061
FXUS63 KIND 080411
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1211 AM EDT Mon Jul 8 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.

&&

.FORECAST UPDATE...

Cu has largely diminished as we pass sunset with the eastern fringes
of a mid level cloud deck associated with a frontal boundary across
the Missouri Valley drifting across the northern Wabash Valley. 01Z
temperatures ranged from the mid 70s to the lower 80s.

The overall forecast for the rest of the night is in excellent
shape. While high pressure continues to move away to the east...
surface ridging will linger keeping skies mostly clear overnight.
The bulk of the mid level clouds will remain to the west although
may see that subtly expand into the region towards daybreak. Lows
tonight will fall into the mid 60s.

Zone and grid updates out.

&&

.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 (06Z TAF Issuance)...
Issued at 1209 AM EDT Mon Jul 8 2024

Impacts:

- VFR Conditions are expected this period.

Discussion:

Strong and large high pressure east of Indiana will continue to
control the weather across the TAF sites for one more day. Once
again diurnal CU will be expected this afternoon as convective
temperatures are reached. Due to the developing SW flow aloft, and
mid and upper moisture across the souther plains, some high cloud
cigs will be pushed across the TAF site through the day.

As the upper trough edges eastward, some isolated convection will be
possible within the Wabash Valley late in the afternoon. Confidence
is low for this, and for now a mention will not be included, but
this could be a chance in a later forecast should trends continue.

&&

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

$$

UPDATE...Ryan
SHORT TERM...MK
LONG TERM...MK
AVIATION...Puma