Aikyam-Lab/Synoptic-Bench huggingface dataset:
255 AM MST Sat Feb 13 2021 Cold upper low continues to slowly meander south and east across southern Canada. Broadly cyclonic flow persists across the upper half of the US with embedded perturbations streaming along the southern periphery of this low.
KGWX WSR-88D radar trends and METAR observations indicate freezing rain has ended across this aforementioned area and the Winter Weather Advisory was cancelled.
439 AM CST Sat Feb 13 2021 The forecast has been on repeat lately, with a large upper low over the region along with a pool of cold air that has kept temperatures below zero at the surface for most of the last several days. The inverted trough appears to lift north through the day today so have gradually removed the flurries from the forecast, but would not be surprised if they need to be put back in at some point.
522 AM CST Sat Feb 13 2021 The forecast has been on repeat lately, with a large upper low over the region along with a pool of cold air that has kept temperatures below zero at the surface for most of the last several days. The inverted trough appears to lift north through the day today so have gradually removed the flurries from the forecast, but would not be surprised if they need to be put back in at some point.
a combination of ground reports and weak radar returns suggest accumulating freezing rain/drizzle has developed over eastern Tucker County. Upper flow is backing to the southwest in response to a digging trough over the central CONUS. Light freezing rain or drizzle is also possible though given the moist sfc layer, but confidence in problematic ice accumulation is low at moment, so no advisory will be issued for now.
and Sunday A short wave trough rotating around the cold upper low east of Lake Winnipeg combined with low level warm advection will produce some snow across the area today.
Arctic high pressure will center itself over our CWA today and tonight, and with this the coldest air mass of the pattern. Before that, northerly flow will still be in place Sun night into Mon, with high pressure centered over the forecast area.
650 AM EST Sat Feb 13 2021 A warm front lifting north today brings some light snow over Central NY and mixed precipitation to NE PA late this afternoon through the overnight hours. Made some changes to the ptypes overnight to increase the chance of some freezing drizzle over southern NE PA and Sullivan and Pike counties. A warm front lifts north into our region late today into the overnight hours providing some weak isentropic lift with QPF amounts amounting to a few hundredths of an inch. Right now NE PA will have the warmest clouds but still below freezing through the column with patchy freezing drizzle mixing with the light snow grains at times especially across some of the higher terrain.
The higher amounts will be in the southern Bitterroot Valley from Hamilton to Darby.
303 AM MST Sat Feb 13 2021 Fine scale features dominating the weather picture overnight where clear skies are allowing temperatures to fall below -20 along a White Sulphur Springs to Billings To Broadus axis, cloud cover north and south of this axis is keeping temperatures a bit warmer. Tonight does look to favor eastern areas to be the cold spot as the stratus over the area retreats late today and the high clouds remain west of the area. As a result early this morning may be the coldest readings of the outbreak for Billings with warmer temperatures tomorrow morning.
446 AM MST Sat Feb 13 2021 Latest WV/IR imagery showed the polar vortex over south-central Canada with its associated trough extending south through the Plains. A weakening upper low was moving east over far northern Mexico. With snow the primary hazard to travel, opted not to issue Wind Chill Advisories and mention the lowest wind chill temperatures in the Winter Weather Advisory products.
Surface temperatures will be well below freezing during this timeframe, while 850mb temperatures are well above freezing. Due to these factors, sleet and freezing rain will likely begin past 1AM Sunday.
Cold upper low continues to slowly meander south and east across southern Canada. Broadly cyclonic flow persists across the upper half of the US with embedded perturbations streaming along the southern periphery of this low.
226 PM CST Sat Feb 13 2021 Just enough moisture at the low levels, and daytime heating have helped produce a few more clouds this afternoon flurries mainly over portions of central SD.
Temperatures slowly warming above freezing across the advisory areas and dynamic forcing/mainly isentropic moving east as well. CDG Chattanooga Airport, TN 43 36 45 37 46 / 70 20 40 50 60 Knoxville McGhee Tyson Airport, TN 42 35 43 37 44 / 80 20 40 50 60 Oak Ridge, TN 42 33 41 35 41 / 60 20 30 50 60 Tri Cities Airport, TN 45 36 44 37 47 / 90 30 40 40 40.
Across our Plateau, some warmer air may allow rain to occur for an uncertain duration. The freezing drizzle has ended and that allowed for the advisory to terminate at 18Z as scheduled. Thus, sleet and freezing rain will be the main types.
The upper-level trough that will be the main player in the upcoming event is currently entering the four corners region. This trough will deepen and continue eastward towards the region. As the upper trough and associated front nears, lift over the area will increase. This low liquid content will allow for the formation of very dry snow, which will blow around easily and cause drifts.
331 PM EST Sat Feb 13 2021 A longwave trough axis extends southeast from near British Columbia to Central America. Temperatures are in the lower to mid 80s with dewpoints in the mid 70s.
Coldest of the airmass over the area tonight so would expect lows to be every bit as cold as last nights if not a few degrees cooler.
We did receive some reports of freezing drizzle and a few flurries in our northwest. Freezing drizzle is possible thru 15z, also.
Isentropic lift/theta-e advection will start to increase across the High Plains this evening and shift east late tonight into Mon morning. Long wave trough will remain over the central CONUS on Tue with yet another impulse tracking across the Desert Southwest and is anticipated to dig across northwest Mex for Tue night into Wed. By Thu afternoon, upper trough will be pushing east of the Plains with upper ridging over the Rockies.
Ongoing winter storm will send a cold front across western Idaho before noon and south-central Idaho mid afternoon. At 9 AM MST KCBX radar at Boise showed enhanced returns in western Idaho, likely indicating the approaching cold front.
Reports of any freezing drizzle have ceased. CSV LIFR with periods of light freezing drizzle through 20Z.
1205 PM CST Sat Feb 13 2021 The forecast has been on repeat lately, with a large upper low over the region along with a pool of cold air that has kept temperatures below zero at the surface for most of the last several days. The inverted trough appears to lift north through the day today so have gradually removed the flurries from the forecast, but would not be surprised if they need to be put back in at some point.
At the surface, a 1046 mb center of high pressure was located over south central Saskatchewan early this afternoon. As mentioned in the previous forecast package, the high pressure center would ideally track a bit further southeast overnight for us to see a record low at Bismarck. The one exception will be across the southwest where we may reach zero or a couple degrees above as the center of high pressure moves out.
Snow levels along and west of the I-15 corridor remain above the valley floors, and that should remain the case through much of the afternoon as although the 700mb trough crosses the area midday, cold air is slow to work its way into the area and may not see a changeover in the valleys until late afternoon and/or sunset. As the trough axis pushes east by this evening moist northwest flow will provide a favorable environment for orographic snowfall along the I-15 corridor through central and southwest Utah, and potentially extending northward into the central and southern Wasatch as well. Confidence is a bit low with respect to this idea, but will closely monitor how the trough evolves today and subsequent model runs before further addressing with the afternoon package.
Temperatures slowly warming above freezing across the advisory areas and dynamic forcing/mainly isentropic moving east as well.
In the lower levels, much of the area remains in northerly flow at the surface in the wake a surface front that remains parked off the coast through the period. An area of weak low pressure along the stalled front develops off the coast south of the region and slowly lifts northeast and then meanders around the coast and Florida panhandle through the rest of the period. On Sunday, will see high temperatures in the low 40s to low 50s northwest of the I-65, and low 50s to upper 50s southeast.
1044 AM MST Sat Feb 13 2021 Latest WV/IR imagery showed the polar vortex over south-central Canada with its associated trough extending south through the Plains. A weakening upper low was moving east over far northern Mexico. With snow the primary hazard to travel, opted not to issue Wind Chill Advisories and mention the lowest wind chill temperatures in the Winter Weather Advisory products.
1049 AM EST Sat Feb 13 2021 A long wave trough axis extends southeast from near British Columbia to west of Central America. The Florida Keys remain within the tropical soup, with temperatures in the lower 80s and dewpoints in the lower to mid 70s. Visible satellite loops reveal cumulus streamers which are anticyclonic, placing the Keys right along the western extent of the low-level ridge axis. From synopsis, the Florida Keys will remain between the influence of a high pressure system over the Atlantic and a cold front over the Gulf of Mexico.
/issued 1001 AM CST Sat Feb 13 2021/ Low stratus continues to blanket all of the Ark-La-Tex this morning, and surface temperatures remain below freezing almost everywhere except for our southern zones.
1231 PM EST Sat Feb 13 2021 A warm front lifting north today brings some light snow over Central NY and mixed precipitation to NE PA late this afternoon through the overnight hours. Made some changes to the ptypes overnight to increase the chance of some freezing drizzle over southern NE PA and Sullivan and Pike counties. A warm front lifts north into our region late today into the overnight hours providing some weak isentropic lift with QPF amounts amounting to a few hundredths of an inch. Right now NE PA will have the warmest clouds but still below freezing through the column with patchy freezing drizzle mixing with the light snow grains at times especially across some of the higher terrain.
1012 AM EST Sat Feb 13 2021 A warm front lifting north today brings some light snow over Central NY and mixed precipitation to NE PA late this afternoon through the overnight hours. Made some changes to the ptypes overnight to increase the chance of some freezing drizzle over southern NE PA and Sullivan and Pike counties. A warm front lifts north into our region late today into the overnight hours providing some weak isentropic lift with QPF amounts amounting to a few hundredths of an inch. Right now NE PA will have the warmest clouds but still below freezing through the column with patchy freezing drizzle mixing with the light snow grains at times especially across some of the higher terrain.
Expansive high pressure centered over Atlantic and a stationary boundary draped across northern FL will help to maintain generally southerly flow across South Florida the remainder of the weekend. Sunday looks similar to today with a slight potential to be a bit more unsettled, especially across Palm Beach County and the Lake Okeechobee region as broad troughing shifts eastward, enhancing southwesterly flow aloft. The mid to upper level trough over the Southeastern United States will weaken while moving east allowing for another mid to upper level trough to work into the Central United States from the west.
We did receive some reports of freezing drizzle and a few flurries in our northwest. CSV LIFR with periods of light freezing drizzle through 20Z.
High pressure remains near the Bahamas, providing southerly flow and bringing increased moisture surges into east central Florida. Afternoon highs expected to reach the low to mid 80s, which is about 10 degrees above average across the area.
248 PM EST Sat Feb 13 2021 Earlier widespread showers continue to lift northeastward as the departing low pressure exits away from the forecast area.
301 PM EST Sat Feb 13 2021 A warm front lifting north this evening brings some light snow over Central NY and mixed precipitation to NE PA through the overnight hours.
Return flow will increase Sunday as high pressure continues to slide off to our east and pressure gradient overhead tightens.
This is keeping clouds socked in, and resulting in some light freezing drizzle and drizzle, depending on temperatures. Most of the area is at or below freezing, with the exception of a few places in the extreme south and southeast. Similar to Saturday, most of the area should not get above freezing on Sunday. In the southeast part of the forecast area, where the POP is the lowest, the precip type is more certain to be freezing rain. In the northwest part of the forecast area where the POP is the highest, a mixture of freezing rain, sleet and snow is more likely, with uncertainty as to exactly where transitions will occur.
Just enough moisture at the low levels, and daytime heating have helped produce a few more clouds this afternoon flurries mainly over portions of central SD.
Widespread snow is expected tonight decreasing some from north to south Sunday as an upper level trough approaches the area. Its also where the highest snow accumulations are expected with 4 to 7 inches.
929 PM EST Sat Feb 13 2021 High pressure will remain to our northwest, while waves of low pressure ride up the coast from the Deep South. The steady period of sleet and freezing rain has ended in our CWA. What is left of concern will be the chance for freezing drizzle across a large portion of our CWA. Not all zones will have this freezing drizzle, but the advancement of some drier air in the mid-levels with low-level moisture will lead to some areas getting affected by it. We will be between waves of low pressure on Sunday. There could still be some freezing drizzle in places early Sunday morning. Temperatures are expected to rise above freezing by late morning across much of the area. Another weak wave of low pressure will pass off the North Carolina coast Sunday night.
With temps forecasted to be below freezing at KAEX, the possibility of frozen precipitation cannot be ruled out. Temperatures across the region are in the lower to mid 40s except upper 30s/near 40 across Central Louisiana. With temperatures expected to fall near freezing across Central Louisiana, may see some light icing on elevated roadways and bridges, but expect only very light accumulations.
832 PM EST Sat Feb 13 2021 Freezing drizzle and freezing fog is expected to wrap up early tomorrow morning under building high pressure.
High pressure was building across the Northern Plains this afternoon as an area of low pressure was over northern Lake Superior with a trough extending northwestward to the Thunder Bay area and into far northwestern Ontario. Think we are too warm in spots across northern Minnesota into the Arrowhead, but lingering cloud cover and a tightening gradient between the low over Lake Superior and the high over the Northern Plains will keep winds up through the night and may temper optimal radiational cooling conditions. Again started with the 10th percentile lows, but will probably need to be cooler in traditional cold spots.
Expect rain and snow to spread eastward and continue through the evening and overnight as a cold front advances southeastward. Behind the front, expect upslope showers to continue along the high terrain of the Mogollon Rim and in the White Mountain Region through the afternoon Sunday.
752 PM EST Sat Feb 13 2021 Adjusted for an earlier onset of freezing drizzle further northwest, but without any substantive change to the night's forecast as a whole. This is keeping clouds socked in, and resulting in some light freezing drizzle and drizzle, depending on temperatures. Most of the area is at or below freezing, with the exception of a few places in the extreme south and southeast. Similar to Saturday, most of the area should not get above freezing on Sunday. In the southeast part of the forecast area, where the POP is the lowest, the precip type is more certain to be freezing rain. In the northwest part of the forecast area where the POP is the highest, a mixture of freezing rain, sleet and snow is more likely, with uncertainty as to exactly where transitions will occur.
Temperatures across the region are in the lower to mid 40s except upper 30s/near 40 across Central Louisiana. With temperatures expected to fall near freezing across Central Louisiana, may see some light icing on elevated roadways and bridges, but expect only very light accumulations.
/Issued 248 PM EST Sat Feb 13 2021/ Earlier widespread showers continue to lift northeastward as the departing low pressure exits away from the forecast area.
Gusty easterly winds appear to persist this afternoon through the overnight hours tonight for the valleys along the Continental Divide to the Highway 93 corridor.
Satan Shoal and Pulley Ridge buoys are respectively reporting 3- and 4-foot seas this evening.
Wide range of conditions across East Idaho tonight, from dangerously cold wind chills in arctic airmass along the Divide, to patchy freezing fog, to persistent light snow, to very strong gusty winds producing blowing snow concerns along major interstate corridor.
Light snow across our CWA has been gradually tapering off this evening as weak short wave ridging builds in.
1122 PM EST Sat Feb 13 2021 Freezing drizzle and freezing fog is expected to wrap up early tomorrow morning under building high pressure.
The main area of concern is the northern Plateau, where temperatures may be cold enough for some freezing drizzle or freezing fog, resulting in some slick spots. Some scting of the lowest cloud deck is possible on Sunday which could support MVFR at TYS, less likely at TRI. CDG Chattanooga Airport, TN 44 39 45 31 40 / 10 50 80 90 0 Knoxville McGhee Tyson Airport, TN 43 37 44 32 38 / 10 60 70 90 10 Oak Ridge, TN 42 36 41 29 38 / 20 60 70 90 10 Tri Cities Airport, TN 45 39 49 37 40 / 10 30 40 90 20 TN.
Surface temperatures will be dropping to freezing over Choctaw and Wayne counties late Sunday night, and after considering model soundings see the potential for a mix of freezing rain and rain, possibly solely freezing rain. Lows for tonight range from the lower to upper 30s generally along and west of I-65 with lower to upper 40s further to the east. Lows Sunday night predominately range from the lower to upper 30s along and west of I-65 with lower to upper 40s east of I-65.
A trough of low pressure will continue to move eastward across Arizona tonight and Sunday. The cold front is draped west to east across central Arizona south of I-40 this evening. The trough of low pressure over northern Arizona will continue to eastward tonight and Sunday. Behind the front, expect upslope showers to continue along the high terrain of the Mogollon Rim and in the White Mountain Region through the afternoon Sunday.
Also of concern across the region will be the below freezing temperatures making for icy conditions overnight. Current winter storm is ending as a cold front moves across southern Idaho. A Winter Weather Advisory has also been posted for the lower elevations including the Treasure Valley and western Magic Valley for late Sunday night through Monday morning. A warm front will pass through Monday morning and temperatures will rise to near 40 degrees soon after at the lower elevations, which will change the snow to rain below 4000 feet and cause a mess due to slush and melting snow.
Widespread snow is expected tonight decreasing some from north to south Sunday as an upper level trough approaches the area. Its also where the highest snow accumulations are expected with 4 to 7 inches. snow chances come to an end as the upper trough axis slowly moves east taking any appreciable moisture for precipitation with it.
The Evening Update: Cloud cover expected to increase over the CWA overnight as moisture spreads SEwd, over the top of the Ern Pac ridge. Warm frontal precip forecast to move into our CWA beginning Sun afternoon and spreading over the CWA Sun nite followed by the cold front and upper dynamics on Mon.
The high ratios are expected to occur late in the event, or basically Sunday evening into Monday morning.
Just enough moisture at the low levels, and daytime heating have helped produce a few more clouds this afternoon flurries mainly over portions of central SD. Upper low over the Western Lakes region and associated mid-CONUS upper trough weaken and begin to migrate east.
Several reports of patchy freezing drizzle coming in this evening, with even some freezing fog along the Plateau. LIFR conditions at CSV with periods of freezing fog through 09Z.
Several reports of patchy freezing drizzle coming in this evening, with even some freezing fog along the Plateau.
gusty winds in association with a cold front crossing the state. The upper level trough will gradually shift away from the region.
Guidance has shown a decrease in qpf over the lower elevations for today. max temps will only be in the low single digits over most of the plains this afternoon. All the highlights for this region remain "as is". Warmer temperatures will overspread a good part of the plains with 30s and L40s along the mtns/plains interface, with lingering colder air over the far eastern plains, where 20s will continue. Over the mtns and valleys snow will once again become likely as another broad trough approaches the region. Another deep trough will be over the area. Max temperatures will be at or below freezing region-wide this day, with a chance of snow over most regions (least chance far eastern plains).
311 AM CST Sun Feb 14 2021 Arctic high pressure to the northwest will bring more frigid temperatures and bitterly cold wind chills to central and southeast Illinois, for today and Monday. 1043 mb Arctic high pressure was centered over the northern Plains early this morning. This should result in a widespread 2-4" snowfall, with the higher amounts southeast of the IL River.
The impressive area of upper level low pressure, currently just east of the Four Corners region will continue to dig southeast and sharpen as we move through the daylight hours. The center of the low has closed over the Four Corners region and seems to be outperforming model guidance. There will be stronger bands responsible for increased snowfall rates locally, especially later this morning and early afternoon, as the base of the closed low/trough draws closer from the west and isentropic lift increases. North-northeast surface winds will increase late this afternoon into the overnight hours as the trough axis pivots east across our latitude this evening.
458 AM MST Sun Feb 14 2021 A few of the highlighted areas (mainly across northern slopes / latitudes as well as portions of West Elk / Sawatch Mountains) sit on the low end of criteria as of early this morning. The trough axis and associated cold front is evident from surface and remote sensing observations this morning.
Currently, Arctic High pressure is situated over central portions of Lake Sakakawea. Upper level low is over southwest Ontario.
After warmer than normal lows tomorrow morning, surface winds will shift from the east to southeast and south by tomorrow afternoon as the wedge weakens across the area, this pattern will bring warmer temperatures across even as the low clouds persist.
Overnight lows will drop into the low 60s across the far north, and mid to upper 60s across the rest of the area.
While minimal precipitation can be expected, low cloud cover over the higher elevations of Tulare and Kern Counties may produce areas of low visibility through parts of this Sunday morning.