868 FXUS63 KFGF 051637 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1137 AM CDT Sat Oct 5 2024 .KEY MESSAGES... - Very windy conditions this today into tonight brings potential for wind-related impacts. Wind gusts as high as 60 mph are forecast late this afternoon into early evening, highest confidence in northeast North Dakota. - Critical fire weather conditions are forecast this afternoon and early evening in southeast North Dakota, southern and central Red River Valley, and west-central Minnesota. Near critical fire weather conditions rest of Minnesota and North Dakota. && .UPDATE... Issued at 1109 AM CDT Sat Oct 5 2024 Confidence remains high in very windy conditions developing today into early evening, potentially resulting in impacts like wind damage and visibility reductions from blowing dust. These high winds combine with dry conditions to also drive fire weather conditions. Behind a cold front currently moving through the Red River Valley, deep daytime mixing will tap into high winds over 50 mph in eastern ND this afternoon, with lower winds elsewhere this afternoon. Winds as high as 58 mph have already been measured near Devils Lake Basin late this morning. Latest guidance also shows potential for even deeper mixing in the dry air mass behind the front, allowing RHs to dip even further than previously forecast. Looking into expanding the Red Flag Warning because of this. A secondary cold front moves through after 7 PM this evening bringing a surge of moderate- strong cold air advection. This brings another opportunity to mix high winds aloft to the surface, this time over most of our area including northwest and west-central MN in addition to eastern ND. This moderate-strong CAA is deep, too, extending up to 800 mb. This increases confidence in wind gusts over 45 mph to all areas for around a 3 hour period between 7 PM and 1 AM. For this reason, will be expanding wind headlines across the entire area during this timeframe. There may be a brief overlap between relatively stronger CAA with winds over 60 mph at 850mb. As such, wouldn't be surprised to see high wind warning criteria winds in areas not currently in the High Wind Warning like southeast ND, northwest and west- central MN in more of a localized fashion. Should confidence increase in these high-end winds not as localized in these areas, will likely need to expand the High Wind Warning for the early evening period. There is generally around a 20% chance of this occurring. UPDATE Issued at 716 AM CDT Sat Oct 5 2024 South-southeast winds in the valley have been gusty as advertised. A few gusts at KFAR and KGFK around advisory level (45 mph) but overall hanging just below as was expected. The winds will diminish gradually toward mid morning then start to turn southwest 15-17z before the arrival of the front/surface trough to the west. Surface trough/west wind shift is from near Rolla to Harvey to Bismarck and the initial wind gusts which were quite strong in western ND have died down considerably. Latest short term model guidance has west wind shift into the RRV midday/early aftn and then into far east fcst area (BDE/BJI) late aftn. Highest winds at 850 mb and best area for strongest winds will remain north central ND into SW Manitoba and SE Saskatchewan and barely gets into Towner and western Benson this aftn. So for the most part west winds gusting 50-55 mph (locally higher) in warning area and 40-50 mph in advisory area of E ND/RRV...and that may be pushing it this aftn. For the RRV, esp north, the best cold advection and pressure rise is 03z-06z period so will need to watch that period as brief wind gusts may approach 45-50 kts that period. && .DISCUSSION... Issued at 359 AM CDT Sat Oct 5 2024 ...Synopsis... Similar to one about a week ago, a strengthening low pressure system will be moving thru central Manitoba this afternoon north of Winnipeg. This is another wind machine, esp for northeast ND and into Manitoba. Low RH values too in SE ND and WC MN for critical fire weather. This system moves out rather quickly and mid week will see a 500 mb broad ridge develop with temperatures warming well into the 70s to around 80. ...High Winds Today/Tonight... 850 mb low level jet of 60 kts thru 15z in the Red River valley and this will bring strong SSE winds to the valley through dawn. Wind gusts 40 kts or so very possible, esp Fargo area where a south-southeast wind direction is favorable for higher wind gusts. Thought about advisory for this early morning but so far seems the wind speeds needed for advisory will be limited in area. Frontal system will move east around the low to our northwest today...with south to west wind shift into the valley midday and east thru MN in the afternoon. Surface gradient honestly not all that tight pressure wise and cold advection not strong. But considering daytime temps in the 60s behind the front and a dry sub 700 mb layer, well mixed layer will be in place where potential for 50kt gusts to mix down to the surface in Devils Lake/Langdon area this aftn/early evening. Farther east and south winds to mix down just a tad less and went advisory for SE ND into the RRV this aftn/eve. Coord with surrounding offices. Mid to late evening cold advection and a stratocu area will work southeast as low moves into NW Ontario tonight. Cold advection will occur with 850 mb temps dropping to zero. 850 mb winds 50 kts and sounding profiles do suggest some chance of those winds mixing to the sfc into the Red River valley 03z-07z period. So not out of the question a warning for high winds may be needed for this period. ...Fire weather today/tonight... Coord with neighbors. Lowest RH values will be found in SE ND into WC MN where it will be warmest too. Widespread sub 30 percent RH values will occur this aftn along with a south wind turning west. Gusts in SE ND and WC MN (near ND/SD border) will be near 40-45 mph. All good enough for critical fire wx conditions due to drying fuels due to lack of rain. Near critical fire weather conditions elsewhere thru NW/WC MN and also NE ND where RH values a tad higher (30s percent for lowest values). ...Sunday and beyond... Next week will see broad 500 mb ridging and warm temperatures with highs by Wed-Thu mid 70s to around 80. Winds fortunately lighter so that will reduce the fire weather concerns some. 00z GFS discounted with its more extreme soln for next weekend with upper low dropping south. But general consensus will be for an upper level trough to move into the Great Lakes region and eastern Ontario. So some cooling may occur with this. && .AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 716 AM CDT Sat Oct 5 2024 Its a day of wind with south winds turning southwest and then west. How high the gusts are is of course uncertain. DVL has better chc of seeing wind gusts 45 kts or maybe higher, with predominately 30-39 kt gusts this late aftn/eve elsewhere. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Wind Advisory until 4 AM CDT Sunday for NDZ008-016-027-029-030- 038-039-049-052-053. High Wind Warning until 1 AM CDT Sunday for NDZ006-007-014-015- 024-026-028-054. Red Flag Warning until 9 PM CDT this evening for NDZ038-039- 049-052-053. MN...Wind Advisory until 4 AM CDT Sunday for MNZ001>005-007-008-013- 014-029. Red Flag Warning until 9 PM CDT this evening for MNZ003-029- 030-040. && $$ UPDATE...CJ/Riddle DISCUSSION...Riddle AVIATION...Riddle