Aikyam-Lab/Synoptic-Bench huggingface dataset:
515 AM CDT Wed Sep 29 2021 Highly amplified upper ridge remains parked over the Mississippi Valley early this morning, with its axis slowly drifting eastward today. Certainly an anomalous ridge by late September standards with 500mb heights sitting near the 99th percentile per NAEFS, though temperatures are expected to remain safely below daily records. The ridge will continue to be nudged eastward tonight by a broad longwave trough spanning the western CONUS. Meanwhile a cold front and accompanying line of convection will be crossing the Northern Plains. The upper ridge, with its axis just east of our area, begins to collapse on Thursday as the upstream trough morphs into a weak closed low over the Four Corners region. That said, models are finally coming into somewhat better agreement on their handling of individual waves as the longwave trough breaks down.
Fog and the lower, near-surface stratus will dissipate by mid morning, but low cloud cover is still forecast across much of the central and southern parts of the state through the day. The upper ridge will continue to slowly shift eastward, with its west side still over the Midwest and South-central states for a few more days. The upper trough and southwest flow will shift farther east as well, expanding coverage of showers and storms across much of the state. Increased cloud cover and precipitation will keep high temperatures over the next few days in the lower to mid 80s range, while low temperatures remain in the 60s.
934 AM EDT Wed Sep 29 2021 High pressure will maintain dry and seasonable conditions for the remainder of the week.
701 AM EDT Wed Sep 29 2021 Outside of a few higher based clouds this morning, high pressure and very dry air will maintain clear skies into tonight. The high pressure will extend across Lake Huron and Se Mi today, providing light winds. * None A closed low system will draw south today from Quebec into New England while ongoing amplification of a trough across the Four Corners region eventually closes off late Wednesday into early Thursday.
630 AM CDT Wed Sep 29 2021 The forecast concerns in the short term will be showers and thunderstorms developing along a slowly advancing cold front this afternoon into tonight. This will interact with a southeast advancing Pacific cold front. Highs today will range from 65 to 75 behind the front across the northwest Sandhills to the low 80s ahead of the front across all of the southeast. 5 inches near and ahead of the slowly advancing Pacific cold front. Temperatures will be much cooler in the upper 60s.
A skinny upper ridge will get squeezed between troughs over the western half of the country and the northeast through Thursday. A weak upper disturbance will lift north from the lower Mississippi Valley today through Missouri Thursday.
Temperatures will warm back to seasonal normals by Thursday as high pressure builds over the region. Many valleys in western Montana and higher valleys of central Idaho will see temperatures drop to or below freezing.
/Issued 216 AM CDT Wed Sep 29 2021/ The main forecast challenge will be rain/convective chances over the next several days, as the hot/dry pattern this past month transitions to a cooler and wetter one. A frontal boundary will push into the High Plains on Thursday, with increasing warm advection over our area ahead of the front setting off convection that will spread into the region.
417 AM PDT Wed Sep 29 2021 Northwest flow exists in the upper levels this morning as the jet stream dividing eastward exiting upper level troughing and westward arriving upper level ridging translates across the forecast area. Temperatures have fallen to near or below freezing across most of Lake County where there has been less cloud cover, and below freezing temperatures are also being observed across portions of Modoc and Klamath counties. With high pressure building in stronger from the southwest today, highs this afternoon are expected to be 7 to 15 degrees warmer than they were yesterday.
720 AM EDT Wed Sep 29 2021 Dry high pressure will persist through the short term. The high amplitude upper ridge will keep us in a stable northwest flow aloft.
High clouds continue to spill southward into NorCal over the eastern Pacific ridge. Clouds have thinned over the past few hours, and mountain valley areas with light winds have cooled into the 30s (some of the mountain valleys will see their first freezing temperatures of the season by sunrise this morning). Across the valley and foothills, sufficient offshore surface pressure gradient remains for local north to east gusts in the teens to low 20s mph and the wind and the breezes are keeping temperatures in the lower to mid 60s. Milder temperatures are expected across the region through the remainder of the week as high pressure rebounds from the early week trough. Highs will warm to a little above average with warmest readings forecast to reach the lower 90s across the Central Valley.
543 AM EDT Wed Sep 29 2021 High pressure will maintain dry and seasonable conditions for the remainder of the week.
A mid- and upper-level ridge axis is currently splitting the state of Alabama in half, providing deeper southerly flow over Mississippi. Otherwise, look for lows in the low to mid 60s. Our pattern over the next few days will be dictated by a high pressure system at the surface anchored over the Appalachians and Mid Atlantic region while an upper level ridge axis remains situated over the Alabama/Georgia state line.
Temperatures currently in the lower/mid 80s for much of the area, cooler near the lake, are running 10-15 degrees above normal for late September. More of the same for highs on Thursday, perhaps a few degrees cooler, but 80s for the most area, still cooler near the lake with easterly flow. cms 220 AM CDT The prominent upper ridge that has been responsible for a period of quiet and unseasonably warm conditions across the region will begin to erode late this week, initiating a large scale pattern change across the CONUS.
As the the surface front moves south toward the I20 corridor tomorrow morning and early afternoon, an open wave associated with the deepening upper level trough axis to the west ejects northeast over the cold front. A limited window of thermal instability (approx 1000 J/K) in the early/mid afternoon may increase general thunderstorm coverage across the southern South Plains and eastern New Mexico, with the most coverage and most intense rainfall expected along the cold front to our south.
1141 AM EDT Wed Sep 29 2021 A weak moisture starved cold front will drop south into South Carolina late today. High pressure will build down from the north behind it Thursday into late week.
The leading edge of the cold front can be seen on radar this morning nudging into north central SD and trailing back into the Badlands. So far, all precip is confined behind the front where upper level support increases in a broad upper trough. Other than some lingering mid level moisture in the morning, the effects of the cold front will have exited to the east.
236 PM CDT Wed Sep 29 2021 Look for showers and thunderstorms to continue for much of the short term as a cold front continues to push through the state. Cold front has slowed its eastward progression today, with showers and a few thunderstorms developing along and behind it.
123 PM EDT Wed Sep 29 2021 Clear skies hold this taf period as high pressure anchored over the region sustains very dry conditions. * None A closed low system will draw south today from Quebec into New England while ongoing amplification of a trough across the Four Corners region eventually closes off late Wednesday into early Thursday.
1224 PM CDT Wed Sep 29 2021 The forecast concerns in the short term will be showers and thunderstorms developing along a slowly advancing cold front this afternoon into tonight. This will interact with a southeast advancing Pacific cold front. Highs today will range from 65 to 75 behind the front across the northwest Sandhills to the low 80s ahead of the front across all of the southeast. 5 inches near and ahead of the slowly advancing Pacific cold front. Temperatures will be much cooler in the upper 60s.
242 PM MDT Wed Sep 29 2021 Scattered showers with northerly to northwest winds ongoing this afternoon with mostly cloudy skies after the cold front passed through the CWA earlier today. Temperatures sit 20-30F degrees cooler than this time yesterday afternoon as more fall- like weather arrives. Skies will begin to clear for Thursday with cooler weather sticking around.
GRB CWA will remain on the western periphery of a large Great Lakes high pressure system. A high-amplitude upper level ridge will also be situated over the western Great Lakes region.
228 PM EDT Wed Sep 29 2021 High pressure ridge that has been over the area for a week will continue to dominate the weather pattern through the short term. This ridge is beginning to weaken and starting to let a bit more moisture in across the area. The ridge is keeping things very stable so still not expecting any precipitation through Thu night.
/Issued 720 AM EDT Wed Sep 29 2021/ Dry high pressure will persist through the short term. The high amplitude upper ridge will keep us in a stable northwest flow aloft.
An upper level trough will deepen over the Four Corners region tonight into tomorrow. Expect mild temperatures tonight, with lows in the 60s and slightly cooler temperatures tomorrow, with highs in the upper 80s.
Light east to NE winds, with temperatures in the mid 70s over central Ohio, topping out in the lower 80s in the greater Cincinnati area. High pressure continues to bring a light east-northeast flow tonight through Thursday with low relative humidity values. Model solutions continue to be in fairly good agreement with amplified mid level flow and a ridge over the Mississippi Valley building east into the area at the end of the week.
Temperatures ranged from the mid 70s in Norfolk to the the lower 80s in the Loess Hills. Through Thursday: Periodic rain and thunderstorm activity should continue across the region as an upper level trough and surface front continue to interact with deep fetch of subtropical moisture (PW values near 1.
Portions of Esmeralda and Nye counties are expected to see their first sub-freezing temperatures of the season overnight tonight. Breezier conditions are expected during the afternoon period today and tomorrow with the highest wind gusts expected tomorrow afternoon in the southern portion of the Colorado River Valley near Laughlin/Bullhead City.
448 PM EDT Wed Sep 29 2021 High pressure will maintain dry and seasonable conditions for the remainder of the week.
With high pressure stretched from the Mid Atlantic Seaboard westward across the northern Gulf of Mexico, our region will remain trapped in an east to northeast flow with little to no southerly flux of tropical moisture.
333 PM EDT Wed Sep 29 2021 High pressure anchored over eastern Canada will keep generally fair cool weather over our region through the end of the week. High pressure over eastern Canada will keep a light northerly flow in place across our region through the period.
337 PM CDT Wed Sep 29 2021 The stretch of dry and unseasonably warm conditions will extend through Thursday, but then the pattern changes for the weekend as a frontal system lifts into the region, threatening us with widespread rainfall and cooler temperatures. Skies will remain mostly clear tonight as temperatures fall into the lower 60s.
Afternoon temperatures will remain cooler than average during much of the forecast. Current water vapor shows a longwave trough moving through the western U. Later this afternoon a vort max will rotate around the western side of the trough into southern Arizona and help drive our weather through Thursday.
1236 PM CDT Wed Sep 29 2021 A mean mid/upper trough remains situated across much of the Rockies and Central Great Basin area while weak southerly/southwesterly mid/upper flow prevails over the Central Plains. A narrow mid/upper ridge axis remained situated from the Southeastern U.
Deep layer ridge will remain over the area and continue the dry weather through Thursday.
315 PM EDT Wed Sep 29 2021 Synoptic-scale ridging fully entrenched across the state supports ample column stability and mild conditions through the next 60 hours. Abundant sunshine with weak ENE flow (outside lake breeze zones) flourishes until an Omega Block pattern breaks down with the progression of a Pacific Northwest longwave trough. Confluence aloft over Lake Huron suggests shearing vicinity jet streak drifts east into southern Ontario with the departing Northeast upper low.
An upper level trough will deepen over the Four Corners region tonight into tomorrow. Expect mild temperatures tonight, with lows in the 60s and slightly cooler temperatures tomorrow, with highs in the upper 80s. In addition to large scale lift generated from the Four Corners trough, a surface boundary is forecast to drop southward into the area late Thursday/Thursday night.
The flow aloft over our area will be west- southwest today, as the southern portion of the western CONUS trough deepens over the Desert southwest. Highs this afternoon are expected to be 90-95 degrees across our area behind the dryline, with considerable sunshine and 850mb thermal ridging. The flow aloft over our area will back to the southwest tonight, as the aforementioned upper trough deepens further over the Four Corners area.
Satellite imagery shows a wave riding over the ridge in the Eastern Pacific and coming ashore in Washington and northern Oregon this morning. At the same time the offshore ridge is amplifying into our area and this will prevent showers from getting very far into our area for the next 24 hours. Have similarly raised them a degree or so where temperatures were running warmer than forecasted.
A fairly amplified upper level pattern was in place over the CONUS with a ridge axis across the central U. and trough axis over the western U. Several waves of energy were noted within the western trough to the southwest of our CWA, with the closest one in Oklahoma, which was aiding in some scattered convection. The increase in cloud cover and scattered rain will keep temperatures cooler than we've had the past several days with highs from the low to mid 80s over the area.
Temperatures in some locations look to be warming a little slowly due to locally dense areas of fog, thus, some minor adjustments to the hourly trend have been made but the high temperature remained untouched. High temperatures for most valley locations today will be in the low to mid 80s with mostly clear skies. Have CHA reaching MVFR at the lowest with TYS and TRI going down to IFR. KS Chattanooga Airport, TN 63 85 63 85 64 / 0 0 0 10 0 Knoxville McGhee Tyson Airport, TN 61 85 61 84 61 / 0 0 0 10 0 Oak Ridge, TN 61 85 61 83 60 / 0 0 0 10 0 Tri Cities Airport, TN 55 82 53 82 55 / 0 0 0 0 0.
1255 PM EDT Wed Sep 29 2021 Aviation - Upper ridging breaks down late week with chance of rain over the weekend Blocking pattern this week with upper low across the NE CONUS and ridge axis near the central Great Lakes. The ridge breaks down late week with some moisture return beginning as the high moves further east.
132 PM EDT Wed Sep 29 2021 High pressure brings dry, pleasant Fall weather through the end of the week. Increasing chance for showers and afternoon storms return by the end of the weekend ahead of a cold front. High temperatures on Thursday will struggle to reach the 80 degree mark across the lowlands, ranging into the mid 50s at higher elevations. Dominating upper ridging will support dry weather for the Central Appalachians through the bulk of the forecast period.
High pressure will build into the region on Thursday and will bring dry and warming conditions through the weekend.
1231 PM CDT Wed Sep 29 2021 Highly amplified upper ridge remains parked over the Mississippi Valley early this morning, with its axis slowly drifting eastward today. Certainly an anomalous ridge by late September standards with 500mb heights sitting near the 99th percentile per NAEFS, though temperatures are expected to remain safely below daily records. The ridge will continue to be nudged eastward tonight by a broad longwave trough spanning the western CONUS. Meanwhile a cold front and accompanying line of convection will be crossing the Northern Plains. The upper ridge, with its axis just east of our area, begins to collapse on Thursday as the upstream trough morphs into a weak closed low over the Four Corners region. That said, models are finally coming into somewhat better agreement on their handling of individual waves as the longwave trough breaks down.
(Modified Previous Discussion) Favorable boating conditions with high pressure north of the area.
149 PM EDT Wed Sep 29 2021 High pressure brings dry, pleasant Fall weather through the end of the week. Increasing chance for showers and afternoon storms return by the end of the weekend ahead of a cold front. High temperatures on Thursday will struggle to reach the 80 degree mark across the lowlands, ranging into the mid 50s at higher elevations.
203 PM MDT Wed Sep 29 2021 19z surface analysis had cold front from eastern ND into central NE, just east of the CWA. Narrow axis of 250-500J/kg MUCAPE behind cold front over south central SD supporting shra/ts lifting northward. Thursday, upper trough weakens as it settles into a weak circulation over the southwest CONUS.
/issued 1119 AM CDT Wed Sep 29 2021/ Upper level ridging across the Mid-South will gradually weaken over the next few days. Temperatures and humidity also remain on the high side as mid to upper level ridging continues to prevail over our area.
146 PM EDT Wed Sep 29 2021 High pressure anchored over eastern Canada will keep generally fair cool weather over our region through the end of the week. High pressure over eastern Canada will keep a light northerly flow in place across our region through the period.
122 PM EDT Wed Sep 29 2021 High pressure will maintain dry and seasonable conditions for the remainder of the week.
Lows tonight will range from the upoer 60s to near 70, while highs tomorrow will be limited to the low 80s due to early morning cloud cover.
Little variation is expected in the upper pattern as a sharp ridge of high pressure remains anchored over the Midwest with cut-off lows both over the northeast U.
Stout meridional upper level ridging begrudgingly shifts eastward over the course of the next 24 hours with an equally long transition window for the sensible weather. High cirrostratus has been infiltrating the forecast area throughout the day as they overtop the upper tropospheric ridge, but any associated showers have been tied closer to the near-surface warm front lifting along the mid-Missouri River Valley. Given the highly amplified nature of the ridge, this is a very plausible scenario and have delayed/shift westward the shower threat for Thursday. Given the westward shift in the forecast, have increased high temperatures for the day on Thursday--pushing the low to mid 80s at most locales.
Low temperatures tonight will range from the lower 50s west of the Missouri River, to around 60 degrees in west central Minnesota. High temperatures on Thursday will be in the lower to mid 70s, with lows Thursday night ranging from the mid 40s across north central South Dakota, to the upper 50s in west central Minnesota.
The highly amplified, blocky pattern will persist across the CONUS for the next several days. Mean layer ridging to our west and northwest will provide upstream support for a high pressure system more or less centered over the southeastern United States and extreme western North Atlantic.
Cooler air is steadily in place to make sure temperatures don't climb over the mid 60s today.
Temperatures as of mid- afternoon were in the upper 70s to the lower 80s over the Bluegrass with readings in the 82-86 degree range across southern Indiana, and across central (I-65) and western KY. For the overnight, high pressure will build into the region with mostly clear skies. Elsewhere, temps will be a bit warmer across southern Indiana and the portion of central Kentucky along and west of I-65. Quiet and dry weather will continue on Thursday, though temperatures should be a bit cooler than what we saw on Wednesday.
Tomorrow will be significantly cooler behind the front with highs expected to be mostly in the mid 60s, which is slightly below average for this time of year. This looks to be the trend for the remainder of the 7-day with most days seeing highs generally in the 60s to right around 70 (again, cooler than average).
Omega block is situated across the CONUS with upper level ridging centered from the Gulf Coast through the Mid-South into the western Great Lakes. A weak upper level disturbance is rotating around the large western trough and slowly approaching the Mid-South resulting in isolated showers across the Delta region.
315 PM CDT Wed Sep 29 2021 (Issued 315 PM CDT Wed Sep 29 2021) Tonight and Thursday: Southern Wisconsin will continue to benefit from a nearly stationary weather pattern across much of the CONUS, with a blocking high pressure ridge providing dry and pleasant conditions for the end of September. Surface dewpoints are 5 to 15 degrees warmer than 24 hours ago.
244 PM MDT Wed Sep 29 2021 Showers and isolated thunderstorms ahead of an upper level trough will continue over the mountains and Front Range Urban Corridor through the evening. Northerly winds behind a cold front are turning northeast west of I-25 and are aiding in the lift for showers. Weak ridging is expected to produce subsidence and keep most of the area precipitation free. Models have an upper closed low to move slowly southward across Utah Thursday night.
102 PM EDT Wed Sep 29 2021 Aviation - Upper ridging breaks down late week with chance of rain over the weekend Blocking pattern this week with upper low across the NE CONUS and ridge axis near the central Great Lakes. The ridge breaks down late week with some moisture return beginning as the high moves further east.
1119 AM CDT Wed Sep 29 2021 Upper level ridging across the Mid-South will gradually weaken over the next few days. Temperatures and humidity also remain on the high side as mid to upper level ridging continues to prevail over our area.
As the trough slowly moves east, surface convergence along a frontal boundary will develop a broken line of storms in western NE/KS this evening.
High pressure is expected to slowly build back into the region allowing for a slight warming trend and dry conditions to settle in hang around for the start of next.
505 PM EDT Wed Sep 29 2021 High pressure anchored over eastern Canada will keep generally fair cool weather over our region through the end of the week. High pressure over eastern Canada will keep a light northerly flow in place across our region through the period.
749 PM EDT Wed Sep 29 2021 A weak backdoor cold front will move through overnight, with a reinforcing high pressure area moving in behind the front for the weekend. Even with a weak backdoor cold front moving in from the north overnight, still expecting mostly clear skies and light winds. This should allow overnight temperature readings to drop down into the lower to middle 60s. An upper level low will remain entrenched over New England and the Canadian Maritimes for the second half of this week.
436 PM MDT Wed Sep 29 2021 19z surface analysis had cold front from eastern ND into central NE, just east of the CWA. Narrow axis of 250-500J/kg MUCAPE behind cold front over south central SD supporting shra/ts lifting northward. Thursday, upper trough weakens as it settles into a weak circulation over the southwest CONUS.
By sunrise a narrow ridge currently along the Mississippi River Valley will shift east of the River and additional showers and thunderstorms should develop. Omega block is situated across the CONUS with upper level ridging centered from the Gulf Coast through the Mid-South into the western Great Lakes. A weak upper level disturbance is rotating around the large western trough and slowly approaching the Mid-South resulting in isolated showers across the Delta region.