Aikyam-Lab/Synoptic-Bench huggingface dataset:
We will see very good radiational cooling conditions tonight, with overnight lows expected to drop below freezing across all of south central Texas. Many areas have already seen a several rounds of subfreezing temperatures this Fall. Conditions look good for subfreezing temperatures across the mentioned areas and we have issued a Freeze Warning for tonight. Another round of subfreezing temperatures appears in store for a good portion of south central Texas Wednesday night. The exception could be out west along the Rio Grande as we should see southeast winds continue through the overnight hours, along with some increase in high clouds which could help to keep temperature just above freezing.
718 PM EST Tue Dec 17 2019 A reinforcing cold front will return snow showers and squalls Wednesday. This front and its associated, upper low will pivot across the region by pre-dawn Wednesday. Steepening low level lapse rates and deep moisture within the dendritic snow growth zone will support a window of efficient snowfall, with reduced visibilities in gusty wind in conjunction with the crossing cold front and in nwly flow thereafter. Snow showers will diminish with building high pressure Wednesday night.
The freezing line could be as far south as the coastal counties (generally along an Edna to Bay City to Alvin line).
As high pressure builds in from the west, these trends will continue southeastward, and mostly clear skies should arrive area wide during the night. Another increase in low clouds is expected to arrive from north to south during the day Wednesday as a trough approaches under brisk northwest flow aloft.
708 PM EST Tue Dec 17 2019 Early evening KTBW radar is showing a squall line moving southeast through the Tampa Bay area just ahead of the cold front boundary.
GAH AFTERNOON DISCUSSION: Even though most model data indicate fog will not form tonight, we felt it was best to proceed with freezing fog in the forecast again tonight, given that, this morning, fog was persistent in the Wolf Point area. Ridge of high pressure moving in from west of here, will continue to dominate the weather pattern over our region.
This afternoon, an amplified upper ridge resides over the western CONUS, with a broad troughing pattern in place over the central and eastern portion of the country. After topping out in the low and mid 30s this afternoon, light winds, clear skies and snow cover will allow for efficient radiational cooling this evening and tonight. Temps will be in the low teens by early tomorrow morning, with isolated spots likely a touch cooler. The western CWA should warm into the low 40s with the rest of the area remaining in the 30s.
/issued 157 PM CST Tue Dec 17 2019/ An upper level low is centered across northwestern Ontario with a sweeping trough axis from the Ohio Valley to SWRN NM. A ridge is present across the spine of the Rockies with another low out off the Pacific coast. The ridge is expected to translate eastward tomorrow with the next low-in-sequence making its way to the Sierra Nevada range by tomorrow evening.
The mid-level trough axis has moved east of the CWA, but the lagging 500 mb axis will swing through tonight.
241 PM MST Tue Dec 17 2019 Even though most model data indicate fog will not form tonight, we felt it was best to proceed with freezing fog in the forecast again tonight, given that, this morning, fog was persistent in the Wolf Point area. Ridge of high pressure moving in from west of here, will continue to dominate the weather pattern over our region.
Been getting a few reports of very light snow or freezing sprinkles, though this does not seem to be causing any impacts at the moment. Cloud cover will help to keep low temps warmer that under clear conditions, with lows in mid to upper teens. Wednesday will feature high pressure becoming more established, with drying conditions and more sunshine. Highs will be a few degrees colder than today, with readings in the lower 20s in our NE counties, and mid to upper 20s farther southwest, from Rushville to Springfield to Lawrenceville.
Convection has weakened this evening and shifted to the se while a cold front extended from near Jesup to Live Oak. Breezy and much cooler conditions for Wednesday with highs only in the mid/upper 50s. Cold front will push across TAF sites between 02z-05z this evening with rain ending and winds increasing/shifting to the nw. Low ceilings behind the cold front will produce MVFR conditions with frontal passage with VFR conditions returning 09z- 12z.
A cold front tracked across the area this morning, and will now watch a high pressure system drop out of Canada toward the area. This high looks to track southward over mainly the eastern part of the CWA late this afternoon into tonight, with a trough beginning to dig over the west. However, still expect the coldest temperatures to be over the east under the high center, where subzero lows are expected east of the James River Valley.
145 PM PST Tue Dec 17 2019 Santa Ana winds will diminish tonight as high pressure over the Great Basin weakens.
While the strong southerly winds kept the south end of the well above the freezing mark, additional cloud cover and an increase in winds will warm-up the rest of the San Joaquin Valley overnight.
724 PM MST Tue Dec 17 2019 High pressure will continue to build over the area tonight.
412 PM MST Tue Dec 17 2019 Strong upper ridging will continue to build into the region tonight through Wednesday, bringing continued dry weather.
High pressure will continue to build over the area through tonight.
High pressure strengthening over the region today will lead to potentially dense fog redeveloping tonight into Wednesday morning.
319 PM CST Tue Dec 17 2019 A cold front tracked across the area this morning, and will now watch a high pressure system drop out of Canada toward the area. This high looks to track southward over mainly the eastern part of the CWA late this afternoon into tonight, with a trough beginning to dig over the west. However, still expect the coldest temperatures to be over the east under the high center, where subzero lows are expected east of the James River Valley.
317 PM CST Tue Dec 17 2019 This afternoon, an amplified upper ridge resides over the western CONUS, with a broad troughing pattern in place over the central and eastern portion of the country. After topping out in the low and mid 30s this afternoon, light winds, clear skies and snow cover will allow for efficient radiational cooling this evening and tonight. Temps will be in the low teens by early tomorrow morning, with isolated spots likely a touch cooler. The western CWA should warm into the low 40s with the rest of the area remaining in the 30s.
228 AM CST Wed Dec 18 2019 Areas of dense fog and freezing fog persist this morning across parts of far northeast OK into northwest AR. Otherwise expect a sunny day, with afternoon temperatures several degrees warmer than yesterday.
200 AM EST Wed Dec 18 2019 High pressure will build across NC today and tonight. A dry arctic cold front will move south across the region tonight. Cold high pressure will follow the front as it builds into NC from the north through late in the week. Highs expected to top out in the mid 40s NW-N into the lower 50s SE. Another dry cold front will push even colder and drier air south into NC from the north as it passes south of the region tonight. GSO 45/23 TDF 47/20 RDU 48/24 Cold high pressure will be centered overhead Thursday and Thursday night.
Bigger concern in the short term is the differential between the surface winds decoupling and the height gradient still in place just off the sfc in the wake of the exiting front/building of the high to the west. PWs generally less than a quarter inch) & clearing skies after midnight, expect good radiational cooling & lows below freezing, with some upper 20s to low 30s areawide. There is some crossover temperatures, so will have to monitor how much we can radiate for any very patchy freezing fog. Wednesday: Tomorrow will be similar as thermal profiles remain somewhat similar, albeit only a touch warmer in the low-levels.
As southerly and even southwesterly breezes setup, warmer temperatures should be realized across the region. After perusing various model data predicted high temperatures, settled on highs a couple/few degrees warmer than NBM. The main headlines for the extended are the warmer temperatures and favorable mixing conditions.
340 AM EST Wed Dec 18 2019 A cold front will cross the Ohio Valley to the southeast early today. High pressure will build over the area and help to entrench some of the coldest air of the season through early Thursday.
The next chance for precipitation is this weekend as low pressure develops to our south. The cold front is along the coast this morning with west-northwesterly winds ushering in a colder and drier air mass in its wake. Strong cold advection expected overnight with lows ranging from the lower to mid 30s west and upper 30s east despite a mixed boundary layer. High pressure will build into the region from the west today. Dry high pressure will move into and settle over the Southeastern. Both the gfs and ecmwf develop a cutoff upper low across the southern plains, then move it eastward through the weekend.
Cloud cover through the morning will keep temperatures a bit warmer from last night, warmer being relative as it will still be very chilly. In addition to the cloud cover, northeast winds will be breezy overnight along and south of the high terrain. Should be about 10 degrees warmer tonight compared to last night. An incoming low pressure system off the California coast will turn the flow more southerly, which will allow for moisture to stream into the region.
1248 AM EST Wed Dec 18 2019 A cold front will push through the region overnight, providing much below normal temperatures. Arctic high pressure will continue the cold temperatures through Thursday before moderating a bit heading into the weekend. High pressure will make it nearly overhead by late Wednesday night. High pressure will be shifting to the east of the region on Thursday.
In the upper levels, a ridge will build into the forecast area Wednesday with high temperatures rebounding to the 50s. Pleasant conditions will continue Thursday with breezy conditions ahead of a trough. By late Thursday night a weak cold front will swing across the forecast area with winds at the surface turning to the north.
Tonight Through Thursday Dry northwest to north flow will prevail aloft over Arkansas tonight through Wednesday night as a massive upper ridge of high pressure over the Rocky Mountain states migrates eastward and moves over the Natural state.
A weak wave approaches the forecast area overnight, which also helps set up an H85 thermal ridge. The upper ridge currently centered over the Rockies also emerges onto the High Plains.
245 AM CST Wed Dec 18 2019 Short term concerns center around ongoing fog/freezing fog. Where fog is dense, freezing fog is being observed with light icing on elevated surfaces and untreated roadways expected.
VFR conditions will prevail at all of the terminals through the entire forecast period as a dry and stable ridge of high pressure settles over the region.
Low clouds, which have kept temperatures in check in the 20s for most of the day, are starting to erode into eastern Iowa leading to a late day charge into the lower to mid 30s in areas north/west of the Quad Cities. Weak ridging/limited mixing will result in gush of warmer air aloft remaining largely untapped. Low level flow does begin to turn southerly in the afternoon especially in our western counties as the high starts to shift toward the Ohio Valley. Signs of potentially even warmer weather exist during the week of Christmas, as a deep longwave trough develops across the western CONUS. Eventually the pattern will turn active as energy lifts out of the trough, favoring after Christmas for this to occur. By late Wednesday afternoon, winds will switch to southwest/south as the high pressure moves east.
An upper-level trough is situated over the area and is helping bring in much cooler temperatures with west-northwest flow. Temperatures are already in the mid 20s to mid 30s and are expected to drop down into the low to upper 20s overnight. High pressure is located upstream and will build in to the region over the next couple of days. The mid-level trough axis has moved east of the CWA, but the lagging 500 mb axis will swing through tonight. Cloud cover will begin to increase Thursday night as a digging trough moves across the Southern Rockies. The 12z global model consensus is for this trough to close off it it ejects into the Southern Plains, moving ESE toward the central Gulf Coast.
This system will bring snow to all elevations Wed night and Thu morning, before warmer air moves in a changes the snow to rain below around 4000 feet.
So how much warmer will it get overnight? Thinking 3 to 5 degrees warmer so in the grand scheme of things, not much of a difference. The ridge that is bringing the nice, cold weather will shift east tomorrow causing winds to shift to the southwest ushering in some warmer temperatures as well as a few higher clouds in the afternoon. Clouds will hang around Thursday morning as an upper level trough moves across the CWA. Unfortunately, moisture associated with this trough will be wrung out over the Sierras and so we'll just see those clouds during the day. After that, another ridge builds in bringing more benign weather for the weekend.
High pressure will begin to move slowly off to the east away from the region today and tonight but the circulating return flow will still be cool. By Thursday a southern stream upper level low pressure area will be approaching from the Rocky Mountains.
This scenario will also eventually produce orographic snow in the ridges. As is usual with these situations, the areas with the highest probability to see accumulations will be across the I-80 corridor and over the ridges. Snow showers will diminish with building high pressure tonight.
A closed low continued to track across Canada north of the Great Lakes, with its trough extending south through the Upper Midwest to the Texas panhandle. West of the High Plains, upper ridging built onto the Rockies. Flow aloft turns to the northwest tonight as the upper ridge noses into the Plains. The ridge progresses over the area on Wednesday, with sunny skies expected through the day and highs in the 50s. Clouds increase from the west overnight as an upper trough makes its way to the Rockies. We will see a slight drop in temperatures on Thursday (mid 40s to low 50s) as the trough passes through and clouds linger.
Temperatures are currently falling into the low 30s and upper 20s. With a light northwest wind and most spots under a clear sky, morning lows are still expected to achieve the low and mid 20s.
1030 PM EST Tue Dec 17 2019 Band of showers/storms will continue to push through the area ahead of a cold front that will cross the area overnight. Cold front will cross the waters overnight.
923 PM CST Tue Dec 17 2019 High pressure over West Texas will bring clear skies and dry air to the region tonight. Urban areas and and along the coast will remain warmer.
Dry air advection continues to prevail across the TN valley this evening favoring clearing skies and an end to earlier/brief light rain/snow showers across the high terrain. MVFR will give to VFR at all sites through the overnight as drier high pressure advects into the region from the west. CDG Chattanooga Airport, TN 29 46 27 49 30 / 0 0 0 0 0 Knoxville McGhee Tyson Airport, TN 28 44 25 46 29 / 10 0 0 0 0 Oak Ridge, TN 27 45 25 46 29 / 0 0 0 0 0 Tri Cities Airport, TN 24 41 22 43 27 / 10 0 0 0 0.
The axis of a mid-level longwave trough will continue to push slowly southeastward across the TN Valley late this evening/early Wednesday morning. As this occurs, we expect further dissipation of the low stratus cloud deck that was in place across the region earlier today, with clear skies anticipated by sunrise. Mid/upper level troughing associated with the departing storm system exiting the Canadian Maritimes will retreat to the north on Wed/Thu, with weak ridging in place over the eastern CONUS.
Arctic high pressure is quickly sliding southeast with return southerly flow setting up across the area this morning. Strong warm air advection up to 700mb will continue to bring warmer air to the area with highs ranging from mid 20s in the Devils Lake basin to low teens in the MN pines this afternoon. Lows overnight expected to be in the single digits with highs on Thursday around 20 for the area as weather remains benign with upper level ridging.
Fortunately, temperatures will warm to above freezing by 9 am. Northerly flow will continue today before an upper level ridge shift across Texas late today and tonight shifting winds to the east. Though temperatures will be a a few degrees warmer, freezing temperatures will again be possible tonight/Thursday morning. Starting Thursday an upper level low will close off as it moves from the Rockies across the Oklahoma and Texas Panhandles before strengthening and diving southeast over Louisiana.
1224 AM EST Wed Dec 18 2019 [Through 06Z Thursday] A cold front is currently exiting the region. Convection has weakened this evening and shifted to the se while a cold front extended from near Jesup to Live Oak. Breezy and much cooler conditions for Wednesday with highs only in the mid/upper 50s.
132 AM MST Wed Dec 18 2019 Western NOAM ridge will shift east this week, supporting mild conds Ongoing WAA aloft per height rises.
A steady NW breeze should also help to keep temps a bit warmer vs. Main focus on Wednesday is on arctic cold front progged to slice through the region. Ribbon of instability present along with isallobaric couplet but marginal moisture means that the front will likely touch off numerous snow showers and a few squalls over the northwest which will likely survive into the NC and C Mountains, but likely dissipate before reaching the Lower Susq River Valley. Deepening cold air and a still tight llvl p-gradient will mean even stronger sustained wind in the teens with gusts into the low-mid 30KT range as the mixing depth increases to 5-6 kft agl.
Surface ridging builds in this afternoon with subsidence and drying causing inversion heights to crash and ending snow showers by this evening.
Santa Ana winds will weaken tonight as high pressure gradients decrease to the high in The Great Basin. The winds turn briefly onshore Wednesday and Thursday when a low pressure trough moves inland to the north.
Cooler temperatures get advected across the region. High pressure will be just east of the region Thursday morning. Aloft, a ridge will move across us during the day, helping us to start breaking out of the below normal temperatures we'll be in today.
Fowler High pressure over West Texas will bring clear skies and dry air to the region tonight. Urban areas and and along the coast will remain warmer.
Slight warmup for Thu afternoon as the thermal troughing attempts to hang on just a tad longer.
Cold Canadian high pressure will quickly move across the region today with colder air in place across eastern Iowa, northwest Illinois, and far northeast Missouri. Return southerly flow will set up across the region Wednesday night into Thursday morning in the wake of high pressure. Ridging across the Plains will result in much above normal temperatures through Christmas Day with high temperatures generally in the 40s. By next Wednesday/Christmas, 500 mb ridging will have pushed to the east of the area with a southwesterly flow aloft setting up with a deep trough across the western US. By late Wednesday afternoon, winds will switch to southwest/south as the high pressure moves east.
However, one challenge is how the low stratus currently covering a large part of the area east of the Mississippi River will morph throughout the day. Assuming the stratus dissipates and sunshine is present to add some warmth to the chill, highs today are only forecast to range from the lower 30s along I-64 to near 40 degrees across the far southern sections of southeast Missouri and western Kentucky. Should the clouds stick around, temperatures could be several degrees cooler where that occurs.
After a ridge moves over the state on Wednesday, an upper level low will cross the state on Thursday. Another upper level ridge is in store for the latter part of the week, and temperatures are expected to climb well above normal for the weekend. An upper level ridge will translate over NM on Wednesday, which will lead to a modest warming of temperatures, though most locations will still see highs a few degrees shy of normal. The upper high will quickly move eastward Wednesday night as a trough shifts over the Desert Southwest.
A weak cold front that has been moving across the area will switch winds to northerly for the early overnight. The air mass behind this front is cold enough in the lowest couple thousand feet to cause some low- layer saturation, so scattered overnight cloud cover can't be ruled out. A building ridge aloft on Wednesday combined with southerly flow near the surface will help boost temperatures to near seasonal normals. Thursday's high temperatures increase a few more degrees with slightly better mixing as the ridge exits eastward.
944 PM CST Tue Dec 17 2019 The axis of a mid-level longwave trough will continue to push slowly southeastward across the TN Valley late this evening/early Wednesday morning. As this occurs, we expect further dissipation of the low stratus cloud deck that was in place across the region earlier today, with clear skies anticipated by sunrise. Mid/upper level troughing associated with the departing storm system exiting the Canadian Maritimes will retreat to the north on Wed/Thu, with weak ridging in place over the eastern CONUS.
Areas that still have some decent snow cover are likely to be a few degrees cooler than areas that lost most of their snow cover.
Brief moderating trend Thu/Fri as next southern stream upper low/trough develops and moves from the S Rockies into the S Plains regions.
As of 2 am, temperatures have already fallen into the low to mid 20s in many locations. Thus, expect some warming today with highs in the low to mid 50s with sunny skies.
With these factors in mind, and lack of early morning fog to slow warming, have favored a nudge toward warmer MOS guidance for today. This brings readings into the lower 40s across south central SD, while southwest MN holds in the lower-mid 20s.
The southern Bitterroot valley for example can expect temperatures in the lower to mid 40s today. This ridge will be short lived as a weather disturbance approaches the Northern Rockies Wednesday night.
Expect winds today to be predominantly northerly, going very light/calm under the ridge axis later tonight. High pressure building in across the region will keep the weather relatively quiet for today. South of I-20 may see highs in the lower 50s later this afternoon. Winds expected to get lighter as the high builds in and the ridge axis sets up over Central Mississippi later this evening.
Strong surface winds, sustained up to 25 mph and gusting over 30 mph, have developed between the Missouri and James Rivers across central North Dakota early this morning in response to a tight pressure gradient on the back side of Arctic high pressure over Minnesota. An upper level ridge will build over the Northern Plains today. At the surface, a north-to-south oriented warm front extending from low pressure over central Saskatchewan/Manitoba will move eastward across the state this morning, with western and central North Dakota remaining in the warm sector through the day. This will give us warmer and dry weather with clearing skies. The upper level ridge slides over us tonight with surface/low level flow becoming weak. Lower heights and high clouds will make for a cooler day on Thursday, with highs around 20 east to near 35 southwest.
mostly sunny skies and warmer temperatures are expected. Expect high pressure aloft to give way to a weakening west coast trough late Thursday.
Did adjust temperatures a little cooler across the portions of the Sandhills and north central Nebraska where snow cover still remains. Models have been running warmer on low temperatures the past few nights.