202 
FXUS63 KIND 101314
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
914 AM EDT Thu Oct 10 2024

.KEY MESSAGES...

- Above normal temperatures Friday and Saturday

- Coldest air of the Fall arrives early next week with frost 
  possible on a few mornings 

- Other than low chances for showers Saturday into early Sunday, dry 
  weather will persist

&&

.FORECAST UPDATE...
Issued at 914 AM EDT Thu Oct 10 2024

- Sunny and Pleasant; Highs in the middle and upper 70s.

Surface analysis late this morning shows strong high pressure in 
place over Michigan. This high was in control of the weather across 
Central Indiana, providing dry easterly lower level flow. GOES16 
shows clear skies across the state and the region. Aloft, water 
vapor imagery shows ridging in place, stretching from eastern CO to 
western Ontario. This was resulting in northwest flow aloft with 
ongoing subsidence across Indiana. Dew points this morning were in 
the comfortable 40s.

The ridge axis to the west is expected to drift slightly east today. 
This will keep Central Indiana within an area of subsidence aloft, 
and surface high pressure will continue to control our weather. 
Forecast soundings show a dry column with unreachable convective 
temperatures. Thus we will expect a sunny day with low relative 
humidity. Given the little change in air mass, highs near 
persistence are expected, in the middle and upper 70s. Overall, 
ongoing forecast is in good shape.

&&

.SHORT TERM (Today and tonight)...
Issued at 252 AM EDT Thu Oct 10 2024

Benign Autumn weather continues for Central Indiana as high pressure 
remains the dominant weather influence through the week. 

Latest satellite and observations show surface high pressure the UP 
of Michigan with clear skies and winds ranging from calm to 5 mph. 
Good conditions for radiational cooling have resulted in 
temperatures plummeting 20-25 degrees into the 40s to low 50s across 
the region. Dew points tonight are running 5-10 degrees higher than 
the past few nights, so not expecting temperatures as low this 
morning. Coldest spots are located in low lying, wind sheltered 
areas and in the Wabash River Valley where temperatures could fall 
into the lower 40s by sunrise. In urban areas, current temperatures 
are in the lower to mid 50s and will fall a few more degrees by 
sunrise. 

High pressure remains over the region today with the weather 
conditions forecast to be nearly a carbon copy of yesterday. Ample 
sunshine and further drying of the surface will result in warmer 
highs reaching the mid to upper 70s once again. A few spots in the 
west and SW may even reach 80 degrees. Very light winds through the 
column will likely limit the over fire weather threat; however very 
dry conditions will still persist with afternoon RH values 
potentially dropping near critical fire weather thresholds in the 
lower 20 percent range.

&&

.LONG TERM (Friday through Wednesday)...
Issued at 252 AM EDT Thu Oct 10 2024

Uncertainty has increased in the weekend forecast for central 
Indiana, especially north. In contrast, confidence in cold air for 
early next week remains high.

Upper energy will move through northwest flow and will bring a cold 
front down into the northern half of Indiana, now as early as Friday 
night. This front will meander until stronger upper energy carves 
out an upper trough across the eastern USA starting Sunday and 
develops a surface wave. This wave will push the cold front through 
sometime Sunday.

Differences arise in model timing and how far south the surface 
front gets on Saturday and then with timing and strength of the 
surface low Sunday, which will impact rain chances and temperatures. 
For example, the difference in blended guidance's 25th and 75th 
percentile for Saturday night's low temperature at Lafayette is 10 
degrees. 

For now plan to stick with the deterministic blended guidance's 
temperatures until certainty increases.

Friday...

A warm and dry day will be in store ahead of the front. Mixing 
should allow dewpoints to get lower than blended guidance suggests 
during the afternoon.

Friday night into Saturday Night...

The front will initially move into at least the far north of the 
area on Friday night/Saturday, with the stronger push coming later 
Saturday night. Will have some isolated shower mention in the far 
north during the day Saturday, but with low confidence. 

Moisture is limited, but the stronger forcing Saturday night could 
squeeze out some scattered showers, mainly north.

Sunday...

A few lingering showers may be in the far eastern forecast area 
Sunday morning. Otherwise dry conditions are expected. Temperatures 
remain in doubt given the aforementioned uncertainty, but for now 
will keep highs in the 70s.

Monday and Tuesday...

Much colder air will build in as a large upper trough takes over the 
eastern USA. Isolated showers may move into the far northern 
forecast area on Monday/Monday night in the cold advection pattern. 

Lows Monday night will get into the middle 30s, but winds may stay 
up enough to prevent widespread frost formation.

Tuesday night and beyond...

Quiet weather will continue, with some moderation in temperatures. 
Just how fast moderation will occur will depend on how fast upper 
ridging returns.

Lows Tuesday night will be in the middle 30s again, but with lighter 
winds, widespread frost looks more likely. There is also some 
indication in the ensembles that freezing temperatures are on the 
table as well.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 621 AM EDT Thu Oct 10 2024

Impacts: 

 - None

Discussion:

Surface high pressure remains the dominant weather influence across 
the region resulting in light winds and VFR conditions throughout 
the TAF period. Calm winds early this morning become light out of 
the northeast later today. While no direct impact to flying 
conditions, it is worth mentioning that the Aurora Borealis may 
be visible tonight across much of the region. 


&&

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

$$

UPDATE...Puma
SHORT TERM...CM
LONG TERM...50
AVIATION...CM