Aikyam-Lab/Synoptic-Bench huggingface dataset:
Upper ridge firmly entrenched across the region which will result in afternoon high temps at or slightly above what was observed yesterday across many locations Current heat advisory for the afternoon/early evening will be left as is with 105-110 heat index values expected. VFR conditions will prevail beneath high pressure aloft. /Issued 320 AM CDT Tue Aug 24 2021/ Dome of high pressure will continue to be the dominate feature across the Southern Plains Today and Wednesday with hot and humid conditions across Eastern Oklahoma and Northwest Arkansas.
Highs today have already reached the lower to middle 90's, with heat index values ranging between 101 and 107 degrees. Temperatures tonight will dip once again into the lower to middle 70s. The upper level ridging over the southeast and south central U. will get shunted northward as an inverted upper level trough approaches from the southeast.
Wednesday will also be hot, but the lack of downslope will keep us just a bit cooler.
246 PM MDT Tue Aug 24 2021 A weak cold front is located up against the east side of the Continental Divide with cooler temperatures today especially over the Bighorn Basin and Johnson County.
Temperatures still on track to reach the lower 90s with a widespread heat index of 103-107. High pressure centered over the Ohio River Valley will remain in control of the weather across central Illinois today. Given continued southerly flow and a good deal of sunshine, high temperatures will be a couple of degrees warmer than yesterday in the lower to middle 90s. Warm/muggy weather will continue into tonight as lows only drop into the lower to middle 70s. As an upper low evident on latest water vapor imagery over Alberta/Saskatchewan tracks eastward along the U. /Canada border, it will flatten the prevailing ridge over the Great Lakes and push a cold front into northern Illinois on Wednesday.
Guidance depicts broad upper level ridge over the central CONUS remaining in place throughout the short term if not slightly shifting toward the area. At the same time, while the primary westerlies will be shifted well north of the area, weak disturbances may be able to produce some thunderstorm activity along the periphery of the ridge, along with the potential for isolated diurnally driven convective activity in the hot and humid airmass. As with today, instability looks to be ample, with a weak cap and very weak shear, so lightning and isolated flood concerns would be the primary threats in the high precipitable water airmass and with very slow storm motions. Upper ridge will stretch across the Ohio Valley through much of the weekend.
An upper level high pressure ridge will remain in place over the Tennessee Valley today, promoting mostly sunny, hot, and humid conditions once again. As a result, expect temperatures to creep into the low to mid 90s during the afternoon hours. The combination of these temperatures and dewpoints in the lower 70s will push heat index values into the 100 to 105 degree range. With high pressure still over the Tennessee Valley, we'll still have a good setup for fog development again tonight into Wednesday morning. High pressure over the Tennessee Valley starts to break down on Wednesday with the Bermuda High becoming more dominant, leading to more moist southerly flow advecting in a more saturated, unstable air mass.
The upper ridge will remain firmly in place tonight and Wednesday, keeping the heat the main weather story. Under clear skies look for lows tonight in the low to mid 70s and highs Wednesday afternoon in the mid and upper 90s.
A subtropical ridge remains in place to start the period across much of the eastern CONUS.
256 PM EDT Tue Aug 24 2021 Hot ridging at the sfc and aloft will continue through Wednesday. Close to a persistence forecast, with temps mainly in the lower/mid 70s overnight, and reaching the lower/mid 90s again Wednesday afternoon. This will limit heat indices to just either side of 100 degrees, with the lower values in the Bluegrass region and higher numbers west of I-65. Hot and mostly dry conditions will continue through much of the rest of the work week as expansive upper level ridging holds sway over much of the lower half of the CONUS. High pressure in the lower levels will remain anchored over the East Coast resulting in warm, moist SW flow resulting in continued sultry conditions for the OH Valley with diurnal potential for isolated showers and thunderstorms each day through the weekend.
210 PM CDT Tue Aug 24 2021 West to east upper level; ridging in place and extends from AR eastward across TN.
305 PM CDT Tue Aug 24 2021 An upper ridge over the area will maintain hot and humid conditions over the next several days. The ridge will shift east and weaken by late week into the weekend, with slightly less hot conditions expected at that time.
At the surface, trough extends from southern SD into western KS setting up decent pressure gradient across the eastern half of KS. Upper impulse is expected to track across southern Canada tonight into Wed as upper ridging remains across the southern CONUS. Not much is expected to change for the surface pattern, keeping lee troughing in place with gusty south/southwest winds. So look for temps Wed to be close to or a degree or two warmer than today with most areas along and west of I-135 over 100 degrees. Luckily we have been mixing out dewpoints into the low 60/upper 50s by the late afternoon which is keeping heat indices from getting too out of control. This will try and push a cold front across the area for Sun afternoon through Sun night and will provide our next decent chance for storms.
Upper level ridging is firmly in control of Middle Tennessee weather late this morning with mostly sunny skies and light winds.
Warmer and drier weather continues as advertised across the region. High pressure remains centered to our northeast. Temperatures this afternoon will be in the mid to upper 90s at most locations as warmer 850 mb temperatures move over portions of the region. Very little clouds, let alone precipitation, is expected across the area with subsidence under the high pressure being dominate. Lows tonight will fall into the low 70s and upper 60s under mostly clear skies. Wednesday will have much of the same weather, but daytime highs should be a degree or two cooler than yesterday. These slightly cooler temperatures will be the result of 850 mb becoming slightly cooler. Lows will also be a degree or two cooler than yesterday with lows in the mid to upper 60s at most locations.
High pressure centered over the Southern Plains today will gradually expand north tonight and Wednesday.
256 PM MDT Tue Aug 24 2021 Most recent surface analysis shows a low pressure system over central ND and associated dry front stretching through our eastern CWA. Frontal passage and northwesterly winds has kept our temps cooler today, with highs only expected to reach into the upper 70s and low 80s.
Scattered thunderstorms continue across the northwest as a weak cold front taps into some elevated instability.
Hot high pressure dome over the lower Mississippi Valley will be drifting westward during the short term, easing subsidence enough to allow isolated diurnal convection to form Wed afternoon as far west as the Plateau.
Cooler, drier air mass working in tonight on northerly winds, with lows in the mid 50s.
The aforementioned cold front will remain oriented roughly west to east near or across the area through the next several days, providing a focus for more thunderstorm potential each day.
Little change forthcoming tonight and Wednesday as a mid-level trough remains to the west of the forecast area. Expect highs on Wednesday to be just a bit warmer than normal.
/issued 311 AM CDT Tue Aug 24 2021/ Upper level high pressure ridge axis just to our south will lift north across the area later today and tonight.
Ridging will continue to be in control across the region tonight and Wednesday. Isolated to scattered showers and thunderstorms will exist again on Wednesday as PW values will remain on the high side.
221 PM CDT Tue Aug 24 2021 Tranquil weather across the Tennessee Valley this afternoon, with high pressure promoting a mostly clear sky and only a few widely scattered Cu dotting the sky. As of of 19z, temperatures across the area are mostly in the lower 90s, with a few locations in the mid 90s. Otherwise, expect another warm and muggy night with lows in the lower 70s. The upper-level ridge begins to break down on Wednesday, with the center shifting off to the east. The end result will be yet another hot and humid day on Wednesday (with highs in the low to mid 90s and heat indices in the 100-105 range), but also a return of afternoon convection in the form of widely scattered pulse thunderstorms.
Later tonight, cloud cover will begin to increase ahead of an approaching upper level trough, and keep overnight lows several degrees warmer than this morning.
As mentioned in the previous short term AFD, the upper level ridge will remain over the area through Wednesday.
Temperatures remain seasonably warm but increased cloud coverage and precipitation takes just enough of an edge off of the highs tomorrow to keep heat index values below advisory criteria. 20 The enhanced moisture advection off the Atlantic continues to keep us in the high PWAT soup along the SW extent of the Bermuda high thru the end of the work week.
The upper level ridge remains in place and will continue to allow for mostly sunny skies and warm temperatures in the middle 90s across the region again today. Some mixing is expected by late this afternoon but warmer temperatures that yesterday will keep heat indexes similar with a heat advisory remaining in effect today.
Broad high pressure over the southern plains and a trough along the west coast will dominate the synoptic pattern for the next few days. This will keep temperatures near seasonable levels this afternoon, followed by a gradual warming trend during the second part of the week as high pressure builds over the area.
150 PM MDT Tue Aug 24 2021 Upper trough over western Canada has pushed cooler air into the area today.
As the dome of high pressure aloft shifts slightly north tomorrow, temperatures will approach 100 off the Caprock with mid 90s in the South Plains and Southern Texas Panhandle. The upper ridge that has been dominating the area will be centered of the Central Plains by Wednesday evening. For the second half of the week, a series of short wave troughs will move across the northern tier of the CONUS. This will cause the upper ridge to split into two distinct centers with one over the southwestern US and the other over the southeastern US.
145 PM MDT Tue Aug 24 2021 Most recent surface analysis shows a low pressure system over central ND and associated dry front stretching through our eastern CWA. Frontal passage and northwesterly winds has kept our temps cooler today, with highs only expected to reach into the upper 70s and low 80s.
Otherwise, moisture advecting into the region, combined with a warm front and low level jet, look to generate some nocturnal showers and thunderstorms over southeastern areas tonight.
Another round of convection is expected to ramp up along the 850mb baroclinic zone and nose of the low level jet over Iowa and southern MN Wed night and this could roll through a portion of our forecast area late Wed night into Thu morning. There seems to be a decent consensus that convection will develop along the nose of the low level jet over central MN that rolls into WI during the overnight hours Thu night.
335 PM CDT Tue Aug 24 2021 A cold front drifting through Nebraska this evening will drop south into KS overnight, remain stationary during the day Tuesday and then begin lifting north Wednesday night. The warm front, low level moisture and the northward migration of a subtropical moisture plume across nwrn Texas should provide excellent focus and moisture for showers and thunderstorms across wrn and ncntl Nebraska Wednesday night. It is possible the models are not picking up on what appear to be weak h700mb trofs moving through or off the Colorado Rockies and the nrn Plains.
1136 AM EDT Tue Aug 24 2021 High pressure builds across the local area through the end of the week. Upper level trough continuing to pull away to the NE today w/ upper level ridge beginning to spread E from the srn plains/lower MS Valley. Outside of the higher terrain far NW.
1122 AM MDT Tue Aug 24 2021 Current surface analysis shows low pressure over far eastern MT, with warm front to the northeast of the region, trough/dryline over northwest into central SD, and a cold front across southeast MT and into eastern WY. Cold front will swing through the area from northwest to southeast through the morning and midday hours, bringing cooler and breezy conditions behind it. Highs will range from the 70s over northeast WY and the Black Hills to the low/mid 90s over south central SD. The rest of the week and the weekend look to be seasonably warm and unsettled at times as a larger scale trough settles over the Pacific NW region and a series of disturbances move through the Rockies and Northern Plains in active west to southwest flow.
Upper level ridging is centered over the Southern Plains and producing stable, dry conditions across a majority of the eastern CONUS, but the heat will be the main consideration for any outdoor plans this afternoon. Tranquil conditions are expected overnight with mostly clear skies and lows in the lower/mid 70s.
134 PM EDT Tue Aug 24 2021 High pressure at the surface and aloft will provide quiet weather through Wednesday. High pressure at the surface and aloft will keep quiet weather conditions through mid day Wednesday. With dewpoints in the lower 70s, expect heat index to climb into the lower 100s over portions of southeast OH, northeast KY and central WV Wednesday afternoon. Showers and storms can be expected Wednesday, particularly across the higher terrain during peak heating hours. Hot and humid conditions will continue across the area, with heat indices touching the lower 100s in spots.
Wednesday should be the last overly hot day this week and temperatures "cool off" into the low 90s instead of the mid to upper 90s. The upper ridge responsible for this weather will weaken and shift out of the area and allow for an increase in rain chances by the end of the week.
High pressure will bring hotter temperatures the second half of the week. Temperatures are 5 degrees warmer in Tucson than 24 hours ago. Isolated to scattered storms will be possible each afternoon primarily east and south of Tucson and over the higher elevations.
Quite the temperature difference late this evening as rain-cooled air has lower temps into the low 70s across the I-4 corridor, while it is still in the low 80s along the Space/Treasure Coasts. The highest rain chances likely to be across the inland terminals.
607 PM CDT Tue Aug 24 2021 (This evening through Wednesday) Dewpoints are currently in the low 70s from central OK eastward along with low to mid 90 temps resulting in triple digit heat index values. Similar and even warmer conditions are expected by tomorrow afternoon under the upper high.
Overnight lows will fall into the low to middle 70s, coolest in east portions of the Midsouth and warmest in the west. Wednesday should be the last overly hot day this week and temperatures "cool off" into the low 90s instead of the mid to upper 90s. The upper ridge responsible for this weather will weaken and shift out of the area and allow for an increase in rain chances by the end of the week.
640 PM CDT Tue Aug 24 2021 A forecast update is in place for isolated showers and thunderstorms forming along a cold front moving through the srn Sandhills. A cold front drifting through Nebraska this evening will drop south into KS overnight, remain stationary during the day Tuesday and then begin lifting north Wednesday night. The warm front, low level moisture and the northward migration of a subtropical moisture plume across nwrn Texas should provide excellent focus and moisture for showers and thunderstorms across wrn and ncntl Nebraska Wednesday night. It is possible the models are not picking up on what appear to be weak h700mb trofs moving through or off the Colorado Rockies and the nrn Plains.
521 PM MDT Tue Aug 24 2021 Most recent surface analysis shows a low pressure system over central ND and associated dry front stretching through our eastern CWA. Frontal passage and northwesterly winds has kept our temps cooler today, with highs only expected to reach into the upper 70s and low 80s.
Hot ridging at the sfc and aloft will continue through Wednesday. Close to a persistence forecast, with temps mainly in the lower/mid 70s overnight, and reaching the lower/mid 90s again Wednesday afternoon. This will limit heat indices to just either side of 100 degrees, with the lower values in the Bluegrass region and higher numbers west of I-65. Hot and mostly dry conditions will continue through much of the rest of the work week as expansive upper level ridging holds sway over much of the lower half of the CONUS. High pressure in the lower levels will remain anchored over the East Coast resulting in warm, moist SW flow resulting in continued sultry conditions for the OH Valley with diurnal potential for isolated showers and thunderstorms each day through the weekend.
722 PM EDT Tue Aug 24 2021 High pressure at the surface and aloft will provide quiet weather through Wednesday. High pressure at the surface and aloft will keep quiet weather conditions through mid day Wednesday. With dewpoints in the lower 70s, expect heat index to climb into the lower 100s over portions of southeast OH, northeast KY and central WV Wednesday afternoon. Diurnally driven convection aided by a passing weak disturbance will dissipate after sunset as upper ridging triumphs over the region.
Increasing onshore flow late tonight will lead to a surge of moisture by early tomorrow with PWATs rising to above 2 inches across the area with an inverted trough leading to developing showers and isolated storms with precip chances increasing into the day on Wednesday. Upper ridge across the western Atlantic on Wednesday will slowly moving westward and eventually into the southeastern States. South of the ridge, a weak low will traverse along the southern portions of the upper ridge. North of that area of low pressure, there will be some increase in low-level moisture.
Winds are expected to freshen again by early tomorrow morning as the subtropical ridge continues to build into the area and the tropical wave located to our east edges closer to our waters. Temperatures will only drop a few degrees to the lower 80s overnight.
Tranquil weather across the Tennessee Valley this afternoon, with high pressure promoting a mostly clear sky and only a few widely scattered Cu dotting the sky. As of of 19z, temperatures across the area are mostly in the lower 90s, with a few locations in the mid 90s. Otherwise, expect another warm and muggy night with lows in the lower 70s. The upper-level ridge begins to break down on Wednesday, with the center shifting off to the east. The end result will be yet another hot and humid day on Wednesday (with highs in the low to mid 90s and heat indices in the 100-105 range), but also a return of afternoon convection in the form of widely scattered pulse thunderstorms.
Virga showers over south-central Idaho continue to move eastward this evening as an upper trough pushes into the Pacific Northwest.
Deep marine layer persists tonight into Wednesday morning with a trough along the West Coast producing coastal drizzle Wednesday morning.
225 PM PDT Tue Aug 24 2021 A slow expansion of high pressure will bring warmer weather this week along with a shallower marine layer and less night and morning low cloud cover.
439 PM CDT Tue Aug 24 2021 A forecast update is in place for isolated showers and thunderstorms forming along a cold front moving through the srn Sandhills. A cold front drifting through Nebraska this evening will drop south into KS overnight, remain stationary during the day Tuesday and then begin lifting north Wednesday night. The warm front, low level moisture and the northward migration of a subtropical moisture plume across nwrn Texas should provide excellent focus and moisture for showers and thunderstorms across wrn and ncntl Nebraska Wednesday night. It is possible the models are not picking up on what appear to be weak h700mb trofs moving through or off the Colorado Rockies and the nrn Plains.
West to east upper level; ridging in place and extends from AR eastward across TN.
810 PM EDT Tue Aug 24 2021 A mid/upper low over the southeastern Bahamas this evening slides toward the southeast FL coast during Wed. At the surface broad Atlantic high pressure continues across the state and out over the Gulf of Mexico. Broad high pressure across the south half of the state lifts north of the waters later in the week as a trough of low pressure approaches from the east.
546 PM MDT Tue Aug 24 2021 A weak cold front is located up against the east side of the Continental Divide with cooler temperatures today especially over the Bighorn Basin and Johnson County.
/Issued 305 PM CDT Tue Aug 24 2021/ An upper ridge over the area will maintain hot and humid conditions over the next several days. The ridge will shift east and weaken by late week into the weekend, with slightly less hot conditions expected at that time.
Light winds and mostly clear skies will allow temperatures to fall into the lower to mid 70s in most locations overnight. /Issued 305 PM CDT Tue Aug 24 2021/ An upper ridge over the area will maintain hot and humid conditions over the next several days. The ridge will shift east and weaken by late week into the weekend, with slightly less hot conditions expected at that time.
CD Chattanooga Airport, TN 73 93 72 88 70 / 10 30 20 50 10 Knoxville McGhee Tyson Airport, TN 71 94 71 90 70 / 10 30 20 50 10 Oak Ridge, TN 71 93 71 89 69 / 0 20 20 50 10 Tri Cities Airport, TN 68 92 68 89 66 / 10 40 10 50 10.
638 PM CDT Tue Aug 24 2021 After this morning's convection temperatures have been cooler than originally forecast thanks to evaporative cooling, cloud cover, and a well mixed boundary layer. These cooler temperatures will lead to diminished instability and less chance for convection across much of central and southern Minnesota as well as west central Wisconsin later today. Behind the passage of a cold front Wednesday should be a much quieter day of weather. Cooler air and a shift to northwest winds will be the story for Wednesday. Despite this cooler air though some of the areas with more persistent cloud cover on Tuesday will not be much cooler if at all with this cooler air.
Cooler, drier air mass working in tonight on northerly winds, with lows in the mid 50s. Height falls from an approaching upper trough will promote convection west of the CWA.
Skies will be clear to partly cloudy with east winds around 10 mph today and slightly warmer temperatures. Flow aloft turns SW this evening as upper trough moves inland from the Pacific.
The upper ridge will remain firmly in place tonight and Wednesday, keeping the heat the main weather story. Under clear skies look for lows tonight in the low to mid 70s and highs Wednesday afternoon in the mid and upper 90s. The Wednesday night through Thursday time frame will continue to be dominated by the upper level ridge and a continuation of of the heat, with daily highs in the mid 90s and lows in the 70s.
Surface dew points have fallen back into the upper 60s F early this morning, but we expect them to surge back into the low to mid 70s F today ahead of the cold front. Storms will likely fire on the upstream cold front and try to move our direction or form in our area on the lake breeze front.
A loosely organized mid and upper level trough resides over much of the US West Coast this evening, with the surface pattern showing weak troughing extending from the interior of CA up through WA and OR and high pressure over the Pacific. Marine stratus will develop along the Coast and should push slightly further inland across the Lower Chehalis Valley and down the western Strait of Juan de Fuca.
143 AM EDT Wed Aug 25 2021 High pressure will build in through Thursday.