700
FXUS63 KIND 230154
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
954 PM EDT Thu May 22 2025

.KEY MESSAGES...

- Showers tapering off by early evening, skies clearing overnight...
  patchy fog possible late tonight into early Friday

- Below normal temperatures into next week, mainly highs in the 60s
  and lows 45-55 degrees

- Scattered showers south Sunday with better chances for rain Monday
  and Tuesday over the entire area

&&

.FORECAST UPDATE...
Issued at 953 PM EDT Thu May 22 2025

A few showers still linger this evening, mainly across far southern
sections of central Indiana. Forcing for these will continue to move
south out of the area. Adjusted PoPs as needed to reflect this, with
dry conditions all areas by midnight.

Some clearing has already occurred, but more clouds are moving south
toward the area. Skies will remain partly to mostly cloudy into the
early overnight, then drier air moving in will allow skies to become
mostly clear.

Cannot rule out some patchy fog in favored areas, especially south
where drier air will arrive last. Left this unchanged from the
previous forecast.

Low temperatures look good with just some minor tweaks made.

&&

.SHORT TERM (This evening through Friday)...
Issued at 300 PM EDT Thu May 22 2025

Recent early-spring type weather conditions will continue across
central Indiana into the beginning of the short term under the
southwest portion of the broad and slowly-departing upper trough.
A tail of embedded forcing has combined with the relatively damp
lower third of the troposphere to produce scattered to briefly
numerous rain showers from the Rockville to Seymour areas this
afternoon.  This sweet spot along a parent 100-mile wide swath from
northern Illinois to the Ohio-Kentucky border...will continue to
stretch across most of the local region into the early
evening...with showers continuing to track from WNW to ESE as the
weakly-organized assemblage decreases in coverage while slowly
sliding south.

Conditions to overall improve tonight as the upper trough lingers
from the Great Lakes to the Northeast, yet its geometry morphs over
the CWA...to a more zonal pattern that will allow surface high
pressure axis to shift into the Middle Mississippi Valley and
Kentucky.  Ridging will build into the region, turning off showers
for most counties early this evening...breaking stratus decks by
late evening, and scattering clouds into the overnight.  Timing of
this cloud decrease coupled with diminishing northwesterly/CAA
winds...will promote fog formation in low-lying areas, especially
along the Wabash Valley and southwestern to southern zones. Readings
should bottom-out in the low 40s for most spots, with generally mid-
40s around Bloomington, Terre Haute and to the southwest.

The workweek will end on a brighter, yet continued cool/breezy note
as Canadian high pressure slowly crosses the realm Friday.  Abundant
morning sun will give way to a partly cloudy, yet bright afternoon.
Moderate breezes will be the rule through the midday and afternoon
with west-northwest gusts to 15-20 mph holding readings to mainly
mid to upper 60s despite the strong late May sun.

&&

.LONG TERM (Friday night through Thursday)...
Issued at 300 PM EDT Thu May 22 2025

The upper low present currently over the Great Lakes will wobble
into New England by Saturday but an overall broad northwest flow
aloft will persist across the region for much of the weekend before
subtle ridging develops on Monday. This will be short lived as a
trailing longwave upper trough extending from the Canadian Maritimes
west into the northern Plains will eventually pivot south into the
region by the middle of next week. This will trend towards a
continued cool regime across the Ohio Valley well into next week
with periodic chances for rain as well...especially early next week.

Friday Night through Sunday Night

The departure of the upper low currently over the Great Lakes will
finally take the rain and thicker cloud cover with it...replaced
with surface ridging poised to persist over most of the area through
Sunday. There will be a gradual increase in sunshine on Friday which
will parlay into increasingly clearing skies Friday night with the
brisk winds of the last few days finally relaxing. This will allow
for another chilly night for central Indiana with low to mid 40s
over much of the area.

Saturday may well be the nicest day of the upcoming extended weekend
with the most sunshine we have seen since several days ago and
lighter northerly winds. Model soundings do show a favorable setup
for scattered diurnal cu formation but highs in the mid and upper
60s are anticipated. Lows will be slightly warmer Saturday night
ranging from the mid 40s to lower 50s northeast to southwest as
clouds increase from the west.

The increasing clouds are courtesy of subtle waves aloft riding from
the northern Plains within the northwest flow pattern interacting
with low level moisture and a warm front that will eventually nudge
into the lower Ohio Valley by Sunday. Model trends over the last day
or so have been to shift the axis of showers setting up with this
system further to the southwest across the region and heavily
influenced by surface high pressure lingering over the Great Lakes.
While scattered showers will likely be present Sunday...confidence
continues to grow in them focusing primarily across southern
portions of the forecast area and south of the Indy metro. Will
continue very low pops for Indy and points north to account for any
late model wobbling but there is strong potential for a dry and
predominantly cloudy afternoon in those areas with highs in the mid
and upper 60s. Clouds will linger into Sunday night.

Monday into Thursday

As mentioned above ridging aloft will briefly establish Monday
while at the same time...surface high pressure will drift off to the
northeast. Low pressure will ride along the warm front located over
the Ohio Valley and provide perhaps the best opportunity for more
widespread rain and embedded thunderstorms Monday afternoon into
early Tuesday. The focus for greatest convective coverage will again
be over southern counties in closest proximity to the warm front and
track of the surface low.

Beyond Tuesday morning...the forecast becomes increasingly
convoluted as quasi zonal flow gradually returns to an upper trough
over the region as the week progresses. Timing individual waves
aloft is challenging at this stage but a continuation of the cool
and mainly cloudy pattern likely will persist into Wednesday with
increasing sunshine thereafter. Low level thermals maintain highs in
the 60s through Tuesday with slow improvement into the lower 70s by
the tail end of the 7 day period.

Should the forecast pan out with highs remaining below 70 through
Tuesday here at Indy...this would mark a consecutive string of 8
straight days of sub-70 degree weather extending back to this past
Tuesday 5/20. The last time Indianapolis experienced this for such a
long period of time this late in the Spring was from 5/25 to 6/2 in
1889. The search for a return to more persistent warmth likely is
still 7-8 days out and possibly beyond with 80s likely to return by
early in the week of June 2.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 657 PM EDT Thu May 22 2025

Impacts:

- Isolated showers possible very early in period
- MVFR visibility possible in fog near KLAF/KHUF/KBMG late tonight

Discussion:

Isolated showers will linger very early in the period, mainly at the
southern sites. With loss of heating, expect cloud cover to diminish
gradually tonight. Ceilings should remain VFR. More
cumulus/stratocumulus will develop on Friday, but again VFR
conditions are expected then.

Will keep the fog mention at all but KIND late tonight given lower
winds and some at least partial clearing. Confidence in the
specifics though remains no higher than medium.


&&

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

$$

UPDATE...50
SHORT TERM...AGM
LONG TERM...Ryan
AVIATION...50