Alert archive / South Dakota / Frost Advisories in 2009

Frost Advisory 1, NWS Sioux Falls, SD

May 15, 20096 counties in South Dakota

NWS Sioux Falls, SD issued this frost advisory at May 15, 2009, 2:39 PM CDT for 6 counties in South Dakota. It took effect at May 16, 2009, 3:00 AM CDT. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued: May 15, 2009, 2:39 PM CDT (19:39 UTC)
In effect from: May 16, 2009, 3:00 AM CDT
Expired: May 16, 2009, 8:00 AM CDT
In force: 5 hr
Issued by: NWS Sioux Falls, SD

Counties Aurora County, SD, Beadle County, SD, Brule County, SD, Jerauld County, SD, Kingsbury County, SD, Sanborn County, SD

The radar

The Sioux Falls radar (KFSD), 140 km from the middle of the area, began a volume at 19:41 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

Omaha, NE (KOAX), launched 12:00Z, 7.7 hours before the alert went out and 344 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 650 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 215 m²/s²
0-3 km storm-relative helicity: 138 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this frost 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 frost advisory went out at May 15, 2:24 PM CDT, 15 minutes earlier.

Area forecast discussion, May 15, 2:24 PM CDT, 15 minutes before

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Hazardous weather outlook, May 15, 11:15 AM CDT, 3 hours 24 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1115 AM CDT FRI MAY 15 2009

SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098-
IAZ001>003-012>014-020>022-031-032-NEZ013-014-161200-
AURORA-BEADLE-BON HOMME-BROOKINGS-BRULE-BUENA VISTA IA-
CHARLES MIX-CHEROKEE IA-CLAY-CLAY IA-COTTONWOOD MN-DAKOTA NE-
DAVISON-DICKINSON IA-DIXON NE-DOUGLAS-GREGORY-HANSON-HUTCHINSON-
IDA IA-JACKSON MN-JERAULD-KINGSBURY-LAKE-LINCOLN-LINCOLN MN-
LYON IA-LYON MN-MCCOOK-MINER-MINNEHAHA-MOODY-MURRAY MN-NOBLES MN-
OBRIEN IA-OSCEOLA IA-PIPESTONE MN-PLYMOUTH IA-ROCK MN-SANBORN-
SIOUX IA-TURNER-UNION-WOODBURY IA-YANKTON-
1115 AM CDT FRI MAY 15 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA...
SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS...
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG A COLD FRONT MAINLY
EAST OF A LINE FROM YANKTON TO BROOKINGS SOUTH DAKOTA. THERE IS A
SMALL CHANCE THAT AN ISOLATED STORM COULD PRODUCE A BRIEF TORNADO
OR QUARTER SIZE HAIL IN SOUTHWEST MINNESOTA THIS AFTERNOON.
OTHERWISE...A FEW STORMS ACROSS NORTHWEST IOWA AND SOUTHWEST
MINNESOTA COULD PRODUCE HAIL UP TO DIME SIZE.

WIND AND FOG...
WINDS AHEAD OF THE FRONT THIS AFTERNOON COULD GUST TO 35 MPH OVER
SOUTHWEST MINNESOTA AND NORTHWEST IOWA. BEHIND THE COLD
FRONT...STRONG NORTHWEST WINDS ARE EXPECTED THIS AFTERNOON INTO
TONIGHT.  WIND GUSTS MAY APPROACH 35 TO 40 MPH LATE THIS
AFTERNOON INTO THIS EVENING BEFORE DECREASING AFTER MIDNIGHT.

EXCESSIVE TEMPERATURES...
AREAS OF FROST MAY DEVELOP WEST OF A LINE FROM LAKE ANDES TO DE
SMET SOUTH DAKOTA. IN ADDITION...A FEW LOCATIONS FROM HURON TO
CHAMBERLAIN MAY FALL BELOW FREEZING. PLEASE PROTECT TENDER
VEGETATION DURING THESE UNSEASONABLY COOL CONDITIONS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

PATCHY FROST IS POSSIBLE ALONG AND EAST OF INTERSTATE 29 SUNDAY
MORNING.  PLEASE PROTECT EXPOSED TENDER VEGETATION.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT.

&&

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT
WWW.WEATHER.GOV/SIOUXFALLS. THIS INCLUDES THE GRAPHICAL HAZARDOUS
WEATHER OUTLOOK.

SCHUMACHER

Nearby

Frost Advisories in South Dakota, 2009 Every frost advisory in 2009

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.