234 
FXUS63 KIND 300915
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
330 AM EST Wed Jan 30 2019

.UPDATE...
The SYNOPSIS, NEAR TERM and SHORT TERM sections have been updated 
below.

&&

.SYNOPSIS...
Issued at 330 AM EST Wed Jan 30 2019

The dangerously cold below zero temperatures and wind chills will 
continue through Thursday morning in the wake of an Arctic front. 
Some snow accumulation is expected late Thursday and Thursday night 
as an upper system moves through.

Then, a big warm up is in store for the weekend and early next week. 
Afternoon highs will climb all the way to the 50s Sunday and Monday. 
Then, rain chances will be on the rise especially early next week.

&&

.NEAR TERM /Today through Thursday morning/...
Issued at 330 AM EST Wed Jan 30 2019

The brutally cold temperatures and wind chills will be the story 
today as Arctic high pressure gradually works its way in across the 
Missouri and Ohio Valleys. 

Lack of snow cover has kept temperatures from falling too fast. 1 am 
temperatures ranged from 4 degrees below zero in far north to 9 
degrees in the far south. However, with several hours to go before 
sunrise, think temperatures could still bottom out at 15 degrees 
below zero or colder in the Lafayette and Kokomo areas, 8 to 12 
degrees along the Interstate 70 corridor and slightly below zero in 
the Vincennes and Seymour areas. Northwesterly winds gusting to 30 
mph or more will produce wind chills below 40 degrees below zero 
over northern sections. Many locales are in danger of setting record 
lows this morning and record low maximum temperatures are a virtual 
lock. For example, the record low temperatures early this morning 
and early tomorrow morning for Indianapolis are both 11 degrees 
below zero while the record low maximum for today is 7 degrees above 
zero.

Low level thermal progs suggest temperatures will not even rebound 
to zero degrees this afternoon north of I-70 despite satellite and 
model rh time sections and soundings suggesting plenty of sunshine. 
Blend looks to handle this reasonably well, but Arctic systems 
typically do not support high confidence in precise temperatures.

The key to the temperature forecast tonight will be if the winds can 
decouple as low levels warm several degrees and cirrus will be 
moving in, both of which would support temperatures not quite as 
cold as this morning. Similar overnight lows look reasonable per the 
blend with low confidence in precise lows. The difference will be 
the wind chill will not be as low although still quite dangerous. 
So, will leave the wind chill warning and advisory going through 
Thursday morning.

&&

.SHORT TERM /Thursday afternoon through Friday night/...
Issued at 330 AM EST Wed Jan 30 2019

Thursday afternoon will see a big improvement to the cold as the 
Arctic high moves to northern Ohio and southerly low level flow 
returns. Isentropic lift on the 285K level will really ramp up 
Thursday and Thursday night as a Clipper approaches from the 
northwest. This should be enough for some accumulating snow late 
Thursday and Thursday night, especially over northern and eastern 
sections. The blend storm total snowfall forecast is one to three 
inches near and north of Interstate 74 with lesser amounts south. 
Further south, may see some freezing rain/freezing drizzle before 
temperatures warm enough and the system moves out. 

Could see the snow change to freezing rain or freezing drizzle from 
southwest to northeast as drier air moves in aloft Friday morning 
before it ends from west to east Friday afternoon as the wave passes 
to the east. Blend suggests temperatures will make it all the way to 
the upper 20s north to around 40 south, The clouds will be 
decreasing Friday night from northwest to southeast with lows mostly 
in the 20s per the blend.

&&

.LONG TERM /Saturday through Tuesday/...
Issued at 225 AM EST Wed Jan 30 2019

Ensembles suggest a progressive nature to the long wave features
during this period. Upper ridging initially over the Midwest will
drift off to the east, while troughing develops over the Rockies
and western Plains.

Ensembles look unsettled overall, especially towards the latter 
parts of the extended, as the potential exists for disturbances to
periodically eject out of the developing western trough. It 
appears a fairly potent short wave will move into the Great Lakes 
around Monday, with hints at a possible second wave moving into 
the area by next Tuesday. Will bring in PoPs for mostly rain 
starting Sunday night and continue them through next Tuesday. At 
this time, ensembles suggest little threat for accumulating snow 
through the period.

&&

.AVIATION /Discussion for the 300900Z KIND TAF Update/...
Issued at 313 AM EST Wed Jan 30 2019

Surface observations and radar indicate an area of scattered snow
showers, and associated MVFR/localized IFR visibility
restrictions, over eastern Illinois and western Indiana. Should
begin to see snow shower activity in the vicinity of the KIND
terminal over the next hour or so. Will add some visibility 
restrictions in occasional snow showers to the forecast through 
the mid morning hours.

Previous discussion follows.

Predominantly VFR through the period. Window of MVFR ceilings
possible near daybreak Wednesday.

Guidance continues to suggest a period of high end MVFR ceilings
at most sites, and upstream obs support this with the core of the
upper wave moving through around daybreak. Will carry 2500-3000
foot ceilings at all sites starting around 8-9Z and continuing
through 11-13Z.

Winds will remain westerly or northwesterly and gusty at times 
overnight, with occasional gusts into the mid 20KT range. While 
gusts may not be constant, they should be frequent enough to merit
a continued mention. These gusts may increase a bit again on 
Wednesday to closer to 30KT before decreasing a bit later in the 
day and dropping off entirely tomorrow evening.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Wind Chill Warning until 1 PM EST Thursday for INZ021-028>031-
035>049-051>057-060>065.

Wind Chill Advisory until 1 PM EST Thursday for INZ067>072.

&&

$$

SYNOPSIS...MK 
NEAR TERM...MK
SHORT TERM...MK
LONG TERM....JAS
AVIATION...Nield/JAS