Severe Thunderstorm Warning 17, NWS Quad Cities, IA

Area Forecast Discussion
National Weather Service Quad Cities IA IL
259 PM CDT Mon Apr 22 2019

.SYNOPSIS...
Issued at 257 PM CDT Mon Apr 22 2019

18Z surface data has a weak low north of KDSM. A cold front ran
south from the low into eastern Kansas. Observation data also
suggested the potential for subtle boundaries running east and
southeast from the low into northern Illinois and along the
Mississippi river down toward KUIN. Dew points were in the 50s ahead
of the cold front with 30s and 40s across the central and northern
Plains.

&&

.SHORT TERM...(This Evening through Tuesday)
ISSUED AT 257 PM CDT Mon Apr 22 2019

Through sunset convection is expected to increase in areal coverage
north of I-80 as the weak low approaches the area. This scenario is
based on conceptual models and what the overall larger picture is
suggesting.  South of I-80 convection should be fairly spotty.

The overall severe risk still looks marginal but a few isolated
severe storms cannot be ruled out. Primary risk looks to be hail
with a small potential for damaging winds.

This evening the cold front and low will sweep through the area with
rain slowly ending from west to east. A few severe storms may be
possible in the vicinity of the fronts. Some wrap around rain
showers or light rain is possible after midnight generally east of a
line from Manchester, IA to Sterling, IL as a weak upper level
disturbance rotates through the area.

On Tuesday much cooler, drier, and initially breezy conditions will
be seen across the area. Temperatures will be close to normal.

.LONG TERM...(Tuesday Night through Monday)
ISSUED AT 257 PM CDT Mon Apr 22 2019

High pressure will be in control for this period, and will provide
quiet and dry conditions across the area. Like the 00z run, the 12z
ECMWF is suggesting a weak shortwave passing across our south early
Wednesday morning, while the American models and CMC show it further
south into southern Missouri and Illinois. Will continue to treat
the ECMWF as an outlier for now, and will not advertise any chance
of POPs across our south. Above normal temperatures will remain in
place with southerly flow, and currently have afternoon highs
Wednesday in the upper 60s to lower 70s.

Thursday and Friday...

Latest guidance remains in decent agreement of bringing a cold front
across the region Thursday. The ECMWF, CMC and NAM have it passing
during the morning, while the GFS advertises an afternoon arrival.
Regardless of timing, this front will not have a lot of moisture and
only limited forcing with it, so not expecting a wide area of
showers or storms to accompany it with passage. The best chance for
any precipitation will be across northwest Illinois, where forcing
will be a little stronger with the shortwave. Here, will advertise
chance POPs through the afternoon and evening.

Temperature-wise, afternoon highs for Thursday will climb into lower
to middle 70s with warmer air in place ahead of the front. For
Friday, cooler air and passing high pressure will keep afternoon
highs in the middle 60s to near 70.

Saturday and Sunday...

Disagreements continue on the handling of an area of low pressure
passing across the Mississippi River Valley. The 12z ECMWF has come
in further south, and has the low passing east across central
Missouri. This would put us underneath easterly flow and rain
provided by isentropic lift. The GFS and CMC show the low much
further north into Minnesota and Wisconsin, which would put us in
the warm sector with a threat of showers and thunderstorms.

I will continue to handle this situation with a blended approach,
which keeps us underneath chance of POPs. Will advertise afternoon
highs ranging from near 60 in northwest Illinois, to near 70 in
northeast Missouri, but expect changes to this as models get a
better handle on the low track and warm front placement.

Monday on...

All models in agreement of unsettled weather continuing into early
next week, as frontal boundary develops across the eastern Great
Plains into the mid Mississippi River Valley. Temperatures will
average near normal for the end of April.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
ISSUED AT 115 PM CDT Mon Apr 22 2019

Unstable atmosphere across eastern Iowa and northern Illinois will
allow convection to develop ahead of the approaching cold front.
VFR conditions should be seen through 06z/23 with potential
MVFR/IFR conditions in SHRA/TSRA. After 06z/23 VFR conditions are
forecast with widespread low clouds moving in behind the front
that are just above 3 kft agl.

&&

.HYDROLOGY...
Issued at 1117 AM CDT Mon Apr 22 2019

Not much change to the forecasts along the Mississippi River as
routed water remains the main contributer to the forecasts.
Scattered showers and thunderstorms today and tonight should have
little affect on the Mississippi River level forecasts. Crests
are anticipated at Dubuque to Bellevue this coming weekend. Sites
downstream of Bellevue are expected to crest next week.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

SYNOPSIS...08
SHORT TERM...08
LONG TERM...Speck
AVIATION...08
HYDROLOGY...14

Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
329 AM CDT Mon Apr 22 2019

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-230830-
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson-
Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll-
Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson-
Warren-Hancock-McDonough-Scotland-Clark-
329 AM CDT Mon Apr 22 2019

This Hazardous Weather Outlook is for portions of north central
Illinois...northwest Illinois...west central Illinois...east
central Iowa...northeast Iowa...southeast Iowa and northeast
Missouri.

.DAY ONE...TODAY AND TONIGHT

The Storm Prediction Center has a marginal risk of severe
thunderstorms this afternoon into this evening, for portions of
eastern Iowa and northwest Illinois. The main risks will be large
hail and damaging winds, but an isolated tornado or two is
possible.

Moderate to major flooding will continue along the Mississippi
River. Please see the latest Flood Statements and Flood Warnings for
details.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

Thursday, there is a slight chance for thunderstorms. Severe weather
is not expected.

Thunderstorms are possible again Saturday and Saturday night. It is
too soon to determine the potential for severe weather.

Moderate to major flooding will continue along the Mississippi
River. Please see the latest Flood Statements and Flood Warnings for
details.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon into this evening.

Haase/Sheets

<!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>

<!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>

<!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>