Aikyam-Lab/Synoptic-Bench huggingface dataset:
Convective development is aided by the presence of an MCV from earlier this morning as well as lingering boundary across the northwest portion of the region and an upper trough across the Mid-South.
338 PM EDT Sun Aug 15 2021 High pressure builds across the Northeast through Monday, then slowly moves offshore Monday night, setting up over the Atlantic through the middle of the week. High pressure continues to build in with slight ridging aloft. A upper ridge axis will be over us on Monday, then begins to shift away to the east Monday night. Highs mostly in the lower 80s. This will result in return flow around the high producing a lgt, onshore, humid flow. High pressure will settle north of the terminals this evening.
This set up continues through the night with monsoonal moisture to our west progged to push eastward into western sections of the forecast area on Monday while an upper level short wave trough progged to move across the central High Plains on Monday will advect additional mid level moisture into the northern zones during the afternoon. The proximity of an upper low to the southwest, weak upper level ridging, and the mid level moisture advection all point to increasing shower and thunderstorm chances Monday afternoon in line with the previous forecast. Much of the model guidance, such as reflected in the HREF, suggests that once again the western counties will see the highest coverage. To cover this potential, we will retain the highest PoPs out west, but also extend the NBM-derived PoPs farther east.
Sfc cold front will accompany the system, although convergence along it looking somewhat weak as this point. Nothing extreme, but some potential to creep toward 90 ahead of that cold front.
There is an upper low which dives through Nebraska and into northern Missouri before lifting into the Great Lakes area through mid week.
101 PM CDT Sun Aug 15 2021 A weak high pressure center in the Upper midwest is keeping weak ridging in the region. As such, kept POPs on the low side to compensate.
(This afternoon through Monday night) In the upper levels a ridge is located over CA/NV with a trough extending from the Great Lakes down through the MS Valley. Not much change in the upper pattern Monday with another trough moving into the NW US Monday night. Overnight lows will only fall into the 60s with some 70s with a warmer day expected Monday. Similar set up Monday with the highest pops centered over the Davis Mountains.
Monday will be nearly a carbon-copy of today, albeit a tad warmer and more moist. Dew points will rise into the lower to mid 60s, making the air feel a bit sticky.
1239 PM EDT Sun Aug 15 2021 High pressure will maintain VFR conditions with just few diurnal cu this afternoon. Cirrus will thicken and gradually lower tonight into Monday morning as this high shifts off to the east. Increase in southwest flow under the large scale deformation eventually allows Gulf Moisture to be drawn northward contributing to what will become a dirty ridge. High pressure gradually drifts eastward throughout the day, continuing to bring dry weather to the central Great Lakes for the remainder of the weekend. Weak surface gradient limits winds to below 15 kts, while southerly winds prevail on the back side of the high pressure center.
Same general setup in place again Monday: mid level troffiness extending from the Great Lakes into Tx, decaying surface boundary, PW's 1.
These conditions will continue right through Monday as high pressure slowly drifts across the Great Lakes region and into New England on Monday. Lows tonight will range form the mid to upper 50s in the colder eastern Ozarks valleys, to the mid 60s over southwest Missouri and highs Monday generally in the low to mid 80s, with some upper 80s likely over far southwest Missouri.
This is an abundance of blowoff moisture from convection yesterday and overnight and because of a persistant upper trough with our region basically located in the base of this trough. Forcing will remain in place for the remainder of the day due to the vicinity of the upper trough and with PWATS at or near 2 inches across the entire region, all we need is a little bit of heating to generate scattered convection today. With the lingering upper trough and sfc boundary just to our north, scattered convection is likely once again today so have included VCTS at all sites through mid to late afternoon.
Winds will mostly be light and variable throughout the period CD Chattanooga Airport, TN 72 85 71 81 71 / 70 50 40 80 50 Knoxville McGhee Tyson Airport, TN 70 86 69 81 71 / 60 70 50 60 50 Oak Ridge, TN 70 84 69 80 69 / 60 80 40 60 50 Tri Cities Airport, TN 68 84 67 80 67 / 60 80 40 60 60.
1258 PM EDT Sun Aug 15 2021 Cooler and less humid air will remain in place today as clouds increase from the south. Increasing moisture ahead of Plains low pressure will bring a chance of rain to the region through much of the upcoming week. Vorticity advection will remain prominent through the early week as we land on the eastern van of a developing midwestern trough. This will increase the chance for thunderstorms, as we fall back into a consistently active pattern blocked between low pressure in the midwest, and high pressure off the east coast. VFR is likely continue through this evening with high pressure centered across the lower Great Lakes region.
300 PM CDT Sun Aug 15 2021 Weak upper level trof axis remained across Eastern Oklahoma and Northwest Arkansas this afternoon.
224 PM EDT Sun Aug 15 2021 The large scale pattern remains fixed in place with broad sprawling high pressure over the East Coast and persistent troughing over the High Plains and Canadian Prairies. Subtle mid- level height falls tomorrow will make for 850 mb temps around 1-2 C cooler than today, and thus highs a couple of degrees cooler, but still in the low to mid 80s for most, cooler near Lake Michigan. Quiet and warm weather is expected through mid-week with southerly flow with ridging over eastern U.
1214 PM CDT Sun Aug 15 2021 A broad ridge of high pressure to the east and a slow moving upper level trough to the west will provide the area with multiple days in a row of similar weather.
Also of note, thought later in the forecast, is a trough moving across the Eastern Pacific on its way to landfall over the Pacific Northwest.
Temperatures near to a few degree warmer Monday with min RHs dropping into the low teens for most places.
This is an abundance of blowoff moisture from convection yesterday and overnight and because of a persistant upper trough with our region basically located in the base of this trough. Forcing will remain in place for the remainder of the day due to the vicinity of the upper trough and with PWATS at or near 2 inches across the entire region, all we need is a little bit of heating to generate scattered convection today.
Monday's highs will be similar to Sunday (80s) except for western MN where 850 mb thermal ridging will shift more overhead. While sustained southerly winds of 10-15 knots (with gusts in the lower 20s in western MN) are expected Monday afternoon, the continued southerly flow will advect slightly moister air into our region.
A weak mid to upper level trough currently responsible for helping form convection across the Lower Ohio Valley region will tend to transmit subtle vorticity aloft toward the Great Lakes region by mid week, but our eastern forecast area near US 127 could see an isolated shower as early as Monday night as the focus for any sort of mid level lift would be across mainly eastern Lower Michigan.
The lower Keys will have a lot less convective activity.
347 PM EDT Sun Aug 15 2021 High pressure over the west Atlantic will funnel copious amounts of moisture into the Carolinas for the next several days. A building ridge aloft should favor an abating trend in the rain late in the week and possibly bring some slightly warmer temperatures. Latest sfc analysis shows a weak trough of low pressure over the local area with high pressure offshore and Tropical Storm Fred over the eastern Gulf Of Mexico. Aloft, an upr-level ridge is in place off the coast. Low temps tonight in the low/mid 70s. Not much pattern change into Mon, with the exception being the upr-level ridge slides W a bit, allowing for rain coverage to be slightly lower Mon than today especially over the Cape Fear region. Low temps in the low/mid 70s.
223 PM CDT Sun Aug 15 2021 (Issued 223 PM CDT Sun Aug 15 2021) Tonight through Monday night: High pressure will continue to bring quiet weather to southern Wisconsin through Monday.
Despite high pressure in place, skies look a bit on the gloomy side with all the smoke in the air.
139 PM EDT Sun Aug 15 2021 High pressure will bring quiet weather to the region through early Monday. A warm front will set off isolated showers or thunderstorms Monday afternoon and evening. Fair weather high pressure will remain over the region through Monday morning. A warm front will approach the northeast on Monday afternoon. Upper level ridge of high pressure remains nearly stagnant over the Atlantic as a trough slowly pushes into the central CONUS.
An upper level trough over the Mississippi Valley deepens into the southern Plains on Monday. Heating and weak forcing from the trough and surface boundaries from today's convection will generate scattered showers and thunderstorms.
The low levels remain dry with dewpoints in the mid 50s.
The weakness in the 500mb ridge persists across the central Gulf Coast. The ridge in the west will retrograde a bit further to the west through tomorrow while a longwave trough digs southward from the Great Lakes. The interaction between the trough and ridges will help serve as steering mechanisms for Fred. At the surface, the western Atlantic ridge will remain along the eastern seaboard.
This yields lows mainly in the low to middle 50s, with a few upper 40s possible in the Northwoods. The upper flow becomes southwest by the end of the week, as an upper trough approaches from the Northern Plains states.
244 PM EDT Sun Aug 15 2021 Forecast models suggest a broad, weak, upper low will develop over the Midwest during this period. At the surface, high pressure over the Great Lakes will gradually drift off to the north, while a diffuse inverted trough eventually develops over the area by Monday night. Models suggest broad and weak troughing to be in place across the Mississippi and Ohio Valleys through much of the week.
We did manage to squeeze out a few rain showers on the far western borders of our CWA from the low level jet that ramped up overnight. Our pattern holds fast for a little while longer with the region caught between an exiting high pressure and a low moving through Canada.
324 PM EDT Sun Aug 15 2021 High pressure centered over Ontario will continue to gradually move east during the up coming week.
For Tue through Sun: Fred slides toward the Ohio Valley as deep layer ridging off the eastern builds southwest across FL and over much of the Gulf of Mexico. This ridging lifts up into the southeast quarter of the nation midweek then resides there. Tropical Storm Fred moves by to the west as high pressure builds in then lifts north as Tropical Storm Grace moves by to the south toward the end of the week.
On Thu, an upper trough will approach and impact us by midday.
Surface map indicates a trough stretching across the western Dakotas. Southerly winds ahead of the trough are breezy across south central SD, where dew points are well into the 60s. Thermal ridge axis pushes over our area over the next couple of days.
119 PM EDT Sun Aug 15 2021 Upper air pattern consists of a 500 mb ridge across the western and sern U. this morning with a trough in New England and a weak trough trailing into the upper Great Lakes. The ridge moves into the Rockies and a weak trough moves into the Mississippi River valley. Quiet and warm weather is expected through mid-week with southerly flow with ridging over eastern U.
138 PM EDT Sun Aug 15 2021 High pressure builds across the northeast through Monday, then slowly moves offshore Monday night.
1218 PM CDT Sun Aug 15 2021 A ridge of high pressure continues to remain in place over the western half of the CONUS, which has left our portion of the country in predominantly NW flow aloft as flow closer to the surface stays nearly calm into the morning hours. As the day starts, we can expect lows in the lower 60s and into the upper 50s farther up north.
The combination of northeast low level flow and a fair amount of clouds across much of the area, will help keep temperatures on the cooler side with afternoon highs in the mid to possibly upper 70s. Lows will range from the lower 60s north to the upper 60s south. As the low levels saturate overnight, cigs will drop into MVFR category with some localized IFR cigs possible late tonight into early Monday morning.
Low temperatures Monday morning will be a little warmer than this past morning, ranging from mid-50s to mid 60s. The slight warming trend will continue Monday as dewpoints creep up from mid to lower 50s today into the upper 50s/lower 60s, while high temperatures will be near 80 except near Lake Michigan, which will continue to remain cooler. A low pressure system will move through Indiana Monday afternoon, creating a slight chance for showers in the far southeastern portion of my forecast area, south and east of I-57.
149 PM PDT Sun Aug 15 2021 A strong ridge, centered over northern California, will team up with a west bound trough over Mexico, to keep a brisk easterly flow aloft over Southern California through Monday. The best chance for any heavy rainfall will be near the mountains and over the high deserts. Occasional clouds and increasing low-level moisture will help to moderate daytime temperatures, except over the high deserts where excessive heat is expected through Monday. Later this week, a trough along the West Coast will bring a drier southwest flow aloft, and cooler weather.
As we progress through the night, the high PW airmass will continue to spread north across the region as a mid level short wave lifts northeast across the mid Ohio Valley. Overnight lows will be in the low to mid 60s. Will keep the highest pops across our southeast through the day on Monday, in the vicinity of the highest PWs. Broad mid-level ridge centered off the Carolina coast will gradually flatten and shift west into the southeast states while weak troughing over the upper Midwest fills heading into mid-week.
Main short-term challenge today continues to be the high temperature forecast with smoke preventing full-potential warming. Upper level ridge is parked along the California-Nevada border about 100 miles north of Reno. We can actually see the anticyclonic / clockwise-flow around this high on visible satellite imagery this afternoon in the smoke that has been lofted to such level in the atmosphere. This ridge is responsible for producing the widespread above normal temperatures across the region. Ridge begins to breakdown after today as a trough approaches the Pacific Northwest. For this evening, locally gusty westerly winds are forecast to develop in/around the Delta, as well as the Coastal Range where favored ridges, gaps, and canyons could see isolated gusts in the 25 to 35 mph range.
308 PM EDT Sun Aug 15 2021 The large scale pattern remains fixed in place with broad sprawling high pressure over the East Coast and persistent troughing over the High Plains and Canadian Prairies. Subtle mid- level height falls tomorrow will make for 850 mb temps around 1-2 C cooler than today, and thus highs a couple of degrees cooler, but still in the low to mid 80s for most, cooler near Lake Michigan. Upper ridging over the eastern U. Models still showing differences with the progression of an upper trough across the northern Plains late in the week.
236 PM CDT Sun Aug 15 2021 A trough is moving southeast through North Dakota this afternoon. Kept a precip mention out of the grids for now, but may need to be added in if convection manages to bust the cap as the trough stalls this evening. As the trough settles into central SD, the airmass will be significantly drier. Temperatures will continue to warm under the upper ridge. However, the HRRR smoke product shows the thicker smoke that is over Montana today making its way into central SD behind the trough on Monday.
241 PM CDT Sun Aug 15 2021 A very weak trough moving across the area is setting off little more than diurnal cu in our very dry air mass. High pressure at the surface has shifted east allowed surface flow to become southeast helping feed the cu field.
As the ridge of high pressure continues to break down tomorrow afternoon, the atmosphere should finally be able to mix out, allowing for upper lever winds to mix down to the surface.
1240 PM CDT Sun Aug 15 2021 Surface analysis early this morning shows sprawling high pressure over the northeastern quadrant of the lower 48 states with a weak north-south oriented surface boundary developing over the eastern Dakotas. The slight shift eastward of the western CONUS ridge and continued warm air advection processes will make for another warm day across the area. Highs will run from the lower 80s in western WI and SE MN to around 90 in western MN. Highs on Monday will be very similar to today, again ranging from the lower 80s to the lower 90s.
650 PM EDT Sun Aug 15 2021 High pressure anchored over the eastern Great Lakes will maintain mainly clear skies and light east-northeast winds through the night. High pressure centered over Ontario will continue to gradually move east during the up coming week.
Overnight lows will range from the lower 60s northwest to the mid and upper 60s southeast. Will keep the highest pops across our southeast through the day on Monday, in the vicinity of the highest PWs. Broad mid-level ridge centered off the Carolina coast will gradually flatten and shift west into the southeast states while weak troughing over the upper Midwest fills heading into mid-week.
A trough is moving southeast through North Dakota this afternoon. Kept a precip mention out of the grids for now, but may need to be added in if convection manages to bust the cap as the trough stalls this evening. As the trough settles into central SD, the airmass will be significantly drier. Temperatures will continue to warm under the upper ridge. However, the HRRR smoke product shows the thicker smoke that is over Montana today making its way into central SD behind the trough on Monday.
Forecast models suggest a broad, weak, upper low will develop over the Midwest during this period. At the surface, high pressure over the Great Lakes will gradually drift off to the north, while a diffuse inverted trough eventually develops over the area by Monday night. Models suggest broad and weak troughing to be in place across the Mississippi and Ohio Valleys through much of the week.
High temperatures will increase a little tomorrow into the lower 90s with less cloud cover.
729 PM EDT Sun Aug 15 2021 High pressure builds across the Northeast through Monday, then slowly moves offshore Monday night, setting up over the Atlantic through the middle of the week. High pressure continues to build in with slight ridging aloft. A upper ridge axis will be over us on Monday, then begins to shift away to the east Monday night. Highs mostly in the lower 80s. This will result in return flow around the high producing a lgt, onshore, humid flow. High pressure will settle north of the terminals this evening.
607 PM CDT Sun Aug 15 2021 A trough is moving southeast through North Dakota this afternoon. Kept a precip mention out of the grids for now, but may need to be added in if convection manages to bust the cap as the trough stalls this evening. As the trough settles into central SD, the airmass will be significantly drier. Temperatures will continue to warm under the upper ridge. However, the HRRR smoke product shows the thicker smoke that is over Montana today making its way into central SD behind the trough on Monday.
Gehring (Issued 223 PM CDT Sun Aug 15 2021) Tonight through Monday night: High pressure will continue to bring quiet weather to southern Wisconsin through Monday.
/Issued 300 PM CDT Sun Aug 15 2021/ Weak upper level trof axis remained across Eastern Oklahoma and Northwest Arkansas this afternoon.
A strong area of high pressure moving down from northwest Nevada will lead to above normal temperatures through Monday.
Temperatures will be milder than they were last night due to the increased cloud cover, with lows ranging from the mid 50s across the northern mountains to the mid 60s in the Lower Susq Valley.
Concur with deterministic NWP model runs that the upper pattern will be characerized by a trough/weakness in the height field over the region during the period.
A very weak trough moving across the area is setting off little more than diurnal cu in our very dry air mass. High pressure at the surface has shifted east allowed surface flow to become southeast helping feed the cu field.
907 PM EDT Sun Aug 15 2021 Mean layer ridging centered over the extreme western North Atlantic supports gentle to moderate east to southeast breezes across the Florida Keys. This ridge is driving Tropical Storm Fred to the north towards the Florida Panhandle. Additionally, this same ridge is sending Tropical Depression Grace to the west into Hispaniola.
By Monday afternoon we'll begin to see scattered to numerous showers and thunderstorms develop with daytime heating with the highest chances over the Nature Coast and interior. For Tue through Sun: Fred slides toward the Ohio Valley as deep layer ridging off the eastern builds southwest across FL and over much of the Gulf of Mexico. This ridging lifts up into the southeast quarter of the nation midweek then resides there. Tropical Storm Fred moves by to the west as high pressure builds in then lifts north as Tropical Storm Grace moves by to the south toward the end of the week.
902 PM CDT Sun Aug 15 2021 The Mid-South remains underneath a broad upper level trough. Convection that developed this afternoon in association with the upper trough and peak heating has now diminished since the sun has set. Most of the Midsouth has warmed into the low to middle 80s.
712 PM EDT Sun Aug 15 2021 The large scale pattern remains fixed in place with broad sprawling high pressure over the East Coast and persistent troughing over the High Plains and Canadian Prairies. Subtle mid- level height falls tomorrow will make for 850 mb temps around 1-2 C cooler than today, and thus highs a couple of degrees cooler, but still in the low to mid 80s for most, cooler near Lake Michigan. Upper ridging over the eastern U. Models still showing differences with the progression of an upper trough across the northern Plains late in the week.
High pressure ridging remains north as Tropical Cyclone Fred ventures northward in the eastern Gulf.
Temperatures will be milder than they were last night due to the increased cloud cover, with lows ranging from the mid 50s across the northern mountains to the mid 60s in the Lower Susq Valley. High pressure will persist over the western Atlantic for much of the week, helping to maintain a moist southerly flow into central PA.
Temperatures will continue to warm on Tuesday as dew points also increase, with continued dry weather as upper level ridging remains in control of the area. Highs on Tuesday are expected to rise into the lower to middle 80s as dew points rise into the upper 50s to lower 60s.
Sfc cold front will accompany the system, although convergence along it looking somewhat weak as this point. Nothing extreme, but some potential to creep toward 90 ahead of that cold front. High pressure expected to provide continued VFR conditions. However, thinking the steady 10-20 kt breeze just a few hundred feet above the surface will provide just enough mixing in the low levels to limit the overall threat for LSE.
251 AM CDT Mon Aug 16 2021 A weak level upper trough axis will remain over the region for the next few days with widely scattered showers/thunderstorms possible.
211 AM EDT Mon Aug 16 2021 Upper air pattern consists of a 500 mb ridge in the western U. Upper ridging over the eastern U. Models still showing differences with the progression of an upper trough across the northern Plains late in the week.