Aikyam-Lab/Synoptic-Bench huggingface dataset:
Dense surface based ground freezing fog has largely remained south of the DTW and the Detroit terminals. Some scattered light snow showers or flurries remain possible this evening into tonight on the back edge of the departing upper low as a weak deformation axis/stretched vorticity lobe pivots back across MI. While highs Sunday push into the mid 30s, the column aloft will remain below freezing with 850mb temps around -8C leading to a nearly all snow (some melting snow/mix is possible with any early onset precip that falls Sunday afternoon when boundary layer temps will be at their warmest).
/Issued 1220 AM CST Sat Jan 16 2021/ /Through Sunday/ Longwave troughing across the eastern CONUS places North and Central Texas beneath a dry northwest flow pattern, which should remain in place through the weekend.
Temps today are expected to be around or slightly above average, with highs over the plains mostly in the 40s, but a few lower 50s are also forecast, the high valleys should see highs in the upper 30s to lower 40s. Upper level ridging builds back into Colorado on Sunday, bringing dry conditions and slightly warmer temps to most of the region.
After that a high pressure ridge centered off the CA Coast will build into the region Sunday.
There remains fog and freezing fog in some locations.
The clouds will keep temperatures in check with highs will be in the low to mid 40s. The low that is responsible for this will continue to track east.
1045 AM EST Sat Jan 16 2021 An upper level low will slowly move east across the Central Appalachians and Mid-Atlantic region today.
1211 PM CST Sat Jan 16 2021 Patchy freezing drizzle has been a persistent threat this morning, and we have had intermittent reports of it in between waves of light snow. Over time I expect the freezing drizzle to convert over the flurries as higher cloud from the west moves in to provide ice nuclei to switch it over to snow instead of supercooled liquid. Slightly stronger signals over NW WI were associated with a mix of snow and freezing drizzle.
Water vapor satellite imagery distinctly shows the back edge of a vort max associated with the upper trough overhead, beginning to move through the plateau and into the TN valley this morning. As surface temperatures rise into the low 30s, expect this trend will continue. CD Chattanooga Airport, TN 31 46 30 46 30 / 0 10 10 0 0 Knoxville McGhee Tyson Airport, TN 31 44 30 41 27 / 0 10 20 10 0 Oak Ridge, TN 30 42 30 41 27 / 0 10 20 10 0 Tri Cities Airport, TN 28 40 27 36 24 / 10 10 40 20 0 NC.
254 PM CST Sat Jan 16 2021 An upper level low was northeast of the area. Lows tonight limited by cloud cover into the lower to middle 20s. Potential to be a bit warmer if more of a blanket of clouds exists.
Return flow will set in as the high pushes into the Gulf of Mexico, supporting increased surface moisture and warming temperatures for Sunday.
Mostly sunny skies expected today with afternoon highs in the low to mid 50s. /Today through Sunday/ Dry northwest flow will be the theme this weekend as the strong upper low over the Ohio River Valley continues to shift eastward. Expect another brisk afternoon today with highs in the low to mid-50s, with much lighter winds out of the northwest at 5-10 mph. Post-frontal wind speeds increase to 15 mph as yet another upper low proceeds through the Great Plains approaching the Ohio River Valley once again.
1106 AM CST Sat Jan 16 2021 (Today and tonight) Early this morning, water vapor satellite imagery shows a large upper level low moving east over the Ohio Valley while northwest flow aloft continues over West Central Texas. This, in addition to sunny skies and strengthening of the 850 mb thermal ridge, will lead to warming today, with highs in the low to mid 60s. Expect lows in the low 30s.
Southwest portions of Wisconsin and areas along the WI/IL border may see a light dusting of snow late tonight into Sunday with a mid level trough digging to our southwest. Temperatures will be below freezing so some slick spots will be possible Sunday morning.
As a winter cyclone departs the region, lake effect snow will become our focus.
Have kept the highest afternoon PoP's east of a Peoria to Effingham line, with a mention of sprinkles or flurries further west. With the trend expected to continue drifting south towards the I-72 corridor, then a more east/southeast movement as the upper Low continues sliding eastward. but additional snow showers re-develop overnight as a secondary Low pressure system tracks through the Midwest. As the upper Low tracks through the Midwest Sunday, this will continue snowfall throughout much of the region.
The trough should serve as nothing more than a wind shift.
1102 AM EST Sat Jan 16 2021 Conditions have warmed up nicely from morning lows in the lower 30s. Conditions will be breezy this afternoon as another cold front pushes through. Upper level troughing will transition to zonal flow as the upper low over the Ohio Valley this morning lifts northeastward into New England tonight. Highs today will range from the lower 50s north to the upper 50s to around 60 south.
The main effect that this feature will have on the area is an increase in cloud cover this evening, along with the passage of a weak cold front. Expect overnight lows in the low to mid 30s, with upper 20s in low lying areas and river valleys.
The strong upper low that produced the windy conditions and snow showers yesterday has moved off to the northeast which has allowed winds to calm considerably today with gusts in the 10-15 mph range.
/DL/ Prior discussion below: Today and tonight: The low pressure system was moving through the mid south with very little impact to the CWA. Looks like there could be more breezy conditions across the north, mainly along the highway 82 corridor today.
Temperatures should struggle to climb much early Sunday with stratus lingering, but building heights aloft should result in a slightly warmer day than today. Nearly 10 degrees warmer where there is little cloud cover and little snowpack vs much cooler where recent snow occurred and stratus lingers. See potential for flurries or patchy freezing drizzle near the Buffalo Ridge tomorrow as the saturated layer deepens and soundings even show some weak instability developing.
Mostly sunny skies expected today with afternoon highs in the low to mid 50s. /issued 510 AM CST Sat Jan 16 2021/ For the 16/12Z TAF update, NW flow continues around the upper low well to our east. Expect VFR conditions through the period as mid to high cloud cover begins to arrive from the north with a weak cold front in our airspace by 17/00Z. /Today through Sunday/ Dry northwest flow will be the theme this weekend as the strong upper low over the Ohio River Valley continues to shift eastward. Expect another brisk afternoon today with highs in the low to mid-50s, with much lighter winds out of the northwest at 5-10 mph. Post-frontal wind speeds increase to 15 mph as yet another upper low proceeds through the Great Plains approaching the Ohio River Valley once again.
There remains fog and freezing fog in some locations. Sites PSC/DLS currently dealing with lingering low clouds leading to MVFR/IFR, with ALW at LIFR this morning due to locally dense freezing fog.
There will be a brief lull in the precipitation this evening but an upper level low pressure system will help to bring additional snow to the area later tonight and early Sunday. This system will move east of the region and the flow will become favorable for snow to continue over the higher terrain.
149 PM CST Sat Jan 16 2021 This afternoon the Upper Mississippi Valley region was situated in between systems, beneath a low-amplitude mid-level ridge.
Otherwise winds will stay on the lower side today. Persistent ridging at the H5 level continues to our west, with troughing to the east.
140 PM CST Sat Jan 16 2021 The lower stratus slowly continues to erode from west to east this afternoon. However, the higher clouds are being pretty stubborn.
The over all environment was on the drier trend precipitation wise, as an upper low over Ohio moves further to the east. The cold air stream and intermittent periods of more direct solar insolation will make for another chilly day, with high temperatures only rising into the lower 40s. Weak ridging will shift east tonight, allowing west-southwest flow and warm air advection to increase in advance of the next trough digging through the lower MO valley.
At 500mb, an upper low is departing up the Ohio River Valley today.
Those clouds may keep temps a bit warmer during the overnight, but a few spots could quickly drop before the clouds arrive if the boundary layer is able to de-couple. For now, lows have been modified a tad warmer, but remain in the upper 20s to lower 30s.
Water vapor satellite imagery distinctly shows the back edge of a vort max associated with the upper trough overhead, beginning to move through the plateau and into the TN valley this morning. As surface temperatures rise into the low 30s, expect this trend will continue. SR Chattanooga Airport, TN 42 31 46 30 46 / 20 0 10 10 0 Knoxville McGhee Tyson Airport, TN 39 31 44 30 41 / 50 0 10 20 10 Oak Ridge, TN 40 30 42 30 41 / 50 0 10 20 10 Tri Cities Airport, TN 37 28 40 27 36 / 50 10 10 40 20 NC.
Upper level trof over the Great Lakes region will swing out into the Atlantic, but a second trof will dive down and replace the current system. However, another weak backdoor cold front will move into the Panhandles tonight.
228 PM CST Sat Jan 16 2021 An amplified weather pattern persists over North America with an upper level trough over the east coast and ridging off the CA coast per the 20Z water vapor imagery. At the surface, weak high pressure was seen across the central plains.
955 AM CST Sat Jan 16 2021 An upper level Low pressure system will continue to shift eastward into the Ohio Valley today. Have kept the highest afternoon PoP's east of a Peoria to Effingham line, with a mention of sprinkles or flurries further west. With the trend expected to continue drifting south towards the I-72 corridor, then a more east/southeast movement as the upper Low continues sliding eastward. but additional snow showers re-develop overnight as a secondary Low pressure system tracks through the Midwest. As the upper Low tracks through the Midwest Sunday, this will continue snowfall throughout much of the region.
High pressure will continue to build into the region today. Upper level ridging will continue to build into the state this morning.
1115 AM CST Sat Jan 16 2021 An upper level trough moving southeastward over northern New Mexico is bringing abundant upper level cloud cover to the South Plains area. This will shift to the southeast of the area early evening as the upper trough passes overhead. /issued 303 AM CST Sat Jan 16 2021/ Today the Lubbock CWA will be situated between an upper level storm near the Lakes Region and upper level high pressure just off the California Coast. Overnight clear skies and light wind will allow temperatures to once again drop below freezing across the entire FA. THE SYNOPTIC PICTURE THIS MORNING IS DOMINATED BY AN INTENSE LOW ACROSS THE OHIO VALLEY AND RIDGING ALONG THE WEST COAST.
259 PM CST Sat Jan 16 2021 Currently aloft, the departing trough has the Middle Mississippi Valley in north/northwest flow aloft. With the ample cloud cover remaining in place and winds holding out of the west/northwest, temperatures yet again will struggle to make it out of the low to mid-30s for most of the CWA.
247 PM CST Sat Jan 16 2021 A cold front will track through the FA late tonight into Sunday, bringing a quick shot of light snow. As the cold front drops down, winds will begin to switch to the northwest and the flurries or light snow will follow.
/Tonight through Saturday/ Take Home Points: *Seasonable temperatures *Periodic light winter precipitation chances over the next few days Discussion: After an eventful, if not unusual, end to the work week, conditions quieted down overnight as upper low continued to shift eastward across the southern Great Lakes Region. A few sporadic areas of light freezing drizzle were seen through the day, but nothing pervasive or widespread enough for concern or inclusion into the prevailing forecast.
The dearth of moisture in the lower and mid levels will keep measurable rain out of the forecast. High res guidance has hinted at a few sprinkles across the Highway 82 corridor Sunday afternoon, but confidence in this solution was too low to warrant mention in the forecast. Low temps tonight will be modulated by how quickly the higher clouds spread in and how much wind persists, but for now lows near freezing still look reasonable.
/Issued 640 AM EST Sat Jan 16 2021/ A deep upper trough will dominate the eastern half of the country during the short term. A couple of short waves will move through the trough across the southern Appalachians.
/issued 326 AM CST Sat Jan 16 2021/ High pressure currently building over the area with some light freezing temps during the overnight mainly for northshore areas over teh weekend.
With cooler nighttime temperatures in the forecast, forecast sounding output suggests the clouds bases will lower to near 1000-3000 ft AGL tonight. A weak cold front moving across the region Sun afternoon, should reinforce the cold air already in place. Cooler air in place, despite more sun will bring a chilly start for a new but abbreviated work week.
Large upper level trough that has been parked over the east coast remains in place through the short term. The second is more of a clipper type wave which will drop from the Canadian plains quickly around the larger trough and affect us tomorrow night.
As a winter cyclone departs the region, lake effect snow will become our focus. Continued CAA Sunday night keeps some lake effect snow going but a mid level ridge building in starts to limit the intensity of the snow across northern Oneida county.
213 PM CST Sat Jan 16 2021 Snow showers from last nights passing upper low/trough now east of the Plateau but an active stream may bring down more flurries/snow showers tonight, as well as on Sunday night.
1215 PM EST Sat Jan 16 2021 An upper level low will slowly move east across the Central Appalachians and Mid-Atlantic region today.
Remainder of early morning forecast is on track with another weak trough and quick shot of show showers expected to come in from the northwest Sunday afternoon and evening. Fog/stratus will continue to create IFR/LIFR conditions in the lower elevations this morning.
For tonight through Sunday morning, a strong ridge of dry high pressure will keep precipitation away from the region and allow for temperatures again above normal, although not quite as warm as today will be.
An upper level impulse will then move over the Deep South Sunday afternoon and evening, moving along the flow of the parent upper trough progressing over the Ohio Valley. At the surface, high pressure will build off the southeastern coast of Texas and over the western Gulf through Sunday. Current temperatures across the local area are merely in the upper 40s inland to the lower 50s near the coast early this afternoon. Not anticipating much more heating this afternoon; therefore, the high temperature forecast is still on track. Lows tonight will be very chilly, in the lower 30s north of I-10 and in the lower to upper 30s south of I-10. Highs Sunday will not be too much warmer than today, but are forecast to be in the mid to upper 50s area-wide.
Main impacts on travel would likely be in the overnight and morning hours, as temperatures creep up to the freezing mark in the afternoon.
Bridges, such as the I-64 bridge over the Kentucky River in Frankfort, have pavement temps just below freezing. Isolated slick areas may linger on bridges and overpasses, but travel impacts through the rest of the daytime will be minimal. Light intermittent snow showers should continue overnight, and another deepening upper level trough moves over the area on Sunday. The broad upper low over the region early this morning will slowly spin eastward only to get replaced by another moving into the Midwest early Sunday.
High pressure continues to dominate the forecast today leaving most of northern California with clear skies and above normal temperatures. Tomorrow, the ridge will continue to hold, thus we're expecting similar weather and high temperatures.
Synoptically, a large area of high pressure remains set up just to the west of the southern Cali coast while a deep low moves from the Ohio River Valley up into New England.
It will be warm enough during the day tomorrow (Sunday) for the precipitation to begin as rain, except for the higher elevations north of US Highway 2. Starting with ground temperatures above freezing it may take a while before snow accumulation really takes hold, so our storm total snow amounts may be a bit on the generous side (2 to 3 inches for these isolated locations).
A weak ridging pattern then sets up for the remainder of Sunday, although moisture ahead of a developing low pressure system looks to stream into the area.
Upper level trough is moving across the area currently leading to gradually clearing skies and a slight wind shift from the northwest. The trough should serve as nothing more than a wind shift.
For the remainder of the afternoon hrs, the persistent northerly flow remains over the area as the CWA still lies between the exiting low east and strong surface ridging coming off the central Rockies. Going into Sunday, upper/surface ridging moves east into the Plains then south by nightfall in advance of an approaching stronger upper trough. The last few days has continued to trend this system to split into the trough that passes north of the CWA, and a cutoff low that settles well south/west of the area.
The lower stratus slowly continues to erode from west to east this afternoon. However, the higher clouds are being pretty stubborn.
As the cold front drops in Today, the drier air over central Kansas will be taken over by higher dew points behind the boundary in the 20s and 30s. The secondary upper branch of the synoptic trough moves in Tonight, providing deep layer subsidence and clearing sky. A reinforcement of cooler air should cap temperatures at about 5 degrees cooler as well.
Lows tonight will be in the lower to mid 20s with highs on Sunday mainly in the 30s.
Nevertheless, will forecast minimum temperatures closer to the NBM, which is cooler than the SREF ensemble mean temperatures at 12z Sunday. No freezing temperatures anticipated.
While unlikely, it is not out of the realm of possibility the DGZ may be drier and allow for patchy freezing drizzle as well.
Could be just enough moisture to produce flurries over the higher mountains at times. Not much synoptic scale lift to speak of during the overnight hours, so much of the accumulating snow should stay confined to the higher terrain, where several inches of snow is expected.
An upper level low was northeast of the area. Lows tonight limited by cloud cover into the lower to middle 20s. Potential to be a bit warmer if more of a blanket of clouds exists.
843 PM CST Sat Jan 16 2021 Weak upper level energy ahead of a larger scale trough slips through the region overnight along with a very minimal uptick in atmospheric moisture. An increase in mid/high level clouds is expected late tonight into SUN morning in association with a passing upper level trough, but VFR is expected to prevail through the period. This will bring mainly just an increase in upper level clouds with no chance of precipitation due to dry low levels thanks to the high pressure.
Otherwise, light winds and mostly clear skies will allow temperatures to drop to the low/mid 30s for northern Lake and Volusia counties, upper 30s for interior rural counties, and lower 40s at the coast and urban locations. As the center of high pressure over the Gulf shifts closer to the region, winds will become light as previously mentioned, lowering the risk of cold wind chill readings, however the ambient temperature will still drop to the 30s for several hours tonight prior to daybreak.
544 PM CST Sat Jan 16 2021 A cold front will track through the FA late tonight into Sunday, bringing a quick shot of light snow. As the cold front drops down, winds will begin to switch to the northwest and the flurries or light snow will follow.
With upper level low pressure currently lifting out of the region, peak afternoon instability has allowed clustered snow showers to bloom over the past couple of hours, mainly north of I-70. Expect intensity and coverage to drop off after sunset as the boundary layer starts to stabilize and the upper low departs. While snow showers will become more scattered overall during the nighttime hours in most cases, the ridges will maintain a favorable upslope component for orographic enhancement through the night, along with a saturated boundary layer through the DGZ until at least midnight. In the wake of the exiting upper low, heights will briefly rise and most of the snow shower activity should be confined to the I-80 corridor and ridges with the minor cold advection and westerly winds.
An increase in mid/high level clouds is expected late tonight into SUN morning in association with a passing upper level trough, but VFR is expected to prevail through the period. This will bring mainly just an increase in upper level clouds with no chance of precipitation due to dry low levels thanks to the high pressure.
Low temperatures overnight are forecast to drop into the low 30s with the upper 20s possible in the normally colder locations. For tomorrow, an approaching upper level trough will bring increasing clouds to the area and another cold front by the evening hours. Temperatures will be a few degrees warmer on Sunday afternoon and climb into the mid to upper 50s.
The trough that brought strong winds to the Plains has moved to the East Coast. Afternoon temperatures ranged from the upper 30s in the northeast of the state to the lower 50s in central and western portions. A strengthening low pressure system could bring about another day of breezy conditions which will peak during the afternoon as wind speeds approach 20 to 25 mph.
This will bring mainly just an increase in upper level clouds with no chance of precipitation due to dry low levels thanks to the high pressure.
By Sunday evening, a quick moving upper level low will pass through the flow, bringing snow showers across most of the region, though little accumulation is expected across most of the region.
Sunset, and the departure of an upper level low, brought about a reduction in intensity and coverage of snow showers with the loss of some surface- based instability, although a few pockets remain generally near and east of I-79. In the wake of the exiting upper low, heights will briefly rise and most of the snow shower activity should be confined to the I-80 corridor and ridges with the minor cold advection and westerly winds.
544 PM CST Sat Jan 16 2021 Currently aloft, the departing trough has the Middle Mississippi Valley in north/northwest flow aloft. With the ample cloud cover remaining in place and winds holding out of the west/northwest, temperatures yet again will struggle to make it out of the low to mid-30s for most of the CWA.
The next round is stratiform on radar, and model examination shows warm air advection in the precip bearing layer, resulting from the warm conveyor belt wrapping around the massive, wound up low pressure system which was stacked over the Midwest. On Sunday and Sunday night another upper low is forecast to dive southeast and move through the Ohio Valley. The colder air aloft associated with the low will again steepen our lapse rates through a deeper layer, with soundings suggesting another round of snow and snow showers on Sunday night.
There will be some clearing in the western part of the area, however, an upper wave will push some clouds into the area before the lower clouds exit the region.
Lows tonight will be in the low to mid 20s with highs on Sunday mainly in the 30s.
Temps across the plains were generally in the 40s across the divides and 50s along the lower Ark Rvr valley. Along the mtn ridges, it will be a bit windier with gusts to the 20s/30s range.