Mesoscale Discussion 233

Issued

Mar 18, 2016, 6:04 AM CDT (11:04 UTC)

Expired

Mar 18, 2016, 8:30 AM CDT

In force

2 hr

Issued by

the Storm Prediction Center

Chance of a watch

20%

The Altus AFB radar (KFDR), 122 km from the middle of the area, began a volume at 11:05 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.

485 
ACUS11 KWNS 181105
SWOMCD
SPC MCD 181104 
OKZ000-TXZ000-181330-

MESOSCALE DISCUSSION 0233
NWS STORM PREDICTION CENTER NORMAN OK
0604 AM CDT FRI MAR 18 2016

AREAS AFFECTED...PORTIONS OF SOUTHERN OK AND FAR NORTH TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 181104Z - 181330Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ELEVATED THUNDERSTORMS ARE EXPECTED TO DEVELOP BY AROUND
12Z IN SOUTHWEST OK AND ADJACENT NORTHWEST TX WITH COVERAGE
EXPANDING AS STORMS DEVELOP/SPREAD TO THE EAST-SOUTHEAST IN VICINITY
OF THE RED RIVER THROUGH SOUTHERN OK AND NORTH TX THIS MORNING. 
HAIL IS EXPECTED TO BE THE MAIN THREAT...WITH SOME OF THE HAIL
EXCEEDING 1 INCH DIAMETER.  THE OVERALL SEVERE RISK IS FORECAST TO
REMAIN LIMITED...PRECLUDING A WATCH ISSUANCE AT THIS TIME.

DISCUSSION...LOW-LEVEL MOISTURE HAS BEEN SPREADING NORTHWARD DURING
THE OVERNIGHT...GIVEN SOUTH-SOUTHEASTERLY SURFACE WINDS FROM CENTRAL
INTO NORTHWEST TX AND A 30-40-KT LOW-LEVEL JET EXTENDING FROM
CENTRAL AND WEST TX INTO THE RED RIVER AREA OF NORTH TX AND SOUTHERN
OK.  MEANWHILE...00Z SOUNDINGS DETECTED THE PRESENCE OF STEEP
MIDLEVEL LAPSE RATES ACROSS THE SOUTHERN PLAINS /7-8 C PER KM/...AND
COMBINED WITH THE MOISTURE RETURN IS RESULTING IN MUCAPE OF
1000-2000 J/KG.  OBJECTIVE ANALYSES CONTINUED TO SHOW WARM ADVECTION
ALONG AND WITHIN THE NOSE OF THE LOW-LEVEL JET.  THIS WAA REGIME AND
WEAK HEIGHT FALLS AHEAD OF A DIGGING TROUGH INTO THE CENTRAL HIGH
PLAINS WILL PROVIDE FURTHER FORCING FOR UPWARD VERTICAL MOTION...AS
A COLD FRONT ADVANCES TO THE SOUTH-SOUTHEAST INTO SOUTHERN OK AND
NORTHWEST TO NORTHERN TX.  AS UVVS BECOME MAXIMIZED IN SOUTHWEST
OK/NORTHWEST TX BETWEEN 11-12Z...ELEVATED TSTM DEVELOPMENT IS
EXPECTED.  THE PRESENCE OF MODERATE INSTABILITY...STEEP MIDLEVEL
LAPSE RATES...AND 30-40 KT OF CLOUD-LAYER SHEAR PER STRENGTHENING
WESTERLY MIDLEVEL WINDS SHOULD PROVE FAVORABLE FOR HAIL GROWTH WITH
SOME EXCEEDING 1 INCH IN DIAMETER.

MOST CAMS SUGGEST STORM DEVELOPMENT ACROSS SOUTHWEST AND/OR
SOUTH-CENTRAL OK INTO ADJACENT NORTH TX BETWEEN 11-13Z WITH ISOLATED
TO SCATTERED COVERAGE.  EARLY STAGES OF THIS SCENARIO APPEAR TO BE
UNDERWAY AS IR SATELLITE IMAGERY SHOWS COOLING CLOUD TOPS IN FAR
SOUTHERN OK FROM MURRAY AND STEPHENS COUNTIES TO TILLMAN
COUNTY...AND INITIAL INDICATIONS OF REFLECTIVITY IN SOUTHERN OK AND
JUST WEST OF CHILDRESS TX.

..PETERS/EDWARDS.. 03/18/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...TSA...FWD...OUN...LUB...

LAT...LON   33209711 33349837 33569935 33729999 33830025 34270032
            34719983 34899874 35019801 35029726 34839614 34519567
            34079547 33639549 33289569 33189649 33209711

Mesoscale Discussions in Oklahoma, 2016Mesoscale Discussions in Texas, 2016Every mesoscale discussion in 2016

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.