Aikyam-Lab/Synoptic-Bench huggingface dataset:
Otherwise not much cloud cover as high pressure combines with drier mid level air to keep the CWA virtually weather free. Another cold morning on tap for tomorrow as this mornings temperatures were already near or below freezing at many sites. Coastal areas will continue to have below normal temperatures with overnight lows dipping down to freezing. Also, some high thin clouds will spill through the ridge and may hinder the longwave cooling slightly by tomorrow morning. The block will retrograde over the weekend as a trough sags southward over Washington and Oregon.
149 PM PST Tue Dec 13 2022 High pressure builds over the region this week, which will deflect storms away from the region through at least this weekend. * A ridge will continue to build over our area, leading to clear nights. Our fresh snowfall with abundant low level moisture, light winds, and subsidence from the ridge will facilitate extended cold temperatures, valley inversions, and urban haze. We could also see freezing fog each night in Sierra Valley, the Martis Valley, and the Lake Tahoe Basin.
546 PM 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.
There were some cold temperatures around freezing this morning, quite a bit cooler than yesterday, due to light winds and clear skies. For tonight, temperatures could trend a degree or two cooler, with more frost expected. Ridging will bring continued dry conditions through the rest of the week with cold overnight temperatures. For the Valley this means around, or slightly below the freezing mark, and single digits and teens in the mountains.
The low pressure center associated with everything from the severe weather down south, heavy rain here, to the blizzard warnings to our north, will gradually glide northeast as it slowly occludes over the next few days. As the aforementioned low pressure center takes it sweet time exiting the region, very light winter precipitation is forecast along the northern and northwestern MO/IA border.
738 PM CST Tue Dec 13 2022 Already we are seeing echoes enter West Tennessee as a strong cold front bears down on the Mississippi Valley this evening.
Upper low continues to weaken and shift east, leaving northerly flow in place over East Idaho. Erosion of the low cloud cover to the north per satellite imagery, with ample sunshine working over the fresh snow cover. As high pressure continues to settle in, we expect to see combination of low clouds/freezing fog to develop across the region.
449 PM CST Tue Dec 13 2022 (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.
236 PM MST Tue Dec 13 2022 This evening and tonight, snowfall will gradually diminish across the lower elevations behind the exiting system. Expect persistently mostly cloudy skies over the high country, and over the plains clearing will be slow and incomplete due to lingering moisture. Expect high temperatures in the upper 20s to mid 30s across the lower elevations and mostly teens and 20s in the high country.
Leading edge of precip this morning was areas of freezing drizzle out of the surface fog bank, making roads already slick before the snowfall.
447 PM MST Tue Dec 13 2022 This evening and tonight, snowfall will gradually diminish across the lower elevations behind the exiting system. Expect persistently mostly cloudy skies over the high country, and over the plains clearing will be slow and incomplete due to lingering moisture. Expect high temperatures in the upper 20s to mid 30s across the lower elevations and mostly teens and 20s in the high country.
(Tonight) Big changes coming later tonight into early Wednesday morning as scattered to numerous showers (50-80%) and a few storms will overspread the region after Midnight ahead of an approaching low pressure system. Ahead of this boundary, deep southerly flow is attempting to advect in warmer, moist air mass as seen by PWATs reach 1.
514 PM CST Tue Dec 13 2022 (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.
(Today) A quick moving mid level vort max currently rounding the base of the large scale trough is aiding in pushing through a Pacific frontal boundary. Winds will increase out of the west northwest throughout the day today in the wake of the passing boundary and much cooler/drier air is forecast across the area today.
1048 PM CST Tue Dec 13 2022 (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.
Inland frost and freezing temperatures are expected over the next several mornings. After a cool afternoon with readings in the 50s our attention turns to another chilly night with frost and freezing conditions likely for many.
Sharp moisture gradient on eastern flank of plume with dry/easterly low level flow across CWA with 1036 mb anticyclone over eastern Ontario.
The trough will cause severe weather across the central Gulf Coast and portions of the southeastern United States today and Thursday. The Keys remain somewhat stable due to the scant surface and mid- level ridge holding over the area. The clear skies and relatively light winds caused overnight temperatures to fall to the lower to mid 60s.
1033 PM CST Tue Dec 13 2022 (The rest of tonight) Skies have cleared this evening, and with light winds preceding a cold front, fog has developed through the Arkansas River valley and in some other valley locations across southeast OK. Cold front moving into northeast OK at present will Result in a switch to NW winds and may even provide a brief rise in temperatures in some places, but forecast lows should be be in the ballpark.
Freezing fog will persist for a couple more days. There is a 10-20% chance for the aforementioned sites to experience light freezing drizzle from 06Z to 12Z before transitioning to all snow.
A bit slower ewd translation of deep cntrl NE upper low seen in model trends since last night and not surprising given intensity of this system back west. Very intense LLJ draws a substantial low level theta-e ridge north into se areas and may be sufficient to support some slant-wise convection for a time late evening. Deep upper low over WI Fri morning will steer north into srn ON per downstream blocking. Slow wwd veer follows into Sat as low level thermal trough intensifies and mid level moisture plume enhances snow showers through srn MI. Precipitation start time and the lowering of ceilings was delayed with this TAF issuance.
1021 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.
Mean-layer ridging centered near the Gulf of Honduras squeezes north into the Ohio River Valley. The northern branch of this ridge is progressive, lending to 20 m rises at 500 mb on the 00Z KKEY RAOB. Ridging is not the story across the CONUS and North Atlantic, with two large cyclonic gyres noted over the Plains and north of Bermuda. The forecast calls for very slight rain chances overnight with overnight lows in the lower 70s.
1149 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.
Tonight into tomorrow morning, areas of near to below freezing temperatures are expected in the valleys and deserts where frost is likely.
Through the day, the upper H500 trough will continue to dig east across the northern Plains opening up KS/MO to colder west-northwest flow. Highs will be noticeably cooler today for most, in the upper 30s and lower 40s. As has been discussed the past several mornings, as the low tracks east through Thursday, some light snow and/or flurries will likely skirt the MO/KS border region during the daylight hours.
(The rest of tonight) Skies have cleared this evening, and with light winds preceding a cold front, fog has developed through the Arkansas River valley and in some other valley locations across southeast OK. Cold front moving into northeast OK at present will Result in a switch to NW winds and may even provide a brief rise in temperatures in some places, but forecast lows should be be in the ballpark.
Today should remain mostly rain-free, then a cold front will push through the area on Thursday, with a line of strong showers and storms moving through the area ahead of it.
Some patchy fog and freezing fog are possible overnight, so be prepared for areas of reduced visibility and black ice. 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.
1100 PM CST Tue Dec 13 2022 (Tonight) Big changes coming later tonight into early Wednesday morning as scattered to numerous showers (50-80%) and a few storms will overspread the region after Midnight ahead of an approaching low pressure system. Ahead of this boundary, deep southerly flow is attempting to advect in warmer, moist air mass as seen by PWATs reach 1.
1057 PM CST Tue Dec 13 2022 Already we are seeing echoes enter West Tennessee as a strong cold front bears down on the Mississippi Valley this evening. Trailing cold front extends southward through the Arklatex region.
(Today and tonight) Surface observations depict a cold front early this morning that is gliding southward across our CWA. The overall thermal gradient is not enormous, but with somewhat drier air being advected in, temperatures are noticeably cooler on the cold side of the front. The cold front will clear the area by daybreak.
Temperatures will remain slightly cooler than normal through the end of the week.
/Issued 1121 PM CST Tue Dec 13 2022/ /Tonight through Wednesday/ Elevated showers are beginning to blossom across the western zones as a lobe of energy rotates around the base of the main upper low currently centered over Nebraska.
Cells continue to develop over the southeast where dewpoints were in the lower 70s. Model guidance highlight a large closed low spinning over Iowa.
521 AM CST Wed Dec 14 2022 (Today) A quick moving mid level vort max currently rounding the base of the large scale trough is aiding in pushing through a Pacific frontal boundary. Winds will increase out of the west northwest throughout the day today in the wake of the passing boundary and much cooler/drier air is forecast across the area today.
The low pressure system has initialized very well with the latest model updates geographically, but it did initialize a little on the weaker side compared to observations, mainly on the west and southwest side of the system.
The low level wind profile will strengthen throughout the night.
320 AM PST Wed Dec 14 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. Biggest weather impact this morning, and for the next several mornings, will be freezing temperatures across the San Joaquin Valley.
331 AM MST Wed Dec 14 2022 Radar and observations continue to show a sharp cutoff to the steady snowfall over portions of NE Montana as low pressure tracks northeast into the Dakotas. In any event, snow will continue steady at times through this evening before gradually diminishing and becoming more intermittent on Thursday as the low begins to depart. That said, north to northwest winds wrapping around the backside of the low will range from 15 to 25 mph with gusts to 35 mph at times today and Thursday, leading to blowing snow concerns.
This is all developing in response to a large upper low/trough axis rotating eastward thru the Plains states. This rainfall is also advancing ahead of a strong cold front that is just now crossing into the Midwest/lower MS Valley regions. The axis of this rainfall will continue to gradually spread more into the mid TN Valley today, as an attendant low pressure system out of the middle Plains drifts to the NE and becomes occluded as it approaches the Great Lakes. Current temps in the lower/mid 50s will struggle to climb into the upper 50s/lower 60s later today given the abundant cloud cover/rainfall.
Currently, a powerful mid/upper low is spinning over the northern central plains. With slightly drier conditions, winds diminishing to around 5 knots, and clear skies tonight, overnight lows are expected to be 5 to 10 degrees cooler than this morning, with lows near freezing in most areas, and even cooler in valley areas.
A strong upper level low is currently situated over eastern Nebraska/southeastern South Dakota and will basically continue to spin over that general area until it slides east on Thursday. At the surface, the low center associated with the ongoing storm system is pretty much situated directly under the upper level low, with the dry slot of the system bringing a respite in the precipitation to the eastern CWA. The low will track slightly northeastward by morning, then will track just a bit further east by this evening, to generally the area where Minnesota and Iowa meet up with South Dakota. The low will finally pick up some speed tonight, tracking to over Wisconsin.
Turning much cooler into this weekend. The main cold front has pushed through over half of the western portion of the CWA, with another frontal passage close behind over southwest MO. Can expect afternoon highs today to range in the mid to upper 40s over southwestern MO (mainly north and west of I-44) and the low to mid 50s in south central MO.
A high amplitude pattern with a strong dirty ridge near the west coast and a broad and deep mean trough position through most of the rest of the CONUS will keep a cool airmass in place even as we see some moderation in temperatures over the next few days.
Highs around to just below freezing today will fall into the 20s for Thursday.
(Today through Thursday night) The main H850-700 sub freezing airmass is beginning to move south into the Panhandles. This will solidify the CAA in the aforementioned levels on the backside of the departing H500 low pressure system. Some lingering breezy winds for the northeastern Panhandles closer to the center of the departing low pressure. Latest 14/00Z model and numerical guidance hint at a more notable perturbation on the slowly departing H500 low pressure system, centered over Minnesota by tomorrow afternoon. A main backside H500 positive tilted trough will cause height gradients to set up.
Flow aloft has become northerly today behind a strong departing low pressure circulation.
After another snowy day in northern Arizona, cold temperatures are quickly setting in for the High Country. With the mix of recent snowpack, clear skies, and cold temperatures, areas of patchy fog and freezing fog are possible during the overnight/early morning hours today (Wednesday). We'll continue to stay under the influence of this longwave trough that is currently centered over Nebraska through at least the end of the week. But what do we mean by cold temperatures? Well, morning lows are expected reach single-digit temperatures for the next several mornings for much of the High Country, along with afternoon highs around/below freezing for many northern Arizona locations.
A few high clouds are beginning to break through the eastern Pacific ridge into NorCal, otherwise skies remain mostly clear. Temperatures will remain below average with overnight lows around the freezing mark in the Central Valley resulting in widespread frost.
521 AM CST Wed Dec 14 2022 (Today and tonight) Surface observations depict a cold front early this morning that is gliding southward across our CWA. The overall thermal gradient is not enormous, but with somewhat drier air being advected in, temperatures are noticeably cooler on the cold side of the front. The cold front will clear the area by daybreak.
A deep, vertically stacked low pressure remains centered over Nebraska this morning, and will continue to dominate our weather for the next several days.
A bit slower ewd translation of deep cntrl NE upper low seen in model trends since last night and not surprising given intensity of this system back west. Very intense LLJ draws a substantial low level theta-e ridge north into se areas and may be sufficient to support some slant-wise convection for a time late evening. Deep upper low over WI Fri morning will steer north into srn ON per downstream blocking. Slow wwd veer follows into Sat as low level thermal trough intensifies and mid level moisture plume enhances snow showers through srn MI.
(Today through Thursday Night ) Satellite/surface observations this morning shows a powerhouse upper low centered along the NE Nebraska/SE South Dakota border.
546 AM CST Wed Dec 14 2022 (Today through Thursday night) The main H850-700 sub freezing airmass is beginning to move south into the Panhandles. This will solidify the CAA in the aforementioned levels on the backside of the departing H500 low pressure system. Some lingering breezy winds for the northeastern Panhandles closer to the center of the departing low pressure. Latest 14/00Z model and numerical guidance hint at a more notable perturbation on the slowly departing H500 low pressure system, centered over Minnesota by tomorrow afternoon. A main backside H500 positive tilted trough will cause height gradients to set up.
1050 AM CST Wed Dec 14 2022 Snow continues to wrap around the low pressure system, which is centered near Yankton. A strong upper level low is currently situated over eastern Nebraska/southeastern South Dakota and will basically continue to spin over that general area until it slides east on Thursday. At the surface, the low center associated with the ongoing storm system is pretty much situated directly under the upper level low, with the dry slot of the system bringing a respite in the precipitation to the eastern CWA. The low will track slightly northeastward by morning, then will track just a bit further east by this evening, to generally the area where Minnesota and Iowa meet up with South Dakota. The low will finally pick up some speed tonight, tracking to over Wisconsin.
This line is currently shifting towards to the northeast and will be affecting the Lower and Middle Keys here over the next couple hours before dissipating. A mid to upper level ridge axis is just to our west and is sliding eastward.
259 PM EST Wed Dec 14 2022 Showers will increase in coverage tonight as a cold front moves through the region. The showers clear out for Thursday with highs mainly in the lower to middle 40s.
Still looking for more rainfall this afternoon as the cold front to our west approaches.
It was a very cold morning across the high country. Highs will top out in the 20s and 30s along and north of the Mogollon Rim, while the low deserts stay stuck in the 40s and 50s. Our current cold spell is one result of a persistent longwave trough over the western two-thirds of the country.
Rain chances sharply drop during the early morning hours after the passage of a cold front.
The best moisture content looks to be across the western portions of the area towards the Magic Valley and into portions of the lower Snake Plain. Opted to issue a winter weather advisory across the far western edge of the forecast area where forecast accumulations are the highest.
Persistent troughing across the CONUS ends up being replaced over the next several days with a northwest flow regime.
1148 AM CST Wed Dec 14 2022 GOES-16 satellite trends and 12Z upper air analysis places an upper level trough over the Rockies with a stacked upper level low located over Northeast Nebraska. Regional WSR-88D radar trends show the majority of the rain showers have moved south and east of the Mid-South with some stratiform rain occurring across western sections of the Lower Mississippi Valley.
Another low is expected to develop in MS near the cold/warm front intersection. The cold front slides east overnight, ending rain and thunderstorm chances from west to east around midnight.
1112 AM CST Wed Dec 14 2022 (Today through Thursday night) The main H850-700 sub freezing airmass is beginning to move south into the Panhandles. This will solidify the CAA in the aforementioned levels on the backside of the departing H500 low pressure system. Some lingering breezy winds for the northeastern Panhandles closer to the center of the departing low pressure. Latest 14/00Z model and numerical guidance hint at a more notable perturbation on the slowly departing H500 low pressure system, centered over Minnesota by tomorrow afternoon. A main backside H500 positive tilted trough will cause height gradients to set up.
1058 AM CST Wed Dec 14 2022 GOES-16 satellite trends and 12Z upper air analysis places an upper level trough over the Rockies with a stacked upper level low located over Northeast Nebraska. Regional WSR-88D radar trends show the majority of the rain showers have moved south and east of the Mid-South with some stratiform rain occurring across western sections of the Lower Mississippi Valley.
1259 PM CST Wed Dec 14 2022 The intense winter cyclone is centered near Sioux Falls this afternoon. An attendant mid level trough extends southwest into central Kansas where scattered low/mid level stratus continues moving through the subsidence regime.
(Tonight through Thursday night) GOES-16 Satellite imagery shows the cold front well offshore, leaving behind clear skies and dry weather across S TX.
Despite afternoon mixing, the passage of the associated jet from this system and decreasing observed winds have allowed us to expire the High Wind Warning across the Guadalupe and Davis Mountains. Tonight will see light winds and clear skies leading to efficient radiational cooling, with low temperatures falling below freezing everywhere except along the Rio Grande. Some upper level clouds will move in late tomorrow night which could hinder cooling some, but lows will still fall below freezing along and north of I-20.
Locations across our plains have cooled into the low teens, while areas in higher terrain have cooled into the single digits. As the low begins to occlude and push east, we are left in strong northerly and northwesterly flow for our Wednesday.
A southeast wind also meant a little warmer and more muggy conditions with temperatures reaching into the lower 80s with dew points near 70 degrees.
Increasing clouds today ahead of the next trough expected late this afternoon. The trough is currently over Northern Idaho and will move almost straight south reaching the Nevada/Idaho/Utah border early Thursday. A trough will move through the region this evening through early Thursday, ushering in mountain obscuration and the chance for MVFR/IFR conditions for most sites due to ceilings and secondarily visibility restrictions.
A cold front is pushing east across North and Central Texas at this time, adding some some chill in the air with temperatures the rest of today staying in the 50s. Temperatures tonight will drop to/below freezing across areas west of I-35, with areas along and east of I-35 in the mid 30s. The cool temperatures will continue tomorrow as highs stay in the lower 50s along the Red River to upper 50s in Central Texas.
1109 AM CST Wed Dec 14 2022 (Today and tonight) Surface observations depict a cold front early this morning that is gliding southward across our CWA. The overall thermal gradient is not enormous, but with somewhat drier air being advected in, temperatures are noticeably cooler on the cold side of the front. The cold front will clear the area by daybreak.