Aikyam-Lab/Synoptic-Bench huggingface dataset:
Models show a mid/upper level high centered over the Arklatex region today into the early part of the work week, with broad ridging extending into the upper Mississippi valley and Great Lakes region. At the surface, models show a weak cold front sinking south of the PAH forecast this morning. An isolated shower or storm is not completely out of the question today, but the upper level ridge is most likely going to tamp down any convection and will go with a dry forecast for now.
The mid/upper low over WV/northern VA, which is helping to direct Henri northward, is also directing minor impulses into the area from the NW. Northeast SC zones will have the highest chances for showers/tstms this afternoon/early evening, but expect better chances into southeast NC zones as well during Sunday afternoon/evening. Rain chances continue for the Short Term period, however they will be a bit lower than Sun as an upr-level trough axis pulls offshore.
A ~594 dam upper high will develop over the Ark-La-Tex region by Monday afternoon, bringing drier air and more substantial subsidence to the region. High temperatures Monday should easily reach the low-mid 90s (and there is a chance the blended guidance is a couple degrees too low). Mid-level ridging will persist over the central Plains for early-mid week, keeping the TN Valley mostly dry, seasonably hot, and very humid.
422 AM EDT Sun Aug 22 2021 Light to moderate rain showers are currently moving southeastward across central and eastern portions of the CWA, associated with a weak upper-level disturbance rounding the base of the trough parked over the Eastern Seaboard. Upper-level ridging will build in from the west across the TN Valley on Monday, leading to subsidence and drying over the northern two- thirds or so of the CWA. High temps should be a few degrees warmer on Monday compared to Sunday across much of the area thanks to less cloud coverage.
/CME/ Stout sub-tropical ridging remains centered over the ArkLaTex this evening. Low temperatures will be mild in the low to mid 70s. /TW/ Prior discussion below: Tonight and Sunday: Despite the low level boundaries and better flow, deep convection has been slow to develop this afternoon due in large part to the proximity of the mid level ridge centered over east TX. The sprawling ridge will once again allow temperatures to climb as mid 90s look probable.
303 AM EDT Sun Aug 22 2021 Mid level ridging and broad enhanced subsidence will be sustained across Se Mi today as Henri affects New England. Meanwhile, high pressure expanding across Upper Mi will drive a slow moving back door cold front into Se Mi from the north today. Expansion of the subtropical ridge into the Ohio Valley and srn Great Lakes Mon into mid week and a more S-SW low level flow into Se Mi (with 850mb temps of +18 to +22C) will result in hot and humid conditions Tues and Wed, possibly into late week. A cold front is progressing through Lower Michigan this morning.
(Today through Monday afternoon) A ridge anchored across the southern CONUS, its axis near the TX/LA border, will continue its westward expansion today. This westward expansion of the ridge will yield increasing subsidence, as well as shunt a majority of the subtropical moisture plume to the west, limiting storm chances this afternoon to all but the higher terrain and immediately adjacent plains. Upper 80s are once again expected across the higher terrain, with upper 90s and lower 100s through portions of the Pecos and Rio Grande Valleys. Monday will mark the beginning of what looks to be a prolonged period of warm, dry weather across Southeast New Mexico and West Texas as the aforementioned ridge broadens and intensifies. Mountain areas will still be a bit cooler, in the upper 80s, with no rain or storms expected.
Today Through Monday Night An upper ridge will build over the southern U. Upper low pressure will continue along the east coast today and Monday. Included a slight chance of precipitation in the east for Monday with another weak trough. Temperatures will heat up this afternoon and highs will be in the lower to mid 90s. A warm night is expected tonight with lows in the lower to mid 70s.
Then post-frontal ridge to slide in and scour out things with lower RH and cooler temps. Lows in the lower 60s southeast, to the mid 50s northwest. High pressure with northeasterly sfc winds under pronounced H85 to H8 MB inversion. Limited mixing may keep high temps more in the low 80s, but sunshine and lower DPTs/lowered RH's may allow heating into the mid 80s in some locations. That repeating process is known for knocking down the ridge placement, and allowing the convectively active warm frontal zone to shift southward with time. Models are all hinting at nocturnal storms in Iowa, which in zonal flow would move east, but more likely even is the low level jet veering into eastern Iowa after 2 AM.
Some early morning low clouds and patchy fog will give way to a mostly sunny afternoon as a surface warm front lifts north across western Kansas.
/issued 133 PM CDT Sat Aug 21 2021/ West Texas is situated between an elongated high along the Gulf Coast and a negatively tilted trough just east of the northern Rockies.
254 AM EDT Sun Aug 22 2021 Surface analysis early this morning shows broad high pressure in place from IA/MN and into the Ohio Valley. Water vapor showed ridging in place over Illinois. Models show the strong ridge building across Indiana today. Ensemble means suggest upper ridging will hold over the Ohio and Tennessee Valleys for most of this week, as a couple of short wave trough move through the northern Great Lakes.
Temperatures on Monday will be cooler than average with highs in the upper 60s to mid 70s. The highs for the Sunday will be in the 70s. By Monday, the low has exited and the region is under a weak trough pattern.
257 AM CDT Sun Aug 22 2021 High pressure will provide a quiet and rather comfortable (dew points in the mid- to upper 50s) Sunday. High temperatures will range from the lower 70s to lower 80s. However, soundings indicate that much of this shear is located in the lowest 1 km and that this shear should be located below the nocturnal inversion. On Monday, dew points will climb into the lower to mid-70s along and south of Interstate 90. The combination of these dew points and temperatures in the mid to upper 80s will result in heat indices climbing into the lower and mid 90s.
With daytime heating and the interaction of the upper trough and the llj late this afternoon into the evening from the James Valley east, there will be the potential for some strong to severe storms. Dry, warm air will quickly push in from the west behind the low helping to set up a cap. Seeing any redevelopment in the upper trough interaction is more unlikely the farther west you go. The other concern of the day is the dry air mass behind the low. Areas west river will see RH fall to around 20 percent with some breezy winds still in place in the upper trough until closer to 0z.
1030 AM EDT Sun Aug 22 2021 A slow-moving, cut off upper level low will be located over southern and eastern PA and the Virginias through the remainder of this weekend. This weather feature will combine with the western edge of abundant tropical moisture from Hurricane Henri to bring the threat of localized heavy rainfall and flooding to portions of the Lower Susquehanna Valley and Western Poconos.
The pattern taking shape in the near term is one of building mid/upper level heights as the overall ridge amplifies. As this occurs today, we will still see some s/w feature move southward on the periphery of the ridge. Additionally, the low level temps will be on the warm side with around 20C at 850mb.
1017 AM EDT Sun Aug 22 2021 Mean layer ridging centered to the southeast of Bermuda stretches west across Florida and reaches all the way to Texas. The ridge's midline is fractured across Florida, although the 12Z FL RAOBs sampled rising heights in the lower and mid levels, with no change aloft. Scattered thunderstorms have been favored across the Straits of Florida, although portions of the Lower Keys have had a couple rounds since sunrise. High pressure extending from the Western Atlantic across the Florida Peninsula will maintain moderate east to southeast breezes this afternoon through Monday.
A low pressure system continues to sit over New England, but that's not stopping a positively tilted upper ridge from stretching from Texas towards Lake Huron. This places the ridge over the CWA. Tonight, winds go mostly calm and skies remain mostly clear as high pressure and upper ridging take a stronger hold over the area. Louisville remains warmer in the mid 70s. Strong upper level ridge centered near the ArkLaTex region Monday morning will result in a hot and muggy week ahead for southern Indiana and central Kentucky. Afternoon highs will steadily climb going into midweek as the ridge slowly inches toward the region.
605 AM CDT Sun Aug 22 2021 (Today and tonight) An upper level ridge will dominate the weather across West Central Texas through the next 24 hours, resulting in dry conditions.
High pressure was in control across the region early this morning. Low pressure was observed along the Wyoming/Montana border and this feature will bring the potential for showers and thunderstorms tonight as it lifts to the northeast. Skies will remain clear through much of today as the area of high pressure shifts off to the east. A tightening pressure gradient on the western periphery of the high will lead to gusty winds this afternoon and into tonight from the southeast. Clouds will also begin to increase as the low lifts into southern Manitoba and drags a front into the Red River Valley this evening.
526 AM MDT Sun Aug 22 2021 The H5 trough continues to sweep across the state this morning, dragging along a weak cold front. As the trough sweep northeast this morning, showery activity will quickly wane, with most activity complete by noon. Jet streak along the bottom of the trough will help mix some gusty winds down to the sfc for the wind corridor from RKS to CPR through this afternoon. Monday will see another breezy day for much of the region, as southwesterly flow sets up ahead of a trailing trough along the US/Canada border. Models are hinting at some weak instability trying to bubble up some showers along the I-25 corridor down to eastern Sweetwater County during peak heating hours, but model soundings show very dry profile in the lowest 10000 ft, along with some capping.
Cooler temperatures this weekend under a robust marine layer providing a chance for patchy drizzle along the coastline. The cloudy start and persistent upper level trough locked in overhead will lead to seasonably cool temperatures today. Toward the end of the work week the upper level trough will weaken as high pressure builds over the region.
/issued 307 AM CDT Sun Aug 22 2021/ A return to generally benign weather is expected across the CWA today as an upper level anticyclone continues to build over Texas. This will be occurring in tandem with the departure of upper troughing over the Rockies, resulting in a slight veering of upper level flow as the day progresses. Another impact of the building upper level ridge over Texas will be an increase in afternoon high temperatures, especially over the Rolling Plains. /DWK No major changes once again with upper level high pressure expected to build across the area early to mid week with 500 millibar heights in the lower to mid 590's.
1100 AM EDT Sun Aug 22 2021 A slow-moving, cut off upper level low will be located over southern and eastern PA and the Virginias through the remainder of this weekend. This weather feature will combine with the western edge of abundant tropical moisture from Hurricane Henri to bring the threat of localized heavy rainfall and flooding to portions of the Lower Susquehanna Valley and Western Poconos.
347 AM MDT Sun Aug 22 2021 An upper level trough will travel from the Northern Rockies this morning and to the Northern Plains this afternoon. Once the trough axis passes through, subsident drier air will move into the area. A strong ridge over the Southern Plains will slide slowly eastward as the week progress.
A narrow upper level ridge axis can be found over central Indiana this morning, which will persist through the day. Although a fairly deep near-dry adiabatic mixed layer will be present this afternoon, winds are quite light through the lowest couple hundred millibars of the column, so expect no gustiness or decent breeze to mitigate the building heat today. Surface analysis early this morning shows broad high pressure in place from IA/MN and into the Ohio Valley. Water vapor showed ridging in place over Illinois. Models show the strong ridge building across Indiana today. Ensemble means suggest upper ridging will hold over the Ohio and Tennessee Valleys for most of this week, as a couple of short wave trough move through the northern Great Lakes.
Otherwise, dry elsewhere this morning, with higher presence of mid/upper level cloud cover due to moisture wrapped around the trough over the Mid-Atlantic.
743 AM EDT Sun Aug 22 2021 A slow-moving, cut off upper level low will be located over southern and eastern PA and the Virginias through the remainder of this weekend. This weather feature will combine with the western edge of abundant tropical moisture from Hurricane Henri to bring the threat of localized heavy rainfall and flooding to portions of the Lower Susquehanna Valley and Western Poconos.
347 AM MDT Sun Aug 22 2021 The H5 trough continues to sweep across the state this morning, dragging along a weak cold front. As the trough sweep northeast this morning, showery activity will quickly wane, with most activity complete by noon. Jet streak along the bottom of the trough will help mix some gusty winds down to the sfc for the wind corridor from RKS to CPR through this afternoon. Monday will see another breezy day for much of the region, as southwesterly flow sets up ahead of a trailing trough along the US/Canada border. Models are hinting at some weak instability trying to bubble up some showers along the I-25 corridor down to eastern Sweetwater County during peak heating hours, but model soundings show very dry profile in the lowest 10000 ft, along with some capping.
510 AM CDT Sun Aug 22 2021 High pressure will provide a quiet and rather comfortable (dew points in the mid- to upper 50s) Sunday. High temperatures will range from the lower 70s to lower 80s. However, soundings indicate that much of this shear is located in the lowest 1 km and that this shear should be located below the nocturnal inversion. On Monday, dew points will climb into the lower to mid-70s along and south of Interstate 90. The combination of these dew points and temperatures in the mid to upper 80s will result in heat indices climbing into the lower and mid 90s.
The low cloud deck is staying north of DRT for now and is not showing signs of spreading southward. Last evening's upper air analysis and this morning's water vapor satellite imagery show the subtropical ridge over Texas. There is good model agreement for the subtropical ridge remaining in place through the short term period. Models are also in good agreement in the lower levels with southerly to southerly flow continuing. The upper ridge will suppress convection for Sunday and Monday. Temperatures will be about the same as the last couple of days, perhaps a degree or two warmer.
622 AM CDT Sun Aug 22 2021 Upper-level ridging is currently present over the Middle Mississippi Valley with an area of high pressure settling in over the Upper Midwest at the surface.
/Issued 422 AM EDT Sun Aug 22 2021/ Light to moderate rain showers are currently moving southeastward across central and eastern portions of the CWA, associated with a weak upper-level disturbance rounding the base of the trough parked over the Eastern Seaboard. Upper-level ridging will build in from the west across the TN Valley on Monday, leading to subsidence and drying over the northern two- thirds or so of the CWA. High temps should be a few degrees warmer on Monday compared to today across much of the area thanks to less cloud coverage.
555 AM CDT Sun Aug 22 2021 A weak cold front will bring slightly less humid conditions to central Illinois today. Cold front continues to inch eastward early this morning, with 07z/2am wind analysis suggesting it is now along I-57. Drier air is trickling into the western KILX CWA as evidenced by dewpoints dropping into the lower 60s well behind the front across the Illinois River Valley.
Looking at the big picture this morning, upper ridging has begun to expand across the Southern Plains, while a weak trough is in place over the Mid-Atlantic states. This trough is directing Hurricane Henri northward on its final approach towards the southern New England coast.
A stacked low pressure system is spinning through central and eastern Montana this morning, and is expected to lift away through northeast Montana later this afternoon and evening. A brief small-scale ridge of high pressure will bring a break in the weather tonight through Monday morning. Monday afternoon through through late Monday night will see another low pressure system sliding along the international border bringing scattered shower and thunderstorm again to portions of NE Montana.
Mid level ridging and broad enhanced subsidence will be sustained across Se Mi today as Henri affects New England. Meanwhile, high pressure expanding across Upper Mi will drive a slow moving back door cold front into Se Mi from the north today. Expansion of the subtropical ridge into the Ohio Valley and srn Great Lakes Mon into mid week and a more S-SW low level flow into Se Mi (with 850mb temps of +18 to +22C) will result in hot and humid conditions Tues and Wed, possibly into late week. A cold front is progressing through Lower Michigan this morning.
401 AM CDT Sun Aug 22 2021 Looking at the big picture this morning, upper ridging has begun to expand across the Southern Plains, while a weak trough is in place over the Mid-Atlantic states. This trough is directing Hurricane Henri northward on its final approach towards the southern New England coast.
/issued 340 AM CDT Sun Aug 22 2021/ Mid-level heights are building over the Lower MS Valley, indicating the much advertised pattern chance is commencing. The subtropical ridge is currently anchored over east TX and LA, nosing poleward to near Lake Michigan. A weak cold front will dip into the area this morning, bringing drier air into the region. Afternoon dewpoints are forecast to remain in the mid 70s with temperatures climbing into the low/mid 90s.
/issued 410 AM EDT Sun Aug 22 2021/ Narrow ridge axis aloft bisecting the peninsula this morning between W Atlantic and S/Central CONUS ridging, south of troughing extending down through the Mid-Atlantic along with Henri approaching New England. E CONUS troughing gradually fills and lifts out by mid week as ridging builds to our north over the Central/Eastern CONUS and deeper E'ly flow returns along with a W'ward moving U/L low that gradually crosses the state mid to late week. with temps running in the low/mid 90s and heat indices topping 100 each afternoon. High pressure remains over the Gulf waters into mid week with mostly tranquil conditions. An area of upper low pressure expected to move into the region by mid week.
One more fairly wet day as we remain on the northwest flow side of the upper level ridge. By Monday, high pressure works in under the upper level ridging.
402 AM CDT Sun Aug 22 2021 The pattern taking shape in the near term is one of building mid/upper level heights as the overall ridge amplifies. As this occurs today, we will still see some s/w feature move southward on the periphery of the ridge. Additionally, the low level temps will be on the warm side with around 20C at 850mb. /CME/ Ridging aloft and at the surface really dominates much of the forecast.
Near the surface, a lee side trough of low pressure is slowly strengthening in eastern Colorado. Some early morning low clouds and patchy fog will give way to a mostly sunny afternoon as a surface warm front lifts north across western Kansas.
Surface analysis early this morning shows broad high pressure in place from IA/MN and into the Ohio Valley. Water vapor showed ridging in place over Illinois. Models show the strong ridge building across Indiana today. Ensemble means suggest upper ridging will hold over the Ohio and Tennessee Valleys for most of this week, as a couple of short wave trough move through the northern Great Lakes.
At 3 AM, an upper level trough was evident on satellite over Montana/Idaho/Wyoming. This should prime the atmosphere with 1500-2500 J/kg of MLCAPE ahead of an advancing cold front, and lead to scattered thunderstorm development across central Nebraska between 5 PM and 8 PM. Warmer with Lingering Storm Chances Monday: Model guidance suggests a stalled front across our region Monday.
Cooler temperatures this weekend under a robust marine layer providing a chance for patchy drizzle along the coastline. The cloudy start and persistent upper level trough locked in overhead will lead to seasonably cool temperatures today. Toward the end of the work week the upper level trough will weaken as high pressure builds over the region. KSFO Bridge Approach.
Thunderstorm activity will be on a gradual rise over the next couple of days with best chances remaining over the higher elevations and in areas to the south and east of Tucson.
guidance is insistent on advecting the low level moisture out of the region this morning as surface flow is forecast to shift to southwesterly and increase as the day progresses.
A longwave trough remained stationed over the western states with high pressure centered over Texas this morning.
635 AM EDT Sun Aug 22 2021 A weak trough of low pressure will approach the area today and then dissipate, offering an isolated chance of a shower or thunderstorm this afternoon. High pressure will follow and prevail for the early part of the week resulting in hot and humid conditions. Temperatures will be slightly warmer with highs in the upper 80s to around 90. Mid level ridge top begin building into the region Monday. A mid level high will be centered over the central plains states Monday night with a ridge axis oriented toward the northeastern United States. At the same time, the long wave trough will be situated over the west coast with short wave energy ejecting over the north side of the high into the upper Midwest and Great Lakes.
Once this occurs, generally west to southwesterly flows set up across the area and while monsoonal moisture remains to our south, the area of high pressure will elongate and keep the deeper moisture in New Mexico. The region will remain sandwiched between a broad rotation of high pressure over the Southern Plains and lower heights anchored to the PacNW for several days.
An area of showers has developed across northwest Montana this morning ahead of an upper level low pressure system digging southward through British Columbia. A weak cold front will swing through Monday morning, resulting in cooler conditions, and continued breezy winds, especially across southwest Montana and Lemhi County in Idaho.
Warmer weather returns as temperatures climb to above seasonal normals through the week.
For today, the area will be under a west to southwest flow aloft as an upper low pressure system sits across British Columbia, Canada. The upper low pressure system will move across southern Canada during the Monday timeframe.
The models are in very good agreement building an upper level ridge across Texas north toward Nebraska early this week.
1056 AM EDT Sun Aug 22 2021 A weak trough of low pressure will approach the area today and then dissipate. High pressure will follow and prevail for the early part of the week resulting in hot and humid conditions. Appears that there is a weak trough in western Indiana. Mid level ridge top begin building into the region Monday. A mid level high will be centered over the central plains states Monday night with a ridge axis oriented toward the northeastern United States. At the same time, the long wave trough will be situated over the west coast with short wave energy ejecting over the north side of the high into the upper Midwest and Great Lakes.