Aikyam-Lab/Synoptic-Bench huggingface dataset:
Valley fog in the mornings will become more of an issue under stable high pressure. An upper level ridge building over the Pacific Coast places our region under a light northerly flow aloft. With the valley temperature inversions, freezing fog becomes possible as well, especially for the Gallatin and lower Milk River valleys where significant snowpack remains. This is followed by yet another upper level ridge providing fair weather through the end of the week. Ensemble clusters show differences in position of this ridge axis, but not enough to cause any meaningful departures from an overall fair weather pattern.
(Monday through Tuesday night) High pressure over the region Monday will slowly push offshore on Tuesday leading to breezy southerly flow and Max temps close to 80 degrees by Tuesday afternoon. Low temps will generally continue above normal in the mid/upper 50s Monday Night and in the lower/middle 60s Tuesday Night as dense fog potential is much lower Tuesday Night with stronger southerly flow at 5-10 mph through the night.
After that, broad mid-level ridging will keep the forecast dry this afternoon. Broad mid-level ridging downstream from the storm system developing over the southern/central Plains will build across the UP on Monday, resulting in dry conditions. Model 850 mb thermal fields and model fcst soundings now suggest the threat for any sleet/freezing rain on Tue should stay confined to south central and eastern portions of Upper Mi. Models continue to show a sharp cutoff to northern extent of precip associated with a very dry Canadian ridge north of this system, which could reduce QPF amounts for the northern Keweenaw.
1247 AM EST Mon Jan 2 2023 An approaching warm front will bring rain to much of the Commonwealth on Tuesday.
When looking at visibility with latest guidance along with light to calm winds and inversion seen today, there is growing confidence in more widespread freezing fog tonight. Meanwhile, a trough along the Pacific Northwest and British Columbia coastline will weaken as it is blocked by said ridge over Alberta and Montana.
344 AM EST Mon Jan 2 2023 High pressure offshore will continue to bring warm air into the region.
1013 PM EST Sun Jan 1 2023 An approaching warm front will bring rain to much of the Commonwealth on Tuesday.
Today through Tuesday Difluent flow continues over much of the CWA this morning, as the main upper low moves over the Four Corners region. The focus for the snowfall today will be from Johnson County to southern Lincoln County and all points eastward, as the upper low tracks toward eastern CO by 00Z Tuesday. Light snow will redevelop over far western portions tonight into Tuesday, as a weak trough moves over the area from the Great Basin. This trough will produce just enough lift and upslope flow to generate the snow, but accumulations will be very minor.
103 AM EST Mon Jan 2 2023 High pressure will persist through early this week. A cold front will then pass through the region mid week, followed by more high pressure through the end of the week. Given some influx of cooler air within a deep west to northwest flow, which will allow for min temperatures down in the mid and upper 40s mainly west of I-95, and lower 50s further east. Monday and Monday night: Aloft, broad ridging will move across the eastern half of the CONUS while high pressure at the surface starts the day centered along the Southeast coast before shifting just offshore. Another warm afternoon is expected with highs rising into the low to mid 70s.
After that, broad mid-level ridging will keep the forecast dry this afternoon.
Deep southerly flow will develop in between these two systems, as a warm front lifts northeast through the area -- advecting in a warm, moist air mass into the region. 4" by the afternoon (in the 95th percentile for this date per the Nashville and Birmingham sounding climatology) as dewpoints creep up into the low to mid 60s.
Details: Precipitation is expected to slowly work its way in from the west as a mixture of light rain and freezing rain. More models are now indicating that temperatures will above freezing for most of the area during the daytime today (except for our far northwest. We then see a transition to snow later this evening through the overnight on the backside of the low.
Some freezing rain could also create light ice accumulations. The negative tilt will allow the Gulf moisture to be advected westward into the High Plains. North-northwest winds will be on the increase in the tightening pressure gradient located across the area northwest of the low. As far as the freezing rain potential. A mix of freezing rain and sleet can be expected.
Although, there is a bit more agreement now with more of a northward penetration into the eastern CWA on Tuesday as the low begins moving northeast across the plains.
207 AM MST Mon Jan 2 2023 A series of upper-level ridges build over the region throughout the week, keeping fair weather conditions across much of the region with temperatures near or just below seasonal average average and light winds for the first few days of the new year. Valley fog in the mornings will become more of an issue under stable high pressure throughout the week. However, a temperature trend still suggests warmer temperatures by the end of the week. Afternoon temperatures will reach the lower 40s in some locations, and the mid to upper 30s for most elsewhere.
Unseasonably warm again today and tomorrow before a cold front Tuesday brings temperatures a bit below normal midweek. A positively tilted upper trough was positioned just west of the Rockies at 00z and as an upper low forms over the Four Corners area it will take on a negative tilt as it shifts eastward into the Plains today. this higher moisture driven cluster is expected to advect into the eastern Ozarks by early to mid afternoon.
Strong High pressure is providing plenty of stable air and dry weather over the Northern Rockies this morning.
Infrared and water vapor satellite imagery at 0630Z Monday depict an impressive, textbook baroclinic leaf signature overspreading a significant portion of the central CONUS, indicative of ongoing cyclogenesis ahead of a strong upper level trough centered over the Intermountain West. By 12-14Z Monday, guidance has finally agreed continued theta-e advection as the upper level trough progresses east will provide sufficient ascent for rain to develop across western KS, moving east-northeast through the day. Otherwise, temperatures will likely be a bit warmer for most locations Monday thanks to the aforementioned theta-e advection, with highs mainly in the 50s. If this scenario verifies, a period of wintry mix or snow could overspread these areas as cold air wraps around the western periphery of the low.
High pressure, clear skies, light winds, and moisture trapped near the surface will be around again late tonight into Tue morning for yet another dose of (dense) fog. Average temperatures for December were within a degree (+/-) of normal, and for the year were mostly around 1 to 2 degrees warmer than normal, ranking within the top 10 warmest at all sites.
Upper low transiting eastward across Colorado today and into Nebraska tonight. Benign upper flow pattern otherwise prevails over our region with ridging over the Canadian Rockies keeping subsidence and dry conditions in place.
A series of upper-level ridges build over the region throughout the week, keeping fair weather conditions across much of the region with temperatures near or just below seasonal average and light winds for the first few days of the new year. Valley fog in the mornings will become more of an issue under stable high pressure throughout the week. However, a temperature trend still suggests warmer temperatures by the end of the week. Afternoon temperatures will reach the lower 40s in some locations, and the mid to upper 30s for most elsewhere.
209 AM MST Mon Jan 2 2023 Showers will linger today along with cooler temperatures and breezy winds.
Given the high density of the snow associated with this atmospheric river event, this has resulted in about 30 inches of snow. Expect widespread snowfall to continue over the mountains with rain changing over to snow across the lower elevations of the north. The moisture wrapped system will continue to impact the region tonight and Tuesday as instability and orographics driven by northwest flow is expected to continue to generate snowfall, mainly over the higher terrain.
618 AM EST Mon Jan 2 2023 High pressure offshore will continue to bring warm air into the region.
Low level moisture will continue to increase today as a warm front lifts northward slowly. By mid day the warm front should move into northern OK and dewpoints will continue to surge upward into the low to mid 60s from central to southern OK. A Pacific cold front/dryline will also enter western OK. Then, later today as the closed low nears the KS/CO border, the cold front will move to near the I-35 corridor.
WV imagery indicates an upper level trough of low pressure edging eastward through the Four Corners Region. Infrared and water vapor satellite imagery at 0630Z Monday depict an impressive, textbook baroclinic leaf signature overspreading a significant portion of the central CONUS, indicative of ongoing cyclogenesis ahead of a strong upper level trough centered over the Intermountain West. By 12-14Z Monday, guidance has finally agreed continued theta-e advection as the upper level trough progresses east will provide sufficient ascent for rain to develop across western KS, moving east-northeast through the day. Otherwise, temperatures will likely be a bit warmer for most locations Monday thanks to the aforementioned theta-e advection, with highs mainly in the 50s. If this scenario verifies, a period of wintry mix or snow could overspread these areas as cold air wraps around the western periphery of the low.
642 AM MST Mon Jan 2 2023 Upper low moving through the Central Rockies with a ridge over western Canada. High pressure over the northern Plains will keep the Colorado storm well south, for generally clear and dry conditions over northeast Montana. Another low pressure system moves across Wyoming late in the week and could push some light precipitation northward across Montana. Slightly warmer temperatures are also expected as the low pressure partially scours out the lingering cold airmass. KGGW and KOLF will go in and out of IFR/LIFR conditions due to areas of low clouds and freezing fog along the Milk/Missouri River Valley.
Low level ridging is beginning to consolidate over the Florida Peninsula this morning as it drifts eastward. The low level ridge will continue to consolidate and strengthen over the next couple of days.
Unseasonably warm again today and tomorrow before a cold front Tuesday brings temperatures a bit below normal midweek. A positively tilted upper trough was positioned just west of the Rockies at 00z and as an upper low forms over the Four Corners area it will take on a negative tilt as it shifts eastward into the Plains today. this higher moisture driven cluster is expected to advect into the eastern Ozarks by early to mid afternoon. Hi-res models indicate some probabilities for visibilities dropping to IFR levels at times, with the highest chances at the BBG site. The highest chances for impacts at the forecast sites look to be from 20Z Monday to 06Z Tuesday.
The low that finally brought some snow yesterday continues to inch slowly eastward.
A winter storm system is making its way across the state this morning as upper level low pressure is centered near the Arizona/Utah border.
A Pacific cold front will sweep across the area overnight, but low temperatures will still be well above the seasonal averages.
The Pacific cold front/dryline has also begun to move into western parts of the fa with moisture continuing to increase east of the boundary. A few tornadoes can not be ruled out with the highest potential in SE portions of the fa. Cooler air behind the Pacific front and then another shot of cool air Tuesday will drop temperatures down a bit tonight into tomorrow with lows tonight ranging from upper 20s to upper 40s (NW to SE) and highs Tuesday ranging from upper 40s to low 60s (N to S).
Light rain chances, potentially mixed with snow late, will linger across central Kansas through early evening as an increasingly negatively- tilted upper level trough lifts northeast across the Western High Plains. Based on short range models/CAMs, a secondary band of light rain will be possible in an axis of increased forcing associated with an attendant cold front as it pushes through west central/southwest Kansas later this evening. Expect temperatures tonight to drop below freezing with lows generally in the 20s(F). With northwesterlies reinforcing the colder air mass across the high plains, look for highs only up into the mid/upper 30s(F) to possibly the lower/mid 40s(F) farther south closer to the Oklahoma border Tuesday afternoon, despite clearing skies.
Cold temperatures will slowly increase this morning as the low stratus and patchy fog continues to clear through the day.
Seasonable temperatures persist with highs Tuesday in the mid teens for most areas and slightly warmer in the southwest.
(The rest of this afternoon) Issued at 1218 PM EST MON JAN 2 2023 Low level clouds remain atop of us as a low pressure system from the Great Plains lifts towards the Upper Midwest this afternoon. As seen on radar imagery, weak lake-effect snow/drizzle/freezing drizzle has ceased across the area (save for possible the far east near Whitefish Point). Observation sites across the area show that temps have already gotten into the low to mid 30s across the south central and east early this afternoon, whereas the interior west still looks to have only gotten into the upper 20s. Expect temps to warm only a degree or two more across the area as the low sun angle and cloud coverage should limit sfc warming.
In any case, the dry air on the north side of the system should make for a tight gradient, so subtle shifts in the low track could still result in much greater or lesser impacts in and around the aforementioned line.
Sufficient low level/deep layer directional and speed shear is in place for the development of multi-cellular and discrete mesocyclones through the remainder of the afternoon hours and into the mid to late evening.
(This afternoon through Tuesday night) An upper low swinging across CO today will move over KS tonight and into NE Tuesday. A secondary trough associated with this low will cross SE NM and W TX Tuesday before an upper ridge over the Western US begins to build into the area Tuesday night. Temperatures will be a little cooler tonight with lows in the 30s and 40s. Highs Tuesday will be 10 to 15 degrees cooler than today with readings in the 50s and 60s with a few 70s along the Rio Grande. Lows Tuesday night a few degrees cooler than tonight.
(Today and tonight) An upper low will move from the Utah/Arizona border east-northeast into Colorado today. A trough will extend south from this low along the New Mexico/Texas border this evening. The upper low will then lift northeast into Nebraska overnight. Temperatures today will be a little cooler than yesterday, but still well-above normal with highs 73-77 degrees across our area.
1243 PM MST Mon Jan 2 2023 Weak upper level ridging will shift east of the Northern Rockies through Tuesday, which will lead to increasing winds in wind prone locations.
The aforementioned weather conditions are all associated with perturbations on the leading edge of an H500 low pressure system moving northeast across western Colorado. As the main low pressure system continues to move into the central Plains through tonight, leftover sprinkles and/or flurries will be possible through very early AM on Tuesday before all of the Panhandles dry out. Temperatures tonight will range from the lower 20s in the NW Panhandles to mid 30s in the SE TX Panhandle.
325 PM EST Mon Jan 2 2023 High pressure offshore will continue to bring warm air into the region.
(This evening through Tuesday) An upper level low is currently ejecting out of the Four Corners region and is expected to to rotate north and east into the Central Plains.
(Rest of today through Tuesday) High pressure around the area is keeping conditions dry and warm today across South Florida and is expected to continue through tomorrow as well. As the high shifts more eastward and expands over the Atlantic, winds become breezier tonight out of the east and will start to veer more southeasterly tomorrow. Temperatures are expected to peak in the low to mid 80s both today and tomorrow for the region.
Weaker lead trough is still supporting light snow across most of the region, with more persistent moderate to heavy snow ongoing across south central SD. The main upper trough will support very strong FGEN response over the NE panhandle into scentral SD, with very heavy snow still on track there.
High pressure aloft will continue to push east as a splitting weather system approaches western Washington today.
A deep upper level low pressure system centered over the Four Corners region will be moving to the northeast. The orientation of the front to the warm air brings the warm front across the southeastern portions of the CWA and it will slowly progress to the north as the cold front pushes east. This orientation, along with a strong low level jet just north of the warm front will raise the specter of thunderstorms this afternoon and evening. Finally, with the high PW values in the CWA and the approaching frontal system, this brings the possibility of some heavy rain with this thunderstorm activity.
Mean-layer ridging remains in control of the sensible weather across the Keys, with the low-level ridge gaining height across FL. Temperatures are nearing 80, and dewpoints are in the lower to mid 70s. The forecast calls for highs in the lower 80s, mostly sunny skies, and nil rain chances.
945 AM MST Mon Jan 2 2023 A series of upper-level ridges build over the region throughout the week, keeping fair weather conditions across much of the region with temperatures near or just below seasonal average and light winds for the first few days of the new year. Valley fog in the mornings will become more of an issue under stable high pressure throughout the week. However, a temperature trend still suggests warmer temperatures by the end of the week. Afternoon temperatures will reach the lower 40s in some locations, and the mid to upper 30s for most elsewhere.
Water vapor imagery highlights a potent mid-latitude storm system over the southern Rockies, an amplifying ridge over the eastern US, and a series of weak southern-stream short waves sliding east across the southeastern Gulf and the Bahamas. Mean-layer ridging remains in control of the sensible weather across the Keys, with the low- level ridge gaining height across FL (see 12Z FL RAOBs). Temperatures are a few ticks above 80, and dewpoints are in the lower to mid 70s. Mean-layer ridging will persist over the Western Caribbean for the next couple of days. Enhanced low-level ridging will result in moderate to fresh east to southeast breezes tonight through Tuesday night. Moisture above 900 mb will be scant despite the freshening east to southeast breezes on the southern flank of the building ridge.
108 PM EST Mon Jan 2 2023 High pressure offshore will continue to bring warm air into the region.
Latest observations snow falling snow confined to areas near and south of I-90, with high pressure positioned over northeastern SD. Although, there is a bit more agreement now with more of a northward penetration into the eastern CWA on Tuesday as the low begins moving northeast across the plains.
(This evening through Tuesday) The high clouds that encompassed the area this morning has quickly pushed eastward as the upper low swings into Colorado today. Temperatures are to be cooler than the previous few nights, which were more mild. However, temperatures will be kept near or above freezing tonight across the area given the elevated winds expected overnight. A disturbance in the broad troughing aloft behind the closed low pushing into eastern Nebraska and western Iowa will help to give way to a weak lee low development.
1049 AM EST Mon Jan 2 2023 Fair weather and above average temperatures can be expected through tonight as high pressure remains over the area.
1053 AM CST Mon Jan 2 2023 Latest observations snow falling snow confined to areas near and south of I-90, with high pressure positioned over northeastern SD. Although, there is a bit more agreement now with more of a northward penetration into the eastern CWA on Tuesday as the low begins moving northeast across the plains.
Be prepared for slick spots from Freezing Fog as temperatures hover right around the freezing mark. Across the cwa this morning, skies are cloudy with mainly light snow and light freezing rain/drizzle occurring over a good portion of the area. Latest guidance is showing a bit better low/upper low track for this event. As with previous forecast, dry air aloft is expected to put a mixed focus for precipitation on snow and freezing rain. Southern and eastern locales are still going to see a brief period of light rain as temps expected above freezing for a few hours. High pressure returns by midday Tuesday through the rest of the short term period. For temps, highs in the short term will range in the lower to mid 30s north of the Interstate, with upper 30s to lower 40s south.
Visibilities are expected to improve from south to north overnight as a warm front begins to lift across the region.
617 PM CST Mon Jan 2 2023 (Tonight through Tuesday night) Key Messages: - Weak cold front overnight into tomorrow morning - Slight chance of showers and thunderstorms, mainly over Victoria Crossroads - Patchy to areas of fog possible in advance of the front A weak cold front will enter our western CWA shortly after midnight and push southeastward through South Texas overnight, reaching the coast in the mid-morning. Highs on Tuesday will be a few degrees cooler ranging from the mid 70s to around 80.
614 PM CST Mon Jan 2 2023 (This evening through Tuesday) An upper level low is currently ejecting out of the Four Corners region and is expected to to rotate north and east into the Central Plains.
High pressure will build in for later Tuesday, but more active weather is expected to return by mid-week. Snow amounts are generally less than a half inch in the valleys with about an inch or two across the higher terrain passes and summits. On Tuesday and Tuesday night, the weak low pressure system will have moved eastward, though some leftover isolated snow showers will be possible in the late morning and early afternoon. High pressure is then expected to build in for the latter portions of the afternoon into Tuesday night. Highs on Tuesday will be in the upper 20s to mid 30s while overnight lows will dip into the teens to the low 20s.
342 PM MST Mon Jan 2 2023 Large trough with some negative tilted aspects occurring. The main focus for the short term is the advancing trough that will turn into a low over northern portions of the area. Any freezing rain looks to occur to the east of Highway 27 with freezing rain transitioning to all snow as the entire moisture profile falls below 0C. Freezing rain looks to end across the entire area by 04Z. the center of which (ridge) will be situated over the Intermountain West/4-Corners. With the Tri- State area situated on the eastern periphery of the ridge. and western periphery of a stalled upper level low invof the Great Lakes.
Another mild day on Tuesday, however a cold front will be pushing through.
Accordingly, the highest snow reports have been from the Lander foothills and Casper areas, which have been particularly favored for snow in this pattern. Snow will decrease by sunset as the low moves farther east and 700mb flow becomes weaker and less favorable.