660
FXUS63 KIND 280525
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
125 AM EDT Tue May 28 2024

.KEY MESSAGES...

- Partly cloudy and cooler Tonight and Tuesday

- Dry and Seasonable Thursday and Friday, Rain chances late Saturday
  into Sunday

&&

.FORECAST UPDATE...
Issued at 936 PM EDT Mon May 27 2024

Radar was showing a couple of strong to severe thunderstorms moving
southeast across Illinois from just southwest of Aurora to just
southeast of Peoria. That said, downstream instability is very weak
to non-existent. So, think this convection will run out of steam
around or shortly after moving into the Wabash Valley. This
convection was aided along by an upper wave over SW Wisconsin and NW
Illinois embedded in the broad cyclonic flow. With instability
lacking and sunset at hand, will only keep small PoPs in across the
upper Wabash Valley and only through Midnight.

Otherwise, upstream obs, GOES-16 IR satellite and soundings are
supportive of some patches of mid and high clouds with otherwise
breaks in the cloud cover. Winds will also drop off and allow for
decent cooling and overnight lows should approach upstream dew point
temperatures in the 50s.

&&

.SHORT TERM (This evening through Tuesday)...
Issued at 234 PM EDT Mon May 27 2024

Synopsis:

Surface analysis early this afternoon shows low pressure northeast
of Lake Huron. This system was providing cyclonic lower level flow
across the Great Lakes and central Indiana. A weak trough pivoting
around the low was found entering Ohio, and a second weak trough was
found over northern IL. GOES16 imagery shows a stratocu deck in the
wake of the trough across most of Central Indiana. Aloft, water
vapor shows an upper trough over Michigan extending south across
eastern Indiana. Another upper low was found over Minnesota.
Subsidence was shown over Indiana and Illinois and Ohio. Dew points
have fallen to the middle 50s and cooler westerly flow was in place.

Tonight -

Models suggest that tonight the upper low near Lake Huron will push
east and away from Central Indiana. However the other upper low over
MN will also push east, pushing another upper trough axis across MI
and Indiana overnight. Moisture for this next system will be limited
as subsidence that has been occurring through the day along with the
prevailing west to northwest lower level flow. Forecast soundings
are showing a relatively dry column through the night, so mainly
some passing high clouds will be mainly expected. With cooler
northwest flow in place, lows in the mid 50s will be expected

Tuesday -

The upper flow will remain cyclonic across the Great Lakes and Ohio
valley on Tuesday as strong ridging builds aloft over Rockies and
high plains. An embedded short wave looks to pass within this
cyclonic flow aloft through the afternoon, but once again, moisture
remains lacking. Forecast soundings fail to show deep saturation,
but do hint at CU deck development in the late afternoon. An
inversion aloft will prevent any deep growth. Thus expect mainly
partly cloudy sky through the course of the day, as Indiana will lie
between departing surface low pressure and approaching high
pressure. An isolated afternoon shower or sprinkle cannot be ruled
out in the late afternoon. Any amounts will be very light and
isolated, mainly across the north and east parts of central Indiana
during the late afternoon and early evening. Overall there will be
many dry hours. Cold air advection will still be ongoing, although
it will be rather weak. Look for highs in the lower to middle 70s.

&&

.LONG TERM (Tuesday night through Monday)...
Issued at 234 PM EDT Mon May 27 2024

Wednesday and Thursday...

The broad upper trough that was in place for the early half of the
week begins to push east with one final shortwave moving across the
area Wednesday. Steep low level lapse rates and very limited
instability combined with a cold front moving in from the NE should
allow for some afternoon showers to develop. Any thunder chances
would be limited and mainly focused along the IN/OH border. A
secondary shortwave moves over the eastern Great Lakes on Thursday
keeping conditions on the cooler side with winds remaining out of
the NE/E. Highs on both Wednesday and Thursday should stay in the
lower 70s for much of the area with the exception of the far
southern portions of the area where mid 70s are possible. Overnight
lows may drop into the lower 50s to upper 40s with clear skies,
light winds, dewpoints in the lower 40s, which will setup some good
radiational cooling.

Friday through Sunday...

High pressure over the area on Friday will keep skies clear and
temps near normal. Upper level ridging over far southern TX and into
northern Mexico will allow for a fairly wavy zonal flow pattern over
the central US as we head into the weekend and into the following
week. Increasing return flow off of the Gulf of Mexico will bring
upper 60 to lower 70 degree dewpoints back to the region this
weekend with highs gradually warming into the 80s by Sunday. A
shortwave moving out of the Rockies will push into the Ohio
Valley/Great Lakes region on Saturday but there remains a lot of
spread amongst ensemble members on the timing of any precipitation
into central IN. Expect increasing rain chances Saturday evening
through Sunday as the shortwave moves through. Lapse rates aloft
and wind shear aren`t overly impressive and the position of the
potential surface wave would suggest general thunderstorm
potential for the weekend.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 124 AM EDT Tue May 28 2024

Impacts:

- Predominately VFR conditions expected through the period

- Low chance for an isolated light shower near IND/HUF over the next
  few hours

- Better chance for showers and storms after 22Z today, mainly near
  LAF/IND

Discussion:

Predominately VFR conditions are expected through the period. An
isolated light shower cannot be ruled out near IND/HUF over the next
few hours. A better chance for showers and storms is expected after
22Z today when an upper wave moves into the area. Gusty winds and
brief MVFR or worse conditions will be possible in any heavy showers
or storms.

Winds will be relatively light and out of the west through daybreak.
By mid-late morning mixing allows for winds to increase and become
northwesterly. Occasional gusts around 18-21 kts are possible this
afternoon. These gusts are not expected to remain consistent enough
to warrant a TAF for any sites other than IND.

&&

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

$$

UPDATE...MK
SHORT TERM...Puma
LONG TERM...Stumpf
AVIATION...Melo