Aikyam-Lab/Synoptic-Bench huggingface dataset:
Chattanooga Airport, TN 44 26 41 25 52 / 30 10 0 0 0 Knoxville McGhee Tyson Airport, TN 45 26 38 22 48 / 80 50 10 0 0 Oak Ridge, TN 44 26 38 22 48 / 60 50 0 0 0 Tri Cities Airport, TN 49 25 33 20 44 / 80 50 30 0 0 TN.
Warmer days, chilly nights and low humidity. A weak trough in NW flow aloft will weaken the offshore flow pattern on Monday, allowing a sea breeze to work inland for a few hours. This should help moderate RH levels for a time, but behind the trough, a dry easterly flow will return, maintaining our chilly nights and dry, warm days.
Upper level ridging will slide overhead on Monday as northwest winds turns southerly.
Forecast Confidence: High 00Z upper air analysis and GOES16 water vapor imagery depicted a fairly amplified pattern over the CONUS, with an upper trough over the upper Midwest/Great Lakes region and a sharp upper ridge axis thru the northern Rockies. At the sfc, low pressure was continuing to develop across the Ohio River valley with a strong high centered over the central Plains. Although the coldest air aloft will gradually shift eastward, highs will remain cool today with readings only topping out in the lower 30s far north to around 40 in southwest Iowa. High pressure will result in mostly clear skies and light winds overnight with chilly low temps generally in the teens.
258 AM CST Mon Nov 30 2020 A cold front that passed through on Sunday has brought a much colder air mass into the region with temps now in the mid 20s to lower 30s. A cold day is on tap as low-level cold air advection continues between a strengthening eastern Great Lakes low and approaching high pressure in the Plains. Forecast highs in the low to mid 30s would make today the coldest of the season so far. The winds finally subside tonight as temps fall into the lower 20s and teens for lows.
1229 AM EST Mon Nov 30 2020 South winds continue to veer southwest through the overnight hours out ahead of an approaching cold front.
Winds will be light and variable today as the high shifts east and southeast across much of Texas. Temperatures will be on the cool side with highs generally in the lower 50s.
1006 PM CST Sun Nov 29 2020 The Northland was situated between departing low pressure near Sault Sainte Marie, MI and building high pressure over the Northern Plains. The upper-level trough which is supporting the light snow and strong winds over the region today will phase with a southern stream low pressure system and deepen into a cutoff low over the Ohio River Valley on Monday night and is forecast to lift into New England and the eastern Great Lakes by midweek. The evolution of that trough will produce a blocking pattern with ridging over the Northern Plains and Upper Midwest while another trough digs into the central Rockies.
The aforementioned low will continue along its present track into the Appalachians later tonight, and this will result in a tightening pressure gradient on the back side of the low and also plenty of wrap-around moisture to go along with the cold advection. The latest HRRR shows most of tonight's precipitation exiting the mid state by 12Z, after which light echoes resulting from the wrap-around moisture and closed upper low will begin to fill in across Middle Tennessee. Rain from the low will move out west to east near dawn before an upper low brings more precipitation in as a rain/snow mix to start before turning to all snow.
/issued 950 PM CST Sun Nov 29 2020/ Current observations and satellite imagery shows a cold front just to our west, but will approach eastern Arkansas soon. Otherwise, temperatures are dropping slowly to the lower 40s to upper 30s with lows tonight approaching freezing in most areas. Latest surface analysis places a 1008mb low pressure system over New Orleans, Louisiana, with a cold front extending from Alpena, Michigan southwest into Chicago and back through St. A broad rainshield extends northeast of the low affecting much of the Lower Mississippi Valley. Another trough will swing down across the Mississippi Valley and squeeze out any remaining moisture over the Tennessee Valley.
An upper level ridge over the Plains keeps any active weather well-removed from the area.
Evening satellite pics showing an area of stratus/fog is lingering over central Malheur county with smaller pockets elsewhere across southeast Oregon and the lower Treasure Valley.
We still have a tight pressure gradient over the Beartooth Mountains that are producing gusts up to 45 mph at Livingston, through gusts up to 55 mph will be possible through this afternoon as low pressure lee-side of the northern Rockies moves south and helps to strengthen the gradient even more. Winds near Harlowton will have a brief window for 50 mph gusts as the gradient shifts late tonight ahead of an upper trough. As it crosses over Montana, the flow will split, with an upper low forming over Wyoming, and a second upper low forming and lingering over far eastern Montana. Dry conditions expected today with humidities dropping into the teens, and temperatures will climb back into the low 50s. Vertz Tuesday system drops quickly to the south, with ridging building in behind it.
Dry and stable high pressure aloft will remain in place today.
West winds today will bring slightly warmer temperatures and mostly sunny skies. A powerful cold front will arrive on Tuesday with strong northerly winds and colder temperatures.
The axis of an upper level trough of low pressure axis was directly over the Ozarks this morning, and will continue to advance east of the region today, bringing a deeper continental dry airmass into the area. We're looking at plenty of sunshine today on the inflection of the passing trough, with highs ranging from the middle 30s in the central Missouri, to the middle 40s in far southwest Missouri. Lows tonight will fall into the teens over the eastern Ozarks, to the low to mid 20s in the western Ozarks. Meanwhile, a digging upper level trough is expected to evolve lee of the Rockies.
402 AM CST Mon Nov 30 2020 Steady northwest surface flow has kept cooler air feeding into the area, resulting in a 20 degree drop from 24 hours ago. Given the 10- 15 mph winds and the lower 20 degree temperatures, wind chills this AM are widespread in the lower to middle teens, making for a rather unpleasant morning. The focus then shifts to the mid to late week slow moving mid level trough, which until recent model runs appeared to move through wind minimal consequence.
A slight warm up for the mid week is expected as a ridge passes through the Midwest. As the low pressure system that affected our area yesterday departs to the east, lake effect snow is expected to continue through the rest of the morning in Iron and Ashland counties due to the fetch of north-northwesterly winds across the lake. Flurries across the rest of northwest Wisconsin and northern Minnesota are possible this morning under the low stratus deck. As the day progresses, both snow and clouds should dissipate for a sunny rest of the day under the influence of a high pressure system.
310 AM CST Mon Nov 30 2020 Dry northwesterly upper flow in the wake of the exiting upper low will result in a seasonally cool day areawide, with highs generally in the 40s.
609 AM CST Mon Nov 30 2020 Morning lows have stayed in the lower 20s in western North Dakota where winds are just strong enough to keep temperatures from bottoming out, whereas some locations in the central part of the state are in the mid single digits.
Ridging aloft builds into the region for today and tonight, but is then followed by a trof/energy developing over the Western High Plains on Tuesday. The ridging aloft will allow for a milder airmass to infiltrate the forecast area.
357 AM CST Mon Nov 30 2020 Stratus across eastern Minnesota and Wisconsin will erode from west to east this morning as a trough axis shifts east. Southeast flow will begin across western Minnesota late as the ridge axis slides slightly to the east, allowing for a little milder temperatures there. We should start to see some warmer temperatures late this week into the weekend as westerly winds advect some warmer air into the region. Warmer, now that we will be in early December, is upper 30s into low 40s for high temperatures.
A cold front was moving through the forecast area this morning also. The main upper trough will deepen over the southeast through tonight. Snow accumulations should be around an inch or less except locally higher amounts in the higher elevations and on west and northwest facing slopes. Temperatures should be falling during the day and overnight lows will range below freezing area wide. The one thing to mention though is the GFS has been the most consistent with this system showing a single low pressure center that weakens as it moves east. IFR/LIFR conditions will gradually improve toward sunrise as a cold front crosses the taf sites.
Right now, watching the upper low slide to our east-northeast this morning. If we see any accumulations at all, it would in the higher elevations mainly in the northeast. The bigger story will be the temperatures on the back side of the low.
It does look like the upper low will deepen and push a little further south than previously expected, so snowfall totals over an inch may make it as far south as Grundy and Warren Counties. Added in the potential for up to half an inch on the Highland Rim and through Davidson and Rutherford Counties with minimal if any impacts in those areas. This should help to dry off roads throughout the morning, but will make for wind chills in the low 20s later today. The upper low pushing this system along will deepen and dive south today, bringing with it much colder temperatures. At this time tomorrow we should be in the low to mid 20s with wind chills in the teens. Clouds will gradually move off to the east with the low on Tuesday.
A quick moving cold front this afternoon will cause some gusty west winds and snow showers today.
The cold front which was in the region last night is now moving across north Mississippi.
133 AM PST Mon Nov 30 2020 A dry cold front will move through northeast California and western Nevada today and tonight. It will be cooler Tuesday, but still seasonable daytime temperatures. A dry cold front will push through the region today and tonight. The main upper low along with the deeper colder air will largely remain well to the north and east of the region, so temperatures on Tuesday will be similar to today.
Clear skies will allow for good radiational cooling, that in combination with northerly winds, temperatures will bottom out near to below freezing tonight.
first on grassy areas and elevated surfaces and then eventually over the rest as temperatures fall below freezing. An upstream blocking ridge will develop over the northwest CONUS and persist this week.
Temperatures will have fallen below freezing for the entire region by midnight, with lows falling into the 20s areawide on early Tuesday morning. Temperatures will remain below freezing between 6 to 12 hours depending on location. the week will remain cooler, with temperatures averaging around 10 degrees below seasonal normals. Overall, looking at the 500mb pattern, a deep narrow trough is rotating through the Mississippi River Valley and moving into the eastern half of the CONUS. Narrow ridging is briefly building in over the Plains. but that loses out to another wave dropping 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.
Another cold front will be approaching the FA by tomorrow morning as an upper ridge builds along the western US coast and a trough digs southward along the foothills of the Rockies. The main energy from this upper trough will become a closed low that will situate itself over the southern plains mid week. Models continue to stay in decent agreement by splitting the upper low into two separate lows with the original low being phased into the main upper flow associated with the trough across the northeastern US. Models begin to diverge with the placement and evolution of the remnant upper low by late week into the weekend. The GFS keeps the low over the Texas Panhandle before splitting it into two more separate lows.
533 AM CST Mon Nov 30 2020 A thermal ridge will develop across wrn Nebraska today and move overhead through ncntl Nebraska tonight. The temperature forecast today leans on the warmer deeper mixed GFS guidance for highs in the 40s and 50s. Teens are in place in the valleys where drainage winds will support cooler lows. A strong cold front, currently across nrn Canada, will sweep through wrn and ncntl Nebraska Tuesday. The cooler short term model blend plus bias correction was the basis for highs in the lower 40s Tuesday.
500mb ridge will slide across the northern plains tonight into Tuesday allowing the dry weather to persist with little in the way of cloud cover.
This should allow temperatures to bounce back into the low to mid 50s across much of the area. The warmer airmass will keep low temperatures from spiking downward as much tonight with low to mid 20s expected. This will push a cold front south across western Kansas during the day.
A cold front was moving through the forecast area this morning also. The main upper trough will deepen over the southeast through tonight. Snow accumulations should be around an inch or less except locally higher amounts in the higher elevations and on west and northwest facing slopes. Temperatures should be falling during the day and overnight lows will range below freezing area wide. The one thing to mention though is the GFS has been the most consistent with this system showing a single low pressure center that weakens as it moves east. IFR conditions will continue to improve in the wake of a cold front.
520 AM CST Mon Nov 30 2020 The upper trough that moved over the region overnight will strengthen into a closed low system as it moves northeastward over across the eastern CONUS. Weak ridging will be building over the Plains today and tomorrow bringing seasonable temps and dry conditions for the next couple of days. The next wave comes out of the Pacific Northwest and tracks across the Colorado Rockies, with the trough axis progged to be over the western Plains by tomorrow night.
/issued 332 AM CST Mon Nov 30 2020/ high pressure continued to build in across the area this morning with temperatures some 7 to 16 degrees cooler than this time yesterday. a large upper level trough was over the central and eastern US with cold fronts over the eastern Gulf of Mexico extending up the eastern US. another cold front was poised to sweep through the area today. it will be noticeably cooler today with highs only in the 50s areawide. Temperatures will fall overnight into the upper 20s north to the lower 30s south.
654 AM EST Mon Nov 30 2020 Rain associated with a low pressure system will change over to snow today.
/Issued 310 AM CST Mon Nov 30 2020/ Dry northwesterly upper flow in the wake of the exiting upper low will result in a seasonally cool day areawide, with highs generally in the 40s.
An upper level ridge over the Plains keeps any active weather well-removed from the area. Winds remain light on Tuesday as the ridge slowly migrates eastward.
409 AM CST Mon Nov 30 2020 A thermal ridge will develop across wrn Nebraska today and move overhead through ncntl Nebraska tonight. The temperature forecast today leans on the warmer deeper mixed GFS guidance for highs in the 40s and 50s. Teens are in place in the valleys where drainage winds will support cooler lows. A strong cold front, currently across nrn Canada, will sweep through wrn and ncntl Nebraska Tuesday. The cooler short term model blend plus bias correction was the basis for highs in the lower 40s Tuesday.
332 AM CST Mon Nov 30 2020 high pressure continued to build in across the area this morning with temperatures some 7 to 16 degrees cooler than this time yesterday. a large upper level trough was over the central and eastern US with cold fronts over the eastern Gulf of Mexico extending up the eastern US. another cold front was poised to sweep through the area today. it will be noticeably cooler today with highs only in the 50s areawide. Temperatures will fall overnight into the upper 20s north to the lower 30s south.
Also beginning to get reports of snow across portions of Middle Tennessee and the Cumberland Plateau where temperatures are in the low to mid 30's. A deep upper level trough will continue to dig into the Tennessee Valley. Chattanooga Airport, TN 43 27 43 25 51 / 30 20 0 0 0 Knoxville McGhee Tyson Airport, TN 44 28 38 23 49 / 80 50 10 0 0 Oak Ridge, TN 43 28 39 24 49 / 60 50 0 0 0 Tri Cities Airport, TN 49 29 35 20 45 / 80 70 20 0 0 TN.
This is generally the most favorable wind orientation for robust warming via downslope flow, so have leaned temperatures to the high side of consensus blends, with highs in the mid 50s expected. Tuesday, the Pacific NW wave continues to move southeast, with the attendant surface cyclone and cold front ahead of this feature shifting south of the CWA as well.
This ridge axis will shift eastward through the day, with light winds backing to the west and eventually southwest as it moves through. Despite sunny skies, cold temperatures aloft will keep highs in the low to mid 40s, as any WAA on the back side of the ridge axis will be slow to occur.
Upper level ridging will slide overhead on Monday as northwest winds turns southerly. Tuesday: Conditions on Tuesday will be similar as ridging begins to shift away from our area ahead of two approaching waves. Expect sunshine through the first part of the day with temperatures reaching the lower 40s.
359 AM CST Mon Nov 30 2020 Yesterday kicked off with below normal high temperatures in the 50's and the Rio Grande reaching the low 70's. An upper level trough will develop Tuesday over the TX/OK Panhandle causing surface west winds to warm temps up to near normal. High temps Tuesday will be in the low to upper 60s area wide making it the warmest day of the week. The trough will dig southward transitioning into a cutoff low over the southern plains by Tuesday evening. This will allow for a series of dry cold fronts to make their way into the area Wed/Thu plummeting temps to below normal again.
High pressure was situated across western MN southwestward into the Central Plains, while low pressure moved through the Ohio Valley. High temperatures should range from the middle to upper 20s northwest to the lower to middle 30s southeast. Clouds will linger over northern and eastern WI this evening, but gradually decrease overnight, as high pressure moves into western WI. Lows should range from 10 to 15 in north central and central WI, to the lower to middle 20s in eastern WI.
343 AM CST Mon Nov 30 2020 A thermal ridge will develop across wrn Nebraska today and move overhead through ncntl Nebraska tonight. The temperature forecast today leans on the warmer deeper mixed GFS guidance for highs in the 40s and 50s. Teens are in place in the valleys where drainage winds will support cooler lows. A strong cold front, currently across nrn Canada, will sweep through wrn and ncntl Nebraska Tuesday. The cooler short term model blend plus bias correction was the basis for highs in the 30s Tuesday.
A low pressure system over the Southeast United States early this morning, will lift rapidly northeastward and intensify, pulling a cold front across the Island Chain, starting from west to east during the mid afternoon through early tonight. In wake of the frontal boundary, windy, cooler and much drier air will quickly overspread our entire area by Tuesday morning. Beyond that, a formidable high pressure cell over the Southeast United States will slide into the Mid Atlantic States toward the end of this week.
459 AM EST Mon Nov 30 2020 Rain associated with a low pressure system will change over to snow today.
Northwest to north winds will increase later this morning as a surge of high pressure arrives. High temperatures today will be in the low to mid 60s with moderate to breezy north winds. This will allow overnight temperatures to drop into the low to mid 30s across the northern ranchlands and the mid to upper 30s across the lower Rio Grande Valley. There is some potential for portions of Kenedy, Brooks, and Jim Hogg counties to briefly fall to or below the freezing early Tuesday morning. However, all of the latest MOS guidance keeps the northern counties above freezing for tonight. A coastal flood statement maybe needed for beach runup during the high tide cycle late this afternoon.
340 AM CST Mon Nov 30 2020 The upper trough that moved over the region overnight will strengthen into a closed low system as it moves northeastward over across the eastern CONUS. Weak ridging will be building over the Plains today and tomorrow bringing seasonable temps and dry conditions for the next couple of days. The next wave comes out of the Pacific Northwest and tracks across the Colorado Rockies, with the trough axis progged to be over the western Plains by tomorrow night.
Winds will be light and variable today as the high shifts east and southeast across much of Texas. Temperatures will be on the cool side with highs generally in the lower 50s. The high will continue to shift south and east tonight, and will be centered from the lower Mississippi Valley across the Texas coast by early Tuesday morning. A few locations in low-lying areas and river valleys could have lows in the lower 20s.
/issued 359 AM CST Mon Nov 30 2020/ Yesterday kicked off with below normal high temperatures in the 50's and the Rio Grande reaching the low 70's. An upper level trough will develop Tuesday over the TX/OK Panhandle causing surface west winds to warm temps up to near normal. High temps Tuesday will be in the low to upper 60s area wide making it the warmest day of the week. The trough will dig southward transitioning into a cutoff low over the southern plains by Tuesday evening. This will allow for a series of dry cold fronts to make their way into the area Wed/Thu plummeting temps to below normal again.
809 AM EST Mon Nov 30 2020 A cold front will move east through our forecast area (FA) early this morning, bringing showers with a slight chance of thunderstorms. Expect breezy conditions through Tuesday as cooler and drier air filters in behind the cold front.
This will allow the Eastern Pacific Ridge axis to shift slightly east over the next several days. This will bring slightly higher heights to the region, which should allow temperatures to be slightly warmer overnight than previous nights. While that might be the case but overnight cooling will still drop temperatures across much of the San Joaquin Valley to below freezing. This low will retrograde into the Desert Southwest by the weeks end.
High temperatures today will be in the low to mid 60s with moderate to breezy north winds. This will allow overnight temperatures to drop into the low to mid 30s across the northern ranchlands and the mid to upper 30s across the lower Rio Grande Valley. There is some potential for portions of Kenedy, Brooks, and Jim Hogg counties to briefly fall to or below the freezing early Tuesday morning. However, all of the latest MOS guidance keeps the northern counties above freezing for tonight. A coastal flood statement maybe needed for beach runup during the high tide cycle late this afternoon.
Warmer today, with winds becoming a little breezy ahead of a cold front, which will bring the chance for very light snow showers mainly to the Jarbidge area.
to the lower to mid teens elsewhere. with most locations reaching the mid to upper 40s this afternoon as a weak ridge of high pressure begins to transition across the local area. As this upper level ridge rapidly transitions east on Tuesday. The broad troughiness for mid week will result in cold air sinking back south across the local area.
942 AM EST Mon Nov 30 2020 Rain associated with a low pressure system will change over to snow today.