Aikyam-Lab/Synoptic-Bench huggingface dataset:
The band will slowly move eastward this afternoon and evening, with additional chances for some light snow/freezing drizzle through the evening. Some patchy freezing fog can not be ruled out either. Friday will not be much warmer as the upper trough axis slides eastward overhead, but clouds should begin to diminish during the day and allow the sun to help clear the roads. Highs are only going to be around freezing at best, but any sun will help melt snow during the day.
An additional update was issued this aftn to downgrade the ridge Winter Storm Warning to Advisory and to trim the previous advisory out of Pennsylvania as per lower additional snowfall totals as well as collaboration. With cold air at the surface, and warm advection still occurring above the boundary layer, the WV ridges could still see light freezing rain this evening. Warm advection on the van of the approaching trough will moderate temperature back to the seasonal averages.
However, low stratus and patchy freezing fog is forecast to re-develop overnight. Observations are king and I am impressed with the amount of moisture coming out of Mexico on WV as well as the low cloudiness in our southwest. Seminole has seen light snow, reported to be grainy, and given the northward advancement of the low level cloudiness, have little reason to not buy into some light snow down that way. We should see some clearing this afternoon once again before conditions go downhill tonight with a focus on freezing fog.
252 PM CST Thu Feb 18 2021 High pressure now stretching out over the Plains will slide east into the region later tonight/Friday. Expect yet another sub-freezing day Friday despite an expected return to more sunshine at most locations as the high sets in overhead.
1) Scattered rain showers will change over to snow showers and flurries, mainly across the higher elevations. Light snow accumulations of 1/2 to 1 inch possible across the higher terrain. Upper trough shear axis remains west of the area with a fronto- genetic band across middle Tennessee. The upper jet dynamics producing these bands of light precipitation moves east of the Tennessee valley this evening, the inverted trough across the southern Appalachians will move east as well. Mid level trough will continue to move out over the weekend and will be replaced by increasing ridging, and high pressure near the surface.
230 PM EST Thu Feb 18 2021 We are still on track to see a cold front push through the area overnight and tomorrow. Once the front pushes through high pressure will build back in and cold air will return. As we go into the weekend high pressure will be in control giving us beautiful weather across the area.
This is taking place in the weak flow north of the deep trof, where another strong wave is rounding the base, which just happens to be in the Gulf of Mexico right now.
202 PM EST Thu Feb 18 2021 Another wave of low pressure will pass off the southeast coast tonight.
A widespread snowpack and radiational cooling will allow for overnight lows to fall into the low single digits across the Ozarks region. However, warming will be tough to come by on Friday as a 6 to 8 inch snowpack will keep surface temperatures in check, and likely stay just below freezing in the lower 30s.
Meanwhile, satellite shows cloudy to mostly cloudy skies across the region, with snow producing mid and high clouds above the low stratus clouds. This snow is associated with an upper level trough which is currently moving across the region. A Winter Weather Advisory continues for Irion County and the I-10 corridor and by early this evening, the trough axis will be east of our region, with any lingering snow showers across Kimble/Sutton counties dissipating by mid evening. This, in addition to sunny skies and warming at 850 mb, will help bring warmer temperatures Friday, with highs in the mid to upper 40s. On Friday night, temperatures will dip once again below freezing.
950 AM MST Thu Feb 18 2021 The broad central US trough will be shifting east today (finally), bringing a brief stop to snowfall across western and central WY. The northwest flow aloft will help bring warmer temperatures to areas east of the divide Friday, with widespread 30s to near 40 degrees for most lower elevations.
1156 AM CST Thu Feb 18 2021 Water vapor imagery and RAP 500 mb analysis indicated a weak upper level trough scooting across eastern IA early today while a more prominent trough was situated across ND. Surface ridging will build in from the west, sliding overhead Friday night.
An inverted trough across far eastern Tennessee will be a focus and weaker jet dynamics will produce another area of showers for TRI and possibly TYS later this afternoon through the evening hours. The upper trough axis will eventually move east of the region Friday allowing for drier air to advect into the TAF sites with ceilings improving. The lower MVFR ceilings will continue overnight tonight.
Wintry precipitation has moved east of the area with temperatures above freezing across most of the area. An inverted trough is across the far eastern areas of Tennessee and southwest North Carolina. The lower MVFR ceilings will continue overnight tonight. TD Chattanooga Airport, TN 44 28 43 22 47 / 60 20 0 0 0 Knoxville McGhee Tyson Airport, TN 42 28 39 20 41 / 90 40 10 0 0 Oak Ridge, TN 41 27 40 18 42 / 70 40 0 0 0 Tri Cities Airport, TN 44 30 38 19 37 / 100 50 10 0 0.
1054 AM MST Thu Feb 18 2021 Snowfall has ended across the area, except for a few light snow showers ongoing on some of the high western slopes in the mountains. Cross sections still show flow aloft increasing tonight beneath increasing ridgetop stability with subsidence behind the exiting trough. Some lesser gusts could reach the lower foothills as well. Cross barrier flow increases to 40-50kt Friday morning, but looks like the strongest winds would remain across the higher elevations as parameters not conducive to an amplified mountain wave due to strong shear and upstream mountain moisture. Warmer again as 700mb temperatures climb to about - 7C which will result in temperatures back into the 40s.
145 PM MST Thu Feb 18 2021 Scattered flurries across northern areas associated with a weak disturbance embedded in the complex upper trough over the central plains will dissipate early as the trough begins to move away from the area tonight. Upper ridge will build in from the west on Friday but flatten into more of a northwest flow by late in the day. However, it will allow temperatures to warm above freezing in most locations, with the possible exception of lower elevations along the Republican in southwest Nebraska, including McCook.
Until we're on the backside of the upper trough, we'll continue to have scattered flurries, particularly during the day when lapse rates are a bit better. At the beginning of the period, high pressure will be centered over the southeastern U. A long wave trough over the southwestern U.
Most deterministic and ensemble data readily agrees on temps exceeding average values by late weekend, with a very good chance at pushing above the freezing mark by Mon. Low pressure will traverse the central Provinces of Canada, and another system affecting the Central Plains may just brush our extreme south Sat night/early Sun, however impacts appear inconsequential at this time.
Temperatures will rise above freezing in the valleys this afternoon, but are expected to lower to near or below freezing when the snow arrives tonight and may cause difficult travel. More showers later in the day with the passage of a cold front Friday afternoon.
1137 AM CST Thu Feb 18 2021 The mid/upper trough across the central CONUS continues to shift slowly eastward.
High pressure will start to build into the region tonight with dry weather expected.
The associated warm front has struggled to make much northward progress over the last several hours and is currently draped across southern Georgia, just south of our CWA border. At the upper levels, divergence ahead of the approaching upper trough has supported broad ascent and deep moisture advection across the area, driving a plume of light to moderate rain across eastern-central Georgia. The threat for strong to severe storms across central Georgia today appears to be waning, as the warm front and attendant instability remains south of the CWA. It will stay rather cool through the day, with highs in the lower 40s north to mid-50s south.
940 AM CST Thu Feb 18 2021 Radar returns increasing this morning in advance of an upper level low pressure trough with light snow at Aberdeen. The upper wave slides off to the east tonight, leaving weak ridging overhead on Friday. High temperatures today will be range from the teens east to the lower 20s west, with lows tonight in the single digits either side of zero. Warmer air will begin to infiltrate into the area as this frontal boundary passes through during the course of the upcoming weekend.
The trough will bring flurries and light snow to the area at times tonight, but any accumulations look to be on the light side (mainly just a dusting to a few tenths) due to limited deep level moisture and weak lift. the trough will swing across the area and into MI through the day.
1108 AM EST Thu Feb 18 2021 Temperatures have risen to near 80 degrees this morning, with dewpoints in the lower to mid 70s. Temperatures are expected to reach the lower to mid 80s this afternoon. The main weather story for this weekend remains a strong cold front moving through the area tomorrow night, which will bring a quick shift in wind direction to the northwest to north as well as a sharp increase in winds. Drier and cooler conditions will follow the frontal passage.
Observations and reports continue to confirm the returns as snow even as soundings continue to lean towards freezing drizzle along and southeast of a line from Bowling Green to Cincinnati. High pressure builds across the CWA from the west. Partly sunny skies will result, but won't be able to lift temperatures above freezing. The low-level thermal trof will afford us one more cold night on Fri night.
The highest terrain of the Park Range generally east and north of Steamboat Springs are likely to see a few a quick few inches of new snowfall on Friday.
This will result in refreezing of any water left on the roadways making for hazardous travel conditions and the hard to see black ice. Although much cooler than normal temperatures will continue, afternoon highs will reach into the mid 40s southeast and perhaps top out near freezing for the first time in days across portions of our delta region.
The cooler model blend is probably a better approach to the temperature forecast because of existing snow cover and the fact that the snowpack will have to warm up.
No major changes were needed for the late eve update as areas of light snow will linger tonight with the encroachment of the cold longwave trough. The Advisory was maintained for the ridges of WV as per additional accumulation potential, albeit light, in addition to the potential for some freezing drizzle given ongoing ascent and low level saturation. Warm advection on the van of the approaching trough will moderate temperature back to the seasonal averages.
219 PM MST Thu Feb 18 2021 WV imagery this aftn shows broad troughing over much of the cntrl CONUS, with an associated polar jet as far south as the Gulf Coast.
The longwave trough axis continued to push east across the Central Plains with rising mid level heights to our west across the Rockies. This will yield a continued warming of the lower-mid troposphere, and this will end up resulting in temperatures on Friday above 32F, commencing the thaw.
657 PM EST Thu Feb 18 2021 A low pressure system over northern Florida/Southern Georgia will track northeast towards the South Carolina coast overnight. High pressure will build over the region late Friday through the weekend providing fair weather.
This band of light snow will gradually push east this evening before fading away as an area of freezing drizzle as temperatures drop back below freezing tonight. Given the potential for freezing drizzle and the ongoing snow, opted to hang onto the advisory as is with no changes.
The heaviest snowfall with this system is expected through the higher terrain of central Idaho, where 5 to 10 inches of snowfall is possible through the day Friday.
Temperatures tomorrow are forecast to be a couple degrees warmer than today, and based on today's warmup this seems reasonable. If it not for increasing midlevel and high clouds, I think most of the area would have a good chance to rise near or above freezing.
Expect warmer temperatures on Friday with less wind.
An area of low pressure will move off of the Mid-Atlantic coast this evening, dragging a strong cold front across the Keys overnight tomorrow.
423 PM MST Thu Feb 18 2021 WV imagery this aftn shows broad troughing over much of the cntrl CONUS, with an associated polar jet as far south as the Gulf Coast.
Most deterministic and ensemble data readily agrees on temps exceeding average values by late weekend, with a very good chance at pushing above the freezing mark by Mon. Low pressure will traverse the central Provinces of Canada, and another system affecting the Central Plains may just brush our extreme south Sat night/early Sun, however impacts appear inconsequential at this time. Low pressure system over the area bringing some VFR cigs around the area with areas of MVFR (2K to 3K) cigs.
However, a band of mid-level clouds looks to sweep across northeast Oklahoma and northwest Arkansas overnight which may keep temperatures a little warmer. A few places could drop to around 1/2 mile visibility which would result in freezing fog. However, confidence is not high enough at this time to add mention of freezing fog.
534 PM CST Thu Feb 18 2021 Overnight, high pressure currently over the central Plains will slowly drift to our southwest beneath northwest flow aloft. With weak winds on the northeast periphery of the high, mostly clear skies, and relatively fresh snow across the region, temperatures should get quite cold tonight and tomorrow morning.
757 PM EST Thu Feb 18 2021 The early evening regional radar mosaic is showing bands of showers and a few thunderstorms pushing southeast through the Apalachee Bay towards the Nature Coast ahead of the approaching cold front. This front and associated convection will continue to sweep southeast across the forecast area tonight through Friday, with breezy northwest winds bringing a cooler and drier air mass in behind the front. VFR conditions should hold through the early evening, then MVFR/IFR ceilings are expected to develop by around 08z ahead of the approaching cold front, with the highest chances around the Tampa Bay area.
Friday will be slightly warmer, but still well below normal with highs in the low to mid 20s. A broad upper level trough continues to influence our weather through the short term.
There is a Skies will clear midday tomorrow and highs near the hi-line south may even break above freezing which has not occurred since the third this month.
Warmer daytime temperatures are forecast for Friday.
504 PM EST Thu Feb 18 2021 Weak low pressure will pass by our south and east tonight, and our region will pick up some light accumulating snow and possibly some freezing drizzle.
/issued 210 PM CST Thu Feb 18 2021/ Upper trough swings across TX today and pushes off to the east.
534 PM CST Thu Feb 18 2021 High pressure now stretching out over the Plains will slide east into the region later tonight/Friday. Expect yet another sub-freezing day Friday despite an expected return to more sunshine at most locations as the high sets in overhead.
221 PM MST Thu Feb 18 2021 Through Friday night, mostly tranquil weather should prevail for the lower elevations of south central-southeast MT and north central WY. Downsloping flow during this time period should keep most of the lower elevations dry.
With drier air filtering into the region, clouds are expected to clear out early tonight which should allow temperatures drop into the lower to mid 20s. With temperatures dropping below freezing tonight, a freeze warning has been issued until tomorrow morning with the possibility of another warning needed for tomorrow night.
With good caa mixing in the low levels along with help from a vort lobe from the northwest, kept scattered flurries into the early evening. The issue again tonight will be the low temperatures. Otherwise, it looks like we will finally get a warmer southerly wind on Friday.
A possibility of fog in the west and relatively warmer temperatures tomorrow highlight the short term forecast. Warmer temperatures expected Friday with low level warm air advection gradually taking place.
VFR conditions look to prevail for the remaining TAF period with a clearing trend taking place on the backside of this low. The trough axis will be east of our CWA by the start of this period and precipitation will have moved off to the east. In the wake of this trough colder air will move in. High pressure will build over Texas Friday bringing dry weather. Skies will be mostly sunny and temperatures will climb above freezing. Low temperatures will be warmer than tonight, but still very cold ranging from the upper teens to near 30.
946 PM EST Thu Feb 18 2021 Steady snow will end tonight as low pressure moves east. Cold temperatures and snow flurries are expected Friday as high pressure advances from the southwest. Dry weather and gradually rising temperatures are forecast for the weekend as the high tracks across Kentucky and West Virginia. Flurries and freezing drizzle will still be possible through the overnight hours. High pressure in the southern Plains will begin to slowly move northeastward into the Midwest on Friday. Mid-level flow will gradually shift more towards the northwest with a s/wv trough propagating through. There does appear to be a trend towards slightly warmer temps compared to what has been previously shown - mainly due to greater cloud coverage lingering across the fa.
Then, shower chances increasing after midnight along and north of the I-4 corridor, as a cold front approaches the area from the northwest. (previous) A cold front begins moving through the FL peninsula late tonight, crossing Central FL during the day tomorrow. Extensive cloud cover will limit instability, and most of the high res models only show a broken line of storms moving through. Further south, with daytime heating through at least late morning expect highs to reach the low 80s from the Space Coast south. A cold front approaching central Florida will increase rain chances, beginning with KLEE, late tonight into early tomorrow morning. Then, a cold front will approach east central Florida late tonight into early Friday morning, increasing shower and storm chances after sunrise.
Friday will be a tad warmer but still stuck in the mid 20s. A broad upper level trough continues to influence our weather through the short term.
Some flurries or light snow will be possible at the Amarillo TAF site between about 05Z and 16Z Friday and patchy freezing fog at both the Amarillo and Dalhart TAF sites through around 14Z to 16Z Friday.
637 PM CST Thu Feb 18 2021 Latest hourly temperatures showing areas both east and west of the valley as the coldest areas despite the cloud cover, with warmer temperatures in the valley highlighted on 3. Most deterministic and ensemble data readily agrees on temps exceeding average values by late weekend, with a very good chance at pushing above the freezing mark by Mon. Low pressure will traverse the central Provinces of Canada, and another system affecting the Central Plains may just brush our extreme south Sat night/early Sun, however impacts appear inconsequential at this time. Low pressure system over the area bringing some VFR cigs around the area with areas of MVFR (2K to 3K) cigs.
Flurries and some patchy very light freezing drizzle can't be entirely ruled out through midnight, but advisory-level impacts are not expected. Observations and reports continue to confirm the returns as snow even as soundings continue to lean towards freezing drizzle along and southeast of a line from Bowling Green to Cincinnati. High pressure builds across the CWA from the west. Partly sunny skies will result, but won't be able to lift temperatures above freezing. The low-level thermal trof will afford us one more cold night on Fri night.
211 PM MST Thu Feb 18 2021 Scattered flurries across northern areas associated with a weak disturbance embedded in the complex upper trough over the central plains will dissipate early as the trough begins to move away from the area tonight. Upper ridge will build in from the west on Friday but flatten into more of a northwest flow by late in the day. However, it will allow temperatures to warm above freezing in most locations, with the possible exception of lower elevations along the Republican in southwest Nebraska, including McCook.
637 PM EST Thu Feb 18 2021 Weak low pressure will pass by our south and east tonight, and our region will pick up some light accumulating snow and possibly some freezing drizzle.
431 PM MST Thu Feb 18 2021 Scattered flurries across northern areas associated with a weak disturbance embedded in the complex upper trough over the central plains will dissipate early as the trough begins to move away from the area tonight. Upper ridge will build in from the west on Friday but flatten into more of a northwest flow by late in the day. However, it will allow temperatures to warm above freezing in most locations, with the possible exception of lower elevations along the Republican in southwest Nebraska, including McCook.
858 PM EST Thu Feb 18 2021 A low pressure system over northern Florida/Southern Georgia will track northeast towards the South Carolina coast overnight. High pressure will build over the region late Friday through the weekend providing fair weather.
Will continue to mention possiblity of isolated snow showers and freezing drizzle across locations just west of and across Cumberland Plateau Region. Will continue to also mention patchy freezing fog formation after midnight.
Additionally, some areas may see some freezing fog, as T/Td's may support fog development. While this freezing fog is not a surefire thing, I felt the need to include it in the short-term given current travel conditions. These freezing fog chances will spill over into tonight, where I have once again introduced them area- wide. While temperatures today won't get too toasty, they will get above freezing, with some of our southern zones pushing 40 degrees.
Meanwhile, satellite shows cloudy to mostly cloudy skies across the region, with snow producing mid and high clouds above the low stratus clouds. This snow is associated with an upper level trough which is currently moving across the region. A Winter Weather Advisory continues for Irion County and the I-10 corridor and by early this evening, the trough axis will be east of our region, with any lingering snow showers across Kimble/Sutton counties dissipating by mid evening. This, in addition to sunny skies and warming at 850 mb, will help bring warmer temperatures Friday, with highs in the mid to upper 40s.
Models indicating some decent height rises/ridge building in the mid- levels Friday night into Saturday for a dry period with warming temperatures.
Freezing fog is also expected to reduce visibilities at both the Amarillo and Dalhart TAF sites to around or less than one mile between about 10Z and 16Z Friday. Some flurries or light snow will be possible at the Amarillo TAF site between about 05Z and 16Z Friday and patchy freezing fog at both the Amarillo and Dalhart TAF sites through around 14Z to 16Z Friday. Today's high temperatures will continue to be below freezing, with 20s expected region wide. Another round of freezing fog, favoring the western Panhandles, is expected overnight tonight under fairly light winds. On Friday, skies should clear out completely as ridging aloft moves into the region. Have opted to go with the lowest guidance, especially along the I-40 corridor, in order to account for the melting snowpack regions.