Alert archive / Indiana / Mesoscale Discussions in 2012
Mesoscale Discussion 21
The Storm Prediction Center issued this mesoscale discussion at Jan 17, 2012, 1:50 AM CST for 37 counties in Illinois; 55 counties in Indiana; 5 counties in Missouri. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- Jan 17, 2012, 1:50 AM CST (07:50 UTC)
- Expired
- Jan 17, 2012, 3:15 AM CST
- In force
- 85 min
- Issued by
- the Storm Prediction Center
All 97 counties
Bond County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Douglas County, IL, Edgar 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, Macon County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Moultrie County, IL, Perry County, IL, Piatt County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Shelby County, IL, Vermilion County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Bartholomew County, IN, Benton County, IN, Blackford County, IN, Boone County, IN, Brown County, IN, Carroll County, IN, Cass County, IN, Clay County, IN, Clinton County, IN, Daviess County, IN, Decatur County, IN, Delaware County, IN, Dubois County, IN, Fayette County, IN, Fountain County, IN, Fulton County, IN, Gibson County, IN, Grant County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Huntington County, IN, Jasper County, IN, Jay County, IN, Johnson County, IN, Knox County, IN, Lawrence County, IN, Madison County, IN, Marion County, IN, Martin County, IN, Miami County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Owen County, IN, Parke County, IN, Pike County, IN, Pulaski County, IN, Putnam County, IN, Randolph County, IN, Rush County, IN, Shelby County, IN, Sullivan County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion County, IN, Vigo County, IN, Wabash County, IN, Warren County, IN, Wayne County, IN, Wells County, IN, White County, IN, Jefferson County, MO, Perry County, MO, Saint Francois County, MO, Sainte Genevieve County, MO, Washington County, MO
The radar
The Lincoln radar (KILX), 132 km from the middle of the area, began a volume at 07:51 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
Lincoln, IL (KILX), launched 00:00Z, 7.8 hours before the alert went out and 90 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.
- Mixed-layer CAPE
- 2 J/kg
- Mixed-layer CIN
- -49 J/kg
- Mixed-layer LCL
- 748 m above ground
- 0-6 km bulk shear
- 65 kt
- 0-1 km storm-relative helicity
- 431 m²/s²
- 0-3 km storm-relative helicity
- 500 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
012
ACUS11 KWNS 170750
SWOMCD
SPC MCD 170750
INZ000-ILZ000-MOZ000-170915-
MESOSCALE DISCUSSION 0021
NWS STORM PREDICTION CENTER NORMAN OK
0150 AM CST TUE JAN 17 2012
AREAS AFFECTED...SW THRU E CNTRL MISSOURI...INTO CNTRL IL INTO NRN
AND CNTRL INDIANA
CONCERNING...TORNADO WATCH 1...
VALID 170750Z - 170915Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 1 CONTINUES.
SEVERE THREAT IS DIMINISHING ACROSS SOUTHWEST AND SOUTH CENTRAL
MISSOURI. TRENDS ARE BEING MONITORED FOR THE POSSIBILITY OF AN
ADDITIONAL WW EAST OF WW 0001.
VIGOROUS CONVECTIVE DEVELOPMENT APPEARS GENERALLY ASSOCIATED WITH
DEEP LAYER UPWARD VERTICAL MOTION...SUBSTANTIALLY FORCED BY A SHORT
WAVE IMPULSE/MID-LEVEL JET STREAK NOW TURNING EASTWARD ACROSS THE
CENTRAL PLAINS. THROUGH THE 09-12Z TIME FRAME...MODELS SUGGEST THAT
THIS STRONGER LIFT WILL RAPIDLY SHIFT EAST OF THE ST. LOUIS
AREA...ACROSS CENTRAL ILLINOIS...INTO NORTH CENTRAL INDIANA. EVEN
WITH A 40-60 KT WEST SOUTHWESTERLY 850 MB JET AIDING THE TRANSPORT
OF INCREASINGLY MOIST LOW-LEVEL AIR INTO THIS REGION...THE EVOLVING
MESOSCALE CONVECTIVE SYSTEM WILL PROBABLY BEGIN OUTRUNNING MORE
FAVORABLE WARM SECTOR NEAR SURFACE INSTABILITY. WHEN THIS
OCCURS...ACTIVITY SHOULD BECOME INCREASINGLY ELEVATED IN
NATURE...WITH A DIMINISHING SEVERE THREAT...ALTHOUGH MORE HIGHLY
LOCALIZED STRONG SURFACE GUSTS ASSOCIATED WITH THE DOWNWARD
TRANSPORT OF HIGHER MOMENTUM AIR MAY STILL NOT BE OUT OF THE
QUESTION. GIVEN THE CURRENT 50 KT STORM MOTION...AND UNCERTAIN
TIMING OF WEAKENING TRENDS...IT MAY BE THAT THE SEVERE THREAT
REMAINS HIGH ENOUGH TO REQUIRE AN ADDITIONAL WW ALONG THE INTERSTATE
70 CORRIDOR OF ILLINOIS AND INDIANA EARLY THIS MORNING.
..KERR.. 01/17/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...ILN...LMK...IWX...IND...PAH...LOT...ILX...LSX...
LAT...LON 40168892 41098709 41028498 39768483 38228706 37559015
37979130 38948975 40168892SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 16, 11:47 PM CST | Tornado Watch | SPC | Bond, Calhoun, Clinton, Fayette, Greene, Jersey and 8 more | 7 hr |
| Jan 17, 6:25 AM CST | Mesoscale Discussion | SPC | Clark, Clay, Crawford, Cumberland, Edgar, Edwards and 15 more | 65 min |
| Jan 16, 10:24 PM CST | Mesoscale Discussion | SPC | Andrew, Atchison, DeKalb, Gentry, Harrison, Holt and 3 more | 5 hr |
| Jan 16, 11:23 PM CST | Mesoscale Discussion | SPC | Barry, Camden, Cedar, Christian, Cole, Crawford and 20 more | 2 hr |
Nearby
Mesoscale Discussions in Indiana, 2012Mesoscale Discussions in Illinois, 2012Mesoscale Discussions in Missouri, 2012Every mesoscale discussion in 2012
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.