Aikyam-Lab/Synoptic-Bench huggingface dataset:
This afternoon and upper level ridge was located from the southern Rockies into the northern Plains while a longwave trough extended from southern Ontario into eastern Texas. A closed low develops tonight and Tuesday over the lower Mississippi Valley as a mid level trough moves across the western states. The lower Mississippi Valley cut off low meanders northward Tuesday night and Wednesday before being kick off to the northeast Wednesday night. Wrap around moisture as well as energy rotating around the low may bring a small chance of showers to far east central Kansas Wednesday afternoon when the center of the low moves into southern Missouri.
A sharp, yet fairly narrow ridge of high pressure in the mid/upper troposphere remained anchored from New Mexico northeast into Nebraska and South Dakota. The cutoff upper low over the lower Mississippi Valley will also remain essentially unchanged through this period, hence the "squeeze play" going on with the ridge axis in between these two low pressure features.
342 AM CDT Tue Oct 5 2021 A broad upper low over the Lower Mississippi Valley has become cutoff from the stronger westerlies that have retreated well north of the region.
347 AM EDT Tue Oct 5 2021 Our region will be between a frontal boundary to the south and High pressure to the north. High pressure builds further south into the area for the middle of the week. The next chance of showers and associated low pressure looks to hold off till the end of the week. High pressure will slowly build southward into the region today and through the day Wednesday. Clouds should keep the lows from falling much below the mid and upper 50's. More clearing Wednesday as the high pressure system continues building southeast and slightly warmer daytime highs as a result. Upstream is a closed upper level low over Missouri which fills and lifts slowly northeast into the western Great Lakes.
An upper level low was currently in the process of closing off over Arkansas this afternoon with a ridge of high pressure from southwest to northeast from the four corners region into the northern plains. The low will eventually become cut off late tonight into Tuesday and is expected to meander over Arkansas and southeast MO into the later part of the week. The chance for showers/thunderstorms will be the main focus as this low slowly tracks to the northeast. Temperatures will be in the mid to upper 50s tonight with the warmer readings in northeast portions of the CWA where there will be more cloud cover. The better chances of precipitation will arrive on Wednesday into Wednesday night as the upper low begins to shift into southern Missouri.
345 AM CDT Tue Oct 5 2021 (Issued 345 AM CDT Tue Oct 5 2021) Today and tonight: High pressure to the north will strengthen a bit today, but decent low level moisture will linger across northern Wisconsin. There may be some breaks in the clouds at times today into tonight, especially in the north towards the high.
A sharp ridge axis extends from eastern NM north-northeastward through portions of the Central Plains and toward the western Great Lakes region. sandwiched between a larger area of low pressure spinning over the AR/LA border area and a couple of disturbances over the Nrn Rockies and just off the coast of srn CA. At the surface, a ridge axis extending southwest from high pressure over the Great Lakes is keeping winds light and variable this morning. Aloft, not that flow was overly strong to begin with under this ridge, but models show flow becoming at least briefly more variable over the area, driven by the low over AR/LA and the disturbance over CA coast shifting more northward with time.
353 AM EDT Tue Oct 5 2021 A backdoor cold front is expected to move through the area today.
The anticipated dry air continues to move south as an mid to upper level low over the southeast CONUS drifts to the northeast. High pressure will build in today and tonight keeping the dry air firmly in place through Wednesday.
1040 PM MDT Mon Oct 4 2021 Water vapor shows upper ridge axis extending from the Four Corners north/northeast through the Northern Plains, with upper trof just offshore the Pac NW. Nearly cut-off low is noted offshore southern CA with secondary and weaker low over far northern UT. At the surface, broad trof covers the Northern Rockies/Northern Plains. Upper low currently over far northern UT will shift through the Northern Rockies tonight, with surface trof becoming more pronounced and lifting through eastern WY/MT into the western Dakotas. Thermal ridge then builds overhead on Tuesday, resulting in temps being a few degrees warmer than today. On Wednesday, upper low (currently offshore southern CA) will lift northeast as an open wave into the Central Rockies, with gusty southerly winds developing across much of our area.
Winds will remain light aloft with high pressure overhead.
High temperatures will slowly increase as the ridge builds. Today will be a couple degrees warmer than yesterday with widespread mid 80s expected.
This upper low will then remain in place for through the near term allowing southwesterly flow aloft to persist. Lows will range from the mid 60s inland to the lower 70s along the coast.
128 AM EDT Tue Oct 5 2021 A weak coastal trough will approach the area late tonight, before moving onshore Tuesday. High pressure will build inland later in the weekend. The remains of lingering showers across far interior Georgia will gradually fade and/or pull west of the forecast counties, as the formation of isolated to scattered showers and a few t-storms out near the Gulf Stream heads closer to shore late in response to an inverted trough.
/issued 221 PM CDT Mon Oct 4 2021/ Northerly flow aloft will continue into Tuesday with upper level low pressure lodged across the lower Mississippi Valley and an upper ridge axis from eastern New Mexico across the central high plains.
(Today and tonight) Expect a fairly nice day out there today as a closed low to our east maintains dry northerly flow over the area, keeping skies mostly clear and temperatures in the low 80s for highs this afternoon. The light winds and clear skies will produce excellent radiational cooling conditions tonight, allowing lows to fall into the low to mid 50s, with a few upper 40s possible in northwest Oklahoma.
140 AM MDT Tue Oct 5 2021 High pressure over the Tri State region at this early morning hour is currently giving the area clear skies, with light winds and temps ranging from the mid 40s into the mid 50s. The latest RAP40 500mb analysis, in tandem with the latest mid level water vapor imagery, is showing an elongated upper ridge through the Plains region. As with the past few days of guidance, this upper ridge will continue to play a role in the wx over the area for the entire short term period. A cutoff low over the southeast, and a system coming onshore in the Desert SW, will aid in keeping the ridge in place over the area.
910 PM MDT Mon Oct 4 2021 Only minor adjustments to tonights forecast as we're under the influence of high pressure, a clear sky and low dewpoints.
Drier weather is expected late in the weekend as the upper low moves away from the region. The closed upper level low over ArkLaMiss will be the the main synoptic driver of increased moisture transport across the southeast. Main front remains well west of us with weak high pressure ridging hanging on over the Carolinas. The area of deeper moisture will slowly shift west and north through the day as the upper low inches away from the Gulf Coast, bringing PWATs closer to 1. With the high amplitude upper level pattern and the cut off low over the Lower MS Valley the synoptic situation will be slowly to change. Current expectation is the moisture associated with the wave will move inland across NC however depending on the upper low to the west this could shift further south and will be monitored.
Over the next few days, the surface pressure pattern stays pretty stagnant with our region right in the tightest surface pressure gradient between high pressure to our east and low pressure to our west. On Wednesday, with high temperatures a little cooler along with dewpoints a few degrees higher, the winds will again meet red flag but the rhs will be about 5 to 10 percent higher across central and north central sd. Wednesday's highs will range from the mid 70s to the lower 80s again under sunny skies.
/Issued 818 PM EDT Mon Oct 4 2021/ Water vapor imagery and 500 mb analysis show a positively-tilted longwave trough extending from the Great Lakes region down through the Lower MS River Valley. A pronounced vort max is currently digging across OK/AR/TX as it rounds the base of the trough. This piece of energy will pinch off from the trough tonight, becoming a closed low.
(Today and tonight) A little cooler today across the eastern portions of the area, as weak low level east and northeast flow brings a slightly cooler air mass into the area.
Today Through Wednesday Night To begin the period, an upper level trough is positioned to the east of the CWA, located in the Mississippi Valley. Model guidance has showed this upper level trough closing off sometime over the course of today. Models then show the closed low moving towards the north over the course of the period. The areas with the highest likelihood to see severe weather will be those closest to the center of the upper level low. There is still some uncertainty on where the low will track as we are still waiting for the low to close off.
Temperatures a good bit above climate, particularly morning lows the next couple daybreaks, although beyond this period we see slight cooling from high pressure advection from the north. Cutoff low in the Lower Mississippi River Valley lifts northward towards the Lower Ohio River Valley through the end of this period, soon transitioning into an open wave. Meanwhile, a CAD wedge develops in the Northeast, and a coastal trough forms east of SC Low Country, moving northward.
422 AM EDT Tue Oct 5 2021 Weak ridging will remain in place across the local area as a stalled boundary to the northwest lingers.
With the recent rain and the high pressure that is building over the region, light winds and even partly cloudy skies will allow for enough radiation, that patchy to areas of fog is likely to be occurring for the mornings. A few places, like some of the ridges will probably have a decent wind over 5 knots, which would keep the fog from forming. High impact weather potential: None expected Synopsis/Forecast: The southern Mississippi Valley cut-off starts to make its way through Missouri on its way to the Great Lakes midweek, while ridging persists over our region. Meanwhile a longwave trough moves onto the west coast.
An upper level trough, extending from TX to the lower Mississippi Valley, is predicted by the ECMWF/GFS/NAM to transition to a cut- off low late tonight/Tuesday, with the center meandering over the ARKLATEX region. Owing to significantly drier conditions tonight, expect cooler temperatures tonight with lows generally 60-65F, and maximum temperatures mid 80s to the lower 90s Tuesday, similar to the SREF ensemble mean values.
With a stalled front in the western and northern portions of the area and a low pressure system sliding along and ahead of the front, the southerly flow will remain for the time and period of showers and embedded storms will continue through the next 36 plus hours. The main upper low remains over MS, LA, and AR for today before retreating to AR on Wednesday.
356 AM EDT Tue Oct 5 2021 Isolated showers and thunderstorm chances will continue this week within a warm, humid airmass ahead of low pressure. A split flow pattern will persist today as elongated, southern stream low pressure deepens near the lower Mississippi River Valley and begins to slowly retrograde late today. The exception would be across the far sern ridges in WV; where a few terrain-driven showers, due to low-level easterly flow, are possible this afternoon. By Wednesday, ridging overhead will begin to erode late in the day as a trough digs across the Pacific Northwest region and shunts the southern stream, closed low farther east.
349 AM CDT Tue Oct 5 2021 Highly amplified blocking pattern in place across the CONUS with the notable local feature being the upper low currently centered over SE AR.
(Today through Wednesday afternoon) WV imagery shows West Texas and Southeast New Mexico to be on the backside of an exiting upper trough over the MS Valley. A secondary trough is off the coast of Baja del Norte, sandwiching a highly- amplified ridge between it and the MS Valley trough. Rain chances in the short term are slim to none under upper-level ridging.
145 AM EDT Tue Oct 5 2021 Unsettled conditions are expected as a deep upper level trough develops over the eastern U.
1041 PM CDT Mon Oct 4 2021 A mid/upper trough over the Great Lakes area is progged to weaken while another mid/upper trough develops across the Mississippi Valley area through tonight and into Tuesday. As this developing mid/upper trough deepens it is progged to lift northward over the Middle Mississippi Valley area towards the middle of the week.
The upper low will continue spinning over the deep south today while the frontal boundary will gradually shift west across the state. The highest Pops will be over the southern half of the area. Overnight lows remain mild in the lower 60s. The upper low slowly drifts north on Wednesday and will be in the vicinity of Missouri by late in the day. With the rain and mostly cloudy skies, temps will be a bit cooler with afternoon highs in the middle 70s, although some upper 70s are possible in far eastern KY where rain chances are lowest. A large trough of low pressure aloft will be the primary weather maker in the extended for eastern Kentucky.
This will allow for yet another day of above average temperatures with highs in the lower to middle 70s.
The lingering low level moisture and cloudiness also applies a ceiling to the high temperatures today keeping highs in the low 70s at their highest. Dew points fall back towards 60 degrees and the lingering low level moisture, once again caps the low temperatures to around 60 degrees as well. For the mid to late week period, the upper low that formed at the tail end of the vorticity streamer down in the Gulf rises north again towards the area.
It is possible, looking at some of the models, that coastal LA will not see as much rainfall as is forecast over the next couple of days if the low progresses eastward a bit more quickly. But most of the model consenus has the low lingering a bit more into tomorrow and tomorrow evening, so it is more likely that the rainfall will be along the easternmost portions of SE Louisiana and along coastal MS. Consequently, heavy rainfall and flash flooding will be a concern for our easternmost areas, mainly coastal MS and eastern coastal Louisiana as the low pressure system moves eastward.
230 AM CDT Tue Oct 5 2021 Another nice day is upcoming for West Texas as we'll remain positioned east of a narrow high-amplitude ridge axis and on the western fringes of a broad closed low centered over the southern Mississippi River Valley. The developing upslope flow and weak CAA will secure slightly cooler temperatures than experienced yesterday for all but the southwestern zones, where the cooler easterly flow won't reach until late afternoon or early evening. Dry weather is expected through the rest of the week as an upper ridge will dominate the pattern over the region. 500 mb heights will increase over the area through this week as an upper-level high builds to our south, and an upper trough deepens over the west coast, resulting in increasing temperatures through the end of this workweek.
1054 PM MDT Mon Oct 4 2021 A strong ridge remains centered over our region today with well above normal temperatures and dry weather continuing. Due to increased cloud cover, temperatures on Wednesday are expected to be a few degrees cooler than Tuesday.
204 AM MDT Tue Oct 5 2021 High pressure over the Tri State region at this early morning hour is currently giving the area clear skies, with light winds and temps ranging from the mid 40s into the mid 50s. The latest RAP40 500mb analysis, in tandem with the latest mid level water vapor imagery, is showing an elongated upper ridge through the Plains region. As with the past few days of guidance, this upper ridge will continue to play a role in the wx over the area for the entire short term period. A cutoff low over the southeast, and a system coming onshore in the Desert SW, will aid in keeping the ridge in place over the area.
Synoptically, a large upper-level closed low will continue to spin over the Mississippi River Valley ushering in dry, northerly flow into SE Texas through Wednesday. Afternoon high temperatures will continue to be in the mid to upper 80s with overnight low temperatures in the low to mid 60s.
1110 PM MDT Mon Oct 4 2021 Dry air mass and lack of support/focus with upper ridge in place will support dry weather during the period. Near freezing temps are once again possible in the mountain valleys early Tuesday morning, with above normal temps returning Tuesday. Upper ridge expected to shift east at the start of the period, as upper trough lifts across the western CONUS. This lifting trough will provide the next chance of mainly rain showers to the region late Tuesday night into Wednesday.
1212 AM EDT Tue Oct 5 2021 High pressure will ridge across the region through mid week, with a nearly stationary frontal boundary remaining to the south.
Areas of fog were also observed over the higher terrain of north central and parts of far northeast WI. Upper level ridging will bring a dry day to northeast WI today.
920 PM PDT Mon Oct 4 2021 An upper level low pressure system off the northern Baja California coast will move slowly northeast across the area through Tuesday.
With respect to convection affecting terminals, have the highest confidence at KCHA where storms should more easily make it into the vicinity of the terminal. CD Chattanooga Airport, TN 73 65 74 64 75 / 90 90 90 80 80 Knoxville McGhee Tyson Airport, TN 73 63 75 64 76 / 80 80 80 80 90 Oak Ridge, TN 73 63 74 63 75 / 80 70 80 80 90 Tri Cities Airport, TN 76 61 75 60 75 / 60 50 70 70 80.
Temperatures were in the lower 80s with dewpoints in the lower 70s.
935 PM MDT Mon Oct 4 2021 Only minor adjustments to tonights forecast as we're under the influence of high pressure, a clear sky and low dewpoints.
A cold front to the west and moist southeasterly flow will allow for showers to increase, first at KSSI by 09Z and then the remaining TAF sites between 12-14Z. The region will be between high pressure to the northeast, and an area of low pressure to the west this period.
Recent CAM guidance is showing the possibility of a few showers tomorrow afternoon over lower Acadiana in association with the meandering mid-level cutoff low and nearby sfc trof.
Water vapor satellite imagery shows a mid to upper level low over the southern Mississippi River valley this morning. High pressure at the surface has brought cooler, drier air in the low levels. The upper low will stall and then lift out to the north during this period.
459 AM EDT Tue Oct 5 2021 High pressure will ridge across the region through mid week with a nearly stationary frontal boundary remaining to the south.
An upper level low has been developing over southeast Arkansas. This low is expected to move slowly east today into northwest Mississippi. Tonight, the upper low will start to wander more northwest into northeast Arkansas. Temperatures will be slightly above normal tonight with lows Wednesday morning in the low to mid 60s. The upper low will continue to move slowly north on Wednesday moving into southeast Missouri with more showers and isolated thunderstorms expected mainly over northern sections of the Mid- South. Temperatures will be a little cooler on Wednesday with highs in the mid to upper 70s. As the upper low moves into central Missouri Wednesday night, rain should be confined to far eastern sections of the Mid-South.
The ridge continues to build aloft on Tuesday as two upper-level lows move across the south.
1254 AM EDT Tue Oct 5 2021 Isolated showers and thunderstorm chances will continue this week within a warm, humid airmass ahead of low pressure. A split flow pattern will persist today as elongated, southern stream low pressure deepens near the lower Mississippi River Valley and begins to slowly retrograde late today. The exception would be across the far sern ridges in WV; where a few terrain-driven showers, due to low-level easterly flow, are possible this afternoon. By Wednesday, ridging overhead will begin to erode late in the day as a trough digs across the Pacific Northwest region and shunts the southern stream, closed low farther east.
Thus, with the aid of CAA expect afternoon highs to be a touch cooler than yesterday, as temperatures only climb into the low to mid 70s east of I-29, with mid to upper 70s more common elsewhere. Otherwise, expect quiet conditions to continue during the overnight period, with lows in the lower 50s. Look for ridging to degrade by mid-week as an upper level low near Arkansas lifts northward toward the region. As a result, expect afternoon highs to only rise into the low to mid 70s.
We are situated on the back side of a cut(ting)off low over the Southeastern CONUS with dry northerly flow and surface ridging overtop of us. Tuesday night and Wednesday will be similar to today's weather but slightly warmer and cooler, respectively, largely due to slightly increased cloud cover as the low slowly fills and pulls north. /Issued 315 PM CDT Mon Oct 4 2021/ /Wednesday Night and Beyond/ North and Central Texas will be situated beneath the western flank of a cut-off low, which will be centered over Arkansas at the start of the period.
Fog may be locally dense in spots, especially across WNY over to Rochester with abundant low level moisture in place with surface dewpoints in the lower 60s, and some added moisture within a light northeast flow off Lake Ontario. This pattern will include high pressure that will be centered over Quebec. A broad area of upper level ridging will span across much of the Mid- West and East coast with an embedded closed low across the lower Mississippi Valley.
An upper lvl trof ovr the region rmns fcst to bcm closed off ovr the next 24 hours and meander acrs AR. Cannot rule out a few hailers each aftn, as colder air aloft wl produce steeper lapse rates in the vcnty of the upper low center.
Brusda Beginning on Wednesday, a North Pacific upper level trough moves more moisture into the region. At least light measurable snow is possible in the higher mountains. A North Pacific trof remains along the U. Wednesday, marks the beginning of a transition to a cooler and wetter weather pattern. The northern portion of the upstream upper level trof moves onshore the Canadian west coast. The southern portion of this trof follows, entering the U.
623 AM EDT Tue Oct 5 2021 Isolated showers and thunderstorm chances will continue this week within a warm, humid airmass ahead of low pressure. With the lower, autumn sun angle, expect foggy conditions to persist through mid morning before diurnal mixing eventually improves visibility. Dry conditions should otherwise prevail for most of the region today under a building ridge. A split flow pattern will persist today as elongated, southern stream low pressure deepens near the lower Mississippi River Valley and begins to slowly retrograde late today. The exception would be across the far sern ridges in WV; where a few terrain-driven showers, due to low-level easterly flow, are possible this afternoon. By Wednesday, ridging overhead will begin to erode late in the day as a trough digs across the Pacific Northwest region and shunts the southern stream, closed low farther east.
600 AM CDT Tue Oct 5 2021 (Today and tonight) Expect a fairly nice day out there today as a closed low to our east maintains dry northerly flow over the area, keeping skies mostly clear and temperatures in the low 80s for highs this afternoon. The light winds and clear skies will produce excellent radiational cooling conditions tonight, allowing lows to fall into the low to mid 50s, with a few upper 40s possible in northwest Oklahoma.