Aikyam-Lab/Synoptic-Bench huggingface dataset:
339 AM CST Sat Jan 23 2021 Light snow and freezing rain will spread across central and southeast Illinois overnight, before diminishing to drizzle on Sunday.
/issued 344 AM EST Sat Jan 23 2021/ Cold front continues to push south of the area as high pressure bridges across the Ohio valley but a wide expanse to affect the local area. Low level moisture has been slow to scour out across far southeastern sections and consequently, the arrival of the cooler air has resulted in dense fog conditions. Although overall it will be a slightly cooler airmass, full sun today will allow for temperatures to rise into the upper 50s to lower 60s. Went with the lower MAV/MET blend for the dewpoints and we therefore get close to Fire Danger for the northern tier. Deese A warm front will be lifting northward across the forecast area at the start of the forecast period Sunday night as the parent low tracks northeastward across the Southern Plains.
Today through Sunday An upper low pressure center is located over southern NV around 07Z this morning, with diffluent flow evident on IR satellite over northern UT/NV and southern WY. This low is progged to move toward the northeast through 12Z, with the remaining energy continuing over southern WY through the day today. A cold front from an upper low over central Canada has already progressed to the Continental Divide. A trough will rotate around this low and move over the region this evening. This trough will bring in drier and colder air to the Cowboy State and thus, push all the moisture eastward over the Plains.
353 AM CST Sat Jan 23 2021 Return flow on the back side of cool high pressure will continue today. A cold front will sag south tonight through southwestern Kansas, with a wind shift to the north at 10-13 kts. Some drizzle may occur in central Kansas tonight, changing to freezing drizzle.
We will begin to see some increase in clouds across the west after midnight, so temperatures will be warmer there. As we move into Sunday, a warm front will slowly edge northward associated with a low that will be in Oklahoma during the day.
300 AM MST Sat Jan 23 2021 High pressure continues to push east towards the Great Lakes with a slow moving weather system crossing the Intermountain region through Saturday. Temperatures will be much cooler Sunday with highs in the low to mid 30s east of Laramie, and in the 20s to the west.
This will continue to be the case through the TAF period as a warm frontal boundary slowly begins to push north out of the Gulf through the overnight hours. with ridging southward to the Louisiana & Texas coastal waters where the stationary front is located. South of the front, warmer temperatures & dewpoints with patchy fog. North of the front, northeast winds and slightly cooler temperatures. A weak surface front currently extends over the outer coastal waters this morning where it is expected to meander through most of the day before lifting north as a warm front this evening into Sunday.
1030 AM EST Sat Jan 23 2021 High pressure will prevail through the weekend.
The modified max temps may still be a bit too warm, but prefer to give a little wiggle room for the potential that the weak overrunning may generate some areas of -DZ/-RA which may help carry some of the slightly warmer temps aloft down to the sfc, especially along/S of I-20.
Thereafter, CIGS will lower from southwest to northeast through the remainder of the TAF period as a warm front approaches the forecast area from the south. -SHRA/RABR will also begin to develop from southwest to northeast mostly after 08Z tonight as warmer air and weak lift advects into the area from the south ahead of the front. Included a mention of sprinkles early this mrng as drier air in the low lvls conts to advect Swd. On Sun, the upper flow pattern rmns progged to transition to the SW as an upr trof wl be lifting out of the Swrn states towards Wrn TX.
One is along the cold front across northern North Dakota, with better chances north central due to the proximity of better mid level PVA. The main concern for the overnight period into Sunday morning is the Arctic air mass moving in behind the cold front. Given the higher SLRs, snow accumulations of 1 to 2 inches are possible.
Trends in the high res guidance are perhaps an hour or two slower, with snow arriving in western areas by mid afternoon and towards the MS River by around 6 pm.
323 PM EST Sat Jan 23 2021 High pressure will build overhead tonight.
A cold front will enter northwest Oklahoma early Sunday morning.
128 PM EST Sat Jan 23 2021 Light snow showers north of Pittsburgh will dissolve as a high pressure builds in western PA. Ridging will keep conditions dry through Sunday afternoon. Cold sfc temps and warm advection may create a wintry mix situation, specifically freezing rain. Hi-Res models keep a this swath of precip near I-70 and in the WV ridges due to orographic lift.
A warm front will begin to slowly lift N across SE TX/SW LA late tonight, although areas of LIFR/VLIFR cigs and FG should develop late this evening into the overnight hours across E TX/N LA. Afterwards, areas of dense FG should set in by/just prior to daybreak, and will likely remain locked in across the region through much of the morning before slow improvement occurs by late morning/early afternoon as the warm front begins to lift N across E TX/N LA. The modified max temps may still be a bit too warm, but prefer to give a little wiggle room for the potential that the weak overrunning may generate some areas of -DZ/-RA which may help carry some of the slightly warmer temps aloft down to the sfc, especially along/S of I-20.
Focus shifts Sunday afternoon into overnight as a hybrid CAD wedge front/warm front interacts with upglide bringing increased shower chances mainly to north GA.
As for temperatures, colder air will filter into western Kansas late tonight in wake of the aforementioned cold frontal passage. Although a low level stratus layer is expected to retreat westward back into western Kansas overnight, expect lows generally down into the 20s(F) across west central and portions of southwest Kansas to the lower/mid 30s(F) in south central Kansas.
135 PM MST Sat Jan 23 2021 Water vapor shows upper trof over the Northern Plains with cut-off low along the CA coast. At the surface, inverted trof extends northeast from southwest through north central SD.
Meanwhile, broad upper ridging begins to build this afternoon that will persist through Sunday. The center of the large eastern conus high pressure over the lower midwest states will move southeastward over the Carolina coasts by late Sunday afternoon. This aforementioned upper and surface patterns will result in dry conditions through noon Sunday, but moisture will begin to increase once again as a warm front lifts over the region, but PWATs will only increase to be between 1. Lows tonight are expected to be in the mid 40s to lower 50s north of I-10 and in the lower to mid 50s to the south. The advancing warm front will result in warmer temperatures on Sunday, with highs ranging from 62 to 66 degrees along and northeast of U.
1026 AM MST Sat Jan 23 2021 High pressure continues to push east towards the Great Lakes with a slow moving weather system crossing the Intermountain region through Saturday. Temperatures will be much cooler Sunday with highs in the low to mid 30s east of Laramie, and in the 20s to the west.
106 PM EST Sat Jan 23 2021 High pressure will prevail through the weekend.
These appear to be tied to a weak low level trough oriented from southwest to northeast. Deep upper level low resides over central Canada, with several waves rotating around this feature. This feature will drive a cold front through the Northern Plains today, and will bring a chance of snow within an area of low/mid clouds to northern areas of the state. Coldest temperatures of the season so far tonight, with lows ranging from 10-15 below north to the lower single digits south.
Showers offshore and near the coast will gradually diminish through the afternoon as an upper level ridge begins to develop aloft and upper level forcing lessens.
with ridging southward to the Louisiana & Texas coastal waters where the stationary front is located. South of the front, warmer temperatures & dewpoints with patchy fog. North of the front, northeast winds and slightly cooler temperatures. A weak surface front currently extends over the outer coastal waters this morning where it is expected to meander through most of the day before lifting north as a warm front this evening into Sunday.
Until the warm front begins lifting through after midnight, we may not see consistent improvement to the marine fog and may need to extend the advisory much further.
High res models like the NAM, HRRR, and RUC show the low clouds holding on all day and tonight, as low level moisture above the boundary begins to spread north across the area. Will stay on the cooler side of guidance and keep highs in the 50s. At the same time, the NAM12 shows a warm front coming up from the south during the evening and eventually interacting with a stalled west-to-east oriented front over the Big Country. So, although instability is modest, shear will be plentiful, moisture will be sufficient, and the surface fronts and nearby upper trough will provide more than enough lift for scattered to numerous showers and thunderstorms Sunday evening through late Sunday night, some of which could be strong to marginally severe.
As the front departs a building mid-level ridge across the northwest Caribbean Sea and southeast Gulf of Mexico will support surface ridging extending into our area from a high pressure center located over the Mid Atlantic region. Highs on Sunday will range from the upper 70s on the beaches to the lower 80s across inland areas. There is a 500mb ridge of high pressure over the area, and an all but stalled frontal boundary to the east, that may bring some light showers or sprinkles to the Atlantic waters, but is not a significant enough boundary to be of a concern to mariners. Through the course of the week, a 500mb trough will dig south over the western US, helping to amplify the trough in the east. The trough migrates eastward, inducing leeward side cyclogenesis over northern Texas.
400 PM EST Sat Jan 23 2021 High pressure will move off to the east overnight.
151 PM MST Sat Jan 23 2021 The first piece of the southern trough is getting sheared apart this afternoon by the passing trough to the north. Sunday will be a clearer day, especially to the north, and any areas with new snowfall will be very bright! Higher elevations to the west will be slightly cooler Sunday, with temperatures in the teens and 20s.
High pressure continues to dominate our weather pattern for the day with no clouds apparent on latest satellite scans.
315 PM EST Sat Jan 23 2021 Building high pressure will bring a drying and cooling trend this weekend.
The low level inversion will be stronger tonight as the upper level ridge strengthens over WA/OR which will better provide opportunities for fog.
Sunday will be warmer with temperatures back in the 60s and 70s. with the main upper level trough still back to our west and a capping inversion evident on model soundings. At the same time, the NAM12 shows a warm front coming up from the south during the evening and eventually interacting with a stalled west-to-east oriented front over the Big Country. So, although instability is modest, shear will be plentiful, moisture will be sufficient, and the surface fronts and nearby upper trough will provide more than enough lift for scattered to numerous showers and thunderstorms Sunday evening through late Sunday night, some of which could be strong to marginally severe.
1002 AM EST Sat Jan 23 2021 High pressure should continue to build overhead through today and tonight.
For tonight, south to southeasterly flow in the low-levels will strengthen as the above mentioned stationary front moves northward as a warm front. Looking at some of the SREF data, it appears a few spots over the Hill Country and southern Edwards Plateau could see some of the lower visibilities. It will be warmer on Sunday and despite plenty of cloud cover, most areas should manage to reach the mid 60s to mid 70s. For Sunday night, an approaching upper level trough will strengthen the southwesterly flow aloft over much of Texas.
1045 AM MST Sat Jan 23 2021 Current surface map places low across Colorado, with weak inverted trof into western South Dakota.
337 PM EST Sat Jan 23 2021 Water vapor imagery highlights a large mid-upper level cyclone over the western United States. Downstream ridging continues to amplify in response to the upstream cyclone.
Slightly warmer than expected morning low temperatures lead to a rise in hourly temperatures with some slight increase for the high temperatures. Also, local downsloping in portions of southwestern Virginia and northeast Tennessee has allowed for notable drying in the lower levels, evidenced by dew points near or below 10 degrees. BW Chattanooga Airport, TN 34 52 45 65 50 / 0 30 90 70 90 Knoxville McGhee Tyson Airport, TN 30 52 43 62 51 / 0 20 90 80 90 Oak Ridge, TN 30 51 42 62 49 / 0 30 90 80 90 Tri Cities Airport, TN 25 50 39 58 48 / 0 20 60 90 90.
High pressure continues to push east towards the Great Lakes with a slow moving weather system crossing the Intermountain region through Saturday. Temperatures will be much cooler Sunday with highs in the low to mid 30s east of Laramie, and in the 20s to the west.
302 PM EST Sat Jan 23 2021 Weak cold front has for the most part stalled along and just north of the Interstate 4 corridor this afternoon with considerable clouds and a few showers north of it with partly to mostly sunny skies to the south. The boundary will begin to move once again tonight as high pressure well to the north builds south and this will shift the low level winds to northeast to east across the entire region overnight through Sunday. With the abundant low level moisture in place we're looking for another round of low clouds and fog late tonight into Sunday, but the expect the lowest visibilities to be mainly across southwest Florida with mainly low ceilings from around Tampa Bay and the Interstate 4 corridor northward.
Thus, it appears the baggy ridge axis lingers across the area. Temperatures have rebounded into the lower 70s, with some locations falling into the mid 50s earlier this morning. From synopsis, weak high pressure will linger across the Straits of Florida and the Florida Keys.
Highs will remain on the cold side for much of the area through the rest of the afternoon with highs ranging from the low 30s in Kansas and Nebraska to the low 50s in eastern Colorado. Southwest flow aloft remains over the Tri-State area with a trough located over central California. Sunday night, the trough will continue to lift to the northeast, into the Tri-State area. The trough is expected to be a little further north and west than models were indicating yesterday.
Early this afternoon, we saw a burst of light snow move through the southeastern half of the forecast area, followed by increasing coverage of freezing drizzle. This light freezing drizzle/mist will continue to be the predominant precipitation type through the afternoon and evening. Portions of Kansas could see temperatures rise above freezing later this afternoon and evening, which would mitigate impacts in those areas, but Nebraska will remain solidly below freezing. High temperatures will likely remain below freezing for most of Nebraska, and only reach the low to mid 30s across most of Kansas. The forecast becomes very active again starting late Sunday night as an upper trough ejects out of the southwest.
A cold front moving east overnight could transition the drizzle to snow but not for several hours. The snow will be operating on weak upper level dynamics and an arctic cold front dropping south through MT. NDOR cams are picking up on freezing drizzle east of highway 83 this afternoon. Until the better lift moves in tonight, areas of light freezing drizzle are in the forecast across parts of ncntl Nebraska. Cloudy skies continue Sunday and arctic high pressure will back into wrn and ncntl Nebraska.
Issued by National Weather Service Topeka KS 305 PM CST Sat Jan 23 2021 21Z water vapor imagery shows an upper low over the southwestern US with southwesterly flow over the central plains. At the surface, low pressure in the central high plains and high pressure east of the MS river valley is causing southeasterly winds over the forecast area and better low level moisture to advect north through the southern plains. Will need to keep an eye on temps across central KS where lows are forecast to be below freezing. But at this time temps look to remain above freezing while the upglide is ongoing.
Fog will clear out by late tomorrow morning with the low cloud deck retreating eastward. A 500 hpa trof will have deepened over the CA coast and swing across AZ/NM. Also, a Pacific front assocd with the approaching trof will race ewd.
A trough moving across the northern Plains is expected to bring accumulating snow to the area through Sunday morning. QPF values are on the lower end, with only around 0. Tomorrow morning, this system is expected to exit the area as the trough axis moves into eastern Lake Superior and a cold front crosses the area. Dry air on the backside of the cold front is likely to develop mostly sunny skies for Sunday. Temps will be noticeably cooler on Sunday, particularly in northeast Minnesota where highs will be in the single digits to mid teens.
346 PM MST Sat Jan 23 2021 The first piece of the southern trough is getting sheared apart this afternoon by the passing trough to the north. Sunday will be a clearer day, especially to the north, and any areas with new snowfall will be very bright! Higher elevations to the west will be slightly cooler Sunday, with temperatures in the teens and 20s.
The concern remains that on the back edge of the snow, which likely exists from about Columbus southward to Beatrice, we lose the deep saturation for snow and we transition to several hours of freezing mist/freezing drizzle. The freezing mist gradually ends overnight with dry weather expected Sunday.
Additionally, temperatures are now starting to warm above freezing in the area and this trend should continue with weak WAA into the region. GEOS satellite imagery is showing a digging and deepening Pacific trough over the SoCal region. As a lead wave lifts out of this trough and traverses the area late tomorrow, lee side cyclogenesis quickly develops an area of low pressure over the TX panhandle region and rapidly intensifies it as it lifts northeast.
This brings cool air into Siouxland, with highs just below seasonal normals, in the lower to mid 20s.
This flow will begin pushing the old frontal boundary back north over LA during the evening as a warm front with sufficient lift for showers to break out after midnight. Showers will continue mainly along and north of the northward moving warm front Sunday and mainly over northwestern sections in the best ascent.
/issued 302 PM EST Sat Jan 23 2021/ Weak cold front has for the most part stalled along and just north of the Interstate 4 corridor this afternoon with considerable clouds and a few showers north of it with partly to mostly sunny skies to the south. The boundary will begin to move once again tonight as high pressure well to the north builds south and this will shift the low level winds to northeast to east across the entire region overnight through Sunday. With the abundant low level moisture in place we're looking for another round of low clouds and fog late tonight into Sunday, but the expect the lowest visibilities to be mainly across southwest Florida with mainly low ceilings from around Tampa Bay and the Interstate 4 corridor northward.
Going into the overnight hours at least parts of Northwest Montana (perhaps additional areas) will remain in the low cloud cover.
335 PM CST Sat Jan 23 2021 Upper level divergence/lift from an low pressure trough in southern Canada dropping into our region along with right rear quadrant lift from a jet streak off to our northeast were the primary contributors to our snowfall this afternoon.
940 PM EST Sat Jan 23 2021 As a weak cold front continues to move southward over the FL peninsula and away from the local area, a high pressure builds in from the north. As a cold front pushes south of the area, winds will veer from northeast to east tonight and increase to 15-20 kt across the nearshore Atlantic waters north of Sebastian Inlet and all the offshore.
915 PM EST Sat Jan 23 2021 Light snow showers north of Pittsburgh will dissolve as a high pressure builds in western PA eventually overnight. Ridging will keep conditions dry through Sunday afternoon. Cold sfc temps and warm advection may create a wintry mix situation, specifically freezing rain. Hi-Res models keep a this swath of precip near I-70 and in the WV ridges due to orographic lift.
922 PM EST Sat Jan 23 2021 High pressure over us tonight will move offshore later Sunday.
with ridging southward to the Louisiana & Texas coastal waters where the stationary front is located. South of the front, warmer temperatures & dewpoints with areas of patchy to dense fog across the lakes, bays and coastal waters out 20nm. North of the front, northeast winds and slightly cooler temperatures, with gradual lowering of visibilities across the coastal parishes/counties south of I-10.
654 PM EST Sat Jan 23 2021 Building high pressure will bring a drying and cooling trend this weekend.
310 PM CST Sat Jan 23 2021 Early this afternoon, we saw a burst of light snow move through the southeastern half of the forecast area, followed by increasing coverage of freezing drizzle. This light freezing drizzle/mist will continue to be the predominant precipitation type through the afternoon and evening. Portions of Kansas could see temperatures rise above freezing later this afternoon and evening, which would mitigate impacts in those areas, but Nebraska will remain solidly below freezing. High temperatures will likely remain below freezing for most of Nebraska, and only reach the low to mid 30s across most of Kansas. The forecast becomes very active again starting late Sunday night as an upper trough ejects out of the southwest.
832 PM EST Sat Jan 23 2021 Light snow showers north of Pittsburgh will dissolve as a high pressure builds in western PA. Ridging will keep conditions dry through Sunday afternoon. Cold sfc temps and warm advection may create a wintry mix situation, specifically freezing rain. Hi-Res models keep a this swath of precip near I-70 and in the WV ridges due to orographic lift.
Upper level divergence/lift from a low pressure trough in southern Canada dropping into our region, along with right rear quadrant lift from a jet streak off to our northeast were the primary contributors to our snowfall this afternoon.
Ridging aloft will also favor above normal temperatures during this time. Expect overnight lows to range from the upper 20s north to the low 30s in the CSRA. High pressure will remain centered over the Mid Atlantic by tomorrow morning, ridging into our area leading to a chilly start to the morning. Models have trended slower in pushing this high offshore which will limit warm advection at the surface tomorrow with some thin high and mid level clouds passing over the area ahead of a warm front. At 850 mb, SW flow will bring in more moisture, increasing cloud coverage in the low levels and limiting highs in the 50s across the area.
21Z water vapor imagery shows an upper low over the southwestern US with southwesterly flow over the central plains. At the surface, low pressure in the central high plains and high pressure east of the MS river valley is causing southeasterly winds over the forecast area and better low level moisture to advect north through the southern plains. Will need to keep an eye on temps across central KS where lows are forecast to be below freezing. But at this time temps look to remain above freezing while the upglide is ongoing.
A 500 hpa trof will have deepened over the CA coast and swing across AZ/NM. Also, a Pacific front assocd with the approaching trof will race ewd.