Aikyam-Lab/Synoptic-Bench huggingface dataset:
427 AM CST Tue Jan 21 2020 (Today and Tonight) An upper level ridge will move east of the area today as an upper level short wave tracks east across the Southern Rockies.
Showers linger behind the front until the next system brings a warm front onto the coast early Wednesday morning.
A few things stand out today into Wednesday: * This morning: Spotty light freezing rain/light snow will be possible in the valleys. Wednesday night through the weekend the region remains under the influence of a ridge. With the ridge axis to our east it sets up southwest flow into the Northern Rockies with moderate amounts of moisture. Due to the dynamics of the ridge there won't be much precipitation, but what we do get will be light and persistent and will add up over time.
836 AM EST Tue Jan 21 2020 High pressure will track east and cross the Ohio Valley early on Wednesday.
531 AM CST Tue Jan 21 2020 High pressure slides on out to the east and southerly flow returns across the region. With mid-level ridging in place, quiet weather is in store for today with mostly sunny skies. An active weather pattern returns for the middle of the week as a short wave trough begins to slide in across the region. There are some hints that the onset of the event could start out as some spotty freezing rain. This would be possible if ground temperatures remain below freezing, but after Tuesday night temperatures will be on the increase. Daily high temperatures will warm above freezing for most of the area.
Surface observations reveal an arctic high pressure system over the Ohio River Valley. To the east of Florida over the northern Bahamas, visibile satellite imagery portrays the beginning of a weak swirl in the low level cloud fields. This developing low pressure system is helping to enhance the northerly breezes across the Florida Keys. Chilly morning low temperatures have barely recovered into the lower 60s, although portions of the Middle and Upper Keys are still 55-56 degrees. From synopsis, a strong high pressure center will descend into the eastern United States this afternoon, maintaining strong north breezes over the Keys waters. Late this afternoon through early Wednesday, north breezes will freshen further on the back side of low pressure system that will rapidly develop northeast of the northern Bahamas.
1245 PM PST Tue Jan 21 2020 Weak high pressure will rebuild over the area this week with mainly dry weather.
By sunrise on Wednesday, temperatures will be in the lower and mid 20s east of the Mississippi River and in the mid and upper 20s elsewhere. Upper ridging exits Tuesday night, with southerly flow filling in behind it.
However, if anyone remains socked in, you will remain cooler than everyone else.
TFJ Upper ridge currently over eastern Montana will move to the east today. The inversions will be the strongest along and north of US 2 which will also have snow cover to keep temperatures cooler. Will mention patchy freezing fog tonight in some valley areas. There may be enough moisture for a chance of light rain, light snow, or light freezing rain on Wednesday.
Upper ridging will generally dominate the short term period, keeping dry and warming conditions over the TN Valley. The axis of the ridge will move overhead on Wednesday, and then shift east of the area Wednesday night as a trough moves into the Plains. Southwesterly flow will strengthen as the ridge moves east, with moisture quickly filtering into the region.
110 PM MST Tue Jan 21 2020 Current surface analysis shows warm front across the central Dakotas into the central high plains, with an area of low pressure well northwest of the region. Another area of low pressure has developed along the warm front over southeast CO. Main forecast concern will be the cold front and upper level wave that will track across the region Wednesday into Wednesday night. Any accumulations will mostly be an inch or less, but the higher elevations of the northern Black Hills and possibly parts of far southern SD could see a bit more.
902 AM MST Tue Jan 21 2020 Satellite imagery this morning shows the next upper trough to affect the region now moving onto the west coast, with a fairly moist SW flow aloft downstream across the Northern Rockies. Quiet day weather-wise overall before the trough arrives late this afternoon/evening with varying cloudiness and temperatures near to above seasonal averages.
Temperatures to warm enough during the day across most locations for ongoing precip to remain liquid, however temperatures across the higher terrain across far eastern/southeast Oklahoma and northwest Arkansas may very well lag to rise above freezing, which would result in mixed precipitation for a good part of Wednesday.
Warm front continues to work its way eastward through the Dakotas, with temperatures in its wake pushing into the 30s with some 40s over far western areas.
Upper level ridge over the Central Great Lakes this evening/tonight reaching the East Coast tomorrow evening. Strong warm advection pattern tonight as return flow around the high pressure departing into the Mid Atlantic States kicks in. 850 MB temps progged to reach zero Wednesday morning, +10 C warmer compared to this morning. Further low level warm advection (925 MB temps near -1 C) tomorrow should assure temperatures rise above freezing, even with thickening high clouds, although the MAV/MET guidance appears to be a bit too warm. Longwave upper level trough spreading into the Central Plains on Wednesday.
Surface observations reveal an arctic high pressure system over the Ohio River Valley. To the east of the northern Bahamas, visibile satellite imagery portrays the beginning of a weak swirl in the low level cloud field. This developing low pressure system is helping to enhance the northerly breezes across the Florida Keys. The KBYX radar is echo free and the Lower Keys are occluded by a field of stratocumulus. Cold air advection will ramp up this evening as the low pressure system east of the Bahamas strengthens, driving an arctic airmass down the spine of Florida.
Temperatures were generally in the mid-upper 20s and highs look to top out in the lower 30s this afternoon. By mid to late morning, although the inversion remains in place, high pressure at 850mb will be moving into Indiana, cutting off the moisture supply from Lake Michigan. Also at that time the strong high at the surface will be entering the lower Ohio Valley, introducing a much drier air mass. Went on the cool side of guidance for highs today given the expected morning clouds, with temperatures peaking around the freezing mark this afternoon. As we move into more southerly flow, expect high temperatures Wednesday to warm to near normals into the lower 40s.
Clouds have finally cleared or become scattered at all TAF sites, and clear skies are expected to continue through tonight and tomorrow as high pressure builds in.
At H7 positive theta-e advection ahead of the H7 trough can be seen in the deterministic models through about 06Z Wednesday. The higher dewpoints will keep overnight lows from dropping too dramatically. Some areas could see some snow mixed in with the rain, but will not see any accumulating snow with the surface slightly above freezing for most areas.
Temperatures overnight drop down into the lower 20s and its quite possible some places see the upper teens.
145 PM CST Tue Jan 21 2020 Water vapor shows an upper low moving across AZ with a long fetch of mid/upper level moisture stretching across Baja into NM and a 100kt 3h jet nosing into SE AZ/SW NM. In wake of mid-level trof/jet the flow will veer to the w Wed PM aiding in warmer high temps. Surface winds will continue to veer around to the n into Thur as a cold front will be pushed s by shrtwv trof moving through the central plains.
High pressure will return late in the week. Precipitation across southern Utah this morning continues with snow in the higher elevations near Cedar City and Bryce Canyon and points north through Soldier Summit and light rain in St George. A brief lull in precipitation this afternoon and evening before a northern trough glances through the northern Rockies bringing better snow chances to northwest favoring slopes of the northern mountains and some light valley accumulations in the Cache Valley and the Wastach Mountain Valleys.
910 AM MST Tue Jan 21 2020 Satellite imagery and radar showing areas of light precipitation pushing through central Oregon this morning along with the main cold front moving over the Cascades at this time. Light winds overnight along with additional low level moisture may bring the threat of fog across the lower elevations, which will reassess for the afternoon package. Precipitation ending before midnight, but potential for fog developing across the lower valleys.
111 PM EST Tue Jan 21 2020 Chilly high pressure into midweek.
1146 AM CST Tue Jan 21 2020 High pressure slides on out to the east and southerly flow returns across the region. With mid-level ridging in place, quiet weather is in store for today with mostly sunny skies. An active weather pattern returns for the middle of the week as a short wave trough begins to slide in across the region. There are some hints that the onset of the event could start out as some spotty freezing rain. This would be possible if ground temperatures remain below freezing, but after Tuesday night temperatures will be on the increase. Daily high temperatures will warm above freezing for most of the area.
With southerly flow in the low-levels, temperature profiles will be dependent on evaporational cooling effects to sufficiently cool the column to support snow. Models have trended slightly warmer across the board with the most recent runs, but are still supportive of some snow across parts of central and northern Oklahoma. Where surface wet-bulb temperatures are near or below freezing, a couple hour period of moderate to heavy snow appears possible. South and west of there, precipitation type is more uncertain as temperature profiles and surface temperatures are slightly warmer. Southwestern Oklahoma and western north Texas should remain all rain through the duration of the event as temperature profiles remain above freezing.
356 PM EST Tue Jan 21 2020 High pressure will slide south of the area tonight.
Cold high pressure is located to the east of the high plains; and despite the return to low level southerly boundary layer flow, cool air is being recirculated around the high. Temperatures are only expected to fall into the lower 30s tonight (at or just above freezing) so that icing (or re-freezing of any snow melt) won't be an issue. A benign and mild weather pattern will develop Wednesday and persist through the weekend as upper level ridging develops over the Rockies and shifts slowly toward the high plains. A deep upper level trough may develop over the southern Rockies on 27 January and then amplify over the southern plains by the 28th.
Temperatures, even without the clouds, have only made it into the low 30s so far and while we'll see a couple of degrees more, we'll still fall just short of forecast highs.
310 PM EST Tue Jan 21 2020 Effective mixing has allow the low-stratus deck to mix out and skies were mostly sunny across the region this afternoon. Despite full sun, temperatures remained cold with readings in the upper 20s to the lower 30s. For the overnight period, high pressure will move through the region while upper level ridging builds overhead. With the high pressure cell to our east, we'll be on the backside with a south to southwest flow. The southern half of Kentucky should be able to warm into the lower 40s with some mid 40s down along the Kentucky/Tennessee border. An upper trough drops south over the Plains and continues to dive farther south as the trough moves east.
Deep/intense upper low moving thru the state today and will continue to move quickly away with strong subsidence in its wake.
As the ridge axis crosses the area tomorrow, high clouds will start to spread in from the west in the afternoon.
1047 AM MST Tue Jan 21 2020 Water vapor shows dirty ridge building into the plains with next upper trof just offshore the Pac NW. At the surface, lee trof is deepening along the Rocky Mountain front. Thermal ridge overhead today and advancing surface trof will likely result in the warmest day of the week, with readings in the 50s west to 40 east. Upper trof/surface front works into the northern plains Wednesday and will bring a good chance of rain/snow to the area, especially in the afternoon and evening hours. An upper level system and cold front will approach the area Wednesday morning, with ceilings lowering and chances for light rain and snow increasing by late morning across northeast WY and the Black Hills.
1259 PM EST Tue Jan 21 2020 High pressure will track east and cross the Ohio Valley early on Wednesday.
Overnight lows will be above seasonal normals, in the low to mid 40s. Highs on Wednesday will generally be in the low to mid 60s, with locations in our far eastern counties only reaching the upper 50s.
/issued 310 AM CST Tue Jan 21 2020/ The upper ridge that has brought dry weather to the region the last few days will move east and exit as an upper level trough across the west coast moves quickly east into the Rocky Mountains by late this afternoon. Large scale Lift will increase significantly today as the trough/upper jet approach the forecast area.
234 PM CST Tue Jan 21 2020 An upper level trough axis extending roughly from SERN WY into the Sun Country of Texas will move eastward tonight helping to enhance lift across the region. Northwest flow aloft then returns late tomorrow as ridging builds along the west coast.
Forecasted soundings for the mountains today and tomorrow show deep saturation through the boundary layer and temperatures well below freezing supporting efficient snowfall rates and snow ratios near 16-18:1. Euro brings the trough more southeasterly and becoming a strong Colorado low system with widespread precipitation. GFS has a trough similar to the systems we have been experiencing the past few weeks that barely clip the area. Weather Systems In Vicinity: Warm front moving to the east northeast across COlorado and eastern Wyoming. A cold front will move in from the west late in the period early Wednesday.
/GG/ Expect dry weather tonight as high pressure remains in control. Lows will be chilly, ranging from the lower 20s to near 30. Highs tomorrow will still be on the cool side, ranging from the lower 40s north to near 50 far south.
846 PM CST Tue Jan 21 2020 One last really cold night across the Valley, with temperatures falling into the lower 20s to perhaps upper teens as clear skies and light winds allow for good radiational cooling.
Finally, a cold front will move across the area around mid to late morning Wednesday with north winds in its wake. At H7 positive theta-e advection ahead of the H7 trough can be seen in the deterministic models through about 06Z Wednesday. The higher dewpoints will keep overnight lows from dropping too dramatically. Some areas could see some snow mixed in with the rain, but will not see any accumulating snow with the surface slightly above freezing for most areas.
601 PM CST Tue Jan 21 2020 Southwesterly winds remain strong through the evening hours tonight, particularly across the Buffalo Ridge where there is greater potential to mix into the greater low-level winds at the surface. As the winds die down, focus shifts to the latest chance of precipitation, mainly east of I-29, ahead of a trough entering the region. Soundings show saturation struggles, so could see a brief period of freezing rain/drizzle as the atmosphere struggles to saturate. However, another issue with freezing rain potential is the much colder temperatures below the warm air aloft. As the trough begins to push out, winds will shift more northwesterly late on Wednesday.
Initially today our airmass is very dry, however it will flip to the opposite extreme overnight as a combination of Plains short wave ridging and an approaching AZ PV anomaly result in favorable return flow into the MO Valley. This will mainly be in form of snow, however confidence is low at times, especially NW, where a warm layer and/or periods of 1-2km dry air could result in a mix of freezing rain or freezing drizzle during lulls in seeder-feeder processes. Thus the whole range of wintry mix is possible ranging from freezing rain/drizzle to sleet and what will be a predominate wet, slushy snow.
954 PM EST Tue Jan 21 2020 High pressure will remain over Pennsylvania the next couple of days.
A slow-moving area of low pressure will bring the potential for widespread and significant snow or mixed precipitation this weekend. Mostly clear skies late tonight, combined with light wind and snow cover should allow temperatures to fall well below seasonal averages with readings by dawn in the single digits across the northern mountains and the low to mid teens elsewhere. High pressure directly over the state will ensure mostly sunny skies, light wind and seasonable temperatures Wednesday.
In this case however surface temperatures are more likely to be near or just above freezing.
Flow aloft will be switching from southwesterly this afternoon to west and northwesterly behind the passage of the upper trough. On Wednesday, a cold front is forecast to push through during the afternoon, which will produce some gusty winds up to 25 or 30 MPH. High temperatures should still reach around 50 degrees before the cold front arrives.
The higher snow levels and low snowfall rates should decrease travel impacts, although still could see chain controls.
Strong southerly winds will continue across the eastern part of the area into this evening as that region remains between high pressure to the east and an approaching low pressure trough to the west. The trough/front slides across the area during the day Wednesday, with the potential for light post frontal snow showers Wednesday night, with little to no accumulation expected. Temperatures will remain mild through the period, with lows tonight in the lower to mid 20s, and highs on Wednesday in the 30s.
Effective mixing has allow the low-stratus deck to mix out and skies were mostly sunny across the region this afternoon. Despite full sun, temperatures remained cold with readings in the upper 20s to the lower 30s. For the overnight period, high pressure will move through the region while upper level ridging builds overhead. With the high pressure cell to our east, we'll be on the backside with a south to southwest flow. The southern half of Kentucky should be able to warm into the lower 40s with some mid 40s down along the Kentucky/Tennessee border. An upper trough drops south over the Plains and continues to dive farther south as the trough moves east.
Cirrus continues to spill into the region this evening overtop mid level ridge moving across the area. /GG/ Prior discussion below: Expect dry weather tonight as high pressure remains in control. Lows will be chilly, ranging from the lower 20s to near 30. Highs tomorrow will still be on the cool side, ranging from the lower 40s north to near 50 far south.
With high pressure shifting east, and a low pressure trough approaching from the northern Plains, there is a tight pressure gradient across southern WI. The precip spreading in will have some dry air in the low levels to overcome, but we should saturate in south central WI by early Wednesday afternoon.
529 PM EST Tue Jan 21 2020 High pressure will slide south of the area overnight.
The trough will cross the Divide later this evening leaving westerly flow in it's wake, which will support orographic lift through most of the overnight. While the main energy associated with this trough will pass to the north of the area, the southern extent looks to clip the northern and central mountains Wednesday morning.
With temperatures at or slightly below freezing ahead of the impulse, a wintry mix of precipitation can be expected across portions of southeast Oklahoma, southeast Arkansas and northeast Texas tonight. As surface and upper-ridge shift east, southerly flow will race northward quickly warming the atmospheric column. However, as this process occurs, a sleet snow mix will gradually transition to freezing rain across southeast Oklahoma and southwest Arkansas by daybreak. Although this will be a short lived event, could see snow accumulations of up to a quarter of an inch with freezing rain amounts of up to a tenth of an inch on elevated surfaces. This could cause some hazardous driving conditions on area bridges. Precipitation to transition to rain across the entire region by mid-morning, continuing throughout the day as the upper-trough shifts east.
333 PM CST Tue Jan 21 2020 Expect dry weather tonight as high pressure remains in control. Lows will be chilly, ranging from the lower 20s to near 30. Highs tomorrow will still be on the cool side, ranging from the lower 40s north to near 50 far south.
700 PM EST Tue Jan 21 2020 Southeast Michigan will increasingly feel the effects of southwesterly return flow as strong surface anticyclone center slowly tracks eastward along the Ohio River. Upper level ridge over the Central Great Lakes this evening/tonight reaching the East Coast tomorrow evening. Strong warm advection pattern tonight as return flow around the high pressure departing into the Mid Atlantic States kicks in. 850 MB temps progged to reach zero Wednesday morning, +10 C warmer compared to this morning. Further low level warm advection (925 MB temps near -1 C) tomorrow should assure temperatures rise above freezing, even with thickening high clouds, although the MAV/MET guidance appears to be a bit too warm. Longwave upper level trough spreading into the Central Plains on Wednesday.
Temperatures have warmed into the low/mid 30s across most of the Mid-South but skies have finally cleared out and winds are diminishing.
The best chance of accumulating snow is along the west facing slopes of the Absaroka mountains, while the lower elevations will not likely see more than a skiff of snow at most locations by the time the system exits the region Wednesday evening. Any precipitation that does fall in the lower elevations will be light, and a mix of snow and rain.
Forecasted soundings for the mountains today and tomorrow show deep saturation through the boundary layer and temperatures well below freezing supporting efficient snowfall rates and snow ratios near 16-18:1. Euro brings the trough more southeasterly and becoming a strong Colorado low system with widespread precipitation. GFS has a trough similar to the systems we have been experiencing the past few weeks that barely clip the area. Lowered ceilings are expected with the approaching cold front.
936 PM EST Tue Jan 21 2020 High Pressure will continue to move eastward from the Mississippi Valley, resulting in dry weather through Wednesday. The high will shift offshore during the second half of the week.
408 PM MST Tue Jan 21 2020 Current surface analysis shows warm front across the central Dakotas into the central high plains, with an area of low pressure well northwest of the region. Another area of low pressure has developed along the warm front over southeast CO. Main forecast concern will be the cold front and upper level wave that will track across the region Wednesday into Wednesday night. Any accumulations will mostly be an inch or less, but the higher elevations of the northern Black Hills and possibly parts of far southern SD could see a bit more.
706 PM MST Tue Jan 21 2020 Added patchy fog/freezing fog to portions of the west and central for tonight, especially where models indicate low level moisture will linger. Widespread MVFR to IFR cigs/vsbys in rain, snow, and fog/freezing fog.
All terminals are currently VFR, but will soon drop to MVFR and could even spend some time at IFR as the low-levels saturate. A cold front will follow with a northerly wind shift mid-late afternoon. /issued 234 PM CST Tue Jan 21 2020/ An upper level trough axis extending roughly from SERN WY into the Sun Country of Texas will move eastward tonight helping to enhance lift across the region. Northwest flow aloft then returns late tomorrow as ridging builds along the west coast.