Aikyam-Lab/Synoptic-Bench huggingface dataset:
952 PM CDT Thu May 21 2020 High pressure to our east along with low pressure developing over the high plains will continue to produce moisture into the area from the south. Temperatures to remain on the warm side during this time frame with the warm air moving into the area, and afternoon highs should get back into the low 70s on Friday.
/issued 333 PM CDT Thu May 21 2020/ The persistent, closed upper low over the OH Valley will finally begin to lift north tonight as the Rex Block weakens with the upper-level ridge over the Great Lakes shifting east. We'll continue to see a few showers through early evening, but the effects of the approaching trough will be felt overnight into early Friday. Lift will be enhanced by warm advection in the lower troposphere, resulting in scattered showers and thunderstorms after 06z and continuing into early Friday before diminishing from west to east around midday. A few of the CAMS indicate a second round of storms moving into the area during the afternoon, the remnants of an MCS that will develop across the High Plains this evening.
The upper low over the OH Valley should continue to pivot north keeping these clouds in place through Friday. MVFR cigs are building back northward as the low stratus deck moves over all of southern WI. Forecast confidence is medium to high: It should stay mainly dry through Friday night, as weak high pressure lingers over the Great Lakes. Persistent onshore winds should keep it cooler in the east.
Highs tomorrow look to be slightly cooler than today by about 5 degrees or so.
The closed upper low over northwest Washington will open to a tiled trough, and swing through the region tomorrow.
The cutoff upper low is centered over south central KY with the most concentrated showers moving towards it from northern middle TN moving northeast across the northern plateau. TD Chattanooga Airport, TN 61 78 64 86 66 / 30 60 30 40 10 Knoxville McGhee Tyson Airport, TN 58 76 63 83 65 / 30 70 30 50 20 Oak Ridge, TN 57 75 62 83 64 / 30 70 30 50 20 Tri Cities Airport, TN 52 74 59 80 60 / 20 70 50 40 20.
Isolated/scattered activity is expected by tomorrow afternoon via the seabreeze and/or any em- bedded disturbances aloft (as the upper ridge has flattened). High temperatures should range from the lower to mid 90s inland; mid to upper 80s along the coast. The slow eastern progression of an northern Great Basin upper trough/low will lower Southern Plains heights and finish what is left of late work week shallow upper ridging.
The low clouds will begin to lift with all sites becoming VFR after 15Z. /27/ Prior discussion below: A warm front is progressing north across the region, ushering in very muggy air from the Gulf. As the afternoon progresses, this may need to be revisited as the dwpts in the SE are still in the lower 70s.
The low will finally work its way into Ohio tonight, drying things out overnight. A warm front will cross the area Friday night, leaving overnight lows elevated in the mid 60s. The associated low pressure system positioned to the northwest will bring a line of showers and storms to the area late Friday night towards Saturday morning. Also over time, the pattern does evolve to where high pressure aloft strengthens its grip upon the Commonwealth. With the 06z Friday WFO PAH TAF issuance, most of the TAF locations will be sandwiched between the western limb of the upper low to the east and northeast and an approaching southwest to northeast oriented trough axis to the west during the first 12-15 hours of the forecast period.
The upper low bringing the rain chances the past few days is lifting northward and losing its hold across the area. Friday will be a return to southerly flow at the surface with weak ridging aloft and diurnally driven afternoon and early evening convection associated with the sea breeze circulation. Mostly hot and dry conditions are expected in the short-term period as low-amplitude ridging replaces the departing upper-level low. High temperatures are forecast to be in the low 90s (upper 80s where precipitation persists) with the Tallahassee area seeing heat indices close to 100.
Temperatures are going to warm up to the lower 80s with surface dewpoints 60 to 65.
Isolated/scattered activity is expected by tomorrow afternoon via the seabreeze and/or any em- bedded disturbances aloft (as the upper ridge has flattened). High temperatures should range from the lower to mid 90s inland; mid to upper 80s along the coast.
251 AM CDT Fri May 22 2020 A cut-off closed upper low over the Ohio Valley will finally lift out today, allowing stronger westerlies to return to the Midsouth. In the interim, a warm front will lift through northeast AR and west TN this afternoon, perhaps providing focus for storms. NAM Bufr soundings depict MUCAPE in excess of 3000 J/KG in the vicinity of the warm front, accompanied by 3KM bulk shear of 30 knots. Saturday will see robust upper level ridging centered over GA, and isolated showers and pulse thunderstorms under the western periphery of this strong ridge.
Low temperatures in the low to mid 50s. The NAM is slower eroding the low cloud cover from southwest to northeast through the day compared to the GFS.
Showers have ended across the Columbia Basin this evening, but a few will remain possible overnight into tomorrow, mainly over the higher terrain and possibly into the Bend/Redmond area. Scattered showers possible over the higher terrain, but should mostly evade the terminals.
252 AM EDT Fri May 22 2020 High pressure will maintain dry and seasonably warm conditions across the North Country through the holiday weekend.
Warmer with a chance for thunderstorms expected Saturday. Models also show slight chances for light showers much like yesterday with the highest chances focused across NW Ohio, far NE Indiana, and SE lower Michigan. Weak ridging builds over the area in the wake of the departing low overnight. A weak warm front is forecast to lift NNE across the forecast area during the day with S to SW flow at 850mb. Models show scattered convection developing along this warm front late Saturday afternoon/evening as the associated upper low moves across NE IA/S WI. Convection looks to become better organized as the upper low moves over Lake Michigan Saturday evening/overnight, especially for locations along and north of Hwy 30. General agreement exist between the GFS/NAM/ECMWF on the low tracking over central/northern Lake Michigan Saturday evening and delays convection until after 00z.
Upper low approaches southwestern Wyoming Saturday morning as the front moves into our western zones.
The cutoff upper low is centered over south central KY with the most concentrated showers moving towards it from northern middle TN moving northeast across the northern plateau. RG Chattanooga Airport, TN 78 64 86 66 87 / 70 30 40 10 50 Knoxville McGhee Tyson Airport, TN 76 63 83 65 86 / 60 30 50 20 40 Oak Ridge, TN 75 62 83 64 87 / 60 30 50 20 60 Tri Cities Airport, TN 74 59 80 60 83 / 80 40 40 20 50.
Scattered showers and isolated thunderstorms associated with an upper trough will continue through this evening. The center of the trough will move into our area on Friday, resulting in more showers. The bulk of the showers are expected in south-central Idaho in the vicinity of a cold front. At 22/02Z surface cold front along -KSNT-KWMC moving east. The area of low pressure aiding in the development of this activity will move across the forecast area through Friday evening, leaving additional opportunity for shower activity, including periods of snowfall above 5000 ft. On Saturday, the area of low pressure will move east of the forecast area, with a building northwest flow.
With the radar beam overshooting the low-topped cell, and with the goal to be as helpful and timely as possible, a special marine warning was issued for the near shore waters. Scud clouds form when a wet, cold downdraft meets the warmer surrounding air. It will be a cool start to Friday, and a couple or so degrees cooler in most locales on Saturday morning. Meantime, freezing temperatures are expected across the east side.
158 PM EDT Sun Sep 1 2019 High pressure will weaken north of the area as Hurricane Dorian moves slowly north along the Southeast U. Weak mid and upper level ridge over the region will slip east overnight as an upper trough over the Midwest moves east to the Appalachians. The ridge will move off the New England coast tonight.
The low levels have remained quite dry, which has supported ceiling heights mainly above 8000 ft.
The upper trough will slide northeastward today, but looks to at least provide enough lift for some partly cloudy skies and even a passing shower. On Monday, the trough will be over the east coast and Dorian looks to be beginning its track northward just off the FL coast.
Temperatures will remain above seasonable averages today but a cold front will bring cooler temperatures and windy conditions on Monday. A disturbance aloft will sweep through southern Canada on Labor Day with an associated Pacific cold front moving through the northern half of the forecast area Monday afternoon.
High temperatures are expected to range from the upper 80s to around 90 in the east to the low 90s along and west of the CO/KS border. Dry weather returns for the overnight hours with lows in the low 60s west to around 70 east.
348 PM CDT Sun Sep 1 2019 An upper level ridge across the Four Corners region will expand east across the southern Plains Tonight and Monday. The stronger upper jet will round the ridge axis across the northern US and southern Canada. The low- level WAA will allow high temperatures to reach the upper 80s to around 90 degrees.
Isolated thunderstorm may develop along a lee trough located from Montana to the Colorado/Nebraska border. Any storms that do develop along this trough will have a hard time sustaining itself as it moves east due to decent MLCIN. High temperatures will climb into mid to upper 90s for portions of western and southwest Nebraska, with the warmer temperatures across the southwest. Elsewhere, temperatures will range from the lower 80s across north central Nebraska to the lower 90s.
Monday-Monday night: Main forecast focus is still on severe potential as a much stronger trough moves in the region (generally depicted as negatively tilted) and strong forcing/shear environment overspreads our CWA. Further north of warm front/stalled front an MCS should develop and move in a east- southeast direction, and there is some concern of QLCS features due to strong orthogonal shear component and at the very least widespread heavy rain and strong winds.
We could have some of the activity linger into Monday morning, and then plenty of moisture flux before a cold front comes through will send dew points well into the 70s, giving us a heat index near 100 in some spots.
Upper ridging will continue to build tonight with light southerly surface winds.
Little change to the short term forecast with another day of above average temperatures expected across the NorCal interior as high pressure continues to influence the region.
147 PM EDT Sun Sep 1 2019 Scattered to numerous showers and thunderstorms are expected today and tonight with a crossing low pressure trough. Another crossing trough will maintain scattered shower and thunderstorm chances on Labor Day.
These were associated with an inverted trof moving through that area. Closer to home the 12z upper air charts placed the upper high near the four corners with favorable easterly flow over the area. The second area of concern this afternoon into this evening is from Tucson north as thunderstorms move off the higher terrain.
High pressure aloft locked in over the interior west will result in dry and hot conditions the next couple of days. This high pressure will shift east and allow moisture to spread north across Utah beginning Monday. The center of the rather strong and broad upper ridge will remain near the four corners region through Monday.
Our rain chances will diminish just as quickly as high pressure builds back in aloft after today, and Hurricane Dorian has modified the circulation across a broad region of the southeast U. Thus, with persistent high pressure aloft and scant moisture advection, our rain chances will remain at a nadir for several more days.
Upper level ridging will develop across the central and southern plains over the next several days.
139 PM PDT Sun Sep 1 2019 High pressure over Central California will keep the forecast area warm through Labor Day.
Upper ridging will build back over the area through the rest of the week and essentially end precipitation chances for most if not all of the region.
As the distance between the broad tropical wave and the hurricane shortens, a ridge will be produced and will become and extension of the ridge axis back toward the western CONUS.
Otherwise, warming mid-level temperatures in response to western CONUS upper ridging nudging a bit further east should support dry weather today, with afternoon highs a bit warmer than yesterday, reaching the mid-upper 80s.
Warm air advection into the region will allow for continued warmer temperatures across the region. Southwest Nebraska may even see the low 90s. These thunderstorms are expected to be weakly forced; however, with over 2000 J/kg of CAPE and plenty of low level moisture combined with the upper level warm front, an isolated thunderstorm cannot be completely ruled out.
Broad upper level ridging continues to support warm and very dry conditions across Southwest Montana. Temperatures will trend cooler along the HiLine with the passing front, but warm conditions continue one more day for most of central and Southwest Montana.
An upper ridge remains over the forecast area today though it is slowly drifting east as an offshore trough nudges it. Some cooler air has filtered into the area as the ridge axis drifts east and today should be 3-5 degrees cooler than yesterday with highs in the 80s and lower 90s.
229 PM CDT Sun Sep 1 2019 /Tonight/ North and Central Texas currently resides beneath the eastern edge of a mid level ridge, which is anchored over the Four Corners region for now. A weakness in the ridge over Central Texas is enough to allow for the development of isolated storms this afternoon, primarily south of I-20. A slight warmup is expected the second half of the week as the upper ridge builds overhead. Although a very weak cold front is still progged to move in from the northeast around midweek, it will do little more than bring slightly drier air and a subtle wind shift to the east/northeast.
1010 AM CDT Sun Sep 1 2019 Upper-level ridge to continue to build across the region today maintaining mainly dry conditions areawide. A weak surface boundary across southeast Oklahoma and deep east Texas to possibly trigger isolated convection this afternoon despite the ridge. Otherwise, afternoon high temperatures forecast to climb into the low to mid 90s. /Today through Labor Day/ The trend going forward into the month of September indicates a hot start with meager rain chances as the upper level ridge out to our west reasserts itself across much of the southern U. In addition, our extreme SE zones may also be skirted by afternoon convection shifting westward along an inverted trough. Overnight lows will generally range from the lower to mid 70s with mostly clear skies and light winds.
1158 AM CDT Sun Sep 1 2019 Upper level trof continues to move east and support showers with a few thunderstorms early this morning. Expect showers to gradually end from west to east this morning, then linger across eastern and southeastern portions of the CWA as the trailing trof interacts with the surface front. Have therefore trended cooler for temps today. Temperatures moderate on Monday as weak southerly flow returns to the area and an upper ridge begins to build into the region. Tilly Period begins with heights falling ever so slightly as a trof approaches the Upper Midwest.
Clearing skies will give way to slightly warmer temps today, though the overall air mass in place will undergo little change. Thus temps will once again remain below seasonal values, into the lower 80s this afternoon.
The quiet weather pattern should continue into tonight as the ridge over the Rockies continues to expand eastward. Winds will be light out of the southeast keeping the low level moisture plentiful and as a result dew points will fall into the low to mid 60s tonight and overnight low temperatures will fall into the mid to upper 60s.
However, an upper level trough axis pushing across Central Texas and part of the Hill Country late this morning is expected to utilize additional lift from a weakness area over the southern portion of the subtropical high currently centered over the desert southwest.
This is mainly in response to weak upper disturbances, and perhaps development of east winds as weak high pressure builds in from East Texas.
A weak mid level inverted trough is dipping down from the northeast this afternoon but will weaken as the night progresses.
Today/tonight, upper/thermal ridge amplifies modestly. Monday, upper ridge breaks down as upper trough zips across MT into the Dakotas.
With overnight lows warming from yesterday into the lower 60s north to the mid 60s south; highs tomorrow will climb into the mid to possible upper 80s south and in the lower 80s north.
Also removed showers over the northwest as best source of lift along warm front in MN and another front well west of our area in northeast Nebraska.
Labor Day is looking hot and dry, with highs in the low to mid 90s and mostly sunny skies. An upper level ridge will begin to migrate east across the desert southwest and bring with it, a prolonged streak of hot and dry conditions for most of our area.
The environment ahead of this trough/front is still quite dry, although we will see a sliow rise in dewpoints and low level moisture through the night. Quiet weather is expected to continue through the first part of September as we're under a relatively dry atmosphere and quasi- zonal to weak troughing pattern in the mid-levels.
221 PM MDT Sun Sep 1 2019 Latest upper analysis shows a building upper ridge over the western half of the CONUS this afternoon leading to rising heights over the forecast area. If any strong storms develop, expect it to occur near the intersection of the convergence zone along the higher terrain of the Black Hills and then shift southeastward depending into the evening hours. On Monday, the upper ridge will break down over the northern plains as an upper trough drops out of the Canadian prairie provinces and affects the Dakotas.
Record or near record highs look a good bet over the lower elevations Monday as sunshine and dry air allow temperatures to warm well into the 90s.
Surface analysis this morning places high pressure over the Tennessee valley and extending into portions of the Lower Mississippi Valley. Upper level high pressure begins to build in from the west.
This is due to sufficient moisture in the lower levels despite the subsidence from the mid-level ridge.
The lowest visibilities and denser fog will be along I-70 over central Missouri, but this fog will extend out in all directions.
For today, highs are on track to reach into the lower 90s most locations with scattered to numerous showers and thunderstorms possible this afternoon and evening.
High pressure will continue to dominate the weather across the Tennessee Valley region today, promoting tranquil weather and another hot/dry day to kick off the month of September. With a crystal clear sky (save for a few afternoon Cu), most locations should be able to warm into the lower 90s, with a couple of mid 90s readings possible. The upper trough will move east of the area tonight, as the ridge builds eastward from the west. Surface flow will back to the north during the day Monday, as high pressure settles in over the Great Lakes and Ohio Valley. The upper ridge will hold over the central CONUS, with its eastern flank over the TN Valley. The ridge in place should keep Hurricane Dorian well east of the area, with dry air and subsidence the only impacts over the local area.
1122 AM EDT Sun Sep 1 2019 Scattered to numerous showers and thunderstorms are expected today and tonight with a crossing low pressure trough. Another crossing trough will maintain scattered shower and thunderstorm chances on Labor Day.
657 PM EDT Sun Sep 1 2019 A crossing trough will bring another round of showers and thunderstorms to the region through tonight.
High pressure over Central California will keep the forecast area warm through Labor Day.
440 PM MDT Sun Sep 1 2019 H5 ridge axis continues to build overhead now through tomorrow, keeping skies clear and temperatures well above September normals. Winds will reach 15 to 20 mph for the lower elevations, while higher elevations will see winds of 20 to 30 mph with higher gusts during the afternoon.
530 PM MDT Sun Sep 1 2019 Latest upper analysis shows a building upper ridge over the western half of the CONUS this afternoon leading to rising heights over the forecast area. If any strong storms develop, expect it to occur near the intersection of the convergence zone along the higher terrain of the Black Hills and then shift southeastward depending into the evening hours. On Monday, the upper ridge will break down over the northern plains as an upper trough drops out of the Canadian prairie provinces and affects the Dakotas.
739 PM EDT Sun Sep 1 2019 A crossing trough will bring another round of showers and thunderstorms to the region through tonight.
948 PM EDT Sun Sep 1 2019 A weak cold front will move southeast across the region tonight into Monday morning.
Gusty winds in the higher elevations have diminished but will return Monday afternoon, otherwise winds will be light.
Chattanooga Airport, TN 68 91 70 92 / 0 10 0 10 Knoxville McGhee Tyson Airport, TN 67 89 67 90 / 0 20 0 10 Oak Ridge, TN 66 89 68 91 / 0 20 0 10 Tri Cities Airport, TN 60 87 62 89 / 0 20 10 10.
/Tonight through Monday Night/ Upper-level ridge to dominate the weather pattern in the short term ending Monday night.
Outside of the fog, conditions will be VFR all sites with low level wind becoming southerly/southeasterly all sites by end of the forecast, as lee trough develops through the Plains. Otherwise, a hot and humid week for September is in store across eastern Oklahoma and northwest Arkansas as a strong upper ridge builds over the area.
658 PM CDT Sun Sep 1 2019 A trough of low pressure and associated cold front in eastern Montana Sunday evening, will move east into North Dakota by Monday morning. The trough and cold front will be the focus for thunderstorm development. Some scattered showers and weak thunderstorms are just beginning to cross into both north-central and far western North Dakota, associated with a mid-level lee trough in central Montana and a cold front draped west to east across North Dakota. High-res models have a few brief showers form, but overall height rises from ridging aloft is likely hindering any major development in the next few hours. The better chance for thunderstorms begins late tonight, as the low-level jet quickly strengthens and helps provide a better source of lift.
923 PM EDT Sun Sep 1 2019 A crossing trough will bring another round of showers and thunderstorms to the region through tonight. Because of this, the instability in the lower dewpoint areas is markedly less then what was occurring earlier in the evening.
724 PM EDT Sun Sep 1 2019 High pressure will weaken north of the area as Hurricane Dorian moves slowly north along the Southeast U. Weak mid and upper level ridge over the region will slip east overnight as an upper trough over the Midwest moves east to the Appalachians.
The warm front has lifted just north of our area, leaving us in the warm sector with southwesterly winds. Isolated precipitation chances also exist tomorrow as a weak frontal boundary pushes through, but chances will mainly be confined to the Bluegrass region as the western ridge begins to expand across the area.