Aikyam-Lab/Synoptic-Bench huggingface dataset:
117 PM EST Sat Dec 17 2022 Isolated to scattered snow showers will be possible through the weekend with accumulating snow possible in the higher elevations of the Allegheny Mountains. Latest WV imagery shows the broad upper low which will be the dominant feature this weekend currently centered over lake Michigan as it slowly transitions east. The exception will be the higher terrain where orographic enhancement should maintain light snow during the night.
Some patchy freezing fog will also continue to be possible the next few evenings as temperatures remain quite cold.
(This evening through Sunday) Closed 500mb low over the Great Lakes region will continue to drive our weather, with a westerly flow containing another weak overnight ripple that will wring out some precip over the higher elevations late tonight.
1154 AM CST Sat Dec 17 2022 Mid morning temperatures have warmed above freezing across all of the Midsouth. Most of the Midsouth should warm into the middle 40s with northeast Mississippi perhaps into the low 50s.
GOES-16 visible satellite imagery has started to detect a few breaks in the low-level cloud deck, mainly in the vicinity of the Lower and Middle Keys.
852 PM EST Sat Dec 17 2022 A weak cold front will move southeast across the area through around midnight.
High pressure keeps a lid on temperature inversions with cold conditions prevailing. Have therefore issued a Freezing Fog Advisory through 11 am Sunday for southwest and south central Elko County. /ISSUED AT 241 PM / High pressure keeps a lid on temperature inversions with cold conditions prevailing.
Key Messages: * Dry, warmer, and much less windy this weekend.
Tonight, weak ridging will move over Colorado with continued warm air advection. Low temperatures will be slightly below normal but still warmer than the past couple of days. Tomorrow, the weak ridging will turn to a slight trough by the afternoon. Warm air advection continues and highs will be warmer than today's level. The only thing that may limit the high at DIA will be the snow cover to the east. Long wave trough sets up over southern Canada and the northern U. Over Colorado, northwestly flow on the backside of the trough will put the area on the edge of the colder air most days.
524 PM CST Sat Dec 17 2022 (This afternoon through Sunday night) Trough axis associated with strong low over the Great Lakes passed over the region today with next low sitting off the CA coast. This low will open up into a trough as it moves inland passing over AZ into NM Sunday. Highs Sunday will be a bit warmer mainly in the 50s.
304 PM CST Sat Dec 17 2022 Key Messages: * Dry, warmer, and much less windy this weekend.
611 PM CST Sat Dec 17 2022 (Tonight) The Tennessee Valley sits between a large upper low spinning near the Upper Great Lakes and a cold front pushing southeast across AL/GA/FL. High pressure begins to filter in tonight. Overnight lows bottom out in the low to mid 20s.
Water vapor imagery shows a weak upper level low off the southern coast of California with a longwave trough over most of the eastern U. Temperatures are a few degrees warmer today after a chilly start to the day this morning. The low in the Pacific will be the driver of the weather through Sunday. After the low passes through weak troughing will be in place over Arizona with high pressure building over the eastern Pacific into the middle of the week. Thereafter the ridge builds further east into the western U. Ensembles are in good agreement with their being a ridge in place and only differ in how strong and how far east it will build.
Areas across the Laurel Highlands and the higher terrain of West Virginia will see more numerous snow showers with accumulation.
Areas across the Laurel Highlands and the higher terrain of West Virginia see more numerous snow showers with accumulation.
641 PM EST Sat Dec 17 2022 (This evening through Sunday) Closed 500mb low over the Great Lakes region will continue to drive our weather, with a westerly flow containing another weak overnight ripple that will wring out some precip over the higher elevations late tonight.
241 PM PST Sat Dec 17 2022 High pressure keeps a lid on temperature inversions with cold conditions prevailing.
Weak high pressure builds southward into the region behind the aforementioned front. Temps on Sun will be cooler than the past couple days, with highs in the L-M60s from Orlando northward, and M- U60s southward, and L70s for southeast St.
With relatively light winds the next two nights, a bit of freezing fog is possible but not likely at this time (especially with Fort Peck Lake now partially ice covered).
A cold front will push across the region tonight with cloudy skies and scattered showers. Overnight lows vary widely with temperatures in the lower 40s along the Nature Coast to the lower 60s in SWFL.
140 PM PST Sat Dec 17 2022 A weak low pressure system will bring increasing high clouds today along with slight cooling.
Ridging over the east Pacific will result in dry northwesterly flow aloft across the region. Current infrared and water vapor satellite imagery shows a weak low pressure system pushing east through southern California. This low is responsible for the mid-to-upper level clouds currently covering the southern half of the forecast area.
This low is a reflection of a weak wave in a southwest flow regime, which might enhance flurry activity.
A weakness in the arctic high gives way to a small high pressure system nestled deep into Texas. Winds are variable across the Upper Keys, tending to the south across the Lower and Middle Keys, with southeast winds at Smith Shoal and NDBC 42026. Strong thunderstorms approached the coastal waters of the Florida Keys from the west and south this evening, but quickly eroded as they encountered significant BL inhibition (see 00Z KKEY) and cooler waters. High pressure will build across the Southeast in the wake of the front, resulting in freshening north to northeast breezes Sunday afternoon through Monday.
Clear and colder conditions will continue overnight, with lows reaching the low to mid 20s by early tomorrow morning. Very similar weather pattern expected again tomorrow, although highs will generally be around 5 degrees cooler. however highs will only be in the lower to middle 40s today.
Temperatures will remain below freezing for most of the area.
125 AM MST Sun Dec 18 2022 Deep upper trough over the eastern Canadian Rockies will shift south with a series of southern periphery impulses undulating the sfc front the next couple days. First batch of cold air will settle into the region today in the form of a backdoor cold front. Have issued a freezing fog adv for this through noon. Very cold conds will continue into Fri before warmer air begins to move back east this weekend, esp over NE WY and the BH where the shallower arctic air will have a chance to mix out. A cold front slipping southeastward into the area tonight will result in widespread IFR/LIFR conditions in stratus and FZFG over much of the western SD plains, probably pushing into parts of northeastern WY after 14z Sunday.
Scattered snow showers continue to affect the Allegheny Plateau and the Ridge and Valley region. There has been some light accumulation in the Laurel Highlands, especially on the ridge tops, and this should continue overnight. A westerly breeze will dip wind chills into the teens (and perhaps single digits on the ridge tops) for all but the Lower Susq Valley. Across the Laurel Highlands and Ridge and Valley Region, flurries and scattered snow showers could bring an additional coating (to locally an inch or two on the ridge tops).
941 PM CST Sat Dec 17 2022 (This afternoon through Sunday night) Trough axis associated with strong low over the Great Lakes passed over the region today with next low sitting off the CA coast. This low will open up into a trough as it moves inland passing over AZ into NM Sunday. Highs Sunday will be a bit warmer mainly in the 50s.
With few exceptions, most of the Four State Region looks to drop below freezing overnight.
High pressure will build in from the northwest behind a departing low pressure system with mid and high level clouds thinning over the next few hours with winds becoming northwest 5-8 knots. Clear skies and increasing northwest winds around 10 knots with gusts approaching 20 knots at CRG, SSI and SGJ will occur after 14Z at all sites as the high builds in further from the northwest.
High pressure will build back behind the front. Northerly winds will begin to increase allowing for the cooler, drier air to advect into the peninsula.
The higher snow amounts look to affect locations mainly northeast of a Hutchinson to El Dorado line into northeast Kansas.
Models have trended a little more amplified with this trough along with better moisture to work with. The GFS, Canadian, and HRW FV3 all hint at us wet bulbing down to at or below freezing, which would favor all snow and potentially accumulating snow. However, the ECMWF, RAP, and HRRR are all warmer and would support only a mix. For portions of east- central Kansas where confidence is higher for cooler temps, a transition to all snow appears more likely. A cold front will move through behind the system and we should see highs below freezing for most of the area except for southeast Kansas.
Temperatures will be falling very slowly during the evening due to cloud cover and lack of cold advection, and should still be above freezing when the precipitation starts.
A fairly robust and compact upper low will move through the state today, exiting the eastern border this evening. This low has a decent amount of moisture contained within the cold pool, but 500mb temperatures of around -21C are not outstanding for mid-level convection. Most areas will see just a few hundredths, but there will be a sweet spot at the higher elevation of the White Mountains, where an inch of two is possible. After today, an eastern Pacific ridge establishes itself for the remainder of the week. This is a "dirty" ridge and Arizona resides on the eastern side of the ridge all week.
Strong, cold high pressure in the interior continues to generate dry offshore flow all along the north coast. This regime has allowed for another clear night with widespread freezing temperatures all along the coast with colder interior valleys in the teens. All cluster ensembles show a very strong upper level ridge building by late in the week.
A weak low pressure system will move through the Desert Southwest today, bringing with it considerable cloudiness along with isolated sprinkles and virga.
Water vapor imagery this morning showed a weak upper level low over San Diego county with considerable mid to high level cloud cover over the forecast area. Upcoming week: High pressure building to our west will keep a dry west to northwest flow aloft over the area with high temperatures 2 to 5 degrees above normal with day-to-day variability. A weak weather system will move across the area today bringing a chance for precipitation mainly east of Tucson with the best chances being over the higher terrain. Cooler than average temperatures will continue today and Monday then warmer the rest of the week.
Upper ridging is currently moving overhead and will push east of the FA by the late afternoon. An upper low currently just off the southern coast of California will transition to an open wave as it moves over the Four Corners by the late afternoon/early evening. Though the system will overall be dry, there should be enough moisture for some light precip to develop ahead of the upper trough.
(Today through Monday afternoon) An upper level trough is approaching West Texas and Southeast New Mexico from the west. The upper trough will pass over the region tonight with temperatures across the area warmer than this morning.
118 AM PST Sun Dec 18 2022 Dense fog in the mornings along with freezing temperatures will continue until Monday.
The front is expected to move southward towards the I-90 corridor by tonight, with snow expected to impact the Monday morning commute for locations in the Mission valley, Missoula/Bitterroot valleys, and the I-90 corridor and the Highway 12 corridor from Lolo Pass west into central Idaho.
Overall quiet weather as a cold front exits the forecast area to the south. Cooler temperatures across the area today with highs only reaching into the lower 60s along the Nature Coast and into the mid 70s in SWFL.
Dry conditions will then develop from west to east across the BRO CWFA on Monday as the low moves away.
Inverted trough will settle into the area today, with fog likely re-developing along the eastern BH foothills this afternoon and evening. Deep upper trough over the eastern Canadian Rockies will shift south with a series of southern periphery impulses undulating the sfc front the next couple days. First batch of cold air will settle into the region today in the form of a backdoor cold front. Have issued a freezing fog adv for this through noon. Very cold conds will continue into Fri before warmer air begins to move back east this weekend, esp over NE WY and the BH where the shallower arctic air will have a chance to mix out.
258 AM MST Sun Dec 18 2022 Updated Aviation A weak low pressure system will move through the Desert Southwest today, bringing with it considerable cloudiness along with isolated sprinkles and virga.
824 AM EST Sun Dec 18 2022 Scattered snow showers will gradually taper off on Sunday as high pressure begins to build. Dry weather will then prevail through the first half of the work week before a strong cold front brings rain, snow, and much colder weather into the area just in time for the holiday weekend. Light snow showers should taper mid-morning in the lowlands, and mid-evening in the ridges. Temperatures will drop to the low 20s.
509 AM CST Sun Dec 18 2022 (Today through Monday night) Tranquil conditions persist area wide this morning thanks to a 1024 mb surface anticyclone centered over AR. Height falls downstream of this trough will induce coastal low development in the northern Gulf on Monday with a defined frontal boundary draped along the coast.
425 AM MST Sun Dec 18 2022 Deep upper trough over the eastern Canadian Rockies will shift south with a series of southern periphery impulses undulating the sfc front the next couple days. First batch of cold air will settle into the region today in the form of a backdoor cold front. Have issued a freezing fog adv for this through noon. Very cold conds will continue into Fri before warmer air begins to move back east this weekend, esp over NE WY and the BH where the shallower arctic air will have a chance to mix out.
If enough cooling of the column can occur in the higher precipitation rates, we could see some snow showers with some very light accumulations. High temperatures today will range from the lower 40s to near 50 degrees. Similar temperatures tomorrow compared to today with highs in the 40s into the lower 50s.
An upper low is spinning over Alberta with a broad upper trough extending through much of the PAC NW this morning.
(Today through Monday night) Tranquil conditions persist area wide this morning thanks to a 1024 mb surface anticyclone centered over AR. Height falls downstream of this trough will induce coastal low development in the northern Gulf on Monday with a defined frontal boundary draped along the coast.
(This afternoon through Monday) Breezy southerly flow will continue across the area through this evening, causing slightly warmer temperatures and some moisture to filter into the area. Given the increased cloud cover, overnight lows are expected to remain slightly warmer than previous nights, in the low to mid 40s, with the exception of upper 30s in a few low lying areas across the area.
1110 AM EST Sun Dec 18 2022 Dry conditions throughout the remainder of today as drier air filters into the area behind a cold front. With the cold front passage last night, afternoon highs will be cooler than yesterday and even slightly below the climatological normal for this time of year. Clearing skies will allow temperatures north of I-4 to reach the low to mid 60s, with areas south reaching the upper 60s to low 70s. Dry conditions are expected today across the local waters thanks to a cold front moving south of the area. Conditions remaining dry today with skies slowly clearing throughout the daytime hours as drier air filters in from the north behind a cold front.
The cold front has slid through the CWA. Patchy freezing fog continues across parts of the CWA, but visibilities have improved since this morning. Freezing fog will redevelop this evening as light upslope winds continue and RH increases, especially around the BH region and SW SD. With much worse conditions expected the rest of the week and the watch in effect, opting to forgo issuance of this low-end advisory event in order to keep things simpler.
A light rain/snow mix is possilbe late tonight or early Monday, but subfreezing temperatures should quickly warm into the middle 30s by mid morning. Highs tomorrow are expected to be in the low to middle 40s.
Some light snow has started falling at the highest elevation of the White Mountains with webcams at Sunrise Peak showing the light snow nicely. A fairly robust and compact upper low will move through the state today, exiting the eastern border this evening. This low has a decent amount of moisture contained within the cold pool, but 500mb temperatures of around -21C are not outstanding for mid-level convection. Most areas will see just a few hundredths, but there will be a sweet spot at the higher elevation of the White Mountains, where an inch or two is possible. After today, an eastern Pacific ridge establishes itself for the remainder of the week. This is a "dirty" ridge and Arizona resides on the eastern side of the ridge all week.
Maxes will be even colder than Sat with readings only reaching the mid-upper 20s across the Mtns, near freezing in the Central Mtns and mid to upper 30s throughout the Lower Susq Valley. Across the Laurel Highlands, scattered snow showers could bring an additional coating (to locally an inch or two on the ridge tops). Flurries and the lightest dusting should be what the Ridge-and-Valley region gets. Downsloping flow into the Lower Susq on Monday should produce more sunshine than elsewhere.
(This evening through Monday) An upper level low over Arizona early this afternoon is opening up and the emerging upper trough will move quickly to the east- northeast across northern New Mexico this evening and the Texas Panhandle overnight. Will favor the slightly warmer MOS numbers over the NBM for most areas, the exception being the favored cold areas in the sandhills around Muleshoe. Westerly winds to increase in the morning behind the departing upper trough and ahead of a fairly weak cold front that will move into the forecast area late in the day. Downslope component and modest pre-frontal compressional warming underneath abundant sunshine should favor a blend of the warmer MOS values over the NBM.
High clouds along the southern periphery of a large upper trough will filter the sun but otherwise dry and cold today.
(The rest of today ) Light south winds and warmer temperatures expected this afternoon and current forecast is on track.
Current temperatures are in the upper 70s and dewpoints are in the lower 70s, making for a muggy start to this mid-December day. Dewpoints will gradually begin to decrease, so we will finally feel some relief! High pressure will build into the region this afternoon, so an increase in winds is expected. High pressure will build across the Southeast in the wake of the front, resulting in freshening north to northeast breezes this afternoon through Monday night.
Inverted trough will settle into the area today, with fog likely re-developing along the eastern BH foothills this afternoon and evening. Deep upper trough over the eastern Canadian Rockies will shift south with a series of southern periphery impulses undulating the sfc front the next couple days. First batch of cold air will settle into the region today in the form of a backdoor cold front. Have issued a freezing fog adv for this through noon. Very cold conds will continue into Fri before warmer air begins to move back east this weekend, esp over NE WY and the BH where the shallower arctic air will have a chance to mix out. Conditions over the higher Black Hills and far southern SD will deteriorate tonight as stratus/BR expands.
1147 AM CST Sun Dec 18 2022 (Today through Monday afternoon) An upper level trough is approaching West Texas and Southeast New Mexico from the west. The upper trough will pass over the region tonight with temperatures across the area warmer than this morning.
Mostly clear skies are expected tonight and into Monday as high pressure builds back into the region. Elsewhere, overnight lows will fall into the lower to upper 40s.
(This afternoon through Monday night) Upper trough moving across AZ today as a weak ridge stretches over the region. The trough will cross NM tonight and swing across the Panhandle Monday morning with a secondary portion of the trough swinging across the area Monday night. Temps will be warmer tomorrow which looks to be the warmest day of the coming week as a W wind kicks in behind a Pacific front.
1156 AM CST Sun Dec 18 2022 (Today through Monday night) Tranquil conditions persist area wide this morning thanks to a 1024 mb surface anticyclone centered over AR. Height falls downstream of this trough will induce coastal low development in the northern Gulf on Monday with a defined frontal boundary draped along the coast.
1121 AM CST Sun Dec 18 2022 (The rest of today ) Light south winds and warmer temperatures expected this afternoon and current forecast is on track.
Subsidence from this high pressure will keep conditions dry with mostly clear skies through the remainder of the afternoon and into tonight.
Winds across the Reef have gradually begun to increase as high pressure builds in, and marine observation platforms are recording a range of 11 to 14 knots. The secondary cold front that is still moving through South Florida is nearing forecast area. High pressure has already begun building into the region, and the gradient is beginning to tightened, as seen with increasing winds along the island chain and surrounding coastal waters.
Current thinking is that there won't be much spread between highs and lows with increased sky cover over the region, but they could quickly tank to the low end of model guidance if there are any breaks in the clouds like they did early this morning.
245 PM PST Sun Dec 18 2022 Freezing temperatures in the San Joaquin Valley Monday morning.
Ridging over the east Pacific will result in dry northwesterly flow aloft across the region allowing for the continuation of dry conditions with occasional high clouds at times. At this point, confidence is not high enough that freezing temperatures will be reached and elected not to go with a freeze warning at this time. With the moderating temperatures, overnight lows will start to increase and freezing temperatures for locations that normally don't freeze will become less likely.
In the case of dynamic cooling would like to see a close upper low instead of an open one that is currently being showed. Temperatures should warm back in the low 40s during the day Monday and would melt any snow that does fall. A cold front will move through Monday night bring the first push of Arctic air.
The moisture and lift from this trough will miss our CWA to the south and the dry conditions will continue for our area. Some of the flow aloft will mix down to the surface especially over the higher terrain. Winds were a bit light in the higher terrain in the previous forecast so they were increased. Denver will be in the low 40s with colder temperatures on the eastern plains over the snow cover.
Elsewhere, inland temperatures will drop to the lower 30s, and stay in the lower 40s along the coast and St.