Aikyam-Lab/Synoptic-Bench huggingface dataset:
1138 AM MDT Sat Sep 26 2020 An expansive trough will deepen on the lee side of the Northern Rockies today, nudging an upper level jet southward and tightening the pressure gradient across the CWA. A cold front draped across the intermountain west will sag into the northern portion of the forecast area, however, any chance for precipitation will remain to our north. Instead, this frontal boundary will mainly provide northeast Utah and northwest Colorado with slightly cooler weather, decent cloud cover and gusty winds. Fall weather noses into the area by Sunday, as the deepening trough drives the cold front south and across the region. Moisture tied to this system will be confined to the Front Range with only isolated showers potentially clipping the highest peaks along the Divide.
307 PM EDT Sat Sep 26 2020 An upper level low over the ARKLATEX area will lift into the MS Valley and open by tomorrow morning.
Lows tonight will stay warmer than the past several nights, generally in the lower 70s across the region. This system will send in a cold front into the area after midnight Sunday night.
The forecast calls for little change in these observations through the evening hours with winds improving in the Lower Snake Plain and East Magic Valley areas closer to 03z. Interestingly enough, the low pressure system responsible for all of these boundaries does not give up all its energy before leaving our area tomorrow and in fact pushes another boundary through our area tonight/Sunday morning. Cooler temperatures are expected Sunday, with morning temps in the teens for the Stanley Basin and mid to upper 40s across the Snake Plain. Cooler daytime temperatures are also forecast with upper 50s or low 60s for highs.
The cold front and associated cigs and storms will be just beyond the scope of this forecast. Dense fog was focused mainly over portions of the lower Ark River and Red River valleys, but was not widespread or dense enough in the forecast area to warrant an advisory this morning. /Issued 406 AM CDT Sat Sep 26 2020/ Warm and humid weather will prevail today and most of Sunday in advance of a cold front that will sweep south across the area late Sunday afternoon and evening.
Cloud cover will gradually decrease during the next several hours, but considerable cloudiness will remain as an upper trough swings across Middle Tennessee tomorrow, bringing isolated showers to portions of the mid state, albeit continued warm temperatures.
347 PM CDT Sat Sep 26 2020 (Issued 345 PM CDT Sat Sep 26 2020) Tonight through Sunday night: Low pressure passing by to the north tonight will drag a cold front through southern Wisconsin. May get into the low 70s farther southeast ahead of the next system, with 60s likely elsewhere.
Upper ridge starts building in tonight with clearing skies.
223 PM CDT Sat Sep 26 2020 More "Fall-like" weather is on our doorstep this afternoon as a cold front begins to slowly push across the Dakotas. High based light rain risks tied with mid-lvl frontogenesis will begin to develop along and south of the Highway 20 corridor after midnight and quickly shift south of the forecast area by daybreak. Sunday: Upper troughing beginning to push further into the Northern Plains on Sunday with low-lvl CAA intensifying through the morning.
High pressure is centered over Georgia and is moving east while a system digs into the plains. With the ridge exiting a more onshore flow has developed and a few isolated showers can be expected over Acadiana through sunset.
207 PM EDT Sat Sep 26 2020 Stacked ridging over the region to keep the warm and humid conditions in place through tonight as slow moving afternoon thunderstorms around inland and southern areas dissipate through the evening hours.
1144 AM EDT Sat Sep 26 2020 Weak high pressure will settle into the area this weekend, bringing warmer and mostly dry weather. Showers and a few storms will be back in the forecast Sunday night to midweek, as as an upper level disturbance moves through followed by a strong cold front. Dry and cooler weather is expected into late week, No big changes necessary from the ongoing forecast with this update.
1202 PM MDT Sat Sep 26 2020 Current surface map places weak trof across the western Dakotas, with cold front moving through central Montana/Wyoming. Cold front races through the forecast area this morning. Deep upper trof sets up over the eastern CONUS for much of week with upper ridge along the west coast. Periodic dry cold fronts with gusty northwest winds will lead to elevated fire weather conditions at times. Cold front will move through this morning, with strong northwest winds developing behind the front. Another round of very strong northwest winds are expected Sunday, but temps should be cooler and relative humidity slightly higher.
Timing of the cold front moving through the area hasn't altered much in recent guidance, entering the northwest zones near midnight and exiting the southeast midday Sunday. The upper trough pushing the cold front through carves out a persistent northerly flow through the bulk of the coming week.
A surge of winds have gusted across portions of central South Dakota into the low 50 mph range, on the leading edge of a pressure bubble/CAA. This evening, the cold front will continue moving east. Behind the front, skies are expected to clear amidst a cooler air mass, and winds should reduce. Precipitation is possible Sunday as well, primarily across northeastern SD and west central MN, as a secondary trough/cold front drops across the CWA.
Dense fog was focused mainly over portions of the lower Ark River and Red River valleys, but was not widespread or dense enough in the forecast area to warrant an advisory this morning. /Issued 406 AM CDT Sat Sep 26 2020/ Warm and humid weather will prevail today and most of Sunday in advance of a cold front that will sweep south across the area late Sunday afternoon and evening.
237 PM CDT Sat Sep 26 2020 Unseasonably warm conditions will continue overnight into Sunday ahead of an approaching cold front. The front will surge southward as an upper trough digs into northern tier of the US.
SHORT TERM (Now through Sunday Night): Closed 500 mb low pressure centered over the Lower Mississippi Valley and an associated mid- level trough stretching southwest into the BRO CWFA will gradually shift northeast and east, respectively, during the period. This will allow weak 500 mb high pressure to nose into Deep South Texas and the Rio Grande Valley.
The low clouds and fog will linger overnight, but begin to improve by mid morning Sunday. While cloud cover will remain for the day, increasing warm advection will create more breaks than yesterday, allowing temperatures to warm into the low to mid 80s. /GG/ Prior discussion below: Patchy fog has developed across the region this morning and will begin to become slightly more widespread, especially in the south where the low stratus has begun to degrade. Highs today will range from the lower to mid 80s. A few showers will be possible in the afternoon as a weak impulse rotating around the upper low swings through the southern portions of the region. The upper low will continue to swing through the region on Saturday night.
A cold front will move into northwest Oklahoma around sunrise and continue to move south through the day on Sunday.
The mid tropospheric pattern will be changing tonight through Sunday as a trough develops from south central Canada into the central part of the Plains.
Initially, high pressure will set up along the Oregon coast, which will keep the probability of regional smoke from returning to the Northern Rockies very low.
1142 AM CDT Sat Sep 26 2020 Models continue to underestimate the high RH fields in the mid- upper lvls today, along with the lingering smoke overhead.
High pressure will bring dry conditions with temperatures well above normal through Sunday. A ridge of high pressure aloft will continue to provide the area with above normal high temperatures and dry conditions.
WV imagery shows the upper trough now over the ArklaTex, w/the west coast ridge nosing into West Texas and Southeast New Mexico behind it. Models have sped up the cold front over the past 24 hours, but diurnal heating should slow it some Sun afternoon between KLUB and KMAF, as is typical, and then the front should pick up speed after peak heating. The NAM, ECMWF, and SREF all keep developing isolated thunderstorms along/ahead of the front on the higher terrain down south.
A weak warm front was also lifting north through central AL and was also clearing the sky as it moves northward. The upper low over the ArkLaTex region will move east and then northeast into northeast MS and southwest TN by Sunday morning. The upper level low will continue moving northeast through middle TN and KY Sunday morning. Showers may linger into Sunday night as a secondary trough axis pushes east behind the low/trough.
Attention turns to what has been advertised for a few days now, a digging large scale trof over the nation's mid section. Sunday night, a band of moisture coincident with forcing tied to the approach of and deepening of the trof means we will bring in a chance of showers and possibly thunder to SEMO, SW IL by 06z, spreading chances east overnight.
1225 PM CDT Sat Sep 26 2020 Although VFR will likely prevail through the TAF period, a strong cold front will move through the area Sunday morning. /issued 244 AM CDT Sat Sep 26 2020/ Persistent ridging pattern will produce another day of above normal heat, breezy afternoon winds and dry conditions. Overnight lows will remain mild, mostly in the 60s, ahead of a cold front arriving later in the morning tomorrow. Models remain in good agreement in an amplification of the upper pattern over the CONUS on Sunday with the amplified western ridge and eastern trough remaining in place through the week ahead. The initial short wave trough that helps carve out the eastern long wave trough will be the sharpest and most significant one of the week and will unlock much cooler air from Canada into the southern Plains.
321 PM EDT Sat Sep 26 2020 Mean layer ridging persists across the Florida Keys, with a low- level axis extending southwest through Andros, the Cay Sal Bank, and central Cuba. As expected, storms are favored in the lee of the Lower Keys and also over extreme southeast Florida. The mid- level ridging will erode at the same time.
High temperatures today will be 5 to 10 degrees cooler than yesterday's highs.
It will remain breezy through the night as strong winds are noted in the lowest couple thousand feet.
159 PM CDT Sat Sep 26 2020 The main forecast concerns this afternoon revolve around the strong cold front set to move through the area tomorrow afternoon and into tomorrow night, particularly the potential for a few strong to severe thunderstorms. Overnight, additional stratus may develop and affect parts of the area, and depending on how quickly it erodes tomorrow, there could be some impact on the high temperatures, currently expected to be above normal values. The earlier mentioned cold front should begin to enter parts of northeast Oklahoma mid afternoon tomorrow, with showers and thunderstorms likely to be along and behind the front.
By early evening a cold front will move through southwest Nebraska and will help to clear out the haze. An upper trough will move across the Northern Plains tonight. A deep upper level trough will persist across Hudson Bay Canada south into the eastern U. flanked by an upper ridge across the West Coast and Great Basin.
233 PM MDT Sat Sep 26 2020 Strong winds still occurring in the wind prone areas as of 2 Pm and with a bit slower movement of a cold front have opted to extend the High Wind Warning until 6 PM. The cold front that is pushing south across the CWA is expected to clear the CWA early this evening.
323 PM EDT Sat Sep 26 2020 Tonight the Ohio Valley will sit between high pressure off the East Coast and a cold front crossing the Midwest and southern Plains. On Sunday the cold front to our west will continue its approach and will be positioned roughly from Detroit to Tulsa by the end of the day. Southerly flow will keep temperatures a few degrees warmer than normal through the short term, with lows tonight around 60 and highs tomorrow around 80. Cooler weather, along with light rain, will make up the weather through the work week. Clouds will increase from the northwest Sunday night as an upper level trof and associated surface cold front move in from the Great Lakes and mid Mississippi Valley.
A cold front will push through the area switching winds to the northwest. The coldest air lags the front but will come in on Sunday as a deep upper trough shifts east across the state.
Overnight, a weak upper level low pressure system will begin to track northeastward through the Lower Mississippi River Valley. The upper low will move off into Middle Tennessee by late in the afternoon hours of Sunday. By midnight, a cold front will begin to approach the Mid-South.
This will be along a weak trough that precedes an approaching cold front that will traverse the region Sunday. For tonight, look for increasing shower chances as the cold front approaches. Highs will be much cooler for Sunday, with highs generally in the upper 50s to lower 60s. By Mon there will be a sharp mid-CONUS trough diving down through the mid and lower Mississippi Valley, and the cool down that commenced on Sun will be more pronounced on Mon, with highs only in the low to mid 50s. A brief rebound into the 60s is possible on Tue before a reinforcement of cooler air establishes high temps in the 50s (40s Thu) for a while. For tonight, cloud cover fills back into the region ahead of an approaching cold front.
So expect some fog formation tonight in the low lying areas and river valleys, but am not expecting widespread dense fog.
Nevertheless, deep mixing near and behind the advancing cold front has allowed temperatures to quickly climb into the 90s in several locations. This is associated with frontogenetic forcing on the leading edge of the deep upper trough sinking through the northern Plains. The main story will be the cooler pattern, and possibly a few frosty mornings.
Despite the dry low levels, have added sprinkles to account for the higher reflectivity across north central SD this morning. Otherwise, the forecast remains largely on track as we await the cold frontal passage. Weak cold advection with a secondary front will also aid in mixing, however fire weather may be slightly less of a concern thanks to a much cooler airmass, with some higher humidity behind this secondary front.
Zonal flow aloft this afternoon will transition to northwesterly as upper level ridging builds into the Pacific Northwest, with the next disturbance to impact the Northern Rockies quickly diving southeast tonight and into Sunday morning.
1050 AM CDT Sat Sep 26 2020 Despite the dry low levels, have added sprinkles to account for the higher reflectivity across north central SD this morning. Otherwise, the forecast remains largely on track as we await the cold frontal passage. Weak cold advection with a secondary front will also aid in mixing, however fire weather may be slightly less of a concern thanks to a much cooler airmass, with some higher humidity behind this secondary front.
By the very end of the period a cold front will be approaching the area, thinking the moisture will still be north, so have kept the Sunday night period dry. Temperatures wise, lows will be warmer again tonight, in the lower to mid 70s. Highs tomorrow will be a few degrees warmer riding on a southerly flow.
By Sunday morning, broken to overcast cloud cover associated with the approaching cold front will be established in northeast Missouri and west-central Illinois. The cloud cover will limit high temperatures in northeast Missouri and west-central Illinois to the low to mid 70s, before the cold front moves into the area Sunday afternoon and quickly cools temperatures. The cold front will move through the forecast area Sunday afternoon and evening, driven by a mid-level trough digging into the upper and mid-Mississippi Valleys.
smoke and haze resulting from wildfires northwest of the area will steadily move south and out of the area around midnight as a cold front moves through. north winds increase during the late morning through afternoon hours behind a strong cold front. It will be much cooler compared to the past few days with high temperatures below normal in the low 60s to low 70s.
433 PM MDT Sat Sep 26 2020 Gusty northwest winds of 25 to 35 mph will continue through sunset as a cold front moves through the area. Strong winds still occurring in the wind prone areas as of 2 Pm and with a bit slower movement of a cold front have opted to extend the High Wind Warning until 6 PM. The cold front that is pushing south across the CWA is expected to clear the CWA early this evening.
604 PM MDT Sat Sep 26 2020 The High Wind Warning for the South Laramie Range, North Snowy Range Foothills, and Central Laramie Range/Southwest Platte County expired at 6 PM. Sustained northwesterly winds of 20 to 30 mph with gusts to 50 mph will diminish this evening following the passage of a cold front. Gusty northwest winds of 25 to 35 mph will continue through sunset as a cold front moves through the area. Strong winds still occurring in the wind prone areas as of 2 Pm and with a bit slower movement of a cold front have opted to extend the High Wind Warning until 6 PM. The cold front that is pushing south across the CWA is expected to clear the CWA early this evening.
/issued 207 PM EDT Sat Sep 26 2020/ Stacked ridging over the region to keep the warm and humid conditions in place through tonight as slow moving afternoon thunderstorms around inland and southern areas dissipate through the evening hours.
609 PM MDT Sat Sep 26 2020 Winds will turn north and increase this evening as a cold front approaches and begins moving across the forecast area. As the cold front moves through, visibilities with smoke and haze may decrease for a short period of time as smoke concentrations near the surface increase. Visibilities should improve again following the passage of the cold front. smoke and haze resulting from wildfires northwest of the area will steadily move south and out of the area around midnight as a cold front moves through. north winds increase during the late morning through afternoon hours behind a strong cold front. It will be much cooler compared to the past few days with high temperatures below normal in the low 60s to low 70s.
9 micrometer difference low cloud/fog imagery, as well as the night-time microphysic view indicated most of the lower altitude clouds have dissipated (for the moment) across the Tennessee Valley. A look at various water vapor imagery indicated an upper low spinning over the AR-LA-MS region. 2 um respectively) but was present at the lower 7. Low temperatures in the lower 60s look good. The upper level low will continue moving northeast through middle TN and KY Sunday morning. Showers may linger into Sunday night as a secondary trough axis pushes east behind the low/trough.
333 PM MDT Sat Sep 26 2020 An upper trough axis is moving into the Dakotas this afternoon with subsidence occurring over eastern MT to the west of the trough axis. Tonight, the trough axis will move eastward farther away from the area and take the subsidence with it. Any shower activity will then diminish Sunday evening as upper ridging builds over the Northern Rockies.
Further down the Keys, weak low-mid level flow is supporting some pulse convection near the Lower Keys this evening. The ridge axis is better defined at 500 mb as an east-west axis across the southern tip of Florida. Weak flow under the ridge will keep convection with our moist and moderately unstable air mass pulsy and short-lived. The light and variable flow may support one or two cloud line cycles on Sunday, particularly over the Lower Keys.
Tonight the Ohio Valley will sit between high pressure off the East Coast and a cold front crossing the Midwest and southern Plains. On Sunday the cold front to our west will continue its approach and will be positioned roughly from Detroit to Tulsa by the end of the day. Southerly flow will keep temperatures a few degrees warmer than normal through the short term, with lows tonight around 60 and highs tomorrow around 80. Cooler weather, along with light rain, will make up the weather through the work week. Clouds will increase from the northwest Sunday night as an upper level trof and associated surface cold front move in from the Great Lakes and mid Mississippi Valley.
Timing of cold front still on track with boundary pushing to near I-44 by late afternoon.
609 PM CDT Sat Sep 26 2020 Unseasonably warm conditions will continue overnight into Sunday ahead of an approaching cold front. The front will surge southward as an upper trough digs into northern tier of the US.
This will be along a weak trough that precedes an approaching cold front that will traverse the region Sunday. For tonight, look for increasing shower chances as the cold front approaches. Highs will be much cooler for Sunday, with highs generally in the upper 50s to lower 60s. By Mon there will be a sharp mid-CONUS trough diving down through the mid and lower Mississippi Valley, and the cool down that commenced on Sun will be more pronounced on Mon, with highs only in the low to mid 50s. A brief rebound into the 60s is possible on Tue before a reinforcement of cooler air establishes high temps in the 50s (40s Thu) for a while. Wind speeds are on the diminishing trend right now, and they should stay on the lower end until late tonight or close to Sunday morning.
As a cold front approaches late in the period, cigs should begin to decrease from the west.
528 PM MDT Sat Sep 26 2020 Gusty northwest winds of 25 to 35 mph will continue through sunset as a cold front moves through the area. Strong winds still occurring in the wind prone areas as of 2 Pm and with a bit slower movement of a cold front have opted to extend the High Wind Warning until 6 PM. The cold front that is pushing south across the CWA is expected to clear the CWA early this evening.
This will be along a weak trough that precedes an approaching cold front that will traverse the region Sunday. For tonight, look for increasing shower chances as the cold front approaches. Highs will be much cooler for Sunday, with highs generally in the upper 50s to lower 60s. By Mon there will be a sharp mid-CONUS trough diving down through the mid and lower Mississippi Valley, and the cool down that commenced on Sun will be more pronounced on Mon, with highs only in the low to mid 50s. A brief rebound into the 60s is possible on Tue before a reinforcement of cooler air establishes high temps in the 50s (40s Thu) for a while.
Intervals of shallow cumulonimbus clouds and sunshine are expected today with temps maxing out around 60, perhaps a bit warmer in the Valley. Isolated showers still remain possible tonight with winds decreasing and temps dipping into the low-mid 40s.
1145 PM MDT Sat Sep 26 2020 Winds will turn north and increase this evening as a cold front approaches and begins moving across the forecast area. As the cold front moves through, visibilities with smoke and haze may decrease for a short period of time as smoke concentrations near the surface increase. Visibilities should improve again following the passage of the cold front. smoke and haze resulting from wildfires northwest of the area will steadily move south and out of the area around midnight as a cold front moves through. north winds increase during the late morning through afternoon hours behind a strong cold front. It will be much cooler compared to the past few days with high temperatures below normal in the low 60s to low 70s.
Although relative humidity values will be higher today than yesterday, near critical fire conditions are likely southwest as strong winds combine with minimum relative humidity values in the low 30s to perhaps upper 20s. A cooler day is expected today as strong cold air advection and clouds remain in place through most of the day.