Aikyam-Lab/Synoptic-Bench huggingface dataset:
945 AM: Dense freezing fog has moved into the Helena Valley. The dense freezing fog will reduce visibility to less than a quarter mile and cause slick bridges and elevated surfaces. So far the low this morning has been between -5 and -9 degrees. For West Yellowstone, temperatures overnight have been between -10 and negative 20 degrees with some freezing fog in the area. As this weak low pressure system moves southwest, winds along the Rocky Mountain Front has a 60% probability of gusting up to 55 mph.
955 AM EST Mon Dec 25 2023 High pressure will slowly move off the northeast coast and linger through Tuesday. A warm front will push through the region Tuesday.
856 PM EST Mon Dec 25 2023 Rain will move in this evening in the moist southerly flow ahead of low pressure.
200 PM PST Mon Dec 25 2023 Dry weather will prevail under a high pressure ridge through most of this week with temperatures near or slightly above seasonal normals. A trough of low pressure could bring precipitation this weekend along with cooler weather, but precipitation amounts are likely to remain low. Otherwise, fair weather will prevail through Thu/Fri with highs generally a little above seasonal normals, though the high temperatures may be tempered a bit from the clouds. A trough of low pressure could finally be deep enough to bring some rain to the area.
very light, cold, NE flow down the Snake Plain corridor with patchy nocturnal/AM freezing fog and low stratus concerns under a synoptic ridge of high pressure. RH analysis suggests tonight might be ever so SLIGHTLY drier than last night (which featured only VERY localized fog), and both the HRRR and NBM are less aggressive with fog development tonight, but to be safe we continue to carry patchy freezing fog in the forecast for portions of the Snake Plain, Arco Desert, Mud Lake, and Fremont County corridor eastward into some valley locales between I-15 and the WY border. In fact, looking at the 12z HREF suite, one can almost visualize a wall existing from about Dubois to Pocatello where model- simulated echoes coming in from the west "wash out" as this trough tracks through.
Moving toward mid to late week, a pattern change is expected as troughing from the Gulf of Alaska drops southward toward the Pacific Northwest.
628 PM EST Mon Dec 25 2023 Rain will move in this evening in the moist southerly flow ahead of low pressure.
- Precipitation has begun to lessen along and south of the highway 20 corridor as the dry slot has started to move in. A very sharp gradient exists between where the precipitation is falling as snow, a wintry mix/freezing rain, and rain. The system has continued to shift westward, wrapping in more dry and warmer air with it. The westward shift has also lead to warmer surface temperatures over northwestern IA where the precipitation has remained mostly rain and sleet. Southwestern MN has seen more freezing rain and sleet.
The GFS and NAM are the furthest north and east with the low which keeps much of the snow showers north and east of the Kansas Turnpike Tuesday afternoon.
243 PM CST Mon Dec 25 2023 - As the upper low over western KS shifts east Tonight, light snow will move back into the western counties of the CWA.
Deepening of this low overnight was not as drastic as previously anticipated, causing surface winds to primarily gust up to 25-30 mph. There are a few peeks of sun this morning as a dry slot wraps around a negatively-tilted 500-mb trough, clearing out the rainfall much sooner than previously anticipated.
seriously! Cool, dry conditions have overtaken SE Texas following yesterday's cold front passage. High pressure will continue to dominate tomorrow continuing the cool, dry conditions.
Latest surface map places the isobaric trough right along the Tennessee River, but it's really not a true front since the wind shift is lagging so far behind. We will start to see cooler temperatures and lower dew points work their way in from west to east mainly after 06Z. A cold front then sweeps eastward through the area tonight, putting an end to any lingering showers. In the wake of the cold front, Tuesday's high temperatures will trend about 10 degrees colder than today's highs.
High pressure will start to build in to help scatter the current stubborn clouds in our area as well.
Strengthening valley cold air pools across Lemhi County and southwest Montana have allowed for temperatures to drop into the low single digits, with Salmon and Butte reporting 4 and 3 degrees, respectively. A weak disturbance will be moving through the ridge on Tuesday. For the lower elevations, there is a 40 to 60 percent probability for up to 0.
While winds have remained higher than all guidance today, we should start to see a downwards trend overnight as the high in the western North Atlantic shifts farther eastward.
High pressure off the southern California coast will bring a slow warming and drying trend over Arizona this week. Meanwhile, high pressure begins to builds off the Pacific gradually extending eastward into Arizona. By the weekend, ensemble guidance shows the ridge beginning to break down and shift east.
314 PM EST Mon Dec 25 2023 Rain will move in this evening in the moist southerly flow ahead of low pressure.
(Tonight) At 01Z, a pre-frontal trough has moved east into southeast TN And GA. This trend may continue until the cold front now just entering northwest AL and middle TN pushes through late tonight.
Early evening radar imagery is showing lingering showers over southwest Florida continuing to dissipate as the warm front exits the area, with overcast skies filling in and expected to hold overnight and through at least Tuesday. Winds are subsiding over the waters in the wake of the cold front, with some lingering showers expected to clear out overnight. The Small Craft Advisory has been allowed to expire, with winds continuing to relax and turn to northwesterly late tonight and Tuesday morning as a weak cold front moves through.
- Some freezing rain will also be possible, especially across northwestern SD Tuesday night, resulting in some light icing. A strong upper low spins over the central US, with water vapor showing the baroclinic leaf over the eastern Dakotas.
537 PM CST Mon Dec 25 2023 - As the upper low over western KS shifts east Tonight, light snow will move back into the western counties of the CWA.
518 PM CST Mon Dec 25 2023 (This evening through Tuesday night) In the short term, all eyes remain on the progression of the upper low to our northeast as it slowly churns northeastward.
Lows will be below freezing everywhere north of the Big Bend region Tuesday morning, so grab a jacket as you head out the door! Zonal flow transitions more northwesterly by Tuesday afternoon as a large upper level low pivots into the Mississippi Valley, and the region will return to a slow warming trend. Highs will reach the 50s to low 60s on Tuesday, around 10 degrees warmer than Monday but still slightly below normal. Periods of gusty winds will be possible Tuesday morning and early afternoon in the higher terrain with a disturbance moving across, but winds will quickly drop off around sunset as mixing diminishes and the low pushes eastward.
The upper-low/trough that brought accumulating snow to portions of the area is now in the Central Plains. The cut-off low is producing heavy snow/blizzard conditions and Mixed precipitation in portions of the Central/Northern Plains. Very dry air in the lowest couple thousand feet above the surface should prevent any accumulating snow for Casper, but a flurry or two is certainly possible.
236 PM CST Mon Dec 25 2023 The rain has moved out of the area and cooler air is slowly moving into the region. Guidance doesn't show much fog for tonight, could see some fast developing fog in a few spots where cooler air is moving, but not looking for widespread dense fog this afternoon or tonight.
A cold front then sweeps eastward through the area tonight, putting an end to any lingering showers. In the wake of the cold front, Tuesday's high temperatures will trend about 10 degrees colder than today's highs.
Dirty ridge over the western U. provides generally dry and mild weather though features moving thru the ridge bring opportunities for light precipitation. Tonight through Tuesday Night Deep closed low over the central U. maintains a high amplitude ridge over the western U. Little to no accumulation expected for the valleys with the high elevations seeing less than an inch of new snowfall. Look for low temperatures tonight in the low teens to low 20s. Ridge rebuilds Tuesday as showers exit to the east in the early afternoon with dry weather expected overnight under partly to mostly cloudy skies.
pdf Widespread showers will build across the forecast area as the warm front continues to lift northward throughout the day. High temperatures for today will be in the lower 70s with overnight low temperatures dropping down into the lower 60s.
(Through Tonight) Persistent cloud cover from nearby upper low that brought the rain yesterday has held temperatures near steady in the upper 30s to lower 40s across much of northeast Oklahoma and northwest Arkansas. A brief period of clearing is expected to encompass most of the forecast area overnight tonight, with temperatures dropping below freezing. Bowlan (Tuesday through Monday) Cyclonic flow aloft will continue over the next several days as the upper low continues to be cut off from the main belt of westerlies and wobbles east southeast through the middle of the week.
Surface cyclogenesis across the Central Plains on Tuesday right underneath the core of the lumbering upper low will induce breezy south to southwest winds 10 to 20 mph for Tuesday.
However, in areas where winds stay up, mainly west, it will feel like its in the lower 40s across NE Louisiana and portions of W Mississippi. Tuesday night through Monday The beginning of the period starts with an area high pressure stretching the length of the MS river valley sandwiched between two large closed lows directly to the east and west. With high pressure aloft our CWA will remain dry with mild temps being very close to climatology.
Look for lows in the 30s, freezing in some Hill Country areas. On Tuesday, winds will turn to the SW for a little while, and we'll be a bit warmer as a result, in the upper 50s to mid 60s.
Rainfall amounts are not expected to be very high, with coastal areas likely to see the highest totals (up to a half inch or so). Hi-res guidance has been fairly consistent in ending the bulk of the rain before 00Z, but a few showers are still possibly overnight as the cold front itself shifts eastward.
GOES-16 satellite trends indicate the back edge of the low stratus layer now located near Little Rock and progressing east.
A ridge of high pressure will hold over our region much of this week allowing temperatures to gradually warm along with periods of high clouds.
This will bring the potential for some light wraparound precipitation to move into far northern Oklahoma, but dry air in the low-levels will limit much from reaching the ground.
1245 PM MST Mon Dec 25 2023 - A retrograding cut-off low in the Central/Northern Plains will bring snow to eastern WY tonight into tomorrow. The upper-low/trough that brought accumulating snow to portions of the area is now in the Central Plains. The cut-off low is producing heavy snow/blizzard conditions and Mixed precipitation in portions of the Central/Northern Plains. Very dry air in the lowest couple thousand feet above the surface should prevent any accumulating snow for Casper, but a flurry or two is certainly possible.
Steadier showers will end tonight, with drizzle/sprinkles late tonight into Tuesday morning as drier air aloft filters into the area, but the low levels remain saturated.
Temperatures will remain above normal into mid-week, but cooler conditions are expected late this week and over the upcoming weekend following the passage of a cold front. A closed H5 upper level low pressure system gradually progresses into the Midwest and Ohio River Valley during the middle of the week. The cooler air does not begin to filter into the Southeast U.
(Tonight through Tuesday night) The current weather pattern, with high pressure spreading over the area, will remain relatively unperturbed in the short term. On the backside (west side) of the low, a mid level ridge will build over the West, and underlying high pressure over the Rockies will cascade south into the Southern High Plains and Texas. A modest mid level trough attached to the Plains low will sag over South Texas, but the impact will be minimal with stable underlying high pressure already in place. The Pacific origin upper moisture will keep skies at least partly to mostly cloudy, and additional low clouds could further increase coverage to cloudy for the lower Valley. Overnight low temperatures will range from the mid to upper 40s for the RG Plains and Brush Country to the mid 50s for the lower Valley.
657 PM EST Mon Dec 25 2023 Rain continues to be over the area through tonight, with rain chances remaining fairly high into Tuesday night until a cold front pushes through the region. Temperatures will remain above normal into mid- week, but cooler conditions are expected late this week and over the upcoming weekend following the passage of a cold front. Large closed upper low continues to spin over the Central Plains with broad southwesterly flow across the southeastern states. A closed H5 upper level low pressure system gradually progresses into the Midwest and Ohio River Valley during the middle of the week. The cooler air does not begin to filter into the Southeast U.
528 PM CST Mon Dec 25 2023 (Through Tonight) Persistent cloud cover from nearby upper low that brought the rain yesterday has held temperatures near steady in the upper 30s to lower 40s across much of northeast Oklahoma and northwest Arkansas. A brief period of clearing is expected to encompass most of the forecast area overnight tonight, with temperatures dropping below freezing. Bowlan (Tuesday through Monday) Cyclonic flow aloft will continue over the next several days as the upper low continues to be cut off from the main belt of westerlies and wobbles east southeast through the middle of the week.
- Hit and miss snow showers and possibly light freezing drizzle will persist through Tuesday. The upper level low is forecast to drift eastward across Kansas, deepen a bit and continue to spin across northeast Kansas through Tuesday.
(This evening through Tuesday night) In the short term, all eyes remain on the progression of the upper low to our northeast as it slowly churns northeastward.
Temperatures will remain near to slightly below normal through the first half of the week before high pressure builds in and leads to a gradual warming trend for the latter half of the week. Skies continue to clear this afternoon as a drier northwesterly flow between a closed low in the Plains and a ridge across the Great Basin predominates. As the lower levels continue to dry out, the main weather concern will shift to the potential for cold conditions.
This pattern ushers drier and cooler air into the region, with lows tonight in the 40s along and west of I-65 and 50 to 55 further to the east. Highs on Tuesday will be around 60 along and west of I-65, and in the lower to mid 60s east of I-65.
A weak disturbance will be moving through the ridge on Tuesday. For the lower elevations, there is a 40 to 60 percent probability for up to 0.
1206 PM CST Mon Dec 25 2023 - Widespread rain today with windy conditions and mild temperatures in the low to mid 50s.
Added some sky across our south and a few areas of freezing fog. Air temps are showing freezing already in Magnolia and DeQueen this hour and both with patchy fog already being near or at saturation. So we added some freezing fog areas along and east of I-49.
Today seems like one of those days where there may be a rather sharp gradient in high temperatures - in the cloudy airmass, highs remaining in the lower 40s, while sunny areas get up to the 50 degree mark. Lows will drop to near or below freezing across the area.
A ridge of high pressure building over the area will provide us with pleasant weather conditions for much of the week. Temperatures will be a little warmer today but remain seasonably cool before warming to around 5-7 degrees above normal through the rest of the week.
Some gusts over 20 MPH are possible this afternoon ahead of a weak cold front that should push through the area by this evening. Overnight, clear skies and light winds should allow temperatures to drop to around freezing.
840 PM PST Mon Dec 25 2023 Dry weather will prevail under a high pressure ridge through most of this week with temperatures near or slightly above seasonal normals. A trough of low pressure could bring precipitation this weekend along with cooler weather, but precipitation amounts are likely to remain low. Otherwise, fair weather will prevail through Thu/Fri with highs generally a little above seasonal normals, though the high temperatures may be tempered a bit from the clouds. A trough of low pressure could finally be deep enough to bring some rain to the area.
Well defined upper low over the central plains will move slowly eastward during this period. This feature will assist in moving another cold front toward the forecast area late Tuesday and early Wednesday. Although overall available moisture will be limited, lapse rates associated with the upper low may be sufficient to support light rain or snow showers across the extreme north late Tuesday and on Wednesday.
Highs will be in the 50s but with southerly winds between 10-20 mph, it'll likely feel a bit cooler than the actual temperature. A reinforcing shot of cool air will arrive this evening with tonight's temperatures ranging from the lower to mid 30s.
348 AM EST Tue Dec 26 2023 Periods of rain will continue through the next several days with a upper low slowly moving through the region.
Lows will be below freezing everywhere north of the Big Bend region Tuesday morning, so grab a jacket as you head out the door! Zonal flow transitions more northwesterly by Tuesday afternoon as a large upper level low pivots into the Mississippi Valley, and the region will return to a slow warming trend.
Our colleagues to the east are not as fortunate though as a big bowling ball, AKA an upper level low continues to spin over the central Plains States. Once the low moves eastward later tonight, the weather looks rather benign for the rest of the calendar year.
(Today) The upper low centered on the Kansas/Nebraska border this morning will continue to influence the weather across eastern Oklahoma and northwest Arkansas today. Dew point depressions remain relatively high this far south, with satellite derived soundings showing that this extends through much of the low levels. Forecast soundings indicate some modest moistening through the day as the vort max approaches, supporting the low chance of measurable precipitation, especially by the afternoon.
958 PM CST Mon Dec 25 2023 (Tonight through Wednesday night) The cold front has passed through most of the region. This will moderate our temperatures overnight and keep our lows above freezing through Tuesday night. Wednesday night will be the start of a cold streak, with lows reaching freezing for much of the area.
940 PM CST Mon Dec 25 2023 (Through Tonight) Persistent cloud cover from nearby upper low that brought the rain yesterday has held temperatures near steady in the upper 30s to lower 40s across much of northeast Oklahoma and northwest Arkansas. A brief period of clearing is expected to encompass most of the forecast area overnight tonight, with temperatures dropping below freezing.
(Today) The cold front has now reached the I-65 corridor this early Tue morning, as sfc flow along/behind the front veers to the NW. Otherwise, high pressure out of the mid/southern Plains will begin to build into much of the region in the wake of the frontal passage later today. This should begin to usher slightly cooler/drier air into the mid TN Valley, as afternoon highs trend more in the mid/upper 50s. With the upper low lagging behind over the mid Plains, cloud cover may be slow to clear for at least part of the day.
Lows tonight drop below freezing for most locations with warmer temps along the Rio Grande.
1249 AM EST Tue Dec 26 2023 Early evening radar imagery is showing lingering showers over southwest Florida continuing to dissipate as the warm front exits the area, with overcast skies filling in and expected to hold overnight and through at least Tuesday. Winds are subsiding over the waters in the wake of the cold front, with some lingering showers expected to clear out overnight. The Small Craft Advisory has been allowed to expire, with winds continuing to relax and turn to northwesterly late tonight and Tuesday morning as a weak cold front moves through.
No significant adjustments were necessary for the overnight as cooler air continues to advect into the forecast area from the west. However, in areas where winds stay up, mainly west, it will feel like its in the lower 30s across NE Louisiana and portions of W Mississippi.
945 PM MST Mon Dec 25 2023 - A retrograding cut-off low in the Central/Northern Plains will bring snow to eastern WY tonight into tomorrow. The upper-low/trough that brought accumulating snow to portions of the area is now in the Central Plains. The cut-off low is producing heavy snow/blizzard conditions and Mixed precipitation in portions of the Central/Northern Plains. Very dry air in the lowest couple thousand feet above the surface should prevent any accumulating snow for Casper, but a flurry or two is certainly possible. By Wednesday the cut-off low will begin its slow trek eastward as a ridge comes in behind it. This ridge should hang around until this weekend, which will keep conditions dry and mild. A retrograding strong low pressure system across Nebraska will push FL060 cigs into eastern parts of the region.
Northwesterly winds will peak this afternoon around 20-30 mph with higher gusts at times, especially across the northern Panhandles closer in proximity to the center of the closed low. This established NW flow due to the closed low will advect H850 0C to -3C temperatures into the Panhandles. Went a bit cooler than NBM guidance due to higher albedo surfaces of snow cover across the central Plains. North and northwesterly breezy diurnally driven winds will continue to with cool high temperatures ranging from the lower to upper 40s. Cannot completely rule out (less than 20%) a chance of a rain shower and/or flurries in the far northern combined Panhandles as subtle PVA round the west side of the cut off low aided by mid level moisture transport around the closed low.
(Today and tonight) A deep upper level low currently located over Kansas City will only make small movements eastward through Wednesday morning.
(Today through Wednesday) An upper level low pressure system to the north will continue to advance into the Midwest through Wednesday. A couple of those cooler drainage valleys could again fall to around the freezing mark.
(Through Late Tuesday Afternoon) A large upper level closed low is spinning over the Great Plains this afternoon. Temperatures behind the front are falling quickly into the 40s, and lows tonight will likely drop to near or slightly below freezing across most of the forecast area for the first time in almost a week. Tuesday's highs will be around 15 degrees cooler than today's were ahead of the front. If this is the case we'll be somewhat cooler and many parts of the area may not warm above 40 degrees.
Showery weather will then follow through the end of the week with a passing upper low. --------------------------------------------------------------- As the mentioned low pressure system continues to lift north into the Great Lakes, the occluded boundary over the IL/IN region will; slowly lift to the northeast as well.
The latest midlevel analysis is showing a high amplitude ridge with its axis over the Northern Rockies, along with a trough of low pressure off the coast of the Pacific Northwest, and a closed low pressure circulation over the Mississippi Valley. Western Clearwater and Idaho Counties will be favored for freezing rain, rain, and snow above about 3000 ft.