Aikyam-Lab/Synoptic-Bench huggingface dataset:
An upper level impulse will then move over the Deep South Sunday afternoon and evening, moving along the flow of the parent upper trough progressing over the Ohio Valley. At the surface, high pressure will build off the southeastern coast of Texas and over the western Gulf through Sunday. Lows tonight will be very chilly, in the lower 30s north of I-10 and in the lower to upper 30s south of I-10. Highs Sunday will be a touch warmer than today, with temperatures in the mid to upper 50s area-wide.
An amplified weather pattern persists over North America with an upper level trough over the east coast and ridging off the CA coast per the 20Z water vapor imagery. At the surface, weak high pressure was seen across the central plains.
534 PM CST Sat Jan 16 2021 This afternoon the Upper Mississippi Valley region was situated in between systems, beneath a low-amplitude mid-level ridge.
A cold front will track through the FA late tonight into Sunday, bringing a quick shot of light snow. As the cold front drops down, winds will begin to switch to the northwest and the flurries or light snow will follow.
Conditions should improve a little more through the rest of this afternoon ahead of our next weather system, set to bring more light snow to the valleys and light to moderate snow to the higher terrain. Snow will continue to remain in the high terrain while valleys will see a bit of a break by Sunday afternoon.
An upper level trough will amplify through the southeast CONUS today with the axis passing to the east of the forecast area tonight. Rain is not expected as there is weak and limited duration of onshore flow ahead of the associated cold front. Lows tonight will range from the lower to mid 30s across most inland areas and around 40 for the coastal locations and southeast Big Bend. Some of the normally colder locations may briefly see minimum temperatures at or just below freezing by daybreak Monday.
/NEW/ /Through Monday/ Large-scale troughing across the eastern half of the CONUS will keep North and Central Texas beneath northwest flow for the next 36 hours or so. Light northwest winds behind the frontal boundary will become light and variable Sunday evening as a ridge axis enters, then shift to the south overnight Sunday night as the ridge moves east of the area. South winds will increase on Monday as a tightening pressure gradient occurs ahead of the next upper level low, which will be dropping south along the West Coast. Low level warm advection should allow for the development of scattered showers across the region late Monday night ahead of a cold front.
A couple of spots just east of the Red in northwest MN have dropped into the low teens with even a couple of single digits reported. A cold front will track through the FA late tonight into Sunday, bringing a quick shot of light snow. As the cold front drops down, winds will begin to switch to the northwest and the flurries or light snow will follow.
1042 PM CST Sat Jan 16 2021 Currently aloft, the departing trough has the Middle Mississippi Valley in north/northwest flow aloft. With the ample cloud cover remaining in place and winds holding out of the west/northwest, temperatures yet again will struggle to make it out of the low to mid-30s for most of the CWA. One such disturbance and associated cold front will pass through the Middle Mississippi Valley on Monday, and both GEFS and EPS have high probability of measurable precipitation with this feature, extending as far south as our region. Warmer members of the GEFS and EPS have values similar to Monday, and colder members are around 5-10 degrees colder. That being said, I feel confident in forecasted values, as more members are clustering on the warmer solution.
1050 PM CST Sat Jan 16 2021 This afternoon the Upper Mississippi Valley region was situated in between systems, beneath a low-amplitude mid-level ridge. Associated troughs extending from this low pass through the local area.
Gusty northwest winds in wake of the front will bring a reinforcing shot of cooler and drier air to the region, with temperatures falling to near freezing area-wide by Monday morning.
/issued 843 PM CST Sat Jan 16 2021/ Weak upper level energy ahead of a larger scale trough slips through the region overnight along with a very minimal uptick in atmospheric moisture. An increase in mid/high level clouds is expected late tonight into SUN morning in association with a passing upper level trough, but VFR is expected to prevail through the period. This will bring mainly just an increase in upper level clouds with no chance of precipitation due to dry low levels thanks to the high pressure.
225 AM CST Sun Jan 17 2021 Areas of mid cloud continuing to push SSE across eastern Kansas as an upper trough digs through the mid-Mississippi Valley.
Northwesterly winds continue to decrease as an area of high pressure moves in closer to the area. Dew points will remain on the low side with 20s persisting through Sunday morning. Low temperatures for Sunday night will be a bit warmer due to onshore flow returning as the high pressure begins to move off to the east. Expecting temperatures to be in the low-to-mid 40s for most with upper 30s for our far northern counties. This is because the trough is positively tilted, instability is very low, PWATs are less than 0. 5", plentiful dry air remains in the low-levels, and there will be quite a bit of upper-level convergence. The area of high pressure moves off to the east on late Sunday night/early Monday morning.
There will be some clearing in the western part of the area, however, an upper wave will push some clouds into the area before the lower clouds exit the region. High pressure will start to build into the region on Sunday bringing fewer clouds and dry weather for Sunday and Monday.
Tonight Through Monday H500 flow will remain out of the NW through the period as yet another trough deepening into a low looks to follow a similar path into the Ohio Valley as yesterday's. Sfc ridging will begin to shift east on Sunday providing winds out of the S-SW.
Main impacts on travel would likely be in the overnight and morning hours, as temperatures creep up to the freezing mark in the afternoon. Will add some chance PoP's for light snow Monday night across mainly the middle third of the forecast area, though soundings show it may end as a bit of freezing drizzle as ice crystals aloft are lost.
1218 AM EST Sun Jan 17 2021 Cooler and dry weather will continue for the next several days.
Widespread stratus clouds persist across southeast Idaho this evening while surface observations were showing areas of freezing fog at a number of locations. This will keep overnight lows only a few degrees cooler than daytime highs. This will produce some light snow mainly across the higher terrain of the Central Mountains and eastern Highlands. Most of the hi-res solutions keep precip out of the Snake Plain and Magic Valley and remain focused on the higher terrain. In areas where snow is more likely, accumulations will still be around 1-2 inches at the most with the highest totals likely along and near the Wyoming border.
West-northwest flow aloft in the wake of the upper low will back to the west-southwest as this occurs, with elevated warm advection and the onset of weak synoptic scale ascent maintaining a fairly widespread coverage of clouds through much of the morning on Sunday. Due to the combination of the lower clouds and southwesterly winds (which should begin to increase slightly once again after Midnight), we have raised predicted lows a bit above suggested blended guidance. Temps on Sunday morning will range from the u20s-l30s for much of the CWFA, and perhaps a few degrees warmer near larger bodies of water. A weak cold front moving across the region Sun afternoon, should reinforce the cold air already in place. Cooler air in place, despite more sun will bring a chilly start for a new but abbreviated work week.
Slowly moderating temperatures are expected today, with a dry cold front passing through on Monday.
Low temperatures overnight are forecast to drop into the low 30s with the upper 20s possible in the normally colder locations. For tomorrow, an approaching upper level trough will bring increasing clouds to the area and another cold front by the evening hours. Temperatures will be a few degrees warmer on Sunday afternoon and climb into the mid to upper 50s. As a trough moves out of our area overnight Sunday into Monday, we'll see clearing skies as we begin to transition into a zonal upper level pattern. This means clear and dry conditions while being slightly warmer than the previous day.
The upper trough should cross the state overnight. This upper trough should be east of the forecast area Monday morning.
Have adjusted PoPs to account for the threat of additional snow showers into the early morning hours, mainly over W PA and the ridges of N WV. Once this wave races eastward, focus for additional snow shower activity late tonight will be over the I-80 corridor and the ridges. Expect a break in the snow showers for a large portion of the region today as weak ridging aloft, ahead of the next upper low, will provide subsidence that will hinder snow shower development. Snow showers are still possible over the ridges and I-80 corridor as winds aloft will remain optimal for orographic and lake enhanced activity. In the wake of the exiting trough, heights will briefly rise Monday, and most of the snow shower activity should be confined to the I-80 corridor and ridges.
Clear skies, light winds and a dry atmosphere will allow good raditional cooling conditions with lows in the lower to mid 30s.
High clouds are streaming in from the northwest this evening, obscuring the satellite's view of low cloud and fog that is widespread across eastern Oregon and the Lower Treasure Valley. Some of this fog may become dense as the night progresses, but the high clouds building in will act to inhibit this.
234 AM EST Sun Jan 17 2021 Low pressure will gradually exit through the Canadian Maritimes today, but upper level low pressure will continue to provide for accumulating snow showers to the mountains.
By Sunday evening, a quick moving upper level low will pass through the flow, bringing snow showers across most of the region, though little accumulation is expected across most of the region. Monday, as winds diminish and snow showers tapper off over the course of the afternoon behind Sunday night's cold front, will note the colder temperatures with highs 5 to 10 degrees lower than they were the previous day.
A synoptic trof will continue to move east away from the region today. At the low levels, fairly light northwesterly winds of 10 to 20 mph are expected during the daytime. This should keep minimums slightly warmer than climo. On Monday, a large trof will continue to sink southward across the western United States. This will allow for a weak downslope flow to resume with some compressional warming ahead of a trof/front. Afternoon relative humidity will continue to remain on the marginal side, so am not expecting any major fire weather concerns, even with the warmer highs.
However, temps will be quite mild with this system, hovering in the low 30s, another factor in limiting the WW adv area to mainly higher terrain. However, a trend to much cooler/below normal temps is expected toward the end of the week, which will include chances for snow as an arctic front settles into/near the region.
A cold front will approach the region on Monday and then move through the region Monday night.
1019 PM EST Sat Jan 16 2021 High pressure centered over the southern Gulf of Mexico supports gentle to moderate northwesterly breezes across the Florida Keys. The high will lose continuity overnight as it slides east, degenerating into a fractured ridge axis. Temperatures in the lower 60s will fall a few more degrees, with some locations touching the upper 50s. A pressure ridge will build eastwards across Florida tonight. Breezes will slacken further on Sunday as the ridge axis shifts into the Keys. Another high pressure center will move east along the northern Gulf Coast Sunday through Monday, with gentle north to northeast breezes prevailing across the Keys.
A cold front will pass through the region Monday, supporting another round of stout/gusty northwest winds, especially northwest of the Flint Hills corridor.
950 PM CST Sat Jan 16 2021 (Issued 950 PM CST Sat Jan 16 2021) Went with patchy freezing drizzle over south central WI into the overnight in addition to very light snow or flurries. If the freezing drizzle becomes more widespread a Winter Wx Advisory may be needed. Southwest portions of Wisconsin and areas along the WI/IL border may see a light dusting of snow late tonight into Sunday with a mid level trough digging to our southwest. Temperatures will be below freezing so some slick spots will be possible Sunday morning.
The 19Z MSAS surface analysis indicated an area of low pressure well to our east over extreme southeast Ontario. A weak trough extended westward from the low pressure through Upper MI to the northeast corner of MN.
318 AM EST Sun Jan 17 2021 An upper level trough will swing across the region early today, moving offshore by late morning.
Under this scenario, I am inclined to lean toward the higher end of the QPF forecasts, which in this case is closer to 0. Pavement temperatures are forecast to be near to above freezing for much of Sunday.
Broad troughing pattern continues to our east and will keep Texas under a northwesterly flow aloft, keeping mid to upper levels dry. Temperatures will be slightly warmer on Monday thanks to persistent southeasterly flow.
With a 175 kt 300mb jet streak and strong low-level lapse rates late Sunday through Sunday night, additional scattered rain and snow showers will be possible primarily across the higher elevations and SW VA. SR Chattanooga Airport, TN 47 31 46 30 54 / 10 10 0 0 10 Knoxville McGhee Tyson Airport, TN 43 30 40 28 49 / 10 20 0 0 10 Oak Ridge, TN 42 29 41 28 49 / 10 20 10 0 10 Tri Cities Airport, TN 39 27 36 25 45 / 20 40 20 0 10 TN.
Temperatures near or just above freezing for areas along and north of I-10, upper 30s to lower 40s across the coastal parishes and counties. The slight increase in clouds this morning expected to give way to mostly sunny skies by the afternoon hours, with highs in the lower to mid 60s expected.
Temperatures should struggle to climb much early Sunday with stratus lingering, but building heights aloft should result in a slightly warmer day than today. Nearly 10 degrees warmer where there is little cloud cover and little snowpack vs much cooler where recent snow occurred and stratus lingers. See potential for flurries or patchy freezing drizzle near the Buffalo Ridge tomorrow as the saturated layer deepens and soundings even show some weak instability developing. Upper ridging and the previous jet max move south of the region by Monday, when a deeper upper longwave trough begins to dig into the Northern Plains and Intermountain West.
After that a high pressure ridge centered off the CA Coast will build into the region Sunday. A flat ridge will remain over the center of the country Monday but the high will be displaced by the next upper low moving down the West Coast.
For the remainder of the afternoon hrs, the persistent northerly flow remains over the area as the CWA still lies between the exiting low east and strong surface ridging coming off the central Rockies. Going into Sunday, upper/surface ridging moves east into the Plains then south by nightfall in advance of an approaching stronger upper trough. The last few days has continued to trend this system to split into the trough that passes north of the CWA, and a cutoff low that settles well south/west of the area. For Monday night, upper ridging resumes over the CWA with a slightly colder airmass in place.
Cooler with lingering light snow. Pattern Synopsis/Forecast: Overnight composite analysis reveals larger scale deep troughing encompassing most of the central and eastern CONUS. Embedded within the larger scale trough. closed low is working it's way into New England followed by a second deepening wave working into western Illinois.
The upper trough will pull east quickly tonight with good subsidence in it's wake. On Monday, high pressure over TX will shift into the northeast Gulf of Mexico with a weak ridge axis northward through the TN valley.
An upper level impulse will then move over the Deep South Sunday afternoon and evening, moving along the flow of the parent upper trough progressing over the Ohio Valley. At the surface, high pressure will build off the southeastern coast of Texas and over the western Gulf through Sunday. Thus, no precipitation is expected throughout the near term period, but there will be an increase in high level clouds ahead of the upper trough through the day on Sunday. Lows tonight and Sunday night will be very chilly, in the lower 30s north of I-10 and in the mid to upper 30s south of I-10. Highs Sunday will be a touch warmer than today, with temperatures in the mid to upper 50s area-wide.
As high pressure settles to the east of the area tomorrow, winds will become more southerly but as stated above will remain light. The trough should serve as nothing more than a wind shift. Fairly benign weather is expected at the beginning of the work week (Monday), with a weak cold front moving through the CWA on Monday.
231 AM EST Sun Jan 17 2021 Cooler and dry weather will continue for the next several days.
Sunday: A broad look at the upper levels currently shows a deep trough over the Appalachians all the way down the east coast. To the west, a ridge has begun to move in off the coast. Despite the gloominess, temperatures today will still be a hair warmer than yesterday with highs heating to the mid to upper 30s and low 40s across Nebraska and the lower 30s in Iowa. Besides the snow, temperatures will remain quite similar as they were on Sunday with the exception of locations near the KS boarder reaching the low to mid 40s.
Expect a break in the snow showers for a large portion of the region today as weak ridging aloft, ahead of the next upper low, will provide subsidence that will hinder snow shower development. Snow showers are still possible over the ridges and I-80 corridor as winds aloft will remain optimal for orographic and lake enhanced activity. In the wake of the exiting trough, heights will briefly rise Monday, and most of the snow shower activity should be confined to the I-80 corridor and ridges.
107 AM EST Sun Jan 17 2021 Low pressure will lift north across the area overnight then continue north through eastern Canada Sunday into Monday.
At 500mb, an upper low is departing up the Ohio River Valley today. As the upper low continues to depart the area on Monday, we will end up in northwesterly flow aloft and a high pressure ridge overhead.
212 AM EST Sun Jan 17 2021 Colder air has arrived overnight as building high pressure helps to drive in cooler/drier air. This morning, lows will bottom out near the freezing mark across Levy county, low mid 30s across the remainder of the Nature Coast, with 40s elsewhere across West Central and Southwest FL. Not everyone is experiencing these clouds of course, and cloud free locations can expect to see cooler morning temps and warmer afternoon highs. High pressure builds into the area.
329 AM EST Sun Jan 17 2021 An upper level low, over Pennsylvania this evening, will lift northeast of the state tonight. Mostly cloudy sky extends into the Lower Susq.
232 AM EST Sun Jan 17 2021 An upper level trough will swing across the region early today, moving offshore by late morning.
As the cold front drops in Today, the drier air over central Kansas will be taken over by higher dew points behind the boundary in the 20s and 30s. The secondary upper branch of the synoptic trough moves in Tonight, providing deep layer subsidence and clearing sky. A reinforcement of cooler air should cap temperatures at about 5 degrees cooler as well. All of this is just in advance of a noticeable cold front on Monday night.
Weak high pressure and drier conditions will build into the Ohio Valley for Monday. Axis of widespread snow pivoting thru the southern 2/3rds of ILN/s is a result of isentropic lift ahead of a surface trof. 9 inches of snow thus far today, with the higher reports for the day around an inch. Best coverage of snow shifting to the east across the lower Scioto Valley. Mid level ridging will shift east of our area through Sunday morning as a fast moving secondary mid level trough/low approaches from the west. Temperatures will push into the low to possibly mid 30s through the day.
High pressure will continue to build into the region today.
Temperatures are hovering in the lower 60s, and winds on land are from the north around 5 mph. Surface analysis depicts weak high pressure extending from the Rockies into the western Gulf of Mexico, while powerful low pressure is centered over Maine. Dry and cool weather will continue today, with thickening high cloud cover blocking the sun especially this afternoon. Any shower activity should exit quickly eastward into the Straits by sunrise Monday, and we then expect dry weather to prevail through the remainder of the week and into the weekend, as flat ridging gradually builds northward from the Caribbean with no additional frontal passages expected.
347 AM CST Sun Jan 17 2021 Early this morning, an upper longwave TROF was over eastern North America. At the surface, a weak trof stretched from northeastern Illinois through our region. The large scale pattern of a longwave TROF over eastern North America will remain in place through this period. The best upper support region will edge our far northeastern part of the forecast area, or portions of west-central and central IL and this is where the highest confidence of measurable snowfall will be. A few isolated spots may also see freezing drizzle for brief periods, where icing in the clouds may temporarily be less.
The system develops a warm front across Nebraska. This forecast is slightly warmer than the short term model blend. Warm air advection aloft, mixing, increasing moisture and cloudiness supports warmer lows then the guidance would suggest.
928 AM EST Sun Jan 17 2021 Cooler and dry weather will continue for the next several days. Weak high pressure over the Southeast will move offshore Wed with moderating temperatures expected Thu. A low pressure system will up rain chances Fri. The East Coast trough will get reinforced as another upper disturbance pinwheels southeastward across the Carolinas late tonight. Upper trough lifts to the NE on Monday afternoon.
320 AM CST Sun Jan 17 2021 Patchy freezing drizzle early this morning over northwest Wisconsin. A closed upper low near the Ohio River Valley today will move to the East Coast Monday.
/22/ Today and tonight: Quiet and dry conditions are expected through the short term period even as a series of weak disturbances embedded in the long wave troughing pattern over the eastern US move through the region. Highs today will be near normal values with lows on Sunday night falling back to near freezing.
Areas of mid cloud continuing to push SSE across eastern Kansas as an upper trough digs through the mid-Mississippi Valley.
645 AM EST Sun Jan 17 2021 An upper level trough will swing across the region early today, moving offshore by late morning.
The highest QPF (albeit very small) will also be focused in the same area, yielding the highest potential for snowfall, which is still expected to remain less than a half inch.
Weak ridge of high pressure noses into the RRV tonight and there could be some clearing of the clouds.
High pressure will maintain warm and dry conditions into Monday.
Meanwhile an upper low will begin to swing down on the west side of the trough in place over the CONUS east.
414 AM CST Sun Jan 17 2021 Today and tonight: Quiet and dry conditions are expected through the short term period even as a series of weak disturbances embedded in the long wave troughing pattern over the eastern US move through the region. Highs today will be near normal values with lows on Sunday night falling back to near freezing.