Aikyam-Lab/Synoptic-Bench huggingface dataset:
Boxell (Issued 221 PM CST Sat Dec 18 2021) Tonight through Sunday night: High pressure is gradually building in behind the the exiting low pressure system this afternoon. Cold Air Advection will bring in some cooler temperatures this evening into the overnight hours as the high pressure moves overhead. As high pressure continues to shift east Sunday, winds will shift to southerly and bring in some warmer air.
633 PM EST Sat Dec 18 2021 Low pressure will quickly move off the New England coast tonight. High pressure will build east across the region Sunday into Sunday night, resulting in seasonable temperatures.
The only exception to this will be freezing fog that can form in the valleys during the morning hours. Fair weather continues across the silver state for today and Sunday as a ridge slowly drift across the region. The exception to this will be in the formation of freezing fog in the valleys during the morning hours. Freezing fog can cause slick spots on the roads where it does form so use caution if it is encountered. Highs looks to be near to a little above freezing.
Meanwhile, at the surface, a backdoor cold front has slipped in from the east, with a few breezes especially east of Tucson.
/19/ For 19/00Z TAF period, post-frontal cloud cover and precipitation continue to lag well behind the cold front with MVFR/IFR cigs still affecting SHV/LFK/ELD/MLU this evening. Winds will continue to veer N/NW in wake of the cold front with speeds from 10-15 kts and higher gusts closer to 20 kts possible through the evening hours. A colder than normal day is in store on Sunday with afternoon highs in the low 50s, and mostly sunny skies. This chance of precipitation will be slight and mainly approach Deep East Texas areas overnight, which, with enhanced cloud cover, also moderates temperatures there into the low 40s. Elsewhere, a gradient of temperatures will take effect ranging from the lower 30s, north of the I-30 corridor, to the mid-30s, south of the I-20 corridor.
315 PM MST Sat Dec 18 2021 Temperatures have struggled to warm today given light winds and a cold airmass behind the upper trough axis. Tonight will be another cold night for most areas though with lee troughing taking place along/west of the I-25 corridor. should see warmer minimum temperatures for places like Canon City and Walsenburg where breezy west winds will kick up overnight. Breezy west winds will spread from the higher peaks into the lower eastern slopes and portions of the I-25 corridor on Sunday afternoon. Southerly winds will also increase east of the surface lee trough with the tightest surface gradient across Baca county.
926 PM EST Sat Dec 18 2021 Low pressure will quickly move off the New England coast tonight. High pressure will build east across the region Sunday into Sunday night, resulting in seasonable temperatures.
A warm front--currently (as of 230 pm MST) located from roughly Zortman to Jordan to Cow Creek-- will continue to lift its way northward through the area tonight. Temperatures on Sunday should peak around sunrise or so before a cold front moves through the region, exiting the area by noon.
Latest surface analysis has the cold front southeast of our CWA with anafrontal light rain generally along and east of Interstate 55. The cold front will continue moving southeast and the light rain will continue to gradually taper off from the northwest the remainder of the night. A gusty north wind will continue to usher in much cooler and drier air. /22/ Prior discussion below: Late afternoon through Sunday: the strong capping inversion noted previously has helped to erode the convective system as it approaches, and as a result, it is deflecting the most significant convection to a more coastal route - this in spite of the highly anomalous boundary layer warmth/humidity over the forecast area. /EC/ By tomorrow night, the cold frontal boundary will have completely pushed through the region, leaving noticeably cooler temperatures in its wake.
Otherwise, cool and dry air continued to flow into the Midsouth, behind a cold front that had reach south MS and southwest AL at 9 PM. Areas of west of the MS River may see some clearing, once the high clouds exit. Temperatures are in the low to mid 40s behind a cold front, with the exception of northeast Mississippi, where temperatures are still in the upper 60s. The latest surface analysis places a 1009mb low pressure system near Pittsburgh, Pennsylvania with a cold front extending southwest into Parkersburg, West Virginia and back through Jackson, Kentucky and into Tupelo, Mississippi. Expect temperatures to fall into the lower 30s. Cool Canadian high pressure will build into the region to begin the workweek.
Key Messages: 1)Light showers early giving way to drier and cooler weather. Regional radar imagery continues to depict light rain showers developing in a post frontal airmass as the main trough brings one last round of forcing for ascent. High pressure will settle in across the area bringing much drier weather. Cold air advection will continue to advect a cooler airmass into the area. High pressure remains in control tonight with clear skies and light winds.
Last night's cold front has ushered in a much more typical mid-December airmass, with temperatures early this morning settling into the 20s, and even the upper teens in a few of the coldest spots.
239 AM EST Sun Dec 19 2021 High pressure continues to build in behind the cold front, which is now over the Appalachian spine, and northerly flow continues to pull cooler air into the region. Cloudy skies, decreasing 1000-850mb thickness, and continued CAA on NE flow this afternoon will result in max temps in the upper 30s to low 40s, a few degrees on the cooler side of climo.
SFC winds are less southeast than guidance would suggest, and some stations have backed to the east-northeast, which may be a sign of weak low-level troughiness to our south. Water vapor imagery highlights a sharp mid- upper level trough axis over the southeastern Gulf of Mexico and the Yucatan Channel. The lift with this trough likely has translated to the east of the Keys, but the steepened mid- level lapse rates are still available along the trough's axis. Long story short, after a pronounced lull in activity after the late afternoon round of showers, we expect convection to increase in coverage as the troughiness works to the north. From synopsis, high pressure moving east over the western North Atlantic will result in slackening breezes late tonight as a frontal boundary approaches the Southeast United States.
Scattered to numerous showers will continue through the overnight hours as a cold front moves through the CWA.
Ceilings could lower a bit further as clouds, associated with a cold front, pushes through the area.
237 AM CST Sun Dec 19 2021 08Z water vapor imagery showed an upper low over northern Mexico that was left behind by yesterdays upper trough. Surface obs showed a ridge of high pressure from the Red River into the the mid MS river valley.
1135 PM EST Sat Dec 18 2021 Building high pressure will end residual showers and provide a dry start for the new week. Scattered rain and snow showers invof an 850mb trough should gradually taper off overnight as moisture depth and inversion heights decrease. Otherwise, a mostly cloudy and more seasonable day is expected in cold NW flow, with low convective temperature thresholds and a crossing upper trough maintaining a stratocu layer.
- Rather benign weather expected the next 7 days - We will see skies become partly cloudy tonight in northerly flow behind low pressure which is passing off to the east.
1248 AM EST Sun Dec 19 2021 Low pressure will quickly move off the New England coast tonight. High pressure will build east across the region Sunday into Sunday night, resulting in seasonable temperatures.
Most models show at least a period of unsaturated low levels and weak subsidence which makes sense given the ridge moving through, however clouds across the Lower Peninsula redeveloped overnight, perhaps via some moisture contribution from northern Lake Michigan but there is a patchwork of stratus in the states to our south and west without help from the Great Lakes. On the other other hand, it usually pays to lean toward clouds this time of year whenever the low levels are expected to be fairly moist without strong subsidence.
Motion and dissipation trends from satellite imagery indicate this lower deck of clouds should thin overnight. /ISSUED 540 PM CST Sat Dec 18 2021/ High pressure will continue to filter into the area this evening, so expect CAVOK with moderate to strong and gusty north winds at all sites through 09Z. An approaching trough will bring BKN-OVC skies from west to east across the area and lowering CIGS after 09Z.
1024 PM MST Sat Dec 18 2021 Temperatures have struggled to warm today given light winds and a cold airmass behind the upper trough axis. Tonight will be another cold night for most areas though with lee troughing taking place along/west of the I-25 corridor. should see warmer minimum temperatures for places like Canon City and Walsenburg where breezy west winds will kick up overnight. Breezy west winds will spread from the higher peaks into the lower eastern slopes and portions of the I-25 corridor on Sunday afternoon. Southerly winds will also increase east of the surface lee trough with the tightest surface gradient across Baca county.
1106 PM CST Sat Dec 18 2021 For 19/06Z TAF period, post-frontal cloud cover continues to lag well behind the cold front with MVFR/IFR cigs still affecting LFK/MLU late this evening. Winds will continue to veer N/NE in wake of the cold front with speeds from 10-15 kts and higher gusts closer to 20 kts possible through the overnight hours.
315 AM EST Sun Dec 19 2021 Cold front is currently situated from around Athens to Columbus and will continue to push southeast across the remainder of the CWA for the first part of today. The cold front will push well to the south of the CWA tonight with a wedge of high pressure building in from the northeast.
312 AM EST Sun Dec 19 2021 Upper air pattern consists of a 500 mb trough across the upper Great Lakes region this morning with a trough in the Pacific NW. This western trough will move to the Lake Winnipeg region 00z Mon.
Stratus has remained trapped under subsidence inversion as the ridge axis pushes through Iowa early this morning.
The higher moisture content is advecting in from the western Atlantic waters, and portions of the Caribbean waters. Similar conditions are still continuing over the Straits of Florida and the Lower and Middle Keys.
305 AM EST Sun Dec 19 2021 Building high pressure will end isolated snow showers this morning, and provide dry weather for much of this week. Isolated snow showers are expected to continue this morning with cold NNW flow across the Great Lakes, and with an approaching upper trough. Building high pressure should result in a clearing trend by later in the afternoon.
300 AM CST Sun Dec 19 2021 At 09Z, a cold front was moving into north central MT. For Today, warm temperatures aloft will mix to the surface ahead of an advancing cold front. Tonight, a fairly strong cold front moves through.
There are no significant weather concerns with high pressure in control today. This pattern changes late in the week as a deep trough moves inland over the western US.
This, in response to a low pressure system tracking across southern Saskatchewan Canada, and winds will continue to increase through the rest of the morning, especially across the higher elevations and downslope-prone areas of the Prairie Coteau. So patchy blowing snow to sporadic/isolated whiteout conditions appears most likely through this mid-morning, again especially for the higher wind- prone areas. Continued southerly winds and WAA into the afternoon should increase temps to 32 F or warmer for the majority of the CWA (40s near/west of the MO River), though snow-covered areas may struggle. The warmth is short-lived however, as a cold frontal passage ushers in colder air once again, starting already this evening.
The coldest temperatures are east of the Highway 65 corridor, where cloud cover has cleared this morning. High temperatures will reach into the low 40s this afternoon as clouds clear the region. A closed upper level low will track across the southern CONUS early in the week.
Overnight temperatures will hold in the lower 20s along the lake plains, but fall into the teens and single digits inland.
Cold front has moved through the entire area this evening with temperatures now ranging from the mid 50s in the southeast down into the upper 30s in the northwest. An increase in coverage is expected after midnight over our eastern counties as the main upper trough axis moves overhead, with higher pops in that area. Post cold front moisture will keep mainly MVFR cigs in place through the rest of tonight into Sunday morning.
The band will shift further south and intensify on Sunday, with additional snow accumulations expected across mainly the higher elevations of Baker County and the West Central Mountains. Upper level low pressure system will continue southward along the Washington coast tonight through Sunday.
That WAA combined with low-level clouds, mostly in the northern part of the forecast area, should keep low temperatures tonight in the low to mid-20s, keeping conditions mild.
Notable changes included adjusting PoPs based on radar trends and adjusting the hourly temperature trend as a fair amount of sites were observing temperatures a little warmer than the forecast. However, no changes were made to the low as cooler and drier air will continue to filter in with NW flow behind the front, which is now located along the TN/NC border. Diegan Chattanooga Airport, TN 51 33 54 38 55 / 10 0 0 10 10 Knoxville McGhee Tyson Airport, TN 48 29 52 35 53 / 10 0 0 0 10 Oak Ridge, TN 47 29 51 34 52 / 10 0 0 0 0 Tri Cities Airport, TN 45 24 50 30 51 / 20 0 0 0 0.
Some concern with freezing precipitation just west of Towner County exists, however wet bulbs in the column still below 0 C. Could see some patchy freezing drizzle following the light snow along the border, while NBM continues to show this signal west of the CWA. This system is going to result in building low pressure/increasing gradient and WAA within building southerly flow later. Initially temperatures should drop rapidly at sunset and we will likely see our lows shortly after before a combination of increasing clouds, WAA, and increasing winds recover temperatures above freezing. As temperatures increase with the winds and highs approach freezing Sunday probabilities may be lower for blowing snow impacts.
1010 PM CST Sat Dec 18 2021 Tonight into Sunday, an upper-level trough will advance east of the Midwest, promoting large-scale subsidence as mid-level heights rise in its wake. This evolution will cause a surface pressure ridge to shift into the CWA Sunday morning with winds becoming light as the attendant pressure gradient relaxes. Although some areas of stratus may linger overnight/Sunday morning and limit fog development below, confidence was high enough near the ridge axis to include mention of fog across northeastern MO and west-central/south-central IL Sunday morning.
/issued 302 AM CST Sun Dec 19 2021/ Satellite analysis early this morning depicts a slow-moving upper trough centered roughly over El Paso as of 08z with a shield of mid and upper level moisture downstream over the Permian Basin. This trough is forecast to slowly shift eastward today with its center progged roughly over Midland by late this evening. Otherwise, expect continued dry and cool conditions as the close proximity of the upper troughing keeps thicknesses in check. Thickness trends continue to increase every day with upper level ridging and rising heights overhead.
330 AM MST Sun Dec 19 2021 Another dry day in store today with an upper level ridge slowly building over the area. Today's highs should be 10-15F warmer than yesterday withs highs in the 50s to near 60F across the plains. A weak mountain wave has already provided a few gusts to the typical windy spots in the Foothills and occasionally gusty winds are possible through the day, especially across the higher spots of the Front Range. Lows for the urban corridor should remain in the 20s to low 30s, while typical cool spots across the plains will fall into the low to mid 10s. A few of the colder spots in Middle/North Park are expected to fall below zero overnight again, though overall the night should be a bit warmer than the current temperatures this AM.
allowing the pressure gradient to increase across the local area as low pressure intensifies on the lee side of the Rockies. ahead of a cold front anticipated to cross the local area overnight Sunday night through Monday morning. These warmer temps. expect the aforementioned cold front to cross the local area bringing a more seasonable start to the work week. ahead of a cold front that should bring a shift in winds to west and then northwest late in the period.
High pressure continues to build in behind the cold front, which is now over the Appalachian spine, and northerly flow continues to pull cooler air into the region. Cloudy skies, decreasing 1000-850mb thickness, and continued CAA on NE flow this afternoon will result in max temps in the upper 30s to low 40s, a few degrees on the cooler side of climo.
(Today and tonight) Early morning water vapor imagery shows the upper level low spinning over northern Mexico. Tonight as the primary upper level low moves across the region highest PoPs will be focused across our eastern counties or roughly east of a Abilene to Ballinger to Junction line. Cannot rule out some sleet pellets or snow flakes mixing in with the rain due to dynamical cooling aloft from the upper low. But with surface temperatures above freezing no accumulations are expected.
Our temperatures will once again remain seasonably average for late December as a weak upper trough passes overhead. We did go slightly warmer everywhere for this afternoons MaxT using the NBM 75th percentile. As a result, went closer to MOS guidance going slightly warmer and windier across northwest Oklahoma using the NBM 95th percentiles. With very dry air in place across the Panhandles, along with windy and unseasonably warmer temperatures and dry vegetation, the fire danger will be elevated this afternoon across portions of western Oklahoma. Tonight will be seasonably cold again with mostly subfreezing temperatures across our area. An upper low digging across north Texas may brush a couple a couple of our counties in western north Texas with a light wintry mix of precipitation toward sunrise Monday.
This, in response to a low pressure system tracking across southern Saskatchewan Canada, and winds will continue to increase through the rest of the morning, especially across the higher elevations and downslope-prone areas of the Prairie Coteau. So patchy blowing snow to sporadic/isolated whiteout conditions appears most likely through this mid-morning, again especially for the higher wind- prone areas. Continued southerly winds and WAA into the afternoon should increase temps to 32 F or warmer for the majority of the CWA (40s near/west of the MO River), though snow-covered areas may struggle. The warmth is short-lived however, as a cold frontal passage ushers in colder air once again, starting already this evening. High temperatures Monday will be ~5 to 10 F below average, in the 10 to 25 F range, under clearing skies as high pressure overtakes the region.
Areas along the international border will have the best chance for seeing precip which could start off as a mix before turning to snow as warm layer of 4 to 5C melts some precip with the wet bulb temps slightly above freezing for a couple hours. HREF fram modeled max freezing rain areal coverage reinforces this thinking with some pockets in the northern valley and also in the Devils Lake basin.
They aren't moving much with a ridge axis in place, but southerly flow will increase this morning which should kick them north and scatter them out. A cold front will pass through tonight and cold air advection will keep temperatures dropping through Monday. Low temperatures Monday night will fall into the single digits as high pressure drifts across the area.
302 AM CST Sun Dec 19 2021 Satellite analysis early this morning depicts a slow-moving upper trough centered roughly over El Paso as of 08z with a shield of mid and upper level moisture downstream over the Permian Basin. This trough is forecast to slowly shift eastward today with its center progged roughly over Midland by late this evening. Otherwise, expect continued dry and cool conditions as the close proximity of the upper troughing keeps thicknesses in check. Thickness trends continue to increase every day with upper level ridging and rising heights overhead.
405 AM CST Sun Dec 19 2021 A colder and more December-like day is on tap in the wake of a cold front that has now pushed east of the area. With the low/mid level trough axis still lingering to the northwest, remaining low level moisture is resulting in widespread low cloudiness. With the persistent CAA into late in the day and some breaks in the clouds farther north, it will be cold tonight with freezing temps possible in our northern counties. Cooler temperatures behind the front continue into the first part of the work week. Starting from the 30s Monday morning, the highs will range from the upper 40s to mid 50s. This low pushes some showers northward into the forecast area for Monday and into Monday night.
900 AM CST Sun Dec 19 2021 A cool, stable air mass has settled into the Tennessee Valley region in wake of the cold front that moved through the area yesterday. The one caveat may be a plume of dry air over part of the lower Ohio Valley that is currently helping to erode a small portion of this broad status shield in northern middle Tennessee. The clearing trend should continue into the evening/overnight hrs, as high pressure becomes layered from the mid Atlantic states into the Mid South region. An upper low/trough axis is then expected to traverse ewd across the srn Plains into the Gulf Coast states Mon/Tue. Overall temps look to remain near seasonal, with highs Mon/Tue in the lower/mid 50s while lows Mon night trend mainly in the lower/mid 30s.
Overnight temperatures will hold in the lower 20s along the lake plains, but fall into the teens and single digits inland. Monday, a mid level trough will slide across southern Canada, pushing a surface cold front across our region Monday Night.
Low clouds will hang on well into the afternoon and perhaps even longer according the low level NAM moisture fields. Clearing skies and lots of moisture from recent rainfall could result in some fog/freezing fog.
244 AM MST Sun Dec 19 2021 A wide range in temperatures are present across NE Montana early this morning as low level inversions are present even though the warm front has lifted north of the region. A cold front will move through the area between 12Z and 16Z (5 am and 9 am MST) this morning and bring falling temperatures with it. This will result in the high for today occurring this morning.
354 AM CST Sun Dec 19 2021 The main concern for the short term period is light freezing rain this morning. A warm front is bringing areas of light freezing rain across much of western and central North Dakota this morning. But it takes very little freezing rain to cause significant impacts to travel. Behind the warm front, temperatures are forecast to rise above freezing for all but far northwest North Dakota later this morning and afternoon. A cold front will begin to move down from Canada later today, and may enter northwest North Dakota by noon. Other than perhaps a few flurries, measurable precipitation is not likely with the cold frontal passage. Arctic high pressure will slide across the Northern Plains on Monday, keeping afternoon highs in the single digits above zero and teens for most areas.
Outside of major urban areas, near freezing temperatures are expected in the San Joaquin Valley through Sunday night.