available with times of large scale ascent.
weak mbe vectors and boundary parallel flow may allow for
backbuilding or training. through the day, the heavy rain parameters
and moisture content appear to dry out some so even as the vectors
appear to zero each other out, heavy rain may be harder to come by
at all. perhaps there could also be some moisture loaded cores
dropping out to create marginally severe wind gusts. dcape increases
through the afternoon.
the biggest thing to worry about sunday is that a warm front moves
northward so instability moves into the area with 1000 to 2000 j/kg
of mucape and 20 to 30 kts of effective shear (highest near lk mi).
forcing will be the limiting factor of this, but if a lake breeze
can develop (may be unlikely given southeast sfc winds), perhaps
there`d be enough forcing to start some thunderstorms.
a much better moisture surge comes in for monday with sfc dew points
reaching the upper 60s to low 70s fahrenheit and a low level jet
filling across the area. in theory and in pattern recognition, this
would bring the best chance for severe weather between saturday and
tuesday, but shear is a limiting factor. we`ve got 1000+ j/kg of
mucape, but only the gfs introduces a pocket of 30 kts of effective
shear during the evening. so, we`ll have to use cell collisions and
boundary interactions to get necessary lift. an eml works in sunday
night into monday morning and that may also be able to help create
larger hail despite a lack of shear.
model differences emerge on tuesday as a wave ejects out of the
southwest. typical model biases show themselves with the ecmwf
taking longer to eject a wave out of the southwest and the gfs being
much faster with that evolution. the aigfs is closer to the ecmwf`s
speed. as a result of this difference, the gfs brings a cold front
through earlier tuesday, whereas the ecmwf holds on until wednesday
night. so, a tuesday or wednesday severe weather event is possible
with the cold frontal passage, but there still remains uncertainty
in timing it out.
&&
.aviation /18z tafs through 18z friday/...
issued at 130 pm edt thu may 14 2026
high pressure and dry air in the low levels will maintain vfr
conditions through the period. mid/upper level clouds will
steadily increase overnight into friday as high pressure exits
and return flow develops but anticipate dry/vfr conditions
through this forecast period.
&&
.iwx watches/warnings/advisories...
in...none.
oh...none.
mi...none.
marine...none.
&&
$$
discussion...roller
aviation...agd