Aikyam-Lab/Synoptic-Bench huggingface dataset:
1148 PM CDT Sun Aug 16 2020 Updated aviations section The thicker area of high clouds has shifted a bit east this evening as the 500 mb heights rise and trough moves east. CAMs are still showing light showers/weak thunderstorm activity possibly developing late this afternoon ending before sunset, but considering the lower instability (ML CAPE less than 250 J/KG) and less organized forcing, combing with higher mixed layers lowers confidence in more that very light amounts where this would track. Loss of daytime heating should help stabilize the low levels and activity should fall apart. Ridging continues to amplify/shift east tonight into Monday with dry weather favored. Regarding temperatures: Lingering cooler air mass and good radiational conditions should support 50s for most with cooler spots in the upper 40s tonight.
The weak cold front is starting to move across the northern sites and is expected to continue southward, slowly, during the rest of the night hours into early Monday morning.
331 AM CDT Mon Aug 17 2020 The high dewpoints we have seen lately will be shunted far to the south the next couple of days as the mid to upper level flow becomes northerly.
High pressure will approach the region from the northern Plains today. Highs will range from the lower 70s northwest to around 80 south. High pressure will reside over the region tonight into Tuesday, and bring dry conditions.
The persistent area of high pressure is currently centered just to our west with moisture riding around the periphery of the high evident on satellite this afternoon. Enhanced drainage may briefly enhance winds in the Grand Valley and Glenwood Canyon, but overall the high pressure should keep winds on the light side. The smoke has also kept high temperatures slightly cooler than guidance and this trend will continue on Monday. Monday will also see the high reposition slightly, allowing for a gradual increase in moisture. The high will wobble from the southern Great Basin to the Southwest then back late in the period. As aptly pointed out in the previous discussion, mid-level heights reach their peak on Tuesday and the highest temperatures during the period are expected to be reached then.
208 AM EDT Mon Aug 17 2020 A weak cold front approaches from the Ohio River Valley tonight into Monday before dissipating over the mountains. Overnight lows will fall back into the low to mid 60s with widespread areas of patchy fog across the region. Much warmer conditions expected Monday so staying close to guidance as highs return into the mid to upper 80s and overnight lows fall back into the low to mid 60s with upper 50s west of the Blue Ridge.
Highs will be in the low to mid 90s, but with lower humidity, heat index values should remain below 100 F for the entire CWA. Low temperatures Monday night will also be much more comfortable, with rural locations falling into the lower 70s, and mid 70s in urban areas.
Showers should come to an end shortly after sunrise as high pressure nudges in from the northwest, with decreasing clouds by late morning. Under steady cold air advection and northwest flow, highs are expected to top out in the 70s for most, with a few 80s in typical warmer valley locations. Tuesday will feature plenty of sunshine and light winds as the high drifts overhead. Persistent upper ridging over the western CONUS and troughing over the east will yield a northwest flow pattern over the region.
1120 PM CDT Sun Aug 16 2020 A pretty typical late summer flow pattern is in place across the US, with mid/upper level ridging centered across the western US and a relatively quiet northwest flow pattern across the Midwest. Over the next 24 hours, predominantly tranquil weather will continue with little change in the upper flow pattern and surface ridging approaching from the northern plains. Some recent high res models have indicated a few showers later on overnight into WI, so have brought low chance north and eastward, but the highest likelihood looks to be across northeast IA.
314 AM CDT Mon Aug 17 2020 A stout ridge remains in place across the western half of the conus to start the workweek. With a persistent low over Canada's Hudson Bay and troughing across the eastern states, the central conus will see more of a meridional flow pattern over the next few days. The remainder of the workweek shows that the western ridge does not appear to weaken much and keeps much of the Plains in northwest flow. Precipitation chances don't look overly great, but will be tied to several weak disturbances kicking off convection over the higher terrain, or across the Northern Plains, and translating them along the periphery of the ridge.
Broad upper level troughing remains over the Great Lakes region early this morning. Weak short waves continue to ripple thru the upper level trough. Skies will clear as low level ridging builds into the region.
212 AM MDT Mon Aug 17 2020 Varying degrees of upper ridging will dominate the weather across Montana this week. This ridge will bring highs near 100 over many parts of NE Montana this afternoon, tonight, and Tuesday. There will be weak waves at times this week moving across the ridge as monsoonal moisture moves across Montana.
Weak high pressure is settling over the region along with a much drier airmass. Lows tonight will be in the 60s, though a couple of degrees warmer than this morning. An upper level disturbance and associated reinforcing cold front will push through. Northerly winds will restrengthen a bit and temps will be a couple of degrees cooler than Monday.
Similar storm evolution is forecast for Monday afternoon and early evening, with a few storms forming over the higher terrain of the Rim and White Mtns and moving southwestward into Yavapai and Gila counties.
A little warmer to the west of the valley compared to the cooler temps in the east this afternoon. Tuesday will see a slight chance for showers or thunderstorms develop/advect in as there remains some possibility of convection with weak wave sliding SE along the periphery of the western conus ridging. If the wave arrives earlier and clouds limit daytime heating much cooler max temps would be expected.
There have been a few showers associated with this system across the highway 20 corridor so far tonight. The best chances for a few storms today are south of I-80 as the trough moves through this area during peak afternoon heating. Steady north winds behind the boundary will lead to cooler temps with near normal highs in the low to mid 80s. It will also be a bit cooler tonight with lows back into the 50s.
302 AM EDT Mon Aug 17 2020 Expect a day or two of drier conditions as high pressure builds across the area. A brief break in the action for most of today as dry air settles into the region under a weak high pressure system. Another advancing cold front from the west will bring chances for showers and thunderstorms for the I-95 corridor later this afternoon into the evening, although confidence along the frontal boundary is low given available atmospheric moisture. The approach of an upper trough and surface front (still not too common for August) will bring a return of fairly unsettled weather though in the absence of instability this ramp up may be gradual Tuesday night.
Coverage should continue to decrease this morning as the upper trough and cold front moves farther south. Northerly winds will advect relatively cooler and drier air into the region in the wake of the cold front. Despite clearing skies from north to south, daytime high temperatures will range from the lower to mid 90s today.
Drier air looks to move into the area during the day today (dewpoints dropping into the lower 60s), behind a weak frontal boundary. With mostly high cloudiness pushing more to the southeast during the day, think that highs in the upper 80s to around 93 degrees west of I-65 will be the general rule (expect more breaks in cloud cover/warmer temperatures west of the I-65 corridor). Later tonight, another weak front rotates southeastward towards the Tennessee Valley around an upper low over the Great Lakes region. Northerly low level flow should remain in place and keep lows in the lower to mid 60s. Most models amplify the longwave trough axis associated with this front on Tuesday and by the mid-afternoon and evening hours, move it southeast through northern Alabama and into Georgia.
858 AM EDT Mon Aug 17 2020 Expect a day or two of drier conditions as high pressure builds across the area. A brief break in the action for most of today as dry air settles into the region under a weak high pressure system. Another advancing cold front from the west will bring chances for showers and thunderstorms for the I-95 corridor later this afternoon into the evening, although confidence along the frontal boundary is low given available atmospheric moisture. The approach of an upper trough and surface front (still not too common for August) will bring a return of fairly unsettled weather though in the absence of instability this ramp up may be gradual Tuesday night.
Surface winds will become northerly at all terminals in the wake of a cold front. Coverage should continue to decrease this morning as the upper trough and cold front moves farther south. Northerly winds will advect relatively cooler and drier air into the region in the wake of the cold front. Despite clearing skies from north to south, daytime high temperatures will range from the lower to mid 90s today.
1057 AM EDT Mon Aug 17 2020 A weak trough of low pressure will swing through the area tonight through Monday, resulting in a few showers and isolated thunderstorms. Dry and quiet weather returns for the middle of the week as high pressure drifts over the region. Previous Discussion Below A trough will slide through the eastern border of our forecast area early this morning with scattered showers. Thereafter, clouds will begin to break during the late morning as a cold front approaches from the west. Clearing skies late Tuesday night with cool high pressure building into the region.
Highs in the 90s to near 100 F will be common through at least Tuesday, and any chances for showers & thunderstorms will be extremely limited with strong subsidence beneath persistent upper-level ridging.
A fractured low-level ridge axis stretches west across the islands, lending to light southerly breezes. Afternoon highs should climb into the lower to mid 90s despite the occasional anvil debris from the Mainland.
High pressure will build in from the Great Lakes for midweek, then pass off the east coast by the end of the week. Radar is showing a broken line of showers over the northern mountains at 09Z in association with a dying cold front. Early morning satellite loop is showing patchy fog across the Lower Susq Valley and northwest mountains, which should mix out by around 13Z based on latest HREFV3 and LAMP guidance. However, conditions will be more favorable across eastern Pa, where heating of modestly unstable airmass in vicinity of remnant cold front results in afternoon capes near 1000 j/kg per latest HREF. Mixing down ensemble mean 850mb temperatures of around 14C support highs today ranging from the mid and upper 70s over the Alleghenies, to the low and mid 80s elsewhere.
This is all occurring with an upper level trough over Ontario, and we have deep northwest flow over the area.
This fairly dry and stable airmass will keep the threat for warm front thunderstorms over the eastern Dakotas through the day. The massive upper ridge bringing record heat to the west will try to build east to the Upper Midwest throughout mid to late week. The 500 mb ridge centered over western UT and eastern NV early this week could shift eastward to the Colorado vicinity toward the end of the period. ECMWF and Canadian models have been trending warmer, especially this weekend with widespread highs in the lower 90s. These models are a good 5-10 degrees warmer than the NBM. GFS is also cooler by maintaining some weak troughiness just to the north.
1047 AM EDT Mon Aug 17 2020 Thunderstorm chances return to typical mid-August levels today through Tuesday, then increase through the rest of the week as an upper level trough becomes well established. As of 300 AM EDT Monday: a mid-lvl trough will continue to dig across the Ohio Valley to the central Gulf Coast Tuesday, bringing a weak front into the area. PWATs remain slightly below normal ahead of the front, and instabilty will be confined mostly to the high terrain.
418 AM CDT Mon Aug 17 2020 The center of upper level high pressure is over AZ this morning. Upper level high pressure expands and strengthens across the western CONUS during the upcoming week. Northwest flow aloft across our region will prevail on the eastern periphery of the high.
634 AM CDT Mon Aug 17 2020 High pressure and dry air will continue over the area through the period. Today Through Tuesday Night An upper ridge is centered over Utah will continue to provide northerly flow over the Plains. This ridge will remain stationary through Tuesday and the pattern will remain the same over Arkansas.
There is some ongoing patchy light fog across the area this morning just along and south of the approaching cold front from just south of Highway 84 south to the coast. So today, the mid- and upper portion of the front approaches with a notable trough tilting back to the northwest with height from 500- to 300 hPa (kind of interesting for this time of year). Highs today will range form the mid 90s east to the lower 90s over interior SE MS and Choctaw Co Alabama.
650 AM EDT Mon Aug 17 2020 A weak trough of low pressure will swing through the area tonight through Monday, resulting in a few showers and isolated thunderstorms. Dry and quiet weather returns for the middle of the week as high pressure drifts over the region. A trough will slide through the eastern border of our forecast area early this morning with scattered showers. Thereafter, clouds will begin to break during the late morning as a cold front approaches from the west. Clearing skies late Tuesday night with cool high pressure building into the region.
High pressure ridge will hold across southern Florida through the first half of the week with westerly winds generally less than 15 knots and seas 3 feet or less. The ridge will lift north some during midweek, with winds turning south to southeast with an afternoon sea breeze near the coast.
Overnight, the cold front has progressed to the south, as drier air filters in behind it. Should be a quiet day as high pressure builds in over the middle of the country. Although high temperatures will likely remain in the low 90s, the lower dewpoints will keep the heat indices generally in the 90s as well. Overnight lows will drop into the mid to upper 60s in the cooler and drier air. Upper-level ridging stretched across the western half of the CONUS along with troughing in the south east, will keep conditions pretty much the same each day through out the forecast period.
Generally dry and seasonable weather is then expected through much of the week under high pressure. Morning fog and the low-level stratus deck will dissolve in the next few hours with daytime heating. Dry weather is expected this morning under brief ridging.
Chattanooga Airport, TN 90 67 90 68 89 / 0 0 20 10 60 Knoxville McGhee Tyson Airport, TN 87 65 87 66 85 / 10 0 20 10 60 Oak Ridge, TN 88 64 87 66 85 / 0 0 30 10 50 Tri Cities Airport, TN 84 60 84 63 82 / 10 0 30 20 70.
638 AM CDT Mon Aug 17 2020 A stout ridge remains in place across the western half of the conus to start the workweek. With a persistent low over Canada's Hudson Bay and troughing across the eastern states, the central conus will see more of a meridional flow pattern over the next few days. The remainder of the workweek shows that the western ridge does not appear to weaken much and keeps much of the Plains in northwest flow. Precipitation chances don't look overly great, but will be tied to several weak disturbances kicking off convection over the higher terrain, or across the Northern Plains, and translating them along the periphery of the ridge.
Otherwise, look for high temperatures to be cooler than yesterday, with highs in the middle 90s.
convection is progged to develop across south- central Texas this afternoon along a weak cold front moving towards the coastal bend tonight.
437 AM CDT Mon Aug 17 2020 Overnight, the cold front has progressed to the south, as drier air filters in behind it. Should be a quiet day as high pressure builds in over the middle of the country. Although high temperatures will likely remain in the low 90s, the lower dewpoints will keep the heat indices generally in the 90s as well. Overnight lows will drop into the mid to upper 60s in the cooler and drier air. Upper-level ridging stretched across the western half of the CONUS along with troughing in the south east, will keep conditions pretty much the same each day through out the forecast period.
657 AM EDT Mon Aug 17 2020 Expect a day or two of drier conditions as high pressure builds across the area. A brief break in the action for most of today as dry air settles into the region under a weak high pressure system. Another advancing cold front from the west will bring chances for showers and thunderstorms for the I-95 corridor later this afternoon into the evening, although confidence along the frontal boundary is low given available atmospheric moisture. The approach of an upper trough and surface front (still not too common for August) will bring a return of fairly unsettled weather though in the absence of instability this ramp up may be gradual Tuesday night.
521 AM MDT Mon Aug 17 2020 Will be under a northerly flow through the short term period on the eastern periphery of a large ridge centered over the Great Basin which is not going to move at all.
Will be under a northerly flow through the short term period on the eastern periphery of a large ridge centered over the Great Basin which is not going to move at all.
519 AM MDT Mon Aug 17 2020 09Z upper level analysis has large ridge over the Great Basin area with west northwest upper flow over the Northern Plains. At the surface, high pressure resides across the Northern Plains with light winds in most locations. Upper ridge will bring mostly sunny skies to the area today. Great Basin upper ridge will continue to dominate the weather pattern for the remainder of the week into the weekend. Isolated afternoon and evening thunderstorms could occur just about every day this week over the higher terrain of northeastern Wyoming and the Black Hills, but a majority of the area will remain dry.
543 AM CDT Mon Aug 17 2020 The high dewpoints we have seen lately will be shunted far to the south the next couple of days as the mid to upper level flow becomes northerly.
High pressure will build in from the Great Lakes for midweek, then pass off the east coast by the end of the week. Dying cold front can still be located via sfc obs over the Ridge and Valley Region of southeast PA, although earlier showers dwindled as expected. This boundary will drift southeastward through early afternoon and perhaps touch off a few showers and thunderstorms over the Lower Susq. Mixing down ensemble mean 850mb temperatures of around 14C support highs today ranging from the mid and upper 70s over the Alleghenies, to the low and mid 80s elsewhere.
636 AM EDT Mon Aug 17 2020 A weak cold front moves slowly through the Mid Atlantic region today and tonight. Tuesday low pressure will be over the Tennessee Valley then slide southeast into the Deep South.
Excessive heat will continue into the middle portion of this week as strong high pressure remains in the region.
Line of thunderstorms on the cold front from earlier tonight is dissipating, but some showers and thunderstorms are lingering into the early morning hours.
Expect VFR conditions to prevail across the Rio Grande Valley today even as a weak 500mb low across east Texas moves slowly southward across south Texas today around the periphery of the 500mb subtropical ridge across the southwest United States. convection is progged to develop across south- central Texas this afternoon along a weak cold front moving towards the coastal bend tonight.
The cold front will be stalled just south of our coastal waters.
628 AM CDT Mon Aug 17 2020 The center of upper level high pressure is over AZ this morning. Upper level high pressure expands and strengthens across the western CONUS during the upcoming week. Northwest flow aloft across our region will prevail on the eastern periphery of the high.
524 AM EDT Mon Aug 17 2020 Scattered showers and a few thunderstorms are expected today, mainly north of Pittsburgh, with a weak crossing cold front. Generally dry and seasonable weather is then expected through much of the week under high pressure.
320 AM MDT Mon Aug 17 2020 09Z upper level analysis has large ridge over the Great Basin area with west northwest upper flow over the Northern Plains. At the surface, high pressure resides across the Northern Plains with light winds in most locations. Upper ridge will bring mostly sunny skies to the area today. Great Basin upper ridge will continue to dominate the weather pattern for the remainder of the week into the weekend. Isolated afternoon and evening thunderstorms could occur just about every day this week over the higher terrain of northeastern Wyoming and the Black Hills, but a majority of the area will remain dry.
305 PM CDT Mon Aug 17 2020 A strong subtropical ridge over the Great Basin will remain anchored over the western CONUS through the weekend. Northwesterly winds aloft downstream of this ridge will flow into a trough over the eastern CONUS.
256 PM MDT Mon Aug 17 2020 High pressure remains in control over the western CONUS today. This high pressure system is centered over western Utah, placing eastern Utah and western Colorado in light northerly flow in the mid and upper-levels. A meager amount of moisture has circled around this high pressure system, and has encroached on the Sawatch and Sand Juan mountains this afternoon. High pressure is not expected to move much, if at all, and isolated showers and thunderstorms will once again be possible in the San Juan range.
107 PM EDT Mon Aug 17 2020 Upper-level trough axis will continue to swing through the airspace during peak heating mid to late afternoon, and will attempt to spark isolated to perhaps widely scattered showers and thunderstorms mainly focused over the Thumb region.
Have you been outside today? Dew points in the low to mid 60s with highs in the 80s? What is this? Spring? Seriously, though.
Generally dry, seasonable weather is expected midweek as high pressure builds. So if convergence along the afternoon frontal zone is sufficient to develop deep, moist convection, brief, isolated- scattered showers capable of heavy rain are the most likely outcome given CAPE entirely below the freezing level. High pressure should maintain dry weather thereafter through Wed night. Model ensembles suggest with high confidence that an expansive wrn- CONUS ridge and sern-CONUS trough will remain dominant through the remainder of the week. The Upper Ohio Valley will remain amid weak nwly flow aloft downstream of the wrn ridge.
232 PM CDT Mon Aug 17 2020 Weak cold front moving through the dvn cwa with only isolated showers along the front, but convergence near the front was weak. Elsewhere, northwest/north winds behind the front were ushering cooler and less humid air into northern IA and into MN/WI where temperatures were in the 70s and dewpoints in the 50s. Then high pressure building into the area from the the Upper Midwest will bring clear skies, cooler and less humid conditions. Tuesday: Delightful mid August day with plenty of sunshine and comfortable temperatures and humidity, thanks to high pressure. 3) Gradually warmer temperatures as the week progresses. Overview: Split flow with big heat dome in the western United States (hottest in 70 years!) and large trough from Quebec to the eastern states.
A light southwest flow ahead of upper trough axis with slight cooling aloft will mean slow moving scattered storms this evening with the main threats being locally heavy rainfall with frequent lightning and strong gusty winds mainly in cell and boundary mergers.