642
FXUS63 KIND 191900
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
300 PM EDT Sat Oct 19 2024

.KEY MESSAGES...

- Dry weather with warm daytime temperatures will continue through
  next Wednesday

- Thursday-Friday...transition to seasonably cool conditions, albeit
  mainly dry

&&

.SHORT TERM (This evening through Sunday)...
Issued at 259 PM EDT Sat Oct 19 2024

Temperatures have rebounded nicely into the upper 60s this afternoon
under full sunshine courtesy of surface and upper ridging from New
England to the southern states along with a bone dry column per Hi-
Res and ACARS soundings. Although the RH has fallen to around 30% at
most locations and fuel moisture was closing in on 8%, very light 20
foot winds will keep wildfire spread from being a concern.

Although, the upper ridge will flatten over the Great Lakes and Ohio
Valley late today ahead of a closed low over the Southwest, the
surface ridge will remain strong over central Indiana and with a
continued very dry column, look for the clear skies to continue. Fog
will not be a concern with how dry the boundary layer is. With light
winds below the 3.500 mixing height, will not need to lower NBM dew
point outputs the remainder of the afternoon or Sunday afternoon,
due to limited mixing potential.

With a prime radiational cooling setup tonight and how things played
out with this air mass night this previous overnight, plan on
cutting a few degrees off overnight via a slightly modified
NBM25 percentile with lows tonight in the middle 30s to lower 40s.
The dry air mass has also allowed temperatures to exceed most
guidance the past few days, so will lean towards the max DESI grand
ensemble 2m temperatures with highs well above normal in the middle
70s on Sunday. These temperatures are around 10 degrees above normal
for this time of year.

&&

.LONG TERM (Sunday night through Saturday)...
Issued at 259 PM EDT Sat Oct 19 2024

Mainly dry conditions will oversee a trend from above normal to near
normal temperatures next week as the seasonably strong autumnal jet
stream quietly trends from southern Canada to around the US border.

The overall pattern through Wednesday will find a zonal ridge
occupying at least the eastern half of the CONUS while the broad
surface reflection`s axis is maintained along the Appalachians.
Resultant conditions for central Indiana will be warm afternoons
into the 70s courtesy generally light southerly breezes...while cool
overnights trend from slightly to well above normal.  Abundant early
week sunshine will lead to scattered clouds and probably moderate
breezes Tuesday as a moisture-starved short wave crosses the
southern Great Lakes.

The Wednesday timeframe is expected to bring transition to the
Midwest when a more impressive and broader upper trough plunges
south out of Canada before advancing east through the Great Lakes.
This will drag a cold front across Indiana and replace the upper
pattern with a more zonal and somewhat stronger west-northwesterly
flow. Lower heights amid Canadian high pressure will bring a
seasonably cool end to the work week...before perhaps modest
moderation at the end of the long term and into next weekend.

The mid-week`s two waves are not expected to offer organized rain
chances, with very dry lower levels likely consuming most virga
production...however a few light showers are occasionally possible
through the second half of the long term.  The normal max/min at
Indianapolis through the long term will continue to fall from 63/44
to 61/42.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1216 PM EDT Sat Oct 19 2024

Impacts:

- None

Discussion:

Broad high pressure, from New england to the southern states, and a
very dry column per Hi-Res soundings will result in clear skies and
calm or very light SSW winds. There is a vry small chance of brief
MVFR or worse, very shallow fog 09z-12z at the smaller airports.

&&

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

$$

SHORT TERM...MK
LONG TERM...AGM
AVIATION...MK