Aikyam-Lab/Synoptic-Bench huggingface dataset:
A more substantial piece of mid-level energy is expected to eject northeast from the 4 Corners region after around 06z, impacting the high plains of southeast WY and western NE thru 18z Monday. In general, expect an inch or two in the low elevations with 3-6 inches in the mountains through late afternoon on Monday.
351 PM MST Sun Nov 8 2020 20z surface analysis had low near KMOT with initial cool front/trough into central NE and main cold front from KPHP to just north of KDGW. 5km visible loop depicting narrow thin line of CU along main cold front. Rest of forecast features mean upper trough and periodic cyclonic flow over the region.
353 PM CST Sun Nov 8 2020 Conditions this afternoon and evening are expected to be quiet as the CWA briefly remains in the warm sector of a low pressure system currently over North Dakota.
Also, brief patchy fog possible along/near waterways but will not mention in TAFs due to the low confidence of occurrence. SR Chattanooga Airport, TN 59 77 62 75 67 / 0 0 0 30 60 Knoxville McGhee Tyson Airport, TN 54 77 57 76 64 / 0 0 0 20 70 Oak Ridge, TN 54 76 56 75 64 / 0 0 0 20 70 Tri Cities Airport, TN 52 76 55 75 62 / 0 0 0 20 70.
623 PM EST Sun Nov 8 2020 A strong high pressure system will lead to a continuation of dry and unseasonably warm conditions through Monday. A cold front will move into the Ohio Valley through mid week, bringing the next chance for showers. Our area will remain on the western fringe of a strong high pressure system centered just off the mid Atlantic Coast tonight. The high pressure will continue to push slowly east Monday into Monday night with some better return flow setting up across the upper Ohio Valley. We continue to overachieve guidance with temps so will trend a little warmer and go with highs on Monday in the upper 70s to around 80 degrees.
Looks as though we will remain stuck in a broad swly mid/upper level flow pattern tonight through Monday night, with deep low pressure out over the Rockies and amplified ridging off the se U.
There is some concern of mixed precipitation and freezing rain as indicated with bufkit soundings. The best chance for this will be during the transition from rain to snow so freezing rain/mixed precip will be brief and accumulations will remain light less than 0.
Big changes are on the way starting today, thanks to a potent upper level trof approaching from the west. A strong, 988mb sfc cyclone associated with the upper low, is lifting its way northward over the Dakotas with the attached sfc cold front just off to our west, over the NE panhandle. This cold front is expected to push through the area during the day tomorrow, which will lead to an interesting temperature gradient.
Significant snow accumulations over the higher terrain are forecast for tonight, with hazardous travel conditions.
This snow is eventually anticipated to pull east along with the low pressure ahead of it, but with the rapid movement north that is currently being observed, it may exit the area before pulling east. GAH AFTERNOON DISCUSSION: A the storm matured earlier this morning, many locations reported a mix of rain, freezing rain, and sleet.
The clouds are associated with an upper level trof that remains located over the Lower Mississippi River Valley. /issued 333 PM CST Sun Nov 8 2020/ High pressure continues to dominate the eastern half of the US. Southerly flow on the upstream side of the high has brought us very warm temperatures for this time of year.
A the storm matured earlier this morning, many locations reported a mix of rain, freezing rain, and sleet.
557 PM CST Sun Nov 8 2020 Conditions this afternoon and evening are expected to be quiet as the CWA briefly remains in the warm sector of a low pressure system currently over North Dakota.
Strong, gusty southerly winds will diminish this evening as the low responsible exits into Canada. Winds will shift to the northwest behind the low, as well. Cold air will advect in on the edges of an upper trough that is transitioning into the northern Plains tonight and Monday. Freezing rain may mix in along the western edge of the Coteau southwest into the bootheel of Lyman county on the edge of the temp gradient. High pressure builds in at the sfc Monday night. Temps plummet from highs in the lower 70s this afternoon to the 30s for highs on Monday.
Six-hour rain totals for the island chain are generally less than a half inch, although there is a 12-hour total near 10 inches in a lengthy line just to the south of the Lower Keys. Temperatures are in the mid to upper 70s and dewpoints are in the lower 70s. The strong tropical storm conditions will persist into Monday morning, especially for the Lower Keys.
Areas east of I-29 maintain breezy conditions overnight as they remain well ahead of the incoming cold front. Cold air advection increases Monday as the cold front makes its way eastward. Widespread low cloud cover along with much cooler temperatures makes it feel more like late autumn instead of late summer.
The snow ends by Monday morning for most areas, with lighter winds and a bit warmer temperatures.
Persistent strong high pressure over the Mid Atlantic will continue to sustain light south-southeast winds through the night. An area of scattered clouds are streaming northward through southeast Michigan within the 825-650 mb theta-e plume this afternoon, but have had little impact on the high temperatures given the limited coverage. Temperatures this afternoon have already reached the low to mid 70s and broken daily high temperature records again across southeast Michigan.
A cold night will be in store tonight with lows in the teens and single digits with high temperatures remaining in the lower 30s on Monday. Breezy north winds and lingering spotty snow showers will continue in the wake of the departing upper level low. Chilly conditions again continue for Monday afternoon with highs remaining in the low to mid 30s.
As trof to our north continues to lift into Canada, we will see the tail end of a trowal wrap back over south central and southeast MT late tonight and Monday. Otherwise, most of our cwa will be dry tonight thru Monday night with persistent downslope winds and an eventual shift to upper level ridging. Regarding Monday night, developing lee side trof will allow winds to increase along the western foothills.
203 PM MST Sun Nov 8 2020 20z surface analysis had low near KMOT with initial cool front/trough into central NE and main cold front from KPHP to just north of KDGW. 5km visible loop depicting narrow thin line of CU along main cold front. Rest of forecast features mean upper trough and periodic cyclonic flow over the region.
333 PM CST Sun Nov 8 2020 High pressure continues to dominate the eastern half of the US. Southerly flow on the upstream side of the high has brought us very warm temperatures for this time of year.
Broad troughing is present this afternoon over the western half of the CONUS, with increasing clouds across the region as the next weather system approaches. Current temperatures (08/21Z) are running about 8 to 12 degrees cooler than 24 hours ago.
will be under a deep trough of low pressure through tonight. Flow will shift to northeasterly this evening as an upper-level low spins off of the main trough to the east of the Continental Divide.
/issued 333 PM CST Sun Nov 8 2020/ High pressure continues to dominate the eastern half of the US. Southerly flow on the upstream side of the high has brought us very warm temperatures for this time of year.
533 PM CST Sun Nov 8 2020 Cloud cover is working into the western portions of the region this afternoon in association with our next cold front. The warm front, that lifted northward into the region this morning, has facilitate near record high temperatures this afternoon across much of the forecast area. Southerly winds preceding the cold front will impact the Red River Valley and areas to the west with gusts up to 50 mph. Temperature gradients tonight continue to be rather sharp, with lows in the low 20s for Devils Lake and low to mid 40s in the Park Rapids area. The entire area will be in the 20s and 30s by midday, and in the lower to middle 20s by sunset.
Near the surface, a lee side trough of low pressure remains anchored in eastern Colorado. These winds will only diminish slightly throughout the day as the surface cyclone in North Dakota moves farther north. The surface cyclone will move slowly east during the day maintaining a tight surface pressure gradient over southwest Kansas, and therefore another day of strong south winds can be expected. Temperatures will warm into the low 70s before a cold front moves through our area early Monday evening.
955 PM CST Sun Nov 8 2020 Isolated light showers continue to traverse the region from south to north this evening within a plume of deeper moisture associated with a weakening upper level trof.
1009 PM EST Sun Nov 8 2020 A strong high pressure system will lead to a continuation of dry and unseasonably warm conditions through Monday. A cold front will move into the Ohio Valley through mid week, bringing the next chance for showers. Large mid level ridge remains centered off the Mid Atlantic, placing ILN/s area on its western fringe. Expect overnight lows from the mid 40s to the lower 50s. The high pressure will continue to push slowly east Monday into Monday night with some better return flow setting up across the upper Ohio Valley. We continue to overachieve guidance with temps so will trend a little warmer and go with highs on Monday in the upper 70s to around 80 degrees.
232 AM CST Mon Nov 9 2020 A high-amplitude wave pattern continues over the United States with a trough over the western half of the country and a ridge for areas east of the Mississippi.
Forecast soundings indicate the possibility of freezing rain across south central SD early Monday morning, so added mention to forecast. 20z surface analysis had low near KMOT with initial cool front/trough into central NE and main cold front from KPHP to just north of KDGW. 5km visible loop depicting narrow thin line of CU along main cold front. Rest of forecast features mean upper trough and periodic cyclonic flow over the region.
A Pacific cold front will move across the area late tonight, sweeping the low level moisture to the east of our area.
Precip chances return late in the period as short range models indicate the amplified upper level trough of low pressure in the Intermountain West pushing eastward across the Four Corners Region late today, then lifting northeast into the Western High Plains tonight. Near the surface, prevailing southerlies will continue to supply a decent amount of moisture with surface dewpoints well up into the 50s(F) ahead of an approaching cold front projected to push into southwest/central Kansas sometime around late afternoon/early evening. As for temperatures, expect highs generally up into the lower/mid 70s(F) considering the timing of the front's arrival toward early evening.
1153 PM EST Sun Nov 8 2020 Persistent strong high pressure over the Mid Atlantic will continue to sustain light south-southeast winds through the night. An area of scattered clouds are streaming northward through southeast Michigan within the 825-650 mb theta-e plume this afternoon, but have had little impact on the high temperatures given the limited coverage. Temperatures this afternoon have already reached the low to mid 70s and broken daily high temperature records again across southeast Michigan.
1211 AM EST Mon Nov 9 2020 A strong high pressure system will lead to a continuation of dry and unseasonably warm conditions through Monday. A cold front will move into the Ohio Valley through mid week, bringing the next chance for showers. Large mid level ridge remains centered off the Mid Atlantic, placing ILN/s area on its western fringe. Expect overnight lows from the mid 40s to the lower 50s. The high pressure will continue to push slowly east Monday into Monday night with some better return flow setting up across the upper Ohio Valley. We continue to overachieve guidance with temps so will trend a little warmer and go with highs on Monday in the upper 70s to around 80 degrees.
A highly amplified upper pattern continues over the CONUS through the near term, with a five-wave scale trough firmly entrenched over the western half of the country and a broad ridge located downstream over the eastern seaboard. At the surface, high pressure over the western Atlantic continues to ridge southwestward into the Southeastern CONUS, maintaining a generally east to northeast low-level flow across the local area. Subsidence beneath the upper ridge will keep rain chances out of our local forecast through the next 24 hours, but moisture streaming in from Eta's broader circulation and influence will keep dewpoints elevated and allow this pesky cloud cover to linger.
CHA is expected to see some cigs spread in toward sunrise, likely in the low VFR levels. DGS Chattanooga Airport, TN 77 62 75 67 76 / 0 0 30 60 70 Knoxville McGhee Tyson Airport, TN 77 57 76 64 74 / 0 0 20 70 80 Oak Ridge, TN 76 56 75 64 73 / 0 0 20 70 80 Tri Cities Airport, TN 76 55 75 62 74 / 0 0 20 70 80.
/issued 217 PM CST Sun Nov 8 2020/ An upper level trough is over the western half of the country with an upper ridge over much of the east coast. High temperatures today will be a little warmer than yesterday but will generally be in the 70s and 80s. The upper trough to the west will progress eastward on Monday with a Pacific front accompanying the trough. Temperatures across southeast New Mexico and west of the Upper Trans Pecos will be a little cooler on Monday with the approach of the upper trough but temperatures across the rest of the area should be similar to those today. High winds are possible in the Guadalupe Mountains as the base of the upper trough approaches and begins to move over the region.
134 AM MST Mon Nov 9 2020 Western NOAM trough continues its slow eastward progression. A period of freezing drizzle may be possible in far eastern scentral SD before CAA changes all precip to snow there. Otherwise, mean upper trough will persist over the region through the week, supporting cool but seasonal and mainly dry conds in NW flow. Another cold front is progged Wed, with the bulk of CAA passing NE of the FA. This system will re-enforce cooler air for a day or so before a mild warm up late in the week. Snow from SW to central SD and rain/freezing rain across south central SD will produce MVFR/IFR/local LIFR conditions.
/issued 955 PM CST Sun Nov 8 2020/ Isolated light showers continue to traverse the region from south to north this evening within a plume of deeper moisture associated with a weakening upper level trof.
Meanwhile the main trough axis is forecast to slowly translate east impacting primarily central and southern Utah along the I-15 corridor. As this trough axis continues east Monday any lingering snowfall should taper off late morning into early afternoon.
/EC/ Prior discussion below: Tonight through Tomorrow: Low-level moisture has remained in place across our region today, though high pressure to our northeast has nudged deeper moisture been nudged south and west of the area. Apart from an area of denser low clouds that has kept east-central Mississippi a little cooler today, most locations in our forecast area hit the 80 degree mark for afternoon temperatures. With ridging aloft in place through tomorrow, trapped low-level moisture tonight will lead to low clouds and some patchy fog around the region overnight, and then another day of warmer than normal temperatures tomorrow.
/Tonight/ Isolated -SHRA continues to develop this evening across portions of NW LA/SW AR, along a H925-850 theta-e ridge that persists across SW AR/much of N LA. Despite the lack of large scale forcing aloft, believe that the potential for isolated -SHRA development will continue, and thus have added slight chance pops for much of N LA/SW AR overnight, and extended slight chance pops after 06Z for portions of extreme Ern TX as the theta-e ridge should shift a bit farther W overnight. Any FG should lift by mid-morning, although the low cigs will take much of the morning to lift, with MVFR cigs expected to linger through early to mid-afternoon before returning to VFR.
A few sprinkles will again be possible tonight (mainly across the higher terrain of NW AR and SE OK) given the moisture being advected into the area. Winds will also continue to be gusty ahead of the incoming cold front and a slowly deepening low pressure emerging from the Rockies. Cold front moves into NE OK late Monday night and sweeps through western AR by mid Tues afternoon.
High pressure off the Mid-Atlantic coast will continue to dominate our weather through tonight.
Clearing skies across northwest Montana and north central Idaho will allow some patches of freezing fog to develop this morning and again on Tuesday morning. Many locations above 3000 feet elevation will struggle to warm to freezing today.
Arctic air will continue to invade northern Nebraska with temperatures falling below freezing throughout northern Nebraska this morning from west to east. Temperatures will decrease throughout the day today in the wake of a cold front, with most of the area experiencing its daily high temperature early in the morning. This produces a northwest-southeast gradient of high temperatures from around freezing in the northeastern Panhandle to the 50s in central Nebraska. POPs begin to decrease in the afternoon before a second band of snow develops over southwest Nebraska due to the combination of a positively tilted trough drawing warm air into the region and decent convective instability as indicated by the RAP and NAM. Flow aloft will become zonal and high pressure will begin to build in at the surface over the Great Plains.
Precip chances return late in the period as short range models indicate the amplified upper level trough of low pressure in the Intermountain West pushing eastward across the Four Corners Region late today, then lifting northeast into the Western High Plains tonight. Near the surface, prevailing southerlies will continue to supply a decent amount of moisture with surface dewpoints well up into the 50s(F) ahead of an approaching cold front projected to push into southwest/central Kansas sometime around late afternoon/early evening. As for temperatures, expect highs generally up into the lower/mid 70s(F) considering the timing of the front's arrival toward early evening. Once an upper level short wave trough kicks east out of the Central Plains late Tuesday, a drier pattern returns through the remainder of the week as a more zonal flow aloft sets up across the Western High Plains.
/issued 345 AM CST Mon Nov 9 2020/ WV imagery shows the first trough of discussion the past few days has ejected into Canada, only to be replaced by a secondary trough that will pass through the Four Corners this afternoon, and has put West Texas and Southeast New Mexico under SW flow aloft. These sfc winds will veer to southwest and west today as leeside troughing strengthens on the Front Range ahead of the upper systems.
Tomorrow a cold front will make its way into the region. The disturbance along the base of the trough will struggle to continue its eastward motion into the area as it is forced northeastward due to the ridge parked off the SE Atlantic coast. Max temps are 5 to 10 degrees warmer and min temps are 10 to 15 degrees warmer than climatological norms.
A high-amplitude wave pattern continues over the United States with a trough over the western half of the country and a ridge for areas east of the Mississippi. A trailing surface cold front from this system will cross the Quad State Tuesday night. Tuesday will also be affected by a moisture plume from the Atlantic directed by the high pressure system and Eta. The aforementioned cold front will bring a line of showers through during the evening and overnight. After the cold frontal passage, temperatures will drop significantly, which in this case would still leave near average conditions. The high-amplitude trough-ridge pattern will weaken, and the Quad State will be just inside a much lower amplitude trough.
Upper trough will linger of eastern Montana today. A band of snow associated with this trough will continue mainly over the northern parts and at times as far south as Petroleum and Garfield Counties this morning. Skies will become clear to partly cloudy from west to east in most areas this afternoon and evening with the high pressure.
623 AM CST Mon Nov 9 2020 The current synoptic weather pattern across the CONUS is defined by a large, high amplitude trough across the western US with mid level ridging across the East Coast. Widespread showers and some thunderstorms are likely along and ahead of this cold front.
SHORT TERM (Now through Tuesday): A weak mid-level ridge will maintain dry and warm conditions through the short term period. A mid-level trough traversing across the western CONUS and into the Plains will then aid in pushing a weak cold front across Deep South Texas on Tuesday. Winds over the northern Gulf of Mexico will continue to be influenced by high pressure over the Mid-Atlantic states and also by Tropical Storm Eta over the southeastern Gulf, maintaining a large easterly fetch.
/Today through Tuesday/ Swly flow aloft continues again today, as our region remains pinned between a longwave trof over the Four Corners region and an amplified upper trof axis over the E Coast. Unseasonably warm temps are expected once again today Meanwhile, disturbance movg ewd around the base of the trof will drive a cold front towards our region tonight. However, the disturbance will be forced to take a newd track as the ridge holds its ground, which will slow the intrusion of cooler air and reduce our chances for convection associated with the front. Nevertheless, we should see some shwrs during the day Tuesday, with cooler/drier air beginning to filter swd late Tuesday aftn/evening.
Issued by National Weather Service Binghamton NY 942 AM EST Mon Nov 9 2020 Strong high pressure will remain over the eastern seaboard early this week.
Guidance has once again picked up a bit on shower activity across the Rolling Plains overnight as sfc winds veer NWRLY as winds ahead of the southwestern storm system mix downward further drying the lower levels. In the wake of the front drier and cooler air will fill in from the west.
High pressure continues to be the main driver over the eastern half of the US. Warm and dry conditions can be expected today and into Tuesday before a cold front moves through Tuesday night.
The surface cold front over Colorado and Nebraska will move southeast today moving into the northwest corner of the area late this evening. Scattered showers are expected to develop near and ahead of the front as the longwave trough approaches the Plains from the Western United States.
Cold overnight lows will be the highlight for this morning and Tuesday morning with widespread 30s, and some upper 20s in the coldest inland valleys.
A cold front move into northeast Oklahoma late tonight with showers likely, including a few embedded thunderstorms. /Issued 423 AM CST Mon Nov 9 2020/ Upper level low pressure system. will allow for afternoon temps to again warm into the low/mid 70s over the CWA. as the upper low lifts into the Plains. a cold front is progged to drop southeastward reaching the CWA around 12z Tuesday. The low pressure system quickly lifts northeast Tuesday morning reaching Southern Nebraska by the afternoon hours. At the same time the cold front quickly moves east southeast through Eastern Oklahoma Tuesday morning and across Northwest Arkansas early afternoon. Associated instability lifts northeast of the CWA in response to the departing upper low which will help to weaken the marginal severe potentials during the morning hours Tuesday. Behind the cold front.
We will remain under the ridge aloft so temperatures will be on the warm side. At the beginning of the forecast period, rich tropical moisture will be in place Tuesday night as the area remains situated between Eta in the southeast Gulf of Mexico and the ridge of high pressure over the western Atlantic.