Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 232051

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
351 PM CDT Fri Mar 23 2018

.SHORT TERM...(This evening through Saturday)
Issued at 351 PM CDT Fri Mar 23 2018

The drier and cooler air mass that was centered over Hudson Bay this
afternoon, has kept the persistent dry easterly flow across most of
the Upper Midwest. Thus, all the precipitation has nearly dissipated
as it moved eastward into Minnesota since this morning.

Earlier today, we delayed the onset of the precipitation a few
hours, but at the same time, models continued to support a drier
trend, and thus, limiting the amount of precipitation to the east,
holding off the initial start, and overall amounts. Therefore,
several of the counties along the eastern edge of this storm have
been either downgraded to an advisory, or have been cancelled. Only
areas along the Minnesota River Valley, and southward to the Iowa
border, will still see the bulk of the heavy snowfall overnight,
through Saturday morning.

The main feature of interest this afternoon was moving out of the
central Rockies. Bands of showers have already developed over
northern Nebraska in response to the increasing lift with the upper
energy. These showers will move northeast into South Dakota this
evening, and into far western Minnesota after 9 pm, before changing
over to all snow toward midnight.

As discussed earlier, the persistent dry easterly flow will play
havoc for the onset of precipitation in central, and east central
Minnesota. This area may not see any precipitation until Saturday
morning. The best location of both moisture availability and jet
energy, will occur along the Iowa border toward midnight. This is
where some of the HIRES models indicated a heavier band of
precipitation developing.

Eventually, which coincides with increasing moisture, and jet
energy, areas south and east of a line from Montevideo to Mankato,
and Albert Lea will see locally heavy snowfall toward midnight. A
period of moderate, or occasional heavy snowfall is likely in this
area before tapering off toward 9 am. Localized 9-10 inches of snow
could fall in far southern Minnesota, especially along the I-90
corridor. Later shifts will need to evaluate on how strong the short
wave evolves overnight, and whether snowfall rates beginning to
increase further. The highest weather impacts will occur near the
Iowa border after midnight. By noon, most of the precipitation will
have ended from north to south, with lingering flurries possible
along the Iowa border through the afternoon.

.LONG TERM...(Saturday night through Friday)
Issued at 351 PM CDT Fri Mar 23 2018

Ridging aloft dominates on Sunday with dry conditions expected.
Southeasterly flow at the surface will allow temperatures will
rise into the upper 40s across eastern MN & west-central WI, with
areas seeing the heaviest snowfall from the Friday/Saturday system
struggling to warm past the mid-30s.

The main forecast concern in the long term will be associated
with a system approaching from the southwest on Monday. Warm
advection & plenty of isentropic ascent will generate a broad
swath of precip during the day on Monday. Will likely see a
diurnal pattern with regard to precip types with forecast
soundings supporting light snow & potentially some freezing
drizzle across SW MN during the morning. Mixed precip should
transition fully over to rain as temperatures warm during the day
with another changeover to a rain/snow mix possible again as
temperatures cool at night. Total precip amounts look to be on the
order of 0.25-0.5" with the heaviest amounts falling along the
MN/IA border.

A fairly quiet pattern dominates for the rest of the week under
west/northwest flow aloft & temperatures near average for the end
of March.


.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1252 PM CDT Fri Mar 23 2018

Dry air continues to move in from the east, with less likelihood
for low visibilities and ceilings from snow along and northeast of
I-94 and into part of southeast MN. This has also delayed the
arrival of snow in west central and south central MN. Most short
term models confirm this trend. Only taf sites that should see
IFR and maybe LIFR are KRWF and KMKT. Other issue is the east
winds will strengthen and some parts of southern MN will likely
have gusts around 30 knots as low pressure tracks east and
gradient increases, especially over southern MN.

KMSP...Have delayed snowfall and also improved the visibility
forecast as heavier snow will be farther southwest of the metro.
Snow has been pushed back to at least 06z so the morning rush may
have some light snow or flurries. Heavy snowfall rates are quite
doubtful for KMSP. East winds will remain blustery, with gusts of
20-25 knots for most of the night.

SAT AFTN/NIGHT...VFR. Wind E 10-15 kts.
SUN...VFR. Wind SE 10-15 kts.
MON...MVFR with -RASN, possibly IFR. Wind SE 5-10 kts.


MN...Winter Weather Advisory from 10 PM this evening to 10 AM CDT
     Saturday for MNZ041-048.

     Winter Weather Advisory from 1 AM to 10 AM CDT Saturday for

     Winter Storm Warning from 7 PM this evening to 10 AM CDT
     Saturday for MNZ047-054>056-064-065-073-074-082-091.

     Winter Storm Warning from 10 PM this evening to 10 AM CDT
     Saturday for MNZ057-058-066-067-075-076-083>085-092-093.



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