Aikyam-Lab/Synoptic-Bench huggingface dataset:
Showers are expected to continue across the southern areas the next few hours with possible embedded thunderstorms but then shift north this afternoon as the lower level flow becomes southerly and as a low pressure area develops along the front over the southern MS Valley and moves northeast. Temperatures have warmed into the lower to mid 60s south and 50s elsewhere except upper 40s NW corner in Scott County north of the boundary. Timing the lower conditions with any confidence is about impossible, so will cover with TEMPOs.
240 PM CST Wed Feb 5 2020 High pressure and dry low level air have kept the area dry today, with light snow well to the south.
223 PM CST Wed Feb 5 2020 As a weak cold front across southern Canada sags south tonight and Thursday we believe the focus for snow will follow this feature.
Cold front has pushed through the area this morning with low ceilings, fog and drizzle. Tonight ceilings should remain MVFR at the worst but this will hinge on the next round of precip due to the main trough axis and jet streak moving over the area. Cold front has pushed south into the Gulf with temperatures falling into the 40s/50s. We are not expecting any travel impacts since roads have been warm and surface temperatures will be near or just above freezing during the time of precipitation.
342 PM EST Wed Feb 5 2020 Upper air pattern consists of a 500 mb trough in the southern Rockies and also into the northern plains 12z Wed. The northern plains trough slowly moves east and remains over the area through 00z Fri. Starts off with a quiet forecast, then a cold front moves through late tonight into Thu and lake effect snow starts up later in the forecast with 850 mb temperatures falling to -12C by 12z Thu over Lake Superior. Only problem is airmass is pretty dry and soundings in the low levels show an inverted-v look to them. Moisture is pretty shallow with this cold front as well. Currently, the amounts look to remain on the low side, although some lake-enhancement under NE flow could assist in locally bumping up amounts a smidge.
1013 AM MST Wed Feb 5 2020 The upper trough is slowly crossing the CWA at this time, with northwest flow behind it moving in from the west.
255 PM CST Wed Feb 5 2020 Upper level trough moving across the area was producing an area of moderate to heavy snow in extreme eastern MO and into portions of central IL but this is moving northeast and will remain south of the dvn cwa. Thursday: Any lingering snow in our far southeast counties will end early otherwise partly to mostly sunny skies are expected with weak ridging.
Regarding severe thunderstorm potential, Instability is gradually ramping up in areas experiencing somewhat higher temperatures in the low to mid 70s to go with the very favorable shear profiles and large scale ascent. Southerly winds will also remain moderate with gusts near 20 knots or higher at times through tonight before the cold front shifts the winds to west to northwest during the 06z-15z time period. As temperatures warm with daytime heating today, instability in the low and mid-levels should further increase. This LLJ is resulting in ample shear in the lowest 3km with 42 knots of speed shear and 345 M2/S2 of helicity noted. These values are high enough to support tilted updrafts and mesocyclone development with any deeper convection that forms today. This low LCL would support any severe convection becoming surface based.
Showers are expected to continue across the southern areas the next few hours with possible embedded thunderstorms but then shift north this afternoon as the lower level flow becomes southerly and as a low pressure area develops along the front over the southern MS Valley and moves northeast. Temperatures have warmed into the lower to mid 60s south and 50s elsewhere except upper 40s NW corner in Scott County north of the boundary. Timing the lower ceilings and visibities is difficult, so will cover with TEMPOs early this afternoon.
Dew points in the single digits and teens continue to advect into the region, and the low stratus clouds, flurries and patchy fog have all but dissipated. High temperatures will modify some Thursday as warmer air just off the surface at H85 arrives. The H85 temperature at North Platte for instance will warm to near -2C on Thursday, which is about 6C degrees warmer than today. Deep mixing will allow this warmer air to the surface with highs topping out in the upper 30s to mid 40s.
Individual showers will continue to push to the northeast, while the entire system exhibits a slow eastward transition as the upper trough pushes eastward as well. Additional amounts should remain at a half inch or less in most spots, with the highest amounts likely to affect areas that are near or just at warning criteria snow already.
The dominant precipitation type should be light snow, but freezing drizzle will also occur for portions of east-central and southeast Missouri and southern Illinois. The freezing drizzle will occur due to loss of cloud ice as midlevels of the atmosphere dry out. Additional accumulations look mostly on the light side across the area, with the highest totals of 1 to 1. The only other change to headlines was to cancel the advisory in parts of south-central Illinois as any wintry precipitation looks very light with temperatures only dropping to near freezing late tonight. There may be some lingering light snow Thursday morning as another vorticity maximum ejects northeastward out of the longwave trough. The remainder of the day is expected seasonably cold and dry, with high temperatures in the lower 30s across the bi-state region.
519 PM CST Wed Feb 5 2020 Water vapor imagery and H5 heights show a defined trough continuing to dig into Mexico. This elongated, positively tilted trough will become more neutrally oriented this evening as it moves out into the Plains. Broad lift out ahead of this trough will become more defined over the ArkLaTex region northeastward towards the lower Great Lakes overnight tonight. A slight shift east in the system keep the highest snow totals south and east of the KC metro today with the metro just seeing a light dusting of snow. Locations further south may hang onto clouds a bit longer depending on how quickly the trough moves trough.
Thursday: The upper level trough that brought us our morning snow will continue to be the the main influencer of our weather over the next few days.
Tonight, skies will clear as the trough axis continues to push east and subsidence works its way into the area.
435 PM MST Wed Feb 5 2020 Latest upper level analysis has large trof across the Northern Plains into the southern Rockies with ridging over the western CONUS. At the surface, a weak trof of low pressure extends from far northeastern Montana southward into western Kansas. Western upper ridge will slowly edge into the area overnight with partly to mostly cloudy skies expected.
Expect the broad trough of low pressure to our west to organize a low that will set up over southwestern to south central ND by daybreak Thursday.
By Thursday morning, some upper level ridging will build into the region which will help the skies clear for Thursday with weak westerly and northwesterly flow expected.
ceilings are forecast to begin clearing out across much of Eastern Oklahoma with varying winds as an upper level trof axis moves over the region. MVFR ceilings are forecast to hold for much of the day for Northwest Arkansas with some possible clearing just outside of the TAF period as the upper trof exits. Individual showers will continue to push to the northeast, while the entire system exhibits a slow eastward transition as the upper trough pushes eastward as well. Additional amounts should remain at a half inch or less in most spots, with the highest amounts likely to affect areas that are near or just at warning criteria snow already.
A patch of mid level clouds currently over eastern NM and the lower RGV will drift southeast overnight.
301 PM CST Wed Feb 5 2020 Copious amounts of sunshine will round out the day today before clouds move in from the north associated with an approaching weak wave/cold front. Tonight's cold front will bring the chance for light snow over the majority of the area. Behind the cold front will be cooler, more seasonable temperatures with lows in the single digits on either side of zero and highs in the teens above zero.
250 PM MST Wed Feb 5 2020 Latest upper level analysis has large trof across the Northern Plains into the southern Rockies with ridging over the western CONUS. At the surface, a weak trof of low pressure extends from far northeastern Montana southward into western Kansas. Western upper ridge will slowly edge into the area overnight with partly to mostly cloudy skies expected.
547 PM CST Wed Feb 5 2020 Copious amounts of sunshine will round out the day today before clouds move in from the north associated with an approaching weak wave/cold front. Tonight's cold front will bring the chance for light snow over the majority of the area. Behind the cold front will be cooler, more seasonable temperatures with lows in the single digits on either side of zero and highs in the teens above zero.
339 PM MST Wed Feb 5 2020 2130Z infrared and water vapor satellite imagery show the upper level trough axis just east of the Tri-State area oriented from northeast to southwest.
541 PM CST Wed Feb 5 2020 Mostly clear skies this afternoon and evening from an area of strong high pressure which is slowly moving off to the east. A cold front will move south from Ontario overnight, bringing in low clouds after midnight. However there is poor model agreement with the movement of the trough axis, which will affect far south the snow will spread Thursday afternoon.
Our 00Z balloon flight is showing saturation between about 900mb and 760mb and there appears to be some weak lift with the upper trough axis moving over. Flurries and freezing drizzle have been reported, and will likely continue until at least 03/04Z. At that time, some drier air should move into the low levels. Freezing drizzle could cause slick spots on roads and sidewalks. Tonight, skies will clear as the trough axis continues to push east and subsidence works its way into the area.
A warm front will bring only a few sprinkles south of the Oregon border this evening.
407 PM CST Wed Feb 5 2020 Water vapor imagery and H5 heights show a defined trough continuing to dig into Mexico. This elongated, positively tilted trough will become more neutrally oriented this evening as it moves out into the Plains. Broad lift out ahead of this trough will become more defined over the ArkLaTex region northeastward towards the lower Great Lakes overnight tonight. A slight shift east in the system keep the highest snow totals south and east of the KC metro today with the metro just seeing a light dusting of snow. Locations further south may hang onto clouds a bit longer depending on how quickly the trough moves trough.
322 PM CST Wed Feb 5 2020 Mostly clear skies this afternoon and evening from an area of strong high pressure which is slowly moving off to the east. A cold front will move south from Ontario overnight, bringing in low clouds after midnight. However there is poor model agreement with the movement of the trough axis, which will affect far south the snow will spread Thursday afternoon.
On and off showers from this morning are still the case across most of the area, but as the warm front (currently draped approx west to east across southern Middle TN) lifts northward, heavier showers and a few thunderstorms have started moving in from the south. As this warm front inches northward over the next several hours, multiple upper level waves are expected to traverse along it. By this time tomorrow, the cold front associated with this system should be moving through the mid-state, dropping temperatures fairly rapidly.
The last bit of snow is quickly exiting the eastern column of the forecast area as the final piece of energy associated with this upper trough rotates northeastward toward northwest Texas and southwestern Oklahoma.
A cold front currently bisects the area in two with a much colder air mass spilling in behind the boundary and a warm unstable air mass ahead. Aloft a sharp trough is noted through the plains into Mexico.
Further northwest across the remaining taf sites, these areas will be to the northwest of the low track.
719 PM EST Wed Feb 5 2020 Upper air pattern consists of a 500 mb trough in the southern Rockies and also into the northern plains 12z Wed. The northern plains trough slowly moves east and remains over the area through 00z Fri. Starts off with a quiet forecast, then a cold front moves through late tonight into Thu and lake effect snow starts up later in the forecast with 850 mb temperatures falling to -12C by 12z Thu over Lake Superior. Only problem is airmass is pretty dry and soundings in the low levels show an inverted-v look to them. Moisture is pretty shallow with this cold front as well. Currently, the amounts look to remain on the low side, although some lake-enhancement under NE flow could assist in locally bumping up amounts a smidge.
Upper level trough moving across the area was producing an area of moderate to heavy snow in extreme eastern MO and into portions of central IL but this is moving northeast and will remain south of the dvn cwa. Thursday: Any lingering snow in our far southeast counties will end early otherwise partly to mostly sunny skies are expected with weak ridging.
532 PM CST Wed Feb 5 2020 High pressure and dry low level air have kept the area dry today, with light snow well to the south.
Copious amounts of sunshine will round out the day today before clouds move in from the north associated with an approaching weak wave/cold front. Tonight's cold front will bring the chance for light snow over the majority of the area. Behind the cold front will be cooler, more seasonable temperatures with lows in the single digits on either side of zero and highs in the teens above zero.
The clouds will very likely take the edge off with overnight lows a few degrees warmer in some locations. Strong height and thickness gains over the next 72 hours with the eastern flank of the ridge near the west coast dominating.
Per sfc obs/88D imagery, cold front slowly approaching the Acadiana terminals at this time. A cold front currently bisects the area in two with a much colder air mass spilling in behind the boundary and a warm unstable air mass ahead. Aloft a sharp trough is noted through the plains into Mexico.
314 PM MST Wed Feb 5 2020 2130Z infrared and water vapor satellite imagery show the upper level trough axis just east of the Tri-State area oriented from northeast to southwest.
521 PM CST Wed Feb 5 2020 Latest surface map shows a cold front near the International Border this evening. Low pressure is expected to develop over southern Saskatchewan this evening, then ride southeast along the front overnight. As a weak cold front across southern Canada sags south tonight and Thursday we believe the focus for snow will follow this feature.
1138 PM CST Wed Feb 5 2020 Mostly clear skies this afternoon and evening from an area of strong high pressure which is slowly moving off to the east. A cold front will move south from Ontario overnight, bringing in low clouds after midnight. However there is poor model agreement with the movement of the trough axis, which will affect far south the snow will spread Thursday afternoon.
1010 PM MST Wed Feb 5 2020 Latest upper level analysis has large trof across the Northern Plains into the southern Rockies with ridging over the western CONUS. At the surface, a weak trof of low pressure extends from far northeastern Montana southward into western Kansas. Western upper ridge will slowly edge into the area overnight with partly to mostly cloudy skies expected.
Weak ridging continues to move into the rest of the forecast area, with clearing skies and light winds.
Temperatures have been slow to warm in the valleys where the cold air remains trapped in the lower valleys due to weak surface winds, including the Treasure Valley and Baker Valley. The snow levels will continue to rise through Thursday with precipitation continuing mainly in the higher elevations in the north, including central Idaho and Baker County.
1219 AM EST Thu Feb 6 2020 Upper air pattern consists of a 500 mb trough in the southern Rockies and also into the northern plains 12z Wed. The northern plains trough slowly moves east and remains over the area through 00z Fri. Starts off with a quiet forecast, then a cold front moves through late tonight into Thu and lake effect snow starts up later in the forecast with 850 mb temperatures falling to -12C by 12z Thu over Lake Superior. Only problem is airmass is pretty dry and soundings in the low levels show an inverted-v look to them. Moisture is pretty shallow with this cold front as well. Currently, the amounts look to remain on the low side, although some lake-enhancement under NE flow could assist in locally bumping up amounts a smidge.
Thunderstorms will continue to increase in coverage to our west and move eastward as an upper trough to our west moves east and takes on a neutral to negative tilt. Instability and shear profiles will continue to favor the potential of severe storms this morning as a squall line is expected to develop ahead of the eastward moving cold front. The cold front and associated squall line will move east of the area by late this afternoon. Overcast skies and a few lingering showers will linger into this evening until the upper trough moves east of the area late tonight.
IFR to MVFR conditions should continue across Southeast Oklahoma and Northwest Arkansas overnight as a mid level trof axis moves through the region. behind the mid level trof axis. ceilings should continue to begin clearing out from west to east with Northwest Arkansas forecast to scatter out late afternoon/early evening as the upper level trof moves through.
With this update we did raise hourly/low temperatures a bit across the south/west tonight as the current widespread stratus deck should keep temperatures fairly warm ahead of the slow-moving cold front out of the north. An area of low pressure was located from northwest North Dakota into southeastern Saskatchewan, with a cold front dropping south of the International Border at this time. Latest surface map shows a cold front near the International Border this evening. Low pressure is expected to develop over southern Saskatchewan this evening, then ride southeast along the front overnight. As a weak cold front across southern Canada sags south tonight and Thursday we believe the focus for snow will follow this feature.
An area of low pressure was located from northwest North Dakota into southeastern Saskatchewan, with a cold front dropping south of the International Border at this time. Latest surface map shows a cold front near the International Border this evening. Low pressure is expected to develop over southern Saskatchewan this evening, then ride southeast along the front overnight. As a weak cold front across southern Canada sags south tonight and Thursday we believe the focus for snow will follow this feature.
Upstream, we're seeing quite a bit of overrunning precip in association with the main trof axis pushing ewd across TX which has had to be inserted into this TAF package as it appears it will continue to sweep ewd through the forecast area through the overnight hours. Per sfc obs/88D imagery, cold front slowly approaching the Acadiana terminals at this time. A cold front currently bisects the area in two with a much colder air mass spilling in behind the boundary and a warm unstable air mass ahead. Aloft a sharp trough is noted through the plains into Mexico.
226 AM CST Thu Feb 6 2020 Main upper trough was still west of the CWA early this morning with 850 mb front along the I44 corridor and the surface front over the OH/TN valley.
A positive tilted longwave trough continues to slowly move eastward through the central and southern plains. Winds by the afternoon will increase as a trough of low pressure in eastern Colorado develops. slight cold air advection returns from the north as a cold front moves in from Nebraska along with periods of mid level clouds streaming in from the north. it shouldn't be as cold a night with lows in the lower to mid 20s.
Just tweaked the timing of the higher pops moving back in, tweaked hourly temps, Td's, and winds based on recent obs, and expanded coverage of patchy fog. Likely to categorical pops will ramp back up from west to east over the next few hours as a line of showers and thunderstorms crosses the region ahead of the surface cold front that is finally starting to make some eastward movement. The cold front looks to slide into the western Carolinas by Thursday afternoon taking the heaviest rain out of the region, but upper level support will keep periods of light rain going through the afternoon. The cold front will begin to move across the terminals after 12z but precipitation is forecast to continue.
940 PM MST Wed Feb 5 2020 2130Z infrared and water vapor satellite imagery show the upper level trough axis just east of the Tri-State area oriented from northeast to southwest.
Very low dewpoint depressions across northern/northeast ND suggest that the low level environment is supportive of snow reaching the ground in our region as well, so flurries/light snow is expected to begin once the stronger radar returns begin to move in within the next few hours. Copious amounts of sunshine will round out the day today before clouds move in from the north associated with an approaching weak wave/cold front. Tonight's cold front will bring the chance for light snow over the majority of the area. Behind the cold front will be cooler, more seasonable temperatures with lows in the single digits on either side of zero and highs in the teens above zero.
1034 PM CST Wed Feb 5 2020 High pressure and dry low level air have kept the area dry today, with light snow well to the south.
248 AM CST Thu Feb 6 2020 Areas of light snow will linger into this evening across eastern Illinois, but a drying trend is expected west of I-55 as high pressure edges toward the Mississippi River.
A ridge extending from the Atlantic towards the FL peninsula will continue to retreat east but the pressure gradient will increase on Thu.
1026 PM EST Wed Feb 5 2020 The broad expanse of mean-layer ridging persists across the Caribbean, noted by the dry and stable air on water vapor imagery. Compared to 24-hours ago, the ridge has receded to the east, giving up ground to the long wave trough axis pivoting through the Plains. The forecast calls for nil rain chances with overnight lows assimilating to the SSTs, which are in the lower to mid 70s.
1031 PM CST Wed Feb 5 2020 Water vapor imagery and H5 heights show a defined trough continuing to dig into Mexico. This elongated, positively tilted trough will become more neutrally oriented this evening as it moves out into the Plains. Broad lift out ahead of this trough will become more defined over the ArkLaTex region northeastward towards the lower Great Lakes overnight tonight. A slight shift east in the system keep the highest snow totals south and east of the KC metro today with the metro just seeing a light dusting of snow. Locations further south may hang onto clouds a bit longer depending on how quickly the trough moves trough.
Most of the area is warmer at 230 am versus 24 hours, but there pockets in the Hard Freeze Warning area in Pima and Pinal counties that are running 2 to 4 degrees colder. The biggest change overall is in the mountains were temperatures were running 8-12 degrees warmer.
GOES-16 Satellite trends early this morning depict a deep upper level trough axis stretching from Northern Minnesota back through the Central and Southern Plains. Meanwhile, a cold front is located from Middle Tennessee back through Central Alabama, Southern Mississippi and Southeast Louisiana.
There will be warm advection across the area today and with the sunshine, temperatures will be warmer today. During the evening, with temperatures above freezing it could be light rain or sprinkles, then as the temperatures cool off, there will be rain/snow changing to snow/flurries during the evening.