Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 241425

Area Forecast Discussion
National Weather Service Grand Forks ND
925 AM CDT FRI JUN 24 2016

Issued at 923 AM CDT Fri Jun 24 2016

Elevated convection across SE ND weakening rapidly as it outruns
what instability there is. Maintained some low pops for blending
purposes but anticipate sprinkles at best this am across the south
as cap builds. No other significant changes.

UPDATE Issued at 633 AM CDT Fri Jun 24 2016

A few small convective cells have started to develop just to the
west of the CWA along the weak shortwave coming over the top of
the upper ridge. Earlier runs of the HRRR seem to have a decent
handle on this activity although the current run does not have
much until later this morning. Think that the threat for some
isolated thunderstorms will continue for a while this morning as
the shortwave moves through, so included some isolated mention in
the southern Red River Valley through mid day. Current activity is
elevated in nature and the severe convection will hold off until
later today.


.SHORT TERM...(Today and tonight)
Issued at 401 AM CDT Fri Jun 24 2016

Convective placement and strength will be the main challenge for
the short term.

Models are all in decent agreement on the upper ridge building
over the northern plains today, but vary quite a bit on where
exactly they bring precip. A weak embedded shortwave along with
some mid level warm air advection has allowed overnight storms to
develop over the western Dakotas near the ND/SD border. The high-
res models have some decreasing in the convection as it moves
east, but then redevelops it over our southern counties towards
morning. The activity will be elevated but with MUCAPE around 1500
J/kg there could be some stronger cells. Just have some isolated
thunderstorms in the southern CWA towards dawn but may make some
last minute adjustments depending on current radar trends.

After that weak shortwave moves off the question is where storms
will redevelop later today and into tonight. The main surface low
will be to the west, although there are signs of a weak warm front
developing and lifting across the northern counties towards the
Canadian border later this afternoon and evening. The NAM and GFS
go crazy with instability of over 4000 J/kg, which may be overdone
looking at current vs progged dew points. Even the less bullish
RAP has around 2000 J/kg which along with 40 kts of deep layer
bulk shear will be plenty to bring severe convection. The main
spoiler will be the strength of the cap. With the ridge moving
overhead the 700mb temps get up into the low to mid teens C. Think
that there will be some isolated to scattered activity along the
warm front late this afternoon and evening, with more widespread
convection coming out along the northern tier overnight as the
main surface trough comes east. Some severe storms with hail and
winds the main threat although with some shifting winds along the
warm front a tornado or two isn`t out of the question in the
evening. Heavy rain will also be possible as the ECMWF and NSSL-
WRF bring some high QPF to our northern counties which are already
saturated. However, storms could very well track further north so
with the uncertainty will hold off on any flood watch for now.

.LONG TERM...(Saturday through Thursday)
Issued at 401 AM CDT Fri Jun 24 2016

Saturday through Sunday...The upper trough moves out into the
plains and the surface trough axis and cold front move through the
eastern counties. Think that storm development along the surface
boundary is likely, although much will depend on what happens
Friday night. Will continue to keep high POPs and included a
chance for severe over western MN. After the cold front pushes by
Saturday evening there will be a few wrap around showers in the
north into Sunday, but strong convection will be off to our south
and east. Temperatures will be split by the front on Saturday with
hot and muggy still in the south and east and a bit cooler in the
70s in the northwest. Cooler air will come in even more for Sunday
and highs in some areas will stay in the 60s. Winds will be strong
both Saturday and Sunday as the surface low tracks through
southern Canada and there should be good mixing.

Monday through Thursday...A zonal long wave pattern was over the
Northern Plains with an east- west upper ridge over the southern
half of the United States. Pattern amplifies by the end of the
period with a long wave ridge building over the High Plains of MT
into Canada. The GFS and ECMWF were in reasonable agreement
through the period. However the GFS was a little faster solution.

Little change to high temperatures through the period especially on
Wed. Mon, Tue and Thu were decrease by a degree or less.


.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 633 AM CDT Fri Jun 24 2016

Cirrus has started to move into the west, but all sites remain
VFR. A few isolated thunderstorms are not expected to impact TAF
sites. More scattered to widespread activity will move in later
this afternoon and into tonight. There is still a great deal of
uncertainty as to placement and there is some indication that the
storms will all be north of the TAF sites. Will leave out any
mention for now and add VCTS at a later issuance. Some MVFR cigs
will be possible at KBJI and possibly KTVF late in the period.
Southeast winds will become rather gusty by this afternoon, but
then start to decrease this evening. Some shift to the southwest
to west at KDVL will be possible at the end of the period as a
cold front comes in, but think it will be the only site impacted
before 12Z Saturday.


.FGF Watches/Warnings/Advisories...


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