Aikyam-Lab/Synoptic-Bench huggingface dataset:
High pressure overhead has resulted in sunny skies and light winds this afternoon. This will be associated with weak upper energy rotating around the upper low moving across the northern Great Lakes/Ontario region. High temperatures in the lower 60s on Sunday will warm into the 65- 70 range on Monday as sunshine returns.
1037 PM MDT Sat Apr 18 2020 A secondary mid-level short wave trough combined with jet divergence working on a conditionally unstable atmosphere will continue to bring scattered showers to the region this evening. Moisture will continue to stream eastward over the region ahead of a weakening closed mid-level low pressure system moving southward from the northern Intermountain West to the Great Basin on Sunday. Weak perturbations moving through a weak transitory ridge aloft, combined with upper-level divergence and steepening lapse rates are expected to produce another round of showers and thunderstorms across the forecast area with the afternoon period favored. The mid-level closed low to the west opens and weakens as it begins to move eastward over the Great Basin during the night.
As with previous discussions, both the EC/GFS support a gradual weakening of the upper ridge centered in the Gulf of Alaska. By the end of the week, there is a good possibility that this ridge will break down and form a large trough. Downstream energy will flatten the ridge over the Rockies with several weak short waves riding eastward across the northern tier of the nation.
211 AM EDT Sun Apr 19 2020 High pressure will give the area a mostly sunny and mild day. A cold front approaching will bring showers late in the day and this evening. Cooler and drier weather will return for Monday.
Despite the front, with drier air and more sunshine we expect warmer temperatures this afternoon.
The northern branch upper jet remains in place over the northern Plains with another wave ushering a cold front south into northern Nebraska. Isentropic lift via the upper wave and ahead of the cold front is focused south of east-central Kansas, while decent upper forcing from wave late tonight into Sunday morning encounters modest moisture in central portions of the state. Winds steadily drop off ahead of the front tonight with modest cold-air advection on NNE winds and some early-day cloud keeping Sunday's highs in the lower to middle 60s. Midday and afternoon clearing and good mixing should lead to a warmer day despite a northwest wind direction.
Breezy southwest winds will become westerly and then northwesterly overnight as a cold front passes through the area. Gusty winds will continue to diminish this evening as a cold front moves southward across Lake Michigan. Winds will ultimately be lighter tomorrow owing to approaching high pressure. An upstream cold front just pushed into far northwest Wisconsin will continue to move east and pass across southern WI overnight. Weak high pressure will affect the area on Monday with slightly cooler temperatures and much less wind.
This ridging coupled with the loss of daytime heating has allowed convection to largely diminish across the area with only a few lingering showers remaining.
1049 PM CDT Sat Apr 18 2020 A weak cold front has been pushing its way across the area today, with only portions of SW MN and NW IA remaining for it to travel through.
Moist unstable air mass was located over the coastal waters to the east of the slowing retreating warm front. Poor aviation conditions with low stratus and dense will remain prevalent over south Texas overnight as the weak warm front moves inland. Ended the Advisory for the waters earlier than the Advisory for land to account for the anticipated movement of the warm front.
Light snow will persist through far SE montana later this morning and early afternoon alongside a small warm front associated with a meso-low over NE Wyoming, but again, minor accumulations expected. As the upper trough moves eastward, it will be replaced with ridging late Sunday and through the mid-week.
Warmer and drier conditions remain on tap to begin the upcoming work week.
Radar returns show showery precipitation across much of western Colorado favoring the higher elevations along and south of the I-70 corridor.
High pressure will bring dry and mild weather through early this week.
1153 PM EDT Sat Apr 18 2020 High pressure slides through the area tonight with a cold front arriving on Sunday.
At the surface, cold front extends from the western Great Lakes, across Iowa and into southern Nebraska. As far as temps go, highs are expected to remain fairly steady around the 70 degree mark through Tue with overnight lows staying above freezing. While there is good model agreement in troughing setting up again from the Great Basin into the Plains to end the work week, the GFS is much more agressive than the ECMWF in digging a stronger piece of energy further south.
Temperatures today will feel just a bit cooler with upper 50s to low 60s expected across the area.
113 AM CDT Sun Apr 19 2020 For the 06Z TAFs, north winds behind passage of a cold front will diminish later today. A cold front will move south across the region overnight behind the departing short wave.
High pressure will drift southeastward across the Northern Plains and into the middle Mississippi River Valley Sunday with lighter winds and mostly sunny to partly cloudy skies for the Northland. Temperatures Sunday will trend a bit cooler with highs in the upper 30s in the eastern portions of the Arrowhead and the upper 40s from central Minnesota east into northwest Wisconsin. Deep boundary layer mixing should produce wind gusts of 20 to 30 knots, with the highest gusts over central Minnesota into northwest Wisconsin.
Expect these trends will continue over the next several hours given moist east/ northeast upslope in the low-levels behind the cold front. We will begin to see a more dramatic warming trend Monday with upper-level ridging becoming more established.
1228 AM CDT Sun Apr 19 2020 Quiet conditions are expected over the next day as north central Nebraska remains on the northern fringe of strong high pressure. This high will allow warm air advection into the region keeping temperatures on the warm side. Highs in the mid 50s are expected across the north on Sunday and in the low 60s south of I-80. If thunderstorms do develop, the best chance will be across southwest Nebraska where afternoon and early evening peak CAPE values are the highest.
1040 PM CDT Sat Apr 18 2020 Cold front currently dropping in across northern MN will continue to sink southeast through the afternoon, sliding across and through the forecast area tonight. A leading trough/cool front precedes the trough, slipping across the forecast area during the late morning/early afternoon, while another cold front, more tied to the wave, drops across the region Monday evening. Bufkit soundings point to more stability above the low layers without much impetus for deeper/stronger convection. Another shot for showers will come as the cold front drops in for the late afternoon/evening.
High pressure over Virgina will quickly exit east this morning as a cold front stretching from Wisconsin to North Central Kansas will push across Indiana today and tonight. High pressure will build across the region tonight and provide dry weather through Monday Evening.
300 AM EDT Sun Apr 19 2020 Persistent troughing in the upper levels will lead to periodic precipitation chances into the middle of the week, along with below normal temperatures. Wind of 5-10 MPH continues across the region thanks to a modest pressure gradient away from the high centered over the Central Appalachians. Stronger low pressure tracking across the southeast CONUS could spread some showers northward along the Appalachians tonight, but will continue to maintain only a slight chance in the far southeastern CWA as most models still keep this activity suppressed mainly to the south. Monday will feature quiet weather as weak high pressure crosses in quasi-zonal mid-level flow. A slightly cooler air mass behind the Sunday night cold front will keep temperatures several degrees below climatology.
359 AM EDT Sun Apr 19 2020 Scattered light showers or sprinkles are possible today as a cold front moves across the area.
An area of high pressure over the northern High Plains this morning will move south/southeast across the Midwest through tonight.
A stronger wave will make its way east across Texas today, driving severe convection over the Deep South, while a weak and moisture- starved cold front across Wisconsin and Iowa will push south into the Ohio Valley. However, the lack of available moisture will limit POPs to low-end chance with the cold front across southern Indiana, with better chances but still modest amounts near the KY/TN border with the southern system. Temperatures will be fairly seasonable, or perhaps a little cooler as there is little change in air mass with the passage of these two impulses. Behind the departing system, expect mostly dry and sunny weather for Monday as a ridge of high pressure briefly builds across the area, with high temperatures warming into the low to mid 60s.
Through tonight and into Sunday, the longwave pattern will amplify as troughing digs down into the southern Rockies and the plains of Texas. However, if the low tracks further north into Arkansas, this will increase the tornado threat, as storms will have a better chance of becoming surface based. The low pressure system will drag a cold front through the region Sunday afternoon and evening, with any lingering storms ending fairly quickly. Not expecting a big cooldown in the wake of this frontal passage, as high pressure will quickly move through behind it and southerly flow attempts to re-establish itself.
Showers may linger into the late afternoon hours, but short range models keep the highest precipitation chances in the afternoon south of the I-44 corridor and closer to the Missouri- Arkansas border. Rain chances quickly end across the area by this evening as weak high pressure builds over Missouri and eastern Kansas.
Still expecting temps in the low to mid 60s. Slightly cooler than yesterday with the passage of the front. It'll be a fairly nice day, only about 10-15 degrees cooler than yesterday, which compared to the previous week is welcome. Behind this wave cooler air will creep in, winds will become northwesterly and temps behind the precip will drop.
259 AM MDT Sun Apr 19 2020 Weak cold front moving through the area early this morning supporting a few isolated showers in northeast Colorado, which will end by 12z. It will be partly sunny and a bit cooler today behind the front, with high temperatures in the 60s.
The first to be later this morning, with the second later tonight as vertical motion elevates with incoming upper trough and weak SFC boundary. Upper trough axis should be just east of the area by sunrise Monday, with residual light showers exiting the Plateau.
This is occurring in an area of moisture convergence associated with the low level jet. The RAP shows this area of showers moving off to the east by mid morning as the low level jet veers to the east. The chance for showers will persist into the afternoon as a cold front currently over Iowa will move southeast across Missouri and Illinois. Britt Showers will move out of the area on Monday evening as the trough moves east of the area.
Much cooler air has settled in following the front yesterday evening. The parade of cold fronts continues into Monday. A modifying/ warming airmass tonight into early Monday will be replaced by much cooler air again by evening.
These storms were rooted in an elevated layer, in the vicinity of a 925mb warm front. This morning's model consensus did not bring the surface warm front as far north as yesterday's guidance, with the nearest approach about 60 miles south of Monroe County, MS. Tornado threat should remain limited given the weak low level winds 60 to 100 miles north of the synoptic warm front. Looking beyond tonight, northwest flow will prevail early in the week, under a broad longwave trof centered over Ontario.
As the low moves further towards the base of the trough, which is expected to be in northwest Nevada, the lifted index value grows, with CAPE remaining around 200 J/kg. After this time, the low will move east of modoc County and precipitation will fade. The next best chance for rain exists Monday along the higher terrain in the Cascades and in Siskiyou County, with cumulus buildup possible in other westside locations. Most west side valleys should still experience enough solar heating for high temperatures to climb into the high 60s or very low 70s.
Temperatures will remain cooler than normal on Sunday with dry conditions through the early evening.
Southern ND: winds will be weaker, sustained at around 20mph on average, although both the RAP/HRRR show min RH values the lowest in the state across the south central in the upper teens.
332 AM MDT Sun Apr 19 2020 High pressure over the area now will pull away by late this morning. Otherwise, the main story this week is the warming temperatures expected under the building ridge.
816 AM EDT Sun Apr 19 2020 Persistent troughing in the upper levels will lead to periodic precipitation chances into the middle of the week, along with below normal temperatures. Stronger low pressure tracking across the southeast CONUS could spread some showers northward along the Appalachians tonight, but will continue to maintain only a slight chance in the far southeastern CWA as most models still keep this activity suppressed mainly to the south. Monday will feature quiet weather as weak high pressure crosses in quasi-zonal mid-level flow. A slightly cooler air mass behind the Sunday night cold front will keep temperatures several degrees below climatology.
516 AM MDT Sun Apr 19 2020 Upper level analysis has a broad trof across much of the CONUS with a series of weak trofs from the West Coast into the Southeast. At the surface, high pressure is centered over southern Saskatchewan with weak north to northeast boundary layer flow across the forecast area. Snowfall totals of 2 to 4 inches are expected across Crook County and the higher elevations of the Black Hills, with up to an inch across the plains of northeast Wyoming and the foot hills areas. Ridging builds back into the area early in the week.
853 AM EDT Sun Apr 19 2020 Persistent troughing in the upper levels will lead to periodic precipitation chances into the middle of the week, along with below normal temperatures. With the aforementioned low/trough staying primarily south and east, dry weather is expected as weak high pressure crosses in quasi- zonal mid-level flow.
656 AM CDT Sun Apr 19 2020 For the 12Z TAFs, the cold front has moved through the terminal sites as of this writing, with northwest to north winds in its wake.
Chattanooga Airport, TN 60 53 70 49 71 / 80 100 50 0 10 Knoxville McGhee Tyson Airport, TN 64 50 67 48 68 / 50 90 50 10 10 Oak Ridge, TN 63 50 68 47 68 / 50 90 40 10 10 Tri Cities Airport, TN 66 47 63 44 63 / 40 90 50 10 20.
615 AM EDT Sun Apr 19 2020 High pressure will give the area a mostly sunny and mild day. A cold front approaching will bring showers late in the day and this evening. Cooler and drier weather will return for Monday.
Temperatures may be a tad cooler across the northern Big Country where the NAM indicates a weak frontal boundary dropping southward during the afternoon. Overnight lows will fall into the lower 50s under clear skies and light winds.
Trough axis starting to swing through our CWA so scattered rain/snow showers will continue this morning before decreasing northwest to southeast around midday. Light snow will persist through far SE montana later this morning and early afternoon alongside a small warm front associated with a meso-low over NE Wyoming, but again, minor accumulations expected. As the upper trough moves eastward, it will be replaced with ridging late Sunday and through the mid-week.
This wave will move east and fill in this evening, with H5 ridging setting up across WY for Monday.
326 AM MDT Sun Apr 19 2020 Upper level analysis has a broad trof across much of the CONUS with a series of weak trofs from the West Coast into the Southeast. At the surface, high pressure is centered over southern Saskatchewan with weak north to northeast boundary layer flow across the forecast area. Snowfall totals of 2 to 4 inches are expected across Crook County and the higher elevations of the Black Hills, with up to an inch across the plains of northeast Wyoming and the foot hills areas. Ridging builds back into the area early in the week.
625 AM EDT Sun Apr 19 2020 Scattered light showers or sprinkles are possible today as a cold front moves across the area.
Rain chcs wl diminish fm the W tngt as the main storm sys/upr trof shift E of AR.
However, low pressure to the southwest will push some light showers into areas south of Pierre.
This will drag a weak cold front through the area and produce northwest downslope winds this afternoon. Over the higher terrain where the airmass will be slightly unstable, scattered showers and perhaps a few weak storms are expected. Where snow remains on the ground it will be about 10 degrees cooler.
A weak cold front will move into the Panhandle of Texas early this morning where it will become nearly stationary late today and Sunday night. A weak area of high pressure at the surface will be crossing western Kansas early in the day.
635 AM CDT Sun Apr 19 2020 Cooler temperatures today with highs slightly below average in the 50s.
544 AM EDT Sun Apr 19 2020 Persistent troughing in the upper levels will lead to periodic precipitation chances into the middle of the week, along with below normal temperatures. Wind of 5-10 MPH continues across the region thanks to a modest pressure gradient away from the high centered over the Central Appalachians. Stronger low pressure tracking across the southeast CONUS could spread some showers northward along the Appalachians tonight, but will continue to maintain only a slight chance in the far southeastern CWA as most models still keep this activity suppressed mainly to the south. Monday will feature quiet weather as weak high pressure crosses in quasi-zonal mid-level flow. A slightly cooler air mass behind the Sunday night cold front will keep temperatures several degrees below climatology.
516 AM MDT Sun Apr 19 2020 Weak cold front moving through the area early this morning supporting a few isolated showers in northeast Colorado, which will end by 12z. It will be partly sunny and a bit cooler today behind the front, with high temperatures in the 60s.
403 AM CDT Sun Apr 19 2020 Cooler temperatures today with highs slightly below average in the 50s.
1046 AM EDT Sun Apr 19 2020 Mean layer ridging persists across the Western Caribbean, giving way to screaming westerlies across the Gulf of Mexico. Breezes will freshen through the afternoon as the low pressure system over the Twin States (MS/AL) deepens.
337 PM EDT Sun Apr 19 2020 With high pressure in place and lows dropping to near freezing, frost is possible tonight. Rain showers arrive briefly Monday night as a cold front sweeps through.
Radar imagery shows only a few light showers remain east of the Highway 77 corridor this afternoon. This activity will continue to push eastward over the next 1-2 hours as a Pacific cold front moves in from the west. A weak cold front will move into portions of central Texas early tomorrow morning. Southerly winds will return on Monday and we will see a dry day with afternoon highs in the lower 80s north of Highway 71 to the mid 90s out west along the Rio Grande.
There is a slight chance for some isolated rain showers in southwestern Minnesota, primarily east of the Buffalo Ridge on Monday afternoon. While this will lower our winds, it will also limit our daytime highs to the lower 60s east of I-29 with areas west of I-29 approaching 70s.
Short-fuse models and CAMs continue to show another round of showers and isolated thunderstorms possible this evening across portions of southwest Kansas as a series of H5 vort maxima associated with a +110kt jet core kick out of the southern Colorado Rockies into the high plains. As for temperatures tonight, little change to the general air mass across the high plains and likely increased cloud cover will keep lows dropping much below the 40s(F). Expect highs pushing the lower/mid 70s(F) Monday afternoon.
The wave clouds mainly over Boulder and Larimer counties may cause even cooler max temperatures today than already forecasted, however with west- northwesterly winds expected to increase, some warming will likely come from that. This will drag a weak cold front through the area and produce northwest downslope winds this afternoon. Over the higher terrain where the airmass will be slightly unstable, scattered showers and perhaps a few weak storms are expected. Where snow remains on the ground it will be about 10 degrees cooler.
242 PM MDT Sun Apr 19 2020 Convection in the northwest flow aloft is spreading across the higher terrain and over the Palmer Divide.
This afternoon through Monday night A weak cold front will make its way over areas east of the Divide Sunday. A ridge will build over the PACNW Monday, putting the Cowboy State on the downstream side of the ridge and under northwest flow.
218 PM MDT Sun Apr 19 2020 Latest upper air analysis shows the long wave trough persisting over the Plains. Within the northwest flow were a couple upper level short wave troughs, with multiple smaller scale troughs. Satellite imagery shows cumulus clouds developing during the afternoon ahead of these troughs. For the rest of the day and tonight, confidence is on the low side regarding precipitation potential for the forecast area. The strongest upper level short wave troughs will move near the northeast and southwest parts of the forecast area late this afternoon and this evening. Monday night a weak upper level short wave trough will move through Southeast Colorado. Most of this trough will be southwest of the forecast area, so confidence of any rainfall for Cheyenne County is low.
Into the late evening and overnight hours, a backdoor cold front will spill into the eastern plains, bringing shifting winds and low stratus clouds that will drop ceilings to MVFR status.
/Issued 656 AM CDT Sun Apr 19 2020/ For the 12Z TAFs, the cold front has moved through the terminal sites as of this writing, with northwest to north winds in its wake.
235 PM CDT Sun Apr 19 2020 18Z surface data has high pressure over the Plains while a cold front runs from lower Michigan into Oklahoma. Quiet and dry conditions will be seen through sunrise Monday as high pressure moves quickly through the Midwest. However given the cool temperatures so far this month, seasonal vegetation is not 'yet' susceptible to frost or freezing temperatures. Heating ahead of the approaching cold front will make the atmosphere capable of producing diurnal convection. The cold front looks to enter the highway 20 corridor west of Dubuque in the late afternoon. A potent cold front will arrive Monday evening, and with it, a chance for showers and thunderstorms.
As the upper Low continues east in Canada, this will also drop wind speeds overnight. The upper level flow pattern across the Midwest remains driven by a large-scale Low pressure system situated across eastern Canada. This will continue to circulate Low pressure waves into the Midwest and Great Lakes regions through mid-week.
Weak cold front moving through the area early this morning supporting a few isolated showers in northeast Colorado, which will end by 12z. It will be partly sunny and a bit cooler today behind the front, with high temperatures in the 60s.
An area of low pressure will slide southeastward across the region on Monday.