Area Forecast Discussion
Issued by NWS Duluth, MN
Issued by NWS Duluth, MN
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178 FXUS63 KDLH 010606 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 106 AM CDT Wed May 1 2024 .KEY MESSAGES... - Rain and thunderstorms are expected tonight into Wednesday morning. - Another series of rainy systems are expected Thursday into Friday and again Friday night through Saturday evening. - Temperatures gradually warm up through this weekend. && .DISCUSSION... Issued at 235 PM CDT Tue Apr 30 2024 We are nestled underneath a brief ridge this afternoon that has opened up the skies for a little bit of sunshine in some places. The next rain maker will arrive tonight in the form of a negatively tilted upper level trough with what will essentially end up manifesting itself at the surface as an occluded front with some forerunning elevated CAPE (up to 300 J/kg or so) mainly in NW Wisconsin. Lapse rates become around 7 C/km tonight as well, which will be favorable for some elevated thunderstorms. The highest moisture will also be found across northwest Wisconsin, where PWATs approaching around 1" will be hitting around 90th percentile of climatology, and still reaching between 0.75" and 1" further north. All-in-all, the forecast is looking consistent for a widespread 0.40"-0.90" of rainfall with some locally higher amounts up to 1"- 1.25" possible mainly in northwest Wisconsin. Timing-wise, rain should move in from the southwest late this afternoon, hitting the Brainerd Lakes around 6 PM, then spreading northeast through the night, and exiting to the northeast through Wednesday morning. After the rain ends Wednesday morning, some drier westerly flow will set up with upper level ridging, allowing for some blustery conditions and sunshine. With plenty of low-level mixing and the dry air mass moving in, min RH may fall to around 35-40%, but fire weather conditions are expected to be minimal due to recent rains. The active weather pattern continues for the later part of the week as a broad trough deepens as it passes over the Rockies. Southerly flow ahead of this trough will tap into more Gulf of Mexico moisture and bring some more organized rain chances to the region Thursday into Friday. Better chances for any severe weather should remain to our south where the best instability and frontogenesis is likely to be as a broad cold front develops. The low center is likely to be deepening over our region, so we`ll likely be dealing with more synoptic rainfall with a few embedded non-severe thunderstorms (best chances over northwest Wisconsin...similar to tonight`s setup). How much moisture we end up remains in question, and ensembles are all over the place with potential rainfall amounts, but right now we`re looking at a 60-80% chance of rain Thursday into Friday with PWATs potentially reaching into that 0.75"-1" range. I wouldn`t say this system will be a mirror image of tonight`s rainmaker, but it certainly seems to share many synoptic similarities the way things look now. There may be a brief break in rain Friday afternoon and night, but models are starting to come into some agreement that a weaker trough may follow as we head into Saturday and Saturday night and bring some more rain to parts of the region. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 105 AM CDT Wed May 1 2024 A low pressure system sliding northeast across the area this morning has brought an area of predominantly MVFR ceilings with a smaller area of IFR ceilings in rain, reducing visibilities to MVFR at times. The lowest conditions are expected between 09z and 18z, followed by a gradual improvement. Visibilities will improve first, with these returning to VFR by 16z. The ceilings will take longer, but also returning VFR by 23z. Winds early this morning are varied with the low is overhead, but as it moves off to the northeast today, winds will become westerly and then increase for a few hours this afternoon, then decrease again after 00z. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 105 AM CDT Wed May 1 2024 Gusty northeast winds are expected to develop fairly quickly this evening as rain moves in and will persist through the night. Gales don`t appear likely, but a very brief gale-force gust can`t be completely ruled out. Winds will quickly shift to northwest Wednesday morning and some gusty winds and high waves will persist through the day. Small Craft Advisories have been issued. Winds are expected to lighten up Wednesday night. The next chance for stronger winds will be on Thursday with another rainy system moving in. For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt. && .CLIMATE... Issued at 235 PM CDT Tue Apr 30 2024 Taking a step back and looking at the broader picture, a generally wavy upper-level pattern looks to persist into the 8-14 day period, though perhaps becoming slightly less amplified per the Climate Prediction Center (CPC) outlook discussion. We may maintain a pattern of on-and-off rain chances going into early-to-mid May as a result, which should generally be good news for drought conditions that have been persistent up until the past couple weeks. In the past 14 days, around 1-3 inches of rain has fallen (locally higher), which is as much as 150-300% of normal. The CPC 8-14 day outlook (May 7-13) favors slightly above normal chances for precipitation, and drought conditions are expected to improve or perhaps even end for many parts of the region with plentiful rainfall we have received and more chances yet to come. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. MARINE...Small Craft Advisory until 10 AM CDT this morning for LSZ140>143. Small Craft Advisory until 4 AM CDT early this morning for LSZ144-145-148. Small Craft Advisory until 4 PM CDT this afternoon for LSZ146- 147-150. && $$ DISCUSSION...JDS AVIATION...LE MARINE...JDS CLIMATE...JDS