Mesoscale Discussion 3

Issued

Jan 5, 2014, 3:16 AM CST (09:16 UTC)

Expired

Jan 5, 2014, 9:15 AM CST

In force

6 hr

Issued by

the Storm Prediction Center

The St Louis radar (KLSX), 106 km from the middle of the area, began a volume at 09:13 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.

592 
ACUS11 KWNS 050916
SWOMCD
SPC MCD 050916 
ILZ000-MOZ000-051515-

MESOSCALE DISCUSSION 0003
NWS STORM PREDICTION CENTER NORMAN OK
0316 AM CST SUN JAN 05 2014

AREAS AFFECTED...MO...IL

CONCERNING...HEAVY SNOW 

VALID 050916Z - 051515Z

SUMMARY...MODERATE TO HEAVY SNOW IS EXPECTED TO DEVELOP FROM SW TO
NE ACROSS PORTIONS OF CNTRL AND ERN MISSOURI THROUGH DAYBREAK.
SNOWFALL RATES AROUND 1 INCH PER HOUR CAN BE EXPECTED LATER THIS
MORNING WITH THESE RATES SPREADING TO PARTS OF SWRN IL BY 15 UTC/10
AM CST.

DISCUSSION...MID-LEVEL HEIGHT FALLS OF 60-120M/12H WILL OCCUR WITH
TROUGH AMPLIFICATION ACROSS THE SRN PLAINS THIS MORNING AND
CONTRIBUTE TO THE GRADUAL DEEPENING OF A FRONTAL WAVE/SFC LOW OVER
AR. A MODEST INFLUX OF HIGHER PW AIR /0.75-0.90 INCHES/ NEAR AND
EAST OF THE SFC LOW TRACK WILL COINCIDE WITH 850-700MB FRONTOGENESIS
AND LOWERING STATIC STABILITY OVER SRN/CNTRL MO THROUGH THE MORNING.
AS SLOPED ASCENT WITHIN THIS FRONTAL ZONE INTENSIFIES...DENDRITIC
GROWTH LAYER IS FORECAST TO DEEPEN AND CONTRIBUTE TO AN INCREASINGLY
SUPPORTIVE THERMODYNAMIC HABITAT FOR SNOWFALL PRODUCTION. THIS
PROCESS SHOULD RESULT IN THE DEVELOPMENT OF SW-TO-NE ORIENTED BANDS
OF MDT TO HEAVY SNOW.

SYNOPTIC AND HIGH-RES MODELS ARE IN VERY GOOD AGREEMENT DEPICTING A
NARROW RAIN-TO-SNOW TRANSITION ZONE EXTENDING ACROSS SERN MO THROUGH
THE MORNING. MAX HRLY QPF AMOUNTS NORTH OF THE TRANSITION ZONE ARE
AROUND 0.10 INCH WHERE NAM SNOW/LIQUID RATIO IS FORECAST TO BE
AROUND 10/1. THUS...EXPECT SNOWFALL RATES IN THE HEAVIER BANDS TO
REACH ABOUT AN INCH PER HOUR. THE HIGHER SNOWFALL RATES ARE LIKELY
THROUGH THE MORNING AND INTO EARLY AFTERNOON...ESPECIALLY WITH
EWD/NEWD EXTENT...AS MID/UPPER FORCING FOR ASCENT INTENSIFIES AND
SPREADS EAST ACROSS THE MS RIVER INTO SWRN IL.

..CARBIN.. 01/05/2014

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

ATTN...WFO...LSX...SGF...

LAT...LON   38309010 37709112 37199289 37159372 37829365 38529260
            39369070 38899005 38309010

Mesoscale Discussions in Missouri, 2014Mesoscale Discussions in Illinois, 2014Every mesoscale discussion in 2014

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.