Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 221631

Area Forecast Discussion
National Weather Service Indianapolis IN
1231 PM EDT Tue May 22 2018

The AVIATION Section has been updated below.


Issued at 254 AM EDT Tue May 22 2018

A cold front will move through the area today, bringing another
chance for showers and thunderstorms. High pressure will then
provide dry conditions through early Saturday. Another front and
upper system will bring rain chances Sunday into early next week.
Temperatures will remain above normal.


.NEAR TERM /Today/...

Issued at 921 AM EDT Tue May 22 2018

No changes to max temps for now. POPs were adjusted slightly to
account for current showers.

Overall, forecast appears in pretty good shape. Fog is gradually
thinning and lifting into stratus. Convective cloud across
northern and west central counties have been generating a few
showers. As front moves in and across central Indiana late morning
to late afternoon we should see a slight uptick in shower/storm
coverage with daytime heating but less coverage than yesterday
afternoon and evening.


.SHORT TERM.../Tonight through Thursday night/
Issued at 254 AM EDT Tue May 22 2018

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

The short term will be quiet with surface high pressure building in
and upper ridging developing aloft.

Thus expect mostly clear skies most areas. Went a little above the
model blend for highs Wednesday based on recent trends. Otherwise
the initialization`s numbers are decent.


.LONG TERM /Friday through Monday/...

Issued at 224 AM EDT Tue May 22 2018

Confidence is low in this forecast period.

The ECMWF suggests ridging aloft on Friday deteriorating to a
weak trough by Saturday and Sunday. However...little to no upper
support appears to push across Indiana. Best forcing remains
across the northern Great Lakes and Ontario. Meanwhile...the ECMWF
suggests a tropical upper low moving onshore into the lower
Mississippi valley by Saturday before moving to Western Tennessee
by Monday. For the most part...Indiana remains caught between
these two systems until Monday when the upper low to the south
begins to arrive.

Given the lack of support on Friday through Sunday...only triggers
at this point appear to be diurnal convection due to daytime
heating. Best chances here appear to be Sunday afternoon and there
after as models suggest a return of moisture as dew points surge
into the 60s. Thus removed many 20% pops from the forecast
builder...trending toward dry for Friday-Saturday. Kept 30 pops in
for Sunday afternoon for now...but again...confidence remains low.
best chances remain to be on Monday as the upper low to the south
begins to influence weather across Indiana.


.AVIATION /Discussion for 221800z TAFs/...

Issued at 1226 PM EDT Tue May 22 2018

MVFR through the period with winds at or below 10 knots veering
from west to northwest then northeast overnight.

Isolated thunderstorms possible at KIND and KHUF until 19z and
KBMG until 20z.

Cold front is moving southeast across central Indiana this
afternoon. Unstable air ahead of the front has been developing
towering cumulus which should become scattered showers and
isolated thunderstorms this afternoon south of the I-70 corridor.

High pressure will filter in drier air tonight and minimize any
threat for any more than light fog Wednesday morning daybreak.




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