Aikyam-Lab/Synoptic-Bench huggingface dataset:
VFR conditions in the near term will deteriorate by around dawn Sunday morning as low level moisture return occurs ahead of a storm system and cold front. Patchy drizzle is possible overnight with scattered light showers likely developing Sunday as the next cold front passes.
/issued 246 PM CST Sat Feb 20 2021/ A weak cold front will move through Sunday night with a few light showers followed by only a brief modest cool down. This is allowing a light east to southeast flow to develop in the low levels across the forecast area. Next cold front, with air mass from more of a Pacific origin, will move across the forecast area on Sunday night.
The main question now is if this layer will be deep enough for (freezing) drizzle or not. Winds will quickly weaken this evening as high pressure builds in across the greater region. Lows tonight will range from the teens across the lower Ark river basin to mid 20s across south central Kansas.
355 AM EST Sun Feb 21 2021 High pressure and dry air will remain over the region through this evening then give way as the next low pressure system and cold front move into the region.
However, winds will be shifting the southwest and west this morning, ahead of a cold front (entering the N. It should be a little cooler in the Big Country with highs around 59, but temperatures will be warmer in the lower to mid 60s south. With clearing skies, light winds and continued cold advection tonight, lows are expected below freezing in the mid and upper 20s.
248 AM EST Sun Feb 21 2021 High pressure is currently centered across the Mid Atlantic. The high center will move offshore today as a cold front moves into the Lower Mississippi River Valley.
Clear and calm conditions will prevail tonight as high pressure extends across the region. Through the day, clear skies will continue but winds are expected to pick up as a low pressure system develops to the west. Upper ridging will build into the Tennessee valley and southern Appalachians through Sunday producing mostly clear sky. Some increase in high level cloudiness expected Sunday as upper ridge axis moves into the area. Some light snow possible in the higher terrain of East Tennessee and southwest Virginia. Gusty winds expected in the higher terrain of the East Tennessee mountains, and adjacent foothills.
Meanwhile, colder subfreezing temps are expected farther E where mixing is weaker, with 03Z temp/dewpoint depressions quite small over the Ern sections of Ncntrl LA. The low level moisture will continue to deepen throughout the day Sunday ahead of a positive tilt trough that will traverse the Midwest and Srn Plains late Sunday, with isolated to scattered SHRA possible especially later in the day along and just ahead of an attendant cold front. A cold front will begin moving into the region after 00Z Monday, which may focus isolated to sct SHRA near and ahead of the bndry through the overnight hours. The approaching cold front will also result in a lowering of cigs ahead of it during the late afternoon through the evening hours.
This is due to the already increasing maritime incoming flow and warmer gulf and bay side waters. Shower activity should remain largely relegated to the warmer Florida Straits. A high pressure system over the eastern United States will maintain a tight pressure gradient.
Warm air advection today has helped push high temperatures above freezing in southern Iowa and into the upper 20s in northern Iowa. Low temperatures tonight will be more moderate, mainly in the upper teens to mid 20s, with a strong push of gulf moisture in the low levels. This low level moisture is aided by some mid-level moisture from the Pacific causing pwts over 0.
1238 AM EST Sun Feb 21 2021 High pressure and dry air will remain over the region through Sunday afternoon with seasonably cool temperatures. A fast moving cold front will move through the area Monday afternoon bringing rain showers. Dry and warmer conditions expected by midweek. High pressure ridging across the region along with a very dry air mass. High pressure will continue to build in through the evening and into the morning. Highs will range from the upper 50s south to the low 50s north. Atmospheric moisture will continue to increase through the day on Monday as a cold front approaches the area from the west.
1230 AM EST Sun Feb 21 2021 Cold high pressure will build overhead this morning, then shift offshore later today. An upper level trough and associated weak surface cold front will cross the region from west to east Monday.
Temperatures have cooled below freezing for many areas this evening, and on their way to the low 20s. Freezing fog will again be possible overnight, especially near bodies of water and areas with a little more surface moisture. Winds will pick up out of the south after sunrise, but most models keep calm winds overnight with clear skies, so freezing fog will be possible through around 8 am or so. Should freezing fog develop, vulnerable surfaces like bridges and overpasses may become slick, even if they were clear from melting earlier today.
Another round of moisture expected to influence the central mountains by the afternoon, with snowfall generally anticipated to remain over the higher elevations. Areas of MVFR/IFR in low clouds and fog possible aft midnight across the lower valleys. A warm front will move through the area Sunday and Sunday night, followed by a cold front Monday and Monday night. The areas most likely to see showers are the West Central and Boise Mountain zones, but the higher terrain of Baker County will also see some showers. The best chance is Monday night with the cold frontal passage, and showers may extend into lower elevations at that time. Total snowfall through the period (60 hours) will be fairly light, with 3 to 4 inches in McCall, up to 8 inches in the higher terrain, and virtually none outside mountainous areas.
1153 PM CST Sat Feb 20 2021 Expanded Winter Weather Advisory northward due to the freezing rain and sleet occurring. Some reports of light freezing rain and ice this evening. Based on the dry and warm air aloft on the abr sounding, have increased tw aloft temperatures quite a bit to reflect rain, freezing rain, and sleet in the radar echoes lifting northeast in central sd. With the focus of both lows farther south, the higher accumulations are also expected to stay south of the cwa. Upper ridging/northwest flow aloft builds in behind this system on Sunday.
225 AM EST Sun Feb 21 2021 Upper air pattern consists of a 500 mb trough over the northern plains down into the southern Rockies and a trough across the Canadian prairies. Both troughs move east and affect the upper Great Lakes by this evening before the trough axis moves out of the area late tonight.
A cold front will enter the region after 00Z Monday, with isolated to sct SHRA developing along and just ahead of the front as it shifts SE through the area. Meanwhile, colder subfreezing temps are expected farther E where mixing is weaker, with 03Z temp/dewpoint depressions quite small over the Ern sections of Ncntrl LA. The low level moisture will continue to deepen throughout the day Sunday ahead of a positive tilt trough that will traverse the Midwest and Srn Plains late Sunday, with isolated to scattered SHRA possible especially later in the day along and just ahead of an attendant cold front.
1021 PM EST Sat Feb 20 2021 High pressure will build into the region tonight, as upper trough passes east of Pennsylvania. Beyond the Monday system, the weather pattern looks less stormy through the end of February with temperatures trending warmer, becoming near to above average by mid week. High pressure building in from the Ohio Valley will result in diminishing wind and clearing skies overnight. Thickening cloud cover is expected Sunday night, as waa aloft overspreads the region ahead of low pressure lifting through the Grt Lks. Also timing of the event and warming temperatures as the clouds move in will support less impact than recent events, given warmer low level temperatures.
For the first time in almost two weeks, nighttime temperatures across our area will stay above freezing. An upper trough will move east across the Plains states Sunday, with associated cold front pushing south across our area during the afternoon. Southwest to west winds in the morning will shift to northwest in the afternoon with the cold frontal passage. Areas farther to the south will have some downsloping effects with the winds, and will end up warmer than today with highs expected to be 60-65 degrees.
So far not noticing too much impact on temps but think on the next update clear areas will be noticeably cooler and may need to adjust overnight lows in the south (from mid teens to possibly low 20s). As of mid afternoon, the warmest air since mid to late January (sounds weird actually saying that) has made it into the Devils Lake region, where temperatures have crossed into the low 30s. By Sunday afternoon, southwest winds will pick up a little more, which should allow temperatures across the entire area to get into the low to mid 30s. There's a possibility for a system associated with a longwave trough to impact us this weekend, but given that it is so far ahead in time, confidence is low on the system even holding together to produce snowfall in the northern plains.
Water vapor imagery early today shows our system of interest across the central Rockies/plains, and this trough will eject northeast through the day. A surface cyclone will slowly strengthen as it lifts towards the IA/MO border by 18Z and then to Lake Michigan by 06Z Monday. This still would support a general 1 to 4 inch snowfall with the lowest amounts across north-central WI, and the higher amounts near and south of I-90. 40 inches, which would be possible with any banding that sets up as the low passes to the south. 00Z HREF continues to favor areas along and south of I-90 for the highest potential (ensemble max totals as high as 6 inches). Have expanded the Winter Weather Advisory into far southeast MN and southwestern WI where the higher totals are forecast.
1118 PM EST Sat Feb 20 2021 A large area of high pressure over the Ohio valley will pass by to our south on Sunday to end the lake snows and allow abundant sunshine for the vast majority of the forecast area. Otherwise, we will see increasing sunshine for all areas in the morning and afternoon with warm air advection pushing temps into the lower 30s for the lake plains and in the mid to upper 20s elsewhere. As the low enters the central Great Lakes Sunday night, its associated warm front will cross the area. The low crossing the central Great Lakes and eventually southern Canada Monday will drag its associated cold front across the region.
1013 PM EST Sat Feb 20 2021 High pressure remains positioned over the eastern US, maintaining a tight pressure gradient over the local area. Winds will veer gradually NE overnight, becoming E into Sunday morning, as the high pressure repositions itself from the Ohio Valley to the Mid- Atlantic. High pressure moving from the Ohio Valley into the Mid-Atlantic will veer winds from NE to E tonight into early Sunday morning. A Small Craft Advisory remains in effect for the offshore zones and the nearshore waters south of Sebastian Inlet, where the highest winds and seas are expected.
In the upper levels, a weak ridge will be over the region until a trough approaches tonight. At the surface, high pressure will be over the region today with easterly low level flow. Tonight, low level flow will become more southerly as a cold front approaches. POPs will be near zero until late tonight and early Monday morning when showers move into the region ahead of the cold front. Lows will be mainly in the lower 50s.
255 AM CST Sun Feb 21 2021 Morning water vapor showing an upper trough moving through the Four Corners. The trough should be east of the CWA by late this with the associated surface cool front moving through early this morning. All moisture associated with this system will stay well to our north/ However, breezy north-northwesterly winds are expected behind the front along with cooler air. CAA will result in high temperatures around 10 degrees cooler than yesterday and just below normal for this time of year.
By 18z high pressure will be centered along the East Coast, with a low over NW Missouri, in conjunction with a positive tilt trof from the nation's mid section back across the southern Rockies. The low will move to the Great Lakes region by Monday morning with the trof moving over the region tonight. Despite the snow and increase in clouds, guidance insists highs well into the 40s, perhaps a little cooler along I-64 and west of I-55 similar to yesterday. Went with NBM guidance which has certainly been better/cooler than MOS.
1150 PM EST Sat Feb 20 2021 Snow, mixed with rain, is expected Sunday night as temperatures warm into the low to mid 30s. This WAA regime will finally allow the arctic cold to begin its retreat with temps tonight falling or steady in the teens, warming into the low-mid 30s tomorrow. Sunday night's weather maker, now entering the Rockies, will eject east as an amplified positively titled upper trough.
Snow showers have produced some gusty winds at times and sharply reduced visibility, especially over the higher elevation passes, in the last few hours.
the surface temperatures are projected to climb just above freezing overnight for much of the region before cooling it back down to near freezing by daybreak.
High pressure centered north of the area will provide for clear skies and dry conditions for the next 24 hours. Some patchy frost is possible tonight in the cooler, more sheltered locations. In the upper levels, a trough will be moving east across the eastern half of the CONUS pushing along an associated cold front at the surface. Temperatures for this term will start in the low 50s and should warm to the upper 60s by Monday afternoon.
Temperatures warming nicely at midday, as warmer air aloft finally mixes to the surface and the last vestiges of the arctic air mass are removed. Many locations presently warming into the lower to mid 50s for the first time since February 5th. This will also drag in some cooler boundary layer air to our southeast (still snowpack in NW Oklahoma) and cap our temperatures in the lower 50s. Current thinking is surface temperatures will be below freezing, but not by much, in the 28-32 range as any drizzle falls. Carrying areas of freezing fog and freezing drizzle in the grids for several hours late tonight across the eastern zones.
Patchy drizzle is possible for a few hours this afternoon north of the eastern Iron Range as temps warm briefly above freezing. Minor light snow accumulation is expected, with the highest amounts from Sawyer over to southern Price County where just over one inch is possible. A mixed bag of precipitation types will be found ahead of a cold front that is forecast to move through northeast Minnesota Monday afternoon. There may be periods of just rain in the late afternoon into Monday evening as a short wave trof moves across the area. This trof pushes the cold front through the rest of the area Monday night. Some pockets of freezing rain may occur, but any ice accumulation will be very light.
Moisture return ahead of a storm system and cold front will result in developing MVFR conditions across the region around and/or after 12Z Sunday morning.
108 AM EST Sun Feb 21 2021 A large area of high pressure over the Ohio valley will pass by to our south on Sunday to end the lake snows and allow abundant sunshine for the vast majority of the forecast area. Otherwise, we will see increasing sunshine for all areas in the morning and afternoon with warm air advection pushing temps into the lower 30s for the lake plains and in the mid to upper 20s elsewhere. As the low enters the central Great Lakes Sunday night, its associated warm front will cross the area. The low crossing the central Great Lakes and eventually southern Canada Monday will drag its associated cold front across the region.
Some areas could be dense enough to produce freezing fog and a couple of slick spots on the road. Today will be a great day for melting the snow and ice with plenty of sunshine and highs in the low to mid 50s. Behind the front, temperatures will be about 5 degrees cooler on Monday compared to today.
100 AM EST Sun Feb 21 2021 High pressure will build into the area through the weekend. A cold front will move through late Monday, followed by high pressure. Dry high pressure will prevail on Sunday with mostly sunny skies and highs in the mid to upper 50s. A coastal trough will develop Sunday night, bringing an increase in cloud cover and possible rain showers, especially late. Numerous showers are expected Monday, especially in the afternoon ahead of the cold front.
239 AM EST Sun Feb 21 2021 High pressure will pass overhead this morning providing dry, cold, and near calm conditions. A cold front will sweep across the region from west to east Monday morning with the potential for rain and mixed winter precipitation. This cold dome of high pressure will retreat this afternoon, temperatures aloft warming.
Tonight Through Monday An upper ridge has moved back into the area today but will continue to move east. An upper trough in the Rockies will move east tonight and through Arkansas Sunday and Sunday night. Northwest flow will return behind the trough Monday. High pressure will move off to the east tonight. A warm front will move north of the state late tonight and, as warm moist air returns tonight over the snow pack, patchy fog or freezing fog can be expected. Lows tonight will be in the low 20s to low 30s and mid 20s to mid 30s Sunday night.
1130 PM CST Sat Feb 20 2021 Temperatures finally above freezing over a wide area today with abundant sunshine. Looks like temperatures will be above freezing for the most part, but can't rule out brief freezing drizzle in some of the Ozarks hills in the morning with precip onset. Downslope component to the low level winds will help eat away at snow.
Then Monday should feature both west winds as well as warmer 850mb temperatures. Some high-res guidance indicates areas around Dickey county may receive some light snow, but 700mb trough likely too far south to produce much accumulation. A strong northwest flow pattern ahead of a cold front looks to bring warming temperatures and breezy to windy conditions through Monday.
Temperatures are generally expected to be above freezing through morning thus freezing drizzle is not a concern. The latest hi-res guidance continues to show a fairly widespread area of light rain through the morning with a slow shift to the east into the afternoon as a cold front sweeps through the area. Ahead of the cold front, expect gusty winds with gusts near or just above 25mph at times from the south and southwest. Winds will generally decrease through the day today as the low level jet gradually weakens overhead.
and Monday A low pressure system, currently located over the central Plains, will track northeast towards eastern Iowa today, then over northern lower Michigan by tonight. This low will bring several rounds of snow to the area as it passes through, generally bringing 1 to 3 inches of snow to northeast Wisconsin. The system itself appears to have slowed down by a few hours with snow expected to start a bit later today and subsequently end a bit later tonight until the main mid level trough exits the area. The mesoscale models peg the highest totals from this system in a swath from central to northeast Wisconsin where the fgen band is expected to set up this afternoon, with the lowest totals across north-central Wisconsin where moisture and forcing will be limited.
An upper trough is beginning to dig southeastward across the western part of the country. The upper trough to the west will move over the central part of the country on Sunday with the base of the upper trough moving over West Texas and Southeast New Mexico. High winds from the base of the trough are expected to impact the Guadalupe Mountains so a High Wind Warning is in effect there beginning tonight and continuing into the early morning hours on Sunday. The upper trough will result in a cold front moving into the area during the day on Sunday. The previously mentioned upper trough moves eastward on Monday.
1011 PM EST Sat Feb 20 2021 High pressure will build into the region tonight, as upper trough passes east of Pennsylvania. Beyond the Monday system, the weather pattern looks less stormy through the end of February with temperatures trending warmer, becoming near to above average by mid week. High pressure building in from the Ohio Valley will result in diminishing wind and clearing skies overnight. Thickening cloud cover is expected Sunday night, as waa aloft overspreads the region ahead of low pressure lifting through the Grt Lks. Also timing of the event and warming temperatures as the clouds move in will support less impact than recent events, given warmer low level temperatures.
A cold front passing through the region will bring cooler weather through Sunday, with decreasing winds.
335 AM EST Sun Feb 21 2021 Snow showers mainly in the higher terrain will diminish overnight thanks to a ridge of high pressure that will promote dry weather on Sunday areawide.
High Wind Warnings from Livingston east through Nye, and north through Big Timber, Harlowton and Judith Gap look to be in good shape, and will not make any changes to the highlites at this time. Lows in the teens can be expected tonight, with highs in the lower 40s for most places on Sunday. Downslope flow will keep temperatures warmer for Sunday night, with lows in the upper 20s to 30s expected.
358 AM CST Sun Feb 21 2021 Another clear and cool night across the Mid South as high pressure slides east today setting up return flow ahead of a cold front that will bring a chance of rain to the area tonight.
After midnight, ceilings will become MVFR as a cold front enters the area from the northwest passing through GLH by 22/09Z. Also worth noting in these areas was the freezing fog that has formed, likely from the more efficient radiation occurring. All of this occurring ahead of a fast moving mid level wave and its attendant cold front moving out of the Rockies into the High Plains this morning.
Scattered to numerous showers will break out after midnight with a cold front entering northwest Alabama around sunrise Monday. Cloudy skies will prevail through the morning hours on Monday as a cold front pushes through the state. The rain will quickly end from west to east Monday afternoon as the upper trof axis moves into Alabama.
Expect cooler weather today with decreasing winds.
The warming trend will continue across the area through Monday as ridging over the western US slowly shifts east. Monday will be even warmer, with highs in the 40s and 50s.
The upper ridge flattens and transforms into a more zonal flow pattern ahead of the next system that moves in Monday afternoon.
Current surface analysis places low sliding over the Oklahoma panhandle, with trough through the central into the northern plains. Upper level analysis places trough through the northern plains into the four corners region, with ridge over the west coast.
514 AM CST Sun Feb 21 2021 Key messages: - Wintry mix of snow, freezing drizzle, and freezing rain expected for parts of northern Missouri.
233 AM PST Sun Feb 21 2021 A light but cool northerly flow will persist today before high pressure briefly nudges into the region Monday for warmer temperatures.
The highest elevations of the Park Range may see an additional 3-5 inches out of these showers by daybreak Monday, before the snow finally comes to an end.
445 AM CST Sun Feb 21 2021 Breezy and warmer today as a front lifts across the region.
Also worth noting in these areas was the freezing fog that has formed, likely from the more efficient radiation occurring. All of this occurring ahead of a fast moving mid level wave and its attendant cold front moving out of the Rockies into the High Plains this morning.