Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/01/24


AREA FORECAST DISCUSSION
National Weather Service Albany NY
933 PM EST Sat Nov 30 2024 .SYNOPSIS... Lake effect snows continue in the western Adirondacks through the weekend with several inches to multiple feet of snow expected beneath the most persistent bands north of Route 28 and west of Route 30. Elsewhere, cold and brisk but largely dry conditions are expected through the weekend. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Key Message: - Lake-effect snow continues to impact the western Adirondacks. Additional accumulations will be north and west of Routes 28 and 30 tonight. .UPDATE...As of 930 PM EST...Few changes were needed with this update as the forecast generally remains on track. Clouds have decreased from the Capital District south and east courtesy of southwest to westerly winds contributing to downsloping throughout the Hudson Valley and mid-level moisture remaining more confined to areas north. Made minor adjustments to temperatures and sky cover to reflect latest obs, but all else remains unchanged. Additional details can be found in the previous discussion below. .PREVIOUS DISCUSSION... As of 359 PM EST...Cyclonic flow continues over the Northeast as a mid and upper level trough is entrenched over eastern Canada, the Great Lakes Region, Midwest and the Northeast. Lake effect snow band continues to impact the western Adirondacks. The Snow Depth change over the past 24 hours at the Old Forge NYS Mesonet site is 13.0". The band is drifting northward into tonight as the low-level flow backs slightly. The lake temp is about 47F in Lake Ontario. Lake to H850/700 Delta T temps remain 18C/28C with moderate to extreme class instability based on upstream model soundings east of Lake Ontario at KRME. The inversion remains very high at 10 kft AGL. The low-level flow backing to southwest/west will allow for the heaviest snow to fall north of Stillwater Reservoir in the Wilderness tonight. An additional 3-6" of snow may occur. South of the band snow amounts will be very light. Additional light snow showers and flurries may drift in from lake Ontario moisture. We placed these snow showers and flurries mainly west of the Capital Region. Any accums will be light. Lows tonight will be chilly in the teens to lower 20s. Some single digits are possible in the Catskills. It will be partly to mostly cloudy in the moist cyclonic flow with cold advection ongoing. A Winter Storm Warning remains in effect in northern Herkimer County for heavy lake-effect accumulations. A Winter Weather Advisory remains in effect through 7 AM Monday in Hamilton County for lesser additional accumulations. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... Key Message: - Lake-effect snows shift southward out of the west Adirondacks into Monday. Discussion: The holiday weekend and December opens on a chilly note with temps close to 10 degrees below normal. The 3-km HRRR and NAM have the lake effect band start to drift southward off Lake Ontario in the late morning. The flow becomes more westerly an additional snowfall accumulations occur along and north of Old Forge and Route 28. The band should persist into the afternoon and then start to move southward at night. We kept the head lines going until Monday morning. Most of the region will be partly to mostly cloudy with cold and brisk conditions. Highs will be in the 30-35F range in the valleys, southern Taconics and northwest CT. Expect brisk west to northwest winds 5-15 mph. The band is transitory and weakens in extension Sunday night, as a short-wave moves through to disrupt the band. Additional snow accumulations will range from 2 to 6 inches across northwest Hamilton County with totals over multiple days 4-10". Northern Herkimer County north of Old Forge will vary from 6" to 2 feet for the event. Lows temps Sunday night will be in the teens. Mon-Mon night...Will feature a lowering inversion and the low- level flow being more northwesterly. Some multi-bands will form over w-central NY and may shift into the western Mohawk Valley, Schoharie Valley and the northern and eastern Catskills. Some light snow accums of a a few tenths of an inch to a half an inch will be possible. Otherwise it will be variable cloudy and cold with highs close to the NBM values in the 20s to lower 30s over the higher terrain and mid and upper 30s in the valleys. Cold and mainly dry conditions Mon night with diminishing lake effect southwest of the Capital Region with lows mainly in the teens to lower 20s. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Key Message: - High confidence for below normal temperatures to continue with additional chances for accumulating snowfall. The mean mid and upper level trough will remain over southeast Canada, the Great Lakes Region and Northeast to open the long term. Low and mid level temp anomalies based on the latest NAEFS will be -1 to -2 STDEVs below normal. Northwest flow persists with lake effect snow showers and flurries persisting mainly west of the I-87 corridor. Depending on the trajectory, some light snow accums may occur over the western Mohawk Valley, Schoharie Valley and northern Catskills. It will remain chilly with temps close to 10 degrees below normal with mid 20s to mid 30s for highs and some upper 30s in the mid Hudson Valley. The mid level trough weakens Tue night into Wed and the flow become zonal to southwesterly briefly. The lake effect lifts northward and weakens potentially depositing some light snow accums for the western Dacks. Ridging may briefly build in from the south Tue night into early Wed with lows falling into the teens. Clouds thicken and lower from west to east Wed pm for light snow to occur ahead of a clipper low and its warm front. The highest PoPs Tue pm continue to be from the Schoharie Valley and Saratoga Region westward in the 40-70% range for light snow amounts. Max temps will be similar to Tue. Wed night into Thu looks to be the most impactful time for a widespread light snow effect, but perhaps some moderate amounts for the western Adirondacks and the western Mohawk Valley where some south-southwest orographic flow enhancement may occur off the southern Dacks. The isentropic lift increases, as the clipper reaches southern Quebec. The closed H500 low remains near the Quebec/southeast Ontario border. Cyclonic flow persists and PoPs were raised to 60 to 90% across the forecast area based on the latest NBM and guidance. The pcpn may diminish across parts of the area south and east of the Capital Region in the late morning. A strong cold front may move through during the afternoon with some heavier snow showers or isolated squalls. Lows will be in the upper teens to mid 20s over the forecast area. Highs Thu are projected in the mid 20s to mid 30s over the hills and mtns...and mid 30s to around 40F in the valley areas. Thu night strong cold advection occurs over the forecast area. 850 hPa temp anomalies will be -1 to -2 STDEVs colder than normal. The actual values may fall to -12C to -16C. Lake differential temps look favorable for more lake effect snow Thu night into Fri. A shift to multi-bands in northwest flow may occur by Friday. It will be blustery and cold to close the week with max temps struggling to get out of the teens and 20s. Wind Chills in the single digits to 10 degrees or so below zero will be possible over the Adirondack Park. The winds may subside by Saturday, but temps will run 10-15 degrees or so below normal for early Dec. A few snow showers or flurries may linger over the western Adirondacks. The CPC Day 8 to 14 Temp and Pcpn Outlook for eastern NY and western New England is forecasting below normal temps and near normal pcpn for the 2nd week of December. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Through 00Z Monday...VFR conditions prevail at all terminals this evening with variable cloud cover across eastern New York and western New England. VFR conditions will prevail throughout much of the 00z TAF cycle, with ceilings generally ranging between 5-15 kft. However, some guidance hints that KGFL and KPSF could develop MVFR ceilings for a brief time overnight between 06-10z. Mentioned brief TEMPOs in these TAF groups to account for the possibility. Otherwise, winds will prevail out of the southwest to start before gradually backing more towards the west by the end of the period. Sustained speeds will generally fall below 10 kt. Outlook... Sunday Night Monday Night: No Operational Impact. NO SIG WX. Tuesday: Low Operational Impact. Slight Chance of SHSN. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Moderate Operational Impact. Chance of SN. Wednesday Night: High Operational Impact. Likely SN. Thursday: Moderate Operational Impact. Breezy. Chance of SHSN. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Winter Storm Warning until 7 AM EST Monday for NYZ032. Winter Weather Advisory until 7 AM EST Monday for NYZ033. MA...None. VT...None. && $$ SYNOPSIS...Wasula NEAR TERM...Gant/Wasula SHORT TERM...Wasula LONG TERM...Wasula AVIATION...Gant
Area Forecast Discussion
National Weather Service Binghamton NY
656 PM EST Sat Nov 30 2024 .SYNOPSIS... Cold weather expected through the weekend into early next week under as a upper level trough remains in place. Lake effect snow will remain north of our region with mainly flurries at times this afternoon through Sunday but the band shifts south Sunday afternoon, impacting the NY Thruway corridor. && .NEAR TERM /THROUGH MONDAY/... 650 PM Update: Partly cloudy skies out there this evening with a few, isolated light snow flurries on-going across Cortland, Cayuga, Onondaga and Oneida counties. Temperatures have already fallen back into the 20s and low 30s areawide. It will be quite cold tonight with lows in the 10s to low 20s over the region. Another cold and partly cloudy day (with a few isolated flurries) on tap for Sunday; highs in the mid-20s to lower 30s expected. The lake effect doesn`t shift south into Central NY until the Sunday evening hours. Touched up PoPs, and increased details in the PoPs/wx grids for when the lake effect snow band is expected to shift south Sunday evening/night. Was contemplating whether the current winter weather advisories for S.Cayuaga and Onondaga should be extended in time through at least Monday evening, as the 18z CMC regional model keeps steady lake effect snow going through the day...however the HRRR and 3km NAM dissipate or break up the lake effect snow bands at differing times on Monday; so confidence remained low enough to not extend advisories yet. Will wait and take a look at newer guidance before making any decisions on this aspect of the advisory...as uncertainty does remains a bit higher than usual on when the lake effect will break up. So for now, the winter weather advisory remains in place 10 PM Sunday through 10 AM Monday morning for the two forecast zones noted above. 200 PM Update... With the stratocumulus layer sitting right at the dendritic growth zone, there has been widespread light flurries across the region this morning into the afternoon. Forecast soundings show that the DGZ will remain saturated into the evening so flurries have been added into the grids through the afternoon. Some flurries have been added in for tomorrow as well as many forecast soundings show a return of the stratus layer at the DGZ so there will be potential once again mainly north of the Southern Tier. With a long wave trough set up overhead and persistent NW flow under it, we will remain cold through the end of the weekend with temperatures struggling to get above freezing. Lake effect snow is expected to stay north of the region and mainly impact the northern Tug Hill through at least mid day tomorrow before a shortwave moving in begins to turn the flow more northwesterly. Forecast soundings late Sunday afternoon and overnight are favorable for organized snow bands into Onondaga and Cayuga counties. As of now, the forecasted environment is not too favorable for deep inland extent of the snow bands so the heaviest snow accumulations will be limited to the northern western portion of Onondaga and central Cayuga counties. && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... West to northwest winds look to continue into Monday. The flow coming off of a warmer Lake Ontario should result in additional lake effect snow showers. The most concentrated area of snow showers given the wind direction should be focused into eastern Cayuga and western Onondaga counties where a winter weather advisory has been issued for. Even though the QPF looks light given a lack of forcing higher snowfall ratios should be able to offset that some. Snowfall totals of around 4 inches in spots look likely at this time with lower totals further southeast. Some snow showers may advance eastward into Steuben county as well from Lake Erie. These also look to be fairly light Monday. While several degrees warmer, highs still look to only get to around freezing.A break in the action should occur Tuesday night with winds shifting to southwesterly ahead of an approaching clipper system. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... Modeling and ensemble guidance still some differences in the overall track of the clipper. The track looks to be north of the region across New England Wednesday and Thursday. Still, enough lift looks present for an area of light snow to develop Wednesday afternoon and night ahead of a warm front. Might have to watch the Froude number with this event to see if there are any areas of enhancement or missed locations in terms of QPF. Ground temperatures should finally be cold enough for accumulations in valley locations as well. Another inch or two of fluff could occur with possibilities expanding into more of the region. If the track shifts slightly to the north less QPF would be observed in NE PA and the southern Tier of NY. Given the southerly flow, temperatures may warm a few degrees above freezing as well in NE PA Wednesday. So brief mixes with rain can not be ruled out in the Wyoming Valley. Temperatures still generally 20`s and 30`s given the cloud cover and general flow pattern. While to early to get a pinpoint on exact details this far out this looks like a favorable setup for snow squalls ahead of the main cold front early Thursday. This should transition to another Lake Effect event with west-northwest flow into Friday. Yet another clipper may follow with additional snow showers and Lake Effect snow showers on Saturday. A fairly potent cold airmass looks to move in Thursday through Saturday. This looks to knock temperatures back into the teens and 20`s. Model soundings show an increase in winds as well, so wind chills near 0 at times is not out of the question. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... ITH and BGM should see ceilings dipping in and out of MVFR conditions over the next couple hours as some lake clouds continue to move across the region. VFR conditions expected for all terminals through tonight and tomorrow. Ceilings at ITH and BGM could fall into MVFR again tomorrow afternoon, but confidence is not high enough at this time to include it in the TAFs. Winds will remain blustery, gusting to 18-25 kts across the region out of the WSW. Outlook... Sunday Night...Lake Ontario snow band will push south and should bring restrictions to SYR and/or RME. Monday and Tuesday...A shift to NW winds and a multi-lake connection will increase the probability of lake effect snow and associated restrictions at CNY terminals, possibly even extending as far as AVP at times. Wednesday into Thursday...A low pressure system moving through Southern Canada may bring scattered snow showers with associated restrictions. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...Winter Weather Advisory from 10 PM Sunday to 10 AM EST Monday for NYZ017-018. && $$ SYNOPSIS...AJG NEAR TERM...AJG/MJM SHORT TERM...MWG LONG TERM...MWG AVIATION...JTC
Area Forecast Discussion
National Weather Service Des Moines IA
544 PM CST Sat Nov 30 2024 ...Updated for the 00z Aviation Discussion... .KEY MESSAGES... - Flurries may fly over western into parts of central Iowa through this evening. - A 20 to 30% increase in light snow and flurry chances from previous forecast for Sunday afternoon into Sunday night over northwest into central Iowa. Chances are now 30 to 50% in these areas. Accumulations under an inch currently forecast. - Below normal temperatures much of the period. && .DISCUSSION... Issued at 150 PM CST Sat Nov 30 2024 The overall synoptic pattern features a broad trough over eastern North America with a ridge over the West Coast of the same continent. While this pattern will shift a little through the week, Iowa will remain beneath largely northwesterly flow keeping shortwave troughs passing overhead or nearby with generally limited moisture for any significant QPF. Temperatures will be below normal with the only day that may be around our early December normals on Wednesday. At present, the winter friendly Day Snow Fog RGB shows a large area of stratus moving in from northeastern Nebraska and South Dakota with surface observations reporting light snow or flurries beneath these clouds in some areas. Forecast soundings show that much of the saturation within these stratus clouds is near or resides within the dendritic growth zone (DGZ). These snowflakes are overcoming very dry subcloud layer air in the lowest 2000 to 3000 feet with recent mPING reports over western Iowa north of SUX and near CBF showing dewpoint depressions of 15F. Have maintained and slightly expanded the flurry mention about a county north and east from previous forecast through mid-evening. These clouds will depart, but latest HREF continues to advertise a 20% chance or less that low stratus will arrive from the north toward sunrise Sunday morning. These clouds could make it as far south as a Grinnell to Ames to Fort Dodge line. Further, these clouds may have enough moisture for flurries given their moisture resides in the DGZ, but given the chance of occurrence have not advertised that in the official forecast. The biggest change to the forecast is Sunday afternoon and evening with the forecast now advertising light snow and flurries over much of central Iowa. As the previous discussion noted and this morning`s deterministic models showed, there remains a low QPF event in this time frame. This light snow event is due to a stronger shortwave trough that dives southeastward with favorable large scale ascent from upper level jet streaks and low level QG convergence. While it is model dependent, HRRR runs show a very deep layer (8000 feet) of saturation within the DGZ with the NAM and GFS not quite as deep (5000-6000 feet). This depth of saturation coupled with weak omega should result in snow production. The initial National Blend of Models had less than 15% chance PoPs, but given the thermodynamic and kinematic fields at play, feel confident in the increase in PoPs. While QPF will only be a few hundredths and resulting snowfall is forecast to be under an inch, any untreated roadways may result in slick roads, particularly as holiday travel winds down and work week traffic picks up Monday morning. Temperatures will remain below normal through the upcoming week except for Wednesday. As high pressure slides into the Tennessee River Valley, our surface flow becomes more southwesterly and our upper level northwesterly flow becomes a bit more westerly. This will allow for temperatures to peak in the upper 30s to low to middle 40s on Wednesday - the warmest of the week! However, more cold air arrives late this week behind a cold front. Large scale precipitation chances are muted below 20% through the end of the week in the cluster analysis and our official forecast shows a dry forecast as well. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 544 PM CST Sat Nov 30 2024 Mid level clouds largely remain across portions of west/southwest Iowa this evening, with any ongoing flurries or light snow remaining west of KFOD and KDSM. This activity is expected to diminish over the next few hours, with clouds moving out for a brief period that will improve ceilings, before another wave of cloud cover returns mainly after 18z Sunday from northwest to southeast. Additional flurries/light snow become possible near the end of the period Sunday and look to remain through the evening. More details will be included in the next issuance. Otherwise winds remain light out of the northwest. && .DMX WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Bury AVIATION...Ansorge
Area Forecast Discussion...UPDATED
National Weather Service Hanford CA
651 PM PST Sat Nov 30 2024 .UPDATE... Updated AIR QUALITY ISSUES section. && .KEY MESSAGES... 1. Dry weather will prevail through next week with above average temperatures. 2. Late night and morning fog will be possible every day through next week in the San Joaquin Valley. && .DISCUSSION... The ridge over Interior Central California slowly shifts east tomorrow as an upper level weakness develops over the Golden State then hangs around through Wednesday and then shifts south over Baja California Thursday into next weekend as another ridge builds into the region. The focus tonight and for the next several nights and mornings will be fog concerns. The cloud cover has broken up over already along the Highway 198 corridor and west side hills this afternoon. The probabilistic guidance has low probability of the fog and stratus hanging around the rest of the valley this afternoon. The cloud cover is a factor in the the fog for the overnight hours. LAMP probabilistic guidance along with NBM aviation guidance have likely probabilities of low visibilities and dense fog conditions mainly north of Fresno and south of Hanford. The trend of clearing looking at the visible satellite does support the Hanford south solution. Looking at high res ensembles probabilities for the morning hours shows increased or greater than 60 percent probability of dense fog along the Highway 99 corridor. The HRRR highlights the northern areas and the area south of Hanford. The solution for now is to wait to see the extent of the clearing. Then issue the new DFA this evening. This plays out for the next couple of mornings. The upper level disturbance brings a ever so slim chance for High Sierra snow showers late Sunday and Monday. When looking at deterministic model solutions there is mid to upper level upward motion in the atmosphere however in the lowest 100 MB there is suppression that could lead to more fog events through the week. The average high is around 60 to 62 this week. Taking 61 as a proxy for the average in the San Joaquin Valley the probabilities of exceeding 61 range from 85 to near 100% at all locations. Going up to 65 degrees the probability of exceedance ranges from 35 to 65 percent. The alternate solution would be stratus cloud cover that could keep temperatures down. This is dependent on how much mixing is in the lowest levels along with residual moisture. Looking out through the CPC 8 to 14 day keeps the above normal temperatures and below normal precipitation going. && .AVIATION... 00Z TAF issuance: IFR ST deck with IFR-MVFR VSBY continues at all terminals with the exception of KVIS where the CIG has lifted. The probabilistic guidance for 06Z-18Z with the NBM has a likely probability of LIFR/IFR at all terminals. LAMP probabilities show likely LIFR/IFR from 08Z thru 17Z at the terminals. Plan on going IFR for now and allow the 06Z issuance handle the LIFR probs for the early morning hours. The current cloud cover provides just enough of a chance not to bring LIFR across the board for the 06-10Z departures. Elsewhere, VFR with scattered high cloudiness and light wind for the Sierra and Kern County desert. && .AIR QUALITY ISSUES... On Sunday December 1 2024, Fireplace/Wood Stove Burning Status is: No Burning Unless Registered in Fresno, Kern, Kings, Madera, Merced, and Tulare Counties. Burning Discouraged in Kern (Greater Frazier Park Area) and Sequoia National Park and Forest. && .CERTAINTY... The level of certainty for days 1 and 2 is medium. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit www.weather.gov/hnx/certainty.html for additional information and/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... None. && $$ Operations...Proton IDSS.........SM weather.gov/hanford
Area Forecast Discussion
National Weather Service Marquette MI
530 PM EST Sat Nov 30 2024 .KEY MESSAGES... - Long duration moderate to occasional heavy lake effect snow event should be gradually winding down Sunday into Monday, although locally moderate snow accumulation is still expected into east and north central portions of the U.P. Winter storm warnings and advisories remain in effect tonight into Sunday. - Another Clipper system moving through the area late Tuesday into Wednesday will bring widespread system snow late Tuesday into Tuesday night with another uptick in lake effect snow behind it Wednesday into Thursday for the nw-n Lake Superior snow belts. - Temperatures remain below normal through early next week, then will trend well below normal for late next week. && .SHORT TERM /THROUGH TONIGHT/... Issued at 258 PM EST Sat Nov 30 2024 Water vapor imagery and RAP analyses have midlevel troughing in place over the Great Lakes, with a surface low south of James Bay. Another embedded shortwave is seen moving through western Ontario this afternoon, with chilly WNW flow out ahead of it keeping in lake effect snow showers mainly in the westerly or WNW wind snow belts in the western and eastern UP. Thus, much of the UP is currently seeing a brief let-up in snowfall. The heaviest snowfall rates are currently seen across the Keweenaw and in Alger and Luce counties, generally around and east of Munising. HREF continues to point to snowfall rates around a half inch/hr in those eastern zones, perhaps higher at times, and webcams continue to show sporadic heavier bursts of snowfall. So, would not be surprised by some areas picking up another couple of inches through the afternoon and early evening. Meanwhile, as winds remain gusty, particularly nearer to Lake Superior, further reductions in visibility will be possible in snow showers. This evening, the aforementioned wave off to our north drops through. Model soundings show inversion heights increasing once again while winds veer more to the NW. This could spell a reinvigoration in snowfall over the western UP while the bands in the eastern UP drop more westward once again. A widespread 2-4in of snow is expected across the NW wind snow belts in the western UP, with some locally higher amounts around/in excess of 6in in the higher terrain north of Ironwood northeast to around White Pine. To the east, another widespread 3-7in is likely, with some of the "lucky" (depending on your definition) spots picking up as much as 8- 10in by sunrise Sunday. Snow bands may extend farther inland in the eastern UP with the long fetch off of Superior, even reaching as far southward as Lake Michigan. So, lighter snow accumulations will be possible across the US-2 corridor. However, with elevated winds overnight closer to Lake Superior potentially leading to further reductions in visibility, travel conditions would be most hazardous across Hwy-28 in Alger and northern Schoolcraft counties, and traveling from Munising to Grand Marais. Will opt to keep the winter headlines in place despite the brief break in activity this afternoon, in anticipation of this next wave. However, will likely drop the advisory over southern Schoolcraft county as snowfall rates and amounts look to be less impactful the rest of the weekend. && .LONG TERM /SUNDAY THROUGH SATURDAY/... Issued at 348 PM EST Sat Nov 30 2024 Surface-850 mb winds are expected to veer more northerly Sunday into Monday in the wake of a weak shortwave/sfc trough passage late tonight. This more northerly wind direction should allow Lake Superior LES bands to push farther inland Sunday into Monday. However, with surface ridging building in from north of the lake generally light to moderate fluffy LES accumulation is expected Sunday into Monday as 850 mb temps -11C to -12C yield lake-850 mb delta-t values of 18-19C. The only exception will be the likelihood of a locally heavy LES band setting up somewhere over western Alger, where low-level convergence will be enhanced by land breezes and fetch will be effectively lengthened by preconditioning off of Lake Nipigon. Late Mon night into Tuesday, winds back westerly in response to a surface ridge moving across the area from the Plains. The backing winds and associated subsidence from the ridge should further taper LES off from west to east late Mon night into Tue. Models show the next Clipper shortwave and associated low pres system moving into the Upper Great Lakes late Tuesday into Wednesday. Warm advection/isentropic ascent ahead of the system will bring widespread light to possibly moderate system snow to the area late Tuesday into Wednesday. Behind the Clipper system the coldest air mass of the season thus far will be ushered into the region late Wednesday into early Friday on the heels of N-NW winds as 850 mb temps fall to -16C to perhaps as low as -20C. The cold airmass combined with a cyclonic/convergent N-NW sfc-flow will support moderate to heavy LES and considerable blowing and drifting of snow with N-NW winds possibly gusting as high as 30-40 mph late Wednesday into Thursday. Wind chills will also plummet to 0C or below late Wed night into Thu night. Another round of winter storm warning headlines seems like a pretty good bet as we get closer to the event. Models indicate ridging moving in on Friday which should taper off LES from the west. Models then hint at another weak clipper moving through which could bring light snow back into the area Fri night into Saturday. Below normal temps early in the week will trend well below normal late week behind the stronger midweek Clipper system. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 529 PM EST Sat Nov 30 2024 Ongoing northwest wind lake effect snow event continues to result in flight restrictions for all TAF sites. Most impacted will be IWD and CMX, with MVFR predominant at IWD and IFR or worse restrictions at CMX. Elsewhere, SAW will be MVFR with periods of IFR. As winds shift more northerly into early Sunday, CMX may see an improvement to MVFR. Gusts at CMX could reach 30 kts. && .MARINE... Issued at 348 PM EST Sat Nov 30 2024 High pressure to the west and a weakening low pressure over James Bay through the rest of the weekend continues the gusty northwest winds over Lake Superior. Expect northwest winds 20-30 kts continuing through Sunday with gale force gusts to 35 knots over the east half through tonight. With high pressure approaching the Great Lakes for early next week, winds veer north Sunday night, falling back to 15-25 kts. Winds gradually diminish through Monday, falling below 20 kts across the lake by Monday evening. Winds back west for Tuesday and southwest for Tuesday night as the high pressure moves to the southwest. As a clipper low passes near Lake Superior, northwest to north winds are re-invigorated behind the associated cold front on Wednesday. Gales to 40 kts are becoming increasingly likely late Wednesday into Thursday with the strongest winds expected over the east half of the lake, where there is a 20-40% chance of storm force gusts to 50 knots per EPS probability fields during this time. Waves could reach 12 to 16 feet late Wed night into Thursday, highest east half. In the wake of the low, northwest winds gradually diminish to 20-30 kts Thursday night and 15-25 kts for Friday. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Winter Weather Advisory until 7 AM EST /6 AM CST/ Sunday for MIZ001>004-009-084. Winter Storm Warning until 7 PM EST Sunday for MIZ006-007-085. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...LC LONG TERM...Voss AVIATION...07 MARINE...Voss