Aikyam-Lab/Synoptic-Bench huggingface dataset:
High pressure will continue to drift south, with increasing southerly winds. Peak mixed winds across the Coteau are into the low 30s, with a downslope component showing up as well thanks to a southwest warm advection regime. Down towards Pierre and western/south central South Dakota, very shallow/near surface profiles may be deep enough for some melting, with surface temperatures around the freezing mark. GEFS comes in with a 33 percent probability of freezing rain, while the SREF suggest negligible chances. Forecast thereafter is looking up, with a ridge out west gradually progressing east.
Quiet weather continues across western and central North Dakota this morning, with broken high clouds and warm air advection beginning across southwest North Dakota as a warm front begins moving into the area. For today, warm air advection will develop as a warm front slowly advances east across the state through the afternoon, allowing temperatures to rise into the 20s over north central North Dakota and the James River basin. Across the west, temperatures will mainly be in the low to mid 30s with the warmest readings likely in the southwest, which may flirt with 40. The cold front will only cool temperatures down a little bit on Wednesday with highs ranging from the 20s to lower 30s.
A weak cold front is moving into the area this morning and will sweep across the forecast area this afternoon and evening. The ridge of high pressure will quickly begin to rebuild heading into Wednesday.
1122 AM CST Tue Nov 12 2019 Early morning satellite imagery shows plenty of clear sky across the area as high pressure continues to build in. While this will lead to warmer air getting here eventually, it will take a while, as highs will still be in the teens to lower 20s and lows tonight will be in the single digits above zero and lower teens.
An upper low over the Baja region is progged to move into northeastern Mexico on Wednesday afternoon.
Shallow cold air mass will slowly moderate through the afternoon, but sub-freezing 850mb temps coupled with remnant high clouds will maintain surface temps into the 40's for most locations. Southerly winds will slowly advect warmer air across the region for tomorrow with a return to temps into the 50's and 60's.
1019 AM EST Tue Nov 12 2019 Water vapor imagery highlights mean-layer ridging stretching from Central America to the Bahamas. A long wave trough axis pivoting east through the southern Plains is driving a sharp cold front southeast through the Gulf of Mexico. High pressure centered near Bermuda will recede east into the western North Atlantic this afternoon. A cold front will push southeast through the Gulf of Mexico tonight, then stall near, or just south of the Florida Keys Wednesday, resulting in another round of freshening north to northeast breezes.
222 PM CST Tue Nov 12 2019 Cold and clear conditions will persist through the evening and overnight hours with high pressure centered over the region. Will maintain a warmer west/colder east gradient with low to mid teens east and near 20 west where south winds return by mid to late evening. We may see some increasing cloud cover over our northern counties by late afternoon with temperatures rising well above freezing.
Temperatures in the mid- levels are above freezing and this airmass has made it to the ground/surface in SW Phillips county. An upper ridge in NW flow aloft will be over the forecast area this morning. A warm front this morning will turn winds to the west and quickly warm the areas currently in the inversion. The SW areas will be warm enough for rain along with a mix of sleet and freezing rain through early evening.
It is very likely going to keep us from getting to the freezing mark today and it's going to cause temperatures to plunge tonight. The lowest max temperature for today's date is (was) 34 in 1920.
Even for areas that area seeing sunshine already, with temperatures in the lows 20s/upper teens still and winds still whipping through the area, Wind Chills are in the low teens and single digits for most. VFR through the next 24 hours as cold, dry high pressure moves into the area.
Tomorrow will be warmer across the region due to the down-sloping (and therefore, compressional warming) component of a west/west- southwest wind. Another weak, dry cold front will sag through the county warning area (CWA) tomorrow afternoon. Winds will shift to the north post-frontal passage, but given weak pressure rises behind the front and the low magnitude of cold air advection, temperatures will only (and fortunately) fall to near freezing tomorrow night.
1144 AM CST Tue Nov 12 2019 A record cold morning across portions of central Kansas as the core of the Arctic high pressure drifts across the area. However, more noticeable warming is expected on Wednesday ahead of the next upper level trof and associated surface cold front moving southeast across the northern Plains.
Warmer this weekend. With a strong ridge over the region it will still be a mild day with max temps mostly 8 to 15 deg above normal. Pacific trof forecast to move inland Thu/Fri with synoptic cooling and thickening clouds into Fri morning. This system will weaken drastically as it moves into the strong ridge and may bring just a brief period of locally breezy conditions to the NE Sac Vly Fthls, and Valley on Sat. Average gusts in the low 20s MPH at RDD and RBL on the ECMWF ensembles. The 8-10 day 500 mb hgts Cluster suggests a trof will develop over the Great Basin region which could bring some windy conditions to our CWA, and much cooler wx and possible showers mainly over the mtns.
High pressure is centering itself over the region, and will relax the pressure gradient this evening, allowing winds to continue to decrease. Upper-level flow becomes more zonal midweek, with high pressure shifting off to the east.
High pressure at the surface and a dry W-NW flow aloft will make Wednesday a dry and sunny day with highs in the 40s.
Coast and valley areas will be a little warmer today due to the shallower marine layer.
Expect the responsible area of high pressure to our south to continue to shift away from the region today. and for the pressure gradient to increase on the backside of this high pressure system. as this continues to look like a very minor event with a small chance for some sleet at the onset as the dendritic layer becomes saturated but a warmer layer below this combined with cold surface temps continues to support this as a possibility for a couple of hours. dry northwesterly flow with weak ridging this weekend is forecast. BKN to OVC CIGs around 10k ft expected most of the morning, though a rapid decr to near MVFR CIGs expected right around the end of the period, 17-18Z, as a cold front moves through.
Morning water vapor and H5 analysis trends depict a net flattening of the eastern pacific ridge over the PacNW coincident with a short wave trough translating inland, but strong influence remaining further south off the Cali coast. Downstream of these a dry and stable northwesterly flow aloft remains locally, with local stability primarily influenced by the aforementioned ridge.
158 PM MST Tue Nov 12 2019 System moving in tonight looks to bring light snow to most of the area with some rain/freezing rain over the SW zones this evening. Issued a Winter Weather Advisory for Garfield and Petroleum counties with this rain/freezing rain concern.
Lake effect low clouds and even some light snow earlier this morning will continue to erode as the temp difference between the lakes and air above decreases and insolation dries out the low levels.
Expect much cooler temperatures by Wednesday morning over southeast Utah and southwestern Colorado, where skies will remain clear. Temperatures will climb ~5 degrees warmer Wednesday than experienced this afternoon, bumping us back above seasonal normal highs. Ridging builds back into our west Wednesday-Wednesday night, setting us up for another chilly morning under clearing conditions.
Although clouds will begin to clear out this afternoon, strong cold advection will hold temperatures fairly steady in the lower to mid 30s today.
1013 AM EST Tue Nov 12 2019 Periodic snow showers should continue today with an upper level disturbance, before building high pressure returns dry weather Wednesday. The ridge advisory zone can expect another 2-3 inches thanks to upslope enhancement, with other locations from HLG on south and west generally seeing an inch or less.
Tried to go on the low end of available guidance for lows with the snow holding strong over much of the area. This will lead to a modest warm up to above freezing throughout the region, however, guidance has trended downward and most of the region should top out from 35 to 40 degrees.
400 PM EST Tue Nov 12 2019 Cold high pressure will build in from the Plains states tonight, producing clear skies and frigid temperatures.
High pressure and dry conditions will work into the region tonight. Temperatures appear to be on track for afternoon temperatures ranging from the low 20s in northwest to the upper 20s in the southeast. Sky conditions needed a general bump downward, as satellite trends show considerable breaks in the low clouds, particularly in central Ohio east of a remnant lake enhanced snow band stretching from Bellefontaine south through Wilmington. Have dropped the winter weather advisory due to decrease in snowfall and rise in road temperatures above freezing this morning. WAA advection on Wednesday will allow for temperatures to be slightly warmer, although still below normal for this time of year.
Southerly winds kick in tomorrow on the backside of the high, leading to temperatures 15 to 20 degrees warmer than today's.
Cold front has pushed well off the coast and radar only picking up on some light rain in the offshore waters. Question will be how thick will cirrus be overnight as SW flow aloft continues with the upper low moving into Mexico from the Baja peninsula.
1143 AM CST Tue Nov 12 2019 Arctic high pressure will settle across the region today and then slide east of the area tonight. As the high slides east tonight the pressure gradient tightens with increasing southerly winds, especially across the western half of the forecast area. Overnight lows will range from around 20 over southeast Kansas and far western Missouri, to the lower teens over the eastern Ozarks. A breezy day is expected on Wednesday ahead of another cold front. With the south to southwest breeze, temperatures will warm into the low to mid 40s for afternoon hours.
Where they differ is how they sort out the bits of energy that accompany the upper level trough. As for pcpn chances, weak high pressure still slated to be the main weather influence post the Wed system, keeping conditions on the dry- side into Sat.
Even for areas that area seeing sunshine already, with temperatures in the lows 20s/upper teens still and winds still whipping through the area, Wind Chills are in the low teens and single digits for most. Otherwise high pressure moving in and clouds decreasing.
These snow bands developed downwind of warmer bodies of water akin to how lake effect bands form in the Great Lakes; however, on a much smaller scale. We anticipate mostly sunny conditions the remainder of the afternoon, but temperatures will struggle to reach the freezing mark and gusty north winds will keep wind chill readings in the teens and 20s. Temperatures have dropped significantly and will continue to drop to into the lower teens in our northern counties.
255 PM CST Tue Nov 12 2019 Arctic air is firmly entrenched over the Mid-South in the wake of yesterday's cold front. A longwave trough anchored over the Great Lakes will shift east tomorrow with 500mb geopotential heights building ~12 dam over the next 24 hours. Temperatures remain below freezing across most of the CWA as of 2 PM with record cold temperatures anticipated Wednesday morning. A cut-off cyclone over the Baja Peninsula will eject eastward tomorrow as a strong kicker trough dives southeast across the northern Rockies.
Temperatures this afternoon have remained in the 30s for the most part, with the exception of the Pine Belt area which has risen into the lower 40s. With high pressure nearing the area, these winds should relax a bit tonight as the pressure gradient eases and therefore the Wind Advisory will continue through at least 6pm this evening. Another upper trough will swing across coastal Texas toward our region. As a result, there could be some light rain associated with this upper trough mainly across the southern portions of the forecast area.
Cloudier today as a short wave trough moves into the Pacific NW.
1140 AM MST Tue Nov 12 2019 Water vapor shows ridge over the western CONUS with northwest flow through the Northern Plains. At the surface, high is over NE/KS with lee trof along the northern Rocky Mountain Front. Mostly sunny skies expected today with lee trof advancing into the Northern Plains. Ridge topping wave will bring some light precip to much of the area later tonight through Wednesday morning. Thermal profiles generally suggest a rain/snow mix, but there is some potential for light freezing rain on parts of the SD plains, especially south central SD.
327 PM EST Tue Nov 12 2019 Water vapor imagery highlights mean-layer ridging stretching from Central America to the Bahamas. A long wave trough axis pivoting east through the Mississippi River Valley is driving a sharp cold front southeast through the Gulf of Mexico.
603 PM EST Tue Nov 12 2019 A strong cold front has moved off the South Carolina coast.
/Tonight through Wednesday Night/ ArkLaTex will be under the influence of cold high pressure tonight into Wednesday with overnight low temperatures forecast to fall into the upper teens across the I-30 corridor to the lower 20s elsewhere. Light rain showers to return to deep east Texas and north Louisiana on Wednesday night as an upper trough across south Texas swings east into the Gulf of Mexico. No freezing precipitation expected with this system as southerly flow will have advected sufficient warm air to maintain liquid precip. Otherwise, overnight lows to range from the mid 30s south of I-20 to the lower 30s north.
In the mid-levels, ridging is setting up off the coast of CA behind a weak circulation over western Mexico.
220 PM MST Tue Nov 12 2019 Water vapor imagery showing a dry airmass over the region with moisture moving over the upper ridge. Temperatures for Wednesday will be cooler given the passage of the surface cold front with -2 to -3C at 700 mb. This will bring highs into the lower 50s across the plains. Strong northwesterly flow aloft is progged over the CWA Wednesday night as a weak upper trough moves southeastward in the flow.
Daily Record Low Minimum Temperatures Date Chattanooga Knoxville Tri-Cities Oak Ridge 11-13 18(1911) 17(1911) 19(1986) 20(1984) 11-14 18(1969) 20(1986) 16(1986) 20(1986) 00Z TAF DISCUSSION. Northerly winds will weaken as surface ridging builds into the Tennessee valley. Chattanooga Airport, TN 20 47 29 49 34 / 0 0 0 10 10 Knoxville McGhee Tyson Airport, TN 16 44 24 48 32 / 0 0 0 10 0 Oak Ridge, TN 15 44 24 49 30 / 0 0 0 10 0 Tri Cities Airport, TN 13 42 20 47 29 / 10 0 0 10 0.
Conditions look cold enough for the precipitation to be snow over most of the area, with the exception of the far southwestern part of the CWA, where there may be a brief period of warmer air above the surface, so cannot rule out a little light freezing rain or sleet along the leading edge of the precipitation shield. High pressure slides back in behind the exiting front late Wednesday afternoon and Wednesday night, bringing a return to dry conditions.
At 19z, 1040 MB Arctic high pressure was located over central Missouri. With the ridge axis pushing in from the west, lighter winds began to overspread western IL, while a tighter gradient lingering over eastern IL was still producing 10-15 MPH northwest winds and near 0 wind chills. The ridge axis is forecast to shift east into southern IL 00-06z, then into the Ohio Valley Wednesday morning. Temps should steady out after midnight as return southerly flow sets up on the back side of the Arctic ridge. "Warm" advection on brisk south winds through the day will push highs 12-15 degrees warmer than today with most areas inching above the freezing mark. Despite strong warm advection aloft, effects of lingering dry low level Arctic airmass will limit any precip generation on the southwest flank of the surface/mid level trof.
634 PM EST Tue Nov 12 2019 Cold high pressure will build in from the Plains states tonight, producing clear skies and frigid temperatures.
Despite this, and the return of breezy southerly winds on the back side of the high, temperatures remained mostly subfreezing over the region this afternoon. Overnight lows should mostly be in the low 20s, though the Loess Hills will likely be in the teens.
Temperatures will remain warmer than normal with abundant sunshine returning for the weekend.
Upper level ridging in place is bringing much above normal temperatures to the area.
As a high pressure center over the region shifts eastward tonight, initially northwesterly winds will gradually back and become nearly southerly by daybreak. The pressure gradient will also be tightening across the region ahead of an approaching trough axis, and this should produce breezy conditions during the day with gusts up to 25 mph possible. A weak low pressure system and its associated cold front will move through the region on Wed night into Thu.
Cloud cover will increase however on Wednesday across the southern TAF sites as an upper low over northern Mexico moves into south Texas. An upper low over the Baja region is progged to move into northeastern Mexico on Wednesday afternoon.
Warmer this weekend. With a strong ridge over the region it is a mild day with max temps mostly 8 to 15 deg above normal. A Pacific trof, with the low center located near 30N/140W, is forecast to move inland Thu/Fri with synoptic cooling and thickening clouds into Fri morning. This system will weaken drastically as it moves into the strong ridge and may bring just a brief period of locally breezy conditions to the NE Sac Vly Fthls, and Valley on Sat. The average gusts are forecast in the low 20s MPH at RDD and RBL on the ECMWF ensembles. The 8-10 day 500 mb heights Cluster suggests a trof will develop over the Great Basin region which could bring some windy conditions to our CWA, and much cooler wx and possibly a few light showers mainly over the mtns.
A ridge of high pressure will strengthen over Washington on Wednesday resulting in a northwest flow much of the day.
Thermal profiles generally suggest a rain/snow mix, but there is some potential for light freezing rain or ice pellets on parts of the SD plains, especially over south central SD. A few inches of snow may accumulate in the northern Black Hills, where a slight upslope component to the low level winds will be in place. Mainly dry and slightly warmer temps are expected to round out the work week.
A cold front will move through KGUY and KDHT late Wednesday morning, then across KAMA Wednesday afternoon. Northwest flow aloft will continue, driving a wind shift and cold front through the Texas and Oklahoma Panhandles Wednesday and Wednesday night.
This will keep temperatures from falling to far off the highs from today with lows in the mid teens to low 20s. Wednesday, a cold front will move through the area late in the day however, temperatures will be able to warm some out ahead of it despite increased cloud cover with highs in the upper 30s to mid 40s. The cold front will then pass through the area late tomorrow afternoon into tomorrow night.
COD continues to note highly fluctuating temperatures, depending on wind direction, with northerly winds bringing cooler air in the 20s back into town, while westerly downslope winds have pushed to cold pool out and brought the temperature up into the mid 50s. Most areas will settle to around 30 degrees, with cold pool in the Big Horn basin keeping areas like COD and WRL in the lower 20s. Some light snow is possible for the higher elevations late tonight and tomorrow, but overall accumulation will remain 2 inches or less. Slightly cooler air will move into the state tomorrow, mainly affecting higher elevations.
Chattanooga Airport, TN 20 47 29 49 / 0 0 0 10 Knoxville McGhee Tyson Airport, TN 16 44 24 48 / 0 0 0 10 Oak Ridge, TN 15 44 24 49 / 0 0 0 10 Tri Cities Airport, TN 13 42 20 47 / 10 0 0 10.
Northerly winds will weaken as surface ridging builds into the Tennessee valley. Chattanooga Airport, TN 20 47 29 49 34 / 0 0 0 10 10 Knoxville McGhee Tyson Airport, TN 16 44 24 48 32 / 0 0 0 10 0 Oak Ridge, TN 15 44 24 49 30 / 0 0 0 10 0 Tri Cities Airport, TN 13 42 20 47 29 / 10 0 0 10 0.
525 PM CST Tue Nov 12 2019 High pressure will dominate through the period with widespread VFR conditions expected.
Decided to extend the High Wind Warning to end with the other warnings at 9AM. As a ridge with a strong jet streak builds east over the northern plains, mid to high level clouds are streaming over Wyoming and Nebraska. At the surface, humidities are low with much drier air being advected from the west and strong subsidence following the ridge and downsloping winds. Temperatures will also be above freezing making any ice or snow accumulation challenging.
Extremely cold air continues tonight before a shift in air mass tomorrow brings in slightly warmer conditions.
Northwest flow aloft will continue, driving a wind shift and cold front through the Texas and Oklahoma Panhandles Wednesday and Wednesday night.
/issued 255 PM CST Tue Nov 12 2019/ Arctic air is firmly entrenched over the Mid-South in the wake of yesterday's cold front. A longwave trough anchored over the Great Lakes will shift east tomorrow with 500mb geopotential heights building ~12 dam over the next 24 hours. Temperatures remain below freezing across most of the CWA as of 2 PM with record cold temperatures anticipated Wednesday morning. A cut-off cyclone over the Baja Peninsula will eject eastward tomorrow as a strong kicker trough dives southeast across the northern Rockies.
Ahead of this system over CO, there will be an increase in high level clouds tonight, along with some windy conditions over the high terrain and some of the adjacent locations. These winds will help keep the atmosphere mixed in those locations and will keep temps a bit warmer than lower elevations where it won't be breezy.
335 PM MST Tue Nov 12 2019 As a ridge with a strong jet streak builds east over the northern plains, mid to high level clouds are streaming over Wyoming and Nebraska. At the surface, humidities are low with much drier air being advected from the west and strong subsidence following the ridge and downsloping winds. Temperatures will also be above freezing making any ice or snow accumulation challenging.
Dry weather will prevail through most of the week as a strong ridge offshore blocks storms from reaching Northwest California.
403 PM MST Tue Nov 12 2019 As a ridge with a strong jet streak builds east over the northern plains, mid to high level clouds are streaming over Wyoming and Nebraska. At the surface, humidities are low with much drier air being advected from the west and strong subsidence following the ridge and downsloping winds. Temperatures will also be above freezing making any ice or snow accumulation challenging.
Southerly surface winds will gradually increase tonight as high pressure moves out. A weak cold front will begin to move into northwest Oklahoma at the end of this forecast period, resulting in a north wind shift at terminal KWWR.
Building high pressure will provide dry weather for the rest of the week, with continued below normal temperatures. Lake enhanced snow showers will continue to lessen through the evening as ridging builds in the boundary layer decreases. By midnight, expect snow shower coverage to be isolated and confined to areas along/north of I-80 and in the ridges, with all activity ceasing by 12Z as high pressure builds into the Middle Ohio Valley. 850mb warm advection commences during the afternoon, but this will likely happen too late to allow temperatures to rise above freezing for most of the CWA.