Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/14/22

Area Forecast Discussion
National Weather Service Green Bay WI
542 PM CST Sun Nov 13 2022 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Monday Issued at 254 PM CST Sun Nov 13 2022 The latest RAP analysis and satellite/radar imagery show polar high pressure centered over the Mississippi Valley early this afternoon. Although northerly flow has weakened, thermal troughing combined with minor low level instability has led to a diurnal uptick in strato cu and light snow showers/flurries. The most persistent snow showers should occur near the U.P. border over far northeast WI to the northern tip of the Door Peninsula. Don`t think will see any accums larger than a dusting for the rest of the afternoon in these areas. Looking upstream, the next storm system is developing over the northwest Plains and poised to move into the region Monday afternoon. Snow accum potential and timing with this system are the main forecast concerns. Tonight...Surface high pressure will move across the area. As the high settles over the area, north flow will become light and variable by the end of the evening, which should result in the end of any linger snow showers or flurries into far northern WI. A period of partial clearing remains possible tonight, but an influx of mid and high clouds should prevent temps from tanking. Will still trim back on temps in the cold spots where some snow may be on ground. Lows ranging from the middle teens over Vilas county to the middle 20s near Lake Michigan. Monday...Cloud bases will continue to lower as a shortwave trough/PV anomaly moves into the region during the afternoon. Pockets of mid-level dry air look to hang around during the morning, so think light snow will hold off until deep saturation spreads across north-central to far northeast Wisconsin during the afternoon. Snow may reach upwards of 1/2" to 1" by the end of the afternoon over north-central WI, which could impact the evening commute. Winds turn onshore over northeast WI in the afternoon, which also could lead to lake enhanced bands moving into the Door Peninsula. Would be more concerned if 1000-850mb wind speeds were higher than 5 kts. Highs on Monday to range from near 30 in the north to upper 30s over east-central WI. .LONG TERM...Monday Night Through Sunday Issued at 254 PM CST Sun Nov 13 2022 The extended period will see fairly static conditions through the middle of the work week, dominated by a 500mb ridge off of the West Coast and a strong upper trough that extends over the Great Lakes and into the Central Plains. This pattern will keep cold and below normal air flowing into the region and will bring even colder air in for next weekend. Precipitation-wise, the trough overhead will keep shortwaves rotating through the area Tuesday morning through Thursday, which will likely keep scattered snow showers going across the region. The main concern for this time period will be the potential for a lake enhanced band to set itself up sometime Tuesday through Wednesday morning as easterly to northeasterly winds will be in place during this portion of the forecast. If this occurs, will likely need to bump up the currently forecast snow totals. Overall, expect at least an inch or two across most of the area for this extended period of snowfall, with a few locally higher areas near Lake Michigan. By Thursday, the initial system should be winding down, which should bring a brief break everywhere but the far north sometime near the end of the week. Unfortunately for the far north, with the ridge not breaking down until after the upcoming weekend, lake effect seems likely to continue. Finally, there are some hints that another shortwave will swing through the region sometime at the end of the week, but the timing on this is still unclear. && .AVIATION...for 00Z TAF Issuance Issued at 534 PM CST Sun Nov 13 2022 Scattered light precipitation over north central WI and northern Door County should end this evening as high pressure moves into the region. VFR stratocumulus will likely prevail into the overnight hours, but when it erodes late tonight, mid/high clouds will be overspreading the region. Clouds will thicken and lower again on Monday, as an upper level disturbance approaches. Light snow and MVFR conditions should develop in the mid to late afternoon at the RHI/AUW/CWA TAF sites, with a few flurries arriving at the eastern TAF sites late in the afternoon. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM.....MPC LONG TERM......Uhlmann AVIATION.......Kieckbusch
Area Forecast Discussion
National Weather Service Marquette MI
1023 PM EST Sun Nov 13 2022 .UPDATE... Issued at 1023 PM EST SUN NOV 13 2022 Challenging fcst setting up overnight into Mon morning with regard to LES. Occasional +shsn have been streaming onshore in far eastern Marquette County and far western Alger County since late aftn. Would not be surprised if there have been some 4-7 inch accumulations since late aftn roughly along the county line btwn Skandia/Carlshend and Eben Junction/Trenary. While the somewhat organized banding of earlier has diminished, there are still +shsn in eastern Marquette County and far western Alger County. Sfc obs near the Marquette County shoreline show land breeze developing, so this may be responsible for the more disorganized appearance recently as the low- level convergence that supported the loosely organized banding is breaking down. New convergence on the developing land breeze should eventually lead to heavier snow showers organizing more so over the lake, just offshore. KMQT VWP also shows light northerly winds to about 7kft diminishing, now under 10kt. That also explains the now very disorganized appearance of ongoing shsn. To the w, KMQT radar has also been showing returns in far northern Ontonagon County from around Mass City northward. So, there has likely been several inches of snow accumulation in that area this evening as well. More recently, mdt/hvy shsn have also been developing just e of Copper Harbor. Not sure how the land breeze convergence will play out overnight. Some of the 12z CAMS indicated that the strengthening land breeze convergence just offshore during the night would slip back onshore in Marquette/western Alger County late night/Mon morning. CAMS that did show that now keep convergence/+shsn just offshore. However, wrf- arw still clips northern Marquette County to the n of the city of Marquette. Hourly HRRR runs have been supportive of heavier snow also brushing areas farther s from the city of Marquette to Shot Pt. Given the model trends, will hold off on an advy overnight/Mon morning. LES trends per radar and sfc ob wind trends will need to be closely monitored overnight to determine if developing +SHSN on land breeze convergence will slip onshore for the morning commute from Big Bay to Marquette toward Au Train. As gradient winds become ese Mon morning, the land breeze convergent snow band will likely push toward the Houghton area. Will be something to monitor for Mon morning/early aftn. Ongoing mdt/hvy shsn in far northern Ontonagon County will move offshore in the next few hrs as land breeze develops/strengthens. The heavier snow developing near Copper Harbor may shift sw into more of Keweenaw County based on model consensus of low-level wind fields, leading to a few inches of fluff for some locations there. && .SHORT TERM...(Through early this evening) Issued at 306 PM EST SUN NOV 13 2022 LES is slowly winding down, as evidenced on radar and satellite imagery. There are more gaps appearing in reflectivity as well as with the cloud cover, but again, emphasis is on the word slow. The colder air has definitely arrived, with 850mb temps in the negative mid-teens Celsius range. Dendrites/plates have taken over today, and SLRs have raised themselves up quite a bit as compared to yesterday. In other words, much bigger flakes with much fluffier textures today, persisting into this evening. Accums are, as expected, to not be as robust as the last 24 to 36 hours, although locally, amounts could still quickly accumulate, impacting motorists. Nrly winds continue, but their magnitudes are on a downward trajectory, with a slight veering in the far W by the end of this forecast period. Temps have generally gotten close to or already topped out for their highs today, in the mid 20s inland to around the freezing mark along lakeshores and in the south-central. .LONG TERM...(Monday night through Sunday) Issued at 336 PM EST SUN NOV 13 2022 Models and ensembles advertise anomalously strong ridging centered over the Gulf of Alaska which will promote broad downstream troughing over the central CONUS and Great Lakes region through next week. This pattern will continue the below normal temperatures along with periods of lake effect snow over Upper Mi. Lake effect snow looks to be light through much of the week, although there appears to be a potential for moderate to heavy LES into at least the western counties late week into the weekend as a series of shortwaves usher in colder Arctic air while providing additional opportunities for LES enhancement. Tonight, broad sfc ridging and a weakening wind field should bring an end to LES propagating well inland, but that said, CAMs indicate that strengthening land breezes could lead to a LES convergence band or series of mesolows from near Munising west through Marquette to Big Bay and Houghton/Calumet. Models have been latching on to this idea for several days now so there is higher forecast confidence that these LES features will develop, but uncertainly still exists in exactly where and how much snow they will yield. Most likely snow accumulation will be on the order of an inch or two for most of the aforementioned sites with locally higher amounts possible. Monday into Monday night, the prevailing winds take on a more east- southeast component by Mon afternoon. With 850 mb temps of -9C to -11C LES bands will become mainly focused over the Keweenaw and into south central portions of the U.P. Forcing from a shortwave moving in from southern MN/northwest WI could also provide enhancement to the LES into Mon evening while bringing a dusting of light system snow to the rest of the cwa. Tuesday into Wednesday, flow shifts from easterly Tuesday to northeast Tuesday night into Wednesday. A shortwave passing just south and southeast of the region could provide some weak enhancement to LES in the east and northeast snow belts respectively for these days. Thursday into the weekend, a series of shortwaves from the Northern Plains and south central Canada will provide more opportunities for lake enhancement, especially for the west to northwest snow belts while ushering in increasingly colder air for the weekend. 850 mb temps will lower from -11 to -12C on Thursday to -16 to -18C by later in the weekend. Would not be surprised if the colder airmass combined with the enhancement from the shortwaves could result in moderate to heavy LES at times for the west to northwest wind snow belts from late week into the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 634 PM EST SUN NOV 13 2022 Mostly VFR conditions at all TAF sites as lake effect showers are diminishing. What lake effect bands are remaining could still drop vis and cig to MVFR from VFR, though they`re going to be intermittent in nature. North winds turn light and variable tonight and emerge tomorrow out of the east. MVFR conditions return to IWD and CMX tomorrow afternoon. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 336 PM EST SUN NOV 13 2022 High pressure settles across Lake Superior tonight as winds generally remain 20 knots or less through Thursday. West-northwest winds will increase by Friday above 20 knots on Thursday as an arctic air mass begins to spill across the Upper Great Lakes. There could be occasional west to northwest gale force gusts over lake this weekend. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ UPDATE...Rolfson SHORT TERM...lg LONG TERM...Voss AVIATION...GS MARINE...Voss