Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 231809
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
109 PM CDT SAT JUL 23 2016

.UPDATE...
Issued at 109 PM CDT Sat Jul 23 2016

There are still two areas of showers and tstms, the main one
extends from the central to northern Red River Valley. This is
producing rain from Hillsboro up toward Hallock MN. The second
area is brushing Wadena County with some light rain. SPC really
did not change the day 1 tstm outlook with the late morning
update, but they did say there is still quite a bit of uncertainty
yet. The main uncertainty is still with any severe potential this
afternoon into early evening.

Water vapor imagery shows the nice short wave up in southern
Saskatchewan with another weaker impulse associated with the
current convection moving into northwest MN. Drying is already
evident on water vapor imagery moving into most of central ND.
The current convection has limited most of the heating over the
FA. The cold front which is supposed to initiate more afternoon
convection is getting close to a KBIS to KMOT line. SPC meso
analysis shows quite a bit of CIN across the FA in the wake of the
current convection and the cooler worked over air. Therefore at
the moment there is only a thin band of clouds and no radar echoes
along the front. High res models still try to show some
development along this front as it moves east this afternoon into
early evening, but at this point it is looking a little less
likely. Will continue to monitor through the afternoon.

&&

.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 18Z TAFS through 18Z Sunday afternoon)
Issued at 109 PM CDT Sat Jul 23 2016

Tried to show most of the tstm activity with the current echoes
along the Red River Valley, which should only be an hour or two
in duration. After this moves through, the questions begin. There
is supposed to be more development as the cold front from KBIS to
KMOT moves through late this afternoon into early evening.
However, there is very limited instability ahead of the front to
the area behind the current convection along the Red River Valley.
Therefore will only mention VCTS for now and update TAFs with more
definition if it occurs. After the cold front moves through,
expect clearing skies and west winds. These west-NW winds could
become a little gusty by mid Sunday morning.

&&

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

$$

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


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