Alert archive / Iowa / Heat Advisories in 2018

Heat Advisory 5, NWS Sioux Falls, SD

July 4, 20187 counties in South Dakota; 11 counties in Iowa; 4 counties in Minnesota

NWS Sioux Falls, SD issued this heat advisory at Jul 4, 2018, 4:16 AM CDT for 7 counties in South Dakota; 11 counties in Iowa; 4 counties in Minnesota. It took effect at Jul 4, 2018, 1:00 PM CDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Jul 4, 2018, 4:16 AM CDT (09:16 UTC)
In effect from
Jul 4, 2018, 1:00 PM CDT
Expired
Jul 4, 2018, 8:00 PM CDT
In force
7 hr
Issued by
NWS Sioux Falls, SD
All 22 counties

Buena Vista County, IA, Cherokee County, IA, Clay County, IA, Dickinson County, IA, Ida County, IA, Lyon County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Cottonwood County, MN, Jackson County, MN, Nobles County, MN, Rock County, MN, Bon Homme County, SD, Clay County, SD, Lincoln County, SD, Minnehaha County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 69 km from the middle of the area, began a volume at 09:19 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

Aberdeen, SD (KABR), launched 00:00Z, 9.3 hours before the alert went out and 267 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-pSkew-T log-p diagram, Aberdeen, SD at 00:00Z on 2018-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3627 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 00:00Z on 2018-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
3627 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
889 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.7
Supercell composite
4.1

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 Sioux Falls, SD wrote its last area forecast discussion before this heat advisory went out at Jul 4, 4:13 AM CDT, 3 minutes earlier.

Area forecast discussion, Jul 4, 4:13 AM CDT, 3 minutes before
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Hazardous weather outlook, Jul 3, 7:42 PM CDT, 8 hours 34 minutes before
Hazardous Weather Outlook
National Weather Service Sioux Falls SD
742 PM CDT Tue Jul 3 2018

SDZ038>040-050-052>061-063>066-068-069-050045-
Beadle-Kingsbury-Brookings-Gregory-Jerauld-Sanborn-Miner-Lake-
Moody-Brule-Aurora-Davison-Hanson-McCook-Charles Mix-Douglas-
Hutchinson-Turner-Bon Homme-Yankton-
742 PM CDT Tue Jul 3 2018

This Hazardous Weather Outlook is for portions of central South
Dakota, east central South Dakota, south central South Dakota,
and southeast South Dakota.

.DAY ONE...Tonight

There is a chance of thunderstorms generally north of I-90 tonight.
Initially, a few storms could be strong to severe with the threat
gradually transitioning to a locally heavy rain threat as the
evening/overnight progresses.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Heat indices between 90 and 100 degrees are expected for 4th of
July afternoon. The chance of storms will increase during the late
afternoon and evening on Wednesday, with a few strong to severe
storms, as well as locally heavy rain possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not likely tonight.

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ062-067-070-071-050045-
Lyon IA-Osceola-Dickinson-Sioux-O'Brien-Clay IA-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln MN-Lyon MN-Murray-Cottonwood-
Nobles-Jackson-Pipestone-Rock-Dixon-Dakota-Minnehaha-Lincoln SD-
Clay SD-Union-
742 PM CDT Tue Jul 3 2018

This Hazardous Weather Outlook is for portions of northwest Iowa,
west central Iowa, southwest Minnesota, northeast Nebraska, and
southeast South Dakota.

.DAY ONE...Tonight

There is a small possibility of thunderstorms generally north of
I-90 tonight. If they do develop, a few storms could be strong to
severe with the threat gradually transitioning to a locally heavy
rain threat as the evening/overnight progresses.

Moderate to major flooding continues on several rivers and
streams. For specific river details, visit https://water.weather.gov.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Heat indices around 100 degrees are again expected for 4th of
July afternoon. The chance of storms will increase during the late
afternoon and evening on Wednesday, with a few strong to severe
storms, as well as locally heavy rain possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight.

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 4, 9:37 AM CDTRiver Flood WarningFSDLincoln24 hr
Jul 4, 10:22 AM CDTSevere Thunderstorm WarningFSDDickinson, Osceola23 min
Jul 4, 10:36 AM CDTSevere Thunderstorm WarningFSDDickinson, Osceola39 min
Jul 4, 11:07 AM CDTSevere Thunderstorm WarningFSDClay, Dickinson38 min
Jul 4, 5:35 PM CDTSevere Thunderstorm WarningFSDCherokee, O'Brien, Plymouth, Sioux40 min
Jul 4, 6:17 PM CDTSevere Thunderstorm WarningFSDBuena Vista, Cherokee, Clay, O'Brien28 min
Jul 4, 6:46 PM CDTSevere Thunderstorm WarningFSDBuena Vista, Clay29 min
Jul 4, 9:37 AM CDTRiver Flood WarningFSDRock44 hr

Nearby

Heat Advisories in Iowa, 2018Heat Advisories in South Dakota, 2018Heat Advisories in Minnesota, 2018Every heat advisory 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.