533
FXUS63 KIND 072221
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
621 PM EDT Sun Jul 7 2024

.KEY MESSAGES...

- Mostly Clear Tonight

- Beryl will bring rain, heavy at times to central Indiana late
  Tuesday through Wednesday. Areal flooding will be possible within
  the heaviest rainfall axis.

&&

.SHORT TERM (This evening through Monday)...
Issued at 251 PM EDT Sun Jul 7 2024

Surface high pressure, over the eastern Great Lakes, was providing
subsidence and tranquil weather this afternoon. Meanwhile, visible
satellite and obs were indicating just scattered diurnal cu over the
sky. The abundant Summer sunshine has allowed temperatures to warm
into the lower and middle 80s. That said, the heat index has not
been a big issue with this relatively dry airmass. Meanwhile, the
weak pressure gradient is resulting in light southerly winds.

Tonight...

The diurnal cu will dissipate toward sunset and high pressure will
continue to influence the weather with a good radiational setup once
again tonight. A dry column per Hi-Res soundings along with light to
calm winds will allow temperatures to bottom out near afternoon dew
points, in the middle 60s.

Monday...

Surface high pressure, over the eastern Great Lakes, and a dry
column will once again result in benign weather through early
afternoon Monday. However, by afternoon, soundings are indicating
the column moistening ahead of an advancing upper Midwest trough.
Thus, expect an increase in cirrus and perhaps mid level clouds to
go along with diurnal cu. This could keep temperatures slightly
below the above normal model blend. In addition, would not rule out
some late day scattered convection over the upper Wabash Valley.
Instability progs support thunder chances there as well.

&&

.LONG TERM (Monday night through Sunday)...
Issued at 251 PM EDT Sun Jul 7 2024

Monday Night through Thursday...

The main concern through midweek will be heavy rain and potential
flooding associated with the remnants of Beryl. Currently, the
timing for the heaviest and most widespread rainfall will be Tuesday
night and Wednesday. The 12z GFS and ECMWF runs have diverged with
the Euro keeping the northwestern track of the low compared to the
now southeasterly GFS track. Both lie in the cone of the official
NHC forecast track but the preferred Euro is right down the middle
of the track. So, kept the heaviest rain axis over the upper Wabash
Valley with up to 1 to 3 inches in that area and around an inch
elsewhere. This is within reason of ensemble QPF viewed in DESI and
has trended slightly down. If the path shifts towards the GFS, so to
would the heaviest rain axis. Needless to say though, confidence in
exact timing and location of the most impactful rainfall is still
far from ideal but with potential frontogenetical banding, areas
within the axis of heaviest rainfall have the potential to receive
higher amounts than mentioned above. In the end, an areal Flood
Watch may be needed at some point for at least parts of central
Indiana. Meanwhile, OHRFC river ensembles were showing very few
members suggesting minor flooding later next week, so refrained from
an ESF.

In addition to the heavy rain and flooding threats, windy conditions
are also a concern with the remnants of Beryl. Raised the blend
winds in agreement with adjacent offices to cover that as the
official NHC forecast/ECMWF track across the upper Wabash Valley
would favor that. Due to the widespread cloud cover and rain,
temperatures will be below normal and no warmer than the lower 80s.

Thursday night through Sunday...

Broad high pressure will build in for the weekend even as a broad
trough lingers over the Ohio and Tennessee Valleys. Drying column
per soundings and subsidence is expected to provide decreasing cloud
cover and a return to above normal temperatures with lower 90s
possible by Sunday.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 621 PM EDT Sun Jul 7 2024

Impacts:

- None

Discussion:

Even as high pressure moves away to the east...surface ridging will
linger into Monday and maintain dry conditions across central
Indiana. Diurnal cu will diminish near sunset leaving skies mostly
clear with high cirrus passing through overnight. Cu is likely to
form again in the afternoon on Monday with a steady increase in mid
and high clouds by late day as tropical moisture ahead of Beryl
advects into the region from the southwest. Scattered convection may
impact KLAF by Monday evening with rain chances increasing late
Monday night into Tuesday from the west.

Light and variable winds overnight will become S/SW at 5-10kts on
Monday.

&&

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

&&

$$

SHORT TERM...MK
LONG TERM...MK
AVIATION...Ryan