Aikyam-Lab/Synoptic-Bench huggingface dataset:
116 AM PST Sat Dec 23 2023 Freezing fog and a low stratus deck will persist throughout this morning but should clear out by noon. Shallow freezing fog has returned to Sierra valleys this morning but will likely stay contained to the Sierra and NE CA. There will be a weak, dry cold front coming down from the north later this morning, but the chance for any precipitation or gusty winds looks very low.
A cold front continues to move across the region this early morning, bringing light precipitation ahead of it and cooler temperatures behind.
Thanks to stronger winds associated with our cold front and just above the surface with strong cold advection, we may have successfully scrubbed out our boundary layer for today.
657 AM EST Sat Dec 23 2023 Dry conditions with seasonable daytime highs today as high pressure slowly drifts east.
950 AM EST Sat Dec 23 2023 Dry high pressure will extend across the eastern US through the weekend. Aloft, the sub-tropical ridge should gradually progress eastward through the region as an upper low closes off over the central Plains. At the surface, the ridge that had been persistent over the area will breakdown and retreat northeastward and out of central NC Sun/Sun night, with increasing easterly to southeasterly flow into the area. Meanwhile to the west, a low pressure system will move through the Plains and into the mid/upper MS Valley through Sun night. Low level thicknesses will increase as a warm front approaches from the south.
A ridge builds back in again quickly today and tomorrow behind last night's cold front. With recent events, fog and stratus has been the main impact with these ridge events, but this one is different. The cold front last night brought enough wind with it to dry things out and mix up the lower atmosphere more. This means we'll be starting from a drier lower atmosphere as this ridge builds in. At this point, it really just depends on how far east the ridge axis lines up. A cold front moved across the region tonight mixing up the atmosphere and clearing out most of the fog and stratus.
519 AM CST Sat Dec 23 2023 - Today will see anomalous warmth despite cloud cover, with highs in the low to mid-60s.
349 AM CST Sat Dec 23 2023 - Today will see anomalous warmth despite cloud cover, with highs in the low to mid-60s.
Even with some cloud coverage and chilly temps, Santa should have a smooth ride into Nevada on Christmas Eve as ridging builds in. These last showers taper off just before sunrise, and dry conditions settle in as ridging builds in. Highs today are much colder than yesterday with most of the area reaching the 30s, and a few isolated warmer spots reaching the low 40s.
For Tonight & Sunday: Our weather will be increasingly dictated by an upper level trough inching its way eastward from the Plains during this peirod. While this trough won't bring rain to our region tonight or Sunday, it will allow surface winds to gradually build and keep low level WAA in place.
A pleasant late December night continues across the Florida Keys, with partly cloudy skies, temperatures in the mid to upper 60s, dewpoints in the lower to mid 60s, and gentle NE breezes along the island chain. Surface analysis depicts high pressure centered over New England, with a ridge extending SW to the NE Gulf of Mexico.
The low pressure system we have been discussing for several days is currently centered over far southwest Arizona and will be well east of the area by late afternoon.
A cold and dry air mass will continue to spread across the region throughout today as high pressure builds in and supports dry offshore winds across Northwest California. By tomorrow (Christmas Eve), the high pressure will flatten as a trough digs southward from the Gulf of Alaska towards the Pacific Northwest. As the first low pressure system associated with the trough approaches the region, an associated warm front will move across the Pacific Northwest. By late Sunday evening, this high pressure will begin to be pushed out of the region as the trough continues its approach. For Christmas Day, the high pressure weakens and shifts to the east as this upper level trough pushes into the region.
Winds remain generally light this period, transitioning from south or southeast to south-southwest with passage of warm front north into the area today. Height rises arrive between 18Z and 21Z throughout most of the column, but a growing consensus is emerging in maintaining saturation through the lowest 5 kft this evening and overnight as a swath of near-surface convergence emerges over southern Lower. Longwave ridge axis extending into the Gulf amplifies Sunday as it moves across the Great Lakes while unfaltering stratus field butts up against a sharpening inversion.
30-50% chance for any one location to receive freezing rain up to 0.
A low over Arizona will track east out of the area today as a Pacific Northwest cold front crosses northern Utah. High pressure will return Sunday, persisting through the midweek period.
401 AM EST Sat Dec 23 2023 Dry conditions with seasonable daytime highs today as high pressure slowly drifts east.
A powerful upper level low can be seen spinning over southwestern AZ early this morning. Strong lift can be seen ahead of the low with thunderstorms occurring in southern and central New Mexico. As this low approaches, pressure falls will occur along the lee of the southern Rockies, increasing south/southeasterly flow and low level moisture in our area. A Pacific cold front will move east with this trough, combining with lift from the powerful upper level low and abundant surface moisture to result in a line of thunderstorms developing from the Panhandle region south into the Big Bend area this evening.
630 AM EST Sat Dec 23 2023 Dry high pressure lingers through the weekend and keeps temperatures above normal. Colder temperatures and dry weather return behind a cold front mid week. The low clouds should become less common through the afternoon with patchy mid and high clouds remaining. Light S to SW winds develop for the afternoon as the center of high pressure remains to our northeast. While the high pressure breaks down, an upper trough and associated upper low digs across the central plains and begins to lift northward. Guidance from the GFS and EURO cuts the low off as a swath of enhanced vorticity wraps around from the SW.
1138 AM CST Sat Dec 23 2023 (Today through Sunday Night) South/southeast flow continues this morning around high pressure along the East Coast. A large scale trough in the Rockies will intensify into a closed low over the central Plains as the period progresses. At the surface, a storm system will begin ramping up in western or central Missouri by end of the period, and will pull a cold front through the region. Cooler/more seasonal air will be on the heels of the front.
Strong low and mid-level moisture transport occurs tonight into Sunday morning across central/eastern Kansas, ahead of the lead upper trof ejecting northeastward from the southern Rockies across the central/southern Plains. Surface cold front will move eastward across the forecast area during Christmas Eve day with morning highs in central Kansas before falling off in the afternoon. The trailing portion of the southern stream upper trof will become absorbed into the deepening northern stream upper low settling southward into Kansas on Christmas day. As the associated lower level cyclone occludes to our northeast over the Midwest, blustery and colder air will continue to funnel across the area.
(Rest of today through Sunday) An area of high pressure over the Mid-Atlantic continues to influence weather over South Florida this weekend, promoting northeasterly flow and mostly dry sensible weather. The synoptic pattern begins to change on Sunday as an area of low pressure and an associated cold front drag across Texas and the Plains.
1240 PM EST Sat Dec 23 2023 Dry high pressure will extend across the eastern US through the weekend. Aloft, the sub-tropical ridge should gradually progress eastward through the region as an upper low closes off over the central Plains. At the surface, the ridge that had been persistent over the area will breakdown and retreat northeastward and out of central NC Sun/Sun night, with increasing easterly to southeasterly flow into the area. Meanwhile to the west, a low pressure system will move through the Plains and into the mid/upper MS Valley through Sun night. Low level thicknesses will increase as a warm front approaches from the south.
(This evening through Sunday) An upper level trough is currently located across the Desert Southwest and will approach West Central Texas overnight into Sunday morning. As the aforementioned upper level trough approaches this evening, expect an increase in large scale lift across West Texas, resulting in the development of showers and thunderstorms in the vicinity of a Pacific cold front. (Sunday night through next Saturday) 500mb trough across the west-central United States Sunday will evolve into a large 500mb low across the central Plains of the U.
Low level warm advection and convergence along the sfc warm front could create enough lift in the stratus deck to cause patchy drizzle or sprinkles. Conditions should gradually improve on Saturday as the warm front pushes north and southeast winds mix out areas of fog by the afternoon. -Warm, cloudy, and wet start to the week As the sun rises (above the clouds) on Christmas Day the upper level weather pattern across the middle of the country will be continuing to amplify, with a deep trough over the eastern Rockies turning into a closed upper low. Correspondingly amplified ridging over the east coast will set Michigan up under warm southerly flow. This will produce Christmas Day temperatures well into the 50s across virtually all of the Lower Peninsula.
(This evening through Sunday) A broad conveyor of elevated moist ascent continued to feed north over the region early this afternoon in advance of a tightly wound upper low about 120 miles west of ABQ. Convection should sweep out of our eastern zones around midnight well ahead of a Pacific cold front and drier westerly flow through daybreak. Opted for a blend of the cooler CONSSHORT highs tomorrow as the NBM continues to look too optimistic given the degree of cold advection.
-IG 1100 AM MST Sat Dec 23 2023 (23/12Z TAF Period) Lingering low cigs and -shsn are expected through this afternoon as cooler air pushes into the area. A cold front continues to move across the region this early morning, bringing light precipitation ahead of it and cooler temperatures behind.
1138 AM CST Sat Dec 23 2023 - Today will see above normal warmth despite cloud cover, with highs in the low to mid-60s.
Upper level ridging shifts across the eastern US through the remainder of the holiday weekend with heights aloft very slightly increasing into tomorrow. Increasing moisture transport ahead of the cold front will yield scattered to numerous showers and some occasional rumbles of thunder on Christmas Day but instability values look to be rather weak so not expecting too much in the way of convective activity.
Turning cooler and unsettled mid-week and beyond. Mild temperatures tonight will generally be in the lower 40s across the lowlands, ranging into the mid 30s higher elevations. Expecting the help of some sunshine to warm afternoon temperatures into the lower 60s across the southern half of the area, ranging into the mid 40s highest elevations of our northeast mountains for Sunday.
High pressure centered over the Northwest will remain in charge through Sunday night. A trough will move through the Mid-West and under-go cyclogenesis over the next day or so. This low pressure will push the high pressure farther eastward into the western North Atlantic. As the eastward motion of the high occurs, the gradient will finally relax across the Keys beginning on Sunday night.
The upper trof that brought light rain showers overnight and this morning has moved off to our east, leaving behind lingering cloud cover. A weak upper level ridge will move over the region tonight, resulting in decreasing clouds from south to north.
Most of the area will experience partly cloudy skies this afternoon, with highs in the low 70s. An amplifying ridge aloft will build into the region today, and will shift east through the region overnight into early Sunday. Meanwhile at the surface, high pressure will remain wedged into the forecast area from the east, resulting in continued southeast winds across the area today. This will really be the case late tonight into early Sunday as southwest flow aloft increases across the region in the wake of the departing ridge and an approaching low pressure system from the west.
(This afternoon through Sunday night) WV imagery shows the upper trough moving through the Four Corners at 18Z, with a line of convection ahead of this feature developing invof KELP. 0-6km shear at 12Z came in at 20kts, but CAMs are all in agreement in ramping it up to 40-50kts or better by mid-afternoon as the trough arrives, making for a rare December severe event. The trough is forecast to be right over West Texas and Southeast New Mexico at 12Z, which is about when convection is expected to clear the southeastern zones. Surface winds will veer to the west as the trough clears the area, ushering in drier, cooler air behind it. Sunday, a cold front drops in in the wake of the exiting trough, with a secondary trough digging into the central Rockies behind it.
At the surface a Pacific cold front continued to slide east across Southwest through North Central Montana this morning which was leading to a wind shift to the west; with this front expected to clear eastern portions of the CWA prior to 15z this morning. Strong and gusty west winds were accompanying the passage of this Pacific front, with a re-enforcing cold front then expected to dive southeast from Canada between 15-21z Saturday and switch winds to the north. A cold front continues to move across the region this early morning, bringing light precipitation ahead of it and cooler temperatures behind.
Turning cooler and unsettled mid-week and beyond. The ongoing warming trend will continue today, allowing daytime highs to rise into the 50s in the lowlands and 40s to low 50s along the mountains. Overnight lows also remain above normal, with 40s expected in the lowlands and 30s for the mountains.
101 PM EST Sat Dec 23 2023 High pressure over the mid Atlantic will keep dry conditions across the forecast area through Sunday with moisture increasing through the day.
High pressure centered over the Northeast is still maintaining moderate to fresh breezes, however, they are expected to start increasing by this evening. From synopsis, high pressure will move slowly offshore from the Eastern Seaboard through the weekend, with moderate to fresh easterly breezes prevailing across the Florida Keys coastal waters.
We were generous in adding patchy freezing fog to the forecast accordingly, especially from the Shoshone lava beds and Snake Plain into some of our srn/ern valleys. Sun will be mostly sunny and quiet as high pressure builds in from the west, with highs in the mid-20s to low-30s.
928 AM CST Sat Dec 23 2023 - Today will see above normal warmth despite cloud cover, with highs in the low to mid-60s.
(This evening through Sunday) An upper level trough is currently located across the Desert Southwest and will approach West Central Texas overnight into Sunday morning. As the aforementioned upper level trough approaches this evening, expect an increase in large scale lift across West Texas, resulting in the development of showers and thunderstorms in the vicinity of a Pacific cold front.
Cooler and potential for wetter conditions for the last weekend in December.
211 PM EST Sat Dec 23 2023 High pressure over the mid Atlantic will keep dry conditions across the forecast area through Sunday with moisture increasing through the day.
20Z water vapor showed the southern stream and northern stream energy more in phase with a high amplitude trough over the Rockies. surface obs showed a lee trough deepening in response to the upper pattern. This low pressure to the west has allowed southerly winds to increase moisture transport to the north. The more significant changes to the forecast are to account for a quicker cutting off of the upper low and cold air moving in sooner on Christmas Day. The consensus from the operational solutions is for the low pressure system to cut of a little further south and west which shifts the higher snow amounts south and west as well.
200 PM EST Sat Dec 23 2023 (This afternoon through Sunday) Current satellite loop shows mid to high level clouds rotating around the developing high pressure ridge/wedge pushing down the eastern seaboard. The main low pressure center over eastern CO will deepen and move SE as it pushes into Eastern OK Sun afternoon/evening. The trailing cold front swings across TX tonight and into the Mid to lower MS river valley Sun.
A few light showers continue to linger across the region today after last night's cold front passage. Valley inversions will once again develop tonight as a ridge builds back over the region.
136 PM CST Sat Dec 23 2023 - Tonight through Sunday night, a wintry mix of light rain and snow, with the possibility of freezing rain will be moving through the area. - The highest impacts will be in the far south central and James River Valley.
126 PM EST Sat Dec 23 2023 Dry high pressure will extend across the eastern US through the weekend. Aloft, the sub-tropical ridge should gradually progress eastward through the region as an upper low closes off over the central Plains. At the surface, the ridge that had been persistent over the area will breakdown and retreat northeastward and out of central NC Sun/Sun night, with increasing easterly to southeasterly flow into the area. Meanwhile to the west, a low pressure system will move through the Plains and into the mid/upper MS Valley through Sun night. Low level thicknesses will increase as a warm front approaches from the south.
731 PM EST Sat Dec 23 2023 High pressure over the mid Atlantic will keep dry conditions across the forecast area through Sunday with moisture increasing through the day.
(Tonight) Warm, moist advection in association with a warm front has generated low/mid clouds across portions of the area today, along with light RA/SHRA mainly in NW portions of the area.
250 PM MST Sat Dec 23 2023 Cold front moving through eastern Montana this afternoon with gusty northwest winds and a band of light snow. The system moves to the east late tonight and skies will clear and winds diminish as high pressure moves into the area for Sunday and Christmas Day. The upper trof moving over the region today is expected to develop into a slow moving closed low in the central plains by Christmas Day. This will keep temperatures a little cooler over eastern Montana, although still slightly above normal, through the holiday. As the closed low slowly drifts toward the Great Lakes through midweek, an upper ridge builds into the northern Rockies for dry weather and above normal temperatures through the end of the week.
757 PM CST Sat Dec 23 2023 * Fog looks to return overnight as a warm front approaches the area with more warm moist air.
An upper level low will then bring more widespread showers, with a few pops of thunder, across the area Christmas Eve afternoon through Christmas Day's end.
516 PM CST Sat Dec 23 2023 (This evening through Sunday) An upper level trough is currently located across the Desert Southwest and will approach West Central Texas overnight into Sunday morning. As the aforementioned upper level trough approaches this evening, expect an increase in large scale lift across West Texas, resulting in the development of showers and thunderstorms in the vicinity of a Pacific cold front. Skies will quickly clear from west to east on Sunday, with highs topping out in the mid to (Sunday night through next Saturday) 500mb trough across the west-central United States Sunday will evolve into a large 500mb low across the central Plains of the U.
(This afternoon through Sunday) Current satellite loop shows mid to high level clouds rotating around the developing high pressure ridge/wedge pushing down the eastern seaboard. The main low pressure center over eastern CO will deepen and move SE as it pushes into Eastern OK Sun afternoon/evening. The trailing cold front swings across TX tonight and into the Mid to lower MS river valley Sun.
Today through Sunday Night: Yesterday's trough passage left a reduced amount of boundary layer moisture in its wake with clearer skies in place across central WA.
537 PM CST Sat Dec 23 2023 - Tonight through Sunday night, a wintry mix of light rain and snow, with the possibility of freezing rain will be moving through the area. - The highest impacts will be in the far south central and James River Valley.
Currently, the region is starting to transition to SW Flow aloft ahead of an upper trough over the SW CONUS. As that trough starts to eject into the front range of the Rockies this evening, expect isentropic lift to pick up across region. By sunrise Sunday, the upper trough will move into the Central and Southern Plains. The moderate to heavy rainfall will push eastward across the region along with the trough throughout the day on Sunday. The convection should move out of the region by Sunday evening well ahead of the associated cold front. Expect northwesterly winds to bring in noticeably cooler temperatures in wake of the front for Christmas.
525 PM CST Sat Dec 23 2023 * Fog looks to return overnight as a warm front approaches the area with more warm moist air.
After the cold front passed through the rest of Montana this morning temperatures have stayed in the low 30s with cloudy skies across the plains of North-central and Central Montana and the valleys of Southwestern Montana.
Cooler and potential for wetter conditions for the last weekend in December. WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO Temperatures at 1 PM this afternoon are running a few degrees cooler than this time yesterday along the coast and in much of the Inland Empire. Elsewhere temperatures are running 5 to 10 degrees warmer than yesterday.
544 PM CST Sat Dec 23 2023 (Tonight) Warm, moist advection in association with a warm front has generated low/mid clouds across portions of the area today, along with light RA/SHRA mainly in NW portions of the area.
413 PM EST Sat Dec 23 2023 High pressure will remain east of the region through Sunday.
605 PM EST Sat Dec 23 2023 High pressure will remain east of the region through Sunday.
544 PM CST Sat Dec 23 2023 (This evening through Sunday) A broad conveyor of elevated moist ascent continued to feed north over the region early this afternoon in advance of a tightly wound upper low about 120 miles west of ABQ. Convection should sweep out of our eastern zones around midnight well ahead of a Pacific cold front and drier westerly flow through daybreak. Opted for a blend of the cooler CONSSHORT highs tomorrow as the NBM continues to look too optimistic given the degree of cold advection.
(This evening through Sunday) As of mid afternoon, the closed upper low across the southwestern US has begun to transition to an open wave as it merges with northern stream energy dropping southward across the northern Rockies. The upper trough axis is currently centered across central New Mexico, with large scale ascent ahead of the trough now spreading into the panhandles and western Oklahoma. As the trough lifts northeastward this evening, showers and thunderstorms will expand eastward into the rest of the area.
716 PM MST Sat Dec 23 2023 Upper trough was splitting as it moves across the northern Rockies, but still plenty ascent on the front side of the trough. STP A quieter period of weather is in store beginning Christmas Day, as an amplifying ridge builds over the Rockies. The ridge amplification is aided by a deepening closed-low pressure system over the Central Plains.