221 FXUS63 KFGF 090737 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 137 AM CST Mon Dec 9 2019 .UPDATE... Issued at 128 AM CST Mon Dec 9 2019 Cancelled the Winter Weather Advisory for the Devils Lake basin and northern Red River Valley counties as snow has ended and winds are weakening. Mid level Fgen snow is orienting itself a bit more northeast/southwest as it moves east ahead of the clipper axis. Heavy snow with snow rates 1-2 inches per hour still remains possible in the far southern Red River Valley into west-central Minnesota over the next 1-2 hours before pushing east further into central Minnesota. Light snow trails behind this heavier snow ending west to east through the morning. All snow still looks to push east of the CWA by 15 UTC. Gusty winds to 30 mph will remain possible in the southern Red River Valley into Minnesota through 12-15 UTC and will continue the chance for blowing/drifting snow. Because of this factor, will be hanging onto the WSW in southeast North Dakota and the rest of the Red River Valley for a little bit longer, until all snow stops. UPDATE Issued at 951 PM CST Sun Dec 8 2019 An area of 700 mb frontogenesis remains along the band of heavy snow between Grand Forks and Fargo. Heavy snow and low visibility remains possible in this band. More widespread light snow to the north and south the the heavier band continues to produce reduced visibility across eastern North Dakota, northwest and west central Minnesota. Look for the snow to move southeast tonight into Monday morning. Snow ratios continue to be on the high end above 20:1 ratios based on snow reports. The main impacts continue to be blowing and falling snow making travel difficult. UPDATE Issued at 704 PM CST Sun Dec 8 2019 With warm moist air moving over the area and a region of 700 mb frontogenesis heavy snow has been reported in band moving across eastern North Dakota and northwest Minnesota. For this reason Winter Storm Warnings and Winter Weather Advisories have been expanded to the north. Heavy snow in Grand Forks has been observed with snow ratios in the 25:1 to 35:1 range. This heavy snow band will move to the south overnight into Monday morning. When in this band visibility may fall to around 1/4 of a mile along with gusty winds and heavy snow. Travel will be very difficult as this band moves through. && .SHORT TERM...(This evening through Monday night) Issued at 335 PM CST Sun Dec 8 2019 A baroclinic zone with associated surface frontal band which stretches across North Dakota and northern Minnesota is steadily intensifying as cold air advection at mid levels and below increases. RAP analysis shows an H7 trof axis starting to swing through the western Dakotas, while 21z GOES 16 RGB imagery shows multiple low to mid cloud layers arcing through western into central ND... coincident with increasing radar returns and surface observations. Light snow is showing in surface observations across much of the Devils Lake and mid to upper Sheyenne River Basins in eastcentral ND. SPC mesoanalysis indicates some potential for a brief period of freezing drizzle or sleet yet this afternoon in southeast ND, but with strong sfc to mid level cold advection occurring would expect any mixed precip to change quickly to snow. Otherwise there is a possibility of some elevated and/or slantwise convection across south central and southeast ND as well, with a heavier banded snowfall potential mainly from southeast ND into west central MN. Expect snow to continue spreading eastward and intensifying through the evening and overnight hours as the associated mid level trof swings southeastward though the area. NAM12 and RAP guidance show the mid lvl trof axis passing through the southern RRV by 15z, which should mark the end of appreciable snowfall there... with some lingering light snow into northcentral MN through 18z. Surface pressure gradient and cold advection will support moderate northerly surface flow at 15 to 20 kts across eastern ND and the central RRV corridor into mid morning on Monday, with winds and snowfall slow diminishing as the system passes. Mondays high temperatures may be near midnight tonight, and in the low single digits, with temperatures steady or falling through the day. Expect some partial clearing around midday on Monday, but bitter wind chills approaching minus 20F throughout the day. .LONG TERM...(Tuesday through Sunday) Issued at 335 PM CST Sun Dec 8 2019 Colder Arctic air settles over the region as the upper level trof sags southward. A reinforcing cold shot Tuesday night into Wednesday keeps temperatures suppressed...with highs near zero and lows in the mid teens to 20 below zero. With persistent northerly winds...lowest wind chill values will remain in the 30 below zero range. For Thursday...the upper level low situated near Hudson Bay shifts eastward and the upper ridge begins to amplify in the west. Surface high pressure shifts east into the Ohio Valley...and return flow behind the ridge will see warmer air advance north into the area. By Friday...northwesterly flow aloft becomes more zonal. A few impulses are forecast to propagate through the flow bringing occasional chances for snow. With a lack of moisture to work with...expect any precipitation that falls to remain on the light side. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1056 PM CST Sun Dec 8 2019 Snow will continue to fall at all terminals at the start of this TAF period. Snow will end from northwest to southeast so first DVL then GFK and TVF then FAR and BJI. The band of heavy snow has moved past most terminals, but could still impact FAR this morning. As this band past GFK earlier on Sunday it lead to a period of VLIFR conditions for about an hour. The same could happen early Monday morning at FAR. Winds will continue to be gusty across eastern North Dakota and northwest Minnesota Monday morning with sustained winds between 10 and 15 knots with some occasional gusts up around 20 knots. Ceilings will remain mostly IFR while snow is still falling this morning, before rising late in the morning to afternoon up to MVFR or VFR as the snow moves off to the southeast. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Winter Storm Warning until 9 AM CST this morning for NDZ039-053. Winter Weather Advisory until 6 AM CST early this morning for NDZ027-029-030. Winter Storm Warning until 6 AM CST early this morning for NDZ038-049-052. MN...Winter Storm Warning until 9 AM CST this morning for MNZ002-003- 022>024-027>032-040. Winter Weather Advisory until 6 AM CST early this morning for MNZ001. Winter Weather Advisory until 9 AM CST this morning for MNZ008- 009-013>017. && $$ UPDATE...CJ SHORT TERM...Gust LONG TERM...Hopkins AVIATION...NC