553 
FXUS63 KIND 131626
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1226 PM EDT Sun Oct 13 2024

.KEY MESSAGES...

- Cooler and breezy today

- Wind gusts around 20-30 mph possible this afternoon with gusts up 
  to 35 mph this evening 

- Coldest air of the Fall for first half of the week with frost expected
  a few mornings. Some areas could see freezing temperatures a 
  morning or two

- Other than low chances for showers across the northern counties 
  through Monday night, dry weather will persist

&&

.FORECAST UPDATE...
Issued at 921 AM EDT Sun Oct 13 2024

- Partly Cloudy and Cooler

Surface analysis late this morning shows low pressure centered over 
NW Ohio. A trailing cold front was found stretching SW from the low, 
across Central Indiana to southern IL and southern MO. Strong high 
pressure was found over the northern Plains. Aloft, a moderate upper 
wave was found over MN/Ontario. Northerly flow around this feature 
was found over the northern plains, before that flow turns more 
westerly across Illinois and Indiana. GOES16 shows some low clouds 
over NW Indiana, but these were beginning to mix out as heating 
returns this morning.  A moderate pressure gradient was in place 
across the area as the low was departing. Surface flow was from the 
west, becoming northwest.

The upper low trough over MN will dig southeast today, continuing to 
provide cyclonic flow aloft. However any forcing with this feature 
will remain north of Central Indiana. Through the afternoon the 
surface low will push east to PA, and the associated cold front will 
also dive farther south. This will result in continued NW flow 
through the day along with ongoing cold air advection. Forecast 
soundings through the day show a dry column and subsidence is 
expected through the afternoon. The morning clouds are thus expected 
to dissipate as mixing continue. Overall, will look for just partly 
cloudy skies across Central Indiana with highs in the middle 70s.

&&

.SHORT TERM (Today and tonight)...
Issued at 309 AM EDT Sun Oct 13 2024

Current surface analysis shows a weak low pressure centered near the 
IL/IN border with a cold front stretching back into western 
Illinois. This front will move through later this morning helping to 
shift winds to northwesterly and filter in cooler air. No 
precipitation is expected from the approaching front due to dry air 
in the low-mid levels. Look for cold air advection to keep highs 
today about 10 degrees cooler than yesterday. Highs will generally 
be in the low-mid 70s.

The main concern in the short term is the potential for strong wind 
gusts later today. Steepening lapse rates will likely promote the 
potential for 20-30 mph gusts by this afternoon. Even stronger gusts 
are possible during the evening hours as models show another cold 
front and strong low-level jet moving in after about 5pm. Steep low-
level lapse rates combined with the strong LLJ could support wind 
gusts up to 35 mph. Sustained winds around 20mph are also expected 
so make sure to secure any loose outdoor items. These strong winds 
may continue through much of tonight as the elevated winds make it 
difficult for the PBL to decouple.

While elevated winds will keep the PBL mixed, temperatures are still 
going to cool considerably tonight thanks to strong cold air 
advection. Look for lows to fall well into the 40s which is near 
normal for this time of year. There is a low chance for a few light 
showers across northern counties late tonight as a weak surface low 
traverses the region.

&&

.LONG TERM (Monday through Saturday)...
Issued at 309 AM EDT Sun Oct 13 2024

The upper trough over and north of the Great Lakes will continue to 
be an influence on the region's weather through at least midweek. 
The northerly to northwest flow will bring in cooler than normal 
temperatures for much of the week with highs in the mid 50s to near 
60 Monday through Wednesday. Morning lows through Thursday morning 
will also be colder than normal with widespread frost being a 
concern and some areas may even drop to or slightly below freezing. 

Moisture on the backside of the trough system may be enough to 
provide a few light showers during the first few days of of the 
weeks with best chances across the north. Models have been 
continuing to hint that there may be a few showers but inconsistent 
on timing and location, plus there will be a lot of dry air to 
contend with which all lead to a lack of confidence. However, would 
expect best chances of precip to come from lake effect showers 
thanks to the northerly flow that will be in place. 

As we get to the latter half of the work week, ridging will start to 
move in and temperatures will gradually warm back to near to 
slightly above normal. At the surface a large high will encompass 
the eastern US providing clear skies and drier air. Min RH values 
are forecasted to be near 30% for the latter half of the week so 
elevated fire weather may be a concern. 

Models are showing another trough moving in around the weekend but 
there is quite an array of solutions coming from models so not sure 
at this time when it will arrive yet. This will lead to lower 
confidence on the forecast for next weekend. Precipitation is 
expected with it which could arrive Sunday or could arrive the 
following week.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1225 PM EDT Sun Oct 13 2024

Impacts: 

- Brief MVFR ceilings possible at LAF band IND on Monday Morning; 
Otherwise VFR.

Discussion:

A cold front has pushed east of the TAF sites. GOES16 shows a MVFR 
cloud deck in the wake of the front, passing across IND and just 
about to exit LAF. These clouds should be exiting all TAF sites by 
18Z-19Z. A moderate pressure gradient remains across Central 
Indiana. This will continue to result in gusty winds this afternoon 
and continued mixing overnight.

Strong cold air advection overnight and good mixing suggests the 
development of an MVFR Stratocu deck overnight. Forecast soundings 
show the development of lower level saturation. Thus MVFR at IND and 
LAF during the daybreak hours. MVFR should dissipate as mixing and 
heating returns on Monday morning, but VFR stratocu is expected.

&&

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

$$

UPDATE...Puma
SHORT TERM...Melo
LONG TERM...KF
AVIATION...Puma