Aikyam-Lab/Synoptic-Bench huggingface dataset:
533 AM CST Sun Feb 21 2021 (Today and tonight) Stratus has been spreading northeast into the area this morning, but it appears that stratus will be less widespread than previously expected given the current trajectory and the expected veering low-level winds ahead of a cold front. The cold front is likely in northern Harper County as the winds at Medicine Lodge KS and Perryton TX have become north/northwesterly. It will bring cooler air into the area, although some areas will still see warmer temperatures today with the decreasing influence of the melting snowpack.
Otherwise, mainly dry weather is ahead this upcoming week with temperatures warmer than the past 2 weeks, but still mostly below normal with highs in the 30s to around 40. Have also favored some of the higher resolution models over the GFS which appears to be too aggressive with warm air advection in the lower levels given evaporative cooling.
541 AM CST Sun Feb 21 2021 Breezy and warmer today as a front lifts across the region.
630 AM EST Sun Feb 21 2021 High pressure will rule today.
Upper level ridging will build in over the region and this is going to bring a period of quiet weather with warming temperatures. Highs today will generally be 5-10 degrees warmer than yesterday.
A cold front moves into the area this evening, clearing clouds and switching winds to northerly. Meanwhile, an upper trough in the Four Corners region will push a cold front through the area this evening. The cold front sends drier and slightly cooler air to the area via northerly winds, only shaving off a few degrees from the previous highs.
/issued 349 AM CST Sun Feb 21 2021/ WV imagery shows an upper trough digging through the Four Corners, and set to move through West Texas and Southeast New Mexico later today. If KMAF stays above freezing this morning, it'll be the first time in almost 2 weeks. To the north, sfc analysis shows a cold front moving through the panhandles, and this will drop into the area behind the front around noon or shortly thereafter. Areas over the SE CWA, which were cool yesterday due to lingering snow cover, could actually see warmer highs than yesterday before the front reaches them.
654 AM CST Sun Feb 21 2021 Well some good news this morning is that so far the freezing drizzle potential has yet to be realized , so concerns for ice accumulation have significantly decreased. Will still need to monitor the corridor east of HWY 281 this morning though, since this is the area that still has a chance to see some freezing drizzle should we lose the saturation in the DGZ. Since we will be in a post cold frontal airmass, our highs today aren't exactly expected to increase from yesterday's.
(Today and tonight) Stratus has been spreading northeast into the area this morning, but it appears that stratus will be less widespread than previously expected given the current trajectory and the expected veering low-level winds ahead of a cold front. The cold front is likely in northern Harper County as the winds at Medicine Lodge KS and Perryton TX have become north/northwesterly. It will bring cooler air into the area, although some areas will still see warmer temperatures today with the decreasing influence of the melting snowpack.
A good inversion has setup between the valleys and higher elevations with temperatures ranging from the lower/mid 20s to the mid 30s. Patchy freezing fog looks a bit more doubtful at this time. However, cannot rule out some patchy freezing fog from Meridianville east into the Scottsboro area and near Tullahoma, Tennessee through 8 AM. Although retreating to the east, the western edge of a large area of high pressure will continue to dominate the weather today. Cooler air will push into the region behind the front, but nothing too cold, due to the source region of the high.
08z WV satellite shows quick moving positively tilted upper trough over CO/NM moving eastward over the High Plains. At the surface, cold front has begun to push into the northwestern Panhandles, with resulting surface winds, measured at 20 to 30 mph at the Kenton, Boise City, and Stratford mesonets, higher than all consensus blends. With surface wind speeds overachieving overnight, have trended toward the high end of consensus blends and short term models through around 16z, when surface pressure rises and the 850mb jet begin to subside, yielding gusts up to around 40 mph. Largely dry northwesterly flow aloft takes over in the wake of the aforementioned upper trough for Monday. Have similar concerns about the impact of bias correction in NBM for Monday, so have trended a bit warmer using Superblend, which has a bit more weight toward non bias corrected guidance.
417 AM EST Sun Feb 21 2021 A sprawling, strong high pressure resides along the Appalachians this morning and is moving eastward.
/Issued 248 AM EST Sun Feb 21 2021/ High pressure is currently centered across the Mid Atlantic. The high center will move offshore today as a cold front moves into the Lower Mississippi River Valley.
A passing system will much cooler air today before another warmup through the middle of this week. Significantly cooler today and much less wind in the wake of an upper level trof passage and its associated colder airmass. Highs today will range for 7 to 16 degrees cooler than yesterday or be 1-5 degrees below normal in the valleys and 7 to 13 degrees below normal in the mountains.
516 AM EST Sun Feb 21 2021 High pressure will rule today.
The upper trough axis will push through our eastern areas toward midday and afternoon which clear the last of the snow out. Afternoon readings will have no trouble reaching the low to mid 40s east to upper 40s to upper 50s west of the James valley.
Also, there is still some light snow falling over the higher mountains. The water vapor picture are showing the upper trough axis over the western CWA at this time. There should be a tad of low level moisture lingering the in the high mountains both today and tonight. Will let the highlights in the mountains expire at 5 AM MST this morning.
349 AM CST Sun Feb 21 2021 WV imagery shows an upper trough digging through the Four Corners, and set to move through West Texas and Southeast New Mexico later today. If KMAF stays above freezing this morning, it'll be the first time in almost 2 weeks. To the north, sfc analysis shows a cold front moving through the panhandles, and this will drop into the area behind the front around noon or shortly thereafter. Areas over the SE CWA, which were cool yesterday due to lingering snow cover, could actually see warmer highs than yesterday before the front reaches them.
943 AM EST Sun Feb 21 2021 High pressure builds eastward over the region today with a frontal system approaching Monday.
301 AM CST Sun Feb 21 2021 Key messages: - Wintry mix of snow, freezing drizzle, and freezing rain expected for parts of northern Missouri.
Meanwhile, an upper trough in the Four Corners region will push a cold front through the area this evening. The cold front sends drier and slightly cooler air to the area via northerly winds, only shaving off a few degrees from the previous highs.
541 AM EST Sun Feb 21 2021 Upper air pattern consists of a 500 mb trough over the northern plains down into the southern Rockies and a trough across the Canadian prairies. Both troughs move east and affect the upper Great Lakes by this evening before the trough axis moves out of the area late tonight. Positively-tilted trof bringing light snow showers across much of the Upper Great Lakes Sunday evening, should be east of the CWA by Monday morning.
A passing trough and building high pressure aloft will set up gusty and warmer Santa Ana conditions through Monday.
/issued 358 AM CST Sun Feb 21 2021/ Another clear and cool night across the Mid South as high pressure slides east today setting up return flow ahead of a cold front that will bring a chance of rain to the area tonight.
SHORT TERM (Today through Monday): A 500mb trough across the central United States extending southwest into New Mexico today will move eastward tonight bringing a Pacific cold front into north Texas this afternoon and into south Texas tonight. The pressure gradient will increase across the lower Texas coast today ahead of the front and breezy to windy conditions will develop across the Rio Grande Valley and northern ranchlands. The cold front will move through the Rio Grande Valley Mon morning bringing an end to rain chances. Cooler air will filter into deep south Texas Mon afternoon and highs will be in the lower to mid 70s across the Rio Grande Valley.
514 AM CST Sun Feb 21 2021 Cold front will move through the terminals this morning shifting winds to the north and increasing speeds. /issued 255 AM CST Sun Feb 21 2021/ Morning water vapor showing an upper trough moving through the Four Corners. The trough should be east of the CWA by late this with the associated surface cool front moving through early this morning. All moisture associated with this system will stay well to our north/ However, breezy north-northwesterly winds are expected behind the front along with cooler air. CAA will result in high temperatures around 10 degrees cooler than yesterday and just below normal for this time of year.
243 AM MST Sun Feb 21 2021 MORNING DISCUSSION: Synoptic Setup: Forecast begins with a trough exiting into the Dakotas while a ridge builds over the Pacific Northwest and British Columbia spilling onto the Canadian Plains and dropping south. Behind this is a weak pacific Trough and a series of ridge trough couplets. Today through Monday: As a trough exits the area a chinook ridge will rapidly fill in behind it.
419 AM EST Sun Feb 21 2021 High pressure builds eastward over the region today with a frontal system approaching Monday.
High pressure aloft building off the North Coast will lead to a period of drier weather expected to last through much of the coming week. High pressure aloft from the E Pacific to N and central CA will allow inland daytime temperatures to warm to 5-10 degrees above normal, while temperatures along the coast remain close to normal. The upper ridge is expected retrograde back over the E Pacific by mid-week, with flow becoming increasingly NW-N. As substantial high pressure builds offshore, associated ridging in the area blocks for a zonal flow and an AR/pineapple express, to impact the north Pacific coast. A high pressure ridge builds NE today and into mid week. A weakening cold front will make its way through the waters late Monday.
Warmest temps just off the surface so warmest readings today likely downslope areas off the Turtle Mountains and the higher terrain of the west edge of the RRV and then in central ND such as Carrington and points west. 925-850 mb warm advection increases tonight into Monday and a west wind Monday will help bring the warmer temps down to the sfc esp in E ND and even the RRV where west winds are favourable for warmth. Looks good for a day into the low 40s for many areas.
High pressure will bring a warming and drying trend through Monday.
700 AM EST Sun Feb 21 2021 Upper level ridging across the Gulf region begins to sink southward as a long wave traverses east over the nation's mid- section. High pressure centered along the VA/NC line and sprawling over the eastern US slips offshore tonight. High pressure north of the waters will maintain robust northeast and east winds.
Surface observations and webcam networks indicate light snow associated within these areas of enhancement with little in the way of reported freezing drizzle. Ahead of the system, southerly low-level flow has increased Gulf moisture in the low levels while the system has also advected mid-level moisture eastward from the Pacific.
431 AM CST Sun Feb 21 2021 Current surface analysis places low sliding over the Oklahoma panhandle, with trough through the central into the northern plains. Upper level analysis places trough through the northern plains into the four corners region, with ridge over the west coast.
High pressure will continue to shift east to offshore of the Mid- Atlantic region today and tonight. A cold front then approaches the area early Monday, with scattered to numerous showers and a few thunderstorms possible mainly Monday afternoon ahead of the front.
636 AM EST Sun Feb 21 2021 High pressure will pass overhead this morning providing dry, cold, and near calm conditions. A cold front will sweep across the region from west to east Monday morning with the potential for rain and mixed wintry precipitation. This cold dome of high pressure will retreat this afternoon, temperatures aloft warming.
655 AM CST Sun Feb 21 2021 Cold front will move through the terminals this morning shifting winds to the north and increasing speeds. /issued 255 AM CST Sun Feb 21 2021/ Morning water vapor showing an upper trough moving through the Four Corners. The trough should be east of the CWA by late this with the associated surface cool front moving through early this morning. However, breezy north-northwesterly winds are expected behind the front along with cooler air. CAA will result in high temperatures around 10 degrees cooler than yesterday and just below normal for this time of year.
East southeasterly winds in the lower levels will continue to pull low level moisture back into the region this morning. Winds will increase through the afternoon in advance of an approaching cold front that will initialize scattered showers across the area late this evening through early Monday morning.
402 AM MST Sun Feb 21 2021 As an upper trough continues to shift east early this morning, have noted precip diminish over much of the area.
High pressure will build for today, bringing quieter weather to all locations through Monday.
1152 AM PST Sun Feb 21 2021 A storm system will bring windy weather, warmer temperatures and heavy mountain snow to the Inland Northwest today into Monday night.
A warm front will move through tonight, leading to a mild Monday, but a cold front Monday night into early Tue will return us to below-normal temperatures.
Today's cold front is now entering our northwestern counties as I'm typing this discussion. Most of us will warm up a few more degrees before the cold front shift the winds to the northwest, bringing cooler and drier air. For tonight, expect temps to drop below freezing for most locations with the help of a good radiational cooling effect.
119 PM EST Sun Feb 21 2021 High pressure and dry air will persist over the region through this evening then give way as the next low pressure system and cold front move into the region.
Upper ridging aloft will produce another quiet day across the southern Appalachians and east Tennessee Valley. DGS Chattanooga Airport, TN 57 43 57 32 61 / 0 60 90 0 0 Knoxville McGhee Tyson Airport, TN 54 40 54 32 56 / 0 30 90 0 0 Oak Ridge, TN 55 40 54 31 58 / 0 60 90 0 0 Tri Cities Airport, TN 51 32 51 30 54 / 0 20 90 0 0 TN.
1247 PM EST Sun Feb 21 2021 High pressure builds eastward over the region today with a frontal system approaching Monday.
With temperatures expected to climb well into the 50s and the dry antecedent conditions across north central SD, fire danger will be in the high to very high categories. The ridge begins to collapse Monday night.
This is allowing drier air to enter Northeast Kansas late this morning and into the afternoon which brought the freezing drizzle and slight snow to a close.
The high temperature for Monday, which is already expected to be considerably warmer for many areas, will be highly influenced by fog and inversion development. The lower conditions will return tonight and persist into Monday with some improvement Monday afternoon.
Warm southwest and downsloping west winds, and lack of snow cover on the ground, is leading to warmer conditions than anticipated, so the forecast hourly temperatures and highs have been increased for today. However, winds will be shifting the southwest and west this morning, ahead of a cold front (entering the N. It should be a little cooler in the Big Country with highs around 59, but temperatures will be warmer in the lower to mid 60s south. With clearing skies, light winds and continued cold advection tonight, lows are expected below freezing in the mid and upper 20s.
219 PM EST Sun Feb 21 2021 Upper level ridging across the Gulf region continues to sink south and out of the area as a long wave trough above the nation's midsection moves into the eastern US Mon then along the eastern seaboard Mon night. High pressure over the eastern states this afternoon slides offshore tonight and tracks east Mon. while ridging back to south FL. A cold front accompanying the upper trough reaches the eastern Gulf Mon then traverses FL Mon night. By then the lower level flow has become southerly and the upper level flow southwesterly.
Within that window, light winds will help some freezing fog to become more widespread until westerly winds begin increasing overnight.
/issued 700 AM EST Sun Feb 21 2021/ Upper level ridging across the Gulf region begins to sink southward as a long wave traverses east over the nation's mid- section. High pressure centered along the VA/NC line and sprawling over the eastern US slips offshore tonight. High pressure north of the waters will maintain robust northeast and east winds.
The next upper level trough currently across the central U.
145 PM MST Sun Feb 21 2021 Upper level analysis shows a trough over the central states, and ridges over the coasts.
Well some good news this morning is that so far the freezing drizzle potential has yet to be realized , so concerns for ice accumulation have significantly decreased. Will still need to monitor the corridor east of HWY 281 this morning though, since this is the area that still has a chance to see some freezing drizzle should we lose the saturation in the DGZ. Since we will be in a post cold frontal airmass, our highs today aren't exactly expected to increase from yesterday's.
359 PM EST Sun Feb 21 2021 Windy condition will continue to be the weather highlight through this evening, as the Keys lie in the strong easterly flow under the southern periphery of strong high pressure near Chesapeake Bay. The strong high pressure cell near Chesapeake Bay will quickly scoot out to near Bermuda by mid-day Monday. On Monday, it will extend a blunt ridge southwest across the southern FL Peninsula, leading to a rapid decrease in wind speeds on Monday morning. Meanwhile, an increasing southerly component to the low-level flow tonight and Monday will tap into the deeper moisture and thicker cloud cover near the Cay Sal Bank, pushing them toward the Keys this evening. A cold front is currently making its way across the Southern Plains.
1248 PM EST Sun Feb 21 2021 Expect increasing cloud cover through tonight, with crossing low pressure supporting widespread rain and snow early Monday. A warm up is then anticipated before interruption by a midweek trough. After the coldest temperature so far this season, gradual condition moderation is anticipated as ridging aloft ensues. Cold nwly flow will veer swly as the ridge axis treks overhead in response to a deepening, positively tilted central CONUS trough. It should also be noted that as sfc wind veers sly ahead of an approaching cold front, snow should mix with rain, especially for locations south of I-80. Accumulating precipitation will end by midday for most of the area, though snow may linger in the ridges for a bit longer before transitioning to light snow showers/flurries and/or freezing drizzle/fog with lack of ice crystallization and lingering llvl moisture.
The clouds are ahead of a cold front which is currently moving through eastern Oklahoma and Texas. Temperatures will turn colder tonight with lows Monday morning from the lower 30s to lower 40s. With the cold front over middle Tennessee Monday morning, the last of the rain should be exiting northeast shortly after sunrise. High pressure will start to build into the region during the afternoon bringing a period of dry weather to the Mid-South. Temperatures will be cooler on Monday but still milder than they were last week with highs in the mid 40s to lower 50s.
222 PM CST Sun Feb 21 2021 Weak cold front has entered NE OK and will clear western AR by early evening. This along with an expanding low level thermal ridge and plenty of sun will allow temps to warm well above normal.
Main story today will be the stout onshore winds due to a tight pressure gradient with strong high pressure becoming centered across the Mid-Atlantic.
Upper trough approaches and strong isentropic ascent and moisture advection develops within a strengthening 60 knot LLJ this evening with widespread precipitation developing into our IN/sw MI zones between 00-03z, and into nw OH shortly thereafter. A few snow showers and drizzle could linger into Monday morning with breezy cyclonic flow and seasonable temps in the low-mid 30s in the wake of tonight's system.
/Updated at 1042 AM CST Sun Feb 21 2021/ High pressure remains in control for much of the afternoon and evening, although some modest moisture return has already settled in across the state.
10 will likely remain below 32F tonight, while the remainder of Southwest Lower Michigan will pop up above freezing for a time. Southern Lower Michigan will be above freezing for several hours tonight which should mitigate significant issues/impacts on area roadways. the surface temperatures are projected to climb just above freezing overnight for much of the region before cooling it back down to near freezing by daybreak.
SHORT TERM (Tonight through Monday Night): A mid-level trough moving east will bring an associated cold front through Deep South Texas tonight. Tonight's lows will fall into the low 50s across the northern Ranchlands to upper 50s in the Valley. Temperatures will be a bit cooler with highs in the low 70s across much of the CWA with 60s along the coast. Monday night winds will begin to diminish with temperatures falling into the low to mid 40s with some low 50s along the coast and in the lower Valley.
1120 AM EST Sun Feb 21 2021 Windy condition are the weather highlight today, as the Keys lie in the strong easterly flow under the southern periphery of strong high pressure near Chesapeake Bay. The strong high pressure cell will exit off the Delmarva Peninsula and into the Atlantic late today, quickly scooting out to near Bermuda by mid-day Monday. On Monday, it will extend a blunt ridge southwest across the southern FL Peninsula, leading to a rapid decrease in wind speeds starting late tonight and Monday morning. A cold front is currently making its way across the Southern Plains.
1131 AM CST Sun Feb 21 2021 Increased pops across the east this morning as snow and freezing drizzle continue to wrap back into the region. The upper trough axis will push through our eastern areas toward midday and afternoon which clear the last of the snow out. Afternoon readings will have no trouble reaching the low to mid 40s east to upper 40s to upper 50s west of the James valley.
Patchy freezing fog will bring MVFR visibility to BNA/MQY at the very beginning of the TAF period.
With the clear skies, decreasing wind and drier air tonight, colder/subfreezing temperatures expected tonight. With significant melting continuing into this evening, the freezing temperatures will lead to areas of black ice, especially on less traveled and untreated roadways. With saturated soils and still plenty of sheltered snowpack, opted to not go on the higher end of guidance for highs tomorrow - closest to NAM/WRF guidance.
For late tonight, MVFR ceilings are expected to return across the area ahead of a cold front with a few patches of IFR ceilings possible. In the upper levels, a weak ridge will be over the region until a trough approaches tonight. At the surface, high pressure will be over the region today with easterly low level flow. Tonight, low level flow will become more southerly as a cold front approaches. POPs will be near zero until late tonight and early Monday morning when showers move into the region ahead of the cold front. Lows will be mainly in the lower 50s.
Later tonight a weak cold front will push through providing the area with showers, however shower activity could be seen ahead of the front.