420
FXUS63 KIND 061746
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
146 PM EDT Thu Jun 6 2024

.KEY MESSAGES...

- Patchy fog this morning, breezy and drier today.

- Cooler, less humid Friday through Wednesday

- Rain chances early Saturday through Sunday and Wednesday.

&&

.FORECAST UPDATE...
Issued at 1004 AM EDT Thu Jun 6 2024

Only slight adjustments to current temperatures were needed as the
forecast is on track. Today will be less humid than yesterday as dew
points have dropped back to the upper 50s to low 60s. Still
expecting breezy winds this afternoon with gusts up to 25 to 30 mph
possible.

&&

.SHORT TERM (Today and tonight)...
Issued at 259 AM EDT Thu Jun 6 2024

A much more pleasant day is expected across central Indiana today in
the wake of the initial cold front passage last night, followed by a
secondary cold front today which will finally allow the humidity to
relent.

Some patchy dense fog has developed in mostly fog prone areas with
the lingering higher dewpoints and light winds. This will mix out in
typical diurnal fashion after sunrise, with the boundary layer
quickly deepening this morning. This will promote the development of
both some scattered to perhaps broken high based cumulus and also
breezy conditions, as the deep mixing promotes momentum transfer of
25+KT winds to the surface at times. Gusts to 30 MPH will be common
by afternoon, with a few higher gusts possible.

High temperatures should end up near numbers from yesterday, given
the ample mixing, decent insolation, and the lack of significant
cold air advection behind the initial front.

Tonight, skies will clear once the remaining cumulus dissipates,
though a bit of high cloud will be possible. This and steadily
dropping dewpoints will allow lows to drop into the mid 50s across
the area, perhaps even the low 50s in some spots. NBM numbers
appeared a bit too high and were nudged downward.

&&

.LONG TERM (Friday through Wednesday)...
Issued at 259 AM EDT Thu Jun 6 2024

Much better agreement is found in the models this morning as
compared to 24 hours ago.

Friday and Friday Night...

As expected, strong ridging aloft over the western CONUS looks to be
in place allowing for northwest flow aloft to stream across the
northern plains to the Ohio Valley. A deep upper low is expected to
be found over Ontario and Quebec. Models suggest forcing within the
flow aloft on Friday and Friday Night to remain well north of
Indiana, across the Great Lakes and southern Ontario flowing into
the low. Mid levels on Friday and Friday night show strong
subsidence in place, spilling across Indiana with the northwest flow
aloft. Meanwhile within the lower levels, strong high pressure over
the lower Mississippi Valley will provide mainly anti-cyclonic lower
level flow and west to northwest flow. Forecast soundings on Friday
and Friday night show a dry column with a steep mid level inversion
in place that should prevent CU development. Thus a mostly sunny day
and mostly clear night will be in store. Given our cooler NW flow,
highs in the middle 70s and lows around 60 will be expected.

Saturday and Sunday...

As the surface high to the south continues to drift east through the
deep south on Saturday, warm air advection is expected to begin.
Also, models suggest a weak wave of forcing arriving within the NW
flow aloft on Saturday morning. Forecast soundings trend toward
saturation at that time, however, deep saturation is never really
achieved as a cold front passes by Saturday night. Thus given these
features at least small chances pops will be needed through the day
as they pass. On Sunday, a secondary upper trough pivoting around
the upper low is expected to push across Indiana. A limiting factor
with this feature will be available moisture as mainly NW flow is in
place. However, given the forcing, forecast sounding show a period
in the late afternoon where saturation is sufficient for showers.
Thus many dry hours will be expected on Sunday, but chances will
still be needed late in the day as this upper wave passes. Again,
with the cooler northwest flow in place, highs in the lower to
middle 70s will be expected.

Monday through Tuesday...

Models no longer suggest an upper low swinging across Indiana on
Monday, but rather feature a  trough axis pivoting across the
eastern Great Lakes, associated with the stronger upper low to the
northeast. This feature has trended farther east since yesterday,
and much stronger ridging aloft is show to be developing across the
upper Midwest by Monday night, leading to subsidence across central
Indiana.  This upper ridging and a large associated surface high
pressure system should result in mainly dry weather and continued
cooler temps through Tuesday.

Wednesday...

Chances for precipitation appear to return on Wednesday as a weak
upper trough and surface low may pass across the southern Great
Lakes. Thus for now some small chance pops will be needed.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 145 PM EDT Thu Jun 6 2024

Impacts:

- Wind gusts 18-25KT from around 280 degrees through early overnight
hours

Discussion:

VFR conditions are expected through the period with primary concern
being gusts up to 25 kts this afternoon to evening and again at the
tomorrow afternoon. Wind direction will largely be from the NW with
sustained speeds from 7 to 13 kts.

Some diurnal Cu has formed this afternoon which is expected to
diminish after sunset. The cumulus will also dissipate in the
evening as is typical, with some high cloud overnight tonight.

&&

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

$$

UPDATE...KF
SHORT TERM...Nield
LONG TERM...Puma
AVIATION...KF