Area Forecast Discussion
Issued by NWS Indianapolis, IN

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560
FXUS63 KIND 201657
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1257 PM EDT Sun May 20 2018

.UPDATE...
The AVIATION Section has been updated below.

&&

.SYNOPSIS...
Issued at 156 AM EDT Sun May 20 2018

Unsettled weather is expected to continue across Central Indiana
the next few days. A warm and humid air mass is expected to remain
in place across the Ohio Valley as a series of upper level weather
disturbances pass across the state. This will result in daily
showers and thunderstorms across Central Indiana...with best
chances during the afternoon and evening hours.

High pressure is expected to settle across the region for the
middle of the week...leading to some dry and warm weather. More
shower and storm chances will return next weekend.

&&

.NEAR TERM /Rest of Today/...

Issued at 914 AM EDT Sun May 20 2018

Warm and humid conditions continue for today. Of note right now is
the small cluster of strong thunderstorms making their way
eastward across southern Illinois. Radar is picking up the
possibility of small hail and it look like the activity will
cross thr border during the next hour effecting the southwest
corner of the area.

&&

.SHORT TERM /Tonight through Tuesday Night/...

Issued at 156 AM EDT Sun May 20 2018

Confidence for precip timing and locations remains rather low
during this period. The GFS and NAM continue to suggest poorly
defined SW flow in place aloft with several embedded short wave
with in the flow poised to push through the Ohio Valley tonight
through Monday Night. Confidence in these wave is low as the model
tend to not handle them well. Forecast soundings however once
again show the warm...humid and unstable airmass in place through
Monday Night. Thus...with best forcing aided by diurnal
heating...best chances for precip will be during the afternoon and
evening hours. That being said will trend highest pops at those
times...and given the possible hit and miss nature of these
showers and storms will trend the pops a little lower than the
forecast builder Guidance. As for temps through Monday night Night
will trend lows warmer than the blend and stick closet to the
blends on Highs.

By Tuesday and Tuesday Night...the GFS and NAM suggest some weak
ridging aloft and the SW moist flow aloft to be diverted somewhat
to the southeast. Broad lower level high pressure also appears to
be in place for Tuesday and Tuesday Night. Forecast soundings
also trend to introduce some drier air within the column. Thus
will try to aim for a dry forecast at that time....sticking close
to the blend on temperatures.

&&

.LONG TERM /Wednesday Through Saturday/...
Issued at 227 AM EDT Sun May 20 2018

Models are close enough that the model blend initialization
was accepted for most items.

Upper ridging and surface high pressure will work to keep the area
dry Wednesday and Thursday. However, there remains some uncertainty
if all areas will remain dry Wednesday with a surface front just to
the south.

A frontal system will bring rain chances Friday afternoon and again
Saturday.

Temperatures will remain above normal through the period.

&&

.AVIATION /Discussion for 20/1800Z TAF Issuance/...

Issued at 1249 PM EDT Sun May 20 2018

Low pressure is located over western MO with a quasi-stationary
front that extends eastward across central Indiana. A weak short
wave trough is moving into northwest Indiana with some weakening
showers that extend through central Indiana. A second, strong
shortwave is associated with the low in MO and this complex of
convection is expected to move into the region early tonight.

VFR conditions for the most part is expected,but MVF near VCTS
expected overnight.

&&

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

$$

SYNOPSIS...Puma
NEAR TERM...DM
SHORT TERM...Puma
LONG TERM....50
AVIATION...DM



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