Aikyam-Lab/Synoptic-Bench huggingface dataset:
259 AM CST Thu Jan 7 2021 Closed low will move along the LA/AR border region this morning with light rain/snow mix pinwheeling across the Flint Hills and southeast Kansas. Temperatures are now expected to remain just above freezing where precip falls, which will mitigate any ice potential. The position of the inverted trof axis and associated moisture across the area will allow the very light precip to linger into midday before dissipating/exiting the area.
Chattanooga Airport, TN 48 36 43 31 43 / 50 90 30 0 0 Knoxville McGhee Tyson Airport, TN 46 35 41 30 40 / 10 90 40 0 0 Oak Ridge, TN 45 35 41 28 40 / 10 80 30 0 0 Tri Cities Airport, TN 48 33 40 27 38 / 0 60 60 10 0 NC.
Upper low is trending slightly weaker overall and earlier runs showing available moisture lessening fairly quickly as you move west, and especially west of I-65 tomorrow night as cooling occurs.
Early morning GOES vapor imagery indicates the main weather of note is a closed upper low tracking well to our south across the lower Mississippi Valley.
359 AM EST Thu Jan 7 2021 An upper level low pressure system passing south of the region as it moves eastward will bring a chance of flurries along and south of the Ohio River tonight. The upper low will bring some moisture and ascent to areas south of the Ohio River as it pushes into the western Tennessee Valley this evening.
The quiet weather period with warmer than normal temperatures looks likely to continue for much of this period. In addition to providing a chance for precipitation it could also bring in some warmer air as suggested by on the NBM temperature percentiles. IFR-or-worse conditions expected across all TAF sites this cycle as warmer easterly flow atop the snowpack will allow for low stratus and fog (BR and FZFG) to develop further west across central-southern MN, in addition to western WI.
1057 PM CST Wed Jan 6 2021 Light to occasionally moderate precipitation continues over parts of Arkansas as an area of low pressure passes just to the south of the state. The precipitation will end Thursday evening as the low pulls away but low level moisture will prevail. Southeast winds initially will become northeast as the low passes.
1049 PM EST Wed Jan 6 2021 The return of clouds along with warmer and moister air is expected over the next 24 hours, bringing a moderation of the cool and dry air mass over the Keys right now. High pressure over the Ohio Valley and the Great Lakes region will extend a ridge axis off to the southeast. Showers should develop over the Straits on Thu morning, which will be visibile from the Lower and possibly Middle Keys. High pressure over the Great Lakes region overnight will extend a ridge southeast off the Carolina coast and into the Atlantic on Thursday. Meanwhile, low pressure will form over the northwestern Gulf of Mexico.
With no airmass change, high temperatures should be able to climb to about the same degree as today, if not warmer in some locations.
230 AM CST Thu Jan 7 2021 A wintry mix and freezing drizzle highlight the short term.
259 AM CST Thu Jan 7 2021 A vertically stacked upper low over the Arklatex region with an inverted upper level trough to the north will shift east with time. This isn't an ideal overall setup for a significant snow (or mixed precip) event for our area with the main low so far south, but guidance does continue to indicate that the northern extent of precip will continue to rotate around the main upper low over southern MO over the next few hours before overall lift gradually weakens after 15z/9am.
257 AM EST Thu Jan 7 2021 High pressure over the region will make for quiet weather through the weekend.
1257 AM EST Thu Jan 7 2021 A high pressure ridge builds from the west and north today. This ridge then persists over northern Ohio and northwest Pennsylvania through this weekend with quiet weather and seasonable temperatures. Temperatures near the lakeshore dropped to about 30 degrees where it cleared out but as the clouds returned, temperatures warmed back up into the lower and middle 30s. So, will go ahead and remove the drizzle/freezing drizzle from the overnight hours. This will result in some drizzle and freezing drizzle (depending on surface temperature) occurring, especially in the weaker showers where cloud top temperatures are warmer. Temperatures at night will be in the upper 20s, increasing to the low to mid 30s during the daytime hours. Ridging will persist across the region through the forecast period, with dry conditions expected.
Evening satellite loop is showing a few breaks developing in the stratocu deck across the Lower Susq Valley. Readings at dawn should range from the mid 20s over the northern mountains, to the low 30s over the southeast counties. Mixing down model 925mb temps of around -4C should yield highs ranging from the low 30s over the higher terrain of northern Pa and the Laurels, to the low 40s across the Lower Susq Valley.
1039 PM MST Wed Jan 6 2021 The synoptic pattern will consist of an upper level ridge developing overhead later this evening and will persist through tomorrow afternoon. Expect low temperatures ranging from the low teens to upper teens across the plains and Fremont and Teller Counties, the single digits over the upper Arkansas River Valley and Wet Mountain Valley, the negative single digits over the San Luis Valley and the upper Rio Grande River Valley, and the negative values to teens over the mountains. High temperatures will be in the low to upper 40s over the plains and Fremont and Teller Counties, the low to upper 30s over the mountain valleys, and the teens to 20s over the mountains.
Upper trough extends from the northern through southern plains this afternoon. Overnight, expect the northern H5 circulation to gradually weaken, with the base of the trough across the southern plains intensifying and becoming dominate as an upper jet rounds the base of the trough. Of more concern is the development of fog and possibly even some patchy freezing drizzle overnight tonight into Thursday morning. Sounding profiles do show some weak lift within the moist layer, and area soundings support a mention of some patchy freezing drizzle.
Vertz High pressure over the area today and gusty winds in the foothills. Cold front will arrive after 6 AM in western zones tomorrow. A better and deeper push of cooler air will kick in during the afternoon with a notable switch to brisk north winds.
This trend will continue overnight as the low shifts eastward with some uptick in precip intensity possible. However with increasing frontogenesis along and ahead of the low and limited elevated instability, a few claps of thunder are not out of the question. The low will move across Mississippi on Thursday, with mainly rain associated with it as temperatures will be to warm for any snowfall.
Early this morning satellite imagery has greeted the region with a pesky stratocu shield of clouds, as anti-cyclonic ridge parked over the Upper Midwest just sits. This has resulted in ceilings maintaining a grip over Central Indiana around 3kft AGL, but fortunately this has inhibited the possibly of any freezing fog from developing. With this setup, it doesn't appear temps will be able to radiate much from the lower 30s, likely bottoming out in the upper 20s by daybreak. What this means for Central Indiana is that we will likely get a strong glimpse of the sun from some clearing midday Fri, but with a weak thermal trough overhead temps will likely remain in the 30s from light northerly flow.
We'll maintain very weak flow through the short term, with high pressure currently south of Hudson Bay slowly building southwest over us through the period. Main area of uncertainty for fog is that as the high builds in from the northwest, we will see lower dewpoint air slowly work into the region, which may keep this more of a low stratus as opposed to a fog.
1057 PM CST Wed Jan 6 2021 (This evening through Thursday) Water vapor imagery depicts the center of an upper level low is currently dropping southeastward across the TX panhandle into western north Texas. Ahead of this feature a cold front at the surface has pushed eastward into central Oklahoma with gusty north winds and a drop in temperature seen behind it. As ascent ahead of the upper low increases this afternoon expect showers to continue to develop within a nearly stationary band, roughly along and east of the I-35 corridor. Temperatures will stay well above freezing tonight in areas with precipitation, so no winter weather concerns are expected. With the widespread clouds and cold air advection, highs tomorrow will only reach into the low to mid 40s.
Lack of moisture in dendritic growth zone could allow some of the precipitation to fall as light freezing drizzle. High pressure ridge from Northern Plains across the Great Lakes holds while low pressure system lifts offshore of the East Coast.
Surface winds will veer to east and southeast by the end of the day as surface ridging moves to the east of the forecast area.
The current elongated upper level low over the Missouri River Valley into the lower Mississippi River Valley will get kicked east by the system currently over the Pacific Northwest.
1037 PM CST Wed Jan 6 2021 (This evening through Thursday) Cold front had pushed across Wet Central Texas and brought gusty north winds in its wake. The upper trough swinging across the area today will shift east tonight and bring dry northwest flow for Thursday.
Could see some enhanced snowfall amounts roughly along the Highway 60 corridor from Fordland east if this verifies. A dusting of snow is possible across portions of the area tonight into Thursday, with greatest potential for measurable snowfall of up to 1-2 inches generally along and south of the highway 60 corridor. Surface temperatures will be a big player in amounts and impacts, with most areas staying at or above freezing tonight. Rest of the forecast period is cooler and quiet.
310 AM EST Thu Jan 7 2021 Latest surface analysis places high pressure over the Great Lakes with a low pressure center over LA. Current satellite shows a westward redevelopment of stratus across much of our central and eastern counties (roughly along and east of I-65) while mid and high clouds, associated with the aforementioned low pressure system, begin to nudge into our southern CWA. Expect mostly cloudy skies this morning to become overcast by this afternoon with increasing chance of precipitation beginning this evening as the upper low tracks across the TN Valley.
1052 PM MST Wed Jan 6 2021 Quiet weather expected through Thursday as an upper ridge moves across the region.
Pcpn will be rain or wet snow in the Lower Snake Basin later tonight but little if any snow accumulation is expected. Clearing Thursday as the trough exits east.
1237 AM EST Thu Jan 7 2021 A weak upper level low will remain parked over New England overnight supporting abundant cloud cover and occasional flurries and light snow showers with spotty minor accumulations. Spotty drizzle and freezing drizzle are possible as well. Lack of moisture in dendritic growth zone could allow some of the precipitation to fall as light freezing drizzle.
Dry northwest flow expected aloft as an upper low exits east Texas into the southeastern US. We may start to see clouds moving into the northeastern areas by tomorrow morning, which may limit radiational cooling and keep lows in the lower 30s for the western Big Country.
Thinking the clouds will be hard to get rid of, especially with a region of isentropic upglide across the Sandhills and a stagnant upper trough over the eastern 2/3rds of the Conus. Considering yesterday's highs in the lower 40s and likely expansive cloud cover today, felt the mid/upper 30s suggested by most guidance seemed reasonable. The main synoptic pattern changes little over the weekend, comprising the main upper trough and alternating broad high pressure with weak boundaries/fronts at the surface.
12Z TAF discussion: A low pressure system moving across the region today will bring persistent low stratus deck to most locations, with ceilings either currently or soon to drop into the MVFR and then IFR or lower range. Winds will be gusty at times, with directions subject to change quickly as the low pressure system passes through the region. /NF/ Today and Tonight: Early morning water vapor satellite imagery and regional radar loops show a low pressure system spinning currently over northeast Louisiana and southeast Arkansas. Low level moisture in place with continued cold air advection on the back side of the low pressure system will keep cloudy and cool conditions through tonight, and periods of sprinkles or drizzle may continue to be possible through that time as well.
/issued 316 AM CST Thu Jan 7 2021/ With the cold front now completely through our area, temperatures this afternoon will warm up slightly with 50s across the Permian Basin and 60s S of the Trans Pecos. Light winds and clear skies will allow us to cool off tonight, and all but the Rio Grande will drop below freezing.
438 AM CST Thu Jan 7 2021 Today and Tonight: Early morning water vapor satellite imagery and regional radar loops show a low pressure system spinning currently over northeast Louisiana and southeast Arkansas. Low level moisture in place with continued cold air advection on the back side of the low pressure system will keep cloudy and cool conditions through tonight, and periods of sprinkles or drizzle may continue to be possible through that time as well.
Looking at surface observations as of 09z, the axis of the inverted trough extended northward out of south-central Kansas to approximately Seward County, then northwestward into north- central Nebraska. With above freezing temperatures and some light precip, road surfaces will likely stay damp but still above freezing as some additional snowpack melts. With continued melting and low dewpoint depressions, the cooling overnight is expected to cause freezing fog development as crossover temperatures are achieved and icing of any surfaces that remain damp going into late Thursday night and Friday morning.
The second part of this system will be the cold front, which looks to move through the region mid-morning through Friday afternoon. Winds will increase early Friday morning with Sierra ridgetops gusting as high as 90-100 mph with valley gusts in the 35-45 mph range.
Northerly flow around daybreak gradually shifts northeasterly through this afternoon in response to an approaching shared energy low near in the Lower Mississippi Valley this morning. This should yield some clearing along and downwind of the higher terrain through this afternoon, possibly a bit further west, although short term guidance does appear to be a little overzealous with clearing. Forecast temperatures generally reflect a more conservative forecast with a fairly compressed diurnal range for a bulk of the Lowlands and a decent warm-up off morning lows for mountains, foothills, and southern coalfields. Farther north across the remainder of the CWA, radar reflectivity data may indicate a lot of precip on Friday, but only a few flurries or light rain spritzes are expected due to the amount of dry air in the lower levels.
Another trough is located over the Pacific NW coast.
316 AM CST Thu Jan 7 2021 With the cold front now completely through our area, temperatures this afternoon will warm up slightly with 50s across the Permian Basin and 60s S of the Trans Pecos. Light winds and clear skies will allow us to cool off tonight, and all but the Rio Grande will drop below freezing.
Mostly dry and cooler conditions can be expected on Friday.
A couple of upper level lows work their way through the lower/mid MS River Valley during the period.
Models generate no more than a hundredth of an inch in central Kansas, and have added drizzle mainly through the highway 183 corridor mid morning to about noon. For Tonight, freezing fog was introduced into the weather grids given the duration of near zero or zero dew point depressions and weak convergent surface winds.
Cloud cover will remain entrenched across the region through Friday but signs point to clearing skies during the weekend as a low pressure system over the Canadian maritimes finally exits eastward. As with previous nights, pockets of flurries or very light freezing drizzle will be possible but no accumulations or impacts are expected from this very light precipitation. Based on the low Froude numbers, this seems like a hard feat to do but pockets of sun will be possible Friday afternoon.
350 AM CST Thu Jan 7 2021 Early morning sfc analysis/regional 88D imagery show our cold front now east of the forecast area with the bulk of the associated precip also across the Atchafalaya. As stated before, a few light showers associated with the low aloft spinning ewd across nrn LA will continue to brush mainly the nern zones perhaps as late as mid-morning before this activity fully departs the region. Thereafter, drier and cooler conditions are expected for today and lingering into the weekend as Canadian high pressure builds over the region.
Temperatures are expected to remain above freezing for most areas making rain the dominant p-type; however, a little bit of snow mixing in is possible. An upper level high proceeds swiftly across the US/Canadian border meeting up with an upper level low along the east coast.
SHORT TERM (Now through Friday): Dry west to southwest flow aloft and high pressure at the surface will provide subsidence through the period. High temperatures today are expected to reach the low to mid 70s under mostly sunny skies and light northwest winds. Temperatures at a few locations across the northern ranchlands may briefly reach the freezing mark. Lows tonight are expected to range from the mid to upper 30s across the ranchlands to the low to mid 40s across the Rio grande Valley. Another surge of high pressure arrives Friday with moderate northeast winds and slightly cooler temperatures.
Heights increase aloft this afternoon as the upper level high strengthens over Thunder Bay helping terminate the shallow layer of ascent and associated flurries even as light north-northeast flow persists off the lake. Even though there will be more solar insulation than previous days, daytime highs retreat a couple degrees from Thursday to the low 30s due to a cooler start.
/NEW/ /Through Tonight/ With a low pressure system departing the area to the east, its circulation will continue to pull wrap-around moisture into North and East Texas today. Clear skies across the west will allow overnight lows to fall into the low 30s, while persistent stratus keeps our eastern areas closer to 40 heading into Friday morning.
The chance that snow will mix will persist through the morning hours, so be alert to changeable conditions as temps hover right around the freezing mark. Moisture will move out of the region and be followed by brief high pressure, keeping conditions dry later today into Friday.
408 AM MST Thu Jan 7 2021 Latest GOES-E nighttime microphysics shows our approaching upper level trough moving across ID/MT this morning while low clouds and fog are present from the middle Dakotas into central Nebraska. Lacking decent support aloft and quick progression of the trough will keep these winds mainly fixated in short 2-3 hour period around sunrise this morning for Arlington and after 7 PM MST for Bordeaux today. Short-lived ridging ahead of the trough today will keep daytime highs into the upper 30s and mid 40s with increasing cloud cover as a detached vorticity max advects ahead of the main trough. Moisture with this trough fairly minimal given the decent forcing associated. Short-lived ridging sets in the wake of the passing trough from Thursday as our progressive weather pattern continues with another trough digging in across the Pacific Northwest.
, and persistent high pressure extending from the Upper Midwest to the Mid Atlantic region, will maintain tranquil weather conditions with near average temperatures and no precipitation in central PA through the upcoming weekend.
Cloud cover will remain entrenched across the region through Friday but signs point to clearing skies during the weekend as a low pressure system over the Canadian maritimes finally exits eastward. A few light flurries or patchy freezing drizzle still possible, especially on east side of CPV, as winds turn ever so slightly to the north/northwest by early this aftn. As with previous nights, pockets of flurries or very light freezing drizzle will be possible but no accumulations or impacts are expected from this very light precipitation. Based on the low Froude numbers, this seems like a hard feat to do but pockets of sun will be possible Friday afternoon.
Early morning GOES vapor imagery indicates the main weather of note is a closed upper low tracking well to our south across the lower Mississippi Valley. Drier low level northeast flow around the eastern periphery of the high has helped to clear out much of the fog and very low stratus which had been across the forecast area for the past several days. Otherwise, with subsidence associated with the upper ridge, a stout inversion based around 900mb/3500 feet AGL is expected to persist, and trap moisture beneath it in the form of stratus.
/Issued 1231 AM CST Thu Jan 7 2021/ /Through Thursday Night/ Wrap-around moisture on the western periphery of a low pressure system will keep a large portion of the forecast area socked in with stratus over the next ~24 hours.
High pressure ridge from Northern Plains across the Great Lakes holds while low pressure system lifts offshore of the East Coast. As the high becomes bigger weather factor, it appears that we finally will see some more sunshine as we work into the day on Friday.
We'll maintain very weak flow through the short term, with high pressure currently south of Hudson Bay slowly building southwest over us through the period. Main area of uncertainty for fog is that as the high builds in from the northwest, we will see lower dewpoint air slowly work into the region, which may keep this more of a low stratus as opposed to a fog. For temperatures, the high coming in will result in progressively colder air moving into the area, with 30s less common today and highs remaining in the 20s for Friday.
301 AM MST Thu Jan 7 2021 Latest GOES-E nighttime microphysics shows our approaching upper level trough moving across ID/MT this morning while low clouds and fog are present from the middle Dakotas into central Nebraska. Lacking decent support aloft and quick progression of the trough will keep these winds mainly fixated in short 2-3 hour period around sunrise this morning for Arlington and after 7 PM MST for Bordeaux today. Short-lived ridging ahead of the trough today will keep daytime highs into the upper 30s and mid 40s with increasing cloud cover as a detached vorticity max advects ahead of the main trough. Moisture with this trough fairly minimal given the decent forcing associated. Short-lived ridging sets in the wake of the passing trough from Thursday as our progressive weather pattern continues with another trough digging in across the Pacific Northwest.
However, given the very dry air in the low levels, any precipitation will likely only occur aloft before evaporating before it reaches the ground for another 4 to 6 hours. Luckily temperatures do look to remain primarily above freezing through the period. However, a few locations could see brief freezing temperatures around and just after daybreak on Friday. With temperatures remaining above freezing much of that period and road/ground temperatures still remaining fairly warm, not expecting more than a trace to around one half of an inch of snowfall accumulation through Friday. However, the highest elevations such as Sewanee, TN could see up to an inch.