030
FXUS63 KIND 051714
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
114 PM EDT Fri Jul 5 2024

.KEY MESSAGES...

- Chances for showers and thunderstorms this afternoon.
- Becoming partly cloudy this afternoon and mostly clear tonight.
- Rain chances return late Monday into Tuesday.

&&

.FORECAST UPDATE...

Radar was showing a dying MCS moving ENE across central Indiana.
Only weak surface based instability was in place over far south
central Indiana which has been keeping the convection sub-severe and
should continue to do so before it moves out Midday. Meanwhile, more
convection was lifting northeast across the upper Wabash Valley,
just ahead of a cold front, that extended from near a Chicago to
southeastern Missouri line. The cold front is expected to move to
extreme eastern sections of central Indiana by 18z this afternoon.
This should result in convection for the most part ending, although
CAMs suggest a few storms could still pop up ahead of the upper
trough. Regardless, drying soundings and upstream visible satellite
both support increasing sunshine which should allow temperatures to
recover to the lower and middle 80s.

Confidence in severe storms is non-zero but very low as the dying
MCS is getting closer to moving into northern Kentucky and Ohio.
Confidence in flooding is also low based on MRMS radar estimate
trends.

&&

.MESOSCALE UPDATE...
Issued at 1229 PM EDT Fri Jul 5 2024

Radar and lightning data was indicating the MCS remnants were well
east into southwestern Ohio midday. Otherwise, scattered convection
has developed over the Wabash Valley just ahead of an approaching
cold front. No lightning has been detected with these showers and
lightningcast procedure was not keying in on any imminent lightning
strikes. That said, RGB day convection satellite imagery hinted that
glaciation may be nearing and SPC mesoanalysis page was showing weak
instability was moving into this area from the west. Thus, expect a
few storms to fire up as we move into the afternoon. 30 to 35 knot
sfc-3km bulk shear and 40 to 50 knot 0-6km bulk shear along with
increasing instability suggests a few of these storms could produce
damaging winds this afternoon, mainly east of US-31 per the DAY1 SPC
Severe Weather Outlook Marginal Risk.

The cold front was running a little slow compared to previous progs.
It may now not exit east of the forecast area until after 4 PM. That
said, pops still look on target, so will not make any changes.
Breaks in the overcast may still allow temperatures to reach the 80s
but if these so not occur or last long, it may not quite reach the
forecasted highs.

&&

.SHORT TERM (Today and tonight)...
Issued at 240 AM EDT Fri Jul 5 2024

Surface analysis early this morning shows low pressure in place over
the upper Mississippi River Valley with a cold front extending south
across eastern IA, western IL to SE MO. A convective complex was
found over SE MO, ahead of the front and was showing signs of
warming tops.  Flow across Central Indiana was weak and
disorganized. Dew point depressions across the area were less than
2F and some areas of fog were developing.

Today...

Upper pattern today shows a broad upper trough in place across the
northern CONUS with a trough axis over western MN and western IA.
This trough axis is expected to push east to the Great Lakes and
toward Central Indiana today. The accompanying surface low will also
reach Michigan and drag a cool front across Central Indiana by late
afternoon. HRRR suggests best forcing will be the result of the
decaying convective complex over MO as is reaches Central Indiana
this morning and passes by this afternoon. This system will be
passing across Indiana during the diurnal minimum, thus
showers/storms will look to be more scattered in nature. Hence only
chance pops will be used.

By this afternoon the lower level flow becomes more westerly in the
wake of the front as forecast soundings start a trend of drying out.
Thus will try and contain pops to hours before 18Z.  Highs in the
lower and middle 80s are expected.

Tonight...

Broad troughing aloft looks to remain in place over the CONUS
tonight. However little to no forcing appears to push across Central
Indiana. Meanwhile within the lower levels high pressure over the
plains is expected to build eastward into the Ohio Valley. This
should lead to mostly clear skies and light winds overnight.
Forecast soundings support this with a dry column through the night.
Lows overnight in the lower to middle 60s will be expected.

&&

.LONG TERM (Saturday through Thursday)...
Issued at 240 AM EDT Fri Jul 5 2024

Saturday Through Tuesday.

A quiet and cool start  to the weekend is expected with zonal flow
aloft and light westerly winds expected for Saturday. Slightly drier
air will move into central Indiana after the rain comes to an end on
Friday with afternoon dewpoints around 60 with highs near 80. Dry
and quiet conditions will continue into Sunday with a gradually
warming trend going into early next week as the surface flow becomes
more southerly. Skies will remain mostly clear through Sunday night
before the pattern shifts going into Monday.

A broad trough will slowly exit the Central Plains late Monday into
Monday night with a broad area of light precipitation expected to
push into Indiana during the daytime hours on Tuesday. Models are
suggesting a localized area of convergence where higher
precipitation amounts are likely, but there remains quite a bit of
model spread as to where exactly that settles.  There is some model
clustering across the upper Wabash Valley for this axis, but it may
be as far north as the Chicago area or as far south as south central
Indiana. Instability will be the limiting factor keeping the severe
potential to near zero.

Wednesday and Thursday.

Forecast confidence then falls off Wednesday into Thursday in the
aftermath of the rain on Tuesday.  There is some signs that there
could be some residual precipitation along the stalled frontal
boundary but where that stalls remains very uncertain.  Weak
northwesterly flow aloft will help to keep temperatures mild,
especially if cloud cover sticks around longer than models currently
suggest.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 113 PM EDT Fri Jul 5 2024

Impacts:

- MVFR conditions in thunderstorms through 20z at KIND and KBMG

- MVFR/VFR ceilings through 01z

Discussion:

Visible satellite, radar, obs and Hi-Res soundings support bkn
afternoon diurnal VFR or brief MVFR cu as well as the potential of
MVFR flying conditions in thunderstorms through late afternoon over
mainly KIND and KBMG. Otherwise, high pressure will build in tonight
and combine with a dry column to support VFR conditions. Cu
development progs suggest more diurnal cu will form Saturday
afternoon.

Winds will be from the west less than 10 knots in the wake of a cold
front that was move across from west to east.

&&

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

$$

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