Alert archive / Oklahoma / Special Weather Statements in 2015

Special Weather Statement, NWS Norman, OK

April 18, 2015Alfalfa County, Oklahoma

NWS Norman, OK issued this special weather statement at Apr 18, 2015, 12:49 PM CDT for Alfalfa County, Oklahoma. It was in force for 26 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 18, 2015, 12:49 PM CDT (17:49 UTC)
Expired
Apr 18, 2015, 1:15 PM CDT
In force
26 min
Issued by
NWS Norman, OK

County Alfalfa County, OK

The radar

The Vance AFB radar (KVNX), 29 km from the middle of the area, began a volume at 17:51 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

Dodge City, (KDDC), launched 12:00Z, 5.8 hours before the alert went out and 179 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, Dodge City, at 12:00Z on 2015-04-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 192 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, Dodge City, at 12:00Z on 2015-04-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -48 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
192 J/kg
Mixed-layer CIN
-124 J/kg
Mixed-layer LCL
897 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
-48 m²/s²
0-3 km storm-relative helicity
9 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Norman, OK wrote its last area forecast discussion before this special weather statement went out at Apr 18, 11:50 AM CDT, 59 minutes earlier.

Area forecast discussion, Apr 18, 11:50 AM CDT, 59 minutes before
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Hazardous weather outlook, Apr 18, 11:50 AM CDT, 59 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1150 AM CDT SAT APR 18 2015

OKZ004>048-050>052-TXZ083>090-191000-
HARPER-WOODS-ALFALFA-GRANT-KAY-ELLIS-WOODWARD-MAJOR-GARFIELD-
NOBLE-ROGER MILLS-DEWEY-CUSTER-BLAINE-KINGFISHER-LOGAN-PAYNE-
BECKHAM-WASHITA-CADDO-CANADIAN-OKLAHOMA-LINCOLN-GRADY-MCCLAIN-
CLEVELAND-POTTAWATOMIE-SEMINOLE-HUGHES-HARMON-GREER-KIOWA-JACKSON-
TILLMAN-COMANCHE-STEPHENS-GARVIN-MURRAY-PONTOTOC-COAL-COTTON-
JEFFERSON-CARTER-JOHNSTON-ATOKA-LOVE-MARSHALL-BRYAN-HARDEMAN-
FOARD-WILBARGER-WICHITA-KNOX-BAYLOR-ARCHER-CLAY-
1150 AM CDT SAT APR 18 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHERN...
WESTERN...CENTRAL...AND SOUTHERN OKLAHOMA...AND WESTERN NORTH
TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

.THUNDERSTORMS...
THERE IS AN ENHANCED RISK OF SEVERE STORMS ACROSS MUCH OF
OKLAHOMA AND ALL OF WESTERN NORTH TEXAS.

LOCATION...
THE ENHANCED RISK AREA IS ALONG AND EAST OF A LINE FROM BUFFALO...TO
CHEYENNE...TO MANGUM IN OKLAHOMA...TO QUANAH AND BENJAMIN IN WESTERN
NORTH TEXAS....AND WEST OF A LINE FROM MEDFORD...TO OKLAHOMA CITY..TO
. THE REMAINDER OF OKLAHOMA AND WESTERN NORTH TEXAS IS IN
A SLIGHT RISK.

TIMING...
3PM TO MIDNIGHT.

IMPACTS...
HAIL UP TO THE SIZE OF GOLF BALLS TO TENNIS BALLS...AND WIND GUSTS UP
TO 70 MPH WILL BE THE MAIN CONCERNS. LOCALLY HEAVY RAIN WILL ALSO BE
POSSIBLE.

DISCUSSION...
SHOWERS AND ISOLATED STORMS ASSOCIATED WITH A WEAK DISTURBANCE
WILL CONTINUE TO DRIFT EASTWARD FROM CENTRAL THROUGH NORTHERN
OKLAHOMA. THIS ACTIVITY WILL REMAIN NON-SEVERE WITH OCCASIONAL
CLOUD TO GROUND LIGHTNING THE MAIN CONCERN.

ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER THIS
AFTERNOON AND MOVE ACROSS THE AREA THROUGH TONIGHT. SUBSTANTIAL
LOW CLOUDS OVER WESTERN OKLAHOMA AND WESTERN NORTH TEXAS HAVE
RESULTED IN SLOW SURFACE HEATING AND DESTABILIZATION...BUT THESE
WILL LIKELY LIFT WITH FURTHER SURFACE HEATING. WITH VERY LITTLE
CAPPING...STORMS MAY DEVELOP MOST ANYWHERE ACROSS OKLAHOMA AND
NORTH TEXAS...BUT THE MOST LIKELY AREA FOR STRONG TO SEVERE STORM
DEVELOPMENT WILL BE NEAR A DRYLINE IN WESTERN OKLAHOMA AND WESTERN
NORTH TEXAS. INSTABILITY AND WIND SHEAR THIS AFTERNOON AND EVENING
WILL BE SUFFICIENT FOR VERY LARGE HAIL. THE STORMS COULD DEVELOP
INTO ONE OR MORE LINES OR CLUSTERS THIS EVENING...RESULTING IN MORE
OF A DAMAGING WIND THREAT. SHOWERS AND THUNDERSTORMS WILL LIKELY
CONTINUE INTO SUNDAY BUT THE SEVERE WEATHER POTENTIAL IS EXPECTED
TO DECREASE OVERNIGHT.

.SPOTTER AND EMERGENCY MANAGEMENT STATEMENT...

STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL ACROSS THE
AREA SHOULD PREPARE FOR SEVERE WEATHER OPERATIONS THIS AFTERNOON
THROUGH THIS EVENING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY...

.THUNDERSTORMS...
SHOWERS AND THUNDERSTORMS WILL LINGER INTO SUNDAY. SEVERE WEATHER
IS UNLIKELY BUT A FEW STORMS MAY BECOME STRONG PRODUCING SMALL
HAIL.

SHOWER AND THUNDERSTORM CHANCES WILL RETURN MONDAY NIGHT THROUGH
FRIDAY...AS A SERIES OF UPPER LEVEL SYSTEMS MOVE ACROSS THE SOUTHERN
PLAINS. STRONG TO SEVERE THUNDERSTORM POTENTIAL WILL LIKELY EXIST
FOR A TIME FROM MID TO LATE NEXT WEEK.

GET GRAPHICS AND MORE DETAILS AT WEATHER.GOV/NORMAN...AND FOLLOW
OUR WEATHER FORECAST OFFICE ON TWITTER AND FACEBOOK.

EM/MBS/AUSTIN

In the hours before

Special weather statement, Apr 18, 12:49 PM CDT, 0 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
1249 PM CDT SAT APR 18 2015

OKZ006-181815-
ALFALFA OK-
1249 PM CDT SAT APR 18 2015

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN ALFALFA COUNTY UNTIL
115 PM CDT...

AT 1247 PM CDT...A STRONG THUNDERSTORM WAS LOCATED NEAR CARMEN...
MOVING NORTH AT 15 MPH.

HAZARDS INCLUDE...
HAIL UP TO THE SIZE OF NICKELS...
WIND GUSTS TO 40 MPH...

LOCATIONS IMPACTED INCLUDE...
CHEROKEE...CARMEN...LAMBERT AND INGERSOLL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MONITOR THE WEATHER SITUATION CLOSELY AND BE ALERT FOR THREATENING
WEATHER CONDITIONS.

&&

LAT...LON 3656 9840 3656 9853 3680 9853 3680 9834
TIME...MOT...LOC 1747Z 187DEG 15KT 3660 9849

AUSTIN

The office that day

Everything else NWS Norman, OK issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 18, 1:15 PM CDTSpecial Weather StatementOUNAlfalfa30 min
Apr 18, 1:58 PM CDTSpecial Weather StatementOUNAlfalfa, Major32 min
Apr 18, 2:02 PM CDTSpecial Weather StatementOUNHarper28 min
Apr 18, 2:32 PM CDTSevere Thunderstorm WarningOUNHarper43 min
Apr 18, 2:54 PM CDTSpecial Weather StatementOUNWoods36 min
Apr 18, 3:01 PM CDTSevere Thunderstorm WarningOUNWoods, Woodward44 min
Apr 18, 3:08 PM CDTSpecial Weather StatementOUNMajor37 min
Apr 18, 3:15 PM CDTSpecial Weather StatementOUNCaddo30 min
Apr 18, 3:40 PM CDTSpecial Weather StatementOUNBlaine35 min
Apr 18, 3:45 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Woods45 min
Apr 18, 3:47 PM CDTSpecial Weather StatementOUNMajor28 min
Apr 18, 3:49 PM CDTSevere Thunderstorm WarningOUNBlaine, Kingfisher41 min
Apr 18, 3:54 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Major, Woods51 min
Apr 18, 4:28 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Woods47 min
Apr 18, 4:36 PM CDTSevere Thunderstorm WarningOUNComanche, Cotton, Tillman39 min
Apr 18, 4:43 PM CDTSpecial Weather StatementOUNEllis32 min
Apr 18, 4:47 PM CDTSevere Thunderstorm WarningOUNAlfalfa43 min
Apr 18, 5:01 PM CDTSpecial Weather StatementOUNBeckham29 min
Apr 18, 5:10 PM CDTSevere Thunderstorm WarningOUNComanche, Cotton, Jackson, Kiowa, Tillman50 min
Apr 18, 5:13 PM CDTSevere Thunderstorm WarningOUNBeckham, Greer, Roger Mills, Washita47 min
Apr 18, 5:19 PM CDTSpecial Weather StatementOUNGarfield26 min
Apr 18, 5:26 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Grant49 min
Apr 18, 5:36 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Woods39 min
Apr 18, 5:51 PM CDTSevere Thunderstorm WarningOUNCaddo, Comanche, Kiowa, Washita39 min
Apr 18, 6:01 PM CDTSevere Thunderstorm WarningOUNCarter, Jefferson, Love44 min
Apr 18, 6:03 PM CDTSpecial Weather StatementOUNCuster27 min
Apr 18, 6:11 PM CDTSevere Thunderstorm WarningOUNGrant49 min
Apr 18, 6:22 PM CDTSpecial Weather StatementOUNGrady38 min
Apr 18, 6:24 PM CDTSpecial Weather StatementOUNHarper36 min
Apr 18, 6:30 PM CDTSevere Thunderstorm WarningOUNCaddo, Comanche, Kiowa, Washita45 min
Apr 18, 6:35 PM CDTSevere Thunderstorm WarningOUNCarter, Garvin, Murray40 min
Apr 18, 6:38 PM CDTSevere Thunderstorm WarningOUNCanadian, Cleveland, Grady, McClain, Oklahoma52 min
Apr 18, 6:44 PM CDTSevere Thunderstorm WarningOUNJackson, Kiowa, Washita31 min
Apr 18, 6:45 PM CDTSevere Thunderstorm WarningOUNHarper20 min
Apr 18, 6:56 PM CDTSevere Thunderstorm WarningOUNCuster, Washita19 min
Apr 18, 6:59 PM CDTSpecial Weather StatementOUNGarvin, McClain31 min
Apr 18, 3:26 PM CDTSevere Thunderstorm WarningOUNArcher, Baylor49 min
Apr 18, 4:10 PM CDTSevere Thunderstorm WarningOUNArcher, Baylor, Wichita, Wilbarger50 min
Apr 18, 6:46 PM CDTSpecial Weather StatementOUNWichita29 min

Nearby

Special Weather Statements in Oklahoma, 2015Every special weather statement in 2015

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.