Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/15/22


Area Forecast Discussion
National Weather Service Denver/Boulder CO
830 PM MST Mon Nov 14 2022 .UPDATE... Issued at 830 PM MST Mon Nov 14 2022 Very minor updates to the forecast for tonight. We`ve been watching run after run of the high resolution models this evening. The HRRR in particular hasn`t been all that consistent about where snow could develop, but in general it is favoring the southwest foothills and adjacent plains from central Boulder County southward into Douglas County, as well as the mountains of Summit County and the Park/Gore Ranges. Amounts were left alone in the high country where 1-4" are possible overnight, but along the east slopes down to areas just west of I-25, feel like the HRRR has been consistent enough to marginally increase snow amounts to around an inch early Tuesday morning. So we`re still not talking much for those areas along the east slops of I-70, I-25 south of Denver, US-285 and the west and northwest parts of metro Denver. Current radar trends seem to favor the direction the HRRR is going with some bands of light snow currently over the mountains and east slopes. Webcams are also showing snow across the I-70 corridor, and US-40, generally where the HRRR has some. We also refreshed temperatures though they were very much on track to drop to the teens across the plains and single digits in the mountain valleys. The main message here is that roads are below freezing right now as light snow develops, so snow should stick and there could certainly be some slick spots for tomorrow morning`s commute across metro Denver/Boulder, especially west and south sides, and any route through the mountains. Mountain webcams are already showing some snow on the roads with some slick spots likely. && .SHORT TERM...(This evening through Tuesday) Issued at 243 PM MST Mon Nov 14 2022 One system has exited to the southeast of CO this afternoon with another one expected to drop out of the western WY and into CO tonight. the RAP/HRRR models are trending up in terms of qpf around Denver later this evening. The cold front is expected to push into the Denver area around 9 pm with a weak/shallow northeast/east upslope component. In addition, the models show a brief period of weak mid/upper level QG ascent dropping north to south across the forecast area this evening. The RAP soundings suggest deepening moisture this evening from 800 to 550 mb with descent instability in that layer. For this reason, I have increased the pops to 40-60 percent range, with the best chance of snowfall accumulation in/near the foothills/Palmer Divide to the west/south of Denver. Snowfall accumulations around one inch possible in this area, primarily between 11 pm-3 am. As the system shifts southward towards 5-6 am, the airmass will dry from north to south with decreasing pops through the morning. Temperatures will remain cold, similar to today with brisk north/northwest winds across the plains east/northeast of Denver. Strongest gusts of 30-35 mph will occur along the WY/NE border in the afternoon. In the mountains, persistent light snowfall has benefited Winter Park the most today, but that has finally tapered off. Another round of light snow expected overnight. Most areas should see an inch or two of snowfall, especially on the west/northwest facing aspects, with localized amounts of 3-4 inches possible. Snowfall by Tuesday will be primarily orographic and confined the those favored areas in the afternoon. .LONG TERM...(Tuesday night through Monday) Issued at 243 PM MST Mon Nov 14 2022 On Wednesday, there will be northerly flow aloft over Colorado between a trough over the upper Midwest and a ridge near Seattle. There will be subsident flow due to AVA from a departing shortwave trough and since Colorado will be under the left entrance region of a jet over the southern US. Conditions will be dry and mostly sunny. High temperatures will be below normal reaching the upper 30s and low 40s across the plains. Winds will be gusty across the northeastern plains with gusts up to 40 mph due to stronger winds aloft mixing down. Winds will be much lighter in the Denver metro. A large shortwave trough will move southward out of Canada towards Colorado on Thursday. A strong jet streak with 250 mb winds up to 130 knots will position itself over our forecast by the latter half of the day which will aid in creating QG ascent. At the surface, a cold front will move across northern Colorado around midday and northeast winds behind it will develop upslope flow especially across the southern foothills, Denver metro, and the Palmer Divide. In addition, there will be frontogenesis that helps to develop a few bands of snow that will orient themselves from northwest to southeast. While the QPF won`t be very high with this system over the foothills and plains, model soundings indicate an isothermal layer in the dendritic growth zone that will lead to a large dendritic growth layer. Therefore, snow ratios will be rather high in this event and snowfall amounts appear to be in the 2-4 inch range in the Denver metro at the moment. The strong northwesterly flow will create moderate snowfall in the mountains with the highest amounts along the northwest slopes. The Park Range and northern Front Range will likely see snowfall amounts in the Winter Weather Advisory criteria. Travel conditions may be poor to hazardous at times during the heavier bands of snowfall so highlights may be needed. The focus will then turn to the bitter cold weather expected Thursday and Friday night. The fresh snow cover will aid with radiational cooling and the exact low temperatures will be a result of whether or not there will be cloud cover. If the system on Thursday moves through on the quicker side of guidance, skies will clear Thursday night and lows will bottom out. The ECMWF ensembles have a mean low of 3 F at DIA Thursday night with some members below zero. The NBM lows were on the warm side of guidance so they were lower in the forecast a few degrees. After a quiet weather day on Friday, temperatures will again be well below normal Friday night. If winds end up being light Friday night, lows could reach below zero in Denver and may approach the daily record low of -2 F. The higher terrain will easily get below zero each night with the mountain valleys potentially seeing the negative teens. Northwesterly flow aloft will slowly become more zonal this upcoming weekend and into next week. There will be a long stretch of dry weather with a good signal in the ensembles that temperatures will warm to near normal and then above normal by the middle of next week. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 433 PM MST Mon Nov 14 2022 Light winds and VFR conditions are the rule for the next several hours until late this evening. Light snow should move in after 10 PM across the terminals. ILS conditions with CIGs around 020 and VIS 1-2SM are possible with the snow, and the best chance of snow should be from 10 PM through around 4 AM. Air temperatures will be cold, and runway temps should be below freezing such than any snow that falls should stick. Snow amounts will be light, anywhere from a trace to an inch. However, winds should be under 10 kts during the snowfall. Any lingering light snow/flurries should come to an end by 5 or 6 AM, with light SSW winds expected at the terminals. VFR conditions should also return by 5 or 6 AM. On Tuesday afternoon VFR conditions with north winds that could gust >20 kts at DEN, but there should be much less wind at BJC and APA. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Schlatter SHORT TERM...Cooper LONG TERM...Danielson AVIATION...Schlatter
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
547 PM CST Mon Nov 14 2022 .DISCUSSION...(This evening through Monday) Issued at 216 PM CST Mon Nov 14 2022 Key Messages: * Area of light snow will continue to impact areas along and south of the NE/KS state line through early evening. Accumulations are expected to be 1 inch or less. * Well below normal temperatures will continue across the regions through the work week and into the weekend. * Temperatures will start to increase toward normal around this time next week, but there is still a lot of model spread so exactly when this occurs is uncertain. Forecast Details: There were no major changes regarding snow today, but made some adjustments. Elected to use the RAP for PoPs in the near term this afternoon and early evening as it seems to have the best handle on the ongoing precipitation today. A band of light snow has set up mainly over Rooks, Osborne, and Mitchell counties in north central Kansas and extends into Thayer and parts of Fillmore counties to the northeast. As expected, the low level dry air to the north has stopped the advancement of this system to really anywhere near the tri-cities. We continue to highlight the potential for some impacts to highways across north central Kansas. With cloud cover expected to return this evening along with another upper level shortwave, ended up increasing low temperatures in the overnight forecast tonight. Still, temperatures will be below normal with lows in the teens. With that cloud cover and cold temperatures, we will probably see a few flurries across portions of south central Nebraska tonight through Tuesday morning. High temperatures will be in the 30s for the most part, with a couple locations in north central Kansas potentially getting into the 40s where clouds clear out a little earlier in the day. Some model guidance indicates that our next chance for precipitation will be Thursday associated with an upper level shortwave transiting across the central Plains. There isn`t great model consensus regarding this though, and while a few places may see a few flurries or even a light snow shower, confidence isn`t high enough to add this to the forecast at this point. Ensembles and model blends do continue to show moderating temperatures starting the end of the weekend into at least early next week. Ensemble spread for temperatures is high for that entire period, especially Saturday and Sunday. Still, it is becoming clearer that a warming trend is likely on the horizon, with temperatures likely increasing to near normal (40s and 50s) next week. The negative to this forecast is that other than the occasional chance of flurries this week, this remains a dry forecast. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Wednesday) Issued at 540 PM CST Mon Nov 14 2022 VFR conditions persist through the forecast period at KGRI and KEAR terminals. Winds become light and variable overnight, increasing to 7-12kt from the northwest after sunrise. Ceilings are expected to lower as clouds move in from the west overnight. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ DISCUSSION...Hickford AVIATION...Wekesser
Area Forecast Discussion
National Weather Service Green Bay WI
558 PM CST Mon Nov 14 2022 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Tuesday Issued at 240 PM CST Mon Nov 14 2022 The latest RAP analysis and satellite/radar imagery show a shortwave trough and weak low pressure moving northeast across southern Minnesota early this afternoon. Widespread light snow is occurring over Minnesota and northwest Wisconsin ahead of this system. The leading edge of the light snow moved into north- central WI around midday while cloud bases are falling elsewhere. The 12z KGRB sounding showed ample dry air through the column of which some of the lift will go towards eroding. But still think will see light snow progress northeast from central to far northeast Wisconsin this afternoon. Up to a half inch appears possible by the start of the evening. A secondary system is moving over the southern Plains and poised to move into the region on Tuesday. Forecast concerns mainly revolve around snow accumulations and timing. Tonight...The lead shortwave trough will exit northeast WI by mid-evening. Although moisture above 10kft will scour out behind the shortwave, the moisture profile below this level will remain nearly saturated through the night within a weak isentropic ascent regime. In addition, low level southeast to east flow will strengthen modestly, augmenting low level moisture and leading to scattered snow showers/flurries over much of northeast WI through the night. As a result, expect a mostly cloudy to overcast night with occasional light snow and flurries for most locations. Amounts will be very light and generally a half inch or less, though some areas near the lakeshore or over north-central WI could see up to an inch. Temps shouldn`t fall much and remain in the 20s. Tuesday...The southern Plains storm system will be lifting into the Great Lakes. Deep saturation will overspread the region during the morning which should lead to a return of widespread light snowfall. Lift will be strongest over northeast WI where synoptic scale lift will be enhanced by easterly flow off Lake Michigan. Therefore think the highest precip rates will occur in the lake enhanced bands over northeast WI. If the boundary layer were colder, decent snow fall would be possible. But with temps forecast to warm into the middle 30s with surface wet bulb temps above freezing, some accumulations will be lost to melting. Snowfall accumulations are looking to be around an inch at most locations, perhaps a little higher where lake bands set up, and a little lower over far north-central WI. Highs will range from the low to mid 30s. .LONG TERM...Tuesday Night Through Monday Issued at 240 PM CST Mon Nov 14 2022 Jet streaks moving around the upper trough over the Western Great lakes will produce periods of snow showers at times through the end of the week. Temperatures will average 5 to 10 degrees below normal Wednesday, and 10 to 15 degrees colder than average the remainder of the week. Cold, easterly winds in low and mid levels of the atmosphere will produce lake enhanced snow across eastern Wisconsin Tuesday night through about midday Wednesday. 3 to 5 inches of snow look likely over parts of the Door Peninsula as well as Oconto and Marinette counties by midday Wednesday, with 1 to 3 inches elsewhere. Snow showers will be most common across the Northwoods Thursday through Saturday, but conditions are not ideal for significant lake effect snow in that area. && .AVIATION...for 00Z TAF Issuance Issued at 552 PM CST Mon Nov 14 2022 An upper level disturbance will continue to bring light snow and MVFR/IFR VSBYs to areas northwest of a line from MFI-IMT early this evening, but the snow should taper off before 9 pm. In addition, southeast to east winds off Lake Michigan should bring some lake-enhanced snow or mixed rain/snow showers to parts of eastern WI later this evening and into the overnight hours. Another more significant upper level disturbance will bring widespread wintry precipitation to the region starting around mid-morning Tuesday. Most places should deteriorate to IFR once the steadier snows arrive. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM.....MPC LONG TERM......RDM AVIATION.......Kieckbusch
Area Forecast Discussion
National Weather Service Grand Rapids MI
1053 PM EST Mon Nov 14 2022 LATEST UPDATE... Update .UPDATE... Issued at 1053 PM EST Mon Nov 14 2022 No changes planned to the forecast for tonight into Tuesday. Latest HRRR still shows the bulk of the snow developing after 12z Tuesday morning. We are still looking at a widespread snow (1-3" in most locations by Wednesday morning) developing on Tuesday in advance of a mid level shortwave that drives in from the south and southwest. At 850mb a low moves towards Detroit from Northern Indiana Tuesday into Tuesday night and at the surface a low moves from the Ohio Valley to Western Lake Erie. Given the track of these features, the heaviest precipitation will be from the I-94 corridor towards the I-96 corridor. We should stay mainly snow given soundings that are primarily sub freezing. Surface temperatures appear to be in the lower to middle 30s on Tuesday which should lead to mainly wet roads. The equation changes Tuesday night as the surface temperatures dip to near and below +32F. Some icy spots and slippery travel may develop Tuesday night. && .DISCUSSION...(This evening through next Monday) Issued at 345 PM EST Mon Nov 14 2022 --Occasional Snow Tuesday into Wednesday; 1-4" accums-- Potent negatively tilted srn stream shortwave lifting northeast from OK spreads snow showers into the area on Tuesday and is followed by another (nrn stream) shortwave Tuesday night. The second one is currently diving into the west side of the main longwave trough over the center of the nation. Yet another third wave rotating through that upper trough follows for Wednesday, so we are looking at a prolonged period of widespread/frequent synoptic snow showers Tuesday into Wednesday. Snow accumulation and travel impact potential is problematic with this system for a few reasons. First, the snow is expected to have a banded/non-uniform character as it arrives due to FGEN forcing within the deformation zone. Second, the OK shortwave is weakening/shearing as it arrives, and third, sfc temps will be marginal with highs temps Tuesday in the mid or perhaps upr 30s. This may cause to the snow to mix with rain. Also ground temps are still warm so accumulating snow may be difficult to do during the daylight hours Tuesday-- unless any heavier rates set up under any FGEN bands. Potential for travel impacts may ramp up Tuesday night though as sfc temps fall back to around or just below freezing. Snow will have more of a chance to accumulate after dark with bridges and overpasses most susceptible to slick spots. The other thing to consider Tuesday night is possible enhancement from Lake Huron in cyclonic northeast low level flow, as well as enhanced sfc convergence along the east-west oriented sfc trough hanging back over Lwr MI from the east coast low. HREF guidance suggests the possibility of 3-4 inches in the MOP/AMN/LAN areas. Model QPF decreases on Wednesday and snow showers should become scattered by that time. However we will have to watch the wind direction closely for later Wednesday into Wednesday night. Guidance is hinting at the possibility of heavier lake effect returning to the southwest corner of Lwr MI as the low-level flow becomes NNW. Decent lake enhanced accums could set up in Van Buren and wrn Allegan; possibly other parts of the lakeshore too. --Heavy Lake Effect Snow Possible Thursday through Sunday-- Ideal set-up will be in place Thursday through Sunday to see some potentially significant lake effect snow and travel impacts. Deep upper trough will be overhead with near record cold sweeping in from the west and several shortwaves passing through. The Lk MI water temp is still near 10C at the srn buoy which would create extreme instability by Friday when air colder than -15C is arriving from the west. Warm ground and marginal sfc temps may limit accumulation/impact potential initially on Thursday but projected highs in the 20s Friday through Sunday could certainly lead to some problems on area roads. At that point the lingering warmth of the ground may actually make matters worse as the falling/melting snow quickly re-freezes. We could be looking at a treacherous combination of ocnl near whiteouts and icy roads over the weekend, with westerly flow sometimes carrying the bands well inland. There could also be some periods of enhanced low-level FGEN at the interface between the lake modified air and colder non-lake modified air that sometimes sneaks around the bottom of the lake and into our southeast CWFA in these colder air outbreaks. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 706 PM EST Mon Nov 14 2022 The main weather feature to affect the area the next 24 hours will be a low pressure system moving from the Ohio Valley northeast to Western Lake Erie by Tuesday evening. VFR weather is expected to prevail tonight with light easterly winds under 10 knots and VFR ceilings at or above 4,000 feet. The low will spread snow into the area from north to south Tuesday morning between 12z and 15z. Conditions will quickly trend to MVFR during this time frame with all sites in the MVFR category by midday/16z. IFR and LIFR conditions are likely during the bulk of the afternoon and early evening hours as ceilings try to trend towards 1,000 feet and visibilities trend towards 1 mile. We may need to trend TAFs more pessimistic in later issuance`s, in terms of ceilings below 1,000 feet and vsbys below 1 mile. && .MARINE... Issued at 345 PM EST Mon Nov 14 2022 Prolonged period of hazardous conditions expected on Lk MI starting Wed night and lasting through Sunday with brisk westerly flow. Periods of gales can`t be ruled out Friday-Fri night with arrival of coldest air. We may even have some freezing spray at times over the weekend. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...None. && $$ UPDATE...Duke DISCUSSION...Meade AVIATION...Duke MARINE...Meade
Area Forecast Discussion
National Weather Service Lincoln IL
901 PM CST Mon Nov 14 2022 .SYNOPSIS... Issued at 315 PM CST Mon Nov 14 2022 A widespread area of light snow is expected late tonight into Tuesday across central and southeast Illinois, with a few inches possible west of I-55. Additional snow showers are expected Wednesday and Thursday afternoons as fast moving disturbances zip across the area, though any accumulations will be minor. The cold weather pattern will stick around for several days, with potential for near zero wind chills by the end of the week. && .UPDATE... Issued at 900 PM CST Mon Nov 14 2022 Very little in the way of updates is needed this evening as the approaching upper level wave and associated snow is well on track, heading into MO and IA at present, with no observations of snow quite reaching the Mississippi River yet in these states. 00Z HREF ensembles have delayed arrival of snow ever so slightly through early morning, but not enough to alter PoPs. Snowfall rates have also shrunk ever so slightly, but snowfall measurements behind the system are consistent with previous forecasts, so have no plans to back off precipitation amounts. Still expecting measurable snow to start in west central IL mainly after midnight, spreading northeastward across central IL through 3-4 AM, with heaviest snowfall rates 3 to 9 am over most of the area. Current temperatures are mid to upper 30s, only scheduled to fall a few more degrees overnight, leaving areas south of I-70 in potential for a rain/snow mix, struggling to reach the freezing mark. && .SHORT TERM...(This evening through Tuesday night) ISSUED AT 315 PM CST Mon Nov 14 2022 Key messages for this period: 1) Snowfall amounts bumped up a bit, requiring a northward expansion of the Winter Weather Advisory. 2) Main impacts starting around 2-3 am near I-72 and across the Peoria metro toward sunrise. 3) Snowfall rates should average around a quarter inch per hour, but will be around a half inch per hour in the heavier bands. Afternoon water vapor imagery shows a strong shortwave moving across northern Texas and western Oklahoma. This will lift northeast and should be moving into central Illinois before sunrise. Still quite a bit of dry air currently in place as far away as southern Missouri, so some top-down moistening will need to take place in our area. Latest HRRR and NAM Nest tries to bring in some light snow from Springfield westward as early as 8-9 pm, though more of the impacts will be after midnight there as upper level forcing increases across west central Illinois. Further north, impacts along the Illinois River valley start increasing after 3-4 am. Latest NBM guidance suggests snowfall rates may reach a half inch per hour in the heavier bands between 3-7 am. Given the first significant snow of the season in that area and the impacts coming around rush hour, we have expanded the Winter Weather Advisory northward, to include Galesburg-Bloomington northward, with total accumulations of 2-3 inches in the advisory area. Wild card will be the pavement temperatures, which likely remain somewhat elevated with the recent warm spell. Air temperatures will likely be around 30-32 degrees while the snow is flying, Main impacts may be on bridges and overpasses where ground temperature isn`t a factor, but if the snow falls heavy enough, the main roads would have some impacts as well. By midday Tuesday, the main bands of snow should be north of the I-74 corridor, however some increase in light rain/snow is expected again northwest of the Illinois River as a separate wave swings ahead of the upper low dropping southward into the Dakotas. Have increased PoP`s across that area late afternoon into the early evening. .LONG TERM...(Wednesday night through Monday) ISSUED AT 315 PM CST Mon Nov 14 2022 Main highlight for this period is the unseasonably cold air mass that will remain firmly in place. Lobes of Arctic air will continue to drop into the Midwest through Sunday, with the coldest weather on Friday as 850 mb temperatures drop to around -17C. Extreme Forecast Index off the ECMWF is down to -0.8 to -0.9 late week. Wind chills Friday and Saturday mornings are likely to drop to near zero across central Illinois, with air temperatures in the mid teens. A number of areas have record lows in the single digits on Friday, though a few may be within reach around Springfield and Peoria. Some moderation is expected early next week as the upper flow starts to come more from the Pacific Northwest, and the 8-14 day outlook trends more toward near normal temperatures. Precipitation-wise, a few shortwaves will swing across the region through mid week. Have added some scattered snow showers to the forecast for Wednesday and Thursday. A last wave arrives on Saturday evening, though only the Canadian model is showing any precipitation at this time. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 542 PM CST Mon Nov 14 2022 Deteriorating conditions expected after 06Z as an area of light snow overspreads central Illinois. Between 09-12Z, visibility and ceilings expected to drop to IFR levels. While the visibility significantly improves after 16Z as the snow moves out, the ceilings will likely remain IFR through 00Z, perhaps for a few days. Winds E-NE 4-8 kts through at least 18Z. && .ILX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from midnight tonight to noon CST Tuesday for ILZ027>031-036>038-040>042-047>051. && $$ UPDATE...37 SYNOPSIS...Geelhart SHORT TERM...Geelhart LONG TERM...Geelhart AVIATION...37
Area Forecast Discussion
National Weather Service Marquette MI
732 PM EST Mon Nov 14 2022 .SHORT TERM...(Through early this evening) Issued at 310 PM EST MON NOV 14 2022 Two processes are at play this afternoon with the SN falling across portions of the U.P. Band that has been nearly stationary just off of the Marquette shoreline and stretching into the Keweenaw Peninsula is lake-driven whereas synoptically-driven SN is increasingly moving into the W and S-C. Although the CMC-reg has had a sufficient handle on that aforementioned band, the previous run, 06z, had a better placement than the 12z run. The 12z HRRR has had the best handle overall, with both models indicating the band finally getting kicked N as the afternoon continues to progress. This appears to be due to the incoming synoptic push, with a ML vort max/UL trough axis providing the kick it needs to move from its current position. SN from the S and W will continue overspreading the Wrn two-thirds of the forecast area by tonight, with Lake Michigan providing an enhancement into at least Delta and Schoolcraft counties. Luce County may be the only county to not see precip reaching the ground until after this forecast period. As for accums, highest accums will occur within the highlighted band area, with less than an inch anticipated elsewhere through sunset. Warmest temps are found in the S-C in the Ern U.P. as well as along the Lake Superior shoreline, particularly E of the Keweenaw. Highs have/are topping out in these warmer areas in the low to mid 30s, with upper 20s to generally less than the freezing mark in much of the Wrn portions. .LONG TERM...(Tonight through Monday) Issued at 335 PM EST MON NOV 14 2022 Some light snow showers expand a little more into the western UP tonight as a low pressure over the Northern Plains digs towards the Chicago area; expect less than an inch of accumulation from this snowfall. Some southeasterly upslope flow may bring some modest snow bands off of Lake MI over northern Menominee, Delta, and far southern Marquette counties tonight. These bands may bring an inch, maybe two, of snow to these areas. Otherwise, a strong snow band over Lake Superior (impacting the Keweenaw this afternoon) looks to slowly lift north over the Copper Country tonight. As it does, expect it to only really remain in Keweenaw County a couple of hours after 00z tonight; that being said, some heavy snowfall rates could be seen north of the Keweenaw/Houghton County border tonight into Tuesday. Visibilities could be greatly reduced and snowfall could accumulate quickly in this heavy snow band. Therefore, take caution if you must travel tonight (and possibly Tuesday too) if you are going through Keweenaw County. Moving into Wednesday, easterly flow sets up across the area. As it does so, expect lake-enhanced snow showers to begin moving over the south central. Some of the snow showers in Delta and Menominee counties may be heavy, as CAM composite reflectivities show 30+dbzs across the area Tuesday afternoon (the HRRR shows 40+dbzs!). While high temps are expected to just peak above freezing across most of the area Tuesday, with snow bands that intense, snowfall could quickly accumulate on roads and greatly reduce visibilities to 1/4 mile or less. Therefore, if you must drive in the south central tomorrow afternoon and evening, be sure to have your low-beam headlights on and to leave plenty of space between the car in front of you and yourself. As the low pressure begins to lift through Lower MI Tuesday night, the flow over the area becomes northeasterly. This should shift the heavier snow bands over Lake MI to around the city of Menominee. In addition, some light lake- enhanced snowfall looks to start up over the north central UP Tuesday night, with the Michigamme Highlands seeing slightly higher snowfall rates due to upslope flow from the lake. As the low pressure continues to lift away from the region Wednesday, expect the flow to become northerly by the afternoon and northwesterly by the evening. Model guidance shows a mesoscale low setting up over western Lake Superior Wednesday night ahead of an approaching shortwave. As that shortwave moves over Upper MI Thursday and Thursday night, expect heavy snowfall rates to be wrapped around the center of the mesolow, particularly on its western side. As the mesolow moves east over the lake Thursday, some heavy snow showers could be seen as it moves over the Keweenaw. Otherwise, some light snow showers are expected across the UP Thursday as the shortwave moves through (with some lake-enhancement being possible in the W to NW snow belts). Behind this shortwave, west to northwest flow sets up across the Upper Great Lakes, continuing snow showers across these snow belts. However, in the areas outside of the west to northwest snow belts, temps could become quite frigid for this time of year, as ensemble guidance shows temps approaching the 5th percentile of modeled climatology. Therefore, while the clouds may help to moderate nightly temps a little over the west to northwest snow belts this weekend, we may see low temps dip into the single digits starting Friday night. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 726 PM EST MON NOV 14 2022 Looks like conditions are already improving at CMX with the heavy snow band lifting north. They have rebounded to MVFR and generally expect them to stay MVFR through the period under an easterly onshore flow. At IWD and SAW, conditions should lower to MVFR this evening with the arrival of an upper disturbance and maybe some light snow. Expect prevailing MVFR conditions to continue at IWD and SAW through much of the period. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 358 PM EST MON NOV 14 2022 A few SE to E`rly gusts up to 25 knots are possible tonight and Tuesday near Isle Royale as a low pressure digs SE towards Chicago. Once the low begins lifting through Lower MI Tuesday night, expect winds to become generally 20 knots or less. These light winds continue until around Thursday night, when NW`rly winds pick up to 25 knots behind a shortwave leaving Lake Superior. W to NW`rly wind gusts up to 25 knots are possible through this weekend as another shortwave moves through Saturday. With well below normal temps moving through the Upper Great Lakes region this weekend, some moderate freezing spray is possible Friday night into Sunday. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Winter Weather Advisory from 1 PM Tuesday to 1 AM EST Wednesday for MIZ012. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...lg LONG TERM...TAP AVIATION...Voss MARINE...TAP
Area Forecast Discussion
National Weather Service Pueblo CO
545 PM MST Mon Nov 14 2022 .UPDATE... Issued at 541 PM MST Mon Nov 14 2022 I have updated the pops across the Pikes Peak Region (PPR) for the early morning hours of Tuesday (i.e., later tonight). Short range guidance is indicating a better chance of some light snow over this region, especially the northern half of Teller county and the northwest sections of El Paso county. I would not be too surprised if a few of these areas get an inch or so of snow by sunrise tomorrow morning. /Hodanish && .SHORT TERM...(This evening through Tuesday) Issued at 237 PM MST Mon Nov 14 2022 Key Messages: 1) A broad trough aloft will pass overhead. Its associated cold front increases PoPs over Teller and El Paso County during the overnight tonight - accumulations will be very light. 2) The same broad trough keeps lingering snow showers over the mountains with the best chances over the higher peaks of the eastern mountains. Meteorological Discussion: Some snow showers have materialized over the middle Arkansas River Valley, the Continental Divide, and the San Luis Valley (SLV). Looking at the HRRR and the SPC mesoanalysis page`s snow squall parameter, there are fairly high values within that parameter over the southern eastern San Juan Mountains. We`ve blended the QPF with the HRRR, which places the strongest band over the southeaster San Luis Valley and the southern San Juans. So during the current through evening period there may be very localized moderate to heavy snow bands limiting visibility and creating hazardous travel conditions. A second broad trough that is associated with a closed low located over the north-central plains will propagate over southern Colorado tomorrow, but ahead of the upper trough its associated cold front will push over the plains early tomorrow morning. As the front passes overhead the PoPs increase to isolated and scattered from around midnight through around 6am over Teller and El Paso Counties. Snowfall amounts will not amount to much, less than a quarter of an inch. The trough axis will pass overhead from mid-morning on Tuesday through shortly after the short term forecast period ends (5pm Tuesday), which keeps isolated PoPs over the higher elevations and scattered PoPs over the higher peaks of the eastern mountains, including the Pikes Peak region, the Wet Mountains, and the Sangre de Cristo Mountains. Precipitation should remain confined to the topography, however. Low temperatures tonight will be in the teens over the plains, the single digits to low teens over the mountain valleys, and below zero over the mountains. Highs warm up a little tomorrow with the upper 30s to low 40s over the plains and mountain valleys, whereas the mountains will remain in the single digits to teens. .LONG TERM...(Tuesday night through Monday) Issued at 237 PM MST Mon Nov 14 2022 Key Messages: 1) Another chance for snow Thursday afternoon through Friday 2) Temperatures well below normal through Saturday, then warmer. Tuesday night...Upper shortwave will exit the state to the south- southeast Tue evening, with just some isolated showers over the southern mts and Raton Mesa until around midnight. Any additional snowfall is expected to be very light. After midnight, skies will be clearing with north-northwest flow settling in and it will be a very cold night with overnight lows of around 0 to 10 above for the high valleys, and 10 to 20F for the plains. Wednesday through Thursday morning...Cool but dry north to northwest flow settles in across the region, with another stronger upper shortwave approaching from the north for Thu. Until then, expect dry conditions with highs in the 30s to around 40F for the high valleys, and mid 30s to mid 40s for the plains. Thursday afternoon through Friday...A cold front pushes south across the Palmer Divide around midday Thu, with increasing cloud cover and isolated to scattered showers developing from north to south through the afternoon and evening. The upper disturbance crosses the forecast area Fri morning, continuing to produce isolated showers for the higher terrain and much of the plains through the day due to the persistent easterly upslope flow at the surface. Not a lot of new snowfall is expected with this system, but a significant drop in temperatures is forecast. Maximum temps on Thu are expected to only warm into the 30s to near 40F for most areas, then the 20s to lower 30s for Fri. Saturday through Monday...Dry conditions and sunny skies are anticipated over the weekend and into the next work week, as cool northwest flow aloft transitions to a more westerly direction Sun and Mon. It will still be rather cool on Sat, with highs in the 30s for the high valleys and mid 30s to lower 40s for the plains. Temps then start to warm, with Sun highs forecast in the mid 30s to mid 40s for the high valleys and 40s for the plains. On Mon, plan on upper 30s to upper 40s for the high valleys, and mid 40s to lower 50s for the plains. Moore && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 237 PM MST Mon Nov 14 2022 KALS: A snow band has been resolved persistently by higher resolution models over the southern San Luis Valley, so a TEMPO group will continue through portions of the evening tonight with MVFR and IFR conditions possible. After the bands end tonight, dry conditions are expected over KALS, however VCSH is possible tomorrow afternoon as a broad trough passes overhead. KCOS and KPUB: A weak cold front is expected to pass overhead during the overnight tonight, which increases snow chances for KCOS but not KPUB. So a chance during the overnight period for very light snow resulting is a low end chance for MVFR conditions. As a broad trough passes overhead, the higher peaks of the eastern mountains are expected to get light snowfall, which will keep VCSH over KCOS, but the cell tracks will be from north to south, so we are not expecting snow over KCOS or KPUB tomorrow. VFR conditions are expected throughout the forecast period with the exception of the aforementioned time period for KCOS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HODANISH SHORT TERM...SKELLY LONG TERM...MOORE AVIATION...SKELLY
AREA FORECAST DISCUSSION
National Weather Service Charleston WV
900 PM EST Mon Nov 14 2022 .SYNOPSIS... Cold weather persists this week. A southern system brings mixed wintry precipitation changing to rain Tuesday and Tuesday night. Upslope snow event Wednesday into Thursday. && .NEAR TERM /THROUGH TUESDAY/... As of 900 PM Monday... Lowered overnight temperatures a bit to reflect current trends. This had little impact on the morning ice forecast, other than to increase confidence in the advisory a bit. As of 705 PM Monday... Forecast on track, as southern stream system approaches from the lower and mid Mississippi Valley. Area temperatures were already down to or below freezing in spots. As of 525 PM Monday... Tacked on a sliver in our central mountains to the winter weather advisory from 5 AM until 1 PM Tuesday, based on HRRR ensemble and MET guidance, which better depicts temperatures in the cold air damming regime. Likewise, removed ice in southwest Virginia, outside the cold air damming wedge, where morning temperatures should climb above freezing in time for arrival of precipitation there. As of 1230 PM Monday... Quiet day although well below your average temperatures which will continue to trend this way. Another night of cold temperatures is in the forecast along with the advection of clouds to deter any fog formation and possibly radiational cooling, however the clouds will tend to be mid to high clouds, therefore we could get some extra cooling still. A broad upper level trough will sweep a storm system across the region which will spread very good chances for precipitation possibly by mid morning to our southern parts of the County Warning Area, especially across the Coal Fields. Depending on how early hydrometeors fall, will determine if a wintry mix will start off in the lowlands. Although this will be short lived quickly changing over to an all rain regime. The mountains will be a mixed bag of wintry precipitation starting off as a mix, then freezing rain, then just rain until the late evening when temperatures fall just enough to bring back a wintry mix. Snow accumulations going into the evening will be on the lighter side, possibly 1-2 inches in the northeast mountains with little to none elsewhere. The main issue is ice accumulation in that same area which will be limited to the highest elevations and right around a tenth of an inch through the day. This may warrant an advisory or at the very least an SPS which will be determined in the very near future. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 150 PM Monday... The southern stream system will pull out of the region Tuesday evening bringing an end to the precipitation, including any lingering freezing rain in the higher elevations of the mountains. Any additional freezing rain accumulations should just be a few hundreths. Colder air will filter in behind the system. This will create an upslope event for Wednesday into Wednesday night. An upper level disturbance Wednesday night will combine with the upslope flow to provide some enhancement to the snow. Looking at 1-3 inches in the higher elevations, with even the lowlands possibly seeing a dusting of snow. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 1150 AM Monday... An upper level trough will remain over the region through the period, keeping cold air well below normal for this time of year. A couple of disturbances will combine with a northwest upslope wind flow to create a chance for snow at times, more likely in the northern mountains of West Virginia. Unfortunately, models do have disagreements on the timing and strength of these disturbances. High pressure does eventually build over the area by Monday, but models disagree how cold it will be at that point. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... As of 705 PM Monday... A VFR night is on tap, as clouds increasing ahead of a system approaching from the southwest should preclude a repeat of the fog that formed at southern sites this morning. Rain will quickly overspread the area midday Tuesday, with MVFR ceilings and visibility beginning 15-17Z south and 17-18Z northern sites. Widespread IFR visibility in a cold rain is then expected much of the afternoon Tuesday, with ceilings lowering to IFR across the middle Ohio Valley after 20Z, with BKW on the edge of IFR ceilings on southeast flow Tuesday afternoon. A wintry mix is expected for the higher elevations but should not affect any of the sites. Light and variable to northeast surface flow across the lowlands tonight will become light southeast Tuesday. Light southeast flow in the mountains will become gusty along the ridges including at BKW, where sustained winds around 10 kts will gust into the 15 to 20 kt range, even a bit higher overnight. Light south flow aloft tonight will strengthen to moderate during the day Tuesday, while starting to veer to the southwest Tuesday afternoon. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z WEDNESDAY... FORECAST CONFIDENCE: Medium to high. ALTERNATE SCENARIOS: Restrictions will likely vary with the onset of precipitation on Tuesday. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE TUE UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 00Z WEDNESDAY... IFR conditions possible Tuesday night in stratus, and also mixed wintry precipitation for the higher elevations. IFR possible in snow showers in the mountains Wednesday into Thursday, even briefly out across the lowlands Wednesday night into Thursday morning. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...Winter Weather Advisory from 5 AM to 1 PM EST Tuesday for WVZ516-518. Winter Weather Advisory from 7 AM Tuesday to 1 AM EST Wednesday for WVZ523-524-526. OH...None. KY...None. VA...None. && $$ SYNOPSIS...RPY/JZ NEAR TERM...TRM/JZ SHORT TERM...RPY LONG TERM...RPY AVIATION...TRM