Aikyam-Lab/Synoptic-Bench huggingface dataset:
Although the low level flow will increase this evening/overnight with some drying, it appears will keep at least a partly cloudy sky this evening and overnight.
This, along with some warm air advection as surface winds shift to the west as a weak trough swings through, will keep overnight temps a bit higher than they have been lately. While deterministics have some differences in the degree of warmth, ensemble data readily agrees on temps exceeding average values by late weekend, with a very good chance at exceeding the freezing mark by Mon. Pcpn would generally be on our mind with a warm advection regime such as this, however any of that would most likely be associated with low pressure traversing the central Provinces of Canada, likely remaining north of the International border. Temps at the sfc should be in the teens to start on Fri, graduating to just above freezing Sun, and a little higher the next couple of days.
This could lead to a wintry mix or even a change to freezing drizzle at least as far north as the Western Kentucky and Bluegrass Parkways, perhaps lifting almost to the Ohio River. Sleet is not in play as the entire sounding is below freezing, and it's just a question of keeping ice in the clouds. Will see intervals of freezing drizzle, light snow, and just cold, damp, and miserable weather through the day. There will still be substantial inconvenience to travel given the overnight snow and continued freezing drizzle.
240 PM EST Wed Feb 17 2021 The cold front that has pushed through west central Florida yesterday just couldn't get enough of us and decided to head back north again. This is resulting in typical weather you would expect with a warm front.
At the surface, a quasi-stationary front is located just west of the Texas/New Mexico state line, extending southward and bi-secting a largely diffuse surface cyclone in the Big Bend region. Temperatures have "warmed", generally speaking, to above 20 deg F in areas where clouds have mixed out and should peak in the lower-middle 20s this afternoon. After sunset, clouds should develop quickly again as the low-level columns moisten owing to the presence of the snowpack greatly accelerating radiative cooling processes. Patchy freezing fog and freezing drizzle will develop overnight, though confidence remains low on the extent in both space in time. Conditions are already very slick, and light icing from freezing fog/drizzle will only exacerbate the situation even more (it only takes a thin glaze to cause major problems for travel and commutes).
1036 AM PST Wed Feb 17 2021 High pressure will make a brief visit to the Inland Northwest later today and Wednesday night bringing a good chance of clearing skies.
A return to southeasterly flow has allowed temperatures across the island chain to warm generally into the lower 80s this afternoon, and dew points into the lower to mid 70s.
Band of light snow across NE OK aligns with the mid level trough axis and this feature will slowly track eastward through the day.
Lift from the trough will combine with increasing moisture, and below freezing temperatures from the surface through the upper levels, to bring light to moderate snowfall to the Northern Edwards Plateau, Concho Valley, and Northwest Hill Country Thursday (which are the regions where models indicate deeper moisture and better lift). On Thursday night, a 1035mb area of high pressure will be centered right over West Central Texas.
1236 PM EST Wed Feb 17 2021 Influence of a building high pressure system will reinforce dry and stable conditions across SE MI today, with VFR conditions expected through the night. An approaching low pressure system to then travel across the southern Ohio Valley region through the morning on Thursday which will draw southern moisture and will result in the ongoing covering of mid and upper-level clouds from south to north. High pressure rooted in the mid-Mississippi Valley early this morning tracks east today with the center of the anticyclone passing over the southern Great Lakes. Lows tonight not as cold /single digits above 0/ as today's thermal trough moves out and clouds provide some insulation.
213 PM CST Wed Feb 17 2021 Upper level trough swinging across the area has produced some light snow in our southern counties, with a report of dendrites in the southeast part of McDonough county. With the extensive cloud cover, temperatures will be way warmer than early this morning when we had record lows.
Any lingering precipitation will continue to exit the region Thursday night as high pressure builds in from the west and the deeper longwave trough slides off into the eastern CONUS.
236 PM CST Wed Feb 17 2021 The DEEP meridional long wave upper trough pattern that brought all the frigid arctic air southward across Kansas, and well into Texas will finally shift east of the region this period.
Brief high pressure will develop later tonight through Thursday.
Given upstream trends in central Kansas and Nebraska within the broad cyclonic flow, have erred more aggressive on sky coverage through Thursday afternoon, though confidence in when the skies will clear later in the week is on the lower side.
Dry weather will dominate on Thursday as an upper ridge moves over the region.
552 PM CST Wed Feb 17 2021 The DEEP meridional long wave upper trough pattern that brought all the frigid arctic air southward across Kansas, and well into Texas, will finally shift east of the region this period.
As far as tonight is concerned, winds will remain very light, and this should allow temperatures to bottom back down into the lower single digits for lows most locations.
One short wave trough will be leaving the eastern cwa by evening taking the light snow/flurries/clouds with it. The models all then show two more short wave troughs coming out the northwest and into/across our region tonight through Thursday night. Otherwise, the next short wave trough spinning into northwest North Dakota this afternoon will be moving into our region tonight. Thursday is expected to be a few degrees warmer with partly to mostly cloudy skies with highs in the teens and lower 20s.
523 PM CST Wed Feb 17 2021 1025mb high pressure across Alberta/MT this afternoon will build south and strengthen to around 1030-1035mb across wrn and ncntl Nebraska by 12z Thursday. The forecast wagers the strength of the high pressure will cause skies to partially clear by morning with precipitable water falling a few hundredths down to near 0. This is several degrees cooler than the guidance blend which suggests lows in the single digits above zero. Skies continue to clear Thursday as the Canadian high pressure system builds south toward Texas. The bias corrected short term model blend suggested highs in the low to mid 20s.
512 PM CST Wed Feb 17 2021 One short wave trough will be leaving the eastern cwa by evening taking the light snow/flurries/clouds with it. The models all then show two more short wave troughs coming out the northwest and into/across our region tonight through Thursday night. Otherwise, the next short wave trough spinning into northwest North Dakota this afternoon will be moving into our region tonight. Thursday is expected to be a few degrees warmer with partly to mostly cloudy skies with highs in the teens and lower 20s.
With reports of freezing rain and sleet mixing in with snow received, broke out a late afternoon zone grouping in zone forecast product to address.
High temperatures should begin to breach 40 F in the west by late this weekend with NBM probabilities showing strong probabilities of 40 to 50 degree temperatures across western and central North Dakota (25th percentile highs pushing into the low 50s in the southwest).
The axis of the trough pushes east of the area and QG fields show decent positive omega values indicating subsidence and drying overnight.
With reports of sleet becoming dominant precipitation type approaching 6 PM CST, updated suite of forecast products to address with chances of freezing rain and snow continuing. Snow, sleet and some freezing rain will continue to move across the BNA MQY and CKV areas, The amounts will be a little lighter at CKV, but still IFR. more in the way of a sleet and freezing rain mix is expected.
347 PM CST Wed Feb 17 2021 One short wave trough will be leaving the eastern cwa by evening taking the light snow/flurries/clouds with it. The models all then show two more short wave troughs coming out the northwest and into/across our region tonight through Thursday night. Otherwise, the next short wave trough spinning into northwest North Dakota this afternoon will be moving into our region tonight. Thursday is expected to be a few degrees warmer with partly to mostly cloudy skies with highs in the teens and lower 20s.
Patches of freezing rain and snow also continue to be possible through remainder of afternoon hours.
Patches of freezing rain and snow also continue to be possible through remainder of afternoon hours. Snow, sleet and some freezing rain will continue to move across the BNA MQY and CKV areas, The amounts will be a little lighter at CKV, but still IFR. more in the way of a sleet and freezing rain mix is expected.
/issued 329 PM CST Wed Feb 17 2021/ Almost to the midpoint of the midweek snow/sleet/freezing rain event - the Midsouth's third major winter storm event over the past seven days. The possible exception will be northeast MS, rain, sleet and freezing rain will continue. Lower level clouds will remain, but with the absence of snow feeder clouds above, some patchy light freezing drizzle may mix with flurries overnight.
Light easterly winds tonight are expected to slowly transition to northerly overnight as high pressure builds into the western Plains. With snow cover across the area, expect temperatures to fall towards 0 F with wind chills slightly cooler than that. Cooler air remains aloft with northerly flow, which should keep high temperatures in the lower 20s.
329 PM CST Wed Feb 17 2021 Almost to the midpoint of the midweek snow/sleet/freezing rain event - the Midsouth's third major winter storm event over the past seven days. The possible exception will be northeast MS, rain, sleet and freezing rain will continue. Lower level clouds will remain, but with the absence of snow feeder clouds above, some patchy light freezing drizzle may mix with flurries overnight.
753 PM EST Wed Feb 17 2021 Another low pressure system will bring wintry precipitation to the region from late tonight through Thursday night. A central CONUS trough will slowly move east with warm, moist, advection on its van and increasing ascent via encroaching jet stream dynamics. Unfortunately, the precipitation-phase situation is expected to alter with sleet and freezing rain again being possible for areas around Morgantown as warm advection contaminates the mid levels. Nevertheless, overall snowfall is expected to exceed 6 inches over the ridges of WV and accumulate sufficiently over areas from roughly Indiana to Zanesville to warrant an advisory, especially in light that heavier precipitation potential will likely occur from late tonight through the morning rush hour.
A wedge of cooler air and ascd clouds remain entrenched across much of the forecast area with modest isentropic lift and trapped LL moisture producing ongoing stratus and lingering showers. More defined southerly flow wl develop ahead of an approaching cold front. Especially along to north of the lifting warm front.
Freezing rain and sleet north of the I10 corridor continues to be the main problem as some accumulations up to 1/4 of an inch could be found in a few locations. Temperatures made it into the low to mid 30s areawide with the warmest locations near 50 near patterson Louisiana. This dry trend should continue spreading eastward into the overnight hours as the low races off to the east. Areas of concern include north of the I-10 corridor where another weak disturbance may allow for some light freezing rain. All of the precipitation is expected to end by noon all areas as high pressure settles in.
A few showers will be possible Thursday afternoon under breezy southerly winds, with the highest rain chances over the interior.
351 PM MST Wed Feb 17 2021 Overview: An omega block -- characterized by ridging along the Pacific/Atlantic coasts and profound troughing over the central CONUS -- will begin to break down and transition to a more progressive /zonal/ synoptic pattern by the end of the short term period. Relatively weak W-NW flow aloft will transition to speedy NW flow aloft as the aforementioned upper trough progresses eastward from the Central Plains to the MS River Valley.
321 PM CST Wed Feb 17 2021 1025mb high pressure across Alberta/MT this afternoon will build south and strengthen to around 1030-1035mb across wrn and ncntl Nebraska by 12z Thursday. The forecast wagers the strength of the high pressure will cause skies to partially clear by morning with precipitable water falling a few hundredths down to near 0. This is several degrees cooler than the guidance blend which suggests lows in the single digits above zero. Skies continue to clear Thursday as the Canadian high pressure system builds south toward Texas. The bias corrected short term model blend suggested highs in the low to mid 20s.
Upper level trough swinging across the area has produced some light snow in our southern counties, with a report of dendrites in the southeast part of McDonough county. With the extensive cloud cover, temperatures will be way warmer than early this morning when we had record lows.
Snow, sleet and some freezing rain will continue to move across the BNA MQY and CKV areas, The amounts will be a little lighter at CKV, but still IFR. more in the way of a sleet and freezing rain mix is expected.
SHORT TERM (Tonight through Thursday Night): Recent satellite data shows a developing area of low pressure just east of the Texas Coastal Bend, which continues to produce an extended area of cloudiness and some precipitation, now concentrated over the Gulf waters. As the area of low pressure continues to move northeastward and away from the Deep South Texas region, the chance for precipitation is expected to diminish, with a slight chance for light showers along portions of Kenedy County and the local waters through early tonight. An arctic high pressure is forecast to push even colder air southward into the Deep South Texas area, which combined with clearer skies will result in overnight temperatures to fall into the mid to upper 20s across the ranchlands, and lower 30s along the Rio Grande River and southern-most sections.
Overview: An omega block -- characterized by ridging along the Pacific/Atlantic coasts and profound troughing over the central CONUS -- will begin to break down and transition to a more progressive /zonal/ synoptic pattern by the end of the short term period. Relatively weak W-NW flow aloft will transition to speedy NW flow aloft as the aforementioned upper trough progresses eastward from the Central Plains to the MS River Valley.
440 PM EST Wed Feb 17 2021 Another low pressure system will bring wintry precipitation to the region from late tonight through Thursday night. A central CONUS trough will slowly move east with warm, moist, advection on its van and increasing ascent via encroaching jet stream dynamics. Unfortunately, the precipitation-phase situation is expected to alter with sleet and freezing rain again being possible for areas around Morgantown as warm advection contaminates the mid levels. Nevertheless, overall snowfall is expected to exceed 6 inches over the ridges of WV and accumulate sufficiently over areas from roughly Indianna to Zanesville to warrant an advisory, especially in light that heavier precipitation potential will likely occur from late tonight through the morning rush hour.
Given the potential for quick bursts of moderate snow and the potential for refreezing of wet surfaces this afternoon and evening a winter weather advisory has been issued. Thursday low pressure will intensify across the Pacific Northwest and move southward into California and the Great Basin.
Models are having a hard time initializing the lowest near-surface saturation, so confidence in fog remains low to moderate at this time.
RAP soundings show a warm nose developing near 850 mb as WAA increases, so snow/sleet mix will gradually change to more of a sleet scenario then eventually all rain as the warmer air makes it back to the surface. Doyle/Garuckas Chattanooga Airport, TN 34 45 29 42 22 / 100 60 20 10 0 Knoxville McGhee Tyson Airport, TN 33 42 30 38 21 / 100 90 40 10 0 Oak Ridge, TN 33 43 28 38 20 / 100 70 30 10 0 Tri Cities Airport, TN 32 43 31 37 19 / 100 100 60 20 0 NC.
An upper trough will move through the region today and latest satellite showed it over the eastern Dakotas. Soundings across much of the Northland continue to show a saturated area on the lower end of the DGZ so some larger flakes and better chance for at least some light accumulation is expected.
A ridge of high pressure will move across the region tonight with mostly clear skies and isolated snow showers over the mountains.
348 AM EST Thu Feb 18 2021 While weak low pressure will pass well to our south and east through tonight. our region will pick up some nuisance light snow and possibly some freezing drizzle.
A chance for a snow to a wintry mix event is expected across locations west of Cumberland Plateau Region late evening and overnight as a developing area of precipitation across southwest mid state shortly before midnight composed of a wintry mixture of snow, sleet, light freezing rain/freezing drizzle spreads southwest to northeast. Snow, sleet and some freezing rain will continue to move across the BNA MQY and CKV areas, The amounts will be a little lighter at CKV, but still IFR. more in the way of a sleet and freezing rain mix is expected.
High pressure to the north will keep with light easterly upslope winds through the overnight and morning hours of Thursday. As the high center moves further east, winds will turn more northwesterly bringing in a downslope component that will scatter and lift clouds out during the afternoon with sun starting to shine across much of the CWA. Temperatures will recover into the mid to upper 20s across the CWA as upper level ridging builds back across the Rockies and high plains.
1234 AM EST Thu Feb 18 2021 Another low pressure system will bring wintry precipitation to the region from late tonight through Thursday night. A central CONUS trough will slowly move east with warm, moist, advection on its van and increasing ascent via encroaching jet stream dynamics. Unfortunately, the precipitation-phase situation is expected to alter with sleet and freezing rain again being possible for areas around Morgantown as warm advection contaminates the mid levels. Nevertheless, overall snowfall is expected to exceed 6 inches over the ridges of WV and accumulate sufficiently over areas from roughly Indiana to Zanesville to warrant an advisory, especially in light that heavier precipitation potential will likely occur from late tonight through the morning rush hour.
147 AM EST Thu Feb 18 2021 Another low pressure system will bring wintry precipitation to the region through Thursday night. Looking at the large scale pattern, deep and broad upper-level troughing exists over the central CONUS, with the Upper Ohio Valley region placed downstream in deep southwest flow. At the surface, strong, cold high pressure currently lies across the northeast CONUS while the first of two surface perturbations is expected to move from the Gulf Coast towards the Mid-Atlantic this morning underneath the right entrance region of a ~180kt anticyclonic jet streak. A winter weather advisory (warning for the WV ridges) is in place.
05 inches expected after midnight as freezing rain/freezing drizzle work in behind this main moisture swath with some locally higher amounts possible too. Snow, sleet and some freezing rain will continue to move across the BNA MQY and CKV areas, The amounts will be a little lighter at CKV, but still IFR. more in the way of a sleet and freezing rain mix is expected.
Even after the low cigs scatter out, considerable AC/cirrus cigs will persist across the region through much of the day ahead of an upper trough that will finally traverse the region Thursday night, gradually clearing the area late. Warmer and sunnier times are eventually coming.
Will also run on the cooler side of temperatures today in the western and northern counties based on the models performance over the last week.
Earlier today, freezing temps phased well with the arrival of an abundant moisture field which helped produce some impressive snowfall rates and totals. This was due to a low level jet that kicked in and helped boost low level temps right at or just above freezing through a deep layer to around 700 mb. While temps will be cold, they will be above freezing and max out in the mid 30s west to low 40s east. Any precip that falls later this afternoon will generally be rain, but cannot rule out some mixing with sleet, especially in NW AL where temps will be cooler. A deeper layer of northerly flow develops on the eastern periphery of a large high pressure system over central TX.
A chance for a snow to a wintry mix event is expected across locations west of Cumberland Plateau Region late evening and overnight as a developing area of precipitation across southwest mid state shortly before midnight composed of a wintry mixture of snow, sleet, light freezing rain/freezing drizzle spreads southwest to northeast. Should see a break in snow beginning around 09Z with a freezing drizzle remaining.
A large and broad upper trof located mostly over the central states gradually amplifies while advancing eastward, with the axis of the upper trof becoming oriented from the Mississippi River valley to the western Great Lakes.
1145 PM CST Wed Feb 17 2021 The DEEP meridional long wave upper trough pattern that brought all the frigid arctic air southward across Kansas, and well into Texas, will finally shift east of the region this period.
258 AM CST Thu Feb 18 2021 The mid/upper trough across the central CONUS continues to shift slowly eastward.
1123 PM CST Wed Feb 17 2021 1025mb high pressure across Alberta/MT this afternoon will build south and strengthen to around 1030-1035mb across wrn and ncntl Nebraska by 12z Thursday. The forecast wagers the strength of the high pressure will cause skies to partially clear by morning with precipitable water falling a few hundredths down to near 0. This is several degrees cooler than the guidance blend which suggests lows in the single digits above zero. Skies continue to clear Thursday as the Canadian high pressure system builds south toward Texas. The bias corrected short term model blend suggested highs in the low to mid 20s.
Our attention quickly turns to tonight, when the main surface system associated with the upper-level trough passes through the Ohio Valley. For Thursday, the upper-level trough will slowly drift eastward, and an area of high pressure will slide southward out of the Northern Plains into the southern United States.
Highs today will warm into the lower to middle 20s.
1039 PM EST Wed Feb 17 2021 Currently - A broad Atlantic high extends westwards across Florida while troughing is located in the Gulf of Mexico. This reflects that there is ridging through the lower levels. Short Term Update - Lower level ridging will remain dominant in the Keys through the overnight period. Winds may increase a bit further over the next few hours as the gradient tightens some between the Atlantic ridge and gulf trough. Forecast soundings indicate the lower level dry air will not go anywhere overnight. Moderate to fresh southeasterly breezes expected overnight due to a somewhat tight gradient between an Atlantic ridge and a trough in the Gulf of Mexico.