Aikyam-Lab/Synoptic-Bench huggingface dataset:
A cold upper level low continues to move eastward through North-central MT this morning, bringing an area of more concentrated rain showers to locations along the Hi- Line. The lingering clouds and showers associated with the upper low will provide one more day of below normal temperatures, with highs mostly running in the 70s. Dry northwesterly flow aloft is expected for much of the work week as high pressure becomes established over the Pacific Northwest and Great Basin.
Briefly cooler conditions are expected across northern Utah today behind a cold front before a warming trend commences for the rest of the week.
Shower and thunderstorm chances will increase later this afternoon and tonight with an approaching trough. Precipitation chances will increase tonight into Tuesday as sly wind advects sufficient moisture into the area ahead of the crossing trough.
555 AM MDT Mon Aug 9 2021 A mid-level low pressure trough was moving eastward across the northern Rockies early this morning. Subtropical moisture will remain well south of the area as high pressure extends across the southern U. The gradient aloft decreases Tuesday as the trough to the north pushes to the northern Plains. Our CWA will be on the fringe of a deep trough that will be centered over the central Plains. High pressure will start setting up though it will be very disjointed to start with. Monsoonal moisture will continue to stream up from the south but the higher pressure over us will keep the heavier precip over AZ and NM.
420 AM CDT Mon Aug 9 2021 Weak ridging was building into the central Plains this morning in between two mid-level troughs: the first across the Mississippi Valley and the other centered over western Montana.
A weak low pressure trough over the area will continue to bring slightly milder temperatures today. Warmer temperatures will return on Tuesday and continue through the rest of the work week as high pressure builds in.
It'll be hotter (well, warmer) and drier on Tuesday for sure, and the winds will be up again, but reaching the elevated fire weather thresholds are borderline at best.
Developing light easterly flow with the ridge axis lifting north will allow earlier onset and inland progression of the east coast sea breeze and its associated convection than previous days, keeping highest chances for showers/storms closer to the coast (esp. Atlc ridge axis will begin to lift north from central FL and the local Atlc.
Slightly cooler and dry today, along with continued haze which may be dense enough at times to cause air quality and visibility issues.
630 AM EDT Mon Aug 9 2021 High pressure overhead will gradually shift off the coast today, setting up offshore through the rest of the week. A cold front will approach the area this weekend. Should be another quiet night as high pressure continues to slide offshore. By this weekend, a weak cold front will move into the area, bringing with it an increase in rain chances. High pressure will remain just offshore Tuesday, and will continue to suppress most shower and thunderstorm development.
Low level convergence along a cold front will support a few strong to potentially severe thunderstorms extending from McCook and Trenton southwest to near the Goodland and Colby areas late in the afternoon. There is a small chance for thunderstorms to exist further west along the cold front but confidence is too low to include in the forecast. an upper level trough moves across the northern plains with its cold front moving through during the day. High temperatures wont be quite as hot as Monday with readings in the low to upper 90s. The NAM solutions remain cooler compared to the numerous other model solutions with high temperatures in the upper 80s to lower 90s.
907 AM EDT Mon Aug 9 2021 High pressure overhead will gradually shift off the coast today, setting up offshore through the rest of the week. A cold front will approach the area this weekend. Should be another quiet night as high pressure continues to slide offshore. By this weekend, a weak cold front will move into the area, bringing with it an increase in rain chances. High pressure will remain just offshore Tuesday, and will continue to suppress most shower and thunderstorm development.
A ridge of high pressure will continue to build over the west coast heating temperatures up each day with temperatures mainly becoming 100 plus throughout the central valley by Tuesday and approaching 110 degrees over the north end of the valley on Tuesday as well.
/issued 343 AM EDT Mon Aug 9 2021/ Compared to yesterday, the ridge axis has shifted a bit farther north and retreated eastward just a bit. Light and rather uninteresting synoptic flow remains overhead with the ridge firmly in control, and likely to remain that way for the next few days at least. High pressure remains in control across the Florida peninsula, allowing scattered mainly afternoon and evening showers and thunderstorms to develop each day.
Weak ridging was building into the central Plains this morning in between two mid-level troughs: the first across the Mississippi Valley and the other centered over western Montana.
This moisture and instability combined with daytime heating will lead to shower and thunderstorm development along the sea breeze and outflow boundaries during the afternoon with an east-southeast steering flow albeit light favoring the highest pops and best convective coverage setting up along and to the west of the I-75 corridor during the late afternoon and evening hours which is in line with the latest trends from the HRRR. High pressure across the area will maintain tranquil boating conditions on the Gulf waters the remainder of today with light east southeast winds and slight seas with an onshore sea breeze component developing along the coast during the afternoon.
637 AM CDT Mon Aug 9 2021 Update Aviation Discussion for 12z TAFS Upper level low over Wisconsin is forecast to weaken and lift northeast by 12z Tuesday.
This high-based activity typically peaks during the coolest time of day, when the mid and upper levels are cooler than the moist layer and thus more unstable.
625 AM CDT Mon Aug 9 2021 Summary: Foggy conditions to the start of the week with warmer temperatures arriving later this afternoon. This will allow for warm temperatures to return to the Northland with highs in the low 80s to near 90 to the west.
The mid/upper ridge is progged to break down across the area as a frontal boundary is forced south in the wake of a vigorous mid/upper trough over the Great Lakes area. There remains differences in how much cooling we can expect within the column and how quickly the mid/upper ridge returns to the central CONUS but with multiple rounds of convection, the effective frontal position is expected to be forced south of the area bringing more seasonable temperatures to the area through the period.
Temperatures are in the upper 80s to low 90s with dewpoints in the low to mid 70s. Some weak troughing extends southward into the Tennessee Valley but overall forcing is weak. The upper trough will also pass to the east this evening as well. Temperatures will once again climb into the upper 80s to mid 90s with dewpoints in the low to mid 70s. The highest heat indices are forecast for locations to the west of I-65.
109 PM EDT Mon Aug 9 2021 Warm and humid conditions with gradually increasing rain chance can be expected until cold frontal passage late this week.
1012 AM CDT Mon Aug 9 2021 Summary: Foggy conditions to the start of the week with warmer temperatures arriving later this afternoon. This will allow for warm temperatures to return to the Northland with highs in the low 80s to near 90 to the west.
(This afternoon through Tuesday night) An upper level ridge is over New Mexico and Texas with northwest upper winds over the area. Upper ridging will remain across the region on Tuesday with temperatures a little cooler than today.
Briefly cooler conditions are expected across northern Utah today behind a cold front before a warming trend commences for the rest of the week. Utah and southwest Wyoming remain under a predominately zonal flow aloft this morning due to the flattening of the ridge by the trough currently centered over Wyoming and Montana. West to northwest winds are expected to become occasionally gusty this afternoon over the higher terrain and some valleys of eastern Utah and southwest Wyoming. A dry cold front will continue to sag across central Utah today, with cooler temperatures behind the front along with some locally breezy westerly winds in the higher terrain as well as some eastern valleys. High pressure will then gradually build into the area from the northwest through the week with warmer temperatures expected and generally light and terrain driven winds.
Confidence is not overly high on how far southeast the cold front will be during the day Tuesday and feel that the combo of high dewpoints and heat will impact southeastern portions of the area.
High pressure ridge with light winds located across the area today. Similar conditions expected on Tuesday as the subtropical ridge remains over the area.
There will be some lingering influence from an upper trough across our eastern counties.
Given the higher levels of moisture and cloud coverage, temperatures will be cooler this week. As high pressure again shifts east of the area, we will have a deeper monsoon flow pattern this week. We'll also be open for more inverted trough and easterly wave activity to focus storm coverage. The ridge east of the area will weaken around mid week as a broad trough through the northern and central plains tries to temporarily reverse the flow.
The heat advisory has been reissued for Tuesday, however due to the lower dewpoints and heat index, the heat advisory has been pulled east a bit compared to Monday.
Showers and thunderstorms develop across the high terrain early this afternoon, becoming a bit more widespread later and into the evening hours.
A moist surface layer this morning characterized by dew points around 70 degrees F or a little higher over the lower plains and in the 60s farther west is part of the forecast challenge this afternoon. There is a synoptic cold front hanging from north central CO across northwest Nebraska into northeast South Dakota. Ahead of the cold front is a general area of surface toughing across southwest Nebraska into northwest Kansas where the convective allowing models erupt convection later today. A mid level wave will be moving across the northern plains during the period, driving and 850 mb/surface cold front southward across western Nebraska into Kansas.
Meanwhile, upper level high pressure will build over the southeastern CONUS and persist through the short term period. At the surface, high pressure will dominate over the Appalachians down into the northern Gulf of Mexico. High temperatures will climb into the lower to mid 90s this afternoon and Tuesday afternoon, with low temperatures in the mid to upper 70s tonight.
Will see where the surface cold front lands at the end of peak heating, and if there will be enough forcing/lift along it to overcome today's mid-level thermal capping inversion and get a few storms to initiate in the portion of the slight risk region currently out here over South Dakota. A potent upper level closed low is currently situated over Montana and will track east, being the main driver of thunderstorm development across the northern plains tonight. At the surface, low pressure is becoming more defined across the western Dakotas this morning, with a tightening pressure gradient on the back side. Drier, cooler air follows for Tuesday.
1246 PM CDT Mon Aug 9 2021 Summary: Foggy conditions to the start of the week with warmer temperatures arriving later this afternoon. This will allow for warm temperatures to return to the Northland with highs in the low 80s to near 90 to the west. HYR my see brief lowering of ceilings to MVFR as the low pressure system exits to the east through the early afternoon.
/Tonight through Tuesday Night/ Upper-level ridging will continue to dominate the prevailing pattern through the short term forecast period. Coupled with dewpoints in the low-mid 70s through the afternoon, this will result in heat indices climbing into the 100-105F range areawide, with some sites seeing as high as 106 or 107. Otherwise, we look to remain dry through the short term period, thanks to the persistent effects of the upper level ridge.
700 and 500 temps will warm throughout the day with some broad, weak ridging with a strengthening cap likely.
226 PM MDT Mon Aug 9 2021 Cooler air continues to filter into the area today, with highs limited to the upper 70s to upper 80s. Upper low along the MT/Canadian border will continue E/NE tonight. as the upper low continues eastward, an upper wave will cross western SD. Warmer temperatures are expected tomorrow.
(This evening through Tuesday) Hot and dry conditions will persist across the area through Tuesday, as upper level ridging dominates. Warm and muggy conditions will prevail tonight, with lows in the lower and middle 70s.
There is a north-south oriented cold front positioned just east of the Missouri River valley. Between 03Z and 06Z, is when the cold front is moving, in earnest, through the northeast corner of South Dakota and west central Minnesota.
A similar pattern is expected for Tuesday with the addition of a Lee side trough combining with good moisture which will bring chance POPs across the area with the highest POPs expected across north Georgia. Models remain fairly consistent with the pattern of a broad ridge over the southeast. and a broad trough over the northern states. However, little run-to-run consistency and little to no agreement as to the strength or positioning of the low between the models right now.
258 PM MDT Mon Aug 9 2021 As the day progresses, a weather system moves eastward out of the area, leaving The Treasure State much cooler than when it arrived. A low pressure system exits eastward out of our area leaving The Treasure State much cooler in its wake. Even as the associated upper level trof is moving eastward, an upper level closed area of higher heights and the associated ridge builds over The Pacific Ocean off the U. Northwesterly flow on the leading edge of the upstream ridge aids in keeping temperatures considerably cooler than normal for the day.
In the overnight hours, transient surface ridging will provide some clearing. Behind the potential morning convective activity, a warm front lifts through WI bringing mid to upper 70 degree dewpoints to the region. While 0-6km shear continues to remain post cold frontal with maximum values >55 kts displaced north and west of the main region of instability, low-level 0-3km shear remains sizeable at ~45 kts. As for the upper-level dynamics, the upper-level closed low is forecasted to rejoin it's parent trough more to the north than previously forecasted. If convection does initiate along the cold front, temporal expectations are for the early afternoon to late morning in west-central Wisconsin moving southeast as the cold front expectedly sags in that direction.
253 PM CDT Mon Aug 9 2021 Pre-frontal trough pushing into far western counties of the forecast area as of 19Z, with cold front a bit farther west over central SD into the Nebraska panhandle. Aside from the aforementioned boundaries, main upper level support will remain well north with the trough sliding across North Dakota tonight. Later tonight into early Tuesday morning, HRRR/RAP continue to hint at spotty elevated showers/storms developing well behind the surface boundary, closer to an elevated front and the right entrance region of a weak jet rounding the North Dakota trough. Larger impact of the cool front/upper trough moving through the area will be not only cooler temperatures, but more significantly, lower humidity levels. Broad upper trough will be the prominent feature across the northern Plains throughout the remainder of the work week.
High pressure will build back over the region with drier and warmer weather early this week.
Synoptic pattern features a 591 to 593 dm sub-tropical ridge overhead while at the surface, the region sits in-between high pressure over the Gulf of Mexico and thermal troughing across the higher terrain of Mexico.
144 PM MDT Mon Aug 9 2021 Upper level low over northeast Montana will move into southwest Manitoba overnight with drier air progged to move into the region. Will again be cool tonight with temperatures in the lower 50s. This drives another cold front. but weather cold front through Tuesday night. northern Wyoming where the prefrontal trough does not arrive until the evening.
/issued 323 AM CDT Mon Aug 9 2021/ Aloft, upper troughs are noted near New York City, Chicago and and over Montana. Weak ridging is over the Gulf of Mexico and the northern Plains states. At the surface, high pressure extends from the Carolinas to the north central Gulf.
ABM Chattanooga Airport, TN 73 92 73 92 73 / 40 50 20 50 20 Knoxville McGhee Tyson Airport, TN 72 91 72 91 72 / 20 50 20 50 20 Oak Ridge, TN 70 90 72 90 72 / 30 50 20 50 20 Tri Cities Airport, TN 68 89 68 89 69 / 20 50 20 50 30.
Lows will be in the lower 70s. Forecast soundings indicate a cap in place for much of the day, with temperatures soaring into the lower 90s and dewpoints into the lower 80s.
Mid-level ridging continues to dominate over South Texas with a north to northeast flow aloft.
240 PM MDT Mon Aug 9 2021 Upper level Low responsible for the shower and thunderstorm activity today will push east of the area tonight. Another trough moves through Saskatchewan and Manitoba on Tuesday. Temperatures rebound back up to seasonal norms, but cooler than its been most of the summer. As the week progresses, another strong ridge builds over the Eastern Pacific and migrates over our area by the weekend.
334 PM EDT Mon Aug 9 2021 High pressure will prevail across the area into the upcoming weekend. High pressure remains the dominate synoptic feature, both aloft and at the surface. A broad upper ridge will remain over the eastern half of the country while Atlantic high pressure persists at the surface. Highs will be in the lower 90s. The persistent ridge will maintain similar conditions into the first half of the weekend with isolated to scattered diurnal convection and highs in the low 90s.
High temperatures in the low-mid 90s and overnight lows in low-mid 70s. Mid and upper level ridging will extend into the forecast area today, so the support for afternoon convection is limited. It will be another muggy night in the low to mid 70s with some patchy fog around sunrise. Convective debris cloudiness and abundant low level moisture will keep overnight lows in the low to mid-70s.
A potent upper low is moving into an increasingly moist and unstable environment this afternoon in eastern North Dakota, northwestern and west-central Minnesota. Further south, a boundary is draped along the Highway 200 corridor in North Dakota. Forcing is rather strong thanks to an approaching upper low. Ahead of the low, we are seeing moderate instability with CAPE in the range of 1500 to 2500 J/Kg. The northwesterly flow aloft then looks to persist as an upper level ridge once again builds into the Plains through the weekend. Behind the multiple cold frontal passages from earlier in the week, breezy to windy conditions and cooler temperatures in the 70s to low 80s are expected across the latter half of the week.
223 PM MDT Mon Aug 9 2021 Cooler air continues to filter into the area today, with highs limited to the upper 70s to upper 80s. Upper low along the MT/Canadian border will continue E/NE tonight. as the upper low continues eastward, an upper wave will cross western SD. Warmer temperatures are expected tomorrow.
/Tonight through Monday/ At 19z GOES satellite imagery shows an upper low swirling just east of the local area, centered near the WI/IL border. Stratus has been stubborn to dissipate on the northwestern periphery of the low which has hampered temperatures a bit over northern Iowa so far today. Temperatures in the 80s to low 90s with dewpoints in the low to mid 70s are common, pushing heat index values to near or above 100 degrees in some locations. A broad mid-level trough axis swings into the northern Plains tonight.
With ridging dominating at mid levels, subsidence will help to keep PoPs next to nil.
1143 AM MDT Mon Aug 9 2021 A mid-level low pressure trough was moving eastward across the northern Rockies early this morning. Subtropical moisture will remain well south of the area as high pressure extends across the southern U. The gradient aloft decreases Tuesday as the trough to the north pushes to the northern Plains. Our CWA will be on the fringe of a deep trough that will be centered over the central Plains. High pressure will start setting up though it will be very disjointed to start with. Monsoonal moisture will continue to stream up from the south but the higher pressure over us will keep the heavier precip over AZ and NM.
300 PM EDT Mon Aug 9 2021 High pressure will influence the weather through late week. A cold front will approach the area this weekend. Quiet weather to continue for the next several days as high pressure surface and aloft influences the weather across eastern NC. By this weekend, a weak cold front will move into the area, bringing with it an increase in rain chances.
239 PM MDT Mon Aug 9 2021 A low pressure system continues to makes its way through east-central Montana today leaving below average temperatures across the Northern Rockies. These cooler temperatures will not stick around however, as high pressure settles in, temperatures will climb throughout the week.
Valley afternoon highs will peak in the 90s around the Delta, middle/upper 90s in Sacramento, and as hot as the low 100s in the northern Sacramento Valley. Upper level highs over the Four Corners and the Pacific Northwest will build through the week, evolving to a large, broad upper ridge over western North America.
Currently, there are no thunderstorms detected over the area, and just a few showers north of the lower Keys. The Bermuda High continues to build into the southeastern states, with the axis of the ridge well to our north.
Despite hazy skies with smoke overhead, temperatures have still climbed into the lower to middle 90s, with still a couple hours of heating remaining. Thus, the heat advisory continues! Otherwise, CAMs continue to indicate convection may fire along the cold front across central NE 5-7pm.
Once again, temps are expected to rise into the mid 90s under the Deep South mid-level ridge. The region will remain on the westward periphery of an expansive subtropical ridge over the western Atlantic. Heat indices in the W & NW Delta have the highest potential of eclipsing 105 degrees & look to remain persistent through mid-late week (i. As the upper ridge breaks down, global guidance has progged a trough digging down into the upper Great Lakes, with a front diving down into the Ozarks, Mid- South & Tennessee Valley.
This trend is expected to continue through the rest of the afternoon with an upper trough still having some impact across the Upper Cumberland before pulling east this evening.
(This evening through Tuesday) Hot and dry conditions will persist across the area through Tuesday, as upper level ridging dominates. Warm and muggy conditions will prevail tonight, with lows in the lower and middle 70s. (Tuesday night through next Monday) Broad upper level ridging will remain in place across the region through the week.
Temperatures are in the low 90s with our southern counties in the mid 90s. High pressure will begin to strengthen over the area allowing temperatures to increase throughout the week.
High temperatures in the low-mid 90s and overnight lows in low-mid 70s. Mid and upper level ridging will extend into the forecast area today, so the support for afternoon convection is limited. It will be another muggy night in the low to mid 70s with some patchy fog around sunrise.
High temperatures are forecast in the low to mid 90s tomorrow afternoon with heat indicies potentially reaching the 100-105 degree range.
High pressure aloft will gradually build in through the week.