Aikyam-Lab/Synoptic-Bench huggingface dataset:
Most of the area is seeing snow, but the far southeastern CWA has yet to completely switch over and is seeing freezing rain and sleet at times, but should switch soon. Roads remain hazardous in spots, especially on bridges where surface temperatures have cooled much earlier than other surfaces. With clearing skies, lows will be in the low teens.
Gusty north winds in excess of 20 mph will be possible in the wake of the strong cold front that moved through earlier today. MVFR to IFR conditions are expected to gradually improve as drier air and high pressure begins to build in with all sites becoming VFR by morning.
The freezing line sits farther back around northern Arkansas to far southern Illinois. This will make it feel like temperatures are in the low teens through the morning hours and low 20s through the afternoon. While this will help wind chill, this will allow temperatures to plummet into the low 20s with wind chills in the mid teens.
622 PM EST Mon Nov 11 2019 A strong cold front will approach tonight and push through the forecast area Tuesday.
Upper ridging will continue to persist over the area, helping to raise temperatures, but bring about some gap winds yet again in south-central Montana. As low pressure starts to move into eastern Montana this evening and into Tuesday, a pressure gradient will set up over south- central Montana.
A ridge of high pressure rebuilding over the region will continue to produce dry conditions and temperatures well above normal across central CA for the next couple of days.
Light snow ended behind a departing upper trough axis this morning. The airmass moderates (west/east) heading into Tuesday in rising heights aloft behind the departing upper trough. The gusty winds and low RH in the low/mid 20th percentile in our southern zones will need to be monitored for near critical fire weather conditions.
With 4 to 6 inches of snow common and mainly clear skies tonight, temperatures will fall but warmer air will move in at mid-levels.
Warmer this weekend. With the weak gradient over Shasta Co tonight, we don't expect the adiabatic warming effects of the Nly winds tonight, thus better radiational cooling and cooler mins tonight even though ("dirty") high pressure will prevail over the region. Satellite and RH progs indicate a plethora of high clouds will be spilling over the ridge during the next couple of days, reducing the radiational cooling and limiting insolation to some "degree(s)" (pun intended). Strong ridging will push from the W coast into the interior mountain west during the short term forecast period. Low pressure system near 30N/150W is forecast to weaken as it approaches the coast during the middle of the week, but will bring some cooling to the region.
/Issued 918 PM CST Mon Nov 11 2019/ Arctic high pressure system centered over nwrn Kansas continues to build into the Southern Plains this evening.
On Tuesday, despite plenty of sunshine and light north winds, temperatures will only rise into the low to mid 20s for highs.
Mixing did occur in the lower levels of the atmosphere today via moderate east-southeast winds.
1010 PM MST Mon Nov 11 2019 The trough has swung through the Rockies and any lingering moisture is being replaced by much drier air. The question is how thick will the high cloud cover be that is spilling over the ridge upstream of us. The next system to plow over the top of the Western Ridge makes into into the northern Rockies tomorrow night.
256 AM CST Tue Nov 12 2019 Arctic high pressure will settle across the region today and then slide east of the area tonight. As the high slides east tonight the pressure gradient tightens with increasing southerly winds, especially across the western half of the forecast area. Overnight lows will range from around 20 over southeast Kansas and far western Missouri, to the lower teens over the eastern Ozarks.
Light offshore flow through Tuesday is expected to reduce night and morning fog and low clouds, and result in warmer temperatures, especially near the coast. High pressure over California will weaken by the second half of the week, resulting in cooler temperatures and more cloud cover. As mentioned earlier, temperatures finished slightly warmer than yesterday with temperatures reaching into the mid 60 to lower 70s along the coast with 70s to low 80s inland. This shift in the pattern will turn winds onshore and will introduce a cooler airmass.
Clear skies this evening with the arctic high pressure departing the region. This will allow the evening temperatures to fall initially, followed by some non-diurnal temperature trends later tonight as strong warm advection begins in return flow around the high. The center of surface arctic high pressure was over the western Dakotas this afternoon. The high center will slide southeast into the central plains tonight, and our surface winds will become light. Our low temperatures tonight could occur this evening or just after midnight, then begin rising towards daybreak as southerly winds begin to mix the lower atmosphere. On Tuesday, we can expect fairly decent warm advection behind a warm front, allowing temperatures to rise into the 20s over north central ND and the James River Basin.
A flat upper level ridge will build across the Central Rockies through Tuesday. Most of Denver should reach 60F or more, with slightly cooler readings away from the foothills with less downslope component. Potential we could see somewhat warmer readings as 700mb temps warm to +5C, and the liquid content of this morning's snow was rather meager.
With such a low starting point, however, afternoon highs will once again remain below freezing throughout the area, only rising to the upper 20s across the western counties and lower 20s east.
253 AM CST Tue Nov 12 2019 A record cold morning across portions of central Kansas as the core of the Arctic high pressure drifts across the area.
Many locations have already seen temperatures reach the low single digits above and below zero. Arctic high pressure will move south of Nebraska tonight leading to lowest temperatures before or around midnight. The temperature forecast Tuesday uses the cooler deterministic model blend forecast for highs in the 30s, 40s and near 50. This is several degrees cooler than the blended guidance and several more degrees cooler than the bias corrected guidance blend.
However, a wintry mix of precipitation in the form of rain and freezing rain continues to impact the southern terminals.
We are seeing gradual decoupling of the lower atmosphere from the West Texas Mesonet but it may take a few hours to completely decouple and winds revert to light drainage (mostly northwest) components. Winds will gradually return to south-southwest on Tuesday in response to pressure falls with ridge departing to the east. Lower cloud layer was just clearing KLBB, and the high cloud deck will thin and edge southeast later in the evening leaving clear skies. Lows are expected to fall into the low teens area wide.
An upper trough will push from the central U. on Tuesday, pushing a cold front south through the Keys on Wed. A pre-frontal northerly wind shift will occur as soon as late Tue afternoon, but it will take until early Wed for cooler air to spread in. High pressure centered near Bermuda will recede east into the western North Atlantic tonight and Tuesday.
High pressure will begin to work it's way in from the west with warmer air intruding.
Cold Today; Warmer Tomorrow. Winds will shift to the south this afternoon as the ridge moves into eastern Oklahoma. These features, combined with abundant insolation, will result in a much warmer day than today. Highs from the low 50s (east) to low 60s deg F (west) are expected.
This relatively warmer air will slowly move from southwest to northeast overnight into early Tuesday morning. With 4 to 6 inches of snow common and mainly clear skies tonight, temperatures will fall but warmer air will move in at mid-levels.
1233 AM EST Tue Nov 12 2019 A strong cold front will approach tonight and push through the forecast area Tuesday.
Temperatures ranged from the lower/mid teens near the KS border to the lower 20s in southeast OK, and still could see a few spots get close to record lows for the day.
Winds should be decreasing through much of the morning as high pressure begins to settle in, with a gradual shift of south winds after 18z.
However, this ridge will slide to the east this afternoon. Surface lee cyclogenesis/troughing will develop in response to a short wave trough moving across the Intermountain West.
120 AM MST Tue Nov 12 2019 An upper ridge remains over the Western U. Tuesday, the ridge will nose eastward with an upper trough coming ashore over the Pacific Northwest. Winds will become southwesterly overnight, allowing for some warmer air to filter into the area Tuesday. Temperatures are expected to be much warmer, with highs ranging from the upper 40s to the mid-50s.
246 AM CST Tue Nov 12 2019 Early morning satellite imagery shows plenty of clear sky across the area as high pressure continues to build in. While this will lead to warmer air getting here eventually, it will take a while, as highs will still be in the teens to lower 20s and lows tonight will be in the single digits above zero and lower teens.
850 mb flow in turn backs to the west-southwest with strong warm advection resulting but the anomalously-cold anticyclone keeps mixing depths limited and highs should only reach the upper 20s to upper 30s, warmer in the west. Overnight temps tonight again look to be fairly steady though much warmer under a 30-40 knot low-level jet and surface winds brining wind chills back down in the single digits and teens.
918 PM CST Mon Nov 11 2019 Arctic high pressure system centered over nwrn Kansas continues to build into the Southern Plains this evening.
Winds will be gusty from the north and northwest behind the cold front, and continuing for much of the day.
Arctic high pressure will settle across the region today and then slide east of the area tonight. As the high slides east tonight the pressure gradient tightens with increasing southerly winds, especially across the western half of the forecast area. Overnight lows will range from around 20 over southeast Kansas and far western Missouri, to the lower teens over the eastern Ozarks. A breezy day is expected on Wednesday ahead of another cold front. With the south to southwest breeze, temperatures will warm into the low to mid 40s for afternoon hours.
The center of high surface pressure was located right through the Highway 283 and 183 corridors early this morning. Light winds and very dry air characterized by surface dew points in the 0 F to -3 F range immediately west of the high center, allowing temperatures to fall into the low single digits. This should lead to warmer overnight temperatures heading toward early morning Wednesday in the 20s most areas.
With such a low starting point, however, afternoon highs will once again remain below freezing throughout the area, only rising to the upper 20s across the western counties and lower 20s east. A subsequent cold front will advance through the area Wednesday night, though with the lingering dry air mass in place, moisture availability will be limited to the mid-levels.
508 AM CST Tue Nov 12 2019 A record cold morning across portions of central Kansas as the core of the Arctic high pressure drifts across the area. However, more noticeable warming is expected on Wednesday ahead of the next upper level trof and associated surface cold front moving southeast across the northern Plains.
Clouds embedded within mositure rounding the top of the ridge are struggling to reach our area so far this morning. These colder temperatures near the surface combined with warming in the mid- levels will likely keep temperatures a bit cooler today across central and southern low elevations. Little to no precipitation is expected even in the high country.
Radar shows some light freezing rain south of FST early this morning. /issued 344 AM CST Tue Nov 12 2019/ Upper level storm system across Baja has combined with freezing surface temperatures to produce light sleet, light freezing rain across the lower Trans Pecos and Big Bend early this morning. Latest radar and surface observations continue to indicate light freezing/frozen precipitation falling across the lower Trans Pecos and the Big Bend. The latest guidance is indicating that light freezing/frozen precipitation is still possible this morning across portions of the Big Bend, Chisos Mountains, Chisos Basin. Temperatures will climb to above freezing later this morning and this afternoon with much below normal high temperatures expected areawide.
Snow cover strength of the high will result in record cold highs today in the lower to mid 20s.
Upper level ridging will remain in control to start the day, with a quick moving disturbance crossing the region this evening and overnight.
518 AM CST Tue Nov 12 2019 Early morning satellite imagery shows plenty of clear sky across the area as high pressure continues to build in. While this will lead to warmer air getting here eventually, it will take a while, as highs will still be in the teens to lower 20s and lows tonight will be in the single digits above zero and lower teens.
Temperatures have dropped significantly and will continue to drop to into the lower 20s and teens in our northern counties.
Also, with clear skies and light winds tonight, lows will again be below freezing.
Ridging remains the dominant feature in the short term. Winds across the Snake Plain may increase tonight as a weak cold front pushes through. Ridging will get re-established on Wednesday resulting in a return to drier weather and light winds.
345 AM CST Tue Nov 12 2019 High pressure will continue to drift south, with increasing southerly winds. Peak mixed winds across the Coteau are into the low 30s, with a downslope component showing up as well thanks to a southwest warm advection regime. Down towards Pierre and western/south central South Dakota, very shallow/near surface profiles may be deep enough for some melting, with surface temperatures around the freezing mark. GEFS comes in with a 33 percent probability of freezing rain, while the SREF suggest negligible chances. Forecast thereafter is looking up, with a ridge out west gradually progressing east.
244 AM MST Tue Nov 12 2019 Water vapor shows ridge over the western CONUS with northwest flow through the Northern Plains. At the surface, high is over NE/KS with lee trof along the northern Rocky Mountain Front. Mostly sunny skies expected today with lee trof advancing into the Northern Plains. Ridge topping wave will bring some light precip to much of the area later tonight through Wednesday morning. Thermal profiles generally suggest a rain/snow mix, but there is some potential for light freezing rain on parts of the SD plains, especially south central SD.
Will allow the advisory to keep running until 8 AM as originally scheduled for the flash freezing of residual moisture on roadways.
However, this ridge will slide to the east this afternoon. Surface lee cyclogenesis/troughing will develop in response to a short wave trough moving across the Intermountain West. A cold front will be sent through the area Wednesday evening although it will be much weaker than the front observed yesterday.
For today, warm air advection will develop as a warm front slowly advances east across the state through the afternoon, allowing temperatures to rise into the 20s over north central North Dakota and the James River basin. Across the west, temperatures will mainly be in the low to mid 30s with the warmest readings likely in the southwest, which may flirt with 40. The cold front will only cool temperatures down a little bit on Wednesday with highs ranging from the 20s to lower 30s.
428 AM MST Tue Nov 12 2019 Water vapor shows ridge over the western CONUS with northwest flow through the Northern Plains. At the surface, high is over NE/KS with lee trof along the northern Rocky Mountain Front. Mostly sunny skies expected today with lee trof advancing into the Northern Plains. Ridge topping wave will bring some light precip to much of the area later tonight through Wednesday morning. Thermal profiles generally suggest a rain/snow mix, but there is some potential for light freezing rain on parts of the SD plains, especially south central SD.
313 AM CST Tue Nov 12 2019 For today, warm air advection will develop as a warm front slowly advances east across the state through the afternoon, allowing temperatures to rise into the 20s over north central North Dakota and the James River basin. Across the west, temperatures will mainly be in the low to mid 30s with the warmest readings likely in the southwest, which may flirt with 40. The cold front will only cool temperatures down a little bit on Wednesday with highs ranging from the 20s to lower 30s.
Milder air will begin to build into the region today as breezy south winds and warm air advection combine with rising heights aloft, in advance of an upper level ridge building through the Northern Plains today. Cannot rule out some patchy flurries today, but better chance for snow develops tonight through early Wednesday as a mid level disturbance progresses through the Northern Plains in northwest flow aloft as ridging breaks down. Best chance of snow accumulations is for southeast ND and west central MN as sub freezing temperatures at the surface and aloft prevail. Now that NDAWN soil temperature sensors indicate sub freezing temperatures for the top few layers, be prepared for minor impacts to travel due to snow accumulations.
Skies should be clear this evening, and then clouds will increase after midnight as an upper trough approaches from the Plains states.
429 AM EST Tue Nov 12 2019 Currently - High pressure over the northwestern Atlantic is shifting out east as a frontal trough is pushing off the Atlantic coast. Meanwhile, a cold front is spreading south and southeastward through the Gulf of Mexico. Forecast - Winds will collapse today as the high moves out and our pressure gradient goes flat with the prefrontal trough just reaching into northern Florida. The cold front will continue to progress southwards towards the Keys and be just north of the island chain Wednesday morning.
WV indicating upper ridging rebuilding into central CA. This will maintain dry conditions and much warmer than normal temperatures across the area through Wednesday with just some thin high clouds at times.
344 AM CST Tue Nov 12 2019 Upper level storm system across Baja has combined with freezing surface temperatures to produce light sleet, light freezing rain across the lower Trans Pecos and Big Bend early this morning. Latest radar and surface observations continue to indicate light freezing/frozen precipitation falling across the lower Trans Pecos and the Big Bend. The latest guidance is indicating that light freezing/frozen precipitation is still possible this morning across portions of the Big Bend, Chisos Mountains, Chisos Basin. Temperatures will climb to above freezing later this morning and this afternoon with much below normal high temperatures expected areawide.
Temperatures ranged from the lower/mid teens near the KS border to the lower 20s in southeast OK, and still could see a few spots get close to record lows for the day. Stuck closer to blended MOS guidance over the warmer NBM numbers.
319 AM PST Tue Nov 12 2019 With a shallower marine layer, coastal and valley areas will be warmer today.
An upper ridge in NW flow aloft will be over the forecast area this morning. A warm front this morning will turn winds to the west and quickly warm the areas currently in the inversion. The SW areas will be warm enough for rain along with a mix of sleet and freezing rain through early evening.
Chattanooga Airport, TN 35 20 48 29 / 40 0 0 0 Knoxville McGhee Tyson Airport, TN 34 16 44 24 / 60 0 0 0 Oak Ridge, TN 33 15 44 24 / 40 0 0 0 Tri Cities Airport, TN 33 13 43 22 / 70 0 0 0 TN.
North winds will linger within the lower Colorado River today.
Rather breezy today as cooler air invades the region for a day or two. Otherwise dry weather is expected the remainder of the week and through the weekend with occasional high clouds and temperatures running a few degrees warmer than normal. The upper low to our south will continue to gradually lose any influence on our area meaning fewer clouds and the removal of showers from the forecast. The cool air will result in high temperatures today running around 6 degrees cooler than yesterday in Tucson to as much as 15 degrees cooler near the New Mexico border.
Expect the responsible area of high pressure to our south to continue to shift away from the region today. and for the pressure gradient to increase on the backside of this high pressure system. as this continues to look like a very minor event with a small chance for some sleet at the onset as the dendritic layer becomes saturated but a warmer layer below this combined with cold surface temps continues to support this as a possibility for a couple of hours. dry northwesterly flow with weak ridging this weekend is forecast.
521 AM EST Tue Nov 12 2019 Periodic snow showers should continue today with an upper level disturbance, before building high pressure returns dry weather Wednesday. Post frontal snow should continue to taper off from W-E as low pressure and its associated cold front moves east. Scattered to numerous snow showers are then expected to develop through the day with the approach and passage of an upper trough. Steep lapse rates and instability in the lower levels should also enhance any snow bands that become organized. Maintained the Winter Weather Advisory as is for areas N of I 80, and in the PA/WV/MD ridges where another 2 to 4 inches of snow is likely.
A polar air mass continues to build in early this morning behind a cold front that is stretched from near New York to Mobile to Northeast Mexico. A 1043 MB ridge is centered over the plains. Today the front will continue to quickly move south and east while high pressure settles in. Even northern areas of the coastal zones will be at risk of a hard freeze, however winds may stay just elevated enough to keep those areas mixed and therefore slightly warmer.
An unseasonably cold Arctic airmass is rapidly moving into the region behind a strong cold front associated with a deep upper level trough over the eastern Conus. Lingering moisture through the early morning hours today will bring a few lingering showers and the potential for a brief mix of freezing rain and sleet across southwest Mississippi as the inversion weakens and colder air becomes deeper just at or before the column dries out. Skies will rapidly clear out by afternoon as an extremely dry Canadian High pressure builds into the area. Clear skies and laxing winds overnight will allow for temperatures to plummet well into the lower and middle 20's interior North Shore to near freezing south of the Lake.
The focus for heaviest precipitation and snow is still expected along the higher terrain of the Idaho/Montana border, as well as the Mission, Swan, and Lewis and Clark Mountains nearer to the Continental Divide.
Temperatures have dropped significantly and will continue to drop to into the lower teens in our northern counties.
Most of the main roads look to be snow free, but with very cold air moving in behind the front, slick spots will be around especially on bridges and overpasses. Unfortunately, the winds are also bringing in more cold and dry air, so temperatures will struggle to reach freezing or even hit 30 in many areas, so there will not be much relief in the way of warmer temps to help melt the snow today.
That said, this could be a good setup for a 1-3 hour period of a wintry mix of freezing rain, sleet, and rain during the onset of precipitation prior to daybreak Wednesday. The 00Z HREF probabilities also place the chance for measurable freezing rain at 40 to 50 percent. It should be noted that 00Z models have trended temperatures upwards within the warm nose, and that latest NBM guidance is trending warmer, but I've still had to make some manual adjustments to introduce additional precipitation types (perhaps not far enough).