Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 160837

Area Forecast Discussion
National Weather Service Grand Forks ND
337 AM CDT Wed Aug 16 2017

.SHORT TERM...(Today and tonight)
Issued at 337 AM CDT Wed Aug 16 2017

Rainfall amounts and where and when it will fall remain the main
forecast challenge. To start off, rainfall so far early this
morning has mainly been restricted to the Devils Lake region. The
KMVX radar is estimating about 0.50 to 1 inch for a good portion
of that region, with even some localized higher amounts. At this
time yesterday, the models were showing that falling across the
southern Red River Valley into west central MN. Meanwhile, there
has really been hardly anything across the southern valley into
west central MN. The deep convection down over Nebraska has been
producing the really heavy rains. The SPC mesoanalysis page shows
two segments to the low level jet, one feeding into the showers
over the northern valley and the other into the convection in
Nebraska. Through sunrise into the morning hours today, expect a
weakening trend to the showers over the northern valley, but
sporadic showers also occurring most everywhere.

Going forward to this afternoon and tonight, there seems to be a
general slow down to the system. The 700mb low deepens over
eastern SD by 18z Wed, then tracks slowly east-northeast into east
central MN through 12z Thu. The short term high resolution models
show stronger convection breaking out around Sioux Falls SD by
early afternoon then tracking it east-northeast into MN. This
should begin to spread steadier showers with some embedded thunder
mainly into the far southern Red River Valley and west central
MN. Due to the slow movement of the 700mb low, there looks to be a
prolonged period of this steadier pcpn for mainly west central
MN. Therefore this looks to be a longer duration event that it did
at this time yesterday. Pcpn amounts for west central MN from
this afternoon into tonight look to range from 1.00 to 1.50
inches. Much less rain is expected for other areas. So looking at
totals from what is occurring now through what is expected
today/tonight, the least amounts may be from Valley City ND up
toward Hallock MN. Meanwhile, the Devils Lake region received the
decent amounts last evening and west central MN up toward Bemidji
should get the most today/tonight. Since both these areas did not
get the higher end amounts from the past weekend system, it should
not result in any ponding/flooding issues. It will also fall over
a prolonged period, not particularly heavy at any one time. It
looks like clearing will spread into the western FA tonight, and
with light winds and the recent rainfall, there may be some fog.

.LONG TERM...(Thursday through Tuesday)
Issued at 337 AM CDT Wed Aug 16 2017

The above mentioned system should push off to the east on Thu,
with clearing moving in behind it. This will be short lived
however, as the next system will begin to spread in some lower end
pcpn chances for Thu night into Fri. Instability is minimal Thu
night, but some tries to creep into mainly the eastern FA on Fri,
which should bring some thunder back to the area.

For Sat through Tue...The weekend still looks warmer and dry,
owing to building high pressure both at the surface and aloft. A
dry sfc boundary is progged to swing through the forecast area Sat
night or early Sun but the next threat for convection should hold
off until the approach of a short wave on Mon. The GFS and ECMWF
closely agree on the timing of these features with the heart of
the activity likely to favor the southern part of the region on
Mon. High pressure brings tranquil conditions for Tue.

Temps will rise to the low and mid 80s for the weekend before easing
back just a bit for the beginning of the new week.


.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1147 PM CDT Tue Aug 15 2017

MVFR ceilings have made their way to KDVL and will continue to
slowly spread eastward to the other TAF sites overnight and early
Wednesday morning (some pockets of brief IFR possible towards
morning). Rain also continues at KDVL but has been a bit slower
to reach the other sites. KGFK should see some soon while
locations further south and east will be late in the overnight and
into Wednesday.




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