Aikyam-Lab/Synoptic-Bench huggingface dataset:
As of mid afternoon, high pressure was centered across the lower Great Lakes region. Readings were in the 50s, on the way to reach the low 60s across southern IN and north central KY. A warm front, currently across middle AL/GA, will begin lifting toward the area tonight and Monday morning, and is expected to reach the KY/TN border vicinity by Monday afternoon. The best severe thunderstorm chances will be from middle TN southward into Alabama, but a few strong to perhaps marginally severe thunderstorms will be possible right along and south of the warm front across extreme southern Kentucky.
A warm front will be south of the forecast area today. The front will lift northward and into the area tonight ahead of approaching low pressure.
Additional snow accumulations of 4-8 inches are possible over the Continental Divide (Marias Pass), and 1-4 inches in the lower elevations along US-2.
An upper level low, currently over southeastern Colorado will slide into southwestern Kansas this evening enhancing lift. Towards the surface, an area of low pressure and associated frontal boundary will move into far western Kansas this evening then along the KS/OK border overnight.
Temperatures will be cooler today behind the cold front today but high temperatures will still be near normal with help of downslope flow and mostly clear skies. Currently plan on letting the High Wind Warning for the Guadalupe Mountains expire at 3 am mdt with the new package as winds turn more northwesterly aloft.
A weak ridge over the region Tuesday will bring a mostly sunny day.
A low pressure system over the ne pac ocean was spinning disturbances into the pacnw but the bulk of this was over s oregon and n california. The clouds were lessing across the area and this may allow for good radiational cooling as temps fall into the 30s with 20s in the higher elevations.
Winds should then gradually decrease through the mid-late afternoon hours as the pressure gradient finally begins to relax and the upper low races off across the Mississippi River Valley. The winds will turn northwesterly later this morning as another cold front moves through.
Initially winds will be west to northwest behind the front which will usher in drier air, however the cooler airmass will not arrive until tonight. As additional high pressure builds across the area tonight, winds are expected to increase to advisory levels across the coastal waters by late tonight into early Tue morning and begin to relax by early Tue afternoon. This surge of high pressure will also bring colder temps with lows expected to be upper 40s to lower 50s by early Tue morning.
The upper flow will back to southwest tonight and Tuesday, opening the door to additional moisture and warmer air.
1142 PM MDT Sun Mar 18 2018 Trough will eject across the Rockies and close off as it moves along the Kansas/Oklahoma border tonight. No significant accumulations are expected during that time as the upper low moves away and winds will gradually diminish.
High pressure will bring a strong warming trend the first half of the week. Upper ridge axis was just west of the California coast early this morning. Meanwhile, a deep upper low pressure system was further west of the ridge axis, or centered near 34N/140W.
Conditions will improve thereafter, but a cold front moving across the area will generate isolated to scattered thunderstorms as it moves through.
Low level moisture will continue to gradually filter into South Florida, which will result in a little warmer temperatures and better chances of experiencing widespread fog overnight. Model solutions are in fair agreement about an advancing low pressure system migrating across the Tennessee Valley tomorrow and into Tuesday, dragging an associated frontal boundary into the northern half of the Florida peninsula.
High pressure aloft will expand across the region during the first half of this week.
304 AM MDT Mon Mar 19 2018 Rather compact upper low moving across the Ks/Ok border early this morning with cloud tops now warming over the CWA. Dry Tuesday as upper ridging begins moving towards the area. Max temperatures about 10 degrees warmer on Tuesday with more sunshine and warming 700H temps.
Large scale ascent ahead of the main upper low and the core of the low itself it also continue to bring lightning strikes and most likely heavy precipitation bursts late this afternoon from our southern CWA to the Front Range. A good warming trend will take place for the mid week period as the ridge aloft settles over the High Plains with troughs along each side of NOAM. What will be important for the upcoming week will be a moderate atmospheric river forecast to hit the lower half of the Left Coast Tuesday afternoon.
DZ will also be possible over PNC, where the lowest cigs are anticipated, and could drop vsbys to below 5 miles at times. /issued 407 AM CDT Mon Mar 19 2018/ The mid to upper low continues its track along the KS/OK border early this morning. Then, by late this morning thru this afternoon, winds will increase from the northwest behind the cold front. A rapid warmup is still anticipated mid to late this week under an upper ridge axis. The next chance of storms will arrive Sun-Mon with a southern stream mid to upper trough likely impacting the Southern Plains.
Today Through Tuesday Night The SFC warm front remains south of the CWA early this Mon morning. but some strong winds may also be seen along the SRN edge of this line as the warm front to the south begins to lift north over time. the focus for convection will shift to the NRN/NERN sections of the state just ahead of the upper closed low. This area will be north of the SFC warm front. Behind the convection and SFC cold front. but the cooler temps expected will keep RH values elevated.
We'll see a mix of mid and high clouds with low pressure passing well to the south of Wisconsin. A brisk northeast flow will keep it cold by Lake Michigan, warmer west and south of Madison.
Dry weather continues today into early Tuesday under ridging ahead of the upstream low offshore. Plenty of sunshine along with a milder airmass will result in warmer temperatures across the region today with milder portions of the Central Valley likely to approach the 70 degree mark.
This pretty much follows progged track of upper level low. Temperatures this morning below freezing north of highway 2 and in the mid 30s south of that. Raw cool wet day across western Nebraska today with highs in the mid to upper 30s Upper trough moves east across the northern plains over night with areas of snow ending over north central Nebraska through the early morning hours. Lows in the teens where snow on ground over the Pine Ridge and 20s over the remainder of western Nebraska. In the wake of the closed upper low, northwest flow takes over through midweek as a ridge amplifies over the Rockies.
130 AM EDT Mon Mar 19 2018 High pressure will continue to bring dry and pleasant weather to the region Monday and Tuesday. Highs will range from the mid 40s northeast to the low 50s southwest. Wx nil this period as ridging persists across the Great Lakes. Guidance continues previous days trends in ejecting next substantial plains cyclone east through the TN valley. Easterly will strengthen as the pressure gradient tightens between the passing low pressure system to our south and the system to our far north.
The cold front moves through overnight tonight. A cold front will move through the northern gulf overnight bringing strong northwest winds by daylight Tuesday morning.
642 PM EST Tue Feb 20 2018 Dry and warm weather is expected under a high pressure ridge through early Wednesday.
Southwest flow aloft continues as the main upper trough stretches from central Canada down southwest into the western states. Based on upstream satellite and radar observations and hires model trends, have increased the chance of snow across the I70 corridor and over northern Grand and southern Jackson counties in the high country, as well as into lower Larimer County and over the urban corridor down to the Palmer Divide. A strong upper ridge off the southeast coast is going to remain in place while a broad upper trough holds in place over the western United States. Colorado will be under southwesterly flow, downstream from the base of the trough. A high amplitude ridge will also remain in place over the Gulf of Alaska. Through the week, pieces of energy will rotate through the base of the trough at times and move across Colorado.
A cold dome of high pressure will build into western Kansas overnight as an upper level trough begins to establish itself over the Southwest United States. This precipitation may begin as snow but as the warm air advection improves late day/early Wednesday night the precipitation is expected to change over to freezing rain.
Just a few areas of cloud cover still lingering over the eastern part of the CWA this afternoon as high pressure is now pushing in from the west/northwest.
606 PM EST Tue Feb 20 2018 Dry and warm weather is expected under a high pressure ridge through early Wednesday.
By mid-afternoon, the back-edge of the freezing rain was finally exiting the outlook area as the system progressed into Missouri. With these cold conditions in place, there is the potential for some slick road conditions overnight into Wednesday morning on any untreated surfaces from today's freezing rain/sleet event.
753 PM PST Tue Feb 20 2018 Low clouds and light snow have developed along the eastern Sierra as upper trough and light upslope flow combine to produce some lift. The trough will exit by morning and snow showers will decrease after daybreak although clouds will likely linger through the morning. /Issued 332 PM PST Tue Feb 20 2018/ A cold low pressure trough will remain over the region this week with below normal temperatures.
Sleet and/or freezing rain showers may impact KLBB as early as about 13 UTC, but confidence is too low to include in the TAF. Our cold front pushed through must faster than previously thought, and by 3PM, it was making its way into the southern row of our counties.
Precip may linger through the night across far southeast Oklahoma with a mix of rain/freezing rain. Forecast still appears on track to see another round of freezing rain develop and move north impacting much of the area by Wednesday afternoon. Freezing rain and sleet will spread back across the area Wednesday. /issued 407 PM CST Tue Feb 20 2018/ Freezing rain is expected to end across central Oklahoma by the early evening. However, as temperatures continue to cool across southern Oklahoma this evening, some of the precipitation will change to freezing rain. By early Wednesday morning, freezing rain is expected to develop across north Texas and southern Oklahoma as another wave approaches the southern Plains. Overall, precipitation amounts are expected to be much lighter than today, but enough elevated instability may result in areas of moderate to heavy freezing rain.
A strong upper level ridge will remain in place just to our east and it will strengthen through the middle of the week.
Upper trof axis exiting to the east/southeast by evening with clearing skies over the region. Aforementioned short wave will drop into the Great Basin and reinforce the broad upper trof over the inner mountain west for Thu.
But, moisture in the lowest layers has diminished noticeably in the last twelve hours.
Weak impulse will move east across the region this evening with effect limited to some cloudiness as well as a few snow showers over the higher mtns. Quiet day again Weds and warmer but still on the cold side.
The overall synoptic pattern will remain stagnant through the period, as the region will remain situated on the western periphery of deep layer high pressure.
525 PM CST Tue Feb 20 2018 For the rest of today and tonight, the area of freezing rain/sleet/snow will shift east. Initially it looked like they would cool down to or below freezing quickly.
613 PM CST Tue Feb 20 2018 Cold front has recently passed through Decatur, and will arrive soon in Champaign. Forecast soundings show a prominent warm nose around 2,000 feet lingering much of the night, so a changeover to freezing rain and some sleet remains likely.
Warmth will continue much of the night until the cold front currently stretching from Little Rock to west of Poplar Bluff arrives in northwest Middle Tennessee around 11-12Z per HRRR. Latest guidance continues to show a significant heavy rain threat across our northwest counties in the Flood Watch area as the cold front moves into the cwa and stalls.
High pressure will bring mainly dry conditions to South Florida on Wednesday with warm temperatures. Afternoon high temperatures will range in the lower 80s across the east coast to the upper 80s across the interior. A strong upper level ridge will remain in place just to our east and it will strengthen through the middle of the week.
542 PM CST Tue Feb 20 2018 WV imagery was showing the upstream longwave trof has nudged a bit to the east since yesterday and currently extends from about central Canada to Baja. However, models are in pretty good agreement large scale pattern will become stagnant with the upper trof moving little the next several days.
332 PM PST Tue Feb 20 2018 A cold low pressure trough will remain over the region this week with below normal temperatures.
Currently, long wave trough over the western and central United States, with an embedded S/WV trough pushing east across western North Dakota. Combined with lingering cold air associated with the high pressure (with some additional CAA north tonight), resultant wind chill temperatures will fall into the advisory range for much if not all of western and central ND later this evening and into mid morning Wednesday. Models remain in agreement with maintaining an upper level trough over the western CONUS through the work week, placing the Northern Plains in southwest flow aloft.
There may be a few lingering snow showers over the mountain ridges though.
Freezing rain and sleet will spread back across the area Wednesday. /issued 407 PM CST Tue Feb 20 2018/ Freezing rain is expected to end across central Oklahoma by the early evening. However, as temperatures continue to cool across southern Oklahoma this evening, some of the precipitation will change to freezing rain. By early Wednesday morning, freezing rain is expected to develop across north Texas and southern Oklahoma as another wave approaches the southern Plains. Overall, precipitation amounts are expected to be much lighter than today, but enough elevated instability may result in areas of moderate to heavy freezing rain.
A cold front will work east across the Ohio river valley tonight into Wednesday and Wednesday night.
/issued 352 PM CST Tue Feb 20 2018/ The deep trough to our west continues to dig into northern Mexico this afternoon. Strong SSW flow aloft downstream of this trough is pumping abundant mid/upper-level moisture across the Southern Plains and Midwest. The cold front attendant to the Great Lakes cyclone will move south into the CWA late tonight and slide slowly south throughout the day.
Another round of freezing temperatures are expected Wednesday morning in the same areas as this morning.
20Z regional radars show the last bit of rain/freezing rain moving east of the forecast area.
The surface freezing line now extends from Jay to Eufaula, just north of McAlester. Temperatures in Benton and Washington counties in NW Arkansas are in the mid 30s and will drop below freezing by or just after midnight, per hourly trends. It's still raining as far south as McAlester, but this will change over for some light freezing rain before rain moves east and south. Observed soundings from OUN/SGF show pretty classic freezing rain soundings, and the lowest levels at least off the SGF sounding don't support sleet, so the main precip type should stay freezing rain overnight. There is potential for more freezing rain, possibly with some sleet, for Wednesday into Wednesday night.
Latest water vapor imagery shows an amplified long wave trough affecting much of the western CONUS and high pressure offshore the southeast CONUS.
Aloft, flow remains southwesterly across the region, set up between high pressure centered off the southeast coast and a trough draped from central Canada and into the Rockies. At the surface, we are well behind the main cold front, now extending from the western Great Lakes down into northern TX. At the surface, high pressure currently centered roughly over the NE/SD/WY border area will continue to sink south this evening/tonight, ending up in the eastern NE/SD border or northeastern NE area by sunrise tomorrow.
A very cold airmass over Northern California will bring below freezing conditions to the San Joaquin Valley with temps falling to 25 to 30 degrees.
554 PM CST Tue Feb 20 2018 For the 21/00z TAFs, convection is likely to affect all TAF sites this period as a strong cold front gradually move into and across the area. /issued 449 PM CST Tue Feb 20 2018/ The current upper pattern of a longwave trough of low pressure over the Western States and the upper ridge of high pressure off the East Coast continued to provide a strong Southwest flow aloft over the Four State Region. This combination of unstable air and the approach of the cold front will provide showers and thunderstorms the length of the country.
as they are already cooler than prev fcst curve indicated.
Another round of freezing temperatures are expected Wednesday morning in the same areas as Tuesday morning.
Forecast sounding still indicate that the activity should be mainly in the form of freezing rain and sleet and this could cause some travel problems for the morning commute with area roadways becoming slick. Sleet and/or freezing rain showers may impact KLBB as early as about 13 UTC, but confidence is too low to include in the TAF. Our cold front pushed through must faster than previously thought, and by 3PM, it was making its way into the southern row of our counties.
932 PM EST Tue Feb 20 2018 Dry and warm weather is expected under a high pressure ridge through early Wednesday.
Latest sfc obs show the cold front has made it thru KMAF and KHOB, and should be thru other terminals by 12Z or sooner. /issued 133 PM CST Tue Feb 20 2018/ Today there is a strong upper trough extending from the Northern Rockies down through the Great Basin while an upper ridge remains centered off FL Atlantic coast.
Clear skies will continue tonight with temps dropping to well below freezing once again. Southerly flow will set up overnight as high pressure slides east of the region. Wind Chill Advisory has been issued for all areas except the SD Black Hills where temps will be warmer, but still below zero.
With increasing clouds and slightly warmer temperatures aloft, low temperatures will not be quite as cold tonight.
With this trough slipping down the coast, some more energy behind it will bring some precipitation to our region tonight.
/issued 554 PM CST Tue Feb 20 2018/ For the 21/00z TAFs, convection is likely to affect all TAF sites this period as a strong cold front gradually move into and across the area.
Most of the moisture is in the lower 8,000 feet of the sounding below a 2-3C inversion. Freezing level this evening is just below 14,000 feet with the -20C level near 25,000 feet. Shear is fairly limited in the lower levels. /issued 356 PM CST Tue Feb 20 2018/ Steady state onshore flow persisting on what still appears to be an out-of-season Bermuda ridge pattern.
Isltd -SHRA will stream northward over the area tonight, with shower chcs increasing from west to east during the day Wednesday as a cold front moves into the area. The increase in the low level jet and daytime heating has allowed some scattered showers to develop, mainly across northern portions of the forecast area. Over the next few days, a broad upper level trough over the western US will eject energy eastward and help push a cold front to the fringe of the northwestern portion of the forecast area on Wednesday.
At the surface, high pressure will shift off to the east northeast bringing winds around to the east and eventually east southeast. Aloft, a deep trough will begin to lift out of the southwest U.
In general, the precipitation should end before temperatures reach the freezing mark, but a few snowflakes aren't out of the question later this evening over Racine and Kenosha counties. Cold air will slowly filter into the area overnight with temperatures steadily falling below freezing from west to east. Depending on how long the rain lasts across far SE WI and how quickly the cold air can make it that far east, there may be a brief period of freezing rain in far SE WI around 06Z. Forecast confidence is high: High pressure will bring some sunshine and colder temperatures on Wednesday, with highs a couple degrees below normal.
Mid/upper level ridging will hold over the southeast U. Troughing dominates the western half of the country while strong persistent ridging remains over the east coast. The upper high sits off the Carolina coast and ridges southwest over Florida and into the Gulf of Mexico.
Road conditions within this band improved as road and air temperature rose above freezing. Further north patchy drizzle or freezing drizzle may linger through the afternoon. System will move east of Wisconsin this evening which will allow for high pressure to build in at the surface. Temps will be cooler, however, with highs in the lower 20s across central Wisconsin, and in the middle to upper 20 across northeast and east- central Wisconsin.
410 PM MST Tue Feb 20 2018 Weak impulse will move east across the region this evening with effect limited to some cloudiness as well as a few snow showers over the higher mtns. Quiet day again Weds and warmer but still on the cold side.
449 PM CST Tue Feb 20 2018 The current upper pattern of a longwave trough of low pressure over the Western States and the upper ridge of high pressure off the East Coast continued to provide a strong Southwest flow aloft over the Four State Region. This combination of unstable air and the approach of the cold front will provide showers and thunderstorms the length of the country.
626 PM CST Tue Feb 20 2018 For the 00Z TAFs, the sfc cold front is well south of the forecast area.
Chattanooga Airport, TN 61 79 61 76 / 30 40 50 40 Knoxville McGhee Tyson Airport, TN 60 77 59 73 / 20 50 50 50 Oak Ridge, TN 60 77 59 73 / 20 50 50 50 Tri Cities Airport, TN 55 76 56 69 / 10 40 50 50.
High pressure over the W Atlc/Deep South will maintain a moderate SE breeze acrs the area.
854 PM CST Tue Feb 20 2018 Temperatures continue to quickly fall this evening across the area, with the western 2/3 or so of the forecast area already below freezing.
Latest sfc obs show the cold front has fropa'd as far SW as Gail. As far as freezing precip, confidence is too low to mention it attm, as the bulk of it looks to materialize east of the terminals. /issued 133 PM CST Tue Feb 20 2018/ Today there is a strong upper trough extending from the Northern Rockies down through the Great Basin while an upper ridge remains centered off FL Atlantic coast.
825 PM EST Tue Feb 20 2018 Significant ridging in place will continue our record breaking temperatures (see climate section below) with widespread upper 80s tomorrow and maybe even a couple of Although ample low level moisture exists and some clearing will occur, it appears as though boundary layer winds may be too strong for widespread fog development and low stratus will prevail in the morning hours. Strong ridge of high pressure continues to dominate our region with prevailing easterly winds and no rain chances. Meanwhile, the low temperature of 73 degrees this morning at Tampa International would be a monthly record high minimum if it does not drop lower before midnight tonight.