Aikyam-Lab/Synoptic-Bench huggingface dataset:
High pressure will become centered over the forecast area tonight, with low temperatures falling into the middle to upper 20s and very light to calm winds. With lingering moisture trapped in the low- levels, it'll be difficult to completely shake the cloud cover, especially east of the Wabash Valley southward across the KY Pennyrile.
1014 AM MST Sun Dec 19 2021 As of 935 am MST, the wind shift line runs from about Sidney to Glendive to Lufborough Hill, with the cold front from Comertown to Lustre to St. 97 A wide range in temperatures are present across NE Montana early this morning as low level inversions are present even though the warm front has lifted north of the region. A cold front will move through the area between 12Z and 16Z (5 am and 9 am MST) this morning and bring falling temperatures with it. This will result in the high for today occurring this morning.
A cool start will keep temperatures cooler than normal today, about 2-5 degrees cooler. Current temperatures are running 3-6 degrees cooler than this time yesterday for most of our area, and temps will continue to dip lower through sunrise. Aside from the cool temps, high pressure ridge built over the southwest will keep conditions dry with light winds and mostly clear skies today.
North to northeast surface winds will remain over the CWA until the center of the high, to our north, passes to our east causing a veering of winds towards the south, late tonight into the first half of tomorrow. This along with area cloud cover has limited temperatures to the low 40s, and low temperatures tonight will be dependent on if cloud cover remains or dissipates. If clouds are able to completely clear, highs could be a few degrees warmer. Upper level pattern will start off quasi-zonal across much of the lower Ohio Valley, resulting in quiet and dry weather as northern/southern stream systems pass around us.
Temperatures will fall into the 20s tonight, however, with the ridge axis well off to our northeast, we probably won't see maximum radiational cooling.
Our taste of winter will be short- lived, as ridging begins to build west of the region on Monday, with light downsloping westerly surface flow across Southeast New Mexico and West Texas. This will allow high temperatures Monday afternoon to quickly rebound above normal into the lower to middle 60s for most.
Next chance of precipitation will be Monday night with the cold frontal passage. Any additional accumulation will be limited to a dusting, mainly across the higher terrain of the western Southern Tier, and also from eastern Monroe County eastward to western Oswego County. Overnight temperatures will hold in the lower 20s along the lake plains, but fall into the teens and single digits inland. Monday, a mid level trough will slide across southern Canada, pushing a surface cold front across our region Monday Night.
However, elevations around 4000 feet and above will continue to see snowfall, with periods of snow for the lower elevations overnight.
With the cold air advection behind yesterdays cold front temperatures were in the lower to mid 40s at lower elevations most of the day after falling from the 50s early in the morning. This should help to erode the low clouds more. Upper trough that is overhead now will move east with flow becoming more zonal Monday. Temperatures will be near normal for the first half of the week with warmer than normal conditions the last half, including Christmas Day. Discussion: Quiet weather pattern leading up to Christmas Day due to a mainly de- amplified flow across much of the nation and surface ridging over the Tennessee valley and southern Appalachians.
Secondly, a low pressure system approaching southern AR on Monday is expected to wrap some clouds into the area for mainly central and southern terminals.
A cool, dry air mass will settle into the region on Monday, as high pressure remains just to the northeast of the area. Areas of cloud cover will be present across the region during the morning hours on Monday and with an easterly surface flow in place, guidance is hinting that these clouds may be maintained once again for much of the day -- though there will be some breaks present, especially during the afternoon which will allow temperatures to climb back into the lower 50s.
Removed patchy freezing fog for the afternoon as webcams and observations have shown whatever fog was out there has reasonably dissipated into a haze. We start out with westerly flow across central and eastern Idaho, but quickly see high pressure building across the state. the high end on the highest peaks. Also, we are seeing some patchy freezing fog where those winds aren't occurring. We will see this likely continuing, with the ridge building again tonight and tomorrow night. We also are forecasting patchy freezing fog for the Stanley Basin and valleys along the Utah border including our side of the Cache Valley.
Temperature trends continue to mostly occur as anticipated, with sky grids updated to account for lingering low stratus decks across our eastern zones that may keep highs there a degree cooler but still in the upper 40. The eastern band of low clouds is expected to persist for much of the day before finally scattering just before 20/00z as a weak upper trough axis moves east of the region. Elsewhere, VFR conditions should prevail for the duration of the period, but clouds will be increasing from the southwest late in the period ahead of a strong upper trough.
Meaning the valleys will see very cold nights with patchy freezing fog possible along with light winds while the benches and ridges above the inversion will be noticeably warmer at night and see somewhat breezy conditions.
1200 PM CST Sun Dec 19 2021 At 09Z, a cold front was moving into north central MT. For Today, warm temperatures aloft will mix to the surface ahead of an advancing cold front. Tonight, a fairly strong cold front moves through. A deep upper level trough over Canada will direct the coldest airmass into the northern Great Lakes.
At the surface, a weak and elongated high pressure center will shift southeastward from the Midwest to the Ohio River Valley as it follows large-scale subsidence in the wake of an upper-level trough departing the east CONUS coast. Instead, the larger impact will be weak pre-frontal low-level west- southwesterly flow favoring a shot of WAA and high temps Monday approximately 10 F warmer than today, before flow very briefly turns to the north-northwest Monday night.
a backdoor cold front moves through during the day. There are differing solutions on when this happens with the GFS and ECWMF faster (and cooler as a result) while the NAM is slower and warmer with afternoon temperatures. Will again rely on weighing the high temperatures to the better performing guidance the past 7 days which supports lower 40s (northeast 1/2 of the area) to lower/middle 50s (far west and southwest).
An upper low/trof will remain well south of the region, moving across Texas tonight and Monday, then to the lower Mississippi Valley on Monday night. A rather low amplitude upper trof will move along the northern conus/Canadian border with a cold front dropping south across Kansas on Monday.
/Issued 1133 AM EST Sun Dec 19 2021/ Cold front making its way across the CWA with NW winds behind and showers exiting the eastern part of the area here in the next few hours. /Issued 315 AM EST Sun Dec 19 2021/ Cold front is currently situated from around Athens to Columbus and will continue to push southeast across the remainder of the CWA for the first part of today. The cold front will push well to the south of the CWA tonight with a wedge of high pressure building in from the northeast. NListemaa Still a bit of divergence among the medium-range models concerning the path of the compact but deep upper low moving across the gulf coast region to start out the period.
Winds will continue to diminish through sunset, as temperatures fall into the low 20s overnight. A dry cold front will drop through the forecast area Monday, pulling temperatures slightly below normal for northeast Nebraska, where highs will top out in the 20s.
501 PM MST Sun Dec 19 2021 Dry conditions continue with temperatures turning briefly cooler on Monday. Westerly flow aloft across the central Rockies and central High Plains region tonight turns slightly more northwesterly on Monday and Monday night as a trough in the southern branch of the upper flow moves out of the southern Rockies and across the southern Plains, another trough in the northern branch of the upper flow sweeps into southern Canada, and the upper ridge rebuilds over the west coast. The southwest near surface flow remains in place across the area this afternoon, but begins to transition to a westerly direction this evening, and then northwesterly after midnight as a prefrontal trough moves through ahead of a cold front that sweeps across the area early Monday morning. Temperatures will be 10-15 degrees cooler on Monday as a result.
550 PM CST Sun Dec 19 2021 An arctic cold front moving through MT this afternoon will push through wrn and ncntl Nebraska tonight. The model blend keeps temperatures a degree or two warmer than the guidance blend in some areas tonight through Monday night. The strong temperature advections, cold tonight and warm Monday night, suggest leaning toward warmer temperature forecasts.
Very little snow is expected to make it to the lower elevations, but Jackson WY could be an exception, with a few high- resolution models showing a couple hours of snow showers this evening after sunset as the best forcing for lift moves overhead. Snow showers decrease in the northwestern mountains during the day Monday, but the highest peaks and higher elevation western aspects could continue to see isolated snow showers.
518 PM CST Sun Dec 19 2021 VFR and dry air will continue as a weak upper level trough edges slowly east of the area. Modest low level south to southwest breezes this evening will diminish as the lower atmosphere fully decouples in this hour or the next, with light southerly flow expected afterwards.
320 PM CST Sun Dec 19 2021 A frontal boundary currently over the far western part of the CWA as of 20Z will track east/southeast across the CWA this evening, with high pressure nosing in from the northwest by sunrise Monday morning.
305 PM PST Sun Dec 19 2021 A cold air mass over Central California will bring near freezing temperatures to rural areas of the San Joaquin Valley again tonight.
Lee troughing will be found across western Kansas through tomorrow morning with a weak cold front moving through the area tomorrow. As for temperatures, lows tonight are expected to dip into the upper teens to around 20 degrees with highs tomorrow ranging from the low 40s across northern Kansas to low 50s along the KS/OK border. Mostly clear skies and dry conditions continue through the mid part of the week as upper level riding builds above us with high pressure being the dominate feature at the surface.
A cold front will continue to sit stalled over S WA and N OR overnight and then begin to lift back northward on Monday. Some mixed precipitation will become possible over north central OR late tonight as warmer air aloft begins to move northward. This will be the first significant snowfall event for most of the lower elevations so be prepared for slow travel due to wintry conditions.
421 PM MST Sun Dec 19 2021 The northern plains is beneath zonal flow/flattened upper ridging and mostly cloudy skies. The cold front will cross our region tonight. A cold front will move through the area during the evening, with winds changing to the northwest-north winds and MVFR cigs and local IFR cigs behind the front.
The bulk of the lower tropospheric warm sector passes through during the overnight hours, which aids in moderating tonight's low temperatures. The cold front passes through during the day on Monday with the only sensible weather being the winds switching to the northwest and cooling afternoon temperatures in Minnesota and central Wisconsin.
Moist isentropic lift was ramping up this afternoon well ahead of an upper low over Chihuahua. Rain chances shut down from W-E late tonight as an impressive mid- level dry slot swings east south of the upper low. Even with sunshine returning tomorrow, highs will be kept a good 5-10 degrees below normal as cool surface ridging expands south. This ridge stays with us Monday night and should set up the chilliest lows all week with upper 30s northern Coastal Plains and Victoria Crossroads.
Fair weather will last across the silver state through Monday as a ridge slowly drift out of the region. Unsettled winter weather returns to the silver state by mid week as a trough sets up in western CONUS. A ridge is still passing over but is now starting to leave the region. Overall the air has become a little drier which should keep freezing fog from forming in most areas. If freezing fog forms on a road it can cause slick spots so use caution if it is encountered.
Until then, temperatures tonight will fall into the low-30s in northern zones, with the 32-degree isotherm creeping across the Red River Valley and across the Arkansas/Louisiana border.
This will advect the low clouds now entering eastern GA into north AL and southern TN. The clear sky now should allow for adequate radiational cooling before the clouds arrive, so have left low temperatures about as is in the upper 20s in southern TN and northwest AL to the lower 30s in northeast AL. A cool, dry air mass will settle into the region on Monday, as high pressure remains just to the northeast of the area. Areas of cloud cover will be present across the region during the morning hours on Monday and with an easterly surface flow in place, guidance is hinting that these clouds may be maintained once again for much of the day -- though there will be some breaks present, especially during the afternoon which will allow temperatures to climb back into the lower 50s.
329 PM CST Sun Dec 19 2021 An arctic cold front moving through MT this afternoon will push through wrn and ncntl Nebraska tonight. The model blend keeps temperatures a degree or two warmer than the guidance blend in some areas tonight through Monday night. The strong temperature advections, cold tonight and warm Monday night, suggest leaning toward warmer temperature forecasts.
552 PM CST Sun Dec 19 2021 Cold air continues pushing south behind today's cold front that has passed through the entire forecast area except for the southern James River Valley. Associated surface cold front now through western and north central North Dakota, evident by a wind shift to the north/northwest and a considerable drop in temperatures, especially across northwest and north central areas of the state which have seen a 20 degree drop in temperatures over a 2 hour span. Cold front continues to push south through this evening, switching winds to the northwest over the remainder of the area and resulting in temperatures dropping off quickly.
Visible satellite is detecting mostly sunny skies across the island chain, with a few weak, non-precipitating cloud lines evident across the Lower and Middle Keys. Temperatures have taken advantage of the abundant sunshine and range from near 80 degrees into the lower 80s. High pressure will continue to lose its grip across the region overnight. The approaching trough has finally managed to break down ridging that has been reigning over the area for a while.
A cold air mass over Central California will bring near freezing temperatures to rural areas of the San Joaquin Valley again tonight.
An elongated trough sits extends from offshore of the New England states down to the northeastern corner of the Gulf of Mexico. Meanwhile a ridge in the low levels is centered in the Great Lakes region and wedged between the aforementioned trough and a trough digging down from Canada. The ridge will slide eastward overnight keeping winds light and clocking them around to the northwest and north. Despite this, the northwest winds due to being on the backside of the trough, and the lower level ridge skirting by to our north should suppressed organized shower activity. The Florida Keys lie behind a trough that sits just off the Eastern Seaboard and extends down into the northeastern portions of the Gulf of Mexico. Meanwhile, a narrow but expansive lower level ridge is moving across the east-central portions of the U.
North to northeast surface winds will remain over the CWA until the center of the high, to our north, passes to our east causing a veering of winds towards the south late tonight into the first half of tomorrow. This along with area cloud cover has limited temperatures to the low 40s, and low temperatures tonight will be dependent on if cloud cover remains or dissipates. If clouds are able to completely clear, highs could be a few degrees warmer. Upper level pattern will start off quasi-zonal across much of the lower Ohio Valley, resulting in quiet and dry weather as northern/southern stream systems pass around us.
640 PM EST Sun Dec 19 2021 Drier air will continue to filter into the region behind a departing cold front. Cool high pressure will build into the region on Monday.
416 PM MST Sun Dec 19 2021 Things look quiet through the short term period, as high pressure remains in control. Temperatures will be right around what they were yesterday, as the flattened ridge doesn't allow for much warm air advection. However, that starts to change tonight as an area of low pressure drops down out of the Gulf of Alaska and starts to deepen well off the coast of the Pacific Northwest. In response to this, the flattened ridge begins to amplify somewhat over the region, turning flow more southwesterly and pulling in warmer air. This will lead to high temperatures tomorrow to be a few degrees warmer than today and start a slight warming trend for early week.
Temperatures currently range from the low to 40s with wind chills in the mid 30s. With quite a bit of residual low level moisture in place, light freezing fog will be possible. The best chance of freezing fog looks to be over northeast Arkansas and the Missouri Bootheel after midnight. Cool and dry conditions will persist across much of the Mid-South through midweek as Canadian high pressure remains in place.
333 PM MST Sun Dec 19 2021 Things look quiet through the short term period, as high pressure remains in control. Temperatures will be right around what they were yesterday, as the flattened ridge doesn't allow for much warm air advection. However, that starts to change tonight as an area of low pressure drops down out of the Gulf of Alaska and starts to deepen well off the coast of the Pacific Northwest. In response to this, the flattened ridge begins to amplify somewhat over the region, turning flow more southwesterly and pulling in warmer air. This will lead to high temperatures tomorrow to be a few degrees warmer than today and start a slight warming trend for early week.
If it materializes, this should fall as all liquid, given subtle warm advection in the 850-700 hPa layer, and surface temperatures in the low 40's, demonstrated in model soundings sampled in the area.
(The rest of tonight) Upper low currently situated across northwest Texas will gradually shift eastward tonight along the Red River into Monday morning. (Monday through Sunday) Could see some light precipitation spread into far southeast Oklahoma near the Red River Monday morning but temperatures are expected to quickly climb above freezing with any precip remaining in liquid form.
Some patchy valley fog around sunrise can't be ruled out, if we do lose the low clouds as expected. North to northeast surface winds will remain over the CWA until the center of the high, to our north, passes to our east causing a veering of winds towards the south late tonight into the first half of tomorrow. This along with area cloud cover has limited temperatures to the low 40s, and low temperatures tonight will be dependent on if cloud cover remains or dissipates. If clouds are able to completely clear, highs could be a few degrees warmer. Upper level pattern will start off quasi-zonal across much of the lower Ohio Valley, resulting in quiet and dry weather as northern/southern stream systems pass around us.
A frontal boundary currently over the far western part of the CWA as of 20Z will track east/southeast across the CWA this evening, with high pressure nosing in from the northwest by sunrise Monday morning.
251 AM CST Mon Dec 20 2021 An upper level low will still be overhead by sunrise this morning but will move over North Texas by this afternoon. We will still be under the influence of this low with lower heights overhead today.
1146 PM CST Sun Dec 19 2021 An arctic cold front moving through MT this afternoon will push through wrn and ncntl Nebraska tonight. The model blend keeps temperatures a degree or two warmer than the guidance blend in some areas tonight through Monday night. The strong temperature advections, cold tonight and warm Monday night, suggest leaning toward warmer temperature forecasts.
1007 PM EST Sun Dec 19 2021 A cold front pushing east of the area will usher in much cooler and drier air into Monday.
1015 PM MST Sun Dec 19 2021 Things look quiet through the short term period, as high pressure remains in control. Temperatures will be right around what they were yesterday, as the flattened ridge doesn't allow for much warm air advection. However, that starts to change tonight as an area of low pressure drops down out of the Gulf of Alaska and starts to deepen well off the coast of the Pacific Northwest. In response to this, the flattened ridge begins to amplify somewhat over the region, turning flow more southwesterly and pulling in warmer air. This will lead to high temperatures tomorrow to be a few degrees warmer than today and start a slight warming trend for early week.
The northern plains is beneath zonal flow/flattened upper ridging and mostly cloudy skies. The cold front will cross our region tonight. A cold front will move through the area during the evening, with winds changing to the northwest-north winds and MVFR cigs and local IFR cigs behind the front.
350 AM EST Mon Dec 20 2021 High pressure in place over the Mid-Atlantic to start the week.
300 AM EST Mon Dec 20 2021 Building high pressure will support dry and seasonable conditions through the majority of the week. Mostly sunny skies are then expected through the day under the high.
312 AM EST Mon Dec 20 2021 The cold front that passed through the forecast area Sunday will stall out across southern Florida this morning, with widespread stratus filling in behind the front expected to result in mostly overcast skies through at least the early afternoon hours. Although the front was not strong enough to advect in significantly cooler air, dew points will drop a few degrees and the overcast skies will moderate temperatures slightly from what was felt during the weekend.
Fair weather will last across the silver state through Monday as a ridge slowly drift out of the region. Unsettled winter weather returns to the silver state by mid week as a trough sets up in western CONUS. Based off remote observations and satellite imagery, believe there may be patchy freezing fog in the western and southern sections of Humboldt county. A ridge is still passing over but is now starting to leave the region. Overall the air has become a little drier which should keep freezing fog from forming in most areas. If freezing fog forms on a road it can cause slick spots so use caution if it is encountered.
It is getting chilly out there already, with temperatures approaching the freezing mark at 9 PM.
Some low clouds around to start at CHA, with a few hours of MVFR cigs likely, then the low clouds will scatter out. Chattanooga Airport, TN 52 35 53 34 55 / 0 0 10 0 0 Knoxville McGhee Tyson Airport, TN 50 33 52 31 52 / 0 0 0 0 0 Oak Ridge, TN 51 32 52 30 52 / 0 0 0 0 0 Tri Cities Airport, TN 50 29 51 28 48 / 0 0 0 10 0.
349 AM EST Mon Dec 20 2021 A trough axis extends from offshore of the New England states down to the northeastern corner of the Gulf of Mexico. At the low- levels is weak ridging perched above the region.