Aikyam-Lab/Synoptic-Bench huggingface dataset:
High pressure is moving east of the Mississippi Valley today. Given this cold start, it looks unlikely that we'll crack freezing, especially with increasing high and mid clouds today. Stuck pretty close to operational MOS guidance numbers, which were warmer than the ensemble blends. Temperatures will be warmer as low level flow will turn south allowing for temperatures to climb to into the upper 30s and lower 40s per the latest GEFS mean 2m temps.
The upper level trough over the Eastern Seaboard progresses eastward over the Western Atlantic through the day. The Arctic airmass over the region will be slow to modify with highs today only climbing into the low to mid 40s.
443 AM EST Sun Jan 8 2017 An upper level trough has pivoted through the southeastern United States, in its wake, heights are rising through the Rockies and Plains. At the surface, a 1044 mb artic dome of high pressure dominates the Mississippi River Valley, driving a continental- artic air mass deep into the Western Caribbean.
A deep upper trough and associated large upper cyclone has set up where the upper high used to be, just south of Alaska. This will help keep any arctic surges well north of the area through this week as it provides ridging downstream. The next cold front looks to make it approach by the upcoming Sunday. This is, at first glance, of Pacific origin but there is the possibility of some Canadian air mixing to the back side as ridging amplifies into the greater northwest. As the high becomes more centered over the Deep South, winds will veer to the east today and then to the southeast tonight. This southeast flow regime will then dominate through the remainder of the week as a ridge of high pressure sits off the Georgia and Carolinas coast.
high pressure is centered over eastern SD and will continue to drift southeast overnight. especially in the southeast where the high is in the vicinity. Believe we'll be out of criteria (warmer than -25F wind chill) by 9 AM tomorrow morning. Highs will be relatively warm on Sunday ranging from the middle single digits above zero in the Devils Lake basin to the low to mid teens in the east and south. The upper level trof begins to shift east across Ontario and the upper ridge builds back over the area. will see a weak trof crossing the area initially.
So opted to nudge the forecast towards the warmer short range model consensus. But with clear skies and lighter winds as high pressure passes to the north, do not want to fully come back up to that consensus number yet as this would allow for continued strong cooling. These counties would likely not strictly meet the hard freeze thresholds if tonight ends up warmer than forecast. The exception will be Galveston County where northeasterly winds off of Galveston Bay should keep temperatures at and below freezing but high enough to be over the hard freeze criteria. Temperatures will be slow to warm Sunday morning, but should reach above freezing by around 10:00 AM.
For tonight, high pressure will build in from the west. The lowest wind chills will be across portions of southern IN and the Bluegrass region of KY where 0 to -5 degrees will be common. For tomorrow and tomorrow night, high pressure will quickly move through the Lower Ohio Valley and then off to the east. We will see some moderation in temperatures, though they are still expected to remain below freezing.
A quiet pattern will persist across western Kansas today and tonight as upper level ridging across the Intermountain West pushes slowly eastward into the Western High Plains. A developing lee side trough of low pressure will strengthen across eastern Colorado today enhancing warm air advection into western Kansas within a south to southwesterly flow.
330 AM CST Sun Jan 8 2017 Arctic high pressure over the Mid South today will slowly move east later tonight and Monday. Another dry and cold day is anticipated with lingering snow cover and cold airmass helping to keep temperatures near or below freezing again today. A slow warm up is anticipated into Monday as low level southerly flow on the back side of high pressure develops.
328 AM CST Sun Jan 8 2017 Latest 08z surface analysis indicates high pressure over southern Minnesota into northern Missouri.
930 PM PST Sat Jan 7 2017 Sunday will be dry and unseasonably warm with high pressure aloft. The upper high weakens Sunday night as a trough approaches from the north. This trough will bring periods of rain Monday.
A quiet pattern will persist across western Kansas today and tonight as upper level ridging across the Intermountain West pushes slowly eastward into the Western High Plains. A developing lee side trough of low pressure will strengthen across eastern Colorado today enhancing warm air advection into western Kansas within a south to southwesterly flow. Precip chances will remain absent across western Kansas Monday as weak upper level ridging moves eastward across the Western High Plains into the Central Plains early in the period.
The temperature forecast uses the cooler GFS and NAM models plus bias correction for highs in the 20s and 30s. The snow showing on radar is the result of a warm front aloft with dry air below. This warm front should move rapidly east and be mostly clear of the forecast area by 12z Monday.
An increasing pressure gradient due to a developing lee side trough will help strengthen winds to 10 to 20 knots out of the southwest before sunrise. Today will be the last of temperatures well below average for the next several days as winds will shift to southwesterly advecting warmer temperatures into the region. High temperatures starting Monday will be well above average in the lower 70s and throughout the week slowly cool down to slightly below average by the time we get to the end of the week.
Subjective 12Z upper-air analysis indicates upper-level low centered over western ON and troughing through the Great Lakes, with a ridge over the Rockies, and with the next trough just offshore of the Pacific Northwest. A ridge at 850mb extended from southwest TX through the High Plains and into SK. That said, did cool lows a bit as ridge is firmly overhead and clouds are a long ways off.
High pressure over the southern plains is expected to push east through the Tennessee valley tonight and Sunday. warmer southerly winds will return to Central Indiana. allowing most locations to get above the freezing mark.
We expect I-80 between Laramie and Cheyenne to get pretty strong as well, and with models showing at least a modest stable layer over the summit we felt the potential was strong enough to add the southern Laramie Range, and adjacent foothills to the High Wind Warning. We issued a High Wind Watch for the wind corridors for now, but later shifts may need to add CYS if it looks like the low level inversion will be any weaker on Monday. Just not enough confidence right now to add those zones to the High Wind Watch. A band of warm advection snow will likely develop over the high plains on Sunday night, but potential accumulations are uncertain attm.
A high pressure system is expected to pass southwest of the forecast area as the low, that was over eastern Upper Michigan at 20Z, departs.
A weak coastal trough sets up along the Lower Texas coast Sunday morning. Another cold night in store but with less wind as the high pressure ridge settles into the region.
/issued 324 PM CST Sat Jan 7 2017/ (Tonight and Sunday) Dry northwest flow aloft will prevail across the area the next 24 hours, with upper ridging to our west and an upper trough over the eastern CONUS. At the surface, high pressure currently over the area will move off to the east tonight and Sunday, with a lee trough developing. Tonight will be cold again but temperatures won't be as cold as last night, with lows mainly in the lower 20s.
/Tonight through Sunday/ Tranquil but cold weather overnight as high pressure settles into the state. The dry polar airmass associated with the high will lead to clear skies overnight and with light winds, plenty of radiational cooling.
An upper level trough of low pressure will move across the area on Sunday and enhance the potential for snow showers. This system exits the region Sunday night and then another trough passes to the north for a slight chance of snow showers.
Highs today will remain below freezing area wide, but full sun in the afternoon should provide melting of remaining icy spots on roads. High clouds will increase tonight as the upper jet streak dives into the Southeast states ahead of a building ridge.
1135 PM CST Sat Jan 7 2017 High pressure will dominate through the period with widespread VFR conditions expected. Winds will be light and variable, or calm, at most sites overnight as high pressure moves through the state. But expect a SSE wind at all terminals by 18z Sunday as said high pressure moves east of Arkansas and southerly winds resume. but there may be enough moisture to see a brief period of DZ or even FZDZ before temps warm above freezing.
The first system we're looking into is a subtle wave topping the low amplitude ridge to our west Sunday morning. Profiles also suggest some Coteau winds developing as low level flow shifts to southwest ahead of the weak trough during that period of warm advection. Added mention of blowing snow, though as a caveat, its important to note strongest 925mb winds occur when the low level flow is more southerly around mid day.
Upper air analysis this morning showed a deep trough over the eastern half of the country with a ridge over the west. At the surface, high pressure was centered to our northeast and winds were generally light from the north to northeast. High pressure will continue to dominate during this period and the main forecast challenge will be the temperatures.
Shear axis will move through upper ridge in place over the Rockies bringing continued warm air advection as arctic boundary/lee trough strengthens from central MT into eastern CO. Temperatures will rise overnight over the higher terrain and become steady on the plains given partial coupling of 25-40kt low level jet east of the Black Hills. Upper flow will become more zonal as ridge flattens out Monday.
337 AM EST Sun Jan 8 2017 Low pressure tracks into the Canadian maritimes as cold high pressure builds today and tonight. The high moves east Monday. Upper level trough approaches the area today, with the trough axis tracking across the northeast during the afternoon hours. At the surface, deepening low pressure departs across the Canadian Maritimes, and another trough moves across New England. Temperatures warm into the 20s, and will lean toward cooler side of mos. Trough moves east this evening, and weak ridge builds, with subsidence noted. Once again, leaned toward cooler side of mos. On Monday, another weak upper trough moves through with little fanfare other than some mid and high level clouds during the day.
In addition, light winds, clear skies and falling temperatures should set the stage for widespread freezing fog development. Slick surfaces are also possible as temperatures will be below freezing and there is a risk of some patchy freezing drizzle. Temperatures will drop below freezing in most if not all locations so freezing fog and maybe some freezing drizzle will develop. Best chance for freezing drizzle will be in the northeast area around McCook to Norton.
Currently, clouds on the increase as moisture is increasing ahead of a large upper trough/low over the Pacific northwest. This will continue overnight with snow developing over the higher mtns. A cold front will sag slowly south overnight but the main push of cold air will hold off until Monday afternoon. again heaviest over the higher mtns. By late Tuesday some pretty heavy snowfall amounts look possible over the higher mtns as the snow falls at varying intensities through Tuesday so have opted to post a winter storm watch given amounts of 1-2 feet possible through late Tuesday.
With temperatures holding steady in the 50s tonight, it won't take much to see highs into the low 60s on Tuesday. With some limited cooling tonight, stratus build down may bring some MVFR vis in fog to the ridges and a gradual lowering of CIGS to IFR for all but SJS.
It is noticeably warmer out though, and this is due to the warm air advection that is taking hold across the Mid-South this morning. As our dew points climb into the low 60s and we warm up today, instability will be on the rise.
For today, winds will shift to southeasterly as a low pressure system approaches from the southwest. This will usher in warmer and more humid air. The best instability still looks to be south of this low across portions of south central KY this evening. We will see very little cooling tonight and highs tomorrow look to be similar to or just a few degrees cooler than today.
We don't think there will be much of a severe risk given the low amounts of instability present in today's airmass. Although an isolated storm with small hail can not be ruled out since freezing levels are pretty low and shear is strong. A cold front will shift through southern Missouri on Tuesday, bring cooler temperatures into the region.
The upper level trough is is lifting east-northeast out of West Texas and the Big Bend. Clearing and a dry westerly wind will develop behind a Pacific cold front, leading to high temperatures well into the 70s. Dry and warm conditions on Tuesday ahead a stronger cold front.
Warm front extends westward across northern Georgia and Alabama then SW into central Louisiana and Texas. As the warm front pushes NE into the evening and overnight, instability increases and threat of thunderstorms, some possibly strong, will expand south to north across the area through tonight.
Medium range guidance is still not getting along as to agreeing when the second colder front arrives later in the week (or if a warm front moves back inland before that occurs). Winds will then shift to the N/NE by Tues night as a weak cold front moves off the coast. But looking ahead, models are still indicating a series of cold fronts moving across the coastal waters through the end of the week. The passage of the associated cold front with this line of storms later this afternoon should give us prevailing VFR conditions by tonight.
With the low clouds don't expect much improvement until morning or as front starts to move north. An accompanying warm front will also lift north triggering an increase in showers and thunderstorms after midnight. 60F plus dewpoints will overspread into the southern and central portions of the Midsouth as the Low pushes in. The passing cold front will exit the Midsouth by midnight with modified mild Pacific air expected for Tuesday.
Will include a slight chance mention of light snow into the forecast for these areas, but will hold off on any measurable mention as saturation in the lower troposphere is less than ideal, with the best moisture being shallow. Otherwise cold temperatures will rule the forecast through the work week as the front remains well south of the area and Arctic high pressure builds into the region.
Breezy to windy conditions will continue through Monday across much of the region with a slight chance of precipitation over the higher terrain of Lincoln and Mohave counties and the Sierra early this week. A dense plume of high level moisture could be seen on satellite loops being pulled inland underneath the cold upper low along the Pacific Northwest Coast. The high res models indicate Lake Mead will see some gusts over 40 mph along with Red Rock Canyon and the western foothills of the Las Vegas Valley. The EC has swung back about two thirds of the way to its cold solution from two days ago, while the GFS has trended even further toward warmer ridging.
An upper level low will slowly weaken through Monday. A cold upper low will weaken but Fraser outflow will continue through Monday.
Mixing along the lee slopes will help keep temperatures warmer west of I-25 tonight. These winds will also help temperatures warm into the 50s, and perhaps a few low 60s across the lower elevations tomorrow. Mozley The last several runs of the extended models have been trending warmer for the first week of January. A disturbance moving through the northern plains brings a cold front through the southeast plains Monday night with highs Tuesday forecast to be in the 30s at the lower elevations. Surface winds turn upslope Tuesday and Tuesday night, with upper level ridge building to our west.
With the passage of the warm front, radar estimated up to 7" of rain has fallen in northern Walton CO, FL and southern Geneva CO, AL today. A short wave currently near the Arizona/Mexico border this afternoon will gradually dampen out as it translates across the Lower Mississippi Valley and then northeastward toward New England. Lows will be in the lower to mid 60s Monday night and cooling into the lower to mid 50s Tuesday night with clearing skies and a drier airmass filtering into the area.
406 AM EST Mon Jan 2 2017 Warm front pushes northeast today across the region. A cold front crosses late Tuesday.
A low pressure system is expected to move through the area tonight and early Tuesday.
244 AM EST Mon Jan 2 2017 Low pressure will slide slowly into the area from the southwest early this week. The cold front associated with this low pressure area will cross Pennsylvania on Tuesday or Tuesday night.
241 AM CST Mon Jan 2 2017 Rain has been on the downward trend as expected as the upper low pushes off to the east. Drier air is following behind the low and will play a part in the weather later today. Winds will stay in the 15-20 mph range overnight as a cold front currently in southern SD surges southward and approaches the FA. In general, the forecast remains on track with significant changes arriving Tuesday with the first of a pair of cold fronts.
Broad southwest upper-level flow exists across much of the lower 48 states, with numerous impulses embedded within the mean flow.
256 AM CST Mon Jan 2 2017 An upper level trough across west TX will lift northeast across TX into OK and the northern section of the upper trough axis will move across eastern KS this afternoon. Warm advection continues across the southern plains ahead of the upper trough. Temperatures will continue to slowly rise, thus no freezing drizzle is expected across the northern counties. This afternoon the upper trough axis should approach eastern KS. Ascent ahead of the trough will increase and scattered showers will develop across east central and northeast KS during the late morning and afternoon hours. This evening the H5 trough will lift northeast into AR and MO and the showers should come to an end by late afternoon. There could be some drizzle redeveloping ahead of surface cold front this evening.
A cold upper level trough covering the Pacific Northwest and northern Rockies will extend westward off the coast through Monday.
A fairly strong cold front will swing through the area late tonight and send temperatures dropping to below freezing across much of KS and northern MO. Most precipitation should end before any of this sub-freezing air moves in, but can't rule out a few areas of very light wintry precip on the back edge of the rain. Steady cold air advection through the day Tuesday will hold temperatures fairly steady in the lower and middle 30s. The remainder of the week will be cold with temperatures unlikely to rise above freezing again until the weekend.
Low level warm advection ahead of approaching short wave trough will maintain IFR/LIFR ceilings across nwrn AR and sern OK sites through late in the forecast period. Strong cold front timed into nern OK sites just after the end of this forecast period. Stronger forcing/instability however will likely remain south of the Red River as upper low moves into the Arklatex region.
337 AM CST Mon Jan 2 2017 Ahead of a cold front, a southwest flow aloft continues today with weak isentropic lift continuing in the 275-280K layer which is where the moisture is. Currently, a short wave is causing most of the organized light precipitation mainly in the form of freezing drizzle to fall in our eastern zones, east of I 29. This means that the freezing drizzle threat will probably be most acute this morning, with possible lingering trace amounts this afternoon. One exception is in our southern zones, for instance around Sioux City and vicinity, where temperatures will likely warm comfortably above freezing this afternoon. The cold front will then move eastward across the forecast area tonight.
Dry air in the low levels will help to hold off precip across southern WI until after noon today as an inverted trough approaches. This will give surface temperatures time to warm above freezing, so the chance for mixed precip is now limited to areas toward central WI.
A Pacific cold front will usher drier air into the region from southwest to northeast after 02/20z bringing the precipitation to a gradual end and leading to improved ceilings. with the expectation that vsbys will continue to gradually crater overnight as a warm front extending from the Lower Toledo Bend Country of Deep E TX across Cntrl LA/MS begins to slowly lift N across N LA/E TX and possibly into far Srn AR overnight. before conditions slowly improve as sct convection develops ahead of the approaching upper trough now entering W TX. This trough remains progged to traverse E across TX overnight. The progs continue with a slower movement of the trough. this obviously would actually help improve vsbys a bit before convection begins to deepen after 12Z especially over E TX ahead of the trough.
236 AM EST Mon Jan 2 2017 Warm front pushes northeast tonight into Monday night. A cold front crosses late Tuesday.
This feature will be sending a cold front into our area late Monday. Based on moisture and temperatures profiles, a very light freezing drizzle mix is expected across much of northeast Nebraska where surface temperatures are slightly below freezing. Temperatures will drop significantly into Tuesday morning with highs only a couple degrees warmer than the overnight lows.
An upper level low is quasi-stationary over southwest WA this evening. Because the precipitation is showery expect the snow accumulations to be mainly 1 to 4 inches with heavier amounts in areas closer to the low with upslope conditions like the Yakima Valley and north central OR. Cold low pressure to drift over Western Oregon overnight with snow showers continuing to rotate through eastern WA and OR overnight. Upper low over sw Washington will remain nearly stationary the next couple of days before retrograding swwd off the Oregon coast on Tuesday. Blowing snow will also be an issue tonight in Washington as strong northerly winds develop behind the cold front.
The true cold front is still up in South Dakota this morning and will not swing through the entire forecast area until after 00 Z this evening. That said, the leading edge of the cold air will be influencing the northern half, keeping locations like Hays and Wakeeney struggling through the 30 this afternoon while much warmer highs are seen along the OKlahoma line.
As low pressure exits downstream of the CWA Monday evening into Tuesday expect an Arctic high pressure moving into the region. TFJ Forecast confidence with this issuance is significantly less than average given the poor synoptic model agreement regarding timing and placement of upper-level low pressure troughs and high- pressure ridges, etc.
Believe the lower end is about 4" which is more in line with the GFS/ECMWF/Canadian. Have leaned toward the lower amounts with the second system.
333 AM EST Mon Jan 2 2017 WV imagery and RAP analysis indicated a mid/upper level low over Hudson bay with the polar branch jet through nrn Ontario. At the surface a trough extended from James Bay to central Upper Michigan while a ridge prevailed from MN/WI to OH/PA. There is potential for some light freezing precip over the far south central, but it doesn't look like anything significant. Light snow is possible later tonight through the early aftn mainly at CMX, then at all the TAF sites on Mon evening as snow moves in with an approaching low pressure system. East winds of 15 to 25 knots Monday night will give way to w winds to 30 knots Tuesday as low pressure moves through Lake Superior.