Aikyam-Lab/Synoptic-Bench huggingface dataset:
The mass combination of breaks in the clouds, melting snow cover, warm northwest to westerly winds and the passage of a warm front has brought warmer temperatures and drier conditions than the models were handling. Models are not handling this combination well and opted for overnight lows a few degrees warmer under mostly cloudy skies and decreased snow coverage. Some locations are already touching the upper 50s and is a prelude to some warmer weather ahead. But first, a low pressure system over Canada will sweep over Saskatchewan Friday. Precipitation around the corresponding cold front is expected to remain dry, however, the possibility of an isolated, hit and miss rain shower around higher terrain can not be ruled out completely.
1136 AM MDT Thu Oct 29 2020 Flow aloft will begin a gradual shift to the west today as a trough moving from the Gulf of Alaska toward the Pacific Northwest slightly amplifies the ridge over the West Coast. The shift in flow will bring increased warm air advection which will translate into warmer surface temperatures this afternoon. Though warmer, afternoon highs are expected to remain below normal for all but the southern portion of the forecast area where temperatures will be more seasonal. On Friday, the Gulf of Alaska trough sweeps over the Pacific Northwest and moves to the northern Rockies on Friday. Except for continued warming, conditions across the forecast area will remain largely unchanged ahead of the trough.
Hence, that is where the highest pops and accumulations reside. Some freezing rain or freezing drizzle could mix in with a light glaze possible from the Sisseton Hills east. Dry conditions are expected, and slightly warmer temps could result, especially across south central SD. Highs may end up a few degrees cooler than the current forecast of upper 40s even with H85 temps climbing to around +10C.
SHORT TERM (Now through Friday Night): High pressure will dominate in the short term with cool temperatures and northwesterly winds. Friday into friday night continued northwesterly flow with light to moderate winds will keep temperatures below normal once again with highs in the low 70s falling to the upper 40s to low 50s overnight.
The axis of the ridge that has brought dry and warming conditions to the CWA will cross over us today, making Thursday the warmest day of the week thus far. The flattening of the ridge overhead will also work to keep skies clear, allowing for more robust warming.
Cooler and drier air is currently filtering into the area in the wake of this morning's cold front.
/Tonight through Friday Night/ Clouds continue to hold in the wake of a strong cold front/closed upper low.
/issued 626 AM CDT Thu Oct 29 2020/ 12Z TAFS There has been a brief lull in wind speeds early this morning, but northwesterly flow will increase and become gusty after sunrise through the day in the wake of the strong cold front that pushed through the area yesterday evening. /issued 415 AM CDT Thu Oct 29 2020/ What a difference 24 hours makes! Early morning sfc analysis shows now Tropical Storm Zeta zipping quickly newd across the TN Valley while the cold front which brought fall-like weather to the forecast area yesterday is now located over sern LA. sfc obs/IR imagery indicate the last of the low-level cloud cover approaching the Atchafalaya Basin at this time.
The combination of the departing tropical system to our east and an incoming cold front will create gusty winds and scattered showers through this evening.
1155 AM MDT Thu Oct 29 2020 Satellite imagery this morning depicts an area of midlevel cloud cover across much of the High Plains, with broken upper-level clouds streaming across the nrn Rockies through NW flow aloft. Modest westerly flow should preclude much westward progress of the low clouds/fog into our area through daybreak. Sfc trof over cntrl MT/ern WY should gradually shift ewd through the day. In the wake of the trof, will see an increase in NW flow this evening and tonight. Breezy S/SW winds will develop on Friday as another sfc trof approaches the area and deepens. Trof and associated cold front cross the region late Friday.
1238 PM CDT Thu Oct 29 2020 A quiet start to the day is expected following the passage of a cold front from last night. Lake effect snow showers over northwest Wisconsin are expected to come to an end this morning as high pressure builds over the CWA.
1242 PM CDT Thu Oct 29 2020 A sharp clearing line is evident on Satellite this morning as the potent upper level low across Oklahoma is beginning to shift east. This should help temperatures to return to the lower 50s for most areas by afternoon. despite the modestly cooler airmass that advected across the region overnight. went a bit warmer with highs for today than previous forecast. expect seasonably warm to above normal temperatures to dominate along with dry weather as high pressure builds to our west and eventually transitions eastward.
Cooler and drier air continues to filter into the area in the wake of this morning's cold front.
Temperatures at H85 warm through the night tonight as warmer air spreads eastward. Boundary layer is well mixed by afternoon, especially across southwest Nebraska, and boosted highs into the lower 60s there.
918 AM MDT Thu Oct 29 2020 MORNING UPDATE: Precipitation over the northeastern portion with surface temperatures near freezing on radar would suggest areas of freezing drizzle. Temperatures will slowly continue to rise into the lower 40s. Road conditions are not reflective of the freezing variety. Cloud cover and melting snow over the area has kept overnight temperatures a little warmer as well. Roxy PREVIOUS DISCUSSION: A warm front pushing across the region today will bring light precipitation tracking from southwest to northeast. Longer range ensembles show a large building upper level ridge across the western U. VFR conditions will prevail, though times of MVFR ceilings may occur with showers as a warm front lifts through the region today.
The only highlights in the short term will be a chance for fairly widespread freezing temperatures again tonight (A freeze warning has been issued for our south central counties which have not yet received a hard freeze) and a chance for patchy fog / freezing fog tonight as well. Tomorrow we start to warm up closer to normal temperatures under the influence of some minor ridging.
This will likely result in winds gusting 55 to 65 mph at mountain top, with the foothills seeing some gusts in the 45 to 55 mph range - mainly in the higher foothills due to no strong stable layer to force a mountain wave.
The upper low is now situated across southwest Arkansas and continue to track eastward today. GOES-16 Satellite trends indicate a dry slot working in across the Lower Mississippi Valley with KNQA WSR-88D radar trends showing rain showers moving out of the area in the next hour or two. However, this will be short-lived as an upper level low currently located in the Red River Valley in Texas moves into Arkansas this morning and into the forecast area this afternoon. The aforementioned upper level low will move into Middle Tennessee this evening with rain chances gradually diminishing as high pressure builds into the region. Temperatures will be much cooler on Friday with highs only reaching the 50s.
Northerly winds have been blustery/brisk especially along and east of the Mississippi River where the pressure gradient is stronger between incoming high pressure in the Plains and Zeta remnants. For tonight we will see weakening flow, and eventually elevated warm advection late which could serve to strengthen inversion and trap the lower clouds. Highs are forecast to range from the mid 40s north, where more clouds than sun is anticipated, to the lower 50s south where more sun is expected. Key Messages: 1) Windy conditions this weekend 2) Generally dry 3) Typical fall roller coaster on temperatures Models in good agreement taking a strong low pressure system from the Canadian Prairies into Ontario this weekend.
238 PM CDT Thu Oct 29 2020 An upper low is currently situated just east of the Mississippi River along the TN/MS border and will continue to track east this afternoon. CAMs (Convective Allowing Model solutions) indicate showers will diminish this evening as the upper low moves into Middle Tennessee. Behind this system, high pressure will begin to build into the region. Temperatures on Friday are expected to be much cooler with highs in the 50s. Dry conditions are anticipated through the weekend in response to high pressure.
Persistent mid level stratus has kept temperatures confined to the upper 60s/lower 70s across north Central Alabama, while abundant sunshine allowed temps to reach the lower 80s further south. Expect dry conditions to persist throughout the duration of the short term in the wake of a cold front attached to the departing upper trough. Overnight lows will range from the low to upper 40s, a noticeable change from the persistent tropical airmass seen previously this week. Expect temps in the low to mid 60s elsewhere across Central Alabama, and an otherwise beautiful fall day as clouds begin to thin and a broad upper ridge begins to build into the Southeast for the weekend.
With clearing skies and high pressure moving overhead tonight, another chilly night is in store with lows dropping into the low 30s. Temperatures quickly bounce back to slightly below normal on Friday as sunshine returns and a light south wind sets up on the western edge of the departing high pressure center.
This has now given us mainly northwest flow in the 500-700 mb portions of the atmosphere and with a trough moving in from eastern Colorado we should see winds in the 850 mb and surface level turn back to the south to southwest. The main weather feature to keep an eye on is if any fog develops with the warm air advection going over the snowpack in Amarillo's area as well as all the low level moisture over Norman's and our southeast areas. I kept the lows a little warmer despite the clear skies and light winds. increased high temperatures to the mid 60s in the central and north and lower 60s in the southeast with the higher moisture amounts in the ground.
Northerly winds behind the front will begin to usher some cooler drier air late tonight spreading across the entire area during Friday.
A cold front will cross the region tonight, ushering in much colder weather for the weekend. After a brief respite from the wind, expect a surge of winds behind a cold front moving through this evening will bring another round of gust winds overnight, mainly in the Blue Ridge. We get into an upslope/downslope regime overnight with clouds and a few showers west of the Ridge and little in the way of sensible weather to the east. Temperatures will be notably cooler tomorrow with Friday with highs only in the low to mid 60s east, upper 40s/lower 50s west. Brisk northwest winds will follow in the wake of this system with cold high pressure building across the region for the weekend.
Other than that, still looking mainly cloudy today with temperatures remaining on the cooler side. Our high temperatures will climb to near freezing in most areas with temperatures falling into the lower to middle 20s overnight.
124 PM MDT Thu Oct 29 2020 The upper low centered over Texas and Oklahoma will be moving off to the east today. Northwest flow over the central High Plains region will turn more westerly on Friday as a trough approaches from the northwest U.
1003 AM CDT Thu Oct 29 2020 A quiet start to the day is expected following the passage of a cold front from last night. Lake effect snow showers over northwest Wisconsin are expected to come to an end this morning as high pressure builds over the CWA.
The cooler and drier conditions feel great, but they also increase the risk of fire danger. The upper low over the lower MS Valley today will be long gone to the east.
This actually sent a cold front into the region and by 8z was already through about 2/3rds of the CWA. Cooler and much drier air will accompany this cold front and it will lead to well below normal through the remainder of the work week and still quite comfortable over the weekend. The cut off low will merge back into the the main stream with a L/W trough trying to set up over the eastern 2/3rds of the CONUS Friday.
359 PM CDT Thu Oct 29 2020 Tonight into Tomorrow: A much cooler day has prevailed across the region with temperatures 15 to 20 degrees cooler than this time yesterday. This all comes as a front moved through the region earlier today and an upper trough moved across the region. Temperatures tonight will be in the lower 40s. Another cool day is expected tomorrow with highs ranging from the upper 50s in the north to the lower 60s in the south.
Rain showers are finally exiting Eastern Oklahoma and Northwest Arkansas this afternoon as the upper level low pressure system that has been impacting the region the past several days finally departs off to the east. a 30-45KT low level jet behind the departing upper low was continuing to shift eastward as well. There still remains uncertainty with just how much potential there will be for fog as the low level trof axis doesn't reach the CWA until around 12z Friday. have gone ahead and added a mention of patchy frost with the idea of the evening shift re-evaluating before introducing any fog/freezing fog headlines.
1045 AM MDT Thu Oct 29 2020 Some patchy fog remains in the low-lying areas of Grand County where cold air remains trapped under an inversion to about 9000 ft. The high temperature forecast seems to be on track as the model output from more recent runs are now in better concensus with the current forecast in areas both retaining snow cover and not. Over the higher valleys readings will be at least 10 degrees colder than guidance where inversions hold. Finally will continue to see some fog, in the higher valleys of Middle Park, both this morning and again tonight.
Upper level low will approach mid state region late this afternoon and move across mid state region as evening hours progress. Scattered to numerous showers early in the evening will give way to only isolated to scattered showers late evening with upper level low pushing east of mid state region after 30/06Z. Lows tonight will fall to below seasonal normal values into mainly the lower 40s.
This has now given us mainly northwest flow in the 500-700 mb portions of the atmosphere and with a trough moving in from eastern Colorado we should see winds in the 850 mb and surface level turn back to the south to southwest. The main weather feature to keep an eye on is if any fog develops with the warm air advection going over the snowpack in Amarillo's area as well as all the low level moisture over Norman's and our southeast areas. I kept the lows a little warmer despite the clear skies and light winds. increased high temperatures to the mid 60s in the central and north and lower 60s in the southeast with the higher moisture amounts in the ground. High temperatures warm into the 55 to 60 degree range with overnight lows in the low to mid 30s.
A short wave is expected to move from the lower MS Valley this evening. Cooler temperatures are in store for the short term. Deep upper trough digs into the eastern U.
Day (Today and tonight) Light to occasionally moderate rainfall is expected to move out of northern Oklahoma, diminish, and skirt across central Oklahoma around daybreak as the upper low continues eastward along the Red River area of southeastern Oklahoma. Temperatures are a few degrees above freezing, but observation sites continue to report light snowfall there. Finally, fog and freezing fog are expected early Friday over areas that had received rainfall.
Zeta about to exit off the Atlantic Coast as a post-tropical cyclone. High pressure extended from Lake Superior to west Texas. Upper low chugging eastward, just now moving through the Memphis area. A band of lower clouds associated with the upper low remains just north of the local area. Temperatures 15 degrees or so cooler than 24 hours ago with dew points in the 40s instead of the 70s.
Issued by National Weather Service Springfield MO 1241 PM CDT Thu Oct 29 2020 This morning, the closed upper level low, which is the catalyst for this current round of precipitation, is evident on water vapor imagery across the Red River Valley. This upper low will continue to trek east moving into Arkansas this afternoon. A return quasi-zonal flow aloft and late day modest WAA will allow temperatures to rise into the low to mid 50s on Friday.
A much cooler morning has unfolded today as cold air advection takes over behind the departing Zeta and cold front. At the surface, a cold front was analyzed over far eastern Mississippi early this morning with cool dry air quickly filtering into the area in it's wake. Overnight low temperatures will drop into the low to mid 40s area wide beneath partly cloudy skies.
1236 PM CDT Thu Oct 29 2020 Primary concern for the short term revolves around the low stratus and potential for fog overnight into Thursday morning. Forecast soundings show decent lift in the lower levels and only a brief window near sunrise where this lift abates and dew point depressions drop. This low stratus is also leading to lower confidence in today's high temperature forecast. Have trended today's temps upward, into the low to middle 50s west of Highway 83, where clearing looks most probable by this afternoon. Friday looks to be rather quiet with high temps a few degrees warmer area wide than they are today.
1225 PM MDT Thu Oct 29 2020 Moisture laden northwest flow aloft producing some mid and high level clouds across the area while low pressure over the plains is producing some brisk wind in the foothills.
313 PM EDT Thu Oct 29 2020 As TS Zeta begins to embark eastward off of the East Coast, its interaction with the upper level low, now centered over northern MS, will continue to produce rain and drizzle along the deformation band extending from AR/MO through southern IL and into Indiana and KY. Cloud cover will moderate temperatures as Friday morning mins start off in the upper 30s across southern Indiana and the low 40s across central KY. Clouds should begin to break up by Friday afternoon, possibly allowing enough insolation for high temps to reach into the low to mid 50s across the CWA.
While Friday will feature warmer conditions, we will still remain 8 to 12 degrees below normal for daytime highs. I expect that afternoon readings will top out in the low to mid 60s. Fortunately, wind chills won't be quite as low thanks to the lower wind speeds.
The NAM indicates that the low clouds will linger through the night over much of the region, while the GFS aggressively clears us out this evening. If we clear out and the winds can go light or calm some locations from the Ozark Foothills through the KMVN area may briefly reach freezing by daybreak Friday.
210 PM CDT Thu Oct 29 2020 (Issued 210 PM CDT Thu Oct 29 2020) Tonight through Friday night: Pressure gradient between Zeta remnants and high pressure in the plains will relax overnight. Surface ridging takes hold for Friday into Friday evening. Still chilly though with proximity of low level thermal trough.
Cool and dry conditions are expected through the short term as high pressure continues to build over the region. Gusty northwesterly winds will gradually diminish over land as the high settles tonight. Winds will diminish further Friday and Friday night with winds more out of the north to northeast as the high begins to slide to the east. Mostly sunny skies Friday should allow temps to warm into the lower 70s, with another chilly night in store for Friday night.
Model soundings do show some drying aloft after midnight, so may see some freezing drizzle at times, but no ice accumulation is expected. By tomorrow morning, there may be a few flakes here and there across southern Minnesota, but skies will gradually become partly cloudy through the day as high pressure settles in.
Given a further decrease in snow pack and surface moisture today, have opted to play down the low-stratus chances in most locations, except for the Gunnison and Eagle areas. Overnight lows will end up slightly warmer than last night, however have still opted to lower the higher elevation valleys compared to guidance blends given lower chances of stratus.
248 PM MDT Thu Oct 29 2020 Weak ridging continues across the western US today, allowing further warming across the state, except for Jackson Hole, where the inversion trapped snowmelt moisture longer than expected, before clouds finally broke late this morning. Friday will see a continuing day of warmer temperatures, as upper flow shifts more from due west across the state, as a quick trough sweep ashore across the Pacific Northwest. The approaching trough will help increase winds across the central wind corridor during the afternoon, with gusts of 35 mph still expected during the afternoon. The trough will race through the region Friday night, mainly just increasing cloud cover.
235 PM CDT Thu Oct 29 2020 After our prolonged winter storm across the region the past few days today has been quite pleasant with sunny skies and much warmer temperatures. What snowpack we had across the area has been rapidly diminishing this afternoon with only a small patch of widespread snow across the southwest Texas Panhandle which may help to keep temperatures on the cooler side. Tonight, with clear skies and light winds temperatures should plummet across the region with most locations bottoming out near the freezing mark.
1229 PM CDT Thu Oct 29 2020 (Today and tonight) Light to occasionally moderate rainfall is expected to move out of northern Oklahoma, diminish, and skirt across central Oklahoma around daybreak as the upper low continues eastward along the Red River area of southeastern Oklahoma. Temperatures are a few degrees above freezing, but observation sites continue to report light snowfall there. Finally, fog and freezing fog are expected early Friday over areas that had received rainfall.
Strong short wave trough with leading surface cold front will come in from the northwest Friday afternoon and early evening. Cold front will bring a wind shift to west or northwest with speeds 15 to 25 mph for several hours, and showers as far south as Valley County, ID.
Expect mostly sunny skies with highs topping out in the low to mid 40s this afternoon.
304 PM CDT Thu Oct 29 2020 An upper level low was over the southwest tip of TN this afternoon with light rain in the deformation zone over southeast MO and southwest IL. The CAMs shift this precipitation southeast of our forecast area by 00Z Friday as the upper level low weakens and shifts east of our area as it opens up. Even though it will be warmer, the high temperatures will still be around 10 degrees below normal for late October.
A dry slot between Zeta and the mid/upper low moving into the western TN Valley is working into the region and will lead to only scattered light showers the rest of the morning through the afternoon. Periods of MVFR will return tonight with scattered showers as a strong cold front crosses, but any rain will be much lighter. Garuckas Chattanooga Airport, TN 50 59 42 65 50 / 0 0 0 0 0 Knoxville McGhee Tyson Airport, TN 50 56 40 62 46 / 40 0 0 0 0 Oak Ridge, TN 48 57 39 62 47 / 10 0 0 0 0 Tri Cities Airport, TN 48 54 36 61 41 / 60 0 0 0 0 NC.
107 PM CDT Thu Oct 29 2020 Updated for 18Z aviation discussion 18Z TAF discussion: Most sites have returned to VFR conditions following the cold front, but one or two remain MVFR this afternoon. /28/ A much cooler morning has unfolded today as cold air advection takes over behind the departing Zeta and cold front. At the surface, a cold front was analyzed over far eastern Mississippi early this morning with cool dry air quickly filtering into the area in it's wake. Overnight low temperatures will drop into the low to mid 40s area wide beneath partly cloudy skies.
There may be even a brief period of freezing drizzle as the precipitation ends.