Alert archive / South Dakota / Flash Flood Warnings in 2011

Flash Flood Warning 30, NWS Rapid City, SD

July 25, 2011Meade County, Perkins County, South Dakota

NWS Rapid City, SD issued this flash flood warning at Jul 25, 2011, 6:44 PM MDT for Meade County, Perkins County, South Dakota. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 25, 2011, 6:44 PM MDT (00:44 UTC)
Expired
Jul 25, 2011, 9:51 PM MDT
In force
3 hr
Issued by
NWS Rapid City, SD
Area
Storm-based polygon
Flood severity
None

Counties Meade County, SD, Perkins County, SD

The radar

The Rapid City radar (KUDX), 102 km from the middle of the area, began a volume at 00:45 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, 0.7 hours before the alert went out and 330 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 2011-07-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2011-07-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -41 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2164 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
-41 m²/s²
0-3 km storm-relative helicity
83 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 flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Rapid City, SD wrote its last area forecast discussion before this flash flood warning went out at Jul 25, 12:30 PM MDT, 6 hours 14 minutes earlier.

Area forecast discussion, Jul 25, 12:30 PM MDT, 6 hours 14 minutes before
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1230 PM MDT MON JUL 25 2011

.DISCUSSION...AT 19Z SURFACE MAP SHOWS HIGH PRESSURE OVER THE ERN
DAKOTAS WITH SURFACE TROF EXTENDING FROM WRN MONTANA SOUTHEAST
INTO NERN WYOMING. SKIES ARE MOSTLY SUNNY WITH TEMPS IN THE UPPER
80S TO MID 90S. EXPECT TO SEE SCT CONVECTION TO DEVELOP LATER THIS
AFTERNOON AND INTO TONIGHT.

TONITE...UPPER TROF OVER PACIFIC NW WILL CONTINUE TO MOVE
EAST PRODUCING FALLING MID-LVL HEIGHTS. SURFACE TROF OVER CENTRAL
MONTANA WILL DEEPEN LATE THIS AFTERNOON AND MOVE INTO WRN SD BY
12Z TUESDAY. SURFACE FRONT CURRENTLY STRETCHES FROM WRN MONTANA
SE THRU NRN BLACK HILLS INTO CENTRAL SD. STRONG HEATING WILL LEAD
TO CAPE VALUES OF 2000-3000 J/KG. SURFACE BOUNDARY WILL ENHANCE LOW
LEVEL CONVERGENCE. THIS WILL COMBINE WITH DEEP LAYER SHEAR AND
STRONG INSTABILITY TO PRODUCE SCT TSTMS LATE THIS AFTERNOON AND
CONTINUING INTO TONIGHT WITH FRONTAL BOUNDARY MAIN FOCUS FOR SVR
THREAT LATE THIS AFT/TONIGHT.

TUES/TUES NIGHT...SFC LOW EXPECTED TO MOVE ACRS WRN SD/SOUTHERN ND
TUES AND TUES NITE. EXPECT DRY MORNING ON BACKSIDE OF MONDAY NIGHT
SYSTEM. STRONG DAYTIME HEATING WILL PRODUCE CAPE VALUES OF 1500-
2500 J/KG. LI'S WILL BE -4 TO -8 WITH STRONG MID-LEVEL INSTABILITY
ACROSS NRN CAMPBELL/CROOK COUNTIES AND WRN SD NORTH OF I-90. BUT
INHIBITING FACTOR WILL BE CAP ACROSS SD PLAINS. EXPECT ISOLD/SCT
TSTMS TO DEVELOP ACRS NERN WY/FAR WRN SD IN AFTERNOON AND CONTINUE
TO MOVE EAST ACROSS SD PLAINS TUES NITE.

WED/WED NITE...DAYTIME HEATING WILL AGAIN LEAD TO CAPE VALUES OF
1000-2000 J/KG WITH GOOD INSTABILITY. EXPECT TO SEE ISOLD/SCT
THUNDERSTORMS DEVELOP...MAINLY IN THE AFTERNOON AND EVENING HRS.
TEMPS WILL BE SEASONAL WITH HIGHS MAINLY IN THE MID 80S TO LOWER
90S.

.EXTENDED...GENERALLY ZONAL FLOW MIDWEEK WILL EVOLVE INTO RIDGING
OVER THE WEEKEND FOR WARMER AND DRIER CONDITIONS. TIMING OF
IMPULSES THAT COULD TRIGGER THUNDERSTORMS IS DIFFICULT AT THIS
RANGE...BUT SOME CONTINUITY EXISTS FOR A SMALL SHORTWAVE TO PRODUCE
THUNDERSTORMS THURSDAY. LEE SIDE TROF WILL PROVIDE SURFACE
CONVERGENCE FOR ISOLATED THUNDERSTORM DEVELOPEMENT.

&&

.AVIATION...SOME STRONG TO SEVERE THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON INTO THIS EVENING. OTHERWISE...VFR CONDITIONS ARE
EXPECTED THRU TUESDAY MORNING.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.

&&
Hazardous weather outlook, Jul 25, 1:30 PM MDT, 5 hours 14 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RAPID CITY SD
130 PM MDT MON JUL 25 2011

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-261300-
BENNETT-BUTTE-CENTRAL BLACK HILLS-CUSTER CO PLAINS-FALL RIVER-HAAKON-
HARDING-HERMOSA FOOT HILLS-JACKSON-MELLETTE-NORTHEASTERN CROOK-
NORTHERN BLACK HILLS-NORTHERN CAMPBELL-NORTHERN FOOT HILLS-
NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-PERKINS-RAPID CITY-
SHANNON-SOUTHERN BLACK HILLS-SOUTHERN CAMPBELL-SOUTHERN FOOT HILLS-
SOUTHERN MEADE CO PLAINS-STURGIS/PIEDMONT FOOT HILLS-TODD-TRIPP-
WESTERN CROOK-WESTON-WYOMING BLACK HILLS-ZIEBACH-
130 PM MDT (230 PM CDT) MON JUL 25 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN SOUTH DAKOTA AND
NORTHEASTERN WYOMING.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS ACROSS WESTERN AND
CENTRAL SOUTH DAKOTA...ALONG WITH OVER NORTHEAST WYOMING. LARGE HAIL
AND DAMAGING WIND GUSTS WILL BE THE MAIN THREATS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

AN UNSETTLED WEATHER PATTERN DEVELOPING THIS WEEK WILL BRING A DAILY
CHANCE FOR THUNDERSTORMS TO VARIOUS PARTS OF THE REGION. THERE IS A
SLIGHT RISK THAT SOME OF THESE STORMS MAY BECOME SEVERE ON TUESDAY
AFTERNOON THROUGH EARLY WEDNESDAY FOR SOUTH CENTRAL AND PORTIONS OF
WESTERN SOUTH DAKOTA...PARTICULARLY ALONG AND EAST OF A LINE FROM
FAITH TO PINE RIDGE. LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THE
MAIN THREATS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TODAY.

In the hours before

Local storm report, Jul 25, 6:07 PM MDT, 37 minutes before
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Local storm report, Jul 25, 6:11 PM MDT, 33 minutes before
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Local storm report, Jul 25, 6:12 PM MDT, 32 minutes before
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Local storm report, Jul 25, 6:21 PM MDT, 23 minutes before
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Local storm report, Jul 25, 6:24 PM MDT, 20 minutes before
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Local storm report, Jul 25, 6:25 PM MDT, 19 minutes before
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The office that day

Everything else NWS Rapid City, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 25, 6:15 PM MDTSevere Thunderstorm WarningUNRBennett, Haakon, Jackson, Mellette, Todd, Tripp60 min
Jul 25, 6:38 PM MDTSevere Thunderstorm WarningUNRBennett, Jackson65 min
Jul 25, 6:39 PM MDTSevere Thunderstorm WarningUNRMeade, Perkins, Ziebach66 min
Jul 25, 7:15 PM MDTSevere Thunderstorm WarningUNRBennett, Jackson, Mellette, Todd, Tripp28 min
Jul 26, 5:25 PM MDTSevere Thunderstorm WarningUNRMellette, Todd, Tripp65 min

Nearby

Flash Flood Warnings in South Dakota, 2011Every flash flood warning in 2011

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.