Aikyam-Lab/Synoptic-Bench huggingface dataset:
The upper level low along the Colorado/New Mexico border will lift east/northeast toward the Ohio River Valley. The moisture plume ahead of this low will help to maintain an abundant amount of mid and high level clouds over the area. In the low levels, the area of high pressure centered south of KDLH early this morning will shift east over the Great Lakes but the ridge axis will continue to extend back to the southwest and over the area. This will help to keep any precipitation from the passing upper level low well to south of the area. Temperatures will be a bit warmer with highs today expected to mainly be in the 20s with overnight lows in the teens.
Snow melt this afternoon has increased the low level moisture in the boundary layer for continued fog and stratus development. Fog will most likely effect the morning commute in the Lower Treasure Valley and Western Magic Valley Tuesday through it's not expected to be widespread at this time.
224 AM EST Tue Dec 15 2020 Upper air pattern will consist of a 500 mb trough in the central and southern Rockies this morning. This trough heads east into the mid Mississippi Valley by 12z Wed. As ridge axis crosses the area late Tuesday and Tuesday night. High pressure with a moderating trend will boost temperatures back above normal by mid to late week with no real precipitation chances.
The cloud cover limited our warming potential significantly this afternoon, subsequently temperatures were floundering in the lower 20s over most of the region at 3 PM. We're forecasting only a trace to 2 inches, with the highest amounts toward Albion and Columbus.
Temperatures across the snowpack had fallen into the low teens, while elsewhere were in the low 20s. Even though the upper level flow is SW, H85 flow is SSE and while weak WAA will move into the SE CWA today temperatures are not expected to be much above freezing for most of the area. There is a small spread in the high temps today between guidance with mainly MOS suggesting warmer temps. The upper low passes south of the area today and some virga may be seen across the far south.
A closed upper low will shift slowly east across northeast New Mexico into the panhandles of Oklahoma and Texas today, increasing snow chances for portions of southwest and central Kansas.
Temperatures will climb into the lower 50s as a result of the early day sunshine and increasing warm air advection.
Dry weather with a gradual warming trend is expected mid to late week as high pressure prevails.
Aloft, the large open wave trough that is responsible for the snowfall, is slowly beginning to close off as it swings into the Plains from the Four Corners. At the surface, an inverted trough axis is situated over the Nebraska Panhandle, just along the western CWA border. East of this trough axis, southeasterly flow is noted and is leading to moist advection. The snow should end from west to east by this evening as the primary trough axis swings through and shunts the best forcing east of the area. Behind today's system a ridge is progged to begin to build into the Plains and help to slowly warm highs back to the 40s.
Rain-free conditions expected today as weak high pressure sits over the region. Temperatures are ranging from the low to mid 50's along the Nature Coast to the mid 60's over southwest Florida. Max temps this afternoon will top out in the low to mid 70's, which is around average or a couple degrees above. High pressure centered over the eastern gulf will produce light winds less than 10 knots over the gulf waters today. A cold front will then move through the waters on Wednesday producing scattered showers and storms.
413 AM MST Tue Dec 15 2020 Current surface analysis shows weakening frontal boundary just south and west of the forecast area, with main area of low pressure moving into the southern Plains. Upper level analysis shows broad trough moving from the Rockies into the Plains, with upper level low developing across northern NM.
For tonight, embedded S/WV trough/weak clipper system pushes east-southeast across the state.
Clouds continue to overspread the region early this morning with an approaching trough to our west. For tonight, flurries will taper off from west to east with the passing of the trough.
Northeast surface winds have stayed up all night, with wind chill values currently in the low to mid 20s. Latest Water Vapor Imagery shows a large trough over the Central Plains. The aforementioned trough is expected to pivot quickly across the Southern Plains this afternoon. As it does, synoptic models are showing two distinct pieces of energy ejecting into the Lower Mississippi Valley today. Temperatures will be above freezing at the surface, so rain will be the main p-type. There will likely be a dry slot and a lull in precipitation around midnight, before another round of rain spreads up the Delta from the main trough overnight. Rain chances will come to an end by late morning as the trough deepens and lifts into the northeast, where a winter storm is forecast tomorrow.
337 AM CST Tue Dec 15 2020 Tight upper level trough is making its way through CO/NM early this morning with the consensus having shifted a county or two south of what was progged yesterday.
As the center of the anticyclone associated with the cold air mass shifts east from the Lake Superior region, low-level winds will veer to an easterly direction. Mid-level moisture associated with weak forcing will be passing through the area tonight, and forecast soundings/time sections suggest it may be able to seed the lower-level lake clouds, increasing the likelihood of snow showers and flurries.
There is also a cooler spot around the Lake of the Woods, but this area will see fairly thick clouds yet.
Another Cold Front. Another cold front will sweep across West Central Texas today and again bring gusty winds, from the west and northwest. Highs today will be, for the most part, slightly cooler than usual mid December highs, and overnight lows tonight will again be mainly in the upper 20s.
624 AM EST Tue Dec 15 2020 A low pressure system lifting through the Ohio valley spread accumulating light snow across the area Wednesday.
501 AM CST Tue Dec 15 2020 Overall scenario of the upper trough moving out of the Rockies today is still on target. Overall frontogenetic forcing is not exactly impressive either and wind speeds will diminish if anything today as the trough moves in.
Latest CAMs and deterministic models still have some minor timing, strength and placement differences with the upper level trough, but do have very light QPF amounts mainly across eastern portions of forecast area for tonight.
A cool and dry airmass will result in chilly overnight temperatures the next few days with many outlying communities falling to near the freezing mark.
213 AM MST Tue Dec 15 2020 Flat ridging with slightly northwest flow aloft set up across the state today. Other than some limited moisture getting pumped into the west and southwest facing slopes of the higher terrain, the forecast area should be precipitation free. An area of low clouds has formed over the southeast behind a surge of cooler air.
With a colder air mass in place, overnight the lows this morning will be quite cold. Afternoon highs will be quite chilly running 4 to 8 degrees below normal at the lower elevations and 5 to 15 degrees below normal in the mountains depending on elevation.
355 AM CST Tue Dec 15 2020 Late night sfc analysis high pressure centered over the wrn Great Lakes/upper MS Valley ridging swd over the forecast area, while low pressure was noted over the TX/OK panhandle region. The advancing system aloft will this low will lift newd into nwrn Gulf later today, further enhancing lift across the area, allowing a good coverage of mainly shower activity developing from southwest to northeast through the afternoon.
Aforementioned upper trough will race eastward today with a weak area of low pressure developing across west Tennessee then shifting northeastward up the Ohio River. Increasing WAA ahead of the low along with strong upper level divergence will cause light rain to rapidly develop across the area late this evening and overnight, with activity increasing in coverage/intensity Wednesday morning before exiting the area Wednesday afternoon/evening.
As of 09z this morning, an upper trough was located over the Rockies with a swath of clouds present over the central CONUS ahead of this feature. The forcing looks rather weak and dry air in the low-levels will need to be overcome, but model soundings do show lift at least partially in the DGZ with the low-levels saturating enough to support snow by 22-23z. The weather pattern becomes quite benign after today's system with high pressure and northwest flow building across the area on Wednesday.
344 AM CST Tue Dec 15 2020 As of 09z this morning, an upper trough was located over the Rockies with a swath of clouds present over the central CONUS ahead of this feature. The forcing looks rather weak and dry air in the low-levels will need to be overcome, but model soundings do show lift at least partially in the DGZ with the low-levels saturating enough to support snow by 22-23z. The weather pattern becomes quite benign after today's system with high pressure and northwest flow building across the area on Wednesday.
While the ridge tops should see significant warming, there is the potential for the cold air to linger in the northern river bottoms, but the moderating influence of the overnight low clouds will result in a warmer start than anticipated for much of the eastern zones. The Alberta low moves east tonight, pulling a cold front into Montana. There is some potential for snow showers just ahead of the front late tonight, but mostly expecting an increase in the winds, especially over the higher terrain areas near central Montana.
332 AM CST Tue Dec 15 2020 As of 9Z, increasing low level moisture is ongoing over the central plains ahead of an upper level trough over New Mexico. While not in the forecast, patchy freezing drizzle will be possible this morning in the Watertown area as well. Will monitor trends/observations and add freezing drizzle as needed. Jet-level steering flow winds are progged to be directing low pressure systems along a track across the CONUS that is generally west-northwest to east-southeast in the out periods (at least over the western half of the CONUS).
302 AM PST Tue Dec 15 2020 Ridging builds into the region through Wednesday. This will bring patchy overnight and morning dense valley fog and slightly warmer high temperatures over the next few days.
High pressure will continue building across the Midwest into the Upper Ohio Valley today, ensuring dry weather with near-average temperature.
355 AM CST Tue Dec 15 2020 (Issued 400 AM CST Tue Dec 15 2020) Today through Wednesday: High clouds this morning will have prevented temperatures from dropping quite as low as they could but temperatures will still be very cool with temperatures across southern Wisconsin in the low to mid teens to start the day. High pressure will push across the region today and as it pushes out it will bring easterly flow across the region this will quickly bring in lake effect clouds across at least the eastern portion of the CWA and possibly further west as well.
By the early afternoon, expect SHRA overspreading the region from west to east as low pressure slides along the northern Gulf Coast. Later during the overnight hours, a secondary low and reinforcing cold front push through the region, resulting in a shift to slightly drier and more moderate northwesterly winds. /issued 355 AM CST Tue Dec 15 2020/ Late night sfc analysis high pressure centered over the wrn Great Lakes/upper MS Valley ridging swd over the forecast area, while low pressure was noted over the TX/OK panhandle region. The advancing system aloft will this low will lift newd into nwrn Gulf later today, further enhancing lift across the area, allowing a good coverage of mainly shower activity developing from southwest to northeast through the afternoon.
This low stratus has been working in from the E/SE overnight in the low level flow. Over the I-30 corridor, some mid and high clouds are appearing now ahead of the upper low on approach across the plains states. Ground temps even there are likely still well above freezing so accumulations are slim to none due to that and the light amounts of moisture available for the upper low. Morning lows will be above freezing for most of us due to the clouds, but some freezing spots are possible. Once the sun sets, we will be dropping quickly toward freezing by mid evening up north.
Temperatures are currently in the lower/mid 20s over much of the region. A rather stiff east wind today and increasing afternoon clouds will likely hold max temps in the upper 30s far north/west areas to the lower half of the 40s along/south of the OH River. At the surface, an elongated area of low pressure will lift northeast from wrn TN into the lower OH River Valley. Could end up with some snow or a light wintry mix with temps very close to the freezing mark by the time we get to the morning commute.
The higher amounts are expected to be along Highway 2, from Essex to Marias Pass, along with westerly winds gusting as high as 35 mph.
337 AM MST Tue Dec 15 2020 Main circulation associated with the upper low over southeastern CO this morning, and is expected to shift southeast into TX/OK by midday. The trend will continue as the upper trough continues to track south/southeast. Temperatures will stay on the cool side today with highs in the lower to mid 30s. Only light snow possible along the higher west facing slopes. The HRRR indicates gusts above 50 kts, along the higher east facing slopes of Boulder County. Some of the stronger gusts will likely spill out onto the nearby adjacent plains, so we added some blowing snow along the Highway 93 Corridor between Boulder and Golden.
These numbers are generally a few deg cooler than most guidance was advertising yesterday evening. obs have been cooler than even that guidance overall. will trend on the cooler sign of a blend of guidance for temps through this evening. given the cooler temps expected. WRN sections of the CWA may see a period of increased POPs and persistent precip late this afternoon and this evening in closer proximity to the upper trough as it moves into the state. especially in the higher terrain of the Ouachita Mountains. Warmer conditions look to return later in the week.
The upper level low along the Colorado/New Mexico border will lift east/northeast toward the Ohio River Valley. The moisture plume ahead of this low will help to maintain an abundant amount of mid and high level clouds over the area. In the low levels, the area of high pressure centered south of KDLH early this morning will shift east over the Great Lakes but the ridge axis will continue to extend back to the southwest and over the area. This will help to keep any precipitation from the passing upper level low well to south of the area. Temperatures will be a bit warmer with highs today expected to mainly be in the 20s with overnight lows in the teens. On Wednesday, an upper level trough and associated precipitation look to slide by well to the south of the forecast area.
An upper low is on approach with deep SW flow aloft and will bring some scat shwrs which will be spotty and not areawide for this event, but amounts will be light in any case or precip type. This low stratus has been working in from the E/SE overnight in the low level flow. Over the I-30 corridor, some mid and high clouds are appearing now ahead of the upper low on approach across the plains states. Ground temps even there are likely still well above freezing so accumulations are slim to none due to that and the light amounts of moisture available for the upper low. Morning lows will be above freezing for most of us due to the clouds, but some freezing spots are possible. Once the sun sets, we will be dropping quickly toward freezing by mid evening up north.
604 AM CST Tue Dec 15 2020 Overall scenario of the upper trough moving out of the Rockies today is still on target. Overall frontogenetic forcing is not exactly impressive either and wind speeds will diminish if anything today as the trough moves in.
The Florida Keys lie within a weak pressure pattern just south of a stalled, dying front, which is at the far southern periphery of a sprawling winter anticyclone centered in arctic air over the upper Midwest. An upper-level, large-scale composite analysis reveals a deep layer mean anticyclone centered over the northern Caribbean Sea. A broad belt of high-speed, high-altitude westerlies covers a good chunk of eastern North America, with a potent trough from the southern Rocky Mountains to northern Mexico.
333 AM MST Tue Dec 15 2020 Current surface analysis shows weakening frontal boundary just south and west of the forecast area, with main area of low pressure moving into the southern Plains. Upper level analysis shows broad trough moving from the Rockies into the Plains, with upper level low developing across northern NM.
As of 9Z, increasing low level moisture is ongoing over the central plains ahead of an upper level trough over New Mexico. While not in the forecast, patchy freezing drizzle will be possible this morning in the Watertown area as well. Will monitor trends/observations and add freezing drizzle as needed. Jet-level steering flow winds are progged to be directing low pressure systems along a track across the CONUS that is generally west-northwest to east-southeast in the out periods (at least over the western half of the CONUS).
High pressure will continue building over the Upr OH in advance of deepening Plains low pressure.
By late morning, a fast moving cold front will bring windy conditions (especially w/ of KLBB/KPVW) diminishing late this afternoon. /issued 337 AM CST Tue Dec 15 2020/ Tight upper level trough is making its way through CO/NM early this morning with the consensus having shifted a county or two south of what was progged yesterday.
Areas of light snow will move into eastern Oklahoma TAF sites by mid afternoon in response approaching upper low with snow spreading into northwest Arkansas by 00Z. Dry weather with a gradual warming trend is expected mid to late week as high pressure prevails.
Temperatures will climb into the lower 50s as a result of the early day sunshine and increasing warm air advection. The strong and compact upper low will be moving east through OK early this evening, and becoming an open wave by Wednesday morning as it moves into the OH and TN valleys. The low level jet axis and warm sector will be much further south with this system, staying over south AL and the FL panhandle.
The corresponding cold front is expected to move across the CWA this evening/early tonight. Further, convergence along the front will be limited over the ERN CWA as offshore flow develops in advance of the front in response to a coastal trough.
The best locations to receive the highest amount of snow will be along the Oklahoma border as the best 700 mb level energy will rotate through northwest Oklahoma and south central Kansas.
/issued 337 AM CST Tue Dec 15 2020/ Tight upper level trough is making its way through CO/NM early this morning with the consensus having shifted a county or two south of what was progged yesterday.
(This evening through Wednesday) A cold front has brought breezy winds across the region this afternoon. Highs will climb into the low to middle 50s tomorrow.
However, later in the afternoon, some wedging of slightly cooler air may push into NE AL. Based on observations and forecast, believe that highs will only make it into the lower to mid 40s in most locations. The strong and compact upper low will be moving east through OK early this evening, and becoming an open wave by Wednesday morning as it moves into the OH and TN valleys. The low level jet axis and warm sector will be much further south with this system, staying over south AL and the FL panhandle.
1242 PM EST Tue Dec 15 2020 A low pressure system lifting through the Ohio valley spread accumulating light snow across the area Wednesday.
1248 PM CST Tue Dec 15 2020 Clouds continue to overspread the region early this morning with an approaching trough to our west. For tonight, flurries will taper off from west to east with the passing of the trough.
Look for cloud cover to increase through the day as a broad trough moves eastward out of the southern plains. An approaching low pressure system will bring light rain with MVFR cigs/vsbys after 06Z.
200 PM MST Tue Dec 15 2020 A cool, dry airmass will result in chilly overnight temperatures the next few days with many outlying communities falling near the freezing mark tonight.
This precip will have to overcome some drier air in the low levels, so any small accumulation may well be spotty.
924 AM CST Tue Dec 15 2020 Weak isentropic lift in the lower levels of the atmosphere is resulting in patchy in and out drizzle across most of the Four State Region this morning. Also, temperatures, while warming slowly, are still below freezing across portions of our extreme northwest zones north and west of the I-30 Corridor as late as 15z. Also added patchy freezing drizzle where temperatures remain below freezing through the noon hour as well. An upper low is on approach with deep SW flow aloft and will bring some scat shwrs which will be spotty and not areawide for this event, but amounts will be light in any case or precip type.
The pressure gradient over the Beartooth Mountains continues to tighten this morning as low pressure lee-side of the northern Rockies continues to drop south into eastern Montana. Winds at livingston showcase this, as they have now gusted into the low 50s as of 10 AM MDT, and will continue to increase to gust to 65 mph by this evening.
127 PM MST Tue Dec 15 2020 Western CONUS upper trough will re-build east into the region this week ahead of a deeper upper low. Clipper system will slide SE on the front side of the ridge, with WAA FGEN supporting a chance of light snow across mainly NW SD and the northern Black Hills tonight. Lift/snow will taper off Wed morning with a warmer day per deeper mixed flow expected most places.
Otherwise, VFR is expected through the period with N to NW winds through the evening ahead of an approaching cold front.
Then, mostly dry conditions expected today, with yesterday's cold front stalled near the Lake Okeechobee region. Isolated showers will be possible off of the Volusia coast, as the low forms, and a few of these showers may drift onshore. Yesterday's weak cold front is now stalled near the Lake Okeechobee region.
213 PM CST Tue Dec 15 2020 Current satellite analysis has an upper low centered over north- central Texas Panhandle into the Oklahoma Panhandle as of this writing. Tonight this low will move off to the east with snow ending this evening. Northwest flow aloft will be in place by tomorrow with heights rising as an upper level ridge starts build over the area from the west.
This will allow temps to drop well below freezing with temps ranging from the low teens across the southwestern Texas Panhandle to low 20s possible across the southeastern Rolling Plains. While temps will be slightly warmer across the region temps will struggle to get into the 50s as cool air remains in place.
Marquardt (Issued 400 AM CST Tue Dec 15 2020) Today through Wednesday: High clouds this morning will have prevented temperatures from dropping quite as low as they could but temperatures will still be very cool with temperatures across southern Wisconsin in the low to mid teens to start the day. High pressure will push across the region today and as it pushes out it will bring easterly flow across the region this will quickly bring in lake effect clouds across at least the eastern portion of the CWA and possibly further west as well.
(This evening through Wednesday) Upper low over northwest Oklahoma will continue to move east and then northeast this evening. There will be some light snow wrapping around this upper low this evening, so will maintain some pops this evening, especially across northwest and southeast parts of Oklahoma. Clouds will clear across west just early enough with lighter winds to allow temps to drop on off into the lower teens with slightly warmer temps farther east.