731 FXUS63 KDLH 212102 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 402 PM CDT Sat Aug 21 2021 .DISCUSSION...(This evening through Friday) Issued at 402 PM CDT Sat Aug 21 2021 Summary: There will be periodic chances for showers and thunderstorms for the rest of the weekend and into next week with generally seasonable temperatures. Gusty winds are prevalent across the region this afternoon in the wake of a cold front that now resides over eastern Lake Superior and Lake Michigan. An upper level trough will continue to drift northeast into Ontario this evening, which will cause the cloud cover and sprinkles across the region this afternoon to diminish fairly quickly around sunset along with the gusty winds. Mostly clear skies are expected tonight with the exception for the development of some low stratus and fog for a good portion of the area due to the calm to light winds, some added moisture from recent rains, and ideal radiational cooling conditions. Dry weather is expected Sunday with mostly sunny skies during the morning but increasing clouds during the afternoon. Breezy southerly winds are expected especially to the west as the pressure gradient tightens up behind the departing high pressure to the east. An upper level trough with an weak attendant cold front will bring a chance for showers and thunderstorms Sunday evening and night. The timing of this front overnight will rule out nearly all surface-based instability, but a low-level jet and some elevated convection around 500 J/kg will support the potential for some thunderstorms, though strong to severe storms are unlikely. With forcing not being exceptionally strong and PWAT values just over an inch, rainfall amounts are expected to be light except for locally higher amounts in any thunderstorms. A ~26 hour period of dry weather is expected Monday into Tuesday with another upper level trough and cold front bringing shower and thunderstorm chances Tuesday into Tuesday night. With a bit better forcing, instability, and moisture, there is some potential for some stronger storms, though timing of the front will be crucial for storm potential, and there is some timing uncertainty at the moment. High pressure will trek across and north of the Canadian border Wednesday into Thursday, bringing some relatively cooler temperatures and possibly some breezy onshore flow near Lake Superior. With an amplified upper level pattern continuing through next weekend, rain chances will again be likely sometime Friday into Saturday with yet another cold front potentially passing through. While it's still going to be too warm to say that "it feels like Fall", the weather will certainly have that vibe compared to the hot days seen thus far this summer. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) Issued at 1255 PM CDT Sat Aug 21 2021 Gusty westerly winds will persist at all terminals through the afternoon and early evening. Expect frequent gusts from 20 to 30 knots. Winds are expected to diminish fairly rapidly around sunset this evening as winds begin to decouple and surface high pressure settles in over the region tonight. Periods of MVFR ceilings are expected early this afternoon but should become VFR after a couple hours. With calm to light winds and clear skies tonight, fog is likely to develop at HYR/DLH/HIB. Fog is less likely at INL/BRD as a developing pressure gradient may cause a bit of mixing and inhibit fog formation, but there is still a slight chance for fog there. Expect VFR conditions Sunday morning after the fog lifts. && .MARINE... Issued at 402 PM CDT Sat Aug 21 2021 Gusty west to southwesterly winds will continue through the afternoon and early evening with gusts up to 30 knots likely especially over the Apostle Islands. Wave heights of 3 to 6 feet with locally higher waves will be possible through this early evening as well. Just after sunset, winds are expected to diminish pretty rapidly as high pressure moves into the area, so winds will become light and variable overnight with a bit of patchy fog possible especially near the head of the lake. Winds will become northeasterly on Sunday with speeds 5 to 10 knots and gusts to around 15 knots around the head of the lake. Showers and thunderstorms will be possible Sunday night. && .PRELIMINARY POINT TEMPS/POPS... DLH 51 74 59 83 / 0 0 60 0 INL 47 78 57 75 / 0 10 80 10 BRD 49 79 59 83 / 0 10 60 0 HYR 47 77 57 84 / 0 0 50 10 ASX 50 76 57 87 / 0 0 30 10 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...Small Craft Advisory until 10 PM CDT this evening for LSZ121- 140>148-150. && $$ DISCUSSION...JDS AVIATION...JDS MARINE...JDS