Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/16/22

National Weather Service Bismarck ND
918 PM CDT Sat Oct 15 2022 .UPDATE... Issued at 917 PM CDT Sat Oct 15 2022 No major changes are needed for this update. Current conditions and trends were blended into the forecast. The large area of stratus clouds continues to erode from northwest to southeast this evening. UPDATE Issued at 640 PM CDT Sat Oct 15 2022 A large area of stratus continues to blanket much of the forecast area early this evening. RAP RH fields appear to be handling the clouds well, and suggest gradual clearing from northwest to southeast through the evening, which can already be seen in the northwest corner of the state. There was a brief period of drizzle at Beach during the late afternoon, but that appears to have subsided. && .SHORT TERM...(This Evening through Sunday) Issued at 116 PM CDT Sat Oct 15 2022 A western U.S. upper ridge and an eastern U.S. trough will maintain a northwest flow through the short term period. A cold front has moved through the forecast area. Expect northwest winds generally 15 to 30 mph this afternoon. Clouds have developed over a good portion of the western and northern forecast area. Expect increasing cloudiness over the south central into the James River Valley late this afternoon into this evening. Winds will diminish this evening but may remain a little breezy over central ND. Look for overnight lows mostly in the 20s. Mostly cloudy conditions early tonight will give way to clearing skies from northwest to southeast through the night. Cold high pressure traverses the forecast area on Sunday. Highs will be colder than today, mainly in the 40s, with some upper 30s possible around the Turtle Mountains. Winds will be lighter though on Sunday with the surface high overhead. We remain in a northwest upper flow and although we expect a good amount of sunshine early in the day. We do expect increasing mid and high level cloudiness through the day, especially west. .LONG TERM...(Sunday Night through Saturday) Issued at 116 PM CDT Sat Oct 15 2022 Dry conditions and a warming trend highlight the extended forecast period. The western U.S. ridge and eastern U.S. trough pattern to begin the long term period Sunday night and Monday, slowly transitions to a broad quasi-zonal flow along the International Border by Friday with a western trough starting to develop next weekend. This is supported in both the deterministic and ensemble solutions although the deterministic solutions are a bit slower and deeper with the western trough development next weekend. However, until we get there we are looking at mostly dry conditions. With a northwest flow pattern and especially early in the period, a passing sprinkle or shower can`t be ruled out, but most will remain dry through Saturday. Perhaps we could see some small precipitation chances entering into the forecast Saturday night, as a western trough develops east into the Plains States by later in the weekend. Currently, our NBM guidance has introduced some slight chance pops Saturday night, but remains completely dry until then. Expect a wide range of temperatures early in the work week with temperatures ranging from 15 to 20 degrees between the cooler Turtle Mountains to the James River Valley, and the warmer temperatures over western North Dakota. By mid to late in the work week, all will enjoy the warmer temperatures as broad upper level ridging covers the region. Widespread upper 50s and 60s are expected Wednesday through Saturday, with some 70 degree readings possible southwest and south central. At this time we accepted the NBM temperatures through the extended period, but if this trend remains, would not be surprised if we are blending in some warmer guidance temperatures with the NBM mid to late next week. We may see a few breezy afternoons with low daytime humidities, but at this time there doesn`t appear to be any real windy days in the extended period. && .AVIATION...(For the 00Z TAFS through 00Z Sunday Evening) Issued at 917 PM CDT Sat Oct 15 2022 VFR ceilings around 3,000-5,000 ft will continue to erode from northwest to southeast late this evening into the night. VFR conditions are now expected at all terminals through the forecast period. Northwest winds will sustain around 10 kts overnight, increasing slightly Sunday afternoon. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Hollan SHORT TERM...TWH LONG TERM...TWH AVIATION...Hollan
Area Forecast Discussion
National Weather Service Cheyenne WY
510 PM MDT Sat Oct 15 2022 .SHORT TERM...(Late this afternoon through Monday night) Issued at 230 PM MDT Sat Oct 15 2022 The CWA remained wedged between a deep expansive upper trough over the eastern CONUS and high amplitude upper ridge to the west. Cyclonic north-northwest flow aloft prevailed, with a few embedded shortwaves rotating on the backside of the trough. One wave was moving through northern and eastern WY, producing widely scattered showers. Some of these showers will affect areas from Douglas to Wheatland to Alliance northward through late this afternoon. Otherwise, mostly cloudy skies prevailed with temperatures in the mid 50s to mid 60s. The cool dry northerly flow aloft will continue through Sunday night. Expect mostly clear skies tonight through Sunday night. Most frost coverage overnight will be confined along and west of the Laramie Range. The 700mb temperatures Sunday will range from -2C to 2C, yielding afternoon highs in the mid 50s to around 60F. Northwest winds will be breezy at times over the high plains Sunday afternoon. More widespread freezing temperatures are forecast east of the Laramie Range Sunday night with minima from 26F to 32F. Most of these zones have already experienced freezing temperatures. Frost coverage will be more widespread along and east of Interstate 25. A warming trend commences Monday as the upper ridge to the west shifts east toward the CWA. 700mb temperatures will moderate to 2C to 6C in afternoon, yielding highs in the low to mid 60s. Subfreezing temperatures are forecast once again Monday night east of Interstate 25. .LONG TERM...(Tuesday through Saturday) Issued at 230 PM MDT Sat Oct 15 2022 Quiet weather expected for the work week as a somewhat anomalous 500 mb high pressure center sits over eastern Idaho/western Wyoming through mid-week. This will result in dry conditions with above average high temperatures through at least Friday. Low to mid 60s are expected for areas west of the Laramie Range. Areas to the east will see temperatures in the mid 60s to low 70s, which is about 5 to 10 degrees above average. Next precipitation chance looks to be Saturday night as both the GFS and ECMWF are in pretty good agreement of a stark cold front dropping down from the northwest during that time. Lower elevations will likely miss out on the better precipitation as both models peg the mountains with pretty good QPF. If these solutions hold true throughout the week, the Snowy and Sierra Madre Ranges could see a few inches of accumulating snow. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 503 PM MDT Sat Oct 15 2022 Some concern for IFR stratus to develop around KLAR overnight. HRRR guidance suggesting this as well as the latest SREF guidance. Would not happen until early morning around 12Z. For now...went with scattered low clouds and will reevaluate for the 06Z TAFs. Confidence would need to be a little higher before adding to their TAF. VFR elsewhere. && .FIRE WEATHER... Issued at 230 PM MDT Sat Oct 15 2022 A cold front will continue to sag south into northern Colorado late this afternoon. A trailing weak upper level disturbance will produce a few showers this afternoon over east central Wyoming and northern Nebraska Panhandle. Near to slightly below average temperatures will prevail this weekend, followed by slowly warming temperatures next week. Minimum humidities will be above 30 percent this weekend, decreasing to the mid teens percent Wednesday through Friday when elevated to near critical fire conditions develop as winds increase. The next chance for measurable precipitation will not be until late next weekend. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...MAJ LONG TERM...LK AVIATION...GCC FIRE WEATHER...MAJ
Area Forecast Discussion
National Weather Service Gray ME
1118 PM EDT Sat Oct 15 2022 .SYNOPSIS... Mostly dry weather is expected through the rest of the weekend with frontal boundaries pushing east of the area and high pressure moving overhead Sunday. A frontal system approaches from the Great Lakes late Sunday night and Monday bringing a soaking rain into Tuesday. Cooler and dry weather is expected behind this system through the end of next week. && .NEAR TERM /TONIGHT/... 1115 PM Update... Another round of tweaks to the forecast, mainly to account for observed trends in fog... and the status of the stratus tonight. Stratus has expanded in coverage over much of western Maine, turning more patchy up toward the western Maine mountains. Am expecting this to remain in place but gradually erode as a weak cold front pushes in from the coast... remaining most stubborn near the coast, where lowered visibility is also occurring. Don`t foresee widespread dense fog issues with this... but abundant low-level moisture may produce some as the night goes on. 637 PM Update... Little change to the forecast for the majority of the area... I did however have to modify sky grids a bit due to a marine stratus deck that has formed along the Midcoast... pushing through the northern reaches of Casco Bay and all the way across to Penobscot Bay. Some models are hinting that this stratus descends into a dense fog bank... will have to keep a close eye on this in case a dense fog advisory is needed through the morning hours. Previously... A highly amplified 500 mb pattern remains in place across North America through the rest of the weekend with a deep trough over Hudson Bay extending southward through the Ohio Valley. This trough will make little if any progress eastward over the next 36 to 48 hours. A north to south stationary boundary across central and eastern Maine has led to isolated showers to moving ashore along the Mid Coast into the Capital District with latest hi res guidance suggesting these will dissipate prior to sunset. Otherwise, the trough will remain far enough to the west of the area limiting precipitation chances through the rest of the weekend. Latest satellite imagery shows marine stratus/fog along and offshore of the Mid Coast with the latest HREF suggesting this will bring patchy fog to the Mid Coast and portions of interior central Maine tonight. How far inland and the western extent of this fog potential remains somewhat in question as the NamNest brings reduced visibility from fog all the way to the foothills back to the ME/NH border while the HRRR shows little inland penetration of fog. Have tried to find the middle ground between these solutions for fog tonight as well as putting some patchy fog in the CT Valley late tonight. Otherwise, skies will be partly to mostly clear with lows in the 30s north to 40s south. && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... A dry cold front will approach from the west late tonight and crosses the area Sunday morning. Not expecting much in the way of precipitation with this front with the main sensible weather impact being a slight drop in dewpoints and high temperatures running a few degrees lower than today. After any morning fog, skies will turn mostly sunny through late morning before turning partly sunny in the afternoon. Highs will range from the mid 50s north to mid 60s south. Despite the lowering of dewpoints from the cold frontal passage, onshore flow will again bring the threat of marine stratus and patchy fog along the coastal plain of Maine into southeast NH Sunday night. Clouds will start to increase late in the night as low pressure starts to take shape over the Great Lakes with a warm front extending into southern New England. There will also be potential for fog within sheltered interior valleys such as the CT Valley. Lows Sunday night will range from the 30s north to mid 40s south. && .LONG TERM /MONDAY THROUGH SATURDAY/... Overview: Trofing prevails in the extended thru the work week. The slow progression of the pattern will lead to a gradual step down in temps. The best chance for precip will be early in the week. Impacts: The main concern will be QPF as the last event has left rivers running high and soil saturated. While the heaviest QPF looks to be east of the forecast area...a shift westward would be cause for concern that rivers make another run above action stage...especially for western ME. Late in the week will also feature colder overnight temps...and frost/freeze conditions are possible just before the season comes to an end. Forecast Details: Weather will be more active to start the period than ending it. Trof axis will remain over the Great Lakes and leave the Northeast in the WAA portion of the flow. A series of S/WV trofs will pass thru the flow and lead to what looks like two rounds of higher PoP. One on Mon look more warm frontal in nature and showery. The follow up wave is currently modeled to be the stronger of the two with a more robust connection to deep moisture. EFI and ensemble guidance suggest the highest QPF threat is east of the forecast area and despite the time range of the event there is good agreement between suites. Generally looking at mean QPF less than an inch across most of the forecast for parts of the Kennebec River Valley and Penobscot Bay region. After Tue there may be showers...mainly in the mtns...but little QPF on consequence. Temps will be a secondary focus as much colder air dumps into the CONUS. At this time the colder air looks to maximize west and then south of the forecast we remain largely in the southwest flow portion of the upper trof. While colder air will eventually make it here by late in the will be more modified by then. It will introduce a couple nights of widespread 30s however...and with the frost/freeze program still active thru the 21st there may be some need for headlines. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Short Term...Patchy fog in the CT Valley will bring the threat of IFR to LIFR conditions at KLEB for a few hours prior to and through sunrise. Will also need to monitor marine stratus/fog just offshore the Mid Coast that will bring the threat of IFR/LIFR conditions to KRKD and KAUG, although confidence is not high enough to put in the TAF. Otherwise, VFR is expected to prevail tonight through Sunday. Will again need to monitor potential for marine stratus and fog Sunday night as well as radiation fog within interior valleys Sunday night for potential flight restrictions at most terminals. Long Term...Expecting conditions to deteriorate Mon as initial wave of precip approaches. Low clouds in addition to the SHRA will bring periods of IFR conditions thru Tue...especially across western ME. As southerly flow aloft increases Tue there may also be a period of LLWS for ME terminals. VFR conditions will return Wed and without a significant period of high pressure it will be difficult to pin down any potential impacts from valley fog despite recent wet weather. && .MARINE... Short Term...Latest buoy observations show seas 5 to 7 feet outside of the bays, with guidance keeping seas to at least 5 ft through 09Z. Have extended the SCA for seas to 5 ft through 09Z with winds and seas then remaining below SCA thresholds through Sunday night. Long Term...It is getting to be that time of year when SCA conditions become more likely than not. Starting Mon thru the end of the week looks like a period of SCA to near-SCA conditions. While at this time winds/gusts do not appear overly strong...the persistent flow direction may keep seas near 5 ft outside of the bays into Thu/Fri. There may also be areas of fog that develop on the waters ahead of the precip early in the week...but confidence is too low to include in the forecast at this time. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 5 AM EDT Sunday for ANZ150-152-154. && $$ UPDATE...Casey NEAR/SHORT TERM...Schroeter LONG TERM...Legro
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
910 PM CDT Sat Oct 15 2022 .UPDATE... Issued at 910 PM CDT Sat Oct 15 2022 Current forecast remains in good shape for this evening with no major changes made. A quiet and fall-like evening is underway across northeastern Illinois and northwest Indiana with current temperatures sitting in the upper 40s to around 50 degrees. An area of mid-level clouds continues to reside across the area, but the clouds are gradually pushing eastward as a weak frontal boundary continues to move southward across Wisconsin. While this boundary will not bring any precipitation it will allow the cloud cover to persist through much of the overnight hours before skies gradually clear out Sunday morning. The presence of these clouds will help to keep temperatures a tad warmer tonight than last night with lows expected to be in the mid to upper 30s for most of the area with lower 40s for the Chicago metro. Sunday will see similar conditions to what we saw today with mostly sunny skies to start the day becoming partly cloudy by dinner time as an upper-level disturbance moves into the area. Temperatures will once again top out in the mid to upper 50s with breezy northwest winds gusting around 20 to 25 mph during the afternoon. As the aforementioned disturbance moves in guidance is continuing to indicate that a few spotty sprinkles may develop across northern Illinois late Sunday afternoon. However, the shallow moisture forecast to be in place should keep most areas dry. Yack && .SHORT TERM... Issued at 235 PM CDT Sat Oct 15 2022 Through Sunday... A surface high to our west will slip to our south and southeast today, with mostly clear skies and westerly winds becoming southwesterly. Winds will be gusty this afternoon, with gusts up to 25 mph. Cloud cover associated with an approaching front will increase later this afternoon into the evening, but will move off to the east after midnight. No precipitation is expected from this overnight front. Winds will remain a bit gusty this evening, with gusts up to 20 mph possible, but decreasing after midnight. 850 MB temperatures, which started out below 0 C, will climb to around 5 C tonight, which is still below the normal 8 C. This slight increase and slight southerly flow will lead to lows several degrees warmer Sunday morning, ranging from the mid 30s to the north, to around 40 to the south and across Chicago. Temperatures to the north will still be cold enough to create some spotty frost along and north of I-88, and away from Chicago, early Sunday morning. Sunday morning will start with mostly clear skies, but clouds will increase once again midday as a stratocumulus deck develops from a reinforcing shot of cold air Sunday afternoon. Temperatures between 900 and 800 MB will drop below freezing, with a bit of elevated CAPE within the cloud deck, which may lead to a chance for some isolated showers Sunday afternoon, mainly in northeast Illinois. Winds will increase again Sunday afternoon with gusts of 25 to 30 mph. Cold air advection (CAA) at the surface will not start until the later afternoon/early evening, with Sunday high temperatures in the 50s. BKL && .LONG TERM... Issued at 235 PM CDT Sat Oct 15 2022 Sunday night through Saturday... Key messages in the extended forecast period: 1. Blustery conditions expected MON-TUE (Highs in 40s) - Near record cold highs MON - *see climate section below - NNW wind gusts up to 35 mph and sub-freezing wind chills 2. Gradual warming trend expected later in the week 3. Dry for most areas through the period - Flurries possible MON, low chance for snow showers - Lake effect showers MON-TUE into NW IN, some snow may mix in "Cold and blustery" will be the story for the start of the extended forecast period as the upper trough digs into the Great Lakes Region quickly developing into a closed upper low. Heading into Sunday night steady northwest winds will likely persist through the overnight hours. This strong cold air advection will help push overnight temperatures into the upper 20s to lower 30s away from Lake Michigan. Lingering stratus may limit some of the cooling, but the cold advection should make up for any reduction in radiational cooling. Cannot rule out a few flurries or isolated snow showers during the overnight period. The daytime hours on Monday will be notably cold and blustery (for this time of year) with highs struggling to warm out of the lower 40s with low clouds hanging around all day. Strong winds gusting to 30-40 mph will keep wind chill values in the 20s to lower 30s. Time to break out the winter clothing if you haven`t already! Given the cold airmass in place and steep low-level lapse rates, the cloud layer will be cold enough to support at least flurries. Given support for lift beneath a strong short-wave rounding the closed low overhead, if we can get a bit deeper cloud layer there could even be a few more robust snow showers across NE IL. There are hints of this into Sunday night toward the end of the 12Z HRRR and supported by the past couple runs of the ECMWF. However, the GFS/NAM suites are leaning less favorable for anything more than flurries at this range. Still something to keep an eye on! Regardless, the signal for lake effect showers remains favorable for portions of northwest Indiana on Monday, especially into northern Porter County. Some snowflakes again could mix in at times in the lake effect showers as well. Tuesday it looks like the lake effect precipitation axis begins to shift a bit further east, but there may be a few remnant showers into Porter County IN through the AM. While strong northwesterly winds will persist through Tuesday, clearing skies should help us warm up a bit more than Monday, with highs in the mid 40s. Wind chills will likely still be in the mid 30s to near 40, however. Even though Lake Michigan water levels are a foot lower than where they were last year, the persistent strong north northwest winds will result in large waves building across southern Lake Michigan and accordingly increases the risk for beach erosion and minor lakeshore flooding along the Indiana shore. Interests along the Indiana shore, especially in areas that have been prone to flooding in the past should monitor the forecast the next couple days. Wednesday will remain unseasonably cool with forecast highs still in the mid to upper 40s. Winds do begin to turn more westerly helping ease the strong cold air advection of the past couple days. Later in the week the upper trough begins to shift east as the western ridge starts to break down. Accordingly, southerly warm advection will return and help highs warm into the 50s Thursday and Friday, with 60s possibly making a return for the start of next weekend. Petr && .CLIMATE... Issued at 235 PM CDT Sat Oct 15 2022 Here are the current records in place for Monday and Tuesday. Most records appear to be safe, with the record cold max for Rockford for Monday 10/17 being the most likely record to be threatened. Though temperatures will not be all that much above the other records... October 17 October 18 Record Cold Record Low Record Cold Record Low Maximum Maximum Chicago 40 (1880) 26 (1948) 38 (1930) 20 (1948) Rockford 44 (2002) 24 (1992) 41 (1972) 19 (1952) Petr/Izzi && .AVIATION... For the 00Z TAFs... Aviation Forecast Concerns: * Marginal weak LLWS possible this evening. * Breezy west-northwest winds Sunday, with gusts near 25 kts especially during the afternoon. Surface low pressure will pass north of the Great Lakes region tonight, with a trailing cold front pushing southeast across the terminals after midnight. Southwest winds ahead of the front have diminished with sunset already, though a brief period of 30-35 kt winds in the 1500-2000 foot AGL layer may make for some marginal LLWS conditions through about midnight. Given sustained surface winds near 10 kts, this is below criteria for including LLWS in the TAFs however. Surface winds turn west-northwest behind the front during the pre-dawn hours, with the cold frontal passage otherwise expected to be uneventful. West-northwest winds (290-310 deg) will become gusty once again late Sunday morning, with gusts around 25 kts persisting through the afternoon and likely in to the evening within a strong cold air advection regime. Will likely see a VFR stratocu deck develop by midday in the 4000 foot AGL range, and this too looks to linger into the evening hours. Can`t completely rule out a stray sprinkle from this deck Sunday afternoon/evening, though chances of any meaningful precip appears low. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory...nearshore waters until 4 AM Sunday. Gale Watch...LMZ740-LMZ741-LMZ742-LMZ743...10 AM Monday to 10 AM Tuesday. Gale Watch...LMZ744-LMZ745...midnight Monday to 10 AM Tuesday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
826 PM PDT Sat Oct 15 2022 .SYNOPSIS...15/128 PM. Showery and thunderstorms are possible this afternoon, especially in Los Angeles County, with periods of heavy rain. Dry weather expected Sunday with a rapid warming trend through next Wednesday. && .SHORT TERM (SAT-TUE)...15/822 PM. Convection today was confined to the eastern portion of LA county and points to the east and south. Shout out to the HRRR deterministic MDL for really nailing the fcst. While some storms did have fairly impressive rainfall rates they were moving at a good clip and rainfall totals were on the low side with only a couple of stations reporting amounts between .4 and .5 of an inch. Showers and TSTMs will persist through this evening but will only affect eastern LA county. It was another cloudy and cool day as the upper low acted like a super eddy and kept low clouds in across all coasts and vlys all day long. This cloud cover along with lowering hgts lowered Woodland Hills max temp to 69 degrees the first time the max temp there was in the 60s since May 20th. Huge marine layer was not at all disrupted by the convection and now covers all the csts, vlys and coastal slopes. The good news is that without the upper low "super eddy" and the addition of offshore trends will allow for much better if not total clearing by afternoon. The extra sunshine and weaker onshore flow will bring 2 to 5 degrees of warming to most of the area (the SLO interior will likely see 8 degrees of warming) An update will be issued to adjust the pops and shower/TSTM coverage. ***From Previous Discussion*** Offshore trends expected to continue Monday and Tuesday leading to a rapid warming trend with temperatures getting back into the 90s for the valleys and 70s and 80s for the coast. .LONG TERM (WED-SAT)...15/141 PM. Good agreement between the ensembles through later next week, though less so with chances for precip. The warming trend is expected to peak on Wednesday before another slow moving and partially cutoff upper low approaches from the west. Both the GEFS and EPS ensembles show a trough moving through Thursday into Friday, though the GEFS is noticeably wetter with quite a bit of instability, particularly once again across LA County. The EPS much less so which explains the disparity in the precip output which is definitely higher in the GEFS and almost absent in the EPS. So for now just very minimal pops are in the forecast and mostly in the mountains. Will hopefully get better consensus early next week. Certainly higher confidence in a cooling trend for late week. && .AVIATION...15/1747Z. At 1516Z at KLAX, there was a 4000 foot deep moist layer capped by a strong inversion. The top of the inversion was at 6400 feet with a temperature of 14 degrees C. Good confidence in KPMD/KWJF TAFs through 18Z with moderate confidence between 20-03Z with a 20-30 percent chance of SHRA/TSRA. Low confidence in other TAFs, especially KSBA and south, including KLAX. Cigs/vsby may bounce between MVFR/IFR KSBA and south including KLAX, and low MVFR to LIFR to the north. Drizzle is possible for terminals KSBA and south through 20Z. SHRA/TSRA coverage may (10-20 percent chance) increase across this area as early as this time frame, but most likely between 20-03Z and focused across LA county (30-50 percent chance) with a 20-30 percent chance for KSBA, KOXR, and KCMA. Slow to no clearing expected for coast and coastal valley terminals, except for LA county terminals, which have about a 50 percent chance of scattering out between 20-03Z. KLAX...Low confidence in TAF. There is a 30 percent chance that cigs do no scatter out after 20Z. There is a 20 percent chance of SHRA/TSRA 18Z-22Z with a 30 percent chance 22Z-03Z. No significant easterly wind component is expected outside of TSRA. KBUR...Low confidence in TAF. Cigs may at least briefly scatter out as early as 19Z. There is a 20 percent chance of a shower or TSRA 18Z-22Z increasing to 30 percent 22Z-02Z. && .MARINE...15/825 PM. Isolated thunderstorms will continue across zone 655 tonight. Any thunderstorms that do form will generally come from the northeast direction. Gusty and erratic winds, steep seas, and frequent lightning will be possible near stronger thunderstorms. There is a 30 percent chance of Small Craft Advisory (SCA) conditions focused across portions of the outer waters at times Monday night through Wednesday. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...MW/Rorke AVIATION...Sweet/Munroe MARINE...Gomberg SYNOPSIS...MW Experimental Graphical Hazardous Weather Outlook at:
Area Forecast Discussion
National Weather Service Marquette MI
1201 AM EDT Sun Oct 16 2022 .SHORT TERM...(Through Tonight) Issued at 241 PM EDT SAT OCT 15 2022 Latest water vapor imagery and RAP analysis show a broad mid-level trough extending from central Canada into the Great Lakes region with an upstream shortwave of interest diving southeast from southern Manitoba/NW Ontario. Weak forcing ahead of this shortwave and WAA/isentropic ascent along or ahead of its associated sfc trough has led to scattered rain/snow showers mainly along the WI border counties this afternoon and it looks like these showers could continue into the early evening hours. There have also been some ongoing scattered lake effect showers in a westerly flow over Lake Superior today which have mainly affected portions of the Keweenaw and the far eastern Lake Superior shoreline of the UP. These lake showers will also continue into tonight and could increase in coverage and push farther inland later this evening and overnight as the passage of a weak trough/cold front shift winds more northwesterly and CAA lowers 850 mb temps 1-2C over the western lake. Looks like the best chance for a light mix of rain and snow showers tonight will be over the western counties and east half shoreline areas of the UP. Min temps tonight will generally be in the lower to mid 30s under mostly cloudy skies. .LONG TERM...(Sunday through Saturday) Issued at 402 PM EDT SAT OCT 15 2022 Some lake-effect rain showers (with some snow mixing in at times over the west) over the NW flow areas starts out the extended forecast period Sunday. Lake-effect showers become more numerous and intense across the area Sunday afternoon as inversion heights grow up to ~10 kft in response to a low pressure from northern Ontario dropping into Lake Huron Sunday and Sunday night. As we move into Sunday night, expect the rain to transition to snow from west to east as a cold front drops south from Canada. With 850mb temps around -10C from Ironwood to Marquette around 06z Monday, delta-T`s near 20C, and upslope flow in the NNW snow belts, expect heavy, wet snowfall to occur in the interior west and north central Sunday night into Monday. Several inches are expected over the Michigamme Highlands of Marquette and Baraga counties Sunday night, with minor accumulations possible near the western lakeshores as well as sfc temps reach freezing. In addition to the snowfall, with winds increasing up to 45 mph, particularly near the Lake Superior shoreline, expect blowing snow to become a concern. As an inverted trough moves through Lake Superior Monday morning, expect the heavy, wet snow to continue over the north central and windy conditions to continue across the entirety of the UP. Therefore, travel is not advisable Monday morning over the west and north central UP, as slick roads would make travel hazardous. In addition, the windy conditions, in combination with the heavy, wet snow, could also cause some widespread power outages. Widespread lake-enhanced snowfall over the north snow belts, particularly over the north central continues Monday into Tuesday as the low pressure over Lake Huron slowly moves over to Georgian Bay, allowing strong northerly winds and blowing snow to continue over the region. With inversion heights slowly dropping from 20 to less than 10 kft Monday into Monday, expect the heavy snowfall to slowly taper off as we move into the middle of the week. The greatest snowfall looks to occur over the Michigamme Highlands, as upslope convergent flow looks to squeeze out the moisture in the atmosphere quite effectively; would not be surprised if we saw double digit storm snowfall totals by the end of the event over the Michigamme Highlands. As the low lifts out towards Quebec Tuesday, expect drier air to enter into the region, transitioning the snow (and rain in the east) to lake-effect before it ends Tuesday night and Wednesday from west to east. The next shortwave that looks to effect our CWA looks to occur Wednesday night and Thursday, which looks to bring some light rain and snow showers across mainly the eastern CWA. After this, expect temps to warm as the pattern shifts away from the troughing that we are currently experiencing and warm Gulf of Mexico air moves in. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 1200 AM EDT SUN OCT 16 2022 Despite some brief fluctuations to VFR at times early this morning, MVFR conditions will be the predominant flight category for the duration of the TAF period. Persistent lake effect showers will continue to impact the TAF sites today with some transition to snow early this morning, especially as winds shift to the northwest behind a trough/cold front. Those northwesterly winds will also become strong at KIWD and KCMX this morning with gusts up to 23 kts. Further intensification can be expected by this afternoon as sustained speeds top off in the 12 to 15 kt range with gusts up to 29 kts. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 402 PM EDT SAT OCT 15 2022 Westerly wind gusts 20-25kt across the lake will become northwest tonight from west to east as a low pressure trough pushes across the lake and will continue northwest 20-25 kt into Sun morning. Later Sun thru Tue, low pressure develops in the vicinity of northern Lake Huron while high pressure ridge builds south onto the Northern Plains. NW winds increase to 35-40kt gales across the western lake by Sunday evening then increase to high-end 45kt northerly gales across the central lake late Sun night through Tuesday morning. Northerly storm force gusts are possible, mainly across the east- central lake Monday night into early Tuesday. North winds slowly diminish below gales from west to east on Tuesday into Tuesday night and then become west-northwest at 15-25 knots on Wednesday. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... Gale Warning from 8 PM this evening to 11 PM EDT Monday for LSZ162. Gale Warning from 8 PM this evening to 8 PM EDT Tuesday for LSZ240>244-263-264. Gale Warning from 11 PM this evening to 2 AM EDT Wednesday for LSZ245>250-265-266. Gale Warning from 5 AM Monday to 2 AM EDT Wednesday for LSZ251- 267. Lake Michigan... Gale Watch from late tonight through Tuesday evening for LMZ221- 248-250. && $$ SHORT TERM...Voss LONG TERM...TAP AVIATION...TDUD MARINE...Voss