Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 210721
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
220 AM EST Sat Jan 21 2017

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

&&

.SYNOPSIS...
Issued at 220 AM EST Sat Jan 21 2017

Yet another southwestern system will bring mild but wet weather to
central Indiana for the rest of the weekend. Then, a pattern shift
will bring more seasonable weather and snow showers to the area late
next week.

&&

.NEAR TERM /Today/...
Issued at 220 AM EST Sat Jan 21 2017

Mild temperatures are in store today as a warm front moves north of
the area allowing for southerly low level flow over the area. High
resolution suggests all the rain will be well north of the area as
upper system lifts from the Missouri Valley to Lake Superior. This
should keep the minor river flooding from getting worse. The 00z GFS
and ECMWF suggest a few showers are possible far south with an
impulse ejected northeast from developing southern Plains system.
However, not convinced and prefer to hold off on pops today. This
system will be a major player in the short term to follow.

MOS blend highs are very close and looking at low level thermal
progs seem reasonable with highs near 30 degrees above normal in the
upper 50s to mid 60s.

&&

.SHORT TERM /Tonight through Monday night/...
Issued at 220 AM EST Sat Jan 21 2017

Forecast focus will be on system developing over the southern Plains
within the southern jet that has sent system after system our way in
recent days. This will be the last major one for the time being with
more seasonable weather coming late next week.

The 00z GFS and EMWF with some support from the Canadian are showing
good clustering regarding the aforementioned system as opposed the
NAM. The NAM was much more elongated with this system with a
northern sister low developing over the Ohio Valley on Sunday. The
GFS and ECMWF are much more compact and continue to favor the
prefered Mid south track. This track would favor the bulk of the
late weekend and early next week precipitation staying south of the
area. That said, precipitable water values once again climb to three
quarters of an inch to an inch overnight Saturday night and Sunday.

ECMWF and GFS blend brings the southern system to western Arkansas
12z Sunday. Moist low level inflow ahead of this system along
withejected impulses and diffluent flow aloft ahead of it, support
atleast as high as Superblend chance pops Saturday night into
Sundaynight. In addition, model instability progs were showing
enoughinstability to keep thunder around Saturday night per the
previousforecast and SPC Day2 general thunder outlook. Regarding
additionalflooding, the key will be if southern convection is able
to cut offsome of our moisture. With the saturated ground, would not
rule outsome of the heavier convection could cause localized brief
flooding.But, do not think the upcoming showers will exxagerbate the
riverflooding.

By Monday night, any lingering showers should be over our eastern
counties as the system moves over the Appalachians.

Low level thermal progs and MOS blend favor one more day of the 20
plus degree above normal temperatures for Sunday with Monday not as
mild with highs in the 40s.

&&

.LONG TERM /Monday night through Friday/...
Issued at 205 PM EST Fri Jan 20 2017

The long term will begin with above normal temperatures and small
rain chances moving out of the area as an upper ridge builds in
and moves across central Indiana. Tuesday night a low pressure
system will approach from the plains and bring small chances for
rain with it. By Thursday though a broad upper trough across the
western and central U.S. will start to slowly move east, and this
will bring cold more seasonable air back to the area. Temperatures
will drop back to near normal for this time of year. Little upper
waves ejecting out of the upper trough could bring some
precipitation chances to the area for the remainder of the
extended, but right now there isn`t a major forcing mechanism to
focus on so just used the small off and on chance pops from the
initialization. Because of the arrival of the colder air, could
see some snow or a rain/snow mix for anything that falls Wednesday
night on.

&&

.AVIATION /Discussion for 210600Z TAF Issuance/...
Issued at 1145 PM EST Fri Jan 20 2017

Flying conditions lowering to MVFR at KIND...KLAF...KHUF overnight
and early Saturday morning. Otherwise...mostly VFR until late
Saturday night.

Low pressure over the central plains Will move into the upper midwest
Saturday.  Some low level moisture will cause MVFR conditions over
north and central sections while KBMG remains VFR. With daytime
heating Saturday will scatter out leaving mid/high level ceilings.

A second low pressure system will move into the middle Mississippi
valley late Saturday night and showers and lowering ceilings will
spread into our area but mainly after 06Z Sunday.

Winds will be from the south at 5 to 8 knots overnight...Saturday
morning and again Saturday evening.  South winds up to 10 knots
will occur Saturday afternoon.

&&

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

&&

$$

SYNOPSIS...MK
NEAR TERM...MK
SHORT TERM...MK
LONG TERM....CP
AVIATION...JH



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