Aikyam-Lab/Synoptic-Bench huggingface dataset:
Immediately preceding this trough was a band of virga (diminishing with time) evident on the regional radar mosaic from high clouds. Tonight, the high will have departed into the Gulf ahead of moist return flow and a window for some inland fog, mainly over the Coastal Plains and Victoria Crossroads. Throughout the day tomorrow, northwest upper flow will back W-SW and in the process generate rather sharp lee troughing along the Sierra Madres.
530 AM CST Sun Jan 17 2021 Weak trough is sitting across the far eastern CWA generating some mid and low clouds. Otherwise it will be breezy from the northwest and mild with highs around freezing because, for the most part, mixing has kept us mostly steady overnight.
A compact and intensifying upper level low pressure system will move through the heart of Indiana today, bringing another round of light accumulating snowfall to the area.
/Today through Monday/ Positively tilted upper trof axis will continue to pivot sewd today, reinforcing the nwly flow aloft and the cool/dry airmass at the sfc. High pressure to settle in at the sfc tonight, and light winds/clear skies will result in temperatures in the upper 20s to mid 30s areawide.
654 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.
319 AM CST Sun Jan 17 2021 Weak trough is sitting across the far eastern CWA generating some mid and low clouds. Otherwise it will be breezy from the northwest and mild with highs around freezing because, for the most part, mixing has kept us mostly steady overnight.
332 AM CST Sun Jan 17 2021 Some light freezing temps during the next few nights mainly for the most northern portion of the area.
Cooler temperatures will be possible by late week into the weekend feeling more like January. A ridge will build into the region late Sunday night through Monday night.
417 AM PST Sun Jan 17 2021 Morning patchy dense fog and warmer today across the San Joaquin Valley as high pressure remains in place. However, a change from high pressure over the region to a dry cold front and strong winds aloft by Monday will bring strong winds to parts of the area. This will form a southwest to northeast orientated trough into the Great Basin late Monday bringing a northeasterly mono wind trajectory over the Sierra Nevada near Yosemite.
A complex weather scenario this morning, with snow, moderate at times, intermixed with freezing drizzle. Elsewhere, expect periods of snow and freezing drizzle through the morning. This morning, the seeder feeder action that was expected to lead to all snow across the area, failed and we saw mostly freezing drizzle mixed with snow. Satellite showed that ice nucleation occurred, however not many of the flakes made it to the lower level. Temperatures will not be above freezing today, so any melting of snow and ice will be from treatments, meaning that slick surfaces will remain well into the day.
Forecast issue today and tonight will be a weather system and cold front that slices through Wyoming this afternoon and tonight. Scattered light rain and snow will develop over the lower elevations of the north this afternoon, then all snow tonight.
917 AM EST Sun Jan 17 2021 A colder start this morning, with temperatures dropping into the mid 30s with near or at freezing temperatures along the traditionally colder locations in northern Volusia and Lake counties. This will lead to mostly cloudy skies, and keep temperatures cooler than normal, with highs in the low to mid 60s.
Winds will remain light but shift to the south late this afternoon as high pressure settles over the Gulf Coast. Overnight clear skies and light wind will allow temperatures to drop near the freezing mark across the entire area.
538 AM EST Sun Jan 17 2021 Cooler and dry weather will continue for the next several days.
349 AM CST Sun Jan 17 2021 Forecast concerns in the short term will be patchy freezing drizzle, light snow this morning, the continuance of the winter weather advisory and then light snow/freezing drizzle potential again tonight. This combined with temperatures falling to below freezing and re-freeze on pavement resulted in surfaces with a glaze of ice and a mess for drivers/road crews for those traveling on untreated roads. The depth of the cold air was deep enough for the radar returns from Winona to Rochester southward to be mostly light snow, however calls to Juneau and Richland still had freezing drizzle. It does have a good 700mb warm air advection signal and potential for some light snow or a mix of light snow/freezing drizzle. Any freezing drizzle looks patchy at the onset this evening.
A weak disturbance passing through the region starting tonight will bring cooler temperatures, gusty winds and a slight chance of showers to the region.
Unseasonably mild weather likely on Monday as temperatures warm into the upper 50s to near 60 in many locations ahead of weak cold front that will move into northeast Oklahoma by late afternoon.
A cold front will push across the region by late morning into the afternoon.
Upper level analysis places trough over the midwest, and ridge over the western CONUS. For today, modest ridging passing through brings a quiet start to the day, but in the meantime the first in a pair of short waves starts dropping through the flow towards our area.
The highest totals are likely over complex terrain areas such as the Big Sheep Mountains as well as over southern Wibaux County.
High temperatures will generally range from 25 to 30 today and Monday, with lows in the middle teens across the north to the lower 20s across east- central Wisconsin tonight.
Split flow eventually comes back together as one jet by the weekend and as flow becomes more southwest in response to the amplifying western trough, we have a shot of precip during the weekend with an isentropic lift event potentially giving us a mixed bag of precip depending on surface, maxT/Td aloft temperatures.
As this happens, a weak cold front will pass through the region. Winds will diminish somewhat tonight as high pressure passes to our south. The high will move along the Gulf Coast on Monday, and winds around here will switch the south/southwest. A new storm system/cold front will approach the area from the Plains Monday night, and clouds will increase.
500 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.
Otherwise, another forecast issue is the low level stratus and fog, which with increasing upper level cloud cover may not go away, except where it gets breezy to windy. Another forecast problem was the NBM putting in freezing precipitation over large portions of the forecast area. However, consistent with yesterday, I could not find any model sounding near those points that had any kind of warm layer that got even above freezing, never mind the 3 deg C threshold normally needed for freezing rain.
Temps today are expected to be above average in the high valleys, with around to slightly above average highs over the plains. Tonight, ahead of the next weather system over the northern Rockies, a weak disturbance and an increase in moisture, is expected to bring snow to the central mtns, with probably a couple inches of accumulation, mainly over the high elevations in Lake County. Cold front drops through the plains early Monday morning, while strong upper jet digs southward along the Pacific Coast through the day. Upper low develops over the srn Great Basin Mon night, then moves sw off the srn California Coast during the day Tue.
Broad high pressure in the southern plains and western Gulf of Mexico expands and begins to shift toward FL today. Temperatures will be warming throughout the day but the clouds will help inhibit this and the highs are expected to reach the 60s. With a rather weak high pressure pattern across the waters winds will be light to gentle but some residual seas remain. High pressure builds into the area by Tue with an increase in winds and seas.
Overnight clear skies and light wind will allow temperatures to drop near the freezing mark across the entire area.
545 AM CST Sun Jan 17 2021 A cold front will bring increasing mid level clouds to the terminals, as it pushes sewd today. Winds will veer around to the w and eventually nw as the cold front passes, with speeds peaking at 10-12 kts with some ocnl gusts. /Today through Monday/ Positively tilted upper trof axis will continue to pivot sewd today, reinforcing the nwly flow aloft and the cool/dry airmass at the sfc. High pressure to settle in at the sfc tonight, and light winds/clear skies will result in temperatures in the upper 20s to mid 30s areawide.
Temperatures will be mild today ahead of the front, with slightly cooler temperatures expected on Monday.
The passage of a weak 500 mb trough through Deep South Texas and the Rio Grande Valley today may generate some isolated showers over the extreme southeast corner of the inland portion of the BRO CWFA.
An upper level impulse will then move over the Deep South this 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 central Gulf through Monday. 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 today. Lows tonight will be very chilly, in the lower 30s north of I-10 and in the mid to upper 30s south of I-10.
546 AM CST Sun Jan 17 2021 Forecast concerns in the short term will be patchy freezing drizzle, light snow this morning, the continuance of the winter weather advisory and then light snow/freezing drizzle potential again tonight. This combined with temperatures falling to below freezing and re-freeze on pavement resulted in surfaces with a glaze of ice and a mess for drivers/road crews for those traveling on untreated roads. The depth of the cold air was deep enough for the radar returns from Winona to Rochester southward to be mostly light snow, however calls to Juneau and Richland still had freezing drizzle. It does have a good 700mb warm air advection signal and potential for some light snow or a mix of light snow/freezing drizzle. Any freezing drizzle looks patchy at the onset this evening.
904 AM EST Sun Jan 17 2021 An upper level low pressure system will move east across the Ohio Valley today and tonight. Weak high pressure and drier conditions will build into the Ohio Valley for Monday.
515 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.
There could also be some light drizzle or freezing drizzle along and south of the Minnesota River Valley down to about Mankato where the thermal profile hints at a loss of ice. High temperatures today will warm around 10 degrees in western Minnesota compared to yesterday, while highs in Wisconsin will be a few degrees cooler. Cooler temperatures move in for Monday with highs in the teens and 20s.
408 AM CST Sun Jan 17 2021 Expect a nice day across the Mid South as high pressure builds into the area.
/issued 408 AM CST Sun Jan 17 2021/ Expect a nice day across the Mid South as high pressure builds into the area.
As the upper level trough that contributed to today's cloudiness moves out of eastern CONUS by tomorrow morning, zonal flow becomes established.
Unseasonably mild weather will be likely tomorrow as temperatures warm into the upper 50s to near 60 in many locations as low level thermal ridge expands east over the area ahead of an approaching cold front that will move into northeast Oklahoma by late afternoon.
1143 AM CST Sun Jan 17 2021 Forecast concerns in the short term will be patchy freezing drizzle, light snow this morning, the continuance of the winter weather advisory and then light snow/freezing drizzle potential again tonight. This combined with temperatures falling to below freezing and re-freeze on pavement resulted in surfaces with a glaze of ice and a mess for drivers/road crews for those traveling on untreated roads. The depth of the cold air was deep enough for the radar returns from Winona to Rochester southward to be mostly light snow, however calls to Juneau and Richland still had freezing drizzle. It does have a good 700mb warm air advection signal and potential for some light snow or a mix of light snow/freezing drizzle. Any freezing drizzle looks patchy at the onset this evening.
Weak trough is sitting across the far eastern CWA generating some mid and low clouds. Otherwise it will be breezy from the northwest and mild with highs around freezing because, for the most part, mixing has kept us mostly steady overnight.
Flow aloft will back from northwest to west during this period which will induce a southwest to west low level flow early in the day Monday before the passage of the next cold front.
Temperatures are a little warmer than expected so will raise highs a couple of degrees for this afternoon. /issued 408 AM CST Sun Jan 17 2021/ Expect a nice day across the Mid South as high pressure builds into the area.
SR Chattanooga Airport, TN 47 31 46 31 53 / 10 0 0 0 10 Knoxville McGhee Tyson Airport, TN 43 30 42 30 49 / 10 20 0 0 10 Oak Ridge, TN 42 29 40 29 49 / 10 10 10 0 10 Tri Cities Airport, TN 39 27 37 26 45 / 20 40 10 10 20.
158 PM MST Sun Jan 17 2021 20z surface analysis had low over east central AB with trough into western NE. Trailing cold front will sweep across MT through the CWA tonight. 5-2" on the plains of western SD, 1-4" for northeast WY with the highest totals near the MT/SD borders. Isallobaric forcing looks to come in two batches, the first of which will arrive tonight with gusty northwest winds at times behind cold front.
The region will be between high pressure to the south, and a broad trough of low pressure to the north this afternoon and evening. A weak cold front will pass southeast across area Tonight. High pressure will build overhead from the west Monday.
A secondary band of ascent (related to the latter disturbance mentioned above) will brush the region on Monday night, supporting a chance of additional light snow or light freezing drizzle, mainly over our northern and eastern counties. Highs on Monday will be in the low to mid 30s in areas of clouds and snow with around 40 near the KS border.
A weak area of high pressure will move toward the region tonight keeping things dry tonight. High pressure will remain over the region on Monday bringing one more day of dry weather. A cold front will move into Arkansas Monday night.
1149 AM CST Sun Jan 17 2021 Not much movement on the low stratus deck in the east, with some scattered low clouds also moving south through the central part of the state. A weak back door cold front is draped from Bottineau back east through eastern North Dakota, with some light snow ongoing in the Red River Valley this morning. Upper level analysis places trough over the midwest, and ridge over the western CONUS. For today, modest ridging passing through brings a quiet start to the day, but in the meantime the first in a pair of short waves starts dropping through the flow towards our area.
Vigorous upper level trough currently moving into the Ohio Valley is responsible for the increase in mid-level cloud cover across the northern half of our region this morning with this moisture expected to continue drifting south and east through the day.
Some mid-level clouds are passing over the terminals this afternoon as a weak cold front slides through, but these will have no impact on operations at the terminals. /issued 332 AM CST Sun Jan 17 2021/ Some light freezing temps during the next few nights mainly for the most northern portion of the area.
1010 AM EST Sun Jan 17 2021 Upper level low pressure will track across the Ohio Valley, then into New England today through Monday.
This trend will carry on overnight, with Monday night lows ranging from the low to middle 60s across the RGV.
148 PM CST Sun Jan 17 2021 Upper ridge building into area today but the next upper trough will work down the CA Coast on Monday.
Zonal flow is then expected to return by late Monday afternoon as the main trough progresses eastward over the Atlantic. At the surface, a weak, dry cold front is currently making its way over the Deep South. High pressure will then take hold over the northern Gulf coast through Monday. Lows tonight will again be chilly as temperatures dip into the lower to mid 30s north of I-10 and in the upper 30s to lower 40s south of I-10. Highs tomorrow will then be similar to today but be a touch warmer, in the upper 50s to lower 60s. Some high clouds associated with an approaching weak, dry cold front are currently streaming over the region and will move to the southeast through the afternoon.
Vigorous upper level trough currently moving into the Ohio Valley is responsible for the increase in mid-level cloud cover across the northern half of our region this morning with this moisture expected to continue drifting south and east through the day. /issued 545 AM CST Sun Jan 17 2021/ A cold front will bring increasing mid level clouds to the terminals, as it pushes sewd today. Winds will veer around to the w and eventually nw as the cold front passes, with speeds peaking at 10-12 kts with some ocnl gusts.
Winds and dewpoints are forecast to be slightly higher than the last couple of nights, which should result in temperatures a few degrees warmer than what we saw this morning.
(This evening through Monday) Gusty northwest winds will diminish quickly this evening and will then shift back to the southwest overnight ahead of next weak cold front. Otherwise, overnight will be cool with periods of some mid/high clouds, but a bit less than last night, so temps are expected to be a few degrees cooler. Moisture will lift northward ahead of the cold front and by late in the day tomorrow we may see an increase in lower clouds across parts of southern and southeastern Oklahoma. No precip is expected along the front during the day tomorrow and temperatures will be may actually be a few degrees warmer than today.
A cool air mass in the low levels was topped by a very strong subsidence inversion near 5,500 feet. southeast coast in advance of the progressive longwave trough moving past the Mississippi River Valley. Some precip is likely to fall out of the high cloud deck tonight. Both the low-level and upper-level forcing will quickly exit east by late Monday morning. A weak ridge axis across the Gulf and the Florida Peninsula will shift south into the Keys this evening before dissipating.
Moisture from Lake Ontario will move into the region on Monday and bring more snow showers to the higher terrain, especially across southern Vermont. Highs on Monday will be in the lower 20s to lower 30s with lows Monday night generally in the 5 to 15 above range.
Diegan Chattanooga Airport, TN 47 31 46 31 53 / 10 0 0 0 10 Knoxville McGhee Tyson Airport, TN 43 30 42 30 49 / 10 20 0 0 10 Oak Ridge, TN 42 29 40 29 49 / 10 10 10 0 10 Tri Cities Airport, TN 39 27 37 26 45 / 20 40 10 10 20.
843 AM PST Sun Jan 17 2021 A cold front, was working its way across mainly eastern portions of the area, from near Walla Walla to points east.
While a few sprinkles cannot be ruled out later this afternoon, measurable rain is unlikely as dry conditions persist in the lower levels. /DL/ Prior discussion below: 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.
Another upper low currently over NW Illinois will move to the SE during the course of the day, reaching southern Indiana by the early evening. A trough axis extending south of the low should also develop. Under this trough, a weak cold front will form and move across the forecast area during the course of the afternoon and early evening. The infrared/visible satellite view indicated an expansive area of stratus remaining across the NE quadrant of the CONUS (some of it associated with low pressure well to our NE), as well as the western Illinois system. 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.
Clear skies, light winds and a dry atmosphere will allow good radiational cooling conditions with lows in the lower to mid 30s.
Overall the Panhandles will be split between the warm/cold air masses and thus temperatures will be right around normal with highs in the lower to mid 50s tomorrow.
The 19Z MSAS surface analysis indicated low pressure well to our east over Quebec with a pair of troughs extended westward into the Great Lakes. A weak ridge of high pressure was situated over the High Plains. Otherwise, another mostly cloudy night on tap with min temperatures to range from the middle teens far north, to the lower 20s over east-central WI. While better forcing will remain to our north, there should be just enough forcing to combine with lift from the cold front to at least bring a small chance of light snow showers to northern WI by the afternoon. There could be some light lake effect snow in Vilas county at times this week as upper troughs and surface cold fronts go by, but moisture and instability look insufficient for significant lake effect snow.
The steadiest snow in the west should end by midnight but unstable northwesterly flow and cyclonic curvature will keep some snow showers going into tomorrow before tapering off Monday night as high pressure builds in. When temperatures fall to below freezing following the frontal passage and changes to snow, there could be some icy spots on the road. All snow should end later Monday night as ridging folds over the area. Ridging and northwest flow will dominate and bring mainly dry conditions. Temperatures will be a bit cooler than recent days, but nothing out of the ordinary for January.
High pressure will remain across the region today.
This weak boundary will be followed by another upper low crossing the OH valley tonight. This will bring it's associated trough axis across the mid-state tonight as well. Spots on the highland rim and northern Plateau may see up to an inch but overall a few tenths is more likely. Upper flow will relax later Mon becoming more of a weak broad trough by Tues.
246 PM CST Sun Jan 17 2021 Early this afternoon, an amplified upper level trough was located from lake MI, south-southwest into the lower MS River Valley. Temperatures have warmed into the lower to mid 40s across much of the CWA. A weak cold front will move southeast across the CWA through the day but there will not be much of a thermal gradient behind this front.
202 PM CST Sun Jan 17 2021 An upper low that passed by to our south overnight is slowly retreating towards the Ohio Valley this afternoon. On a smaller scale, some weak low level frontogenesis bands have continued to produce light snow/flurries and perhaps some patchy freezing drizzle at times across portions of southwest and west-central WI since this morning. Forecast soundings generally show low level saturation extending deep enough into the snow-growth zone (or at least a seeder-feeder setup in place) to support mainly light snow chances, but can't rule out a lack of ice in the clouds at times that could produce some patchy freezing drizzle.
Light snow will fall in the higher terrain above 3000-4000 feet MSL with isolated rain showers in the lower valleys.