Aikyam-Lab/Synoptic-Bench huggingface dataset:
A cold front was quickly moving through the region and will be through the KLBB terminal within the next half hour as well. Breezy winds will remain at all TAF sites during the overnight hours after the cold frontal passage. INCREASING THREAT FOR LIGHT ICY ACCUMULATIONS ON WEDNESDAY AND Early morning satellite showed the west edge of subtropical cirrus was making steady progress eastward across the region ahead of broad longwave troughing over the western third of the CONUS. Despite an overall drying trend aloft behind the subtropical moisture axis, the low levels will become increasingly moist and eventually saturated tonight following a sharp cold front. Stout thermal ridging ahead of the front will probably secure a 30+ degree temp contrast by late day from SW to NE across our CWA.
133 PM CST Tue Feb 20 2018 Today there is a strong upper trough extending from the Northern Rockies down through the Great Basin while an upper ridge remains centered off FL Atlantic coast.
1023 AM MST Tue Feb 20 2018 Current surface analysis shows low pressure now well south and east of the region, with arctic high pressure over MT. Upper level analysis shows trough axis now over eastern MT and WY, weakening and speeding up as it moves into the Plains. The forecast looks relatively quiet for the rest of the week, though it will remain bitter cold through midweek as arctic high pressure slowly passes over and eventually east of the area.
At the same time a strong arctic cold front will also be pushing south and this will bring additional activity into our northern counties in the evening hours as well. There could be some isolated spots reaching 3-4 inches in the higher rainfall areas. The expected cold front is much stronger than what most guidance was able to pick up on and this is not out of the norm for these shallow arctic airmasses.
The axis of the upper trough that has been responsible for the recent weather is over Utah this morning and will slowly shift east through the day. The cold airmass (around -20C at 700mb over northern Utah and -14C across southern Utah today) will keep max temperatures today from reaching freezing across all but the lower valleys of southern Utah. A weak trough that will cross the area tomorrow afternoon/night is not expected to produce any significant snow but will keep temperatures on the cold side.
Models seem a bit done in over-forecasting fog potential in this warmer than normal regime, so will defer to MVFR ceilings and little to no mention of fog restrictions at this time for the overnight period.
352 PM CST Tue Feb 20 2018 The deep trough to our west continues to dig into northern Mexico this afternoon. Strong SSW flow aloft downstream of this trough is pumping abundant mid/upper-level moisture across the Southern Plains and Midwest. The cold front attendant to the Great Lakes cyclone will move south into the CWA late tonight and slide slowly south throughout the day.
302 PM EST Tue Feb 20 2018 Large high pressure system out over the western Atlantic continues to supply the area with unseasonable warmth and humidity.
1132 AM CST Tue Feb 20 2018 Radar returns continue to dissipate as high pressure builds east across the local area. Slow moving, longwave upper level trough across the western US and associated jet streaks moving across the Northern Plains in southwest flow will slowly shift toward the Great Lakes region. Models are in decent agreement with maintaining trough over the western US through the remainder of the work, placing the Northern Plains in southwest flow aloft.
Near-freezing temperatures will be possible this evening into Wednesday morning.
356 PM CST Tue Feb 20 2018 Steady state onshore flow persisting on what still appears to be an out-of-season Bermuda ridge pattern.
It will be cold and dry today as the upper trough exits to the east. It will be cold again tonight, but not as cold as last night as clouds increase across the area from the northwest ahead of an approaching upper trough. The trough will be accompanied by snow showers late tonight through Wednesday with light accumulations possible, mainly across the north.
Our cold front pushed through must faster than previously thought, and by 3PM, it was making its way into the southern row of our counties.
328 PM CST Tue Feb 20 2018 WV imagery was showing the upstream longwave trof has nudged a bit to the east since yesterday and currently extends from about central Canada to Baja. However, models are in pretty good agreement large scale pattern will become stagnant with the upper trof moving little the next several days.
335 PM CST Tue Feb 20 2018 By mid-afternoon, the back-edge of the freezing rain was finally exiting the outlook area as the system progressed into Missouri. With these cold conditions in place, there is the potential for some slick road conditions overnight into Wednesday morning on any untreated surfaces from today's freezing rain/sleet event.
Cold air will slowly filter into the area overnight with temperatures steadily falling below freezing from west to east. Depending on how long the rain lasts across far SE WI and how quickly the cold air can make it that far east, there may be a brief period of freezing rain in far SE WI around 06Z. Forecast confidence is high: High pressure will bring some sunshine and colder temperatures on Wednesday, with highs a couple degrees below normal.
134 PM MST Tue Feb 20 2018 Weak impulse will move east across the region this evening with effect limited to some cloudiness as well as a few snow showers over the higher mtns. Quiet day again Weds and warmer but still on the cold side.
After dusting off the radar scope, we have tracked several scattered thunderstorms across mainly Barber and Pratt counties, producing plenty of lightning and mainly brief downpours of freezing rain and sleet. Some areas of freezing drizzle will remain possible through sunrise, mainly east of US 283, as shown by 00z NAM. With upslope and stratus, most locations are expected to fail to reach freezing Wednesday afternoon. Pop grids are in the likely category for the eastern counties Wednesday evening (Stafford, Pratt, Barber), with thermal profiles suggesting snow will transition to freezing rain with time.
259 PM CST Tue Feb 20 2018 Cold front has recently passed through Decatur, and will arrive soon in Champaign. Forecast soundings show a prominent warm nose around 2,000 feet lingering much of the night, so a changeover to freezing rain and some sleet remains likely.
321 PM CST Tue Feb 20 2018 Just a few areas of cloud cover still lingering over the eastern part of the CWA this afternoon as high pressure is now pushing in from the west/northwest.
Well below normal temperatures will continue through the end of the week as a deep trough of low pressure remains in place across the western states.
Thanks to relatively weak winds, moderately strong high pressure and fresh snow-cover, low temperatures dropped well below zero across much of western Montana and portions of central Idaho. The coldest spot that we could find was Polebridge which bottomed out at 41 degrees below zero. Thanks to the arctic airmass in place and above freezing water temperatures, a lake effect snow band developed around daybreak and didn't dissipate until the early afternoon near Yellow Bay, Flathead Lake. It is the increase in mid-level clouds, that will help temper the low temperatures tonight.
This may not be warm enough given MOS guidance in some locations 10 degrees warmer than even these updated forecast highs. CC An upper level ridge of high pressure is slowly rebuilding over the Pacific Northwest. As a result warmer temperatures will slowly move back into North Central and Southwest MT over the next few days.
Surface observations indicate low clouds and patchy freezing fog continue across much of the forecast area. Otherwise low pressure system offshore will continue to spread mid and high level clouds across the region. Temperatures will be similar to yesterday with highs in the 20s to lower 30s in the low cloud area with light winds. The upper level ridge remains over the region tonight into Wednesday with a weak short wave passing by to the northwest.
Highs this afternoon will rise above the freezing mark in most areas outside of the Hill Country, but not make it much past the mid 30s.
301 AM MST Tue Jan 2 2018 The arctic airmass that was over the area the past few days will continue to slowly move away from the area as warmer air moves in from the west with approaching high amplitude ridge axis.
Yet another day of staying below freezing. Winds will gradually back to a west to WSW orientation Tuesday night into Wednesday ahead of the passage of an upper-trough and dry cold front Wednesday evening. The result will be some air mass modification and a welcome (but very brief) warming trend as high temperatures should be able to climb into the mid to upper 30s (and above the freezing mark) for a at least a few hours.
Sub zero wind chills are ongoing with the lowest values of -8 in both Clarksville and Crossville. The reinforcing arctic cold front is still expected to moved through on Wednesday afternoon, with clearing taking place behind the fropa. For our near term temps, very cold again today, despite plentiful sunshine, with highs in the lower to mid 20s. Wednesday will feature highs that reach and actually exceed the freezing level. This will be true for all but our northwestern areas where the mercury will reach near freezing for highs.
We get a shot of weak cold advection behind the clipper, however guidance winds and BUFKIT mixed down suggests winds will only top out in the 20 to 30mph range, which shouldn't cause any significant problems with blowing and drifting - unless we get into more sunshine than clouds during peak heating - and we gets some melting/refreezing on pavement. However, the weekend will see a temperature pop an a deep upper trough shifts east and an upper ridge briefly moves over the plains.
Highs across the western half of the combined Panhandles are expected to rise above the freezing mark while the eastern half falls just short of breaking the freezing mark. By Wednesday, the entire area will warm above the freezing mark as highs reach into the mid 40s.
301 AM MST Tue Jan 2 2018 An upper level ridge of high pressure is slowly rebuilding over the Pacific Northwest. As a result warmer temperatures will slowly move back into North Central and Southwest MT over the next few days.
Once the snow moves through, a cold front will bring breezy northwest winds and a reinforcement of cold air for Tuesday night into Wednesday.
303 AM PST Tue Jan 2 2018 High pressure remains overhead into Wednesday as cloud cover gradually increases.
The arctic airmass that was over the area the past few days will continue to slowly move away from the area as warmer air moves in from the west with approaching high amplitude ridge axis.
Otherwise, no cloud development should be observed today in the low or mid-levels of the atmosphere due to the dry and stable airmass in place.
High pressure currently centered to our northwest at this time, will slide southeast today. The center of this high will position itself over the center of the CWA by this afternoon. A weak upper level trough will swing through the area this afternoon into the early evening which may bring some clouds to southern portions of the CWA. Winds will become southwesterly later tonight and that wind shift along with an increase in cloudiness ahead of our next frontal boundary, will yield some warmer temperatures for tonight, but it will still be rather cold. A dry cold front will traverse the area early on Wednesday but there is not enough moisture to precipitate much but we'll see some clouds. However, we will see warmer high temperatures for Wednesday, ranging from the mid 20s north to lower 30s south.
410 AM MST Tue Jan 2 2018 High pressure remains firmly in-place across the Northern Rockies through late tonight. Patchy freezing fog will be present across the Northern Rockies through midday. The high pressure ridge over the Northern Rockies will be disturbed on Wednesday due to weak Pacific waves moving onshore.
High pressure will prevail across the region through the week as temperatures continue to run above normal with highs mostly in the 70s. Like a broken record, the high amplitude pattern persists with well established ridging over the Western U. and a deep longwave trough over central and eastern portions of the country. The extensive cloudiness today will somewhat impact daytime temperatures, but some thinning of the clouds during peak heating this afternoon should allow for highs to reach into the lower 70s across the deserts. The closed low will continue to feed upper level moisture into the region into Wednesday while the low weakens and begins to lift to the northeast.
900 AM MST Tue Jan 2 2018 High pressure will prevail across the region through the week as temperatures continue to run above normal with highs mostly in the 70s. A cutoff cyclonic circulation near 29N 134W was pumping copious amounts of high clouds through a pronounced ridge axis and into the forecast area this morning.
938 AM EST Tue Jan 2 2018 Arctic high pressure will keep bitterly cold temperatures over the region today. Also apparent on the latest sounding is the huge inversion in the low levels. Otherwise, expect decreasing cloud cover as high pressure builds in, the low level flow backs and lake moisture is cut off. Expect clear and very cold conditions tonight as high pressure travels along the Ohio River Valley to the East Coast. For Wednesday, low pressure will develop over the Great Lakes ahead of a sharpening upper short wave.
306 AM MST Tue Jan 2 2018 Ridging still extends along the left coastline of NOAM with deep and expansive troughing takes the eastern 2/3 of the continent. However very dry air and a clear night should allow temperatures to plunge with the Yampa and Upper Gunnison Basins dropping well below zero as well as some of the higher mountain valleys. High level moisture slowly returns on Wednesday as troughing the Eastern Pacific drives the Western ridge inland a bit.
Early morning clouds will give way to clearing skies later today as subsidence develops behind an upper level trough that will be crossing western Kansas during the afternoon. Tonight will not be as cool as the past several nights despite a weak cold front/surface boundary trying to work its way into western Kansas. On Wednesday the weak surface boundary that moved into western Kansas Tuesday night will lift back north as a warm front and warmer/more seasonal temperatures return to western Kansas.
/issued 238 AM CST Tue Jan 2 2018/ A broad upper trough is over the eastern 2/3rds of the country with an upper ridge over the west coast. Temperatures today will remain cold, especially across the Permian Basin and Lea County where highs will remain below freezing. Low temperatures tonight will be below freezing across the whole CWA. The upper trough moves further east on Wednesday allowing temperatures to warm up into the 40s and 50s across the whole CWA during the afternoon.
646 AM EST Tue Jan 2 2018 Bitterly cold and very dangerous wind chills can be expected this morning as arctic high pressure remains entrenched over the Midwest.
The 08z MSAS surface analysis showed a strong area of high pressure centered over the central Plains/Mid-MS Valley. A weak area of low pressure was situated over central Saskatchewan. The area of high pressure is expected to stretch from the southern Plains east-northeast to the OH/TN Valleys, while the low pressure drops southeast into northern sections of the Great Lakes today. Look for amounts to generally range around one-half inch with higher amounts over Vilas County due to lake enhancement as winds veer northwest behind the cold front.
Cloud cover should remain over much of the area through the day until 03-06Z Wednesday with a short wave trough pushes across the area. Temps at the surface should be above freezing though, so no accumulation or impacts are expected.
Light to moderate snow showers are expected in the vicinity of the cold front and over much of northeast Minnesota, where the strongest height falls will be located. With another shot of cold air behind the front, temperatures tonight will trend a bit cooler once again and look for highs Wednesday to wind up in the single digits either side of 0F.
742 AM EST Tue Jan 2 2018 High pressure brings mostly snow-free weather from this afternoon through Wednesday. High pressure passes to the south tonight. Temperatures should rise into the 20s across most areas during the afternoon, reaching the highest levels in over a week.
So, readings east of the mountains will actually be quite a bit warmer, getting up close to averages, in many areas today. Readings in those areas will likely be 2 to 5 degrees warmer as compared to yesterday.
917 AM EST Tue Jan 2 2018 KBYX detects patchy, light rain over the Lower Keys, as well as over nearshore and offshore waters surrounding the Lower Keys.
With high pressure overhead, winds have decoupled allowing temps in the valleys to plummet to near zero and even below zero. As the high continues to slide southeast, the clear skies will persist into tonight. Late tonight, the high will shift far enough southeast to where winds will switch around to the south and southwest as cloud cover begins to move into from the southwest.
High pressure currently centered over northern Missouri will move east toward our area today. A cold front will approach the area on Wednesday afternoon. A few spots across southern Kentucky may break the freezing mark.
528 AM EST Tue Jan 2 2018 High pressure brings mostly snow-free weather from this afternoon through Wednesday. High pressure passes to the south tonight. Temperatures should rise into the 20s across most areas during the afternoon, reaching the highest levels in over a week.
Model trends in the last few runs continue to support upper ridging over the western U.
Otherwise, cloudy, breezy, and cold with afternoon high temperatures ranging ffrom the mid 40s in Williston, the mid 50s along Interstate 4, and the lower 60s in Fort Myers. Another cold front will cross the eastern Gulf of Mexico Wednesday morning.
505 AM CST Tue Jan 2 2018 It remained bitterly cold early this morning across the area with the Arctic high pressure centered just to the northwest of the forecast area. Have adjusted short term grids slightly warmer in the southwest for the early morning hours.
With high pressure established at the surface, a clear sky will allow for abundant sunshine for most of the day. Despite the good heating, northerly winds will keep temperatures in check and keep us once again below freezing all day. An upper-trough will amplify over Missouri and swing into the Mid-South late in day. The dry air at the low- levels will prevent any low clouds and precipitation from developing, however. Winds will gradually back to a west to WSW orientation Tuesday night into Wednesday ahead of the passage of an upper-trough and dry cold front Wednesday evening. The result will be some air mass modification and a welcome (but very brief) warming trend as high temperatures should be able to climb into the mid to upper 30s (and above the freezing mark) for a at least a few hours.
913 AM EST Tue Jan 2 2018 A large area of high pressure will slide east across the Ohio Valley today into tonight. Low pressure will move east across the northern lakes Wednesday, forcing a cold front through the area Wednesday night.
The higher clouds seem to be inhibiting the proper radiative action for dense fog to form. High pressure aloft remains over California along with a weak low pressure trough over the Pacific Ocean to our west that's streaming all these clouds in our direction.
Perhaps the best news is the wind will continue to decrease as the pressure gradient broadens with the low level ridge axis approaching the area. Though there will be a marked increase in mid/upper level moisture (including in the dendritic growth zone) with the passage of this wave, the low levels will remain bone dry. And though the thermal profile will remain safely below freezing to the ground, sadly for snow lovers, this will be falling into a layer of air with single digit RHs. Forecast lows were adjusted to show colder in the west where there will be more clearing to warmer south/east where clouds will hang around more of the night.
A strong ridge of high pressure over the intermountain west will continue the long dry stretch through the end of the work week.
/issued 323 AM CST Tue Jan 2 2018/ Cold arctic airmass will remain in control one more day with temperatures only a few degrees warmer than yesterday. A westerly component to the low level winds will try and warm us up a bit tonight into Wednesday.
558 AM EST Tue Jan 2 2018 A large area of high pressure will slide east across the Ohio Valley today into tonight. Low pressure will move east across the northern lakes Wednesday, forcing a cold front through the area Wednesday night.
Extensive cloudiness, cooler temperatures, and a tight pressure gradient will offer a less than pleasant afternoon. The main adjustment to this update package is the inclusion of a Coastal Flood Watch on top of the High Surf Advisory for coastal counties. The highest values (70%) are indicated along the north coast. Min temps will range from the lower-mid 40s along and west of I-4 to the mid-upper 50s along the Treasure Coast. The highest chance for rain today is from KTIX to KSUA, then late tonight the highest chances should shift northward from KTIX to KDAB.
Currently, temperatures range from the single digits to the low teens across the area with wind chill values ranging from the single digits below zero to near zero. Temperatures will remain below freezing today as Arctic high pressure continues to build into the area. Tonight, an upper trof will swing through the region and could produce some flurries across the area. Clouds associated with the trof will keep lows from dropping as much. Expect readings in the lower teens. Temperatures may briefly get above freezing on Wednesday for 1-4 hours as surface winds quickly turn to the south ahead of another cold front.
545 AM CST Tue Jan 2 2018 High pressure was centered over northwest Missouri at 08Z with ridge axis still located along the IA/NE border. Will continue wind chill advisory into the morning as temperatures remain quite cold and winds should increase after sunrise as the high moves further south. Winds will become southwest and increase into the afternoon bringing some moderation to the bitter cold of the past couple of days before the next cold front arrives late this afternoon and this evening.
544 AM EST Tue Jan 2 2018 Arctic high pressure will keep bitterly cold temperatures over the region today. Otherwise, expect decreasing cloud cover as high pressure builds in, the low level flow backs and lake moisture is cut off. Expect clear and very cold conditions tonight as high pressure travels along the Ohio River Valley to the East Coast. For Wednesday, low pressure will develop over the Great Lakes ahead of a sharpening upper short wave.
High pressure over the region will briefly weaken today. This will allow a weak low pressure system to move across the area tonight for a threat of light snow on the Cascades.
An upper level ridge of high pressure is slowly rebuilding over the Pacific Northwest. As a result warmer temperatures will slowly move back into North Central and Southwest MT over the next few days.
High pressure will slowly weaken over the area today before a Pacific weather disturbance moves up the California coast Wednesday and Wednesday night.
Expect these winds to continue to increase throughout the day with decent mixing and the pressure gradient strengthening in advance of a cold front tonight. Used a blend of the NAM12, HRRR, and RAP for timing of fropa tonight with the higher POPS/QPF in the northeast portions of the forecast area. Tonight, quick moving cold front and clipper system will bring chances of snow over central to northeast portions of the forecast area b/t 00-06z Wednesday.