Area Forecast Discussion
Issued by NWS Duluth, MN
Issued by NWS Duluth, MN
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455 FXUS63 KDLH 140535 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 1235 AM CDT Fri Jun 14 2024 .KEY MESSAGES... - Scattered thunderstorms will occur across the Northland into this evening. A strong storm or two will be possible with gusty winds and small hail the main threats. Fog may develop tonight after the storms/clouds move off. - Chances for thunderstorms return over the weekend into next week with a warm and moist airmass building through that time. - Although still early, there will be a chance for severe storms and heavy rain at times, especially late weekend into the middle of next week. && .DISCUSSION... Issued at 314 PM CDT Thu Jun 13 2024 This afternoon through Friday night... Scattered showers and thunderstorms this afternoon over northern Minnesota may drop into central Minnesota and northwest Wisconsin late afternoon/evening before dissipating. MUCAPE values were 500-1000j/kg over northern Minnesota with effective deep layer shear of 25 to 30 knots. Soundings reveal drier low levels with an inverted-V appearance. Low level lapse rates were also steep, 8-9.5c/km. We`re just entering peak heating and a strong storm or two will be possible into early evening with small hail and gusty winds possible. The storms will end later this evening and skies will clear. Some patchy fog will develop tonight. Dry conditions are expected on Friday with upper ridging building into the Northern Plains. Highs will be in the seventies but off lake winds will keep lakeside areas a bit cooler. Southerly low level flow and warm air/moisture advection may cause some showers/storms to move into southwest portions of the Northland later Friday night. Saturday through Sunday... Chances for showers/storms will increase Saturday into Saturday night with a shortwave moving northeast and continued warm/moisture advection. Chances (60-80%) peak Saturday night from far eastern Minnesota into northwest Wisconsin. CAPE will gradually build but values will be marginal for severe through Saturday night. However, given how moist we`ve been, there will be at least a low chance for some minor flooding. Greater instability will be in place Sunday with PWAT values from 1.3-1.6" and surface temperatures in the upper seventies to mid-eighties leading to MUCAPE values 1000-2500j/kg across the Northland during the afternoon. Shear values will also be supportive for severe storms. However, one limiting factor will be forcing as a shortwave exits by early afternoon leaving behind low amplitude ridging. There will be weak low level convergence though and there will be at least a low chance for strong to severe storms during the afternoon overnight period. Monday through Wednesday... The Northland will be under southwest flow aloft through mid- week. High PWAT values 1.5-2", per the GFS, are expected to be over the area or near which will aid in producing plenty of instability. The stronger southwest flow aloft will produce adequate deep layer shear. There is still uncertainty regarding the location of low level forcing as seen in the global models and with variations from run to run. The main takeaway though is there is potential for both severe storms and heavy rain early to at least the middle of next week. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1235 AM CDT Fri Jun 14 2024 The main challenge through the night is fog potential. We have mostly clear skies and nearly calm winds, which are ideal for fog formation. Temperature and dew point depressions are still a few degrees apart around the region, so fog has been slow to develop. Models are not in good agreement for any particular terminal, with most suggesting no fog (which doesn`t seem likely given current conditions). The best potential may be at HIB/DLH, and possibly at INL/HYR where some models suggest at least some fog. Most likely, for terminals that see fog develop over the next few hours, visibility will likely jump up and down between VFR/MVFR/IFR over short durations. After sunrise, fog should quickly diminish, leading to very quiet and sunny weather. There will be potential again for fog Friday night, but confidence is too low to include in any TAFs at this time. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 314 PM CDT Thu Jun 13 2024 Gusty westerly winds around 25 knots will continue this afternoon but diminish this evening. Small Craft Advisories remain in effect through 7PM CDT. A few thunderstorms will be possible and they may be strong producing small hail and gusty winds to 35 knots. Winds will become onshore Friday and continue Friday night but be at or less than 15 knots. Easterly winds will be a bit stronger on Saturday, from 8 to 15 knots with higher gusts. For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. MARINE...None. && $$ DISCUSSION...Melde AVIATION...JDS MARINE...Melde