Aikyam-Lab/Synoptic-Bench huggingface dataset:
616 PM CST Fri Jan 1 2021 (Issued 424 PM CST Fri Jan 1 2021) Tonight and Saturday: A mix of snow, sleet, and freezing rain spread across far southern and southeast WI early this afternoon as low pressure tracks across IL. The warm nose responsible for the mixed precip will exit to the southeast as the low pushes into IN/MI, so any mixed precip will change to all snow early this evening. Most spots will slowly fall into the teens, with some warmer readings near Lake MI.
Sfc analysis indicates that the cold front is pushing across the Plateau at this time. Gusty WSW winds will decrease this evening as a low pressure system moves away from the area.
510 PM MST Fri Jan 1 2021 Afternoon GOES WV/IR imagery showed two upper lows, one over northern Mexico, and the second over eastern MO/western IL. The Midwest upper low continued to produce a wide swath of snow/ice. A large scale ridge was situated over the Intermountain West. The low/mid level gradients were more relaxed compared to 24 hours ago. Therefore, the High Wind Watch was upgraded to a Warning.
High pressure spreads across the area this weekend bringing dry conditions, occcasional clouds, light winds, and a warming trend.
309 PM CST Fri Jan 1 2021 A very amplified pattern continues to reside across North America at this time, highlighted by ridging on both coasts, and an anomalous trough over the central US. Within that trough, one winter storm system is departing the Central Plains, with another upper low spinning over northern Mexico. That second upper low will briefly open up and lift NE into the Southern Plains, before beginning to deepen again as it approaches the Mid MS Valley. Upper level forcing in conjunction with moisture transport in the lower levels of the atmosphere will, given this comes to fruition, bring another round of precipitation. Low clouds are quickly clearing on the backside of the precipitation shield, and my TAFs may be a bit pessimistic (holding onto the low clouds too long).
A few transient showers are possible early this afternoon as a weak cold front pushes through the area, more defined by lower dew points than cooler temperatures.
526 PM CST Fri Jan 1 2021 (This evening through Saturday) The departing midlevel trough is accelerating through Missouri as it becomes less anomalous. The digging closed mid-upper low over northern Mexico that has complicated the synoptic pattern the last couple days is clearly in a drier environment with absence of well-developed cloud structure.
430 PM MST Fri Jan 1 2021 Latest analysis shows a SW-NE oriented upper ridge over the region this afternoon with an upper trough along the PAC NW coast. The resulting surface pressure gradient will lead to windy southwesterly winds tonight, mainly over parts of northeastern Wyoming and the higher elevations of the Black Hills, possibly downsloping into the northern foothills zones tonight. A cold front will cross the area on Saturday afternoon/evening.
The upper low responsible for today's Winter Storm continues to gradually weaken as the axis lifts through Missouri this afternoon. Deformation band on the northwest quadrant of the low continues to show signs of weakening as the snow intensity has decreased within the past hour. Secondary closed upper low follows a similar track through Missouri during the afternoon Saturday, with the exception of much less associated moisture. Deterministic and a handful of short term models exhibit some weak lift in the low levels so have inserted flurries south of I-35 during the afternoon. Weak CAA and mostly cloudy skies may allow for snow to stick around one final day with highs peaking in the lower 30s. Central Kansas should begin to see improvement in highs, averaging in the low 40s.
Latest surface analysis places two areas of low pressure north of the Mid-South. Both areas of low pressure are expected to lift north away from the Mid-South over the next several hours, with winds relaxing by this evening. A cold front currently extends southward through Centerville, Tennessee from the latter low pressure system.
Upper-level ridging is forecast to move toward the central U.
612 PM EST Fri Jan 1 2021 A wintry mix of light freezing rain, rain, and snow is expected into this evening, especially across far northern Indiana and Michigan were additional ice and snow accumulations are possible.
Main forecast challenge in the short term lies with another upper level low pressure system that will be ejecting northeast from TX/OK area on Saturday. Thermal profiles do hint at the possibility of a touch of light snow over portions of sw IL/se MO, closer to the upper low, with possibly light rain or rain/snow mix farther southeast.
This is occurring as the mid level closed low has now shifted east of the forecast area. This evening the closed low will accelerate off to the east into the southern Great Lakes with precipitation coming to an end. Tomorrow another upper level low will develop in the base of a broader trough over the central CONUS with a enhanced upper level jet out ahead of it.
226 PM MST Fri Jan 1 2021 Latest analysis shows a SW-NE oriented upper ridge over the region this afternoon with an upper trough along the PAC NW coast. The resulting surface pressure gradient will lead to windy southwesterly winds tonight, mainly over parts of northeastern Wyoming and the higher elevations of the Black Hills, possibly downsloping into the northern foothills zones tonight. A cold front will cross the area on Saturday afternoon/evening.
/28/ Tonight and Saturday: Mid afternoon satellite imagery/RAP analysis had a closed low spinning over the mid Mississippi valley with a second closed low spinning over the northern portions of old Mexico. The low pressure system to our north will continue tracking northeast across the lower Great Lakes region tonight and then the New England states Saturday. The closed low over old Mexico will track northeast across Texas tonight and over the mid Mississippi valley by Saturday evening. The cloud cover will help hold temperatures warmer than normal again tonight with morning lows in the upper 30s to lower 40s. Saturday beneath cloudy skies temperatures will be held slightly cooler than normal with the exception of the southeast that should make it into the upper 50s which is near normal there.
Issued by National Weather Service Green Bay WI 426 PM CST Fri Jan 1 2021 (Issued 424 PM CST Fri Jan 1 2021) Tonight and Saturday: A mix of snow, sleet, and freezing rain spread across far southern and southeast WI early this afternoon as low pressure tracks across IL. The warm nose responsible for the mixed precip will exit to the southeast as the low pushes into IN/MI, so any mixed precip will change to all snow early this evening. Most spots will slowly fall into the teens, with some warmer readings near Lake MI.
604 PM CST Fri Jan 1 2021 Low pressure system tracking northeast across IL this afternoon will continue to bring some light snow to far southern portions of the forecast area.
Muggy evening as temps hover in the lower 70s before dropping into the mid to upper 60s overnight. Mostly dry conditions as clouds build in across the I-4 Corridor ahead of an approaching cold front. Ahead of an approaching, but weakening, cold front there is the possibility of patchy, shallow ground fog developing near LEE near sunrise Saturday.
Depending on timing as well as how fast surface temperatures warm, there may be a small window for light freezing rain with the potent warm nose depicted on forecast soundings.
1102 PM CST Fri Jan 1 2021 Low MVFR ceilings are expected to remain in place over all area TAF sites through early Friday morning, and ceilings are expected to lower a bit as we head towards sunrise and an upper level trough spreads some lift over the state. If any fog is able to develop near the northern TAF sites near sunrise, freezing fog could create slick runway surfaces as well as reduced visibilities. Temperatures are expected to drop below freezing in these areas overnight, so freezing fog is a potential if visibilities drop low enough. Winds will shift from the southwest to the northwest overnight as a weak cold front moves across the state.
High pressure spreads across the area this weekend bringing dry conditions, occasional clouds, light winds, and a warming trend.
Surface analysis shows low pressure centered over northern Ohio, with a cold front extending southward from the low through the Ohio Valley and the Southeastern states. The Keys lie within a slowly weakening pressure gradient between this low/front and high pressure over the western Atlantic. Aloft, water vapor imagery depicts strong deep layered ridging holding firm over the Bahamas, South Florida and the Keys, and the SW Atlantic, while a mid latitude trough slides eastward across the Great Lakes. The 00Z Key West sounding found multiple inversions in the lower and mid levels, and a rather dry profile overall, with slightly below normal PW of 1. Evening observations from along the reef show SE winds running 17 to 23 knots, while winds at Smith Shoal Light in the cooler Gulf waters have remained generally less than 15 knots.
1256 AM EST Sat Jan 2 2021 Low pressure and a cold front will track east tonight, allowing drier air to work in briefly on Saturday.
347 AM EST Sat Jan 2 2021 Gusty showers are expected with cold frontal passage this morning. Building high pressure will then yield quiet, dry weather. Frontal passage should end most rain, though isolated light showers may linger through dawn for lower elevations -- through late morning for the ridges. Dry weather will be maintained through most of tonight, but will see the approach of an upper level low which will bring out next bout of precipitation and possible wintry weather.
1049 PM CST Fri Jan 1 2021 (This evening through Saturday) The departing midlevel trough is accelerating through Missouri as it becomes less anomalous. The digging closed mid-upper low over northern Mexico that has complicated the synoptic pattern the last couple days is clearly in a drier environment with absence of well-developed cloud structure.
249 AM CST Sat Jan 2 2021 Overnight water vapor imagery detects a upper cyclone across northwestern TX, which is forecast to deepen some as it lifts across the forecast area today. SREF plumes suggests mainly a dusting to a few tenths of an inch of snow, especially in the higher terrain of northwest AR.
An upper level trof is currently moving across the Central/Southern Plains. Light southerly winds will eventually develop later today as weak lee troughing resumes.
344 AM EST Sat Jan 2 2021 Latest surface analysis shows warm front stalled across portions of north and central Georgia from just south of Atlanta to near Augusta. Models are showing this warm front slowly lifting northward through midday as a strong upper level low lifts from the southern Plains into the Ohio Valley by this afternoon. This will push a cold front through the area by tomorrow morning.
258 AM EST Sat Jan 2 2021 A wintry mix of light freezing drizzle, rain, and snow is expected into this evening, especially across far northern Indiana and Michigan where additional ice and snow accumulations are possible.
1011 PM CST Fri Jan 1 2021 Low pressure system tracking northeast across IL this afternoon will continue to bring some light snow to far southern portions of the forecast area.
The low-level jet is weakening across the southern Appalachians. A cold front is currently located west of the TN Valley, and will be moving through the area overnight. DGS Chattanooga Airport, TN 46 59 42 49 32 / 10 20 40 0 0 Knoxville McGhee Tyson Airport, TN 47 56 42 48 33 / 10 10 50 10 0 Oak Ridge, TN 45 55 42 48 31 / 20 10 50 10 0 Tri Cities Airport, TN 41 56 40 48 33 / 20 10 60 20 10.
1128 PM CST Fri Jan 1 2021 A very amplified pattern continues to reside across North America at this time, highlighted by ridging on both coasts, and an anomalous trough over the central US. Within that trough, one winter storm system is departing the Central Plains, with another upper low spinning over northern Mexico. That second upper low will briefly open up and lift NE into the Southern Plains, before beginning to deepen again as it approaches the Mid MS Valley. Upper level forcing in conjunction with moisture transport in the lower levels of the atmosphere will, given this comes to fruition, bring another round of precipitation.
Though if stratus fails to clear, temperatures may be a bit cooler under the cloud cover. Areas near the highest terrain of the Buffalo Ridge could see enough mixing overnight to hinder dense fog.
Tonight a compact upper low will deepen slightly as it advances from Missouri to Indiana. Road temperatures and air temperatures are expected to remain above freezing and precipitation amounts should be light, so little if any impact is expected at this time.
A weak upper level trough is approaching from the west this evening which will spread light snow showers across the region early Saturday. Models remain consistent on QPF and snow amounts with a dusting in the lower valleys up to 1-3 inches in the mountains. The main trough passage will occur between 3 AM MST and 9 AM MST on Saturday.
321 AM EST Sat Jan 2 2021 Southerly boundary layer flow over the eastern Gulf of Mexico is creating favorable conditions for sea fog to form over the coastal waters today and tonight as warm moist air is advected over the relatively cooler shelf waters. but again the confidence of this part of the forecast is on the low side. A strong U/L disturbance is located over the southern plains with a subtropical ridge centered over the Bahamas and Florida peninsula. The U/L low and associated S/W trough will rotate across the Lower Mississippi Valley today and will lift toward the Ohio River Valley tonight.
Temperatures are already in the low 40s, and once the clouds move in temperatures won't drop much more, so lows will only get down to around 40 degrees.
The surface pattern was generally defined by weak high pressure centered over eastern CO and extending south through west TX where on off shore wind prevented any meaningful moisture return. For today models show some modest vertical motions clipping parts of east central KS as the upper low swings out over the Ozarks. This combined with snow on the ground along and east of the turnpike, highs are forecast to remain in the lower to mid 30s. The lack of snow across the western counties and some filtered sunshine is expected to allow temps to warm into the lower 40s.
1015 PM MST Fri Jan 1 2021 Latest analysis shows a SW-NE oriented upper ridge over the region this afternoon with an upper trough along the PAC NW coast. The resulting surface pressure gradient will lead to windy southwesterly winds tonight, mainly over parts of northeastern Wyoming and the higher elevations of the Black Hills, possibly downsloping into the northern foothills zones tonight. A cold front will cross the area on Saturday afternoon/evening.
While all the snow should be done by midnight, light freezing fog and drizzle are possible with observations well off the west suggesting these conditions may stick around to sunrise. Stumpf (Issued 424 PM CST Fri Jan 1 2021) Tonight and Saturday: A mix of snow, sleet, and freezing rain spread across far southern and southeast WI early this afternoon as low pressure tracks across IL. The warm nose responsible for the mixed precip will exit to the southeast as the low pushes into IN/MI, so any mixed precip will change to all snow early this evening. Most spots will slowly fall into the teens, with some warmer readings near Lake MI.
1253 AM EST Sat Jan 2 2021 A wintry mix of light freezing drizzle, rain, and snow is expected into this evening, especially across far northern Indiana and Michigan where additional ice and snow accumulations are possible.
1141 PM CST Fri Jan 1 2021 Upper trough will move through the local area accompanied by passing clouds. Should note that MVFR ceilings could very well spoil the forecast as the upper trough moves through between 12z and 18z, however. After 18z, trough axis shoves remaining low level moisture east of the local area and VFR conditions should prevail through the remainder of the period. occluding low pressure has a center near Evansville Indiana with the upper low in southeast Missouri. The next in a parade of upper lows was over northern Mexico, with another approaching the Pacific Northwest coastline. Dew points range from the lower 40s northwest to mid 50s over lower Plaquemines Parish.
1018 PM MST Fri Jan 1 2021 Skies were sunny or mostly sunny across much of the region early this afternoon as a positive tilt mid-level ridge moved over the northwest portion of the forecast area. Instability and residual moisture combined with weak lift associated with this disturbance appeared to be generating isolated light snow showers over the higher peaks of the San Juan Mountains according to cooling tops in infrared satellite imagery. In the wake of the trough showers are expected to diminish during the overnight hours.
Sfc analysis indicates that the cold front is pushing across the Plateau at this time.
346 AM EST Sat Jan 2 2021 High pressure will begin to build in from the west as a trough lingers across the area through today.
226 AM CST Sat Jan 2 2021 The axis of the upper low is currently over the West Texas region and will push east of the region by sunrise. The sunny skies and westerly winds will warm highs into the low/upper 50s with lows dipping into the low/upper 20s.
This speed variation is due to both the proximity of the ridge and cooler gulf and bay side waters. Fairly sharp ridging reaches northwards out of the Caribbean Sea to past the Bahamas, while the Keys reside on the western periphery of the lower to mid level ridge. Forecast - The ridge across Florida will sag southwards over the next couple of days as a couple of low pressure system train northeastward through the eastern United States. The relaxing flow and continued dominance of deep layered ridging will keep rain chances slight or less. A prefrontal trough associated with the second of the migratory lows will dig southwards into Florida, but not quite reach the Keys.
235 AM MST Sat Jan 2 2021 09z surface analysis had low over central AB with trough into eastern WY. 2-3mb/3hr pressure falls along trough supporting increasing southwest winds over part of northeast WY. Today/tonight, upper trough zips across the northern Rockies into the northern Plains. Temperatures will be similar to yesterday, but perhaps a bit warmer over areas that lose their snowcover.
544 AM CST Sat Jan 2 2021 H5 analysis tonight had high pressure anchored over the western Caribbean. Ridging extended northeast of the high into Bermuda. West of the high, a trough of low pressure extended from the western Great Lakes, southwest into northern portions of Mexico. Within this trough, a tandem of closed lows were present. West of the trough, a ridge extended from central California, northeast into Montana and western North Dakota. At the surface tonight, high pressure was the dominant weather feature across the central Rockies and high plains. H85 temps along and east of the trough are running 1-1. 5 degrees C warmer than yesterday's temps. This yielded highs generally in the lower 40s.
554 AM CST Sat Jan 2 2021 (Today and tonight) Mid and high level clouds cover all but southwest sections of the forecast area early this morning, and is associated with a short wave trough moving across the area.
Areas of freezing fog are possible, which may lead to some slick spots on area roadways. The pattern of quiet weather continues today as a weak ridge moves over the CWA.
Morning lows should remain above freezing area wide, generally in the mid to upper 30s.
Otherwise temperatures should be a shade warmer today and tomorrow though still follow the trend of cooler over snowcover and eastern areas and warmer across the south/west.
Temps are expected to climb into the low to mid 30s along and west of the valley where more clearing is expected. Temps Sunday have the potential to be warmer than today with more sun and most areas in the 30s with a possible 40 in Devils Lake basin with the west or southwesterly surface flow.
406 AM EST Sat Jan 2 2021 Mixed precipitation to end by mid morning, then weak high pressure builds in with dry weather for this afternoon and tonight. Sites reporting a mixture of snow/freezing rain and rain across NE. Next southern stream upper low lifts into the eastern Great Lakes Sunday. The higher moisture with this system will be directed to the east coast, however there will still be some upper level ascent tied to the mid level circulation that will affect much of western New York. Snow accumulations of 1 to 3 inches are expected, mainly over the higher terrain with any ice accumulation only of a few hundredths. Lingering snow showers will be possible Sunday night as the area of low pressure and trough continue to slowly track east, but dry slotting should decrease shower coverage through the night.
(Today and tonight) Mid and high level clouds cover all but southwest sections of the forecast area early this morning, and is associated with a short wave trough moving across the area.
606 AM CST Sat Jan 2 2021 Widespread, dense freezing fog developed over a large chunk of central and southern Minnesota yesterday evening. The southwestern flank of the fog bank is eroding along the MN River, but this is likely due to downslope from the Buffalo Ridge and is probably not going to clear much beyond the river until later this morning. Kept some patchy/areas of freezing fog in the grids through Sunday morning in these areas, but for now will let the Dense Fog Advisory go until 10 AM due to low confidence the fog will be dense beyond that.
Light precipitation is expected to develop over southern Missouri and spread to the northeast through the afternoon as the low deepens. Thermal profiles on the latest short range guidance are not a straight forward as on earlier runs, and there is the potential for light drizzle/freezing drizzle mixed in with light snow at times. and temperatures will likely be within a degree or two one way or another of freezing, so some of that drizzle will likely not freeze. Expect that much of the drizzle will transition to light snow by early evening as the low continues to deepen and temperatures within the core of the system drop. Snow accumulations from a dusting up to about 1 inch are possible, with the higher end of those amounts from east central Missouri into south central Illinois along the low track.
225 AM MST Sat Jan 2 2021 Slightly warmer temperatures are expected through the period as some weak/broad upper ridging moves our way from the west.
There is a very low potential for a rain/freezing rain/snow shower in the Turner area this morning. Confidence seems low at this time for any freezing rain as warmer air moves slowly into that region.
Snow accumulations across the eastern Permian Basin and higher terrain south of I-10 will keep temperatures cooler today with highs only reaching the 40s. Areas without snow accumulations will be slightly warmer in the 50s. A trough situated over West Texas will sweep through today, although no moisture will be available and we will remain dry. Mostly sunny skies this afternoon will help to melt off much of the lingering snowpack, although whatever remains will refreeze Saturday night when temperatures once again drop below freezing. Warmer and dry conditions are expected for Sunday and beyond.
/issued 226 AM CST Sat Jan 2 2021/ The axis of the upper low is currently over the West Texas region and will push east of the region by sunrise. The sunny skies and westerly winds will warm highs into the low/upper 50s with lows dipping into the low/upper 20s.