Alert archive / Missouri / Excessive Heat Watches in 2012

Excessive Heat Watch 1, NWS St. Louis, MO

July 19, 201222 counties in Missouri; 16 counties in Illinois

NWS St. Louis, MO issued this excessive heat watch at Jul 19, 2012, 2:59 PM CDT for 22 counties in Missouri; 16 counties in Illinois. It took effect at Jul 22, 2012, 1:00 PM CDT. It was in force for .

The area

The counties it named.

The facts

Issued: Jul 19, 2012, 2:59 PM CDT (19:59 UTC)
In effect from: Jul 22, 2012, 1:00 PM CDT
Expired: Jul 20, 2012, 4:00 AM CDT
In force
Issued by: NWS St. Louis, MO

All 38 counties

Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Clinton County, IL, Fayette County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Pike County, IL, Saint Clair County, IL, Washington County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, City of Saint Louis, MO, Cole County, MO, Franklin County, MO, Gasconade County, MO, Jefferson County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Marion County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Shelby County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 41 km from the middle of the area, began a volume at 20:01 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

Lincoln, IL (KILX), launched 12:00Z, 8.0 hours before the alert went out and 230 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: 1080 J/kg
Mixed-layer CIN: -228 J/kg
Mixed-layer LCL: 1472 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 103 m²/s²
0-3 km storm-relative helicity: 111 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this excessive heat watch 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 excessive heat watch went out at Jul 19, 12:40 PM CDT, 2 hours 19 minutes earlier.

Area forecast discussion, Jul 19, 12:40 PM CDT, 2 hours 19 minutes before

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Hazardous weather outlook, Jul 19, 4:39 AM CDT, 10 hours 20 minutes before

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Nearby

Excessive Heat Watches in Missouri, 2012 Excessive Heat Watches in Illinois, 2012 Every excessive heat watch in 2012

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.