Mesoscale Discussion 55

Issued

Jan 31, 2011, 2:45 PM CST (20:45 UTC)

Expired

Jan 31, 2011, 7:45 PM CST

In force

5 hr

Issued by

the Storm Prediction Center

The Indianapolis radar (KIND), 46 km from the middle of the area, began a volume at 20:48 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.

201 
ACUS11 KWNS 312045
SWOMCD
SPC MCD 312045 
OHZ000-INZ000-ILZ000-010145-

MESOSCALE DISCUSSION 0055
NWS STORM PREDICTION CENTER NORMAN OK
0245 PM CST MON JAN 31 2011

AREAS AFFECTED...E-CNTRL IL/CNTRL IND

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 312045Z - 010145Z

MULTIPLE ROUNDS OF WINTER MIXED PRECIPITATION WILL SHIFT EWD ACROSS
E CNTRL IL AND CNTRL IND THROUGH LATE AFTERNOON. FREEZING
RAIN...WITH RATES OF 0.05 TO 0.10 INCH PER 3 HOURS...WILL BE A
CONCERN ALONG AND SOUTH OF THE INTERSTATE 70 CORRIDOR. ACROSS NORTH
CNTRL IND...MODERATE TO LOCALLY HEAVY SNOW WITH RATES OF UP TO 1
INCH PER HOUR COULD OCCUR AFTER 22Z.

A SHIELD OF PRECIPITATION OVER CNTRL IL CONTINUES TO ORGANIZE AND
SHIFT EWD...WHILE SCATTERED PRECIPITATION IS DEVELOPING FARTHER WSW
INTO E CNTRL MO. ALL OF THIS ACTIVITY IS IN RESPONSE TO
WAA/ISENTROPIC UPGLIDE IN THE 285-295 K LAYER ATOP A BROAD
LOW/MID-LEVEL BAROCLINIC ZONE ACROSS THE OHIO VALLEY REGION. THE
ASCENT IS FORECAST TO INTENSIFY THROUGH THE AFTERNOON PER THE 19Z
RUN OF THE RUC MODEL...AS A SWLY LOW-LEVEL JET MAX STRENGTHENS TO
THE EAST OF AN 850-MB VORT CENTER. CONVERGENCE IN THE EXIT REGION OF
THIS JET MAX WILL INTERACT WITH THE BAROCLINIC ZONE TO INCREASE
FRONTOGENESIS ACROSS THE DISCUSSION AREA AND AUGMENT THE LOW-LEVEL
ASCENT...ALLOWING PRECIPITATION TO BE MAINTAINED AND REGENERATE
UPSTREAM. WITH WET-BULB ZERO TEMPERATURES AT THE SFC BELOW
FREEZING...A MIX OF WINTER PRECIPITATION TYPES IS EXPECTED.

ALONG AND SOUTH OF THE INTERSTATE 70 CORRIDOR...FORECAST SOUNDINGS
INDICATE TEMPERATURES WARMING TO 3-4C IN THE 850-880-MB
LAYER...ALLOWING PRECIPITATION TO MELT AS IT FALLS THROUGH THE WARM
NOSE BEFORE FREEZING AT THE SURFACE. FURTHER TO THE
NORTH...TEMPERATURES IN THE WARM NOSE WILL BE SUFFICIENTLY COLD /AOB
3C/ TO ALLOW FOR SLEET...WITH SNOW EXPECTED ACROSS N CNTRL IN. THE
15Z SREF RUN INDICATES THAT SNOWFALL COULD BECOME LOCALLY HEAVY IN
THIS REGION...AS FRONTOGENETIC FORCING POTENTIALLY SUPPORTS BANDED
PRECIPITATION. PRECIPITATION WILL LIKELY CONTINUE ACROSS THE REGION
INTO THE EVENING HOURS.

..COHEN/ROGERS.. 01/31/2011

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

ATTN...WFO...ILN...IWX...IND...LOT...ILX...

LAT...LON   40668790 41208676 41108509 39918480 39108533 38778636
            38948783 39548816 40668790

Mesoscale Discussions in Indiana, 2011Mesoscale Discussions in Illinois, 2011Every mesoscale discussion in 2011

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.