Area Forecast Discussion
Issued by NWS Grand Forks, ND

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683
FXUS63 KFGF 232034
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
334 PM CDT Wed Aug 23 2017

.SHORT TERM...(This evening through Thursday)
Issued at 320 PM CDT Wed Aug 23 2017

Issue this evening is western extent of precipitation. 500 mb
short wave moving over Winnipeg and this will move toward Bemidji
this evening. Area of rain showers near the path of this vort max.
No thunder anticipated as airmass is very stable along its path.
Farther west is where the issue of any showers come into play.
HRRR/RAP indicate development of showers 22z time pd nr GFK-DVl
and moving south from there. CAPE values are very weak sub 250
j/kg in the RRV so did remove thunder. Will keep idea of
some showers forming but lack of any defined cumulus on latest
vsbl sat pic and lack of instability leads me to question how much
will form in the warm sector of this system. Precipitation will
mostly be in the far southeast by 07z and then exit before 12z.

Clearing into far NW MN overnight and with dry airmass moving back
in some upper 30s to low 40s a good bet Roseau, Baudette areas.

500 mb short wave exiting area Thursday morning with very dry
airmass over far NE ND into nrn MN. An area of mid clouds progged
to move southeast from central into SE ND Thursday daytime. No
precip expected. Temps 70-75 most areas.

.LONG TERM...(Thursday night through Wednesday)
Issued at 320 PM CDT Wed Aug 23 2017

High pressure to drop south into the area late Thursday and move
east Thursday overnight with return flow setting up over E ND and
the RRV. Thus not as cool most areas. Some pockets of mid level
clouds may remain over southern fcst area. Friday will see
increasing clouds south and west as next 500 mb short wave moves
into South Dakota. Rain chances Friday night into Saturday mainly
tied to this system as it moves into central MN Saturday with
highest chances of rain SE ND and WC MN. Northern stream short
wave trough moving into western Manitoba during this period will
concentrate showers in that area...with most of NE ND and far NW
MN in the drier regime between systems, which has been the case of
late.

Guidance agrees nicely during the late weekend through mid week
period of next week. Primary sfc low track is more south of that
projected by yesterday`s runs, but it still seems the MN side would
be most likely to receive the greatest POP chances. Upper wave is
also to the east and with minimal CAPE/positive showalters/lack of
LLJ appears just RW would be the best bet. Chances for thunder
increase east of the valley Sun with daytime heating and proximity
to cold pool aloft. Mon and Tue still looking dry with seasonal
highs in the mid and upper 70s. Potential frontal passage on Wed
may knock temps back down a few by mid week.


&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 110 PM CDT Wed Aug 23 2017

VFR thru the pd. Showers moving through the area this aftn/eve
will fall from cloud bases 8000 kt agl and higher...local 4000 kt
agl overnight.  Winds light...mainly east-southeast.


&&

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

$$

SHORT TERM...Riddle
LONG TERM...WJB/Riddle
AVIATION...Riddle



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