Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/08/22

Area Forecast Discussion
National Weather Service Cleveland OH
946 PM EST Mon Feb 7 2022 .SYNOPSIS... High pressure will build north over the area by Tuesday afternoon. Another low pressure system pulls a warm front across the area Tuesday night into Wednesday followed quickly by a cold front Wednesday. A surface trough then lingers through Thursday before the next low pressure system deepens over the Great Lakes Friday. && .NEAR TERM /THROUGH TUESDAY NIGHT/... Only made changes to hourly temperatures and sky cover to reflect current trends. A few flurries still occurring. Will continue to watch for the development of weak lake effect snow showers in the wake of the 850mb trough. Previous Discussion... The cold front is currently moving into far eastern Ohio and western PA with decent pressure rises noted behind the front. METAR observations show a sharp wind shift to west to west- southwest behind the boundary with temps falling through the low 30s. A mid/upper shortwave trough and associated vort max is moving through lower Michigan and increasing low- level moisture and lift from west to east. This is reflected by snow showers and lake-effect snow bands expanding across Michigan this afternoon in the cold air advection. Once this better low-level moisture dives across Lake Erie early this evening, lift from the shortwave passage will generate scattered rain/snow showers across far NE Ohio and NW PA. HREF members continue to support this light precip, so continued with slight chance to chance PoPs in this area this evening, although dialed them back a bit given the drier conditions at the onset. The true cold air arrives tonight behind the mid/upper shortwave with strong cold air advection dropping 850 mb temps to -11 to -13 C by 12Z Tuesday and around -15 C by mid morning behind the passage of a second shortwave and vort max. This combined with a 270 flow will support bands of lake-effect snow east of Cleveland along the I-90 corridor through Erie County PA, as well as northern Crawford County at times. The latest NAM and RAP BUFKIT forecast soundings show inversion levels rising to a marginal 5 to 6 thousand feet after Midnight tonight but lots of moisture through that level and into the DGZ, but the greatest lift (Omega) tends to stay near the bottom of the DGZ. There is also quite a bit of wind shear through the boundary layer which may inhibit the development of a single west- east band leading to more disorganized snow showers moving west- east. Plenty of open water developed the past 2 days due to the ice floes, so given the aforementioned moisture and at least 150-200 joules of lake induced CAPE, feel that lake-effect snow coverage will be decent. However, the negative factors discussed above will certainly limit the organization and efficiency, so kept accumulations across the primary snowbelt in the 0.5 to 1 inch range with 1-2 inches (locally higher) in NW PA. Parts of Erie County could see 4 inches of snow, but not confident enough to put that in official forecast products. Mid/upper shortwave ridging will build across the Ohio Valley Tuesday afternoon with surface high pressure sliding through the Appalachians. Flow backing southwesterly and decreasing moisture and a lowering inversion will push weakening lake-effect bands up the shoreline into western New York during the afternoon. Expect peaks of sunshine to spread in from west to east. Arctic air remaining in place will keep highs in the upper 20s to near 30 with mid 20s in NW PA. The axis of the shortwave ridge will slide east Tuesday night with the surface high moving into the Mid Atlantic as well ahead of the next incoming mid/upper trough. This will set up warm air advection, so early night lows in the mid 20s will rise into the low 30s by Wednesday morning. Brought in slight chance Pops for light snow showers toward Wednesday morning as forcing and moisture increase. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... An upper-level trough will move across the area Wednesday, providing synoptic lift for precipitation to the area. Return flow associated with the warm sector of the associated low moving into the northern Great Lakes region on Wednesday will allow for warm air advection to bring temperatures back to the upper 30s to even low 40s for some locations Wednesday afternoon. This will cause precipitation to fall as a rain/snow mix Wednesday with some areas even experiencing periods of all rain. The weak cold front associated with the low moves across the area Wednesday evening, causing temperatures to drop back below freezing with low near 30 Wednesday night. System precipitation becomes primarily lake effect Wednesday night, and with the temperature drop, precipitation type should become all snow once again. Lake effect snow continues into Thursday and potentially into Thursday night. Total QPF Wednesday and Wednesday is generally expected to be 0.01 to 0.15", so despite decent melting conditions with dew points in the upper 30s and a moderate southerly wind, there shouldn`t be any flooding concerns. Total snowfall with the lake effect snow Wednesday night into Thursday should be around 2" or less, mainly for the snowbelt. && .LONG TERM /FRIDAY THROUGH MONDAY/... Clipper system moves across the Great Lakes region Friday and Friday night. Similar to the Wednesday system, return flow will allow temperatures to rise into the upper 30s to low 40s, allowing for a rain/snow mix and even periods of all rain. Colder temperatures move in for the weekend, allowing for lake effect snow to develop Friday night through Saturday night. Coldest temperatures are expected Saturday night through Sunday night when well below normal temperatures are expected. Wind chills near zero will be possible Sunday morning and Monday morning. && .AVIATION /00Z Tuesday THROUGH Saturday/... MVFR ceilings spreading west to east across the region generally near and in the wake of an 850mb trough. As this boundary moves eastward expect the MVFR ceilings to advance into western PA by 02-03Z. There could be a few flurries across the region but the main area of snow showers will be across NE OH into NW PA. This is where some lake effect snow showers should develop. The only terminal that could see brief IFR conditions with heavier snow showers looks to be KERI. IF this occurs it would be 08Z-12Z. Winds remain westerly through mid morning with speeds 8 to 14 knots with gusts to 20 knots possible. The strongest winds should be along the lakeshore. Winds shift to the southwest and south at 8-12 knots through Tuesday afternoon. Outlook...Non-VFR is possible in rain or snow showers Wednesday into Thursday then again Friday into Saturday. && .MARINE... South to southwest winds will persist through much of the week as high pressure builds in and a warm front crosses the lake, causing more southerly winds through Wednesday. Low pressure and a cold front Wednesday into Thursday causing winds to become southwest. Overall, offshore flow will help keep ice away from the Ohio shoreline and some ice could be pushed towards PA during westerly windows. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ SYNOPSIS...Garuckas/MM NEAR TERM...Garuckas/MM SHORT TERM...Saunders LONG TERM...MM AVIATION...Garuckas MARINE...Saunders
Area Forecast Discussion
National Weather Service Green Bay WI
549 PM CST Mon Feb 7 2022 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Tuesday Issued at 238 PM CST Mon Feb 7 2022 The latest RAP analysis and satellite/radar imagery show low stratus has eroded over northeast Wisconsin early this afternoon. Meanwhile, another swath of stratus along the leading edge of warm advection is slowing moving southeast over the northern Mississippi Valley. MVFR ceilings and light snow/flurries are occurring over northern Minnesota within this warm advection regime. Forecast concerns mainly revolve around light snow chances and cloud/temp trends over the next 24 hours. Tonight...Weak surface ridge axis will be moving across the region during the evening. However, the zone of warm advection will be advancing across Wisconsin at the same time, which will return overcast conditions to the region from northwest to southeast. Deep saturation will be difficult to achieve in this warm advection zone, but upstream obs and forecast soundings suggest saturation up to 700 mb may be enough for light snow/flurries, particularly over north-central WI. Expanded the small chance this evening. Saturation doesn`t look quite as robust over northeast WI so think light snow chances could diminish before reaching that part of the state. Due to the cloud cover, raised low temps a couple degrees. Tuesday...Most clouds will have exited northeast WI by the start of Tuesday morning, so think will see a lengthy period of sunshine. But should see clouds increase again in the afternoon ahead of the next in the seemingly endless series of clippers. Chances of snow should hold off until Tuesday night. With a breezy south wind, temps will warm into the upper 20s to mid 30s. .LONG TERM...Tuesday Night Through Monday Issued at 238 PM CST Mon Feb 7 2022 A Clipper system staying north of lake Superior will bring some light snow showers Tuesday night into Wednesday. Some freezing drizzle is possible in East Central Wisconsin late Tuesday night. A dusting to half inch seems likely with the highest amounts in North Central Wisconsin. Temperatures will be relatively mild. Cooler temperatures are expected Wednesday night and Thursday behind the Clipper system. Northwest winds blowing across Lake Superior should produce lake effect snow showers in Vilas county. AMounts should be an inch or so. A strong Clipper system will bring a better chance of snow to the entire area Thursday night into Friday. One to three inches are expected with the highest amounts in the north. Mild temperatures Friday will be followed by colder weather for Saturday and Sunday as some arctic air returns to the region. && .AVIATION...for 00Z TAF Issuance Issued at 543 PM CST Mon Feb 7 2022 Clouds were overspreading the region early this evening, with 3000-4000 ft ceilings moving into the western part of the forecast area. The ceilings may briefly lower to MVFR at the western TAF sites later this evening. An upper level disturbance may also produce scattered very light snow showers or flurries at RHI for a brief period this evening. Clearing skies are expected overnight, but more clouds will arrive Tuesday afternoon, with a threat of MVFR ceilings returning at RHI/AUW/CWA late in the afternoon. A brief period of LLWS is possible at each of the TAF sites from mid-morning through mid-afternoon Tuesday. Surface winds will also become a bit gusty during the day. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......RDM AVIATION.......Kieckbusch
Area Forecast Discussion...UPDATED
National Weather Service Chicago/Romeoville, IL
913 PM CST Mon Feb 7 2022 .UPDATE... Issued at 913 PM CST Mon Feb 7 2022 For this evening`s update, focus was on fog/low cloud potential into Tuesday morning and how that will play into Tuesday highs as noted in today`s Short Term AFD. In summary, the signal for low clouds and fog on Tuesday looks less of a chance than it had earlier, so have adjusted some to account for that, including bumping up Tuesday highs a couple/few degrees. Surface ridging extends northward up the Illinois/Indiana stateline as of 9 PM and is gradually shifting southeast. While temperatures dropped quickly south of the Chicago metro under this ridging early this evening, the dew points also did, indicating any sublimation from today was limited enough that the moisture was only in a static layer. So radiation fog in our southern CWA is seeming more unlikely, especially as solid mid cloud is spreading southeast. This mid cloud will spread over most of the area with high confidence. The RAP 800 mb RH was used as a proxy as it has a fair handle on this. With this cloud likely to persist for the overnight after it moves in, lows will be milder and have nudged those up a few degrees in the north. As low-level warm advection ensues off the deck, the cooling of the boundary layer now looks to be insufficient enough to result in much of a low cloud/fog footprint in northern Illinois. Do think there could be some to develop in southeast Iowa/northeast Missouri/western Illinois where the surface dew point nose of 20-25 is. If that were to develop, that would expand in after daybreak. But this seems like more of an outlier solution with observational trends as well as guidance trends, with even the more moist NAM having backed off with its 00Z solution. For highs on Tuesday, the midnight shift will assess in full, but did have enough confidence to nudge them up 2-3F degrees, and that may not enough. This nudge up was due to a milder starting point expected, less likelihood in widespread low clouds in the morning, and looking back at climatology. On that last point, with 925 mb temperatures of +5 to +7, such as forecast in the northern CWA from a model blend, this shows an average of mid 40s for Chicago for early February with snow cover. Did not go that mild yet, but mid 40s are plausible, especially over the less snow covered areas of far northern Illinois (Dixon to Rockford to Harvard). Again, midnight shift will evaluate if values need to be nudged warmer area-wide, and will have more observational trends for any low cloud potential into the morning. MTF && .SHORT TERM... Issued at 124 PM CST Mon Feb 7 2022 Through Tuesday... Currently, a 1016mb surface low pressure system is located over Lake Huron beneath broad upper-level cyclonic flow. Meanwhile, a surface ridge extends from a surface high pressure system in central Texas from the Ozarks to eastern Iowa. We find ourselves between both surface features this afternoon in a cold-advection regime with northwesterly winds and flurry-producing stratocumulus clouds. As the surface ridge slides southeastward tonight, clouds will clear and winds will gradually slacken while turning southwesterly. Lows overnight should fall into the teens, with perhaps a few single- digit readings where the snowpack is deepest. Toward daybreak, WAA will increase markedly ahead of a potent low pressure system tracking along the US/Canadian border. With the deep snowpack in place upstream of our area, surface temperatures will lag the warming temperatures aloft leading to the development of a stout low-level inversion. Any low-level moisture trapped under the inversion will likely allow for low clouds and fog to develop, perhaps most likely across central Illinois where sunshine this afternoon is allowing for sublimation of the top-most layer of the snowpack. As southwesterly winds increase after daybreak, any fog that developed across central Illinois would head our way, leading to what could be a somewhat gray morning. As is often the case with advection fog aided by warming temperatures atop a snowpack, confidence is somewhat low on whether fog will actually develop let along advect into our area. However, we felt there was enough of a signal in lowering visibility displayed by high resolution model guidance to justify at least patchy fog in our gridded database. High temperatures tomorrow will ride on how much sun we see, with perhaps the most likely scenario that most areas climb into the mid 30s. Should any sun poke out, especially in areas with little to no snow (e.g. Rockford), temperatures would easily make a run toward 50 degrees considering 850mb temperatures rising near 8C. In addition, southwesterly winds would end up much breezier in in our official forecast. For now, will take the "middle of the road" approach with both winds and temperatures which is often the course of least regret this time of year. Borchardt && .LONG TERM... Issued at 318 PM CST Mon Feb 7 2022 Tuesday night through Monday... A large area of positive upper level height anomalies (upper level ridging) are expected to continue to dominate over the eastern Pacific into the western coast of North America as a large upper vortex dominates near the Bering Strait through much of the week. Between these two features, a strong and active upper level jet will reside from the northeastern Pacific, eastward into northern parts of British Columbia and Alberta through the end of the week. A couple of northern Pacific origin upper level impulses are then expected to be steered eastward over the Canadian Rockies before digging southeastward into the Great Lakes region as clipper systems. The net result of this pattern on our local sensible weather will be a couple of instances of precipitation followed by strong and gusty cold frontal passages. The first digging short wave trough and is expected setup over the region at the start of the period Tuesday night into Wednesday. Forecast guidance then continues to advertise several smaller scale impulses shifting southeastward through the cyclonic upper level flow, and any one of these may be able to produce some light precipitation across the region. This looks to especially be the case on Wednesday into Wednesday evening, especially for areas generally along and north of I-80. Similar to the previous shift, we opted to maintain some low end chances for a rain/snow mix during this period. Overall though, this is not looking to be a big problem for the area. Temperatures will turn colder Wednesday night into Thursday as the heart of the cold arctic airmass quickly clips the area. Expect highs for Thursday to be held down into the 20s. Warm air advection should quickly ramp up overhead Thursday evening and night as breezy southwesterly winds develop in advance of the next quickly approaching potent clipper system tracking into the Upper Great Lakes. These breezy winds should result in rising temperatures Thursday night, with readings likely peaking near 40 during the day Friday. While the primary track of the surface low with this clipper will remain well north of the area, we still stand to see a period of snow, possibly changing to rain Thursday night into Friday as the exit region of a digging upper jet shifts into the area. This again should not be a major precipitation event for the area, as the window for snow should be limited by warming surface temperatures on Friday. A strong cold front then shifts across sometime late Friday into Friday night as the main clipper system shifts over the eastern Lakes Region. Gusty northwest winds will develop in its wake and temperatures will turn much colder again for the weekend as a large area of high pressure builds into the region. Aside from the threat for some lake effect snow showers over the southeastern shores of Lake Michigan, the area looks to remain precipitation free for the weekend at this time. KJB && .AVIATION... For the 00Z TAFs... Issued at 606 PM CST Mon Feb 7 2022 The concerns include: * Chance for IFR CIGs and reduced VSBY Tuesday morning * Wind direction Tuesday AM then breezy SSW winds in the afternoon The upcoming TAF cycle has a conditional risk for low conditions Tuesday morning, but also a realistic chance of VFR prevailing through the period. HREF (NAM and WRF members) are indicating development of radiational fog and low stratus over portions of western and central Illinois later this evening. A strong low level inversion is forecast to develop as warmer air moves in aloft. The conditional scenario for lower conditions (IFR to LIFR CIGs and IFR to MVFR BR/FG) to reach the terminals would be for what forms off to the southwest to be advected northeast as southwest winds increase aloft later tonight into Tuesday morning. This appears to be a low stratus or nothing scenario unfolding, as the strong majority of the remaining guidance, including MOS, supports VFR CIGs with at most a period of MVFR BR on Tuesday morning. A possible fly in the ointment for the HREF preferred low conditions is a not well forecast 6-10kft CIG off to the north and west, which should move overhead this evening. However, despite low confidence, given conditional lower IFR to IFR CIG risk and reduced VSBY, opted to highlight the current favored timing for lower conditions *if they happen* with TEMPO groups. Winds are also a bit uncertain on Tuesday morning, as they could be more south-southeast or southeast even at ORD and MDW. Breezy south-southwest to southwest winds with gusts up to 20 kt to perhaps 25 kt should develop early Tuesday afternoon. A cold front approach and passage Tuesday evening will ease and shift the winds to west-southwest then west. Castro && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
805 PM MST Mon Feb 7 2022 .UPDATE... Issued at 757 PM MST Mon Feb 7 2022 02z surface analysis had cold front from northeast MT into central ID. 4mb/3hr pressure rises behind it with steady southeast movement assisted by shortwave energy diving into MT per water vapour loop. 00z guidance indicates strengthening of pressure rise bubble and better downward momentum transfer during peak boundary mixing tomorrow depicted via Bufkit. Combination of weak cold air advection and strong mixing should result in a corridor of high winds from K2WX-KRAP. First batch should occur with cold front, focused on squeeze area just east of the Black Hills. Second batch occurs Tuesday during peak mixing. HRRR shows 65kt peak gusts with front early Tuesday morning, but it can be too aggressive so have tempered top speeds some. Forecast updated to account. && .DISCUSSION...(This Evening Through Monday) Issued at 123 PM MST Mon Feb 7 2022 Upper ridging covers the western CONUS, and the next shortwave trough to affect our region is pushing into the Pacific NW. Surface map shows a trough over the northern plains, with a warm front along its axis across the eastern Dakotas. Winds across our CWA are westerly 10 to 20 mph. Under mostly sunny skies, temperatures are warming into the 50s and 60s. This week`s weather pattern will consist of west coast ridging and periodic shortwaves moving through northwest flow over our region. The first wave will approach tonight, and the cold front will begin crossing our CWA early Tuesday morning. Northwesterly winds will be strong initially behind the front, and then an early morning lull is expected before winds increase with daytime mixing; however, winds aloft are expected to decrease through the day. The HRRR and NBM 4.0/4.1 show some strong winds just northeast of the Black Hills around 09-10Z as the front moves over the Black Hills, enhanced with downsloping. Additionally, several ECMWF ensemble members show 58+ mph gusts at KRAP early Tuesday morning. RAP/HRRR forecast soundings have 50+ kt winds just off the surface at 10Z at KRAP, so a brief period of very strong winds is possible. This would be supported by strong CAA with the front. However, NAM/GFS forecast soundings have weaker winds near the surface. After a morning lull, NBM 4.1 has 50 kt gusts along the typical NW SD to KRAP corridor Tuesday afternoon, but the NBM 4.0 keeps winds within advisory criteria. Some 60 mph gusts are supported by NAM/GFS forecast soundings, but will depend on warmth, mixing, and the rate winds aloft decrease. Pressure rises are not a supportive factor of this wind event. Interpreting these mixed messages, decided to issue Wind Advisories for western SD, beginning 06Z for NW SD to Pennington Co for the initial push/downsloping, and beginning 15Z for the rest. Some 60 mph gusts are not out of the question, but overall expect this event to be more of a high-end Wind Advisory. Despite the colder air, highs will be generally in the 40s Tuesday and Wednesday. On the backside of this system, a weak shortwave beneath the left exit region of the upper jet will pass over the baroclinic zone, resulting in some light rain/snow Wednesday into Wednesday night. While some light snow accumulation is possible on the plains (an inch or less), a few inches of snow will be possible over the northern Hills from upslope enhancement. Deterministic solutions have anywhere from 3 to 9 inches in the northern Hills; the NBM 75th percentile shows 1-3 inches, while the 95th percentile goes up to 9 inches. With the Froude number expected to stay between 1-2 for nearly 24 hrs, going along with the trend of increasing snow amounts: generally 3-5 inches in the northern BH, with around 6 inches possible in the highest elevations. A brief period of WAA will allow temps to climb back into the 50s Thursday, before the next shortwave arrives. Friday looks blustery with snow showers, but minimal accumulations are expected. Cold airmass then shifts eastward for the weekend, resulting in mild and dry weather. && .AVIATION...(For the 00Z TAFS Through 00Z Tuesday Evening) Issued At 434 PM MST Mon Feb 7 2022 VFR conditions are expected through the TAF forecast period. A cold front will move through the Northern Plains late this evening into early Tuesday morning, switching winds from westerly to more northwesterly, and increasing speeds to 20-30 knots with gusts to 40+ knots. && .FIRE WEATHER... Issued At 123 PM MST Mon Feb 7 2022 Strong winds on Tuesday and dry fuels will create conditions conducive to fire spread. The GFDI will be very high to extreme on the western SD plains. However, since the minimum RH is expected to be 25% or higher, opted to refrain from issuing a Fire Weather Watch. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Wind Advisory from 8 AM MST /9 AM CST/ to 5 PM MST /6 PM CST/ Tuesday for SDZ014-027-030-032-041>044-046-047-049-074. High Wind Warning from 11 PM this evening to 5 PM MST Tuesday for SDZ001-002-012-013-026-031-072-073. Wind Advisory from 11 PM this evening to 5 PM MST Tuesday for SDZ025. WY...None. && $$ Update...Helgeson DISCUSSION...Pojorlie AVIATION...Helgeson FIRE WEATHER...Pojorlie