Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 251649

Area Forecast Discussion
National Weather Service Indianapolis IN
1149 AM EST Sat Feb 25 2017

The AVIATION Section has been updated below.


Issued at 256 AM EST Sat Feb 25 2017

The fluctuating pattern will continue as cooler temperatures
prevail through the weekend, quickly followed by a warm-up early
next week. First, light snow showers will persist this morning in
wraparound moisture on the back side of yesterday`s system.
However, high pressure will quickly strengthen over the region by
this afternoon, resulting in dry conditions through Sunday. At
that point, precipitation chances will increase again as the first
of several disturbances enters central Indiana.


.NEAR TERM /Rest of Today/...
Issued at 1006 AM EST Sat Feb 25 2017

More extensive and heavier snow showers have moved off to the east
as of 15Z...but scattered light snow showers and flurries
lingering across the northern half of the forecast area as upper
trough axis swings across the area. An additional dusting on
grassy areas and elevated surfaces remains a possibility for the
next few hours...but think overall accumulation potential is done
with lighter snowfall rates and melting at the surface. Held on to
a flurry mention through about 19Z with drier air associated with
the approaching high pressure taking over after that. Should see
some scattering of the stratocu by late day.

Nudged temps down slightly for the afternoon based on current
trends. Will see some recovery in temperatures but not that much
as cold advection remains strong across central Indiana. Winds
will remain gusty through the day with gusts up to 35-40 mph over
the next few hours before relaxing late. Wind chills in the teens
will be common today...quite the rude reminder that it is still
technically winter after the warm weather enjoyed over the last
week or so.

Zone and grid updates out.


.SHORT TERM /Tonight through Monday Night/...
Issued at 256 AM EST Sat Feb 25 2017

The main focus of the short term period will be 2 rounds of
precipitation, the first starting Sunday night and the second
beginning on Monday night.

High pressure/zonal flow will result in dry conditions tonight
through tomorrow. However, moisture will start increasing from the
south on Sunday night ahead of the next upper trough.
Precipitation will initially start out as rain tomorrow evening
across the southern counties, but it could transition to a wintry
mix overnight as temperatures drop. This wintry mix will spread
into the central and northeast counties by daybreak Monday and
quickly transition back to all rain before ending early Monday
afternoon.  No snow accumulations are expected.

After a short period of dry conditions on Monday afternoon, rain
will quickly re-develop on Monday evening ahead of the next
system approaching from the west. Latest Superblend initialization
is trending toward likely pops by Monday night, which seem
reasonable as the system moves closer.

A gradual warming trend will prevail through the period with highs
in the low to upper 40s on Sunday and low/mid 50s by Monday.
Meanwhile, overnight lows will jump from the 30s on Sunday night
to 40s on Monday night. Did not need to deviate from latest
Superblend initialization.


.LONG TERM /Tuesday through Friday/...
Issued at 245 AM EST Sat Feb 25 2017

Forecast confidence will start off good as models agree that a cold
front will move east across central Indiana Wednesday. Deep moisture
advected in off the Gulf ahead of the system, along with waves
moving along the front, suggest high pops per the Superblend are a
good bet. In addition, operational 00z GFS and ECMWF both have
decent instability Tuesday through Wednesday. So, have thunder in
the grids in that time period. Kept shower chances in through
Wednesday night, as a trailing upper trough moves through. Could see
some snow mix in overnight across our northern counties as the
roller coaster weather continues.

Less confidence the remainder of the long term as models handle the
next system differently. The 00z has a well defined frontal system
moving through the area Thursday night. The 00z ECMWF has much less
of a surface reflection. However, both have an cyclonic flow over
the area, so small superblend pops are justified Thursday night.
Left small pops in the extreme northeast Friday morning as the
system moves out. Could once again see some snow mix in, mainly over
the northeastern half. Accumulation is not expected at this time.

Superblend looks to be handling the temperature trends well, so no
reason to make any changes. Highs could once again reach the 60s on
Monday with highs in the 40s to follow late week.


.AVIATION /Discussion for 251800Z TAF Issuance/...
Issued at 1149 AM EST Sat Feb 25 2017

Brief MVFR ceilings possible for a few hours this afternoon...
otherwise VFR conditions expected.

Scattered flurries and brief snow showers continue to diminish in
coverage and intensity early this afternoon as the upper trough
axis swings east of the region. Ceilings have largely recovered to
low VFR at the terminals and outside of brief periods of MVFR for
the next couple of hours...expect ceilings to largely hold at
3000ft or higher through the remainder of the afternoon. Winds
will be the biggest factor for the rest of the day as W/NW winds
persist at near 20kts with gusts approaching 30kts.

Stratocu will begin to scatter towards sunset with more
substantial clearing this evening as high pressure builds into
the region. Winds will diminish tonight as the surface pressure
gradient relaxes. The high pressure will serve as the dominant
influence for Sunday with mostly sunny skies. Winds will be light
initially...with potential for renewed gusts approaching 20kts
during the afternoon as flow transitions to S/SW and an upper wave





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