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National Weather Service Grand Forks ND
315 PM CDT SUN AUG 28 2016

.SHORT TERM...(This evening through Monday)
Issued at 315 PM CDT Sun Aug 28 2016

Convection chances and strength remain the headache for the

Surface low pressure remains centered to our west with southerly
winds bringing plenty of warmth and low level moisture into
eastern North Dakota. Mixed layer CAPE as shown on the SPC meso
page is near 4000 J/kg and the cap is starting to break down.
There is a bit of a temp and moisture gradient over the southern
counties indicating a warm front, but with southerly winds
throughout not a lot of convergence along it. Deep layer bulk
shear is around 30 kts, but 0-3km helicity is high and the
effective significant tornado parameter is approaching 2 in the
southwestern counties. Not too much upper support though, and low
level convergence is better further west along the surface trough
axis. However, short range models have been trending more
aggressive on breaking out storms in the Red River Valley between
21 and 01Z. Supercells are possible and some very large hail and
some tornadoes will again be a threat.

Think that storms will move eastward into our MN counties as we
continue into the evening. Think that isolated cells will form a
convective complex as it moves east, and there should be some more
storms along the cold front as it starts to move into the
northwestern CWA later tonight. Kept highest POPs in the
northeastern CWA during the late evening and overnight. 

Tomorrow, the cold front will push the rest of the way through the
forecast area, with high pressure building down behind it. Some
storms developing in our far southeastern counties will be
possible as it seems that the front will not clear out before peak
heating, but any convection should be short lived. Highs will be a
few degrees cooler than today but still in the upper 70s to mid

.LONG TERM...(Monday night through Sunday)
Issued at 315 PM CDT Sun Aug 28 2016

Monday night through Wednesday...The cold front will continue to
push south Monday night and with high pressure digging in behind
it conditions will become more quiet. Tuesday will remain under
high pressure with the upper ridge building up to our west. Highs
should be nearly seasonal during the mid week period. The pattern
will hold through Tuesday night and Wednesday although some of the
models are showing some precip developing with warm air advection,
mostly to our west. Included some low POPs in our far western tier
Wednesday but think the better chances for precip will be later in
the week.

Wednesday Night-Sunday...Upper level ridging will be in place over
the region through Friday with surface high pressure over the Great
Lakes region. This regime will initially result in seasonably mild
temps and a relatively dry air mass.  Moisture will begin to
increase towards the weekend ahead of an upper trough that will
eject northeastward from the Pacific Northwest, helping to break
down the ridge over the central US.  Chances for storms will likely
increase by next weekend as a frontal system crosses the region
within southwest flow aloft.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1248 PM CDT Sun Aug 28 2016

Stratus has finally cleared out of KBJI so all TAF sites are VFR.
This will continue for the afternoon and evening, although there
is always the possibility of lower ceilings and brief reductions
of visibility with thunderstorms. Think that convection will be
possible from the Red River eastward, so have VCTS mention at all
but KDVL. Storms will be most likely between about 22 to 04Z. Some
fog formation is not out of the question towards early morning as
storms move eastward, but so far just have some 3-5SM at some but
not all TAF sites. Winds will shift to the northwest late tonight
into tomorrow morning as a cold front comes through, but speeds
should be mostly below 15kts.


.FGF Watches/Warnings/Advisories...


LONG TERM...JR/Makowski 

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