Indiana’s Weather For Sunday

HEADLINES
– Sometimes smoky sunlight today. Less of a breeze. Nice!
– Northern Lights may be visible tonight.
– Above average temps return tomorrow.
– Muggy, with scattered storms by Wednesday.

TODAY’S MAP

NWS TECHNICAL DISCUSSION

A deep plume of subsidence has overspread much of the forecast area northeast
of the rapidly diminishing boundary extending from central Illinois across
the lower Wabash Valley and into Kentucky. A narrow axis of mid level clouds
accompanied the remnant boundary with clear skies elsewhere. Early morning
temperatures ranged from the 40s into the lower 50s.

We are welcoming June in a chilly way with lows expected in the 40s over
much of the forecast area by daybreak. With dewpoints as low as they are
and ideal radiational cooling conditions for all but the far southwest
counties...there is potential for a few of our normal cool spots to slip
below 40. This is guaranteed to be the coolest start to June in 22 years
at KIND when the morning low was 39 degrees on 6/1.

Other than the chilly start...quiet weather is anticipated through tonight
as the region remains firmly under the influence of high pressure and on the
back side of the east coast upper trough. The aforementioned boundary will
drift further southwest and wash out...taking the band of mid level clouds
with it and out of the forecast area later this morning. Subsidence will
gradually weaken through the day but dry air remains in abundance
through the column ensuring mostly clear skies through the period
with just some passing cirrus. Winds will be noticeably lighter
today as northerly winds generally remain at 10mph or less
becoming light easterly tonight as the high shifts east.

Temps...low level thermals support highs a few degrees warmer than Saturday
generally in the mid and upper 70s aided by the dry airmass which will be
easily warmed. Lows tonight will range from the upper 40s northeast to the
mid 50s in the lower Wabash Valley.

&&

.LONG TERM (Monday through Saturday)...
Issued at 227 AM EDT Sun Jun 1 2025

A surface high will slowly meander eastward Monday onward but largely remain
close enough to the Ohio Valley to keep broad subsidence over the region. This
will be further supported by a very elongated but strong ridge pushing in from
the west early in the week. Starting Monday, moderate 850-700mb WAA within
westerlies will alter the ongoing airmass, leading to the start of above normal
temperatures for central Indiana. This stretch of warmer weather will largely
continue through most of the week, albeit less amplified late week due to
greater cloud cover. The warmest day of the week is likely to be Tuesday as
the upper ridge axis nears and the surface high keeps skies clear; the afternoon
forecast high is currently 88 for Indianapolis. That said, Wednesday likely will
have the highest heat indices as highs remain in the upper 80s but with greater
surface dewpoints.

As midweek arrives, ensemble guidance has continued its strong variance, mostly
focused on the positions of a strong high pressure system over the SE CONUS. If
the high is able to maintain itself upstream of a few passing shortwaves, central
Indiana will likely remain mostly dry outside of some light showers until late
Thursday into Friday. On the other hand, if the surface high depletes and allows
greater moisture advection as it lifts eastward, central Indiana will likely see
multiple periods of rainfall Wednesday and Thursday. We will continue to monitor
trends and update the forecast as needed; in the mean time, probability guidance
is mostly split with a 50% chance of rainy stretches Wednesday afternoon through
Thursday night.

As mentioned by late Thursday, the continued push of upper level troughing from
the west will eventually break down the SE surface high, leading to an
increasingly rainy period. It is still too far out to pinpoint any specifics, but
in general expect multiple opportunities for rain and storms Thursday night
through early Saturday. As of this issuance, this is characterized by 20-40% PoPs
throughout this stretch, but the lower probabilities are more due to uncertainty
in timing than uncertainty on if rainfall will occur late next week.

Despite the low confidence near the tail end of the 7 day period, there continues
to be a semblance of similarities in the 8 to 14 day guidance with mostly weak
teleconnection patterns, but a strong AO. This should lead to
generally strong zonal upper level flow for the second week of
June. These summer patterns typically lead to mostly seasonal
temperatures, with periodic rain chances along shortwaves within
the zonal flow. Generally, these patterns tend to be more active
than typical, but will likely not have a large QPF footprint
within each wave.

NWS CHARTS FOR TODAY/TONIGHT