Mesoscale Discussion 1014

Issued

Jun 14, 2015, 7:34 AM CDT (12:34 UTC)

Expired

Jun 14, 2015, 10:00 AM CDT

In force

2 hr

Issued by

the Storm Prediction Center

Chance of a watch

20%

The Aberdeen radar (KABR), 117 km from the middle of the area, began a volume at 12:34 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.

480 
ACUS11 KWNS 141234
SWOMCD
SPC MCD 141234 
SDZ000-NDZ000-141500-

MESOSCALE DISCUSSION 1014
NWS STORM PREDICTION CENTER NORMAN OK
0734 AM CDT SUN JUN 14 2015

AREAS AFFECTED...PORTIONS OF SOUTH DAKOTA...SOUTHERN NORTH DAKOTA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 141234Z - 141500Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN ONGOING MCS WILL CONTINUE SPREADING EWD ACROSS PARTS OF
SOUTH DAKOTA THIS MORNING...PERHAPS DEVELOPING INTO SOUTHERN NORTH
DAKOTA...AS WELL. THIS SYSTEM WILL POSE SOME RISK FOR ISOLATED
MARGINALLY SVR WIND GUSTS...AND CONVECTIVE TRENDS WILL CONTINUE TO
BE MONITORED. HOWEVER...WW ISSUANCE IS PRESENTLY UNLIKELY.

DISCUSSION...CONVECTION AT THE LEADING EDGE OF AN MCS CROSSING PARTS
OF WRN/CNTRL SOUTH DAKOTA HAS EVOLVED INTO MULTIPLE BANDED
STRUCTURES...SOME OF WHICH HAVE BECOME ORIENTED ORTHOGONAL TO THE
MEAN CLOUD-LAYER FLOW SAMPLED BY ABR/UDX VWPS. THESE VWPS SAMPLE
40-50-KT SWLYS/WSWLYS IN THE MID LEVELS...SUPPORTING SUFFICIENT DEEP
SHEAR FOR MAINTAINED/ORGANIZED CONVECTION THIS MORNING...AS THE
SYSTEM SPREADS EWD. THIS ACTIVITY HAS A HISTORY OF PRODUCING
SPORADIC SVR WIND GUSTS...ESPECIALLY AS IT INTENSIFIED AFTER
ADVANCING INTO THE WRN EXTENT OF GREATER LOW-LEVEL THETA-E INVOF AND
E OF A FRONTAL ZONE BISECTING SD FROM NE TO SW. THE PRESENCE OF A
RESIDUAL MIXED LAYER AND ASSOCIATED DCAPE MAY ALSO BE CONTRIBUTING
TO DOWNDRAFTS PENETRATING THE NOCTURNAL STABLE LAYER.

INITIAL VISIBLE SATELLITE IMAGES SUGGEST WIDESPREAD INSOLATION ON
THE WARM SIDE OF THIS BOUNDARY AND E OF THE MCS-RELATED CIRRUS
SHIELD...WHERE SFC DIABATIC HEATING AMIDST DEWPOINTS IN THE LOWER
60S WILL SUPPORT DESTABILIZATION. THIS MAY CONTRIBUTE TO MAINTENANCE
OF THE MCS AS IT SPREADS EWD...ESPECIALLY WITH A PAIR OF MCVS HAVING
BECOME ESTABLISHED IN N-CNTRL SD...AND ISOLATED STRONG TO MARGINALLY
SVR WIND GUSTS REMAIN POSSIBLE EWD ACROSS SD. THE RELATED MCVS MAY
ALSO ENCOURAGE DEVELOPMENT OF THE MCS NEWD INTO PARTS OF SOUTHERN
ND...WHERE ISOLATED MARGINALLY SVR WIND GUSTS MAY ALSO OCCUR.

HOWEVER...THE SPATIAL EXTENT OF SUCH RISK MAY BE RELATIVELY
NARROW...OWING TO RESIDUAL CONTINENTAL AIR FARTHER E TOWARD THE
UPPER MS VALLEY -- WHERE POLEWARD FLUXES OF HIGHER THETA-E AIR MAY
NOT BE ABUNDANT IN THE SHORT-TERM. FURTHERMORE...THE 12Z ABR RAOB
SUGGESTS THAT THE LACK OF RICHER LOW-LEVEL MOISTURE AND ONLY
MODESTLY STEEP MID-LEVEL LAPSE RATES MAY MITIGATE DIURNAL GAINS IN
BUOYANCY TO SOME EXTENT. THESE FACTORS CAST DOUBT ON THE OVERALL
POTENTIAL FOR A MORE APPRECIABLE RISK FOR SVR WIND GUSTS IN THE
SHORT-TERM...THOUGH CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED.

..COHEN/DIAL.. 06/14/2015

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

ATTN...WFO...FGF...FSD...ABR...BIS...UNR...

LAT...LON   43250144 43740124 44380005 45559946 46159898 46539836
            46309717 45529713 43499820 43159990 43250144

Mesoscale Discussions in South Dakota, 2015Mesoscale Discussions in North Dakota, 2015Every mesoscale discussion in 2015

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.