Aikyam-Lab/Synoptic-Bench huggingface dataset:
Starting further aloft, perturbation around the elongated NW-SE H500 high pressure system has developed convection along the NM/CO high terrain. High temperatures tomorrow will be much cooler with easterly flow and persistent cloud cover, went several degrees below NBM guidance with high ranging from the lower 60s in the NE combined Panhandles to mid 70s in the far SW TX Panhandle.
232 PM EDT Mon Aug 25 2025 A cold upper trough will remain anchored eastern Canada, the Great Lakes, and Northeast states this week. A series of troughs will rotate through the base of this trough and bring shower chances to the Upper Ohio River Valley, especially north of Pittsburgh. KEY MESSAGES: - A few lake effect showers north of Pittsburgh ---------------------------------------------------------------- Initial trough should be overhead this evening, followed by a weak short wave ridge after midnight. KEY MESSAGES: - Seasonably cool temperatures under upper troughing - Rain showers possible Tuesday in NW flow ---------------------------------------------------------------- Next upstream trough currently over MN arrowhead should dig into base of trough and cross forecast area tomorrow afternoon, likely enhancing diurnal convection and lake effect.
Weak surface ridging is in control of our sensible weather as seen by our light and somewhat variable winds. While this would usually point to a possible cloudline day, CIMSS MIMIC TPW notes most of the moist air is found to our north over mainland Florida associated with a slow moving cold front. Following this morning's wave of nocturnal convection, showers are clearly struggling to build under dry air in the lower to mid levels of our profile. From synopsis, a weak subtropical ridge will remain over the Keys through at least mid week. For mid to late week, an early season Canadian high pressure system is expected to traverse the eastern United States which will help to enhance the pressure gradient slightly across the Keys.
However, mid-level ridge is expected to build into the region by the middle of the work week, which will bring subsidence and dry air to the region.
North to northwesterly flow continues into mid-week with heights increasing as ridging builds in to our west. The southwesterly winds will continue into tomorrow and temps should be a bit warmer than today, from the mid 70s to the low 80s.
An upper level low pressure system is situated over eastern Ontario early this afternoon with a broad trough extending south from it across the eastern CONUS. Some weak mid level energy rotating through the trough will result in some lower end pops across our far northern areas into this evening.
Cooler temperatures thanks to these features keep conditions below average - highs in the mid 60s to mid 70s today and slightly warmer on Tuesday as surface flow shifts southerly. Expect slightly warmer Tuesday night.
- Continued cooler than normal conditions are expected through the end of the week with highs in the 70s to around 80. The mid-upper level pattern continues to be dominated by broad troughing across the eastern CONUS with amplified ridging occurring across the West Coast. This places the local area on the western periphery of an anomalously cool airmass situated across the Upper Midwest/Great Lakes region, with temperatures across eastern Nebraska and western Iowa this afternoon only in the upper 60s to mid 70s! At the surface, high pressure remains established over the local area leading to light and variable winds and an overall beautiful late summer day.
This development is being captured well by the high res model guidance today, which show a line of strong showers and thunderstorms moving across the peninsula and potentially impacting the Lake region and portions of the East Coast metro north of Alligator Alley after 3-4PM. A return to the more typical summertime pattern looks likely tomorrow as high pressure begins to nose in from the Atlantic and winds become easterly/southeasterly once again. High temperatures each day will remain elevated, reaching the low to mid 90s across much of the region each day.
High temperatures will rise into the mid to upper 90s inland and the lower 90s over the coasts with heat indices will be in the lower 100s.
1229 PM CDT Mon Aug 25 2025 Updated aviation portion for 18Z TAF issuance - Early fall temperatures are expected early this week with cooler temperatures.
111 PM CDT Mon Aug 25 2025 - Unseasonably cool high temperatures in the upper 70s to near 80 will begin to trend warmer into the lower 80s by the weekend. Upper level troughing over the eastern CONUS prevails with northwesterly flow, providing tranquil weather conditions across the FA.
Updated at 1204 PM CDT Mon Aug 25 2025 - The effects of a cold front will be felt starting today, bringing a few showers and our first taste of fall weather.
146 PM EDT Mon Aug 25 2025 A cold front will move across the area today and tonight with high pressure prevailing through the rest of the week. Early afternoon satellite imagery shows a broad upper level trough over the region, with surface observations showing temperatures in the mid to upper 80s. A convergent line is also observed at the surface just west of the I-95 corridor with southerly winds on the east side and west-northwesterly winds on the west side, which is the cold front we've been talking about the past few days. Temperatures cool into the lower 60s inland to lower 70s along the coast overnight.
127 PM EDT Mon Aug 25 2025 A cold front will work its way across the region today, and will be accompanied by scattered showers and thunderstorms.
High pressure at the surface extends from the Northern Plains south into the Tennessee Valley this morning. The upper level pattern this week will continue to feature troughing across the eastern CONUS placing the region within northwest flow. High pressure at the surface will build further into region centering directly overhead the area by midweek.
310 PM EDT Mon Aug 25 2025 A strong dome of Canadian high pressure will build tonight through mid week with near to below normal temperatures for much of the week.
757 PM EDT Mon Aug 25 2025 A cold front will move across the area today and tonight with high pressure prevailing through the rest of the week. Tonight: A few showers are possible across coastal counties early evening as a cold front approaches from the west and interacts with a moist and moderately unstable environment along the beaches and offshore. The cold front will likely shift offshore by mid evening, tracking further east and away from the coast during the night. This will favor noticeably cooler lows compared to previous nights, generally in the low-mid 60s inland to lower 70s near the coast.
706 PM CDT Mon Aug 25 2025 The main weather story this week is the anomalously amplified eastern CONUS trough and the long duration of cooler and eventually unsettled weather it will bring.
823 PM EDT Mon Aug 25 2025 A cold upper trough will remain anchored eastern Canada, the Great Lakes, and Northeast states this week. A series of troughs will rotate through the base of this trough and bring shower chances to the Upper Ohio River Valley, especially north of Pittsburgh. KEY MESSAGES: - A few lake effect showers north of Pittsburgh ---------------------------------------------------------------- Initial trough should be overhead this evening, followed by a weak short wave ridge after midnight. KEY MESSAGES: - Seasonably cool temperatures under upper troughing - Rain showers possible Tuesday in NW flow ---------------------------------------------------------------- Next upstream trough currently over MN arrowhead should dig into base of trough and cross forecast area tomorrow afternoon, likely enhancing diurnal convection and lake effect.
* Temperatures will be much cooler on Tuesday than in it has been lately. Today through Monday Thunderstorm activity has been focused mainly along the higher terrain from northeast Clark county through Lincoln County and along the Sierra Crest this afternoon.
- The majority of days will have widespread coverage of showers and storms across the higher terrain and scattered coverage across the lower elevations. The higher terrain will see storms begin in the early afternoon with 70-80 percent coverage.
748 PM EDT Mon Aug 25 2025 A noticeably cooler air mass will linger through midweek, with spotty lake enhanced rain showers at times, especially in Central New York.
930 PM EDT Mon Aug 25 2025 A strong dome of Canadian high pressure will build tonight through mid week with near to below normal temperatures for much of the week.
808 PM CDT Mon Aug 25 2025 An anomalously strong longwave trough is currently in place across the eastern half of the CONUS. At the surface, a rather strong cold front (for late August standards) has pushed through much of the local area today and is currently located across our coastal counties this afternoon.
838 PM EDT Mon Aug 25 2025 A cold front will move offshore tonight heralding cooler, drier weather under high pressure through much of the work week.
Shower activity may penetrate farther to the southeast off of the Allegheny Front and perhaps reach the Laurel Highlands and central ridge/valley region by later Tue PM. High pressure builds in for midweek and provides a break in the lake effect/enhanced clouds and passing rain showers.
Cool temperatures will persist under the longwave trough.
Temps today will be much cooler than in previous days. which will aide in keeping temps cooler. temps outside the rainfall will tend to be warmer. lows will dip down into the 50s for most areas due to the high pressure settling into the region.
Numerous outflow boundaries combined with weak helicity in the low levels of the atmosphere will continue the risk for an isolated waterspout offshore Pinellas county for the next couple of hours.
714 PM EDT Mon Aug 25 2025 High pressure arrives from the west with drier air into the end of the week. Will remain in a cyclonic flow so expect some periods of cold advection stratocumulus into Tuesday along with some high clouds from time to time, but overall a dry and cooler airmass for the area. Clouds at times and some mixing will limit it getting cooler with lows ranging from the upper 40s to around 50 in the mountains to to mid to upper 50s east. Early morning temperatures are likely to be in the lower 40s to the lower 50s with afternoon high temperatures in the mid-60s to mid-70s. Dew points will remain in the lower 40s to mid-50s and PWATs will be between 0.
551 PM CDT Mon Aug 25 2025 Updated at 546 PM CDT Mon Aug 25 2025 - The effects of a cold front will be felt starting today, bringing a few showers and our first taste of fall weather.
A weak subtropical ridge will remain over the Keys through at least mid week. For mid to late week, an early season Canadian high pressure system is expected to traverse the eastern United States which will help to enhance the pressure gradient slightly across the Keys.
819 PM EDT Mon Aug 25 2025 A cold front will move offshore tonight heralding cooler, drier weather under high pressure through much of the work week.
Cooler than normal temperatures are likely through the extended. Key Message(s): - Cool and dry tonight in the wake of a cold front. An upper trough entrenched across the Eastern CONUS pushed a cold front through the forecast area today ushering in a drier air mass. Temperatures should fall into the lower to mid 60s. Key message(s): - Drier and cooler air settles into the Southeast Tuesday will be cool and dry compared to the previous day in the wake of a cold front. Lows overnight expected to be in the low to mid 60s. Key message(s): - Cooler than normal temperatures - Rain chances return for late this week and into the weekend A reinforcing shot of dry air will push into the region mid week as a highly amplified trough moves into the eastern US.
729 PM EDT Mon Aug 25 2025 - Cooler weather persists through the week.
556 PM CDT Mon Aug 25 2025 - Unseasonably cool high temperatures in the upper 70s to near 80 will begin to trend warmer into the lower 80s by the weekend. Upper level troughing over the eastern CONUS prevails with northwesterly flow, providing tranquil weather conditions across the FA.
133 AM EDT Tue Aug 26 2025 A noticeably cooler air mass will linger through midweek, with spotty lake enhanced rain showers at times, especially in Central New York.
404 AM EDT Tue Aug 26 2025 A strong dome of Canadian high pressure will build through mid week with near to below normal temperatures for much of the week.
(Rest of tonight and Tuesday) Rather cool temperatures for late August continued across much of the eastern North American domain, as Canadian based high pressure centered over the northern Great Plains builds to the SE. Until an area of high altitude clouds overspread the Tennessee Valley earlier in the afternoon, high temperatures only rose into the upper 70s to lower 80s; most definitely cooler than a usual high around 91 degrees. Whether it rains nor not, low temperatures areawide will chill into the upper 50s southern middle Tennessee and NE Alabama to the lower 60s elsewhere - definitely colder than normal lows in the upper 60s. With more clouds than sun and lower thicknesses, high temperatures accordingly will be a bit cooler, from the mid 70s in the more elevated terrain to lower 80s over NW Alabama.
150 AM EDT Tue Aug 26 2025 High pressure remains in control through much of the week. Cooler and drier airmass will keep below normal temperatures and lower humidity around as a result. No need to give up on the low temp fcst, though. The high cloudiness will help to prevent the usual fog from developing in places. As of 123 AM EDT Tuesday: Broad cyclonic flow aloft and anomalously cooler thickness will remain in place through the forecast period.
Above the surface into the low to mid levels of the atmosphere, wind flow still will maintain a west-southwest direction and thus steer afternoon convection towards the east coast metro areas. High temperatures today and tomorrow are expected in the low to mid 90s for most areas, with isolated locations in the interior reaching the upper 90s. Heat index values are expected in the low to mid 100s, but are expected to stay below advisory criteria.
Afterwards, a drier pattern will return where only isolated activity will remain across the higher terrain.
An open trough centered just off the California coast continues to pump moisture into the forecast area. High pressure remains over the Pacific Northwest and will bring hot temperatures to the area through Wednesday. The high will move eastward by Wednesday as an upper low moves into the northwest.
Clouds skies hanging around across northwest Minnesota will help to prevent any areas of frost tonight but some may still dip into the low 40s. North to northwesterly flow continues into mid-week with heights increasing as ridging builds in to our west. The southwesterly winds will continue into tomorrow and temps should be a bit warmer than today, from the mid 70s to the low 80s.
227 AM EDT Tue Aug 26 2025 High pressure will prevail through mid to late week. A weak area of low pressure could then pass nearby later this week into the first half of the weekend. A weak cold front will slide east of the nearshore coastal waters early this morning. In the wake of the cold front, high pressure centered near the mid-Mississippi valley will gradually build east across the forecast area. A few of the typically cooler inland spots could even fall into the lower 60s.
- Cooler temperatures, increased humidity, and measurable rainfall is expected for most areas this week. A low pressure system depicted over northern Nevada at 700mb will move into southwest Idaho late this afternoon.
The highest rain chances will be in the morning. In addition, there is weak to moderate synoptic lift with the trough. High temperatures will be in the lower and mid-70s. Low temperatures will be in the lower and mid-50s. The weekend average temperature is currently in the lower to mid-60s.
1235 AM CDT Tue Aug 26 2025 The main weather story this week is the anomalously amplified eastern CONUS trough and the long duration of cooler and eventually unsettled weather it will bring.
1258 AM EDT Tue Aug 26 2025 High pressure will prevail through mid to late week. A weak area of low pressure could then pass nearby later this week into the first half of the weekend. This will favor noticeably cooler lows compared to previous nights, generally in the low- mid 60s inland to lower 70s near the coast. Dry conditions and cooler temperatures look to prevail across the region Tuesday and Wednesday in the wake of an advancing cold front.
112 AM EDT Tue Aug 26 2025 - Cooler weather persists through the week.
110 AM EDT Tue Aug 26 2025 A very weak reinforcing cold front crosses the area late today.
Rest of forecast largely dry with slightly warmer at times but still pleasant temperatures continuing. Upper level pattern continues to feature a closed low over eastern Canada with troughing in the eastern U. and ridging over the western U. As such, main forecast concerns in the short term are temperatures with bias corrected guidance still 3-5 degrees or more warmer than raw model guidance due to recent warmer temperatures skewing the bias corrected data.
Cloud cover will remain through most of the day as NW flow along the base of the trough ushers additional moisture into the atmospheric column. Should cloud cover take longer to erode, temps in the low to mid 70s may prevail as opposed to high 70s.
We are going to see a very widespread range of temperatures today, from the mid 70s across our northern zones where rain cooled air and cloud cover will be in place to the lower and mid 90s across our southern zones where more sunshine will prevail today. The cloud shield could reach down towards the I-20 corridor, which could keep temperatures a little cooler than expected, but it will depend on how far south that can make it. At the same time, a warm front will begin lifting into the area from central Texas and will become the source for two things.
1223 AM CDT Tue Aug 26 2025 - Staying cooler than normal this week but gradually warming from the middle to upper 60s today and into the 70s for most by Wednesday.
211 AM EDT Tue Aug 26 2025 A seasonably strong trough will persist to our north and bring scattered showers Tuesday afternoon.
(Today through Wednesday) Cooler and drier weather is anticipated through the next couple of days.
- The majority of days will have widespread coverage of showers and storms across the higher terrain and scattered coverage across the lower elevations.
We have lowered PoPs Tuesday to mostly show 30-50% chances across the lower deserts to 50-70% over the eastern Arizona higher terrain. At the same time, the Pacific trough will nudge into at least western portions of our region leading to lower heights and turning our flow out of the southwest.
Deep troughing over the Midwestern US will continue to promote unseasonably cool conditions through the forecast period.
334 AM CDT Tue Aug 26 2025 - Cooler, below normal temperatures continue through the week - Patchy fog this morning - Slight chances for showers and thunderstorms through the week Low level moisture and light wind under 5 mph will lead to fog development this morning across southwest and western Nebraska. Northwesterly flow will continue to keep temperatures cooler in the upper 70s to low 80s which is still around 5 to 10 degrees below normal across southwest Nebraska and the southern Sandhills. Monsoonal moisture will advect into the High Plains and this combined with weak disturbances through the week will allow slight chances for showers and thunderstorms through the end of the week. Cooler temperatures will continue through the weekend with highs only in the 70s to low 80s.
102 AM EDT Tue Aug 26 2025 A noticeably cooler air mass will linger through midweek, with spotty lake enhanced rain showers at times, especially in Central New York.
- A cold front will bring cooler temperatures and precipitation chances Labor Day weekend (Today and tonight) Current radar imagery shows the cold front has mostly cleared the region. Temperatures will be cooler than normal today.
A little taste of fall this week with cooler than normal temperatures and dry weather. Discussion: Troughing situated over the eastern U. Date Chattanooga Knoxville Tri-Cities Oak Ridge 08-27 53(1942) 50(1879) 46(1945) 54(1966) Upper troughing then loses its grip as higher heights move in.
Breaks in the cloud deck across north central Nebraska has allowed for temperatures to climb into the lower 70s. Further south across the Sandhills and southwest Nebraska, persistent low cloudiness is holding temperatures in the lower to middle 60s. This activity will persist through sunrise across north central Nebraska, before waning as the low level jet veers.
1122 PM CDT Mon Aug 25 2025 - Unseasonably cool high temperatures in the upper 70s to near 80 will begin to trend warmer into the lower 80s by the weekend. Upper level troughing over the eastern CONUS prevails with northwesterly flow, providing tranquil weather conditions across the FA.
- For late this week and into the weekend, generally quiet weather is expected with high temperatures trending a bit below normal in the lower to mid 70s. For tonight with cool high pressure in place, frost will once again be a concern. A cold front will move across the region Wednesday afternoon and Wednesday night, bringing rain showers and perhaps a few thunderstorms back into the forecast. Thereafter, northeast Minnesota and northwest Wisconsin will remain between an upper level low across the northeast US and eastern Canada, and a low amplitude ridge across the west. We could see some patchy fog develop just before daybreak with INL/HIB having the highest chances of being impacted.
Thunderstorms are forecast to develop over the higher terrain and slowly drift northward through the afternoon and evening. While precipitable water remains in the 99th percentile for this time of year, models diverge significantly on Wednesday, the NAM/4km NAM develops a deeper trough over the area than the rest of the models and significantly more precipitation than the rest of the model ensembles. This lines up with the EC and GFS that are much weaker with the upper level trough. As of 2 PM MDT, shower activity has increased along the eastern edge of the weak upper-level trough just west of the forecast area. The main concern will be excessive rainfall, particularly on Wednesday when instability overlaps with a slow-moving upper trough.
213 AM MDT Tue Aug 26 2025 KEY MESSAGES: - Dry weather with warmer temperatures continue through Wednesday.
250 AM EDT Tue Aug 26 2025 Cooler conditions and additional chances for diurnally driven showers will continue through much of the week as an upper level trough gradually shifts eastward across the region.
Unseasonably low temperatures will continue through the short term, with highs in the lower to mid 70s and lows in the mid 40s to lower 50s.
316 AM CDT Tue Aug 26 2025 - Another day with isolated showers and sprinkles possible - Better chances for rain arrive Wednesday as a cold front drops in from the north.
At the surface, this trough will slowly pull the tail end of a long cold front into the northern Florida Peninsula today, then the frontal boundary will stall out across central Florida on Wednesday and linger through the rest of the week.
111 AM CDT Tue Aug 26 2025 The main weather story this week is the anomalously amplified eastern CONUS trough and the long duration of cooler and eventually unsettled weather it will bring.
724 AM EDT Tue Aug 26 2025 A seasonably strong trough will persist to our north and bring scattered showers Tuesday afternoon.
634 AM CDT Tue Aug 26 2025 The main weather story this week is the anomalously amplified eastern CONUS trough and the long duration of cooler and eventually unsettled weather it will bring.