[MCD] SWOMCD

Sun Jan 21 08:48:17 UTC 2007

ACUS11 KWNS 210853
SWOMCD
SPC MCD 210852 
INZ000-KYZ000-ILZ000-211215-

MESOSCALE DISCUSSION 0090
NWS STORM PREDICTION CENTER NORMAN OK
0252 AM CST SUN JAN 21 2007

AREAS AFFECTED...ERN IL...CNTRL IND

CONCERNING...HEAVY SNOW 

VALID 210852Z - 211215Z

A BURST OF HEAVY SNOWFALL WITH RATES OF UP TO AN INCH AN HOUR
APPEARS LIKELY EARLY THIS MORNING FROM EAST-CNTRL IL ACROSS CNTRL
AND SCNTRL SECTIONS OF INDIANA.

INTENSE ISENTROPIC LIFT AND RESULTANT ADIABATIC COOLING WILL
CONTINUE TO COUNTER LOW LEVEL WARMING ON THE NOSE OF THE 850MB JET
TRANSITIONING OVER THE LOWER OH VALLEY EARLY TODAY. GIVEN UPSTREAM
PW VALUES AROUND AN 1 INCH...AND 30-40KT LOW LEVEL JET...
STRONG MOISTURE TRANSPORT WILL SUPPORT HIGH PRECIPITATION RATES OVER
THE NEXT FEW HOURS. ADDITIONALLY...MELTING-INDUCED THERMALLY
INDIRECT CIRCULATIONS DEVELOPING ACROSS THE RAIN/SNOW LINE COULD
FURTHER BOOST SNOWFALL ON THE COLD SIDE OF THE PRECIPITATION
TRANSITION ZONE. DEEP ISOTHERMAL NEAR/BELOW 0C PROFILES WILL ALSO
FAVOR SNOWFLAKE GROWTH THROUGH ACCRETION AND RIMING. LATEST MODEL
GUIDANCE APPEARS TO SUGGEST AN AXIS OF 3-4 INCH SNOWFALL ALONG THE
I70 CORRIDOR...FROM NEAR MATTOON IL TO INDIANAPOLIS THROUGH 12Z.

..CARBIN.. 01/21/2007

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

...NOTICE...
SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A
SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR
TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC
FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.

ATTN...WFO...ILN...LMK...IND...ILX...

38818818 39348874 40098880 40238806 40358669 40038548
39668499 39098502 38678543 38708664 