821 
FXUS63 KDLH 070543
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1143 PM CST Wed Feb 6 2019

.UPDATE...
Issued at 912 PM CST Wed Feb 6 2019

Snow continued to expand in coverage this evening. A narrow band 
of moderate to at times heavy snow was over the Brainerd Lakes to
Pine City into Medford as of 03Z and it will continue to lift
north. Snow has also increased over far northern Minnesota and the
southerly band will also move through those areas as it lifts
north. Few changes were made to the going forecast. We did get
reports of 2 to 3 inches of snow over our northwest Minnesota area
out of the FGEN band prior to 6 PM. The 00Z NAM shows a strong 
area of FGEN, especially around 700MB over/near northern Itasca, 
Koochiching, and northern Saint Louis Counties developing between 
03Z and 06Z. The 18Z GFS is much weaker. If the NAM is correct, 
locally higher snowfall will be possible over far northern 
Minnesota. 

Some freezing drizzle/rain will remain possible over parts of
northwest Wisconsin tonight but most snow is expected with the
band lifting north this evening.

&&

.SHORT TERM...(This evening through Thursday)
Issued at 342 PM CST Wed Feb 6 2019

The main concern for the short term is widespread snow through 
Thursday evening and a potential for freezing rain this evening 
over portions of northwest Wisconsin.

An area of low pressure over central Colorado this afternoon will
lift across the Plains and the Midwest tonight through Thursday 
night. An area of 925-600 mb frontogenesis was found over 
southeast North Dakota and northwest Minnesota, which had produced
impressive snow amounts to our west. Still think snowfall rates 
of 1 to 2 inches per hour are possible this afternoon over our 
northwest zones. Winter Storm Warning which was issued this 
morning for those areas remains on track, albeit with a slower 
onset of precipitation than earlier forecast. Another band of 
frontogenetic forcing for ascent stretched from southwest 
Minnesota to northwest Illinois and is forecast to lift 
northeastward into our southern zones this evening. Look for a 
relatively narrow band of moderate to heavy precipitation oriented
west-northwest to south-southeast to lift into the Northland 
between 00Z and 03Z and will arrive in our northern zones between 
06Z and 09Z tonight. Temperatures aloft may be warm enough for a 
period of freezing rain with this band over portions of Sawyer, 
Price, Ashland, and Iron counties this evening. Onshore flow off 
Lake Superior will boost snowfall amounts along the North Shore as
far south as the Twin Ports. Have upgraded the Winter Weather 
Advisory to a Winter Storm Warning for much of northern Minnesota 
and all of northwest Wisconsin. Our zones in central Minnesota 
remain under a Winter Weather Advisory and there is a possibility 
those areas will need to be upgraded with subsequent updates.

Thursday morning large scale forcing for ascent will be found 
across much of the area with a complicated thermal pattern aloft. 
Several regions of frontogenesis are forecast, which may enhance 
snowfall rates over central and northeast Minnesota. Thaler-QC 
progs indicate strong omega over much of the Midwest Thursday with
the strongest forcing for ascent moving from southeast Minnesota 
during the early afternoon to western Upper Michigan by evening. 
The combination of strong forcing and a tightening thermal 
gradient aloft over northwest Wisconsin should result in a third 
round of moderate snowfall, especially over Iron, Ashland, and 
Price counties. Have upgraded Winter Weather Advisories to Winter 
Storm Warnings over northwest Wisconsin largely due to the intense
snowfall expected Thursday. The system pulls away from the 
Midwest Thursday night with snow tapering off from southwest to 
northeast. Lake effect snow showers are likely in the northwest 
Wisconsin snowbelt areas into Friday morning.

.LONG TERM...(Thursday night through Wednesday)
Issued at 342 PM CST Wed Feb 6 2019

Northwest flow aloft covers the region Friday while high pressure
is building in from the west. This will bring an end to the light
snow in the morning, with some lake effect potential in the 
afternoon. Warm air advection will occur through the day along the
south shore which will limit any lake effect. This scenario 
continues into the evening and have small pops in Iron County. The
ridging moves overhead late Friday night through Saturday 
morning. A fast moving piece of energy in the fast flow aloft will
result in some pops being needed Saturday afternoon through the 
evening. Upper level and surface ridging are in charge late 
Saturday night and Sunday, remaining over the region through 
Monday morning. Monday afternoon finds a long wave trof moving out
into the lee of the Rockies. Model differences with pieces of 
energy lifting northeast out of the base of the trof and how it 
affects the region. Used a blend which placed pops over the 
western third of the forecast area. Model differences grow quite 
large in trying to resolve the progression of the trof and whether
to develop one or two closed lows, or just leave an open wave. 
Used a blend to resolve these differences and placement of pops.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1143 PM CST Wed Feb 6 2019

Widespread snow was occurring over much of the Northland late this
evening but it will diminish for a time tonight, mainly over
southern areas. Widespread MVFR and IFR ceilings will occur
through most of the period. The visibility will range from LIFR to
MVFR for most areas through the period. Snow will diminish from
west to east Thursday afternoon into Thursday evening. There may
some freezing drizzle for a time tonight, from the Brainerd Lakes
region east into northern Wisconsin.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  10  13  -8   1 / 100 100  50  10 
INL   1   5 -14  -2 / 100  90  50  10 
BRD  11  12 -16  -1 / 100 100  40   0 
HYR  17  19  -4   4 / 100 100  90  10 
ASX  15  17  -1   6 / 100 100 100  30 

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...Winter Storm Warning until midnight CST Thursday night for 
     WIZ001>004-006>009.

MN...Winter Storm Warning until midnight CST Thursday night for 
     MNZ012-019>021-037-038.

     Winter Storm Warning until 9 PM CST Thursday for MNZ010-011-018-
     025-026.

     Winter Weather Advisory until 9 PM CST Thursday for MNZ033>036.

LS...None.
&&

$$

UPDATE...Melde
SHORT TERM...Huyck
LONG TERM...Huyck
AVIATION...Melde