Alert archive / Missouri / Special Weather Statements in 2018

Special Weather Statement, NWS St. Louis, MO

July 19, 2018Boone County, Missouri

NWS St. Louis, MO issued this special weather statement at Jul 19, 2018, 10:17 AM CDT for Boone County, Missouri. It was in force for 43 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 19, 2018, 10:17 AM CDT (15:17 UTC)
Expired: Jul 19, 2018, 11:00 AM CDT
In force: 43 min
Issued by: NWS St. Louis, MO

County Boone County, MO

The radar

The St Louis radar (KLSX), 148 km from the middle of the area, began a volume at 15:19 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 3.3 hours before the alert went out and 288 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1220 J/kg
Mixed-layer CIN: -118 J/kg
Mixed-layer LCL: 767 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 79 m²/s²
0-3 km storm-relative helicity: 181 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 5.4

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS St. Louis, MO wrote its last area forecast discussion before this special weather statement went out at Jul 19, 7:11 AM CDT, 3 hours 6 minutes earlier.

Area forecast discussion, Jul 19, 7:11 AM CDT, 3 hours 6 minutes before

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<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
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  <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.
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      <p id="message2">
        Please try again in a few minutes.
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Hazardous weather outlook, Jul 19, 4:33 AM CDT, 5 hours 44 minutes before

Hazardous Weather Outlook
National Weather Service Saint Louis MO
433 AM CDT Thu Jul 19 2018

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-200945-
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Clinton IL-
Marion IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair IL-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
433 AM CDT Thu Jul 19 2018

This hazardous weather outlook is for portions of eastern and
central Missouri as well as west central and southwest Illinois.

.DAY ONE...Today and Tonight

Isolated to scattered severe thunderstorms are possible this
afternoon and tonight. The greatest risk for severe storms will
be across northeast Missouri and west central Illinois. The
primary threats are damaging winds and large hail.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Isolated severe thunderstorms are possible across southwest
Illinois on Friday.

There will be a slight chance for thunderstorms Saturday afternoon
and Sunday afternoon across southwest Illinois, and also on
Tuesday and Tuesday evening for southeast Missouri and southwest
Illinois.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon and tonight. Spotters
are encouraged to report any severe weather, if observed, to the
National Weather Service.

GKS

In the hours before

Special weather statement, Jul 19, 10:17 AM CDT, 0 minutes before

Special Weather Statement
National Weather Service St Louis MO
1017 AM CDT THU JUL 19 2018

MOZ041-042-050-191600-
Audrain MO-Boone MO-Callaway MO-
1017 AM CDT THU JUL 19 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN BOONE...WESTERN
AUDRAIN AND NORTHWESTERN CALLAWAY COUNTIES UNTIL 1100 AM CDT...

At 1017 AM CDT, Doppler radar was tracking a strong thunderstorm near
Clark, moving southeast at 25 mph.

Half inch hail and wind gusts up to 50 mph will be possible with this
storm.

Locations impacted include...
Columbia, Mexico, Centralia, Hallsville, Sturgeon, Murry, Harrisburg,
Hatton and Thompson.

This includes Interstate 70 in Missouri between exits 131 and 144.

This also includes  Finger Lakes State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3925 9243 3925 9231 3935 9231 3935 9228
      3914 9181 3882 9213 3915 9248
TIME...MOT...LOC 1517Z 312DEG 23KT 3923 9236

Carney

The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 19, 10:45 AM CDT	Special Weather Statement	LSX	Cole, Moniteau	45 min
Jul 19, 11:01 AM CDT	Severe Thunderstorm Warning	LSX	Boone, Callaway, Moniteau	44 min
Jul 19, 11:39 AM CDT	Special Weather Statement	LSX	Cole	51 min
Jul 19, 12:23 PM CDT	Special Weather Statement	LSX	Osage	52 min

Nearby

Special Weather Statements in Missouri, 2018 Every special weather statement in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.