Aikyam-Lab/Synoptic-Bench huggingface dataset:
403 AM EDT Mon Aug 31 2020 Rain chances will increase today, mainly south and east of Pittsburgh, as weak low pressure tracks into the central Appalachians. Dry conditions persist early this morning under high pressure, though cloud cover will continue to increase from the south with advancing low pressure. Higher rain chances and QPF will be focused along the eastern facing ridges of WV/MD/PA into the afternoon as SE'ly upslope flow enhances forcing amid increasing moisture from the south. Outside of the ridges and south of the Mason-Dixon line, dry conditions will initially make it difficult to see more than an isolated shower into this afternoon.
The line of storms will clear the area from west to east by early afternoon, parting way to clearing skies as high pressure builds in from the west. High temperatures this afternoon will be on the cooler side, with values in the upper 60s to 70s. Low temperatures tonight will dip down into the upper 40s to low 50s, with locations in the typical cool spots (central into northern Wisconsin) in the low to mid 40s.
Pacific high pressure across ern Wyoming will build through wrn and ncntl Nebraska today presenting generally clear skies today.
QPF amounts could be around 2 inches in some locations overnight leading to isolated flooding in the low lying areas. DGS Chattanooga Airport, TN 86 72 88 73 90 / 70 30 40 20 20 Knoxville McGhee Tyson Airport, TN 85 71 88 72 88 / 60 40 20 20 40 Oak Ridge, TN 84 70 88 72 88 / 60 40 20 30 50 Tri Cities Airport, TN 83 69 86 69 86 / 60 50 20 20 40.
The second area we are watching is now in southeastern Nebraska generally along a cold front. There would be a conditional threat for 70 mph winds if that squall line really matures as it moves in from the northwest given the high amounts of instability present.
A cold front moves through the region today, bringing gustier winds and temperatures cooler Monday than what we have seen on recently.
344 AM CDT Mon Aug 31 2020 500 mb trough axis moving into E ND at 08z. Some cirrus will streak east thru S ND late today and tonight and this will keep southern fcst area lows a bit milder with low- mid 50s vs the low- mid 40s northern fcst area where skies clear.
205 AM EDT Mon Aug 31 2020 High pressure exiting across New England will supply us with another delightful day today. then it will become increasingly unsettled later tonight through the middle of the week courtesy of a slow moving cold front. High pressure exiting across New England will support fair dry weather through today.
This activity is along and ahead of a surface cold front extending from north central Minnesota southwest into eastern Nebraska. The main upper trough associated with it can be seen in water vapor imagery over the central Dakotas. This is maximized near the 850 mb theta-e ridge axis over that same area, with theta-e values dropping quickly over eastern South Dakota. Things are moving more slowly than guidance indicated yesterday, likely due to the upper trough digging a big more than progged.
A weak H7 low over the lower Rio Grande should help tighten the low level pressure gradient, and strong upper trough moving through the Rockies will continue to tighten the gradient. Will stick with previous thinking on the low cloud trends with a peak expected in the late morning, and more commonly closer to the coast. Overnight lows should be mainly in the lower to mid 80s, except upper 70s for the northern ranchlands.
Satellite loops and surface data indicate a weak trough pushing into nrn CA attm. Behind this trough is a very large area of high pressure in the mid levels over the NRN EPAC that is going to move in here and control the regions weather through the week and especially into the holiday weekend.
311 AM MDT Mon Aug 31 2020 Forecast remains on track with a moderately strong jet forced trough digging though the G. Lingering moisture above 600mb will again lead to convection blossoming over the ridgetops slope circulations help release elevated instability. Obviously this will be easier in the higher elevations but deep uplift from frontal forcing up to jet level will be working to squeeze out all it can. Dry north-northwest flow will encompass the region Tuesday night, as the now closed low swings into New Mexico. Another ridge of high pressure quickly builds into the western Great Basin in the wake of the passing trough.
Cloud cover will be quick to build later this morning with the next midlevel trough sweeping southeastward across the state today. With good midlevel lift and good low-level moisture, showers will be likely for most of the state today, especially for the higher elevations. Biggest short-term weather concern remains the potential for freezing temperatures tonight. WHile the trough will be moving out of the region overnight, the cloud cover will be quickly departing as well. A Freeze Warning is in effect for the lower valleys of western WY, along with the Green River Basin, as temperatures will fall into the mid to upper 20s tonight. As the trough exits the area, ridging will start to build back across the western CONUS.
500 mb trough axis moving into E ND at 08z. Some cirrus will streak east thru S ND late today and tonight and this will keep southern fcst area lows a bit milder with low- mid 50s vs the low- mid 40s northern fcst area where skies clear. Low pressure will move southeast from northern Saskatchewan into central Manitoba Tuesday. A bit of a warm up too south of the low track with highs mid to upper 70s.
A cold front will approach the area from the west which will be the main trigger for thunderstorms this afternoon. The 18Z TAF issuance should have a better handle on what to expect this evening and overnight in terms of the duration of thunderstorm activity and when the lowest conditions could occur. As it stands now, TEMPO groups were used to illustrate where confidence was a little higher in terms of the lowest expected conditions from thunderstorms. Cold front will push into far northeast Oklahoma this afternoon with atmosphere becoming very unstable as low level moisture pools ahead of boundary with dew-points climbing in the upper 70s.
Temperatures should reach the lower 90s today before any rain cooling can occur where shower and thunderstorm activity develops. High pressure will be moving towards the area and will be in place by tomorrow and will lower rain chances considerably. Temperatures will be a little higher tomorrow with the lower rain chances but dewpoints will be slightly lower, resulting in another afternoon with heat index values near 100. Models show upper ridges to the east and west of the area for much of the week.
Zonal flow aloft will transition to more southwesterly this afternoon as an upper level low pressure digs down into the northern Rockies. Meanwhile at the surface a cold front (or convectively enhanced outflow boundary) will slide southward to perhaps as far south as the Big Country by this afternoon and evening.
Dry conditions persist early this morning under high pressure, though rain chances will slowly increase through the morning, primarily south of I 68. Higher rain chance and QPF will be focused along the eastern facing ridges of WV/MD/PA into the afternoon as SE'ly upslope flow enhances forcing amid increasing moisture from the south. A broad trough will begin to move out of the upper Midwest on Tuesday, resulting in increased southwesterly flow aloft across our region.
The line of storms will clear the area from west to east by early afternoon, parting way to clearing skies as high pressure builds in from the west. High temperatures this afternoon will be on the cooler side, with values in the upper 60s to 70s. Low temperatures tonight will dip down into the upper 40s to low 50s, with locations in the typical cool spots (central into northern Wisconsin) in the low to mid 40s. Another weak short wave trough is expected to move across the region Tuesday and produce some weak pv advection in the 500-300 mb layer. This, combined with the forcing from the short wave trough, is expected to produce another round of rain along the front with some of this possibly extending back into parts of northeast Iowa and southwest Wisconsin.
Abundant low clouds and lingering showers this morning in the wake of a cold front that is continuing to advance away from the area. A slow transition toward clearing and warming today as high pressure strengthens over the northeastern Pacific and begins to build over the Pacific Northwest. This will set the stage for a stretch of dry and much warmer temperatures across the region through the week and into the Labor Day weekend.
402 AM CDT Mon Aug 31 2020 Showers and isolated thunder continue this morning behind the passing cold front, with some stratus as well. High pressure will work into the area from the west and slowly slide to the east through the day today, keeping winds mostly light and variable. Expect plenty of sunshine this afternoon with temperatures in the 70s and low humidity (thanks again to the aforementioned cold front and northwesterly flow). Otherwise, expect lows tonight in the lower to mid 50s. High pressure lingers to the east of the region on Tuesday, with a bit breezier conditions thanks to better mixing and a bit of an increasing pressure gradient.
518 AM EDT Mon Aug 31 2020 High pressure will build across the region into Tuesday.
609 AM EDT Mon Aug 31 2020 High pressure will build across the region into Tuesday.
353 AM MDT Mon Aug 31 2020 Cold season upper air pattern developing with long wave trof over Canada anchored by a Hudson Bay low. Strong jet pushes through central Canada on Tuesday with stacked trof.
The cold front is expected to stall out over the KC metro around midday.
A ridge of high pressure begins to build over the region tomorrow which will increase temperatures back above normal.
942 AM EDT Mon Aug 31 2020 High pressure will build in from Canada through early Tuesday providing for lovely late summer weather.
Ridging from the eastern Pacific builds into NorCal on Tuesday with breezy northerly winds continuing in the Sacramento Valley.
412 AM MDT Mon Aug 31 2020 Clearing skies overnight have allowed temperatures to decrease rapidly behind the cold front. Colder air aloft has mixed down to the surface in areas across the higher terrain in addition to the radiative cooling aspect. Overall temperatures should stay cool under a quickly moving dome of high pressure and increasing cloudiness. Coupled with a 60-70 knot jet stream max, the inverted-V may create a wet microburst or two across the higher terrain.
613 AM CDT Mon Aug 31 2020 Showers and isolated thunder continue this morning behind the passing cold front, with some stratus as well. High pressure will work into the area from the west and slowly slide to the east through the day today, keeping winds mostly light and variable. Expect plenty of sunshine this afternoon with temperatures in the 70s and low humidity (thanks again to the aforementioned cold front and northwesterly flow). Otherwise, expect lows tonight in the lower to mid 50s. High pressure lingers to the east of the region on Tuesday, with a bit breezier conditions thanks to better mixing and a bit of an increasing pressure gradient.
A cold front in southwestern Kansas will move toward into the area this morning and move into central and southwestern Oklahoma this afternoon.
401 AM CDT Mon Aug 31 2020 An occluded upper low currently sits over central Saskatchewan/ Manitoba, with a trough axis extending down through eastern North Dakota.
A weak stationary bndry was evident through sfc pressure troughing, extending E from Cntrl OK and across Cntrl AR. Mon evening, sfc cyclonic flow over Cntrl OK will result in a cold front positioned from S/W OK into S/E KS. Multiple perturbations will traverse through the mean flow on Tues, and keep PoPs elevated across the Nrn half of the state, with cooler temps fcst under more persistent cloud cover and precip, while Srn AR will stay in the lower 90s on the first day of climatological fall.
The models suggest that the MCS activity will shift south into central MS and AL this evening, leaving cooler and stable air over north AL and southern TN. Convection that results may start to spill into the northwest AL toward Tuesday morning along a pseudo-warm front/remnant outflow boundary from the earlier MCS that lifts back northeast. It may tend to weaken somewhat with weak ridging at 5h developing over the area through the day. With the mid to upper ridge building further across the southeast U.
This activity is along and ahead of a surface cold front extending from north central Minnesota southwest into eastern Nebraska. The main upper trough associated with it can be seen in water vapor imagery over the central Dakotas. This is maximized near the 850 mb theta-e ridge axis over that same area, with theta-e values dropping quickly over eastern South Dakota. Things are moving more slowly than guidance indicated yesterday, likely due to the upper trough digging a big more than progged. Cooler and drier air will then build across the area into Tuesday as high pressure slides east through the region. Northwest upper flow will predominate through the period, with the main upper trough over eastern North America significantly amplifying by the end of the period, signaling the arrival of much cooler temperatures.
The cold front is currently about mid-way through western KS/eastern CO and is pushing south. As for the high temps today, the cooler air filtering in behind the front will bring highs in the 70s to the northern zones and 80s to the southern zones. The mid-level trough now gets closed off over the desert southwest on Tuesday.
655 AM EDT Mon Aug 31 2020 High pressure will build in from Canada through early Tuesday providing for lovely late summer weather.
Mainly widely scattered afternoon and evening thunderstorms expected midweek with weaker forcing and upper ridging. Low pressure off the Southeast Coast will continue moving northeast. Moisture flux increase today as a low/mid level trough moves into the area from the west. High temperatures will range from the mid 80s to lower 90s with lows tonight in the low to mid 70s. A ridge off the southeast U. The GFS is a little weaker than the ECMWF with ridging and appears to advect more moisture into the area along with some weak short wave forcing.
516 AM MDT Mon Aug 31 2020 Clearing skies overnight have allowed temperatures to decrease rapidly behind the cold front. Colder air aloft has mixed down to the surface in areas across the higher terrain in addition to the radiative cooling aspect. Overall temperatures should stay cool under a quickly moving dome of high pressure and increasing cloudiness. Coupled with a 60-70 knot jet stream max, the inverted-V may create a wet microburst or two across the higher terrain.
Scattered showers and t-storms are possible Tuesday evening over the southern portions of the area, but generally the forecast is dry as the cooler weather early this week is replaced by typical early September temperatures for the week's remainder.
Dry conditions persist early this morning under high pressure, though rain chances will slowly increase through the morning, primarily south of I 68. Higher rain chance and QPF will be focused along the eastern facing ridges of WV/MD/PA into the afternoon as SE'ly upslope flow enhances forcing amid increasing moisture from the south. A broad trough is projected to dig across the Midwest on Tuesday, resulting in increased southwesterly flow aloft ovr the Upr OH.
535 AM MDT Mon Aug 31 2020 Forecast remains on track with a moderately strong jet forced trough digging though the G. Lingering moisture above 600mb will again lead to convection blossoming over the ridgetops slope circulations help release elevated instability. Obviously this will be easier in the higher elevations but deep uplift from frontal forcing up to jet level will be working to squeeze out all it can. Dry north-northwest flow will encompass the region Tuesday night, as the now closed low swings into New Mexico. Another ridge of high pressure quickly builds into the western Great Basin in the wake of the passing trough.
500 mb trough axis moving into E ND at 08z. Some cirrus will streak east thru S ND late today and tonight and this will keep southern fcst area lows a bit milder with low- mid 50s vs the low- mid 40s northern fcst area where skies clear. Low pressure will move southeast from northern Saskatchewan into cetnral Manitoba Tuesday. A bit of a warm up too south of the low track with highs mid to upper 70s.
First a synoptic cold front was moving into an increasingly unstable and now weakly capped environment over north central OK. The pattern will remain active with a frontal zone in place in the general vicinity of the Red River and a trough currently over the Northern Rockies continuing to dig south and cut off to our west.
Tonight and Tuesday A few showers will continue through this evening as a weak cold front moves across the region. Expect fairly quiet conditions to return to region behind this as clouds move off to the east and a weak ridge slides into the region. The weak ridge will be fairly short lived, moving off to east by Tuesday afternoon and evening as a low pressure system tracks just south of the area.
An upper ridge which extends from the western Atlantic to across the central Gulf gradually shifts northward to extend from the extreme southeast states to the northwestern Gulf as a positively tilted upper trof evolves from near the 4 Corners area to the Plains. May see some strong storms develop this afternoon, and also on Tuesday as mid level dry air becomes more prominent due to the subsidence associated with the upper ridge. Highs this afternoon and Tuesday afternoon will be in the lower 90s with heat index values of 101 to 107.
321 PM EDT Mon Aug 31 2020 Low pressure is expected to develop off the coast today, but should remain offshore as it moves northeast away from the area Tuesday.
A shallow trof axis is forecast to move through Thu evening, followed quickly by the surface boundary overnight. Until then, the NBM PoPs will remain on the high side for shower and tstm activity, with the best signal for rainfall being Wed at this time, but Wed night is a good candidate, too. Most medium range models indicated that another cold front will swing through our region early Mon, providing a minor interval of shower and tstm activity, more limited in moisture fetch this time.
301 PM EDT Mon Aug 31 2020 After a rather gloomy start to the last day of meteorological summer, low clouds have gradually been eroding from south to north across the forecast area as a warm front slowly lifts northward towards the Ohio River. As we move into Tuesday, quasi-zonal flow aloft is expected to become more southwesterly as an upper level low develops and digs southward over the Four Corners region. For the rest of the work week we'll sit under broad southwest flow aloft ahead of an upper trough moving very slowly across the Plains. Occasional disturbances ejecting out of the trough will help to initiate waves of showers and thunderstorms as they interact with a warm and humid atmosphere over the southeastern United States each day.
1221 PM MDT Mon Aug 31 2020 Forecast remains on track with a moderately strong jet forced trough digging though the G. Lingering moisture above 600mb will again lead to convection blossoming over the ridgetops slope circulations help release elevated instability. Obviously this will be easier in the higher elevations but deep uplift from frontal forcing up to jet level will be working to squeeze out all it can. Dry north-northwest flow will encompass the region Tuesday night, as the now closed low swings into New Mexico. Another ridge of high pressure quickly builds into the western Great Basin in the wake of the passing trough.
An upper trough digs into the northern Plains as a closed low begins to develop on the western slope of the Rockies. Forecast soundings suggest remnant dry air in the lowest 200mb, which should cut into the overall potential for measureable precip. Overall, the lack of sufficient surface forcing and primarily dry air in the low levels should lead to a lot of the initial moisture should evaporating. Temperature-wise, went with the warmer end of guidance for min temps to account for increasing cloud cover and weak WAA. Lows should range from the upper 40s along the Pine Ridge to lower 50s elsewhere. Depending when the morning rain showers depart and clouds clear, highs should reach the lower 80s.
A trough is currently deepening over the Intermountain West and will continue to deepen through midweek while slowly shifting East.
The frontal boundary lingers over the southeastern forecast area for the rest of the afternoon and begins lifting northward in response to the digging upstream trough noted in water vapor imagery over the Northern Rockies.
This ridge building is expected to mainly increase our overall high temperatures tomorrow as higher geopotential heights build over the area. In general, high temperatures will climb into the low to mid 90s in the afternoon, and will start in the mid 70s in the morning hours across the region.
Stronger wave dropping into upper trof over northern Rockies will continue to move south of the forecast area, so we will remain dry for the rest of the week.
A breezy northwest wind continues to pull lower dew points southeast, dropping the relative humidity values into the lower 30s at peak heat.
the low level jet streak is expected to weaken. Moisture pooling along the approaching surface frontal boundary combining with overall dewpoints in the 70s will aid in heat index values in the 100 to near 105 degree range for the warmer locations.
The highest amounts were near Kasson with 2. The cold front has switched winds around to the northwest and at 2pm was located near. Lows tonight should mostly be in the 40s, with a few warmer spots in the lower 50s. High Tuesday will be cooler than normal in the lower to mid 70s.
A cold front is moving through the area currently bring light rain showers and very light snow showers mainly above 10,000 feet. High pressure ridging starts building in overnight and continues through the end of the week.
A cold front will move into the area tonight and Tuesday, bringing breezy north winds and noticeably cooler temperatures. It is worth noting that considerable smoke could be seen on satellite loops and web cams coming down through Inyo County and Esmeralda and central Nye counties and this wide swath will move across the rest of the forecast area this afternoon and evening then clear out overnight as a trough and cold front dive over the Great Basin and Intermountain Region. This will drive a cold front through the southern Great Basin and much of the Mojave Desert this evening through Tuesday morning, with the primary concern being gusty north winds in Lincoln County (discussed in more detail in the Fire Weather section below).
West to southwest flow aloft will bring in some lingering moisture overrunning the surface cold front. Cutoff low expected to eject from the upper level trof and drop over the Four Corners region tomorrow afternoon. This in conjunction with the stalled retreating cold front will put the Panhandles in the moist sector tomorrow afternoon and evening. Warm moist air in the low levels and decent jet aloft with the right entrance region setup over head will allow for scattered to widespread severe storms to develop. Now, if the surface trof pushes further east quicker than expected, we could be completely shut down for the majority of the central and western Panhandles.
This afternoon, a cold front will continue to move southward into central Oklahoma. Thunderstorm development along this cold front is likely through central and southwestern Oklahoma as well as western north Texas, mainly after 4pm. Along with the cold front forcing, this should be sufficient for the initial possible development of a couple supercells. Ongoing cloud cover across central Oklahoma has suppressed the temperatures (upper 80s/low 90s), whereas in northern parts of central Oklahoma where there have been clear skies, surface temperatures are warmer in the mid 90s. These parameters will need to be monitored as the cold front moves southward.