Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 212304
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
704 PM EDT Sat Jul 21 2018

.SYNOPSIS...
Issued at 248 PM EDT Sat Jul 21 2018

An upper level low will continue to bring chances for scattered
rain showers into tonight and Sunday. Lows will drop into the
upper 60s tonight, with highs into the mid to upper 70s on Sunday.
A mainly dry and warmer pattern is expected next week.

&&

.SHORT TERM...(This Evening through Sunday Night)
Issued at 248 PM EDT Sat Jul 21 2018

Ample moisture/forcing with closed low directly overhead will
continue to generate numerous showers and perhaps a few storms late
aftn/early eve. Extensive cloud cover and precipitation has reduced
sfc heating and the potential for funnel clouds/landspouts...though
cannot completely rule it out late this aftn across ne IN/nw OH near
sfc shear zone. Locally heavy downpours/rainfall will be the main
threat otherwise with this activity given slow cell movement and
high moisture content (precipitable water values near 1.70 inches).

The main circulation center broadens southeast toward the OH/TN
Valleys by later tonight and Sunday. Mid level deformation forcing
remains in place on the northern fringe of this wave, while some
drier air infiltrates in east-northeasterly flow. This should bring
an overall decrease in shower coverage/chances during this time,
especially across northern portions of the forecast area. There is
some uncertainty on local impacts from a coastal low that is modeled
to be slung back northwest into Michigan by later Sunday/Sunday
night. Will keep with a mainly dry forecast for now as the latest
model consensus has the more focused deep layer QG forcing and mid
level moisture advection overlap north-northeast of the IWX CWA.

&&

.LONG TERM...(Monday through Saturday)
Issued at 248 PM EDT Sat Jul 21 2018

A lingering mid level trough and axis of deeper moisture will align
from the Deep South through the Eastern OH Valley Monday through
Wednesday. Weak ridging tries to build in on the backside of this
feature and likely provides mainly dry/warmer wx during this time.
Flow becomes increasingly progressive with several lower amplitude
waves to progress through in westerly flow Thursday through
Saturday. This could bring a couple opportunities for showers.
However, expect more active convection to focus well south as broad
Great Lakes troughing forces the main instability/theta-e axis into
the OH/TN/Mid MS valleys. Temperatures should be pretty close to
seasonal norms otherwise through the period.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
Issued at 659 PM EDT Sat Jul 21 2018

Cyclonic flow with vertically stacked circulation over the
forecast area through the TAF period. Periods of showers will
persist through the overnight with isolated moderate to heavy
rainfall. Timing and exact location of the more intense showers
will be problematic and have opted to keep prevailing MVFR with
isolated IFR CIGS through late in the forecast period Sunday.

No signficant changes to wind direction or speed through the
period...however some showers could produce isolated stronger
gusts.

Do not expect fog to be a problem tonight with abundant cloud
cover and good mixing.

Convection and isoalted -tsra possible Sunday...especially closer
to KFWA.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Beach Hazards Statement through Sunday afternoon for INZ003.

MI...Beach Hazards Statement through Sunday afternoon for MIZ077.

OH...NONE.
LM...Small Craft Advisory until 5 PM EDT Sunday for LMZ043-046.

&&

$$

SYNOPSIS...Steinwedel
SHORT TERM...Steinwedel
LONG TERM...Steinwedel
AVIATION...Lewis


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