Aikyam-Lab/Synoptic-Bench huggingface dataset:
Cooler than average temperatures are expected to continue through the end of the week. The low pressure system responsible for this past weekend's weather will continue to push eastward and out of the Intermountain West. The result will be a week of relatively quiet weather, but cooler than normal temperatures. With these cooler than normal temperatures comes the chance for some of our forecast zones to see their first freezes of the season, and for some of our southern zones to potentially see their first hard freeze of the season.
1251 AM EST Tue Dec 13 2022 (Through Tuesday) The low-level air mass is moist and stable. (Tuesday night through Wednesday night) Upper level ridging gets pushed east, making way for the deepening low over the northern central plains. The aforementioned cold front will move which will bring showers and thunderstorms to the region with convective parameters, favoring high shear, low cape.
(Today and tonight) A strong mid to upper level low will move northeastward from southeastern Colorado early this morning to central Nebraska by evening and toward southeastern South Dakota by sunrise Wednesday.
Upper low in northern Utah this evening is slowly shifting away from our CWA, but radar still shows snow showers from the northeast in Idaho south of the Snake River. These will decrease overnight as the low moves away.
Buoyed by ample broad scale ascent and anomalous Gulf moisture spread through the lower levels and across the Plains and lower Missouri Valley, rain will continue well through the morning and toward the midday hours. With this high shear, modest CAPE (250 to 1000 J/Kg SBCAPE) environment, storms have lined out and are moving at a decent clip eastward and pose primarily a straight-line wind hazard overall. Wednesday continues to shape up to be cooler, but near normal for mid-December, as southwesterly flow persists in the wake of the H500 trough wrapping up over eastern NE/SD. As discussed previously, with the occlusion of the low as it swings east across Iowa, winter precipitation is forecast along the northern and northwestern TROWAL structure.
Tonight through early Wednesday morning At the time of issuance, the heart of the low pressure system impacting the forecast area is approximately over the borders where Nevada, Utah, and Idaho meet. As the low follows an eastward track out of here tonight, showers begin to taper off with only a few lingering light showers likely in Lander, Eureka, and Elko counties. With the trough axis transversing the CWA, the northerly flow slowly advects in cold air, but overnight lows tonight are on track to be the warmest of the next few days in the teens and 20s.
The low-level inversion persists, with less than an inch of TPW. Water vapor imagery places a short wave trough to our east, a short wave ridge progressing east across the MS River Valley, and broad storm system over the Rockies. Temperatures range from 64 in Big Pine to the lower 70s. Breezes will clock around to the east then southeast while continuing to freshen Tuesday into Wednesday as the high drifts further east.
1243 AM EST Tue Dec 13 2022 High pressure builds from the north through Wednesday.
1244 AM EST Tue Dec 13 2022 Dry and seasonable weather is expected until a late week low pressure system provides chances for a wintry mix while dropping temperature below normal. More notable clearing is expected overnight as high pressure shifts east and looses lake fetch, causing clearing from the NE to the SW. A strong low pressure system developing over the Rocky Mountains will deepen and slowly shift northeast Tuesday into Wednesday, occluding and becoming negatively tilted. This is expected to provide dry weather and seasonable temperature Tuesday and Wednesday, with plenty of sunshine Tuesday giving way to increasing cloud cover Wednesday as the ridge shifts east. Due to the occlusion of the low pressure system and its expected positioning, upper forcing is expected to be displaced far enough west and south to keep incoming precipitation at bay.
(This afternoon through Tuesday night) After days of stratus and fog over the lowlands, the boundary layer is finally scouring out as surface flow veers to south and southwest and increases. This is in response to leeside troughing over the Front Range, which in turn is in response to a massive upper trough digging ESE into the central Rockies. Latest model data and the slow progression of the trough suggest high winds likely through Tuesday night at least, including advisory conditions eastern Culberson County.
1152 PM CST Mon Dec 12 2022 A large and potent mid/upper trough over the Central Great Basin area today is progged to move into the Central Rockies tonight before emerging over the Northern Plains on Tuesday. A 130 knot upper level jet will round the base of this trough while nosing into the Central Plains this evening. Breezy but mild conditions are anticipated with above average highs topping out in the low 60s in southeast KS while some increasing clouds/low level cold air advection keep highs from reaching 50 over our central KS counties. The slow moving mid/upper trough over the Northern Plains will result in a prolonged period of low level cold air advection across the Central Plains through the upcoming week. Highs are expected to top out in the low to mid 30s on Thu.
- Much cooler temperatures are expected in the coming days. This has enhanced southerly 850mb winds across the center of the CONUS which in turn has pulled warmer and more moist air into the region. This has resulted in the dissipation of low level fog, but has added thickness to the low level stratus. As it does so, isentropic ascent across and ahead of the warm front initiates a broad area of rain showers. The warm front is expected to pass through around midday. The cold front on the back side of the storm will kick this cloudy, drizzly, and dreary pattern we have been experiencing the past couple of days and replace it with much colder temperatures. Wednesday will be a nice intermission of seasonally normal temperatures as the system stalls due to a weakening blocking high to the east.
1201 AM EST Tue Dec 13 2022 High pressure will extend across the region through mid-week.
One was to replace patchy fog to patchy freezing fog in the valleys both west and east of the Cascades.
202 AM EST Tue Dec 13 2022 Cloudy and seasonably mild conditions expected downstream of a deepening cyclone across the central plains.
Coldest temperatures of the season so far expected the next 2 nights, with a freeze warning extending even into the lower deserts and a hard freeze for Tucson Metro. For the rest of the week, high pressure near the west coast with a broad and deep mean trough position across most of the rest of the CONUS.
408 AM EST Tue Dec 13 2022 Weak ridging will be in place across the area through Wednesday as the stalled boundary that's been draped across the area continues to dissipate. Scattered low clouds and patchy fog will continue to be possible each morning, with highs in the mid 70s to lower 80s and lows in the lower to mid 60s.
631 AM EST Tue Dec 13 2022 Weak ridging will be in place across the area through Wednesday as the stalled boundary that's been draped across the area continues to dissipate. Scattered low clouds and patchy fog will continue to be possible each morning, with highs in the mid 70s to lower 80s and lows in the lower to mid 60s.
Temperatures were already below freezing at several coastal sites such as Arcata-Eureka Muni and Woodley Island in Eureka. The low clouds and fog over the interior valleys will mix out with daytime heating and mixing later today, but will reform again tonight. Coastal areas will continue to have below normal temperatures with overnight lows dipping down to freezing. Some high thin clouds will spill through the ridge and may hinder the longwave cooling slightly by Wed. The block will retrograde over the weekend as a trough sags southward over Washington and Oregon.
Satellite imagery early this morning is showing a large-scale circulation of low pressure moving eastward across the central U. The Northern Rockies will be between this low pressure system and a weak, positively tilted ridge to the west. This will be a quick moving trough with shallow moisture, so snow accumulations will be light.
As the low departs, continued breezy conditions and efficient CAA will allow for a much more winter-like feel to the air through the rest of the week and during this upcoming weekend.
608 AM EST Tue Dec 13 2022 Cloudy and seasonably mild conditions expected downstream of a deepening cyclone across the central plains.
Much drier, and somewhat cooler air will move in behind the Pacific front responsible for these storms today, on gusty west winds of 20 to 30 mph. Temperatures will warm into the low to mid 60s for the most part, and skies will clear from west to east, clearing out for most of the area by late morning or early afternoon. With clear skies, lighter winds, and dry air moving in, lows Wednesday morning will be much cooler than we have had for over a week, with temperatures falling into the upper 30s to lower 40s.
511 AM CST Tue Dec 13 2022 (Today and tonight) A strong mid to upper level low will move northeastward from southeastern Colorado early this morning to central Nebraska by evening and toward southeastern South Dakota by sunrise Wednesday.
(Rest of Today) High pressure will hold for one more day before the next system arrives, so enjoy the dry weather.
A weak high pressure promoted fair and stable weather conditions in the Keys late last night and this morning. The clear skies resulted in radiational cooling throughout southern Florida and the Keys, with overnight temperatures across the island chains falling to the low to mid 60s. Similar to the last several days, tranquil and dry weather will prevail in the Keys due to weak high pressure and scant moisture content in the atmospheric column. As for the Keys, model guidance differ on the timing and position of the cold front as it approaches the Keys.
Afterward, dry and cooler than normal conditions will continue through the end of the week. Freezing temperatures are likely in the San Joaquin Valley for much of this week. Will expect the trend in winds to continue lowering next 12 to 18 hours as ridge begins to dominate the region. As mentioned, Central California is experiencing good northerly flow aloft as a cold air-mass settled in behind the cold frontal passage. The northerly flow will continue to provide the region with cold and dry air as the threat of freezing will be possible for several mornings this week.
Skies are mainly clear across the region early this morning as the weekend trough moves east and ridging edges in. Ridging will bring dry conditions through the week with cold overnight temperatures (around, or slightly below, the freezing mark in the Central Valley, and single digits and teens in the mountains).
Southeast winds will increase throughout the day as low pressure currently over the CO/KS border moves northeast. Bands of 500mb positive vorticity advection will also move in ahead of the upper level low with ample warm air advection feeding into the area developing a significant warm nose in the temperature profile. The low level jet will also move in with the rain bringing the strongest winds this evening into Wednesday with gusts around 35-40 mph. As mentioned before bands of 500mb positive vorticity advection will rotate around the upper level low bringing multiple rounds of rain into Wednesday.
236 AM MST Tue Dec 13 2022 Surface and upper low currently over Colorado will drift northeast into Nebraska today.
Weak ridging will be in place across the area through Wednesday as the stalled boundary that's been draped across the area continues to dissipate. Scattered low clouds and patchy fog will continue to be possible each morning, with highs in the mid 70s to lower 80s and lows in the lower to mid 60s.
1214 PM CST Tue Dec 13 2022 (Today and tonight) A strong mid to upper level low will move northeastward from southeastern Colorado early this morning to central Nebraska by evening and toward southeastern South Dakota by sunrise Wednesday.
Previous discussion: Surface and upper low currently over Colorado will drift northeast into Nebraska today.
Turning much cooler into this weekend. The true cold front is still well off to the west, so colder air will not immediately filter into the area. Look for lows tonight from the low 30s west to the mid 40s east. Highs will range from the low 40s west to the low 50s east.
Dew point depressions are about 10 degrees F with Scott City reporting light snow at 1 pm, hence little if any accumulation is anticipated as the main cyclone/forcing is lifting north and the leading edge of the band has shown a dissipating trend.
A low level ridge continues to gradually slide towards and just off the southeastern U. Satellite derived precipitable water imagery does continue to show better moisture slowly pivoting southwest along the periphery of the aforementioned low level ridge. As the low level ridge continues to slide eastward tonight, a surface reflection will take shape and allow for winds to clock around to the east and southeast while increasing. The combination of the low and the high to our east will keep the pressure gradient tightened and therefore relatively higher winds.
The low pressure system responsible for the impressive overnight snowfall noted in many locations is now positioned near the CO/KS/NE border. As the low continues to deepen and transition to the east, snow will decrease across the central basins this afternoon, with additional snowfall focused more on Natrona and Johnson counties.
1131 AM CST Tue Dec 13 2022 (Today through Wednesday afternoon) Large cold broad cyclonic flow across the Desert SW and Great Basin with mid/upper level water vapor showing the main low intensifying INVOF SE CO with a strong secondary shrtwv trof across srn AZ. The attendant Pacific cold front was moving thru the PB and as of 2 AM was well e of MAF with dry air in all but the extreme ern and srn parts of the CWFA. Main story today will be the windy and cooler conditions. High temps will be just a degree or 2 cooler in most areas.
Temperatures will be cooler tomorrow, with highs mainly in the 50s.
Upper low level low pressure system will continue to east this morning ending precipitation across Central Idaho. Northwesterly winds will increase today helping to clear the stratus/fog and allowing temperatures to increase above freezing in the lower valleys. The Lower Treasure Valley as already warmed above freezing and expect the Upper Treasure Valley to follow suit later this morning/early this afternoon.
1116 AM CST Tue Dec 13 2022 (Today through Wednesday) Finally got to see some sun yesterday as the thin cloud deck was able to erode away thanks to the upper ridge moving overhead a bit sooner than models suggested. Cloud cover will increase from west to east during the day today as the strong upper low from the Plains moves eastward.
Wind speeds will become light overnight ahead of a cold front. Then we will see wind speeds pick back up behind the cold front tomorrow afternoon, and speeds could be breezy across the north/northeast. Wind speeds will start to diminish tonight across the area, and we will see a wind shift ahead of an approaching cold front.
246 PM CST Tue Dec 13 2022 A very powerful low pressure system is located across northwest Kansas and southwest Nebraska and is raking much of the northern High Plains with blizzard conditions.
137 PM EST Tue Dec 13 2022 Dry conditions expected through tonight as high pressure builds back across the region.
High pressure over the mid-atlantic brings an E-SE flow around 5-15 mph over the FL peninsula through much of middle of the week. An upper-level trough over the middle of the country should bring a strong surface cold front through the region.
1124 AM CST Tue Dec 13 2022 (Rest of Today) High pressure will hold for one more day before the next system arrives, so enjoy the dry weather.
1232 PM EST Tue Dec 13 2022 Cloudy and seasonably mild conditions expected downstream of a deepening cyclone across the central plains.
A longwave trough remains entrenched across the western U. Use caution if traveling in the high country today and be prepared for winter conditions.
151 PM EST Tue Dec 13 2022 Dry weather is expected tonight under high pressure.
Moisture pivoting along the eastern and southeastern periphery of the aforementioned low level ridge is producing showers between south Florida and the NW Bahamas.
No changes needed to today's issued wind products, however will issue a High Wind Watch for the Davis mountains and extend the High Wind Warning for the Guadalupe and Delaware mountains that will cover the day on Wednesday. Tonight's lows will range from the 20s in the higher elevations in W TX/SE NM to the 30s across the Permian Basin and down towards the Big Bend. With the upper level low beginning to move away from the area, winds will be much lighter for Wednesday night allowing for more efficient cooling and temperatures settling even a few degrees lower for most areas compared to Wednesday morning.
This has brought a redevelopment of scattered snow showers to much of the high country, especially from I-40 southward. Northern Arizona will remain under the influence of the long wave trough the end of the work week keeping a dry but cool pattern in place.
(Through tonight ) Large cyclone centered over the central Plains will be slow moving with a secondary vort max rotating through the local region late tonight into tomorrow along with a reinforcing cold front and a chance of light rain across far eastern portions of the forecast area.
High temperatures for today will reach into the 60s and 70s, with cooler temps occurring over southeast Georgia. Overnight low temperatures will drop down into the 50s over most inland areas and in the lower 60s for coastal areas in northeast Florida.
(This evening through Wednesday) The upper low currently in southwest Nebraska will continue to slowly lift to the north and east, approaching Iowa by tomorrow evening. Portions of our far northwest zones may drop into the teens as the upper trough clears that area first, before sunrise, and gradient forcing weakens enough to further lighten winds. The secondary trough on the backside of the low will continue to transect the remainder of our area west to east during the rest of the overnight.
Areas of heavy snow along with rather widespread blizzard Water vapor and surface obs place the upper low over south central NE early this afternoon. There is another distinct wave on water vapor rotating around the southerly periphery of the upper low. As the next upper wave (previously mentioned and currently rotating around the upper low) lifts north/northwest tonight expect heavy snow to also redevelop across south central SD and continue into Wednesday morning.
Sharp moisture gradient on eastern flank of plume with dry/easterly low level flow across CWA with 1036 mb anticyclone over eastern Ontario. Feature enhancing cold frontal moisture/lift for an uptick in coverage/intensity/ Pockets of sub 100 J/kg point to potential for sporaidic convection/storms Wednesday night in already strong ambient vertical motion environment with 120-150m/12 hr 5H falls, though lack confidence to include just yet with richer moisture in near surface parcels relegated to south of Ohio River.
1127 AM PST Tue Dec 13 2022 Dry and cooler than normal conditions will continue through the end of the week. Freezing temperatures are likely in the San Joaquin Valley for much of this week. The northerly flow will continue to provide the region with cold and dry air as the threat of freezing will be possible for several mornings this week.
The initial mid level wave rotating around the low and through the Northern Plains continues to bring light to moderate snow to central and most of western ND from this morning through early this afternoon. As this 'dry slot' moves through, there will be a chance for some freezing drizzle or at the very least finer snow flakes for a few hours.
Forecast Discussion: Currently, a large and potent mid latitude cyclone is anchored over the central and northern CONUS.
A vertically stacked low pressure system over Nebraska will drift slowly east during the period, and will push a cold front into and across our area Wednesday night. Current QPF forecast for the event generally ranges from a little under an inch to near 2 inches, with the lower amounts primarily across northeast and central areas west of the mountains in the downslope areas. The low level jet is forecast to be in the 40 to 50kt range by late Wednesday into Wednesday night, perhaps even briefly higher Wed night, before beginning to diminish late Wed night.
557 PM CST Tue Dec 13 2022 A very powerful low pressure system is located across northwest Kansas and southwest Nebraska and is raking much of the northern High Plains with blizzard conditions.
Clearing skies with cold temperatures settling in tonight and again tomorrow night with the coldest temperatures of the season for many locations across the lower deserts. Even though those areas will be colder, freeze warnings are not issued after the first one or two each season for that area as below freezing temps are common throughout the winter.
603 PM EST Tue Dec 13 2022 Dry conditions expected through tonight as high pressure builds back across the region.
A couple of very light snow flurries linger this afternoon as the bulk of the low pressure system impacting us recently continues to push eastward.
Dry and cooler than normal conditions will continue through the end of the week. Freezing temperatures are likely in the San Joaquin Valley for much of this week. The northerly flow will continue to provide the region with cold and dry air as the threat of freezing will be possible for several mornings this week.
515 PM CST Tue Dec 13 2022 (This evening through Wednesday) The upper low currently in southwest Nebraska will continue to slowly lift to the north and east, approaching Iowa by tomorrow evening. Portions of our far northwest zones may drop into the teens as the upper trough clears that area first, before sunrise, and gradient forcing weakens enough to further lighten winds. The secondary trough on the backside of the low will continue to transect the remainder of our area west to east during the rest of the overnight.
Sharp moisture gradient on eastern flank of plume with dry/easterly low level flow across CWA with 1036 mb anticyclone over eastern Ontario. Feature enhancing cold frontal moisture/lift for an uptick in coverage/intensity/ Pockets of sub 100 J/kg point to potential for sporadic convection/storms Wednesday night in already strong ambient vertical motion environment with 120-150m/12 hr 5H falls, though lack confidence to include just yet with richer moisture in near surface parcels relegated to south of Ohio River.
(This evening through Wednesday) As of 4:10PM, the cold front was draped from Cherokee to Woodward with temperatures in the 40s behind the front and 60s across central Oklahoma.
730 PM EST Tue Dec 13 2022 High pressure along the mid Atlantic coast extends across the Florida peninsula. Increasing southerly winds across the forecast area on Wednesday ahead of a cold front which will move across the Lower Mississippi Valley. High pressure over the mid-atlantic brings an E-SE flow around 5-15 mph over the FL peninsula through much of middle of the week. An upper-level trough over the middle of the country should bring a strong surface cold front through the region.
Tonight into tomorrow morning, areas of near to below freezing temperatures are expected in the valleys and deserts. The clear skies will lead to radiational cooling and low temperatures in the low to mid-30s, locally into the upper 20s. Areas of frost are expected in the Inland Empire, San Diego County valleys, and parts of the low desert.