912
FXUS63 KIND 101013
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
613 AM EDT Fri May 10 2024

.KEY MESSAGES...

- Isolated showers/sprinkles possible today
- Rain returns tonight, dry and breezy Saturday
- Showers and storms return Monday into Monday night
- Near normal temperatures for next week

&&

.SHORT TERM (Today and tonight)...
Issued at 243 AM EDT Fri May 10 2024

Noticeably cooler air has advected into central Indiana early this
morning as the cold front has shifted off to the south. Still seeing
plenty of low stratus persisting across much of the forecast area
and as the upper trough axis pivots through...light showers continue
to linger across northeast counties but coverage was diminishing.
06Z temperatures were generally in the 50s.

The passage of the cold front late Thursday has finally shifted the
warmer and more humid airmass well south of the area...with a
transition to a cooler regime aided by a broad upper level trough
positioned over the Great Lakes and northwest flow aloft. A quick
moving wave aloft traversing through the broad trough tonight in
tandem with a surface frontal boundary will bring a chance for
showers during the predawn hours Saturday.

Drier air continues to gradually expand into the forecast area from
the north and that will lead to a continued decrease in coverage to
the light rain showers over the next couple hours. Stratus however
is likely to remain in abundance through daybreak over much of the
forecast area as moisture remains trapped beneath a boundary layer
inversion. Model soundings show that not giving way until later this
morning as the progressively drier airmass advecting into the area
slowly infiltrates the boundary layer. Expect increasing sunshine
through late morning and midday as a result but a healthy cu field
will develop for the afternoon as lapse rates steepen beneath colder
air in the mid levels. Model soundings show dry adiabatic conditions
up through nearly 700mb by mid to late afternoon which might be just
enough to generate a few very light showers with the subtle forcing
present in the mid levels. Any light showers that do develop will be
isolated and diminish quickly towards sunset with the loss of
heating.

Quiet weather this evening as the Ohio Valley remains under the
influence of weak surface ridging. The ridge will shift east tonight
as a quick moving front dives southeast in tandem with a wave aloft
poised to reinforced the upper trough over the region. Short range
ensemble guidance remains consistent with a band of showers along
the boundary moving across the northeast half of the forecast area
in particular after 06Z through shortly after daybreak Saturday.
Rainfall amounts will be generally a tenth of an inch or less with
the precipitation late tonight. While winds will drop off and become
light and variable this evening and into the overnight...there is
potential for a burst of wind gusts to near 25mph as the front
passes late.

Temps...breezy northerly flow today will keep temperatures below
normal with low level thermals supportive of mid and upper 60s
across the forecast area. Temperatures tonight will fall into the
low and mid 50s.

&&

.LONG TERM (Saturday through Thursday)...
Issued at 243 AM EDT Fri May 10 2024

The Ohio Valley and Great Lakes will remain under the influence of
the upper trough to begin the weekend with cool northwest flow. A
quasi-zonal pattern will develop by early next week with a slow
moving cutoff upper level low set to bring another round of wet and
unsettled weather for the first half of next week. After a brief
respite...another system will approach towards the end of the 7 day
with another chance for rain. While there will be threats of rain
throughout the extended...it will be especially quieter than the
active and stormy regime experienced over much of the central U S
east into the Ohio and Tennessee Valleys over the last few days.
With the subtropical jet displaced well to our south throughout the
extended...severe weather is not expected and the lack of
appreciable instability will keep even the threat for thunderstorms
limited through much of next week.

Saturday through Sunday Night

In the wake of the frontal passage early Saturday...strong cold
advection within the cyclonic flow aloft will make for a windy
Saturday aided by a tight pressure gradient between the departing
front and an approaching high pressure. Peak gusts Saturday
afternoon could be near if not in excess of 30mph at times. Model
soundings again show a well mixed boundary layer developing through
the course of the day with steep lapse rates present up to near
700mb. This will aid in cu development within the cold advection
regime again during the afternoon but the lack of any substantial
moisture should mitigate most concerns for isolated showers to
mainly eastern counties into the early afternoon.

High pressure will then build in late Saturday and hold serve for
the rest of the weekend as the upper trough finally pulls away to
the east and is replaced by ridging aloft. Skies will clear for
Saturday night with chilly temps falling into the mid and upper 40s
over much of the area. With the high overhead...a fantastic Sunday
is on the docket with abundant sunshine and temperatures recovering
into the 70s across the forecast area. Mid and high clouds will
begin to increase Sunday night as the aforementioned cutoff upper
low and associated surface wave approach from the west. May begin to
see a few showers slip into the lower Wabash Valley prior to 12Z
Monday but generally expect dry conditions to persist all night.

Monday through Tuesday Night

The upper low and associated surface wave will be over eastern
Kansas Monday morning...and will track slowly east on a wobbly track
through the Missouri...mid Mississippi and Ohio Valleys through
early Wednesday. Showers will gradually increase in coverage
throughout the day Monday with the best chances for rain to come
Monday night into Tuesday with the surface low over the region.
Instability will remain weak throughout much of the period with
abundant cloud cover limiting heating. CAPE values are a bit better
on Tuesday in the immediate vicinity of the surface low but expect
thunderstorms to be scattered at best.

Model soundings show precip water values rising to between 1.25 and
1.50 inches late Monday night into Tuesday with deep moisture
present throughout the depth of the column. The setup supports the
potential for pockets of heavy rainfall...particularly on Tuesday
with any slow moving convection. Expect up to an inch for much of
the forecast area by Tuesday night with locally higher amounts
possible. After mid and upper 70s for highs Monday...temperatures
will be held down slightly by rain and clouds on Tuesday with most
areas remaining between 70 and 75.

Wednesday through Thursday

The upper low will weaken and eventually become absorbed by the mean
flow aloft as it moves away from the region on Wednesday. Ridging
aloft will build in and should enable a quiet midweek with
temperatures warming back up into the mid and upper 70s under dry
conditions and sunshine returning. A surface low with an associated
frontal boundary will approach the Ohio Valley for late week but
rain and storms should hold off across central Indiana until
Thursday night continuing into Friday.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 613 AM EDT Fri May 10 2024

Impacts:

- Northwesterly wind gusts to 25kts tomorrow

Discussion:

Cigs have improved to VFR across central Indiana but some lingering
low vsbys at LAF should improve to VFR at or around 12Z. Ceilings
should then be around 050-060 through the day today with a sprinkle
or two in the afternoon with no impacts to vsbys expected. Skies
will further clear overnight tonight with northwesterly wind gusts
to 25kts expected late tomorrow morning into the afternoon.

&&

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

$$

SHORT TERM...Ryan
LONG TERM...Ryan
AVIATION...White