Aikyam-Lab/Synoptic-Bench huggingface dataset:
1141 AM CST Mon Nov 23 2020 As a weak ridge axis slides across the area moving eastwards, we begin to see the influence of our upcoming system changing our flow aloft from northwesterly to west/southwesterly. Our far eastern counties in central IA and MN as well as areas near the Missouri River in central SD could see some snow during the overnight hours, but with surface temperatures expected to remain above freezing will likely only see a light dusting of snow. As the upper level low tightens and becomes a closed off low, the latest model runs have moved this feature further south, which will move the axis of heaviest precipitation off to our south and east.
Chances shift to the west after midnight with approach of the upper low. In central KS, cold air advection and upper low moving across the area will result in decent lift in the deformation axis. At this point, not expecting much if any accumulation, but if colder air arrives a bit sooner, the steep lapse rates/lift with upper low could produce significant accumulations.
This cloud cover is helping to keep temperatures a little cooler than the past couple of days.
327 PM CST Mon Nov 23 2020 As of 21Z Monday afternoon southwesterly midlevel flow was present across the forecast area with an amplifying trough across western CONUS. As the western midlevel trough advances eastward, the lee trough will continue to deepen, resulting in a strong low-level mass response. Drizzle will transition to rain by midday as deeper moisture arrives with the approaching midlevel trough.
956 PM EST Mon Nov 23 2020 Cooler weather today and especially Tuesday as high pressure rebuilds behind a cold front.
/issued 342 PM EST Mon Nov 23 2020/ Today Drier air advecting over the region today, as a 500 hPa ridge of high pressure progresses over the Florida panhandle. The eastern periphery of this ridge will induce cold air advection over the region, further supported by pressure rising at the surface. Maximum temperatures are forecast to be seasonably cooler, with upper 70s/lower 80s across the region. With a low-level trough forecast to progress over the region Monday night/Tuesday morning, a north/northeasterly wind will cause a drop-off in dewpoints temperatures and hence a slight decrease in apparent temperatures as well.
425 PM MST Mon Nov 23 2020 Progressive westerly flow will continue to become more active as passing upper troughs trend more amplified. Splitting long wave upper trough continues to advect east into the region. Sfc cold front will shift through the area tonight supporting breezy spots over NW SD late tonight into Tues. CAA will offer slightly cooler conds most areas, but better mixing will allow temps similar to todayâs numbers over NW SD. The next progressive trough will shift into the region Tues with ridging ensuing and lasting int Wed. This will support slightly warmer conds by Wed, after which another cold front will bring cooler conds for Thanksgiving Day.
As of 21Z Monday afternoon southwesterly midlevel flow was present across the forecast area with an amplifying trough across western CONUS. As the western midlevel trough advances eastward, the lee trough will continue to deepen, resulting in a strong low-level mass response. Drizzle will transition to rain by midday as deeper moisture arrives with the approaching midlevel trough.
454 PM PST Mon Nov 23 2020 High pressure will be over the area through Tuesday.
Quiet day across the mid state today with zonal flow transitioning to upper level ridging by tomorrow morning.
Lows will range from around 30 along Hwy 20 to the lower to mid 30s elsewhere. Tuesday: Widespread rain over the cwa as deep trough swings out of the southern Rockies and into the Plains, providing large-scale ascent.
This is in advance of a poorly organized Pacific system, with Visible Satellite showing the broad upper level trough axis moving into the eastern Great Basin Region at this hour with snow reported in the mountains of Utah. Initiation of steady precip is a little slower compared to previous model runs, but the high res guidance is showing light rain/snow mix developing sometime between 8 PM this evening and midnight tonight. However, not going to message this too aggressively since models have trended more progressive with the upper level trough passage with lighter QPF overall.
332 PM CST Mon Nov 23 2020 Upper level ridging has shifted east of the area with the next system approaching from the west. At the surface, low pressure continues to deepen across northeast CO with a tight pressure gradient across the Plains.
BUFR soundings support snow at times mixed rain or freezing drizzle with ice crystal loss in the column especially on either side of peak saturation in the 10-15Z time frame. Snowfall amounts have trended a bit lower, generally a inch or less for most locations with 2-3 inches for the higher terrain of the North Shore with lake enhancement and orographic lift via southeast winds. Overall, snowfall accumulations and any ice accumulations are rather marginal to justify a Winter Weather Advisory at this time, especially in regards to how much freezing drizzle may occur. However, this will be monitored through the night should confidence increase for greater impacts from freezing drizzle.
544 PM CST Mon Nov 23 2020 Upper level ridging has shifted east of the area with the next system approaching from the west. At the surface, low pressure continues to deepen across northeast CO with a tight pressure gradient across the Plains.
Attention then turns towards Tuesday afternoon and evening with the main upper trough ejecting out onto the Plains. Despite moderate warm air advection, limited instability will keep our overall severe thunderstorm threat on the lower end; however, given progged shear values of around 50 kts.
257 PM PST Mon Nov 23 2020 High pressure will be over the area with Tuesday.
By Tuesday morning, the main trough in the west closes off and the upper low moves into Kansas/Oklahoma during the day. A cold front moves through the area during the day. Even with the cold front temperatures should be warm enough that it will be mostly rain.
Lower dewpoints in the U50s to L60s will usher a pleasantly cooler night ahead with additional drying provided by the Nly wind component. High pressure moves to along the Atlc Seaboard through the day.
929 PM EST Mon Nov 23 2020 Gusty winds in the wake of a cold frontal passage will gradually subside tonight into tomorrow as high pressure approaches from the west.
High pressure is anticipated to quickly surge over the Northern Rockies late tonight and continue to be present through Tuesday evening. The light snowfall today across the region increases the probability of freezing fog to develop at valley locations in the 2000-4000 feet elevation range.
These showers are developing ahead of a weak upper wave pushing through and a weak cold front crossing SW SD at this time. Progressive westerly flow will continue to become more active as passing upper troughs trend more amplified. Splitting long wave upper trough continues to advect east into the region. Sfc cold front will shift through the area tonight supporting breezy spots over NW SD late tonight into Tues. CAA will offer slightly cooler conds most areas, but better mixing will allow temps similar to todayâs numbers over NW SD. The next progressive trough will shift into the region Tues with ridging ensuing and lasting int Wed. This will support slightly warmer conds by Wed, after which another cold front will bring cooler conds for Thanksgiving Day.
618 PM EST Mon Nov 23 2020 Cooler weather today and especially Tuesday as high pressure rebuilds behind a cold front.
736 PM EST Mon Nov 23 2020 High pressure will build along the eastern seaboard including the Florida peninsula tonight and Tuesday. Clear skies overnight with lows dropping into the lower to mid 50s across the nature coast. to around 80 to the lower 80s central and south under sunny skies.
609 PM EST Mon Nov 23 2020 high pressure builds back in with quiet weather expected through Tuesday.
Issued by National Weather Service New Orleans LA 410 PM CST Mon Nov 23 2020 Cool and dry high pressure is settled over the region this afternoon and will be in the process of moving eastward through Tuesday.
Upper level ridging has shifted east of the area with the next system approaching from the west. At the surface, low pressure continues to deepen across northeast CO with a tight pressure gradient across the Plains.
(Tuesday night through Monday) A compact upper low will skirt across Oklahoma and Kansas Tuesday evening, with an associated cold front moving south across West Central Texas Tuesday night.
Upper trough continues to transition across East Idaho through tonight. Main trough axis shifts through the region early tonight, leaving northwest flow aloft in place. Soundings overnight favor development of freezing drizzle in areas where stratus can be realized as high pressure starts to build into the region. Expect ridge axis to transition across the region late Tuesday. Increasing upslope flow into the Island Park region could be enough for light snow Tuesday night before main impact from upper trough moves in.
Tuesday will feature near to below average temperatures, along with increasing clouds as a warm front approaches.
1029 PM CST Mon Nov 23 2020 Upper level ridging has shifted east of the area with the next system approaching from the west. At the surface, low pressure continues to deepen across northeast CO with a tight pressure gradient across the Plains.
500mb high pressure north of the Yucatan Peninsula will slide eastward over southern Florida by this evening, with upper ridging building over the area. Northwesterly upper level flow this morning will become southwesterly tonight as the ridge builds eastward. At the surface, high pressure over the Ohio Valley will shift to the coast of the Mid Atlantic states and then off the coast of the Northeast tonight. An inverted coastal trough east of the area this morning and then push towards the coast late in the day. Highs today will be near 70 along the Atlamaha River in southeast Georgia, and the low to mid 70s elsewhere.
1148 PM CST Mon Nov 23 2020 Warm front will be approaching western Arkansas late in the period with a corresponding increase in moisture.
CD Chattanooga Airport, TN 61 46 62 53 70 / 0 10 80 70 10 Knoxville McGhee Tyson Airport, TN 59 42 63 51 67 / 0 0 80 70 10 Oak Ridge, TN 59 43 62 50 67 / 0 10 80 70 0 Tri Cities Airport, TN 58 36 60 48 65 / 0 0 70 90 0.
1025 PM EST Mon Nov 23 2020 Currently - High pressure is spreading eastward and becoming aligned over eastern North America. The more backed flow has arguably is flushing the remnants of a cold front through the Keys. This evenings soundings indicated considerable dry air above 800 to 850 mb with some drying trough the boundary layer. Short Term Update - High pressure will continue to shift eastward, becoming aligned over the Atlantic Coast states by morning. High pressure moving high pressure moving eastward into the eastern United States will result in moderate to fresh northeasterly breezes across Keys waters overnight.
/issued 736 PM EST Mon Nov 23 2020/ High pressure will build along the eastern seaboard including the Florida peninsula tonight and Tuesday. Clear skies overnight with lows dropping into the lower to mid 50s across the nature coast. to around 80 to the lower 80s central and south under sunny skies.
Conditions are calm across the area tonight ahead of upper ridging that will move in tomorrow. High pressure will be centered over the area this evening, then move off to the east on Tuesday.
Some patchy freezing drizzle or light snow is possible across portions of southeast Idaho. Upper trough continues to transition across East Idaho through tonight. Main trough axis shifts through the region early tonight, leaving northwest flow aloft in place. Soundings overnight favor development of freezing drizzle in areas where stratus can be realized as high pressure starts to build into the region. Expect ridge axis to transition across the region late Tuesday. Increasing upslope flow into the Island Park region could be enough for light snow Tuesday night before main impact from upper trough moves in.
256 AM CST Tue Nov 24 2020 A series of upper level lows will affect the southern plains through 2 December.
311 AM EST Tue Nov 24 2020 Early morning water vapor satellite imagery is showing a dry airmass in place over the Gulf of Mexico and Florida Peninsula, while a mid level ridge builds into the western Gulf.
QPF was lowered over northwestern Wisconsin due to the low being projected to move further south. BUFR soundings support snow at times mixed rain or freezing drizzle with ice crystal loss in the column especially on either side of peak saturation in the 10-15Z time frame. Snowfall amounts have trended a bit lower, generally a inch or less for most locations with 2-3 inches for the higher terrain of the North Shore with lake enhancement and orographic lift via southeast winds. Overall, snowfall accumulations and any ice accumulations are rather marginal to justify a Winter Weather Advisory at this time, especially in regards to how much freezing drizzle may occur. However, this will be monitored through the night should confidence increase for greater impacts from freezing drizzle.
Gehring (Issued 200 PM CST Mon Nov 23 2020) Tonight and Tuesday: Lower level anticyclone shifts east with low level thermal/moist advection increasing throughout the night. Based on collab with KARX and KDVN decided to hoist on advisory in our west closer to some of the higher amounts in concert with the peak morning travel.
Areas of low stratus has also developed in the Lower Treasure Valley, Magic Valley, and Long Valley this evening, and some sites are hinting at mist and reduced visibility.
232 AM EST Tue Nov 24 2020 High pressure will be overhead for most of the day but the temperatures will again be seasonably chilly. A warm front will lift northward tonight and lead to a brief mix of snow and rain across the northern tier.
607 AM EST Tue Nov 24 2020 High pressure remains over the area through Wednesday.
Temperatures across the entire area remain above freezing, and the expectation is that this will remain the case through the morning hours as all model dewpoint guidance has dewpoints rising above 32 degrees for the remainder of the night. To the east where clouds will persist and thermal profiles are warmer, lows will be upper 20s to around 30.
Surface temperatures have remained above freezing and with the stratus in place should remain that way this morning. Cool high pressure builds in with northwesterly surface winds.
12Z surface observations place low pressure center near or just east of the Turtle Mountains. Fog has formed within the center of the low, especially in the southeast upslope flow in Rolette county. This fog should dissipate as the low shifts east and surface winds turn to the west/northwest. Surface temperatures have remained above freezing and with the stratus in place should remain that way this morning. Cool high pressure builds in with northwesterly surface winds.
Strong low-level jet ahead of the trough and associated warm air advection will provide forcing for elevated showers and a few thunderstorms this morning, already seen on radar across west Texas and the Texas panhandle. The low-level jet and ascent shifts eastward by this afternoon, leaving our area in a bit of a lull through mid-afternoon before renewed forcing associated with the main upper low enters northwest Oklahoma.
With temps across the area flirting with freezing, one or two degree difference can impact snowfall amounts. Nonetheless, still looking at 2-4 inches for areas west of I-90 while areas east of I-90 more likely to see 1-2 inches with locations closer to the lake seeing less than an inch given the southeasterly flow and influence of the warmer lake on temps. However, this will also bring in warmer temps, which will result in the morning snow transitioning over to snow/rain mix and then to all rain. Rain chances will continue across WI overnight and into Wednesday as the low lifts east-northeast into central IL. Rain chances are then expected to gradually diminish through the day on Wednesday as the system pushes east and an upper-level ridging builds into the region.
After the lull in precip chances this afternoon, showers will become widespread tonight as an upper trough currently over the Desert Southwest approaches from the west. Low temperatures will drop into the lower to middle 40s. Low pressure associated with the Desert Southwest upper trough will track from Oklahoma this evening to northern Indiana by Wednesday evening. While a few thunderstorms may push into the S/SW CWA late tonight, a better chance for convective development will occur from late Wednesday morning through the afternoon as the low tracks across central Illinois. Given the relatively low CAPE/high shear environment, think any cells that develop in conjunction with the low will be capable of damaging wind gusts and perhaps a tornado. Once the low lifts into Indiana, a trailing cold front will sweep through the region during the late afternoon/early evening.
The winter weather advisory remains in effect along the Highway 20 corridor and Jackson County as well as the northwest Illinois Counties. Temperatures are generally at or above freezing across the area with Cedar Rapids the cold spot at 31 degrees. Models continue to show frontogenetical forcing lifting northward through the Highway 20 corridor this morning through 15 UTC. Several rounds of rain will lift across the area through the remainder of the day as vorticity ejects out of the base of the 500 MB trough moving into the Southern High Plains.
728 AM EST Tue Nov 24 2020 High pressure will be overhead for most of the day but the temperatures will again be seasonably chilly. A warm front will lift northward tonight and lead to a brief mix of snow and rain across the northern tier.
600 AM EST Tue Nov 24 2020 Canadian high pressure will drift across the region today providing fair weather and seasonably cool temperatures today. Low pressure developing in the Southern Plains will move toward the area tonight and Wednesday bringing increasing clouds today and widespread rain to the area beginning early Wednesday.
Forecast generally starting on track as band of isentropic lift associated with 850 mb warm front, continues to push ENE. Mainly rain/snow mix this morning as temperatures will be hovering near freezing at the onset. Once the low passes to the NE, flow will become NW but still only fall into the 40s.
521 AM CST Tue Nov 24 2020 A series of upper level lows will affect the southern plains through 2 December.
Today's weather will feature a cold November rain for the daytime hours as an upper trough emerges from the Rockies and crosses the plains. Cold air advects south across the plains today behind a cold front and fropa will be marked by increasing north winds with gusts around 30 mph gradually falling temperatures. Models have been consistent with Thanksgiving Day temperatures averaging near the 50 degree mark for highs, but a progressing upper trough and an associated cold front will bring a wind shift to the north during the day.
A weak low pressure system will move east of the region today, allowing high pressure to temporarily build into the area.
/issued 311 AM EST Tue Nov 24 2020/ Early morning water vapor satellite imagery is showing a dry airmass in place over the Gulf of Mexico and Florida Peninsula, while a mid level ridge builds into the western Gulf. At the surface, broad high pressure is filling into Florida from the north today, and will shift east into the Atlantic through the rest of the week as the aforementioned trough drags a cold front into the southeastern US, washing out over northern Florida late in the week.
555 AM EST Tue Nov 24 2020 Early satellite imagery and local radars indicate a north-south oriented trough just offshore of the Southeast Florida coast into the Straits of the Florida. A deep layered, massive continental anticyclone covering the entire Eastern United States, the Sunshine State and most of the Gulf of Mexico, will slide eastward while gradually eroding above 700 mb. Meanwhile, the surface reflection of high pressure will track into the western Atlantic Ocean with an extensive ridge axis reaching across the Southeast United States and the Florida Peninsula.
With temperatures still well above freezing, much of this will fall as rain. These warmer temperatures resulting in more rain has had a major impact on the snowfall forecast. Temperatures will then actually rise above freezing by noon, despite the frontal passage, changing any lingering snow back to rain before it completely moves out of the area by mid afternoon.
Downstream warm advection has strengthened across the High Plains within the corridor of returning low level moisture and scattered convection has developed across the TX Panhandle. Low level jet axis will focus across eastern OK and western AR during the afternoon and early evening with showers and scattered storms likely expanding in coverage atop warm frontal zone which will struggle to lift northward due to expansive low cloud cover. The final phase of convective focus will be storms developing along or in advance of the surging cold front / dryline boundary as stronger lift impinges upon the western flank of the deeper moist axis.
Temperatures are generally at or above freezing across the area with Cedar Rapids the cold spot at 31 degrees. Models continue to show frontogenetical forcing lifting northward through the Highway 20 corridor this morning through 15 UTC. Several rounds of rain will lift across the area through the remainder of the day as vorticity ejects out of the base of the 500 MB trough moving into the Southern High Plains.
An upper ridge has shifted over the area, but this feature will be short-lived in our current progressive pattern. A larger upper ridge to forecast to shift over the area late in the week, with dry weather returning, along with nighttime frost. Mostly clear skies and VFR conditions are expected to prevail before a cold front system arrives at the CWA during the late afternoon into the night.
337 AM CST Tue Nov 24 2020 Today's weather will feature a cold November rain for the daytime hours as an upper trough emerges from the Rockies and crosses the plains. Cold air advects south across the plains today behind a cold front and fropa will be marked by increasing north winds with gusts around 30 mph gradually falling temperatures. Models have been consistent with Thanksgiving Day temperatures averaging near the 50 degree mark for highs, but a progressing upper trough and an associated cold front will bring a wind shift to the north during the day.
447 AM MST Tue Nov 24 2020 An upper trof will be moving east today with slight ridging developing over Montana. Some low cloud and fog has moved into the northeast corner of the state with high pressure this morning, but should clear the region by the afternoon. An upper low in the Gulf of Alaska will drop southeast today and tonight, pushing a trof into the northern Rockies by Wednesday. This trof will bring a cold front south from Canada, with cold air advection and instability. This may be enough to mix out the inversion and bring stronger winds to the surface, at least for the higher terrain areas on Wednesday.
Today will be seasonably cool, but warmer temperatures are expected on Wednesday. Upper level heights will slowly rise today and a warm front will pass through the region late this afternoon and during the evening. The passage looks quiet, as deep moisture will be lacking as well as upper level support under the expanding eastern CONUS ridge. Jet support, on the eastern flank of the upper low, will aid in rainfall efficiency, providing a descent soaking of the area.