Aikyam-Lab/Synoptic-Bench huggingface dataset:
We'll retain some decent elevated instability ahead of the cold front and upper trough, but the bulk of boundary layer based instability looks to erode by the time it gets to the I-35 corridor tonight. Left this potential out of the forecast for now, and confined PoPs to the main upper trough and surface frontal passage tonight into early Monday. Any lingering precipitation should quickly exit the eastern portion of the area Monday morning, with high pressure and cooler/drier air working in for the rest of the day.
638 AM CDT Sun Aug 30 2020 The cold front that brought severe weather to the region has moved well south of the Ozarks. A dense fog advisory has been issued for areas that were showing the lowest visibilities and potential to fall below a half-mile through this morning.
332 PM CDT Sun Aug 30 2020 Cold front will continue to push across the state this afternoon/evening bringing some breezy winds and scattered showers and thunderstorms. Currently the cold front has moved across much of the CWA with James River Valley being the last hold out.
By this afternoon, the low RH values and the lack of wetting rain will make the fuels that are out there not know that it rained last night and this morning. Otherwise expect cooler temperatures today and especially tonight. Upper ridging is expected to become more established across the western U. with northwest upper flow setting up across the northern High Plains as the current trough shifts further downstream.
700mb temps will become a bit colder, and ascent will favor our western mountains, so believe there will be a little wet snow falling over the high elevations of the Crazy and Beartooth/Absaroka mountains, with a snow level near 8500 feet. A heads up if you are planning to be in the high country or drive the Beartooth Highway tomorrow. Monday night will be dry as trof sags southward and ridging begins to build from the northwest.
The best chances will be along and north of the highway 84 corridor where destabilization is able to occur and the outflow boundary can provide an area of surface lift. The never-ending HIGH risk of rip currents is expected to continue through Monday as seas struggle to come down in the wake of last weeks tropical cyclones. More storms are expected to develop this afternoon mainly north of I-10 and along the highway 84 corridor.
227 PM MDT Sun Aug 30 2020 Cold front crossing the area is readily apparent in obs, including radar imagery, this afternoon. As temperatures cool to near freezing in the hills and the wind abates, areas of frost will likely develop in higher terrain after midnight. Mid-upper moisture increases again tomorrow as an upper trof axis approaches, then crosses, the area. Sustained winds of 20 to 35 mph with gusts as high as 55 mph are expected, with the highest gusts from Harding and Perkins southward through the Pennington and Custer plains.
128 PM EDT Sun Aug 30 2020 Dry and seasonable weather today will be replaced by increased rain chances Monday, mainly southeast of Pittsburgh, as low pressure tracks into the central Appalachians. Dry conditions will persist overnight, though an incoming area of low pressure will increase cloud coverage. Some uncertainty in the trough positioning remains, with potential for slightly farther northern and delayed track that may allow for isolated convection farther west. Remnant cooler air plus increasing cloud cover will provide near to below average temperatures Monday.
302 PM EDT Sun Aug 30 2020 High pressure will bring clearing skies this evening and cool temperatures overnight.
A cold front will move into northwest Oklahoma around sunrise and move through at least parts of western Oklahoma before perhaps stalling.
If the coverage of the showers and thunderstorms is large enough, then the heat indicies might be a few degrees cooler.
Temperatures have risen into the upper 70s ahead of this boundary, with dew points in the lower 60s. There is the high based/low qpf activity that is moving into areas east of the Red River Valley now, then there is a break behind it (of 1-2 hours).
One trough will extend southeastward to south of Childress, north of which backed southeasterly winds are expected to develop. The second trough will extend through the western South Plains with southwesterly winds to its west. Both of these troughs may have enough convergence along them to serve as the focus for isolated thunderstorms. /issued 302 AM CDT Sun Aug 30 2020/ Upper level ridge to our SW will begin to flatten today putting the area in NW to zonal flow. Nearly zonal flow aloft should be in place Monday morning though this will be short lived as another trough will rotate around a low located in northern Manitoba.
Attention by late evening into tonight will be on developing storm complex moving off the High Plains its evolution through the overnight into early morning hours on Monday.
Garuckas Chattanooga Airport, TN 89 73 86 73 88 / 60 60 70 20 50 Knoxville McGhee Tyson Airport, TN 87 72 85 70 86 / 30 60 80 40 30 Oak Ridge, TN 87 71 85 71 86 / 30 70 70 30 30 Tri Cities Airport, TN 84 68 83 67 85 / 20 60 90 50 20.
Behind this upper wave/trough we look to get some deep-layer drying Mon night, but that will be short-lived as moisture quickly deepens once again Tues morning. This however will leave another cold front to our northwest early Wed. Our upper flow will remain southwest into the end of the week as a fairly sharp trough moves across plains. This upper trough will weaken but eventually move over the mid-state late Fri/early Sat. bringing this cold front across us Fri and well south by early Sat.
346 PM EDT Sun Aug 30 2020 Weak high pressure builds in from the north into Monday.
1059 AM MDT Sun Aug 30 2020 A trough will sweep across the northern Rockies today. The associated cold front at 09Z looks to be from extreme northwest Yellowstone to Billings. Wyoming by 12Z and then begin to stall out briefly along the Bridger/Owl Creek Mts. On Monday, a quick moving trough in the northwest flow will push across the area. Another cool morning is expected behind the front, with freezing temperatures across western valleys and basins.
242 PM EDT Sun Aug 30 2020 A Canadian mid level trough down the eastern seaboard. with an embedded short wave trough aloft northern FL. Meanwhile a subtropical ridge axis near the Florida Keys eases into the southern portion of the state Mon. 4 inches with the higher amounts favoring northern locations. with the highest coverage inland and north. The low temperatures will a a degree or 2 above normal while highs run near normal in the south and just below in the north. Tue through next Sun - The subtropical ridge takes control as it slowly tracks north over FL. The ridge axis lifts north during the last half of the week with winds shifting to southeast and east.
The strong winds over western SD may continue to propagate east behind the cold front, currently gusting to 40kts at D07. We also can't completely rule out the potential for a couple of tornados, with the low LCL heights favorable 0-1km bulk shear, and 0-1km EHI. Upper troughing/northwest flow aloft is expected through the weekend.
Generally dry conditions expected tonight into tomorrow with the exception of southern Indiana as a meandering cold front finally exits.
With a lack of upper-level support amid build high pressure, activity should wane quickly after sunset with another warm and muggy night ahead.
This will support a strong cold front through the region, supporting gusty NW winds, esp in the lee of the Black Hills where adv level winds are expected. Main sfc cold front will accelerate though the region, pushing the main instability axis east, with the severe threat expected east of the FA today. Much cooler and drier air will advect into the region, with lows in the 40s and some upper 30s. A cold front will cross the area today, bringing strong northwesterly winds and cooler temperatures.
Still on track for a cold front passage tomorrow, with some shower activity and increasing winds. Pleasantly below normal temperatures today and tomorrow, then warming as the week progresses with high pressure building in strongly from the south and southwest.
Meanwhile, additional showers and thunderstorms will develop along the approaching cold front over the Dakotas later this afternoon.
311 PM EDT Sun Aug 30 2020 High pressure will build into the region tonight and this will allow for clearing skies and winds becoming light and variable by daybreak on Monday. High pressure remains over the area on Monday and this will result in dry weather, plenty of sunshine, and high temperatures in the upper 60s to lower 70s.
Dry conditions can be expected on Monday as the ridge translates overhead with high temperatures climbing to near 80 degree in many locations.
Overnight lows were a bit cooler in some locations this morning, although these will trend upward over the next couple of days and more noticeably by the end of the week. Per latest water vapor satellite imagery, the baggy upper-level trough is currently centered off the coast of Southern CA and will move southwestward further off the coast over the next couple of days.
218 PM EDT Sun Aug 30 2020 High pressure will gradually push east into our area tonight and early Monday.
An upper level high pressure system with E-W oriented axis is predicted to meander over the region during the period, per deterministic NWP model output.
This occurs just ahead of the approaching cold front moving into central and eastern SD early this evening. Much drier and cooler air moves in immediately behind the front as an upper longwave trough digs into the region.
237 PM CDT Sun Aug 30 2020 Late afternoon/early evening thunderstorms expected to develop along a weak trough axis across the southeastern Panhandle, assuming flow to its north can back sufficiently to generate some low level convergence. The beginning in the change in pattern occurs tomorrow as a sharp upper level short wave trough moves across the northern Plains driving a cold front south into the forecast after sunrise Monday. With the front expected to stall the warmer end of guidance looks the more likely at this time. The first hints of the upper level low impacting our weather this week, will be seen in the form of snow across the northern Rockies tomorrow afternoon.
1124 AM EDT Sun Aug 30 2020 Dry and seasonable weather today will be replaced by increased rain chances Monday, mainly southeast of Pittsburgh, as low pressure tracks into the central Appalachians. Dry conditions will persist overnight, though an incoming area of low pressure will increase cloud coverage. Some uncertainty in the trough positioning remains, with potential for slightly farther northern and delayed track that may allow for isolated convection farther west. Remnant cooler air plus increasing cloud cover will provide near to below average temperatures Monday.
A weak cold front will approach areas west of the Illinois River late Monday, but is expected to diminish upon arrival.
253 PM CDT Sun Aug 30 2020 Its significantly cooler across the Midsouth today.
126 PM CDT Sun Aug 30 2020 Scattered showers with a few weak storms mixed in will continue across southwest MN this afternoon, as warm air advection and the low level jet continue to provide subtle lift in a very weakly unstable environment. A fairly strong late summer cold front will swing through this evening. One thing to note with this set up is that the shear, especially the lowest km or two, has strong speed and directional shear which may support some isolated supercells. The stronger winds aloft appear to lag a bit behind the surface cold front with the strong jet energy moving into the eastern Dakotas after 3z.
Snow levels will be low enough that the higher peaks across the Northern Rockies could experience snow accumulations Monday morning.
214 PM EDT Sun Aug 30 2020 Weak high pressure builds in from the north today. A low pressure system will form offshore along a stalled boundary and lift northeastward Monday. Then, a more seasonable pattern will emerge for the rest of the week with Bermuda high pressure offshore and weak troughing across the interior of the Carolinas. The cold front has now pushed offshore, with north to northeast winds prevailing across the area.
The return of southeast winds has brought back dewpoints in the mid 60s to near 70, and this moisture plume is well-depicted by the low-level cumulus field over the southwest half of the CWA. The cold front will enter the CWA and become stationary Monday afternoon as the upper wave quickly lifts into Canada.
1124 AM EDT Sun Aug 30 2020 High pressure over the Upper Great Lakes will gradually push east and cross our area tonight and early Monday.
A cold front is draped across West Tennessee into Central Arkansas. A deep trough will setup over the Rockies resulting in a quick transition to Southwest flow across the Southern Plains and over the Midsouth.
A few afternoon SHRA are anticipated, however confidence is low of this happening given overcast conds and cooler temps. With precipitation ongoing through the day over much of the region and lingering cloud debris, temps over the Natural State will see some much needed relief from Sat, with highs in the low to mid 80s over Cntrl and Nrn AR, and Srn AR just breaching the 90s.
/issued 802 AM EDT Sun Aug 30 2020/ Canadian mid level troughiness down to the northeast Gulf of Mexico and north FL along with a subtropical ridge axis near the Florida Keys will maintain a deep moist southwesterly flow today. We had one short wave trough embedded in the mid level trough that swept across the northern part of the state overnight with showers and storms from around Tampa Bay northward. These have pretty much cleared our area but a second short wave trough is expected this afternoon which along with the high moisture and daytime heating will support showers and thunderstorms. The ridge axis lifts north during the last half of the week with winds shifting to southeast and east.
230 PM CDT Sun Aug 30 2020 An upper ridge is over West Texas and southeast New Mexico with upper troughs to the north resulting in the ridge being flattened. An upper trough moving over the Northern Plains will send a cold front toward the area on Monday. Showers and thunderstorms will also be possible Monday with the frontal boundary interacting with the low-level moisture. A portion of the previously mentioned upper trough is expected to break away from the main trough and move over Arizona/New Mexico.
1206 PM PDT Sun Aug 30 2020 A cooler air mass has settled over our region and will bring slightly below normal temperatures Sunday and Monday.
Temperatures are expected to be in the lower to mid 90s with some heat index values in the 100 to 105 range due to elevated dewpoints, mainly across the southern half of the area. Overnight lows will be in the low to mid 70s. Low to mid level trough expected across the area by afternoon with some enhanced convergence especially across the north Midlands. Air mass moderately unstable and short wave forcing expected as mid level trough moves east from Tennessee.
CD Chattanooga Airport, TN 73 86 73 88 73 / 60 70 20 50 20 Knoxville McGhee Tyson Airport, TN 72 85 70 86 70 / 50 70 40 30 20 Oak Ridge, TN 71 85 71 86 71 / 60 70 30 30 30 Tri Cities Airport, TN 68 83 67 85 66 / 40 70 50 20 30.
The deep mid level ridging to the west slowly shifts, resulting in weak WAA/an upward tick in mid level and surface temperatures tomorrow. Tomorrow, a combination of the warmer temperatures and increased boundary layer RH from todays precip will push the temps back into the 105-110F range for a large portion of the forecast area west of Interstate 55.
1136 AM EDT Sun Aug 30 2020 Weak high pressure builds in from the north today. A low pressure system will form offshore along a stalled boundary and lift northeastward Monday. Then, a more seasonable pattern will emerge for the rest of the week with Bermuda high pressure offshore and weak troughing across the interior of the Carolinas. The cold front has now pushed offshore, with north to northeast winds prevailing across the area.
335 PM EDT Sun Aug 30 2020 Subsidence courtesy of deep layer ridging has kept the weather mostly sunny and beautiful across the Keys for today.
Mainly widely scattered afternoon and evening thunderstorms expected midweek with weaker forcing and upper ridging. Temperatures are expected to top out in the lower to mid 90s with some heat index values in the 100 to 105 range due to elevated dewpoints, mainly across the southern half of the area. Overnight lows will be in the low to mid 70s. Low to mid level trough expected across the area by afternoon with some enhanced convergence especially across the north Midlands. Air mass moderately unstable and short wave forcing expected as mid level trough moves east from Tennessee.
/issued 253 PM CDT Sun Aug 30 2020/ Its significantly cooler across the Midsouth today.
A short wave trough will enter the area from the north and bring a chance of showers to mainly central Idaho on Monday. Temperatures will be even cooler with highs 10 to 15 degrees below normal. Increasing cloud cover overnight with approaching low pressure system from British Columbia. Winds will increase Monday afternoon with passage of a cold front.
A cold front moves through the region today, bringing gustier winds and temperatures cooler than what we have seen on Monday.
We are in a quiet weather pattern today across NorCal with a an upper level low pushing south along the coast into SoCal and long wave troughing setting up over the northern Plains. Overall temperatures are within a few degrees of yesterday this time except for in the northern Sac Valley where a light north wind is bumping them up 4 to 7 degrees warmer. Northerly flow will continue to increase into Monday as we see a short wave trough dig out of Canada into the eastern Great Basin by Monday afternoon. Highs Monday will be a few degrees warmer as we start to see higher heights over NorCal as a strong ridge of high pressure begins to build into the PacNW.
Overnight lows should be mainly in the lower to mid 80s, except upper 70s for the northern ranchlands.
Much warmer conditions are then expected through much of the week as high pressure rebuilds across the region.
Wind will be mostly light from the southeast before a cold front moves across the area Monday afternoon with northerly winds. /issued 230 PM CDT Sun Aug 30 2020/ An upper ridge is over West Texas and southeast New Mexico with upper troughs to the north resulting in the ridge being flattened. An upper trough moving over the Northern Plains will send a cold front toward the area on Monday. Showers and thunderstorms will also be possible Monday with the frontal boundary interacting with the low-level moisture. A portion of the previously mentioned upper trough is expected to break away from the main trough and move over Arizona/New Mexico.
The cold front has pushed through so the threat of severe convection has ended. Cold front will continue to push across the state this afternoon/evening bringing some breezy winds and scattered showers and thunderstorms. Currently the cold front has moved across much of the CWA with James River Valley being the last hold out.
533 PM MDT Sun Aug 30 2020 Wind gusts 35 to 45 MPH have been common across a large portion of the region this afternoon, courtesy of deep low-level mixing along with strong low-level gradients associated with a very slow moving surface cold frontal boundary. Critical fire weather conditions should persist in advance of the cold front. Latest guidance has trended warmer with over- night lows over the Snowy Range with only a few areas getting near 32 F for an hour or two. This should provide a reinforcing shot of cooler air, and given increasing cloud cover we may only see highs in the upper 60s to near 70 degrees.
846 PM EDT Sun Aug 30 2020 Rain chances increase tomorrow, mainly southeast of Pittsburgh, as low pressure tracks into the central Appalachians. Dry conditions will persist overnight under high pressure. An incoming low pressure system will increase cloud coverage from the south after midnight. Some uncertainty in the trough positioning remains, with potential for slightly farther northern and delayed track that may allow for isolated convection farther west. Remnant cooler air plus increasing cloud cover will provide near to below average temperatures Monday.
603 PM MDT Sun Aug 30 2020 Cold front crossing the area is readily apparent in obs, including radar imagery, this afternoon. As temperatures cool to near freezing in the hills and the wind abates, areas of frost will likely develop in higher terrain after midnight. Mid-upper moisture increases again tomorrow as an upper trof axis approaches, then crosses, the area. Sustained winds of 20 to 35 mph with gusts as high as 55 mph are expected, with the highest gusts from Harding and Perkins southward through the Pennington and Custer plains.
Today, west to northwesterly flow provided plenty of orographic lift to get showers and storms to get going over the higher terrain which is exactly what we've seen. High temperatures north of I-70 will be about 5 degrees cooler than seen today but those cooler temps won't be felt much further south.
GOES image of total precipitable waters shows an area of higher moisture along the Lower Texas coast with PWAT values up to 2. An upper level high pressure system with E-W oriented axis is predicted to meander over the region during the period, per deterministic NWP model output.
726 PM EDT Sun Aug 30 2020 High pressure will bring clearing skies this evening and cool temperatures overnight.
410 PM CDT Sun Aug 30 2020 Persistent area of heavy rainfall over the lower parishes this morning and early afternoon has finally relented over land but continues to bulk up over the coastal waters, mainly driven on strong outflow from earlier convection. Temperatures should reach the lower 90s before rain and cloud canopy provides some cooling.
630 PM EDT Sun Aug 30 2020 Weak high pressure builds in from the north into Monday.
Tonight, a deep northern stream trough will kick through the northern Plains driving a surface cold front into the region. The main limiting factor will be the warmer 700mb temps, but certainly can't discount the very strong moisture transport coming out of northern Oklahoma.
309 PM MDT Sun Aug 30 2020 Wind gusts 35 to 45 MPH have been common across a large portion of the region this afternoon, courtesy of deep low-level mixing along with strong low-level gradients associated with a very slow moving surface cold frontal boundary. Critical fire weather conditions should persist in advance of the cold front. Latest guidance has trended warmer with over- night lows over the Snowy Range with only a few areas getting near 32 F for an hour or two. This should provide a reinforcing shot of cooler air, and given increasing cloud cover we may only see highs in the upper 60s to near 70 degrees.
1024 PM EDT Sun Aug 30 2020 Low level ridging stretches west across the Florida Keys. Like last evening, heights continue to fall between 925 and 500 mb, detailing a general erosion of the ridge.
/EC/ Prior discussion below: Tomorrow, a combination of the warmer temperatures and increased boundary layer RH from todays precip will push the temps back into the 105-110F range for a large portion of the forecast area west of Interstate 55.
High Pressure over the Central Plains states will build across the Ohio Valley Tonight. The high will remain across the Ohio Valley through the rest of the Holiday weekend.
Currently watching a weak cold front stretching from northwest Wisconsin into southcentral Minnesota moving southeast. However, with the widespread cloud cover over the area for much of the day and little to no convergence along the cold front over these areas, it's unlikely that storms will develop in the stronger shear region. High pressure builds in for Sunday providing excellent weather.
Very warm and windy conditions are in the forecast for Sunday, as a cold front traverses southeastward across ND.