Aikyam-Lab/Synoptic-Bench huggingface dataset:
Temperatures have warmed into the low/mid 30s across most of the Mid-South but skies have finally cleared out and winds are diminishing. With temperatures falling into the low/mid 30s, precip type could be tricky initially. Point soundings indicate a deep warm layer around +3C, although the ECMWF does appear slightly cooler.
A trough of low pressure arriving late in the weekend could bring light shower activity to parts of the area and breezy to windy conditions to much of the region. Cooler temperatures and breezy north winds are possible to begin the work week as a cold front rolls through the forecast area.
Coldest Night of the Season with Freezing Temperatures Across. A tightening pressure gradient is forecast on the back side of the low which will bring windy conditions to the coast and usher in a fetch of colder air into central Florida through the late night hours. Low temps will range from near freezing for inland Volusia and Lake counties to mid 30s for metro Orlando and lower 40s from the Cape south along the coast. Wind chills will drop into the 20s for the interior and Volusia county and in the lower 30s from Melbourne south along the coast.
Widespread MVFR to IFR cigs/vsbys in rain, snow, and fog/freezing fog.
/issued 145 PM CST Tue Jan 21 2020/ Water vapor shows an upper low moving across AZ with a long fetch of mid/upper level moisture stretching across Baja into NM and a 100kt 3h jet nosing into SE AZ/SW NM. In wake of mid-level trof/jet the flow will veer to the w Wed PM aiding in warmer high temps. Surface winds will continue to veer around to the n into Thur as a cold front will be pushed s by shrtwv trof moving through the central plains.
By the time sunset occurs and temperatures drop to near freezing, precipitation will be east of our area.
Temperatures are expected to be right around the freezing mark in areas with the greatest chances for precipitation. Thermal profiles are also not as favorable as yesterday for a freezing rain situation. An upper level trough will move through the region on Wednesday with flow aloft becoming northwesterly in the evening. A weak cold front will move through the region in the evening and a very slight chance of light snow will be possible in the extreme eastern portions of the CWA.
312 PM CST Tue Jan 21 2020 Strong southerly winds will continue across the eastern part of the area into this evening as that region remains between high pressure to the east and an approaching low pressure trough to the west. The trough/front slides across the area during the day Wednesday, with the potential for light post frontal snow showers Wednesday night, with little to no accumulation expected. Temperatures will remain mild through the period, with lows tonight in the lower to mid 20s, and highs on Wednesday in the 30s.
As such, clear skies expected overnight with lows near or below freezing for many locations despite winds remaining in the 5 to 10 mph range for much of forecast area. Lows will reach the mid/upper 20s to around freezing along the Nature Coast, with low/mid 30s elsewhere along with upper 30s to around 40 at far southern and immediate coastal locations. It is likely that more than a few central/interior locations reach the freezing mark overnight as well but remain there briefly enough to avoid meeting warning criteria.
Behind the upper trof, north winds are expected over the plains, and should be gusty Wed afternoon. Temps on Wed look warmer in most locations.
However, the mountains will likely see 2 to 4 inches of fresh snowfall with the higher peaks of the Bitterroots, Flathead, Swan and Mission Mountains receiving upwards of 10 to 14 inches of beneficial snowfall. But this will be a temporary reprieve as models begin to spread warm frontal precipitation into Idaho and Montana by Wednesday evening. However, the same will not be said for the lower elevations of North Central Idaho (Idaho & Clearwater County) along with the valleys near the Idaho/Montana border and in far NW Montana (Troy, Libby, Yaak).
Nonetheless, expect temperatures to still fall into the low to mid 20s areawide under mostly cloudy skies. Temperatures have warmed into the low/mid 30s across most of the Mid-South but skies have finally cleared out and winds are diminishing.
1010 PM MST Tue Jan 21 2020 Current surface analysis shows warm front across the central Dakotas into the central high plains, with an area of low pressure well northwest of the region. Another area of low pressure has developed along the warm front over southeast CO. Main forecast concern will be the cold front and upper level wave that will track across the region Wednesday into Wednesday night. Any accumulations will mostly be an inch or less, but the higher elevations of the northern Black Hills and possibly parts of far southern SD could see a bit more.
clouds will slowly increase today and tonight as high pressure slides east of the region.
A weak upper trough moving through tonight into tomorrow will bring just a small chance of a snow shower to the region. TFJ Upper ridge currently over eastern Montana will move to the east today. The inversions will be the strongest along and north of US 2 which will also have snow cover to keep temperatures cooler. Will mention patchy freezing fog tonight in some valley areas. There may be enough moisture for a chance of light rain, light snow, or light freezing rain on Wednesday.
Finally, a cold front will move across the TAF sites around mid to late morning Wednesday with north winds in its wake. Finally, a cold front will move across the area around mid to late morning Wednesday with north winds in its wake. At H7 positive theta-e advection ahead of the H7 trough can be seen in the deterministic models through about 06Z Wednesday. The higher dewpoints will keep overnight lows from dropping too dramatically. Some areas could see some snow mixed in with the rain, but will not see any accumulating snow with the surface slightly above freezing for most areas.
A cold front and accompanying showers has cleared southeast Oregon and is moving through southwest Idaho this evening. Most activity will work through the western Magic Valley by midnight, with lingering activity over the higher terrain along the ID/NV through sunrise.
234 AM CST Wed Jan 22 2020 Vigorous mid-level trough progressing east through the Plains early this morning per GOES Water Vapor/RAP 500mb analysis. In addition, fairly strong pressure gradient between departing high and incoming trough of low pressure was producing gusty south winds with gusts in the 25-35kt range across the open areas of southeast MN / northeast IA. For today, that mid-level trough continues edging eastward with plume of precipitation pushing into portions of northeast IA/southeast MN and western WI. Will probably see a several hour window from 3 am into the early morning commute hours where a wintry mix of light sleet/freezing rain and snow may all be present per latest forecast temperature/moisture profiles in the column.
225 AM CST Wed Jan 22 2020 A cold and quiet night is taking shape across the TN Valley, with temperatures in the lower to mid 20s. High clouds slowly moving in from the west will keep temps from dropping much more through the morning hours, with lows on track to be in the lower 20s by daybreak. Upper ridging is expected to move eastward through the day, while surface flow veers to the east. The ridge will move east of the area tonight, as a trough amplifies over the Plains, with flow aloft becoming southwesterly. High pressure at the surface will move off the Atlantic coast and surface winds over the TN Valley will shift to the south as well.
Mostly dry and warmer conditions will return mid week with rain likely to return over the upcoming weekend. The cold front has generated mainly light rain and drizzle and continues to fizzle out as it moves southeast this evening.
1155 PM EST Tue Jan 21 2020 Southeast Michigan will increasingly feel the effects of southwesterly return flow as strong surface anticyclone center slowly tracks eastward along the Ohio River. Upper level ridge over the Central Great Lakes this evening/tonight reaching the East Coast tomorrow evening. Strong warm advection pattern tonight as return flow around the high pressure departing into the Mid Atlantic States kicks in. 850 MB temps progged to reach zero Wednesday morning, +10 C warmer compared to this morning. Further low level warm advection (925 MB temps near -1 C) tomorrow should assure temperatures rise above freezing, even with thickening high clouds, although the MAV/MET guidance appears to be a bit too warm. Longwave upper level trough spreading into the Central Plains on Wednesday.
149 AM MST Wed Jan 22 2020 Water vapor shows short wave trof moving into the northern Rockies. At the surface, lee trof over central MT/eastern WY is slowly deepening. Upper trof and associated cold front will move into the region this afternoon and tonight. Ahead of the cold front, temps should warm into the 40s most locations. Thermal profiles suggest all snow in northeast WY and the higher Black Hills, with a rain/snow mix initially across the rest of western/central SD before colder air works in.
/issued 1245 PM PST Tue Jan 21 2020/ Weak high pressure will rebuild over the area this week with mainly dry weather.
Forecasted soundings for the mountains today and tomorrow show deep saturation through the boundary layer and temperatures well below freezing supporting efficient snowfall rates and snow ratios near 16-18:1. Euro brings the trough more southeasterly and becoming a strong Colorado low system with widespread precipitation. GFS has a trough similar to the systems we have been experiencing the past few weeks that barely clip the area. KRWL is currently at MVFR ceilings with forecast soundings suggesting that farther lowering to IFR conditions is likely with additional moistening at the low levels. Rain/snow showers could impact KCDR and KAIA late Wednesday afternoon with the approaching cold front.
327 AM EST Wed Jan 22 2020 Exiting high pressure will set the stage for southerly flow in the Ohio Valley to warm temperatures back to above normal for the foreseeable future.
342 AM EST Wed Jan 22 2020 High pressure shifts east today. High pressure ridge continues to move across the area leading to dry conditions and calm to light winds throughout the day today and into tonight. As the ridge axis shifts east of our area tonight, a transition to more southerly flow begins and upper level cloud coverage increases.
An upper level trough moving through the northern Rockies will graze northern Utah later tonight through early Wednesday. High pressure aloft will shift east across the Great Basin and bring dry and stable conditions to the area late in the week.
1145 PM EST Tue Jan 21 2020 High pressure will remain over Pennsylvania the next couple of days.
The axis of a mid/upper level ridge will be over the region today and then shift east as the next trough approaches from the west tonight.
256 AM CST Wed Jan 22 2020 Isentropic lift within a marginally cold airmass to support snow will continue through the morning where surface temperatures will hover near or just above freezing across central and southeast Kansas.
One last really cold night across the Valley, with temperatures falling into the lower 20s to perhaps upper teens as clear skies and light winds allow for good radiational cooling.
Widespread MVFR to LIFR cigs with lcl rain, snow, and fog/freezing fog. Added patchy fog/freezing fog to portions of the west and central for tonight, especially where models indicate low level moisture will linger.
No major changes were needed for the near-term period as dry high pressure will maintain quiet weather through tonight and support a temperature recovery back to the calculated-normals with heights rising in response to a deepening High Plains trough.
146 AM MST Wed Jan 22 2020 Latest upper air analysis and satellite imagery show a shallow trough within the zonal flow over the Plains. This trough has generated light to moderate rainfall and some snow ahead of it. Tonight a cold front will move in from the northwest ahead of the next upper level short wave trough. Late in the night as the upper level short wave trough moves through the northeast corner of the forecast area some light snow may occur.
1211 AM CST Wed Jan 22 2020 Updated for 06Z aviation discussion 06Z TAF discussion: VFR throughout the pd under high pressure ridge axis and sct/bkn cirrus. Cirrus continues to spill into the region this evening overtop mid level ridge moving across the area. /GG/ Prior discussion below: Expect dry weather tonight as high pressure remains in control. Lows will be chilly, ranging from the lower 20s to near 30. Highs tomorrow will still be on the cool side, ranging from the lower 40s north to near 50 far south.
1208 AM EST Wed Jan 22 2020 High pressure will slide south of the area overnight.
The low stratus and fog will gradually be scoured out on Wednesday as winds veer westerly. A cold front will also bring a northerly wind shift to the terminals in the afternoon. /issued 234 PM CST Tue Jan 21 2020/ An upper level trough axis extending roughly from SERN WY into the Sun Country of Texas will move eastward tonight helping to enhance lift across the region. Northwest flow aloft then returns late tomorrow as ridging builds along the west coast.
VFR conditions expected at all sites through the period with a clear sky and calm winds as high pressure remains across the region. As the ridge axis crosses the area tomorrow, high clouds will start to spread in from the west in the afternoon.
We also need to keep in mind that temperatures in the lower trop will warm a few degrees throughout the morning hours. Between the dry air in place along with the expected warming within the lowest 150 mb, snow or sleet accumulations will be difficult to come by.
636 AM EST Wed Jan 22 2020 High pressure remains over the region through Thursday.
Weak radar reflectivity returns were detected across southern and southeast WY, with some light snow showers over the higher terrain. Temperatures ranged from the lower 20s to middle 30s. After highs in the 30s and 40s today, it will be about 5 degrees cooler Thursday, along with gusty northwest winds.
Still looks to start off as light snow, then as warmer air moves in aloft and at the surface, a wintry mix will develop and spread across the region during the afternoon hours and persist through the night tonight. In the meantime, upper level trof will continue to deepen and eventually begin to lift out through forecast area Thursday night.
Current surface map showing temperatures spanning from the low 30s inland to mid 40s closer to the coast.
A weak cold front will move across the area tonight, with light northwest winds following the front. /issued 451 AM CST Wed Jan 22 2020/ (Today and Tonight) Upper level trough axis will move east of the area by early evening, with a weak cold front following behind the system tonight. Temperatures will be warmer today, with afternoon highs mainly in the low to mid 60s. The weak cold front will move south across the area tonight, with light north winds prevailing in its wake.
523 AM CST Wed Jan 22 2020 Southwest winds at AMA and GUY will gradually become northerly by mid to late morning as a cold front moves through the area.
322 AM MST Wed Jan 22 2020 Water vapor shows short wave trof moving into the northern Rockies. At the surface, lee trof over central MT/eastern WY is slowly deepening. Upper trof and associated cold front will move into the region this afternoon and tonight. Ahead of the cold front, temps should warm into the 40s most locations. Thermal profiles suggest all snow in northeast WY and the higher Black Hills, with a rain/snow mix initially across the rest of western/central SD before colder air works in.
740 AM CST Wed Jan 22 2020 The region is being influence by weak ridging, and given the light wind regime there are a few sites reporting visibility (likely due to fog) down to 2-4 miles. Although precipitation will likely begin as light snow, a layer of dry air is expected to advect into the lower to mid-levels with saturation remaining below 850 mb. This will serve to increase our chance for freezing drizzle as we head into Thursday evening and overnight.
Snow covered roads are also occurring on area passes, along with the potential of light freezing rain around Troy, Libby, and Thompson Falls. Once again with the rising snow levels and overnight temperatures near freezing, spotty light freezing rain will be possible early Thursday.
Attempted to estimate road temperatures during this time period between 33-34 degrees, but acknowledge some locations may be at or below freezing. The greater concern will be with elevated surfaces and bridges and sidewalks. The NAM-WRF family, 13km RAP, and Canadian (CMCNH) guidance seemed to have the best initialization of the low level thermal profile during the critical time period. Without compromising the QPF amounts, made a 50-75% reduction to ice accumulation during this time period, as surface temperatures will be around 32 degrees and the low level layer should rise at or above freezing from the south during this time period. The both the NAM and Canadian are similar in deepening and closing off a low over KS Thursday morning, but the increasing lift and moisture advection will develop after most low level temperatures have risen above freezing.
/issued 433 AM CST Wed Jan 22 2020/ Expect dry weather this morning as high pressure remains in control. Satellite depicts cloud cover from the Plains continuing to move eastward into the region, as a mid- level ridge builds over the Mid-South. Some light rain will be possible late this evening into tomorrow morning as a broad trough and closed low moves eastward from the Plains later today. Highs today will still be on the cool side, with temperatures generally in the lower 40s. Temperatures in northeast Arkansas and the Missouri Bootheel are still expected to be near freezing as showers make their way toward the area.
The high resolution models are struggling with this fog to begin with, so as of now do not plan to expand the dense fog advisory due to these uncertainties. The higher totals will occur in the Park, Elkhead, Flat Top and Gore ranges today with amounts of 4-6 inches and an isolated pocket of 10 inches near Tower.
302 AM MST Wed Jan 22 2020 An upper trof will push a cold front through the area this morning. Downslope winds plus afternoon sun will allow temperatures to stay in the 40s this afternoon despite the cold front. Expect snow showers to develop over the higher terrain mainly in the afternoon hours, possibly drifting into the adjacent lower elevations.
753 AM EST Wed Jan 22 2020 Arctic high pressure will remain across the eastern United States through Thursday.
600 AM EST Wed Jan 22 2020 Arctic high pressure will remain across the eastern United States through Thursday.
544 AM CST Wed Jan 22 2020 Have some patchy morning fog behind the higher clouds with some MVFR conditions but so far only HOB has IFR. Wind will become more westerly by midday and gusty as trough moves across.
Moist west to northwest flow aloft will bring periods of snow to the high mountains at times.
The low level flow between a high pressure system over the eastern United States and a deepening low pressure system northeast of the Bahamas will support strong northerly breezes through the remainder of the morning across the coastal waters of the Florida Keys. Low pressure will exit east of Bermuda tonight and Thursday. A high pressure ridge will then extend from New England down the U.
This combination should result in light snow, possibly mixed with freezing drizzle or sleet at the start.
Moderate to strong onshore flow will continue today ahead of the cold front bringing an abundance of moisture into the area.
Winds will start out from a southerly direction this morning, shifting to a northerly direction from west to east by midnight tonight as a cold front moves through the area.
SW to W winds early will shift toward NW and N behind a cold front. This will bring in an initial weak cold front across the area by this evening. A slightly stronger secondary cold front will move into the region early Thursday morning which will help cool Thursday's temperatures a few degrees from today's high temperatures.
An upper level trough moving through the northern Rockies will graze northern Utah today. High pressure aloft will shift east across the Great Basin and bring dry and stable conditions to the area late in the week.
The warm front that is bringing in this light precipitation will become stationary along the coast. Precipitation will become lighter this evening as the warm front finally shifts north ahead of the approaching cold front that brings heavier precipitation as the right entrance region of a 70kt jet swings through the region.
While temperatures were mostly near to above freezing. freezing rain has mostly changed over to light snow for just about everyone. and only a few small pockets of additional freezing rain are expected through the morning hours. The main upper low impacting the region this morning will continue transitioning east by Thursday night as high pressure nudges in from the west.
Precip will continue to move east this morning with areas along the Wyoming border expected to see the highest snow amounts and even this should be limited to an additional 1-2 inches at the most at this point and this will be across the highest elevations.
High pressure will maintain quiet weather through tonight and support a temperature recovery back to the calculated-normals with heights rising in response to a deepening High Plains trough. Further temperature moderation can be expected on Thursday as warmer southwest flow ensues on the western flank of the aforementioned ridge, still in response to the progressing Plains trough. By Thursday night, cutoff upper low pressure is forecast just west of the MO/MS-junction with a broad swath of warm, moist advection on its van blanketing the OH Valley and Great Lakes.
This will bring in an initial weak cold front across the area by this evening. A slightly stronger secondary cold front will move into the region early Thursday morning which will help cool Thursday's temperatures a few degrees from today's high temperatures.
Meanwhile, more energy will dig into the western Dakotas as a mid-level ridge re-asserts itself over the western CONUS.
Although precipitation will likely begin as light snow, a layer of dry air is expected to advect into the lower to mid-levels with saturation remaining below 850 mb. This will serve to increase our chance for freezing drizzle as we head into Thursday evening and overnight.
600 AM CST Wed Jan 22 2020 12Z TAFS High pressure centered across Appalachia this morning is resulting in moderate easterly winds. A widespread precipitation shield associated with this low will spread across the area from west to east through the day with CIGs falling to MVFR late this morning into early this afternoon then to IFR overnight. Current surface map showing temperatures spanning from the low 30s inland to mid 40s closer to the coast.
534 AM CST Wed Jan 22 2020 Isentropic lift within a marginally cold airmass to support snow will continue through the morning where surface temperatures will hover near or just above freezing across central and southeast Kansas. Another period of rain and snow showers is expected on Thursday, mainly from late morning into the afternoon, as an upper trof approaches from the northwest, becoming a closed low across eastern Kansas into western Missouri.
Ensemble 500mb heights form a nice ridge pattern extending into eastern Montana for late in the week, thus leading to temperature recoveries and dry weather conditions with associated large scale subsidence.
On Thursday, an upper level trough will continue digging across the Plains, with a closed upper low expected to develop over the Central Plains by Thursday evening. Under the southerly flow, high temperatures on Thursday will warm into the low to mid 40s.