Aikyam-Lab/Synoptic-Bench huggingface dataset:
A cold front has cleared the region early this AM, with wind- convergence-induced snowfall continuing north of Idaho Falls but activity otherwise winding down/pushing east of the forecast area. Thus, high temps are likely to hold in the 20s today (noticeably colder than recent days but not yet terrifying) while a vicinity mid- level low promotes light instability snow showers favoring the higher terrain this afternoon/eve. Winds will finally turn into the north this eve as the low shifts east. The bigger story will be the cold temps with lows Tue AM ranging from below zero in the north to the low teens near the UT border, heading toward highs in the teens north to mid 20s south. Broad longwave troughing with several embedded waves will keep at least isolated snow showers going Tue/Tue night, but accumulations look quite limited.
In the west of the Cascades lower inland valleys there will be a difference between snowfall and snow depth as a warmer ground and any afternoon sun will melt snow. The winter weather advisories, and one small area of a winter storm warning, continue in effect into Tuesday morning as a moist and cold upper low circulates over the region. This low will shift south and east of the region Tuesday night allowing a very cold air mass to deepen with north to northeast flow. The cold and dense flow around this high will spread arctic air across the Pacific Northwest.
Moisture levels over the Lower Mississippi River Valley have crept up to 1. With best coverage of rain being along and north of Highway 84, cooler temperatures today are expected over northern portions of the forecast area. The west to east gradient in moisture across the forecast area and nearby will also create a west to east gradient in overnight temperatures, with low temperatures ranging from the low 60s west of the Alabama/ Mississippi state line to mid 50s east of the Alabama River. Isolated rainshowers will also be possible overnight west of the state line with the higher moisture values and stronger low level flow. With increasing subsidence from the building upper ridge along the East Coast, combined with more heating, temperatures are expected to top out in the upper 70s to low 80s across the forecast area, well above seasonal norms.
A ridge of high pressure will extend across the region from the northeast Tonight and Tuesday. A wave of low pressure will pass to the northwest of the region this afternoon through Tonight. Highs away from the coast on Tuesday will be in the lower 80s. An onshore southeast flow will keep readings cooler near the coast.
856 AM PST Mon Feb 21 2022 Arctic cold front will move through the region today.
1252 PM EST Mon Feb 21 2022 Atlantic high pressure will lead to unseasonably warm temperatures until a cold front moves through late in the week. Low-level winds have shifted around to be southeasterly and temperatures have warmed nicely into the low 70s away from the immediate coastline. The offshore coastal trough shower activity has been confined to the coastal waters, and we have removed any mention of showers for eastern Charleston County. Tonight: The coastal trough looks to fall apart, while a low level warm front lifts toward the area. Atlantic high pressure will prevail through the period. Mid- week, a cold front will approach the region, although the majority of the moisture will remain just north of the area.
1031 AM PST Mon Feb 21 2022 Arctic cold front will move through the region today.
235 PM CST Mon Feb 21 2022 A cold front is moving southward across the area this afternoon. The high at Hays has already been reached for the day and falling temperatures are likely for the rest of the afternoon, as a large region of intense 850 mb level cold advection continued a southward trajectory across nw KS into CO. There already is a wind chill advisory across roughly the northern half of the forecast area as temperatures plunge behind the cold front and north east winds gain strength overnight into the 20 knot and up range, sustained. Medicine Lodge could see a drop from as warm as 80 degrees this afternoon, to freezing by midnight.
Tue wl be a repeat of today with even warmer temps in the afternoon well into the 80s inland and around 80 at the coast.
Most areas in this zone will have seen 2-5 inches of snow by early this evening with the highest totals in northeast winds upslope areas with several narrow bands of lake effect streaming in from the northeast. Northeast wind upslope and enhancement will continue so highest snow total will continue to be in the highlands of Marquette/Baraga counties and near the Porkies. There could be a little sleet that mixes in this area with 80H warm nose surpassing freezing.
For Tuesday, an arctic front is expected to begin making its way south into the Big Country resulting in cooler highs there tomorrow in the upper 50s to mid 60s.
Deep layer ridging extending from the western Atlantic is maintaining moderate to occasionally fresh breezes in the Florida Keys coastal waters. Deep layer ridging will remain in control of our sensible weather through the work week.
Early afternoon satellite imagery was showing a broad upper trough settling over Idaho with convective snow showers firing across SW Idaho. Upper low circulation NE of Boise is also expected to migrate east into the Wyoming border region by morning as arctic air stacking up along the Montana border spills over the divide and plunges south through the Snake River Plain.
1153 AM CST Mon Feb 21 2022 Another warm day expected today as wind flow becomes southerly, stalling the cold front to our north in Iowa. Low pressure developing in the lee of the Rockies will scoot east along the front and track through northern Missouri and Illinois by Tuesday morning. There will be a threat for damaging winds and perhaps a tornado primarily within and south of the axis of the low level jet. As the low moves off to the northeast Tuesday morning, the cold front will surge southeast behind it. Once the front moves through, the threat for precipitation quickly ends, and temperatures will fall below freezing by Tuesday night.
1154 AM CST Mon Feb 21 2022 For the 21/18Z TAF update, IFR/LIFR conditions are still in place across most of our airspace as a warm front has advanced northward into the Ouachita Mountains. /issued 1027 AM CST Mon Feb 21 2022/ As of 10 AM CST, the warm frontal boundary continues to shift northward approaching the Ouachita Mountains.
ABM Chattanooga Airport, TN 53 71 58 70 54 / 60 40 90 50 60 Knoxville McGhee Tyson Airport, TN 52 72 57 66 50 / 70 40 90 50 70 Oak Ridge, TN 52 71 55 66 49 / 70 50 90 40 70 Tri Cities Airport, TN 49 71 55 65 47 / 70 30 90 60 60 TN.
256 PM CST Mon Feb 21 2022 At 20Z today, a strong cold front bisected the CWA creating a large temperature gradient from northwest to southeast across the area. At KCNK (Concordia) temperatures dropped 10 degrees between 19Z to 20Z and were in the low 40s at 20Z. As the colder air mass overspreads the area, soundings show a saturated layer a few thousand feet deep in the low levels (under 5,000 ft AGL). As lift increases through the layer, drizzle could develop with a possible limiting factor being a layer of drier air in the lowest 1,000 feet. If drizzle can overcome the drier air for a few hours, a few slick spots could develop by early morning since temperatures will be below freezing in most spots.
An upper trough will continue to deepen over the area today. Scattered light snow showers this morning will expand during the afternoon as a result of the instability with the trough. Some of the showers will be capable of producing brief moderate to heavy snowfall rates in the higher elevations with local amounts of up to 2 inches.
High pressure is currently dominating the area and northeast to east winds have quickly moderated the air. Temperatures and dewpoints rapidly bounced back after a brief episode of cold air advection following the cold front.
1027 AM CST Mon Feb 21 2022 As of 10 AM CST, the warm frontal boundary continues to shift northward approaching the Ouachita Mountains. A warm front is knocking on our door moving inland off the Gulf at this time. Our next cold front will be on approach this evening and bring a new batch of showers and thunderstorms into the region overnight and through much of Tuesday with NW winds 22/21Z-03Z from W to E across our area.
When all said and done total accumulations are expected to range from 1-4 inches along Hwy 200, 4-10 inches along I94, and 8+ south of I94, with the highest along the SD border into Grant and Wilkin counties.
158 PM PST Mon Feb 21 2022 A cold low pressure system from the north will bring strong winds, chilly temperatures and widespread rain and mountain snow through the middle of the week.
Low temperatures will range from the upper 50s to low 60s across the interior to the lower to middle 60s near the coast.
358 PM CST Mon Feb 21 2022 Key Message * Cold front ends the warm up tonight.
A strong cold front will then race southward across the terminal sites later this evening and tonight with gusty north winds in its wake. Further Details: A broad positively-tiled longwave trough will be noted over the CONUS through the short term. For tomorrow, it does look like the flow starts to split as a potential closed low forms over Nevada. Additionally, the associated high pressure at the surface is displaced to the north over the far northern Great Plains, which further handicaps the southward extend of the front tomorrow. This means places like Amarillo are going to be extremely difficult to forecast for the high.
This activity is expected to become more widespread overnight as the low level jet strengthens. Most of this activity is expected to occur in advance of a cold front that will sweep across the area tonight into Tuesday morning. (Tuesday through Monday) The showers and thunderstorms are set to exit the area Tuesday morning as the cold front moves to the south and east.
A strong cold front will reach KTCC tonight and remain to the west Tuesday, with low clouds possibly developing.
518 PM CST Mon Feb 21 2022 Key Message * Cold front ends the warm up tonight.
549 PM CST Mon Feb 21 2022 Arctic high pressure continues to build southward this afternoon. An upper trough continues to digs southward from the West Coast across the Intermountain West. The latest storm total snowfall is slightly less than the previous forecast, now at 3-4 inches over the Pine Ridge, to 1 to 3 inches across the remainder of the Advisory area in north central NE. The large upper trough across the western U.
452 PM MST Mon Feb 21 2022 Large upper trough is sitting across the western CONUS, centered across the northern Rockies. This band is associated with a strong wave rounding the base of the trough and moving in from UT/CO. Arctic high pressure will settle into the Dakotas Tuesday night as snow gradually tapers off.
340 PM CST Mon Feb 21 2022 Arctic high pressure continues to build southward this afternoon. An upper trough continues to digs southward from the West Coast across the Intermountain West. The latest storm total snowfall is slightly less than the previous forecast, now at 3-4 inches over the Pine Ridge, to 1 to 3 inches across the remainder of the Advisory area in north central NE. The large upper trough across the western U.
At 20Z today, a strong cold front bisected the CWA creating a large temperature gradient from northwest to southeast across the area. At KCNK (Concordia) temperatures dropped 10 degrees between 19Z to 20Z and were in the low 40s at 20Z. As the colder air mass overspreads the area, soundings show a saturated layer a few thousand feet deep in the low levels (under 5,000 ft AGL). As lift increases through the layer, drizzle could develop with a possible limiting factor being a layer of drier air in the lowest 1,000 feet. If drizzle can overcome the drier air for a few hours, a few slick spots could develop by early morning since temperatures will be below freezing in most spots.
529 PM CST Mon Feb 21 2022 Mild temperatures will continue tonight into Tuesday morning as a cold front approaches. As the cold front passes through the area Tuesday afternoon, showers and thunderstorms will come to an end, with temperatures dropping sharply. Expect lows tonight only in the upper 40s to mid 50s, and highs ranging into the lower 60s east of I-55 Tuesday.
246 PM MST Mon Feb 21 2022 Large upper trough is sitting across the western CONUS, centered across the northern Rockies. This band is associated with a strong wave rounding the base of the trough and moving in from UT/CO. Arctic high pressure will settle into the Dakotas Tuesday night as snow gradually tapers off.
449 PM EST Mon Feb 21 2022 A low pressure system tracking by to our northwest will send a couple rounds of rain through the area during the short term period. The low is currently over southeast CO, being supported by an impulse traveling up the eastern side of a large, amplifying, positively tilted upper trough over the western CONUS. Broad low level flow off the gulf has developed east of the low, with moisture surging northward. The cold front trailing from the low will move in from the northwest on Tuesday night with another round of showers and possibly thunderstorms.
An upper low will set up shop across northern and central Nevada, bringing snow showers to the region. Looking at a wider view, a large upper low can be seen spinning over the western United States. The position of the upper low will shift slightly to the southwest and will take up residence across northern California and northwestern Nevada. The upper low will wobble about and move slightly east, positioning itself over north-central Nevada during the overnight.
For most of the week, deep layer ridging will continue to influence the Keys local weather and cause warm and relatively dry weather conditions.
350 PM CST Mon Feb 21 2022 Mild temperatures will continue tonight into Tuesday morning as a cold front approaches. As the cold front passes through the area Tuesday afternoon, showers and thunderstorms will come to an end, with temperatures dropping sharply. Expect lows tonight only in the upper 40s to mid 50s, and highs ranging into the lower 60s east of I-55 Tuesday.
Expect very cold temperatures to hang around through mid-week, before highs reach above freezing across most of the region for the weekend ahead. Begin this forecast period with a dominant upper level trof deepening across the Western U. The upper level trof uses its energy to deepen; therefore, its movement eastward is slow.
A cold front is moving southward across the area this afternoon. The high at Hays has already been reached for the day and falling temperatures are likely for the rest of the afternoon, as a large region of intense 850 mb level cold advection continued a southward trajectory across nw KS into CO. There already is a wind chill advisory across roughly the northern half of the forecast area as temperatures plunge behind the cold front and north east winds gain strength overnight into the 20 knot and up range, sustained. Medicine Lodge could see a drop from as warm as 80 degrees this afternoon, to freezing by midnight.
633 PM EST Mon Feb 21 2022 Over the next 24 to 30 hours an upper level trough slips down into the central Great Basin. helping to strengthen an upper ridge that stretches northward across the Gulf region and the southeast US. High pressure over the open Atlantic. The lows and highs will run several degrees above seasonal.
Tonight through Tuesday night Breezy south winds contd to bring warmer and more humid air into the FA this aftn. The aforementioned warm fnt wl provide a focus for elevated storms to form as the low lvl jet ramps up later tngt.
Overnight lows will only fall to the low to mid 60s by the morning.
The gradient between the Atlantic high and a boundary retreating northward from the northern Gulf could help keep the stiffer easterly breeze through Tuesday but eventually the deep-layer high pressure should help moderate wind speeds over the area. Temperatures around the State Road 29 corridor should reach into the mid 80s while most other areas remain in the lower 80s except for the seabreeze cooler Atlantic coast which will stay in the upper 70s.
1027 PM MST Mon Feb 21 2022 Large upper trough is sitting across the western CONUS, centered across the northern Rockies. This band is associated with a strong wave rounding the base of the trough and moving in from UT/CO. Arctic high pressure will settle into the Dakotas Tuesday night as snow gradually tapers off. The upper trough will slowly move through the western CONUS on Wednesday.
Low pressure is expected to advance towards the forecast area tonight, with increasing showers expected. The upper trough will continue to settle into the area through Tuesday. Most of the showers will continue to form over the higher terrain through early this evening, then diminish overnight. It will be even colder, with lows at most locations in the single digits and teens (below zero in the higher elevations) and highs mainly in the 20s to mid 30s.
238 AM CST Tue Feb 22 2022 An incredibly tight temperature gradient continues early today on the frontal position, where low pressure is riding up along today. Not to be outdone, Keokuk, is gusting from the south and is 57! North of the front, the freezing line stretches from Pella IA to Cedar Rapids to Jo Daviess county in Illinois. For the northwest 1/3, that means a light freezing rain potential continue to be forecast, which if it starts before 9 AM, would significantly impact the morning commute. Temperatures will start the day in the 40s to lower 50 east, under the low pressure center, and will be falling through the 20s through the day over eastern Iowa.
1050 PM CST Mon Feb 21 2022 For the 06Z TAFs, a strong cold front will move through the southern TX Panhandle very early in this cycle, and will be south of the forecast area by around 08Z. A strong cold front will then race southward across the terminal sites later this evening and tonight with gusty north winds in its wake. Further Details: A broad positively-tiled longwave trough will be noted over the CONUS through the short term. For tomorrow, it does look like the flow starts to split as a potential closed low forms over Nevada. Additionally, the associated high pressure at the surface is displaced to the north over the far northern Great Plains, which further handicaps the southward extend of the front tomorrow. This means places like Amarillo are going to be extremely difficult to forecast for the high.
1117 PM CST Mon Feb 21 2022 Mild temperatures will continue tonight into Tuesday morning as a cold front approaches. As the cold front passes through the area Tuesday afternoon, showers and thunderstorms will come to an end, with temperatures dropping sharply. Expect lows tonight only in the upper 40s to mid 50s, and highs ranging into the lower 60s east of I-55 Tuesday. Expect coverage of showers to continue to increase and lift northeast with the best chances for precip east of the I-55 corridor and especially across east central Illinois this evening on the nose of the low level jet. The highest MUCAPE values are rooted between 800-900 mb. As a cold front approaches from the NW tonight and an upper level disturbance approaches from the southwest, a low level jet aloft will transport copious moisture into the area overnight.
A cold front is moving southward across the area this afternoon. The high at Hays has already been reached for the day and falling temperatures are likely for the rest of the afternoon, as a large region of intense 850 mb level cold advection continued a southward trajectory across nw KS into CO. There already is a wind chill advisory across roughly the northern half of the forecast area as temperatures plunge behind the cold front and north east winds gain strength overnight into the 20 knot and up range, sustained. Medicine Lodge could see a drop from as warm as 80 degrees this afternoon, to freezing by midnight. From a model perspective, looking at lows though the week, it's clear the arctic air settles in over the high plains and will be quite slow to modify/erode.
Expect very cold temperatures to hang around through mid-week, before highs reach above freezing across most of the region for the weekend ahead. Broad upper level trough remains over western North America with north to northeast flow aloft over Montana.
Winds will be 10-20 kts with gusts up to 30 kts out of the S/SW until tomorrow evening when winds at CKV/BNA/MQY shift to the northwest behind the surface cold front. Wind shear in the lowest 2000 ft is possible overnight at BNA.
Dry warmer weather this period with upper ridge building over Florida with increasing low-level thickness values from model guidance. High pressure conditions will continue on through midweek.
A few light showers will continue to stream eastward across our far northwest GA zones this evening as a weak mid level short wave trough streams over a lifting coastal-trough/hybrid warm front lifting northward across GA/SC. The shower activity is expected to lift north of our GA zones through midnight as a mid/upper level ridge across the Caribbean amplifies northward. The main weather impact tonight will be shallow ground across portions of SE GA and NE FL, especially for areas along and east of the Highway 301 corridor toward the I-95 corridor. Weaker boundary layer winds are expected tonight as the 850 mb ridge builds over N FL and with the influx of low level moisture under ESE flow, expect a little better fog coverage tonight, with some father expansion inland.
1057 PM CST Mon Feb 21 2022 Arctic high pressure continues to build southward this afternoon. An upper trough continues to digs southward from the West Coast across the Intermountain West. The latest storm total snowfall is slightly less than the previous forecast, now at 3-4 inches over the Pine Ridge, to 1 to 3 inches across the remainder of the Advisory area in north central NE. The large upper trough across the western U.
Expect very cold temperatures to hang around through mid-week, before highs reach above freezing across most of the region for the weekend ahead. Broad upper level trough remains over western North America with north to northeast flow aloft over Montana. The low clouds and sporadic flurries/fog will help maintain periodic MVFR/IFR conditions at all airfields overnight and through much of Tuesday, especially over the plains.
Area surface observations indicate that surface dewpoints have risen into the lower to mid 60s across southeast MS into far southwest AL and the western FL panhandle this evening, while satellite imagery shows extensive low cloud cover in place across much of the forecast area. Temperatures may struggle to get much below the lower 60s across southeast MS and much of southwest AL and the western FL panhandle. Lows may be a little cooler in the mid to upper 50s over interior south central AL. The flow pattern aloft transitions more southwesterly across our area on Tuesday ahead of an upper level trough moving into the southern plains and as upper ridging continues to build over the southern Gulf. Highs Tuesday and Wednesday will range in the upper 70s to lower 80s inland and in the lower to mid 70s along the coast.
1126 PM CST Mon Feb 21 2022 Key Message * Cold front ends the warm up tonight.
There will be a period of wind shear overnight as the low level jet increases to 50 kts.
Surface winds will strengthen notably today ahead of incoming cold front tonight. May see VCSH arrive at KCHA and KTYS by 03z but think widespread SHRA with cold front will hold off until just after 06z. CD Chattanooga Airport, TN 72 60 70 55 72 / 40 90 60 50 40 Knoxville McGhee Tyson Airport, TN 73 58 66 51 69 / 40 90 60 60 60 Oak Ridge, TN 72 57 67 49 68 / 50 100 50 70 70 Tri Cities Airport, TN 71 56 65 49 65 / 40 90 60 70 70 TN.