Area Forecast Discussion
Issued by NWS Indianapolis, IN
FXUS63 KIND 160449
Area Forecast Discussion
National Weather Service Indianapolis IN
1149 PM EST Sun Jan 15 2017
The AVIATION Section has been updated below.
Issued at 700 PM EST Sun Jan 15 2017
A low pressure system originating in the Southern Plains will be the
main focus early in the forecast period. Moisture will be limited
tonight though with just scattered light showers early, patchy
drizzle, and a slight chance across the northern counties for
freezing rain or patchy freezing drizzle for a few hours late. Rain
showers will then increase across the forecast area tomorrow from
west to east. Increased forcing could also result in some isolated
thunderstorms on Monday night. As the system pushes farther east,
dry conditions will prevail on Wednesday and Thursday.
Further out, three separate systems will approach from the
southwest, bringing periodic rain chances late in the week and next
.NEAR TERM /Rest of Tonight/...
Issued at 1000 PM EST Sun Jan 15 2017
HRRR and RAP continue to show some spotty light precip continuing
across the area through at least 9z or so and their soundings
support this, but very little if any qpf. Decided to add patchy
light drizzle to the area through much of the night as a result. A
quick check of forecast temperatures show a few hours below freezing
in some of the northern counties, so in those added patchy light
freezing drizzle. Any freezing should be pretty short-lived as
temperatures are forecast to start to increase late during the
overnight, but during those few hours it could produce a few slick
spots on roads in the north.
Low temperatures remain unchanged from afternoon issuance, with low
30s in the north to mid to upper 30s in the south.
.SHORT TERM /Monday through Wednesday/...
Issued at 242 PM EST Sun Jan 15 2017
The main focus of the short term period will be a low pressure
system approaching from the southwest. Originating in the Southern
Plains, this system will track through the Missouri Valley on
Monday, advecting much warmer air ahead of it. Temperatures will
soar above normal on Monday and Tuesday with highs topping off in
the mid to upper 50s across portions of Central Indiana.
Isentropic lift with aforementioned system strengthens most during
the Tue 00-12Z time frame. As a result, will mention isolated
thunderstorms during that period which coincides with SPC`s day two
Rain showers will linger through Tuesday and across the northern
sections of central Indiana on Tuesday night. However, thunderstorm
threat will have ended by then as low pushes farther into the Lower
Great Lakes Region. A wintry mix will be possible briefly on
Tuesday night across the northeastern counties on the tail end of
the system, but moisture will be limited by that point. So, no
accumulations are expected.
Further out, GFS and Euro start to differ on day 4. The GFS is
trending toward a moisture deprived upper low, while the Euro is
showing high pressure. Either way, will trend toward a dry forecast
for Wednesday. Temperatures by Wednesday will be a tad cooler with
highs in the low to upper 40s.
.LONG TERM /Wednesday night through Sunday/...
Issued at 200 PM EST Sun Jan 15 2017
Models consistent in dry weather through at least Thursday morning
as an upper ridge moves over the area. Then, three straight
southwest systems will bring warm weather and periodic rain shower
chances to the area late this week and weekend. The ECMWF has been
running the quickest east with these systems compared to the GFS.
Regional blend goes along better with a slower solution that is also
preferred by WPC. So, will go with that. Highs could reach 60
degrees or so next week.
.AVIATION /Discussion for 160600z TAF issuance/...
Issued at 1146 PM EST Sun Jan 15 2017
Deteriorating flying conditions can be expected over the next
few hours, and once ceilings at all the sites drop to IFR they
will stay at IFR or lower through the rest of the period.
Isentropic lift will keep these ceilings in place through the day
Monday and additional showers will arrive Monday evening as well.
Visibilities are generally running MVFR and should stay there with
a little mixing going on in the boundary layer, however there is a
chance lower visibilities could develop as the night wears on.
However this is small enough to leave out at this time. Winds will
remain light through the period.