Aikyam-Lab/Synoptic-Bench huggingface dataset:
346 AM EST Tue Dec 1 2020 A lingering low pressure system will keep snow showers in the region today through early Wednesday morning. Drier weather returns Wednesday afternoon under building high pressure. With cold, moist air advancing into the Ohio River Valley from a lingering low pressure system centered in western NY, widespread snow showers are occurring across the region. Expect an additional 1-2 inches just before dawn across the region; 2-4 inches in the ridges. As the upper-level trough remains nearly stationary over Lake Ontario, steady snow showers will prevail throughout the day. Snow showers will continue, mainly north of Pittsburgh and in the ridges, late tonight through early Wednesday afternoon due to lake enhancement/upsloping. For areas in eastern Ohio and northern West Virgina, precip will likely wrap up early Wednesday morning as high pressure builds to our southwest.
A closed upper level low, easily seen on Infrared (IR) satellite imagery, rotates overhead central Montana. A North Pacific Trough trough passes quickly across The Treasure State. A tight height gradient favors strong gusty west-southwesterly winds ahead of the trough. As the trough exits rapidly to the southeast, accumulating snow ends across the region around noon, with some lingering snowfall continuing over The Little Belt Mountains and some of the mountains of the southwest into the afternoon hours.
222 AM CST Tue Dec 1 2020 06Z surface data has high pressure from Lake Superior south to the Gulf Coast while a storm system was organizing in western South Dakota. Quiet and dry conditions will be seen with moderating temperatures as high pressure moves into the Ohio Valley.
Although there is a lot of local-scale variability in the current temperatures, overall temperatures are a but cooler than forecast.
/issued 316 PM CST Mon Nov 30 2020/ A potent upper-level trough brought occasional flurries to the Mid-South but will continue to pull off to the east overnight. Nonetheless, we'll see a fair amount of isentropic ascent across the Mid-South as a strong, southerly low-level jet develops and advects Gulf moisture poleward over the cooler, surface air mass.
Clouds covered most of IL while high pressure building in from the west was providing sunny skies over most of Iowa west of a line from Dubuque to Fairfield. High pressure building over the area will result in light northwest winds and clear skies overnight and through the day Tuesday. Tuesday night through Wednesday: The surface and upper level ridge overhead Tuesday night will provide mostly clear skies and light winds, allowing temperatures to cool into the teens in the dry airmass. High, thin clouds will likely be on the increase Wednesday with continued light and variable winds to limit highs to the lower 40s at best.
141 AM MST Tue Dec 1 2020 An upper trough is moving through the forecast area this morning with a cold front. The system will bring a chance of light snow with a possibility of a mix with light rain or light freezing rain to parts of NE Montana this morning. An upper low drifts south along the MT/Dakota border tonight which will give the east a chance of light snow.
RH will improve later in the night, particularly after the cold frontal passage around midnight.
Boxell (Issued 200 PM CST Mon Nov 30 2020) Tonight through Tuesday night: Combo of low level thermal trough and broadly cyclonic flow keeping cloud cover in place. Surface and mid level ridging tries to gradually work in here through Tuesday night but suggestion in progs is that it makes only our western cwa by later Tuesday night.
Lows will drop into the low to mid 20s by morning with widespread frost. Beneath a dynamic upper-level low pressure system, enough lift in the cooling lower layers is just enough for some light precip (in this case flurries) to be generated. As we approach the weekend, forecast confidence drops some concerning a weakening trough that is expected to push east across the MS Valley region.
System currently moving through the Northern Rockies will be dropping southeast and slowing up dramatically as mid-level ridge pumps up over the west coast. Meanwhile, a slow moving sfc cold front will edge east over the state today.
335 AM EST Tue Dec 1 2020 An upper level low pressure will pull NE from the central Appalachians to New England through tonight. Cold high pressure will build into central NC today through mid-week. Another low pressure may affect the region again by late week. The mid/upper level low pressure over WVA this morning will lift out to the NE and over New England today and tonight. All the "weather" associated with the mid/upper low will essentially be along and NW of the spine of the Appalachians, where upslope snow and snow showers will continue today. Still, lows in the mid 20s west to lower 30s SE Coastal Plain are expected, but it could end up on the higher end of guidance given the continued mixing.
As the upper trough pivots across the region late this evening, deep lifting for precipitation production will advect east/northeast, leaving only orographically forced precipitation behind. As for the high terrain, still awaiting those reports which likely won't come until the morning with the Mt Leconte and Newfound Gap observations. However, given persistent returns on radar, would expect significant accumulations across the higher elevations. Chattanooga Airport, TN 42 25 51 30 50 / 10 0 0 10 20 Knoxville McGhee Tyson Airport, TN 38 23 49 27 49 / 10 0 0 0 20 Oak Ridge, TN 38 23 49 27 48 / 10 0 0 0 20 Tri Cities Airport, TN 33 19 45 24 51 / 20 0 0 0 10 NC.
1-3 inches for the northern and central mountains, with up to 4 inches at the highest elevations, and less than an inch in the mountain valleys. A north to south oriented jet stream will support another trough/cold front at the surface that will move through the CWA Wednesday afternoon and evening. As the jet drops down, it will carve out an area of low pressure and even though instability and plenty of lift exists.
A cold front will moving into the area near the end of the forecast period, w/fropa at KHOB ~ 03Z, and KMAF/KINK around 05Z. Low dwpnts in the single digits and mostly clear skies will favor below normal temps Tue AM, freezing temps in most areas. Assocd surface winds will be a little on the breezy side at times during the day, but will increase in the evening with the passage of the cold front, initially 20-30 mph post-frontal across the plains. Cold wx will hold into Fri, but a few degrees warmer than Thur. Models struggle to resolve the mid/upper level low, but it should be a little warmer Sat/Sun. Precip is possible Mon AM when the ECMWF lifts out the mid/upper low.
The axis of an amplified longwave trough in the mid/upper troposphere will continue to shift slowly eastward and away from the TN Valley overnight. High pressure will move into the region on Tuesday, with dry conditions and a clear sky expected. Expect perhaps the coldest night of the early winter so far with lows bottoming out in the lower 20s to perhaps even upper Teens in a few spots. We'll start to see some air mass modification on Wednesday as the high shifts east and winds veer back to the south.
Temperatures will gradually warm today and tomorrow as ridging builds over the area. The ridge will be sandwiched between two low pressure systems. The ridging will allow for moisture advection into the area which should lead to about a 10 degree increase in dewpoint temperatures going into Wednesday.
Lows tonight are still forecast to range from 25-30 across most locations, especially along and north of Interstate 10, and in the lower 30s along the immediate coast. The only places that may stay above freezing are along the barrier islands, where winds remain slightly elevated (10 to 15 mph with occasional higher gusts). Mid level cold air advection will continue in the northwesterly flow in the wake of the trough moving off to the east of our area, so continued cool on Tuesday with highs remaining well below normal, generally topping out in the low to mid 50s across the entire region.
936 PM CST Mon Nov 30 2020 The axis of an amplified longwave trough in the mid/upper troposphere will continue to shift slowly eastward and away from the TN Valley overnight. High pressure will move into the region on Tuesday, with dry conditions and a clear sky expected. Expect perhaps the coldest night of the early winter so far with lows bottoming out in the lower 20s to perhaps even upper Teens in a few spots. We'll start to see some air mass modification on Wednesday as the high shifts east and winds veer back to the south.
Strong high pressure is expected for the remainder of the week and into the weekend bringing a prolonged period of dry, stable, and seasonably cool conditions.
There is abundant sunshine across the area in the wake of the upper low, but still cold temperatures with readings only in the mid 30s to low 40s early this afternoon. We have readings dipping down into the teens over a part of south central and central MO and into the low to mid 20s elsewhere. Some upper ridging builds into the area on Tuesday and should see low level winds become more southerly as well. On Wednesday night, the low becomes pretty vertically stacked and colder air aloft will begin to seep into the area. Nighttime lows on Wednesday night look to be near the freezing mark.
In highly amplified flow between the west coast and Mississippi Valley ridges, this trough and associated closed low will translate into northeastern Colorado around midnight with the trough and low rotating southeastward toward northwestern Oklahoma by sunrise Wednesday. A slight chance for snow was introduced after 09Z Wednesday in northwestern Oklahoma for the increased influence of the low. In the opposite corner of the state, a warm front will be crossing the Red River and will increase the chance for rain showers there by sunrise.
Through today, the region will be in between two low pressure systems. Sandwiched between these two systems, upper-level ridging over the area today will result in the quiet and dry weather conditions to continue. Near seasonable to slightly warmer than average temperatures continue through the week and into the new week with minor variations from day-to-day.
258 AM CST Tue Dec 1 2020 Cold temperatures are in store for this morning clear skies and high pressure overhead allow lows to dip into the teens over central and south central Missouri while the remainder of the area bottoms out in the low to mid 20s. Some small-scale upper-level ridging moves overhead today, with surface winds shifting to southerly. Given above freezing surface temperatures and model thermal profiles during the daylight/early evening hours, we expect precipitation to remain as all rain during this time frame.
1033 PM CST Mon Nov 30 2020 Currently, an upper-level trough is digging across the eastern United States with the Middle Mississippi Valley on its western periphery and under northwest flow. Low-level northwesterly flow has advected a notably cooler airmass into the CWA, as current temperatures in the mid-30s are as warm as we're going to get. Under these clear, calm skies, temperatures will drop into the low-20s to upper-teens for overnight lows - some of the coldest air the CWA has seen so far this season. For Tuesday, the Middle Mississippi Valley will be between systems - the previously mentioned trough to the east and another trough digging into the Great Plains. During this period, a weak ridge will build over the CWA and dry low-levels will keep skies mostly clear.
Most of these will move off to the east as the low level winds become off shore through the day. The rest of the period will remain dry for most areas with northerly flow aloft due to an upper ridge over the west. A plume of MVFR stratus will move onshore along the North Shore as upslope flow circling around an area of high pressure over Isle Royale ushers the stratus in. A weak gradient today due to high pressure will keep winds below 15 knots.
1255 AM EST Tue Dec 1 2020 An upper level low pressure will pull NE from the central Appalachians to New England through tonight. Cold high pressure will build into central NC today through mid-week. Another low pressure may affect the region again by late week. The mid/upper level low pressure over WVA this morning will lift out to the NE and over New England today and tonight. All the "weather" associated with the mid/upper low will essentially be along and NW of the spine of the Appalachians, where upslope snow and snow showers will continue today. Still, lows in the mid 20s west to lower 30s SE Coastal Plain are expected, but it could end up on the higher end of guidance given the continued mixing.
High pressure will continue to dominate the Arkansas weather Tuesday and Tuesday night. Highs on Tuesday will be in the lower to mid 50s.
Huston A cold front is starting to move into the Central mountains currently and will slowly move through the area through early this evening. Around 9 pm to around 3 am cold air dropping down over the Montana Divide behind the cold front could trigger light snow, generally less than an inch, from Monida pass down to Idaho Falls and then down as far as Pocatello. Gusty winds are expected with the cold front passage especially for the I-86 corridor. High pressure builds back in across the area Tuesday and Wednesday.
246 AM EST Tue Dec 1 2020 Snows are tapering off this hour, as the core of a broad upper level low pressure system shifts east of our region. As a result, highs on the day will reach into the mid to upper 40s, which is still several degrees cooler than seasonal norms.
1242 AM EST Tue Dec 1 2020 A strong low pressure system will bring rain transitioning to accumulating today and into early Wednesday morning.
No change in the large scale pattern is expect today or tomorrow with an upper level ridge present over the Upper Midwest.
A large upper-level trough will continue east today while high pressure buildings into the Lower Mississippi Valley.
A cold front will then move through late this afternoon/early evening. /issued 307 AM CST Tue Dec 1 2020/ A sharp short wave trough will move across the Rockies today influencing our weather for today and tonight. A cold front will then push through late this afternoon into early evening. Breezy winds out of the north will accompany this cold front. The cold front will be south of the FA by tomorrow morning.
Lows will range from near freezing in the southwest to the mid 20s in the Golden Triangle. In general the forecast has not changed much, with the forecast revolving around two deep lows in the trough over the eastern half of the country. A deep narrow trough is rotating through the Southeast and moving into the northeastern US. Another wave drops into the broader synoptic troughing by tomorrow morning. That deepening and continuation of the troughing over the eastern half of the country will keep the cold air in place for the Gulf Coast states through the week.
Upper level trough remains over the state early this morning and areas of light snow will continue to affect central Montana through the morning. Models continue to indicate that the upper trough will evolve into a cutoff low that dives southward along the eastern slopes of the Rocky Mountains, leaving Montana on the leading edge of an upper level West Coast ridge.
Mid-level clouds will diminish by early this morning as the low pressure system continues moving northeastward. Models continue to develop an upper-level low in the Central Plains; with better agreement towards the ECMWF solution of having the low further west towards Oklahoma Wednesday night and a secondary closed low to the southwest in the Four Corners region.
Have decided to keep the winter storm warning intact given the development of light freezing rain showers mixed with snow as the cloud layers were mostly outside of the dendritic growth zone. Data from Indiana RWIS, road and traffic earlier showed much slower speeds where temps have fallen to freezing or below in the Westville to Wanatah area. It looks like the shallower tops have a rain/snow mix or just rain, but the precipitation was freezing rain away from Lake Michigan were at freezing or colder making for a snowy and icy setup this morning. High pressure building in will give way to clearing skies/VFR conditions by Tuesday evening, with W-NW wind gusts to 20-25kts or so.
Temperatures are starting out this morning very cold, as good radiational cooling has allowed overnight lows to drop into the mid 20s in the low lying areas and river valleys. The warmup will be short-lived, however, as another cold front will move in overnight, with breezy northwest winds and cooler temperatures for Wednesday.
As the upper disturbance moves south today, an associated cold front will push through central and southwest Kansas. Tonight, the lead disturbance deepens and closes off into an upper low over the Texas Panhandle. The upper low moves east out over Oklahoma during the afternoon hours with, snow will be increasing farther east toward south central Kansas.
A downstream blocking low and upstream amplifying ridge is forcing high latitude energy to carve down the spine of the Rockies and High Plains through the day. A trailing wave will be forced to retrograde to the West will dropping Southward by a strong amplification of the ridge into the N. Not much moisture to work with for this second wave but cold air aloft will help create potential instability aloft so showers will linger through Wednesday evening in the high country.
223 AM MST Tue Dec 1 2020 Currently, an upper level trough with associated cold front continue to push southeast through the state of Wyoming. The High Wind Warnings continue through 5 AM this morning, but are considering cancelling them early as 700mb flow has already reached its peak and will continue to trend downward with turning to out of the north over the next few hours. Heaviest snowfall is expected in the higher elevations of the Snowy and Sierra Madres where up to 6 inches is possible through the afternoon. Behind the deep diving upper level trough that will foster itself over the eastern two-thirds of the CONUS, a 500mb ridge will build in over the Pacific coast and northern Rockies extending towards the Canadian border.
Water vapor imagery indicated a trough moving through the northern Rockies. This through is forecast to eventually develop into a closed low across the central Rockies and then the southern Plains during the middle of the week.
North breezes and slightly lower temperatures will likely hold the second half of the week as the low pressure system circulates around the southwest states. Cooler air associated with it will be forthcoming for Wednesday in the form of cooler temperatures that are expected to be several degrees below normal. A second, more potent system will move out of Canada into the Northern Plains later today edging the first system eastward and driving a cold front south through Utah and Arizona tonight through Wednesday night.
The latest trends in model guidance regarding the mid week upper low are a bit warmer if anything and thus the winter weather potential appears less for eastern OK and western AR. As the upper low continues to dig south through the Rockies through tonight, moisture will begin to surge north in response, with rain expanding north into southern parts of the area late tonight and becoming fairly widespread across much of the forecast area Wednesday. Thermal profiles favor all rain during this time frame and all areas should see sfc temps above freezing prior to onset of precip.
06Z surface data has high pressure from Lake Superior south to the Gulf Coast while a storm system was organizing in western South Dakota. Quiet and dry conditions will be seen with moderating temperatures as high pressure moves into the Ohio Valley.
High pressure overhead providing clear skies and calm winds. /issued 328 AM CST Tue Dec 1 2020/ High pressure settling into the area this morning. Temperatures were in the low to mid 30s with the coldest spot. The trend for freezing conditions along and south of the I-10 corridor appears to be on track. Once we get past freezing conditions this morning.
216 AM PST Tue Dec 1 2020 Cooler, but seasonable temperatures persist today. Valley winds will be relatively light, while ridge winds will be quite breezy. Mixing and ventilation for the lower valleys will remain good today as north to east flow persists behind the dry cold frontal passage. The primary concern today and tonight will be the gusty, east ridge winds. The gusty, east ridge winds should begin to subside as high pressure strengthens again across the West on Wednesday. Other than a potential weakness in the ridge, there isn't really any chance for precipitation to speak of at the moment.
Most of these will move off to the east as the low level winds become off shore through the day. The rest of the period will remain dry for most areas with northerly flow aloft due to an upper ridge over the west. Highs will be High pressure will lead to VFR conditions for most areas through the period with sustained winds at or below 10 knots. A weak gradient today due to high pressure will keep winds below 15 knots.
The cold front which led to the rainy weather overnight has just about cleared the entirety of the island chain with rapidly clearing conditions on the Bay and Gulf side waters while cloudiness and patches of light rainfall continue to occupy much of the Florida Straits.
342 AM CST Tue Dec 1 2020 Another cold start to the day with temperatures near freezing across the area as a result from radiational cooling. This afternoon surface SW flow will transport warmer air into the area helping bring high temps into the 60s area wide and upper 70s for the Rio Grande making it the warmest day of the week. By late afternoon an upper level trough will dig into the TX panhandle pushing a cold front through the area late tonight and early tomorrow morning ushering in cold NE flow.
SHORT TERM (Now through Wednesday): Good radiational cooling overnight has allowed temperatures across portions of the northern ranchlands to drop to around freezing early this morning. Highs today should reach the upper 60s to the lower 70 under mostly sunny skies. The next cold front arrives on Wednesday. Wednesday will be warmer with highs in low to mid 70s early, with temperatures falling into the 60s by late afternoon.
328 AM CST Tue Dec 1 2020 High pressure settling into the area this morning. Temperatures were in the low to mid 30s with the coldest spot. The trend for freezing conditions along and south of the I-10 corridor appears to be on track. Once we get past freezing conditions this morning.
Have decided to keep the winter storm warning intact given the development of light freezing rain showers mixed with snow as the cloud layers were mostly outside of the dendritic growth zone. Data from Indiana RWIS, road and traffic earlier showed much slower speeds where temps have fallen to freezing or below in the Westville to Wanatah area. It looks like the shallower tops have a rain/snow mix or just rain, but the precipitation was freezing rain away from Lake Michigan were at freezing or colder making for a snowy and icy setup this morning. High pressure building in will give way to clearing skies/VFR conditions this evening, with W-NW winds continuing to gust to 20-25kts.
A potent trough and associated storm system continues to exit the region to the northeast with heights quickly rebounding throughout today. With these conditions, I also wouldn't be surprised to see freezing fog near lakes and rivers. Sunshine and further rebounds in heights should get us 7-8 degrees warmer on Wednesday afternoon, generally in the 50s area-wide.
303 AM CST Tue Dec 1 2020 Mid-level clouds will diminish by early this morning as the low pressure system continues moving northeastward. Models continue to develop an upper-level low in the Central Plains; with better agreement towards the ECMWF solution of having the low further west towards Oklahoma Wednesday night and a secondary closed low to the southwest in the Four Corners region.