Aikyam-Lab/Synoptic-Bench huggingface dataset:
134 PM EDT Sat Aug 16 2025 A cold front will bring a round of showers and a few thunderstorms Sunday, followed by cooler weather for the start of the work week. An area of low pressure will approach the Great Lakes region through mid-week bringing a period of unsettled weather. Meanwhile, a cold front will be approaching from Ontario and Quebec overnight. The cold front will move through the region Sunday with the threat of showers and storms continuing. Most of the showers/storms should be south of the region by mid to late afternoon as the cold front exits.
208 PM EDT Sat Aug 16 2025 High pressure lingers across the area today before a cold front pushes south across the region Sunday and Sunday night.
Radar and satellite imagery this afternoon shows a cold front pushing a band of rain across eastern WA/OR, with clear to partly cloudy skies developing behind the cold front boundary. Today through Sunday: The cold front will continue to push east and exit the region by this evening, while broad upper level troughing persists overhead. HREF members favor increasing surface instability (250-500 J/kg) across areas that are clearing out behind the cold front boundary this afternoon, resulting in a chance (15-25%) for isolated thunderstorms to develop. Tomorrow, another round of isolated thunderstorms with moderate rainfall will occur across the eastern mountains as daytime heating increases surface instability and taps into remnant moisture behind the cold front passage.
Another, stronger approaching wave out of Wyoming will spark more thunderstorms Saturday afternoon on the high plains. Thereafter, ridging takes hold over the central US, ever so slowly warming us up through midweek. The next shot at more active weather arrives late in the week as a stronger wave looks to ride the top of the ridge, but predictability is too low at this point to pinpoint any impacts associated with its passage. These higher values should lift northward a bit over the next few hours, with the northern fringe of 1000 J/kg making it to about the Highway 200 corridor. Majority of the low to mid clouds clearing out with the exception in the far east, gusty easterly to northeasterly winds starting to pick up for the afternoon.
Band of precipitation associated with a cold front passage will continue to bring precipitation impacts to sites PDT/ALW through 20Z.
The ridge is becoming a stronger influence, but there is plenty of moist/unstable air per morning raobs, and isolated/scattered showers and storms are expected mainly over southern portions of the area. Given vertical totals approaching 27 and very hot surface temps supportive of intense updrafts, a couple of strong to severe microbursts can't be ruled out given the high precip loading expected.
A more northeasterly breeze over the region will pin the seabreeze closer to the coast and led to the highest chances for rain across our Florida counties Sunday afternoon with lesser chances the more north you go. Daytime highs will run in the lower 90s.
- There is a daily low to medium (20-70%) chance of thunderstorms for much of the region, with the highest chances across the western higher terrain early in the week, shifting eastward later in the week. (This afternoon through Sunday night) WV imagery this afternoon shows the upper ridge centered over Missouri/Arkansas, leaving West Texas and Southeast new Mexico vulnerable to mischief on the outskirts of this feature. W/the ridge so far east-northeast, convection should develop a little farther east this afternoon/evening than the past few days. This will combine with abundant cloud cover to yield another uncomfortably warm night of lows ~ 6-8 F above normal, if not warmer. Sunday looks like a repeat of today, if not a degree or so warmer as thicknesses increase a bit.
103 PM EDT Sat Aug 16 2025 (Today through Sunday) Mid to upper level ridging is expected to remain the dominant synoptic feature driving local weather across South Florida through the weekend. It is worth mentioning that a (very) subtle tropical wave will move across the Florida Straits this afternoon, skirting the weakening ridge, and could inject some moisture back over the area through the afternoon and evening. High temperatures will reach the low to mid 90s with heat indices in the low 100s.
223 PM MDT Sat Aug 16 2025 - Afternoon showers and storms will favor the higher terrain this afternoon. - High pressure builds in Sunday onwards bringing a return to warming temperatures and drier air. Short range models are performing well this afternoon as they have picked up on the increased moisture and daytime heating to allow isolated convection to fire over the higher terrain. Sunday, high pressure builds in as southwesterly flow sets up bringing a return to drier air (60 to 70% of normal) and warming temperatures.
(This afternoon through Sunday night) "Dirty" high pressure will remain in place across the Gulf south through the end of the weekend. With ample moisture in place and only weak subsidence aloft associated with the high expect to see isolated to scattered showers and storms both today and tomorrow. Despite the higher than normal temperatures, heat index values don't look overly concerning.
1146 AM MDT Sat Aug 16 2025 - Afternoon thunderstorms will favor the higher terrain today. Enough moisture remains across western Colorado and eastern Utah to day do spawn another round of afternoon convection, especially behind the trough where clearing is occurring, but with drier air moving in, showers and storms will predominately favor the higher terrain. There may still be enough moisture for convection over the high terrain on Sunday, but with drier air moving in dry thunderstorms are possible.
/16/ Ridging is just about centered over the Four State Region, settling into the Lower Mississippi River valley. Long-range guidance suggests the arrival of a frontal boundary and ridging peripherally influenced by Hurricane Erin.
The forecast area still largely on the eastern periphery of upper ridging and high pressure at the surface us warm with isolated diurnally driven showers and storms during the afternoon.
The next system is approaching from the west, with a well-defined cold front moving slowly across central Oregon this morning.
A broad upper ridge then continues to build and remain in place across the central US into mid week, with some slowing of the overall pattern progression as Hurricane Erin approaches the southeastern US. Another upper level trough to move into the Canadian Rockies to set up southwest flow across the region by late week. Thermal ridge to build up through midweek ahead of the developing western troughing, therefore expect warming back into the mid to upper 80s through mid week.
As high pressure sets in overnight tonight, expect clearing skies to allow temperatures to fall to the 50s and perhaps only as far as 60 nearer to the Great Lakes. Look for otherwise quiet and dry weather Sunday, with highs in the 60s near Lake Superior and the lower 70s more inland.
Temperatures trend warmer late week, with areas of Moderate HeatRisk developing.
A slight overall increase in moisture is evident today as dewpoints sit between 10-20 degrees warmer than yesterday at this time, and ACARS soundings show PWAT values approaching 1". Convection is already underway across the higher elevations, and despite early morning cloud cover hindering surface heating, temperatures across the plains are finally at or approaching that 90 degree mark. With MLCAPE values approaching 500 J/kg, once this cap is gone, scattered showers and storms should make their way onto the lower elevations.
405 PM CDT Sat Aug 16 2025 - Drier and cooler conditions are expected tonight with overnight lows in the 50s.
634 PM CDT Sat Aug 16 2025 - Drier and cooler conditions are expected tonight with overnight lows in the 50s.
A weak but well defined cold front has crossed the area through the day today bringing light rain along and the coast and some heavier showers over the Trinity Alps.
735 PM EDT Sat Aug 16 2025 A cold front will bring a round of showers and a few thunderstorms Sunday, followed by cooler weather for the start of the work week. An area of low pressure will approach the Great Lakes region through mid-week bringing a period of unsettled weather. Meanwhile, a cold front will be approaching from Ontario and Quebec overnight. The cold front will move through the region Sunday with the threat of showers and storms continuing. Most of the showers/storms should be south of the region by mid to late afternoon as the cold front exits.
Generally drier and cloudy skies with an upper level trough over the region through midweek. A dry and warmer pattern is favored late in the week through the weekend as an upper level ridge builds over Western Washington.
524 PM MDT Sat Aug 16 2025 - Afternoon showers and storms will favor the higher terrain this afternoon. - High pressure builds in Sunday onwards bringing a return to warming temperatures and drier air. Short range models are performing well this afternoon as they have picked up on the increased moisture and daytime heating to allow isolated convection to fire over the higher terrain. Sunday, high pressure builds in as southwesterly flow sets up bringing a return to drier air (60 to 70% of normal) and warming temperatures.
Our KBYX radar was busy detecting widely scattered clusters of showers and thunderstorms this afternoon, including a couple of persistent cloudlines off of the Lower Keys. Around 2 PM local time, we received a report from broadcast media of a waterspout just south of Bow Channel Bridge, east of Upper Sugarloaf Key. From synopsis, a broad ridge stretching from the North Atlantic westward across the Florida Peninsula will result in light to gentle easterly breezes across the Keys coastal waters for the rest of the weekend, and into the start of the new week.
Hot temperatures are expected today and Monday with mid-upper ridging stretching from MO-TX. Mid-upper ridge migrates toward the Four Corners area during the early and middle parts of the week. 3" range, daytime heating, seabreeze, and intermittent disturbances rotating into the area around the periphery of the ridge.
- Hot temperatures continue Sunday and Monday but widespread heat index values may only reach into the low 100s so have not extended the heat advisory at this time.
PWATs per RAP/SPC mesoanalysis around 2 inches are present which will continue to fuel the ongoing activity and also keep any severe weather concerns such as hail on the lower end of probability. The cold front will present the final chance for showers and storms for the period with better shear allowing for the potential for rotating updrafts unlike the weaker sheared environment that preceded it.
1252 AM CDT Sun Aug 17 2025 The upper ridge extending from the central and southern plains to the Mississippi River will expand eastward over the Ohio River Valley region through late Monday night.
218 AM CDT Sun Aug 17 2025 Upper level high pressure prevails over the area and with the subsidence expect mainly just isolated thunderstorm activity this afternoon. Little will change tomorrow, as upper high pressure remains over the region.
The Subtropical Ridge centers over the southern Plains today. Subsidence under the Ridge along with a drying airmass will keep rain chances out of the forecast today. The Ridge migrates to the west on Monday as upper level troughing approaches the Texas coast.
131 AM EDT Sun Aug 17 2025 A cold front will bring a round of showers and a few thunderstorms Sunday, followed by cooler weather for the start of the work week. An area of low pressure will approach the Great Lakes region through mid-week bringing a period of unsettled weather. Meanwhile, a cold front will be approaching from Ontario and Quebec overnight. The cold front will move through the region Sunday with the threat of showers and storms continuing. Most of the showers/storms should be south of the region by mid to late afternoon as the cold front exits. A longwave trough digging south from Quebec and into New England will slide eastward through Monday as a flattening upper level ridge and northeasterly upper level flow builds back over the Eastern Great Lakes.
400 AM EDT Sun Aug 17 2025 A cold front will move south across the area today.
- The next opportunity for thunderstorms and heavy rain is Monday and Monday night as a front moves back north as a warm front. 50 inches of rain, with the higher totals of 1. There is decent agreement that this cold front reaches southern WI/northern IL tonight, and then hangs out there for Sunday.
Increasing moisture and weak troughing over the area will result in above average rainfall chances both today and on Monday.
(Today through Monday) Mid to upper level ridging across the Southeast CONUS continues to weaken today, but is still expected to remain the dominant feature driving local weather across South Florida to end the weekend. High temperatures will reach the low to mid 90s with heat indices in the low 100s.
The short term period begins with a broad upper ridge extending through the Mississippi RIver Valley and northward towards the western Great Lakes Region. Georgia remains on the eastern periphery of this upper ridge. Subsidence of drier air under this high will contribute to plenty of sunshine and highs this afternoon rising into the low to mid 90s across the forecast area. As the ridge persists into Monday, it will lead to another warm day with relatively low rain chances. Even as Hurricane Erin continues to move northeastward across the Atlantic, the influence of the ridge is expected to keep it offshore and begin to steer it more northward away from the eastern CONUS.
A large ridge of high pressure aloft will continue to reside across the central and southern Plain states. Around the periphery of this ridge is a strong belt of southwest to westerly flow aloft from the Rockies/High Plains into the Northern Plains.
Weak low level ridging remains anchored over the Lower MS Valley early this morning, with the progs remaining in general agreement with this feature retrograding slowly W into SE TX/Sabine Valley later this morning/afternoon, maintaining Lt/Vrb winds through the day. Meanwhile, upper ridging centered over the Ozarks/Mid MS Valley will remain anchored in place through the afternoon, but expand into the region allowing for a deeper wedge of drier air aloft to backdoor farther through more of NCntrl LA by afternoon. Thus, have expanded the slight chance pops areawide over the drier/popless NBM (except for the Srn zones), before the ridging aloft begins to expand farther E through the TN valley into the Mid-Atlantic states later tonight/Monday.
Overnight lows tonight will range between the lower to upper 50s. Generally drier and cloudy skies with an upper level trough over the region through midweek. A dry and warmer pattern is favored late in the week through the weekend as an upper level ridge builds over Western Washington.
High pressure expands westward after today and anchors near the Four Corners region into the weekend.
The good news here is that heat peaks today, diminish a few degrees Sunday and another few into Monday as the thermal ridge is squashed south and east. The attendant cold front pushes across Iowa through the day on Monday with scattered convection likely to percolate much of the day.
The summer subtropical ridge was positioned to our southeast, centered over Arkansas. This regime put western Kansas on the western periphery of the upper high with slightly enhanced lower-mid tropospheric moisture. Later this afternoon, a surface leeside trough axis along the Kansas- Colorado line will likely aid in the initiation of isolated to widely scattered showers and thunderstorms, so we will have some 20 POPs for this potential, but weak mid level winds (8 to 15 knots at 500mb, for example) will prevent any organization.
Behind the system, a ridge pattern will lead to a return of warm, dry conditions across the region. Weak afternoon instability could bring an isolated thunderstorm over Southeast WA and the Lower ID Panhandle this afternoon.
The lee of the Rockies trough will still have the potential for storms to develop over western SD and move east. Monday evening, the upper and mid levels of the atmosphere are forecasting a high pressure to start developing over AZ and NM. This high pressure will help to create an upper and mid level ridge that moves over western areas of SD though the end of the work week.
KBYX radar depicts some light shower activity in the waters south of the Lower Keys, while elsewhere remains quiet this early morning. Current conditions feature temperatures in the lower 80s with dew points in the upper 70s making for a muggy early morning. These light breezes could once again lead to a cloud line development over the Lower Keys later today, potentially producing some shower activity and a few waterspouts. Looking ahead, the western Atlantic subtropical ridge will remain firmly in place through at least the early parts of this week, providing light to gentle breezes that will be occasionally variable. From synopsis, a broad ridge stretching from the North Atlantic westward across the Florida Peninsula will result in light to gentle easterly breezes across the Keys coastal waters through early this week.
Monday, mid level flow will become more zonal, as the upper ridge becomes centered over western Kansas into the Four Corners. A frontal boundary should be located further south, closer to the Highway 2 and 91 corridor. Beyond Monday night, the upper ridge will become established over the Four Corners.
Monday looks like a repeat with the heat with the highest heat index values in the southeast with the humidity, and across north central Oklahoma with higher temperatures in the post-harvest wheat belt.
The upper pattern this morning is defined by a trough of low pressure along the West Coast with a high amplitude ridge of high pressure extending from west Texas into the Ozark Plateau of Missouri.
225 AM EDT Sun Aug 17 2025 Precipitation chances will increase as a cold front drops across the region today. A surface cold front will drop south across our forecast area today bringing a broken line of showers with possible embedded thunderstorms. High temperatures today will be quite variable as a result, ranging from the lower 70s in the St Lawrence Valley to the mid/upper 80s in south-central VT. Much cooler and drier air will spread over the area tonight, clearing out skies and dropping temperatures into the 40s to near 50F. Monday will be a much drier and cooler day with maximum temperatures topping out in the upper 60s to lower 70s. Monday night will feature increasing mid/high clouds ahead of our next system, which should help keep it a little warmer than Sunday night.
758 AM EDT Sun Aug 17 2025 A cold front will move south across the area today.
230 AM PDT Sun Aug 17 2025 Low pressure along the West Coast will bring cool weather and extensive coastal clouds early this week. High pressure will build this week, bringing a warming trend and less marine layer cloud cover.
325 AM MDT Sun Aug 17 2025 - Upper ridge shifts slightly eastward today, bringing drier air and lower chances for thunderstorms to the region. Upper-level ridge moves east into the plains, with main plume of higher moisture shifting south and east of the region.
- Meteorological Overview: Southwesterly flow aloft today will gradually give way to upper level ridging for midweek this week, bringing a change from unsettled weather today and Monday to hot and dry conditions. Even as our upper level pattern begins to shift towards upper level ridging on Monday, just enough moisture will remain to allow for a few isolated showers and thunderstorms to develop.
640 AM EDT Sun Aug 17 2025 Weak high pressure across this morning will give way to a developing pre-frontal trough over western NC in the afternoon.
648 AM CDT Sun Aug 17 2025 The upper ridge extending from the central and southern plains to the Mississippi River will expand eastward over the Ohio River Valley region through late Monday night.
742 AM EDT Sun Aug 17 2025 Precipitation chances will increase as a cold front drops across the region today. A surface cold front will drop south across our forecast area today bringing a broken line of showers with possible embedded thunderstorms. High temperatures today will be quite variable as a result, ranging from the lower 70s in the St Lawrence Valley to the mid/upper 80s in south-central VT. Much cooler and drier air will spread over the area tonight, clearing out skies and dropping temperatures into the 40s to near 50F. Monday will be a much drier and cooler day with maximum temperatures topping out in the upper 60s to lower 70s. Monday night will feature increasing mid/high clouds ahead of our next system, which should help keep it a little warmer than Sunday night.
645 AM CDT Sun Aug 17 2025 Upper level high pressure prevails over the area and with the subsidence expect mainly just isolated thunderstorm activity this afternoon. Little will change tomorrow, as upper high pressure remains over the region.
High pressure continues to build through the week with variable conditions early in the week. Persistent onshore flow until later in the week when winds will become offshore as a thermal trough develops.
/Issued 401 AM MDT Sun Aug 17 2025/ - Meteorological Overview: Southwesterly flow aloft today will gradually give way to upper level ridging for midweek this week, bringing a change from unsettled weather today and Monday to hot and dry conditions. Even as our upper level pattern begins to shift towards upper level ridging on Monday, just enough moisture will remain to allow for a few isolated showers and thunderstorms to develop.
EDT Sun Aug 17 2025 Weak high pressure across this morning will give way to a developing pre-frontal trough over western NC in the afternoon.
This wave sparked off thunderstorms yesterday evening on the High Plains of northeastern WY. Broad southwest flow will give way to ridging by early in the work week. Precipitation chances will be tied to any weak waves that can ride the ridge.
The ridge of high pressure strengthens over the central part of the United States for the first part of the work week allowing temperatures to steadily climb over the Northern Rockies.
Water vapor satellite imagery early this morning shows that dry air has spread across eastern Utah and western Colorado as high pressure builds in overhead. The CAMs and HREF have really backed off on producing convection over the higher terrain this afternoon, but isolated showers and storms cannot be ruled out. High pressure will build over the region early in the week, supporting a shift in flow that will begin to alleviate the dry conditions across the region. The center of high pressure will slowly move south, allowing for a shift to west to northwesterly flow by the weekend. Temperatures will climb to well above normal while the region is under high pressure.
-Wilson /Issued 537 AM MDT Sun Aug 17 2025/ - Meteorological Overview: Southwesterly flow aloft today will gradually give way to upper level ridging for midweek this week, bringing a change from unsettled weather today and Monday to hot and dry conditions. Even as our upper level pattern begins to shift towards upper level ridging on Monday, just enough moisture will remain to allow for a few isolated showers and thunderstorms to develop.
(Today through next Sunday) WEATHER PATTERN OVERVIEW: Current satellite imagery shows mostly cloudy skies across the forecast area, with a trough of low pressure situated along the west coast and high pressure over the southern U.
Satellite imagery this afternoon shows fairly sparse cumulus fields developing over the higher terrain of the OR Cascades and the eastern mountains. Today through Monday: The PacNW will continue to sit under the influence of a broad upper low in the northeast Pacific, keeping temperatures much cooler than normal. Upper level ridging will begin to build northwest into the PacNW Monday, greatly decreasing chances of shower activity across the forecast area.