Aikyam-Lab/Synoptic-Bench huggingface dataset:
1155 AM CST Fri Dec 8 2023 Strong WAA is underway across Middle Tennessee this morning with gusty south winds up to 25 mph bringing in higher low level moisture and warmer temperatures. Current temps are already well into the 50s to around 60, and nudged up highs for this afternoon to the low to mid 60s for most of the area and upper 50s to around 60 on the Plateau. It's going to be the last day like this for awhile, because showers will begin developing later tonight and certainly on Saturday as a strong cold front begins to impact the mid state. In addition to widespread showers, some storms are also possible given modest instability and the strength of the cold front.
High pressure centered to the east of the Atlantic Bight supports moderate east to southeast breezes at the Reef. Moderate to occasionally fresh breezes will veer gradually from the northeast to the southeast through Saturday night, as high pressure over the Southeast moves eastward into the western North Atlantic.
The main source of lift initially will be the low level jet that moves in after midnight tonight along with warm air advection. Not expecting any snow accumulations or impacts due to temperatures remaining above freezing across most of the area.
High pressure over the west Atlantic will continue to shift slowly offshore, producing low level winds out of the E/SE across the area today. High pressure over the west Atlantic will keep winds out of the E/SE up to 10-12 knots today, increasing up to 10-15 knots tonight.
The forecast probability of precipitation has been updated to reflect the lower likelihood of precipitation today.
Single digit lows are expected across many eastern Nevada valleys as well as some areas of freezing fog.
136 PM EST Fri Dec 8 2023 High pressure brings dry weather through today, with a warming trend through Saturday.
Light and scattered rain showers late tonight through Saturday ahead of an approaching cold front. Light and scattered showers continue through the day on Saturday ahead of an approaching cold front. This will allow wind gusts of 30 to 40 mph across the highest elevations of the east TN mountains through the day on Saturday.
A dry cold front moving through the state will bring gusty northeast winds overnight through Saturday, along with well below normal temperatures.
Overnight lows will end up quite mild by December standards, settling in the 40s, with highs Saturday coolest NW as quick shot of slightly warmer air tries to move in SE areas, maybe allowing for a run at 60 degrees (SE of a Portland to Ottawa line). Slightly better chances for measurable rainfall occur mainly Saturday evening as northern stream longwave trough dives quickly south but remains progressive, resulting in bulk of much better lift and QPF potential giving SE third or so of the area a glancing blow of a tenth to maybe quarter inch (third inch Lima area?).
A Pacific Front along with a pre-frontal trough will keep a west to northwest wind overnight shoving any low level moisture well east. The stronger cold front arrives during the day tomorrow with gusty north winds and falling temperatures during the afternoon.
1101 AM CST Fri Dec 8 2023 (Today and tonight) Deep upper level trough passing to the north will allow warm and breezy southwest winds across West Central Texas today. As the trough pushes farther east tonight, winds will shift west and then eventually northwest as the cold front arrives into the area.
* Temperatures generally peak tomorrow morning (50-55 degF) then hold steady or fall during the daytime hours as a cold front departs.
The low cigs may also lift/become low VFR at TYR by mid to late afternoon, but this should be brief before additional MVFR cigs develop/spread N across this terminal after 03Z Saturday.
- Noticeably cooler temperatures move in for the weekend. Difficult to pick out the cold front currently as zonal flow is keeping neutral advection across the region and no discernible wind shift is evident in obs or model output. The upper level trough, supporting the cold front, will move through and with cold air aloft, plenty of instability will be released aiding in snowfall. Highs will run about 10 degrees cooler than yesterday. closer to 15, maybe 20 degrees cooler for the northern valleys. By Saturday morning, a few lingering snow showers may persist over the higher terrain of the northern/central mountains and Flat Tops but any appreciable accumulation will be over. Northerly flow will set up across the entire CWA ushering in much cooler temperatures to the region.
Satellite and profilers show a mid level trough moving across southern Canada and the Dakotas with a 50 to 60 kts mid level jet moving into the Texas Panhandle. Also embedded perturbations were also moving into the Plains in the southern stream trough at 20Z.
Low pressure over northeast ND is wrapping snow back into western and north central SD this afternoon. Some stray snow showers/flurries are as far east as the James Valley as the upper low has migrated just east of the valley. Blended with ConsShort to capture slightly warmer overnight lows tonight in the grids. Warmer air advects in from the west Saturday night under rising heights aloft but clearing skies, diminishing winds and fresh snow should see temperatures tank quickly after sunset.
Upper air analysis and water vapor currently show upper ridging over the Great Lakes and west coast regions, while troughing sits over the rockies/plains, and an embedded wave over ND/SD. At the surface, low pressure sits over northern MN, with a cold front running SW through SD into WY. Models continue to show the higher amounts (1 to 2 inches) along the ND/SD border, and over the northern Black Hills with upslope enhancement occurring. WSSI minor impact probabilities increase to 30-40% along the ND/SD border, where the higher mounts will allow for blowing snow to reduce visibilities, however should not be enough impact to warrant winter headlines.
356 PM EST Fri Dec 8 2023 Clouds will increase tonight ahead of developing low pressure moving into the Great Lakes. This system will provide scattered showers early Saturday, becoming more numerous heading into the evening associated with a cold front.
As a result, the upper low will stall out and strengthen this afternoon. The upper level low and trowal axis will pivot northeastward setting up an increased snowfall gradient from Carrington to Grand Forks. A strong push of cold air advection continues to move on the backside of the low resulting in blowing snow across the northern and western half of the state. As the low progresses eastward winds will increase over central North Dakota and the James River Valley. Temperatures will continue to drop to below freezing across the area as a cold air from behind the upper low moves into the region.
Minor snow accumulations under a half of an inch are possible but some flash freezing on roadways cannot be ruled out. Clouds continue to increase across portions of the region ahead of an approaching large scale trough. Forcing for ascent associated with this trough will bring a small chance for a few hundredths of light rain across far southeast Nebraska and southwest Iowa tonight. Meanwhile, a trailing upper trough axis will approach the area early Saturday morning allowing strong cold air advection to drop into the region. Weak forcing in association with this upper trough combined with a bit of moisture could produce light snowfall mainly across northeast Nebraska and west-central Iowa Saturday morning. In addition, as the cold airmass drops into the area, we could see some flash freezing on roadways if snowfall is able to collect and compact.
High clouds offshore will move into the area later this evening and tonight, but some of the high res guidance shows it will be a thin layer, therefore conditions will be favorable for temperatures to cool down pretty quickly after dark with near freezing overnight lows for many interior westside valley locations. With upper ridging building into the area tonight, the atmosphere will be stable. This in combination with existing moisture from all of the precipitation over the last several days will likely result in low clouds and fog/freezing fog later this evening and lasting through the morning hours Saturday for the interior westside valleys. A warm front will move towards the area Saturday morning into Saturday afternoon.
338 PM CST Fri Dec 8 2023 - Strong northwest winds on Saturday with cold frontal passage.
946 PM EST Fri Dec 8 2023 Clouds will increase tonight ahead of developing low pressure moving into the Great Lakes. This system will provide scattered showers early Saturday, becoming more numerous heading into the evening associated with a cold front.
700 PM EST Fri Dec 8 2023 Clouds will increase tonight ahead of developing low pressure moving into the Great Lakes. This system will provide scattered showers early Saturday, becoming more numerous heading into the evening associated with a cold front.
A ridge overhead and plenty of cold air at the surface will keep inversions in place. Anticipate freezing fog formation overnight into the morning hours in the Sierra and Martis Valleys.
514 PM CST Fri Dec 8 2023 (This evening through Saturday) An upper level trough will swing across the Great Plains overnight, sending a cold front through West Central Texas Saturday morning. Cooler temperatures along with gusty north to northwest winds will filter into the region behind the front. Overnight lows will be in the low to mid 40s.
Those showers will be diminishing this evening with clearing in most areas due to a transient ridge of high pressure.
733 PM EST Fri Dec 8 2023 Broad upper trough currently over the C U.
This area of precipitation is in association with the main upper trough currently seen on water vapor imagery over the northern High Plains. A mix of VFR and MVFR continues to start the period with VFR for all but AXN expected within the first 6-12 hours as bases rise before dropping again as our cold front and snow arrives tomorrow. Timing for the snow was refined compared to the previous TAF, with the lowest visibility expected as winds increase as snow falls into the afternoon.
519 PM CST Fri Dec 8 2023 (Through Tonight) The main concern in the near term is the continued potential for a narrow line of thunderstorms to develop along a cold front early to mid evening in far eastern Oklahoma and shift eastward through late evening. The cold front is currently positioned just west of the forecast area and should begin to move into areas northwest of Tulsa around 4 pm given observations and short term model solutions.
1042 PM EST Fri Dec 8 2023 Update Low pressure centered in Southwest Missouri this evening will move northeast and deepen tonight. By Saturday morning the low will be located over Lake Michigan. Moisture increases in depth tonight as the low and attendant cold front approach. The main source of lift initially will be the low level jet that moves in after midnight tonight along with warm air advection. Not expecting any snow accumulations or impacts due to temperatures remaining above freezing across most of the area. As a cold front moves through Saturday night into early Sunday, 850mb temps will fall supporting increased instability over Lake Michigan.
Winds tend backed east northeasterly near and north of the island chain, and more east southeasterly over the warmer Florida Straits. Needless to say, this easterly shift in winds has brought in warmer and considerably more moist air with temperatures now in the mid 70s and dew points in the mid to upper 60s. Short Term Update - The previously mentioned ridge will remain to our north as the parent high shifts further eastward. The continued influx of relatively warm and humid air will keep overnight lows above normal in the lower to mid 70s and dew points pushing further upwards in the upper 60s. A ridge across Florida will maintain moderate easterly breezes.
A broad upper trough covers much of the CONUS, with the upper low spinning over MN. A tight surface pressure gradient is keeping northwesterly winds gusty, and cooler air is filtering into the northern plains. Upslope enhancement and lingering moisture could allow for a few light snow showers over the higher elevations today, but no accumulations are expected. The upper trough will shift east on Sunday, as a ridge builds over the west.
Already, dew points across Middle Tennessee are mostly in the low to mid 50s, so don't look for temperatures to drop off much more. Low-level winds have strengthened in advance of the cold front. The 00Z sounding from OHX showed 850 mb winds of 32 kts, and we expect 850 mb winds to increase to ~40 kts in advance of the cold front later today. The cold front will still be undergoing frontogenesis when it enters Middle Tennessee during the early afternoon. So there may be a few flakes at higher elevations, but it appears that the precipitation will exit the mid state before freezing temperatures arrive.
(Today) Longwave troughing dominates the central CONUS today with the trough axis moving over our area this afternoon. As this occurs, a reinforcing cold front (most obvious aloft) pushes southeast with breezy north-northwest winds filling in behind it.
1245 AM EST Sat Dec 9 2023 Aviation Low pressure centered in Southwest Missouri this evening will move northeast and deepen tonight. By Saturday morning the low will be located over Lake Michigan. Moisture increases in depth tonight as the low and attendant cold front approach. The main source of lift initially will be the low level jet that moves in after midnight tonight along with warm air advection. Not expecting any snow accumulations or impacts due to temperatures remaining above freezing across most of the area. As a cold front moves through Saturday night into early Sunday, 850mb temps will fall supporting increased instability over Lake Michigan.
This area of precipitation is in association with the main upper trough currently seen on water vapor imagery over the northern High Plains. VFR to start the period with a rapid change to MVFR/IFR once the cold front arrives bringing snow and gusty northwesterly winds with it. Blowing snow is likely the main cause for lower visibility, rather than excessive snowfall rates, but the combination of the highest rates and increasing winds will result in the lowest visibility during the afternoon.
Aloft, a mid- level low crossing the upper midwest and an amplifying mid-level longwave trough moving into the eastern third of the country will propel a cold front across the eastern Gulf of Mexico towards the area on Sunday. As this warm front retreats northward heading into Sunday, rain chances will generally diminish until diurnal heating peaks on Sunday afternoon ahead of the cold front.
1114 PM CST Fri Dec 8 2023 (This evening through Saturday) An upper level trough will swing across the Great Plains overnight, sending a cold front through West Central Texas Saturday morning. Cooler temperatures along with gusty north to northwest winds will filter into the region behind the front. Overnight lows will be in the low to mid 40s.
(The rest of tonight) Showers and thunderstorms that formed along a cold front moving across the area this evening are exiting the eastern part of the forecast area at this time, and thus will remove pops for the rest of the night and Saturday. The rest of the forecast is on track at this time with a return to more seasonable temperatures this weekend behind the cold front.
Conditions will improve and snow will quickly wane this afternoon as drier northerly flow advects in behind this departing trough whose center will be over the upper midwest with the positively tilted base dragging southward through New Mexico and Texas. Many lower valleys will be well into the teens and single digits with below zero readings in the higher valleys and favored cold pools seeing negative teens. For Sunday, a ridge of high pressure tries to build to our southwest but an active Pacific moisture stream will keep high clouds in the picture in northwest flow with some weak orographics generating some light snow for the Park Range Sunday afternoon and evening. Mostly dry conditions will be evident Sunday with exception of the higher peaks of the Park Range across northwest Colorado.
Low pressure over northeast ND is wrapping snow back into western and north central SD this afternoon. Some stray snow showers/flurries are as far east as the James Valley as the upper low has migrated just east of the valley. Blended with ConsShort to capture slightly warmer overnight lows tonight in the grids. Warmer air advects in from the west Saturday night under rising heights aloft but clearing skies, diminishing winds and fresh snow should see temperatures tank quickly after sunset. The period begins on Sunday with upper level ridging building into the region with weak warm air advection.
Early morning analysis showed an upper level trough setting up over the central CONUS with a cutoff low spinning over western MN. That said, the strongest forcing for ascent looks to remain well to the northeast, near the aforementioned cutoff low, so snow looks to taper off toward early afternoon as the low continues to push eastward. For Sunday, the main trough axis will push off to the east, leaving us under northwest flow.
Discussion: Snow continues across western Wyoming today as a trough axis passes east through the state. It will be breezy for much of the area as high pressure builds to our west.
1045 PM CST Fri Dec 8 2023 (The rest of tonight) Showers and thunderstorms that formed along a cold front moving across the area this evening are exiting the eastern part of the forecast area at this time, and thus will remove pops for the rest of the night and Saturday. The rest of the forecast is on track at this time with a return to more seasonable temperatures this weekend behind the cold front.
The base of the trough is moving across eastern Utah and western Colorado at this hour, bringing along the expected uptick in snow shower activity, including several stronger bands of precipitation. As the trough continues to track to the east through the evening and overnight hours, expect rain and snow showers to taper off over the lower elevations and for skies to clear. Across the lower valleys, temperatures will run 5-10 degrees below normal, while the higher elevations will run 15-20 degrees below normal thanks to the fresh snowpack.
1111 PM CST Fri Dec 8 2023 (This evening through Saturday) An upper level trough will swing across the Great Plains overnight, sending a cold front through West Central Texas Saturday morning. Cooler temperatures along with gusty north to northwest winds will filter into the region behind the front. Overnight lows will be in the low to mid 40s.
This longwave trough will continue to dig into the southeastern CONUS through the rest of the weekend, dragging a cold front into the Florida Peninsula late Sunday and into Sunday night. Ahead of this front, southeasterly flow will allow for temperatures and dew points to build today and into early Sunday, with highs topping out in the low to mid 80s this afternoon. With moderate low level shear and lapse rates, a few strong or damaging storms cannot be completely ruled out, with the highest chances over the Nature Coast where dynamics are more favorable.
(Today and tonight) Cold front is making progress through West Central Texas early this morning, and should clear the I-10 corridor around or shortly after sunrise. Otherwise, cold front will drop temperatures today across the area, ranging from mid 50s across the northern Big Country to the mid/upper 60s along I-10.
Throw in that cold advection has been relatively slow and temperatures persist near freezing means less accumulations as well. Low pressure over northeast ND is wrapping snow back into western and north central SD this afternoon. Some stray snow showers/flurries are as far east as the James Valley as the upper low has migrated just east of the valley. Blended with ConsShort to capture slightly warmer overnight lows tonight in the grids. Warmer air advects in from the west Saturday night under rising heights aloft but clearing skies, diminishing winds and fresh snow should see temperatures tank quickly after sunset. The period begins on Sunday with upper level ridging building into the region with weak warm air advection.
231 AM CST Sat Dec 9 2023 Key Messages: - Breezy today with cooler temperatures, back to near-normal. A closed low is centered over Minnesota with a wave of energy on the southern periphery of the low diving south across South Dakota and Nebraska. This wave will pass through the area today bringing increased cloud cover, but a lack of moisture especially in the low-levels will keep the area dry. Northwest winds increase through the day with gusts of 30-35mph bringing in cooler air; temperatures will be 10-15 degrees cooler today than yesterday with highs back near climatological norms in the mid 40s. Surface winds gradually weaken overnight and lows fall into the low to mid 20s.
At this time yesterday, it was expected to be cooler than that at midnight. This low is nearly vertically stacked, and will continue to shift slowly eastward today.
Today, expect our quick shot of snow to exit rather quickly this morning as the upper trough shifts to our south.
Cooler on Saturday and Sunday. Afternoon highs have reached into the middle to upper 50s, with a few locations out west in the lower 60s. Hail is the primary hazard of concern given lower freezing levels in December. Saturday: Cooler across portions of the region on Saturday with highs forecast to range from upper 40s (northwest) to middle 50s (southeast). Sunday: A chilly day expected on Sunday with winds remaining out of the west to northwest as high pressure settles into the area. Highs in the lower to middle 40s.
(Today through Sunday afternoon) The long awaited cold front is traversing the region early this morning, having cleared MAF around 1 AM CST. The much cooler air is lagging the initial wind shift and the much cooler air is located near our shared border with Lubbock's area. Below freezing temperatures are expected across the entire area with most locations in the 20s. With these below freezing temperatures, a Freeze Watch has been issued for the Presidio Valley which has yet to see this kind of cold so far this season.
816 PM PST Fri Dec 8 2023 High pressure building over the Great Basin this weekend will bring sunny days, clear nights and gusty northeast Santa Ana winds to the mountains, foothills, and valleys.
155 AM CST Sat Dec 9 2023 * Cooler and windy today.
(Today and tonight) Upper trough moving through the central Plains will aid in pushing a reinforcing shot of cold air south this morning. These winds along with cooler temperatures in the wake of yesterdays cold front and morning cloud cover will create wind chills in the 20s and 30s across the area this morning.
A positively- tilted mid-level trough will trail behind the frontal boundary shifting southeast across the ArkLaTex allowing for significant height falls areawide. Northwest winds to advect a cooler and drier airmass across the region with overnight lows tonight ranging from near freezing across southeast Oklahoma to the lower 40s elsewhere. Surface ridging and cold air advection will secure a return to near-normal conditions through the beginning of the week with temperature maximums in the lower 60s, and minimums in the lower 40s under mostly sunny skies.
Look for gusty north-northeast winds overnight through this afternoon/evening thanks to a passing cold front.
541 AM CST Sat Dec 9 2023 08z/2am surface analysis shows a cold front along the Illinois River. Meanwhile further north, the parent upper low evident on latest water vapor imagery over Minnesota will push into the Great Lakes and its associated cloud cover will dip southward into north-central Illinois. As high pressure moves overhead and skies clear, excellent radiational cooling will allow lows to dip into the lower 20s Sunday night.
With this system, the heaviest snow looks to be Sunday afternoon into Sunday evening with the best forcing as the trough axis moves across the area.