Aikyam-Lab/Synoptic-Bench huggingface dataset:
-Chance for subfreezing highs and frigid wind chills by the weekend. As this passes through, we'll see cooler highs in the lower 50s to upper 40s paired with calm conditions as winds become light and variable. Calm weather will begin to wane shortly after midnight as a mid-level trough digs through the Central Plains. As rain clears out, afternoon highs will feel like your typical spring day with temps into the lower 60s. A cold front will sweep through the forecast area early Tuesday evening, dropping temps into the upper 20 for area near the KC Metro, and down into the upper 20s for northwest MO and northeast KS.
With weak H5 ridging moving in aloft this evening, there could be partial sky clearing over eastern ND and the Red River corridor, though layer low to mid clouds will linger in northwest MN.
536 PM CST Mon Dec 27 2021 Increasing high cloud cover and limited mixing has kept temperatures several degrees cooler than expected today. A strong cold front then moves into the area by mid morning Tuesday.
Have continued to forecast on the higher side of guidance for temperatures due to the warm/dry pattern and southerly flow. Afternoon highs will be in the low 80s area wide under mostly to partly sunny skies.
/issued 223 PM CST Mon Dec 27 2021/ Another short wave currently in the Intermountain West was rotating around a long wave trough covering western North America. However, the lower levels of the atmosphere will not be conducive for measurable precipitation. This will bring lee cyclogenesis/troughing increasing the surface winds for Tuesday. Broad upper level longwave troughing will continue to engulf much of western North America through most of this week, with the evolution of the synoptic pattern largely controlled by a nearly stationary deep upper low over south-central Canada and expansive upper ridging over the Gulf of Alaska.
Lee troughing will strengthen across eastern Colorado this afternoon bringing breezy southeasterly winds to western Kansas. A warm front will move through the area this evening into the overnight period shifting winds to the southwest. A cold front will then move through the area tomorrow shifting winds to the north. These clouds will dissipate from west to east tomorrow as the aforementioned cold front moves through the area.
Most of the shower activity this afternoon and evening has been concentrated along the warm front which is just north and west of Middle Tennessee. More activity is expected to develop as the night progresses with the high res models favoring the I-40 cooridor. Adjusted PoPs to fit the high res trends through the nighttime hours.
338 PM CST Mon Dec 27 2021 (Issued 338 PM CST Mon Dec 27 2021) Tonight through Tuesday night: Skies will continue to clear this evening with light and variable winds late tonight as high pressure moves overhead. Looking at soundings we should saturate quickly with plenty of cloud ice and wet bulb temps below freezing. With temperatures around freezing a brief period of freezing rain will be possible with only a light glaze expected. A Winter Weather Advisory has been issued for Tuesday due to the high snowfall rates during the day, snow accumulations around 2-4 inches with the highest totals towards the Dells, and the potential for a light glaze of ice before precipitation ends Tuesday night.
643 PM EST Mon Dec 27 2021 Aviation - A couple more rounds of light snow/mix this week The pattern of warm advection "bursts" of light snow and mixed precip going to a mix of freezing drizzle/drizzle repeats again Tuesday afternoon and evening.
514 PM CST Mon Dec 27 2021 (Through tonight ) The front that moved south across northwest Arkansas and eastern Oklahoma has stalled in far southeast Oklahoma and will begin to work north as a warm front tonight. A few areas of fog could occur with warm front as it lifts north. (Tomorrow through Monday) Drier air will come into the region during Tuesday as the warm front lifts out of the area and southwest winds develop in its wake.
The upper ridge that has been entrenched over the region will finally push east and we will be under southwest flow aloft.
The axis of an upper-level trough of low pressure will cross the Northern Rockies this afternoon. Water temperatures on Flathead Lake that are much warmer than the air above the lake will contribute to conditions conducive to localized lake effect snow. Some high-resolution models are more excited about lake effect snow than others, so confidence on intense snow is on the low side. As the trough moves east of the Continental Divide this evening, flow aloft shifts to northwesterly, cutting of the moisture feed that has been coming up from the southwest over the weekend. Some of the colder valleys such as Polebridge, Butte, and the Highway 200 corridor along the Blackfoot River will see lows tonight of 15 to 20 degrees below zero.
Windy conditions are also expected across the high terrain tonight and Tuesday, which could lead to areas of blowing snow.
Adjusted overnight lows downward to account for some of the cooler spots, even as far south as Hugo which has managed to stay on the edge of the thick cirrus and benefited from some radiational cooling. Sufficient instability ahead of the approaching trough should allow for more showery echoes with some thunder possible by daybreak across northeast OK. (Tomorrow through Monday) Drier air will come into the region during Tuesday as the warm front lifts out of the area and southwest winds develop in its wake.
With weak H5 ridging moving in aloft this evening, there could be partial sky clearing over eastern ND and the Red River corridor, though layer low to mid clouds will linger in northwest MN. Light snow begins after midnight and all sites expected to fall into the lower MVFR range during the day tomorrow.
Throughout the remainder of the night the low will move to the east allowing for clouds to clear and low temperatures to drop. Tuesday, a cold front moves through the area resulting in winds becoming NNW as a period of breezy to gusty winds during the morning hours; gusts up to 40 mph are possible. Some guidance does have the cold front stalling over the southern portion of the CWA which if this scenario does occur will cause some locales to be forecasted to cold with this package.
1147 PM CST Mon Dec 27 2021 Increasing high cloud cover and limited mixing has kept temperatures several degrees cooler than expected today. A strong cold front then moves into the area by mid morning Tuesday.
126 AM MST Tue Dec 28 2021 Latest satellite and upper air analysis show a trough moving onshore. Over the forecast area southerly winds were breezy behind an exiting high pressure. Tonight southerly winds will gradually decline tonight then gradually turn to the west ahead of an approaching cold front. Therefore went a bit on the cooler side of the data. Tuesday the cold front will move through nearly all the forecast area. Thu-Sat: An unsettled synoptic pattern -- characterized by deep troughing /cyclonic flow/ aloft over the central/western CONUS -- will persist.
1234 AM EST Tue Dec 28 2021 Aviation - A couple more rounds of light snow/mix this week The pattern of warm advection "bursts" of light snow and mixed precip going to a mix of freezing drizzle/drizzle repeats again Tuesday afternoon and evening.
1248 AM EST Tue Dec 28 2021 High pressure offshore will bring near record warmth for the next several days.
CD Chattanooga Airport, TN 71 64 72 62 71 / 30 80 90 90 40 Knoxville McGhee Tyson Airport, TN 71 62 71 60 69 / 20 80 90 90 50 Oak Ridge, TN 69 62 69 59 69 / 50 90 100 100 40 Tri Cities Airport, TN 69 58 68 56 66 / 30 60 90 90 50.
A lot more clouds remain over the area than forecast, so temperatures may be warmer than forecast overnight due to cloud cover.
Wed-Thu Wednesday will be much colder behind the cold front with the exception of far southern Kansas where highs will remain in the mid 50s.
Today through Wednesday night Nevada is on the backside of the longwave trof that encompasses much of the U. While the next trof still looks to split on Wednesday, it appears that the northern portion of it may be digging a bit deeper into Nevada than previous models and ensembles had indicated. Highs on Wednesday will likely not top the freezing mark after a morning low in the single digits to mid teens.
Still expecting showers/isolated thunderstorms become more widespread through 12Z this morning as the low level jet strengthens and a warm front lifts northward into the area. ) For tonight, the trailing cold front will push through the region as the low weakens and lifts into Illinois. With clear skies, overnight lows will rage form around 30 in central Missouri to the lower 40s along the Arkansas border.
434 AM MST Tue Dec 28 2021 Latest upper level analysis has large upper trof across the western CONUS with deep closed low over Saskatchewan. At the surface, Arctic high pressure has the Northern Plains in its grip, with 2 AM temperatures ranging from 10 above to 10 below zero. Highs will struggle into the single digits across the plains, with teens and some lower 20s across northeast WY, the higher Black Hills, and far southwestern SD.
Temperatures tonight will stay near or above freezing so again few if any weather related travel issues are expected. Kept surface temps above freezing during the day. Kept lows around or above freezing tonight with very limited weather impacts expected. The main upper level trof will stay out west and will prevent much colder air from reaching the forecast area until the weekend.
Low pressure will track across Kansas, with an associated inverted trough sliding across central and eastern South Dakota into Minnesota. The system will be fairly progressive, so snowfall accumulations look to generally remain under two inches, with the higher amounts most likely to occur from the northern James River Valley eastward into west central Minnesota. High pressure will drop southward behind the exiting system tonight, and will remain the dominant feature over the region through the day Wednesday, keeping conditions dry and cold. High temperatures today will range from near zero across far northern South Dakota, to the lower teens across south central South Dakota. Highs on Wednesday will range from around zero across west central Minnesota, to the lower 20s across south central South Dakota.
Models depict a synoptic pattern dominated by deep-layered high pressure, which remains in place over the Florida peninsula and the western Atlantic, while a complex storm pattern will develop over much of the CONUS during the short term. But model solutions keep enough blockage from the ridge to keep any frontal boundaries well to the north of SoFlo.
Snowfall amounts may wind up being less than advisory criteria (3 inches or more) in some places, but will leave it in place as there will be some freezing drizzle as the snow ends and it will create hazardous travel during the afternoon commute in central Wisconsin.
901 AM EST Tue Dec 28 2021 Stable dry conditions associated with deep layered ridging from the western Atlantic extending west across the central Florida peninsula will support another warm dry day across all of west central and southwest Florida. High pressure will maintain tranquil boating conditions over the Gulf waters the remainder of today with southeast to south winds around 10 knots near shore and 10 to 15 knots offshore with seas of 2 feet or less, with an onshore sea breeze component developing along the coast during the afternoon.
401 AM EST Tue Dec 28 2021 High pressure will ridge across the area from the east through the weekend, keeping rain-free, but warm and moist conditions in place with foggy mornings possible each day.
Through the day today will continue to see the front drift to the north as the upper level ridge continues to depart to the east. This will allow the flow to become a bit more perpendicular to the front and help push a cold front to the state from the west.
but high clouds along with morning fog and low clouds south of I-20, should keep the highs below records of 84 in San Angelo and 81 in Abilene.
I think the northwest extent of the Slight Risk may be too far into the cooler air to really get things going, but areas along and south of I-40 will need to watch this unfold on Wednesday.
Although we will definitely be warm today, the ridge that was centered over us these last several days has started to shift east. A stalled cold front to our north will help increase moisture across the area. Highs will climb into the upper 70s to lower 80s and lows tonight will remain on the warmer side with values only dropping to the mid 60s.
The high temperature 90th percentile is below zero, even across the south, for at least 3 of the next 5 days, on days it is above zero it is just barely above.
Still, many locations are in the low single digits, to slightly below zero this morning. While snowfall will be widespread, the moisture will be limited, keeping snow accumulations generally around 1 to 2 inches for the valleys, and up to 4 to 5 inches in the higher terrain. Given the low density of the expected snowfall, areas of blowing snow is a real possibility as the colder airmass slides south through western Montana.
This feature will be lifting northward as a warm front today. Rain chances will increase by late tonight as a cold front approaches from the northwest. Thus, look for the aforementioned boundary to lift quickly to the north as a warm front by Thu night.
436 AM MST Tue Dec 28 2021 Arctic air is firmly entrenched in the region with upper low over the Canadian prairies and arctic high extending into the northern Plains.
225 AM MST Tue Dec 28 2021 Latest upper level analysis has large upper trof across the western CONUS with deep closed low over Saskatchewan. At the surface, Arctic high pressure has the Northern Plains in its grip, with 2 AM temperatures ranging from 10 above to 10 below zero. Highs will struggle into the single digits across the plains, with teens and some lower 20s across northeast WY, the higher Black Hills, and far southwestern SD.
/issued 401 AM EST Tue Dec 28 2021/ High pressure will ridge across the area from the east through the weekend, keeping rain-free, but warm and moist conditions in place with foggy mornings possible each day.
Temperatures are in the upper 70s, dewpoints are in the lower to mid 60s, and skies are partly cloudy. Water vapor imagery highlights sinking air across a majority of the southeast, which is caused by deep layer ridging atop the region. Ridging will remain in control through the afternoon across the region. From synopsis, Gentle to moderate east to southeast breezes will prevail through the remainder of the work week, as high pressure remains centered over the western Atlantic. Winds will veer toward the south and increase to moderate to fresh this weekend, when a cold front is forecast to move into the western Gulf of Mexico.
The weak cold front that was across our northern counties earlier this morning has retreated into Kentucky. MVFR cigs look to develop by late evening/overnight with IFR conditions around 12Z Wednesday morning as a weak cold front sinks southward to near I-40 with winds becoming northwest at CKV/BNA/MQY.
Plenty of virga on the radar to our south and west as the low- and-mid levels overcome the dry air currently in place. A small low-level warm nose is noted in forecast soundings (specifically over Warsaw) which presents a non-zero chance for mixed precip or even freezing rain/drizzle. Confidence is low on that because surface temps will be right near freezing; the freezing rain setup is marginal at best but cannot be totally ruled out. The main upper level trof will stay out west and will prevent much colder air from reaching the forecast area until the weekend.
Beneath cold high pressure, winds are light, and temperatures range from near zero across northwestern SD to the lower 20s across southwestern SD.
No rain is expected through the period as we remain on the western periphery of deep-layer ridging and under the influence of the associated dry mid/upper levels. Moisture advection from the Gulf over top of a cooler landmass will result in cloud development overnight - especially across the easter half of south Florida. Highs should manage to reach the low 80s region-wide tomorrow afternoon.
The 19Z MSAS surface analysis indicated an area of low pressure located over eastern KS/western MO with an inverted trough that extended north into central MN. High pressure was located over central Ontario with a ridge of high pressure that stretched from south-central Canada to the central Plains. This band of light to moderate snow will continue to lift north- northeast across the forecast area late this afternoon through the evening hours before transitioning to freezing drizzle as soundings show a loss of ice aloft. High pressure is forecast to ridge across WI on Wednesday and bring at least some sunshine back to northeast WI.
This would change snow over to freezing drizzle mid to late this afternoon into this evening.
The high pressure system is currently located over the southwest Atlantic and will continue to slowly shift eastward through the day. Above normal temperatures expected once again this afternoon, with highs in the lower 80s, except upper 70s along the Volusia coast. (Previous Discussion) High pressure ridge axis extends westward across central FL from a high center over the SW Atlc.
High pressure just northeast of the Bahamas will continue to build over the western Atlantic through the day. Another above normal day for maximum temperatures, with highs in the low 80s under mostly sunny skies.
Upper trough continues to push through the eastern Dakotas.
Latest upper level analysis has large upper trof across the western CONUS with deep closed low over Saskatchewan. At the surface, Arctic high pressure has the Northern Plains in its grip, with 2 AM temperatures ranging from 10 above to 10 below zero. Highs will struggle into the single digits across the plains, with teens and some lower 20s across northeast WY, the higher Black Hills, and far southwestern SD.
/issued 901 AM EST Tue Dec 28 2021/ Stable dry conditions associated with deep layered ridging from the western Atlantic extending west across the central Florida peninsula will support another warm dry day across all of west central and southwest Florida. High pressure will maintain tranquil boating conditions over the Gulf waters the remainder of today with southeast to south winds around 10 knots near shore and 10 to 15 knots offshore with seas of 2 feet or less, with an onshore sea breeze component developing along the coast during the afternoon.
220 PM EST Tue Dec 28 2021 Deep layered ridging over the western Atlantic and extending back to the west across the south-central Florida peninsula will maintain pleasant dry warm weather across all of west central and southwest Florida through the remainder of the week and into the first half of the New Year weekend.
A weak upper trough moving southeastward through the area today will be accompanied by areas of light snow or flurries, mainly in the higher elevations.
The high temperature 90 percentile is below zero, even across the south, for at least 3 of the next 5 days, on days it is above zero it is just barely above.
With abundant mid clouds and an easterly component to the low level flow, temperatures will remain much cooler compared to the past several days. Afternoon highs are only expected to reach the low to mid 30s across central KS while those near the OK state line may approach 50.
The snow will continue to spread north this afternoon and evening and then a transition to freezing drizzle this evening as the DGZ becomes unsaturated. An area of mixed precip, including freezing rain is expected closer to the low center, which could include our southeast zones. A stretch of fairly quiet conditions the next few days although winds and waves may pick up over the weekend as low pressure tracks near Lower Michigan as arctic air approaches.
The weak cold front that was across our northern counties earlier this morning has retreated into Kentucky.
1053 AM CST Tue Dec 28 2021 The entire Mid-South is back in the warm sector once again with temps in the upper 60s to lower 70s and dewpoints in the lower to mid 60s. I think the northwest extent of the Slight Risk may be too far into the cooler air to really get things going, but areas along and south of I-40 will need to watch this unfold on Wednesday.
This front will bring slightly cooler highs for Wednesday (low to mid 70s).
/issued 220 PM EST Tue Dec 28 2021/ Deep layered ridging over the western Atlantic and extending back to the west across the south-central Florida peninsula will maintain pleasant dry warm weather across all of west central and southwest Florida through the remainder of the week and into the first half of the New Year weekend.
A more powerful low pressure system is poised to impact the area for the weekend. The window for accumulating snow is still expected to be short as a warm front continues to advance into the CWA, with the column warming just off of the ground sufficiently to end snow by 02Z or 03Z. The far northeastern CWA, again mainly Forest County, stands the best chance of receiving a brief period of freezing rain later this evening if temperatures can dip to or just below 32 for a couple of hours.
A weak cold front that was in our northern counties this morning lifted north into KY before noon, leaving a mostly cloudy and very breezy day for the midstate. The highest chance for severe storms should be near and south of Interstate 40 where instabilities will be greatest.
The snow will continue to spread north this afternoon and evening and then a transition to freezing drizzle this evening as the DGZ becomes unsaturated. An area of mixed precip, including freezing rain is expected closer to the low center, which could include our southeast zones. KBTL and KJXN could transition of FZDZ as the temperature slowly fall to at or below freezing. A stretch of fairly quiet conditions the next few days although winds and waves may pick up over the weekend as low pressure tracks near Lower Michigan as arctic air approaches.
302 PM CST Tue Dec 28 2021 A weak cold front that was in our northern counties this morning lifted north into KY before noon, leaving a mostly cloudy and very breezy day for the midstate. The highest chance for severe storms should be near and south of Interstate 40 where instabilities will be greatest.
Snow ratios also may contribute to boosted snowfall amounts with a cooler, more dendritic profile and relatively relaxed winds supporting above climo SLR.
523 PM CST Tue Dec 28 2021 1020 to 1024mb high pressure centered over North Dakota extends in a ridge down into eastern South Dakota and overnight that ridge will strengthen and the gradient to the east and south will weaken.
Some of the high resolution guidance hints at the I-580/US-395 routes between Reno-Carson City, and Geiger Grade into Virginia City at risk for a few quick inches of snowfall within these narrow heavier bands.
Broad upper level ridging will help support a dry forecast through Wednesday night. For Wednesday night, temperatures will be slightly warmer, but still cool for this time of year, as lows drop into the low to mid teens.
429 PM CST Tue Dec 28 2021 Even though snow is ending from west to east across the area, continue to see a classic freezing drizzle signal with loss of ice occurring and relatively decent lift for several more hours through the saturated boundary layer. As conditions improve with plowing services and freezing drizzle threat wains as front passes, we can drop advisories sometime this evening. This would change snow over to freezing drizzle mid to late this afternoon into this evening.