Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 192029

Area Forecast Discussion
National Weather Service Grand Forks ND
329 PM CDT Mon Jun 19 2017

.SHORT TERM...(This evening through Tuesday)
Issued at 308 PM CDT Mon Jun 19 2017

Challenge will be coverage of convective activity this evening as
a potent short wave approaches the FA from the NW. Line of
convection approaching the FA from southern Manitoba will be
watched for down bursts winds and hail. Given meager ML CAPE
values 250 to 500 J/kg combined with strong shear, 30 to 40kts
effective will have storms with marginally severe hail and wind
capability. Wave will quickly translate to the southeast with
activity diminishing rapidly in the 7 to 9pm time frame. Rain
totals will be on the low side except for under the stronger
echoes. Generally less than a tenth for most with up to a quarter
possible under the stronger storms.

Overnight winds will lighten and where skies clear out the
possibility for some patchy fog will develop especially over areas
that receive the higher amounts of rain. Full sun will quickly
erode any fog and temps will rise into the 70s for most areas
Tuesday afternoon. Light north winds with SFC high pressure
gradually moving into the FA during the afternoon.

.LONG TERM...(Tuesday night through Monday)
Issued at 308 PM CDT Mon Jun 19 2017

On Tuesday night, surface high pressure departs eastward and an
upper level ridge rushes through. Cloud cover and rain chances will
increase in eastern North Dakota overnight into Wednesday morning as
a shortwave moves in. At this time, expect an initial round of
showers Wednesday morning in the Devils Lake area with this
shortwave, then mid day/afternoon development of showers and
thunderstorms forced by the cold front that will move through in the
afternoon and evening, eventually moving out of northwest/west
central Minnesota Wednesday night. Favorable convective ingredients
include strong effective 0-6 km bulk shear of 50-60 kts, dew points
in the upper 50s to middle 60s, precipitable water values near 1
inch, and perhaps some 850 mb jet forcing, but morning showers and
cloud cover will likely limit instability, especially in the north.
There is still model disagreement on which areas will be able to
recover, but the NAM and GFS do indicate potential for moderate
instability with MUCAPE values maxing out at 2000-3000 J/kg in the
southern half of the forecast area. Scattered thunderstorms on
Wednesday will have the potential to become strong to severe with
these ingredients. Expect any severe thunderstorms during this
timeframe to have main threats of large hail and damaging winds.

On Thursday, the upper low associated with Wednesday`s system churns
through Manitoba and into Ontario. Weak shortwave energy, combined
with a strong 850 mb jet, will bring small chances for showers to
the northern half of the area Thursday and Thursday night, but
moisture is quite limited as we remain in northwest flow aloft. Of
greater impact on Thursday will be breezy west winds with gusts to
35 mph in the Devils Lake basin region.

For Friday through the weekend, a more active northwest flow pattern
and weak upper level waves moving through will perhaps yield some
showers and storms in the area on and off. The better rain chances
are associated with a shortwave moving through Friday night and
Saturday. That being said, the weekend doesn`t look to be a wash out
by any means, and heavy rain or severe storms are not anticipated at
this time.

Expect Wednesday to be the warmest day through next weekend with
highs reaching the 70s in the north to the 80s in the southern Red
River Valley. For the end of the week through the weekend, highs
will be in the 60s to middle 70s, with lows in the 40s to 50s.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1241 PM CDT Mon Jun 19 2017

CU development early today with SCT-BKN CIGS 5000-7000ft at most
TAF sites. The exception at DVL where its down to 3000ft. Later
this afternoon and into the early evening a line of showers and
thunder will cross the area from NW to SE. DVL and GFK most likely
to be impacted by TSRA in the 21Z to 01Z time frame with gusty
NW winds.




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