253 
FXUS63 KIND 052340
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
740 PM EDT Sat Oct 5 2024

.KEY MESSAGES...

- Elevated fire weather risk Sunday afternoon

- Dry and warm weather continues tonight and Sunday.

- Early next week will return to seasonable temperatures, but warmer
  air will return later in the week

&&

.SHORT TERM (This evening through Sunday)...
Issued at 232 PM EDT Sat Oct 5 2024

Synopsis: 

Surface analysis early this afternoon shows strong high pressure in 
place over Lake Erie and Southern Ontario. This high was in firm 
control of the weather across Indiana and the region. A surface 
ridge extended southwest from the high, stretching across the Ohio 
Valley to Arkansas. GOES16 shows mostly clear skies across Indiana 
as morning mid level clouds have dissipated. Some mid and high 
clouds were found across MN and the Dakotas associated with a cold 
front. Aloft, water vapor showed riding in place over Indiana and 
the Great Lakes and strong subsidence was shown across Illinois and 
Indiana. Southeasterly lower level flow was in place and dew points 
were mainly in the 50s.

Tonight -

Dry weather is expected tonight. The high pressure system and 
ridging across the area is expected to depart to the east this 
evening, allowing the cold front over the northern plains to arrive 
in Indiana toward 12Z. This will result in mostly clear skies and 
warm conditions tonight in the warm sector, across Indiana. The 
arrival of some high clouds will be expected late tonight as the 
front reaches our area. This front is moisture starved as southerly 
gulf flow never develops ahead of this system. Forecast soundings 
and time heights fail to show deep saturation. Thus overall, we 
expect mostly clear skies this evening, partly cloudy skies toward 
daybreak, with lows in the lower to middle 60s. Also, a moderate 
pressure gradient across the area with the approaching front will 
allow winds to remain around 5-10 mph overnight, providing some 
mixing.

Sunday -

Models show the dry cold front will push across Central Indiana and 
exit to the east through the course of the day. Strong high pressure 
is expected to build across Indiana in the wake of the front from 
the northern Plains. Aloft, ridging over the high plains is expected 
to redevelop, allowing for more lee side northwest flow aloft and 
subsidence spilling into the Ohio Valley. All of this will add up to 
partly cloudy skies as forecast soundings remain dry through the 
day. The strongest cold air advection does not begin until later in 
the afternoon and strong mixing is expected as a moderate pressure 
gradient will still be in play. Winds may gust to 20-25 mph. This 
may continue fire weather concerns with highs in the middle 80s and 
low afternoon RH values.

&&

.LONG TERM (Sunday night through Saturday)...
Issued at 232 PM EDT Sat Oct 5 2024

A prolonged dry spell can be expected at least through this week, as 
strong high pressure dominates the region throughout the period, 
bringing pleasant autumn weather but potentially enhanced fire 
danger concerns, as well as potentially deteriorating drought 
conditions after a brief improvement due to rainfall from the 
remnants of Helene late last month.

Normal highs and lows for the time of year are currently right 
around 70 and 50, though steadily declining with time as we push 
inexorably toward the cool season - by mid month we lose another 4-6 
degrees on average.

Dry conditions will likely lead to enhanced diurnal temperature 
ranges, with lows near to a bit below normal much of the week, and 
highs near to a bit above normal. Temperatures will be on a modest 
warming trend through the week, coolest early and warmest late as 
broad upper level ridging over the western CONUS gradually nudges 
toward the region later in the week.

Will likely adjust blend guidance dewpoints downward during the 
afternoons many days this week, as despite relatively light winds, 
it will require only modest mixing in a very dry column to produce 
potentially substantial dewpoint drops in the afternoons. This is an 
area where NBM is known to struggle, often significantly. The 
aforementioned light winds will mitigate fire concern somewhat, at 
least with respect to reaching red flag conditions, but continually 
drying fuels and afternoon RH values potentially nearing critical 
levels will present at least some concern.

Longer term guidance does suggest some potential for precipitation 
near or just beyond the end of the forecast period with another 
quick moving upper low and cold frontal passage late next weekend 
into early the following week, but long term outlooks remain fairly 
strongly warm and dry, and prevailing westerlies look to remain 
displaced well poleward for most of the next couple of weeks at 
least. CPC 6-10 and 8-14 day outlooks are strongly indicative of 
below normal precipitation and nearly as strongly indicative of 
above normal temperatures, and this is well-supported by long term 
guidance, including the CFS.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 739 PM EDT Sat Oct 5 2024

Impacts: 
 - Winds veering from southerly to west-northwest by late day Sunday
 - Low level wind shear at KLAF 08-12Z tonight
 - West to west-northwesterly winds gusting to 16-22KT Sunday 

Discussion:

VFR conditions will continue over central Indiana terminals into 
Sunday evening.  A potent cyclone crossing southern Canada will drag 
its dry cold front across the region Sunday morning.  Sustained 
winds ahead of this passage will slowly increase within mainly a 7-
12KT range tonight, except at KBMG where lighter flow will be 
present...while veering slightly over all terminals to 210-230 
degrees by dawn.

Winds will continue to veer Sunday through westerly direction with 
the frontal passage, while gusting to mainly 16-22KT...before 
diminishing late in the day.

&&

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

$$

SHORT TERM...Puma
LONG TERM...Nield
AVIATION...AGM