Areal Flood Advisory 26, NWS Indianapolis, IN

Area Forecast Discussion
National Weather Service Indianapolis IN
629 PM EDT Sun Jul 11 2021

...Updated Aviation Discussion...

.Short Term...(This evening through Monday night)
Issued at 256 PM EDT Sun Jul 11 2021

GOES water vapor shows well defined upper low this afternoon across
NW MO with a slow meander to the southwest. Moisture streaming
northeast of this low into our local area with weak short waves
moving through the mean southwest flow. These waves coupled with
weak instability, ample moisture and diurnal timing have led to
scattered showers and a few isolated thunderstorms. Poor lapse rates
and weak shear profiles keeping stronger updrafts and storms from
developing today.

Upper low to begin a slow drift northeast over next 24 hours and
will eventually get absorbed by a short wave trough currently along
the western US/Canada border that will be moving eastward and
becoming a bit sharper with time. Models in good agreement on this
scenario and have also slowed the eastward progression of residual
trough that is left after phasing. Really not much change in
thinking to short term forecast as this occurs, with primarily
diurnal driven showers and thunderstorms Monday. Lapse rates remain
poor with marginal instability on Monday. However, weak surface
boundary may end up north of the area which could help give us a few
more breaks in clouds and a Little increase in instability over
today. 850mb winds also look to be a bit stronger on Monday and
while shear is not great, is does look ample to help a few stronger
storms develop. PWATs remain high in the 1.5" to 2" range with good
moisture flux into the region so conditional heavy rain threat
exists if deeper convection can get going. Too much uncertainty on
this low chance condition so no watches planned with this issuance.

Tonight and Monday night will still see chances for rain remain but
coverage expected to be less than daytime unless any subtle short
waves embedded in southwest flow can focus moisture and lift. Better
details can be added to forecast if these waves appear in satellite
or radar trends.

Cloud cover should remain quite high through the period but cannot
rule out pockets of clearing with daytime mixing and subsidence
areas. This will keep daytime temps mostly in the 70s and overnight
lows in the 60s with muggy conditions continuing.

&&

.Long Term...(Tuesday through Sunday)
Issued at 256 PM EDT Sun Jul 11 2021

Ensemble means indicate the upper low currently over the Midwest
will lift off to the northeast around Wednesday. However, another
trough may drop into the area from the northwest towards the end of
the week.

May be a relative minimum in the convective threat around Wednesday
and Thursday, due to the departure of the upper low. However, the
ensembles suggest some remnant weak trough axis may hang back across
the area, so hesitant to take out the PoPs totally at this point.

The next upper trough looks to be weaker and more progressive
overall than the current system, although at this range, there is
quite a bit of variance among the ensembles as to the strength and
timing of this trough. Some of the faster solutions suggest the
convective threat may get shoved off to the south by late next
weekend. For now, will hold onto the PoPs through the end of the
extended, and monitor the trends.

&&

.Aviation...(00Z TAF Issuance)
Issued at 628 PM EDT Sun Jul 11 2021

IMPACTS:
-Flying conditions expected to be MVFR and worse at KIND and KLAF
 most of the TAF period and deteriorate to MVFR and worse at KHUF
 and KBMG after 03z MOnday.
-Scattered or isolated showers tonight and Monday morning. Can
 not rule out a thunderstorm. Widespread showers and possibly
 thunderstorms Monday afternoon.

DISCUSSION: Showers to diminish in coverage overnight but then
increase in coverage Monday afternoon as the quasi-stationary front
lifts north and a cold front approaches from the east. Can not rule
out thunderstorms, but chances too low to put in the TAFs, especially
tonight.

Winds will be problematic with a stationary front over central Indiana.
That said, generally they will become south and southwest Monday as the
front lifts to the north. In any case, wind speeds will mostly be less
than 10 knots.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&

Short Term...Lashley
Long Term...JAS
Aviation...MK

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>