Aikyam-Lab/Synoptic-Bench huggingface dataset:
Cold pool aloft slides east tonight with low pressure builds in east moderating air mass some. Low pressure tracking north of the International border should have a cold front/boundary trailing slowly through ND creating synoptic scale forcing. Winds are generally light and variable this afternoon with high pressure in place. On the eastern edge of the high pressure northwest winds are blowing 10-15 kt with occasional gusts around 20kt, and these winds have impacted KBJI. As low pressure builds late tonight and Tuesday morning winds will shift to the south and then southwest and increase to 10-13kt across the region (late in the TAF period).
However, the difference today is the lower humidities. Temperatures should peak near 90 for most of the region this afternoon Prior discussion below: 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.
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.
Heat indices should be less of a concern for Tuesday as temperatures should be a few degrees cooler behind the weak front.
Late morning analysis shows the region under the influence of a highly amplified broad upper trough that stretches across much of the East CONUS. Despite the mild CAA ongoing today in the low levels, temperatures appear poised to rise into the upper 80s to lower 90s at most locations under mostly clear sky cover. 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.
Our 11 AM observations from various airports and reporting sites are running warmer than 24 hours ago. This is largely due to the warmer start we had this morning. Precipitation amounts with this high based activity will be very light if it materializes.
Cliff PREVIOUS DISCUSSION: 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.
CDG Chattanooga Airport, TN 68 92 68 89 68 / 0 20 10 60 20 Knoxville McGhee Tyson Airport, TN 65 89 66 85 66 / 10 20 10 60 10 Oak Ridge, TN 65 89 66 85 65 / 0 30 10 50 10 Tri Cities Airport, TN 60 85 63 82 63 / 10 30 20 70 10.
335 PM CDT Mon Aug 17 2020 The overall pattern includes a trough from the Hudson Bay to the Great Lakes region and into the Appalachian Mountains; there is the persistent dominating ridge across the western third of the CONUS which has led to record heat in locations across the Desert Southwest and heat advisories and warnings all the way into Washington, Idaho and Montana.
The upper ridge remains in place over the western U. with several weather short wave troughs topping the ridge and moving across the high plains and plains states region.
1110 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.
The upper level flow pattern has the area under northwesterly flow with ridging out west and troughing to the east.
137 PM EDT Mon Aug 17 2020 Thunderstorm chances remain at typical mid-August levels 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.
1218 PM 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.
Not anticipating anything to become severe in this region, due to limited SBCAPE less than 500j/kgIn addition, there is some convection trying get going along the Pine Ridge in the northern Panhandle and southern Niobrara county. The rest of the evening should be fairly quiet due to the influence of the upper level ridge. As a result, it could trigger some more convection along the Pine Ridge.
310 PM EDT Mon Aug 17 2020 Water vapor imagery highlights an upper low drifting northeast near the Cay Sal Bank, contributing to upper level northerlies across the Keys. A mid to upper level trough is punching south through the central Gulf of Mexico. The radar scope is clear, skies are mostly sunny, and temperatures are in the lower to mid 90s. The upper low near the Cay Sal Bank will kick to the northeast tonight and Tuesday. Meanwhile, the subtropical ridge will slowly reconsolidate across South Florida.
105 PM EDT Mon Aug 17 2020 A secondary cold front move across and settling south of the area later today.
Skies will become partly cloudy during the late afternoon as a broken cumulus deck should form with sufficient boundary layer moisture and the 850 mb thermal trough still overhead.
Will monitor temp trends as it's possible we may end up a bit warmer than even yesterday, but so far things are on track. 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.
Upper level northerly flow will continue through the week with dry conditions expected in the lower levels.
However, model dewpoint depressions do support the relatively drier air attempting to work into the lower levels.
Tuesday: Through the rest of the week, we will remain under the influence of an upper level ridge sitting over the southwest United States.
1039 AM CDT Mon Aug 17 2020 Upper level high pressure centered off to the west leaves the forecast area in benign northwest flow. Delightful low dewpoint air will make for a great afternoon with high temps in the lower 90s across most of the area.
The mid level trough axis moves through the region on Tuesday, which should provide plenty of lift for scattered convection to develop. With mostly cloudy skies anticipated, high temperatures should struggle to reach the lower 80s in many locations.
353 PM CDT Mon Aug 17 2020 Tonight and tomorrow: As a steep and stagnant upper ridge continues to reside over the desert southwest, light NW flow will remain apparent over ArkLaMiss this evening and into tonight. Dry conditions will prevail for most of the region tomorrow but can't completely count out a stray shower or storm in the northern portions of our region tomorrow afternoon as a weak surface front associated with increasing upper troughiness over the eastern half of the US swings into the ArkLaMiss. Highs on tomorrow should reach the low 90s areawide.
154 PM PDT Mon Aug 17 2020 Strong high pressure over the southwest states early this week will weaken a little for the latter half of the week. There is a slight chance of thunderstorms, mainly near the mountains and across the high desert, each afternoon and evening with coverage and chances a little greater on Tuesday.
330 PM EDT Mon Aug 17 2020 A secondary cold front move across and settling south of the area later today.
Much warmer air moves into the Dakotas on Tuesday with temperatures in the 80s with some 90s possible. These higher temperatures might be able to get into some parts of far western Minnesota, but much of the area will remain in a cooler airmass. This cooler airmass will be more stable making thunderstorms less likely. The overall pattern across CONUS continues to be dominated by a large upper low and ridge over the western CONUS.
1015 AM CDT Mon Aug 17 2020 Late morning analysis shows the region under the influence of a highly amplified broad upper trough that stretches across much of the East CONUS. Despite the mild CAA ongoing today in the low levels, temperatures appear poised to rise into the upper 80s to lower 90s at most locations under mostly clear sky cover. 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.
This activity is forming along a weak cold front that has moved through the area. Temperatures have climbed into the low to mid 90s with northeast winds behind the front.
/Tonight through Tuesday Night/ Pattern over the next three periods will be characterized by dry high pressure at the surface and aloft maintaining mostly clear skies areawide. Additionally, a cooler airmass in place will bring overnight low temperatures down into the upper 60s to around 70 both tonight and Tuesday night with afternoon highs on Tuesday in the lower to mid 90s.
336 PM CDT Mon Aug 17 2020 High pressure across the area has kept the area clear with light winds. As the high moves off to the east, winds will turn more toward the south, but should remain fairly light through the evening. An upper level ridge holds steady in the western CONUS through much of the period, then builds a little further to the east during the weekend and into Monday. With the ridge in the west, this area is mainly under northwest flow. There are a few on and off chances for thunderstorms as upper level waves move across the ridge and dive south across the area.
Only a few showers will linger over the Lower Atchafalaya Basin area this morning, then this afternoon an isolated shower or two may occur with the seabreeze, which should be confined to right along the coast with the synoptic north flow.
Weak low and trailing trough moving through eastern Iowa into Illinois/Indiana by 00z tonight. Winds have been mixing to near 30 mph at times behind the trough with clouds filling in due to enhanced lift. Otherwise tonight winds will decouple and skies should clear with cooler temperatures. H850 "cool" air advection increasing now with temperatures aloft bottoming out around 06z then rising slowly west as the ridge axis drifts a bit east by 12z. Cool overnight mins in the lower 50s northeast to the mid/upper 50s central and west. On Tuesday, temperatures will remain cooler east/northeast with warmer readings expected west.
1037 AM CDT Mon Aug 17 2020 A 600 dam ridge is anchored over the Southwest CONUS this morning with a trough over the Great Lakes. Dewpoints are currently in the low to mid 60s across most of the CWA and will likely drop a few more degrees this afternoon, pushing minimum relative humidity to 30-40% in many areas. 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.
Issued by National Weather Service San Angelo TX 238 PM CDT Mon Aug 17 2020 Cooler conditions with scattered storms today will turn mostly hot and dry as we go through the week, with a couple exceptions. A very amplified upper ridge over the West has allowed several disturbances to move south across the area the last couple of days. Another disturbance now moving into the area combined with a weak cold front will bring our next chance of rain.
Temperatures will remain warm with highs in the low 90s and a few locations might sneak into the mid 90s depending on the degree of mixing we see each afternoon. Fun fact, the highest temperatures so far this year in Mobile is 95.
/issued 1037 AM CDT Mon Aug 17 2020/ A 600 dam ridge is anchored over the Southwest CONUS this morning with a trough over the Great Lakes. Dewpoints are currently in the low to mid 60s across most of the CWA and will likely drop a few more degrees this afternoon, pushing minimum relative humidity to 30-40% in many areas. 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.
1215 PM CDT Mon Aug 17 2020 VFR conditions to prevail across area terminals as surface and upper-level high pressure build across the region. /issued 1012 AM CDT Mon Aug 17 2020/ Surface and upper-level ridge to rebuild across the region today. Temperatures forecast to climb into the low to mid 90s today with north winds around 5 mph. 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.
1238 PM 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.
1230 PM CDT Mon Aug 17 2020 Sensible weather will largely be tranquil with any precipitation potential coming along a cold front this afternoon and evening. A cold front remains north of the area through early afternoon, allowing temperatures to climb into the 80s, all before encroaching on northern sections of the CWA (Quincy) around 20z. Low temperatures Tuesday night will be quite certainly an open-window kind of night! Maples The upper ridge will continue to dominate over the southwest U.
Generally dry, seasonable weather is expected midweek as high pressure builds. Dry weather is expected this morning amid brief upper ridging in the wake of an early-morning trough. 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. As these move slowly sewd, they may encroach on the I-80 corridor and into the OH zones before waning toward evening as heating diminishes and the trough axis shifts ewd. 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.
205 PM CDT Mon Aug 17 2020 An upper ridge entrenched across the western third of the CONUS will keep conditions dry and hot through the short term.
Cooler air will spread in from the north overnight as the low departs. Highs will be a bit cooler with mid 70s lakeside to around 80 well inland across north-central IL. The result will be a continuation of pleasant summer conditions with light winds, plenty of sun, and highs in the mid 80s (locally cooler along the lakeshore). This weekend, the deep ridging that has been in place across the western United States will finally start to drift eastward placing the Great Lakes more or less in northwest flow aloft.
Expect mostly clear skies with lows tonight in the low to mid 60s and highs Tuesday in the low to mid 80s.
Winds have been gusting to 20 to 23kt behind a trailing trough and will continue this afternoon. Otherwise high pressure will build into the region tonight with cooler temps and light winds.
An upper level high pressure centered to the west has left the area in northwest flow. /Issued 1039 AM CDT Mon Aug 17 2020/ Upper level high pressure centered off to the west leaves the forecast area in benign northwest flow. Delightful low dewpoint air will make for a great afternoon with high temps in the lower 90s across most of the area.
1227 PM 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.
227 PM CDT Mon Aug 17 2020 Cold front has pushed into southeast Oklahoma this afternoon with boundary briefly stalling in the higher terrain across northwest Arkansas.
Latest hi-res guidance have backed off on storm potential this evening, especially at the lower elevations, hence have decreased coverage for isolated, dry thunderstorms and mostly kept it in the mountains and foothills. Although slightly cooler (bringing those temperatures down to the upper 90s!) conditions will remain very dry.
An expansive midlevel ridge axis continues to anchor across the western half of the US, yielding hot and dry conditions.
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. Winds will decrease around sunset, and gradually become southeast across western Minnesota as a low pressure system approaches from the west.
Dry conditions are expected to continue through the remainder of the day, but increasing clouds and precipitation chances will begin tonight ahead of a cold front current in the Midwest. The best chances for showers and storms during this timeframe will be along and south of the Western Kentucky/Bluegrass Parkways, within the vicinity of the cold front. The main weather feature for most of the week will be the exceedingly hot and dry upper ridge over the Intermountain West, with broad trofiness over the eastern CONUS.
311 PM EDT Mon Aug 17 2020 Mid/upper level troughing will remain over the eastern U. south into the central Gulf of Mexico for much of the week then drift west some as ridging tries and builds over Florida from the east late in the week into the weekend.
Tonight and Tuesday The latest RAP analysis and satellite/radar imagery show a large trough positioned over the central Great Lakes. But thermal troughing over northern WI has led to more convective clouds with the heat of the day. Looking upstream, high pressure is positioned across the Plains where skies are mainly clear. High pressure will be centered over the region. Slightly cooler highs in the low to mid 70s. But as warmer and more muggy air slides closer to the region, the threat of severe weather will gradually increase through the weekend.
Strong high pressure aloft centered over the Great Basin will maintain hot temperatures and dry conditions across the region through midweek. Strong high pressure remains centered over Utah this morning. Given the position of the high center over Utah, moisture will continue to rotate around it and largely remain out of Utah.
Strong upper level ridge continues to impact the West, with near record high temperatures expected. Wildfire smoke is wrapping around the high pressure and is notably higher than yesterday on satellite.
This combined with southerly flow may cause a rogue thunderstorm or two to develop along the Pine Ridge this afternoon. 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.
Dew points during the day got into the lower 60s, so cross over temperatures indicate that fog is certainly a possibility tonight into the early morning hours.
High pressure will be centered over Utah. For now, could not argue against the low slight chc pops offered by the NBM and have retained them in the grids for Tuesday night.
244 PM CDT Mon Aug 17 2020 Cooler conditions with scattered storms today will turn mostly hot and dry as we go through the week, with a couple exceptions. A very amplified upper ridge over the West has allowed several disturbances to move south across the area the last couple of days. Another disturbance now moving into the area combined with a weak cold front will bring our next chance of rain.
As a weak cold front approaches and stalls just north of Deep South Texas this afternoon, winds across the Rio Grande Valley will remain light and variable. 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.
/issued 244 PM CDT Mon Aug 17 2020/ Cooler conditions with scattered storms today will turn mostly hot and dry as we go through the week, with a couple exceptions. A very amplified upper ridge over the West has allowed several disturbances to move south across the area the last couple of days. Another disturbance now moving into the area combined with a weak cold front will bring our next chance of rain.
From a synoptic perspective, a strong and broad upper level ridge over the Southwestern United States is responsible for the region-wide excessive heat.