Aikyam-Lab/Synoptic-Bench huggingface dataset:
Today, an upper low pressure system in the southern plains will lift north, bringing a widepsread precip event across much of eastern KS into MO tonight and Friday. SREF probs are highest across south central Nebraska whereas as the HRRR focuses the lower vsbys mainly east of Highway 281 and have opted to cover our entire area with either patchy or areas of fog.
A weak low pressure system is forecast to deliver a few snow showers to portions of northern Arizona from today into Friday. Over the weekend, high pressure will bring a return of dry weather and warmer temperatures. This trough, and associated cold front, will move southeastward across Arizona from today through early Friday. Over the weekend, weak high pressure will bring a return of dry weather and warmer temperatures.
The upper short wave energy will result in some snow showers across our area, mainly affecting the higher terrain, but some flurries are possible at the lower elevations.
923 AM EST Thu Dec 31 2020 Strong high pressure has moved east near Bermuda and continues to ridge southwest over Florida and into the Gulf of Mexico. This is trapping the low level moisture being advected into the region under southeast flow and has allowed for a BKN/OVC SC and CI cloud deck to persist this morning. High pressure near Bermuda ridging over Florida and into the gulf will keep southeast winds around 15 knots over the waters for today and tonight.
A cold front is just south of the Mid-South with an area of low pressure along the front over extreme south Texas. This will pull the cold front north some into extreme southern sections of the Mid-South. This will help drag the cold front northward as a warm front through much of the region. More rain will move across the region tonight but once the warm front moves through, scattered thunderstorms are expected to develop across the Mid-South. Temperatures will depend on where the warm front is with lows Friday morning from the mid 30s to the mid 50s. Drier and eventually cooler air will begin to move into the region in the afternoon. Temperatures will be quite warm on Friday before the cooler air arrives with highs on Friday from the mid 50s to around 70 degrees.
439 AM EST Thu Dec 31 2020 High pressure will build into the area today and move off to the east this evening. Precipitation will spread across the area late tonight into Friday ahead of low pressure and a warm front.
As we get into the late morning hours, a deep closed low along the Rio Grande Valley will begin to take on a negative tilt as it lifts northeastward into the eastern Plains. In response, the cold front currently draped to the west of the region will begin to retreat north as a warm front. The prefrontal airmass will be ripe with parameters indicative of supporting organized severe storms from the late afternoon through the night as storms fire ahead of the approaching cold front. Latest guidance has been more bullish with the development of MLCAPE across the region with values ranging from 500-1100 j/kg with the highest values existing across the southern portions of the region. Deep layer shear values will also be impressive across the region with significant amounts present in the lowest 0-1km of the atmosphere.
The cold front should move through tonight into Friday morning. Front should clear the area Friday morning and we may clear out for a bit but the upper trough is not looking very progressive by that time and some over-running could occur by late Friday night.
/issued 313 AM EST Thu Dec 31 2020/ Deep return southeast flow from the surface to 50H is anchored over the Florida peninsula as the region is wedged between strong high pressure over the western Atlantic and a developing low pressure system over eastern Texas.
312 AM CST Thu Dec 31 2020 The upper level low was churning across Durango early this morning but is still expected to undergo a sharp turn to the northeast later this morning. Moisture and lift will wrap around the system into the Rolling Plains as the center of the low moves through central Texas. A secondary 500 mb closed low will rotate into the Big Bend region by Friday afternoon as a belt of potent meridional flow digs in over central Mexico.
215 AM MST Thu Dec 31 2020 The northern branch of the upper flow progresses east of the region with an upper short wave ridge moving over the forecast area tonight. As the northern branch continues east, the low at the base of the upper trough cuts off over northern Mexico and become less progressive until a kicker drops south through California on Thursday. The low over Mexico begins lifting out over Texas Thursday and across eastern Oklahoma Thursday night into early Friday as the kicker deepens into a closed low that tracks along the U.
Confidence on this occurring is not high, given the low sun angle, and the fact that another area of low clouds is approaching from MN. On Friday, a weakening ridge of high pressure will remain over northern WI as low pressure tracks through the Upper Midwest.
638 AM EST Thu Dec 31 2020 Rain showers will change to snow showers overnight as colder air moves in behind a cold front. Snow showers will end across most of the south by mid-morning as the cold front shifts into the Mid-Atlantic states and stalls. A low pressure system, containing a warm front propagating northward through the Ohio Valley, will bring the chance for freezing rain eventually transitioning to all rain on Friday by way of dynamic jet support. Widespread freezing rain accumulation looks to amount to a few hundredths, with locally higher amounts in the I-80 corridor and the eastern ridges, where surface temperature won't rebound as quickly.
333 AM PST Thu Dec 31 2020 A cold frontal passage this morning will bring some light showers across the regoin.
As it does, flow aloft transitions to more southwest allowing for a warmer push of air to come into the region. Therefore, only expect temperatures to be a few degrees F warmer than yesterday, with highs reaching the mid 40s across the plains and the upper 20s to mid 30s in the high valleys. Despite a weaker cold front moving through this evening, tonight's lows are expected a bit warmer due to the lingering clouds. Temperatures dip down to the teens and lower 20s across the plains, and single digits below zero to single digits above zero in the high valleys. Troughiness is around to help with some snow relief for the Continental Divide, San Juans, and maybe even the Ramparts, but overall it's underwhelming. Otherwise, temperatures remain on the warmer side through much of the period.
Looking at the KBYX Velocity Azimuthal Display (VAD) wind profile over the past several hours, this is likely due to the now nearly unidirectional east southeasterly flow in the lower troposphere and associated limited isentropic lift compared to what was observed over the past twenty-four hours. Skies are partly to mostly cloudy across the island chain, with temperatures generally in the lower 70s. A strong pressure gradient resulting from the interaction of a sprawling area of high pressure centered near Bermuda with a frontal boundary stretched over the Texas and Louisiana coastline will promote continued windy conditions today. As the high slides eastward, the gradient will gradually relax on New Years Day and into the weekend.
High pressure is located over western Iowa early today. West of the high pressure, skies are clear and temperatures have radiated out nicely over the fresh snow, with lows in the single digits above and below zero. However, near the High center and eastward, most areas are cloudy, under a very narrow depth of a stratus deck, found between 1500 and 2200 ft aloft. Guidance highs are actually the same or cooler than some of the current readings, and that might seem wrong, but I think it gives a good idea we're not going to see much of a rise today, especially if the entire day remains under stratus. Unfortunately, stratus over snow with weak flow, becoming easterly/northeasterly at the end of the period, as the large low pressure system begins moving toward the area late tonight.
917 AM EST Thu Dec 31 2020 High pressure will build into the area today and move off to the east this evening. Precipitation will spread across the area late tonight into Friday ahead of low pressure and a warm front.
Cloud cover and weak cold air advection overhead will likely limit high temperatures to the upper 30s/near 40 for most of the plains, which will be a couple degrees cooler than today. The weekend will be relatively quiet, with partly cloudy skies and mild temperatures as an upper level ridge builds over the region.
644 AM EST Thu Dec 31 2020 High pressure will build into the area today and move off to the east this evening. Precipitation will spread across the area late tonight into Friday ahead of low pressure and a warm front.
Cooler than normal temperatures will continue through Friday before warming to normal over the weekend, then a bit above thereafter. This afternoon will be similar to yesterday with daytime highs running a degree or two warmer.
353 AM MST Thu Dec 31 2020 08z surface analysis had low over north central MT with warm front into western NE.
Roads will likely become very slippery for a time until temperatures warm above freezing. Seasonable temperatures with highs in the low to mid 30s with light winds and maybe even some peaks of sunshine late this afternoon. High pressure then slides to the east tonight with an increasing easterly flow ahead of the next system and just a slight chance for a wintry mix in the far southern CWA late. The later arrival of precip should preclude much of an initial light snow as forecast soundings have freezing rain profile in place with 5-6C warm nose and surface based sub-freezing layer. especially across the northern tier as temperatures struggle to go above freezing Friday afternoon.
There is the possibility of some brief freezing rain or perhaps sleet during the onset of precipitation as warm air temperatures aloft will be present. Friday sees a passing ridge of high pressure with slightly cooler temperatures behind Thursday's clipper.
The snow cover will be little if any across central and north central sd which will allow this area to have more surface heating and warmer temperatures. The surface winds through most of the period will be from the south to west bringing in the warmer air.
decided to cancel the High Wind Warnings early. With the trough finally shifting east. New Years Day should be fine as well with weak gradients and 700mb winds in the 20-25kt range as a dry upper trough moves through. with the upper ridge building back into the area.
With the trough finally shifting east. New Years Day should be fine as well with weak gradients and 700mb winds in the 20-25kt range as a dry upper trough moves through. with the upper ridge building back into the area.
The system's cold front (or occluded front, if the warm front doesn't make it through) over central KY will be headed east toward us.
227 PM MST Thu Dec 31 2020 Other than a brief cold surge with gusty north winds on Friday, the short term period should remain dry with warmer than average temperatures across the central High Plains region. The first of a pair of upper low centers begins lifting out of the base of the upper trough over northern Mexico this afternoon. This low center continues to lift out across eastern Texas and eastern Oklahoma tonight and across far eastern Kansas and through northern Missouri on Friday as a second upper low center begins to follow a similar path along the U.
Patchy valley freezing fog is likely to develop overnight, with areas near bodies of water seeing fog becoming dense just before and after sunrise.
Strong WNW winds will persist through the day with gusts nearing Airport Weather Warning thresholds (35 knots), but speeds will taper this evening and especially after midnight as high pressure draws closer.
Conditions will remain fairly deteriorated through the day, with periodic LIFR possible in convective cells and during cold frontal passage. Aside from the convection, expect gusty east/southeasterly winds to persist south of the aforementioned stationary front, continuing until the passage of the cold front. /issued 920 AM CST Thu Dec 31 2020/ Just some minor updates this morning for timing of features and lower temperatures and dewpoints across the north where the cold front has sagged more to the south than expected this morning.
The forecast is still largely on track with the main update being an upgrade of the High Wind Watch to a High Wind Warning for all areas except for the mountains of Polk County. Expect some improvement in conditions, but only to MVFR levels by this afternoon before falling again this evening/overnight as a warm front approaches from the south. CD Chattanooga Airport, TN 59 52 68 47 61 / 30 90 90 20 10 Knoxville McGhee Tyson Airport, TN 58 49 66 49 60 / 20 70 90 30 10 Oak Ridge, TN 56 49 66 48 58 / 30 80 90 20 10 Tri Cities Airport, TN 57 48 59 45 60 / 40 50 70 40 10 TN.
More substantive features evident on CONUS WV imagery include a robust cyclone taking shape across the srn Plains/Lower MS Valley and another upper low digging thru the desert SW. Farther west, an upper ridge axis is shifting from the ern Pacific toward the West Coast. Aforementioned upper ridge will flatten as it shifts ewd toward the Rockies/Plains thru the end of the week. However, given that none of these disturbances are associated with substantial deep moisture or appreciably cooler air, main impact of each will be a period of breezy conditions.
249 PM CST Thu Dec 31 2020 Latest observations across the region show mostly sunny skies, south to southeasterly winds, and temperatures in the low to mid 20s. Heading into the evening, expect a ridge of high pressure to gradually move overhead, allowing light and variable winds to prevail overnight.
Any freezing precipitation should be limited to northwest sections of the forecast area during this period. The cold front has stalled south and southeast of the state. An additional 1 to 2 inches of rainfall is forecast through late Thurs, with the highest amounts expected over southern and western AR. A winter weather advisory has been issued for those areas late Thursday evening and into the overnight hours, when temperatures will be near and just below freezing. Temperatures will begin increasing over southern AR overnight, and over the rest of the state by Friday morning, as the system brings warmer air into the region. Above freezing temperatures are expected by morning, allowing precipitation to transition to all liquid rain. Wind direction will shift from NNEerly Thursday to Serly by Fri morning as the low moves through the state to the NE.
Upper ridging centered over Cuba. Upper low has taken a negative tilt, and is expected to move northeast to Missouri by Friday afternoon.
1015 AM MST Thu Dec 31 2020 08z surface analysis had low over north central MT with warm front into western NE.
252 PM MST Thu Dec 31 2020 There are currently two cut off troughs across the southern US with one over Texas and another over Arizona. For those going out and about during this New Year's Eve night, the weather won't be much of an issue with temperatures in the low 30s to upper 20s across the urban corridor with light winds. These winds won't be strong but will bring in slightly cooler air tomorrow as highs will be roughly 5 degrees colder. Friday night, a large upper level low pressure system will be over the Southern Plains States with a dry northerly flow aloft over Colorado.
The northern stream flow was more tame, with a couple of progressive weak short wave troughs. A weak frontal passage will bring slightly cooler temperatures tonight and Friday.
Potent upper low, currently south of the Big Bend area will lift north into eastern Oklahoma tonight into Friday morning. Still appears temperatures will fall to near or just below freezing in the higher terrain areas of northwest Arkansas as precipitation spreads north into the region tonight with freezing rain likely. As precip spreads into northeast Oklahoma this evening temperatures across far northeast will likely wetbulb below freezing with periods of freezing rain along the OK/KS state line. 1 to 3 inch snow amounts still appear likely west of Highway 75 with the highest amounts across western sections of Osage and Pawnee counties.
318 PM MST Thu Dec 31 2020 The synoptic overview includes a highly amplified ridge aloft over the western CONUS and two closed upper level lows, one over the desert southwest and another over the southern plains. The desert southwest closed low will propagate from southern Nevada towards southern New Mexico, which will bring isolated snow showers over the Continental Divide first, later this evening, and secondly tomorrow afternoon. Mid-level clouds are expected to form, which will keep temperatures warmer than what they have been the last two nights. If those clouds fail to form, the low temperature forecast for the mountain valley will be too warm. A weak cold front passes over the region late this evening and into the overnight, which will bring gusty (up to 25 kts) winds over the plains and slightly cooler temperatures over the plains.
/Tonight through Friday Night/ An upper low previously located across northeast Mexico is starting to eject NNE across the Texas border this afternoon and eventually into Central and North Texas this evening. Showers and thunderstorms will slowly move north and eastward out of the region overnight as the sfc and upper low continue to eject northward.
A weak low pressure system is forecast to deliver a few snow showers to portions of northern Arizona from today into Friday. Over the weekend, high pressure will bring a return of dry weather and warmer temperatures. Current satellite and radar data show a low pressure system centered over southern Nevada. This low, and associated cold front, will move southeastward across Arizona today through early Friday. Over the weekend, weak high pressure will bring a return of dry weather and warmer temperatures.
As the ridge axis centers over central UP this aftn, skies should begin to clear, leading to a beautiful UP day for much of the western interior. SW winds will start to bring some light downsloping winds into Marquette proper, which will likely make them a couple degrees warmer than up the hill in the highlands. Tonight, the slightest of ridges begins to move overhead as weak WAA will likely bring in some cloud cover as the night goes on. Sat-Sun, mid level ridging over the area with sunshine during the afternoon will boost temps into the low to mid 30s. Tue-Wed, Mid level and sfc ridging is expected to give way to increasing WAA and low level moisture as a trough approaches from the Plains.
Lows this morning dipped into the lower to mid 20s across northeast Oklahoma and northwest Arkansas, while southeast Oklahoma remained in the 30s. Much of the precipitation should remain rain throughout the day today, with the possible exception of some of the higher elevations of northwest Arkansas where freezing rain will be possible. After sundown tonight is when the forecast gets a little more tricky with all precipitation types possible across the area as temperatures hover right around freezing across northeast Oklahoma and northwest Arkansas.
327 PM CST Thu Dec 31 2020 The synoptic pattern across the CONUS at 21Z today is featuring a northern stream of energy across the northern tier of the CONUS with a very pronounced upper low and trough with the closed center circulating and translating into southwestern TX. The upper system from TX appears to be highly dynamic with a compact upper low deepening at the current hour. Timing of the low should allow for impacts to last through the morning into early afternoon, so have kept the Advisory/Winter Storm Warning combo in effect through the afternoon on Friday.
Some areas of freezing rain will likely spread into far NW AR by late afternoon,but current fcst maintains all liquid for now with the temperature margin of just a couple degrees making the difference. KBVO will likely experience mixed precipitation tonight with freezing rain/sleet changing to mostly snow by tomorrow morning. Lows this morning dipped into the lower to mid 20s across northeast Oklahoma and northwest Arkansas, while southeast Oklahoma remained in the 30s. Much of the precipitation should remain rain throughout the day today, with the possible exception of some of the higher elevations of northwest Arkansas where freezing rain will be possible. After sundown tonight is when the forecast gets a little more tricky with all precipitation types possible across the area as temperatures hover right around freezing across northeast Oklahoma and northwest Arkansas.
By Friday morning, a weakening lee-of-the Rockies surface trof will be working south and east of the CWA, turning winds around to the west-northwest briefly on Friday. High pressure builds in during the day, causing winds to gradually subside to calm or near calm. Friday night, the next installment of lee-side surface trof begins to deepen off to the west, signaling a switch in the winds back to a southerly or southwesterly direction.
335 PM EST Thu Dec 31 2020 High pressure will provide a mainly cloudy but dry night for most to greet the New Year.
343 PM CST Thu Dec 31 2020 A deep upper low near Del Rio, TX is about to eject in negative tilt fashion to the north-northeast across the southern plains and into eastern Kansas by Friday afternoon. No precipitation is expected with this system since the low to mid level moisture will have been shunted to the east with the first system.
1100 AM MST Thu Dec 31 2020 (31/18Z TAF period) VFR conditions continue over the upcoming TAF period with high pressure overhead. /ISSUED 405 AM MST Thu Dec 31 2020/ Mild and breezy conditions continue today as an upper disturbance moves across the region, with light snow ending by afternoon over the higher elevations of southwest Montana, while continuing toward Marias Pass. Upper ridging moves over the area overnight tonight and then flattens Friday with westerly flow increasing, resulting in another breezy and mild day with increasing cloud cover through the day as the next system approaches from the west. A pair of strong and fast-moving disturbances with jet stream energy will move across the region both days in the wake of the high pressure ridge, both resulting in periods of mountain precipitation and potentially strong downsloping winds over the plains.
The approaching cold front has now moved eastward off the Texas coast and over the western Gulf waters. However, still can't rule out a brief tornado or two as low-level shear vectors ahead of the line remain sufficient for possible mesocyclone generation. Precipitation chances quickly taper off in the wake of the front and drier, cooler air follow into the weekend. Flying weather will improve from west to east Friday morning through afternoon in the wake of a cold front.
200 PM EST Thu Dec 31 2020 Upper ridging near Cuba extends northeastward over the Bahamas and toward Bermuda.
250 PM PST Thu Dec 31 2020 A cold frontal passage this morning brought some light showers across Central California.
with a trough in New England and another in the western U. The low in northern Mexico heads northeast into the mid Mississippi Valley by 00z Sat. Lows tonight could be tricky as well as clouds have been decreasing and the lows could occur around midnight with the lowest wind speeds then before they pick up and it is conceivable that the temperatures could rise after midnight as the wind begins to increase. Sat-Sun, mid level ridging over the area with sunshine during the afternoon will boost temps into the low to mid 30s. Tue-Wed, Mid level and sfc ridging is expected to give way to increasing WAA and low level moisture as a trough approaches from the Plains.
540 PM CST Thu Dec 31 2020 Latest observations across the region show mostly sunny skies, south to southeasterly winds, and temperatures in the low to mid 20s. Heading into the evening, expect a ridge of high pressure to gradually move overhead, allowing light and variable winds to prevail overnight.
Improvement to MVFR is expected after 15-16Z on Friday morning as a warm front moves through and rain ends.