Aikyam-Lab/Synoptic-Bench huggingface dataset:
/issued 254 PM CDT Sat Aug 22 2020/ (Tonight and Sunday) Morning shower and thunderstorm activity has dissipated across the area giving way to mostly sunny skies, with temperatures generally in the lower to mid 90s. The upper level ridge axis will remain anchored across the Four Corners on Sunday, with West Central Texas under northeasterly flow aloft.
625 PM CDT Sat Aug 22 2020 The upper ridge persists over the rockies, with a 500mb high sitting over the 4 corners region. Expect our dry and warm conditions to persist into Sunday afternoon, with highs in the low to mid 90s this afternoon and Sunday. The western CONUS upper level ridge is still propagating over into the central CONUS when the period opens.
Temperatures are running a few degrees warmer than last night with readings in the lower 70s areawide. /issued 345 PM CDT Sat Aug 22 2020/ Showers continue to develop across areas of West Tennessee near the Tennessee River and Northeast Mississippi thanks to a weak upper level low pressure system that is moving through the Tennessee River Valley. The upper low will move off to the northeast tonight.
Kept precip chances on the low end, though could see more widespread activity clip the southwest or south forecast area later tonight into early Sunday morning.
Mid tropospheric ridge is still in place from the Four Corners region up into Saskatchewan and Manitoba. A trough still extends from the Great Lakes region down into the western Gulf of Mexico.
Upper low from this morning continues to weaken, which is pretty much an open trough at this point. An upper trough is currently situated over Middle Tennessee, with scattered showers circulating across the mid state.
As a result, high temperatures look similar to yesterday in the low to mid 90s, warmest toward north central KS which is nearer to the thermal axis. Little change is expected through mid-week as the ridge remains dominant over the western US, keeping hot and dry conditions with highs in the 90s and lows in the upper 60s to low 70s.
An upper level high, centered over the Four Corners region, will be our dominant weather influence and not move much today and tonight.
Late summer heat will build into the region as an upper-level ridge over the Southwest expands eastward through the week. This will result in temperatures generally in the low to mid 90s across much of the area. Additionally, the ridge will suppress any precipitation chances through the work week.
The good news is, the upper trough that has been responsible for our thunderstorm activity over the last couple of days has started to pull out of the region.
Scattered thunderstorms that remain will fade with loss of instability but the chance for showers will continue overnight as weak upper low pressure slides over the region. Otherwise, the low-level disturbance south of our region today will continue north into the Ohio Valley and prompt scattered, mainly diurnally- supported, showers and thunderstorms.
455 AM EDT Sun Aug 23 2020 An axis of scattered showers and isolated thunderstorms continues across far north Georgia this morning in an area where convergence is maximized between the building Atlantic high and lifting upper trough.
Tonight Through Monday Through the short term period, upper level high pressure will remain in place over the Wern CONUS and the Atlantic, with an upper trough over the E/SEern CONUS.
The aforementioned midwestern trough is projected slide over the Upper Ohio on Monday and support additional convection and veer flow to the west and northwest late in the day.
The upper ridge to our west will continue to deflect any systems that could bring substantial precipitation to the region.
An upper trough axis will remain just west of the region through the next 24 hours. Weak waves will rotate around this trough enhancing areas of isentropic lift but overall activity will mainly be diurnal in nature as dynamics are limited. SR Chattanooga Airport, TN 86 70 88 72 89 / 40 20 40 20 30 Knoxville McGhee Tyson Airport, TN 85 68 87 70 89 / 40 20 30 10 20 Oak Ridge, TN 85 68 88 69 90 / 40 20 30 10 20 Tri Cities Airport, TN 84 66 85 66 87 / 40 20 30 10 20.
Slight chances for rain today and tomorrow with a trough overhead. models show a consensus that a trough will persist over the region, producing enough instability to prompt slight PoPs.
Scattered showers and thunderstorms over the lower Ohio Valley this afternoon are associated with a 500 mb trough that is lifting northeast from the Tennessee Valley. On Sunday, the 500 mb trough will be less of an influence as it continues weakening and lifting north. Overall, it will be a little warmer with more sunshine than today. Sunday night through Monday night, 500 mb ridging will strengthen from the central Plains to the Southeast US. Temps will warm a little further under the ridge, with highs mainly around 90 Monday.
Still more of the same Monday but with slightly higher temps and dewpoints as upper heights increase slightly as the large upper ridge over the western half of the U.
All of this heat is, in part, thanks to the large ridge of high pressure aloft set up from the desert southwest up through the Central Plains and into the listening area. At the surface, a trough of low pressure will reside nearby, extending from southwestern SD through north central to northeastern SD/eastern SD.
Cold front approaching Wyoming from the west and northwest this afternoon. Really hot for this time of year over the next few days as upper high pressure remains in place.
324 AM CDT Sun Aug 23 2020 An upper level ridge remains in place across the Rocky Mountain and Plains region. Overall today will be very similar to what occurred yesterday, but highs could be a degree or two warmer with highs in the lower to middle 90s. Overall heat index values will be fairly close to temperatures this afternoon with readings in the lower to middle 90s occur. The upper level ridge will move a little further east early this week allowing slightly warmer conditions.
The passage of a weak, dry cold front Monday will likely produce locally breezy winds.
Strong upper level high pressure centered over Colorado will control SW KS weather through Monday, with little to discuss. Strong subsidence under the eastern flank of the anticyclone will ensure all locations will remain dry, with few if any clouds expected. Smoke/haze will continue to arrive aloft, circulating from the wildfires clockwise around the upper high. The upper level high pressure begins to spread eastward out over the High Plains Sunday night. Upper flow over western Kansas becomes almost light and variable before increasing easterly flow sets up as the upper high lifts a little farther north and an upper low system, possibly the remains of Marco, moves up the Rio Grande valley into west Texas. Later in the week the GFS and ECMWF show the upper ridge breaking down a bit and getting shunted southward.
The high pressure center is forecast to remain over the Four Corners through midweek, with east through south mid level flow expanding across most of Arizona. This is a more typical monsoonal pattern, thus expect scattered afternoon and evening storms across the high country and isolated coverage elsewhere. Storms will develop again after 18Z Sunday over the high country, developing toward the lower terrain to the southwest through the evening.
207 AM MDT Sun Aug 23 2020 Broad ridging persists over the western and central CONUS.
Aloft, a northwest flow continued along the edge of an upper level ridge and axis of very warm air aloft over the Rockies. As this ridge shifts eastward, late summer heat will overtake the forecast area this week, sending daytime temperatures well into the 90s. Otherwise, clearing skies and weak surface ridging may lead to at least patchy late night and early morning fog, as is taking place this morning upstream across portions of northern Iowa and southern MN.
1139 PM MDT Sat Aug 22 2020 The SubTropical Ridge has relocated closer to the 4 Corners today as a stronger upstream system is impinging on the northwest quadrant. Initially this moisture is primed with the remnant tropical moisture then 310-315K theta surfaces show a tap monsoon moisture at least being drawn into the high circulation to be recycled. Expect a slight uptick in convection in this region and really about all the ridgetops as we start to pull in the elevated moisture. Some wetting rainfall is possible on the highest elevations and far south where we have primed it the past few days.
As the mid/upper ridge builds north/northeastward we'll see rising heights and a subtle increase in thickness supporting rising temperatures across the region. The frontal boundary will meander across the region into the beginning of the weekend keeping low pops in the forecast with a somewhat cooler post- frontal regime anticipated toward the end of the period.
1023 PM MDT Sat Aug 22 2020 Daytime CU field trying to bubble up over the higher elevations of the Absarokas due to differential heating. H5 ridge remains steady across the Four Corners, with southwesterly flow continuing to pump stable smoky air across the state. A couple daytime heating showers are again possible on Sunday for the higher elevations of the Absarokas and Winds, and in the vicinity of the Uinta range during the afternoon, but will be very isolated and brief, being capped by the smoky atmosphere and very warm H7 temps.
226 AM MDT Sun Aug 23 2020 Hot, dry and hazy conditions are expected to continue through the short term period with the upper high pressure area expanding across the U. Models are trying to latch onto diurnally driven short waves with convection developing over the high terrain moving across the plains late each evening with some near surface convergence locally enhancing the lift in the vicinity of the surface through that waffles over eastern Colorado the next few days.
Strong upper level high pressure centered over Colorado will control SW KS weather through Monday, with little to discuss. Strong subsidence under the eastern flank of the anticyclone will ensure all locations will remain dry, with few if any clouds expected. Smoke/haze will continue to arrive aloft, circulating from the wildfires clockwise around the upper high.
248 AM MDT Sun Aug 23 2020 A cold front has made it through the forecast area. Northeast to east winds will provide a relatively cooler day today. Ridging builds back for Monday. Atmosphere will be pretty capped in the afternoon, but capping will erode in the evening as a cold front swings slowly across.
Upper low from this morning continues to weaken, which is pretty much an open trough at this point.
We continue to remain under the influence of the effects of a potent ridge aloft that's centered over the SW CONUS. Dew points are also on the warmer side, in the 60s to low 70s, not unusual for this point in the corn growing season. A few of the warmer and more humid spots could actually reach heat index values of 100-101 degrees today. Tomorrow looks to be warmer still, and likely the warmest day of the week. After Monday models are indicating that the broad troughing that is currently over the eastern US, becomes significantly less amplified. This will lead to the upper ridge spreading out broadly over majority of the CONUS.
1056 AM EDT Sun Aug 23 2020 Ridge axis remains north of the area, with an elevated E/SE flow across the area. Drier mid level air and ridge nudging in aloft from the east should keep shower/storm coverage ranging from isolated to scattered, with greatest storm potential across the interior and western portion of the Florida peninsula. Ridge axis remains north of the local waters with deepening onshore flow. The coverage should be greatest for this upcoming night as Tropical Cyclone Laura nears the region.
The over all weather pattern has an area of low pressure over the southwest United States and another area of high pressure off the Florida east coast.
Temperatures stay on the pleasant side and will generally remain in the lower to mid 80s inland, and mid to upper 60s to lower 70s along the coast.
Slight chances for rain today and tomorrow with a trough overhead. A weak upper trough continues to linger across the area this morning. Isolated convection possible this afternoon, especially over the eastern zones, east of the trough axis and where the air mass is least capped. models show a consensus that a trough will persist over the region, producing enough instability to prompt slight PoPs.
Carrothers A cold front has made it through the forecast area. Northeast to east winds will provide a relatively cooler day today. Ridging builds back for Monday. Atmosphere will be pretty capped in the afternoon, but capping will erode in the evening as a cold front swings slowly across.
However, isolated thunderstorms could develop over the mountains this afternoon and again Monday afternoon before the upper ridge axis moves southward and over northern Baja. The upper ridge axis will slide southward into northern Baja over the next few days, which is not a good pattern for monsoonal convection here. Temperatures will continue to run above normal due to the upper ridge dominating. The warmer than normal SSTs will continue to keep lows warmer and humidity rather high towards the coast.
308 AM MDT Sun Aug 23 2020 Hot, dry and hazy conditions are expected to continue through the short term period with the upper high pressure area expanding across the U. Models are trying to latch onto diurnally driven short waves with convection developing over the high terrain moving across the plains late each evening with some near surface convergence locally enhancing the lift in the vicinity of the surface through that waffles over eastern Colorado the next few days.
Showers have continued to overperform compared to what the high res models were showing in earlier runs. SR Chattanooga Airport, TN 86 70 85 72 86 / 40 20 40 20 40 Knoxville McGhee Tyson Airport, TN 85 68 85 70 88 / 40 20 30 20 30 Oak Ridge, TN 85 68 87 69 89 / 40 20 30 20 20 Tri Cities Airport, TN 84 66 84 67 87 / 40 20 40 20 20.
The latest model consensus continues to magnify the aforementioned ridge of high pressure to our west which should serve to steer "Marco" further west into the Louisiana coastline. Based on the current forecast, subsidence from the ridge may once limit diurnal convection across the Tennessee Valley on Monday, with only isolated to widely scattered PoPs expected.
422 AM MDT Sun Aug 23 2020 Broad ridging persists over the western and central CONUS.
The best chance for rain will be across the higher elevations while lower elevations will see a mix of wet and isolated dry thunderstorms with gusty winds, lightning and brief spotty light rainfall possible. Fortunately winds beneath the upper high aloft will be light which will also limit the potential for critical fire weather conditions today.
(see discussion below) 79 Previous Discussion: /Through Sunday Night/ The short term portion of the forecast will remain quiet as the western US ridge nudges to the east, resulting in increasing subsidence over the region.
This drier pattern could translate to warmer afternoon temperatures today and tomorrow, especially across the northern CWA. As it encounters warmer water, low shear and free of any terrain impacts. It should eventually take a turn to the nnw around the western periphery of mid level ridge over the southeast states.
Clockwise circulation around the upper high over the Four Corners was advecting areas of smoke and haze from western CONUS wildfires into the CWA. The stagnant weather pattern characterized by hot temperatures and smoky skies will continue through the short term as the upper ridge dominates the Four Corners and central/southern Rockies.
Marco, currently just below hurricane strength, is posed to continue northwest through the GOM today and Monday as it rides around the western periphery of the Bermuda ridge.
The main trough axis will remain centered near the central/lower Mississippi Valley today. The aforementioned midwestern trough is projected slide over the Upper Ohio on Monday and support additional convection and veer flow to the west and northwest late in the day.
High pressure will continue to result in above average temperatures across the interior through much of the forecast period while seasonable conditions persist near the coast.
an upper level high pressure center was over the four corners area this morning and is forecast to remain nearly stationary through tonight. High temperatures are expected to range from the low 90s to around 100 degrees. Low temperatures fall into the low to mid 60s. the upper level high pressure area is forecast to slide slowly northeast while elongating into the Tri-State area. Lots of sunshine expected with high temperatures again in the low 90s to around 100 degrees. Low temperatures fall into the low to mid 60s.
Notably the northeast quadrant is also the favorable location for tropical cyclone tornadoes, in addition to the expected thundery squalls.
/Issued 1202 AM CDT Sun Aug 23 2020/ /Through Sunday Night/ The short term portion of the forecast will remain quiet as the western US ridge nudges to the east, resulting in increasing subsidence over the region.
SR Chattanooga Airport, TN 86 70 85 72 86 / 40 20 40 20 40 Knoxville McGhee Tyson Airport, TN 85 68 85 70 88 / 40 30 30 20 30 Oak Ridge, TN 85 68 87 69 89 / 40 20 30 20 20 Tri Cities Airport, TN 84 66 84 67 87 / 50 30 40 20 20.
High pressure aloft will remain centered near the Four Corners through midweek. Moisture rotating north along the western flank of the high pressure will bring an increasing threat for showers and thunderstorms beginning early in the week.
949 AM CDT Sun Aug 23 2020 (Issued 948 AM CDT Sun Aug 23 2020) Weak surface/925 trough axis combined with a positive tilt 500 millibar trough may be enough to squeeze out isolated shra/tsra through early this evening.
720 AM EDT Sun Aug 23 2020 Bermuda High Pressure will build in from the east for most of the next seven days, providing warm and humid conditions with fewer showers and thunderstorms around. The pattern aloft will consist of a weakening trough to the west and ridge over the western Atlantic building westward. The wild card for the forecast is a weak trough/wave rotating around the western side of the Bermuda High. Weak high pressure will move off the coast over the course of the period.
556 AM CDT Sun Aug 23 2020 An upper level ridge remains in place across the Rocky Mountain and Plains region. Overall today will be very similar to what occurred yesterday, but highs could be a degree or two warmer with highs in the lower to middle 90s. Overall heat index values will be fairly close to temperatures this afternoon with readings in the lower to middle 90s occur. The upper level ridge will move a little further east early this week allowing slightly warmer conditions.
/Issued 455 AM EDT Sun Aug 23 2020/ An axis of scattered showers and isolated thunderstorms continues across far north Georgia this morning in an area where convergence is maximized between the building Atlantic high and lifting upper trough.
Above-average temperatures return today as the ridge builds back into the region.
303 AM MDT Sun Aug 23 2020 Upper ridging across the region will maintain warm and dry conditions in place for today.
High pressure building back through Arizona will tend to limit thunderstorm coverage and push temperatures back up this week, although there will still be some storms around.
This is unlikely to change much in the next 24 hours as the upper level ridge expands northwest into the region.
SHORT TERM (Now through Monday Night): As Hurricane Marco heads north towards Louisiana, Deep South Texas remains under the influence of a 500mb trough of low pressure, stuck in between ridges of high pressure across the Desert SW and off the Southeastern US Atlantic coast.
155 PM MDT Sun Aug 23 2020 Western CONUS ridge will slowly shift east and flatten in the period. Northern periphery jet stream will eventually sag south, supporting a more active pattern by the middle of the week, along with cooler weather.
Given the drier start to the day, expect highs to be several degrees warmer than today, likely around 90 at SDF/BWG. Broad ridging displaced poleward from Marco and then Laura should generally act to inhibit northward moisture transport.
The smoke over SD has done little to temper the highs for today, so sticking with that mindset for tomorrow and keeping highs in the 90s as per guidance.
Diegan Chattanooga Airport, TN 70 85 72 86 72 / 20 40 20 40 20 Knoxville McGhee Tyson Airport, TN 68 85 70 88 70 / 40 30 20 30 10 Oak Ridge, TN 68 87 69 89 69 / 30 30 20 20 10 Tri Cities Airport, TN 66 84 67 87 66 / 40 40 20 20 10.
205 PM MDT Sun Aug 23 2020 After a dry, slightly cooler day, temperatures will warm back up tomorrow along with a chance of thunderstorms. Temperatures will warm up to near record tomorrow as the ridge begins to build back in. This will be short lived by a cold front moving through Monday afternoon. RH will drop into the lower teens tomorrow afternoon but that combined with the energy of the front will lead to dry thunderstorms mainly over our western CWA.
325 PM EDT Sun Aug 23 2020 Region remains on the under the western periphery of the western Atlantic upper ridge through the short-term forecast period. Ample moisture for continued, diurnally oriented, scattered convection as the center of the upper ridge remains far enough east to keep the better subsidence at bay. The Bermuda ridge is forecast to expand and the tracks of Laura and Marco look far enough west to not directly impact our area.
High pressure aloft will remain centered near the Four Corners over the next several days. Moisture rotating north along the western flank of the high pressure will bring an increasing threat for showers and thunderstorms through midweek. High pressure remains centered in the vicinity of the Four Corners this morning. Southerly flow on the back side of the ridge is allowing moisture to spread northward into the forecast area.
An upper level high system continued to be centered over the Four Corners region this morning. The upper high will begin to build eastward over the central High Plains and into the the mid Mississippi Valley by Monday evening. Over the course of the upcoming week, the upper ridge builds east over the entire CONUS. Weak low pressure areas, along with the remains of Mario and Laura, will move into southeast Texas and Louisiana through mid week but the effects of these systems should stay well off to the east of southwest Kansas. By late week, the upper ridge gets shunted southward somewhat as a strong upper system tracks along the US/Canadian border into the Great Lakes region.
839 AM PDT Sun Aug 23 2020 Slightly cooler weather is in store for today, but it will continue to feel hot and humid out there.
Roxy Previous Discussion: Upper ridging across the region will maintain warm and dry conditions in place for today.
256 PM MDT Sun Aug 23 2020 Warm and relatively dry high pressure will be present over the Northern Rockies for the remainder of today and tonight.
Aside from the trough and lapse rates, there are few other factors that appear promising for thunderstorm development over the forecast area. Farther north, a cold front moves moves through the Dakotas, but this will be too far out of reach to influence weather in Nebraska. After the trough passes, dew points in the Sandhills and southwest Nebraska will drop to the 50s, with 40s present in the far western edge of the CWA. A ridge currently centered over the Four Corners will build north today and tomorrow.
High pressure is expected across the area into the middle parts of this week. Isolated convection remains possible into the early evening hours over the eastern/southeastern zones, due to the presence of a weak upper trough and little to no cap. Otherwise, upper ridging expected to expand into the Midwest by the middle of the week, although some weakness in the upper ridge locally may remain.