Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/09/21

Area Forecast Discussion
National Weather Service Albuquerque NM
455 PM MST Mon Feb 8 2021 .AVIATION... 00Z TAF CYCLE VFR conditions are currently in place across northern and central New Mexico, but a pesky Arctic front is expected to invade the far northeastern corner of the state again overnight and into Tuesday morning. Similar to today, this front will likely overachieve, moving farther west into New Mexico than what forecast models are advertising. Behind (to the east/northeast of) the front a thick and low stratus deck will likely drop ceilings to IFR status with areas of fog and freezing fog occasionally dropping visibility down to less than a mile. This could impact KCAO again and perhaps KTCC and KCVN. Elsewhere just high, fair weather clouds are expected with VFR conditions as afternoon breezes redevelop on Tuesday afternoon. Gusts on Tuesday are not expected to be as strong. 52 && .PREV DISCUSSION...326 PM MST Mon Feb 8 2021... .SYNOPSIS... Windy west winds and critical fire weather conditions will continue through early evening across portions of central and eastern New Mexico. Breezy west winds will return on Tuesday, though are not expected to be quite as strong. A strong cold front will oscillate in and out of eastern New Mexico through Thursday. Above normal temperatures are expected ahead of the front, but below normal temperatures, low clouds and freezing fog will be possible behind the front each day. The front is expected to push farther west into the state by the weekend, resulting in widespread below normal temperatures. In fact, several days of sub-freezing temperatures are possible for portions of eastern New Mexico. Additionally, snow may return to portions of the state late this week and this weekend. Stay tuned to the latest forecast to see how this event evolves. && .DISCUSSION... SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)... Westerly winds have been gusty across much of the forecast area this afternoon, but the gustiness should subside at least partially for many areas this evening. Therefore will allow the current wind advisory for the Central Highlands to continue until it`s expiration at 6 PM. There may be some lingering stronger gusts over the Sangre de Cristo mountains this evening as there is an uptick in the forecast H7 winds, but models indicate those speeds decrease later tonight. Otherwise, the shallow cold air mass that backed into northeast and east central NM last night has retreated east of the state this afternoon. The HRRR indicates it will return tonight, over the same general area as last night, so adjusted some low temperatures and added greater areal coverage of patchy to areas of fog and freezing fog to the weather grids. After eroding eastward by midday Tuesday, there will be a repeat performance Tuesday night with the low clouds and fog possibly making a little more progress westward. Otherwise, mid to high clouds will be increasing by Tuesday night, and an isolated flurry over the far northern high terrain is possible toward sunrise Wednesday. Highs Tuesday will be about 5-15 degrees warmer than normal, and overnight lows will continue to be about 5-10 degrees warmer than average for most areas. LONG TERM...(WEDNESDAY THROUGH MONDAY)... All eyes will continue to be on the progression of the Arctic front later this week. The front will likely be draped over NE NM Wednesday morning and will not retreat much during the day. Thus, a sharp temperature gradient can be expected across the eastern plains Wed aftn, from near 40 around Clayton, to the low/mid 70s around Roswell. Temperatures will be 5 to 10 degrees above normal for most areas ahead of the front. Meanwhile, a shortwave trough will be approaching the state from the west. This will increase cloud cover, but should only result in a few flurries across the northern mtns. This trough will otherwise cross NM Wednesday into Thursday without much fanfare. However, the front will nudge farther into eastern NM Wednesday night and another round of fog or freezing fog will be possible. The front may retreat a bit on Thursday as westerly flow starts to increase again. Forecast uncertainty increases Friday through Monday. Confidence is increasing that a reinforcing cold front will allow the cold air to advance much further south and west into the state, but confidence is low regarding when this colder air/reinforcing front will arrive. If the GFS is correct, it may arrive as early as Friday, pushing the front all the way to the Central Mountain Chain, if not farther, by the aftn. The ECMWF suggests this may occur around 24 hours later, and instead continues to oscillate the front across the plains on Friday. That said, both models show the front having pushed through much of the state by early Sunday. Thus, the weekend will be quite cold. At minimum, it looks like 2 to 4 consecutive days with high temperatures below freezing for portions of the eastern plains are expected (longer durations across the NE). Whenever the front does push through the gaps of the Central Mountain Chain, windy conditions can be expected below gaps in the Rio Grande Valley. Also at minimum, low clouds and/or freezing fog will be possible each day behind the front across the plains. To add to the complexity, another two upper level shortwave troughs may cross the Friday through the weekend as well. The GFS suggests the first will impact the state Friday night resulting in widespread snow. However, the GFS seems to be the more bullish take, as other models take a closed low well to the south of NM resulting in little precipitation. Models are in better agreement with the second trough crossing the state on Sunday with precipitation chances returning Sunday through early Monday morning. 99/34 && .FIRE WEATHER... Single digit minimum humidities are being reported over much of the central and east this afternoon, and are combined with gusty westerly winds, therefore the Red Flag Warning will remain in effect until 5 PM. Potential exists for spotty critical conditions over the Central Highlands including portions of Torrance and Guadalupe counties Tuesday afternoon, but the forecast duration is less than today, and forecast instability is lower. Therefore, at this time, will not issue a Fire Weather Watch for Tuesday. Mid to high level moisture will begin to increase by Tuesday night and will be associated with a disturbance forecast to pass over NM Wednesday. This will result in some cooler, although still mostly above normal temperatures and higher humidities overall, as well as a slight chance for snow showers over the northern mountain peaks. The modified arctic air mass will continue to return to eastern New Mexico each night for the rest of the work week, but likely progressing a little farther west each night. The cold air may finally bleed west of the central mountain chain as soon as Friday or during the upcoming weekend, so the temperature forecast is quite uncertain but it does appear to cool down significantly (and well below normal) by Sunday. In fact, much of the Northeast and East Central Plains may see several consecutive days with highs below freezing. Also uncertain is the strength and timing of a couple of disturbances late this week and early next week that could bring snow to much of the forecast area. Ventilation is forecast to be mostly good to excellent through Wednesday before diminishing. 99 && .ABQ WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 5 PM MST this afternoon for the following zones... NMZ103-107-108. Wind Advisory until 6 PM MST this evening for the following zones... NMZ223. && $$
Area Forecast Discussion
National Weather Service State College PA
1051 PM EST Mon Feb 8 2021 .SYNOPSIS... A fast-moving system will track through the state tonight and Tuesday morning. A deep upper low will remain in place across south central Canada through next weekend, with shortwaves rotating through the base of the trough. A couple of shortwaves are likely to affect Pennsylvania Wednesday night and again late Thursday or Friday. A more potent storm system may affect the area next weekend. && .NEAR TERM /UNTIL 8 AM TUESDAY MORNING/... Good lift over OH/IN is producing brief forays into 1/4-1/2SM vsby as a very narrow ribbon of good lift slides almost parallel to the large-scale flow. It`s headed here on schedule. Earlier updates are what we`re going to roll with. Latest HRRR is a little lighter with the QPF than the wider-grid models, but still in line with current thinking. Without much support to nudge totals up in Dauphin/Lebanon Cos, we`ll leave all the headlines as is. Prev... Minor adjustments made to the snow totals based on the 18Z runs and latest HRRR/RAP progs. These do hint at a little lighter/lower QPF & snowfall numbers for the nrn tier and also generate practically no QPF on the MD border. The snow is reaching the ground already in the nrn few counties, but not measuring just yet. Main forcing for what we`ll get later tonight is still back in srn OH/IN, but moving very rapidly. There is a bit of a snow/precip shadow evident in many model QPFs right over State College and down into Huntingdon and Blair Cos. Some support for a wee bit less snowfall there considering past events with fast westerly flow aloft and the downslope/drying which usually happens. Timing of the main band/bulk of the snow is still solid and axis of the band also solid. One tweak which may be made later would be to up the snowfall an inch over much of Dauphin and Lebanon Cos. This would put them into advy-type accums (avg of 2+"). Will continue to squint at the latest models as they come in to discern the best path for that area. This would affect their morning rush/commute. Prev... Surface high pushing east of the Commonwealth this afternoon, with warm advection and increasing cloud cover spreading into the state ahead of approaching clipper system. Far quarter to half of central PA is enjoying sun for now, but the clouds will thicken towards nightfall. Main focus in the near term is on approaching upstream clipper system, timing and intensity of associated snowbands. 12z guidance came in with a slightly farther northern track of the sfc low, still a favorable one along the Mason Dixon line. Consensus NWP and WPC guidance indicate a swath of 2 to 4 inches probable from portions of the WC Mountains through the Central Mountains eastward to southern parts of the Endless Mountain region, beginning late tonight and continuing into Tuesday afternoon. Favorable crystal growth in the DGZ around 10k feet will enhance efficiency of accumulation, as frontogenetical forcing within negative moist EPV environment forced by strong 140+kt ULJ favors heavy snow banding for several hours along the I80 corridor. It looks like the best snowfall potential is over far eastern portions of my CWA where the bands will have matured and be producing 1"+ per hour rates Tuesday morning into Tuesday afternoon. That is where we believe 4"+ will be possible over Columbia and Sullivan Counties. Slight northward trend in the 12z cycle for the aforementioned ULJ and frontogenetical forcing, and will be important to watch these features in subsequent model cycles and if need be adjust location of swath of heaviest snowfall. && .SHORT TERM /8 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... The precip may linger over the eastern zones a little longer into the early aftn. But, most of the area will be down to nothing` or just flurries in the morning. Prev... Highest POPs still placed between 10Z-14Z, associated with passage of low level jet and best waa. The morning commute will be impacted, but as snow decreases after midday, breaking clouds and temperatures rising above freezing are anticipated by mid afternoon, as the clipper exits the state. Surface ridging is progged to build into the region Tuesday night and early Wednesday, accompanied by fair and seasonably chilly conditions. Beyond that, the bulk of model guidance now supports increasing confidence in a period of light snow Wednesday PM associated with a weak wave riding along stalled frontal boundary south of Pa. Model guidance indicates southern Pa will be in a region of low level frontogenesis beneath right entrance of strong jet streak over NY/New England. Thus, have place the highest POPs across the southern tier counties, with the chance of some snow even into northern Pa. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... The unsettled week of weather continues. Models have converged on a general agreement for the late week storm, with precipitation onset beginning late Wednesday night, then a lull on Thursday and a resurgence Thursday night. Precipitation will be mainly in the form of snow, with a chance of a wintry mix/ice for the short period on Friday morning due to some short-lived warm air advection from southerly flow. Otherwise, this system will produce snow as models have trended to generally colder solutions. Snow should diminish by the evening hours on Friday. Models could not be further from agreement on what will happen this upcoming weekend. There is a hint of another storm system in the late Saturday/Sunday timeframe, but precipitation type, intensity, and timing are all highly uncertain. The Euro is trending drier and colder but the GFS is trending warmer and wetter. One thing that does seem more clear is that frigid air will move in for Sunday night and Monday, bringing low temperatures into the single digits and low teens. Gusty winds will contribute to frigid feeling temperatures, as apparent temperatures will be in the single digits and below zero. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... A few minor adjustments to the TAFS as of 1030 PM. Not a lot of change. BFD had snow earlier, but has ended for the time being. Earlier discussion below. For the 00Z TAF package, an inverted trough will bring some light snow into the western areas by Midnight. This area of snow will spread eastward overnight, before tapering off from west to east Tuesday afternoon. VFR conditions this evening will give way to IFR conditions in the heavier snow pockets. Conditions will improve Tuesday night, before more snow moves into the area later Wednesday afternoon and continues into early Thursday. A series of fast moving systems will bring some winter weather to the area now and then into the weekend. Outlook... Tue...IFR conds in AM light snow gradually improving as the snow tapers off. Western highlands may hold onto MVFR cigs through the PM. Wed...VFR giving way to reductions as light snow spreads in from the southwest. Thu-Sat...Potential for widespread reductions in mixed precipitation. && .CTP WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 4 PM EST Tuesday for PAZ012- 017>019-024-041-042-045-046-049>053-058. && $$ SYNOPSIS...DeVoir/Dangelo NEAR TERM...DeVoir/Dangelo SHORT TERM...DeVoir/Dangelo LONG TERM...Gutierrez AVIATION...Martin
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
935 PM CST Mon Feb 8 2021 .UPDATE... We have trended temperatures down for tomorrow across the northeast CWA, including the Austin metro area. The new 00Z NAM12, which typically handles the shallow cold/dense air masses well, and the HRRR are showing a further south progression of the front into our area tomorrow morning. This may not be too far off based on the current position of the front, density of the airmass, and latest upstream pressure rises across North Texas. Locations near and north of a Llano to Austin to Giddings line may be stuck in the 50s tomorrow, and potentially upper 40s across Burnet and Williamson county if the NAM12 fully verifies. South of the front highs in the 70s to low 80s are forecast, so quite the gradient in temperatures tomorrow across the CWA. Significant changes downward in temps could be required beyond tomorrow as well, but will allow the mid shift to get a better look at the 00Z guidance before making additional changes. Otherwise, the main concern for tonight is fog development. Short- term guidance is still developing fog south of a Fredericksburg to Austin to La Grange line, with a strong signal for dense fog by early Tuesday morning roughly near and south of the I-10 corridor. We have added dense fog into the official gridded forecast. A Dense Fog Advisory could be required as trends become established. && .PREV DISCUSSION... /ISSUED 549 PM CST Mon Feb 8 2021/ AVIATION (OOZ TAFs)... There continues to be a strong signal in the short-term guidance that widespread fog will develop over the region 06Z-12Z, with most locations seeing LIFR conditions eventually. There are also indications of 1/4SM or less visibility and less than 100 foot ceilings developing in the fog near and south of I-10, including SAT/SSF and potentially DRT. At this time have stopped short of this and indicated 1/2SM visibility and OVC002 and will re-evaluate during the 06Z TAF cycle. AUS may be more tricky, as a weak and shallow cold front moves through the terminal around or shortly after 12Z, but have shown LIFR conditions there ahead of the front. Conditions should improve to IFR and eventually MVFR at AUS behind the front through the morning. South of the front, which is forecast to eventually stall north of SAT, conditions will be slower to improve, with LIFR and IFR conditions through most of the morning. Eventual improvement to MVFR and VFR is forecast after 18Z south of the front. PREV DISCUSSION... /ISSUED 311 PM CST Mon Feb 8 2021/ SHORT TERM (Tonight through Tuesday Night)... A rather tricky forecast for the short term as a cold front will attempt to move through the area, but likely get hung up somewhere within our northern and eastern counties Tuesday afternoon. An arctic cold front is slowly pushing southward over NW Texas and the Panhandle into portions of Texhoma, as high level clouds stream in from the southwest over South-Central Texas. Morning clouds and low stratus have begun mixing out, allowing for sunshine to filter through. Temperatures should easily top out in the 70s today, but enjoy it, as this could be one of our warmest days for quite some time. For tonight, expect winds to turn more southerly and variable, with nearly calm conditions at the sfc ahead of the approaching cold front. Widespread fog is expected to form tonight, as shallow moisture pools over the Coastal Plains/Hill Country/I-35 Corridor through Tuesday morning. Visibilities could drop to less than a 1/2 mile for locations mainly along and east of I-35, but some dense fog could materialize at times in the San Antonio and Austin Metros. The fog should lift by mid-morning Tuesday, but then things get even more interesting. The cold front we`ve been talking about for what seems like weeks, will begin pushing into our northeastern counties Tuesday afternoon. This will present a challenge for high temperatures. Have opted to go with a blend of the NAM/TTWRF/GFS with this boundary slipping as far south as the Comal, Caldwell, and Fayette counties Tuesday afternoon. Temperatures north of the front will struggle to get out of the upper 50s and lower 60s, whereas south of the boundary, widespread 70s and even lower 80s look likely. Temperatures will also be on the cooler side behind the boundary for Tuesday night, as it holds up/stalls out over the Coastal Plains and Hill Country. With regard to precipitation chances, the airmass is rather shallow, and so is the moisture when looking at model soundings. We may some drizzle or light mist out of those clouds Tuesday night into early Wednesday am, but not enough to mention any PoPs at this time. Upper level support will arrive just outside of the short term forecast period, warranting precipitation chances. LONG TERM (Wednesday through Monday)... A challenging forecast period is in store from mid-week through the upcoming weekend across south central Texas. The main concern will be the potential for much colder temperatures late this week into early next week. Beginning Wednesday morning, we will likely see the leading edge of a shallow cold front in place across portions of the Hill Country near Burnet eastward into the I-35 and Highway 77 corridors. With shallow, cold air near the surface and moist air just above this layer, this warm air advection pattern favors light shower development across most areas, except out west along the Rio Grande. A few rumbles of thunder are also possible Wednesday afternoon, but overall chances for thunderstorms remain fairly low at this time. The temperature forecast will be tricky as the leading edge of the front may slow its southward progress or retreat northward during the afternoon hours. The cold front looks like it will make some southward progress Wednesday night and with southerly flow just above the cold air remaining in place, some additional showers and possibly a thunderstorm or two (mainly west/south of I-10) can be expected. The cold air looks to deepen on Thursday as a mid and upper level trough approaches from the west. Intermittent showers along with a low chance for a thunderstorm or two along the Rio Grande are in the forecast. With fairly high rain chances in the forecast and cold air advection, we have lowered the high temperature forecast for Thursday. If the rain is a little more persistent, we will need to lower our forecast high temperatures on Thursday. As the upper level trough passes over and eventually to our east Thursday night into Friday morning, we will see a quick decrease in rain chances from west to east. For now, we will only keep a 20% chance of rain Thursday evening for areas east of I-35, then go with a dry forecast as we head into early Friday morning. We do have a decent amount of atmospheric moisture in place as the cold front and upper level trough interact across the region. Rainfall amounts Wednesday and Thursday should average less than one-tenth of an inch across the Rio Grande plains, with amounts increasing to around one-quarter of an inch for the Hill Country and along the I-35/I-37 corridors. Amounts increase over the coastal plains and Highway 77 corridor with average amounts around one-half inch. The forecast for late this week into early next week continues to present a challenge. The upper air pattern late this week (Friday) does favor Arctic air moving southward into the southern U.S. plains. There is plenty of cold air bottled up over northwest Canada and northern Alaska with afternoon temperatures around -35 to -40F and surface pressures close to 1060mb. The mid-level flow pattern somewhat resembles a McFarland signature on Friday, with a ridge just off the west coast and a east-west oriented trough along the Canadian/U.S. border. As of now, it appears this pattern does not remain intact for too long. While our confidence is good we will see colder temperatures, the amount of cold air that will be able to move this far south remains in question. For now, we will keep highs in the mid 40s to mid 50s on Friday, with temperatures set to trend downward for the upcoming weekend into early next week. We have not trended the forecast toward the latest 12Z GFS. We continue to see quite the spread among the ensemble model members and our forecast in the GFS numbers is not very high at this time. However, we did opt to drop our forecast highs and lows for the upcoming weekend, with highs in the 30s and 40s on Sunday, with lows in the teens to upper 20s. The forecast for early next week bears watching as the medium range models show an upper level trough moving in from the west. The atmosphere looks to remain dry as this system moves through, so we will not mention any precipitation in the forecast at this time. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 57 61 54 65 43 / - 0 0 30 60 Austin Bergstrom Intl Airport 57 61 54 68 42 / - 0 0 30 50 New Braunfels Muni Airport 59 73 57 74 47 / - - 0 30 50 Burnet Muni Airport 48 56 51 59 38 / 0 0 0 30 60 Del Rio Intl Airport 52 82 60 80 52 / 0 0 0 10 40 Georgetown Muni Airport 50 54 51 60 39 / - 0 0 40 60 Hondo Muni Airport 54 79 60 79 49 / 0 0 0 20 40 San Marcos Muni Airport 57 70 55 70 44 / - 0 0 30 50 La Grange - Fayette Regional 60 69 59 67 48 / - - - 30 50 San Antonio Intl Airport 59 75 58 74 49 / - 0 - 30 50 Stinson Muni Airport 59 78 60 75 50 / - 0 - 30 40 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term/Aviation...Runyen Long-Term...Brady
Area Forecast Discussion
National Weather Service Grand Rapids MI
1041 PM EST Mon Feb 8 2021 LATEST UPDATE... Update .SYNOPSIS... Issued at 234 PM EST Mon Feb 8 2021 - Light snow tonight - Continued cold - Light snow late weekend && .UPDATE... Issued at 1041 PM EST Mon Feb 8 2021 Our mesolow continues to slowly drop south just off shore. It had broken into two of them around 815 pm but has since consolidated into one larger mesolow about 10 miles west of Holland (1015 pm). A new inland band of snow has developed over southern Ottawa County but this band is not staying over the same location so snowfall rates accumulations will not be like they were late this afternoon when the band stays in the same location for nearly 4 hours. I would think 1 to 2 inches is possible of new snow from Holland south to South Haven through 7 am. Locations more than 5 miles east of US-31 will see less than an half inch overnight. UPDATE Issued at 544 PM EST Mon Feb 8 2021 Heavy snowfall is expected over the next 3 hours over western Ottawa County, near and west of US-31. The band of heavy snow will sink south to northern Allegan County between 7 pm and 10 pm this evening. Locations like Zeeland and Holland may see similar snowfall amounts during the mid to late evening. Our 88D radar Storm Total Snow Algorithm at 5 pm was showing an narrow band of 4 to 5 inches of snow that has fallen since 1 pm this afternoon from just south of Grand Haven to near Port Sheldon to just off shore of Holland. The band is about 5 miles wide. There is a meso-low (can be seen in the radar data and surface observations with a south wind at Holland and east winds at Muskegon. The HRRR slowly tracks this system due south, being centered on Holland by 7 pm. We will continue to monitor this event as it continues to unfold. && .DISCUSSION...(This evening through next Monday) Issued at 234 PM EST Mon Feb 8 2021 -- Light snow tonight -- Local radar shows a band of snow moving north along the lake shore north of Holland. SSW winds in the boundary layer ahead of a short wave moving across the Midwest is responsible for this. The short wave will also bring another 1-2 inches mainly south of I-96 beginning late this afternoon and continuing through the early overnight hours. Closer to the shore line, lake enhancement may boost the snowfall totals by another 1-2 inches. Thus, we early extended the Winter Weather Advisory until noon Tuesday. - Continued cold -- H8 temperatures remain near -18c through the end of the week before an upper trough drags down more cold air Saturday and Sunday. H8 temps fall to -26c or so. ECMWF ensemble averages for high temperatures are solidly in the teens Fahrenheit through Friday and actually fall a bit to closer to 10F by Sunday after the trough moves through. Low temperatures well below 0F are looking more likely Sunday and perhaps Monday. After that, we may see some relief from the arctic air as highs rebound into the upper 20s the following week. It`s worth noting that around that time the Arctic Oscillation is forecast to rise significantly which lends itself to confidence in the ECMWF ensemble forecast. -- Light snow late weekend -- A deep upper trough drops south Saturday through the upper Mississippi Valley. ECMWF is lighter with the snow...2-4 inches...than the GFS, which has quite a bit more. That`s due to the GFS`s stronger surface low which is also farther west and taps into some Atlantic moisture; the ECMWF is quicker and farther northeast with the sfc low. The main message is that accumulating snow looks possible late in the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 638 PM EST Mon Feb 8 2021 We have two events going on at the same time. There is a meso-low near Grand Haven causing locally heavy snowfall near and just south of Muskegon and there is a synoptic light snow event occuring also. Both of these are causing IFR to LIFR conditions this evening. Currently only LAN and GRR are out of the snow and have VFR conditions. I do believe through that both LAN and GRR should have a few hours of IFR in snow between 00z and 06z. After that conditions should improve to MVFR and finally to VFR at all sites by 12z. Some lower clouds should move in by late morning or early afternoon lowing ceilings to MVFR Tuesday. I do not expect any snow with this. && .MARINE... Issued at 234 PM EST Mon Feb 8 2021 Ice continues clog channels and shoreline areas with no reprieve through this week as temperatures will remain mostly in the teens. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Weather Advisory until noon EST Tuesday for MIZ050-056- 064-071. LM...None. && $$ UPDATE...WDM SYNOPSIS...04 DISCUSSION...04 AVIATION...WDM MARINE...04
National Weather Service Wilmington OH
1054 PM EST Mon Feb 8 2021 .SYNOPSIS... A quick-moving weather system will bring accumulating snow to much of the region tonight before dry air takes its place early Tuesday. Another weather system will bring renewed chances for widespread wintry precipitation Wednesday through Thursday night, with drier and colder air filtering in late week into the upcoming weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 04Z UPDATE -- have upgraded to a Winter Storm Warning for Highland, Ross, Pickaway, Hocking, and Fairfield Counties due to persistent snow banding and expectation for storm total snowfall in these areas of 3 to 5 inches. PREVIOUS DISCUSSION... Snowfall spreading east-northeast will continue to develop along a strengthening baroclinic zone as an upper level jet provides significant lift to this area. Have upgraded the advisory to a warning as a 4" total looks more likely running from Ripley County Indiana, cutting through the northern 275 loop outside Cincinnati, to the I-71 corridor running northeast to Washington Court House. Remainder of the forecast was still given a slight bump but the area east of WCH still remains in a potential state of flux as some models are lifting the baroclinic zone northward after the next few hours. Precipitation will taper off from west to east late tonight as the energy moves off to the northeast. Lows will range from the upper teens northwest to near 30 southeast. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... Snow will be exiting the region Tuesday morning. There is a low chance of a few flurries or even some patchy freezing drizzle as deeper moisture exits but some weak low level lift remains. Otherwise, it will be mostly cloudy to cloudy as Arctic high pressure builds east into the Great Lakes. Highs will range from the lower 20s northwest to the upper 30s southeast. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... Main concern during the extended period remains potential for a significant mixed precipitation event late Tuesday night through Thursday. This event will also be followed by bitterly cold conditions late this weekend. To start the period, broad, low-amplitude troughing will exist over the northern tier of the United States with split upper level flow. Primary axis of northern stream will be cutting through the Great Lakes, with a weaker southern stream axis positioned from the mid- Mississippi Valley to the Mid-Atlantic. A shortwave trough will be positioned over the intermountain west. Energy ejecting out of this trough will cause an increasing thermal gradient and low-level convergence (along with isentropic lift) to develop across the lower Ohio Valley. The resulting thermal profile is setting up to result in mixed precipitation, with light snow in the colder air to the north, sleet in the middle, and freezing rain to the south with the warm nose at 850mb. Where the transition zone will be between these precipitation types varies across the guidance, with the NAM on the (very) warm side, and the Canadian on the cold side. Favored a blend in this situation, which places significant freezing rain potential south of the Ohio River across north- central and northeast Kentucky. Expecting sleet and snow mixing in north of this ice axis, with light snow being predominant heading north toward the I-70 corridor. Based on the positional uncertainty of the snow-to-ice transition, have included a tier of counties north of the Ohio River in the Winter Storm Watch, since any slightly warmer solution could bring quarter-inch ice accretion there. As far as timing goes, while ensemble guidance from EPS and GEFS hold off on onset of wintry precipitation until mid-late Wednesday morning, there is some potential of a late Tuesday night start time based on early HRRR runs. Therefore, decided to bracket the Watch to include the late Tuesday night period. Continued over-running in the persistent baroclinic zone to the south will likely continue the steady, light precipitation through Wednesday night into early Thursday morning. By then, the primary axis of weak lift should shift just to the southeast of the forecast area as a northern stream trough shifts toward the region. Mixed precipitation will likely change to snow west to east as it ends late Thursday. Surface high pressure builds in on Friday, then very cold air arrives later in the weekend. Main concern at this time is modified arctic air arriving after a potential winter storm. Currently expecting lows to trend downward from the low-mid teens Friday night to near zero on Sunday night. Highs in the low-mid 20s on Saturday will be likely stay in the teens for much of the area Sunday and Monday. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... Snow will expand northeast and affect the TAF sites beginning in the Cincy/Lunken area in the next hour or two. Ceilings across the board will drop to MVFR and then eventually IFR as the snow begins in earnest, with a corresponding drop in vsbys. Dayton will be on the periphery of the northwest edge of the snow, giving the most uncertainty in the forecast here. Rapid improvement will occur early Tuesday as Arctic high pressure will build east into the Great Lakes. However, considerable low level cloudiness will remain with MVFR cigs. Visibilities should improve to VFR as northerly winds prevail. OUTLOOK...MVFR/IFR cigs/vsbys likely Wednesday and Thursday. MVFR cigs possible Friday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...Winter Weather Advisory until 7 AM EST Tuesday for OHZ045-046- 051>056-060>062-078-079-081-082-088. Winter Storm Warning until 7 AM EST Tuesday for OHZ063>065- 070>074-077-080. Winter Storm Watch from late Tuesday night through Thursday afternoon for OHZ079-081-088. KY...Winter Weather Advisory until 7 AM EST Tuesday for KYZ089>097. Winter Storm Watch from late Tuesday night through Thursday afternoon for KYZ089-090-094>100. IN...Winter Weather Advisory until 7 AM EST Tuesday for INZ050-058- 059-080. Winter Storm Warning until 7 AM EST Tuesday for INZ066-073>075. && $$ SYNOPSIS...Franks NEAR TERM...KC/Franks SHORT TERM...Hickman LONG TERM...Hogue AVIATION...Franks
Area Forecast Discussion
National Weather Service Lincoln IL
747 PM CST Mon Feb 8 2021 .SYNOPSIS... Issued at 258 PM CST Mon Feb 8 2021 Light snow continues this evening. Accumulations up to an inch are possible north of I-70, with 2 to 3 inches possible south of I-70. Tuesday should be dry as high pressure shifts through the area. Temperatures will be below normal through the week. && .UPDATE... Issued at 747 PM CST Mon Feb 8 2021 Evening update focused on 3 areas. From north to south: 1) Band of frontogenetic-based snow which has been across northern Illinois the last several hours is shifting a bit south, with latest RAP model suggesting the higher forcing will clip the far northern CWA. Have added 1 to 2 inches of snow in the northern 3 counties (northern Knox, Stark, Marshall) for this evening. 2) Evening sounding from our office shows ice crystals are largely gone above 700 mb. While surface obs continue to show some light snow, think some freezing drizzle will also be possible. Earlier observation from Peoria switched to unknown precip for a time, suggesting this is indeed the case. Have expanded the mention of freezing drizzle southward through the I-72 corridor, though amounts still expected to be minor. 3) Snow band south of I-70 is most prevalent from the southern St. Louis metro to Bloomington IN. Had a report of 3 inches of snow in Robinson about an hour ago, and 1-hour precip totals at Lawrenceville suggest a 1 to 2 inch per hour rate. No change made to the advisory area, but amounts were increased to 3-4 inches along the highway 50 corridor. Also included a mention of patchy freezing drizzle as the precip winds down after midnight. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 258 PM CST Mon Feb 8 2021 As yet another impulse translates through the long wave trough, a few areas of light snow are ongoing across the CWA this afternoon, one near and north of the I-74 corridor and another south of I-70. Models have shown good agreement in trending higher with QPF in the southeast CWA, with some banding possible. The increase in QPF bumped snow totals up to 2-3". Model cross sections are supportive of this increase, showing a favorable crosshair signal of ascent in the dendritic growth zone. Issued an advisory for locations south of I-70. Included a mention of freezing drizzle as precip winds down, but any freezing drizzle should amount to a glaze or less. Another bitterly cold evening is on tap, especially in the northwestern portions of the forecast area, where snow cover and clearing skies will result in efficient radiational cooling. In those areas, lows below zero and wind chills of -15 to -20 are expected. A brief respite from wintry precip during the day on Tuesday as a 1034mb high across Iowa gradually shifts southward. With the baroclinic zone still draped across the area, the broad spread in temps will continue, with highs on Tuesday ranging from the low teens to upper 20s. Trended lower on temps than the blended guidance, as much of the area has at least some snow cover and modest northerly winds are expected through the day. .LONG TERM...(Tuesday night through Monday) ISSUED AT 258 PM CST Mon Feb 8 2021 The Arctic airmass will remain entrenched across central IL throughout the extended forecast. A couple periods of wintry precip are on tap as well. Tuesday night into Wednesday will see snow advance into our southern counties, south of I-72, before a warm surge of air in the 925-750 mb layer changes precip over to a wintry mix of sleet and freezing rain south of I-70. The 12z GFS update trended colder toward the NAM/ECMWF/GEM solutions with our southeast counties, where previous models had a much stronger surge of warm air and a higher coating of freezing rain/sleet. The 12z runs are showing more snowfall in our SE counties (S of I-70), and even less sleet as well. There is still enough uncertainty in the depth and strength of the warm air surge toward I-70 that we left a mention of freezing rain in the forecast Tuesday night through Wednesday night, but kept ice accum on the lower side. Ice storm potential continues to target far southern Illinois and the Ohio River Valley area. A period of light snow is forecast for Thursday and again Friday night into Saturday, but amounts are uncertain due to wide variations in the extended ensemble blend. Therefore only slight chances of snow were included in the forecast due to timing and coverage differences. One thing that is still looking on track is the bitterly cold air intensifying into next weekend. Wind chill advisory level wind chills (-15 to -24F) appear likely throughout much of next weekend into Monday morning. Late Saturday night into Sunday morning look like the coldest conditions, with wind chills in that range all across our forecast area. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 515 PM CST Mon Feb 8 2021 Steadier visibility-impacting snow is north of the TAF sites at this hour, but latest observations from KPIA and KMQB suggest some freezing drizzle is occurring. Will continue to mention FZDZ at KPIA/KBMI for the first part of the evening, monitoring the potential further south. However, visibility will be restricted for a time this evening from KSPI-KCMI, before improvements occur toward 06Z. Ceilings will remain MVFR in that area through much of Tuesday morning, but should lift overnight further north. && .ILX WATCHES/WARNINGS/ADVISORIES... Wind Chill Advisory from midnight tonight to 9 AM CST Tuesday for ILZ027-028-030. Winter Weather Advisory until 6 AM CST Tuesday for ILZ067-068- 071>073. && $$ UPDATE...Geelhart SYNOPSIS...Erwin/Shimon SHORT TERM...Erwin/Shimon LONG TERM...Shimon AVIATION...Geelhart
Area Forecast Discussion
National Weather Service Pueblo CO
530 PM MST Mon Feb 8 2021 .UPDATE... Issued at 513 PM MST Mon Feb 8 2021 Updated for the expiration of the Red Flag Warning. However, portions of western El Paso County, Fremont County, and the southern portions of the I-25 corridor will experience critical fire weather conditions for about the next hour. In addition, low clouds and fog are making a strong westward push at this hour. The leading edge of these clouds and fog has just about reached the city of Pueblo and is just entering southeastern El Paso County as I am typing this. Observed visibilities along Hwy 50 east of Pueblo are currently in the 4 to 6 mile range; however, webcams in Springfield are showing very low visibility, around one quarter of a mile. Latest guidance indicates that only isolated spots of visibilities this low are anticipated, so will hold off on any Dense Fog Advisories for now. That said, we will continue monitoring visibility trends for the potential of an advisory later on. && .SHORT TERM...(This evening through Tuesday) Issued at 321 PM MST Mon Feb 8 2021 Currently... At 2 pm, a sharp temperature gradient was observed over SE CO. Temperatures just east of the mtns, and extending a bit farther east in Las Animas county were in the 50s and 60s, while to the east of this boundary temperates were in the 20s and 30s. This boundary is the demarcation zone of the Pacific air mass and the modified arctic airmass which are over the region at this time. In the cold air quite a bit of low clouds were still noted while in the drier air skies were mainly clear. Rest of Today... The big question is the Arctic front over the area going to retreat to the east during the rest of today? HRRR runs have been wanting to push this boundary east, but Mother Nature has been holding back. Areas in the dry air have been red flagging with RHs in the single digits and winds in the 30 to 45 mph range, while east of the boundary weak easterlies have been noted. The boundary is probably going to push a bit east, but maybe not as far east as the guidance wants to push it. Tonight... The arctic air is likely going to push back to the west, but once again how far west will it go? NBM1 viewer guidance keeps the cigs rather high but raw model output from HRRR brings low clouds and fog back into KPUB. For COS...the very lowest levels are saturated but that is it. So, based on this, low cigs will likely work back to the west and I would estimate they will reach back to the 6000 ft elevations level. Farther east it is pretty much a slam dunk that low clouds and fog and possibly some light freezing drizzle will occur this evening and last through tonight. In the mountains, especially the central mtns, an upper level disturbance will approach the region this evening and periods of light snow will occur. The best chance of light accumulations will be from Cottonwood Pass on northward. Low temperatures tonight will vary considerably on the plains, with the coldest temps over eastern Kiowa county where low single digits are likely. Along the mtns/plains interface, the warmest temps will occur, with readings in the 30s. Teens and 20s will occur in the mtns, except +/- single digits above treeline. San Luis Valley will be in the teens. Tomorrow... How far will the modified arctic air retreat eastward? At this time I an once again quite confident that immediately east of the mtns it will be warm and breezy again, and over the far eater plains will be in the 20s. It is the areas in between where I have low confidence. I cannot see any good reason to disagree with the NBM guidance, although there will likely be a sharper temp discontinuity then what I have drawn up over the eastern plains. For the mtns...light snow will continue with most if not all the snow continuing over the central mtns in western Chaffee and Lake counties. Another 1-2 inches will be likely. /Hodanish .LONG TERM...(Tuesday night through Monday) Issued at 321 PM MST Mon Feb 8 2021 Models are in fairly good agreement through Thu, indicating that the Canadian low pressure system will gradually drop south into the Great Lakes region, while at the same time rotating a piece of energy south into the Dakotas by Thu morning. Beyond Thursday, the model solutions continue to vary greatly. Tuesday night through Thursday...What has been happening for the past couple of days will most likely continue, with brisk west to northwest flow aloft persisting while the colder more moist air to the east sloshes back and forth into the eastern plains. Snow showers will be a nearly constant threat across the Continental Divide, especially for the central mts, but snow is not expected to be particularly strong with total new snow amounts through Thu totaling up to 4 inches. Across the east, plan on lower clouds and colder air pushing back into the plains each evening, then retreating back to the east during the day. There is the potential for huge temperature forecast busts as the maximum readings will be highly dependent on how far east the cold air retreats during the day. Current forecast high temps both days will in the 35 to 45 degree range for the high valleys, and in the lower 30s to near 50F for the plains. Friday through Monday...This is when the truly cold air pushes back into the forecast area. One lobe of energy rotates down into the northern US Thu morning, pushing a cold front with strong arctic air down into eastern CO Thu night. This deep layer of cold air will provide for a significantly colder Fri, then an absolutely frigid weekend with perhaps a break on Mon. At the same time, upper level disturbances crossing the Four Corners region will tap into this colder air, and models are hinting at snow likely for the higher terrain, and at least a chance for snow across the plains. On Fri, look for high temps in the 30s to around 40 for the high valleys, and in the teens to upper 30s for the plains. High temps will then plummet for Sat through Mon, with readings in the mid 20s to mid 30s for the high valleys, and teens and 20s for the plains. Overnight minimum temps will be in the single digits each night, but Sunday morning readings could drop to below zero across the plains. Moore && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 321 PM MST Mon Feb 8 2021 KALS... VFR next 24 hours. It will be breezy in the afternoon. KCOS... We may see some low clouds/fog just touch the TAF site later tonight and possibly into tomorrow early morning. Will continue with a low scattered clouds at KCOS for later tonight/tomorrow morning. Otherwise VFR likely. KPUB... We will likely see a much better chance of low cigs/fog moving into KPUB late tonight and into tomorrow morning. IFR/LIFR will be possible. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CARLBERG SHORT TERM...HODANISH LONG TERM...MOORE AVIATION...HODANISH
Area Forecast Discussion
National Weather Service Springfield MO
552 PM CST Mon Feb 8 2021 .SHORT TERM...(This evening through Tuesday) Issued at 330 PM CST Mon Feb 8 2021 Another day with widespread freezing drizzle and a cold front pinned along the I-44 corridor. Also seeing snow snow mixing in at times across the northern CWA. North of the front, temperatures are in the teens with freezing drizzle causing road impacts. Road conditions have improved south of the front where temperatures are in the low 30s with peak solar insolation. As freezing drizzle continues through the evening, expect road conditions to deteriorate as the sun sets. On top of the loss of solar insolation, the shallow cold layer north of I-44 will likely surge south, allowing for a flash freeze. HRRR has done well in showing this the last couple of days and it has the front surging southward starting around 6pm CT. Have highlighted this additional risk in the Winter Weather Advisory. Overall, freezing drizzle will taper off over the west late this evening and will diminish, while not stopping completely, over the rest of the area later tonight. The Advisory has been extended in time to cover this. Tuesday may see some linger very light freezing drizzle over the SE in the morning, but should be more of a break. Will continue to see that shallow, cold airmass dominate over the northern half to two thirds of the CWA, with high sin the teens to low 20s along and north of I-44 and closer to 30 closer to the AR border. .LONG TERM...(Tuesday Night through Monday) Issued at 330 PM CST Mon Feb 8 2021 A couple of main items to discuss in the long term: Freezing rain/sleet potential Tuesday night into Thursday morning and much colder conditions late this week into the weekend. Freezing drizzle/rain and sleet are expected over mainly the southeast half to two thirds of the CWA late Tuesday night into Thursday morning. The greatest amounts are currently expected over the far SE CWA, where a Winter Storm Watch has been posted for potential of around a quarter inch of ice accumulations. The threat area has been moving slowly south with later model runs, so that will have to be watched. Regardless, even if warning amounts do not materialize, impactful ice accumulations will be possible across much of the area. A very cold airmass moves in late this week, with the coldest temperatures expected Saturday through Sunday. Forecast highs those days are generally 10-20, with lows in the single digits below zero. This results in wind chills as low as -20. Uncertainty remains with the extent of the cold airmass. Below are NBM MaxT and MinT distributions outlining the 10th and 90th percentile values: MaxT MinT 10th -6F to 2F -17F to 7F 90th 20F to 30F 7F to 20F There will continue to be potential for wintry weather Friday through next Monday, more likely in the form of snow than our recent freezing drizzle thanks to the colder airmass. With the airmass in place, any system that move through with some moisture will have potential to bring impactful accumulations to the area, but confidence is far too low to get into any specifics. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 551 PM CST Mon Feb 8 2021 KSGF/KJLN/KBBG tafs: IFR ceilings and variable visibility in fog/freeing drizzle can be expected through much of the period. Not much change to the basic weather trends with a warm front to the south and lift north of the boundary to produce the clouds and light precipitation. In general, expected precipitation to be more widespread early in the period through 06z-09z. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...Winter Weather Advisory until 6 AM CST Tuesday for MOZ057-058- 069>071-079>083-090>092-094>098-102>106. Winter Storm Watch from late Tuesday night through Thursday morning for MOZ097-098-106. Winter Weather Advisory until midnight CST tonight for MOZ055- 056-066>068-077-078-088-089-093-101. KS...Winter Weather Advisory until midnight CST tonight for KSZ073- 097-101. && $$ SHORT TERM...Titus LONG TERM...Titus AVIATION...DSA
Area Forecast Discussion
National Weather Service San Angelo TX
856 PM CST Mon Feb 8 2021 ...New SHORT TERM... .SHORT TERM... (Tonight through Tuesday) Issued at 851 PM CST Mon Feb 8 2021 Cold front continues to sag south, with low clouds following across the northern Big Country. Latest NAM/RAP/and HRRR all show significantly colder conditions across most of the area tomorrow, colder by as much as 25 degrees than the current forecasts. Will not drop readings quite that much, but will lower forecast highs for much of the area. Also needed to drop tonight`s lows a little as well, although not quite as drastically as the temperatures tomorrow. && .LONG TERM... (Tuesday night through next Monday) Issued at 200 PM CST Mon Feb 8 2021 ..Record-Breaking Cold Temperatures Possible This Weekend... Where to begin? The forecast from Wednesday through the weekend looks very messy with lots of uncertainty from timing and intensity of the cold air to precipitation chances. Overall, the GFS has continue to run colder, so have generally trended temperatures in that direction. The NAM is similar through 84 hours in showing the cold air arriving on Thursday, along with some elevated instability Wednesday night. This instability may result in pockets of light wintry precipitation across the Big Country through Thursday morning. At this point, impacts should be minimal until better detail comes in. The GFS and Canadian models continue to show another surge of even colder air on Saturday through Monday. Low temperatures in the teens or even single digits may occur on Sunday and Monday. In general, we have trended on the cold side for temperatures. There also exists some uncertainty with shortwaves bringing additional chances of overrunning wintry precip on Saturday and Monday, but with the timing discrepancies, we kept PoPs fairly low. For now, the big story is the potential for record-breaking cold this weekend. && .AVIATION... (00Z TAFS) Issued at 533 PM CST Mon Feb 8 2021 VFR conditions will continue until IFR to LIFR ceilings develop across KJCT, KSOA, and KBBD on Tuesday morning. These ceilings will likely last just a few hours before returning to VFR for the later part of the morning and the afternoon. && .PRELIMINARY POINT TEMPS/POPS... Abilene 30 44 32 42 / 5 0 5 10 San Angelo 39 58 51 63 / 0 0 0 10 Junction 44 67 51 68 / 5 0 0 20 Brownwood 36 53 36 49 / 5 0 0 10 Sweetwater 30 51 35 44 / 5 0 5 10 Ozona 44 72 52 69 / 0 0 0 10 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...07 LONG TERM....SK AVIATION...41