Mesoscale Discussion 2107

Issued

Nov 9, 2012, 5:17 PM MST (00:17 UTC)

Expired

Nov 9, 2012, 9:15 PM MST

In force

4 hr

Issued by

the Storm Prediction Center

The Bismarck radar (KBIS), 143 km from the middle of the area, began a volume at 00:15 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.

758 
ACUS11 KWNS 100017
SWOMCD
SPC MCD 100017 
NDZ000-SDZ000-MTZ000-100415-

MESOSCALE DISCUSSION 2107
NWS STORM PREDICTION CENTER NORMAN OK
0617 PM CST FRI NOV 09 2012

AREAS AFFECTED...ERN MT...WRN AND CNTRL ND...FAR NWRN SD

CONCERNING...HEAVY SNOW 

VALID 100017Z - 100415Z

SUMMARY...HEAVY SNOWFALL IS EXPECTED TO DEVELOP ACROSS PARTS OF ERN
MT AND NWRN ND THIS EVENING. SNOWFALL RATES SHOULD APPROACH 1 INCH
PER HOUR WITH SNOWFALL INCREASING FROM SOUTHWEST TO NORTHEAST ACROSS
THE MCD AREA. A MIX OF FREEZING RAIN AND SNOW WILL BE LIKELY ACROSS
PARTS OF SWRN AND CNTRL ND WITH UP TO A TENTH OF AN INCH OF ICE
ACCUMULATION POSSIBLE TONIGHT.

DISCUSSION...THE LATEST WATER VAPOR IMAGERY SHOWS SWLY FLOW IN PLACE
ACROSS THE NRN ROCKIES AND NRN HIGH PLAINS WITH A PLUME OF MID-LEVEL
LEVEL MOISTURE EXTENDING FROM NW WY NEWD ACROSS ERN MT. THE LATEST
MESOANALYSIS SUGGESTS A VORTICITY MAX IS LOCATED ACROSS CNTRL WY
WITH MODEL FORECASTS MOVING THIS FEATURE NEWD ACROSS THE MCD AREA
LATER THIS EVENING. THIS ALONG WITH UPSLOPE ELY SFC WINDS...STRONG
WARM ADVECTION AND INCREASING ISENTROPIC ASCENT WILL CREATE
CONDITIONS FAVORABLE FOR THE DEVELOPMENT OF HEAVY SNOWBANDS. THE
LATEST FORECASTS FROM THE WRF-HRRR3 BEGIN TO DEVELOP BANDS OF
MODERATE SNOWFALL AROUND 02Z TO THE EAST OF BILLINGS AND EXPAND THIS
AREA NEWD ACROSS THE I-94 CORRIDOR TO NEAR WILLISTON BY 04Z. AS THE
BANDS OF SNOW ORGANIZE...1 INCH PER HOUR SNOWFALL RATES WILL BE
POSSIBLE. SFC WINDS AROUND 15 KTS WILL ALSO MAKE BLOWING SNOW
POSSIBLE IN MANY AREAS.

FURTHER TO THE EAST ACROSS PARTS OF SW AND CNTRL ND...FORECAST
SOUNDINGS SHOW A WARM LAYER BETWEEN 850 AND 700 MB WHERE TEMPS ARE
JUST ABOVE FREEZING. THIS COULD KEEP PRECIPITATION AS FREEZING RAIN
WITH SFC TEMPS IN THE MID 20S F. A TENTH OF AN INCH OF ICE
ACCUMULATION MAY OCCUR IN SOME SPOTS DURING THE OVERNIGHT PERIOD.
BOTH THE NAM AND GFS SUGGEST THE AREA WITH THE GREATEST POTENTIAL
FOR FREEZING RAIN WOULD BE AROUND BISMARK AFTER 06Z.

..BROYLES.. 11/10/2012

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

ATTN...WFO...FGF...ABR...BIS...UNR...BYZ...GGW...

LAT...LON   47309903 45940145 45230432 45750642 46610640 48040497
            48870318 49080205 48920059 48139922 47309903

Mesoscale Discussions in North Dakota, 2012Mesoscale Discussions in Montana, 2012Mesoscale Discussions in South Dakota, 2012Every mesoscale discussion in 2012

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.