Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 061832
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
232 PM EDT Thu May 6 2021

.SYNOPSIS...
Issued at 230 PM EDT Thu May 6 2021

Continued cool and unsettled weather through the weekend.

Expect patchy frost Friday morning with more widespread frost
possible Saturday morning.

Scattered rain Friday and Sunday. Rainfall amounts up to a half an
inch is possible on Sunday.

&&

.SHORT TERM...(This Evening through Friday)
Issued at 230 PM EDT Thu May 6 2021

Cyclonic flow over the Great Lakes continues with a number of
shortwaves and ripples through the near term. This will continue the
steady stream of cloud cover...cooler temperatures...and occasional
showers.

Cool air and brief clearing overnight will allow for patchy frost
formation late tonight/early Friday morning. Do not expect this to
be a widespread freeze.

The next more organized shortwave pushes into the GL region during
the day Friday and the timing of this shortwave and limited moisture
will favor more scattered light rain across northern Indiana /
southern lower Michigan. During the late afternoon Friday models
have increased a narrow window of CAPE...the challenge will be the
persistent cloud cover. The cooler air and limited insolation will
limit deep convection. Instability would suggest possible graupel
showers during the afternoon. This exiting wave/front will usher
in another shot of much cooler air Friday night/Saturday morning.

&&

.LONG TERM...(Friday Night through Thursday)
Issued at 230 PM EDT Thu May 6 2021

Cold start to the day Saturday. This also marks the beginning of
what appears to be a progressive and more zonal pattern setup.
Surface low deepens over the Central Plains during the day Saturday.
Surface moisture increases and surges northward into the mid-
Mississippi river valley with an associated warm front pushing into
central Indiana during the day and overnight Sunday. Showers become
more widespread Sunday with the heaviest rainfall along and south of
US 24. Convective potential increases with the warm frontal
surge...however there will be a struggle between cloud cover and
insolation.

After this wave passes the pattern becomes much more zonal across
the lower 48 with a number of short waves sweeping out of the
Northern Plains into the Great Lakes. Regardless this keeps much of
the Great Lakes under the influence of cooler flow and limited
moisture. This will keep below normal temperatures and if timing is
right...overnight lows could be cold enough for patchy frost to
form.

This pattern does not favor significant precipitation and it is
likely that the drought conditions will persist...with little
relief expected.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 115 PM EDT Thu May 6 2021

Latest surface analysis has broad area of low pressure over IL/IN
with band of light to moderate showers moving across northern
Indiana this afternoon. KIWX radar indicating slight uptick in
intensity over the past hour although instability remains marginal
despite favorable diurnal timing. Will continue with previous fcst
and include a mention of thunder in tempo group for KFWA. Mainly
VFR conditions being observed with areas of precip and will use
this as main group as front/low pressure move through. Upstream
obs do indicate a small post-frontal band of MVFR ceilings but
will stick with tempo MVFR associated with precip. Winds become
northwest behind this system with VFR to end the period.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...Lewis
SHORT TERM...Lewis
LONG TERM...Lewis
AVIATION...JAL


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