Aikyam-Lab/Synoptic-Bench huggingface dataset:
111 PM CDT Sun Sep 27 2020 An upper low continues to progress northeast through northeast AL and southern middle TN. Lower clouds will develop and advect northward late tonight as pressure falls develop in advance of the incoming cold front. An MCS will be ongoing to our west early Monday morning along the lower MS River valley along an approaching cold front. The associated upper trough will be lagging well behind the front. The cold front and most of the thunderstorm activity should be relegated to the cold frontal passage and just behind the front, with showers/rain lasting well into Monday evening.
200 PM CDT Sun Sep 27 2020 The main forecast concerns today remain the potential for a few severe storms tonight, as well as a period of strong and gusty northerly winds associated with a strong cold frontal passage late afternoon and into the overnight. The much anticipated cold front sits about a county northwest of the northwestern fringes of the forecast area per surface observations and satellite.
A cold front will move into the GLH area around sunrise and push into the GWO, JAN and HKS areas before the end of the period. The fog will dissipate and the low clouds rise through the morning, but the influx of showers will keep MVFR conditions through the end of the period. Temperatures today should be a few degrees warmer than yesterday. Rain chances will begin to increase late Sunday night as a cold front approaches the region from the west. By Monday morning the cold front should be on our doorstep and will move through the ArkLaMiss region during the day on Monday.
Skies were partly sunny and temperatures were mainly in the upper 60s, and coolest in the lower 60s at Imperial. An upper trough axis will drop southeast through the area this evening. Went colder for lows tonight in the lower to mid 30s western Sandhills and southwest. The upper flow will become northerly on Monday as an upper low and trough extend across the Great Lakes and Midwest. A strong upper ridge will extend from the Pacific Northwest into the Desert Southwest. Western Nebraska will remain on the warmer side of the airmass, and raised highs a few degrees to the upper 60s southwest, to the low 60s north central. Lows were dropped a few degrees to the lower 30s across the western Sandhills and southwest.
The first REAL cold front since last spring looks to be coming through the CWA Monday evening/night.
CIGs may begin to lower ahead of an approaching cold front late tonight into Monday. Have lowered CIGs to MVFR as the cold front pushes through with gusty northerly winds near 25 KTs expected.
The colder air for Monday and cloud cover will result in highs in the low to middle 50s.
Upper trof axis digging sewd across the Plains this aftn will continue into tonight, driving a cold front into our region. While widespread severe weather is not expected due to the elevated nature of the storms, strong lift associated with the trof may allow for a few storms to produce some hail or an isold damaging wind gust across our far nrn areas. Much cooler and drier airmass will bring temps some 10 degrees or so below seasonal normals for Monday/Monday night and beyond.
140 PM CDT Sun Sep 27 2020 An upper trough is coming through Middle Tennessee this afternoon, so we are seeing some cumulus clouds with just a smattering of light showers.
At the surface, high pressure will be to the northeast Today, with a weak inverted trough extending northeast across region from the gulf. At 500mb, a trough will pivot east across forecast area this afternoon, with short wave energy accompanying this upper trough. High pressure will be centered to the northeast Monday, continuing the moist onshore flow in the low levels. At 500mb the region will be in the base of a broad upper trough, with weak waves moving through the flow, with the flow aloft from the west southwest.
109 PM EDT Sun Sep 27 2020 Rain showers return late tomorrow with an approaching cold front. Areas that observe any periods of clearing may experience breezy conditions as the pressure gradient tightens ahead of an approaching cold front. But, the encroachment of that trough/cold front to our west will increase rain chance as the day progresses; showers may be spotty late Monday afternoon due the interference of dry air. Cold frontal passage is not expected to be decisive with a parallel, split-flow regime projected.
Upper ridge building offshore with northwest flow aloft over the region.
A cold front is analyzed roughly over the Texas Panhandle moving south into North Central Texas this afternoon. The cold front should be knocking at the northern tier door around dawn, poised to push through the CWA, i. the Lower Valley, by around noon. Showers along and behind the line with a possible rumble of thunder will have the best go in the afternoon, with the cold front clearing the coast by late afternoon/early evening, followed by stabler conditions and drier air Monday night. Low temps will be in the 70s tonight, but temps may not rise much on Monday as relatively much cooler air moves in.
316 PM CDT Sun Sep 27 2020 Cyclonic mid level flow around a closed low over Ontario and Manitoba was the main feature of the weather pattern over the central U. Further west a mid level ridge was set up just off the west coast as another closed low spun over the Gulf of Alaska. At the surface, a cold front had push southeast and was set up from central OK into central MO at 20Z. However the continued advection of dry air and a stabilizing boundary layer is expected to limit any instability by the mid evening hours and dry out the low level column.
Cliff PREVIOUS DISCUSSION: Upper pattern beginning to amplify with ridge building off the Pacific Northwest and trof digging into the Great Lakes. Pacific upper high will push into the Pacific Northwest early this week, with low over Ontario.
A cold front will enter the NW part of the state this afternoon and move SE through the rest of the state through the overnight and early morning hours. This will allow for warmer temps for much of the CWA this Sun. a cold front will drop SE into the CWA by this evening. Expect drier and cooler air to filter into the state by Mon night.
159 PM CDT Sun Sep 27 2020 Patchy MVFR cigs should gradually mix out through the late aftn, ahead of an approaching cold front. Shwrs and tstms will develop late tonight and move into our area around 06Z along and behind the cold front. /Today/ Pressure gradient continues to tighten across the region ahead of the approaching trof/cold front. Winds to remain elevated around 5 to 10 mph tonight ahead of a cold front the will move through the region on Monday. High temperatures on Monday to average in the lower to middle 70s.
This activity will push east of the forecast area tonight as the upper trough axis shifts further east into Iowa. Later tonight into Monday a closed low will develop within the trough over Minnesota and the Great Lakes. With the axis of the trough along the eastern border, showers will occur over much of central and eastern Iowa on Monday. Beyond Monday, there is little chance for precipitation as the upper trough digs over the eastern CONUS. The low that developed over Minnesota will dive into the Southern Plains and become its own system leaving the trough over the Great Lakes.
/Today/ Pressure gradient continues to tighten across the region ahead of the approaching trof/cold front. A cold front will move into the area after 28/06Z bringing -SHRA conditions to most terminal sites followed by a wind shift to the northwest with winds increasing to 12 kts. Winds to remain elevated around 5 to 10 mph tonight ahead of a cold front the will move through the region on Monday. High temperatures on Monday to average in the lower to middle 70s.
1251 PM CDT Sun Sep 27 2020 The main concerns for this forecast package will be in regards to a cold front that will progress through the region from northwest to southeast today, bringing with it falling temperatures through the day as well as the threat for showers and thunderstorms.
The cold front is moving southeast through northern, central and southwestern Oklahoma right now with the expectation that the storms will develop and expand near and just north of the front between 21Z and 00Z with storms becoming widespread this evening across southeastern sections of the forecast area. Gusty north winds are still expected behind the cold front his evening, although the onset of the gusty winds is lagging the initial wind shift.
Temperatures will top out around 10 degrees below normal, with highs in the low to mid 50s. The upper ridge across the west and troughing to the east will leave the Upper Midwest in a region of northwest flow.
219 PM CDT Sun Sep 27 2020 A cold front was entering the Ozarks this afternoon from the northwest, forcing an area of deep convection along this feature. We will be launching a 20z RAOB to provide the evening shift and users with a snapshot of our environment, and take another look at the low level cape/shear combination.
SR Chattanooga Airport, TN 66 81 56 65 51 / 30 70 80 50 20 Knoxville McGhee Tyson Airport, TN 65 80 57 62 51 / 30 40 70 60 30 Oak Ridge, TN 64 80 55 62 50 / 30 60 80 60 30 Tri Cities Airport, TN 60 80 57 62 51 / 20 20 70 70 50.
This appears to be more closely associated with 700-500mb frontogenesis on the southern edge of the upper trough that digging southward over the Plains. Lows are forecast to be in the low to mid 40s. Winds will decrease Monday night as the upper trough slowly moves east and high pressure passes to our southwest.
High pressure aloft strengthening along the West Coast will bring additional cold air south across Utah today. Expansion of the high pressure across the western states will maintain dry conditions and bring a warming trend beginning early in the week. An amplifying mid level ridge just off the Pacific Coast is inducing a mean northwest flow downstream across the Great Basin. This cooler air will keep max temps suppressed in the 60s across most northern and central valleys this afternoon, and the resultant pressure gradient will result in gusty winds across Castle Country and the western Uinta Basin this afternoon, as well as gap winds across portions of Washington County later this afternoon through tonight.
229 PM CDT Sun Sep 27 2020 Showers and a thunderstorm or two have begun moving into northeast and central Missouri this afternoon along and behind a southeastward moving cold front. The cold front, currently stretched from eastern Kansas through northern Missouri into northern Illinois will continue to drop south through the remainder of the afternoon and evening, driven by a digging mid-level trough. MRM The passage of this cold front will mark a distinct pattern shift for the mid-Mississippi Valley. The mid-level trough pushing the cold front through the forecast area today will linger over the eastern CONUS. Combined with a ridge building in over the western CONUS, this will keep the area in northwest flow and thus largely dry and cool through the end of the period.
Low temperatures are expected to range from the low to mid 30s across far eastern Colorado with mid 30s to low 40s elsewhere across the area. we'll have breezy to windy northwest winds during the day as the pressure gradient remains pretty tight in between low pressure over the Great Lakes and a large high amplitude ridge centered over Oregon. Low temperatures are expected to fall into the low 30s to near 40.
300 PM CDT Sun Sep 27 2020 Temperatures, including potential for frost or localized freezing conditions, will provide the main forecast challenges this week. Cooler air was pushing south into NE and IA from the Northern Plains. Another jet streak of 110 knots was pushing southeast from MT and WY, which should help the mid level trough dig the next 24 hours.
322 PM CDT Sun Sep 27 2020 A cold front will bring some much-needed rain to central Illinois tonight into Monday morning. Once the front passes, drier and much cooler weather will be on tap through the end of the week. 20z/3pm surface analysis shows cold front just east of I-55. Ahead of the front, abundant sunshine and southerly winds have boosted afternoon temperatures into the lower to middle 80s across the E/SE KILX CWA. Meanwhile behind the boundary, clouds have increased and northwesterly winds are beginning to bring cooler air into the region. Despite strongest forcing shifting into Indiana by midday Monday, trailing upper trough axis will provide enough synoptic lift to warrant a continuation of slight chance PoPs through the afternoon. Temperatures will be considerably cooler behind the front, with highs only reaching the lower to middle 60s.
1241 PM CDT Sun Sep 27 2020 (Today and tonight) Strong cold front will enter northwest Oklahoma this morning and become oriented more SW-NE as low level cyclogenesis occurs across southwest portions of Oklahoma.
While an approaching cold front will keep fog in the western portions from realizing its full potential, areas in the southeast will have the best opportunity for dense fog formation and have thus outlooked this area with limited. While good forcing will exist with the cold front as it moves through the area Monday, capping inversion looks to hold until the boundary arrives, limiting the majority of the convective potential to mostly post-frontal.
Cooler air, meanwhile, will continue advecting southward. This, combined with overcast skies for much of the day east of the Missouri River, will lead to high temperatures in the low 50s to low 60s on Monday.
Warm and dry conditions develop this week with strong high pressure aloft over the region.
Overnight lows will be in the low to mid 60s. Tomorrow, heights lower as a long wave trough and associated cold front moves in from the west-northwest. The best chance of showers comes during the late afternoon as the cold front begins to move in and upper dynamics become more favorable. This period will largely be dominated by a long wave trough over the eastern U.
Strong cold front with windy conditions tonight. A strong cold front will move through the area tonight, bringing much cooler and drier air for Monday. Lows tonight will drop into the mid 50s to around 60 degrees, and temperatures will be much cooler on Monday with highs in the 70s area-wide.
1220 PM CDT Sun Sep 27 2020 Although winds have already shifted to the north behind a cold front this morning, even stronger winds are expected this evening from about 00Z through 07Z. /issued 240 AM CDT Sun Sep 27 2020/ A much needed cold front continues its trek south, as of 3AM entering the northern portions of the Texas Panhandle, and will eventually pass south through the South Plains and Rolling Plains toward the I20 corridor by late this morning.
The upper trough over the Great Plains will continue to dig through much of the MS River Valley late tnt-Mon AM. The models do have differences with the deepening and track of the low, but overall the trend is for more of a prolonged period of light to mdt rain for ern WI tnt-Mon. Gehring (Issued 320 PM CDT Sun Sep 27 2020) Monday night through Sunday: Lingered precip chances into Monday evening as low pressure slowly pulls away from the region.
A ridge of high pressure will continue to build and strengthen over the region. Temperatures will be cool overnight followed by slightly warmer then normal high temperatures on Monday.
A cold front advances south through the Rio Grande Valley late Monday morning into Monday afternoon, with strong gusty northerly winds behind the front through the afternoon. A cold front is analyzed roughly over the Texas Panhandle moving south into North Central Texas this afternoon. The cold front should be knocking at the northern tier door around dawn, poised to push through the CWA, i. the Lower Valley, by around noon. Showers along and behind the line with a possible rumble of thunder will have the best go in the afternoon, with the cold front clearing the coast by late afternoon/early evening, followed by stabler conditions and drier air Monday night. Low temps will be in the 70s tonight, but temps may not rise much on Monday as relatively much cooler air moves in.
Near or below freezing temperatures in most locations tonight. High pressure rebuilds over Nevada beginning on Monday, with temperatures trending warmer once again and continuing through the week.
625 PM CDT Sun Sep 27 2020 A cold front will bring some much-needed rain to central Illinois tonight into Monday morning. Once the front passes, drier and much cooler weather will be on tap through the end of the week. 20z/3pm surface analysis shows cold front just east of I-55. Ahead of the front, abundant sunshine and southerly winds have boosted afternoon temperatures into the lower to middle 80s across the E/SE KILX CWA. Meanwhile behind the boundary, clouds have increased and northwesterly winds are beginning to bring cooler air into the region. Despite strongest forcing shifting into Indiana by midday Monday, trailing upper trough axis will provide enough synoptic lift to warrant a continuation of slight chance PoPs through the afternoon. Temperatures will be considerably cooler behind the front, with highs only reaching the lower to middle 60s.
Monday will see an upper low drop south from eastern Manitoba into Minnesota. Otherwise track of upper low will keep scattered showers east of the Red River with dry weather in E ND. Breezy once again and a bit cooler. On Tue there will be a sharp mid-CONUS trough stretching from the Midwest through the southern Mississippi Valley, and although a bit of a warmup will occur over our area, a series of cold fronts sweeping through the region mid to late week will keep the Northern plains at below average temps during this period. Near freezing temps aloft and at sfc Thu early AM could support a touch of -SW, but at this point we'll keep it out of the gridded fcst.
To our west, a line of showers and thunderstorms are moving along a cold front. Temperatures have climbed into the lower to mid 80s. No showers are showing up on radar at this time, but an upper trof continues to move through the area. Meanwhile, a cold front is plunging through Missouri at this time. Much cooler air will filter into the region behind the front. A large upper trof will set up over the Midwest behind the front.
This line was associated with 600-700mb frontogenesis and vorticity advection out ahead of an upper trough. the upper trough will continue to amplify and dig into the Midwest overnight, so southeast WI will be in an area of vorticity advection and frontogenesis for much of the night. The upper trough over the Great Plains will continue to dig through much of the MS River Valley late tnt-Mon AM. The models do have differences with the deepening and track of the low, but overall the trend is for more of a prolonged period of light to mdt rain for ern WI tnt-Mon. Gehring (Issued 320 PM CDT Sun Sep 27 2020) Monday night through Sunday: Lingered precip chances into Monday evening as low pressure slowly pulls away from the region.
Northerly flow aloft on the eastern periphery of a ridge will maintain largely clear and dry conditions across the forecast area. High pressure building over the region will result in a gradual warming trend through the middle of the week, with a dry forecast expected to be maintained through the week.
A strong upper ridge will then build over western North America and expand far enough eastward to bring dry weather and mostly clear skies to the Northern Rockies tonight through much of this week.
After 08Z MVFR cigs and -SHRA will move into the nw ahead of a cold front. The cold front wl move through the area Monday and bring a wind shift to the nw and gradually improving conditions from the nw. While an approaching cold front will keep fog in the western portions from realizing its full potential, areas in the southeast will have the best opportunity for dense fog formation and have thus outlooked this area with limited. While good forcing will exist with the cold front as it moves through the area Monday, capping inversion looks to hold until the boundary arrives, limiting the majority of the convective potential to mostly post-frontal.
MVFR vis and cigs are expected to develop overnight in a relatively warm and moist air mass ahead of an appoaching cold front. Overnight lows will be in the low to mid 60s. Tomorrow, heights lower as a long wave trough and associated cold front moves in from the west-northwest. The best chance of showers comes during the late afternoon as the cold front begins to move in and upper dynamics become more favorable. This period will largely be dominated by a long wave trough over the eastern U.
854 PM CDT Sun Sep 27 2020 A strong cold front continues to plow through eastern Oklahoma and western Arkansas this evening.
513 PM MDT Sun Sep 27 2020 Water vapor shows deep trof extending through the Northern Plains. Little change in the weather pattern expected through the week, with long wave trof gradually shifting into the eastern CONUS.
An upper low continues to progress northeast through northeast AL and southern middle TN. Lower clouds will develop and advect northward late tonight as pressure falls develop in advance of the incoming cold front. An MCS will be ongoing to our west early Monday morning along the lower MS River valley along an approaching cold front. The associated upper trough will be lagging well behind the front. The cold front and most of the thunderstorm activity should be relegated to the cold frontal passage and just behind the front, with showers/rain lasting well into Monday evening.
Similar to today the high moisture content combined with slow storm motion will favor some locally heavy rainfall with amounts of 2 to 3 inches an hour possible with the strongest storms or where training occurs.
A cold front continues to make steady progress southeast across south-central Missouri and the eastern Ozarks early this evening. A cold front was entering the Ozarks this afternoon from the northwest, forcing an area of deep convection along this feature. We will be launching a 20z RAOB to provide the evening shift and users with a snapshot of our environment, and take another look at the low level cape/shear combination.
Latest surface analysis showed the cold front just entering northwest Arkansas and it is progged to enter our northwest most zones around sunrise. Thus, have lowered minimum temperatures a couple degrees anticipating an increase in cloud cover and wind just ahead of the cold front. While an approaching cold front will keep fog in the western portions from realizing its full potential, areas in the southeast will have the best opportunity for dense fog formation and have thus outlooked this area with limited. While good forcing will exist with the cold front as it moves through the area Monday, capping inversion looks to hold until the boundary arrives, limiting the majority of the convective potential to mostly post-frontal.
An upper trough is coming through Middle Tennessee this afternoon, so we are seeing some cumulus clouds with just a smattering of light showers.
639 PM CDT Sun Sep 27 2020 Cyclonic mid level flow around a closed low over Ontario and Manitoba was the main feature of the weather pattern over the central U. Further west a mid level ridge was set up just off the west coast as another closed low spun over the Gulf of Alaska. At the surface, a cold front had push southeast and was set up from central OK into central MO at 20Z. However the continued advection of dry air and a stabilizing boundary layer is expected to limit any instability by the mid evening hours and dry out the low level column.
Temperatures, including potential for frost or localized freezing conditions, will provide the main forecast challenges this week. Cooler air was pushing south into NE and IA from the Northern Plains. Another jet streak of 110 knots was pushing southeast from MT and WY, which should help the mid level trough dig the next 24 hours.
Temperatures will cool a few degrees to start the week before high pressure rebuilds and pushes afternoon highs back to near record levels the second half of the week. A weak back-door cold front will bring slightly cooler temperatures to the area early this week, with the most noticeable drop in readings expected east of Tucson.