034
FXUS63 KIND 271642
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1242 PM EDT Mon May 27 2024

.KEY MESSAGES...

- Gusty winds today and slightly cooler

- Isolated showers possible this evening

- Shower chances and cooler temperatures Tuesday-Wednesday, A few
thunderstorms possible Tuesday with gusty winds

- Dry and Seasonable Thursday and Friday, Rain chances late Saturday
  into Sunday

&&

.FORECAST UPDATE...
Issued at 922 AM EDT Mon May 27 2024

- An Isolated shower possible this afternoon; Otherwise partly
  sunny; Cooler

Surface analysis late this morning shows low pressure over MI and
Lake Huron. This system was providing cyclonic lower level flow to
central Indiana. A weak trough pivoting around the low was found
across Indiana, and a second weak trough was found over Wisconsin.
GOES16 imagery shows a stratocu deck in the wake of the trough
pushing through northwest Central Indiana. Aloft, water vapor shows
an upper trough over Michigan extending south across eastern
Indiana. Another upper low was found over the Dakotas. Subsidence
was shown over Indiana and Illinois.

This afternoon the cyclonic flow is expected to remain across
Central Indiana. Forecast soundings fail to show much in the way of
CU development. HRRR depicts a few diurnal showers possible by mid
to late afternoon within the cyclonic flow mainly across northern
and eastern parts of our forecast area. Coverage of this appears
rather limited and quite light. Also with ongoing cold air advection
and the advancing stratocu deck, heating may be limited somewhat.
Thus will trend to partly sunny skies and only 20 pops for some very
light showers possible mainly north and east from mid afternoon to
early evening.  Afternoon highs should be mainly in the low to mid
70s. Ongoing forecast handles that well.

&&

.SHORT TERM (Today and tonight)...
Issued at 301 AM EDT Mon May 27 2024

Departing shortwave trough and attendant front will bring a slightly
cooler and drier air mass today. MSLP gradient will support breezy
northwest winds, and mixing into stronger winds aloft will create
gusts up to around 30 mph during the afternoon. Residual low-level
moisture will result scattered to broken sky coverage from stratus.

A midlevel low is evident in water vapor over the Dakotas and will
approach tomorrow. So, after a period of subsidence behind the
departing trough, as is evident in forecast soundings, this may be
rectified enough with midlevel cooling/ascent from the upstream
trough for some isolated diurnal convection. This is most likely to
our northwest over Illinois, but toward the end of the diurnal
convective cycle (early evening) could move into Indiana in a
weakening state. By then, with mixing subsiding and convective
intensity decreasing, locally enhanced strong gusts are less likely
than over Illinois, but can`t be completely ruled out. Diurnal
convection should diminish after sunset, as well as wind gusts.

&&

.LONG TERM (Tuesday through Sunday)...
Issued at 301 AM EDT Mon May 27 2024

Tuesday through Wednesday...

Broad upper troughing will remain across the eastern CONUS early in
the extended with multiple shortwaves moving across the region. This
will keep low rain chances in the forecast at times. Moisture return
should remain limited ahead of these disturbances as a cold front
settles across the southeast so look for QPF amounts to be light.
The first shortwave should be exiting to start the day Tuesday. The
best forcing should be east of the area with no precipitation
expected.

A better chance for precipitation is likely towards the late
afternoon and continuing into the early overnight hours as another
shortwave approaches. The best chance for rain will be north of the
I-74 corridor where stronger forcing should be in place. Subtle
moisture return and daytime heating will likely provide sufficient
instability for a few storms. In addition, steep low-level lapse
rates suggest gusty winds are going to be possible in convection.
Severe weather is not expected due to a lack of sufficient deep-
layer shear or instability. A cold front associated with this system
will move through overnight into Wednesday providing a brief
cooldown mid-late week.

Ensemble guidance is in good agreement that surface high pressure
begins to build in Wednesday providing quiet weather conditions for
much of central IN. However, low rain chances remain over east
portions of the area as the aforementioned shortwave will still be
centered over Ohio.

Thursday onward...

Upper ridging and surface high pressure will likely provide quiet
weather conditions for Thursday through early Saturday. Surface high
pressure then begins to slide east late Saturday with the weather
pattern possibly becoming more unsettled as an upper trough moves
into the region. Other than the brief cooldown midweek, temperatures
are expected to generally remain near seasonal through the extended.
Lows are expected to fall into the 40s both Thursday and Friday
morning for much of central IN.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1241 PM EDT Mon May 27 2024

Impacts:

- VFR Conditions expected this TAF period.

Discussion:

Low pressure north of Central Indiana will continue to provide
cyclonic flow across the TAF sites during this TAF period. GOES16
shows a stratocu field over the TAF sites in the wake of surface
trough pivoting around the low. These clouds were transitioning from
MVFR Cigs to VFR due to weak daytime heating.

The low pressure system to the north will slowly push northeast
while a surface high pressure over the plains slowly begins to nudge
toward Central Indiana. This will lead to clearing skies this
evening as diurnal heating is lost. Forecast soundings also trend
toward a dry column, indicative of VFR conditions.

High pressure will be building across Central Indiana on Tuesday.
Forecast soundings hint at some sct CU by midday as convective
temperatures are approached.

&&

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

$$

UPDATE...Puma
SHORT TERM...BRB
LONG TERM...Melo
AVIATION...Puma