Area Forecast Discussion
Issued by NWS Indianapolis, IN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS63 KIND 161443

Area Forecast Discussion
National Weather Service Indianapolis IN
1043 AM EDT Fri Mar 16 2018

The NEAR TERM and AVIATION Sections have been updated below.


Issued at 326 AM EDT Fri Mar 16 2018

A low pressure system will move from the Mississippi Valley to the
Ohio Valley on Saturday. This system will bring widespread
precipitation to central Indiana tonight and early Saturday. Areas
near and north of Interstate 74 will see a wintry mix with mainly
freezing rain. Meanwhile, areas south of Interstate 74 will see just

High pressure will bring dry weather to the area Saturday night into
Sunday night. Then, a southern system will result in a wintry mix
starting early next Monday. Finally, dry weather will follow for the
middle and late parts of next week as high pressure moves in.

Look for below normal temperatures through Saturday, above normal
temperatures Sunday and Monday and then below normal temperatures
for the middle part of next week.


.NEAR TERM /Rest of Today/...
Issued at 1043 AM EDT Fri Mar 16 2018

High clouds are slowly expanding into the region from the west
this morning ahead of the low pressure tracking through the
central Plains. 1430Z temps remained chilly...running from the
upper 20s to mid 30s.

Not much need to change the forecast for the rest of the day.
Cloud cover will continue to steadily increase through the course
of the day as the low tracks east. The initial surge of moisture
will arrive in the lower Wabash Valley by late day and while a
stray shower or sprinkle cannot be entirely ruled out...not
overly excited in precip potential prior to 00Z with such a dry
airmass present over the region. Model soundings indicate that
boundary layer saturation will likely take well into the evening
over the forecast area.

Nudged winds and temps up just a bit based on current trends.
Otherwise...the current forecast is in very good shape.

Zone and grid updates out.


.SHORT TERM /Tonight through Sunday night/...
Issued at 326 AM EDT Fri Mar 16 2018

The main concern for the short term will be overnight and Saturday
morning, when freezing rain will be possible over northern and
eastern sections of the forecast area as a low pressure system moves
into the middle Mississippi Valley and then Ohio Valley on Saturday.
The 00z NAM looked to be a slow outlier, otherwise 00z model blend
looked good and suggests areas near and north of a New Castle to
Anderson to Lafayette line could see precipitation start off as or
switch to a wintry mix of rain or snow this evening. However, after
06z, as the precipitation becomes widespread and increases in
intensity, top down method suggests the main precipitation type in
this area will be freezing rain. Forecast builder and WPC suggest
our far northeastern counties could see over a tenth of an inch of
ice. That said, above normal road temperatures and barely below
freezing forecasted temperatures tonight lend low confidence to icy
roads. Thus, will stick with a Special Weather Statement to handle
things as opposed to a Freezing Rain Advisory. If the models come in
colder with their 12z runs, this would increase confidence in icy
roads and thus an advisory could still be needed with the afternoon

High confidence that the precipitation will be ending from northwest
to southeast Saturday afternoon. Any linger wintry precipitation
will change back to rain by Noon. After that high confidence in dry
weather through Sunday under the influence of high pressure. Can not
rule out light rain far southwest overnight Sunday night as another
low pressure system moves into the central Plains. That said,
confidence is low.

After a cool start to the weekend, low level thermals and increasing
sunshine support temperatures returning to normal on Sunday.


.LONG TERM /Monday through Thursday/...
Issued at 306 AM EDT Fri Mar 16 2018

The long term starts out a couple degrees warmer than normal with
highs in the 50s on Monday, but then reality sets in as a cutoff
upper low moves in to reinforce the upper trough over the eastern
U.S. This will plunge central Indiana back into a below normal
temperatures and a wintry pattern for the rest of the long term.
Short waves will move through the aforementioned upper trough and
bring chances for mainly rain during the day and a wet snow during
the night from Monday through Wednesday night. Timing of the
individual shortwaves is still pretty variable, so generally went
with the blended initialization which should smooth out the
individual model differences.


.AVIATION /Discussion for the 161500Z TAF Update/...
Issued at 1043 AM EDT Fri Mar 16 2018

Bumped up mid and high level clouds for the rest of the day based
on satellite trends. Also nudged winds up for the rest of the day
based on current obs. Rest unchanged.

12Z discussion follows.

High confidence that VFR conditions will continue through 00z. Then,
could see MVFR or worse confidence at times as rain overspreads the
terminals. LAF could possibly see the rain mixed with snow and
overnight freezing rain, but confidence is not good enough.

Winds will be from the east 10 knots or less and from 080 to 110





AVIATION...MK/Ryan is the U.S. government's official web portal to all federal, state and local government web resources and services.