Aikyam-Lab/Synoptic-Bench huggingface dataset:
At the surface, high pressure remained in control of much of the middle part of the country. Areas that see some sunshine will warm into the upper 30s to near 40 degrees while locations that remain overcast will only reach the low to mid 30s.
327 AM EST Sat Jan 9 2021 Synopsis/Discussion/Marine - A sunny Saturday expected - Clouds return tonight and last through the coming week - Trend toward colder with snow remains Friday and beyond - A sunny Saturday expected Today should be a mostly sunny day across most of the area once the low clouds near I-94 move out shortly after sunrise.
At the surface, sprawling high pressure is building across the central CONUS favoring pressure rises into the TN Valley and Southern Appalchians in the wake of the departing low pressure system from yesterday. Otherwise, a few light snow showers continue across portions of the central valley east of I75 in associated with weak frontogenesis, as well as across the higher terrain of the Appalachians via nwly upsloping.
This increased cloud cover will limit cooling tonight with lows expected to be 5 to 10 degrees warmer than those observed this morning.
A warming trend will begin after the weekend as high pressure builds in across the area. A closed upper low could be seen on satellite imagery over northeast Nevada this evening and this system will continue diving through southwest Utah overnight.
811 PM MST Fri Jan 8 2021 The upper level trough that will bring snow to the area Saturday is dropping southeast across northern Nevada. The trough just onshore will drop southeast, bringing a weak closed low across southwestern Colorado on Saturday. Current forecast and model guidance is all good for the rest, with highs around freezing on the plains Saturday and light winds.
341 AM EST Sat Jan 9 2021 Synopsis/Discussion/Marine - A sunny Saturday expected - Clouds return tonight and last through the coming week - Trend toward colder with snow remains Friday and beyond - A sunny Saturday expected Today should be a mostly sunny day across most of the area once the low clouds near I-94 move out, shortly after sunrise.
Lows tonight will be mild again in the lower to mid 20s.
1007 PM EST Fri Jan 8 2021 Low pressure scooting east off the Outer Banks of NC will followed by a ridge of high pressure at the surface and aloft building SE over the region.
354 AM CST Sat Jan 9 2021 Weak mid level ridging will take place today as a rather flat trof slides off to the east.
Area under influence of low pressure with three low pressure centers analyzed at the surface. Finally, the third low pressure system analyzed near Torrington that is helping to pull in low level moisture into the Panhandle and areas east of the Laramie Range. Rather uneventful weather for Sunday as upper high pressure builds back over the area.
In addition to low visibility, wet roadways may be icy in many areas as low temperatures are below freezing in almost all areas where fog is reported. It looks to be almost entirely gradient driven, with higher winds aloft above an inversion, rather than below it, and that inversion is forecast to be below ridgetop level, not above it, so the potential for ducting strong winds to the surface also appears limited. Overall fair weather continues through mid-week with a return to ridging aloft over the region.
If drizzle occurs instead, the chance for it to freeze will be greatest across and east of the Prairie Coteau, given the sub-freezing forecast high temps there (as opposed to further west). While the chance for light precipitation will have decreased by tonight (though not impossible given the development of a very dry layer directly above the saturated layer), the lowest levels should still be fairly saturated. Upper level ridging will exit the region Sunday night, with northwest flow becoming dominant through the rest of the period.
410 AM EST Sat Jan 9 2021 Canadian high pressure will build slowly SE into the region through the weekend.
/Today and Tonight/ An upper-level ridge will swing east across the region today with southwest flow aloft bringing a return of moisture and cloud cover in its wake tonight. However, mid to high level clouds to return overnight as approaching upper-trough begins to destabilize the atmosphere and enhance moisture advection from the southwest. Temperatures today to climb into the mid to upper 40s with near freezing overnight lows.
Surface pressures are high across the region, with a light northern gradient from the high center around 1030 mb across the northern and central Plains.
Current 500mb RAP analysis has the upper level low that will bring our winter event later tonight positioned over west central Utah. This low is expected to dive southeast across New Mexico today before barreling across West Texas into tomorrow morning. PVA ahead of the low will provide some lift in the dendritic growth zone. Again, locally higher amounts are possible as some additional moderate bands may set up during the early morning hours Sunday with the wrap around moisture as the low tracks just to the south of the Texas Panhandle. With snowpack expected, the high temperatures for tomorrow have been lowered a few degrees to encompass the lack of warming, especially as clouds continue to linger through most of the day tomorrow.
These low level clouds will likely remain in place over most of the forecast area through the weekend underneath a subsidence inversion with surface ridging extending from the Northern Plains southeast into MO.
This will ensure mainly clear skies across the lowest 10k ft, with simply a very limited coverage /if any/ of diurnal stratocumulus possible this afternoon. Low level ridging begins to break down into Sunday as the blocking pattern relents and a northern stream wave train ensues across the Great Lakes during the early to mid week period.
855 AM EST Sat Jan 9 2021 High pressure building in the Upper Midwest today and tonight will settle into the northern Ohio Valley on Sunday.
A cold front will move through the area Saturday morning, bringing breezy northwest winds and much cooler temperatures for the weekend. A trough of low pressure will advance across the area today bringing breezy northwest winds along a dry cold frontal boundary. Gusts 20-30 mph are still possible across the high terrain.
With some breaks in the clouds today, we could see a few locations approach the lower 40s but those that remain overcast will likely remain in the low to mid 30s once again with weak H85 cold air advection progged to continue across the area. Some locations across central Kansas will see highs around 50 while far southeast KS remains in the low to mid 40s. Mid/upper ridging over the Southwest will extend northeastward across the Rockies and into the Central Plains Tue-Wed resulting in mild and above normal temperatures and dry weather conditions across the region.
Freezing fog has continued to become more expansive across the area this morning. A dense fog advisory has been issued through the highway 83 corridor and toward the 283 corridor to the east.
This has allowed temperatures to slowly cool over the past couple of hours into the lower to mid 60s.
A storm system brushing by to our northeast will bring gusty winds and cooler temperatures over the weekend. That will bring gusty winds and a cooler air mass, but not enough moisture for any significant shower chances.
These lax for tonight into Sunday along with some rather broad sfc ridging.
504 AM CST Sat Jan 9 2021 Water vapor satellite this morning shows a short wave trough near Lake Winnipeg. In the low levels, the area of high pressure centered over Minnesota will drift slowly south and remain over the region. Forecast soundings show no change in the low level moisture remaining trapped under the inversion. This will keep the low clouds in place over the region, but there is little to no moisture above the inversion for the short wave trough to work with. As a result, do not plan to include any precipitation mention with this passage of the short wave trough.
Accumulations are not expected, except across the northwest (Pine Ridge) where slightly cooler temperatures and enhanced lift over the higher terrain could result in some heavier bands of snow. For temperatures, cooler temperatures will remain in place thanks to mostly cloudy skies with highs only in the low to mid 30s.
440 AM MST Sat Jan 9 2021 Satellite combined with model analyses showed the low center at the base of the positive tilt trough over south-central Utah early this morning. Clouds have formed over east-central Utah and west- central Colorado in the difluent area ahead of the trough. Models carry the low center to just southwest of the Four Corners at 18Z then to west-central New Mexico by 00Z/Sun.
336 AM CST Sat Jan 9 2021 High pressure centered over Nebraska is controlling the weather across the center third of the country this morning.
Temperatures may fall another degree or two resulting in morning lows within a degree or so either side of freezing across the Midsouth. A weak ridge will build in over the Midsouth today, then shift East of the area on Sunday in response to a deepening midlevel trough over Southwest Texas. By Sunday evening the trough over West Texas should be centered over the Dallas area.
Added potential for light snow or freezing drizzle along the SD Missouri River Valley today as well, as a weak mid level disturbance lingers over central SD. Not expecting any significant accumulation or impact, given both weak forcing and the warmer surfaces in this region during daylight hours. This chance of precipitation should taper off this evening as the disturbance is swept up by a strong trough axis progressing through the Great Lakes region. Surface winds become more westerly and eventually southerly, and temperatures should be slightly warmer, especially central SD with highs reaching the 30s for most sites.
347 AM MST Sat Jan 9 2021 Overview: An upper level low presently situated invof Salt Lake City, UT will dig southeast through northern New Mexico this evening-tonight, progressing E-ESE across Texas Sun-Sun night. mainly in association with broad low-to-mid level (850-600 mb) warm advection in advance of an upper level low digging southeastward from UT into northern NM. Sunday-Sunday night: Expect a clearing trend during the day as the aforementioned upper low progresses downstream of the region.
and Sunday High pressure from the Northern Plains to the Great Lakes will keep dry weather across the area through at least Sunday.
Weak mid level ridging will take place today as a rather flat trof slides off to the east.
The 12z KTAE sounding reveals a shallow layer of low level moisture up to around 900 mb that is responsible for the low cloudiness we see this morning. If this were to happen, then overnight lows would be warmer than most of the guidance currently shows.
357 AM MST Sat Jan 9 2021 Satellite combined with model analyses showed the low center at the base of the positive tilt trough over south-central Utah early this morning. Clouds have formed over east-central Utah and west- central Colorado in the difluent area ahead of the trough. Models carry the low center to just southwest of the Four Corners at 18Z then to west-central New Mexico by 00Z/Sun.
Recent model trends have been toward a flattening of the ridge early this week.
203 AM MST Sat Jan 9 2021 Latest upper air analysis shows a long wave trough over the eastern CONUS. Within the larger feature was a short wave trough moving southeast across Kansas. Ahead of and behind this trough was an overcast sky. To the west a ridge was over the Great Basin. Another upper level trough was moving onto the West Coast. Overnight freezing drizzle may occur over primarily Graham and Norton counties where the saturated low levels will be deep enough and isentropic lift strong enough. Bridges and overpasses may develop patches of ice on them.
413 AM CST Sat Jan 9 2021 Freezing fog has continued to become more expansive across the area this morning. A dense fog advisory has been issued through the highway 83 corridor and toward the 283 corridor to the east.
620 AM EST Sat Jan 9 2021 Canadian high pressure will build slowly SE into the region through the weekend.
234 AM MST Sat Jan 9 2021 Light snow, drizzle, and fog will gradually decrease over the area today with clouds diminishing later today and this evening as high pressure moves into the region.
At the surface, high pressure remained in control of much of the middle part of the country. Areas that see some sunshine will warm into the upper 30s to near 40 degrees while locations that remain overcast will only reach the low to mid 30s. A southern stream trough ejects across the Southern Plains late tonight into Sunday although precipitation associated with this wave will remain well south of the forecast area.
345 AM MST Sat Jan 9 2021 Trough continues to drop southward across UT, and should be centered on the Four Corner by noon today. Energy has been weaker than expected on the NE side of this trough, so light snow has been minimal across SW WY overnight. As the trough exits to the south, a piece of energy from the previous trough will get drawn southward into the passing trough, bringing some light snow to areas along and east of the Big Horn Mountains this morning through noon. Ridging starts to build in across the state for Sunday, bringing generally tranquil conditions to the region. Temperatures west of the divide will still only reach the 20s for highs, while warmer temperatures begin to return east of the divide, with highs in the 30s to near 40 around the KCOD region.
341 AM CST Sat Jan 9 2021 Deep boundary layer moisture, cold temperatures and light winds have led to more freezing fog developing early this morning across the region. A freezing fog advisory is in effect for most our area until 10AM CST. Southeast surface flow will increase later this morning as the freezing fog dissipates. The potent upper level low will track south through New Mexico overnight, reaching the I20 corridor over Midland by sunrise tomorrow. With the clouds and snow covered ground, highs on Sunday will hover around the freezing mark as the system exits to the east. Upper level ridging near the West Coast will generally result in northwest flow over the southern High Plains. Freezing Fog Advisory until 10 AM CST this morning for TXZ021>024-027>031-033>044.
428 AM EST Sat Jan 9 2021 High pressure building in the Upper Midwest today and tonight will settle into the northern Ohio Valley on Sunday.
(This evening through Sunday) The upper low just southeast of the four-corners will continue to move east-southeast through New Mexico overnight then east across north Texas Sunday. The upper low will be moving across north central Texas at 11/00Z, but will still expect some snow into Sunday night on the northwest side of this low.
155 PM CST Sat Jan 9 2021 While there is slight upper-level ridging today, stratus and northerly winds have kept temperatures in the mid 30s. Lows tonight are now forecast to be in the upper 20s, near the warm end of the model range but several degrees cooler than last night.
Things begin to change Sunday as flow aloft shifts from NW to SW by Sunday evening ahead of the next wave/low pressure system moving east along the gulf coast.
some flurries, spotty light snow showers or perhaps a touch of freezing drizzle anticipated for parts of the forecast area. Continued weak high pressure will little disturbances through the 48 hour of the short term period gives us barely slight chances for snow in the NW LES flow, mainly Sunday night.
137 PM EST Sat Jan 9 2021 High pressure crosses Sunday.
Western parts of the area will have the highest potential so see some peaks of sunshine in the afternoon.
Overall expected trend tonight into Sunday will be gradual clearing of the low level moisture southward. With a bit drier air in the low levels moving in and a slowly increasing wind at 925 mb moving in tonight not expecting as much dense fog as past nights. An upper level ridge in west will keep the NW flow in place for the area, and bringing in some warmer temperatures. We will warm into the upper 30s and possibly even the low 40s heading into mid-week in the northern plains.
1140 AM CST Sat Jan 9 2021 Water vapor satellite this morning shows a short wave trough near Lake Winnipeg. In the low levels, the area of high pressure centered over Minnesota will drift slowly south and remain over the region. Forecast soundings show no change in the low level moisture remaining trapped under the inversion. This will keep the low clouds in place over the region, but there is little to no moisture above the inversion for the short wave trough to work with. As a result, do not plan to include any precipitation mention with this passage of the short wave trough.
Soundings should enough depth in the low lvl moisture profile to reach the DGZ, so we have seen minor (up to 0. I would anticipate the risk for flurries to continue into the overnight hours as trailing 500 mb trough axis finally moves through after midnight (this is currently producing light snow near Aberdeen). Will trend coldest temperatures in the eastern areas tonight with a rapid cooldown given clear initial evening skies, with warmer low temperatures favored further west with abundance of cloud cover. It's possible to have a few breaks by mid to late afternoon, which will allow temperatures to climb near or above freezing.
A storm system brushing by to our northeast will bring gusty winds and cooler temperatures over the weekend. A system passing through NE AZ this afternoon was bringing some gusty winds and cooler temperatures to the area today.
Once we loose the higher clouds that are cold enough to support ice nucleation (snowflake hydrometeors), probably seeing the potential for snow to be replaced with areas of drizzle/freezing drizzle while the stratus cloud layer remains thick enough and "warm enough" (coldest temp in/near top of the layer around -8C to -10C). If drizzle occurs instead, the chance for it to freeze will be greatest across and east of the Prairie Coteau, given the sub-freezing forecast high temps there (as opposed to further west). While the chance for light precipitation will have decreased by tonight (though not impossible given the development of a very dry layer directly above the saturated layer), the lowest levels should still be fairly saturated. Upper level ridging will exit the region Sunday night, with northwest flow becoming dominant through the rest of the period.
In addition, the SPS for brief freezing conditions was extended to this area and updated to include a mention of patchy frost west of I-95 as far south as Lake Okeechobee tonight. High pressure building into the area today will keep dry conditions in place, despite the robust area of stratocu currently stretching from well northward of the local area. Nonetheless, cooler temperatures than previous days today, as NW flow and CAA persist. Highs remaining near to or below 60 from Orlando northward and in the low 60s southward to the Treasure Coast. Tonight, much cooler temperatures thanks to light NW flow and decreased cloud cover. Brief freezing temperatures are also possible, though coastal Volusia should remain warm enough to only reach frost criteria.
1250 PM EST Sat Jan 9 2021 Canadian high pressure will build southeast across the southern middle Atlantic through Sunday.
For Sunday, minor ridging aloft should aid in finally scattering and clearing the low cloud deck. Will stay with cooler raw numbers for highs in the lower 40s for most areas, perhaps a bit warmer in our eastern counties where clearing is most likely.
Tonight and Sunday The latest RAP analysis and satellite/radar imagery show high pressure stretching across much of the northern Plains into the western Great Lakes early this afternoon. No precip is occurring near the trough, but skies are clearing over south-central Canada behind the trough. The only chance of precip would be if shallow boundary layer moisture can grow deep enough for flurries or freezing drizzle, but this too doesn't appear will be sufficient. But as winds shift to the north behind the trough, there is potential for enough dry air to infiltrate the region and bring clearing skies from late morning through the afternoon.
115 PM EST Sat Jan 9 2021 High pressure crosses Sunday.
However, I suppose you can't rule out isolated or patchy freezing drizzle but confidence is quite low at this time.
Also of concern in shallow moisture depth is ice crystal nuclei introduction that could portend of drizzle/ freezing drizzle, but for now will maintain frozen mention with snow observed yesterday over WI/IL in similar thermal profiles. Plains to western PA ridge to firmly supplant systems north/south of CWA in split flow regime through at least midweek.
331 PM EST Sat Jan 9 2021 High pressure will build across the region through the weekend.
A slow progression is expected due to light boundary layer wind tied to high pressure reaching in from the northern Plains. Coverage may not actually even reach the DTW area before sunrise which adds some complexity to the min temp forecast with warmer lower 20s readings north and colder teens south to lower 20s metro Detroit.
144 PM EST Sat Jan 9 2021 High pressure will move southeast across the Ohio Valley tonight, and across the Mid-Atlantic region Sunday.
A northern stream upper-level trough is expected to reach the Midwest on Sunday into Sunday night but will do little to perturb the stratus with the absence of any significant low-level lift to modify the subsidence inversion.
Areas across the Nature Coast could see at or below freezing temperatures.
We will also see patchy freezing fog persisting into Sunday morning, although the likelihood of dense fog with Advisory-warranting visibility (of 1/4 mile or less) doesn't look as high tonight as it has the past several. On Sunday afternoon we look to see at least a few holes in the stratus deck, which could allow temperatures to sneak above freezing west of the MN River Valley. Can't entirely rule out patchy freezing fog again Sunday night, although increasing southwest flow should minimize the potential.
Overview: An upper level low presently situated invof Salt Lake City, UT will dig southeast through northern New Mexico this evening-tonight, progressing E-ESE across Texas Sun-Sun night. mainly in association with broad low-to-mid level (850-600 mb) warm advection in advance of an upper level low digging southeastward from UT into northern NM. Sunday-Sunday night: Expect a clearing trend during the day as the aforementioned upper low progresses downstream of the region.
This was confirmed on water vapor imagery as well with the center of the low farther to the west and south than expected from this time 24 hours ago. This may lead to a period of freezing drizzle or drizzle before precipitation becomes more widespread.
Fair skies and dry conditions will keep the nights cool, but after this weekend, a warming trend will set in under building high pressure aloft.
1036 AM MST Sat Jan 9 2021 Satellite combined with model analyses showed the low center at the base of the positive tilt trough over south-central Utah early this morning. Clouds have formed over east-central Utah and west- central Colorado in the difluent area ahead of the trough. Models carry the low center to just southwest of the Four Corners at 18Z then to west-central New Mexico by 00Z/Sun.
A cold front will move through the area this morning, bringing breezy northwest winds and cooler temperatures for the weekend.
Garuckas Chattanooga Airport, TN 25 48 31 46 35 / 0 0 0 60 50 Knoxville McGhee Tyson Airport, TN 22 45 28 44 35 / 0 0 0 50 50 Oak Ridge, TN 23 45 28 44 32 / 0 0 0 40 50 Tri Cities Airport, TN 19 45 26 44 32 / 0 0 0 30 60.
The low stratus will hang around overnight while surface ridging slides across eastern Nebraska.
Visibilities as low as one quarter of a mile, as well as freezing fog, will be possible. The freezing fog could result in slippery stretches on untreated roadways and sidewalks.
336 PM EST Sat Jan 9 2021 Canadian high pressure will build southeast across the southern middle Atlantic through Sunday.