Aikyam-Lab/Synoptic-Bench huggingface dataset:
Temperatures on Wednesday will turn warmer out west as a milder airmass pushes in from the west.
202 PM CST Tue Dec 15 2020 An upper level trough is currently digging into Texas and SE New Mexico with a jet max passing overhead today, bringing elevated winds to much of the area. Highs this afternoon will be cooler, only reaching the upper 40s to mid 50s with a few 60s along the Rio Grande. Lows Wednesday morning will be in the upper teens to low 20s, so remember to grab your heavy coat before work! Temperatures will be slow to recover over the next few days as weak ridging begins to build over Texas.
1016 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.
Currently clear skies across southeast Arizona with temperatures running about 8-12 degrees lower than yesterday thanks to colder air that moved in behind a trough. The Tucson metro will see temps right around freezing with areas near washes and drainages a couple degrees colder then freezing.
/issued 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.
A low-pressure system is expected to form off the Mid- Atlantic coast on Wednesday and strengthen.
Wintry Mix Expected Wednesday Morning, Minor Impacts Possible For A mid-level trough is centered over the Plains with an embedded low sitting over Oklahoma. Over the next several hours this low will pivot along the trough to the northeast. Precipitation type has been the focus of today's forecast because temperatures, for the northern part of our CWA, are floating around the freezing line. Model sounding profiles stay below freezing until near the surface. Low temperatures overnight are expected to drop a degree or two below freezing across our northern tier of southern Indiana counties and in the Bluegrass region, but road temperatures are expected to stay above freezing. Areas around Louisville and farther south will likely stay above freezing, with those near the Tennessee border in the mid 30s.
Compact upper low is now centered over the TX Panhandle and will transition into a more open wave as it moves east this afternoon and evening. At present some light snow in the warm advection region of the upper low moving into central OK and some of this will likely translate east over the next few hours proving a window for some light snow accum mainly west of US 75. 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.
As a result of the cooler temperatures any precipitation that makes it into East Arkansas this evening would likely fall as light snow. The mix shouldn't last more than 2-3 hours before drier air moves in from the west behind a cold front. Overnight lows should be in the 30 to 34 degree range across most of East Arkansas, the Missouri Bootheel and West Tennessee so any snow should not stick to roads and the threat of rain freezing on roads looks low.
Look for cloud cover to increase through the day as a broad trough moves eastward out of the southern plains.
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.
Tonight as the upper low shifts east, it transitions into a more open wave and begins a weakening trend which will decrease the potential for any substantial snowfall across eastern Oklahoma and northwest Arkansas. Areas across southeastern Oklahoma stand the best chance at accumulating snowfall tonight before the upper low exits the region, but low level dry air will once again inhibit amounts from being any more than one half to one inch at some of the higher elevations.
259 PM CST Tue Dec 15 2020 Tonight: Upper low continue to track east, with heavier snow likely on the wane near or just after 0000 UTC.
Opportunity for impactful weather will revolve around a cold front slated for Fri. Impacts would result from falling/minor drifting snow and isolated patches of freezing rain. The dry Thu will be followed by the approach of a cold front in time for Fri. This could be problematic with respect to some freezing precipitation at times during the afternoon on Fri.
Low pressure is expected to form off the mid- Atlantic coast Wednesday and undergo cyclogenesis, resulting in a major winter storm for much of New England.
210 PM CST Tue Dec 15 2020 A skiff to a few tenths of an inch of snow has been common in areas along and west of I-29 today, but most haven't had any impact from this current upper trough moving through. Wednesday-Wednesday Night: Another progressive upper trough, with limited moisture, will move through the Northern Plains during the second half of Wednesday. Temperatures climb closer to the freezing mark.
Expect cirrus to continue through the day in the SW flow aloft as the trough over the Plains continues moving toward our region. There is some potential for rain at TRI to start as a brief period of freezing rain between 09 and 11Z, but not confident enough to put in the TAF. Garuckas Chattanooga Airport, TN 37 46 33 44 27 / 80 90 10 0 0 Knoxville McGhee Tyson Airport, TN 35 44 34 40 26 / 70 90 20 0 0 Oak Ridge, TN 35 43 32 41 26 / 60 90 20 0 0 Tri Cities Airport, TN 30 41 33 39 26 / 40 100 30 0 0.
Meanwhile a deepening upper low was crossing the Southern Plains, with its associated mid-level moisture streaming into the Upper Mississippi Valley. This low cloud layer looks fairly shallow as it spreads in from the east late tonight into Wednesday morning.
209 PM CST Tue Dec 15 2020 (Issued 205 PM CST Tue Dec 15 2020) Tonight and Wednesday: Light east winds behind departing high pressure over Ontario may bring some low stratus and flurries later this afternoon and evening to far eastern Wisconsin. East winds will increase slightly on Wednesday as low pressure passes to our south.
Low pressure will strengthen over the coastal waters this afternoon, as it moves toward the north. Due to the strong pressure gradient around this low, gusty winds will be expected through this evening at the coast. This low will move northeast of the region Tonight with winds diminishing, and shower chances ending. A cold front will approach from the west Wednesday morning, then east across area Wednesday afternoon and evening. High pressure will build from the west overnight Wednesday night.
Look for mid and high level clouds to build in from the west this evening as the broad upper trough currently centered over the panhandle region moves eastward. Profiles will cool off fast enough for precipitation to transition to a rain/snow mix and eventually pure snow for the higher elevations on the plateau as the 500 mb lobe moves eastward.
As the low/trof shift eastward to the Eastern Coalfields of Kentucky expect to see snow form and shift northward over the region.
For areas that saw measurable snowfall, mainly across the southeast forecast area, lowered temperatures several degrees and trended towards cooler guidance to account for the fresh snowpack and light winds. As for highs tomorrow, kept areas that received snowpack cooler, again mainly areas of the eastern forecast area. Elsewhere trended towards guidance and went a few degrees warmer with temperatures in the mid 40s.
/Issued 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.
Cooler air will begin to filter into the region quickly late to night and into Wednesday morning as the front progresses through the region. As the cooler air arrives, we could begin to see precip change from all rain to a wintry mix in the extreme northern portions of our area of responsibility. While no accumulation is expected for most, there is a chance that areas in northern Bolivar, Leflore, Sunflower, and Grenada Counties could see light accumulations on elevated surfaces such as bridges and overpasses. Surface temperatures above freezing and warm ground temperatures should limit accumulations elsewhere. Light flurries will be possible along the US 82 corridor through the rest of Wednesday morning as some residual moisture will be present as the cooler air continues to arrive as heavier precip exits the region to the east.
The HRRR is the only model doing this boundary justice and depicts low stratus and some fog reaching the Victoria area from 8-11 PM, before the greater of the two cold front shoves SE ahead of much drier NW winds and clearing skies toward midnight.
However, confidence is too low to include and the cooler air looks to move in after drier air has filtered into the atmospheric column.
352 PM CST Tue Dec 15 2020 Amplified upper trough continues moving across the region this afternoon, with the upper low situated over Oklahoma. While heavier precipitation is located closer to this upper low, across the forecast area precipitation remains tough to come by. Things may try to change over the evening hours, as the trough axis swings eastward through the area. Skies will clear by mid-day as the upper trough moves off towards east, ultimately delivering a high impact winter event to the Northeast CONUS.
Eastern Iowa and northwest Illinois was on the eastern periphery of a large area of high pressure centered in eastern Ontario. This section of the CWA will be right on the northwest edge of a large area of light snow across Illinois and Indiana as weak low pressure tracks through the Ohio Valley. The 500 mb flow on Wednesday will transition to northwesterly flow aloft as a the trough and surface responsible for the nor'easter moves into kentucky and West Virginia.
Amplified upper trough continues moving across the region this afternoon, with the upper low situated over Oklahoma. While heavier precipitation is located closer to this upper low, across the forecast area precipitation remains tough to come by. Things may try to change over the evening hours, as the trough axis swings eastward through the area. Skies will clear by mid-day as the upper trough moves off towards east, ultimately delivering a high impact winter event to the Northeast CONUS.
This afternoon, water vapor imagery reveals closed upper low spinning over OK/KS with broad area of moisture transport centered along the Mississippi River valley out ahead of this feature. 700mb low track expected to be just north of the lower Ohio Valley overnight, and snow is expected left of this feature overspreading portions of central Illinois around or just after midnight and continuing through around midday Wednesday. Given the track of the low, moisture remains fairly meager this far north with the 0.
423 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.
This wave will have some Pacific moisture embedded aloft, and may be able to capitalize on near sfc moisture from melting snow, to bring more widespread snow across the lower elevations. 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.
Temperatures follow a warming trend into and through the weekend as southerly flow advects warmer air through the region.
142 PM PST Tue Dec 15 2020 Dense fog is likely to reform across the San Joaquin Valley tonight as high pressure persists aloft.
A cool, dry airmass will result in chilly overnight temperatures the next few days with many outlying communities falling near the freezing mark tonight.
535 PM CST Tue Dec 15 2020 A skiff to a few tenths of an inch of snow has been common in areas along and west of I-29 today, but most haven't had any impact from this current upper trough moving through. Wednesday-Wednesday Night: Another progressive upper trough, with limited moisture, will move through the Northern Plains during the second half of Wednesday. Temperatures climb closer to the freezing mark.
825 PM EST Tue Dec 15 2020 Low pressure off of the northeast FL coast will gradually shift E/NE into tonight. Low clouds and some patchy fog west of this low will continue to spread south and inland from Volusia and northern Brevard counties through Lake, Orange and Osceola counties late this evening into the overnight. However, any VFR conditions look to be brief as band of showers and isolated storms ahead of next cold front begin to shift eastward through the area into the afternoon and early evening. Low pressure off the NE FL coast is generating breezy/windy conditions toward the coast, north of Volusia County.
Winds will pick up and shift to northwesterly as a cold front passes through the area. /issued 323 PM CST Tue Dec 15 2020/ A cold front is expected to move through overnight tonight and into Wednesday morning.
612 PM CST Tue Dec 15 2020 (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.
It has been dry for the most part, despite radar returns, due to the very dry air in the lower levels. The DGZ is quite deep, and while there is a lot of dry air in the lowest 4kft, occasionally enough saturation is taking place to allow for some flakes to reach the ground. The system across the southern Plains today will become an impressive Nor'Easter Wednesday and Wednesday night, while a weak disturbance slides southeast across the northern Plains on the backside of the longwave trough.
Dense fog is likely to reform across the San Joaquin Valley tonight as high pressure persists aloft.
The highest chance for warning level winds will be through 18z Wednesday, but gradients are still projected to stay high enough to keep winds elevated through Thurs morning. Good orographics and strong upper-level forcing in the left exit region of a 110+ knot H25 jet could quite possibly support near Advisory amounts over the highest elevations of the Snowys and Sierra Madres. High pressure dominating the great basin with a low pressure cell digging southeast into Texas. Upper level ridging is expected to build in the region bringing milder conditions through southeastern Wyoming and the Nebraska panhandle.
The next in a series of low pressure troughs is making its way across the Northern Rockies today. As lower elevation temperatures hover near the freezing mark, travelers should be wary of freezing roadways once any liquid precipitation falls with the showers near and after sunset. The next trough of low pressure moves onshore in the Pacific Northwest by Wednesday evening.
The cold front will approach the region near the end of the forecast period. Short-fused amendments are likely tonight due to the low cigs/fog. A temporary weak 500mb ridge is over the area today, which should help keep the weather quiet. This low also become entwined with a stalled front, which is sitting just north of Lake Okeechobee, and pull it to the north. The main cold front approaches the area tomorrow.
High pressure will be in place on through Wednesday, leading to mostly sunny skies and a few degrees of warming. The next weather system will provide another round of gusty winds and a chance of showers over the higher terrain. Another ridge of high pressure will build into the region over the weekend providing dry and tranquil conditions. Gusty north winds of 30 to 35 mph were common down the lower Colorado today, but gradients are weakening and winds should diminish by early evening. A ridge of high pressure will continue to build into the region tonight with the ridge axis centered over the area on Wednesday afternoon, providing a few degrees of warming and lighter winds.
607 PM EST Tue Dec 15 2020 A deep longwave trough with an embedded short wave progressing eastward will lower surface pressures in the Eastern Gulf overnight. The highest CAPEs will be just offshore and skimming the coast. Cloud cover should increase as the low develops in the Gulf.
The broad cloud shield north of the low extended north through Kansas, and into Nebraska and Iowa. Forecast lows for tonight are in the lower teens, with temperatures closer to 10 degrees expected where the snowpack is thicker along the Interstate 80 Corridor. Temperatures should struggle to get above freezing Wednesday, with most of the region (Metros included) topping out in the upper 20s.
Temperatures will be relatively warmer than normal for this time of year for the next several days. 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. Clouds will continue to increase this evening as a leeside trough off the Northern Rockies moves east overnight. The associated cold front will bring the potential for light snow showers just ahead of the front. Winds will also pick up, especially over the higher terrain areas near central Montana.
/issued 202 PM CST Tue Dec 15 2020/ An upper level trough is currently digging into Texas and SE New Mexico with a jet max passing overhead today, bringing elevated winds to much of the area. Highs this afternoon will be cooler, only reaching the upper 40s to mid 50s with a few 60s along the Rio Grande. Lows Wednesday morning will be in the upper teens to low 20s, so remember to grab your heavy coat before work! Temperatures will be slow to recover over the next few days as weak ridging begins to build over Texas.
323 PM CST Tue Dec 15 2020 A cold front is expected to move through overnight tonight and into Wednesday morning.
545 PM CST Tue Dec 15 2020 Tonight: Upper low continue to track east, with heavier snow likely on the wane near or just after 0000 UTC.
Wrap-around clouds from the upper low over north central Oklahoma will linger through the night with clearing coming to southwestern Oklahoma before sunrise.
834 PM CST Tue Dec 15 2020 A wnw-ene oriented light snow band has formed along the deformation zone just north of the track of the upper low as it transitions into an open wave. Some light accumulations have occurred in the Tulsa metro, mainly on grassy and elevated surfaces with temps near freezing and ground temps above freezing.
Meanwhile, high pressure is set to return for the end of the week into the weekend.
555 PM CST Tue Dec 15 2020 (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.
305 PM CST Tue Dec 15 2020 Eastern Iowa and northwest Illinois was on the eastern periphery of a large area of high pressure centered in eastern Ontario. This section of the CWA will be right on the northwest edge of a large area of light snow across Illinois and Indiana as weak low pressure tracks through the Ohio Valley. The 500 mb flow on Wednesday will transition to northwesterly flow aloft as a the trough and surface responsible for the nor'easter moves into kentucky and West Virginia.
515 PM CST Tue Dec 15 2020 Upper low continues to pull away from the forecast area. 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.
Models indicate a rather tight surface pressure gradient developing along the central mt chain by 12Z as high pressure builds over nw NM, therefore nw winds may become gusty in favored areas along the central mt chain and adjacent east slopes, persist through 17/00Z.
Otherwise, expect mostly light N-NW winds across all terminals, although CRP still looks to gust to around 20 knots by mid/late morning before tapering throughout the afternoon as high pressure draws closer. The HRRR is the only model doing this boundary justice and depicts low stratus and some fog reaching the Victoria area from 8-11 PM, before the greater of the two cold front shoves SE ahead of much drier NW winds and clearing skies toward midnight.
Tonight: Upper low continue to track east, with heavier snow likely on the wane near or just after 0000 UTC.
Winds are slowly beginning to turn more towards this developing low pressure system. Temperatures are steadily falling into the lower 70s with dew points holding in the lower 70s as well. As the aforementioned low pressure system becomes better organized, it will lift northward and merge with another low pressure system, currently taking shape along the north Gulf coast.
Near the surface, a weak lee side trough of low pressure is anchored in eastern Colorado. 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.
Temperatures will be a bit higher today than yesterday, but we'll see a slow moderation of temps Thu and Fri as weak ridging establishes over the lee side of the Rockies into west TX. The end of the week is trending the warmest with the addition of a downsloping westerly wind on the base of a trough axis over the Four Corners. Cold front will sweep through the area as the previously mentioned trough passes to our north and plunges southeast.
204 AM CST Wed Dec 16 2020 Fresh snow cover, light winds, and small dewpoint depressions will support patchy freezing fog overnight into this morning across the region. Since temperatures are below freezing, patchy slick roads are likely.
1035 PM CST Tue Dec 15 2020 (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.
Tranquil conditions are likely today and tonight as ridging aloft builds in across the Intermountain West while a prevailing downslope flow ushers drier air into the high plains of western Kansas. Temperatures will warm a little today under mostly sunny skies as prevailing downslope westerlies help draw slightly warmer air into the area.
1028 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.