Aikyam-Lab/Synoptic-Bench huggingface dataset:
A few showers or thunderstorms are possible over the higher terrain and far southeast Montana this afternoon. Temperatures will be almost 10 degrees cooler today than yesterday with highs in the upper 70s to 80s. High pressure will build over the region on Wednesday, with a weak disturbance undercutting the ridge producing a few showers and thunderstorms over the mountains during the afternoon.
Wake winds from the tropical storm are out of the west, which is producing downslope subsidence and lack of cloud cover east of the Blue Ridge and into the piedmont. then as heating persists yielding to deeper convection and chance for a thunderstorm or two along a weak cold front that is progged to cross the mountains from the northwest. This is warmer than yesterday but seasonal with respect to normal. High pressure will reside over the Ohio River Valley on Wednesday, while a frontal boundary will remain stalled along the East Coast. Meanwhile, an upper level trough will linger east of the Mississippi River.
Northwest flow around the upper low over south central Canada will send another piece of energy into southeast Montana this afternoon. Cooler day in store today with highs in the lower to mid 80s. A few showers or thunderstorms are possible over the higher terrain and far southeast Montana this afternoon. Temperatures will be almost 10 degrees cooler today than yesterday with highs in the upper 70s to 80s. High pressure will build over the region on Wednesday, with a weak disturbance undercutting the ridge producing a few showers and thunderstorms over the mountains during the afternoon.
259 PM EDT Tue Aug 4 2020 A weak cold front will cross the central Appalachians from the northwest tonight, then stall and dissipate Wednesday. The remainder of the week will feature building high pressure aloft which will result in typical summertime weather favoring near seasonal temperatures and scattered afternoon and evening thunderstorms. Scattered showers and a few thunderstorms are expected this evening associated with a cold front that is crossing the mountains from the northwest.
Otherwise, isolated to widely scattered thunderstorms will develop over and near the mountains this afternoon and move east across parts of the lower elevations. Models show a push of cooler air into the north this morning and this cool front moves into the central zones this afternoon and into the south this evening. High temperatures will be cooler over the north and central today with 80s. In the southwest and far west, highs will be slightly cooler but still in the 80s.
Northerly winds are slowly diminishing this afternoon and that trend will continue into this evening as high pressure slowly builds into the area tonight. Dewpoints have dropped into the mid/upper 40s across much of the area this afternoon and as the high builds in tonight. winds will become light and variable or calm across much of the area allowing low temps to drop into the lower 50s away from the immediate metro area. as expected that some upper 40s will be possible in outlying/usually cooler spots by sunrise.
126 PM EDT Tue Aug 4 2020 Crossing low pressure will support periods of showers with some thunderstorms today. Building high pressure will then return sunshine and seasonably cooler temperature Wednesday through late week. Mosaic radar imagery suggests scattered showers and isolated tstms beginning to develop across the region as a cold front approaches. Provided breaks in cloud cover within the warm sector, coverage should increase by afternoon as a sfc cold front begins a slow trek across the forecast area.
SHORT TERM (Tonight through Wednesday Night): Ridging at all levels will dominate across the CWA through the short- term forecast period.
A large upper level low continues to sit and churn over eastern Ontario/northwestern Quebec, with a strong ridge in the west, centered over the Four Corners Region. At the surface, high pressure has been steadily building into the area today and weak cold/dry air advection continued through the morning and early this afternoon.
352 PM CDT Tue Aug 4 2020 Latest UA analysis shows the large scale trough over the eastern CONUS, with the main trough axis extending fm the Great Lakes to the lower MS Valley along the Gulf Coast. While some drier air aloft has spread over the region in the wake of the trough, GOES TPW imagery shows deeper moisture (PWAT near 1. The eastern CONUS trough will gradually begin to de-amplify on Wednesday as the Bermuda ridge builds west into the Gulf while subtropical ridging acrs the Desert SW builds east. However, nwly flow will persist acrs the region on the eastern flank of the SW ridge, sending another weak impulse over the area.
Given this scenario, we are messaging the possibility of isolated strong to severe thunderstorms along and west of the Highway 83 corridor, all the way northward to the Canadian border, with the main threat being large hail up to half dollars.
200 PM EDT Tue Aug 4 2020 Tropical cyclone Isaias will continue north northeast into southeastern VA through early this morning. A slow moving cold front is expected to stall over central NC Wednesday afternoon and evening. Lows generally in the lower 70s, with some upper 60s in the north-central Piedmont.
305 PM EDT Tue Aug 4 2020 A cold front will approach the area overnight and stall out over central NC through the rest of the work week, allowing a more typical summertime pattern of afternoon and evening thunderstorms. Lows will be in the low to mid 70s. Today's cold front will stall across central NC tomorrow, allowing for scattered showers and thunderstorms to continue during the afternoon and overnight.
246 PM CDT Tue Aug 4 2020 The amplified upper-level trough extending from southern Canada into the central U. As a result of this cooling, and light surface winds under the high pressure, patchy radiational fog is possible across eastern Missouri and southwestern Illinois for a few hours before sunrise. Tomorrow's high temperatures will be similarly much cooler than normal across the region, with 850mb temperatures remaining anomalously cool. The afternoon may be a tad warmer than today, given the slightly diminished cloud cover and slow advancement of a low-level thermal ridge over the area from the west. Remaining under the influence of high pressure, a lack of forcing and little instability to speak of will curtail any chance of precipitation through Wednesday night.
1023 AM MST Tue Aug 4 2020 Updated Aviation High pressure will persist across the Desert Southwest this week resulting in a continuation of the well above normal temperatures and dry conditions. Daily high temperatures across the lower deserts will mostly range from 107 to 112 degrees for the bulk of the week. The strong upper level ridge that has brought just over a week of well above normal temperatures continues to weaken while also getting pushed southeastward due to an approaching dry trough off the California coast.
Further west, model soundings indicate much warmer air at 500 mb which would limit vertical growth, plus the 700 hPa 3210 dm ridge is also depicted by regional/global guidance to edge into the region, further suppressing precipitation chances.
An upper trof over the Eastern States weakens somewhat through Wednesday but otherwise remains in place. A weak cold front currently extends from southeast Louisiana to across the forecast area into northern Georgia and will slowly advances southward to near the coast of the forecast area this evening then into the near shore waters overnight. Have made some small upward adjustments to daytime highs for the remainder of this afternoon which still range from the lower to mid 90s.
High pressure will exit to the east today. CAPE is not overly impressive except in a narrow corridor in the trough. Temperatures will remain a bit below average in the upper trough with highs in the upper 70s to lower 80s today. In the upper levels, the upper ridge over the rockies weakens somewhat as it shifts towards the midwest, creating a bit more zonal flow by the weekend.
236 PM MDT Tue Aug 4 2020 Weak moisture and energy present in northwest flow over the east and to the south, over the higher terrain. Temperatures should be a touch warmer with upper 80s to near 90 degreas expected.
A weak, dry cold front will stall across central Utah today. A dry southwesterly flow aloft prevails across the forecast area this morning, between amid level ridge axis located across the Four Corners/Colorado Plateau region, and an upstream trough situated along the Pacific Coast. This will keep temperatures along the Wasatch Front below triple digits for the first time in a few days, while temperatures remain in the 100-105 range across the lower elevations of southern Utah.
Tonight and Wednesday Diurnally driven afternoon cumulus clouds should dissipate shortly after sunset across northeast Wisconsin as high pressure slides south of the area. Temperatures will rebound a bit on Wednesday as the high drifts south and the area experiences some warm air advection as winds back to the southwest throughout the day. This will allow high temperatures to rise into the lower to middle 70s.
Models have been having a tough time with precip forecasts, with the GFS adding erroneous showers overnight the past couple nights, while the NAM underdoing the daytime precip for the higher elevations.
420 PM EDT Tue Aug 4 2020 An upper trough will advance through the eastern states as Tropical Cyclone Isaias ejects northeast along the eastern Seaboard and into New England. Highs both today and Tuesday should be in the lower to mid 90s for inland areas, with lows around 75-80. Latest model solutions depict a mid-level trough dominating most of the eastern seaboard and into the Florida panhandle for the end of the work week. Simultaneously, an area of high pressure will slowly build back into the area, though the far western periphery of the high barely makes its presence known, keeping a W component in the winds, i. By the weekend, the aforementioned ridge expands more west, giving us that typical east flow and pushing us back into our typical summertime pattern with afternoon sea breezes.
Cooler and drier air in place tonight will result in overnight lows dropping into the 60s. Broad mid level trough over the MS and OH valleys will begin to break down moving forward as ridging occurs over the Gulf of Mexico.
355 PM CDT Tue Aug 4 2020 This afternoon, broad upper troughing remained across the eastern CONUS with upper ridging over the southwest US.
/This Afternoon/ The morning sfc analysis indicates that our weak sfc front has mixed just S of the region into SE TX and SCntrl LA, with the onset of mixing allowing for the drier air noted in the lowest 7kft (as noted in the 12Z KSHV raob) to mix down to the sfc. Sfc ridging has also begun to build S into the area this morning from the Cntrl Plains, which will help to maintain the cooler than normal dewpoints in across the region. Some areas of AC and cirrus remains progged to continue spilling SE into SE OK/portions of E TX and Wrn LA in the NW flow aloft behind the parent longwave trough along the Mid and Lower MS Valley, while the stratocu field noted over Wrn and Cntrl AR gradually advects Swd along a H925 trough.
(This evening through Wednesday) Still expect storms to move off the high plains late tonight initially into western northwestern OK, and then spread/develop southeastward into central OK.
222 PM EDT Tue Aug 4 2020 A weak cold front exits east this evening. High pressure sails north of the area late week, and then builds down the eastern seaboard. Weak cold front exits east of the mountain later this evening with little convection associated with it. This high will be take control of weather conditions through the end of the period, allowing for only low probabilities for showers or storms confined across the eastern mountains during the afternoon hours Wednesday. Temperatures will remain near normal for this time of the year generally in the mid to lower 60s for lows tonight, and mid 80s across the lowlands for Wednesday afternoon. An upper level trough continue to hold over the area and models indicate some moisture present, mostly along the southern and eastern parts of the area.
The synoptic pattern has changed little over the past 24 hours, w/an upper ridge still centered over SE AZ/SW NM, and extending up thru the wrn CONUS. A trough just off the west coast is still slated to make landfall by 12Z Wed, and this will nudge the ridge into West Texas and Southeast New Mexico. Given that, Heat Advisory criteria is right on the fence on the lower threshold. Models continue nudging the ridge east, to central Texas by 00Z Sat, before it begins building back west into the extended. Rain remains elusive, confined mainly to the higher terrain for the next day or so. But chances remain minimal until the ridge breaks down.
Models indicate the upper ridge will be the dominate feature.
Lows will be in the lower 70s. A trough to the west continues to approach on Wednesday with southwesterly winds aloft bringing more moisture into the area. Convergence between the trough and the east coast seabreeze will cause higher rain/storm chances in the eastern half of the area. Highs will be in the lower to mid 90s with heat index values around 99-102.
443 PM EDT Tue Aug 4 2020 Crossing low pressure will support periods of showers with some thunderstorms into this evening. Building high pressure will then return sunshine and seasonably cooler temperature Wednesday through late week. Scattered to numerous showers, and a few thunderstorms, continue across the region this afternoon ahead of an approaching mid-level trough axis. This activity will continue eastward into this evening, eventually decreasing in coverage as instability is lost and as the trough axis swings through.
A touch of late September-like weather across the region this afternoon, as temperatures have only reached the lower 70s and dew points are steadily falling through the 50s and into the 40s in a few areas. With the low dew points, temperatures should fall into the lower 50s in many areas overnight, which will be near record levels in some locations (see Climate section below). Wednesday should see similar conditions to today, though a degree or two warmer in the afternoon.
230 PM EDT Tue Aug 4 2020 Tropical cyclone Isaias will continue north northeast into southeastern VA through early this morning. A slow moving cold front is expected to stall over central NC Wednesday afternoon and evening. Lows generally in the lower 70s, with some upper 60s in the north-central Piedmont.
Storm total precipitation is on the low side with QPF less than a quarter of an inch. Rain activity will diminish in the night as a weak ridge aloft builds in from the west.
500mb RAP analysis and water vapor imagery showed a ridge prevailing over the western half of the country with a trough dominating the eastern CONUS. Temperatures climb into the mid to upper 80s on Wednesday as the upper ridge builds east into the Plains. Long range guidance suggests that (1) an upper level ridge will persist over the Southern Plains and (2) that the mid-latitude westerlies will be confined to higher latitudes (i.
A broad ridge of high pressure stays planted over the western U. The ridge will remain over the Northern Rockies through Wednesday. On Wednesday night, the ridge shifts to east, resulting in southwest flow aloft.
Another cool night ahead, though a tad warmer than last night with lows in the 40s across cranberry/marshy areas of central WI to low to mid 50s elsewhere.
352 PM EDT Tue Aug 4 2020 A cold front will drift eastward into the mid-Atlantic States tonight as a low pressure trough persists over the eastern Great Lakes. High pressure to the west will gradually build east over the region Wednesday night and persist into the weekend. Meanwhile a surface pressure trough will persist across Lake Erie and lake induced instability will remain rather high with SBCAPE over 1000 J/KG given the rather warm lake waters in the 76-77 degree range. Cooler overnight lows in the 50s inland to near 60 along the lake are expected. High pressure will build into the region later Wednesday and Wednesday and produce clearing conditions with lower humidity. This will result in little to no chance for precipitation with slightly cooler to near normal temperatures expected.
For tonight, high pressure is expected to build into the region from the north and west. Overnight lows will drop into the mid-upper 50s with a few of the typical colder spots possibly dropping into the lower 50s. For Wednesday, high pressure looks to hold sway across the region with mostly sunny skies and dry conditions. High pressure will be over the Great Lakes region by Wednesday night, and slowly slide eastward through the forecast period. For the overnight period, light and variable winds are expected along with mainly clear skies with high pressure building in.
238 PM CDT Tue Aug 4 2020 An upper-level anticyclone was centered over the Four Corners, and is drifting eastward.
The highest risk of large hail/damaging winds will be across these far western zones (roughly west of US 83), and relatively early this evening per SPC's 1630z outlook. Below normal temperatures will continue Wednesday afternoon, ranging from the lower 80s east, to mid 80s SW zones. A strong 594 dm upper high is forecast to be centered near Midland, Texas Wednesday evening.
This is tied to a developing speed max, albeit weak, as Isaias begins to phase with the upper trough over the eastern US. Most of the precip today should be focused over the valley and points east as a cold front is already positioned over the plateau region, and trended PoPs in this direction. CD Chattanooga Airport, TN 68 89 68 89 68 / 10 30 10 20 10 Knoxville McGhee Tyson Airport, TN 67 87 67 88 68 / 10 30 20 40 10 Oak Ridge, TN 67 87 66 88 67 / 10 30 10 30 10 Tri Cities Airport, TN 63 85 64 85 65 / 10 50 20 60 20.
Concur with the deterministic runs that the upper ridge will build, and drying will continue, over the region from the west during the period.
Flow aloft will become southerly and increasingly moist Wednesday as a weak Pacific upper trough comes inland via California. Wednesday will be hot with high temps 95-100 in the lower valleys.
207 PM CDT Tue Aug 4 2020 A welcome relief from the summer heat continues this afternoon and will continue through tomorrow thanks to influence from a deep 500mb trough over the eastern half of the US. Sinking air on the backside of the trough is allowing for higher surface pressures this afternoon and, as a result, mostly clear to partly cloudy skies with light winds. A baroclinic zone embedded within the the northwesterly flow of the trough was evident on satellite with it located over central Oklahoma and extending southeastward into far SE OK over Pittsburgh, Push, and Choctaw counties.
However, instability is a lot less certain with clouds possibly keeping west central MN in the low 70s or even cooler. At this point think that the threat will be mainly non-severe showers and thunderstorms but can't completely rule out something funky happening under the center of the upper low. The precip will move quickly off to the east as the system exits through MN and we get ridging building back into the Western Plains. As this is going on a broader Pac NW trough will be heading toward the northern Rockies before sweeping well up into Canada over the weekend. High pressure moving off to the east will allow southeast winds to pick up to the 8 to 12 kt range this afternoon if they haven't already.
A weak short wave trough dropping SE as the Atlantic ridge builds west toward Florida to the south of departing Tropical Storm Isaias.
Increasing moisture along with an upper level trough and higher daytime temperatures Wednesday through the weekend will result in chances of showers and thunderstorms each day. Upper level trough will be slowly moving toward the forecast area from the central Gulf States with weak southerly flow continuing to advect moisture into the area. With short waves rotation through the trough axis expect increasing chances of showers and thunderstorms.
218 PM MDT Tue Aug 4 2020 Small upper low over Sask this afternoon will move southeast tonight. A ridge will then move in Wednesday while a broad trough will begin to move in from the West Coast.
Surface analysis this afternoon places a weak cold front over portions of Middle Tennessee, Northern Alabama, Northeast and Central Mississippi. GOES-16 Satellite trends still indicate some residual post-frontal stratus over the area with temperatures in the lower to middle 80s over Northeast Mississippi and 70s elsewhere. /issued 252 AM CDT Tue Aug 4 2020/ A cold front continues to push through the Mid-south this morning. Thereafter, temperatures will begin creeping back up as an upper ridge over the Southern Plains begins building eastward into the weekend. There remains some differences amongst the models on how far east the upper ridge will build.
Models are in rather good agreement activity will develop along instability axis/0- 3km lapse rates ahead of a cold front from eastern SD to n-central NE.
This Afternoon: The area will remain in a west-southwest mid-lvl flow between a trough of low pressure extending across the Midwest/Deep South and a ridge of high pressure centered well offshore across the western Atlantic. Afternoon high temps should range in the low/mid 90s away from the coast, warmest across Southeast Georgia. These temps combined with sfc dewpts in the low/mid 70s, support heat index values around 105 degrees along the I-95 corridor in Southeast Georgia. Tonight: The mid-lvl trough axis of low pressure will approach from the west. The area will remain in a weak troughing pattern which will lead to at or above normal rain chances each day given the deep moisture continuing in place. This Afternoon and Tonight: A weak pressure gradient will prevail between high pressure across the western Atlantic and a trough of low pressure well inland.
A cold front was located from just southeast of Nashville through the northwest tip of AL into central MS. Showers and thunderstorms should end within a few hours of sunset this evening, as a drier and more stable airmass is advected into the region in the wake of the cold front. Although dewpoints in the l-m 60s would normally result in cooler low temperatures than we have indicated in the grids, it does appear that a 2-3 mb pressure gradient will support at least light NNE flow throughout the night, and with indications of lingering mid-level cloud cover we have kept temps generally in the mid 60s.
However, expect the current SHRA along the cold front and in advance of the front to become TSRA soon.
Quiet conditions to persist for much of the overnight as surface ridging slides gradually east of the state with good radiational cooling once again. Models continue to show a weak upper low across the Dakotas sliding southeast tonight and towards northern Iowa by later Wednesday. Mid level forcing increases slightly in the north by later in the day with the approach of the low and this should support some isolated to scattered convection in the late afternoon/evening with propagation southeast into the CWA.
117 PM CDT Tue Aug 4 2020 High pressure continues to hang around the area resulting in another gorgeous day.
358 PM CDT Tue Aug 4 2020 Rather straightforward typical summertime regime at the surface despite upper level large amplitude troughing over the eastern U. and high amplitude ridging in the west.
However, those surface dewpoints in the lower 70s are actually a little slower to dry out compared to yesterday at this time. Prior discussion below: Today and tonight: A relatively drier airmass remains in place across the region today, yet a lingering upper trough remains overhead.
The low-level jet really isn't very strong tonight and there is a lack large scale lift. Otherwise warmer temperatures (mid to upper 80s) expected Wednesday as heights slowly rise with the upper ridge building northward. The axis of the ridge will be oriented south to north across the Rockies. Low-level moisture will also be slowly increasing with dew points rising into the lower 60s.