Aikyam-Lab/Synoptic-Bench huggingface dataset:
Cooler interior temperatures expected following a weak frontal boundary this morning. A weak cold front moved through the region this morning, bringing high cloud cover and some light drizzle to the north coast. Temperatures in the interior expected to be cooler today, with highs in the upper 70's and low 80s. An upper trough will extend into NorCal and remain fixed over the area through late week, bringing a daily possibility for thunderstorm development across interior Del Norte, Humboldt and eastern Trinity county. Mid-level moisture and cooler upper temperatures show greatest thunder potential beginning Tuesday afternoon - hi-res models show convective initiation over Siskiyou potentially drifting west into eastern Humboldt and Trinity, but confidence is still low on coverage.
Beginning mid-week, ensembles show weak high pressure building over Southeast Idaho through late week as a closed low develops along the northern CA coast. By this time, 500mb ensemble clusters start to differ a bit regarding how long the upper low to our west will influence our weather. We expect areas to meet critical criteria at times during the day today, but humidity will trend higher as moisture increases courtesy of the incoming trough.
- Cooler temperatures and continued unsettled weather conditions will continue into the midweek. - Warm and dry weather will return late in the week or this weekend as upper ridging once again builds across the region. WEATHER PATTERN OVERVIEW: Southwest flow this afternoon is in place ahead of an upper trough over the Pacific Northwest. A theta-e ridge is building again over eastern Montana which should help the scattered showers over northern Wyoming to continue building as they move northeast. An upper trough over the Pacific NW will keep the SW flow aloft over the CWA again tomorrow, but with cooler temps, severe thunderstorms look to be mainly to our south.
The storms today are certainly focused in the lower levels, below 20,000 ft and are efficient rainfall producers. Showers and thunderstorms should diminish this evening but as a weak 700- 500mb trough approaches tonight through Tuesday, we could see some lingering shower activity through the overnight.
103 PM EDT Mon Jul 21 2025 High pressure and a drier airmass will build into the region tonight into Tuesday. A few showers will linger across our far southwest through this afternoon in association with the remnant cold front. A broad h5 ridge over the southeastern third of the country will be shunted to the south Thurs night in response to weak s/w energy crossing the Great Lakes region.
Precipitation associated with the a cold front is currently ongoing in eastern Oregon. Surface winds: SW-NW 5-15 kt with gusts to 30 kt with cold front, mainly in the afternoon. A 15% chance of light rain after 21Z due to slow-moving cold front.
(Tonight) Storms are currently building along a thetaE ridge throughout middle Tennessee and will continue to work southward through the evening hours, moving into southern middle Tennessee and northeastern AL around 00-02Z. A Heat Advisory remains in effect overnight as low temperatures drop into the low to mid 70s- not providing much relief from the daytime highs/heat indices.
A closed upper-level low pressure system is moving over the Pacific Northwest this morning. While the primary band of more persistent rain associated with the system is moving northeast over Wallowa County, a secondary region of showers is ongoing near the center of the low over south-central WA and far north-central OR. As the low tracks northeast overnight, anticipating partially clearing skies with mostly light winds of 10 kts or less.
On Tuesday, the mid/upper ridge will be building across the region, and the weak backdoor front appears to be to our south. A northerly flow through the low and mid levels and slightly lower surface dewpoints will mean less instability tomorrow afternoon. Convection should mainly be focused along the mountains and SW NC, where models show a weak inverted trough developing. High pressure aloft will lower rain chances through mid week. Rain chances increase late in the week as the upper ridge weakens. Discussion: The heat that was expected under the large high pressure ridge does not appear to be quite as impactful as previously expected.
25" or more is highly probable Polson and northward, the highest amounts will depend on being under a stronger core and orographic uplift of higher terrain. At least 1 model suggests the highest terrain of the Purcell, Salish, and Cabinet Mountains could receive rainfall rates of 3/4 to 1" per hour.
High pressure is currently in place over Deep South Texas and seasonably hot weather with mostly sunny to partly cloudy skies is expected to continue through the remainder of the week.
Should the warm front lift through the state, heat index values of 100-110 may occur by the afternoon.
High pressure near James Bay is producing a light northeast wind flow today, However, as the high drifts east tomorrow, a southerly flow will develop at the surface.
Issued by National Weather Service Albuquerque NM 109 PM CDT Mon Jul 21 2025 (Tonight through Tuesday night) Model agreement continues to see an upper-level high pressure situate itself to our southeast over Florida with the western extend of the high just reaching into the Panhandles. This positioning of the high keeps us in a unique situation where we remain stagnate enough at the upper and mid levels to allow us to warm, but keep enough of a flow at the lower levels to keep moisture present from the gulf.
1224 PM CDT Mon Jul 21 2025 Upper ridging dominates the forecast to start the week allowing for hot temperatures and generously isolated to scattered shower and storm chances through Tuesday, best coverage east of the I-65 corridor. Thanks to mid level dry air rotating around the ridge into the forecast area, we should be able to mix out afternoon dewpoints into the lower to middle 70's for most locations.
/NEW/ /Monday through Tuesday Night/ Another warm day is in store for North and Central Texas as we remain on the western periphery of a lower Mississippi River Valley ridge.
* Cooler than normal temperatures will continue through the end of the week.
An Atlantic ridge has been nudged southward across South Florida due to troughing taking shape along the Atlantic Coast. As a result, convective activity near the island chain was relegated primarily to a round of early afternoon cloud line buildup in the Lower and Middle Keys. Winds in the Keys will remain light out of the east to southeast through the overnight period due to the nearby Atlantic ridge. Overnight lows will range in the lower to mid 80s with dew points remaining in the mid 70s. Troughing that setup along the Atlantic Coast has nudged an Atlantic ridge southward into South Florida and the Keys.
822 PM EDT Mon Jul 21 2025 Lower rain chances and lower humidity are expected through the middle of the week as a strong area of Canadian high pressure builds to the north. This activity is in association with a cold frontal boundary that continues to sag south across southwest and southeast Virginia. Urban areas will be a touch warmer with lows just under 70 degrees. Canadian high pressure will dominate across the region through mid week.
Thunderstorms with heavy rain and small hail developed in eastern Oregon this afternoon and early evening behind a cold front clearly evident on satellite imagery in western Idaho. The cold front and thunderstorms were due to an upper trough over the northwest US that will stretch NE-SW and weaken overnight and Tuesday. Showers will decrease tonight, and fewer showers and afternoon thunderstorms will re-develop Tuesday afternoon, and those mainly over the central Idaho mountains and southern mountains near the dissipating cold front.
Will lighten up by the evening hours as the low progresses east. An anomalously deep, closed upper-level low centered over the OR/WA border will continue to drive active, cooler-than-normal weather through Tuesday. Partial clearing across the Blue Mountains, coupled with daytime heating, steepening lapse rates beneath the upper low, and orographic lift has facilitated isolated showers and thunderstorms early this afternoon over the Blue Mountains and the east slopes of the Washington Cascades. Elsewhere, NBM probabilities paint lower chances of showers (20-50%) and thunderstorms (10-25%) for the Blue Mountain foothills, portions of central Oregon, and the lower Columbia Basin. Ensemble and deterministic NWP guidance are in excellent agreement that the closed low will transition to an open wave as it departs to the northeast overnight through Tuesday.
- A warmer, drier airmass gradually moves in for the latter half of the week. A digging trough out west, will tighten the upper level gradient, thereby continuing a steady supply of moisture along the well defined monsoonal plume. Dry boundary layers are expected to persist in the lower valleys Tuesday and will likely abet gusty outflow winds again.
/Issued 1228 PM CDT Mon Jul 21 2025/ /Monday through Tuesday Night/ Another warm day is in store for North and Central Texas as we remain on the western periphery of a lower Mississippi River Valley ridge.
Thanks to the higher rain chances there should be more clouds which will help keep high temperatures in the upper 80s along the coast to lower 90s inland, with heat indices mostly between 100 and 105.
- Heat index values will top out in the 100 to 110 range Tuesday over much of the area, with slightly lower values over the higher elevations (Leola Hills and Prairie Coteau). A persistent area of low pressure over western South Dakota will continue to bring in rounds of showers and thunderstorms through Tuesday. CAMS continue to show the highest chance across ND, with some movement over northern portions of SD/west central MN closer to daybreak Tuesday.
The WPC 12Z surface analysis shows a cold front has drifted south of the area, into central West Virginia.
743 PM EDT Mon Jul 21 2025 High pressure and a drier airmass will build into the region tonight into Tuesday. A few showers will linger across our far southwest through this afternoon in association with the remnant cold front. A broad h5 ridge over the southeastern third of the country will be shunted to the south Thurs night in response to weak s/w energy crossing the Great Lakes region.
533 PM CDT Mon Jul 21 2025 High pressure is currently in place over Deep South Texas and seasonably hot weather with mostly sunny to partly cloudy skies is expected to continue through the remainder of the week.
1203 AM CDT Tue Jul 22 2025 Mid to upper ridging gradually undergoes anticyclonic wave breaking over the region as an inverted upper trough shifts westward across the northern gulf by mid to late week.
123 AM EDT Tue Jul 22 2025 High pressure and dry conditions are expected through the middle of the week.
(This evening through Tuesday) Upper level low continues to spin slowly across West Central Texas early this afternoon, although actual weather from it it is small.
- Cooler temperatures (70s and 80s) Tuesday and Wednesday with continued daily chances of showers and thunderstorms.
147 AM EDT Tue Jul 22 2025 Dry and less humid weather will continue today under high pressure.
Falling hghts and cooler air aloft Tuesday could overcome this, most likely in our east-central CWA. Finally, further hght falls and dry air advection begins Wednesday as a larger-scale trough settles over the western United States.
The center of the aforementioned upper ridge will become anchored over the Four State Region over the next couple of days.
(Tuesday through Wednesday) High pressure remains in place across much of the Southeastern CONUS today through tomorrow leading to little change in the overall forecast from the previous few days.
An upper trough will move eastward into Tuesday. Brief high pressure returns around midweek for warmer and drier conditions before a weak disturbance drops across the region late in the week. Weak high pressure begins to build late Tuesday and builds more significantly into Wednesday.
(Tonight through Wednesday Night) Dangerous heat will continue to be the main forecast concern as an upper level ridge builds over the region. Sinking and drier air under the ridge will result in lower, but not zero storm coverage midweek.
Forecast area remains on the western periphery of a large upper ridge over the southeastern CONUS. Weak disturbances rotating around the ridge will result in another round of scattered storms this afternoon and tonight, mainly in Colorado this afternoon and west of Highway 25 in Kansas/Nebraska in the evening hours. The upper level ridge is expected to be the dominant pattern for much of the continental U.
123 AM MDT Tue Jul 22 2025 KEY MESSAGES: - Widespread showers and thunderstorms today, some moderate to heavy north of I-90, especially along the Canadian border - Warming and drying trend Wednesday onward Low pressure centered over northern Idaho is continuing to produce widespread showers across northwest Montana today. Instability will increase this afternoon as above-average precipitable water, daytime heating, and colder air aloft associated with the passing trough combine to destabilize the atmosphere. Low pressure over northern Idaho continues to support widespread showers across northwest Montana today, with low ceilings for July and obscured terrain common.
(Today and tonight) Expect mainly hot and dry conditions today across much of the area as west central Texas will remain on the western side of an upper level ridge located to our east.
Beginning mid-week, ensembles show weak high pressure building over Southeast Idaho through late week as a closed low develops along the northern CA coast. By this time, 500mb ensemble clusters start to differ a bit regarding how long the upper low to our west will influence our weather. We expect areas to meet critical criteria at times during the day today, but humidity will trend higher as moisture increases courtesy of the incoming trough. RH will increase on Tuesday but trend drier again beginning Wednesday as weak high pressure builds over the region.
- A warmer, drier airmass gradually moves in for the latter half of the week. A digging trough out west, will tighten the upper level gradient, thereby continuing a steady supply of moisture along the well defined monsoonal plume. Dry boundary layers are expected to persist in the lower valleys Tuesday and will likely abet gusty outflow winds again. As moisture ebbs and flows across the region, coverage of afternoon convection over the high terrain will shift but otherwise conditions will remain fairly consistent from day to day.
Dry and much warmer conditions return midweek, peaking Wednesday with inland highs reaching well into the 80s and into the low 90s.
Coverage continues to shift eastward by the middle of the week as a cut-off low off the California coast begins to usher in drier air. A strong area of high pressure then begins to build to the east, with the rising heights, a return of hot temperatures look to gradually rise through the week and into the weekend. From 18Z-03Z, scattered to numerous SHRA/TSRA, some with brief and localized MVFR conditions, with the highest coverage SE of a KPAN-KINW-K0V7 line.
/NEW/ /Overnight through Wednesday/ The slow moving broad upper wave that has been meandering across Central TX the last few days appears to be off to our west now and rather ill-defined through the lower half of the atmosphere.
* Cooler than normal temperatures will continue through the end of the week. This will eventually become a closed low pressure system off the coast of California. The primary impact of this cut-off low in our forecast area will be lower 500 mb heights that will allow cooler than normal temperatures to linger through the end of the work week and into the weekend.
Water vapour loop had upper ridge centered over LA, upper trough over the northwest CONUS, and disturbance-laden southwest flow aloft over the CWA. Oppressive dew points in the lower 70s combined with MaxT in the 90s over south-central SD will lead to heat indices in the lower 100s (HREF 60-90% chance).
On Tuesday, the mid/upper ridge will be building across the region, and the weak backdoor front appears to be to our south. A northerly flow through the low and mid levels and slightly lower surface dewpoints will mean less instability tomorrow afternoon. Convection should mainly be focused along the mountains and SW NC, where models show a weak inverted trough developing.
- Becoming increasingly hot and humid Wednesday with heat indices in the low 90s.
In the low levels, gusty south winds are expected to develop on Tuesday in response to the deepening of a surface over SD.
- Cooler temperatures (70s and 80s) today and Wednesday.
- Heat index values will top out in the 100 to 110 range Tuesday over much of the area, with slightly lower values over the higher elevations (Leola Hills and Prairie Coteau). A persistent area of low pressure over western South Dakota will continue to bring in rounds of showers and thunderstorms through Tuesday. CAMS continue to show the highest chance across ND, with some movement over northern portions of SD/west central MN closer to daybreak Tuesday. The high dewpoints and high temperatures will bring heat index values into the 100 to 110 degree range Tuesday, with the highest values over south central South Dakota.
206 AM EDT Tue Jul 22 2025 Canadian High Pressure maintains dry conditions with lower humidity through the middle of the week. Canadian High Pressure centered over NY to Southern New England today maintains dry conditions across our area. Seasonal high temps this afternoon in the low to mid 80s, with abundant sunshine.
High pressure surface and aloft will remain centered over the region resulting in temperatures topping out in the mid to upper 90s at most locations. Normal afternoon highs run in the lower 90s. The high temperatures will combine with the high humidity to result in heat index values between 105 and 110 east of Interstate 55 warranting a Heat Advisory but, west of I-55, heat index values will be between 110 and 115 where an Extreme Heat Warning remains in effect until this evening.
The latest guidance suggests a vort max associated with this convection will lift northeast along the upper ridge this morning and into the early afternoon. Stronger warm air advection still looks possible on Wednesday ahead of an approaching cold front. Consistent signals for large scale forcing with the cold front Wednesday evening and overnight lends some confidence in storms developing somewhere over the region.
1243 AM EDT Tue Jul 22 2025 A ridge of high pressure will build into the region through Tuesday before exiting towards the Mid-Atlantic on Wednesday.
High pressure near James Bay is producing a light northeast wind flow today, However, as the high drifts east tomorrow, a southerly flow will develop at the surface. Aloft, a ridge will build as Wednesday approaches and the heat pump will be in full gear.
Mid to upper ridging gradually undergoes anticyclonic wave breaking over the region as an inverted upper trough shifts westward across the northern gulf by mid to late week.
242 AM EDT Tue Jul 22 2025 High pressure will crest over the area today and tonight then slide south of the region on Wednesday.
/Issued 115 AM CDT Tue Jul 22 2025/ /Overnight through Wednesday/ The slow moving broad upper wave that has been meandering across Central TX the last few days appears to be off to our west now and rather ill-defined through the lower half of the atmosphere.
This southerly flow due to upper trof over srn CA and an upper high near the ArkLaTex.
542 AM EDT Tue Jul 22 2025 High pressure and dry conditions are expected through the middle of the week.
521 AM EDT Tue Jul 22 2025 Dry and less humid weather will continue today under high pressure.
Coverage continues to shift eastward by the middle of the week as a cut-off low off the California coast begins to usher in drier air. A strong area of high pressure then begins to build to the east, with the rising heights, a return of hot temperatures look to gradually rise through the week and into the weekend.
855 AM EDT Tue Jul 22 2025 High pressure will crest over the area today and tonight then slide south of the region on Wednesday.
- A warmer, drier airmass gradually moves in for the latter half of the week. A trough pushing inland across the Intermountain West as well as a drier low pushing inland across SoCal will help push this remnant moisture boundary further east, ushering in drier air across the western portions of the forecast area. Conditions continue to slowly dry out Wednesday as the SoCal low pushes the high pressure ridge and moisture plume further east, continuing to usher in drier air across eastern Utah and portions of western Colorado. Storms are expected to develop again Wednesday afternoon, limited to the higher terrain along the Divide. As moisture ebbs and flows across the region, coverage of afternoon convection over the high terrain will shift but otherwise conditions will remain fairly consistent from day to day.
- Meteorological Overview: The most significant weather impacts are on the decrease for our CWA, as an upper level trof begins to pull away into Canada. This exiting trof will allow for some scattered showers/thunderstorms to affect the CWA today. Do expect some morning fog today, along with low cloud ceilings because of all of the low level moisture. - Forecast Confidence & Scenarios: The overall confidence in showers/thunderstorms is on the lower side now, as the main upper level energy has moved to our east.
- Cooler high temperatures across the north today and across the entire state Wednesday, returning to near to slightly above normal later in the week through the weekend. Although this is possible, CAMS currently more favoring thunderstorm development later this evening through tonight as the stalled front turns into more of a weak cold front and pushes back south. Otherwise, look for cooler temperatures in the north, and continued warm temperatures in the south today. Cooler temperatures in the 70s will be found on Wednesday behind the mentioned front.
A slow moving cold front continues to move into northeastern North Dakota this morning.
509 AM MDT Tue Jul 22 2025 KEY MESSAGES: - Cooler temperatures and generally wet conditions are expected for today and Wednesday. - Warm and dry weather will return late in the week or this weekend as upper ridging once again builds across the region. WEATHER PATTERN OVERVIEW: Upper trough over the Pacific Northwest will lift into central Canada over the next two days. This will briefly suppress the ridge and bring cooler temperatures into the state.
900 AM EDT Tue Jul 22 2025 Canadian High Pressure maintains dry conditions with lower humidity through the middle of the week. Earlier patchy fog has burned off, with some stratocu in the I-64 corridor/east of the Blue Ridge as of mid morning. Canadian high pressure centered over NY to Southern New England today maintains dry conditions across our area. Seasonable high temperatures are expected this afternoon in the low to mid 80s with abundant sunshine.
An upper trough will finally progress off and away on Tuesday. Brief high pressure returns on Wednesday for warmer and drier conditions before a weak disturbance drops across the region late in the week.
(Today through Wednesday) The upper tropospheric trough of the last few days continues to move away north of our area. The Subtropical Ridge builds over most of our area today through Wednesday. Subsidence under the Ridge along with a drying airmass with PWs below seasonal averages keeps rain chances out of the forecast for most areas.
735 AM EDT Tue Jul 22 2025 Dry and less humid weather will continue today under high pressure.
718 AM CDT Tue Jul 22 2025 The upper trough over Central Texas is overproducing this morning with a small area of showers and thunderstorms moving across the Hill Country.
626 AM CDT Tue Jul 22 2025 Mid to upper ridging gradually undergoes anticyclonic wave breaking over the region as an inverted upper trough shifts westward across the northern gulf by mid to late week.