Brownsburg, Indiana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

834
FXUS63 KIND 041048
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
648 AM EDT Mon May 4 2026

.KEY MESSAGES...

- Much Warmer Today. Chances for showers and thunderstorms today,
  especially across southern Central Indiana.

- Cooler and rainy on Tuesday.

- Largely below normal this upcoming week, with multiple chances for
  rain; heavy rain possible at times.

&&

.DISCUSSION (Today through Sunday)...
Issued at 240 AM EDT Mon May 4 2026

Surface analysis early this morning shows strong high pressure in
place across the southeastern states and FL. Deep low pressure was
found over western Ontario. These two systems were combining to
allow a mild southerly surface flow. Aloft, water vapor continued to
show mainly NW flow in place across the upper midwest spilling down
into Indiana. That flow was due to a deep upper low over Hudson Bay.
Beneath that flow was a plume of Pacific moisture streaming across
the Plains to KY and TN. Radar shows some storms developing on the
northern edge of this plume over southern IL, while subsidence
remained in place across Central Indiana.

Today and tonight...

Central Indiana will spend today and tonight within the warm sector
as a weak upper short wave passes across Indiana within the flow
aloft this afternoon. Warm air advection will be ongoing and the
short wave should be able to tap the Pacific upper moisture that are
resulting in some shra/tsra at that moment. Forecast soundings this
afternoon suggest a favorable set-up for convection, showing deep
saturation by mid afternoon. HRRR suggests scattered showers and
isolated thunderstorms moving across Central Indiana, especially
southern central Indiana, this afternoon as the forcing from the
passing wave passes. Thus will trend pops a bit higher this
afternoon across most of the southern 2/3rds of the forecast area.
Ongoing warm air advection today should allow highs to reach the low
to middle 70s with good mixing in play along with wind gusts to
around 25-30 mph.

This evening, heating will be lost along with forcing as the short
wave exits to the east. Little change will occur with the airmass,
as winds will remain southerly through the night and a cold front
begins to advance from the northwest. Lows tonight should be in the
mid 50s.

Tuesday and Tuesday Night...

Higher confidence for more rain and cooler weather on Tuesday. A
cold front will be slowly crossing Central Indiana through the
course of the day starting in the northwest in the before reaching
the southeast parts of Indiana by late afternoon. Forecast soundings
during this time shows favorable column for convection. Models hint
at overnight convection over the plains reaching Cenilder but
still ltral Indiana by the afternoon. Thus with plenty of
ingredients available, high pops will be used on Tuesday and
Tuesday evening as these features pass. Brief heavy rain will be
possible as pwats over 1 inch are expected. With clouds and rain
expected on Tuesday, will trend highs only toward the upper 50s
and lower 60s.

Wednesday and Wednesday Night...

A secondary short wave looks to pass on Wednesday as the nearly
zonal flow remains in place. GFS continues to suggest a stream of
mid level moisture available, streaming across Central Indiana while
the ECMWF is a bit less aggressive. Within the lower levels,
Tuesday`s cold front will be well east of Indiana as the day
progresses and high pressure is suggested to be building from the
northwest with cooler northerly winds in place across Central
Indiana. Forecast soundings suggest subsidence through the day. Thus
confidence here is low and and will use some pops for the time
being.

Thursday through Sunday...

Overall upper pattern remains unchanged during this period. Models
suggest the predominate upper low remaining over eastern Canada,
keeping the continued cyclonic flow in place aloft over much of the
eastern 1/2 of the country including Indiana. This will keep a
steady stream of below normal temperatures in place across Indiana
from Thursday through the weekend. Meanwhile at the surface, a
series of weak highs and lows will look to pass. High pressure is
expected to push across the area on THursday, before a weak trough
passes on Friday. Another high arrives for Saturday followed by a
slightly more organized low on Sunday. Given the cyclonic flow in
place aloft, and forecast soundings suggest cold air aloft with
steep lapse rates available each day, daily convection cannot be
ruled out and for the moment, additional support appears available
on Friday and Sunday. Thus daily chances for rain will be expected
in the forecast, however, this will be mainly due to daily diurnal
chances and the passing of the trough and low on Friday and Sunday
respectively. Overall, high confidence periodic showers during this
period, but low confidence on specific timing.

Given the cool, NW flow, temperatures will remain at or below
seasonal normals.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 647 AM EDT Mon May 4 2026

Impacts:

- Scattered showers and storms from 17Z-23Z at all sites
- Gusty SW winds late this morning through the afternoon
- Additional thunderstorms arriving from NW to SE after 02Z
- Low MVFR to IFR ceilings late tonight and tomorrow

Discussion:

A few showers will be possible this morning at KBMG, but otherwise
TAF sites should remain dry through 15Z. Moisture will lift
northward late this morning through the afternoon, providing chances
for scattered showers and storms mainly between 17-23Z. CIGs should
remain above 3000ft within showers/storms, but a brief reduction to
MVFR is possible.

Overnight, additional showers and thunderstorms will develop over IL
and push to the east over all TAF sites. Coverage is expected to be
greater overnight, with CIGs dropping to low MVFR and potentially IFR
by dawn tomorrow morning.

SW winds will increase throughout the day, with frequent gusts to
26kt this afternoon and evening. Winds will likely be more variable
within showers and storms.

&&

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

$$

AVIATION...Updike
DISCUSSION...Puma