Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 172035
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
335 PM CDT Sat Jun 17 2017

.SHORT TERM...(This evening through Sunday)
Issued at 314 PM CDT Sat Jun 17 2017

Timing and placement of convection this afternoon and its
evolution into the evening will be the main challenge tonight.
Tomorrows challenge will be max temps under low stratus, thick
clouds and in the cold air advecting south tonight.

This afternoon convection has developed primarily along and south
of a Devils Lake to Fargo to Detroit Lakes line. Mesoanalysis
shows effective bulk shear values generally between 20 and 30kts
with MLCAPE between 500 and 1000 J/kg. Primarily pulse types cells
with an occasional stronger storm producing hail half up to an
inch in size and gusty downbursts generally 40 to 50mph. SPC has
maintained the marginal risk for severe across the southern two
thirds of the area for the low probability of a stronger storm
becoming severe with 1 inch hail and or a gust to 60mph. Activity
is expected to increase in coverage through the early evening
with a tenth to a quarter inch of rain expected in the southern
valley into west central MN.

Cold advection overnight with stratus deck sliding south out of
Manitoba and 925mb temps nearly 5C cooler than today. Clouds and
cooler thermal profile will help keep temps on the low side with
highs Sunday in the 60s to upper 50s in some locales of NW MN. A
few showers with embedded thunder will be possible in the west
along a weak baroclinic zone tomorrow afternoon.

.LONG TERM...(Sunday night through Saturday)
Issued at 314 PM CDT Sat Jun 17 2017

The long term period begins with a continuation of a NW flow pattern
aloft with a series of short waves creating periods of isold to sct
SHRA and TS.  A minor short wave ridge will keep Sun night and Mon
morning dry before the first wave crops into srn MB and brings a
chance for SHRA and TS Mon aftn through Mon night.  A more amplified
ridge then sets up from cntrl MT across Alberta which will bring
dry conds Tue through late Tue evening.  The next shortwave then
moves into srn MB late Tue and Wed to bring showers/storms to mainly
the northern and eastern zones overnight Tue night as a clipper like
sfc low tracks across ern MT and into s cntrl SD.  The remainder of
the week transitions to more zonal flow aloft with a closed low
dropping into srn MB by 12Z Fri.  This brings more low POPs to the
region Thu and Fri.  Confidence is low by this point in the fcst pd
as the ECMWF depicts this low well to the east of the GFS solution,
over cntrl Ontario.  Upper pattern shifts back to NW flow by Sat
with another SWT bringing chances for activity across the north.
Daytime highs will continue to be cool...generally in the 60s and
70s throughout the long term period except Wed, as the upper ridge
allows a bit more solar and temps should rise into the 70s and
80s.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1134 PM CDT Fri Jun 16 2017

Not much difference from the previous set of TAFs. Overall winds
look to remain on the lower end. Models still indicating some low
end VFR or high end MVFR clouds along the highway 2 corridor
toward Saturday morning, which could affect KDVL/KGFK/KTVF. Not
high confidence in this occurring, so kept them in the low end of
the VFR range for now. Models continue to show the better
potential for afternoon thunder across the south (KFAR) along with
the better pcpn amounts. Therefore mentioned a thunder potential
at KFAR from mid afternoon into the early evening. Thereafter
coverage should decrease along with the thunder threat.


&&

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

$$

SHORT TERM...JK
LONG TERM...Speicher
AVIATION...JK



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