Alert archive / Arkansas / Heat Advisories in 2017

Heat Advisory 4, NWS Memphis, TN

July 21, 2017Clay County, Craighead County, Greene County, Arkansas

NWS Memphis, TN issued this heat advisory at Jul 21, 2017, 2:55 PM CDT for Clay County, Craighead County, Greene County, Arkansas. It took effect at Jul 22, 2017, 8:00 PM CDT. It was in force for 18 hr.

The area

The counties it named.

The facts

Issued: Jul 21, 2017, 2:55 PM CDT (19:55 UTC)
In effect from: Jul 22, 2017, 8:00 PM CDT
Expired: Jul 23, 2017, 1:34 PM CDT
In force: 18 hr
Issued by: NWS Memphis, TN

Counties Clay County, AR, Craighead County, AR, Greene County, AR

The radar

The Memphis radar (KNQA), 104 km from the middle of the area, began a volume at 19:56 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

Little Rock, AR (KBYH), launched 12:00Z, 7.9 hours before the alert went out and 151 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: 1306 J/kg
Mixed-layer CIN: -51 J/kg
Mixed-layer LCL: 1315 m above ground
0-6 km bulk shear: 3 kt
0-1 km storm-relative helicity: -18 m²/s²
0-3 km storm-relative helicity: 45 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 heat advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Memphis, TN wrote its last area forecast discussion before this heat advisory went out at Jul 21, 12:32 PM CDT, 2 hours 23 minutes earlier.

Area forecast discussion, Jul 21, 12:32 PM CDT, 2 hours 23 minutes before

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Hazardous weather outlook, Jul 21, 11:36 AM CDT, 3 hours 19 minutes before

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The office that day

Everything else NWS Memphis, TN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 21, 11:30 AM CDT	Excessive Heat Warning	MEG	Dyer, Lake, Lauderdale, Obion, Shelby, Tipton	33 hr
Jul 21, 11:30 AM CDT	Heat Advisory	MEG	Dyer, Lake, Lauderdale, Obion, Shelby, Tipton	3 hr

Nearby

Heat Advisories in Arkansas, 2017 Every heat advisory in 2017

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.