Aikyam-Lab/Synoptic-Bench huggingface dataset:
125 PM MST Wed Dec 20 2017 Upper flow over the northern plains is zonal ahead of an approaching trough. At the surface, low pressure is located over northeastern WY. The warm front stretches across the CWA, from northeastern WY through south central SD. Arctic air will begin pushing into the region this afternoon and evening behind a cold front, as the low pressure system shifts southeastward. The northern Hills may get an inch or so with some slight upslope enhancement, but southwestern SD and parts of northeastern WY are expected to receive the highest amounts of 1-3 inches.
Warm-air advection will bring temperatures into the 50s across the southern half of the area, but advection and muted diurnal rises will battle cold low-level air behind a southeastward-advancing cold front especially north of HWY 36. Temperatures will fall during the late afternoon and evening and continue to plummet overnight, possibly allowing for patchy freezing drizzle along the MO/IA border. Road temperatures should remain above freezing and drizzle should end as the coldest temperatures arrive, so not expecting any impacts at this time.
Expect precip to taper off as the trof axis pushes to our east, so will most likely be confined to a pre-1st period timing.
Much of the region still remains encased in low clouds and fog; however, a few locations are starting to mix out the lower clouds.
In short, for these valley locations below 2500 feet, temperatures were a couple degrees warmer than anticipated overnight into this morning, and post frontal showers were lesser in both coverage and intensity than model guidance anticipated. Thus, amounts were on the lower end of the forecast realm of possibility at these lower elevations, while the forecast at higher elevations verified better. The freezing level at Medford is 3100 feet, therefore pilots could experience snow showers around 2000 feet and maybe as low as 1500 feet in heavier showers until around 17z. If the lower conditions were to develop, the best chance is in the Rogue Valley, including Medford and this has been added in the TAF. Cloud cover will diminish early this evening, but this is likely to lead to developing valley LIFR with freezing fog.
Temps are expected to warm well above normal by Thurs afternoon ahead of the next cold front.
Although cooler temperatures are expected for tonight as opposed to last night, the clouds, fog, and drizzle will keep us from going down quite as low behind this system with lows in the 40s/50s as our lower levels remain quite moist.
VFR conditons could be found just behind the cold front. Narrow band of showers and thunderstorms moving across the forecast area at this time aligned along an eastward advancing cold front.
Overall, mild temperatures will continue, somewhat tempered by the cloud cover Main concerns for impactful weather will be precip chances and type (possibly snow) with the cold frontal passage late in the week Fri-early Sat.
The sharp high pressure ridge expected to build along the coast as far north as the Arctic Circle the next couple of days, along with the very cold air plunging south through the Upper Plains States is not being handled by models well.
1145 AM EST Wed Dec 20 2017 A ridge of high pressure will build across the region today.
Skies to be mostly sunny over CWA today, and little cooler than previous day. As this system tracks into the Tennessee River Valley and a weak bubble of high pressure builds southward from Iowa, the cloud cover will gradually get suppressed south of the area by midday. Despite a good deal of sunshine, northeasterly winds will ensure cooler temperatures today than yesterday. with afternoon highs in the lower to middle 40s. A weak cold front will approach from the northwest on Thursday.
The low level southerly flow will continue to push moist air northward into central and parts of southwest Kansas this evening. West/northwest winds behind this low should keep fog out of the far western and southwest counties. Some potential for dense fog to develop but there is uncertainty as to the coverage and extent as model soundings show a fairly shallow layer with increasing winds/mixing in the upper part of the low level inversion. In addition to the fog, there will be the possibility for some drizzle developing toward central Kansas where the low level moist layer will be deeper. There is some potential for freezing drizzle if temperatures fall quickly enough behind the front.
/issued 319 AM CST Wed Dec 20 2017/ As the upper low moves off to the east, flow will become more zonal ahead of the trough over the west coast. Timing is still on track for the first cold front to move through as a dry front Thursday evening. Models have become less consistent from previous runs on how they are handling the upper low as it moves across the Rockies. Previous runs had an open trough with little precipitation. The GFS keeps a closed low before opening up to a wave over New Mexico and has less precip ahead of the trough.
Cold front to the nw will approach this evening and move across the area late tonight. The cold front will stall on Thursday as it reaches central Fl while the associated upper trough moves well off the se coast. Temperatures will be cooler behind the front especially across se Ga and near the east coast where winds will become onshore.
1244 PM EST Wed Dec 20 2017 High pressure building into the Ohio Valley from the northwest will keep any rain south of the area today. Southerly winds will pick back up late Thursday, ahead of the next low pressure system ejecting northeast into the area from the lower midwest.
as the front/low center move east of the state we will see a wedge of high pressure quickly build in across the CWA with the surface flow turning eastward over night.
A cool upper level trough over Eastern Washington will continue to move southeast today. An upper level ridge will build offshore bringing dry northerly flow aloft over Western Washington later today through Thursday.
/issued 342 AM CST Wed Dec 20 2017/ (Today and Tonight) Quieter, sunnier, and warmer weather expected today. Dry, zonal flow aloft will replace the upper level low that moved across the area yesterday. Farther west, an upper level trough will dig south into the intermountain west. This will cause increasing southwesterly flow across the Rocky Mountains, and lee troughing along the eastern Rockies.
324 PM EST Wed Dec 20 2017 High pressure will build over the region tonight then move east on Thursday.
1223 PM EST Wed Dec 20 2017 Low pressure will track eastward across the region this afternoon, followed by a back door front, bringing showers and isolated thunderstorms.
329 PM CST Wed Dec 20 2017 Surface data shows ridge of high pressure extending south into region through day today. Moisture channel satellite data and upper air display trough aloft over western US, with series of waves into the west southwest flow over the rockies. Models consistent in development of low pressure system in the central plains as the upper trof moves east toward the plains.
1155 AM CST Wed Dec 20 2017 A few areas across southeast Oklahoma and west-central Arkansas are trying to scour the low clouds.
Tonight, an upper low moving across the Rockies will push a cold front across the northern Great Plains and into Nebraska. Overnight lows will range from the upper 20s to mid 30s, potentially allowing some of this drizzle to transition to freezing drizzle as temperatures approach 32 degrees 10-12Z Thursday. The NAM and GFS continue to advertise that drizzle and freezing drizzle along and near the cold front will be the main precipitation type for the forecast area. Temperatures will initially be above freezing, then will drop steadily as cold air moves in behind the front through the morning and afternoon. While impacts won't be large, the ice, along with wet roads refreezing will probably lead to a few slick roads on Thursday.
Clouds and humidity will increase through Thu along with warmer temps and strengthening southerly flow. In addition, the low level moisture will be sufficient for isol -shras across the far northern CWA and waters in response to increasing convergence ahead of a cold front and its associated upper trough. Could see patchy fog as well, but it should be light as the low level jet is progged to strengthen Thu night and keep the airmass mixed along with increasing the cloud cover.
Patchy drizzle chances will increase tonight, initially across eastern Kansas within zone of strong low-level warm/moist advection, and later across central and east-central Kansas along/north of a developing warm front/triple point. A strong cold front is still on track to blast southeast across the forecast area Thursday, with falling temperatures and strong/gusty northwest winds in its wake. Cooling thermal profiles in wake of the cold front may support pockets of flurries and/or very light freezing drizzle Thursday afternoon and evening.
A cold front will cross Utah through early Thursday. The associated upper level low will gradually strengthen later this afternoon and evening. The upper level low will shift eastward through the day Thursday, bringing the threat of snow to the often missed eastern valleys. In addition, dry air entrainment is expected in the lower levels, which will preclude significant convective development.
As this airmass advects over the cooler shelf waters, the chance for sea fog will return Thursday morning along the coastal counties. Cloud cover will also thicken as a stratus deck develops early Thursday, and should keep temperatures a touch cooler.
This system will bring gusty winds and much cooler temperatures but little chance of precipitation.
As the ridge moves eastward, expect a band of warm advective snow to develop across ND, northern MN, and into northern WI later this afternoon and evening. Otherwise, expect increasing clouds through the day with light easterly wind and afternoon highs ranging from the lower 20s across the north to near freezing across the south. Focus turns to inverted trough/f-gen induced precipitation Thursday into Thursday night. Looking more and more like a 1-3 inch snowfall event along with perhaps some mixed rain/snow/freezing rain for areas south of I-90. As far as freezing precipitation, thinking a few hundreths of an inch at most south of I-90.
251 PM CST Wed Dec 20 2017 (Tonight and Thursday) Southwest flow will continue across the area through Thursday ahead of am upper level trough diving south across the Great Basin region. Meanwhile, a strong cold front will be approaching the northern Big Country by late Thursday afternoon. The combination of a strengthening low level thermal ridge and compressional warming ahead of the cold front will result in an unseasonably warm day tomorrow, with afternoon highs topping out in the mid and upper 70s.
Models continue to show a cold front moving across the Panhandle during the day on Thursday. A recent development in the 12Z NAM shows a closed low traversing southern New Mexico before lifting towards northern Texas. Models have greatly backed off on the strength of the weekend trough which was to bring our precip chances. As such, have continued the lowering trend from the previous forecast and removed precip mention entirely. Also, the weaker trough won't allow as much cold air to seep into the area. The result is above freezing temperatures on Christmas Eve, near normal temperatures for Christmas and beyond. A cold front is anticipated to drop across the Panhandles on Thursday which will start our temperature trend of being near normal for highs. The cooler highs will prohibit fire weather conditions.
Lows by sunrise will range from the upper 30s over the extreme north, to the lower and middle 40s elsewhere.
Once ridge moves off, will see this deck of clouds to begin advecting east towards forecast area.
129 PM MST Wed Dec 20 2017 Upper trough currently over the western coast moving SE into the UT/NV region. Cold frontal boundary will move south out of Wyoming around 2-3 am bringing a surge of cooler air and gusty winds. Temperatures overnight will dip into the lower 20s before the cold frontal push and not get above the mid 20s on the plains on Thursday. Amounts at this time will range from 4 to 8 inches over the mountains with locally up to a foot possible over the western facing slopes of the higher elevations. Positively tilted upper trof and low will continue to weaken and shear apart into New Mexico on Thursday night.
A cold front will move across KGUY and KDHT Thursday morning, and will impact KAMA just after this fcst period. Near-zonal flow today over the Texas and Oklahoma Panhandles becomes southwest tonight as a potent upper- level trof crosses the Great Basin and deepens into a closed low west of the four corners by early Thursday morning. Cold front on Thursday results in sharply cooler conditions, with highs ranging from the mid-30s in northwest sections to lower 60s southeast.
258 PM EST Wed Dec 20 2017 A ridge of high pressure will build across the region today.
A strong cold front will move across northern and central Nevada today bringing accumulating snow, gusty winds, and much colder temperatures. A strong cold front will move across northern and central Nevada today bringing accumulating snow, gusty winds, and much colder temperatures.
Locally for E Iowa/NW Illinois, subsidence associated with the high has led to quiet conditions so far tonight.
Should start to see areas of fog/freezing fog develop in the late evening and continue through the overnight until the cold front arrives. Surface temperatures will remain above freezing basically east of Hwy 83, but will drop to near or slightly below to the west of Hwy 83, so if fog develops it may be in the form of freezing fog or even light freezing drizzle. Cold front will blast through the western half of the forecast area between 09z and 12z, with a brief period of gusty northwest winds of up to 40kts possible with tight pressure gradient.
1237 PM EST Wed Dec 20 2017 VFR will give way to IFR cigs and MVFR vsbys after 06Z tonight as low clouds and patchy fog develops over the region as a cold front sinks south into the region.
/Issued 1202 PM CST Wed Dec 20 2017/ Forecast continues to be challenging as models are struggling with the low level moisture and clouds.
The effects will be short-lived, however, before more widespread southerly surface flow returns, ahead of the next upper-level trough, expected to advance across the Four Corners by Thursday morning.
643 AM EST Mon Jan 8 2018 Some patches of light snow and light freezing drizzle will taper and end by late morning. With the snow and freezing rain that fell last night, and given the cold ground temperatures, expect slick roads and sidewalks into midday.
1034 AM EST Mon Jan 8 2018 Clouds and a slow warm up after this low pressure system passes Tuesday morning.
The main upper trough currently over the Great Lakes will move off to the east today, with northwesterly flow aloft behind it. The models are all in pretty good agreement on bringing in some slightly colder air into mainly our northeastern counties as a backdoor cold front.
This should be watched closely though since temperatures will be at or below freezing. Would expect some slick spots on bridges/overpasses across SE OK if dense fog does manage to develop. Otherwise, a warming trend is expected during the day Tue as southerly sfc flow increases ahead of a closed low moving into SOCAL. Wind chills won't make it above freezing for most of the area, and a wind advisory may eventually be needed.
Upper ridging across the western CONUS will translate eastward today and tonight from the Rockies across the Plains. Temperatures will be a bit warmer as well with western portions of central Kansas likely around 60F on Tuesday.
A surface lee low/trough will develop by Tuesday ahead of the aforementioned Pacific system and temperatures should soar to much above normal levels as low level thermal ridging develops in downslope flow.
The front's associated area of low pressure will be moving east across Ontario today. Even though the Northland can expect partly to mostly sunny skies today with mild air temperatures in the low to upper 20s, wind chills will be substantially lower because of 10 to 20 mph winds. There could be wind gusts to nearly 30 mph in the higher terrain of the MN North Shore. Highs will reach the upper 20s and nearly the freezing mark thanks to southerly flow bringing in warmer air.
GOES-16 WV imagery shows the upper trough axis southeast of the forecast area with subsident and northwest flow regime overhead. Some high thin cloud is beginning to work into the area with spill over rounding the western CONUS ridge that has translated into Four Corners region. Points east near the KS/MO border likely see a bit cooler highs around 50. Monday night, winds increase and become breezy out of the south as upper flow transitions to a zonal regime and the lee trough becomes activated.
528 AM EST Mon Jan 8 2018 Low pressure will return wintry precipitation to the area today.
/issued 411 AM CST Mon Jan 8 2018/ The vast majority of the convection associated with the passing cold front has cleared out of southeast Texas at this hour with just a few trailing light showers across Jasper and Newton counties. Behind the front moderate northwesterly winds will develop which will usher in some slightly drier, although not appreciably cooler, air. Afternoon highs today will be comparable to yesterday with overnight lows tonight about 5 degrees cooler than we're seeing this morning.
A frontal system is still stalled along 130W this morning with its upper level trough stretching and splitting into 2 streams. Just to the east of this feature is another upper level trough and low pressure off south-central California coast that will bring moisture to northern California today.
A low pressure system advancing toward the California coast will pump moisture north across the region the next couple of days.
649 AM EST Mon Jan 8 2018 There will be increased moisture and a moderation in temperature associated with an onshore flow between the ridge shifting off the East Coast and low pressure moving from the Lower Mississippi River Valley into the northeast Gulf of Mexico through Tuesday. Upper trough will dig from the Mississippi Valley region today into the north-central Gulf Coast this evening. Temperatures tonight finally set to remain at or above freezing for entire cwa. Upper flow begins to flatten out across the cwa as the main upper low cuts off and moves into the northern Gulf of Mexico through the night. Tuesday and Tuesday night, best chance for rainfall will be across the extreme southern cwa, closer to the upper low moving through Florida.
641 AM EST Mon Jan 8 2018 WV imagery and RAP analysis indicated a mid/upper level trough from ne Manitoba into the wrn Great Lakes.
Have not heard of anything down near the TN border, but given that road temps are hovering near freezing on the main roads, its not out of the question there could be a few slick spots in rural areas. Looking at some road sensors temps, many are near freezing in IN. This is the area most likely to see temps fall below freezing before daybreak. However, confidence is not high on how far temps will fall and most areas should see air temps stay just above freezing. Some travel problems are still expected this morning, though ice accumulations will remain on the lower side - a few hundredths or less. Tuesday looks to be dry and warmer with highs in the 40s.
Surface temperatures will remain above freezing where precipitation occurs, so the winter weather advisory has been cancelled for the entire forecast area. With temps expected to be settling down into the upper 20s and lower 30s, areas of freezing fog or drizzle cannot be ruled out.
618 AM EST Mon Jan 8 2018 A cold front will move through the area today.
High pressure builds in today bringing gradually diminishing west winds. High pressure will build in from the west today.
The cold front has made it through most of South Texas with pressure rises reaching all the way toward the coast. Drier and cooler air will filter in behind the front today, but under mostly clear skies, temperatures should be able to warm into the upper 60s to even lower 70s this afternoon as H95 and H8 temps do not cool down drastically as with past fronts. Overnight, temperatures will feel chilly in the drier air, cooling into the low to mid 40s. Winds will become lighter for Tuesday as high pressure settles in later tonight. Small Craft Advisories are in effect for the bays and gulf waters in wake of an early morning cold front. High pressure will move east on Tuesday night with moisture return resuming.
Upper trough moving through the Mississippi River Valley and W Gulf this morning to move through the Central Gulf and become a closed low later today/tonight then sink into the SE Gulf Tuesday with associated upper energy keeping cirrus shield streaming over the Peninsula. At the surface, Western Atlantic high pressure to weaken today as low level moisture continues to increase off the Atlantic and expect slight chance for light rain in southern interior zones today. Weakening Gulf low pressure system to precede upper feature with winds veering SE Tuesday to combine for a slight chance of showers areawide with highest diurnal POPs in chance category over interior areas.
Temperatures are also a bit cooler than expected currently, so adjusted temperatures down into the upper 50s for the next couple of hours.
411 AM CST Mon Jan 8 2018 The vast majority of the convection associated with the passing cold front has cleared out of southeast Texas at this hour with just a few trailing light showers across Jasper and Newton counties. Behind the front moderate northwesterly winds will develop which will usher in some slightly drier, although not appreciably cooler, air. Afternoon highs today will be comparable to yesterday with overnight lows tonight about 5 degrees cooler than we're seeing this morning.
A ridge of high pressure will continue to build over the Northern Rockies today. Urban snowmelt will continue today with another day where temperatures rise above freezing. There still remains a threat for light freezing rain for the valleys of western Montana and north-central Idaho Tuesday morning. Though, this greatly depends on where the cool pools set up with the building ridge today. Confidence remains low with the freezing rain scenario.
Although a cold front will move through this morning, sky conditions will remain mostly clear. Winds will decrease around sunset tonight and become light and variable overnight as a high pressure system moves into the region. /issued 354 AM CST Mon Jan 8 2018/ SHORT TERM (Now through Tuesday): A cold frontal boundary and parent short wave were moving into the region from the north. As afternoon highs climb into the 70s and dew points drop into the 30s, expected RH values between 20-30 percent with the lower values in the northern Ranchlands. The ridge that has been sitting across the Baja will slowly begin to migrate eastward toward our general area. High pressure will be in control of our sensible weather throughout the remainder of the short term period with dry conditions expected.
Tuesday will be the last warm day of the week as Pacific trof moves across the west coast, knocking down the ridge. Main energy with the initial trof will be moving through the desert southwest but northern portion of the trof will pull arctic air southward along the front range.
Further west, an area of fog has developed immediately ahead of the cold front, with visibilities in west central Illinois falling below a mile as far northeast as Peoria. This should be a fairly short lived event, generally only 2-3 hours with the lower visibilities in any given area, so will handle this with a Special Weather Statement. Otherwise, temperatures will rebound again late morning behind the front, and most areas should stay above freezing during the afternoon. Concern will shift toward some fog potential tonight, as high pressure settles southeast across Illinois.