123
FXUS63 KIND 161349
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
949 AM EDT Thu Apr 16 2026

.KEY MESSAGES...

- Generally dry Thursday and Friday with low rain chances Thursday
afternoon

- Near record warm temperatures expected through Saturday with
  multiple days in the 80s and lows in the 60s

- Much cooler Sunday into early next week with the potential for
  frost

&&

.FORECAST UPDATE...
Issued at 949 AM EDT Thu Apr 16 2026

Remnants of a decaying MCS are currently passing through central
Indiana, with a majority of the moisture convergence confined to
north of I-70. This will lead to a brief 30-45min of rain for these
locations with total QPF of 0.25" or less. There are a few breaks in
the cloud just behind the moisture convergence due to weak mesoscale
subsidence, but otherwise, mostly cloudy skies will likely remain
through the late morning until some dry air advection arrives this
afternoon. With SW flow remaining behind this, temperatures should
remain mild, but with the diurnal curve slightly dampened beneath
the aforementioned clouds and latent heat fluxes. For this reason
highs are expected to be near 80 degrees this afternoon.

&&

.DISCUSSION (Today through Wednesday)...
Issued at 306 AM EDT Thu Apr 16 2026

Overview.

An active and progressive spring pattern remains firmly in place
across the Ohio Valley with a broad surface low currently over the
upper Great Lakes and a trailing boundary with embedded waves
extending south through the midwest. This whole system is embedded
within a broad southwesterly flow regime that is characterized by an
80-90 kt upper-level jet with a mid level jet streak across Illinois
this morning placing Indiana within an area of enhanced lift. Rain
associated with these waves pushes through the area early this
morning, giving way to a 36 hour break in the precipitation. While a
brief period of ridging will bring a temporary reprieve on Friday, a
strong cold front is expected to sweep through the region on
Saturday with additional showers and thunderstorms expected. This
transition will usher in a much cooler airmass for the early part of
next week, introducing potential frost concerns for the local area.

Today and Friday...

Latest satellite imagery clearly depicts a few waves along an
approaching boundary to the west. Satellite and radar imagery show a
complex of weak showers and a few storms near Lafayette with an
embedded meso-low. A secondary wave is on the heals of the first one
over Missouri with associated weak convection with it as well. Local
ACARs soundings show an environment conducive for rainfall locally,
especially for western Indiana... however weak lapse rates and
little instability will limit the overall severe threat this morning.
CAMs guidance shows these waves of precipitation pushing northeast
into Illinois and western Indiana through the early morning hours.
Lower confidence in rainfall chances along and east of the I-65
corridor as drier air and lack of instability have been resulting in
rapid weakening of any complex moving into the area. Overall, expect
clouds and showers to continue over portions of Central and Western
Indiana through daybreak, becoming more scattered in nature through
the late morning hours as everything weakens and gradually
dissapates with its eastward progression. Short term guidance shows
much drier air filtering in behind the boundary today with clouds
breaking up during the afternoon and evening hours. Overall, the
latter half of today may be fairly nice as incoming ridging and
clearing skies allows for a drying trend and highs potentially
reaching 80 degrees again.

Friday looks to be the warmest and driest as strong warm air
advection ahead of the next major trough pushes 850mb temperatures
toward the 90th percentile of climatology. Highs in the mid 80s are
probable, and record high minimums in the 60s are also at risk as a
humid airmass remains entrenched across the state.

Saturday through Wednesday...

Medium range models and ensembles have been consistent in showing a
significant pattern shift beginning on Saturday. A deep longwave
trough ejects out of the Rockies with a strong surface cold front
crossing Indiana late Friday night into the first half of Saturday.
While the dynamics associated with this next system would suggest a
slight risk for severe weather over Indiana, latest trends have sped
up the arrival of the front to the early morning hours Saturday.
Given the timing and lower instability during that time of day,
thunderstorms are still possible as the front pushes through, but
confidence is lower regarding the severe weather potential. Higher
confidence exists in a forecast calling for rain showers and largely
sub-severe storms late Friday night into the first half of Saturday
with a drying trend during the latter half of the day. This front is
fairly robust with strong cold air advection on the backside,
ushering in the aforementioned pattern change to a much cooler
regime.

A 1030mb surface high slides south from Central Canada behind the
front with much cooler air advecting southward into the Ohio
Valley.. Ensemble means indicate temperatures dropping 15-20 degrees
below normal for Sunday and Monday. Lows Sunday and Monday morning
are currently projected to be in the mid 30s to low 40s with a few
locations possibly dropping lower. The frost threat looks minimal
for Sunday morning as elevated winds should prevent temperatures
from dropping into frost territory. The main concern for frost
exists Monday morning as the center of the incoming high pressure
settles in over the lower Great Lakes and sets the stage for better
radiational cooling. Highest threat for frost appears to be along
and north of I-70 corridor outside of urban areas. If trends
continue, frost products may be needed late Sunday night into Monday
morning.

Going into next week, longer range guidance suggests a gradual
moderating trend by Tuesday and Wednesday as the high shifts east,
returning the region to a much warmer southwesterly flow pattern.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 149 AM EDT Thu Apr 16 2026

Impacts:

- Mainly VFR conditions this TAF period.
- Low chances for TSRA 06-09z, more likely around KHUF
- MVFR to IFR vsbys/cigs during any TSRA
- Wind shift to 250-280 deg today with gusts to 25 kts this afternoon

Discussion:

VFR conditions remain across the TAF sites this evening even as an
area of showers and isolated thunderstorms cross the IN/IL border.
Upstream observations indicate there is enough near surface dry air
to keep cloud bases above 5000ft agl during the rainfall. Still a
small chance at MVFR cigs under a heavier shower or storm early this
morning, however not mentioning it in the TAFs as the probability is
very low and there is low confidence in exactly when it may occur.
Best chance for reduced vsby from rain will be at KHUF and KLAF with
a lesser threat at KIND and KBMG as this entire complex of showers
and storms will rapidly weaken with eastward progression. Keeping
TSRA chances confined to KHUF as instability is rapidly waning as
well, keeping the threat for thunder along the IL/IN border. Will
update the TAFs as needed if the TSRA threat looks to persist
further east this morning.

Fairly light winds early this morning as a rather stable boundary
layer is preventing stronger winds from mixing down to the surface.
Upstream obs in Illinois indicate that KLAF may see a few higher
gusts to 20 kts as this area of rain moves through 06z-11z. Gusty
winds possible under any heavier shower at all sites early this
morning but these should be isolated. Winds shift from SSW to W
during the day today with gusts of 20-25 kts during the afternoon
hours as winds mix down to the surface. Expect winds to
significantly diminish toward and after sunset tonight become light
and variable out of the WNW to N.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

UPDATE...Updike
AVIATION...CM
DISCUSSION...CM