Aikyam-Lab/Synoptic-Bench huggingface dataset:
311 PM EST Sun Dec 6 2020 A mid-level trough is parked over the eastern United States. Two low pressure systems from Canada are going to work their way along this trough through the region over the next 24 hours. All the low level moisture will produce low ceilings and some area sprinkles and flurries, but aren't expecting anything measurable. Even with a north wind, cloud cover will help to limit overnight lows to the mid to upper 20s west of Interstate 65 and areas east of 65 will likely remain slightly warmer up to near freezing.
122 PM MST Sun Dec 6 2020 High pressure ridging will hold firm for a couple more days across the forecast area.
Temperatures will start off seasonably cold to slightly below normal, but trend warmer and rise above average from late week into the weekend. Otherwise, the lower clouds in the W/NW will hang on. Two lobes of upper energy rotating around a larger upper trough will coalesce into one and move along the Mason-Dixon line on Monday.
Northerly flow at the surface and aloft will persist through Monday although the flow aloft will slacken as the upper trough shifts farther east past the Miss Vly and we are left with broad ridging and a loose height gradient across the region. Upper ridging will continue to dominate the region into mid week.
Based on similar setups a couple/few days ago, have bumped temperatures toward the higher guidance with mid 40s to mid 50s.
Max temps tomorrow will be similar to today, reaching the low to mid 60s with ample sunshine. On Monday night temps will also be similar to tonight, possibly a degree or two warmer.
With the low clouds in place, temperatures tonight are not expected to drop as much as the past couple nights, with lows in the lower to middle 20s. At this time, expect mostly cloudy skies to remain in place over the area, which will keep highs a touch cooler than previously forecast. Highs will likely still range from the lower to middle 30s.
A reinforcing dry cold front is moving through SE Texas this afternoon.
The highest chance for seeing any light dusting of snow from this would appear to be Juneau/Adams Counties in the far east, but 06. Given saturation through about the lowest 1 km, we might have to watch out for some patchy drizzle or fog, though the lack of an obvious source of low-level lift and ho-hum/marginal saturation depth are mitigating factors against drizzle. Guidance also keeps the lowest visibilities from fog off to the southwest of the area in south-central MN. After the short wave trough departs the area Monday night, the upper level flow looks to become zonal before transitioning to a southwest flow pattern toward the upcoming weekend.
Satellite imagery showing dense freezing fog and fog beginning to clear. The lowest CIGs will occur from TYS and northeastward toward TRI. SR Chattanooga Airport, TN 37 43 28 49 30 / 10 10 0 0 0 Knoxville McGhee Tyson Airport, TN 36 42 27 45 28 / 20 20 0 0 0 Oak Ridge, TN 34 41 27 46 28 / 10 10 0 0 0 Tri Cities Airport, TN 33 39 25 41 25 / 20 20 10 0 0.
Temperatures will start off seasonably cold and below normal, but trend warmer and rise above average from late week into the weekend. Otherwise, the lower clouds in the W/NW will hang on.
Occasional light echoes from high level cirrus have been noted on radar this afternoon, along with reports of virga, which is all in association with increasing lift from an upper level trough that will swing across Middle Tennessee this evening and overnight. Latest thinking is that as the trough axis swings across late this afternoon into the evening, sprinkles will develop west of I-65 then intensify into a few light rain showers as they spread east of I-65. Rest of the work week is anticipated to be dry with a gradual warming trend as a weak upper ridge builds along the Gulf Coast and we remain in northwest flow aloft.
113 PM MST Sun Dec 6 2020 Latest water vapor imagery shows an upper low over the Pacific Northwest, a skinny ridge over the Rockies, and northerly flow bringing some high level moisture into the Northern Plains. At the surface, high pressure remains over the area with temperatures mainly in the 50s, with a few 60s around the eastern foothills. A more unsettled, progressive pattern sets up the second half of the week, resulting in cooler temperatures and some chances for showers.
Cooler temperatures and light rain and snow work their way in towards the end of the week, as a series of disturbances crosses the state. The warming trend continues under a sharp ridge of high pressure. Highs will be 5-10 degrees warmer than normal today, and 5-15 degrees warmer than normal on Monday. Lows tonight will remain cooler than normal over northwest, west central and north central New Mexico while continuing to be within a few degrees of average elsewhere.
(This evening through Monday) Issued at 1151 AM CST Sun Dec 6 2020 High pressure at the surface and northerly winds aloft will continue a quiet weather pattern through tonight. Afternoon highs should reach to near 60 with the exception of the residual snowpack which will keep the highs a few degrees cooler. An upper level longwave ridge will remain anchored over the western CONUS through mid-week, effectively inhibiting any impactful weather during that time period.
Unusual synoptic pattern with a 500 mb closed upper low over northeast Nevada this evening, retrograding to the southwest into central/southern CA by Monday afternoon. In its place a ridge axis stretches east/southeast from the eastern Pacific, across Oregon and into the central Rockies by Monday afternoon.
(This evening through Monday) No significant weather issues tonight or tomorrow as the area remains under northwest flow aloft between the exiting storm system and the upper ridge developing from the southern High Plains to the northern Rockies. The biggest local influence will remain the remnant snowpack keeping high temperatures much cooler in far northwest Oklahoma again on Monday.
1107 AM CST Sun Dec 6 2020 Areas along and east of I-29 are dealing with stratus and patchy fog this morning as a low pressure system/wave in eastern IA/western IL/southern WI spins to the south. Models continue to show mid and upper level ridge taking hold across the western US, with a cut off low pressure stuck in the southwestern US.
However, low level moisture will become more and more shallow overnight as subsidence inversion lowers, but even though snow shower activity will diminish, the low clouds will remain.
An upper low across the East Coast and another upper low approaching southern California.
1150 AM CST Sun Dec 6 2020 (Today and tonight) The center of the upper level low is spinning near the DFW area early this morning. Highs will warm into the low to mid 60s with north winds of 10 to 15 mph.
357 PM EST Sun Dec 6 2020 Low pressure will develop offshore and bring occasional rain late tonight and tomorrow. Cool high pressure will then follow into the midweek, with a gradual return of seasonable temperatures late in the week.
The sunshine should still provide enough insolation to reach previously forecasted highs in the low 40s.
107 PM CST Sun Dec 6 2020 An upper trough now located over the upper Midwest will drop southeast this evening. An attendant cold front will become more defined tonight and shift southeast through the region. Satellite shows increasing clouds along the lower and upper level frontal band over AR/TN and from eastern OK through the lower OH valley. The cold front will continue to push southeast of the area on Monday morning. Temperatures will be much colder with highs only in the upper 30s- around 40 atop the higher Cumberland Plateau areas in TN and far northeast AL, with middle 40s further southwest.
The western US ridge will remain in place through the short term. The ridge axis moves across the Dakotas tonight, popping back up to the west on Monday behind the passage of the aforementioned wave.
As of 19z GOES water vapor imagery depicted nearly meridional flow aloft over the region, sandwiched between a highly amplified ridge to the west and broad cyclonic flow eastward to the Atlantic. No change through the middle of the week as the western conus ridge begins to deamplify and translate east over.
This trough was co-located with some low-level cloud cover across eastern Missouri, with our CWA remaining primarily cloud-free. High temperatures in the upper 40s to low 50s this afternoon should drop back into the upper 20s to around 30 degrees overnight given the dry airmass and light northerly winds as high pressure builds into Kansas and the central Plains. Upper level height rises on the eastern edge of a amplified ridge across the western CONUS paired with southwesterly surface winds will funnel slightly warmer temperatures into the Ozarks region with highs ranging from around 50 in central Missouri to the mid 50s in southeast Kansas and far southwest Missouri.
Temperatures this afternoon have been slower to warm compared to yesterday across the area with light surface winds as surface ridging slowly traverses eastward. The lowest RH values, sub 20 percent, look to remain largely along and west of Highway 83.
A low pressure system moving through eastern Iowa pushed a deck of low clouds and a bit of fog into the forecast area this morning. With this cover shielding much of the area from insolation, temperatures below the deck this afternoon have only reached the low to mid 30s. Meanwhile, locations that have had more abundant sunshine are about 10 degrees warmer, in the low to mid 40s. We will remain dry under the edge of the ridge umbrella that is centered over the western half of the country for the next several days, as multiple waves ripple through just off to our east.
Max temps are approaching forecast values, so will have to monitor for temps to be a few degrees warmer is a few locations than expected, but not significantly. As expected, still looking for rain chances to be increasing across western portions of our area this afternoon and spreading east this evening as an upper trough currently over eastern Texas moves east to the lower Mississippi River Valley by this evening. Clouds scatter out by late tonight as the axis of the upper trough moves east of our area.
100 PM CST Sun Dec 6 2020 An upper level low continues to drift south toward the area this afternoon, currently over central IL, IN and east central MO. Secondary upper low will be over IN by 12z Monday.
142 PM CST Sun Dec 6 2020 Temperatures will continue to rise into the 60s for much of the forecast area today under full sunshine as our trough axis from yesterday has pressed east, leading to rising heights and dry northerly flow aloft. There will be a "cooler" spot aligned over the high terrain to the southwest where snow fell yesterday.
Southern jet stream system energy producing weak low pressure area on stalled front in SE Gulf of Mexico this afternoon to move into the C-S FL Peninsula tonight while Deep South cold front sweeps into N FL Peninsula.
(This evening through Monday) Issued at 1151 AM CST Sun Dec 6 2020 High pressure at the surface and northerly winds aloft will continue a quiet weather pattern through tonight. Afternoon highs should reach to near 60 with the exception of the residual snowpack which will keep the highs a few degrees cooler.
A couple of upper lows will move across the area tonight into Monday, bringing some flurries to the area. Cloudy conditions will continue tonight as one upper low tracks across the area tonight, closely followed by another upper low approaching from the NW by daybreak. The upper lows will be exiting the area tomorrow but will be followed by a weak short wave Monday night.
A frontal boundary moved through the area this morning behind the upper trough axis that passed to our east. A few outlying locations in the Hill Country could flirt with the freezing mark by morning.
1133 AM CST Sun Dec 6 2020 Upper level ridging will remain anchored across the Rockies today, with northerly flow aloft across our area on the eastern periphery of the ridging. At the surface, the center of high pressure will settle southward along the Missouri river across eastern NE and western IA.
1146 AM CST Sun Dec 6 2020 Our pattern of overall dry conditions look to continue for the next several days, with a trend toward warmer temperatures by mid-week. This would indicate the potential for some light snow and/or freezing drizzle.
Initially, the ridge is pushing against weak troughing in the in the Western Gulf of Mexico leading to a moderate northwesterly wind this afternoon, gradually subsiding this evening. Mainly light winds are then expected Monday and Monday night as the ridge moves more overhead. Low temperatures will continue to fall into the upper 30s and lower 40s tonight and Monday night with highs on Monday a couple degrees warmer than today. into the lower 70s west.
911 AM CST Sun Dec 6 2020 A pair of upper lows, one over northeast TX and the other over IL, will eventually merge over the Southeast early this week. A few sprinkles may have fallen near the Red River in Choctaw county on the northern fringe of the TX upper low. A weak boundary has shifted winds to the north and northwest, and will lead to a cooler, near normal day today. Upper low over north Texas early this morning will continue to translate eastward today, as a short wave trough dives southward from the Midwest. /Issued 401 AM CST Sun Dec 6 2020/ A few sprinkles or very light showers will remain possible early this morning across far southeast Oklahoma as an upper low moves across northeast Texas.
1020 AM EST Sun Dec 6 2020 Low pressure tracks northeast across the Canadian Maritimes today.
244 PM EST Sun Dec 6 2020 500mb analysis shows a low pressure system across western TX with zonal flow aloft across the SE. At the surface, weak high pressure centered near the ARKLAMISS will translate quickly eastward overnight and early tomorrow. Low pressure is expected to develop across the northern Gulf of Mexico and move across the peninsula of Florida late Sunday into Monday. All of the moisture remains in the low levels.
Rising heights/thickness along with abundant sunshine will yield highs in the low to mid 50s across the area. Warmer temperatures are expected by mid week with ridging over the southern and central Plains as highs reach into the 60s. A closed upper low early in the period is forecast to be absorbed as northern stream energy dives southeastward into the Plains by the end of the week.
1016 AM MST Sun Dec 6 2020 High pressure continues over the Rockies with clear skies and dry weather.
Satellite imagery showing dense freezing fog and fog beginning to clear. VFR will prevail tonight at CHA, but scattered rain and snow showers will bring periods of MVFR and IFR to TYS and TRI as a cold front approaches. Garuckas Chattanooga Airport, TN 54 37 43 28 49 / 10 10 10 0 0 Knoxville McGhee Tyson Airport, TN 51 36 42 27 45 / 0 30 10 10 0 Oak Ridge, TN 50 34 41 27 46 / 0 10 10 0 0 Tri Cities Airport, TN 47 33 39 25 41 / 0 30 20 10 0.
The temperatures have risen nicely into the lower 60s where the clouds have cleared. clouds have been thinning from west to east with Lafayette remaining overcast with temperatures in the low 50s so far this afternoon. The two systems were connected by trough axis that did extend down into south Texas. Both of these upper level lows will move east tonight allowing for a weak dry cold front to sweep through our area overnight. High pressure will settle in on Monday with below normal temperatures for tonight and Monday. No freezing weather is expected tonight so that is the good news.
Overnight lows will drop into the middle to upper 20s, while highs on Monday reach the lower 40s. Lows tonight will dip into the middle to upper 20s, with highs only rebounding into the lower 40s on Monday.
Presently, the upper levels are a bit interesting as ridging over the high plains is flanked by an upper level Pacific Northwest low and low pressure over Ontario and the Great Lakes region. Towards the end of the workweek, a separate tightly wound upper low will crash into western Canada with a trough ejecting off and rapidly digging down through the Pacific Northwest.
Dealing with freezing fog again this morning, but this should clear up by 15Z.
200 PM EST Sun Dec 6 2020 Weak high pressure over the Ohio Valley will build south into North Carolina today. A low pressure system will move into the Carolinas tonight, slowly moving through central North Carolina and offshore by Monday night. High pressure will once again build into the area from the west through the middle of the week. Today will remain dry as weak upper-level ridging builds across the region, with high clouds increasing across the area. Temperatures this afternoon will increase into the low to mid 50s. By tonight, the low across eastern TX will weaken and absorb into a trough associated with the low across IL, which will then traverse across central NC late tonight.
For tnt, the upper low over Ontario will track swd along the axis of Lake MI.
124 PM MST Sun Dec 6 2020 Ridging remains in place through the next 36 hours, with warmer air aloft capping off the cold pools trapped around the region. Temperatures making above freezing this afternoon will finally help erode some of the remaining snow in the area, helping to add a bit of mixing to the sfc areas with remaining cold pools.
The upper level pattern remains very similar for Monday, but increasing winds hint that we will see deeper mixing and a bit warmer temperatures.
Upper heights will rise into the first half of the work week as ridging nudges into the central CONUS.
All of lower Michigan remains socked in low clouds this afternoon, with temperatures only around/slightly above freezing. Thus, activity should be very light with the shallow cloud depths, and could even be a touch of light freezing rain tomorrow with the lack of ice nuclei (note the Sarnia obs today).
255 PM CST Sun Dec 6 2020 An upper level trof is moving into Mississippi at this time while a weak cold front continues to slowly move through the area of West Tennessee near the Tennessee River and Northeast Mississippi. Showers continue to blossom over Southern Arkansas underneath the upper trof. Expect the activity to quickly come to an end once the upper level trof moves east this evening. Meanwhile, another upper level trof is digging southward across the Ohio Valley at this time. This trof will move into the Mid-South around sunrise. Don't expect any precipitation with the system, but expect low clouds associated with the upper trof to move into the area and will keep temperatures chilly on Monday.
/Issued 911 AM CST Sun Dec 6 2020/ A pair of upper lows, one over northeast TX and the other over IL, will eventually merge over the Southeast early this week. A few sprinkles may have fallen near the Red River in Choctaw county on the northern fringe of the TX upper low. A weak boundary has shifted winds to the north and northwest, and will lead to a cooler, near normal day today. Upper low over north Texas early this morning will continue to translate eastward today, as a short wave trough dives southward from the Midwest. /Issued 401 AM CST Sun Dec 6 2020/ A few sprinkles or very light showers will remain possible early this morning across far southeast Oklahoma as an upper low moves across northeast Texas.
102 PM EST Sun Dec 6 2020 Some light snow is possible tonight and Monday with crossing low pressure. Even with the ridging today, cloud cover will continue with saturation below a temperature inversion.
Some of the high resolution guidance goes bonkers for a time producing a little over 0.
1022 AM CST Sun Dec 6 2020 Our pattern of overall dry conditions look to continue for the next several days, with a trend toward warmer temperatures by mid-week. This would indicate the potential for some light snow and/or freezing drizzle.
331 PM EST Sun Dec 6 2020 Low pressure tracks through the Canadian Maritimes tonight with breezy northwest winds relaxing tonight. Another area of low pressure passes well south of the area Monday with quiet weather expected for much of the week. Strong low pressure will slowly track through the Canadian Maritimes with breezy NW to W winds relaxing after sunset. Broad scale upper trough remains over the East Coast Monday as an area of low pressure passes well south of the area.
/Tonight through Monday Night/ Nwly flow aloft will bring decreasing clouds and usher in high pressure at the sfc tonight in the wake of the upper low that moved ovhd today.
1020 AM MST Sun Dec 6 2020 High pressure will remain amplified over the Rockies today with mild afternoon temperatures and light winds aloft. A low pressure trough will move into the Pacific Northwest this morning, allowing the Rex-ish block to break down as the southern low finally exits into Texas. The high pressure ridge will stand firm as this PacNW low closes off and drops southward through the Great Basin this afternoon. The closed low will then drop southwestward just off the Southern California/Baja coastline, in turn forming yet another Rex Block, although this one is positioned further west rather than directly overhead.
likewise, high level moisture above 12kft in association with an upper level trough currently ovhd will quickly shift east of our region as well. /Tonight through Monday Night/ Nwly flow aloft will bring decreasing clouds and usher in high pressure at the sfc tonight in the wake of the upper low that moved ovhd today.
803 PM CST Sun Dec 6 2020 New Information added to update section A little more active evening than initially anticipated with freezing drizzle developing across portions of central/north- central Wisconsin. Have extended the Special Weather Statement farther south into Marathon County as observations continue to show some southward advancement of very light freezing drizzle or mist. With the low clouds in place, temperatures tonight are not expected to drop as much as the past couple nights, with lows in the lower to middle 20s. At this time, expect mostly cloudy skies to remain in place over the area, which will keep highs a touch cooler than previously forecast. Highs will likely still range from the lower to middle 30s.
In the short term, an upper-level low pressure center will pinch off from the northern stream flow and separate completely by moving southward through the western US states. Further downstream for our region, high pressure remains in control.
501 PM EST Sun Dec 6 2020 Some light snow is possible tonight and Monday with crossing low pressure.
/issued 255 PM CST Sun Dec 6 2020/ An upper level trof is moving into Mississippi at this time while a weak cold front continues to slowly move through the area of West Tennessee near the Tennessee River and Northeast Mississippi. Showers continue to blossom over Southern Arkansas underneath the upper trof. Expect the activity to quickly come to an end once the upper level trof moves east this evening. Meanwhile, another upper level trof is digging southward across the Ohio Valley at this time. This trof will move into the Mid-South around sunrise. Don't expect any precipitation with the system, but expect low clouds associated with the upper trof to move into the area and will keep temperatures chilly on Monday.
An upper level low continues to drift south toward the area this afternoon, currently over central IL, IN and east central MO. Secondary upper low will be over IN by 12z Monday.
714 PM EST Sun Dec 6 2020 Low pressure tracks through the Canadian Maritimes tonight with breezy northwest winds relaxing tonight. Another area of low pressure passes well south of the area Monday with quiet weather expected for much of the week. Strong low pressure will slowly track through the Canadian Maritimes with breezy NW to W winds relaxing after sunset. Broad scale upper trough remains over the East Coast Monday as an area of low pressure passes well south of the area.
With a ridge of high pressure overhead, high temperatures are forecast to vary from a few to around 16 degrees above normal through the first half of the work week. Cooler temperatures and a chance for light rain and snow are expected daily during the latter half of the week as one weather system crosses from the Baja Peninsula, then another from the northwest.