Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 211802
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
102 PM CDT Sat Oct 21 2017

.UPDATE...
Issued at 102 PM CDT Sat Oct 21 2017

Showers have been developing further west than any of the high res
models indicate, so bumped up POPs in our southwestern counties
for the rest of the day. More showers also developing further
east to track into west central MN and given MUCAPE values around
500 J/kg some isolated thunder is not out of the question in that
area. As the surface trough pulls east and we lose daytime heating
late this afternoon, most of the activity will transition to our
eastern tier of counties before tapering off this evening.

&&

.SHORT TERM...(Today and tonight)
Issued at 359 AM CDT Sat Oct 21 2017

A low pressure system centered in southwest MB will steadily shift
eastward through the day with surface trof and closely following
surface cold front dragging across eastern North Dakota this
forenoon and northwest MN through the afternoon. Gusty south winds
will slow just a bit as the trof axis passes any area but then
sharply turn and increase from the west... gusting from 20 to 30
mph. Widely scattered showers are possible across portions of
central ND to include the Devils Lake Basin and mid to upper
Sheyenne Valley areas... though scant amounts of rain are expected.
Showers are more likely across the MN Lakes country from west
central into northcentral MN... where accumulations of a tenth of
an inch to a quarter of an inch are possible... mainly in the mid
to late afternoon. Winds should taper of a bit with sunset though
a light westerly wind will persist into the overnight periods.
Temperatures today and tonight will drop a good 10 to 15 degrees
from Friday... but remain nearly 10 degrees above long term
averages.

.LONG TERM...(Sunday through Friday)
Issued at 334 AM CDT Sat Oct 21 2017

A progressive and active pattern is expected for the coming week
with closer to seasonal temperatures and periods of precipitation,
some of which could be the season`s first flakes of snow. Overall
confidence deteriorates notably in the latter half of the forecast
period.

Another short wave trough moves in Sunday from the west on the nose
of an upper jet that begins to amplify into a deep trough over the
Midwest Monday into Tuesday. Scattered showers will be possible
across the region Sunday afternoon through Monday with a surface low
moving across southern Canada with a couple of passing cold fronts
sweeping to its south. The amplifying upper trough Monday into
Tuesday will act as a conduit for colder temperatures to move
southward, although it seems the core of this migrating colder air
will stay within Minnesota/Wisconsin. With light forecast
precipitation amounts and lower level temperatures just warm enough,
rain appears to be the dominate type Monday.

A surface ridge is expected to keep Tuesday dry. The upper trough
axis moves east bringing relatively warmer temperatures back into
the region, but only briefly as an embedded short wave moves out
of eastern Manitoba/western Ontario into the upper Mississippi
Valley. This short wave pushes a surface low through Minnesota
from north to south. The 21/00Z GFS, Euro solutions vary on how
developed and deep this low is by Wednesday morning. Both
solutions agree on keeping the bulk of precipitation to its
eastern quadrants, some of which could be snow mainly in eastern
Minnesota, although Wednesday is expected to be mostly dry with
perhaps a few passing rain showers in northwestern/west-central
Minnesota. An associated cold front will bring cooler temperatures
across the area as well as gusty northwesterly winds Wednesday.
This sets up the scene for Thursday`s storm.

Better precipitation chances accompany a developing low dropping
in from Canada Thursday. Cooler morning temperatures could mean
some flakes of snow mixing in, although confidence is low for this
due to model run to run discrepancy. After Thursday, guidance
varies significantly on pattern development. There is the
potential for yet another low moving into the region already
entrenched in cooler temperatures from the northwest Saturday, but
will hold off on specifics due to large model differences.

Temperatures through the period will be closer to seasonal normals,
i.e. highs in the 50s and lows in the 30s, possibly becoming
slightly cooler than normal later in the forecast period. As of now,
it looks like Thursday through Saturday look to be coldest days.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 102 PM CDT Sat Oct 21 2017

Some MVFR to low VFR ceilings over the MN TAF sites as well as
KFAR. The low clouds will push eastward as the surface trough axis
moves into our eastern forecast area later this afternoon. Some
lingering mid and high level clouds before skies clear out
completely later tonight. Winds are currently from the south only
at KBJI, with all the other sites shifting to the southwest or
west. Some higher gusts above 20 kts for a while this afternoon,
but speeds should drop below 12 kts for tonight with directions
from the southwest. Winds will start to pick up again late in the
period tomorrow but most of the higher gusts will be after 18Z.


&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&

$$

UPDATE...JR
SHORT TERM...Gust
LONG TERM...CJ
AVIATION...JR



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