Aikyam-Lab/Synoptic-Bench huggingface dataset:
211 AM CDT Sat Aug 22 2020 Widely scattered showers and the occasional rumble of thunder continue across Middle TN at forecast time as we continue to feel the effects of an upper level trough axis draped over the region. 70 inches off the 06Z OHX sounding, rainfall rates have and will continue to be fairly decent with any of the higher radar reflectivities, even if there isn't thunder associated with the storm. With the extra cloud cover and rain chances also comes cooler than normal temperatures. Another day with highs in the low 80s is very likely today -- well below seasonal averages. Temperatures will start to rebound as this upper trough starts to pull northward and high pressure reasserts itself over the region.
Cold front sags south of our region tonight with waning shower activity.
Weak high pressure remained in control of the weather pattern overnight. As we've seen the past few nights under this ridge, patchy fog has once again developed.
300 AM MDT Sat Aug 22 2020 Hot today with a strong ridge in place over the central rockies. 700mb temperatures range from 13-15c across the area today and this with downslope winds ahead of a cold front, should allow highs to reach the mid to upper 90s, with a few places possibly hitting 100 degrees, which will challenge some records. A cold front will move in from the west this afternoon and decrease dewpoints, sending humidities into the lower to mid teens. This will lead to a cooler day on Sunday. Highs on Sunday will be 5 to 10 degrees cooler, but still above normal for this time of year.
1210 AM CDT Sat Aug 22 2020 The extended dry period will continue through the weekend (and beyond) as the westerlies remain along the Canadian border leaving the forecast area in the downstream shield of the upper ridge over the western U. The upper ridge will however flatten a bit as it shifts eastward into the Plains. An important weakness in the ridge though is expected to form from Missouri southward potentially offering an alley for the remnants of the tropical systems to venture northward.
500-mb flow according to this morning's 12z observations is a lazy 15-20 knots in the vicinity of the aformentioned trough. Given the slower trough, the slim rain chance now shifts to Sunday.
An upper level low centered over the Tennessee Valley will slowly lift north into our region tonight. A dampened H5 trough will keep scattered showers and storms in the forecast on Sunday, with better forcing present east of I-71.
Our weather will be dominated by the large 500mb high centered near the 4 corners region that will extend a ridge through SD and western MN.
A few lingering showers and storms expected Sunday mainly east of the Mississippi River with that departing mid-level trough. Mid-level ridging continues into Sunday night for quiet conditions.
Upper level low continues to rotate across the area. SR Chattanooga Airport, TN 84 68 87 70 89 / 60 40 40 20 40 Knoxville McGhee Tyson Airport, TN 84 68 86 69 88 / 50 20 40 10 30 Oak Ridge, TN 84 66 86 67 88 / 50 20 40 10 30 Tri Cities Airport, TN 83 64 84 65 85 / 50 20 40 10 30.
Large scale pattern over the CONUS through the long range periods is dominated by ridging centered over the southwest US that eventually flattens in the later periods.
147 AM MDT Sat Aug 22 2020 Upper ridge persists over the western CONUS, with its axis over the Rockies.
Otherwise, expect morning low temperatures to again be in the low to mid 60s with more seasonable temperatures over the weekend with near zero chances for any measurable precipitation as well.
This activity has formed in a local region of moderate instability, weak surface forcing, and underneath a somewhat persistent upper level trough over the mid south. The upper trough will start to lift to the northeast by late Saturday.
1025 PM CDT Fri Aug 21 2020 Temperatures continue to rise into the lower 90s this afternoon, once again challenging forecast highs. Any multicellular development should track along the edge of the +10C 700 mb isothermal, moving into western Minnesota and along the Buffalo Ridge late in the evening.
Highs today will range in the lower to mid 80s, with northern Kentucky forecast to be cooler than the northern portions of the fa, opposite of what we typically see. The H5 trof will continue to fill this evening. Lows will drop back to the lower to mid 60s. Highs will once again push into the lower to mid 80s. The slightest inflection remains in the 500mb trough Sunday night with any lingering showers fading by the late evening.
Weak low pressure is projected to dig up the Ohio and shunt that weak boundary northward today. Expect an increase in humidity for areas south of I 80 and the development of scattered convection given lessening convective inhibition under the troughing with afternoon temperature a few degrees above the calculated- normals. Upper troughing will continue to linger over the Ohio Valley through Sunday with scattered, mainly diurnally-supported showers and thunderstorms are expected again.
A weak cold front will continue to move through the region today, causing most places to have around a 10-degree high temperature decrease from yesterday, and breezy winds are still expected by this afternoon. Smoke continues to move into central Idaho and western Montana from the southwest, but today's cold front will shift the winds enough that some improvement is possible north of Highway 12. Warm temperatures are forecast to remain with the Northern Rockies positioned on the southwesterly flow side of the dominant high pressure system.
437 AM CDT Sat Aug 22 2020 Another quiet weather night is occurring tonight, albeit slightly warmer than the last night. A weak ridge of high pressure will extend from the TN/OH Vlys east to the Ozarks and southern Plains.
416 AM CDT Sat Aug 22 2020 It will be a hot one today as the upper level ridge over the western United States continues to build.
Forecast hourly temperatures are in great shape this morning with temperatures in the low to mid 70s. Guidance agrees that showers and thunderstorms will initate across the higher terrain of the Southern Appalachians and Cumberland Plateau. SR Chattanooga Airport, TN 84 68 86 70 88 / 40 40 40 20 30 Knoxville McGhee Tyson Airport, TN 83 68 86 68 87 / 60 40 40 10 20 Oak Ridge, TN 84 66 86 67 87 / 50 40 40 10 20 Tri Cities Airport, TN 83 64 84 65 85 / 50 40 50 10 30.
Otherwise, the short term is dry, with afternoon highs warmer than usual, for late August.
317 AM MDT Sat Aug 22 2020 Overnight WV/IR imagery showed the strong upper high centered near the Four Corners of the Southwest CONUS. The clockwise circulation around the high was advecting smoke from Western CONUS wildfires into the CWA. Persistence will be the operative word this weekend with the continuation of hot daytime temperatures and low humidities as the upper high remains parked over the Four Corners. Fortunately, winds will be relatively light under the influence of the ridge aloft. The upper ridge axis will flatten and weaken as a upper trough tracks east from the Pacific Northwest across the international border during the upcoming week.
Current temps are still in the lower 70s but latest model data suggests that some warming should commence.
617 AM CDT Sat Aug 22 2020 It will be a hot one today as the upper level ridge over the western United States continues to build.
1047 AM EDT Sat Aug 22 2020 Ridge axis will continue to lift northward across the area today, with low level winds becoming E/SE through late day. Satellite imagery showing some breaks in the higher cloud cover, and will still have some weak mid level disturbances crossing the area ahead of mid-upper level trough well to the northwest. Highs will reach the upper 80s/~90 deg along the coast, and should enough sunshine exist across the interior, temps should max out in the low 90s. Transition of a more onshore flow today across the area as ridge axis shifts northward across central Florida. (Previous Discussion) The Atlantic ridge axis lifts northward from central FL during this period.
High pressure centered over the four corners region will lead to continued southwesterly flow aloft across northern and central NV through the weekend. As such, isolated thunderstorm activity on Sunday may only reach as for north as the highway 50 corridor.
Strong short wave trough located over north-central Texas will continue to move south toward the upper Texas coast this afternoon. Area of convection associated with this short wave trough moving through south-central Texas at this time.
528 AM EDT Sat Aug 22 2020 Dry and stable conditions held firm within low to mid level ridging will again provide clear skies across the lowest 10 kft through the period. * None Deep layer stability held firm within a gradually increasing upper height field and general low level ridging ensures another day of benign weather conditions today. The resident above average thermal profile will inch higher today under increasing thickness readings, but with the lack of meaningful warm air advection given weak gradient flow placing a ceiling on this warmer trend. Southeast Michigan will continue to reside within the outer expanse of a predominant large scale upper ridge anchored across much of the southern conus.
Scattered showers and isolated thunderstorms are beginning to proliferate to the south and west of the Lower Keys, along an area of apparent surface convergence.
437 AM MDT Sat Aug 22 2020 Upper ridge persists over the western CONUS, with its axis over the Rockies.
521 AM MDT Sat Aug 22 2020 Overnight WV/IR imagery showed the strong upper high centered near the Four Corners of the Southwest CONUS. The clockwise circulation around the high was advecting smoke from Western CONUS wildfires into the CWA. Persistence will be the operative word this weekend with the continuation of hot daytime temperatures and low humidities as the upper high remains parked over the Four Corners. Fortunately, winds will be relatively light under the influence of the ridge aloft. The upper ridge axis will flatten and weaken as a upper trough tracks east from the Pacific Northwest across the international border during the upcoming week.
Today and Tonight: Upper level high pressure remained centered just southwest of the Four Corners region, with ridging extending north into the Rockies and northeast into the Central Plains.
An upper low was located over middle TN where light rain was diminishing rapidly. An associated trough axis extended south-southwest through MS. On visible imagery, the lower cloud animation depicted this axis with weak cyclonic circulation over northeast MS, northwest AL into southwest TN. The greater chances will be along the trough/lower level convergence axis from northwest AL into middle TN, and along the higher terrain in east central through northeast AL. The trough will continue to weaken and lift northward tonight, as ridging builds into the Plains. Meanwhile, the subtropical ridge will build westward and into the southeastern CONUS, allowing flow aloft to remain to the southwest on Sunday.
444 AM MDT Sat Aug 22 2020 The upper level high that continues to dominate our weather will center itself near the Four Corners area today. High temperatures should be at least another couple degrees warmer than yesterday per 1-1. 5C warming aloft, but the smoke will likely be thicker than yesterday considering the plume of smoke from the numerous California fires rotating around the upper high. This had some effect on temps yesterday already, as we noted that we only mixed dry adiabatically through the lowest 6 thousand feet yesterday. We are starting off a touch warmer today, though, and inversions may be more shallow. The strong upper ridge over the western United States will hold its position through the middle of the week, but with a gradual increase in moisture.
502 AM EDT Sat Aug 22 2020 The upper low that has remained situated west of the area the last several days is opening and lifting northeastward today as ridging over the Atlantic builds westward. Regardless, PoPs will remain elevated as southwest upper flow around the periphery of the ridge will keep the area in a moist regime.
357 AM MDT Sat Aug 22 2020 Hot upper high will sit firm over western CO today with quite of bit of wildfire smoke from CO and western U. Some higher mountain valley temperatures will drop into the 40s and upper 30s, with 50s and 60s for the lower elevations.
511 AM CDT Sat Aug 22 2020 An upper level trough dominating the region will begin to lift to the northeast. At the same time, a broad ridge axis will begin to extend eastward across the eastern Gulf of Mexico. A mid-level dry slot will continue to wrap around the base of the trough across the Gulf South today, and this will keep precipitable water values on the lower end at 1. Sunday and Sunday night will see a significant increase in precipitable water values as moisture feeds into the region in response to increased southeast flow on the western periphery of the extending ridge axis across the eastern and central Gulf.
Mid level ridging continues to strengthen overhead leading to mostly sunny skies.
Widely scattered showers and the occasional rumble of thunder continue across Middle TN at forecast time as we continue to feel the effects of an upper level trough axis draped over the region. 70 inches off the 06Z OHX sounding, rainfall rates have and will continue to be fairly decent with any of the higher radar reflectivities, even if there isn't thunder associated with the storm. With the extra cloud cover and rain chances also comes cooler than normal temperatures. Another day with highs in the low 80s is very likely today -- well below seasonal averages. Temperatures will start to rebound as this upper trough starts to pull northward and high pressure reasserts itself over the region.
323 AM PDT Sat Aug 22 2020 Even though it will be slightly cooler this weekend, hot humid weather will still prevail.
A weak cold front will continue to move through the region today, causing most places to have around a 10-degree high temperature decrease from yesterday, and breezy winds are still expected by this afternoon. Warm temperatures are forecast to remain with the Northern Rockies positioned on the southwesterly flow side of the dominant high pressure system.
242 PM CDT Sat Aug 22 2020 The upper ridge persists over the rockies, with a 500mb high sitting over the 4 corners region. Expect our dry and warm conditions to persist into Sunday afternoon, with highs in the low to mid 90s this afternoon and Sunday. The western CONUS upper level ridge is still propagating over into the central CONUS when the period opens.
254 PM CDT Sat Aug 22 2020 (Tonight and Sunday) Morning shower and thunderstorm activity has dissipated across the area giving way to mostly sunny skies, with temperatures generally in the lower to mid 90s. The upper level ridge axis will remain anchored across the Four Corners on Sunday, with West Central Texas under northeasterly flow aloft.
Will continue to keep higher PoPs in the forecast with the assumption that moisture should increase in the lower levels during the rest of the afternoon.
A weak cold front arriving late in the day on Sunday could potentially trigger isolated shower/thunderstorm activity during the evening. * None Deep layer stability held firm within a gradually increasing upper height field and general low level ridging ensures another day of benign weather conditions today. The resident above average thermal profile will inch higher today under increasing thickness readings, but with the lack of meaningful warm air advection given weak gradient flow placing a ceiling on this warmer trend. Southeast Michigan will continue to reside within the outer expanse of a predominant large scale upper ridge anchored across much of the southern conus.
This is because the northeast quadrant of the storm is expected to be the strongest and largest quadrant, so the Lower Keys will have the highest chance of realizing tropical storm conditions.
Carrothers Hot today with a strong ridge in place over the central rockies. 700mb temperatures range from 13-15c across the area today and this with downslope winds ahead of a cold front, should allow highs to reach the mid to upper 90s, with a few places possibly hitting 100 degrees, which will challenge some records. A cold front will move in from the west this afternoon and decrease dewpoints, sending humidities into the lower to mid teens. This will lead to a cooler day on Sunday. Highs on Sunday will be 5 to 10 degrees cooler, but still above normal for this time of year.
Overnight WV/IR imagery showed the strong upper high centered near the Four Corners of the Southwest CONUS. The clockwise circulation around the high was advecting smoke from Western CONUS wildfires into the CWA. Persistence will be the operative word this weekend with the continuation of hot daytime temperatures and low humidities as the upper high remains parked over the Four Corners. Fortunately, winds will be relatively light under the influence of the ridge aloft. The upper ridge axis will flatten and weaken as a upper trough tracks east from the Pacific Northwest across the international border during the upcoming week.
345 PM CDT Sat Aug 22 2020 Showers continue to develop across areas of West Tennessee near the Tennessee River and Northeast Mississippi thanks to a weak upper level low pressure system that is moving through the Tennessee River Valley. The upper low will move off to the northeast tonight.
134 PM PDT Sat Aug 22 2020 High pressure will continue to weaken this weekend, bringing cooling to the region, although it will continue to feel hot and humid.
an upper level high pressure center is located over southern Utah/northern Arizona this morning and is forecast to lift slowly toward the four corners area overnight. Lows tonight are expected to be in the low to mid 60s. Lows are expected to be in the low to mid 60s.
SHORT TERM (Tonight through Sunday night): Broad mid level troughing is sagging south over the area. An upper low/short wave will move south along the western side of the trough over East Texas during the next 24 hours, settling over South Texas near Corpus Christi on Sunday.
1129 AM MDT Sat Aug 22 2020 Hot upper high will sit firm over western CO today with quite of bit of wildfire smoke from CO and western U. Some higher mountain valley temperatures will drop into the 40s and upper 30s, with 50s and 60s for the lower elevations.
Forecast hourly temperatures are in great shape this morning with temperatures in the low to mid 70s. Guidance agrees that showers and thunderstorms will initate across the higher terrain of the Southern Appalachians and Cumberland Plateau. SHRA/TSRA will develop across the higher elevations and move north into the valley. Diegan Chattanooga Airport, TN 68 86 70 88 71 / 40 40 20 30 20 Knoxville McGhee Tyson Airport, TN 68 86 68 87 69 / 40 40 10 20 10 Oak Ridge, TN 66 86 67 87 68 / 40 40 10 20 10 Tri Cities Airport, TN 64 84 65 85 65 / 40 50 10 30 10.
/Issued 502 AM EDT Sat Aug 22 2020/ The upper low that has remained situated west of the area the last several days is opening and lifting northeastward today as ridging over the Atlantic builds westward. Regardless, PoPs will remain elevated as southwest upper flow around the periphery of the ridge will keep the area in a moist regime.
Weak cold front continuing to move across south- central Idaho at 830 AM MDT. This will be short- lived as more smoke moves into the region today which will filter back into the lower valleys late this evening. Worse conditions expected Sunday with increased southwesterly flow ahead of an approaching upper level trough. A weak cold front this morning has provided some improvement to the haze and smoke to some areas, although it will be temporary as southwest flow will bring more haze and smoke to the region this afternoon and evening.
A long wave trough at high levels remains draped from the OH River Valley to the TX coast. To the east of this feature, a deep layer ridge was positioned over the southwest Atlantic. For today, model guidance indicates pockets of drier air rotating around the larger scale flow around the mean trough position, with the deeper moisture mostly positioned to the east of I-65.
902 AM PDT Sat Aug 22 2020 High pressure will continue to weaken this weekend, bringing cooling to the region, although it will continue to feel hot and humid.
229 PM MDT Sat Aug 22 2020 Hot, dry and hazy conditions are expected to continue through the short term period with the upper high pressure area expanding across the U. Models are trying to latch onto diurnally driven short waves with convection developing over the high terrain moving across the plains late each evening with some near surface convergence locally enhancing the lift in the vicinity of the surface through that waffles over eastern Colorado the next few days.
1207 PM CDT Sat Aug 22 2020 It will be a hot one today as the upper level ridge over the western United States continues to build.
1125 AM MDT Sat Aug 22 2020 Upper ridge persists over the western CONUS, with its axis over the Rockies.
224 PM MDT Sat Aug 22 2020 Daytime CU field trying to bubble up over the higher elevations of the Absarokas due to differential heating. H5 ridge remains steady across the Four Corners, with southwesterly flow continuing to pump stable smoky air across the state. A couple daytime heating showers are again possible on Sunday for the higher elevations of the Absarokas and Winds, and in the vicinity of the Uinta range during the afternoon, but will be very isolated and brief, being capped by the smoky atmosphere and very warm H7 temps.
245 PM CDT Sat Aug 22 2020 Scattered showers and thunderstorms over the lower Ohio Valley this afternoon are associated with a 500 mb trough that is lifting northeast from the Tennessee Valley. On Sunday, the 500 mb trough will be less of an influence as it continues weakening and lifting north. Overall, it will be a little warmer with more sunshine than today.
Otherwise, the low-level disturbance south of our region today will continue north into the Ohio Valley and prompt scattered, mainly diurnally- supported, showers and thunderstorms.
METRO Roadcasts show road temps warming above freezing by late this morning through the afternoon. Flat upper level ridge was over the area with an upper trough over MT and southern ALTA.
1219 PM EDT Sun Apr 8 2018 High pressure to the west builds toward the region today.
Chattanooga Airport, TN 55 43 62 44 / 0 50 20 10 Knoxville McGhee Tyson Airport, TN 51 40 57 41 / 0 50 30 10 Oak Ridge, TN 52 40 59 40 / 0 50 30 10 Tri Cities Airport, TN 49 36 56 38 / 0 50 50 10.
Gusty westerly winds this afternoon, mainly in the 20-25kt sustained range, will decrease around 09/01Z before a cold front moves into the area, and winds become north/northeast and gusty behind it. A fast WNW flow aloft along with deep sfc lee side troffing will allow temps to soar this aftn. therefore the High Wind Watch has been upgraded to a Warning for this aftn/early evening.
A weakening cold front just north and west of the Keys is advancing slowly southeastward, and should arrive late this afternoon or this evening. For tonight, a high pressure cell will shift quickly eastward from the southeastern United States to the western North Atlantic. As a consequence, local breezes will shift from northwest to north, with a northeasterly surge associated with the fast-moving high pressure area, moving south-southwestward off the southeast Florida coast and into the Keys overnight.
Winds should be light with high pressure over the area with a gradual shift to southerly winds late in the period.
a bit less in the immediate RRV due to slighly warmer temps. Freezing precipitation per HREF looks negligble in our area so removed mention. Sat - Tue Longwave trough over Hudson Bay will shift into eastern Canada. Longwave ridge over western Canada will shift into central Canada by Tue. Precip should be trending east by late evening, but lingering low level moisture may support low stratus, fog, or even patchy freezing drizzle (low confidence on the fog/drizzle).
An 850mb trough axis will shift east of the area today with low- level winds shifting from NW to W to SW by this evening.