Area Forecast Discussion
Issued by NWS Grand Forks, ND

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699
FXUS63 KFGF 241733
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1233 PM CDT TUE MAY 24 2016

.UPDATE...
Issued at 1229 PM CDT Tue May 24 2016

Uncertainty continues on potential for T redevelopment this
afternoon. Wind field weak with modest instability with no real
area of concern other than the far SE where 60 degree dewpoints
reside. Did expand low pops farther SW with this thinking. No
other changes.

UPDATE Issued at 919 AM CDT Tue May 24 2016

Adjusted pops across the eastern FA based on current radar trends.
No other changes necessary.

UPDATE Issued at 649 AM CDT Tue May 24 2016

Adjusted POPs for current radar trends. The HRRR seems to have a
fairly good handle on what is currently going on so have our
current showers and thunderstorms moving off into northwestern MN
and weakening as the model indicates. Still think that there will
be some redevelopment later this afternoon as the next weak
shortwave comes through along with daytime heating, so have 20-30
POPs later in the afternoon.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 400 AM CDT Tue May 24 2016

Convective chances and strength will continue to be the main
challenge for the short term.

Water vapor loop shows the main upper lows rotating over southern
Saskatchewan and the West Coast, with southwesterly flow aloft
into the Plains. One shortwave riding through the flow is
currently along the ND/SD border and bringing some showers with a
few claps of thunder into our western CWA. The short range models
all have this precip moving off into our northeastern CWA through
the morning. A very weak surface trough axis and boundary will
settle over the eastern counties by this afternoon. Afternoon
temps will rise into the 70s and 80s again today, and with dew
points near 50 moving back to the area, some CAPE values of around
1000 J/kg are possible by afternoon. With another weak shortwave
coming through, more storms could fire mainly near the boundary in
the eastern CWA. Not really expecting widespread severe weather,
but a few storms producing hail or damaging winds are possible.

Tonight, southwesterly flow aloft continues, and the models begin
to show a decent surface low starting to develop to our south,
with the surface low moving north into our area as the main upper
low over Saskatchewan begins to wobble eastward into the Northern
Plains. The surface low will lift northward across the Dakotas
towards the Canadian border by Wednesday afternoon. The NAM is
much faster and stronger with the surface low, but is an outlier
from the other deterministic models, so leaned towards the slower
solution. There does seem to be good agreement on precip entering
our southern counties during the early morning hours Wednesday,
moving northward throughout the day. North of the surface low
there will not be too much instability, but the GFS brings some
1500-2000 J/kg into our southern counties by afternoon as the
surface low center moves in. Some isolated severe is not out of
the question and there is a marginal risk for our southern
counties. With clouds and precip for a good chunk of the day went
a bit cooler for highs on Wednesday with low to mid 70s.

.LONG TERM...(Wednesday night through Monday)
Issued at 400 AM CDT Tue May 24 2016

Wednesday night through Thursday night...the surface low will pull
off to the north Wednesday night/Thursday, but with the upper low
continuing to rotate over the area precip will linger at least in
some areas. Continued to keep fairly high POPs Wednesday night
with a transition to mostly over the northern CWA as the low moves
north. However, kept some low POPs even over the southern CWA to
cover any redevelopment under the upper low. Temps will be
slightly above seasonal averages with lows in the 50s and highs in
the 70s.

Friday through Monday...Split flow remains across North America
with northern stream over central Canada and southern stream over
the states. Long wave over the western states with southwest flow
over the Northern Plains through much of the period. Ripples move
through the flow. After day 7, a long wave ridge axis is over the
area.

The GFS has been trending farther south while the ECMWF is
oscillating around. Models in reasonable agreement with the ECMWF
farther east solution than the GFS. Will blend the models.

Little change to high temperatures on Fri. A degree or two lower for
Sat. A degree higher for Sun and one or two degrees higher for
Mon.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1229 PM CDT Tue May 24 2016

Wind speeds look to remain pretty light until Wednesday morning,
when they will take on more of a steady SE direction. Not much for
clouds out there now, but expect at least some mid level clouds to
move in later tonight into early Wednesday. At this point will leave
any clouds in the VFR range. Not a lot of confidence in the pcpn
forecast so have left VCSH for most locations by Wednesday morning.

&&

.FGF Watches/Warnings/Advisories...
ND...None.
MN...None.
&&

$$

UPDATE...Voelker
SHORT TERM...JR
LONG TERM...JR/Hoppes
AVIATION...Godon



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