Aikyam-Lab/Synoptic-Bench huggingface dataset:
Model guidance usually does not handle these low inversions well, but as for now they show stratus dissipating late morning then transitioning to pockets of shallow cumulus over the higher terrain later today. A few clouds may form over the higher terrain this afternoon but won't pose any aviation hazards.
1123 AM CST Thu Nov 28 2024 (Rest of today through Friday) Happy Thanksgiving! Obs this morning show that the cold front has completely moved through Middle TN with current temperatures chilly in the mid-40s. (Friday Night through next Thursday) Even colder mornings are ahead as low temperatures Friday night fall into the low and mid-20s.
For temperatures, tonight should be near or a couple of degrees warmer overnight. Upper level low over northeast North America with ridging along the west coast will bring northwest flow aloft over a good amount of the central and eastern U.
(This evening through Friday) Thin high clouds spreading over the area from the south today due to a deep upper low situated well off the coast of SoCal. This low will promote general upper-level cloudiness, but no real impacts expected at the surface aside from more limited outgoing longwave radiation overnight. This will help keep temps a bit warmer tonight, but only by a couple of degrees. Another 2-3 degrees added to the high temperatures tomorrow as the cloud cover overnight keeps our starting temperature a bit higher and warmer, more moist southerly flow increases in the low to mid levels as the upper low approaches SoCal.
556 PM CST Thu Nov 28 2024 Updated at 527 PM CST Thu Nov 28 2024 - A Freeze Warning is in effect from late tonight through Friday morning for the Central and Eastern Permian Basin into portions of the Lower Trans Pecos. However model guidance suggests that a quick moving upper disturbance will bring in drier air aloft that will clear skies and should send temperatures below freezing in several areas that have not seen subfreezing temps yet. These southerly winds won't be reflected in afternoon highs but lows tomorrow night begin to edge upward again and should be above freezing everywhere.
Brisk northwest flow aloft will continue across Colorado tonight and Friday as upper trough deepens over the Great Lakes.
609 PM CST Thu Nov 28 2024 (This evening through Friday Night) Cold and quiet weather is expected for the short-term, as the main trough axis begins to move through the region tonight.
Still, we don't expect to see a great deal of clearing until very late tonight and especially tomorrow throughout the day as the upper trough finally swings through the area. Winds will remain somewhat gusty tomorrow owing to a strong surface pressure gradient, but high pressure building in from the west will at least keep us dry, albeit quite chilly for the foreseeable future. (Rest of today through Friday) Happy Thanksgiving! Obs this morning show that the cold front has completely moved through Middle TN with current temperatures chilly in the mid-40s. (Friday Night through next Thursday) Even colder mornings are ahead as low temperatures Friday night fall into the low and mid-20s.
521 PM CST Thu Nov 28 2024 (Rest of today through Friday) Happy Thanksgiving! Obs this morning show that the cold front has completely moved through Middle TN with current temperatures chilly in the mid-40s. (Friday Night through next Thursday) Even colder mornings are ahead as low temperatures Friday night fall into the low and mid-20s.
HRRR guidance picked up on the low stratus this morning over Gunnison, Steamboat Springs and around Eagle but is showing no sign of it for tomorrow morning. Temperatures will start out 5-10 degrees below normal, but as ridging builds in, temperatures will gradually warm to near or slightly above normal. Dry weather dominates, although a few weak waves clipping the northern mountains will bring a low (<15%) but non-zero chance of light snow showers over the high peaks, with little, if any, accumulations. A few clouds may form over the higher terrain this afternoon but won't pose any aviation hazards.
Northwest flow will ease up a bit overnight but still may be enough to get some very light snow accumulations in the higher elevations in the East Tennessee Mountains and SW Virginia mountain peaks. Elsewhere, will be dry with temps dropping tonight to at or near freezing in the Tennessee Valley. A deep and broad longwave trough will be in place across the central U.
645 PM CST Thu Nov 28 2024 High pressure settling over the region overnight and clear skies will yield optimal radiational cooling conditions, especially at the valley sites (KBVO, KFYV).
Drier conditions today with areas of sunshine as ridging begins to build into the Pacific Northwest.
As of 900 PM EST, low pressure continues to depart the region with the center moving across the Gulf of Maine. Key Messages: - Lake effect snows into portions of the western Adirondacks - Colder air arriving for the weekend with temperatures below normal Discussion: Near zonal flow will be in place across the region heading into the weekend with an upper level low parked across northern Ontario and Quebec. This low will usher in a much colder air mass into the Northeast, with 850 hPa temperatures dropping to around -10 C by Friday afternoon.
HRRR guidance picked up on the low stratus this morning over Gunnison, Steamboat Springs and around Eagle but is showing no sign of it for tomorrow morning. Temperatures will start out 5-10 degrees below normal, but as ridging builds in, temperatures will gradually warm to near or slightly above normal. Dry weather dominates, although a few weak waves clipping the northern mountains will bring a low (<15%) but non-zero chance of light snow showers over the high peaks, with little, if any, accumulations.
High pressure will gradually build into the area and persist through at least the next seven days, providing dry, quiet conditions. An amplified long-wave pattern across the CONUS is locking a stagnated pattern of ridging along the Pacific Northwest Coast, while a downstream amplified trough brings colder air across the eastern half of the country.
534 PM CST Thu Nov 28 2024 Updated at 206 PM CST Thu Nov 28 2024 - Below freezing temperatures Friday morning, with below-average temperatures persisting through the weekend. With the high over the area, light winds are expected tonight. Temperatures are expected to fall below freezing across the area by Friday morning with lows ranging from the mid 20s in northern OK to around 30 near and south of the Red River.
Highs will be in the lower teens to 20s, with lows in the single digits below and above zero.
838 PM EST Thu Nov 28 2024 A strong cold front will move off the coast this evening with much colder air arriving Friday and lingering through the weekend.
452 PM CST Thu Nov 28 2024 Happy Thanksgiving! The remainder of today will remain cool and breezy in the wake of an upper system that brought a cold frontal boundary through the CWA. By this afternoon into the evening, temperatures are expected to drop into the lower 50s to upper 40s. This will allow for efficient cooling along and north of the Hwy 82 corridor overnight, decreasing temperatures to below freezing. Elsewhere, cloud cover will prevent lows from dipping below freezing overnight. 0 inch across the Lower MS River Valley. Despite sunny skies, temperatures will remain in the lower to upper 50s, which will call for a brisk day across the region on Friday.
841 PM CST Thu Nov 28 2024 High pressure settling over the region overnight and clear skies will yield optimal radiational cooling conditions, especially at the valley sites (KBVO, KFYV).
With temperatures below freezing some slick spots are also possible. With the area of cold, foggy air expanding northeast into Friday it is likely that the Spokane Airport will struggle to reach freezing and lowered their high temperature forecast. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: With a light wind regime expected Friday, the low cloud deck could spread into Pullman.
1105 PM CST Thu Nov 28 2024 Updated at 1103 PM CST Thu Nov 28 2024 - A Freeze Warning is in effect from late tonight through Friday morning for the Central and Eastern Permian Basin into portions of the Lower Trans Pecos. However model guidance suggests that a quick moving upper disturbance will bring in drier air aloft that will clear skies and should send temperatures below freezing in several areas that have not seen subfreezing temps yet. These southerly winds won't be reflected in afternoon highs but lows tomorrow night begin to edge upward again and should be above freezing everywhere.
(Today through Saturday) Cold high pressure continues to build into our area early this morning. Temperatures will continue to fall there with some low temperatures around freezing around sunrise.
358 AM EST Fri Nov 29 2024 Broad high pressure remains over the region through mid week. Key Messages: 1) Dry and below freezing overnight temperatures. Lows by morning should be below freezing across the mountains and near freezing elsewhere. Tonight, expect even colder air as widespread temps drop below freezing throughout the CWA.
Deep layer troughing is evident across the southern Hudson Bay with and low amplitude ridging centered over the desert southwest extending north into the Canadian Rockies is bringing northwest flow both at the surface and aloft to the northern plains. Currently we are in the sweet spot between the low to the east and ridging to the west with convergence aloft reinforcing building arctic high pressure at the surface which extends from Saskatchewan to Kansas along the front range of the rockies. This high is characterized by bitterly cold late november temps with Saskatoon already hitting - 20F at 1AM and teens as far south as western Kansas.
(Today through Saturday) A cold front currently over North-Central Florida will continue to move southward today, and end up pushing through South Florida by tonight. Winds will be out of the south/southwest over South Florida today ahead of the front, allowing for temperatures to again warm up into the low to mid 80s across the area. Highs on Saturday will be cooler then today, ranging from the low 70s across the Lake Okeechobee region to the mid to upper 70s across the rest of the area.
Upstream obs have been showing periodic flurries this afternoon, which should continue tonight as an upper trough swings through the region. However, upper ridging over the western U.
Despite the decreasing clouds, a seasonably cool airmass will remain in place (925 mb temps only 6-8C) which will only support highs in the low to mid 60s. The lower clouds will begin to lift back north late tonight as the 850mb flow veers more southerly, but they don't look to arrive early enough in the night to result in warmer overnight mins.
19z subjective surface analysis suggests a cold front is located from near Fort Smith, to near Jonesboro. A high pressure ridge axis, aligned through much of the plains, will move slowly eastward during this period.
This increase is likely associated with a weak disturbance rounding the base of the upper trough over the region. A much cooler and drier airmass will continue to move into the area tonight. Areas in the clearing will see temps fall to freezing or below, so a Freeze Warning has been issued for counties/parishes that are expecting freezing temps, that haven't experienced a first freeze yet. /20/ (This evening through Friday Night) Cold and quiet weather is expected for the short-term, as the main trough axis begins to move through the region tonight.
Still, we don't expect to see a great deal of clearing until very late tonight and especially tomorrow throughout the day as the upper trough finally swings through the area. Winds will remain somewhat gusty tomorrow owing to a strong surface pressure gradient, but high pressure building in from the west will at least keep us dry, albeit quite chilly for the foreseeable future. (Rest of today through Friday) Happy Thanksgiving! Obs this morning show that the cold front has completely moved through Middle TN with current temperatures chilly in the mid-40s.
Updated at 1228 AM MST Fri Nov 29 2024 - Seasonal temperatures expected today - Warmer this weekend as dry and calm conditions persist A very quiet weather pattern is expected through the forecast period. Today will be the coolest day of the period as high pressure settles into the southern Plains. However, global models are signaling for a cut-off low strengthening off the SoCal/northern Baja coast underneath a Rex block around midweek. The ensembles keep the low too far west for us to see any real impacts, just more high clouds streaming overhead. The warmer conditions result in lower humidities as the cooler airmass shifts to the east.
The forecast has been updated to account for fog/freezing fog and low clouds in many of the places expected tonight, which are very similar to last night and this morning. This is the time of year for persistent fog, and with high pressure overhead and plenty of moisture at the surface due to recent rains, suspect fog will remain widespread across the region well into the morning, and much like today, some areas may never clear from fog or low clouds throughout the day tomorrow. Dense fog or freezing fog advisories may be necessary by daybreak, but will issue those if/when and where conditions warrant as the night goes on. IFR and LIFR ceilings and visibilities with fog and freezing fog remain in the forecast for area terminals and other low-lying areas.
Tonight temperatures plummet below freezing once again, but it is almost Dec already, so this is near normal. This will allow surface temperatures to be a couple to three degrees warmer tomorrow afternoon than today.
316 AM EST Fri Nov 29 2024 The region will be in between broad low pressure to the northeast and high pressure building into the Mississippi and Tennessee Valleys through the weekend.
Updated at 226 AM CST Fri Nov 29 2024 - Cooler than average high temperatures expected today with another chilly night expected tonight. (Today and tonight) Dry and quiet weather is expected through the short term period as an upper level low spirals across the eastern Canadian provinces and a weak ridge builds to our west. High clouds are expected to roll into the region this afternoon, but won't limit daytime heating with temperatures a few degrees warmer than yesterday in the 50s. Another chilly night is in store, in the upper 20s to mid 30s with warmer lows across the southern South Plains and Rolling Plains where a few mid-level clouds could limit radiational cooling.
Northwest flow will ease up a bit overnight but still may be enough to get some very light snow accumulations in the higher elevations in the East Tennessee Mountains and SW Virginia mountain peaks. Elsewhere, will be dry with temps dropping tonight to at or near freezing in the Tennessee Valley.
The thicker the clouds, the less outgoing longwave radiation is emitted, thus temperatures run relatively warmer. The thinner the clouds, the more outgoing longwave radiation is emitted, thus temperatures run relatively cooler.
The forecast has been updated to account for fog/freezing fog and low clouds in many of the places expected tonight, which are very similar to last night and this morning. This is the time of year for persistent fog, and with high pressure overhead and plenty of moisture at the surface due to recent rains, suspect fog will remain widespread across the region well into the morning, and much like today, some areas may never clear from fog or low clouds throughout the day tomorrow. Dense fog or freezing fog advisories may be necessary by daybreak, but will issue those if/when and where conditions warrant as the night goes on. Freezing fog may be possible as well.
(Today through Saturday) A longwave trough is currently stretched across much of the eastern CONUS, which features a quasi split flow, and a westerly mid- to upper-level jet emanating over the Southeast. A large high pressure system is currently spilling across the Plains and this is associated with a Polar airmass overspreading our region this morning. Saturday will be quiet with high pressure remaining - I've got highs in the 50s with ample sunshine.
Temperatures in the lower to mid 50s, expected to fall into the lower to mid 40s by daybreak Friday. 08/DML (Tonight through Saturday night) Much cooler air is driving down into the region behind a cold front. Temperatures were largely able to warm into the low 60s today, but obs indicate temps are dropping already this afternoon. Cloud cover and elevated winds will limit just how cool we can become overnight; lows should bottom out in the low to mid 40s. Central Louisiana is expected to drop into the low 30s with many areas experiencing a brief period at or below 32F.
Drier conditions persist tonight as ridging begins to build over the northeastern Pacific.
Clouds this morning clear throughout the day with a few lingering flurries across the higher terrain of northeast Tennessee and southwest Virginia. Discussion: Longwave troughing is evident in WV imagery and observations across the Eastern CONUS this morning. Tonight, high pressure across the region will result in mostly clear and dry conditions. Troughing and the 850mb temperatures below the 10th climatology percentile will result in much below normal temperatures.
Synoptic overview and current conditions: Water vapor imagery and upper level analysis show a broad upper level trough south of upper level low pressure over central and eastern Canada. Lows will be in the low 20s in the east to around 30 in the west. Some light snow will be possible there on Saturday morning, but temperatures will likely be rising above freezing during the afternoon there and if any impacts occur with this system it should be short lived. 60 and the higher POPS near the Lake of the Ozarks and Rolla. Temperatures through the weekend: We could see temperatures warm into the low 50s in our southwest CWA away from the precipitation chances on Saturday while further northeast in the upper 30s to around 40.
Many locations, especially areas farther east, are likely to wake up to some cooler overnight low temperatures early Saturday morning in comparison to early Friday morning.
1256 AM EST Fri Nov 29 2024 A strong cold front will move off the coast this evening with much colder air arriving Friday and lingering through the weekend.
High pressure offshore will maintain cool and dry weather across the region through at least the start of the upcoming week.
Discussion: Near zonal flow will be in place across the region heading into the weekend with an upper level low parked across northern Ontario and Quebec. Discussion: A broad mid and upper level trough will be over the eastern US through the middle of the week, which will continue to funnel colder air into the region.
BNA was expected to hit freezing this morning as we are already at the latest date on record for the first freezing temps of fall. It will be tricky as the low clouds hold temps up slightly. If BNA does indeed reach freezing this morning, it will be brief. (Saturday Night through next Friday) Northwest flow aloft will keep the chilly air coming our way with occasional weak impulses and surface cold fronts.
1123 PM CST Thu Nov 28 2024 A nearly stationary gravity wave developed downwind of the North Shore terrain ridge.
As it does, the low level flow will begin to slowly back around more to the west and then southwest.
Currently - A weak dying ridge stretching across South Florida, along with earlier mainland day time heating, is driving light broadly northerly breezes across the Keys and surrounding waters. Mild conditions continue with temperatures in the lower to mid 70s with dew points in the upper 60s. The atmosphere remains fairly dry and stable despite the Keys residing within the far southern periphery if an expansive mid and upper level trough blanketing the eastern United States.
345 AM EST Fri Nov 29 2024 (Today through Saturday) Cold front has pushed well south of the CWA this morning. Stratus will continue to stream down from the north through the morning, but the lower clouds will be on the decrease.
Meanwhile, a cold front trailing from this low is extending through central and east Georgia. As the low becomes displaced further away, forcing ahead of the front continues to weaken. Low temperatures tonight are forecast to be in the low to mid 30s in north Georgia (with some upper 20s in the highest elevations) and upper 30s to low 40s in central Georgia. Subsidence under the high is expected to promote clear skies and the mixing down of drier air aloft. As such, elected to run on the lower side of guidance for dewpoints for Friday, blending in hi-res and NBM10percent guidance.
The pattern is defined by an amplified ridge off the West Coast leaving us under dry northwest flow aloft. Some of the high snow covered valleys that we call the typical cold pools are stuck under strong low level inversions, which is preventing much warming during the day and resulting in overnight lows well below zero. Temperatures will start out 5-10 degrees below normal, but as ridging builds in, temperatures will gradually warm to near or slightly above normal. Dry weather dominates, although a few weak waves clipping the northern mountains will bring a low (<15%) but non-zero chance of light snow showers over the high peaks, with little, if any, accumulations.
Northwest flow aloft continued through Saturday with slightly cooler than normal temperatures continuing. Will have similar conditions Saturday with only slightly warmer conditions perhaps a couple of degrees milder.
831 AM EST Fri Nov 29 2024 The region will be in between broad low pressure to the northeast and high pressure building into the Mississippi and Tennessee Valleys through the weekend.
(Today through Saturday) A cooler airmass will sit atop the region following a cold front, keeping our temperatures today, tonight, and Saturday a bit more fall-like. Gusty winds in the Lower Valley and along the coast will subside today. Cloud cover will persist, as well as a return of moisture thanks to an inverted trough to our southeast redirecting moisture our way.
437 AM MST Fri Nov 29 2024 Updated at 435 AM MST Fri Nov 29 2024 - Seasonal temperatures expected today - Warmer this weekend as dry and calm conditions persist A very quiet weather pattern is expected through the forecast period. Today will be the coolest day of the period as high pressure settles into the southern Plains. However, global models are signaling for a cut-off low strengthening off the SoCal/northern Baja coast underneath a Rex block around midweek. The ensembles keep the low too far west for us to see any real impacts, just more high clouds streaming overhead. The warmer conditions result in lower humidities as the cooler airmass shifts to the east.
554 AM CST Fri Nov 29 2024 (Today through Saturday) A longwave trough is currently stretched across much of the eastern CONUS, which features a quasi split flow, and a westerly mid- to upper-level jet emanating over the Southeast. A large high pressure system is currently spilling across the Plains and this is associated with a Polar airmass overspreading our region this morning. Saturday will be quiet with high pressure remaining - I've got highs in the 50s with ample sunshine.
Readings dropping into the 30s areawide away from the coast are almost certain, with the question being freezing/subfreezing temperatures across parts of central LA. This will result in winds backing to the E/SE with temperatures moderating and getting a little warmer than today.
There is a 10 to 20 percent probability of low temperatures below freezing on Saturday morning in the rural areas of Merced and Madera Counties. There is a rex block pattern offshore with a very strong ridge of high pressure with it. The fog is favored due to the sinking subsidence affiliated with ridges and the abundant moisture from the rain earlier this week. However, there is a 10 to 20 percent chance of below freezing temperatures in the rural areas of Merced and Madera Counties on Saturday morning. It is not as favored due to the possibility of fog forming overnight which leads to temperatures being above freezing due to dewpoints.