000
FXUS63 KFGF 171137
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
637 AM CDT Thu Aug 17 2017

.UPDATE...
Issued at 632 AM CDT Thu Aug 17 2017

Slight adjustments made to dense fog advisory as Cavalier county
has seen increased vsbys while Hallock/Grafton have been down for
quite some time. Adjusted headlines to include all four counties
in northern valley while removing Cavalier. Expect conds to
improve by 8 AM CDT.

&&

.SHORT TERM...(Today and tonight)
Issued at 315 AM CDT Thu Aug 17 2017

The main forecast challenge for the short term will be fog
potential this early morning as well as dissipation of rain in the
far east and southeast.

Pembina and Cavalier counties showed early signs of dense fog
issues...with vsbys dropping across the counties to one-quarter
mile or less. Concerned most of NE North Dakota will see similar
conditions by 4 AM to 5 AM as winds are calm and dew point
depressions 0 or 1. For the moment, addressed issue in the far
northeast with a dense fog advisory and will monitor and expand
if necessary. Receiving no help from MOS guidance which keeps
unrestricted visibilities. Fog should clear up quickly aft
sunrise.

In the east and northeast, the latest low pressure system that
brought the valley and surrounding areas more rain continues to
slowly shift east-northeast as the upper low over southern MN
ejects NE into the upper Great Lakes. Expecting precip to end mid-
to late morning.

The next upper wave moves across the region tonight. Evening hours
will see Showalters around neg 2 although NAM showing very little
CAPE until Fri. GFS does bring low CAPE values into far western
zones during the evening hours so do have mention of thunder west
of the valley.

.LONG TERM...(Friday through Wednesday)
Issued at 315 AM CDT Thu Aug 17 2017

On Friday, an advancing upper level wave digging toward the
southeast part of the forecast area will provide chances for
another batch of showers or storms. The wave position should be
superimposed over sfc based CAPES of 1-2 K J/kg later Fri,
portending a reasonable thunder chance primarily over the MN lakes
country.

Sat looks to be more tranquil with high pressure at sfc and aloft
coupled with approaching 850 mb thermal ridge. This should boost
temps into the mid to upper 80s for afternoon highs. The next system
then heads this way late Saturday night into Sunday morning,
bringing chances. for isolated to scattered showers and storms.

Look for unsettled conditions Mon and Tue with waves focusing on
the southern half of the forecast area. By Wed high pressure will be
back in control with associated dry weather. Temps ease back about 5
degrees on Sun then drop a couple more early next week, remaining
within seasonal norms.|

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 632 AM CDT Thu Aug 17 2017

Early morning fog across the northern valley with some areas of
lower vsbys at GFK/DVL as well...generating reports of vertical
visibilities around 200 feet. GFK vsbys have increased and believe
that VV cig will soon dissipate...however DVL vsbys have dropped
and with lighter winds may linger closer to 13Z before improving.
All sites VFR by 14Z to 15Z. Another round of showers and a few
isolated storms move into eastern North Dakota tonight...but
placement/timing still in question and will hold off on mentioning
in TAFs.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Dense Fog Advisory until 8 AM CDT this morning for NDZ008-016.

MN...Dense Fog Advisory until 8 AM CDT this morning for MNZ004-007.

&&

$$

UPDATE...Speicher
SHORT TERM...Speicher
LONG TERM...WJB
AVIATION...Speicher