Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 231458
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
958 AM CDT SAT JUL 23 2016

.UPDATE...
Issued at 958 AM CDT Sat Jul 23 2016

Lots of questions remain in regard to convection today. To start
off, there is a lot more cloud cover and rainfall occurring right
now than was expected yesterday. There is one area of
showers/tstms from Langdon down through east of Bismarck. The
strongest portion of this line is east of Bismarck, where NWS BIS
has issued a severe tstm warning. SPC has also issued a Mesoscale
Discussion for this area, saying that this line may hold together
and strengthen as it moves ESE this morning. However it has
weakened a bit recently, so will just have to keep an eye on it.

There is another large tstm complex over eastern SD into southern
MN. Some light showers may affect the Elbow Lake to Wadena area as
this complex moves east this morning. Both these system could
impact the severe weather potential that was expected this
afternoon. There is a lot of uncertainty yet in the degree of
recovery that could occur after both these systems slowly move
east. See a lot of differing solutions in the high resolution
model guidance, which reflects this high uncertainty. So
basically will have to wait and see how things progress through
the late morning into early afternoon. Until then, steady rain
will continue around the Devils Lake basin.

&&

.SHORT TERM...(Today and tonight)
Issued at 321 AM CDT Sat Jul 23 2016

The forecast challenge for today will once again be convection. A
cold front will move across the CWA this afternoon, reaching the
RRV around mid afternoon and then into west central MN in the
early evening. One concern will be how much heating can occur due
to morning cloud cover across most of eastern ND. If the
atmosphere clears out and becomes well heated, PWAT values on the
order of 2 inches will provide ample juice to have a potential
severe outbreak this afternoon. GFS/NAM indicating a MCS
developing mid afternoon over eastern ND in an area of 3000 to
3500 J/KG BL CAPE and then shifting to the southeast into the MPX
CWA. While CAPEs are quite impressive, deep layer shear should
only be around 30 to 40 knots however DCAPEs around 1500 J/KG will
makes severe winds a threat mainly across the southern valley and
portions of west central MN. This region is where SPC has issued
an enhanced threat for severe weather. Heavy rainshowers are also
expected with storms in this region with the high PWAT
values...however storms are expected to be moving quick enough
across the south to limit flash flooding potential.

The front will move quickly across the CWA and convection should
begin to decline by mid-evening, moving out of eastern zones by
midnight.

.LONG TERM...(Sunday through Friday)
Issued at 321 AM CDT Sat Jul 23 2016

Upstream ridging aloft will keep the region dry for Sunday and
Monday, and cooler air behind the departing cold front will bring
daytime highs into the upper 70s for most of the region Sunday
before climbing back into the 80s on Monday. Zonal flow then sets
up and a series of short waves will impact much of the long term
period.

Long wave pattern is quite zonal. Long wave pattern amplifies a bit
by the end of the period with a flat ridge over western Canada and a
flat trough over eastern North America. Short waves will move
through the flow over Ontario and send frontal boundaries into the
area on Tue/Wed. The ECMWF was a little faster than the GFS. Will
blend the models.

Little change to high temperatures for Tue through Fri...a degree or
higher on Tue and Wed and a degree or lower for Thu and Fri than
yesterdays forecast package.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 634 AM CDT Sat Jul 23 2016

Main aviation concern will be afternoon thunderstorms as a frontal
system moves through the area. Easterly winds will become
southeasterly as frontal boundary approaches in the afternoon, and
shifting to the west late tonight. While all sites have a chance
of thunderstorms today, with rain already being reported at DVL
and TVF, the strongest storms will be around and south of FAR,
where dangerous winds and large hail are possible in the late
afternoon.


&&

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

$$

UPDATE...Godon
SHORT TERM...Speicher
LONG TERM...Hoppes/Speicher
AVIATION...Speicher



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