National Weather Service Raw Text Product

515 
FXUS63 KIND 050108
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
908 PM EDT Thu Apr 4 2019

.UPDATE...
The NEAR TERM Section has been updated below.

&&

.SYNOPSIS...
Issued at 334 PM EDT Thu Apr 4 2019

A wetter pattern is setting up for central Indiana along with above 
normal temperatures for much of the next seven days. Chances for 
rain will increase tonight as a frontal system moves through central 
Indiana. Rain will move out during the morning, but then after a mostly 
sunny Saturday rain and thunderstorm chances will return for late
Saturday night through Monday. 

&&

.NEAR TERM /Tonight/...
Issued at 902 PM EDT Thu Apr 4 2019

Mid level trough currently moving into western Illinois is progged
by the short term models to lift into the Great Lakes by sunrise
Friday. 

Fairly widespread rain present over the local area, ahead of the
approaching feature. Most of the organized lift is expected to
push off to the east during the pre dawn hours of Friday, so
precipitation should begin diminishing by then.

Current forecast is handling the precipitation threat well.
Decided to lower the mins tonight over the north a few more
degrees. Current temperatures are close to the lows in those area,
and may fall a bit more due to evaporative cooling in 
precipitation areas.

Previous discussion follows.

Rain should arrive across central Indiana this evening and become 
widespread tonight as low pressure moves from Arkansas into 
Tennessee and then Kentucky, bringing isentropic lift along and 
north of the warm front. Not much in the way of instability so no 
thunder anticipated. Expect cloudy skies through the overnight, but 
even with this expect to see a continued decent temperature gradient 
across the area for overnight lows, with lower 40s in the north and 
lower 50s in the south. 

&&

.SHORT TERM /Friday through Sunday/...

Issued at 334 PM EDT Thu Apr 4 2019

As Friday morning begins an upper wave will be off to the east, but 
part of a surface trough may still be hanging around. This could be 
enough to keep some small shower chances going through around mid 
morning across central and eastern parts of the area. After that, 
weak surface high pressure will build just east of here as a small 
bit of ridging moves to and across the area on Saturday. This will 
bring in dry weather and some subsidence from Friday afternoon 
through Saturday afternoon. By Saturday night, though, the small 
ridge axis will be off to the east and an upper disturbance will 
swing out of the southwest flow to bring chances for rain back to 
the area. With an approaching surface system as well drawing more 
warm moist flow from the Gulf, will see enough instability along 
with good forcing to prompt chances for thunderstorms as well, 
starting late Saturday night and running at least a slight chance 
for thunderstorms through early Sunday night when the cold front 
associated with the system moves through.

&&

.LONG TERM (Sunday Night Through Thursday)...
Issued at 242 PM EDT Thu Apr 4 2019 

Models are close enough that the model blend initialization
was accepted for most items.

A couple of upper troughs and their associated surface low pressure 
systems will move through central Indiana during the long term 
period. These will bring frequent chances for rain to the area. The 
only exception will be around Tuesday, when dry conditions will rule 
with the area in between systems.

For the most part, temperatures will remain above normal. However, 
colder air will try and work into at least the northern half of the 
area on the back side of the low pressure systems. Confidence is 
lower on temperatures as models have been a little inconsistent on 
the extent of the cooler air intrusion.

&&

.AVIATION /Discussion for the 050000Z TAFS/...
Issued at 630 PM EDT Thu Apr 4 2019

Mid level disturbance currently over northern Missouri is expected
to drift into the southern Great Lakes by Friday morning. Rain
expected to increase in coverage over the next couple of hours in
response to the approach of this system. Short term model data
suggest most of the lift will pass off to the east of the
terminals around 050700Z, so should see precipitation diminish
after that.

Advection of dry air from the east should help to keep
ceilings rather high tonight, with ceilings 040-050 developing 
with time. Potential for MVFR ceilings 015-030, mainly over the 
southwestern terminals, towards daybreak Friday.

Surface winds generally 070-100 degrees at 8-13 kts tonight.
Occasional surface gusts 18-20 kts possible this evening, mainly
in the KLAF/KIND vicinity. Given the passage of a weak surface low
through southern Indiana early tonight, winds in the KHUF/KBMG
area may be variable in direction for a period this evening,
before settling into an easterly direction later this evening.
Surface winds expected to veer a bit towards 100-120 degrees at
5-8 kts by sunrise Friday.

&&

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

$$

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