Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 211750
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1250 PM CDT Wed Jun 21 2017

.UPDATE...
Issued at 1250 PM CDT Wed Jun 21 2017

Showers/isolated thunder from this morning has been progressing to
the east-southeast, so as of now most of it was over northwest
MN. However there is a thin line extending from Grand Forks back
toward Jamestown. All this activity will keep moving east
southeast through the mid afternoon. Models continue to develop
convection along the cold front over eastern ND by 5 pm or so,
then quickly move it eastward across northwest MN so it is out of
the FA by mid to late evening. This is what previous forecast had
gone with, so no changes to the forecast needed yet.

&&

.SHORT TERM...(Today and tonight)
Issued at 350 AM CDT Wed Jun 21 2017

Challenges for the short term include rain coverage, severe
potential and temperatures. Uncertainty continues for severe
potential this afternoon. A majority of short range high
resolution and CAM model guidance currently overdoing shower
coverage in warm advection zone ahead of boundary over e Mt.
Degree of development and associated cloud cover will have
implications on severe potential and maximum temperatures this
afternoon. SPC has upgraded to slight risk over the valley and
adjacent areas for this afternoon into the evening. Surface
boundary will reach the western fa at prime heating. Plenty of
shear to work with however still looks like best upper support
will either be along and north of the international border or
south of the fa in the central plains. Will also be some capping
across the far southern fa to overcome during the afternoon.
Convective temperatures do lower into the lower 80s by 00z and an
increasing amount of guidance developing convection along boundary
at this time. Tsra should propagate into western Mn during the
evening hours exiting the fa by midnight.

.LONG TERM...(Thursday through Tuesday)
Issued at 350 AM CDT Wed Jun 21 2017

Will maintain some low pops Thursday however at this point feel
most areas will be dry. Cloud cover will determine temperatures.

Cold front drops through the FA Thursday night with cold advection
continuing Friday. Cannot rule out some showers however main
message will be breezy and cooler with highs only in the 60s and
lows dropping into the 40s for Saturday morning.

Split flow remains across North America with northern stream over
central Canada and southern stream along the northern states. Long
wave trough shifts south along the east side of Hudson Bay through
the period. Long wave ridge over AK will shift to Yukon while long
wave trough over the Gulf of AK will shift into BC. Another long
wave ridge off the Pacific Northwest coast will move into the US
Rockies. Northern stream will become more dominate through Sun then
southern stream ridge will become more dominate late in the period.

The ECMWF was not available this morning. Current model run of the
GFS and the previous ECMWF was doing a better job with the timing of
the short wave in the northern stream

High temperatures decreased one to two degrees for Sat, Sun, and
Mon. Little change to high temps for Tue.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1250 PM CDT Wed Jun 21 2017

Cold front will move through by mid afternoon into the evening.
This will bring some thunderstorms to the area, but not confident
any will necessarily hit any of the TAF sites. So at this point
kept anything as VCTS, but did hit the times that it is expected.
For most TAFs it will be a period of about 3-4 hours at most.
Other than thunder, there will be a west to northwest wind shift.
Winds are fairly gusty across western ND behind the front, and
some of this may move into the area briefly behind the cold front,
before winds die down after sunset. Rest of the TAF period looks
pretty quiet.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&

$$

UPDATE...Godon
SHORT TERM...Voelker
LONG TERM...JH/Voelker
AVIATION...Godon



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