Aikyam-Lab/Synoptic-Bench huggingface dataset:
Short term progs and latest HRRR output suggests that as we go through the afternoon and early evening hours, we should continue to see convection develop ahead of a cold front and thus have VFR and VCTY Showers becoming VCTS and or prevailing TSRA with variable wind gusts and ceilings becoming MVFR and eventually IFR just ahead of the frontal boundary itself.
For Saturday, a trough is expected to move through the area with the upper low centered over the state. Much of the precipitation with the trough looks to be focused from NV eastward into western CO. Another area that may see the best potential for accumulating snow is over the Bighorn Mountains near the upper low where another 1-2" is possible with cold air aloft keeping it more unstable. Total snow accumulations for the storm look to be around 4-5 inches The Tetons and YNP: 4-5" Western Valleys: 1-3" Wind River Basin: up to 1" Bighorn Mountains: 2-3" Sweetwater County: 1-2" Casper: <1" Casper Mountain: 1-2" Bighorn Basin: little accumulation Saturday night the first trough will be departing to the SE, with a few lingering flurries in the Casper Mountain vicinity.
The tail end of a weak trough has brought some light snow to the region this morning.
The lowest visibilities are up around Cando, North Dakota, with another smaller area from Fosston to Bemidji. Wind speeds will also stay on the lower side, so although the lowest visibilities should improve after the noon hour, some haziness will likely linger into the afternoon. Sounding profiles thru the day into tonight keep the low level moisture up thru 925 mb in place in weak cold advection. Some small holes in the low clouds may form mid afternoon for that reason did decrease sky a tad based on collab.
Currently seeing increasing clouds across the area ahead of an approaching cold front that is just west of the Mississippi River. Despite a cold front moving into the TN valley during the afternoon and evening hours, upper level support will be waning.
Cold front near a Miami to Okmulgee line and making slow but steady progress eastward. A brief window of showers and storms along the cold front remains possible primarily later this afternoon and early evening across SE OK through west central AR. A brief strong storm is possible before the cold front clears the forecast area by mid evening.
229 PM EST Fri Dec 11 2020 Fair and much warmer than normal weather will last into Saturday.
119 PM CST Fri Dec 11 2020 Center of deepening low pressure system currently located on the KS/MO border as of 1 pm this afternoon. Precipitation has been filling in north of the low into our area (northeast IA into southwest WI) going into this afternoon. 5 inches on ridgetops/grassy areas by this evening. Should see more steady-state snow going into this evening and overnight across that area as temperatures at the surface and column continue to cool as the low lifts northeast toward Chicago by morning. locally higher on the bluff/ridge tops. Northwest winds on the backside of the low will be gusting pretty good across this freshly fallen snow Saturday which may cause some blowing and drifting on mainly bluff ridgetops and open areas. In the wake of the departing system, cooler conditions are in store.
140 PM EST Fri Dec 11 2020 Rain returns tomorrow as a low pressure system advances into the Ohio River Valley. Lingering high pressure will keep our area dry and quiet this evening. A strengthening low pressure system will advance into the western Great Lakes early tomorrow morning.
1115 AM CST Fri Dec 11 2020 (Today and tonight) Short wave trough will move across the area today, with associated cold front entering the Big Country this afternoon and moving across the rest of the area this evening and overnight. Highs this afternoon will range from the 60s across the Big Country, to the lower and middle 70s across the rest of the forecast area.
1212 PM PST Fri Dec 11 2020 A cold front will move through the region today, bringing gusty wind through the wind-prone areas of Central California during the day.
A weakening upper level trough will move across Utah today. A stronger trailing upper trough will move across Utah on Saturday, with widespread snow expected for the mountains.
254 PM CST Fri Dec 11 2020 Abundant high clouds cover the region today as a broad longwave trough sits over the central CONUS. Light north winds advect in a more seasonal air mass, with highs in the low to mid 30s. Despite being much cooler than the first half of the week, these temperatures remain about 5 degrees above seasonal averages.
/Updated at 1050 AM CST Fri Dec 11 2020/ Dense fog across the southern-third of the CWA has mostly mixed at this hour leaving cooler morning temperatures in its wake.
Temperatures will start off on the cooler side with afternoon highs in the 20s to low 30s and overnight lows in the teens.
VFR to periodic MVFR ceilings ongoing across NE OK through western AR as cold front continues eastward. Cold front near a Miami to Okmulgee line and making slow but steady progress eastward. A brief window of showers and storms along the cold front remains possible primarily later this afternoon and early evening across SE OK through west central AR. A brief strong storm is possible before the cold front clears the forecast area by mid evening.
As we go throughout the weekend a weak cold front will stall to our north.
Rain will move into the area this evening into Saturday morning as a cold front moves through. Cooler temperatures will follow with highs reaching the upper 50s and low 60s with lows dipping down into the upper 20s and 30s. Another upper-level trough will develop out of the Rockies and move south of the forecast area.
An upper level trof will approach the region today, resulting in increasing clouds, and rain chances by afternoon from SEMO into SW IL. As the upper system and associated cold front move over/across the area tonight, we have categorical PoPs in for rain.
247 PM EST Fri Dec 11 2020 High pressure has slid to the east into the western Atlantic and will continue to dominate across South Florida. Tomorrow temperature will be in the upper 70s to around 80 closer to normal this time of year A 500 hPa ridge of higher pressure continues to have a strong influence on the South Florida weather pattern, acting to quell any shower/storm activity.
The high center will move east and arrive north of Bermuda tonight. This will act somewhat like a warm front spreading across the Keys, with the influx of warmer and moister air from the east overriding the shallow layer of cool air that remains in place near the surface.
Clouds will be on the increase today ahead of an approaching low pressure system that will bring a chance for rain to our western most zones by late this afternoon. The cloud cover will continue to increase from the west today in the warm advection regime in advance of a mid/upper level trough moving out of the Plains today and into the mid MS valley tonight. Also, the system will be in a weakening state by the time its attendant cold front moves into the area tonight. /GG/ This weekend: By Saturday morning, the cold front and associated band of showers will continue to push across east/southeast MS, clearing the area by midday. However, we will remain in a rather progressive pattern as the longwave trough remains centered over the CONUS.
The upper level trough responsible for the scattered rain will begin to lift northward and eject out over the central CONUS, allowing for a weak cold frontal passage overnight. Temperatures will drop off much quicker than last night, in the presence of a drier airmass, expect clearing skies and lows in the low to mid 40s areawide.
Water vapor satellite imagery shows an upper level trough moving across the Southern and Central Plains, while at the surface, a dry-line, with westerly winds and dewpoints in the 30s/40s, was moving through the Concho Valley/Edwards Plateau, while a weak cold front has moved through the Big Country. The cold front is keeping temperatures cooler in the Big Country (mid to upper 50s), while temperatures are in the mid to upper 60s south of the front. Look for the cold front to very slowly move through the region tonight through Saturday morning, with cold lows in the low to mid 30s early Saturday morning, and cooler highs Saturday afternoon in the mid/upper 50s in the Big Country and low to upper 60s elsewhere.
High pressure across the area will shift NE, with inverted trough off the east central FL coast breaking down into the afternoon. Slow warming trend continues, with afternoon highs expected to be closer to normal today, in the low 70s. Inverted trough off the coast is leading to a N/NW flow up to 5-10 knots near the coast and E/SE flow farther offshore. This trough will weaken, with winds becoming more E/SE across the waters this afternoon, with speeds remaining around 5-10 knots or less in some areas.
Winds will continue to be light on Saturday before a cold front moves in Saturday Night.
1041 AM MST Fri Dec 11 2020 Current surface analysis shows high pressure centered over ND, with an area of low pressure over central CO. An inverted trough extends north from the low into WY. Upper level analysis shows trough over the central and southern Rockies, with strong jet wrapping around it from the west coast to the desert southwest and into the southern and central Plains. An area of low pressure is also located off the southern British Columbia coast.
The track of the low set to impact southeastern Montana tonight into tomorrow has continued to be more southern.
Latest guidance indicates the prefrontal trof will become diffuse.
1217 PM CST Fri Dec 11 2020 Current satellite imagery shows increasing clouds from the west with a cold front stretching through AR, OK, and TX. The only changes made were to temperatures as temperatures in eastern AR are much cooler than anticipated due to cloud coverage. Rain will move into the area this evening into Saturday morning as a cold front moves through. Cooler temperatures will follow with highs reaching the upper 50s and low 60s with lows dipping down into the upper 20s and 30s. Another upper-level trough will develop out of the Rockies and move south of the forecast area.
0230z/830pm surface analysis shows a 1006mb low over northeast Missouri with a warm front extending into central Illinois. S/SE winds and temps in the middle 50s prevail south of the boundary, while NE winds and much cooler readings in the lower to middle 40s are noted north of the front.
With cooling this evening, expect the low clouds to all fill back in. There was still some fog on webcams this afternoon and expect this to continue tonight with visibilities lowering with light winds in the lower levels mainly out west. With the cloud cover, dont expect much fall in temperatures tonight and went higher with the lows. There may be a few breaks but dont expect the clouds to move out until Saturday night as the winds finally turn west in the low levels and push the clouds east. Expect highs in the upper 20s to the lower 30s.
450 PM EST Fri Dec 11 2020 Fair and much warmer than normal weather will last into Saturday.
547 PM CST Fri Dec 11 2020 Updated for 00Z aviation discussion 00Z TAF discussion: Deteriorating conditions expected this evening as MVFR/IFR cigs lower from west to east and -shra spreads along and ahead of the approaching cold front. Tonight and Saturday: warmer than normal temperatures will continue through the period with increasing rain chances from the west tonight before the rain ends from the west Saturday. This will lead to the cold front slowing as it moves through our CWA and model consensus has come in slower to end the rain Saturday afternoon over our southeast. The waa ahead of this approaching cold front is expected to help keep temperatures warmer than normal tonight. Despite the cold front moving through our CWA Saturday, temperatures are expected to climb warmer than normal before getting knocked down with the fropa.
647 PM EST Fri Dec 11 2020 A low pressure system will bring widespread rain to the area tonight and tomorrow.
403 PM MST Fri Dec 11 2020 A broad upper-level trough covers most of the CONUS, with a low pressure system moving over the Pacific Northwest. At the surface, high pressure sits over ND, and an inverted trough persists over WY. Approaching Pac NW upper low and little change in the surface pattern overnight will result in light snow across northeastern WY/far western SD tonight into Saturday morning. Upper low will weaken as it slides south of the area Saturday. Dry weather will then resume beneath northwest flow, and cooler air will filter into the region this weekend.
High pressure will be northeast of the region Tonight, then more toward the east Saturday. So the airmass near the coast will have air passing over the relatively warmer waters at night, but the waters will be relatively cooler for the day time Saturday.
Precipitation chances with this system remain along our northern zones, with highest chances in the higher elevations of Lincoln County.
623 PM EST Fri Dec 11 2020 Upper ridging over the region sliding into the W Atlantic in response to upper trough moving through the S Plains states this evening. As we go throughout the weekend a weak cold front will stall to our north.
Snow amounts have varied depending on where snow bands were located with 2" of snow reported in the Wilsonville/Cambridge areas, 3-4" in the Kearney area, 3" at Grand Island and 1. The winter storm system/mid level closed low was located along the Neb/KS stateline in central Neb/KS around mid day with the deformation precip band oriented across central Neb. The higher snow totals are expected to orient either side of the Interstate 80 corridor generally east of Kearney.
533 PM CST Fri Dec 11 2020 Abundant high clouds cover the region today as a broad longwave trough sits over the central CONUS. Light north winds advect in a more seasonal air mass, with highs in the low to mid 30s. Despite being much cooler than the first half of the week, these temperatures remain about 5 degrees above seasonal averages.
The temperature forecast leans on the short term model blend plus bias correction tonight and Saturday which is warmer at night and cooler during the day than the guidance blend.
338 PM CST Fri Dec 11 2020 Active weather pattern will persist through at least the next 7 days with multiple troughs and fronts forecast to move through the area. The front is forecast to stall over the northern Gulf by tomorrow night as the upper trough lifts northeastward and upper level flow becomes more parallel to the frontal boundary.
845 PM EST Fri Dec 11 2020 Rain chances increase tomorrow as a low pressure system advances into the Ohio River Valley.
601 PM CST Fri Dec 11 2020 Expansive stratus is entrenched across the area and dense fog has returned south and west of the Missouri River where the low cloud deck intersects the higher terrain and easterly low-level upslope flow is contributing to reinforcement of the low-level saturation. We are closely monitoring that area for possible issuance of a Dense Fog Advisory, and nearly issued one with this update, but chose to hold off and monitor the persistence of the lowest visibilities into the early evening for now. Otherwise, a rather quiet day expected, with the main question being - will we clear out some the low clouds.
A broad upper-level trough covers most of the CONUS, with a low pressure system moving over the Pacific Northwest. At the surface, high pressure sits over ND, and an inverted trough persists over WY. Approaching Pac NW upper low and little change in the surface pattern overnight will result in light snow across northeastern WY/far western SD tonight into Saturday morning. Upper low will weaken as it slides south of the area Saturday. Dry weather will then resume beneath northwest flow, and cooler air will filter into the region this weekend.
552 PM CST Fri Dec 11 2020 Center of deepening low pressure system currently located on the KS/MO border as of 1 pm this afternoon. Precipitation has been filling in north of the low into our area (northeast IA into southwest WI) going into this afternoon. 5 inches on ridgetops/grassy areas by this evening. Should see more steady-state snow going into this evening and overnight across that area as temperatures at the surface and column continue to cool as the low lifts northeast toward Chicago by morning. locally higher on the bluff/ridge tops. Northwest winds on the backside of the low will be gusting pretty good across this freshly fallen snow Saturday which may cause some blowing and drifting on mainly bluff ridgetops and open areas. In the wake of the departing system, cooler conditions are in store.
435 PM MST Fri Dec 11 2020 Early afternoon WV/IR imagery revealed a large scale upper trough over much of the CONUS.
354 PM CST Fri Dec 11 2020 Radar imagery shows light-to-moderate rain moving into eastern AR ahead of a cold front. The cold front is located over eastern OK and eastern TX with rain downstream along the front. The low pressure center is situated over west-central MO. We may see some lightning as well, mainly over NE AR - closer to the low center with elevated isolated thunderstorms possible, however, instability is really lacking. Much cooler temperatures will follow behind the front by Saturday afternoon. Highs are expected to reach the low 50s to low 60s with lows dipping down into the 30s.
307 PM CST Fri Dec 11 2020 Tonight and Saturday: warmer than normal temperatures will continue through the period with increasing rain chances from the west tonight before the rain ends from the west Saturday. This will lead to the cold front slowing as it moves through our CWA and model consensus has come in slower to end the rain Saturday afternoon over our southeast. The waa ahead of this approaching cold front is expected to help keep temperatures warmer than normal tonight. Despite the cold front moving through our CWA Saturday, temperatures are expected to climb warmer than normal before getting knocked down with the fropa.
216 PM MST Fri Dec 11 2020 Dense fog and areas of freezing drizzle over North Central MT will give way to increasing chances for snow showers this afternoon. Temperatures today will be a bit cooler than they have been.
Our focus this afternoon has been on the evening and overnight period as the trough axis pivots northeastward, bringing the deformation zone into northern KS where we have the best chance of light snow.
As a closed low pressure system moves over the Northern Rockies this evening around sunset, snowfall intensities are expected to increase, particular for locations in west-central Montana south of the Mission Valley, and for north-central Idaho. North-central Idaho and portions of west-central Montana (I90 from Lookout Pass to Clearwater and south) will likely pick up the highest snow accumulations of 2 to 5 inches through tomorrow morning. The stretch from Yellow Bay to Polson will have the highest probability of receiving these higher amounts.
405 PM EST Fri Dec 11 2020 Rain returns tomorrow as a low pressure system advances into the Ohio River Valley. Lingering high pressure will keep our area dry and quiet this evening. A strengthening low pressure system will advance into the western Great Lakes early tomorrow morning.
A cold front will move through the region today, bringing gusty wind through the wind-prone areas of Central California during the day.
Recent precipitation analysis and short-term forecast soundings show the quick saturation of the lower levels continuing south of the precipitation shield, with radar CC values in the lower 90's in terms of percent indicating very well where mixed precipitation in the form of sleet and rain is falling. Temperatures have been holding above freezing for much of the area, but with the ongoing precipitation and dwindling sunlight, expect them to crash after sunset.
213 PM MST Fri Dec 11 2020 Early afternoon WV/IR imagery revealed a large scale upper trough over much of the CONUS.
/issued 354 PM CST Fri Dec 11 2020/ Radar imagery shows light-to-moderate rain moving into eastern AR ahead of a cold front. The cold front is located over eastern OK and eastern TX with rain downstream along the front. The low pressure center is situated over west-central MO. We may see some lightning as well, mainly over NE AR - closer to the low center with elevated isolated thunderstorms possible, however, instability is really lacking. Much cooler temperatures will follow behind the front by Saturday afternoon. Highs are expected to reach the low 50s to low 60s with lows dipping down into the 30s.
A low pressure system will cause light snow and fog, with a small chance of freezing drizzle, to continue through this evening.
Surface cold front should approach TN River Valley by around 12/12Z and push E to just W of CSV by 12/24Z.
As the center of high pressure lifts northeastward away from the area tonight and tomorrow, the pool of higher moisture will subsequently move closer to the local area. As mentioned prior, low temperatures will be coolest across the north where areas should still remain clear, in the lower 50s; south of Orlando temps in the mid to upper 50s; low 60s at the coast south of Cape Canaveral. (previous) As weak inverted trough continues to break down through late day, winds will gradually become E/SE across much of the waters with speeds less than 15 knots.
647 PM EST Fri Dec 11 2020 Rain returns tomorrow as a low pressure system advances into the Ohio River Valley. Lingering high pressure will keep our area dry and quiet this evening. A strengthening low pressure system will advance into the western Great Lakes early tomorrow morning.
/issued 132 PM CST Fri Dec 11 2020/ Upper trough swinging through today as the next low comes ashore WA coast. This low will open up to a trough as it dives down across WY with the energy rotating through the base.
A large break in the high/mid level clouds has allowed temperatures to drop lower than expected. Chattanooga Airport, TN 47 61 45 60 42 / 30 70 20 0 90 Knoxville McGhee Tyson Airport, TN 46 60 45 58 40 / 10 60 20 0 90 Oak Ridge, TN 42 59 42 57 39 / 10 60 10 0 90 Tri Cities Airport, TN 39 60 44 56 38 / 10 40 30 0 90.
A ridge of high pressure will move east today across the Central Plains. This and the cool airmass in the low levels will keep highs on the cool side. A large trof this is currently across the Northern Rockies will dive southward today.
Early afternoon WV/IR imagery revealed a large scale upper trough over much of the CONUS.
222 AM EST Sat Dec 12 2020 Deepening low pressure will quickly advance through the area today as rain diminishes southwest to northeast this afternoon.
1044 PM CST Fri Dec 11 2020 Center of deepening low pressure system currently located on the KS/MO border as of 1 pm this afternoon. Precipitation has been filling in north of the low into our area (northeast IA into southwest WI) going into this afternoon. 5 inches on ridgetops/grassy areas by this evening. Should see more steady-state snow going into this evening and overnight across that area as temperatures at the surface and column continue to cool as the low lifts northeast toward Chicago by morning. locally higher on the bluff/ridge tops. Northwest winds on the backside of the low will be gusting pretty good across this freshly fallen snow Saturday which may cause some blowing and drifting on mainly bluff ridgetops and open areas. In the wake of the departing system, cooler conditions are in store.
Models persist on driving this precip forward and through the region overnight ahead of an advancing cold front. Prior discussion below: Tonight and Saturday: warmer than normal temperatures will continue through the period with increasing rain chances from the west tonight before the rain ends from the west Saturday. This will lead to the cold front slowing as it moves through our CWA and model consensus has come in slower to end the rain Saturday afternoon over our southeast. The waa ahead of this approaching cold front is expected to help keep temperatures warmer than normal tonight. Despite the cold front moving through our CWA Saturday, temperatures are expected to climb warmer than normal before getting knocked down with the fropa.