Mesoscale Discussion 30

Issued

Jan 19, 2016, 9:36 PM CST (03:36 UTC)

Expired

Jan 20, 2016, 2:30 AM CST

In force

5 hr

Issued by

the Storm Prediction Center

The Little Rock radar (KLZK), 141 km from the middle of the area, began a volume at 03:38 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.

269 
ACUS11 KWNS 200337
SWOMCD
SPC MCD 200336 
MOZ000-ARZ000-200830-

MESOSCALE DISCUSSION 0030
NWS STORM PREDICTION CENTER NORMAN OK
0936 PM CST TUE JAN 19 2016

AREAS AFFECTED...PORTIONS OF NRN/CNTRL AR AND S-CNTRL/SERN MO

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 200336Z - 200830Z

SUMMARY...A MIXTURE OF SLEET AND FREEZING RAIN IS EXPECTED TO
INCREASE IN COVERAGE OVER THE NEXT FEW HOURS. FREEZING RAIN RATES IN
EXCESS OF 0.05 INCH PER 3 HOURS APPEAR PROBABLE ACROSS PORTIONS OF
NRN/CNTRL AR THROUGH AT LEAST 08Z.

DISCUSSION...LARGE-SCALE ASCENT ASSOCIATED WITH A SHORTWAVE TROUGH
OVER OK/NRN TX WILL CONTINUE TO SPREAD OVER MUCH OF AR AND MO THIS
EVENING. LOW-LEVEL WARM AIR ADVECTION MAINLY IN THE 850-700 MB LAYER
WILL ALSO CONTRIBUTE TO ASCENT ACROSS THE MCD REGION. RECENT RADAR
IMAGERY SHOWS A RECENT INCREASE IN LIGHT TO MODERATE
PRECIPITATION...MAINLY ACROSS NRN/CNTRL AR. THE 00Z SOUNDING FROM
LITTLE ROCK AR REVEALED A +5.5 DEC C WARM NOSE CENTERED AROUND 900
MB. A SHALLOW DRY SUB-CLOUD LAYER WILL MOISTEN/COOL WITH ONGOING
PRECIPITATION...AND SFC WET BULB TEMPERATURES BELOW FREEZING ACROSS
PORTIONS OF NRN/CNTRL AR COMBINED WITH THE WARM NOSE ALOFT SUGGEST
LIGHT TO LOCALLY MODERATE FREEZING RAIN SHOULD BE THE MAIN P-TYPE
THROUGH EARLY WED MORNING OVER THIS REGION...WITH FREEZING RAIN
RATES IN EXCESS OF 0.05 INCH PER 3 HOURS PROBABLE. AS MID-LEVEL
TEMPERATURES COOL WITH THE APPROACH OF THE UPPER TROUGH FROM THE
W...RELATED SLIGHT STEEPENING OF MID-LEVEL LAPSE RATES MAY ENCOURAGE
SOME CONVECTIVE ENHANCEMENT TO PRECIPITATION RATES...MAINLY OVER
CNTRL AR. RECENT RADAR IMAGERY FROM KLZK DEPICTING SHOWERY/CELLULAR
REFLECTIVITY CORES MOVING NEWD FROM SWRN AR/SERN OK SUPPORTS THIS
IDEA...ALTHOUGH SUFFICIENT INSTABILITY TO SUPPORT LIGHTING WILL
PROBABLY REMAIN SW OF THE MCD AREA.

FURTHER N ACROSS PORTIONS OF S-CNTRL/SERN MO...RECENT REPORTS OF
SLEET SUGGEST THE LOW-LEVEL WARM NOSE IS LESS PRONOUNCED THAN
FURTHER S ACROSS AR...WHICH IS WELL SUPPORTED BY RECENT SHORT-TERM
MODEL GUIDANCE. THIS TREND SHOULD CONTINUE THROUGH EARLY WED
MORNING...WITH LIGHT TO LOCALLY MODERATE SLEET MORE PROBABLE WITH
NWD EXTENT ACROSS THE MCD AREA...AND FREEZING RAIN MORE LIKELY IN
NRN/CNTRL AR WHERE SFC TEMPERATURES ARE BELOW FREEZING.

..GLEASON.. 01/20/2016

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

ATTN...WFO...PAH...MEG...LZK...SGF...TSA...

LAT...LON   36029444 36729261 37049077 37229028 37118999 37068941
            35779004 34999074 34869200 34779326 35119396 36029444

Mesoscale Discussions in Arkansas, 2016Mesoscale Discussions in Missouri, 2016Every mesoscale discussion in 2016

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.