Aikyam-Lab/Synoptic-Bench huggingface dataset:
Strong Canadian high pressure builds south over the Great Lakes region through the middle of the week. The high will shift towards the Northeast region by the end of the week. Quiet weather continues as high pressure remains overhead through the forecast period. Strong Canadian high pressure will move overhead early this week leading to continued dry weather. Warm on Tuesday with highs in the upper 70s to lower 80s before a cooler airmass enters the region.
Otherwise we remain primarily under the influence of the upper ridge that extends from south Texas to the Great Lakes region and any unsettled weather remains well to the west. (Monday through Tuesday night) An upper low located over the Wickenburg AZ area early this afternoon is forecast to weaken and then lift northeast toward the central High Plains. High temperatures Monday will be slightly lower than today with the cloudiness and the lower heights/thicknesses over the area as the upper ridge gets shifted east, but will still be above average for this time of year.
- Widespread rain Tuesday evolves into an unsettled and progressively cooler pattern for the rest of the week. The pattern change commences today as a Pacific trough to the west drives southerly flow over western Montana and north central Idaho.
Afternoon RAP analysis and GOES satellite imagery reveal barely a cloud across the entire central CONUS underneath a very dry ridge. More of the same is expected tomorrow (Monday) with daytime temps reaching the upper 70s to low 80s as the ridge axis shifts overhead. Breezy E to NE flow behind the front will keep Tuesday in the low to mid 70s. Upper level ridging persists through much of the midweek, keeping above normal temps and little to no precip chances in the forecast until this coming weekend. VFR conditions continue as high pressure ridging persists over the region.
Air mass is dry enough to preclude much in the way of frost development in areas that do fall into the 30s and do not expect temperatures to fall to freezing in more than a very isolated way. Pattern Synopsis: A blocky pattern remains over the region for most of the week, with broad upper-level ridging remaining in place across most of the lower 48 states. However, a back door cold front is forecast to slip south across the area Monday night into Tuesday bringing cooler, but still mostly above normal temperatures to the area for midweek. The ridge axis shifts to the eastern portion of the country by late in the week with stronger energy pushing in from the Pacific coast.
- Much cooler temperatures for Tuesday. A slow moving cold front will approach the region today. Southwest flow aloft continues with upper low churning off Seattle/Vancouver coast.
229 AM EDT Mon Sep 29 2025 High pressure slides south of the region today and a cold front will cross the area tonight.
Much warmer weather is on the way as upper level ridging continues to strengthen over the Midwest & low-level southerly flow continues to increase, especially beginning midweek. The really warm temperatures today look to be limited to west- central & southwest Minnesota, where a bit of downsloping winds off of the Buffalo Ridge could boost afternoon temperatures near 90 degrees. Elsewhere temperatures will still be quite warm in the low to mid 80s. Precipitation chances will continue to be negligible with the strong ridging overhead, so we'll likely have to wait until at least this weekend when the jet amplifies over the US-Canada border & flattens out the ridge.
* Cooler, unsettled weather prevails through much of the week, and possibly over the weekend. Elongated low pressure in the eastern Pacific continues to approach the western states per latest moisture-channel imagery, eventually pivoting through the region later today. Gusts of 30-40 mph will be common across valleys while Tahoe Basin ridges gust to 60-80 mph in the late afternoon into the overnight hours. Otherwise, temperatures will be noticeably cooler today with daytime highs only reaching the 60s and 70s.
637 AM EDT Mon Sep 29 2025 High pressure will guarantee fair dry weather through the entire week and this weekend. A dry cold front will bring a more seasonable airmass around midweek with some risk for nocturnal frost at the higher elevations. A moisture starved cold front drops through the region Tuesday, with a cooler airmass advecting into the region.
503 AM CDT Mon Sep 29 2025 - Breezy winds return this afternoon - Dry and warm conditions through the workweek - Small probability (10-20%) of rain in the later part of the weekend 07Z upper air analysis shows a large anticyclone centered near the Great Lakes with a large ridge over the eastern CONUS and a nearly stationary open wave trough approaching the four corners region. At the surface a weak lee side trough is located in eastern Colorado with a strong high pressure centered in southern Illinois. Today as the upper trough enters into Colorado and New Mexico more upper level Pacific moisture will stream into western Kansas through the day and we should see a thicker mid and high level cloud deck.
614 AM CDT Mon Sep 29 2025 - High pressure at the surface and aloft will keep a dry air mass in place through midweek with no chance for rain, very warm days, and mild nights.
Although all the showers/thunderstorms have ended across the state, the upper level low still remains positioned near the NE portion of Arizona. This system will continue to pull northward throughout the day, leaving behind warmer temperatures and drier conditions. By Tuesday, a broad trough will take over much of the West Coast, but should only bring slightly elevated southwest winds and maybe a light showers towards the Kaibab Plateau. This trough will pull northward by the middle of the week, putting Arizona back into a zonal flow. This zonal flow doesn't look to last long, due to high pressure quickly building over the Southwest.
556 AM CDT Mon Sep 29 2025 (Today) High pressure extends from the Northeast, through the OH Valley, into the Midwest, and down into the Southeast. Otherwise, today will be warm with highs in the lower 80s in NE AL and the mid to upper 80s elsewhere, which is ~5 degrees higher than normal.
1021 AM EDT Mon Sep 29 2025 High pressure will guarantee fair dry weather through the entire week and into the coming weekend. A dry cold front will bring a more seasonable airmass around midweek with some risk for nocturnal frost at the higher elevations. A moisture starved cold front drops through the region Tuesday, with a cooler airmass advecting into the region.
- Hottest day of the week today, trending cooler thereafter. Brusda /Issued 114 AM MDT Mon Sep 29 2025/ - Meteorological Overview: Upper level ridging ahead of a Pacific trough is beginning to shift eastward, away from the region early this morning. A leading wave ejecting out of the main troughing setting up just off the Pacific NW coastline today will result in scattered showers and thunderstorms this afternoon into tonight, mostly across Southwest Montana and along the Continental Divide. Additional rounds of showers and thunderstorms (Mainly in the late afternoon and evening) look to develop through much of the rest of the week as weak disturbances continue to eject from the Pacific NW troughing.
500 mb trough will continue to push east gradually into Washington state and British Columbia the next few days with 500 mb heights building gradually northward into Manitoba and NW Ontario.
/Issued 1209 AM CDT Mon Sep 29 2025/ /Overnight through Monday Night/ A period of quiet weather will continue to start out the work week but water vapor imagery shows an upstream trough that will eventually spread into West Texas later today. This upper trough will be accompanied by fairly strong mid level forcing for ascent as it overspreads North Texas this evening.
749 AM EDT Mon Sep 29 2025 Dry weather is expected through the week with high pressure in control.
732 AM EDT Mon Sep 29 2025 Fair weather will continue under high pressure. A cooler period will begin tomorrow behind another dry cold front, leading to seasonable temperatures and chances for frost midweek. In central Canada there is evidence of a moisture-starved cold front, which will be steered southward through tonight. On its western flank we'll see a wind shift overnight and the anticipated cooler air mass filter in tomorrow. Humidity will remain low, especially east of the high peaks of the Adirondacks and higher terrain in central and eastern Vermont, dropping as low as the 25 to 35% range this afternoon. Tomorrow, cooler conditions with highs averaging 7 to 12 degrees lower than today will lead to humidity likely not dropping as low as today.
643 AM EDT Mon Sep 29 2025 High pressure will lead to dry and mild conditions through the week. High pressure over the Great Lakes and Ohio Valley weakens slightly today as pressures decrease to the southeast. Tonight, a stronger high pressure descending through southeast Canada begins to compress the pressure gradient over the Ohio Valley. Expect a noticeable northeast wind Tuesday afternoon as the strong high pressure to north continues to move closer to the region. This northeast wind will bring in air originating from a cooler region, allowing for subtle drop in the afternoon high temperatures, however, it will still be very warm.
Water vapor imagery this morning showed upper trof lifting across the 4-corners with mostly clear skies across the area. Thus warmer high temperatures as the work week closes with highs up to 5 degrees warmer than normal.
Drier and cooler conditions are anticipated by midweek. Overnight low temperatures will trend 5 degrees above average with elevated dew points and no radiational cooler with lingering clouds. The upper level trough axis is forecast to shift atop our area, yielding upper level convergence for much of the day. The clouds and low-level northeasterly flow should maintain cooler temps across the area, with highs in the mid to upper 70s.
- Cooler, more seasonable conditions, and 20 to 30 percent rain chances return at the end of the week. Most of the area looks to be in a warm thermal ridge today, which tends to be capped.
811 AM MDT Mon Sep 29 2025 - Hottest day of the week today, trending cooler thereafter. Brusda /Issued 429 AM MDT Mon Sep 29 2025/ - Meteorological Overview: Upper level ridging ahead of a Pacific trough is beginning to shift eastward, away from the region early this morning. A leading wave ejecting out of the main troughing setting up just off the Pacific NW coastline today will result in scattered showers and thunderstorms this afternoon into tonight, mostly across Southwest Montana and along the Continental Divide. Additional rounds of showers and thunderstorms (Mainly in the late afternoon and evening) look to develop through much of the rest of the week as weak disturbances continue to eject from the Pacific NW troughing.
640 AM EDT Mon Sep 29 2025 Strong high pressure provides dry weather through much of the week. Afterwards, expect a mostly sunny, dry and unseasonably warm day, as a large high pressure system builds across the Great Lakes, the Ohio Valley, West Virginia and the northeast U. The mountains will be cooler, with highs ranging from the mid 60s to mid 70s. Its only impact on our region will be the high level cloud cover mentioned above.
- As the ridge breaks down, chances for precipitation begin by Tuesday night into the second half of the week. WEATHER PATTERN OVERVIEW: The upper ridge will remain over the northern plains through at least Tuesday. Temperatures will be above average through Tuesday as the upper low of the desert southwest opens up and lifts north. With the weakening of this low and the movement onshore of the east Pacific trough, moisture will begin to increase across the region with southwest flow aloft.
644 AM EDT Mon Sep 29 2025 High pressure will produce a prolonged period of dry weather across the area through the entire week.
These probabilities will be mainly north of Tulare County, and the highest chances in Mariposa County and Yosemite National Park. This is due to an incoming trough from the Pacific, which will bring in enough energy along the Sierra Nevada to uplift the remaining moisture into becoming thunderstorm cells.
With an upper level ridge remaining firmly in place through much of the week, unseasonably warm and dry conditions are expected to prevail.
Meanwhile, moderate to fresh northwest to north breezes are observed along our offshore observation stations with the higher magnitudes unsurprisingly found in the northeast portion of our area closer to Imelda. High pressure over the Eastern Seaboard will slowly slide eastward into the western North Atlantic, with mainly gentle northwesterly breezes eventually veering to the northeast to east for the middle to latter part of the work week. While a stray shower cannot be ruled out, the low likelihood of formation will leave mention out of either TAF for now.
Increased mid-level cloud cover will overspread the area from west to east, keeping highs today slightly cooler or similar to yesterday's temperatures. Highs will be warmer tomorrow reaching into the mid-90s for many locations in the coastal plains and along the I-35 corridor with lows back into the 60s for Tuesday night.
220 PM EDT Mon Sep 29 2025 A cold front will pass through tomorrow completely dry and cloudless, but it will drop temperatures by around ten degrees. The cooler airmass will persist through mid-week, and patchy frost is expected in a lot of places overnight. High pressure builds down from the north Tuesday and Tuesday night, bringing with it a cooler and drier airmass. Highs will be around ten degrees cooler tomorrow due to the front passing through. While temperatures will drop into the 30s and 40s most places tomorrow night, continuing wind from the advection and some possible cloud cover should prevent much frost formation, even in areas that fall to around freezing.
* Cooler, unsettled weather prevails through much of the week, and possibly over the weekend. The highest wind gusts will be found along the OR border and in northern Washoe county.
(Rest of Today and Tonight) The Tennessee Valley sits underneath an upper level trough which is in between high pressure over the southern Plains and two tropical cyclones over the Atlantic.
An upper level trough moving into west Texas is responsible for this increased cloud cover. With the lower heights over the area and cloud cover, temperatures are cooler today than they have been the past couple days. The upper level trough will continue moving slowly to the northeast across the area with the trough axis moving northeast of the area by later tonight/early Tuesday.
High temperatures ranging in the low to mid 80s. A stout mid to upper level ridge remains over most of the central U. At the surface, high pressure prevails over the northeastern U. For today, as the mid to upper level ridge continues to influence the area, highs today will remain in the mid 80s. Increased cloud coverage slightly impeding the effects of diurnal heating could yield high temperatures closer to the low 80s mainly for northeastern KS and northwestern MO. As we enter the mid-week, a stout mid to upper level low nearing the Pacific Northwest will help in nudging the whole pattern to the east.
The gradual loss of diurnally driven instability will cause storms to abate late this evening, but we'll keep some clouds around through most of the night, particularly across Kansas where the warm conveyor east of the trough axis will maintain broad isentropic upglide.
(This evening through Tuesday) A well defined short wave trough on water vapor imagery was passing overhead early this afternoon bringing weak large scale ascent to the region. The trough axis and subsidence will sweep into the area later this afternoon ending what little precipitation chances we already have. This lift was acting upon a slug of mid-level moisture surging overhead in the meridional flow ahead of the trough axis. Low level easterly upslope flow will likely generate showers and thunderstorms on the higher terrain of eastern New Mexico this afternoon. Short wave ridging in the wake of the trough will bring rising heights and warming temperatures for Tuesday back above seasonal averages.
(This evening through Tuesday night) Today, PoPs have been expanded across the FA; however, they remain on the lower end (10%) due to our lack of confidence in coverage and minimal QPF. Tomorrow, high temperatures should be slightly warmer across the CWA.
- Warmer temperatures and dry weather conditions return Tuesday through the upcoming weekend. (This afternoon through Tuesday night) Upper level trough continues to swing through the area through tonight and ejects to the east over the course of Tuesday. Upper level ridge strengthens and moves in from northern Mexico. The low desert along the Rio Grande sees temperatures jump into the low to mid 90s. Rain chances fall towards zero as the aforementioned ridge moves overhead.
220 PM EDT Mon Sep 29 2025 - Much above normal temperatures to continue on Tuesday with highs in the low to mid 80s.
- Much cooler temperatures for Tuesday. There is a bigger threat of thunder before midnight, which lends some credence toward the higher end amounts. 10", but the overall risk is on the low end of things. A slow moving cold front will approach the region today. Southwest flow aloft continues with upper low churning off Seattle/Vancouver coast.
Drier and cooler conditions are anticipated by midweek. Overnight low temperatures will trend 5 degrees above average with elevated dew points and no radiational cooler with lingering clouds.
350 PM EDT Mon Sep 29 2025 A large area of high pressure remains over the northeast and mid Atlantic through next Monday. Aside from this, only a dry cold front passage is expected this Tuesday into Tuesday night. High pressure will be in place with high/thin clouds continuing to stream in from the south. However, still blended in cooler MAV/MET MOS for low temperatures over the northernmost zones as this would be the area where the cloud cover probably isn't as thick. Upper ridging east of the Mississippi River Valley and troughing across eastern Canada will allow a cold front to drop down across the area Tuesday into Tuesday night with a cooler airmass to follow.
159 PM EDT Mon Sep 29 2025 High pressure builds south from eastern Canada through much of the week. A strong cold front will track across the area Tuesday night bringing cooler and drier weather for the middle and latter part of this week. Overcast skies will keep temps mild overnight as lows settle in the low to mid 60s. The weak high pressure over the northern Mid-Atlantic to Northeast is forecast to dissipate Tuesday, then a stronger Canadian high builds in from Ontario through mid week. This high will push south any leftover tropical moisture in the area from T. Additionally, this high helps protect the area from Imelda and Hurricane Humberto as both move out to sea by mid week. A cold front moves through Tuesday night, bringing a much drier and cooler airmass to the area.
116 PM EDT Mon Sep 29 2025 High pressure to the north will combine with the circulation around Tropical Storm Imelda to bring a cool and moist northeast flow to the region through late Tuesday.
- Cooler, more seasonable conditions, and 20 to 40 percent rain chances return at the end of the week. This could bring some elevated fire weather concerns, although the lower RH values are more west of the higher winds.
We have another warm and sunny day in southern Missouri as high pressure continues to sit over us through the next couple of days as we stay in this blocking pattern.
Depending on cloud cover, sub-freezing mornings possible late week. Much of western Montana and Lemhi County are warming up into the 70s, on their way to the low 80s. This is likely near the surface cold front boundary that is expected to shift eastwards with time later today. High resolution models depict the higher probabilities for 35 to 45 mph winds extending from the Bitterroot Valley north and east this afternoon into the evening hours.
142 PM EDT Mon Sep 29 2025 A cold front will cross the area tonight.
However, since lows tonight will be a few degrees warmer, the chance of development and its coverage (if any) will be lower than this morning. Otherwise with mid and low-level ridging still centered overhead, tomorrow's forecast will be very similar to today's with highs near 90 degrees and dry conditions. Though ridging at all levels will slide east from mid to late week, its influence will still hold strong in the Mid-Mississippi Valley. Despite an expansive upper level trough dipping into the region, a sub-optimal path of the best forcing and minimal if any moisture advection keeps rain chances at bay. If the low-level ridge is able to slide east enough to unlock Gulf moisture for us this may change, but as of this forecast that does not look like the likely scenario.
- Increased northeast winds on Lake Superior tomorrow will lead to cooler by the lake conditions.
1226 PM EDT Mon Sep 29 2025 High pressure will result in a prolonged period of dry weather across the area through the entire week.
- As the ridge breaks down, chances for precipitation begin by tomorrow night into the second half of the week. WEATHER PATTERN OVERVIEW: The upper ridge will remain over the northern plains through tomorrow. Temperatures will slowly trend downward this week as a trough from the southwest moves in followed by a trough coming in from the northwest this weekend.
Further east, temperatures are in the low to mid 80s. Another change from the past few days is that Tds have climbed into the low 60s thanks to the return of southerly flow. This increase in moisture coupled with a weak wave embedded in the ridge could lead to a few sprinkles early tomorrow morning. Forecast soundings are still fairly dry in the low levels, so anything that does fall will be very light.
117 PM EDT Mon Sep 29 2025 Strong high pressure provides dry weather through much of the week. With high pressure at the surface and aloft the area is widely supported by fair weather and sunny skies although the cirrus shield from Tropical Storm Imelda is invading the area from east to west across much of West Virginia. During this period high pressure will dominate as an impressive Omega Block pattern moves in directly overhead of our region.
Persistent ridging aloft lingers over the Midwest and MS Valley. Temperatures will continue to settle into the mid/upper 50s early this morning, with warmer spots near 60 F. Mid and upper level ridging will still be anchored over the Midwest and MS Valley on Tuesday. The ridge aloft then slowly builds east across the eastern CONUS during mid to late week. Highs in the low to mid 80s will be common, with morning lows in the low to mid 50s. The weekend also looks beautiful with high pressure lingering near the East Coast. A cold front may push southeast through portions of the Plains and Upper Midwest, but will not approach the forecast area.
1154 AM EDT Mon Sep 29 2025 Strong high pressure provides dry weather through much of the week. With high pressure at the surface and aloft the area is widely supported by fair weather and sunny skies although the cirrus shield from Tropical Storm Imelda is invading the area from east to west across much of West Virginia. During this period high pressure will dominate as an impressive Omega Block pattern moves in directly overhead of our region.
200 PM EDT Mon Sep 29 2025 High pressure to the north will combine with the circulation around Tropical Storm Imelda to bring a cool and moist northeast flow to the region into Tuesday.