Aikyam-Lab/Synoptic-Bench huggingface dataset:
Showers and thunderstorms continue across the eastern mountains of Oregon and Washington as the cold front pushes east of our forecast area. An upper low approaches the region and will move across through the early weekend. This low brings with it chances of precipitation along with a risk of some storms possible, primarily near Kittitas County as well as Wallowa County in our CWA. Further into the borders of WA and OR, the chances of precipitation decline, but a slight chance at some rain could occur as this low moves through. Also with the low, breezy winds are expected.
Behind this stronger convection, and ahead of the advancing cold front, stratiform rain and a few weak showers/storms are lingering across east-central Kansas. Farther northwest behind the cold front, cooler and drier air is filtering southward into the area. This will continue throughout the day as the cold front pushes farther south. This break will not last long though, as the approach of the next upper trough onto the Plains will cause the front to lift back north late tonight as a warm front. However have reduced PoPs tonight and tomorrow morning as most guidance struggles to develop much in the way of precipitation, with the greater synoptic forcing from the upper trough staying northwest of the area. The bigger story will be the return of the heat and humidity, as upper ridging builds over the southern Plains and sits there.
Expect scattered storms to continue to develop along the boundary overnight with a period of backbuilding or training cells possible late tonight into early Saturday morning before the low level jet weakens and the outflow and convection once again surge southeast. Confidence in amount of afternoon regeneration of storms along the boundary remains low given the lack of low-level forcing and influence from upper level ridge building with time.
(Today and tonight) Summer returning to West Central Texas, as upper level high pressure builds over the top of the area. Mostly mid 90s expected today, perhaps pushing into the upper 90s across the eastern Big Country closer to the middle of the ridge.
220 AM EDT Sat Aug 21 2021 Tropical cyclone Henri will move north, well off the Atlantic coast today through Sunday.
Into Sunday, the ridge of high pressure continues to build across the state and the possibility of extending the Heat Advisory will need to be monitored into Sunday as well. Later Sunday, a weak cold front approaches the state accompanied with a surface boundary that will keep some low confidence for the possibility of rain across the CWA.
130 AM MDT Sat Aug 21 2021 Southwest flow aloft persists over the Central High Plains today with an upper trough moving across the West River region of South Dakota this afternoon. A ridge remains to the east on Saturday with high pressure persisting over Texas and Louisiana. High temperatures this afternoon and tomorrow will range from the low to mid-80s. Lows will be in the low 50s to low 60s tonight and the upper 50s to mid-60s Saturday night/Sunday morning.
With high pressure continuing to build across the Southern Plains, all of North and Central Texas should remain precipitation-free today and tonight. Southerly low-level flow will keep dew points in the lower to mid 70s this afternoon, yielding heat index values in the triple digits across much of the region.
Otherwise, the main story for the day will be resulting northerly flow aloft and fairly weak flow in the lower levels. Also, with generally weaker flow in the lower levels, locally heavy rainfall does remain possible with any stronger storm.
Ridge of high pressure is still in place across the northern Gulf of Mexico, while the Atlantic ridge stays to our east. Afternoon highs will range from the low to mid 90s, while overnight lows stay in the low to mid 70s through the period.
The low and wave will continue to move northeast this afternoon and evening, allowing for the rain to come to an end. A weak Pacific cold front will cross the CWA Sunday in association with the upper trough, leading to gusty westerly winds, especially across southwestern SD.
Cooler than normal temperatures and some breezy conditions come Sunday, with showers and thunderstorms possible across the north.
125 AM EDT Sat Aug 21 2021 Tropical cyclone Henri will move north, well off the Atlantic coast today through Sunday.
with high pressure in control. An upper level ridge that began to build into the region today limited activity this morning and this afternoon as well.
Dry conditions will likely stay near and to the west of Pittsburgh throughout the day tomorrow under high pressure. Temperature trends will remain at or slightly above average throughout this period under high pressure. A building ridge over the center of the CONUS will keep the area warm and humid at the beginning of the week.
Wind gusts have been consistently in the 30 to 40 mph range at the highest, so it's looking like more of a heavy rain and localized flooding event for the remainder of the night and part of Saturday morning. Models show the warm front will begin to lift back to the north tonight as a secondary upper wave in the Rockies lifts northeast into the northern plains. Very mild temperatures are expected tonight, especially in the southwest after the front lifts back to the north, with lows in the low to mid 70s. On Sunday, the warm front will have lifted north of the area and an upper level ridge will begin building over the region.
Showers and thunderstorms will initiate across portions of southeast Oregon and the West Central Idaho mountains this evening as an upper low moves into the Pacific Northwest. Temperatures will be cooler on Saturday and warmer on Sunday, although remaining below normal.
Storms are expected to develop along an associated cold front across Eastern Nebraska and Western Iowa this afternoon.
207 AM CDT Sat Aug 21 2021 Showers and thunderstorms were ongoing early this morning along and north of a frontal boundary that extended south from a vigorous mid/upper trough over the Northern Plains. We could see some storms redevelop this evening and tonight as a subtle impulse approaches in weak southwest flow on the northern periphery of the mid/upper ridge across the Southern Plains/Lower Mississippi Valley area. Rising heights and increasing thickness are anticipated as we move through the period as the mid/upper ridge amplifies over the Lower Mississippi Valley and Southern Plains. The Southern Plains mid/upper ridge will continue to build into the area bringing a period of quiet weather with above normal temperatures continuing through much of the upcoming week.
We'll start to see building upper-level heights as the upper-level ridge over ArkLaTex builds eastward into Mississippi and Alabama.
The closed low pressure that brought the active weather is lifting out over the northern plains today. Lows tonight will be warmer than this morning and skies will be mostly clear. Tomorrow the next trough tracks over the Pacific Northwest and northern Great Basin. Although the better chances reside across the northern third of the CWA closer to the lift associated with the trough passing to our north. The trough will clip us tomorrow night so the precipitation will generally be confined up north overnight. Westerly flow aloft will transition to the southwest by Sunday evening as an upper level trough elongates off the west coast. Meanwhile, a broad area of high pressure will extend from Baja towards the southeast CONUS.
339 AM CDT Sat Aug 21 2021 A cold front will move east through the area this morning. On Sunday, high pressure will provide dry weather.
Ridging aloft continues to build directly overhead which should help to keep the remainder of the overnight quiet and precip-free.
421 AM EDT Sat Aug 21 2021 Weak high pressure will lead to patchy early morning fog with fair weather for the remainder of the day.
Aloft, the mean flow pattern over the CONUS features ridging over the south, with two troughs evident on water vapor imagery within the stronger flow across the north.
625 AM CDT Sat Aug 21 2021 As an upper trough exits this morning and high pressure builds in at the sfc, winds will diminish across the area. Temperatures will remain cooler than average today with highs only in the 70s and dry conditions are expected. Winds will increase out of the southeast tonight ahead of a front and upper trough that will sweep from west to east on Sunday. A drier and warmer airmass will build in quickly behind it with temperatures rising into the 90s across south central SD. Cold front and upper wave is just about out of the CWA to open things up Sunday evening, taking convection with it.
1031 AM EDT Sat Aug 21 2021 Weak high pressure will lead to patchy early morning fog with fair weather for the remainder of the day.
Flow aloft today will increase as another trough, digging into southern Idaho this morning, pushed east and lifts out over the N plains. This feature will bring a chance of scattered thunderstorms the higher terrain today, with the best coverage over the central mtns. Best forcing with the trough lifting to our northeast will be north over the region.
516 AM MDT Sat Aug 21 2021 Current surface analysis shows cold front well south and east of the region, with weak high pressure over eastern MT into WY. Upper level analysis shows trough moving northeast into Canada. Some 30s are noted across the highest elevations of the Black Hills. Cooler conditions will continue today, with high temperatures in the 70s to around 80 degrees under mostly sunny skies. Most of the activity should move east of the forecast area by Sunday afternoon as the trough moves quickly east-northeast and a Pacific cool front pushes through. Breezy conditions will develop behind the frontal passage, with highs ranging from the 70s over the Black Hills to the lower 90s toward south central SD.
643 AM CDT Sat Aug 21 2021 (Today and tonight) Summer returning to West Central Texas, as upper level high pressure builds over the top of the area. Mostly mid 90s expected today, perhaps pushing into the upper 90s across the eastern Big Country closer to the middle of the ridge.
/Issued 414 AM EDT Sat Aug 21 2021/ Similar to yesterday, the CWA is situated between an upper trough over the Mid-Atlantic States and an upper ridge centered over TX and LA. A similar synoptic setup is on tap for Sunday, although the upper ridge will amplify a bit across the central U. and flatten the upper trough, pushing it further up the Eastern Seaboard.
702 AM CDT Sat Aug 21 2021 Showers and thunderstorms were ongoing early this morning along and north of a frontal boundary that extended south from a vigorous mid/upper trough over the Northern Plains. We could see some storms redevelop this evening and tonight as a subtle impulse approaches in weak southwest flow on the northern periphery of the mid/upper ridge across the Southern Plains/Lower Mississippi Valley area. Rising heights and increasing thickness are anticipated as we move through the period as the mid/upper ridge amplifies over the Lower Mississippi Valley and Southern Plains. The Southern Plains mid/upper ridge will continue to build into the area bringing a period of quiet weather with above normal temperatures continuing through much of the upcoming week.
1033 AM EDT Sat Aug 21 2021 A fractured low-level ridge axis stretches west across Florida.
424 AM CDT Sat Aug 21 2021 Fairly quiet weather to start the weekend across Nebraska with cool high pressure centered over the High Plains. Expect weak short wave energy will move through flat ridging and push some cloudiness from the south into the state by this afternoon. High pressure will move off to our east with a warm front moving across the region. However as storms grow upscale the core of the low level jet will be moving more into eastern Nebraska over time, taking the severe threat to our east Sunday evening. Extended ensemble guidance continues to feature low amplitude ridging in a progressive flow regime allowing for a steady stream of short waves to ripple through the flow.
437 AM CDT Sat Aug 21 2021 As an upper trough exits this morning and high pressure builds in at the sfc, winds will diminish across the area. Temperatures will remain cooler than average today with highs only in the 70s and dry conditions are expected. Winds will increase out of the southeast tonight ahead of a front and upper trough that will sweep from west to east on Sunday. A drier and warmer airmass will build in quickly behind it with temperatures rising into the 90s across south central SD. Cold front and upper wave is just about out of the CWA to open things up Sunday evening, taking convection with it.
621 AM CDT Sat Aug 21 2021 Fairly quiet weather to start the weekend across Nebraska with cool high pressure centered over the High Plains. Expect weak short wave energy will move through flat ridging and push some cloudiness from the south into the state by this afternoon. High pressure will move off to our east with a warm front moving across the region. However as storms grow upscale the core of the low level jet will be moving more into eastern Nebraska over time, taking the severe threat to our east Sunday evening. Extended ensemble guidance continues to feature low amplitude ridging in a progressive flow regime allowing for a steady stream of short waves to ripple through the flow.
A trough will bring thunderstorms and gusty winds to the silver state today. Fair weather will return to the region on Sunday along with warmer temperatures which will last into the foreseeable future.
A low pressure system, currently located along the western Washington/Oregon border will continue to dig southeastward today and into central Idaho this evening. As it does so, several spokes of energy will rotate around the low, producing waves of precipitation. The low quickly exits the region by Sunday morning, bringing overall drier conditions. A secondary low pressure system will move along the Canadian border, bringing the potential for some showers to northwest Montana by Sunday afternoon.
955 AM EDT Sat Aug 21 2021 Tropical cyclone Henri will move north, well off the Atlantic coast today through Sunday.
555 AM CDT Sat Aug 21 2021 A cold front will move east through the area this morning. On Sunday, high pressure will provide dry weather.
606 AM EDT Sat Aug 21 2021 Tropical cyclone Henri will move north, well off the Atlantic coast today through Sunday.
607 AM CDT Sat Aug 21 2021 A strong, negatively tilted trough was moving through the Northern Plains and Upper Midwest early this morning. Its associated cold front was pushing through the forecast area with the line of convection now slowly pushing south and east of the forecast area. A slightly cooler but noticeably drier air mass will settle over the area today.
957 AM CDT Sat Aug 21 2021 Morning surface analysis and satellite imagery shows a clear, persistent convergence axis (almost a warm front) draped from Paducah KY SSE to about near Muscle Shoals. A strong storm or two are possible as well should we ever realize any clearing in this low stratus deck. We'll start to see building upper-level heights as the upper-level ridge over ArkLaTex builds eastward into Mississippi and Alabama.
649 AM EDT Sat Aug 21 2021 Weak high pressure will lead to patchy early morning fog with fair weather for the remainder of the day.
833 AM EDT Sat Aug 21 2021 Water vapor imagery and upper air plots showing upper low spinning over the Virginias this morning wrapping drier air into N FL and steering TS Henri in the W Atlantic. At the surface, weak high pressure remains over the local region with light steering flow. Ridge of high pressure is still in place across the northern Gulf of Mexico, while the Atlantic ridge stays to our east. Afternoon highs will range from the low to mid 90s, while overnight lows stay in the low to mid 70s through the period.
Low pressure was centered over Washington and Oregon this morning with high pressure over Texas. In addition, warmer air aloft has moved over the area placing a capping layer to convection across northern Arizona.
Tonight and Sunday The main focus from this forecast period has been precipitation trends with the expected passing of a weak cold front. Behind this cold front, dry conditions and near normal temperatures are forecast for tonight and Sunday. This afternoon's satellite imagery and surface observations indicated the cold front was positioned along a line from Iron Mountain to Wautoma. High pressure and dry air following the cold front will provide clear skies overnight into Sunday. In addition, cooler air will spread across the area, allowing near normal low temperatures overnight ranging from the upper 40s to upper 50s inland, and the lower 60s along the lakeshore.
Upper level ridge building into the area will limit diurnal activity, keeping us dry and warm. Stigger/87 18Z 21AUG2021 TAFs (As of 1600Z) VFR conditions are expected to prevail past the end of the forecast period due to an upper level ridge limiting diurnal activity.
With clear skies, a few locations around central Wisconsin, the typically cooler areas, may even get into the mid 40s by sunrise Sunday morning. A high pressure system Sunday makes for beautiful weather to finish off the weekend.
/This Afternoon/ The morning water vapor imagery reveals that upper ridging is firmly in place across the region, with a sct stratocu field recently developing beneath the ridge over much of E TX/N LA/Srn AR. While the air mass has become moderately unstable over SW and SCntrl AR ahead of this approaching outflow bndry, subsidence beneath the ridge has increased over this area as well, which will inhibit the convection from developing much farther S into the region.
Afternoon winds are expected to be a tad stronger compared to yesterday's all thanks to an upper-level trough pushing through the Pacific NW region. Low pressure was centered over Washington and Oregon this morning with high pressure over Texas. In addition, warmer air aloft has moved over the area placing a capping layer to convection across northern Arizona.
Cooler highs in the 70s look good by late afternoon. As an upper trough exits this morning and high pressure builds in at the sfc, winds will diminish across the area. Temperatures will remain cooler than average today with highs only in the 70s and dry conditions are expected. Winds will increase out of the southeast tonight ahead of a front and upper trough that will sweep from west to east on Sunday. A drier and warmer airmass will build in quickly behind it with temperatures rising into the 90s across south central SD. Cold front and upper wave is just about out of the CWA to open things up Sunday evening, taking convection with it.
After the passage of last nights cold front, we are looking at pleasant highs in the lower to mid 80s this afternoon and low humidity. Sunday: We will start to see a pattern shift on Sunday as a upper level ridge starts to build over the southern Plains.
148 PM EDT Sat Aug 21 2021 Weak high pressure will lead to fair weather today.
In the 4-5 years we've been using this radar rainfall estimation this product, we think this is the highest we've seen it as it's maxed out the color scale.
The low pressure system that brought us the rain this morning will bring the region thunderstorms this afternoon and evening.
311 PM EDT Sat Aug 21 2021 A fractured low-level ridge axis stretches west across Florida. Mean layer ridging will stretch west across Florida throughout the forecast period.
CDG Chattanooga Airport, TN 71 90 71 93 71 / 30 40 0 10 0 Knoxville McGhee Tyson Airport, TN 70 90 69 92 70 / 10 30 0 10 0 Oak Ridge, TN 69 90 69 91 69 / 20 30 0 10 0 Tri Cities Airport, TN 65 88 65 90 66 / 10 10 0 10 0.
This trough was interacting with a deep moisture axis of high dew points/PWATS stretching from western TN into central IL. Surface cold front works into central IN overnight and washes out as it reaches the Ohio Valley by tomorrow morning. Heat will build during the first half of the week as upper ridging centered over the ArkLaTex expands NE across the Ohio Valley. Hottest temperatures are expected on Tue-Wed, with highs in the lower/mid 90s, and dewpoints will gradually increase during this period.
1118 AM MDT Sat Aug 21 2021 Current surface analysis shows cold front well south and east of the region, with weak high pressure over eastern MT into WY. Upper level analysis shows trough moving northeast into Canada. Some 30s are noted across the highest elevations of the Black Hills. Cooler conditions will continue today, with high temperatures in the 70s to around 80 degrees under mostly sunny skies. Most of the activity should move east of the forecast area by Sunday afternoon as the trough moves quickly east-northeast and a Pacific cool front pushes through. Breezy conditions will develop behind the frontal passage, with highs ranging from the 70s over the Black Hills to the lower 90s toward south central SD.
Winds should increase overnight as downward omega strengthens & 700-800 mb flow increases with the passage of the trough axis. A generally warm & dry forecast period expected as ridging remains in control aloft for much of the central and eastern US. Ahead of this disturbance it will be quite breezy overnight especially over the Nebraska panhandle in response to the low level jet. Precipitation chances will be limited to the higher terrain where one cannot rule out some virga showers along with gusty winds up to 50 mph. A change toward considerably warmer & drier conditions will likely yield critical fire weather conditions for areas along and east of I-25 on Sunday.
Weak cold front remains north of the CWA, stretching across southeastern Kansas into north central Oklahoma.
358 PM CDT Sat Aug 21 2021 591DM ridge centered along the TX/LA border continues to be the biggest influence on the local weather. The eastern side of the nearby ridge looks to erode slightly tomorrow. At the same time, temps should still be quite warm, in the mid 90s with the ridge still as close as it is. Another aspect that'll start to change tomorrow due some erosion of the ridge is a few more updrafts actually developing into storms and not being capped. The ridging aloft will be a little weaker each day.
The ops models, ensembles, and hi-res models all show this short wave trough bringing showers/storms to much of the cwa. Highs on Sunday will range from the mid 70s in the northeast cwa to the lower 90s in the southwest cwa.
The mid/upper low over WV/northern VA, which is helping to direct Henri northward, is also directing minor impulses into the area from the NW. Northeast SC zones will have the highest chances for showers/tstms this afternoon/early evening, but expect better chances into southeast NC zones as well during Sunday afternoon/evening. Rain chances continue for the Short Term period, however they will be a bit lower than Sun as an upr-level trough axis pulls offshore. Scattered thunderstorms each day along the sea breeze front and a trough over the piedmont of the Carolinas each day.
The ridge flattens and shifts westward enough to lead to slightly cooler temperatures by the latter part of the week, in addition to some small, mainly afternoon thunderstorm chances sneaking in from the east.
/Issued 1239 PM CDT Sat Aug 21 2021/ /This Afternoon through Sunday/ Mid level ridging will sit over the Southern Plains through the rest of the weekend resulting in hot and dry conditions. Temperatures at this hour are in the upper 80s and lower 90s with dewpoints generally in the lower 70s.
They suggested an initial round of semi- organized showers/storms in the late morning-early afternoon (verifying so far), with a 2nd round in the early evening (generally 00-03Z) expected to develop within the highly unstable airmass to the west.
With the upper level ridge returning, wind will calm down Sun but get breezy again Mon afternoon.
1221 PM CDT Sat Aug 21 2021 (Today and tonight) Summer returning to West Central Texas, as upper level high pressure builds over the top of the area. Mostly mid 90s expected today, perhaps pushing into the upper 90s across the eastern Big Country closer to the middle of the ridge.