Aikyam-Lab/Synoptic-Bench huggingface dataset:
As an upper level trough continues to move through the northern Plains, a surface cold front associated with a surface cyclone along the South Dakota/Nebraska border continues to push into northern Oklahoma. This cold front will progress through central Oklahoma, before stalling overnight. On Wednesday, another round of lee side cyclogenesis will develop another surface cyclone in Colorado which will strengthen and shift the winds out of the southwest across most of western north Texas and southern Oklahoma, which will lead to another day of fire weather concerns.
Weak high pressure centered NE of the Bahamas with ridge axis extending back across the central FL peninsula will continue to slide slowly eastward over the next 24 hours. Overnight lows will remain mild and generally in the U50s to L60s; save for M50s for normally cooler interior locales. Weak high pressure ridging remains fixated over the local waters.
520 PM CST Tue Dec 28 2021 Even though snow is ending from west to east across the area, continue to see a classic freezing drizzle signal with loss of ice occurring and relatively decent lift for several more hours through the saturated boundary layer. As conditions improve with plowing services and freezing drizzle threat wains as front passes, we can drop advisories sometime this evening. This would change snow over to freezing drizzle mid to late this afternoon into this evening.
The ebb and flow of a very cold airmass over northwest Montana will interact with warmer, moist air from the west over the next couple days to produce snow for north-central Idaho and west-central Montana. This process will hold especially true across the lower elevation valleys in Idaho, where places like Riggins and Orofino could still pick up a few inches of snow.
307 PM CST Tue Dec 28 2021 1020 to 1024mb high pressure centered over North Dakota extends in a ridge down into eastern South Dakota and overnight that ridge will strengthen and the gradient to the east and south will weaken.
A more powerful low pressure system is poised to impact the area for the weekend. The warm front remains in the southern portion of the CWA at this time. Some pockets of freezing rain remain possible in the far northeastern CWA where a few readings near 32 degrees remain, but this threat will be brief and spotty at best. Low pressure riding up the Ohio Valley late tonight and Wednesday morning will then push the front back southeastward.
1020 to 1024mb high pressure centered over North Dakota extends in a ridge down into eastern South Dakota and overnight that ridge will strengthen and the gradient to the east and south will weaken.
The snow will continue to spread north this afternoon and evening and then a transition to freezing drizzle this evening as the DGZ becomes unsaturated. An area of mixed precip, including freezing rain is expected closer to the low center, which could include our southeast zones. A cold front will move across the terminals around noon at which point we'll see drier air move in and cigs/vsbys will being to rise to MVFR and eventually VFR late in the day. A stretch of fairly quiet conditions the next few days although winds and waves may pick up over the weekend as low pressure tracks near Lower Michigan as arctic air approaches.
CD Chattanooga Airport, TN 74 62 72 56 70 / 90 90 60 20 70 Knoxville McGhee Tyson Airport, TN 73 59 69 54 69 / 90 90 70 20 70 Oak Ridge, TN 71 59 69 53 67 / 90 90 50 20 70 Tri Cities Airport, TN 70 55 66 50 66 / 80 90 70 20 50.
Current thinking is that temperatures will be just above freezing to keep things all rain for any precip in southeast Kansas today. Highs today will struggle to make it out of the 40s with of the exception of extreme south Kansas along the Oklahoma border where highs may hit the low 50s. A vigorous upper level trough will approach the U.
CIMMS layer mean winds show the Keys on the western periphery of the ridge. The high position to the Keys has induced an east to southeast flow today, over the island chain, with the wind flow remaining through the end of the week. Gentle to moderate east to southeast breezes will reign over the local waters through the end of the work week due to high pressure that will hold over the western Atlantic waters. Winds will veer to the south and increase this weekend ahead of a cold front that will move into the Western Gulf of Mexico.
This will last Wednesday afternoon ending with the passage of a cold front.
Temperatures also continue to tank as expected after sunset, with a couple of sites in Divide county touching 30 below zero and wind chills as low the lower 50s below.
Skies should clear to some degree allowing us to remain well above normal in the lower 70s.
A more powerful low pressure system is poised to impact the area for the weekend. Aloft, the progressive flow continues but with a deepening trough over the Plains and strengthening jet, the boundary will begin to push southeast through the rest of the forecast area by dawn.
Mid level cloud cover should be the main effect from this weak wave as well as bringing some slightly warmer low level temperatures. Weak southerly flow will remain in place through the night and will keep temperatures warmer than this morning. Broad troughiness to the south will remain in place Thursday which will bring warm advection and milder low to mid level temperatures to thew area.
This in response to low pressure on the Nebraska and South Dakota border with its inverted trof extending into southern North Dakota, and a H5 short wave, albeit weak, supporting some mid level upward motion. The H5 pattern is kinked with a trough passing through and this is in response to H5 ridging building across the Rockies and Montana. This ridge is what will become our reprieve from the coldest air, and that reprieve comes Thursday. The aforementioned H5 ridge builds in with warm air advection across the southwest.
The relatively warmer airmass from the Pacific Northwest, will overrun the already in place arctic airmass. This includes the lower valleys of Orofino down to Riggins.
Areas west of the dry line, like portions of Starr, Jim Hogg and Zapata Counties, will see temperatures climb into the lower 90s this afternoon.
and Thursday Leftover snow and rain showers will end over the Door Peninsula by daybreak as a cold front exits the region.
Low pressure was located over the Minnesota Arrowhead early this morning with an occluded/cold front trailing from this low across eastern Wisconsin and Illinois down into the Red River Valley of the South. High pressure was building across the Northern Plains and pushing into western Minnesota leading to a tight pressure gradient across the eastern half of the state and breezy winds. Very cold air will arrive with the area of high pressure leading to highs today in the single digits above and below zero across northeastern Minnesota with single digits and teens above zero across northwestern Wisconsin. Temperatures warm a bit heading into Thursday, but will remain below freezing for highs.
Warm temperatures will continue during the short term with afternoon highs in the low to mid 80s, highest over central/northern areas.
808 AM EST Wed Dec 29 2021 An active pattern will keep periodic precipitation chances in the forecast through the week, with a more potent low pressure system set to impact the area this weekend. Though dry the rest of the day, continued warm/moist advection within SW flow ahead of the longwave Rockies trough will maintain heavy cloud cover and well above normal temperature for the region. The combination of deep moisture, very strong jet dynamics, and enough sfc lift will promote rain showers favoring northern WV and the higher terrain east of Pittsburgh.
318 AM CST Wed Dec 29 2021 High pressure currently over the area has resulted in temperatures falling into the single digits below and teens below zero this morning. Several models are indicating an area of snow developing north of the low and sliding across portions of the western and northern CWA.
718 AM EST Wed Dec 29 2021 An active pattern will keep periodic precipitation chances in the forecast through the week, with a more potent low pressure system set to impact the area this weekend. Though dry the rest of the day, continued warm/moist advection within SW flow ahead of the longwave Rockies trough will maintain heavy cloud cover and well above normal temperature for the region. The combination of deep moisture, very strong jet dynamics, and enough sfc lift will promote rain showers favoring northern WV and the higher terrain east of Pittsburgh.
Latest upper level analysis has a broad trof across much of the western CONUS with closed low over northern Saskatchewan. At the surface, Arctic high pressure resides across the Northern Plains. Temperatures at 2AM across the forecast area range from near zero in the north, to the lower 20s in southwest SD. Arctic high pressure will remain entrenched across the Northern Plains for the next several days, with well below average temperatures continuing.
405 AM EST Wed Dec 29 2021 High pressure will remain over the area today.
As an upper trough over the northern Plains departs the region, northwesterly flow aloft is expected to take its place.
Temperatures are trending colder over North-central Montana today after a cold front brought periods of snow.
415 AM EST Wed Dec 29 2021 Mostly clear skies prevail across the Florida Keys on this early Wednesday morning, with temperatures hovering in the lower to mid 70s, and winds on land from the southeast near 10 mph. Radar and satellite images clearly show the Cuban land breeze boundary moving northward from the Lower Straits across the Lower Keys and into the Gulf waters, but there does not appear to be any significant shower activity along this boundary. Composite analysis shows ridges at the surface and aloft centered over the western Atlantic to the east of the Bahamas.
High pressure remains anchored over the western North Atlantic this morning. Though there is plenty of moisture in the boundary layer, the low inversion height is severely limiting vertical growth. Southeast winds will help to draw in warmer air, thus keeping temperatures above normal. Already seeing dew points near 70 degree or in the lower 70s. From synopsis: Gentle to moderate east to southeast breezes will prevail across the Keys waters through the end of the work week, as high pressure remains over the western Atlantic. Winds will veer to the south and increase this weekend ahead of a cold front moving across the Gulf of Mexico.
Locating the exact location of the warm front this afternoon will be the key to determining the location of the strongest storms.
The front will become nearly stationary today with shower and thunderstorm chances on the low side through at least midday. Upper level southerly component remains quite noteworthy and thus, look for a warm front to lift northward by Thu nt.
347 AM MST Wed Dec 29 2021 Temperatures are trending colder over North-central Montana today after a cold front brought periods of snow.
937 AM EST Wed Dec 29 2021 A broad ridge of high pressure remains in control of the weather pattern across South Florida this morning. Winds will remain out of the south southeast today which will result in warmer temperatures this afternoon. High temperatures this afternoon will generally range from the lower 80s across the east coast metro areas to the mid 80s over the interior sections. Warm temperatures will continue during the short term with afternoon highs in the low to mid 80s, highest over central/northern areas.
Meanwhile, Arctic high pressure moves in today. Temperatures will moderate somewhat on Thursday as the high moves to the east but a cold front Thursday afternoon and evening will bring bitter cold air back into Northeast Montana Thursday Night with another round of Wind Chill Warnings and Advisories likely.
Helicity should be the highest across northeast Mississippi and LCL heights are expected to be very low and it will not take a whole lot for tornado development if a storm can take advantage of the atmosphere that will be in place.
421 AM MST Wed Dec 29 2021 Latest upper level analysis has a broad trof across much of the western CONUS with closed low over northern Saskatchewan. At the surface, Arctic high pressure resides across the Northern Plains. Temperatures at 2AM across the forecast area range from near zero in the north, to the lower 20s in southwest SD. Arctic high pressure will remain entrenched across the Northern Plains for the next several days, with well below average temperatures continuing.
231 AM MST Wed Dec 29 2021 Latest upper level analysis has a broad trof across much of the western CONUS with closed low over northern Saskatchewan. At the surface, Arctic high pressure resides across the Northern Plains. Temperatures at 2AM across the forecast area range from near zero in the north, to the lower 20s in southwest SD. Arctic high pressure will remain entrenched across the Northern Plains for the next several days, with well below average temperatures continuing.
Broad upper level ridging will help support a dry forecast through Wednesday night. For Wednesday night, temperatures will be slightly warmer, but still cool for this time of year, as lows drop into the low to mid teens. A weak trough will push through the region during the day, but precipitation is not expected.
High pressure currently over the area has resulted in temperatures falling into the single digits below and teens below zero this morning. Several models are indicating an area of snow developing north of the low and sliding across portions of the western and northern CWA.
High pressure will remain well entrenched over the local area today, with no shower chances in the forecast. Highs overall rising into the low to mid-80s. Favorable boating conditions persisting under a lingering high pressure system.
Temperature should rise to around 40 this afternoon, although readings will be cooler over areas where snow cover remains.
The mountains are expected to get between 2 and 9 additional inches of snow with the higher totals from around I-80 southward.
Low temperatures will remain fairly mild for late Dec in far southeast KS where lows will bottom out around 30 while those in central KS will see lows fall into the lower teens. Afternoon highs are expected to top out in the low to mid 50s for most areas.
New guidance has a pretty good handle on this and keeps these areas cooler through the afternoon with expected cloud cover and rain showers. Diegan Chattanooga Airport, TN 63 73 56 71 63 / 90 50 20 70 90 Knoxville McGhee Tyson Airport, TN 59 70 53 69 61 / 90 50 10 70 90 Oak Ridge, TN 57 69 52 67 61 / 90 30 20 70 100 Tri Cities Airport, TN 55 66 49 67 54 / 90 40 10 50 90.
Surface lee troughing will expand by Thursday afternoon, encompassing the CWA and backing low-level flow to the southwest.
High pressure in the southwest Atlantic will maintain south to southwest flow of around 10 kts nearshore and around 15 kts offshore through the remainder of the day.
A persistent trough will remain straddled across the forecast area through the New Year. This will give cold temperatures and wind chills to the western portions of the area; however, the trough will shift eastward on January 1st and bring the cold across the entire forecast area before it shifts east on January 3rd giving a warm up.
Light snow across north central and northast sd this morning shown on radar and surface obs associated with a short wave trough. High pressure currently over the area has resulted in temperatures falling into the single digits below and teens below zero this morning. Several models are indicating an area of snow developing north of the low and sliding across portions of the western and northern CWA.
Afternoon highs will struggle through the 30s and 40s warmer further south due to the upslope northeast surface winds continually advecting colder temperatures across the CWA. Afternoon highs will be warmer with the warmer downslope winds seeing 50s widespread across the CWA.
Communities in the southern Sacramento Valley and northern San Joaquin Valley will be several degrees warmer.
1251 PM EST Wed Dec 29 2021 An active pattern will keep periodic precipitation chance in the forecast through the week, with a more potent low pressure system set to impact the area this weekend. High pressure and subsidence will provide dry weather across the Ohio River Valley through much of the evening as an earlier frontal boundary remains stalled just south of the region. The combination of deep moisture, very strong jet dynamics, and enough sfc lift will promote rain showers favoring northern WV and the higher terrain east of Pittsburgh starting early Thursday morning.
The band of snow is expected to slowly shift southward through the afternoon as a cold front enters from the north. Snow will end north of the Treasure Valley in the evening with the passage of a cold front.
(The rest of today ) Synoptic cold front draped across far southeast OK, with just a few elevated thunderstorms noted across the forecast area over the past few hours.
New guidance has a pretty good handle on this and keeps these areas cooler through the afternoon with expected cloud cover and rain showers. CD Chattanooga Airport, TN 73 63 73 56 71 / 70 90 50 20 70 Knoxville McGhee Tyson Airport, TN 68 59 70 53 69 / 70 90 50 10 70 Oak Ridge, TN 67 57 69 52 67 / 80 90 40 20 70 Tri Cities Airport, TN 65 55 66 49 67 / 80 90 40 10 50.
The current Wind Chill warning and Advisory continues to look good for expiring tomorrow morning as the warm front moves far enough north to take that biting cold off the extremely cold temperatures to just a simple cold.
A surface boundary bisects Middle Tennessee this morning, with much cooler, drier air across northern portions of the mid state and warmer air with higher dew points generally south of I-40. Hourly temperatures continue to run below forecast values, so have lowered today's highs a few degrees, especially in the cooler regions of the mid state north of the boundary.
Otherwise, expect cool lows in the low to mid 40s. On Thursday, southwest flow aloft will continue, while at the surface, low pressure developing across eastern CO during the day and high pressure across the Gulf will lead to warm and breezy southwest surface winds during the afternoon. The warm southwest flow and warming of the 850 mb thermal ridge will likely lead to slightly warmer highs in the mid to upper 70s.
1045 AM CST Wed Dec 29 2021 Light snow across north central and northast sd this morning shown on radar and surface obs associated with a short wave trough. High pressure currently over the area has resulted in temperatures falling into the single digits below and teens below zero this morning. Several models are indicating an area of snow developing north of the low and sliding across portions of the western and northern CWA.
108 PM EST Wed Dec 29 2021 High pressure will ridge across the area today.
For tonight, despite cold high pressure across the region, another embedded wave will push east across the state and bring a little more light snow to some areas, maybe a tenth or so before ending late.
VFR conditions will prevail at all of the terminals throughout the day as continued high pressure remains in control. High pressure in the southwest Atlantic will maintain south to southwest flow of around 10 kts nearshore and around 15 kts offshore through the remainder of the day.
High pressure will be southeast of the region this period, with troughing to the northwest. A few thunderstorms will move into far inland counties this afternoon along the trough. Another wave will move along trough to the northwest Thursday afternoon, with the chance for storms well inland.
1003 AM EST Wed Dec 29 2021 High pressure will ridge across the area today.
A surface boundary bisects Middle Tennessee this morning, with much cooler, drier air across northern portions of the mid state and warmer air with higher dew points generally south of I-40. Hourly temperatures continue to run below forecast values, so have lowered today's highs a few degrees, especially in the cooler regions of the mid state north of the boundary. All terminals will start VFR and will stay that way through at least 21Z, but conditions will become poor after 21Z as a low pressure system moves across the areas with showers and scattered storms followed by low clouds and areas of BR.
154 PM MST Wed Dec 29 2021 Upper trough persists over the western 2/3 of the CONUS, with the upper low still over Saskatchewan. At the surface, a trough/boundary stretches across southern SD, and high pressure is moving across ND. Highs Thursday are expected to be about 10 degrees warmer than those of today, under partly cloudy skies. Thursday night, a piece of energy will eject from the approaching trough, beneath the right entrance region of the jet streak.
Northern and northeast zones will be stuck near freezing this afternoon, while areas adjacent to Oklahoma, on the periphery of this air mass, will warm well into the 50s. Cooler air and associated higher minimum relative humidity, as well as much lighter winds, will reduce fire danger substantially Wednesday.
The transport of deep moisture is weaker than the event yesterday, as shown in model soundings that maintain a dry wedge in lower levels through the event, so we expect amounts to be limited to a dusting to an inch with the highest amounts across the southern forecast area.
219 PM CST Wed Dec 29 2021 Latest 19z surface analysis shows high pressure over Minnesota and the eastern Dakotas.
With the area under full sunshine, temps have rebounded with a range currently in the upper 20s to the lower 30s. Latest models continue to show ridge axis east of the CWA late tonight into Thursday. For temps, another cold night across the area with a range in the upper single numbers above zero to the lower teens. Fri-Sat night: An unsettled synoptic pattern characterized by deep troughing /cyclonic flow/ aloft over the central/western CONUS will persist. Sun-Wed: An abrupt transition to a more benign synoptic pattern -- characterized by broad ridging aloft over the central CONUS -- is anticipated late this weekend. VFR conditions will persist thru the forecast period as high pressure slowly moves east.
Light snow across north central and northeast sd this morning shown on radar and surface obs associated with a short wave trough. High pressure currently over the area has resulted in temperatures falling into the single digits below and teens below zero this morning. Several models are indicating an area of snow developing north of the low and sliding across portions of the western and northern CWA.
1121 AM CST Wed Dec 29 2021 (The rest of today ) Synoptic cold front draped across far southeast OK, with just a few elevated thunderstorms noted across the forecast area over the past few hours.
423 PM MST Wed Dec 29 2021 Upper trough persists over the western 2/3 of the CONUS, with the upper low still over Saskatchewan. At the surface, a trough/boundary stretches across southern SD, and high pressure is moving across ND. Highs Thursday are expected to be about 10 degrees warmer than those of today, under partly cloudy skies. Thursday night, a piece of energy will eject from the approaching trough, beneath the right entrance region of the jet streak.
Otherwise, a large upper level low pressure area in central Canada will continue to pump bitter cold air across our region through Thursday night.
Communities in the southern Sacramento Valley and northern San Joaquin Valley will be several degrees warmer with some lingering cloud cover.
Weak high pressure ridging begins to sink a bit more south/east from ECFL. Overnight lows will remain mild and generally in the U50s to L60s; save for M50s for normally cooler interior locales. Then, more of the same conditions expected, dry and very warm, as high pressure remains locked in over the western Atlantic and stretched into east central Florida. Highs tomorrow afternoon rising into the low to mid- 80s once again. Rather persistent pattern, though the ridge axis does sink gradually south/east with the slow approach of the next weather system.