135 
FXUS63 KIND 010433
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1133 PM EST Mon Nov 30 2020

.UPDATE...
The AVIATION Section has been updated below.

&&

.SYNOPSIS...
Issued at 1000 PM EST Mon Nov 30 2020

Snow chances continue tonight and will exit to the E/NE during the 
overnight along with the low pressure system. Cold temperatures 
continue Tuesday but near normal temps return for the rest of the 
week. Ridging will help keep the rest of the week dry, but another 
low will return precipitation chances for the weekend. 

&&

.NEAR TERM /Rest of Tonight/...

Issued at 1000 PM EST Mon Nov 30 2020

For the update...included some PoPs for the next few hours in all 
but the westernmost parts of the forecast area based on radar loop 
and trends. Not much will be seen in the way of accumulation, but 
scattered light snow showers will continue for the next few hours, 
some of them enhanced by lake effect. A tight pressure gradient with 
low pressure center slowly moving northeast away from the area will 
keep northwesterly wind gusts of 20 to 30 mph in place through the 
overnight hours, and temperatures dropping into the 20s will allow 
untreated roads to freeze. Issued an SPS to this effect to heighten 
awareness especially for the morning commute. Previous discussion 
follows...

Light snow will continue into tonight across east central Indiana
with some scattered to isolated snow across other parts of 
central Indiana. The low will keep slowly tracking east to 
northeastward tonight, with the snow exiting with it. The 
northerly to northwesterly winds have allowed for a skinny lake 
effect snow band to reach the central to southern part of the 
state this afternoon. This band looks persist into early tonight, 
and it will track E to NE, following the periphery of the backside
of the low. Snow could become a little heavier at times under 
this band due to enhanced moisture and energy coming from Lake 
Michigan, but as it will keep shifting NE, snow accumulations will
remain relatively low. By the early morning hours, total snowfall
totals across the area will range from around a tenth to quarter 
of an inch across the west and central counties, up to 1 to a 
little over 2 inches in the NE counties. Temperatures will 
continue dropping overnight as the cold air fully settles in 
behind the upper trough; lows down to the mid 20s. 

Tight pressure gradients on the back side of the low remain 
overhead, thus breezy conditions will continue tonight. Expect 
sustained winds of 10 to 15 kts with gusts up to 25 kts. These winds 
will slowly diminish towards sunrise.  

&&

.SHORT TERM /Tuesday through Wednesday/...

Issued at 359 PM EST Mon Nov 30 2020

By the start of the short term, the center of the low pressure 
system will have moved off to Pennsylvania and New York, but some 
lingering snow is possible Tuesday morning for the NE counties of 
the forecast area. This continued moisture is coming from moisture
wrapping around the back side of the low, as well as some lake 
effect snow coming off of Lake Michigan due to northerly to 
northwesterly winds over the lake pulling snow into the central 
part of the state. Ridging behind this system will bring in drier 
air and subsidence which will clear out clouds through the day 
Tuesday. Mostly clear skies will continue through Wednesday. 
Temperature wise, Tuesday will be cold with the continuation of NW
flow, but Wednesday will warm to near normal as more westerly to 
southerly flow moves in on the back side of the ridge.

&&

.LONG TERM (Wednesday Night Through Monday)...
Issued at 232 PM EST Mon Nov 30 2020 

Models continue to differ on how an upper level low will lift out of 
the Plains early in the long term period. At any rate, deep moisture 
looks limited with better moisture off to the south. Thus will go 
dry or very low PoPs in the far south on Thursday.

The next feature that could bring some light precipitation is a cold 
front/surface trough that will move through on Saturday. Moisture 
will again be a problem, so will only have some very low PoPs 
Saturday into Saturday night.

An upper trough will dig into the area on Sunday into Sunday night. 
Went dry for now with this, but may have to add some PoPs later as 
colder air moving in might be able to squeeze out a little 
precipitation.

Temperatures will remain near normal to a little below normal for 
the most part. Cooler than normal readings may move in behind the 
upper trough Sunday night into Monday.

&&

.AVIATION /Discussion for 010600z TAF issuance/...

Issued at 1127 PM EST Mon Nov 30 2020

IMPACTS:
-Winds from 290 to 320 with gusts of 18 to 27+ kts. Higher end of
 gusts will drop in speed to around 22 kts after 9z.
-MVFR ceilings, rising to VFR from west to east. Could start to
 come to VFR soon at KLAF and KHUF, with KBMG and KIND after 9z.
-Snow showers could continue to impact the sites for the next
 couple hours but no accumulation expected. May also see a brief
 period of freezing drizzle.

DISCUSSION: Low pressure pulling off to the northeast will keep 
lower ceilings and chances for snow or freezing drizzle in the 
forecast tonight for at least the next few hours. Strong 
northwesterly wind gusts will decrease to 18 to 22 kts over the
next few hours as well.

CONFIDENCE: High confidence in gusty northwesterly winds through
the period. Medium confidence in MVFR ceilings for parts of the
next 6 hours, with some potential for VFR especially west. Low
confidence in the timing of VFR at KBMG and KIND. Low confidence
in any lower visibilities occurring at the sites. Low confidence
in any freezing drizzle occurring.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...KH/CP
NEAR TERM...KH/CP
SHORT TERM...KH
LONG TERM....50
AVIATION...CP