Aikyam-Lab/Synoptic-Bench huggingface dataset:
353 PM CST Tue Feb 4 2020 Surface analysis shows a cold front extending across west Texas to the Missouri Bootheel. However, a strong to perhaps an isolated severe thunderstorm may be possible tonight across East Arkansas south of I-40 and into North Mississippi, but overall confidence remains low at this time due to the less than ideal instability and timing of the upper-level support with the cold front. By Wednesday, as an upper-level trough pushes toward the region, the severe weather potential will increase. Temperatures Wednesday will range from the lower 70s in our southern areas to lower 40s in far northeast Arkansas.
Cold anticyclonic flow continues to usher in increasingly cooler air from the north and establishing an elongated baroclinic zone from central Texas into portions of New England. This frontal zone will serve as the focus of multiple waves of low pressure as the trough over the 4-corners region lifts northeast during the latter half of the week.
308 PM CST Tue Feb 4 2020 Cool high pressure over the eastern Dakotas/Minnesota this afternoon is forecast to drift southeast towards Iowa tonight, with developing low pressure in the Lee of the Canadian Rockies. This will result in a light southwesterly surface flow of 5 to 10 mph across western and central North Dakota, keeping the lower atmosphere mixed.
Cold air drainage from the Bighorn Basin kept temperatures lower in the Billings area, and a combination of that, snow cover, and clear skies will keep temperatures in south-central Montana on the cooler side tonight, with lows in the upper single digits to low teens.
By sunrise, temps are still expected to range from the upper 50s far south, to the lower 40s far northwest. Southerly winds will become more westerly/northwesterly as a weak cold front moves into the mid state this evening/overnight.
Low temperatures tonight will be a few degrees warmer than last night in most locations. A warm front will pass to our north on Wednesday, bringing an increase in cloudiness to northern portions of our area.
Ridging moves over our CWA during the day tomorrow with west to northwest winds increasing at the surface.
1020 PM MST Tue Feb 4 2020 Latest upper level analysis has positively tilted trof sliding through the Northern Plains and Central Rockies this afternoon with ridging across the western CONUS. At the surface, high pressure is located across the eastern Dakotas and across the Northern Rockies, with a weak lee trof in between. Temperatures across the area at 2pm are in the teens and 20s in snow covered areas, and in the lower 30s across northwest South Dakota. Steep lapse rates along the upper trof axis are producing the light snow showers currently. As diurnal heating wanes and trof shifts east, snow showers will slowly dissipate by late afternoon or early evening. Upper ridging will move in overnight with mostly clear skies expected and chilly temperatures.
By sunrise, temps are still expected to range from the upper 50s far south, to the lower 40s far northwest.
1047 PM CST Tue Feb 4 2020 /06Z TAFS/ A mix of wintry precipitation, including snow, freezing rain, and ice pellets will make its way southward overnight. An upper level trough currently across the Southwest United States will approach the forecast area overnight. Farther south across the Concho Valley, northern Heartland and Northern Edwards Plateau, expect the precipitation to changeover from rain to freezing rain/sleet mainly after midnight due to a low level warm layer on top of shallow sub freezing surface air. Significant travel impacts are possible, especially across the Concho Valley due to icy roads, especially bridges and overpasses.
Lowered some temps on the NE side of the Tucson Metro where temperatures are already in the lower to middle 30s. Also made adjustments to some of the higher elevation sites to lower a couple degrees.
Could get a glancing blow of light pcpn across the far south as upper level trough axis tracks east across the region, but consensus from the NAM/GFS/EC is to keep that just south.
DGS Chattanooga Airport, TN 68 58 62 37 47 / 80 100 80 60 20 Knoxville McGhee Tyson Airport, TN 67 58 64 37 43 / 90 100 90 80 20 Oak Ridge, TN 65 58 63 35 43 / 90 100 90 70 20 Tri Cities Airport, TN 63 56 64 36 40 / 90 100 90 90 50 NC.
/Today through Tuesday/ Deep trough over the western Plains will continue to dig and pivot east slowly. A closed low is progged to develop over Nebraska/South Dakota.
Snow will continue over the higher terrain Wednesday night, but change to rain in the valleys below 4k ft MSL by 06/00z.
A rather significant winter storm was underway across the Southern Plains at the time of this overnight writing (shortly before 08Z), as a slightly positive-tilted trough was pulling out of the Rockies entering the Southern and Central Plains. Moderate to heavy precipitation, much of it in the form of snow, sleet, and freezing rain, extended from near Oklahoma City southwest all the way down to Southwest Texas.
High pressure aloft locked in over the eastern Pacific will leave Utah under a north to northwest flow aloft through the end of the week.
1135 PM CST Tue Feb 4 2020 Mostly clear skies this afternoon thanks to a broad area of high pressure over the region, with a few clouds and perhaps some isolated flurries possible across Iron county this evening.
Current satellite shows a positively tilted upper trough located over an NE Panhandle - NM axis with several disturbances in the southwesterly flow aloft ahead of this feature. Tough call on temperatures today as skies are clearing west to east, but with the higher than normal surface albedo due to the recent snowfall, coupled with the relatively light northerly winds expected as surface pressure gradient weakens, have gone with highs around freezing.
1242 AM EST Wed Feb 5 2020 Moisture will slowly increase across the area as a low pressure system approaches from the Lower Mississippi Valley the next few days.
Freezing line currently located near/just north of I-44 early this morning. Latest dual pol radar/surface observations indicate a mix of rain/freezing rain/sleet lifting into northeast Oklahoma. 5 to 6 inches of snow still appears likely along the I-44 corridor through tonight with a fairly sharp gradient of lower amounts further south due to a mix of sleet/freezing rain. Given latest temperatures trends and CAM solutions, increased ice amounts somewhat for portions of southeast Oklahoma and in the higher terrain areas of northwest Arkansas. If ice amounts are higher than currently forecast, the advisory would need to be upgraded to a winter storm warning, mainly in the higher terrain of NW AR for both ice and snow amounts.
A warm front will push across Washington and Oregon today, bringing some clouds into portions of northwest California, but expect only a few sprinkles to make it south of the Oregon border.
305 AM MST Wed Feb 5 2020 The upper trough is slowly crossing the CWA at this time, with northwest flow behind it moving in from the west.
The cold front will finally push east of the area late tonight into Thursday with some residual rain possible.
Scattered SHRA and TSRA will become more numerous by this afternoon and continue tonight as a low pressure center moves across the area followed by a cold front. Early morning satellite imagery/RAP analysis showed the circulation around a deep upper level trough that extended southwest from the Central Plains to the Baja region. Temperatures will continue much warmer than normal today but the cooler air in the wake of the cold front will knock temperatures down closer to normal by morning, especially over the northwest half of the CWA.
Temperatures aloft are forecast to continue to cool through the morning hours as an upper level trough slowly approaches. Some freezing rain is possible across mainly the southern counties, but accumulations are forecast to remain low.
311 AM CST Wed Feb 5 2020 A warm front emanating from a low situated near the Gulf Coast has developed across Middle Tennessee, and is providing the focus for numerous showers that have been ongoing since yesterday. Expect the surface boundary to remain stationary over Middle Tennessee today and tonight as the low center deepens and moves northeastward along the boundary.
Across the Tri State region this morning, there is a mix of cloudy and clear conditions as a ridge axis is extending SW into the region. Despite westerly flow for the area, cold air slow to push out giving the region below normal temps in the lower 30s.
354 AM MST Wed Feb 5 2020 The upper trough is slowly crossing the CWA at this time, with northwest flow behind it moving in from the west.
All other TAF sites, except KFSM, will see a transition (if it hasn't happened already) from rain to a sleet/freezing rain/snow mix a little later today. Freezing line currently located near/just north of I-44 early this morning. Latest dual pol radar/surface observations indicate a mix of rain/freezing rain/sleet lifting into northeast Oklahoma. 5 to 6 inches of snow still appears likely along the I-44 corridor through tonight with a fairly sharp gradient of lower amounts further south due to a mix of sleet/freezing rain. Given latest temperatures trends and CAM solutions, increased ice amounts somewhat for portions of southeast Oklahoma and in the higher terrain areas of northwest Arkansas. If ice amounts are higher than currently forecast, the advisory would need to be upgraded to a winter storm warning, mainly in the higher terrain of NW AR for both ice and snow amounts.
Temperatures will remain quite cold today, with daytime highs approaching the lower 30s across the CWA. Roads will remain very slick and icy long after the snow ends with overnight lows dropping into the lower teens and wind chills near zero degrees. Expect impacts to regular travel once again tonight due to the re-freezing of any meltwater.
Our next chance for accumulating snow moves in tonight ahead of an upper level trough. Northeast winds will also pick up tonight and paired with warmer water temperatures may provide a lake enhanced area of snowfall once saturation takes place through early Thursday afternoon.
332 AM CST Wed Feb 5 2020 Today: An upper level trough currently extends from the western Dakotas southwestward to the Four Corners area. Some weak mid-level perturbations ahead of the trough axis continue to move across eastern Kansas/western Missouri to produce some light snow.
Lexington has been reporting snow for a few hours, but web cams do not appear to have the low visibility that the observations are reporting. With some sunshine and light winds it will feel much warmer today, but temperatures will only be a few degrees warmer than yesterday. By Thursday night, there will be a weak upper level wave and cold front that will affect the northern part of the forecast area.
424 AM MST Wed Feb 5 2020 Still some patchy low clouds/fog and flurries hanging around the eastern plains early this morning, though expect these to dissipate shortly after sunrise as surface gradient turns weak w-nw and mid level subsidence strengthens behind departing upper trough. As upper trough moves east today, n-nw flow aloft will strengthen, keeping max temps rather cold again today, with only a few spots along the eastern mountains reaching the freezing mark by late afternoon. Overnight, moisture deepens along the Continental Divide, with snow showers breaking out after midnight, mainly across the higher peaks north of Monarch Pass.
307 AM CST Wed Feb 5 2020 Early morning surface observations show a weak and diffuse warm frontal zone across eastern ND/northwest MN with temperatures in the single digits across northern MN and upper teens across central/southeast ND.
We'll be transitioning from split flow to northwest flow aloft through the day today, as an upper trough shifts east and away from the Northern Plains. At the surface, high pressure will continue exiting to our southeast while a clipper low advances towards the Northern Plains from southern Alberta. Light snow is also possible throughout the day as this area of low pressure tracks through the CWA.
5 to 1 inch per hour in the high elevations during the day Thursday. Today should be the last day (at least for the next few days) of widespread sub-freezing high temperatures across the lower valleys of eastern Utah/western Colorado. Although not as extreme as this morning, thanks to a little better cloud cover, most locations will bottom out several degrees warmer tonight. Warmer air works into portions of the CWA by Thursday bringing us closer to, but still several degrees below, normal.
High pressure ridging over the western Atlc continues to pull seaward in advance of an approaching strong cold front. Southerly flow increases into Thu ahead of an approaching strong cold front. High pressure ridging influence begins to weaken as it pulls further seaward into the western Atlc with the approach of a strong low pressure system. High pressure begins to pull seaward into the western Atlc, though conditions remain dry through tonight.
This is cooler than the guidance blend but the southwest winds and very cold temperatures across the cntl high Plains will support a bora condition which could hold down highs. The guidance blend plus bias correction is in place for lows tonight which is several degrees cooler than the short term blend. Winds should decouple in the evening and dry air would support cooler lows but midlevel clouds move in late in the evening. A Pacific cold front accompanied by cold air aloft moves in Thursday setting off rain or snow showers across nrn Nebraska followed by a back door arctic cold front Thursday night. A broad long wave trof will slowly evolve across the wrn U.
SHORT TERM (Now through Thursday): A cold front currently moving into the northern ranchlands is expected to reach the coast later this morning. Fairly light winds and low level moisture pooling along and ahead of a cold front has allowed some fog to develop across the mid and lower Valley early this morning. As the GFS is significantly warmer with high temperatures today (especially in the Rio Grande Valley) and indicates that temperatures could reach the lower 70s this afternoon. Will lean towards a blend of the cooler NAM and short term model blends. The 500 mb trough axis will swing over the region tonight and may generate a few showers.
Southerly flow will continue today as well, with high pressure across northeastern MN and northern WI.
Still some patchy low clouds/fog and flurries hanging around the eastern plains early this morning, though expect these to dissipate shortly after sunrise as surface gradient turns weak w-nw and mid level subsidence strengthens behind departing upper trough. As upper trough moves east today, n-nw flow aloft will strengthen, keeping max temps rather cold again today, with only a few spots along the eastern mountains reaching the freezing mark by late afternoon. Overnight, moisture deepens along the Continental Divide, with snow showers breaking out after midnight, mainly across the higher peaks north of Monarch Pass.
A warm front emanating from a low situated near the Gulf Coast has developed across Middle Tennessee, and is providing the focus for numerous showers that have been ongoing since yesterday. Expect the surface boundary to remain stationary over Middle Tennessee today and tonight as the low center deepens and moves northeastward along the boundary.
Areas closer to Interstate 70 will see a mixture of freezing rain, sleet and snow. Initial area of light snow/sleet/freezing rain is exiting eastern Illinois early this morning. Southeast of there, a warm nose around 6,000 feet is still indicative of a sleet/freezing rain mixture in the vicinity of I-70, with a changeover from rain south of there late in the evening.
Other than a few lake- induced flurries/very light snow showers, this high responsible for dry and seasonably cold conditions across the Northwoods. Overhead high pressure will only slowly move off to the east. Ejection of that Rockies trough into the central Plains will force strong moisture advection and that southern front north rapidly this evening, with an attendant expanding area of wintry precipitation into the southern Great Lakes. Elevated moisture/warm air advection spreads north in response to that deepening central Plains trough later this evening. Pattern synopsis/forecast: A deepening low pressure system over the Ohio River Valley will begin to impact the forecast area Thursday morning.
A rather significant winter storm was underway across the Southern Plains at the time of this overnight writing (shortly before 08Z), as a slightly positive-tilted trough was pulling out of the Rockies entering the Southern and Central Plains. Moderate to heavy precipitation, much of it in the form of snow, sleet, and freezing rain, extended from near Oklahoma City southwest all the way down to Southwest Texas. For the remainder of the week going into the upcoming weekend, we will be looking at temperatures continuing a slow rebound back into the lower 50s, especially closer to the Oklahoma and Colorado border.
355 AM CST Wed Feb 5 2020 We'll be transitioning from split flow to northwest flow aloft through the day today, as an upper trough shifts east and away from the Northern Plains. At the surface, high pressure will continue exiting to our southeast while a clipper low advances towards the Northern Plains from southern Alberta. Light snow is also possible throughout the day as this area of low pressure tracks through the CWA.
Upper level low pressure trough will steer east of the area during the afternoon with clearing skies into the evening. Temperatures will remain quite cold today, with daytime highs approaching the lower 30s across the CWA. Roads will remain very slick and icy long after the snow ends with overnight lows dropping into the lower teens and wind chills near zero degrees. Expect impacts to regular travel once again tonight due to the re-freezing of any meltwater.
Today: An upper level trough currently extends from the western Dakotas southwestward to the Four Corners area. Some weak mid-level perturbations ahead of the trough axis continue to move across eastern Kansas/western Missouri to produce some light snow.
As temperatures warm with daytime heating today, instability in the low and mid-levels should further increase. This LLJ is resulting in ample shear in the lowest 3km with 42 knots of speed shear and 345 M2/S2 of helicity noted. These values are high enough to support tilted updrafts and mesocyclone development with any deeper convection that forms today. This low LCL would support any severe convection becoming surface based.
525 AM CST Wed Feb 5 2020 Early morning surface observations show a weak and diffuse warm frontal zone across eastern ND/northwest MN with temperatures in the single digits across northern MN and upper teens across central/southeast ND.
Accumulations of a dusting to around 3 inches are expected through Thursday afternoon with the highest amounts along Lake Michigan. Our next chance for accumulating snow moves in tonight ahead of an upper level trough. Northeast winds will also pick up tonight and paired with warmer water temperatures may provide a lake enhanced area of snowfall once saturation takes place through early Thursday afternoon.
Early morning satellite imagery/RAP analysis showed the circulation around a deep upper level trough that extended southwest from the Central Plains to the Baja region. Temperatures will continue much warmer than normal today but the cooler air in the wake of the cold front will knock temperatures down closer to normal by morning, especially over the northwest half of the CWA.
307 AM MST Wed Feb 5 2020 Across the Tri State region this morning, there is a mix of cloudy and clear conditions as a ridge axis is extending SW into the region. Despite westerly flow for the area, cold air slow to push out giving the region below normal temps in the lower 30s.
432 AM EST Wed Feb 5 2020 Under partly cloudy skies and east to southeast winds of around 10 mph, temperatures are averaging in the lower 70s along the island chain.
The threat is on the low end of the spectrum, but it's one of these events you'll want to keep at least one eye on.
502 AM MST Wed Feb 5 2020 Dense fog/freezing fog continues to spread eastward this morning based on latest obs/satellite coverage. Across the Tri State region this morning, there is a mix of cloudy and clear conditions as a ridge axis is extending SW into the region. Despite westerly flow for the area, cold air slow to push out giving the region below normal temps in the lower 30s.
428 AM PST Wed Feb 5 2020 The cold, very dry atmosphere across southern California will begin to modify today as the cold low pressure system over the Rockies moves east and high pressure over the eastern Pacific moves toward the West Coast.
Limited lingering areas of stratus will continue to dissipate through this afternoon, as the positively-tilted trough axis arrives aloft. As such, temperatures this afternoon will remain well below normal, struggling into the lower 30s. Trough axis will finally be clear of SW KS early Thursday, followed by increasing NW flow aloft through the day.
Several other CAMs represent similar outcomes while others are less aggressive on the warm front. The cold front will finally push east of the area late tonight into Thursday with some residual rain possible.
Partial melting of snow on some road segments in sunlight will yield wet conditions, prone to refreezing with additional light snow overnight. The first wave of snow will taper early Thursday at lower elevations, with temperatures near or above freezing by Thursday afternoon.
1239 PM CST Wed Feb 5 2020 As a weak cold front across southern Canada sags south tonight and Thursday the focus for snow will follow this feature.
1029 AM EST Wed Feb 5 2020 Currently - The Keys currently are located within the western flank of a deep layered ridge over the northwestern Atlantic. Skies are a mix of mostly sunny to partly cloudy, with most of the cloud elements over the warmer Florida Straits. With that said, a band of clouds, originating from a couple of cuban cloud lines, do stretch northwestward across the Lower Keys. Short Term Update - Surface winds winds will remain gentle to moderate out of the east to southeast through the afternoon due to the nearby ridge across Florida. A broad ridge across Florida and our area will maintain gentle to moderate southeasterly breezes on Keys waters this afternoon.
Skies are expected to slowly clear tonight, especially towards sunrise as the upper level trough axis moves east of our area. For Thursday, mostly sunny skies and west to southwest winds in the low levels will allow temperatures to quickly warm across most of the forecast area, except for parts of the Big Country where deeper snowcover will have to be melted before significant warming can occur.
121 PM MST Wed Feb 5 2020 Across the Tri State region this morning, there is a mix of cloudy and clear conditions as a ridge axis is extending SW into the region. Despite westerly flow for the area, cold air slow to push out giving the region below normal temps in the lower 30s.
We will likely not get above freezing until the afternoon when roads should begin to improve. Elsewhere, temperatures will climb into the 50's with gusty winds developing over the higher terrain. It appears winds will be strong enough on the backside of the upper trough to meet high wind criteria across the Guadalupe and Delaware Mountains Thursday afternoon.
The threat is on the low end of the spectrum, but it's one of these events you'll want to keep at least one eye on. BNA and MQY will see a shift to southerly winds this evening before the warm front sinks south and east and turns winds out of the north early Thursday morning.
South central Missouri has generally remained above freezing with with just rain. Main upper level trough swings through the area late tonight. Will have to watch for the loss of cloud ice as well, which would result in mainly some freezing drizzle occuring. Temperatures will fall into the lower and middle 20s for overnight lows.