Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/28/22

Area Forecast Discussion
National Weather Service Cleveland OH
1006 PM EST Thu Jan 27 2022 .SYNOPSIS... Low pressure moving through the eastern Great Lakes tonight will drag an arctic cold front across the region. High pressure will slide into the Ohio Valley late Friday through Saturday, moving east Sunday allowing a clipper system to progress through the Great Lakes. High pressure will return early next week. && .NEAR TERM /THROUGH FRIDAY NIGHT/... At 10 PM the approaching cold front was located across Southeast Michigan accompanied by a broad area of light snow. A better band of west to east oriented snow is developing across Central Lake Erie where there is some enhanced convergence ahead of the front. We did get a few reports of freezing drizzle in NW Ohio where mid-level moisture may not have been sufficient for ice nuclei in the cloud. Continued with a slight chance of freezing drizzle in the forecast ahead of the front although moisture is returning aloft and chances will likely diminish over the next couple hours. Snow will move in off Lake Erie after midnight as the cold front crosses the lake. The quality of snow may not be great initially as lift is focused beneath the dendritic growth zone. Lowered snow ratios initially to account for this. By morning, flow across Lake Erie will become northeasterly and focus snow showers across the Cleveland Metro area and perhaps into north central Ohio. Raised pops into Friday afternoon and despite moisture decreasing aloft, we can not rule out scattered snow showers persisting into Friday night as the dendritic growth zone lowers below 4K feet. Previous discussion...Mid/upper longwave troughing continues to dig across the Upper Midwest and Great Lakes this afternoon downstream of a sharp ridge over the west coast of the U.S. The leading shortwave is currently analyzed on water vapor loops over the central Great Lakes and will continue to progress through the eastern Great Lakes this evening and tonight. This will drag an arctic cold front southeastward across northern Ohio and NW PA late this evening through the overnight. An initial wave of light snow moved through most of the region early this afternoon tied to the left exit of a 110-115 knot H3 jet over the lower Ohio Valley which is rounding the base of the shortwave trough. Most of this has exited the west half of the CWA, but light snow continues east of I-77. A lull in the snow is still expected behind this initial wave from late afternoon through most of the evening ahead of the arctic front. It is during this time when NAM and RAP BUFKIT forecast soundings have consistently showed a loss of moisture and lift above 5000 feet or so while deeper moisture persists in the low-levels well below the DGZ. This supports periods of freezing drizzle which will lead to slick spots on untreated surfaces. Temps through the evening will hold in the mid 20s ahead of the front. For tonight, deeper moisture will return from north to south as the arctic front crosses the area. An initial west-southwest flow over Lake Erie will veer westerly around 03Z then northerly in the roughly 09 to 12Z timeframe. The lake is quickly icing over, but 850 mb temps cooling to -12 to -15 C, open water remaining east of Cleveland, and strong south shore convergence with the wind shift will lead to a band of brief, heavy lake-enhanced snow with the frontal passage. Inversion levels are quite low around 5000 feet, but BUFKIT soundings depict a surge in Omega within a saturated DGZ as the arctic boundary crosses, so this gives confidence in a quick burst of heavy snow. The latest HREF members have a consensus of this band reaching Erie County PA around 03Z then pushing south/southwest through the primary and secondary snowbelts of NE and north central Ohio between 07 and 12Z. This will put down a quick 1 to 2 inches of snow over a 1 to 2 hour window along with visibilities dropping to under a half mile at times. However, confidence on the exact timing of this band is low to medium. Outside of this lake enhanced band, general light snow will continue through Friday morning over most areas east of roughly I-71 as the axis of the mid/upper trough and associated jet support slowly rotate east. Lows tonight will drop into the low/mid teens over NW and north central Ohio with upper teens farther east. By Friday afternoon, the axis of the deep mid/upper trough will be centered over the Ohio Valley supporting a strong surface cyclone moving up the east coast late Friday through Friday night. Deep northerly flow between this Nor`Easter and a 1025 mb arctic high building east from the Midwest will keep scattered, weak lake-effect snow showers going across the secondary and primary snowbelts inland from the lakeshore (mainly in the hills). There continues to be agreement among HREF guidance for a Lake Huron connection to bring a little more snow to Lorain, Medina, and Cuyahoga Counties, but significant ice on Lake Erie, increasingly anticyclonic flow, drying profiles, and inversion levels dropping below 5000 feet will keep amounts very light. Additional accumulations in the aforementioned hills will only be an inch or less Friday afternoon. The arctic high building overhead Friday night will shut down any remaining lake- effect, although east-northeast flow and some rare moisture from Lake Ontario could keep some flurries going near Erie, PA. Highs Friday will be limited to the mid/upper teens with lows Friday night falling into the low single digits and even below zero again in western areas as skies clear. Wind chill values will reach or exceed -10 F again in western and southern areas. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... We start the weekend cold but largely dry. A north-northeast flow on the backside of a strong low pressure off the New England coast may continue some minor lake effect into Saturday morning into parts of Northeast OH and Erie County PA before high pressure moves in through Saturday and causes the inversion to clamp down. For now introduced some <20% POPs for parts of the Snowbelt Saturday morning. If this lake effect occurs it should be minor with an inversion height below 5000 feet and an icy lake, but NAM forecast soundings for KERI show moisture and a bit of instability and lift through the dendritic growth zone (DGZ) so can`t rule out some flakes. Elsewhere, it`ll be a dry but cold Saturday. Highs will probably stay in the 10s. High pressure slides through quickly Saturday evening. There will be favorable conditions for strong radiational cooling again the first half of the night, before clouds and a bit of a pressure gradient spread in from the west overnight ahead of an approaching clipper system. Lowered temps a bit east of I-71 for lows Saturday night, with negative values in the forecast once again for southeastern portions of our CWA. If the pressure gradient/wind pick up quickly enough into early Sunday before we start warming up, wind chills may flirt with advisory criteria east of CLE and BJJ late Saturday night into early Sunday. Models are in fairly good agreement in dropping a vort max with a modest clipper system through the upper Ohio Valley on Sunday. Weak mid-level warm-air advection / isentropic left beneath the left-exit quadrant of an upper-level jet streak may be enough to squeeze out some light snow on Sunday, especially from northern and eastern OH points east into PA. Most of the operational models have some light (<0.05" of QPF) and the GFS and Canadian model ensembles have fairly decent odds of non-zero QPF on Sunday. Forecast soundings from the NAM and GFS from CLE and CAK points east also indicate weak lift at times in a saturated DGZ. Given this, brought POPs up to "chance" for snow on Sunday from roughly CLE and CAK points east, with "slight chance" added farther south and west. This won`t be anything exciting but a Coating to 1" is possible in parts of Northeast OH and Northwest PA with this system as it looks. Pretty small / minor system so want it to be consistent another couple of cycles before ramping POPs up too much more. Highs on Sunday a bit more tolerable, mid to upper 20s. Not cold enough aloft for any lake effect off the icy lake behind this system Sunday night, so we should dry out as the synoptic lift exits. Lows Sunday night into the 10s. && .LONG TERM /MONDAY THROUGH THURSDAY/... We start the long term on Monday and through Tuesday with a relative break in "the weather". Departing high pressure will keep us dry to start next week, with highs nearing freezing on Monday. If we do manage to stay a bit below freezing on Monday, we`ll surge past it on Tuesday with highs in the low to mid 40s in the forecast. Showers may get into the I-75 corridor late in the day Tuesday, but much of the day will be dry with high pressure and a very dry airmass gradually departing to the east. The Tuesday night - Thursday period will turn busy once again. Deterministically there`s not a ton to say as models and ensembles are all over the place in terms of when our best windows for precipitation are and when we`re warm enough for rain, cold enough for snow, or perhaps seeing mixed precipitation. For now we can say that likely POPs are in the forecast from late Tuesday night or early Wednesday through Wednesday night and Thursday. Occasional precip is likely through that time period. We have rain and some snow in the grids for that period, but it`s really a fool`s errand to try to pin down when or where each type will fall at the moment, so expect refinement. In general, you`re probably more likely to see snow or mixed precipitation at times the closer to Northwest Ohio you are and more likely to see rain the farther south and east you head. The general set-up is fairly well-agreed upon by our models and ensemble guidance, with a deep trough carving out into the western US early-mid week as a ridge builds over the southern and eastern US. Anomalously warm and moist air will build under the ridge with a prolonged flow off the Gulf, with Arctic air over Canada and dropping into the trough to our west...some models show a 1050mb high dropping into the northern Plains later next week. This will set-up a sharp frontal boundary / thermal gradient *somewhere* over or near our region mid-late next week. How the trough ejects out of the west is what`s not agreed upon consistently on the models and will make a big difference in our sensible weather. The western trough ejecting in one piece would likely cause a stronger storm to cut into the Great Lakes Wednesday or Thursday, bringing us more warmth and rain than anything else with colder weather returning by the weekend. However, if the trough comes out in smaller pieces, the Arctic air pressing in to our north and northwest may push the frontal boundary far enough south to introduce colder weather and more wintry precip into at least northern portions of our forecast area. Regardless of precipitation type, a fair amount of QPF is a possibility across our area mid-late week. With now-frozen rivers, a surge of milder air and rain possibly releasing some of the water contained in our snow pack could cause flooding concerns from ice jams and increasing run-off into our waterways. Most areas east of I- 71 have over an inch of water in the snow pack, with 2-3"+ of water held in the snow in the Snowbelt. We could spend another couple of paragraphs speculating on if we`ll see any winter / mixed precip issues and / or hydro issues mid-late next week, but we`ll save it for now until we get some more clarity on how much precip and when, and in what form it falls. I`ll leave this with the tidbit that today`s 12z European has high temperatures in the low-mid 50s on Thursday for our entire area, while 60% of the European ensemble members have temperatures below freezing at KCLE at 1 PM Thursday. So, there`s plenty of uncertainty in how this goes. && .AVIATION /00Z Friday THROUGH Tuesday/... Initial round of snow has exited the area with MVFR ceilings in place at most terminals. A cold front extends across lower Michigan to South Bend and will settle south into northern Ohio after 02Z. Scattered snow showers may accompany the front with the best coverage expected from Cleveland east to Erie after 05Z. Visibilities may occasionally drop to MVFR in snow showers at eastern terminals with IFR visibilities. The flow will shift to northeast off Lake Erie by Friday morning and scattered snow showers may continue at CLE through the morning. Ceilings will gradually improve to MVFR through the morning on Friday. Winds will be out of the southwest ahead of the front at 5-10 knots this evening, veering to north with the passage of the cold front overnight. Outlook...Non-VFR likely with occasional snow showers and lower ceilings Friday afternoon. Non-VFR may return across NE OH and NW PA late Sunday. && .MARINE... Gusty southwest winds will turn north-northeast late tonight into early Friday as a cold front drops across the lake. Breezy north- northeast flow then continues across the lake Friday - Friday night as low pressure moves up the Eastern Seaboard. Winds turn southerly Saturday night into Sunday ahead of a weak low pressure, with gusty southerly winds over the lake early next week on strong / persistent warm air advection. Much of the lake is ice covered and winds are expected to be sub-gale for the next several days, so no concern for any marine headlines for the foreseeable future. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Garuckas NEAR TERM...KEC/Garuckas SHORT TERM...Sullivan LONG TERM...Sullivan AVIATION...KEC MARINE...Sullivan
National Weather Service Kansas City/Pleasant Hill MO
234 PM CST Thu Jan 27 2022 .Discussion... Issued at 234 PM CST THU JAN 27 2022 Key Messages: - Flurries/light snow looks possible late this evening/overnight across eastern KS and western MO. - Trending near to above normal for Saturday - Monday. - Eyeing the potential for a winter storm mid next week. Tonight: Surface winds have shifted to the north behind a surface trough. Colder and drier air will begin to advect into the area this evening. A clipper system will move southeast across the area tonight and bring with it a chance for flurries or light snow. This system will really be fighting the drier air but there appears to be fairly strong lift around 900mb, at the base of the dendritic growth layer, that helps to saturate the atmosphere between about 2500 feet and 10000 feet. With the sounding completely below freezing and good potential for ice crystal growth, there is at least a chance for flurries and potentially some light snow. Have added some slight chance PoPs based mainly on the HRRR and the NAMnest that had this area of light snow persisting the farthest southeast. Other models had light precipitation dissipating before making it into the area. This Weekend - Early Next Week: A broad upper ridge will expand eastward in the wake of the trough moving through tonight. Our area will be in northwesterly flow aloft with southwesterly flow in the lower levels. This will support warmer temperatures Saturday into Monday. Highs Saturday should be able to climb into the low to mid 50s over eastern KS and western MO as a result. Temperatures will be stuck in the lower 40s further northeast towards the Kirksville area. Temperatures will likely cool down a bit for Sunday with high pressure sitting over the area limiting mixing potential. Southwesterly low-level flow will kick in again Monday and allow temperatures to climb into the 50s to near 60 degrees across much of the area. Middle of Next Week: Will go ahead and lump Tuesday into this as it`s a bit of mess, like the rest of the forecast potentially will be. As the trough that will eventually bring us our mid-week storm deepens over the Intermountain West on Tuesday, it will lead to tightening baroclinic zone from the High Plains eastward. This is where models really begin to diverge and that has really profound impacts on the forecast. The GFS is further north with this front, splitting the forecast area Tuesday afternoon. South of the front it shows temperatures climbing into the 50s with temperatures falling into the 30s behind the front later in the afternoon. The ECMWF has already pushed the front south of the area with temperatures 10 to 15 degrees colder. Tuesday night into Wednesday, as the upper wave begins to move into the Plains, the GFS shows the surface temperature gradient strengthening with strong mid-level warm advection being undercut by strong low-level cold advection. Where there is that warm air aloft, there will be potential for mixed precipitation and some icing. However, the colder ECMWF has almost no warm air aloft over the forecast area, favoring more potential snowfall. With critical temperatures thresholds potentially sitting right over the forecast area, there remains a large amount of uncertainty with this system. && .Aviation...(For the 18Z TAFS through 18Z Friday Afternoon) Issued at 1124 AM CST THU JAN 27 2022 VFR conditions are likely for the entire forecast. Scattered to broken mid and high level clouds will move through the area through the period. Tomorrow, will need to watch for either low VFR or MVFR ceilings in eastern KS that could possibly affect the terminals. Forecast soundings and model relative humidity fields show higher humidity values, indicating potential for the lower clouds, in the 2000 to 4000 ft level. Confidence in this affecting the terminal sites isn`t high enough to mention at this time but will need to be watched if it shifts east. Winds will be from the northwest to the north through the forecast and be strongest this afternoon before diminishing overnight into tomorrow. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ Discussion...CDB Aviation...CDB