588 FXUS63 KDLH 160914 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 414 AM CDT Sun Oct 16 2022 .UPDATE... Issued at 1015 PM CDT Sat Oct 15 2022 Light widely scattered rain showers remain across northeastern Minnesota late this evening and over very limited parts of northwestern Wisconsin. Forecast updates have been made to track these PoP trends. Some showers could turn over to a rain and snow mix early tonight and then light snow by early Sunday morning. Tomorrow will feature another day of scattered showers over the Northland; yes, much like the last few days. Lake effect rain showers along the South Shore continue Sunday afternoon, but are very likely to turn over to snow showers by that evening. The Special Weather Statement is in effect for Ashland and Iron Counties to highlight this first notable lake effect snowfall event in far eastern Ashland County and across Iron County in northwestern Wisconsin into Monday. Localized amounts of 6-8" of snowfall are possible in the highlands of northern Iron County by Monday afternoon. Expect impacts to travel for those commuting Monday morning in these snowbelt regions. Other notable weather out of this continuous low pressure system will be very strong winds along the northern half of the North Shore starting late Sunday afternoon and building through the overnight hours. Wind gusts were increased a few knots with the evening forecast update, but have largely continued the trend of the last couple of days of gusts to 40 mph into Monday morning. Locations between Tofte and Grand Portage, but specifically around Grand Marais, could experience wind gusts closer to 45 mph in a few hour period of late Sunday night into Monday morning per forecast model soundings. .DISCUSSION...(This evening through Friday) Issued at 400 PM CDT Sat Oct 15 2022 Summary: Scattered rain and snow showers are expected to continue tonight. Lake-effect rain will likely begin around Iron County tonight and switch over to snow late Sunday afternoon. Snow accumulations in Iron County on Sunday through Monday afternoon may be as high as 6 to 8 inches. This could lead to potential travel impacts for the Monday morning commute. Much lesser snow accumulations of an inch or less will be possible along and north of the Iron Range. Temps will be on the upward trend starting mid-week, with highs likely returning to the 50s by Friday. Scattered rain and snow showers have been persisting this afternoon as a shortwave trough propagates through the CWA. This shortwave is the result of an upper-level low pressure system currently located over northern Ontario. This system is expected to eject several more shortwaves over the CWA throughout the weekend. This will result in precip chances remaining in the forecast for most of the CWA throughout the weekend. CAMs indicate that much of this precip will be scattered, potentially presenting as a series of horizontal convective rolls over northern Minnesota. Abundant cloud cover will keep high temps relatively cool for the remainder of today and tomorrow. Expect precip type to vary between rain and snow, as diurnal temps swing above and below freezing. The main inland forecast concern over the next few days will be lake- effect snow developing along the South Shore of Lake Superior. In addition, minor accumulations may also develop downwind of Lake of the Woods, Rainy Lake, and Kabetogama. As the upper-level low pressure system advects southeast, a surge of cold air at 850mb is likely to move over the CWA. Since winds will be from the north- northwest, this will maximize the available fetch over Lake Superior for Iron County and to a lesser extent, Ashland County. Lake sfc temps per latest obs around the South Shore are currently around 10-12 degC. Aloft, 850mb temps will start around -5 degC on Sunday morning and plummet to around -12 degC by Sunday night. This increased delta-T will likely up lake-induced CAPE from a few hundred J/kg on Sunday morning to near 1000 J/kg by Sunday night. Expect lake-effect rain to begin along the South Shore tonight and continue on Sunday. This rain is progged to transition to snow in the late afternoon to early evening on Sunday and persist through Sunday night into Monday. Snow accumulations on Sunday through Monday afternoon will be highest in Iron County. Ensemble plumes show 2 main clusters, with one being around the 5 inch mark and a second around the 7 inch mark. Forecasted on the higher end of ensemble members in this update, since snow totals have been on the upward trend in recent model runs. Impact-wise, the main window of concern will be Sunday night into early Monday morning. This will be the time-frame when the most snow will likely fall. This could lead to slippery conditions for the Monday morning commute. Outside of Iron County, snow accumulations tomorrow into Monday will be much less at an inch or less along and north of the Iron Range. Highest snowfall amounts outside of the WI lake-effect snowbelts will likely be found in the lee of Lake of the Woods, Rainy Lake, and Kabetogama Lake, where up to 1.5" of snow will be possible. Expect conditions to dry out starting Monday as the upper-level low pressure system propagates downstream. Winds will slowly shift more southerly throughout the week, which will result in WAA. This WAA will increase temps throughout the week, with highs returning to the 50s to near 60 by Friday and continuing into next Saturday. && .DISCUSSION...(This evening through Friday) Issued at 400 PM CDT Sat Oct 15 2022 Summary: Scattered rain and snow showers are expected to continue tonight. Lake-effect rain will likely begin around Iron County tonight and switch over to snow late Sunday afternoon. Snow accumulations in Iron County on Sunday through Monday afternoon may be as high as 6 to 8 inches. This could lead to potential travel impacts for the Monday morning commute. Much lesser snow accumulations of an inch or less will be possible along and north of the Iron Range. Temps will be on the upward trend starting mid-week, with highs likely returning to the 50s by Friday. Scattered rain and snow showers have been persisting this afternoon as a shortwave trough propagates through the CWA. This shortwave is the result of an upper-level low pressure system currently located over northern Ontario. This system is expected to eject several more shortwaves over the CWA throughout the weekend. This will result in precip chances remaining in the forecast for most of the CWA throughout the weekend. CAMs indicate that much of this precip will be scattered, potentially presenting as a series of horizontal convective rolls over northern Minnesota. Abundant cloud cover will keep high temps relatively cool for the remainder of today and tomorrow. Expect precip type to vary between rain and snow, as diurnal temps swing above and below freezing. The main inland forecast concern over the next few days will be lake- effect snow developing along the South Shore of Lake Superior. In addition, minor accumulations may also develop downwind of Lake of the Woods, Rainy Lake, and Kabetogama. As the upper-level low pressure system advects southeast, a surge of cold air at 850mb is likely to move over the CWA. Since winds will be from the north- northwest, this will maximize the available fetch over Lake Superior for Iron County and to a lesser extent, Ashland County. Lake sfc temps per latest obs around the South Shore are currently around 10-12 degC. Aloft, 850mb temps will start around -5 degC on Sunday morning and plummet to around -12 degC by Sunday night. This increased delta-T will likely up lake-induced CAPE from a few hundred J/kg on Sunday morning to near 1000 J/kg by Sunday night. Expect lake-effect rain to begin along the South Shore tonight and continue on Sunday. This rain is progged to transition to snow in the late afternoon to early evening on Sunday and persist through Sunday night into Monday. Snow accumulations on Sunday through Monday afternoon will be highest in Iron County. Ensemble plumes show 2 main clusters, with one being around the 5 inch mark and a second around the 7 inch mark. Forecasted on the higher end of ensemble members in this update, since snow totals have been on the upward trend in recent model runs. Impact-wise, the main window of concern will be Sunday night into early Monday morning. This will be the time-frame when the most snow will likely fall. This could lead to slippery conditions for the Monday morning commute. Outside of Iron County, snow accumulations tomorrow into Monday will be much less at an inch or less along and north of the Iron Range. Highest snowfall amounts outside of the WI lake-effect snowbelts will likely be found in the lee of Lake of the Woods, Rainy Lake, and Kabetogama Lake, where up to 1.5" of snow will be possible. Expect conditions to dry out starting Monday as the upper-level low pressure system propagates downstream. Winds will slowly shift more southerly throughout the week, which will result in WAA. This WAA will increase temps throughout the week, with highs returning to the 50s to near 60 by Friday and continuing into next Saturday. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 1240 AM CDT Sun Oct 16 2022 Strong northerly winds aloft will continue over the area today and tonight. Scattered rain and snow showers are likely and may briefly lower visibility into MVFR or even IFR at times, particularly as temperatures cool after 16.10Z. Gusty winds will be a concern through this forecast cycle and beyond through Monday. Have kept primarily MVFR ceilings with this update, but partial clearing is possible late tomorrow afternoon as mid-level moisture is shunted eastward. && .MARINE... Issued at 414 AM CDT Sun Oct 16 2022 Strong winds will develop early this morning and continue into Tuesday and perhaps Wednesday in response to a strong and slow- moving low pressure system over Ontario and Quebec this morning. Northwest winds are expected through midweek. Wind speeds and gusts will increase today and be hazardous for smaller vessels initially. Gales of 35 to 40 knots are expected over portions of the South Shore and Outer Apostle islands starting this afternoon and along the North Shore from Silver Bay to Grand Portage starting early this evening. The gales will subside by late Monday afternoon and additional Small Craft Advisories will likely be needed after they expire. In addition to the dangerous winds, waves will build to 6 to 10 feet along the South Shore from Port Wing to the Outer Apostle Islands and from Oak Point to Saxon Harbor. Please refer to the latest Marine Weather Message for details on Small Craft Advisories and Gale Warnings in effect. && .PRELIMINARY POINT TEMPS/POPS... DLH 40 22 34 21 / 30 20 10 0 INL 36 20 33 19 / 30 30 0 0 BRD 39 23 34 20 / 10 0 0 0 HYR 41 20 35 20 / 70 30 20 0 ASX 44 25 37 25 / 70 60 60 10 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...Winter Storm Warning from 7 PM this evening to 7 PM CDT Monday for WIZ004. MN...None. LS...Small Craft Advisory from 10 AM this morning to 10 AM CDT Tuesday for LSZ121. Small Craft Advisory from 10 AM this morning to 7 PM CDT this evening for LSZ140. Gale Warning from 7 PM this evening to 10 PM CDT Monday for LSZ140>142. Small Craft Advisory until 7 PM CDT this evening for LSZ141-142. Small Craft Advisory until 10 AM CDT Tuesday for LSZ143>145. Small Craft Advisory until 4 PM CDT this afternoon for LSZ146- 147-150. Gale Warning from 4 PM this afternoon to 10 PM CDT Monday for LSZ146>148-150. Small Craft Advisory from 10 AM this morning to 4 PM CDT this afternoon for LSZ148. && $$ DISCUSSION...Unruh AVIATION...Huyck MARINE...Huyck