Aikyam-Lab/Synoptic-Bench huggingface dataset:
351 PM MST Sun Jan 26 2020 Upper trough approaches the area overnight, leading to thickening mid/high level cloudiness after sunset. On Monday, trough swings through the state, with weak upper level low closing off over ern NM by evening. Should be enough lift for fairly widespread snow showers over the mountains through the day, and some light accumulations (generally 1-3 inches) will be possible, especially over the high peaks back toward the Divide. Max temps at many lower elevation locations will get well above freezing in the morning/early afternoon, before precip arrives and temps begin to fall late in the day.
There may be enough moisture toward morning to start up some light orographic snow over the mountain ridges. The best lift and mid and high level moisture comes over the mountains in the morning and the plains by early afternoon, but the low levels will still have northwest winds and fairly dry air. The trough axis in the afternoon to early evening comes with only a few degrees of cooling aloft, so while there will be a mid level pocket of instability, it won't be a lot and will be accompanied by a little drying. Models have an upper trough over the CWA Monday night.
542 PM CST Sun Jan 26 2020 Yet another weak impulse will drop across the area tonight, and bring a threat for freezing precipitation to the western portion of the forecast area. There is virtually no model that shows moisture in the dendritic growth zone, so if precip does reach the ground it will be freezing not frozen. Slightly cooler air does filter in for Monday night, so slightly lower readings from 10-20 degrees are expected. Patchy freezing mist/freezing fog will be possible each night as snow gradually melts during the day and keeps the near-surface boundary layer near-saturated when temperatures cool overnight. Temperatures look to warm this weekend as well with at least some ridging building into the central US as the jet comes ashore.
A brief period of very light snow or freezing drizzle could clip Lafayette and Green County late this afternoon and early evening. This feature will aid in bringing the cold front currently over Upper MI slowly swd across srn WI and Lake MI late tnt. A low potential for patchy freezing drizzle and very light snow has been be added to the forecast with this frontal passage.
/issued 235 PM CST Sun Jan 26 2020/ A broad upper level trough extends from the central part of the country to the east coast with another trough moving over the west coast. The trough from the west coast will move over New Mexico on Monday with winds strengthening out of the west across West Texas and southeast New Mexico. Strong winds from the base of the trough will mix down and may result in high winds across the Guadalupe Mountains. There is a slight chance for rain across portions of the area Monday night as the upper trough moves overhead and proceeds eastward.
High pressure at the surface will then build in from the north. Upper low over NY state is lifting quickly to the northeast with fast NW flow over the eastern lakes and PA. The snow showers will gradually diminish in coverage and intensity through the day on Monday as the trough axis left behind from the upper low will be overhead in the afternoon.
Temperatures will be several degrees warmer Monday morning than this morning.
Another batch of mid level clouds was moving across central and western Nebraska ahead of a mid level trough over South Dakota this afternoon. On Monday the trough over South Dakota is forecast to track southeast into Iowa and northern Missouri early Monday morning, then track into the Mid Mississippi Valley. Will see and increase in clouds as well as cool advection as the trough passes through the day.
The main concern in the short term will be for fog including dense freezing fog tonight into tomorrow morning. This setup with persistent light winds as high pressure is in control at the surface will lead to widespread dense fog tonight into tomorrow morning and as such a dense fog advisory has been issued for visibilities being reduced less than 1/4 mile. Fog will again be persistent tomorrow morning and that will again act to hold temperatures down to the lower 30s across the north to the lower 40s south where fog will be less persistent and under partly sunny skies.
Areas of patchy fog along with the low stratus clouds are possible tonight around the Opheim Plateau.
Areas north of I-80 and the ridges have the best shot of snow accumulation; 1-2 inches is likely. If ground temperatures fall just below 32F, isolated freezing drizzle may prevail. With building high pressure in eastern Ohio, drier air may advance into the DGZ, especially south of Pittsburgh. With shallow low-level lift, freezing drizzle may continue to impact isolated areas during tomorrow's morning commute. Snow accumulation potential will continue to be best along the ridges and the far northern CWA due to lake enhancement, with another 1 to 2 inches expected.
524 PM CST Sun Jan 26 2020 The main concern in the short term will be for fog including dense freezing fog tonight into tomorrow morning. This setup with persistent light winds as high pressure is in control at the surface will lead to widespread dense fog tonight into tomorrow morning and as such a dense fog advisory has been issued for visibilities being reduced less than 1/4 mile. Fog will again be persistent tomorrow morning and that will again act to hold temperatures down to the lower 30s across the north to the lower 40s south where fog will be less persistent and under partly sunny skies.
352 PM CST Sun Jan 26 2020 Active weather pattern will continue for the next 7 days as we are affected by low pressure systems every 48ish hours.
329 PM MST Sun Jan 26 2020 High pressure aloft will move east of Utah ahead of a weakening weather disturbance for tonight through early Monday.
The resultant cloud cover is in response to an upper level trough axis moving across the Central Gulf states. As a result, temps will be noticeably warmer than what we woke up to this morning but still near average.
625 PM EST Sun Jan 26 2020 Aviation Fairly quiet weather pattern this week with just occasional chances for light snow showers or freezing drizzle.
Dry weather is expected for much of the week with weak high pressure in place. An upper level low pressure system will be approaching the area this weekend with a mixture of rain and snow possible. There is some uncertainty of whether temperatures aloft will be cold enough for the ice nucleation necessary for flurries, but based on current upstream observations and soundings that show some saturation up to 500mb during the day today, confidence is higher in flurries than for freezing drizzle. Winds will generally be out of the northwest at less than 10 mph through the day with high temperatures climbing into the low to mid 30s.
Areas of freezing drizzle this morning and tonight. Possibility of some freezing drizzle this morning and tonight. Upper low still slowly moving east and into Quebec with trough extending back across the Great Lakes this morning. At the surface, low pressure over Nova Scotia with associated trough extending back through the southern Great Lakes. High pressure was centered over Saskatchewan. Thinking is that precipitation is very light and surface temps are near freezing, so impact should not be great. Inversion top still around -10C so ice nucleation not definite and therefore at least the chance of some more freezing drizzle or light snow showers tonight and into Tuesday morning. Perhaps a few flurries or a little freezing drizzle. Amount/timing/extent of freezing drizzle. This may prolong flurries or a touch of freezing drizzle as model soundings show moisture hugging the -10 C isotherm.
The low pressure circulation will remain offshore with a warm front bringing in ample moisture. Initially the increasing southerly flow will erode the low clouds from the south during the afternoon, but then conditions will deteriorate Monday night with the precipitation.
Temps will remain in the narrow range with highs in the lower 30s. Thus, think this will be all snow rather than freezing drizzle. Ridging will be moving in Tuesday night. It appears that there won't be enough subsidence to get rid of the low lake-effect clouds, however, so that should keep a lid on temps.
An upper level ridge will move out over the High Plains later tonight and Monday. This will push a backdoor cold front south through western Kansas early Monday morning.
Latest surface analysis indicated a weak trof along the Ohio Valley, while a narrow ridge axis off northern Plains high extended east across northern MO and into central IL. Areas of fog are evident in surface obs under the low cloud deck. Have also seen a few reports of freezing drizzle near Davenport and south of Kankakee, and a few light radar returns showing this tracking southeast. Will issue an SPS to highlight scattered slick spots on area roads this morning due to patchy fog/freezing drizzle.
Warmer temperatures around 10 degrees above seasonal normals are expected for the second half of the week. The Evening Update: Isolated persistent showers E of RBL and into the NE Foothills since late this afternoon are finally showing signs of moving ENEwrd as warm front begins to lift NEwd.
1035 PM MST Sun Jan 26 2020 Mean western CONUS ridge will persist through the week supporting mild westerly flow most of the period. Cold front is settling south across the region with low clouds and some light drizzle affecting portions of NW SD. Warmer conds on track for Tues and Wed with perhaps a few diurnal showers over the higher terrain per mixing and weak impulses. A cold front will push through Monday afternoon.
Highs still on the warmer side of average for late January - afternoon readings peaking just above freezing. However, moisture advection remains quite limited and confined to the lowest 5000 ft, while forcing stays elevated above this level with any attendant low level convergence lacking. Otherwise, similar environment as noted today - high temperature distribution in the vicinity of freezing and another day of extensive stratus. Weak low level troughing may emerge Tuesday night as flow starts to veer upon exit of the upper wave. This simply maintains the possibility for flurry production or generation of some patches of freezing drizzle through the overnight hours.
As the evening progress, low level moisture looks to become deep enough (more than 1km) at times, along with a weak mid-level trough providing weak lift, to produce some patchy freezing drizzle. , but prefer to have at least a slight chance for the freezing drizzle, so added it to the forecast. The freezing drizzle and refreezing of wet pavement could lead to some slippery roads and surfaces. For Monday, any lingering freezing drizzle will end early in the day as mid and upper level ridging builds in from the west.
1250 AM EST Mon Jan 27 2020 Aviation Fairly quiet weather pattern this week with just occasional chances for light snow showers or freezing drizzle.
Still not expecting any accumulations outside the higher elevations, so the SPS will be left as is. CDG Chattanooga Airport, TN 53 34 53 38 47 / 30 10 0 20 30 Knoxville McGhee Tyson Airport, TN 50 34 49 35 45 / 70 10 0 10 20 Oak Ridge, TN 50 32 49 34 45 / 70 10 0 10 20 Tri Cities Airport, TN 46 33 44 31 44 / 70 20 0 10 20.
1132 PM CST Sun Jan 26 2020 Tonight-Monday: Main concern this period will be location/timing of backdoor cold front.
Low pressure will move across northern Arizona tonight through Monday afternoon bringing scattered light rain and snow showers, mainly along and north of the Mogollon rim.
Additional snow amounts today will remain light, with any accumulations approaching an inch likely confined to some of the ridgetops, although lake enhancement may allow for some slight bumps to coverage and amounts north of I-80. Low inversion heights and marginal moisture in the dendritic growth zone are leading to the overall low snow expectations, and also raise the possibility of a lack of ice crystals leading to drizzle and/or freezing drizzle. Have added these chances in for today using NBM ice crystal probabilities - leading to the addition of drizzle chances to the ridges initially, and then to areas north of Pittsburgh later this morning. The drizzle/freezing drizzle threat may continue into at least tonight as moisture remains shallow, but confidence remains low and will allow the day shift to evaluate this chance.
The weak isentropic lift ahead of the trough will keep these light rain showers or drizzle over the region overnight. The axis of the upper level trough will move off to our east with nearly zonal flow setting up for Monday night through Tuesday.
810 PM PST Sun Jan 26 2020 Building high pressure will bring warm weather and mostly sunny skies Monday and Tuesday.
1143 PM CST Sun Jan 26 2020 Yet another weak impulse will drop across the area tonight, and bring a threat for freezing precipitation to the western portion of the forecast area. There is virtually no model that shows moisture in the dendritic growth zone, so if precip does reach the ground it will be freezing not frozen. Slightly cooler air does filter in for Monday night, so slightly lower readings from 10-20 degrees are expected. Patchy freezing mist/freezing fog will be possible each night as snow gradually melts during the day and keeps the near-surface boundary layer near-saturated when temperatures cool overnight. Temperatures look to warm this weekend as well with at least some ridging building into the central US as the jet comes ashore.
Cloud cover will help keep temperatures in the low to mid 40s tonight under light southerly winds. Also, temperatures should remain above freezing with the expected clouds. Will stick close to suggested blended max temps on Tuesday in the lower to middle 50s with weak warm advection.
/issued 235 PM CST Sun Jan 26 2020/ A broad upper level trough extends from the central part of the country to the east coast with another trough moving over the west coast. The trough from the west coast will move over New Mexico on Monday with winds strengthening out of the west across West Texas and southeast New Mexico. Strong winds from the base of the trough will mix down and may result in high winds across the Guadalupe Mountains. There is a slight chance for rain across portions of the area Monday night as the upper trough moves overhead and proceeds eastward. A cold front associated with this upper trough will push into the area on Tuesday.
230 AM EST Mon Jan 27 2020 A weak trough axis is propagating eastward across the southeast.
Models are little overdone with some of the lower vis and how far east it gets, while Bufkit and other models do not carry it very far east.
Also watching some speckles of very light freezing drizzle working westward toward the Mississippi River. Per guidance trends, not as much of a freezing drizzle signal as existed this time yesterday as that wave passes, though still some hint for sufficient moisture depth to near 1. Temperatures look a little warmer today as shallow warm advection wraps in from the east, giving way to another slight cooling trend Tue-Wed, though still well above normal for the time of year. That setup will favor broad anomalous upper ridging developing over much of the western states, extending eastward through the Plains and Upper Midwest briefly through the weekend (per current trends, of course). Strong signals are in the model guidance for northeast flow to begin to scour the lower visibilities southward, but with an LIFR CIG remaining.
By early Tuesday, a sharpening upper level trough will approach from the west.
this could be slightly too cool, if stratus moves in as expected it could keep temps a bit warmer. Monday-Tuesday: Monday is quiet, cloudy and cooler than this past weekend was, but the next disturbance approaches during the day and will impact the area Monday night in to Tuesday morning. Precipitation is expected to move in from the High Plains in the late afternoon/early evening and move south-southeast across the area.
Patchy freezing drizzle is possible into early Monday morning.
A cold front was working its way east as of 230 pm MST, located roughly from McCall to just east of Ontario to near Rome, OR. This front, and the accompanying upper level trough axis, will bring snow levels down considerably from where they have been most of today. Snow levels will increase during the day as southwest flow aloft brings in warmer air, beginning the day ranging from 4000 feet in the north to 4500 feet in the south.
A low pressure system will begin developing over Texas Tuesday and as it moves this way, should remain south of us, traversing the Gulf States.
Steep mid-level lapse rates and adequate shear, coupled with the strong forcing with the approaching trough could produce some strong storms producing small hail. Gusty Northwest winds behind the front will bring drier and slightly cooler air to the area, shaving a few degrees off of the highs for tomorrow.
328 AM EST Mon Jan 27 2020 High pressure will return this afternoon and prevail into Tuesday.
1008 PM MST Sun Jan 26 2020 The upper ridge over the Intermountain region moves over the Rockies tonight and across the central High Plains region as it flattens ahead of the approaching broad latitude upper trough on Monday. That upper trough moves across the forecast area late Monday night into early early Tuesday morning with the trough axis moving east of the forecast area by late Tuesday afternoon.
247 AM EST Mon Jan 27 2020 Upper low level pressure will keep skies mainly cloudy through Tuesday with snow showers possible in the mountains. The weekend may be fair also, but there is a chance that low pressure may affect the region later in the weekend. A short wave trough will pass across the region today keeping skies mostly cloudy. While the main short wave trough moves off to the east tonight and Tuesday, broad and moist cyclonic flow will persist over New England, allowing for clouds to persist. Under this regime southern stream energy will pass well to our south with high pressure building into the Northeast. High temperatures will be around seasonal averages mid week warming to above average by the end of the week as high pressure shifts to our east.
KMLB WSR-88D is picking up some light reflectivities across north Lake/Volusia counties this evening but evening soundings from JAX and XMR show considerable dry air in the low levels so unlikely much if any of this precip is reaching the ground; at most, a few sprinkles. The mid level trough will dampen as it approaches the Florida peninsula on Monday with a swath of deeper moisture moving through during the morning hours and then some drying aloft in the afternoon. Will carry a low 20 percent chance for a light shower or sprinkles across central and nrn sections mainly during the morning but continue a low shower chance mainly northern sections ahead of a weakening trough in the afternoon.
Best chances of seeing up to an inch remain north of I-80 and in the ridges. Also, cloud top temperatures should remain colder than -10C in most precipitating cases, which will keep any further threat of freezing drizzle isolated at best. With building high pressure in eastern Ohio, drier air may advance into the DGZ, especially south of Pittsburgh. With shallow low-level lift, freezing drizzle may continue to impact isolated areas during tomorrow's morning commute. Snow accumulation potential will continue to be best along the ridges and the far northern CWA due to lake enhancement, with another 1 to 2 inches expected. With building high pressure over the Midwest, dry conditions shall prevail mid-week. An upper-level ridge is expected to build over the West Coast and expand into the Great Plains late week.
Showers may begin to affect portions of East Texas, including KTYR, near the end of the TAF cycle as the next upper trough and cold front move approach the area. However, the clouds should break enough this afternoon for temperatures to still warm into the lower to mid 60s.
Rain will end from west to east late this morning into the afternoon hours as the low heads east with some return of the sun is possible in our southeast Alabama and western Florida panhandle counties late this afternoon. Those western sections could reach the low to mid 60s whereas eastern sections will be in the upper 50s to lower 60s.
340 AM CST Mon Jan 27 2020 Temperatures and dew points are both in the low to middle 40s across most of the Midsouth under clearing skies.
Early morning satellite imagery shows a compact closed low progressing southeast through Iowa, which prompted freezing drizzle and flurries across a portion of the region overnight. The latest surface observations and webcam images show that freezing drizzle and dense fog have developed across much of southwest MN with flurries and freezing drizzle across portions of southeast SD. in mainly northwest flow aloft, ahead of strong ridging off the west coast. On Tuesday and Tuesday night, a north-south oriented trough passing through the Northern and Central Plains is expected to develop light precipitation in the region.
With the exception of the NAM, there is excellent model agreement on the track of this upper trough through nearly the next 48 hours. The NAM also pull the low rapidly to the north, phasing with another trough moving out of the Central Plains; however, this northern low, present on other models, is shunted south into our system by a developing high over Ontario and the Great Lakes. With the currently forecasted track of the trough, a good portion of our FA will be squarely sitting in the dryslot for most of the passage of this one, though a very small window exists for a quick shot of some very meager precip. The bigger impact from this system will likely be the winds on the backside as the cold front is dragged through.
/issued 340 AM CST Mon Jan 27 2020/ Temperatures and dew points are both in the low to middle 40s across most of the Midsouth under clearing skies.
Moving into the overnight period, cooler air will filter into the region as high pressure builds in. Went with MAV/MEX for forecast highs instead of NBM as the NBM is typically too cool on the return of warmer air. Showers and a few thunderstorms should be returning to the local area mid week as a slightly more amplified trough moves right in the path of the one before it. Winds will weaken slightly and become easterly tonight as the low pressure shifts east and high pressure builds in from the north. A stronger open wave trough will move through the area mid week.
Still some question on efficiency of rain to snow transition over areas outside of western/northern Oklahoma due to warmer/moist air wrapping around system. Track of mid level low would suggest the higher snow chances and accumulations will be across the northern-third or so of Oklahoma. Farther east and south into central parts of Oklahoma, as mentioned above, a pesky warm nose wrapping around system, along with warmer boundary layer conditions, minimal or no snow accums expected at this time.
Due to the abundant low level moisture in place over the area, and frontogenesis along the NW-SE oriented surface boundary, some precipitation will develop as the upper trough affects the area later today and tonight. While most of the precipitation is expected to fall as light snow, there may be some periods of rain, drizzle or light freezing drizzle. While much of the area may see some light snow later today and tonight, the best chance for any accumulation will be over parts of northeastern Wyoming, the Black Hills and far southwestern South Dakota where the low and mid-level frontogenesis will be strongest. An inch or two of snow accumulation is possible in those areas, however due to the timing, mainly during the afternoon/early evening, the accumulation will be mainly on grassy surfaces and over the higher terrain.