Alert archive / Indiana / Mesoscale Discussions in 2012

Mesoscale Discussion 114

February 10, 20126 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at Feb 10, 2012, 7:53 PM CST for 6 counties in Indiana. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Feb 10, 2012, 7:53 PM CST (01:53 UTC)
Expired
Feb 11, 2012, 12:00 AM CST
In force
4 hr
Issued by
the Storm Prediction Center

Counties Jasper County, IN, Lake County, IN, LaPorte County, IN, Newton County, IN, Porter County, IN, Starke County, IN

The radar

The Chicago radar (KLOT), 92 km from the middle of the area, began a volume at 01:57 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, 1.9 hours before the alert went out and 186 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 00:00Z on 2012-02-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2012-02-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -133 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
674 m above ground
0-6 km bulk shear
66 kt
0-1 km storm-relative helicity
-133 m²/s²
0-3 km storm-relative helicity
64 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.

832 
ACUS11 KWNS 110153
SWOMCD
SPC MCD 110153 
INZ000-110600-

MESOSCALE DISCUSSION 0114
NWS STORM PREDICTION CENTER NORMAN OK
0753 PM CST FRI FEB 10 2012

AREAS AFFECTED...NWRN IND

CONCERNING...HEAVY SNOW 

VALID 110153Z - 110600Z

SNOWFALL RATES OF 1-2 INCHES PER HR /WITH LOCALLY HIGHER RATES/ ARE
FORECAST TO DEVELOP WITHIN A LAKE EFFECT BAND OVER FAR NWRN IND THIS
EVENING AND INTO EARLY SAT MORNING. SUSTAINED SFC WINDS OF 20-30 MPH
COULD ALSO RESULT IN LOCALLY REDUCED VISIBILITIES. 

WATER VAPOR LOOP SHOWS A SHARP POSITIVE TILT UPPER TROUGH TRAVERSING
EWD ACROSS THE UPPER GREAT LAKES/MID-MS RIVER VALLEY THIS EVENING.
LOW-LEVEL COLD FRONT HAS MOVED THROUGH PORTIONS OF NRN IND/IL...WITH
POST-FRONTAL NLY WINDS /20-30 KTS IN THE 0-2 KM AGL LAYER PER LOT
VWP DATA/ BECOMING ESTABLISHED IN IT/S WAKE. FAVORABLE N-S
ORIENTATION OF LOW-LEVEL FLOW WILL CREATE A LONG FETCH OFF LAKE
MICHIGAN...WHILE OBSERVATIONS FROM SRN LAKE MICHIGAN INDICATE WATER
TEMPERATURES GENERALLY RANGE FROM 3-4 DEG C...SUPPORTING A NARROW
LAKE EFFECT SNOW BAND ALONG/DOWNWIND OF THE SRN SHORE OF LAKE
MICHIGAN. 0145Z RADAR REFLECTIVITY LOOP SHOWS WEAK BANDED STRUCTURES
ALREADY DEVELOPING OFF SRN LAKE MICHIGAN. RUC/WRF-HRRR POINT
FORECAST SOUNDINGS INDICATE STRONG LOW/MIDLEVEL COLD ADVECTION WILL
CONTINUE THROUGH THE NEXT SEVERAL HRS...AND WILL RESULT IN
STEEPENING LOW-LEVEL LAPSE RATES AND INCREASING UPRIGHT INSTABILITY.
SNOWFALL RATES OF 1-2 IN/HR APPEAR PROBABLE TO DEVELOP WITHIN THIS
BAND...ALTHOUGH ISOLATED LOCATIONS MAY APPROACH 3 IN/HR AT TIMES.
MODEL GUIDANCE SUGGESTS HEAVIEST SNOWFALL WILL SHIFT EWD AFTER 06Z
AS LOW-LEVEL FLOW BACKS SLIGHTLY TOWARDS THE NNW AS THE MID/UPPER
TROUGH MOVES E OF THE REGION.

..ROGERS.. 02/11/2012

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

ATTN...WFO...IWX...LOT...

LAT...LON   40888708 40948744 41298748 41638747 41598729 41688697
            41748678 41698659 41348658 40998673 40888708

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 10, 11:50 PM CSTMesoscale DiscussionSPCLaPorte, Porter, Starke4 hr

Nearby

Mesoscale Discussions in Indiana, 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.