Aikyam-Lab/Synoptic-Bench huggingface dataset:
A pleasant day across the Tennessee Valley today with 2PM temps around 50 in most areas or a few degrees cooler. Normal highs for this time of year are around 50-54 so we're right about there! The base of an upper trough is shifting through the area this afternoon with a slight increase in the northwest flow, making it feel a little breezy out there. Could be a few isolated spots of freezing fog but not enough to include in the forecast at this time. A broad mid level ridge builds over the northern Gulf and much of the southeast on Thursday.
524 PM CST Wed Jan 24 2018 Temperatures have not warmed up much this afternoon as the low clouds and fog have been slow to dissipate with some areas of low clouds and fog remaining across northeast SD.
359 PM MST Wed Jan 24 2018 An upper ridge covers the western CONUS, with a trough over the east. A few strong gusts will be possible over the northern Hills/foothills, especially over the higher elevations, and especially towards midday Thursday during better mixing. A cold front will cross the region Thursday night ahead of an upper trough, bringing some light snow to northeastern WY and the Black Hills.
702 PM EST Wed Jan 24 2018 Light lake effect snow will taper off tonight, then high pressure will bring clearing skies for Thursday. Ridging at the surface will largely bring this activity to an end tonight, though a few flurries will persist over our far northern forecast area. With surface ridging not forecast to begin until tonight, we increased POPs for today and extended the lake bands farther to the south and east.
The lower and mid levels of the atmosphere were quite dry with most of the moisture in the profile confined to the upper levels. Moderate north to northwest winds were observed in the lower levels while moderate to strong west to west-southwest winds prevailed throughout the remainder of the column. Thursday morning lows will dip to near freezing across northern and inland areas thanks to ideal radiational cooling and cold air drainage.
Models indicate the high clouds will begin to clear Se Ga before dawn so have made no adjustments to temps there.
As the trough moves to the east today clouds and precip chances will move to the east out of the region.
A Pacific cold front will then move across the state on Thursday, resulting in the potential for precipitation that will mainly fall as snow.
Chattanooga Airport, TN 28 55 30 59 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 26 50 28 59 / 0 0 0 0 Oak Ridge, TN 26 51 28 59 / 0 0 0 0 Tri Cities Airport, TN 22 47 24 58 / 10 0 0 0.
Upper heights start to fall on Thursday ahead a minor short wave trough moving northeast out of Mexico and ahead of a much stronger short wave moving east through the northern and central Rockies. High temperatures will also be about 5 degrees warmer than today.
Somewhat better mixing in the Sandhills should keep lows near 20 or the lower 20s, with upper teens expected elsewhere.
High pressure ridging will continue over the forecast area for the remainder of the afternoon continuing through the overnight hours. Lee-side troughing will be in place resulting in tight surface pressure gradients across the Upper Yellowstone and Upper Stillwater Valleys. We are not expecting much, if any, precipitation across the lower elevations along and behind the front through Thursday night with the exception of a slight chance for a rain or snow shower.
Current observations show downslope warming pushing off the Front Range through Denver Metro, while areas to the north are stuck in the low level inversions due to enhanced mountain wave clouds and snow cover. 700 mb temps rise to near +4C across the plains, and with further melting of the snowpack and weaker inversions daytime highs will be several degrees warmer. We should see a few spots in/near the foothills and parts of Denver push into the lower to mid 60s. Thursday night, an upper trough will move into Colorado bringing 60 to 70 mph wind gusts and snow chances to the northern and central mountains. Snow accumulations over the higher terrain will be between 2-6 inches, predominantly on west facing slopes and mountain peaks.
240 PM PST Wed Jan 24 2018 Storm system will pass through the area tonight through tomorrow bringing light showers to the higher elevations of the southern Sierra and southern Great Basin. Breezy conditions will shift southward through tomorrow across the Mojave Desert ahead of an approaching cold front.
Onshore winds will return on Thursday as the high moves east.
North breezes have freshened substantially during the last few hours over the extreme southeastern Gulf of Mexico, as a high pressure cell over the southern United States exerts increasing influence.
The winds will become light overnight, and thus strong radiational cooling will allow temperatures to fall to around freezing or just below for much of the area. This combined with sunny skies will allow temperatures be a little warmer, with highs mostly in the low 60s. /15/ Tomorrow Night through Wednesday: Cloud cover Thursday night will start to increase from the southwest as an upper level low develops to our west and Gulf moisture pushes through.
1032 PM EST Wed Jan 24 2018 The trough axis has shifted off to the east, taking with it any lingering light precipitation. Do not anticipate any issues with freezing drizzle but that will have to be watched if precip lingers longer than currently anticipated. High pressure will provide quiet weather Thursday and Thursday night. Stayed close to the blended model guidance for temps on Thursday with highs in the 40s to near 50 but took temps down below blended guidance Thursday night in the valleys as favorable radiational cooling conditions should allow valleys to fall deep into the 20s while ridges remain near freezing.
A cold front is slowly moving east across the forecast area currently stretching from from the Tri- cities area back into central Oregon.
536 PM CST Wed Jan 24 2018 Much of the low level stratus clouds has either dissipated with diurnal heating, mixing, and drying, or advected east of the forecast area this afternoon. Warmer temperatures can be expected tonight with unseasonably warm highs on Thursday due to low-mid level warm air advection, surface winds becoming southwesterly on Thursday, and rising upper level heights as an upper level ridge shifts eastward into the central US on Thursday. GKS A ridge of high pressure over the region will quickly shift east away from the area due to a progressive upper air pattern in place.
456 PM CST Wed Jan 24 2018 Much warmer conditions were observed over extreme southeast Kansas and the Missouri Ozarks today. Relative humidities will drop into the low to middle 20s west of Highway 65, with surface winds exceeding 20 mph.
Dry northerly to northeasterly surface flow will continue as high pressure builds from the Lower Mississippi and Tennessee Valley regions tonight to the eastern states Thursday. High temperatures Thursday should modify into the lower 60s.
VFR conditions will prevail as high pressure remains situated across the region. South winds return during the morning hours on Thursday as high pressure begins to slide east of Arkansas.
The consensus of that guidance suggests the lowest visibilities and thus highest probability of Dense Fog Advisory issuance is across the James River Valley, but forecast soundings suggest a slightly more turbulent near-surface layer than last night and thus the longevity of the lowest visibilities is still too uncertain for us to issue a headline just yet. Followed the Superblend for Thursday's highs but did raise the high temperatures a few degrees southwest into the mid 40s. The building ridge across the region Thursday will maintain mild temperatures in the 30s to middle 40s Thursday with the warmest temperatures southwest.
934 PM EST Wed Jan 24 2018 Pressure gradient will continue to tighten into tonight between high pressure building across the southeast U. This will continue to transport drier/cooler air into the region, with lows in the 40s for most locations, except low 50s forecast along the Treasure Coast.
Light southerly low level flow will allow for a warmer sunny day tomorrow with highs in the 50s.
So far this conv has not shown any lightning activity over the past 1-2 hours and the conv has weakened somewhat as it has moved off of the higher terrain in NE Mex. A 500 mb closed low over NW Mex will gradually push NE into northern/central TX through Thurs Night. Weak pockets of PV will move around the base of this closed low moving over the RGV throughout the short term forecast period. The cld cover and rain chcs will tend to hold down the high temps tomorrow. The low level flow will be shifting around from the N-NE tonight and tomorrow morning to a more milder easterly direction by Thurs Night.
/issued 211 PM CST Wed Jan 24 2018/ A fairly benign weather pattern remains in place across the region, as water vapor imagery indicates a trough across the eastern CONUS, ridging across the west, and a cutoff low over northwestern Mexico. A persistent very dry airmass will slowly begin to modify under southerly surface flow and southwest flow aloft around the aforementioned cutoff low, which will result in slightly warmer overnight temperatures the next couple days. As upper ridging shifts eastward Thursday, a trough will develop across the west, and the aforementioned closed low will open up and lift northeastward across the Texas Panhandle.
357 PM MST Wed Jan 24 2018 Strangely and interestingly enough, reduced visibility in haze, frost, or freezing fog showed up in Wolf Point during the middle of the day. Felt it was best to include some patchy freezing fog in the lower Missouri River valley in the forecast for now through tomorrow morning. Thanks to a strong and broad upper level ridge of high pressure over the region as a whole, today's warmer temperatures and mainly dry conditions will persist through tomorrow (Thursday). As soon as Thursday afternoon, southwest flow aloft slides into eastern Montana, and a cold front moves eastward through the area by Thursday night.
Issued by National Weather Service TAUNTON MA 620 PM EST Wed Jan 24 2018 Canadian high pressure builds in for the rest of the week.
Currently, a large upper level longwave trough was established over the western US, with upper level impulses streaming northeastward from the trough base over the 4-corners area into the central US plains. Little or no snow is expected from Selfridge to Bismarck and Carrington.
This area seems to be moving northeast along the freezing line that has steadily but painfully slowly moved north. But with temperatures near freezing, and staying steady through the late evening, there should be minimal impact to roads. Northwestern and northern MO and extreme northeastern KS though, where temperatures will likely remain below freezing, may see some additional light glazing this evening with this activity.
The band of showers will shift a little farther eastward this morning, before lifting back northward this afternoon as the upper ridge over the Southeast states builds westward.
A band of SHRA/TSRA in association with a cold front extends from NE Louisiana across SE Arkansas and NW Mississippi.
Another area of light freezing rain and sleet is expected to develop and I went more with the NAM solution that had the area of precipitation a little further west.
May steady off for awhile overnight, but in general, expect temperatures tomorrow morning at sunrise to be warmer than they are at sunset this afternoon.
Temperature and dewpoint spreads narrowing over far eastern Wyoming and western Nebraska, thus have added patchy freezing fog through mid morning there. Primary trough aloft moves overhead, with the greatest snow chances in the evening, then decreasing after midnight in the wake of the trough.
East of there there should be more sleet and freezing rain and less snow, and by the time you get to the lakeshore the boundary layer could be warm enough for rain.
Frontal boundary will remain stalled over the offshore waters today and then slowly drift back toward the coast as a warm front through the night. Vsbys are expected to improve to MVFR by 15Z over the coastal plains as the warm front begins to move through. The cold front has stalled over the offshore waters this morning. The hi-res mesoscale models show warmer temperatures will approach the Rio Grande by late afternoon, but the wedge of colder air will remain over the coastal plains with highs only in the lower to mid 50s. Overnight, will likely see LIFR conditions in either CIGS and/or VSBYS with the isentropic pattern and the boundary moving north as a warm front.
329 PM CST Thu Feb 22 2018 An upper trough will track south and east from the Pacific Northwest tonight and across the Rockies Friday.
This feature, which is embedded in the large-scale trough situated over Washington and Oregon State, will spread light to moderate snow northward into central Idaho through tonight.
A mix of freezing rain, freezing drizzle, and some sleet have been the primary precipitation types with this system. Elsewhere (mainly areas north of I-35) will continue to see freezing temperatures and lingering, patchy freezing drizzle through late evening. The low clouds stick around tonight regulating low temperatures overnight, which fall into the 20s and low 30s. As for tomorrow, dry conditions are finally forecast during the day as high pressure moves into the area behind the departing system.
The cold front has stalled over the offshore waters this morning. The hi-res mesoscale models show warmer temperatures will approach the Rio Grande by late afternoon, but the wedge of colder air will remain over the coastal plains with highs only in the lower to mid 50s. Overnight, will likely see LIFR conditions in either CIGS and/or VSBYS with the isentropic pattern and the boundary moving north as a warm front.
All climate sites have already set record highs for the day with highs in the low 80s. So far the high of 81 degrees at Chattanooga makes it the all time warmest temperature observed in February. The SBCAPE values are in the 500- 1000 J/Kg range with the high heat and humidity across the region. The cold front will be located near the Ohio River on Friday.
1139 AM CST Thu Feb 22 2018 Temperatures across the Ozarks and southeastern Kansas early this morning remained at or just the below the freezing mark with the exception of south central MO along the MO/AR border. Freezing drizzle or light freezing rain continued. The freezing drizzle/rain is expected to continue through sunrise today before temperatures slowly warm above freezing and the light precipitation tapers off. Temperatures with this system will remain well above freezing so all this precipitation will fall in liquid form.
1029 AM MST Thu Feb 22 2018 Current surface analysis shows high pressure east of the region, with low pressure across southern CO. Upper level analysis shows large scale trough digging southeast across the western states, with southwest flow ahead of the trough across the Rockies and Plains. A wide range of temps across the area as usual this morning, ranging from the teens below zero in the valleys of northwest SD to the teens above zero over far southern SD where there is some wind to mix out the low levels.
An cold front and upper level low will bring numerous showers and low snow levels to northwest Arizona later tonight and across portions of northern and central Arizona during the day Friday.
Warm front now along a line from just se of Lufkin to just s of Monroe, pushing nwd. Warm front to continue its trek nwd tonight, lining up parallel to the disturbed swly flow aloft.
Aloft, an amplified pattern remains in place, with an unseasonably strong ridge across the western Atlantic, and troughing across the West. Expect showers to gradually shift southeast with time through this morning, as a surface wave makes it way northeast along the boundary, along with a passing short wave trough traversing the Ohio Valley aloft, helping to lend some upper level support. Temperatures will be cooler today, with highs ranging from the lower 50s in the north, to around 70 in the far south.
Aloft: RAP analyses/RAOB/sat imagery show a longwave trof in the W with SW flow over the Plns. This trof will cross the CWA this eve. As it reaches the trof base tomorrow. the Wrn trof will begin moving E. It will lose its influence as a weak sfc trof crosses the area tonight in response to the forcing aloft. Friday will see a break in the weather ahead of the main western upper trough which will be edging into the Rockies.
A dry and windy day will develop today, as another cold front approaches.
In addition to the low ceilings/fog. scattered showers/t-storms continue to develop and move northward across the TAF sites as a frontal boundary just south of the region continues to move northward as a warm front.
Synoptically, a deep upper level trough was anchored in the western United States with a fast southwest flow aloft over the Midwest. Tonight: Weak wave ejecting out of the main trough will provide forcing, and along with increasing moisture, will spread light rain into our western cwa by early to mid evening, with this rain then pushing across the remainder of the cwa by around midnight. Lows should bottom out in the lower to mid 30s.
The system will bring several more inches of new snow to the Continental Divide and the higher elevations of the Sangre de Cristo Mountains today. The San Juans could see another 4-8 inches while the Continental Divide north of the San Juans and the higher elevations of the Sangre de Cristo Mountains could see another 3-6 inches. The high valleys, such as the San Luis, the Upper Arkansas and Wet Mountain Valleys, have already seen some light accumulations of generally an inch or less overnight.
A stronger low pressure system will take shape over the plains and result in increasing flow off the Gulf.
Forecast soundings also a loss of ice later tonight, so have some freezing drizzle mixed in with the snow.
Top down methodology has introduced some isolated mention of freezing drizzle, however this probably won't be very impactful as soundings do quickly saturate. Energy will continue to carve out a western conus/west coast mid level trof, with the energy then ejecting across the Rockies and plains.
Toward the Missouri border, temperatures are at/a little below freezing, so patchy freezing drizzle could occur.
Low pressure will sit over the region with the center of the upper level low centered over the Upper Columbia Basin. Although not a lot of moisture is wrapping in around the low, it is enough to produce intermittent flurries for portions of the ID Panhandle and extreme eastern WA. /SVH 18Z TAFS: Low pressure will reside over the region today with enough low level moisture to produce intermittent flurries.
Snow looks to be the primary precip type through 12Z with periods of freezing drizzle or mixed precip after that through most of the day, especially southeast half. Snow amounts look to remain limited today across southern parts of the area with soundings suggesting mid level drying coming into the area and impacting dendritic layer resulting in mainly freezing drizzle or sleet at times. Models differ on QPF for the evening period so not real confident on amounts currently in forecast and extent of freezing rain or drizzle in parts of the south.
In the meantime, only light snowfall will occur in the west as the asct troughiness tracks across the area.
Arctic high pressure was centered over the Great Lakes with low pressure developing over Colorado. Clear and cold to begin the day as weak high pressure remains over the forecast area. Little or no snow is expected west of a line from Selfridge to Bismarck and Carrington.
Issued by National Weather Service MIAMI FL 357 PM EST Thu Feb 22 2018 The persistent and highly anomalous dome of high pressure over the western Atlantic continues to be the dominant feature on the weather map this afternoon. Patches of enhanced moisture have been translating through the easterly flow south of the ridge.
Warmer Times Ahead. Upper trough over the West with a broad SW flow over the East will continue through the weekend.
Still looks like this secondary wave of snow could bring a dusting down to the lower foothills. Meanwhile in the valley, latest hi-res guidance is indicating the possibility of some pop up showers this afternoon and evening as trough swings through NorCal. Depending on how fast cloud cover clears out, could be fairly chilly Friday morning with valley temperatures dropping below freezing again.
253 PM EST Thu Feb 22 2018 High pressure will crest over Maine late tonight. A weak area of low pressure will cross the area Friday night.
350 PM CST Thu Feb 22 2018 The persistent Bermuda Ridge flow continues to persist and win out against cold air intrusion into the middle of the nation. Typically, this time of year, colder water temperatures serve as an inhibitor due to cooler marine layer processes.
116 PM CST Thu Feb 22 2018 Temperatures continue to gradually warm to around or slightly above freezing along the turnpike corridor. KED Today: As expected most of the good lift ends around 1200 UTC, with mainly freezing drizzle during the morning. Appears area roughly along/west of the turnpike will remain cold enough for freezing rain/freezing drizzle well into the afternoon. Temperatures should finally warm above freezing areawide on Friday although there still may be fairly extensive cloud cover.
High level clouds will be increasing this afternoon as a cold front drops into the area. A deepening trof to the west of the area will induce divergent flow over the area today, helping to pull a surface front with reinforcing cold air into the area this afternoon. Split the difference about 60/40 toward the American models which puts temperatures 3 to 5 degrees cooler than previous forecast. Upper trof to the west today, slides east into the area Friday.
247 PM MST Thu Feb 22 2018 Deep upper trough is persisting across the western CONUS, with southwesterly flow over the central Rockies through the northern Plains and upper Midwest. It still looks like the higher snowfall amounts will be limited to Tripp County.
Upper low center is tracking through southeast Oregon this morning with an area of steady snow across southwest Idaho. The steady snow will taper off across southeast Oregon and the lower Snake Plain of Idaho by early afternoon, while developing in the western Magic valley by early afternoon. Later today the snow will shift to central Idaho as a cold front moves across from west to east.
Low temperatures in the lower to middle 30s will occur in the evening with slowly rising temperatures overnight.
The good news is that the entire area is now above freezing and we are done with the winter weather threat.
It is uncertain if the lower cloud deck will dissipate Friday morning as winds remain light and moisture abundant, but if it does lift at least partly cloudy skies are expected for a time before increasing middle and high clouds during the afternoon.
Satellite imagery shows an upper level low in south central Oregon this morning with a weaker low in eastern Washington. In central Oregon snow will taper off this afternoon as the low swings east.
During this process of drying in the mid levels, there could be a period of freezing drizzle following the end of accumulating snow due to continued saturation in the low levels.
At 9 AM CST, a cold front was sitting along a line from about Dale Hollow Lake, back to Lebanon, Franklin, and Waynesboro. Northwest of the front, temperatures were in the upper 40s to mid 50s, and southeast of the boundary, temps were in the low to mid 60s.
Main concern continues to be damaging straight line winds in this low CAPE but high shear expected environment.
A stationary boundary stretches across Middle TN southward into the Lower Mississippi River Valley.
A weak cold front will drop into the area by this evening allowing for winds to switch to a northeasterly direction.
1204 PM EST Thu Feb 22 2018 High pressure will build toward the region today and crest over Maine late tonight. A weak area of low pressure will cross the area Friday night.