Aikyam-Lab/Synoptic-Bench huggingface dataset:
High pressure continues to influence conditions this evening, and will continue into the overnight hours. An approaching area of low pressure will move into eastern Oregon later tonight, but is expected to have little to know impact to area weather other than briefly resulting in cooler temperatures on Friday.
345 AM EST Fri Dec 4 2020 Precipitation chances return south of I-70 today followed by periodic flurries along the I-80 corridor and in the ridges through the weekend. The remainder of the weekend will be largely dry with occasional light snow / flurries along the I-80 corridor and in the ridges with cold northwesterly flow and just enough moisture and lift in the boundary layer. Temperatures will slowly trend up in the extended as upper troughing through the first half of the week will gradually transitions to a more progressive/zonal pattern. Cigs will deterioration this morning as warm, moist air advances with an approaching trough from the south.
157 AM MST Fri Dec 4 2020 Not much change from the previous forecast as anomalously strong ridge of high pressure moves slowly E across the area.
An area of low pressure develops over the northern gulf coast by Friday evening and moves northeastward through the southeast U.
An elevated nrly flow will remain in place through the night and through much of Friday before high pressure approaches and winds settle. /issued 413 PM CST Thu Dec 3 2020/ The cold front has remained stalled today across south central Louisiana with temperatures in the upper 60s to lower 70s generally east of the Mississippi river and 50s to the west. Cooler temperatures on tap for tomorrow morning with lows around 40 or so. winds will relax as the high settles in and the the gradient loosens.
1028 PM MST Thu Dec 3 2020 The CWA was sandwiched between a upper ridge over the western CONUS and upper trough from the Great Lakes to the southern Great Plains. Some thin cirrus clouds were spreading northeast to southwest over the high plains.
239 AM EST Fri Dec 4 2020 Precipitation chances return south of I-70 today followed by lingering flurries along the I-80 corridor and in the ridges through the weekend. The remainder of the weekend will be largely dry with occasional light snow / flurries along the I-80 corridor and in the ridges with cold northwesterly flow and just enough moisture and lift in the boundary layer. Temperatures will slowly trend up in the extended as upper troughing through the first half of the week will gradually transitions to a more progressive/zonal pattern. Cigs will deterioration this morning as warm, moist air advances with an approaching trough from the south.
/NEW/ /Through Friday Night/ Low clouds will continue to clear from west to east overnight as large scale subsidence increases behind a departing upper low.
High pressure continues to influence conditions this evening, and will continue into the overnight hours. An approaching area of low pressure will move into eastern Oregon later tonight, but is expected to have little to no impact to area weather other than briefly resulting in cooler temperatures on Friday.
Overnight conditions bringing clear skies and light winds but any fog potential appears to be to the southeast as warm/dry advection occurs in the lower levels. This WAA brings a warmer day today and have sided with the warmer end of guidance given recent cool biases.
Have mixed in a bit of the raw guidance to get a better handle on the temps behind the exiting trough. So far, the forecast has drier air and 30s dewpoints working into the region overnight with the cooler temps.
Low pressure located over southern MO will lift to the NE today with skies clearing from west to east as drier air works in. VFR conditions are expected at all terminals by early afternoon with winds generally light as high pressure settles in. Upper pattern over the region this morning is characterized by a positively tilted trough extending from eastern Oklahoma northeast into the Ohio valley. All short term/high res models agree in moving this trough/low to the east and into southern Illinois by late morning. Otherwise, upper pattern across the CONUS features ridging over the west with an extension of the positively tilted trough into the desert southwest. Another upper low, currently over northern Mexico will lift out and be located over eastern Texas by the end of the period.
An area of low pressure develops over the northern gulf coast by Friday evening and moves northeastward through the southeast U. The associated cold front will move through the Florida peninsula bringing increasing rain chances Friday evening through early Saturday morning, with the highest coverage over the Nature Coast and eastern gulf waters. High pressure builds back in by Saturday afternoon bringing clearing conditions and cooler air for the weekend.
It should wind up about 10 degrees warmer than yesterday.
That chance will persist in the ridges through the weekend. The remainder of the weekend will be largely dry with occasional light snow / flurries along the I-80 corridor and in the ridges with cold northwesterly flow and just enough moisture and lift in the boundary layer. Temperatures will slowly trend up in the extended as upper troughing through the first half of the week will gradually transitions to a more progressive/zonal pattern. Condition deterioration is confidently forecast today as a cold front encroaches from the north and as low pressure crosses the Virginias and shunts moisture and precip over areas south of PIT.
Weak sfc ridging moving in tonight should allow some shallow radiation fog development into early Saturday. This period looks quiet with a western upper level ridge slowly shifting east into the central/southern Plains by the end of the period.
79 Previous Discussion: /Through Friday Night/ Low clouds will continue to clear from west to east overnight as large scale subsidence increases behind a departing upper low.
425 AM MST Fri Dec 4 2020 Latest upper air analysis shows a long wave ridge building onto the Plains. To the south the long wave trough continued to slowly move southeast. Satellite imagery shows a clear sky over the western half of the CONUS where the ridge is in place. Due to WAA occurring as the ridge slowly builds in, highs will be warmer today than yesterday. After midnight a weak cold front will move through as a shallow upper level short wave trough moves overhead. Due to moisture advection behind the front lows will be warmer than last night. Saturday highs will be a few degrees cooler than today due to the cooler air mass in place.
Highly amplified flow persists across the Plains as deeper troughing continues to dominate the eastern CONUS with ridging building back in across the west. With the aforementioned ridging redeveloping upstream and nosing into the local area by the weekend, we'll see fairly mild temperatures return to much of western and central Nebraska. Slightly cooler on Saturday as we lose a few degrees aloft with a plume of cooler Canadian air working in.
525 AM CST Fri Dec 4 2020 (Today and tonight) Patchy fog (freezing fog) will be seen across the region this morning, with most of the fog confined to low lying areas.
The latest upper level analysis reveals a split flow pattern that almost gives appearance of rex block given weak upper low beneath amplified ridge over the western CONUS. This low which is just south of AZ/NM border will become cutoff from mean flow and track northeast across TX through Saturday night, staying south of the TX and OK Panhandles.
658 AM CST Fri Dec 4 2020 While the backdoor cold front has moved into our northwest MN counties the post frontal stratus has been slower to spread west, and latest guidance is backing on on how far west it will get and how long it will persist. Ridging remains well entrenched across the western us into Canada and the Northern Plains, with influence continuing to support above average temperatures and quiet weather across our CWA. A backdoor cold front should stall this morning, with low clouds behind this front spreading mainly across northwest MN (high clouds increasing further west). This would impact temperatures this afternoon with locations under the stratus struggling to reach 30 (closer to seasonal average) and locations west of the stratus possibly reaching the low 40s.
The region comes under the influence of western ridging aloft and mid level warm air advection during the day.
357 AM MST Fri Dec 4 2020 Upper level ridge will continue to build into Colorado today, as old upper low sinks south through TX. Did keep snow covered areas of the far sern plains slightly cooler than blended guidance another day, especially ern Las Animas and Baca counties.
Elongated vortmax centered over southern MO this hour will get a push eastward as a longer-wave trough dives into the Midwest. By Saturday morning, high pressure will begin building in from the west as deep layer dry air advects in overhead resulting in clearing skies throughout the afternoon.
Low pressure was centered over northwest Mexico this morning, heading eastward.
Despite ample sunshine and weak surface winds, temperatures will be at or slightly cooler than normal this afternoon with our forecast area on the north side of the upper level shear axis that ultimately extends into the Ohio River Valley. By this evening the upper level low in northern Mexico will begin to shift northeast into West Texas and increase cloud cover from the south to north later tonight into Saturday morning.
Low level convergence and thus light rain/drizzle associated with an inverted surface trof will continue over southern parts of the Purchase and Pennyrile areas of western KY through 12Z or so as the parent mid level low over southern MO gradually moves eastward. trof departs and broad Central U. ridging works overtop the PAH FA. The NBM is bullish on this ridging, driving its temps upwards to the 75th percentile of the envelope of model guidance as this metamorphosis occurs. This looks to be a mostly dry period, though there is some collaborative interest expressed in adding trace or low qpf pops on the front end of the package as the aforementioned trof spins out, before the broad ridging takes over.
(Today and tonight) Clear and cold morning ongoing across West Central Texas with temperatures falling into the lower 20s already in some areas. Upper low over northern Mexico will move slowly southeast tonight, with models showing increasing cloud cover across the areas of the Edwards Plateau and Concho Valley by morning.
A weak warm front is right along the coast and will remain south of the area through mid morning. A secondary low pressure system may develop late morning and could pull the warm front northward by midday.
An upper level trough over Texas will split today, with the northern portion forming a cut off low to the northeast and the southern portion forming a cut off low over northern Mexico. A mid level ridge will develop between these two lows, keeping us dry. Mostly sunny skies will develop through the day today, leading to slightly warmer temperatures today. Light northerly winds will become variable then southeast as the low over Mexico shifts over west Texas Friday night.
243 AM MST Fri Dec 4 2020 A warm & dry weekend ahead for the central Rockies w/ broad upper- level ridging remaining anchored over much of the western US. Temperatures continue to trend warmer today with day- time highs in the mid/upper 50s for areas along and east of I-25 & low to mid 40s over our western zones. Saturday should be slightly cooler w/ the passage of a weak cold front, but generally speaking it will be another mild day.
531 AM CST Fri Dec 4 2020 (Today and tonight) Clear and cold morning ongoing across West Central Texas with temperatures falling into the lower 20s already in some areas. Upper low over northern Mexico will move slowly southeast tonight, with models showing increasing cloud cover across the areas of the Edwards Plateau and Concho Valley by morning.
422 AM CST Fri Dec 4 2020 An increasingly complex upper level pattern has developed with a main trough over the Great Lakes, a low over Missouri and another west of West Texas. The low centered near MO is driving the cold front currently tracking east through the CWA. The MO low will be drawn eastward with the main trough over the Great Lakes on Friday night into Saturday. The low currently west of Texas will track across that state, moving into LA and MS late this weekend.
547 AM MST Fri Dec 4 2020 In addition to a ridge across the Rockies there is a compact upper low that pulls into southeast Idaho today, and then back westward on Saturday. Under high pressure winds will be light in most locations except today across southeast Fremont and Natrona where a common southwest breeze will be observed. Have kept those areas on the low end of the guidance or even cut a few degrees below that.
650 AM EST Fri Dec 4 2020 A strong upper closed low will rotate from the lower MS River Valley into the southern Appalachians during the short term. there could be some instability developing mainly this afternoon as the warm front tries to move north.
543 AM CST Fri Dec 4 2020 Quiet weather continues with warmer than normal temperatures.
345 AM CST Fri Dec 4 2020 Low level convergence and thus light rain/drizzle associated with an inverted surface trof will continue over southern parts of the Purchase and Pennyrile areas of western KY through 12Z or so as the parent mid level low over southern MO gradually moves eastward. trof departs and broad Central U. ridging works overtop the PAH FA. The NBM is bullish on this ridging, driving its temps upwards to the 75th percentile of the envelope of model guidance as this metamorphosis occurs. This looks to be a mostly dry period, though there is some collaborative interest expressed in adding trace or low qpf pops on the front end of the package as the aforementioned trof spins out, before the broad ridging takes over.
430 AM MST Fri Dec 4 2020 A warm & dry weekend ahead for the central Rockies w/ broad upper- level ridging remaining anchored over much of the western US. Temperatures continue to trend warmer today with day- time highs in the mid/upper 50s for areas along and east of I-25 & low to mid 40s over our western zones. Saturday should be slightly cooler w/ the passage of a weak cold front, but generally speaking it will be another mild day.
Accumulating snow to affect the higher terrain of west Texas We are looking at an interesting winter weather situation overnight into Saturday for portions of the area! An upper low has cut off from the main jet stream and settled over N. We won't see much of an effect from the upper low initially this afternoon other than increasing clouds across southern areas. This system will be moisture-starved, but enhanced lift associated with the low should compensate somewhat. Forecast soundings show rain in the lower elevations with snow above 3-4 Kft where models indicate saturation within the dendritic growth zone. A deformation band is expected to develop on the north side of the upper low as it moves across the Big Bend Saturday morning. Skies will clear Saturday night as the upper low continues east across Texas.
351 AM MST Fri Dec 4 2020 Latest upper air analysis shows a long wave ridge building onto the Plains. To the south the long wave trough continued to slowly move southeast. Satellite imagery shows a clear sky over the western half of the CONUS where the ridge is in place. Due to WAA occurring as the ridge slowly builds in, highs will be warmer today than yesterday. After midnight a weak cold front will move through as a shallow upper level short wave trough moves overhead. Due to moisture advection behind the front lows will be warmer than last night. Saturday highs will be a few degrees cooler than today due to the cooler air mass in place.
The upper low is currently south of the bootheel and continuing to move south into north central Mexico. No worries though as a warm-up is forecast with plenty of sunshine today and temperatures 5 to 15 degrees warmer than yesterdays, though still below normal for most locales. Temperatures will generally range from 5 to 10 degrees above normal through mid-week, as a "dirty ridge" builds west of the state. However, the low continues to undercut the ridge Saturday/Saturday night, bringing nothing more than additional cloud cover and maybe a few sprinkles to the southern portion of the state.
A PV trof southeast of the area is producing some showers in the Ohio River valley while a dominating ridge continues over the Rockies. That persistent ridging over the western CONUS leaves Nebraska and Iowa under dry northwesterly flow.
and Saturday A weak cold front will move across the area today and produce some clouds and maybe some virga or flurries at best. Despite the passage of a cold front, highs today and Saturday will be around five degrees above normal.
(Today and tonight) Patchy fog (freezing fog) will be seen across the region this morning, with most of the fog confined to low lying areas.
The low clouds that formed yesterday morning in the Mission Valley stuck around much of the day keeping high temperatures from rising and the clouds spread north into the Flathead Valley last evening. From the southern third of Flathead Lake south to Ronan, dense freezing fog has been observed.
On Saturday the Midwest becomes situated between a longwave upper- level trough over the eastern U. and a longwave upper-level ridge over the western U. The departure of a cutoff low interacting with the upper-level trough will also allow large- scale subsidence via mid-level height falls to momentarily dominate the region and provide mostly clear skies Saturday.
Ridging remains well entrenched across the western us into Canada and the Northern Plains, with influence continuing to support above average temperatures and quiet weather across our CWA. A backdoor cold front should stall this morning, with low clouds behind this front spreading mainly across northwest MN (high clouds increasing further west). This would impact temperatures this afternoon with locations under the stratus struggling to reach 30 (closer to seasonal average) and locations west of the stratus possibly reaching the low 40s.
511 AM EST Fri Dec 4 2020 Precipitation chances return south of I-70 today followed by periodic snow showers along the I-80 corridor and in the ridges through the weekend. The remainder of the weekend will be largely dry with occasional light snow / flurries along the I-80 corridor and in the ridges with cold northwesterly flow and just enough moisture and lift in the boundary layer. Temperatures will slowly trend up in the extended as upper troughing through the first half of the week will gradually transitions to a more progressive/zonal pattern. Cigs will deterioration this morning as warm, moist air advances with an approaching trough from the south. A new trough over the Great Lakes will return colder air into region late Friday/early Saturday.
A convoluted pattern downstream of an upstream blocking ridge was portrayed with several seemingly dissociated systems in a broad upper trof bounded over the eastern CONUS. Some ridging will increase the west to east upper flow and help temperatures rise a little more into the mid 40s; otherwise, no significant weather is expected. A positively tilted upper level trough across the lower MS Valley will shift across the Tennessee Valley today which will eventually suppress better low level moisture transport south of northern Indiana today. Otherwise, Great Lakes upper trough sinking southeast will allow sfc cold front to drop across northern Indiana this afternoon. Southwest winds may gust into the 15 to 20 knot range preceding the front for a few hours late morning into early afternoon before sfc pressure gradient slackens with the approaching trough.
407 AM MST Fri Dec 4 2020 Upper ridge will dominate over the northern Rockies through the weekend, keeping warm and dry conditions over the region.
Upper pattern over the region this morning is characterized by a positively tilted trough extending from eastern Oklahoma northeast into the Ohio valley. All short term/high res models agree in moving this trough/low to the east and into southern Illinois by late morning. Otherwise, upper pattern across the CONUS features ridging over the west with an extension of the positively tilted trough into the desert southwest. Another upper low, currently over northern Mexico will lift out and be located over eastern Texas by the end of the period.
Clearer skies will allow for radiational cooling and we could see temperatures dropping near freezing in the northern parts of the CWA. Our next chance of rain will be over the weekend as a closed upper level low moves across Texas and into the Arklatex region. Despite this feature, drier air and northerly flow keep POPs onshore low (10-30%) with the highest POPs concentrated offshore (20-40%).
A convoluted pattern downstream of an upstream blocking ridge was portrayed with several seemingly dissociated systems in a broad upper trof bounded over the eastern CONUS. Some ridging will increase the west to east upper flow and help temperatures rise a little more into the mid 40s; otherwise, no significant weather is expected. Southwest winds will gradually veer to the west with approach of the cold front this afternoon.
445 AM CST Fri Dec 4 2020 Quiet weather continues with warmer than normal temperatures.
347 AM CST Fri Dec 4 2020 Showers are quickly shifting out of the Midsouth as a strongly positively tilted longwave trough approaches the lower to mid Mississippi River valley.
/Today through Saturday/ Closed upper low/trough which has plagued the region over the past 24-36 hours will continue to slowly lift NE into the TN Valley today with wrap-around low clouds still lingering through much of the day. As a result, only expect a modest warm-up later today with highs reaching into the lower to mid 50s by this afternoon. Along with winds decoupling, this will provide near ideal conditions for radiational cooling with overnight lows expected to land either side of the freezing mark by daybreak on Saturday. As we shift farther into Saturday, SW flow aloft will become more enhanced once again with another closed upper low lifting north out of Mexico into West Texas. High temperatures will run a bit warmer and near seasonal normals on Saturday, averaging right around 60 degrees.
Full sunshine will combine with a NWly downslope component of 10-15 mph to allow for significant warming of the lower troposphere Friday.
The low clouds that formed yesterday morning in the Mission Valley stuck around much of the day, keeping high temperatures from rising while the clouds spread north into the Flathead Valley last evening. From the southern third of Flathead Lake south to Ronan, dense freezing fog has been observed.
A positively-tilted trough with an embedded mid-level cutoff low over the Mid Mississippi Valley will deepen this morning as it swings through the TN Valley. As the cutoff low deepens this afternoon, it will transition to an open wave as it phases with a longwave trough over the Northeast, but also leave an additional cutoff low over the Baja region that will impact our weather later in the forecast period. Decreasing wind speeds underneath clear skies will allow overnight low temperatures to drop into the low 30s tonight. High temperatures this weekend will peak in the low 50s with overnight lows dropping into the upper 20s to low 30s Saturday night due to ideal radiational cooling conditions.
329 AM CST Fri Dec 4 2020 This morning, we find ourselves sandwiched between an upper ridge that comes out across the northern Rockies and a deep upper low coming down off of Hudson Bay. From that upper low, there is a backdoor cold front dropping southwest across Lake Superior, whose western tail will wash out at about I-94 today. Therefore highs for Saturday will be similar to today, perhaps a degree or two cooler thanks to the cloud cover. Little change in the pattern is expected through the period, with anomalously strong ridging over the western half of the CONUS expected to maintain our mild and dry stretch of weather.