Aikyam-Lab/Synoptic-Bench huggingface dataset:
956 AM MST Mon Dec 23 2019 Amplified upper trough off the west coast as strong jet continues to dig into the SW US. WV/IR show ample upper-level moisture and broad area of cloud cover ahead of the trough. A weak cold front is slowly moving southward across northwestern SD. The trough upstream will begin to impinge upon the central and northern plains late Christmas Eve through Christmas Day. Weak upslope flow along the periphery of high pressure dropping out of Canada and the developing low across the central plains may yield a period of fog/freezing fog/drizzle Tuesday night into Christmas Day.
956 AM PST Mon Dec 23 2019 A cold front will bring cooler temperatures today, along with rain and snow.
Otherwise, no major changes to high temps, although abundance of the low/mid/high cloud combinations may keep temps down a touch, and have made some minor changes here and there. With high pressure to the north we are seeing weak cold advection, however the high clouds (and pockets of stratus) along with a little mixing has kept the temperatures stable for the most part.
Some eroding locally across southern Iowa has allowed for temperatures to soar into the low to mid 50s, while areas north have remained in the the upper 30s to low 40s.
229 PM CST Mon Dec 23 2019 The increased cloud cover has kept temperatures about 10 to 15 degrees cooler than yesterday. Weak southerly winds will continue tonight into Tuesday as the upper level ridge slowly shifts eastward. Cloud cover will continue to increase on Tuesday as a weak cold front pushes into the forecast area. Highs should range from the mid 40s up north to the low 60s in portions of Kansas. This precipitation would likely occur as a mix of drizzle and freezing drizzle, but we could briefly see some snow over northern portions of the area where there is better dendritic moisture. This may lead to some slick roads in areas that fall below freezing Christmas morning. The rest of Christmas day should be precipitation-free, and temperatures have trended even warmer over the last couple forecast cycles.
High pressure in place, continued mostly clear skies, and light winds will support radiational cooling and stable low level conditions, contributing to fog formation. Patchy dense fog continues in the Mid-Valley this morning due to high pressure and light winds over the region. /issued 449 AM CST Mon Dec 23 2019/ SHORT TERM (Now through Tuesday): 500mb high pressure continues to build over the Central U. At the surface, high pressure is also overhead, leading to areas of fog this morning.
203 PM EST Mon Dec 23 2019 High pressure will stay in control of our weather through Christmas Day.
221 PM EST Mon Dec 23 2019 A backdoor cold front will drop south out of New England tonight into Tuesday, then oscillate over the Mid-Atlantic through late in the week. A cold front may approach from the Ohio Valley at the end of the week, followed by a second frontal system this weekend. Given stagnant pattern of high pressure, strong inversion, and light winds some patchy light fog and/or haze is possible overnight into tomorrow morning before mixing out later in the day Tuesday. Lows tonight should be about 5F degs warmer than this morning and higher elevs will also be warmer than lower elevs. Cooler on Tuesday as backdoor front pushes through the area. Highs generally 5 to 10F degs cooler than today. Christmas Day will be a carbon copy of Tuesday with similar daytime highs and slightly cooler nighttime lows.
Bigelbach PREVIOUS DISCUSSION: Area of low clouds and fog over the northeast corner of the state this morning, with high pressure dropping into the upper midwest, and a cold front over central Montana. Southwest flow aloft will help push the front back to the east later today, with the low clouds lifting back into Canada. Upper trof moving onshore, with an upper low spinning up over the northern Rockies tonight. This low is expected to slowly lift northeast into central Saskatchewan by Christmas Day.
Winds will become light and variable across the state over the next 24 hours as high pressure moves east across the state. VFR conditions with winds generally less than 10 kts to prevail through the TAF period under building high pressure. Today Through Tuesday Night A strong and progressive ridge of high pressure, both at the surface and aloft, will cross the forecast area through the period bringing fair and dry conditions with much above normal temperatures and light winds. Lows Tuesday night will be warmer and range from near 40 north to the mid 40s south.
Afternoon highs may top out in the lower 60s across much of central KS, while some areas across southeast KS struggle to reach 50. the mid/upper ridge will translate slowly eastward while the low level pressure gradient is progged to increase with pressure falls across the high plains of eastern Colorado. A vigorous mid/upper trough is progged to dig across southern California late in the week with southwest mid/upper flow progged across the central CONUS. The trough will eventually lift over the Southwest and into the Southern Rockies early in the weekend. Upper ridging will continue to build over the Plains into the Mississippi Valley as a deep upper trough approaches the western CONUS. This will allow lee troughing to continue deepening which will also increase return flow.
Another mostly clear night will lead to chilly, although slightly warmer, overnight temperatures. Tomorrow's high temperatures will be in the low 70s.
Amplified upper trough off the west coast as strong jet continues to dig into the SW US. WV/IR show ample upper-level moisture and broad area of cloud cover ahead of the trough. A weak cold front is slowly moving southward across northwestern SD. The trough upstream will begin to impinge upon the central and northern plains late Christmas Eve through Christmas Day. Weak upslope flow along the periphery of high pressure dropping out of Canada and the developing low across the central plains may yield a period of fog/freezing fog/drizzle Tuesday night into Christmas Day.
220 PM CST Mon Dec 23 2019 The upper ridge over the area today will shift to the eastern CONUS tomorrow with a deepening trough in the western CONUS.
High pressure ridge will build across the CWA, allowing for sunny skies and light northerly winds today. Tuesday, winds will shift east and then southeast as the ridge axis moves east into LA/MS. In fact, it will even be more pleasant than yesterday as it will not be as breezy and temperatures will be about five degrees warmer as high pressure sits over southeast Texas. Tuesday will be a continuation of the mostly sunny skies and near 70 degree weather as high pressure remains overhead. High pressure should remain in control for the next several days.
255 PM EST Mon Dec 23 2019 Water vapor imagery reveals a photogenic mid-upper level low sliding southeast near the Big Bend of Florida. Clearing skies are nearing the Lower Keys as the breezes increase. Cloud cover will be slow to erode tonight through Tuesday evening as the lagging cyclonic curvature within the western half of the low complex lumbers east of Florida.
An upper level trough currently along the west coast will weaken as it shifts east the next couple of days. Impacts from this weakening trough could be felt across Utah Christmas Eve through Christmas day. Deep layer southwesterly flow continues to persist across the Intermountain Region this morning, downstream from an upper trough situated along the Pacific Coast. In the wake of this feature, a better defined but weakening mid level trough will lift through the forecast area Christmas Eve, with a deformation axis setting up somewhere across central and perhaps into portions of northern Utah.
Where some breaks have developed, primarily across the ArkLaMiss Delta, temps have snuck into the lower 60s. With the loss of vertical mixing after sunset but continued cyclonic low level flow, we'll likely see the low clouds hang around through tonight in most areas. Ridging surface to aloft will build on Christmas Eve, with low clouds and fog finally clearing out and making way for good last-minute Christmas shopping and travel weather.
225 PM CST Mon Dec 23 2019 High pressure to the east is keeping winds light and skies clear ahead of a building ridge. A ridge builds into the Mississippi River valley Tuesday with a shift to southerly flow in the evening.
155 PM CST Mon Dec 23 2019 (Tonight and Tuesday) With upper ridging over Texas, temperatures across our area have climbed into the upper 60s to lower 70s early this afternoon. The upper ridge will shift east into the lower Mississippi Valley on Tuesday morning, and our area will be under southwest flow aloft. At this time, expecting enough radiational cooling to allow temperatures to drop into the lower 30s in the favored low-lying areas and river valleys of some of our eastern and southern counties.
1011 AM EST Mon Dec 23 2019 High pressure will stay in control of our weather through Christmas Day.
With upper ridge overhead and decent WAA, kept highs on Tuesday well above seasonal averages in the upper 50s to upper 60s.
Lows tonight will still drop back a little below freezing under a partly cloudy sky and with light winds.
These same areas may also struggle a bit to reach forecast highs, however given the warming in the low levels evident on OUN sounding this morning, even mixing to about 950mb will do the trick.
Like the previous couple nights, temperatures dropping below freezing could create some slick road conditions and freezing ground fog. Tuesday, there will be some question as to how quickly fog lifts out, as the lower level cloud deck may inhibit a quick dispersal of the fog. Once winds pick up by late morning to noon however, we should get enough mixing to disperse most of the fog, and perhaps a bit of the lower clouds as well.
Ridge over the eastern US starts to shift eastward as the trof over the Pacific coast digs into the great basin.
Temperatures are currently in the upper 50s to the lower 60s across the area. Winds will be weaker across south central Missouri tonight closer to the area of high pressure, and some patch fog may be possible in these locations into Tuesday morning. An upper level ridge will be over the region through the middle of the week along with warm conditions.
221 PM EST Mon Dec 23 2019 High pressure will stay in control of our weather through Christmas Day.
320 PM EST Mon Dec 23 2019 Updated at 254 pM EST Mon Dec 23 2019 High pressure - both at the surface and aloft - moves through the Ohio Valley tonight and tomorrow. Overnight lows will range through the 30s - a few degrees warmer than this morning in most areas except the southeast corner of our forecast area, where clouds this morning held temperatures up into the lower 40s. While most highs will be more than 20 degrees above normal for the date, they still fall shy of climatological records, which are in the lower 70s. A ridge of high pressure will linger over the eastern US, keeping things warm and dry locally.
Moisture will continue to stream into the area with a split upper trough to our west.
236 PM EST Mon Dec 23 2019 A mild evening will be replaced by cooler conditions overnight as a cold front sweeps through the region. High pressure will build into the region from Canada through midweek.
1129 AM CST Mon Dec 23 2019 Dry conditions to start off the Holiday week with cooler air filtering in, but still above average for this time of year. Ridge aloft that brought mild temperatures through the weekend has shifted eastward, leaving the region under the influence of west to southwest flow aloft. At the surface, a weak cold front currently extending from south central South Dakota into central Minnesota will continue to move southward into the region today. This will result in cooler conditions, easterly winds and hence, mostly cloudy skies. The cold front nearly stalls out south of the region tonight. Light precipitation chances and cooler conditions are the main features this week.
High pressure over Missouri and Indiana is expected to continue to maintain its influence over Indiana through the end of the work week as it slowly moves to the east coast.
GAH AFTERNOON DISCUSSION: Much of the change this afternoon revolved around the idea that the fog won't move out of the region completely, rather stay in the higher elevation areas along and north of the Hi-Line until sundown or a bit thereafter, when the fog and low clouds surge back to the south and lower-lying areas. Bigelbach MORNING DISCUSSION: Area of low clouds and fog over the northeast corner of the state this morning, with high pressure dropping into the upper midwest, and a cold front over central Montana. Southwest flow aloft will help push the front back to the east later today, with the low clouds lifting back into Canada. Upper trof moving onshore, with an upper low spinning up over the northern Rockies tonight. This low is expected to slowly lift northeast into central Saskatchewan by Christmas Day.
645 PM EST Mon Dec 23 2019 High pressure will stay in control of our weather through Christmas Day.
/issued 322 PM CST Mon Dec 23 2019/ The deep cutoff low which brought the rain and clouds to the Midsouth over the weekend is moving eastward and away from the region while an upper ridge is moving in from the west. Clouds are quickly dissipating across northeast Mississippi and temperatures are noticeably warmer this afternoon. Conditions will be much warmer than normal through the rest of the week as the upper ridge continues to dominate the region.
524 PM CST Mon Dec 23 2019 For tonight, A weak cold front will move into the northwest Sandhills. The NAM model sounding is saturated, with the potential for light freezing drizzle, while the GFS is much drier. Have a slight chance mention for light freezing drizzle and light snow.
The increased cloud cover has kept temperatures about 10 to 15 degrees cooler than yesterday. Weak southerly winds will continue tonight into Tuesday as the upper level ridge slowly shifts eastward. Cloud cover will continue to increase on Tuesday as a weak cold front pushes into the forecast area. Highs should range from the mid 40s up north to the low 60s in portions of Kansas. This precipitation would likely occur as a mix of drizzle and freezing drizzle, but we could briefly see some snow over northern portions of the area where there is better dendritic moisture. This may lead to some slick roads in areas that fall below freezing Christmas morning. The rest of Christmas day should be precipitation-free, and temperatures have trended even warmer over the last couple forecast cycles.
Weak trough remains over NorCal and is keeping a few showers over the mountains. Dry conditions over the Valley, although will likely see fog develop overnight possibly becoming dense much like last night, especially over the lower Sacramento Valley. Snow levels will be quite low with this system down to 2500 feet, but the low moisture amounts will only give 1-3 inches over the Sierra.
935 PM EST Mon Dec 23 2019 After a rainy and cloudy day across east central FL, the local Doppler radar shows only a few light showers swirling around an area of low pressure. This low was moving from west to east across the center of the peninsula and will bring variable sky conditions for tonight. Temperatures will drop to the lower to mid 50s. As a low pressure moves east, clouds and wind direction will vary from site to site but should remain below 15 kt overnight.
An upper ridge axis will slowly depart Texas by daybreak on Tuesday ahead of weak southwesterly flow. Retained the prior shift's mention of dense fog, but expanded it to include much of the Coastal Bend and neighboring plains given good clustering among the high resolution models. Behind the upper ridge axis, thicknesses don't change that much, so highs tomorrow should fall within a degree or two of today for most areas.
Updated at 254 pM EST Mon Dec 23 2019 High pressure - both at the surface and aloft - moves through the Ohio Valley tonight and tomorrow. Overnight lows will range through the 30s - a few degrees warmer than this morning in most areas except the southeast corner of our forecast area, where clouds this morning held temperatures up into the lower 40s. While most highs will be more than 20 degrees above normal for the date, they still fall shy of climatological records, which are in the lower 70s. A ridge of high pressure will linger over the eastern US, keeping things warm and dry locally.
Scattered to broken high level clouds continue to stream across eastern OK/northwest AR this evening ahead of a large Pacific trough. Otherwise, model soundings and delayed clearing late this morning suggests some low level moisture likely remains trapped beneath the low level inversion. /Issued 350 PM CST Mon Dec 23 2019/ Upper level low continued to push off to the east along the Gulf Coast this afternoon. which had allowed for a ridge of high pressure to filter into the Southern Plains. Underneath the ridge. another long wave trof was located just off the West Coast with an upper low just west of the Baja. Between this trof and the ridge over the region. Upper ridge shifts eastward Tuesday allowing for a more southwesterly flow across the Southern Plains.
Additional snow and rain showers will continue on Christmas mainly over the higher terrain.
632 PM EST Mon Dec 23 2019 High pressure will stay in control of our weather through Christmas Day.
/issued 155 PM CST Mon Dec 23 2019/ (Tonight and Tuesday) With upper ridging over Texas, temperatures across our area have climbed into the upper 60s to lower 70s early this afternoon. The upper ridge will shift east into the lower Mississippi Valley on Tuesday morning, and our area will be under southwest flow aloft. At this time, expecting enough radiational cooling to allow temperatures to drop into the lower 30s in the favored low-lying areas and river valleys of some of our eastern and southern counties.
350 PM CST Mon Dec 23 2019 Upper level low continued to push off to the east along the Gulf Coast this afternoon. which had allowed for a ridge of high pressure to filter into the Southern Plains. Underneath the ridge. another long wave trof was located just off the West Coast with an upper low just west of the Baja. Between this trof and the ridge over the region. Upper ridge shifts eastward Tuesday allowing for a more southwesterly flow across the Southern Plains.
High pressure to the east is keeping winds light and skies clear ahead of a building ridge. A ridge builds into the Mississippi River valley Tuesday with a shift to southerly flow in the evening.
However, the upper level ridge will move farther east and cloud cover is expected to begin to increase. Tomorrow, increased cloud cover and a weak cold front passing through the area will lead to slightly cooler temperatures than today. An analysis of upper levels winds shows that the trough off the west coast has reached maturity. This closed low will be absorbed into the southwest flow and the remnants of that system could lead to precipitation across eastern Nebraska. Freezing drizzle is in the realm of possibility and could lead to some slick spots Christmas morning.
Amounts will be near an inch for Cooke City with amounts up to 5" in the highest peaks. Any snow that falls in the lower elevations will accumulate to less than a half inch. Challenge is whether this shallow saturated cold layer is deep enough to support light freezing drizzle/freezing rain for a period before it deepens and saturates further to support snow. Latest deterministic models are split on this question with the NAM being supportive of some freezing precip from Hysham to Broadus and east while the GFS soundings appear too shallow initially and then quickly cool and saturate for snow as the predominant precipitation type. NBM ensemble currently downplaying freezing rain potential, so for now removed mention of it from the forecast.
936 PM EST Mon Dec 23 2019 A backdoor cold front will drop south out of New England tonight into Tuesday, then oscillate over the Mid-Atlantic through late in the week. A cold front may approach from the Ohio Valley at the end of the week, followed by a second frontal system this weekend. High pressure remains in control and with a persistent strong inversion (seen the 00Z sounding), and light winds, haze and/or patchy fog could develop again tonight into Tuesday. Lows tonight should be about 5F degs warmer than this morning and higher elevations will also be warmer than lower elevations. Cooler on Tuesday as backdoor front pushes through the area. Highs generally 5 to 10F degs cooler than today. Christmas Day will be a carbon copy of Tuesday with similar daytime highs and slightly cooler nighttime lows.
921 PM EST Mon Dec 23 2019 High pressure will stay in control of our weather through Christmas Day.
/issued 220 PM CST Mon Dec 23 2019/ The upper ridge over the area today will shift to the eastern CONUS tomorrow with a deepening trough in the western CONUS.
Dense fog continues to affect areas north of Highway 2, and the highlight could be extended after 3 PM for a portion of the region.
The trailing cold front extending from the low over Quebec will continue south across srn WI and Lake MI this afternoon. For tnt-Tue nt, a portion of the wrn upper trough will move out into the Great Plains.
Subtle cold front slides from northwest to southeast overnight, with 925mb winds becoming west to northwest, which will advect more stratus/fog from west to east tonight.
303 PM CST Mon Dec 23 2019 For tonight, A weak cold front will move into the northwest Sandhills. The NAM model sounding is saturated, with the potential for light freezing drizzle, while the GFS is much drier. Have a slight chance mention for light freezing drizzle and light snow.
533 PM CST Mon Dec 23 2019 As a deep low continues to batter the southeast US, the central US continues to sit comfortably under an upper ridge that will slowly creep east over the next couple of days. Lee troughing will continue to bring southerly flow to the region and act to tighten the sfc pressure gradient across the area tomorrow. Late in the week a robust trough will deepen along the western US coast with what may be our weekend precipitation maker. There are still quite a few model differences, with respect to strength/timing/location of the 500mb closed low.
713 PM EST Mon Dec 23 2019 A mild evening will be replaced by cooler conditions overnight as a cold front sweeps through the region. High pressure will build into the region from Canada through midweek.
322 PM CST Mon Dec 23 2019 The deep cutoff low which brought the rain and clouds to the Midsouth over the weekend is moving eastward and away from the region while an upper ridge is moving in from the west. Clouds are quickly dissipating across northeast Mississippi and temperatures are noticeably warmer this afternoon. Conditions will be much warmer than normal through the rest of the week as the upper ridge continues to dominate the region.
645 PM EST Mon Dec 23 2019 High pressure will weaken over the middle Atlantic states, while low pressure will meander offshore the southeastern US coast, through Tuesday. Upper low will cross the Florida Peninsula this evening and then off the Florida coast by daybreak. Meanwhile, high pressure will weaken while remaining situated over the middle Atlantic states. Sunshine returns Christmas Eve with prominent ridging and associated subsidence overspreading the region from the west as the upper low moves out into the Atlantic. Lows in the lower to mid 30s.
1120 PM EST Mon Dec 23 2019 High pressure will stay in control of our weather through Christmas Day.
Wind will be light and variable overnight but pick up out of the S to SW tomorrow as leeside trough deepens.
1243 AM EST Tue Dec 24 2019 High pressure will stay in control of our weather through Christmas Day.