Aikyam-Lab/Synoptic-Bench huggingface dataset:
However, subsidence associated with strong high pressure in both the lower and upper levels of the atmosphere continue to limit the coverage area and overall vertical growth of the activity. The most notable difference will be that the H5 high pressure of 596dam will become increasingly centered over the southern Appalachians. Afternoon and evening thunderstorms possible outside of the mountains by week's end as high pressure weakens slightly. This will also weaken the ridge a bit too.
Near the surface, an anchored lee side trough of low pressure is deepening across eastern Colorado.
610 PM CDT Sat Jun 21 2025 - Upper High to keep rain chances at a minimum today with hot and humid conditions as max afternoon heat index values will be around 100-103 degrees. - The upper level high will begin to move away from the forecast area tomorrow with rain chances increasing.
Near normal high temperatures expected today as modestly cooler air has moved into the region. Aloft a strong trough for this time of year is centered over the Pacific Northwest with its axis extending down into the Great Basin.
Latest surface analysis places high pressure near Bermuda. Southerly return flow on the back side of high pressure is present across the Lower Mississippi Valley this evening.
High pressure and a dry airmass will lead to mostly clear skies overnight. Expect diurnal cumulus once again with temperatures a bit warmer than today.
Upper level ridging will build offshore in the wake of the unsettled conditions today.
* Gusty pre- and post-frontal winds will peak across the region today as a low pressure system digs into the Desert Southwest. A low pressure system dropping through the Great Basin will extend an associated trough through the Desert Southwest today. The trough axis and corresponding cold front will pass through the region this evening, which has resulted in strong pre-frontal southwesterly gusts with speeds between 40 and 50 mph this afternoon. The aforementioned cold front will allow temperatures to drop 4 to 6 degrees between today and Sunday afternoon. Despite generally weak troughiness expected across the region through the work week, heights will slowly rise as a ridge of high pressure builds over northern Mexico.
(This evening through Sunday) Upper-air observations and water vapor imagery reveal subsidence associated with an upper high anchored over the mid-MS Vly extends west to roughly longitude 100W, while to the west and northwest, a upper-level trough is slowly advancing from the Pac NW into the Great Basin.
Scattered showers and isolated thunderstorms continue to move southeast across the region this evening as the upper low slowly moves east of the area.
For Sunday, the center of the upper ridge will be displaced more to the northeast when compared to this afternoon.
The exception is in extreme northwestern Alabama, where highs have reached the 90 to 92 degree range already with dewpoints in the lower to mid 70s.
Earlier this afternoon and evening, KBYX radar showed shower and thunderstorm activity across the offshore Gulf waters to the north of the Island Chain as well as surrounding nearshore waters of the Lower Keys. Deep mean layer ridging remains anchored over the southeastern United States with much of Florida remaining on the southern side of this ridge. From synopsis, High pressure over the eastern seaboard will gradually build over the next few days.
Strong high pressure in the Mid Atlantic States will keep our winds mainly out the east through mid week.
Satellite image shows the upper trough just east of the Cascades. On the backside of the upper low, a thinker cloud layer is moving in from the north along with enhanced steadier precipitation. The high res short range models show the steadier precipitation moving from north to south during the afternoon and they have been showing this trend the past couple of runs. A few locations east of the Cascades could get towards freezing for an hour ot two towards daybreak Sunday. Afternoon temperature Sunday will rebound and will be warmer for the interior.
This will result in a mostly clear and calm night across the Tennessee Valley with high pressure nosing in from the north. Despite the clear conditions, the boundary later remains very moist and as a result a warm/humid night is anticipated as overnight lows will remain in the lower 70s in most locations. This fog will dissipate quickly by early Sunday morning and with high pressure nosing in from the north and east, a mostly clear and dry day will be on tap. Ample sunshine will allow highs to again reach the low to perhaps mid 90s in most locations, with higher RH values creating heat concerns again, especially across northwest Alabama. A few storms may develop along any lingering outflow boundaries during the late afternoon -- but strong subsidence from the ridge should limit convection, capping PoPs at 10-20%.
753 PM EDT Sat Jun 21 2025 (Through Sunday) Currently, ridging in place over the eastern US is helping keep Daily highs 3-6 degrees above normal. The most visible boundary keeps the higher moisture west of a line stretching from just east of Tallahassee to just east of Albany.
TODAY (SUNDAY) through Saturday The center of a stout H500 ridge will be positioned over the Mid- Atlantic region of the CONUS to close out the weekend and remain into the beginning of the workweek. By mid workweek, the H500 ridge begins to become less amplified and breaks down slightly becoming more elongated, extending from over the Southern Plains region of the CONUS to over the Mid-Atlantic region of the CONUS. The ridge will remain firmly the dominant feature over Arkansas over the forecast period despite the slight breakdown of intensity and elongation. At the sfc, a center of high pressure will meander slightly in the Mid-Atlantic region of the CONUS.
- Highs will warm into the lower 90s with overnight lows only cooling into the 70s each day through mid week.
Temperatures will trend warmer, with heat indices in the mid to upper 90s expected. Discussion: The heat begins to build today as a large high pressure ridge expands across the region. Based on the CAMS, some isolated convection is expected to develop this afternoon in the higher terrain areas near the TN/NC border, and possibly in the Cumberland Plateau.
Dangerous heat continues to plague the region as an upper level ridge continues to spin over the eastern half of the CONUS.
A cold upper trough continues to move eastward across the region, bringing scattered cloud cover and a slight chance for isolated light showers to develop during the early morning hours of Sunday (after 10Z), especially for coastal Del Norte and northern Humboldt counties. Slightly warmer daytime temperatures in the mid to upper 70's expected for the interior with continued fire weather concern as gusty northwesterly winds resume in Mendocino and Lake counties.
334 AM EDT Sun Jun 22 2025 Upper ridging establishes itself over the eastern CONUS this weekend with an early week warming trend. Hot and humid conditions, and dangerous heat index values, are expected during the mid-week period under the continued influence of the upper ridge. Rain chances increase later in the week as ridging should begin to break down. The high clouds should be thin enough to allow for a few degrees of additional cooling, with lows this morning ending up in the low 70s. For the remainder of today, high pressure through the column will dominate our sensible weather, kicking off a warming trend as highs reach the mid 90s. Should be a bit of rinse and repeat this evening and overnight, with lows in the low 70s and the potential for some patchy fog.
For early in the upcoming week, a long wave troughing pattern will remain over the Western United States.
138 AM EDT Sun Jun 22 2025 Heat and humid will increase as a mid level ridge builds into the area. High pressure and a dry airmass will lead to mostly clear skies overnight. Expect diurnal cumulus once again with temperatures a bit warmer than today.
- Slightly above normal temps across most of the area today, but will be slightly cooler than Saturday. At the surface, low pressure is situated over the Nebraska Panhandle with a cold front extending from northeast SD into western Nebraska. Temps today will be a couple degrees cooler than yesterday, but will still be slightly above normal.
High temperatures will top out in the lower to middle 90s.
- A cooler weather pattern will be found to start this week, followed by a very gradual warmup, with near daily chances for showers and thunderstorms. These circulations will bring scattered to numerous showers and thunderstorms and much cooler temperatures to northern and western ND.
- Temperatures behind the cold front will be 15 to 20 degrees below Saturday temperatures. The main midlevel trough continues to slowly shift east, and is currently centered over western Idaho. The trough will be ejecting to the northeast by Sunday evening, with quickly clearing skies in its wake.
326 AM EDT Sun Jun 22 2025 Heat and humid will increase as a mid level ridge builds into the area. Expect few to scattered diurnal cumulus once again with temperatures a bit warmer than yesterday. High temperatures look to top out in the lower and middle 90s. These hot temperatures combined with dewpoints in the lower 70s produce afternoon heat indices between 100 and 105 degrees. Lows tonight will only drop to the lower and middle 70s.
As the southeast remains under the influence of an upper level ridge, heat continues to be our primary concern as we close out the weekend. High temperatures are forecast to reach the low to mid 90s through the Tennessee Valley with heat index temperatures climbing up to 107 degrees in portions of NW AL.
Key Messages: 1) Confidence is high for temperatures rising above normal due to a large upper level ridge building overhead. Temperatures could soar into the 80s in the mountains, near 90 degrees for the New River Valley, and into the lower to mid 90s across the Piedmont. High-resolution models hint at a low chance of a stray shower or thunderstorm popping up in the afternoon along the Blue Ridge in North Carolina, but the ridge aloft could suppress most of this activity from materializing.
Morning WV imagery shows building area of strong high pressure aloft over the E U. While this area of high pressure will fuel a potent early summer heat wave from the Midwest through the Mid-Atlantic and Northeast U. for much of this week, locally it will lead to drier conditions aloft and, coupled with W Atlantic surface ridging extending west across the E U.
H5 ridging continues to work eastward into the Upper Midwest and Great Lakes region today. Dew points ahead of the front are in the low to mid 70s, which will combine with afternoon highs in the upper 80s to low 90s to allow heat index values upwards of 100 degrees. The cold front will bring a chance for showers and thunderstorms this afternoon and evening with severe thunderstorms possible.
The highest chances can be expected across the eastern half of the CWA towards the latter part of the week, as an inverted trough reaches the Texas coast.
1110 PM CDT Sat Jun 21 2025 - Upper High to keep rain chances at a minimum today with hot and humid conditions as max afternoon heat index values will be around 100-103 degrees. - The upper level high will begin to move away from the forecast area tomorrow with rain chances increasing.
807 AM EDT Sun Jun 22 2025 Morning WV imagery shows building area of strong high pressure aloft over the E U. While this area of high pressure will fuel a potent early summer heat wave from the Midwest through the Mid-Atlantic and Northeast U. for much of this week, locally it will lead to drier conditions aloft and, coupled with W Atlantic surface ridging extending west across the E U. ridge aloft to the north strengthens further, however, sufficient moisture will remain in place to support isolated to scattered showers/storms north of I-4 and scattered convection southward, with highest chances over SWFL.
H5 ridging continues to work eastward into the Upper Midwest and Great Lakes region today. Dew points ahead of the front are in the low to mid 70s, which will combine with afternoon highs in the upper 80s to low 90s to allow heat index values upwards of 100 degrees. The cold front will bring a chance for showers and thunderstorms this afternoon and evening with severe thunderstorms possible. Much cooler temperatures return on Monday, along with lower humidity.
Slightly cooler air aloft with 500 MB temps of -8 to -10 C may allow for a few stronger storms including some hail over inland and SW FL.
625 AM EDT Sun Jun 22 2025 Upper ridging establishes itself over the eastern CONUS this weekend with an early week warming trend. Hot and humid conditions, and dangerous heat index values, are expected during the mid-week period under the continued influence of the upper ridge. Rain chances increase later in the week as ridging should begin to break down. The high clouds should be thin enough to allow for a few degrees of additional cooling, with lows this morning ending up in the low 70s. For the remainder of today, high pressure through the column will dominate our sensible weather, kicking off a warming trend as highs reach the mid 90s. Should be a bit of rinse and repeat this evening and overnight, with lows in the low 70s and the potential for some patchy fog.
Highs will be in the low/mid 90s with overnight lows in the 70s. While mornings will continue to be muggy with dewpoints in the 70s and Gulf moisture return demarcated by morning stratus intrusions, this low-level moisture will continue to mix out rapidly with daytime heating, allowing dewpoints to fall into the 60s during the afternoon.
1024 AM EDT Sun Jun 22 2025 Heat and humid will increase as a mid level ridge builds into the area. Lows tonight will only drop to the lower and middle 70s. The 500H ridge remains over the Mid-Atlantic, but will be beginning the process of flattening out thanks to waves moving through Canada.
(Today and tonight) The upper ridge will park itself near the Ohio Valley today with a longwave trough across the Mountain West.
West Central Texas will be in between upper level high pressure to our east and an upper level trough out west. At the surface, a lee trough will remain in place again today, which will result in gusty south winds once again. Temperatures will be near normal again today, with afternoon highs mainly in the low to mid 90s. Temperatures will be warm again tonight, with lows mainly in the lower 70s.
Today's high temperatures across the region will be around 10+ degrees cooler than normal. Temperatures will gradually climb back up to near normal by mid week as 500 mb heights increase thanks to a ridge trying to push into the area. Warmer than normal temperatures will return to the region during the second half of the week, resulting in increasing HeatRisk as we head into the weekend.
Temperatures will be cooler in the 80s to low 90s as a result of rain and cloud cover.
- A cooler weather pattern will be found to start this week, followed by a very gradual warmup, with near daily chances for showers and thunderstorms. These circulations will bring scattered to numerous showers and thunderstorms and much cooler temperatures to northern and western ND. Overall temperatures for this week are expected to be much cooler. Highs today will range from the 60s north and west to the low 90s far southeast.
605 AM EDT Sun Jun 22 2025 Heat and humid will increase as a mid level ridge builds into the area. Expect few to scattered diurnal cumulus once again with temperatures a bit warmer than yesterday. High temperatures look to top out in the lower and middle 90s. These hot temperatures combined with dewpoints in the lower 70s produce afternoon heat indices between 100 and 105 degrees. Lows tonight will only drop to the lower and middle 70s. The 500H ridge remains over the Mid-Atlantic, but will be beginning the process of flattening out thanks to waves moving through Canada.
647 AM CDT Sun Jun 22 2025 An upper ridge will continue across the area through the near term with a summer pattern of isolated to scattered showers and storms. Temperatures remain warm in the lower to middle 90s for highs with lows in the lower to middle 70s. /13 An upper ridge will continue through the work week across the eastern half of the U. Higher rain chances return by the end of the week as the ridge weakens and moisture levels increase. Temperatures will average up to 5 degrees above normal through the extended, with highs in the middle 90s inland and the lower 90s along the beaches and barrier islands. Low temperatures across interior areas will be in the lower to middle 70s and the upper 70s along the beaches and barrier islands.
(Today through next Sunday) WEATHER PATTERN OVERVIEW: Persistent upper level trof resides over the western U. Main concern will be another night of cold overnight low temperatures tonight, though temperatures will be a few degrees warmer than last night and early this morning. Overnight lows will reside in the low 30s to low 40s with upper 20s in the typical colder valleys.
421 AM CDT Sun Jun 22 2025 An upper ridge will continue across the area through the near term with a summer pattern of isolated to scattered showers and storms. Temperatures remain warm in the lower to middle 90s for highs with lows in the lower to middle 70s. /13 An upper ridge will continue through the work week across the eastern half of the U. Higher rain chances return by the end of the week as the ridge weakens and moisture levels increase. Temperatures will average up to 5 degrees above normal through the extended, with highs in the middle 90s inland and the lower 90s along the beaches and barrier islands. Low temperatures across interior areas will be in the lower to middle 70s and the upper 70s along the beaches and barrier islands.
Today's high temperatures across the region will be around 10+ degrees cooler than normal. Temperatures will gradually climb back up to near normal by mid week as 500 mb heights increase thanks to a ridge trying to push into the area. Warmer than normal temperatures will return to the region during the second half of the week, resulting in increasing HeatRisk as we head into the weekend. The unseasonable cold front will be the main concern. An unseasonably strong cold front was pushing south, nearing Interstate 15 around midnight and making it through nearly all of the Mojave Desert by sunrise.
An upper trough is over the area this morning with an upper low centered over Idaho. The low will gradually shift northeastward today with showers tapering off by afternoon. Temperatures will trend warmer today compared to the last couple days, but will still remain slightly below normal. Lingering cool air, clearing skies and light winds will result in some cold overnight/morning temperatures with some areas east of the Cascades expected to see temperatures in the lower 30s, especially for areas in northern Klamath and northern Lake Counties.
A deep trough sits over the western CONUS this morning, centered over Idaho into the Great Basin. With the periphery of trough base over southern California, southeastern Arizona sits under dry southwesterly flow.
The upper level low from the Intermountain West continues to lift to the north-northeast, with a secondary low developing over Northern CA while an upper level high sits over the eastern Pacific.
As high pressure deepens over the Eastern Seaboard, we can see as a result the gradual freshening of breezes this morning with the Reef currently measuring 10 to 15 knots. From synopsis, high pressure will gradually build over the Eastern Seaboard over the next few days.
- Warmer temperatures and less precipitation mid to late week. (Today through Monday afternoon) Upper air analysis continues to depict ridging over the eastern CONUS with a broad trough developing across the Pacific Northwest. Lee troughing ahead of the mid-level trough has developed across the High Plains, continuously bringing strong southeast winds into the region. The highest chances (50-70%) of showers and storms Sunday extend from western Eddy County through the Presidio Valley (including the Davis Mountains), which is where the greatest forcing for ascent will be located.
- Cooler midweek with several chances for showers/ storms. The main focus today will be the ongoing hot and humid conditions as upper-level ridging remains firmly in place across the eastern CONUS. Otherwise, the rest of the day will be dry as ridging continues to build overhead. Slightly cooler conditions can be expected near the lakes and where cloud cover lingers.
Dangerous heat continues to plague the region as an upper level ridge continues to spin over the eastern half of the CONUS. A cold front is forecast to push through the northern Plains tonight and stall just north of the forecast area by Monday night. If it falls in the early afternoon, this may be enough to shave a degree or two off the high temperature, but it won't be enough provide relief from the heat. On top of this, the center of the mid-level ridge slides east and 850 mb temperatures fall slightly.
Maintaining a 20-30% chance in the lower Valley with lesser chances north and west. Temperatures will be near to slightly below normal with afternoon highs in the low to mid 90s with overnight lows in the mid to upper 70s.
(Tonight through Monday Night) The heat is still the main talking point over the next several days with strong high pressure remaining in the area. Despite strong high pressure, there remains abundant instability and enough moisture to allow for hit-and-miss thunderstorms to develop.
Otherwise warmer today, though highs will still be around 5-10 degrees below normal.
A normal distribution of sh/ts each day and quite warm with highs in the low to mid 90s.
Water vapor and upper level analysis show an area of low pressure over Idaho with a jet streak east of the low from WY into eastern MT and western Dakotas. Center of the upper ridge has shifted east of the area into the OH valley, but still encompasses much of the central and eastern U. Lows will remain warm again tonight in the low to mid 70s. Highs Monday in the low to mid 90s with HI values from around 95 to 103 and the highest values in the far eastern CWA. Continued heat and humidity: Upper ridge will remain over the central and eastern U. through much of the period but will flatten out by the middle of the week as a storm system moves across the top of the ridge.
206 PM EDT Sun Jun 22 2025 An upper level ridge continues hot and humid continues through mid-week.
This should enable temperatures to climb more prevalently into the lower 90s near and east of the I-65 corridor this afternoon. Despite weak lift, some general boundary layer convergence is shown by models into the afternoon hours along with some weak upper level forcing on the southwest portion of the upper level ridge. Dewpoints should mix a bit more later this morning and afternoon, but with temperatures climbing into the lower to mid 90s and dewpoints still expected to be in the 70 to 75 degree range primarily this afternoon.
The widespread precip will end by early afternoon as the low moves further away to the east. However, lingering moisture combined with daytime heating will promote scattered showers and isolated thunderstorms - mainly over the higher elevations - this afternoon.
low to mid level moisture remains high across portions of northern Mexico into west Texas between the 500mb ridge across the eastern United States and the 500mb trough along the Pacific coast of the western United States.
The strength of an H5 ridge of high pressure that runs 592-596 DM thru much of the week puts us in the E-SAT 30 yr Return Interval for such a strong, season opening pattern. Thus the weekend highs in the low-mid 90s with dew points in the low-mid 70s just really look like there is not a lot of diurnal variation thru the course of the week. Tmrw will see similar cu development trends at about the same low VFR heights under similar strength of high pressure, over the course of the day.