Alert archive / Illinois / Mesoscale Discussions in 2016

Mesoscale Discussion 217

March 15, 201627 counties in Illinois; 10 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Mar 15, 2016, 5:32 PM CDT for 27 counties in Illinois; 10 counties in Missouri. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued
Mar 15, 2016, 5:32 PM CDT (22:32 UTC)
Expired
Mar 15, 2016, 7:00 PM CDT
In force
88 min
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 37 counties

Bond County, IL, Clay County, IL, Clinton County, IL, Crawford County, IL, Cumberland County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Hamilton County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Lawrence County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Perry County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, City of Saint Louis, MO, Iron County, MO, Jefferson County, MO, Madison County, MO, Perry County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 96 km from the middle of the area, began a volume at 22:33 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

Lincoln, IL (KILX), launched 12:00Z, 10.5 hours before the alert went out and 222 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, Lincoln, IL at 12:00Z on 2016-03-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 127 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, Lincoln, IL at 12:00Z on 2016-03-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 170 square meters per square second.1939587897Sfc1 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
127 J/kg
Mixed-layer CIN
-165 J/kg
Mixed-layer LCL
750 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
170 m²/s²
0-3 km storm-relative helicity
230 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

211 
ACUS11 KWNS 152232
SWOMCD
SPC MCD 152232 
INZ000-ILZ000-MOZ000-160000-

MESOSCALE DISCUSSION 0217
NWS STORM PREDICTION CENTER NORMAN OK
0532 PM CDT TUE MAR 15 2016

AREAS AFFECTED...PORTIONS OF EASTERN MO AND SOUTHERN IL

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 152232Z - 160000Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...A CONDITIONAL THREAT FOR ONE OR TWO STRONG/SEVERE
THUNDERSTORMS WILL EXIST THIS EVENING. WHILE THIS SCENARIO APPEARS
UNLIKELY...CONDITIONS WILL BE MONITORED FOR A POSSIBLE EXTENSION OF
WW 44 AND/OR NEW WATCH ISSUANCE. ANY SUSTAINED/ORGANIZED
THUNDERSTORM WILL BE CAPABLE OF LARGE HAIL...A TORNADO OR TWO...AND
STRONG WINDS.

DISCUSSION...AS OF 22Z...VISIBLE SATELLITE DEPICTS A FIELD OF
DEVELOPING CU/TCU S/SW OF ST. LOUIS...GENERALLY ALONG/BEHIND AN
EASTWARD-PROGRESSING SFC TROUGH. UPSTREAM 12Z RAOBS AND FORECAST
SOUNDINGS INDICATE DRY AIR AROUND 850-700 MB IS CONTRIBUTING
CONSIDERABLE MLCIN ACROSS THE AREA...KEEPING CONVECTIVE POTENTIAL
FAIRLY LIMITED...ESPECIALLY WITH SOUTHWARD EXTENT. AS SUCH...RAPID
DEVELOPMENT OF CONVECTION WITHIN THIS FIELD OF CU IS NOT
ANTICIPATED. NONETHELESS...THE GLANCING INFLUENCE OF A STRONG
SHORTWAVE TROUGH TO THE NORTHWEST...AS WELL AS LOW-LEVEL CONVERGENCE
NEAR THE SFC TROUGH...MAY BE ENOUGH TO INITIATE ONE OR TWO STRONG
UPDRAFTS OVER THE NEXT SEVERAL HOURS. SUCH CONVECTION WOULD BE ABLE
TO UTILIZE STEEP MID-LEVEL LAPSE RATES AND MLCAPE AROUND 1500-2000
J/KG. ADDITIONALLY...EFFECTIVE SHEAR AROUND 50 KTS WOULD PROMOTE
UPDRAFT ORGANIZATION/ROTATION...AS WELL AS DYNAMIC PARCEL LIFTING TO
SUSTAIN ROTATING UPDRAFTS FARTHER EAST INTO SOUTHERN IL...DESPITE
THE PRESENCE OF DRY LOW/MID-LEVEL AIR. 

WHILE THIS POTENTIAL REMAINS QUITE CONDITIONAL...A STRENGTHENING
LOW-LEVEL JET AND A VEERING PROFILE WITH HEIGHT...WOULD SUPPORT THE
POTENTIAL FOR A TORNADO OR TWO...AS WELL AS LARGE HAIL /CONSIDERING
AMPLE BUOYANCY ABOVE -10 C AND SUFFICIENT DEEP SHEAR/.
SATELLITE/RADAR OBSERVATIONS WILL BE MONITORED FOR POTENTIAL
DEVELOPMENT...WHICH MIGHT REQUIRE AREAL EXTENSION OF WW 44 OR NEW
WATCH ISSUANCE. HOWEVER...THIS SCENARIO APPEARS UNLIKELY AT THIS
TIME.

..PICCA/EDWARDS.. 03/15/2016

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

ATTN...WFO...IND...PAH...ILX...LSX...

LAT...LON   38379084 38879085 38948948 39378837 39128756 38048789
            37678869 37469032 37559074 37979092 38379084

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 15, 2:24 PM CDTMesoscale DiscussionSPCAdams, Brown, Bureau, Carroll, Cass, Christian and 37 more66 min
Mar 15, 3:31 PM CDTTornado WatchSPCAdams, Brown, Bureau, Calhoun, Carroll, Cass and 40 more7 hr
Mar 15, 6:29 PM CDTMesoscale DiscussionSPCBureau, Cass, Fulton, Henry, Knox, Logan and 11 more91 min

Nearby

Mesoscale Discussions in Illinois, 2016Mesoscale Discussions in Missouri, 2016Every mesoscale discussion in 2016

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.