Aikyam-Lab/Synoptic-Bench huggingface dataset:
(This afternoon through Sunday) Models are in good agreement; the upper low will remain over KY through the period with the associated mid-level trough impacting portions of TN/AL and north GA.
829 PM EDT Sat Sep 28 2024 (This afternoon through Sunday) Satellite and model data show the remnants of Helene lingering around the Tennessee valley and combining with a mid level trough/low complex. Bands of showers with embedded thunderstorms will continue to stream SW to NE across SoFlo through the rest of the weekend as moisture advection between the decaying front and building high pressure over the west Atlantic continues. Rain chances will fall below climatological norms and the lower humidity will help drop heat index values a few degrees but not enough to make up for the southerly flow and abundant sunshine, bringing 105 to 110 degree values across much of the area.
An upper ridge over the four corners region nudged just far enough northwest to impact the forecast area this afternoon. temperatures were generally 3 to 7 degrees warmer across the inland areas compared to 24 hours ago. The coastal locations were around 2 to 6 degrees cooler. An upper trough and associated cold front will dip southeast toward Oregon late tonight. with the dry cold front moving through the region by early Sunday morning. ridging builds back over the Pacific Northwest.
712 PM EDT Sat Sep 28 2024 Dry weather will continue for the next few days as high pressure remains centered just to our east.
442 PM CDT Sat Sep 28 2024 (This afternoon through Sunday night) WV imagery shows the upper ridge centered over southeast Arizona, resulting in meridional flow this afternoon over West Texas and Southeast New Mexico. As such, the short term continues to remain dry, but with mild temperatures due to the displaced nature of the ridge. Sunday, a trough will make landfall on the west coast in SoCal, nudging the ridge up to just south of the Four Corners.
The upper low centered over Kentucky will continue to generate rain from the Ohio Valley to the Mid Atlantic, while a ridge remains planted from the southern Rockies into the Plains. The result will be tranquil weather with lows in the lower and middle 60s and highs in the 80s through Sunday.
The main midlevel deformation axis is quasi-stationary this evening as the main upper level low pressure circulation will move very little during the next 24 hours.
608 PM EDT Sat Sep 28 2024 A broad area of low pressure will persist over the Southeast U. A cold front is then expected to push through the region mid-week, with cooler high pressure building in from the west thereafter. Deep low pressure will prevail aloft across the southeastern states on Sunday.
621 PM CDT Sat Sep 28 2024 (Tonight through Sunday night) The pressure gradient remains weak through the weekend across the western Gulf of Mexico, with an elongated mid level trough extending from the remnants of Helene in the Ohio River Valley southwest across Texas. With a southwesterly downsloping flow, expect temperatures a few degrees warmer for both today and Sunday afternoon, into the mid to upper 90s.
718 PM EDT Sat Sep 28 2024 Dry weather will continue for the next few days as high pressure remains centered just to our east.
A subtle trough will enter western Washington tonight into Sunday increasing precipitation chances. An upper level ridge will set up to start the new week, however a series of troughs will influence the pattern.
805 PM EDT Sat Sep 28 2024 (This afternoon through Sunday) Satellite and model data show the remnants of Helene lingering around the Tennessee valley and combining with a mid level trough/low complex. Bands of showers with embedded thunderstorms will continue to stream SW to NE across SoFlo through the rest of the weekend as moisture advection between the decaying front and building high pressure over the west Atlantic continues. Rain chances will fall below climatological norms and the lower humidity will help drop heat index values a few degrees but not enough to make up for the southerly flow and abundant sunshine, bringing 105 to 110 degree values across much of the area.
932 PM EDT Sat Sep 28 2024 A closed off upper low across the Ohio/Tennessee valleys with waves rotating is helping to produce low-level isentropic lift.
1009 PM EDT Sat Sep 28 2024 Dry weather will continue for the next few days as high pressure remains centered just to our east.
High winds will also be a factor in the next few days as high pressure sets in. Satellite pictures show plenty of sunshine skies in the interior this afternoon, however high level clouds are expected to stream across the area as a weak upper level trough approaches northern California. Afternoon temperatures are running 3 to 10 degrees cooler compared with yesterday's reading. Sunday, high temperatures are expected to run another few degrees a cooler as the aforementioned weak trough swing through the region tonight into Sunday morning. High pressure is expected to builds into the Pacific Northwest and Northern California downstream of the trough. Breezy conditions with gusty north to Northwest winds will develop along the North Coast with northeast winds over the high terrain of Del Norte county late Sunday afternoon and evening where gusts up to 40 mph are likely.
A large cutoff upper low pressure system sits over the Tennessee River Valley.
509 PM MDT Sat Sep 28 2024 -Dry weather, much warmer than average temperatures, and critical fire weather conditions on Sunday.
(Modified Previous Discussion) The cut-off low pressure over the Tennessee Valley will continue to shift eastward and weaken through the day as the Atlantic high pressure ridge builds westward over the Florida peninsula and out into the GOMEX.
With the center of low pressure slowly increasing, the pressure gradient continues to weaken. Right now the low center is just to the north of Clarksville and it will generally stay in that area and gradually weaken in pressure. Light showers and drizzle will spin around the low throughout the day and overnight. The low will continue to weaken and slowly drift eastward some. The low clouds will start to break up some in the afternoon and that will help to bring slightly warmer temperatures with highs around 70.
514 PM MDT Sat Sep 28 2024 - High pressure remains in control for the next several days. - Some models indicate very isolated convection over the higher terrain while others keep dry weather in place. Plenty of cumulus clouds have popped over the higher terrain this afternoon but the question remains whether we'll see any showers or storms. The location of the high pressure center won't change all that much despite an area of low pressure to our west. In fact, the low won't move much either.
The closed low noted on satellite imagery spinning over the Tennessee valley will continue to stream broken layers of mid and high level clouds across our CWA. These clouds have worked their way south to the Highway 84 corridor. /22/ Tonight through Sunday: Afternoon global guidance continue to show an upper low associated with remnants of Helene rotating over Tennessee Valley as we go through the weekend. Overnight low will in the low 60s across our forecast area. Heading into tomorrow, the remnants of Helene will continue to stall over the Tennessee Valley as global guidance shows mid- troughing lagging across north MS. Expect afternoon highs to peak in the low to mid 80s across the CWA.
Currently - An Atlantic ridge reaches across the Bahamas and across the Keys this evening, resulting in light breezes ranging widely out of the southeast. Deep layered ridging is in place, centered just northeast of the Bahamas, and the lower level swath of enhanced lower level moisture has finally pushed off to our northwest. Expect overnight lows to settle broadly in the lower 80s with dew points remaining in the upper 70s. An Atlantic ridge will remain across Keys waters overnight.
923 PM EDT Sat Sep 28 2024 An upper level low will propagate eastward the next several days, bringing occasional showers and possible thunderstorms. A cold front will move through midweek with high pressure building thereafter. Showers will spread eastward later tonight from the Appalachians to the Blue Ridge Mountains as a closed low inches closer. Overnight lows will drop down into the low to mid 60s for most areas. As upper low advances slowly eastward, expect more showers and possible thunderstorms.
727 PM EDT Sat Sep 28 2024 The remnants of Helene, along with an upper level low, are currently over western KY/TN and will move very slowly eastward through tonight.
858 PM CDT Sat Sep 28 2024 Showers associated with the remnants of Helene and an associated upper level low should continue to diminish in coverage through the night, then likely redevelop tomorrow assisted by daytime heating. A period of several dry days should begin Sunday night as a ridge builds in from the west.
648 PM CDT Sat Sep 28 2024 Tonight through Sunday: Afternoon global guidance continue to show an upper low associated with remnants of Helene rotating over Tennessee Valley as we go through the weekend. Overnight low will in the low 60s across our forecast area. Heading into tomorrow, the remnants of Helene will continue to stall over the Tennessee Valley as global guidance shows mid- troughing lagging across north MS. Expect afternoon highs to peak in the low to mid 80s across the CWA.
(Today and tonight) The synoptic pattern continues to remain rather stagnant with broad upper troughing over the eastern CONUS and a gradually flattening upper ridge over the Four Corners region. Light winds and clear skies will continue today as surface ridging persists and a dry airmass lingers overhead.
- A return to cooler, more seasonable weather is forecast for the first few days of October behind a cold front.
Upper level low pressure will result in cooler than normal temperatures and scattered light afternoon showers through Monday.
Tonight: As the core of the upper low lifts east across the TN Valley into the Appalachians, the sfc reflection will slowly wash out. The aforementioned remnant low will promote increased clouds and a few isolated showers Monday, particularly along and north of the HWY 82 corridor in closer proximity to the low.
Dry Cold Frontal Passage with strong gusty winds today.
Scattered to broken high level cloud cover, evident in infrared satellite imagery, will gradually clear from north to south through the day today as the upper-low proceeds northeast and mid/upper-level ridging stretches over OK/AR. With ridging building aloft, another unseasonably hot late-September day is in store.
Upper low will shift only slightly eastward through Sunday with northwesterly winds resulting in continued dry conditions across the local area. Expect morning lows in the low to mid 60s across northern areas, and in upper 60s to lower 70s in southern areas. Afternoon highs will flirt with or rise just higher than 90 degrees, but will still feel reasonably comfortable given dewpoints in the low to mid 60s.
(Modified Previous Discussion) The cut-off low pressure over the Tennessee Valley will continue to shift eastward and weaken through the day as the Atlantic high pressure ridge builds westward over the Florida peninsula and out into the GOMEX. (Modified Previous Discussion) The upper level Atlantic ridge will strengthen toward south Florida Monday with lingering higher moisture levels across the northern peninsula into mid week.
344 AM EDT Sun Sep 29 2024 A broad area of low pressure will persist over the Southeast U. A dry cold front is then expected to push through the region mid-week, with cooler high pressure building in from the west thereafter. Today: Aloft, the forecast area will continue to be situated within the southwest flow between the large upper low south of the Great Lakes and the ridge situated over the southwest Atlantic. Lows should mostly fall into the upper 60s inland and the low 70s along the coast.
125 AM EDT Sun Sep 29 2024 A broad area of low pressure will persist over the Southeast U. A cold front is then expected to push through the region mid-week, with cooler high pressure building in from the west thereafter. Lows in the mid to upper 60s inland are on track, along with lows in the low 70s along the coast. Deep low pressure will prevail aloft across the southeastern states on Sunday.
121 AM EDT Sun Sep 29 2024 Dry weather will continue for the next few days as high pressure remains centered just to our east.
pdf High pressure ridging over the area will help limit any convection that forms today with the deepest moisture over northeast Florida.
939 PM MDT Sat Sep 28 2024 -Dry weather, much warmer than average temperatures, and critical fire weather conditions on Sunday. -A cold front Monday morning will bring gusty northwest winds. Strong upper ridging continues across the central CONUS. Ensemble guidance shows highs reaching to an impressive mid to upper 90s across much of the lower elevations. A cold front will quickly push through eastern Montana Sunday evening. Ahead of the front, guidance is suggesting even stronger winds developing over southwest to central SD on Sunday evening, as the low level jet strengthens. Highs will be 20 to 30 degrees cooler than Sunday's, ranging from the low 60s over northeast Wyoming to mid 70s over south central SD.
Abundant cloud cover is expected across most of the state today and tonight associated with the aforementioned surface/upper lows. High temperatures should top out a few degrees warmer than observed on Sunday.
Little change is expected as the deep trough over the country east of the MS River will slowly pull off to the east in the coming days.
1240 AM CDT Sun Sep 29 2024 - Northerly wind 15-25 MPH, gusting as high as 35 MPH, and minimum relative humidity between 15-25% will move in behind a cold front Monday afternoon.
1238 AM CDT Sun Sep 29 2024 The closed low noted on satellite imagery spinning over the Tennessee valley will continue to stream broken layers of mid and high level clouds across our CWA. These clouds have worked their way south to the Highway 84 corridor. /22/ Tonight through Sunday: Afternoon global guidance continue to show an upper low associated with remnants of Helene rotating over Tennessee Valley as we go through the weekend. Overnight low will in the low 60s across our forecast area. Heading into tomorrow, the remnants of Helene will continue to stall over the Tennessee Valley as global guidance shows mid- troughing lagging across north MS. Expect afternoon highs to peak in the low to mid 80s across the CWA.
/NEW/ /Through Monday/ Deep northerly flow prevails through the column as we remain situated beneath an amplified western CONUS ridge axis and a deep upper low (and the now-absorbed Helene) to our east.
The forecast for Sunday can only be described as fab-brew-lous as we start out the morning in the low to mid 60s. With 850mb temperatures approaching the 90th percentile, we'll be firmly in above normal territory with warmer air mixing to the surface leading to high temperatures in the low to mid 90s. I suppose asking for cooler temperatures to stick around for more than three days at this point in the year is a tall order. The main axis of an upper level trough extending southwestward from the Ohio River Valley will finally shift eastward on Monday night, which will allow for additional low level moisture to filter in.
Temperatures will gradually warm with values looking to be a few degrees warmer than normal by Monday.
Daytime highs will run several degrees cooler than yesterday's observed highs but still remain 10 or more degrees above normal for most of us. A Canadian trough and associated cold front will shift eastward today, bringing gusty winds and cooler temperatures to southeast Idaho. The dry cold front will bring much cooler air into the area, sending high temperatures into the below normal range on Monday, with much of southeast Idaho only warming into the 60s or below.
An elongated mid-level trough extending from the Ohio River Valley southwest over Texas will continue to provide quiet weather across the region.
1114 PM CDT Sat Sep 28 2024 (Tonight through Monday night) Subsidence on the west side of decaying upper low pressure to the northeast and dry air in the region will result in dry but generally seasonable conditions through the forecast period. As the upper low spins across the eastern US, a few clouds may droop down into north central Louisiana.
Aloft, water vapor imagery continues to indicate a blocking pattern over the CONUS with ridging over the Four Corners Region extending across the northern Plains bookended by a broad trough over the eastern CONUS and another trough off of the southern California coast. Locally, subsidence and high pressure remain the rule with weak northerly flow aloft, maintaining dry conditions that allow for moderately warm daytime highs and cool overnight lows.
Lows will be cooler than they've been the past several nights, in the 40s.
310 AM CDT Sun Sep 29 2024 - A cut-off upper low over the Ohio River Valley will continue to bring clouds and a few showers to parts of central Illinois today.
1132 PM CDT Sat Sep 28 2024 Showers associated with the remnants of Helene and an associated upper level low should continue to diminish in coverage through the night, then likely redevelop tomorrow assisted by daytime heating. A period of several dry days should begin Sunday night as a ridge builds in from the west. Cool temperatures and light rain showers will continue today through Monday as an upper level low pressure system remains overhead.
112 AM EDT Sun Sep 29 2024 A closed off upper low across the Ohio/Tennessee valleys with waves rotating is helping to produce low-level isentropic lift. The closed low over western KY and West TN today will track slowly east-northeast, moving to the central Appalachians by Monday evening. The greatest shower coverage should be in the northern sections, closer to the center of the closed low where cooler temperatures aloft will generate some weak instability. Shower coverage will decrease on Monday evening as the low pulls away.
- Cold front brings cooler temperatures for mid week, but with little chance for rain. High pressure over eastern Ontario will shift east tonight, with winds turning southerly for Monday, ahead of a cold front. With the southerly flow, highs tomorrow look to be just a touch warmer than today, with readings in the low 80s.
113 AM CDT Sun Sep 29 2024 (This evening through Monday) A Low pressure system over western TN/KY continues to produce cloud cover across much of AR, extending eastward across the OH and TN valleys and some mid-Atlantic states. An upper ridge will shift across the forecast area through the period and cloud cover will gradually decrease over the next 48 hours. By Monday afternoon, high temperatures will top out in the lower to upper 80s, with lows in the upper 50s to lower 60s.
(Today through Monday) In the short term, conditions remain relatively uneventful as a broad area of high pressure aloft will maintain dry air and clear skies.
The weakening remnant low pressure from Hurricane Helene is currently located over the Bowling Green area. This low will continue to weaken over the region today and tonight. Thinning skies will allow temperatures to warm a few degrees more than yesterday, into the low-mid 70s. Upper-level low will finally spin down on Monday with remaining vorticity shifting eastward as an open wave given the influence of northern-stream trough quickly moving across the US/Canada border.
(Today through Monday) The remnants of Helene linger around the Tennessee River valley as high pressure tries to build in over Florida from the Atlantic. Rain chances will fall below climatological norms and the lower humidity will help drop heat index values a few degrees but not enough to make up for the southerly flow and abundant sunshine bringing 105 to 110 degree values across much of the area. The northern extent of the trough may not reach far enough north to introduce additional tropical moisture to the region.
The main midlevel deformation axis remains quasi-stationary this evening as the main upper level low pressure circulation moves very little during the next 18 hours. This will result in more influence to Se Mi from the mid level ridge anchored across the northern Great Lakes and will transition the deeper moisture south of the forecast area.
with upper level high pressure centered over the Four Corners region and an upper level low over the eastern U.
High pressure will remain in control over the state, with well above normal temperatures.
1229 AM CDT Sun Sep 29 2024 (This afternoon through Sunday night) WV imagery shows the upper ridge centered over southeast Arizona, resulting in meridional flow this afternoon over West Texas and Southeast New Mexico. As such, the short term continues to remain dry, but with mild temperatures due to the displaced nature of the ridge. Sunday, a trough will make landfall on the west coast in SoCal, nudging the ridge up to just south of the Four Corners.
(Today through Monday) An upper level trough centered over the Ohio Valley, an upper level ridge centered over the Four Corners, and surface ridging extending from the Plains into Central Texas persist. The only clouds would be some cirrus off to our northeast due to remnant moisture of Helene within the upper level trough.
In the mid to upper-levels, a closed low composed of the remnants of Helene continues to slowly move northeast through the Ohio River Valley this afternoon. Closer to the surface (at 925mb), a lower- level low pressure associated with this disturbance can also be observed meandering across the southeastern CONUS. The proximity of this vertically deep low east of our region in tandem with a persistent ridging pattern in the western CONUS with yield a pressure gradient substantial enough to produce windy conditions across the forecast area throughout the evening hours. Northeasterly winds associated with the cyclonic rotation of the closed low pressure will range from 10-15 knots, with occasion gusts over 20 knots possible before relaxing after 23Z.
1241 AM CDT Sun Sep 29 2024 (Tonight through Sunday night) The pressure gradient remains weak through the weekend across the western Gulf of Mexico, with an elongated mid level trough extending from the remnants of Helene in the Ohio River Valley southwest across Texas. With a southwesterly downsloping flow, expect temperatures a few degrees warmer for both today and Sunday afternoon, into the mid to upper 90s.
(Today through Monday) Center of upper low circulation was over central Kentucky this morning, with an axis extending from Pennsylvania to the Arkansas- Louisiana border. Ridge axis extended from the Four Corners region to Minnesota. While the axis of the upper trough doesn't really change much over the next 36 hours, the center of the circulation begins to lift out to the northeast.
Satellite imagery showing clouds associated with the approaching dry cold front lined up across w-central Oregon this evening. After today's record highs in the 90s at lower elevations, we'll see temperatures 10-20 degrees cooler across the region on Sunday. Turning cooler Sunday as a Pacific cold front moves through. The air mass behind the front is much cooler and also very dry.
This is due to broad troughing that will continue to weaken across the Appalachian Mountains.
A few light showers may be associated with this moisture associated with the ripples rotating around the upper low feature. For highs today, readings in the S should be similar in the lower to middle 80s. The NRN half of the area should see slightly warmer highs today with less low stratus, in the middle 70s to around 80.
A weak trough and associated dry cold front will brush the area today into Monday.
The upper low will make slow progress toward the Appalachians today and tonight.
The low had filled significantly during the past 24 hours, but scattered showers were still abundant north of the low in a large waning deformation zone.
With the low further north, the coverage should be a bit less than yesterday with the best chances north of the Tennessee River. Overall, another cool day for late September with highs this afternoon topping out in the lower 70s.