Aikyam-Lab/Synoptic-Bench huggingface dataset:
Scattered showers and isolated thunderstorms are expected along the high terrain this afternoon and into the evening. The northerly flow over the region will shift more northeasterly by morning as the high pressure over the Pacific Northwest shifts east. Monday precipitation chances increase across much of the area, with a surge of monsoonal moisture expected as a low becomes trapped over Arizona between the strong high over the northwest and another ridge over the south eastern United States. Later in the week, heights begin to rise as a trough begins to move into the Pacific Northwest nudging the ridge into the Rockies. EPS members shows moisture remaining in place, but temperatures look to rise for the second half of the week as the ridge nears.
Showers and thunderstorms developed along a very weak convergence/deformation axis in the lower-mid troposphere where there was about 1000 J/kg MLCAPE. The broad mid-level trough axis centered across the Great Plains will not change much in shape and position through Sunday. Despite the dry forecast going for Sunday afternoon/evening for much of the area (less than 15% POPs), there may still be an isolated or widely scattered thunderstorms just about anywhere given the fairly cool middle troposphere in vicinity of the mid level trough axis. The absence of the summer-subtropical ridge and a mean polar trough axis from the central to eastern CONUS will be the primary reasons for the below normal temperatures.
The areal coverage of this activity may shrink a little as the low level jet begins to wane. Temperatures today will range from the low 80s out west, to the upper 80s in the eastern Ozarks. Temperatures will be cooler with highs generally in the low 80s on a daily basis. A broad trough of upper level low pressure will retrograde back to the west, allowing for rising mid level heights to return from the east. We get back into a weak northwest flow regime by late in the week as a strong closed off upper level low pressure system develops over the Great Lakes Region. This low seems strong for the time of year, and I think models will adjust this with time.
A cold front will move through the region late in the week. Temperatures will be a few degrees warmer than yesterday, ranging from the upper 80s to around 90. Deeper moisture rotating around a ridge centered off the mid Atlantic coast will push into the region late tonight and tomorrow. Temperatures, both lows and highs, will be near if not a shade warmer than persistence.
Then moisture will increase across all of southern Arizona Monday through the work week resulting in scattered showers and thunderstorms and cooler afternoon temperatures. Today: Last rather hot day of the month, especially for the lower deserts. The tail-end of a trof will be along the AZ/NM border with scattered afternoon storms for the Whites. 5" range per GEFS/EPS ensemble while the above mentioned trof transitions into an easterly wave.
Showers and thunderstorms are likely to develop in the higher terrain of the central and southern Colorado mountains, and drift west-southwesterly through the afternoon.
More breaks in the cloud cover and a warmer boundary layer combined with slightly better pwats could lead to a higher coverage of storms Monday afternoon.
A strong ridge of high pressure still dominates the western US while a positively tilted trough remains relatively stagnant over central parts of the country. Ahead of the front, the moist airmass remains with dewpoints in the low 70s. Tonight, the stalled boundary begins modifying into a warm front, returning southerly winds for all except the northernmost parts of the CWA.
330 AM PDT Sun Jun 27 2021 Strong high pressure will continue hot weather this week, particularly for the northern half of the Sacramento Valley and surrounding terrain. Skies remain nearly cloud-free across interior NorCal early this morning as very strong high pressure remains centered to the north over the PacNW. Another hot day is in store for the region as it remains on the periphery of the high over the PacNW.
With this higher moisture, instability will be higher today and should see storms develop later this morning and into the afternoon. Skies should clear out tonight, but overnight temperatures will remain mild in the lower 70s. Some patchy fog may be possible in areas that see rain today, but have left it out of the current forecast package given the low confidence in it occurring.
We continue to have surface ridging across the Atlantic States with east to southeast flow into Central Alabama. In the upper levels, ridging is present over the Carolinas into the Western Atlantic stretching WWD into TN and TX. Across C AL we have overall weak easterly upper flow and building of this ridge. Temperatures will continue to moderate through the period as ridging aloft builds and warm flow off of the Gulf of Mexico feeds into Central Alabama in the lower levels.
643 AM EDT Sun Jun 27 2021 The area will remain in warm, humid air for several days on the western periphery of Atlantic High Pressure.
The High Wind Warning for Guadalupe Pass expires it 14Z and we will let it expire as scheduled. There is a cold front somewhere in the area whose presence is masked by numerous outflow boundaries present from recent convection.
Convection will redevelop this afternoon as the atmosphere destabilizes along and just ahead of the cold front which will move further southeastward today and then become nearly stationary. High temperatures will be slightly cooler today, but humidity levels will continue to be high along and ahead of the front across southeast and east central MO and southwest IL.
/issued 340 AM CDT Sun Jun 27 2021/ SHORT TERM (Now through Monday): An inverted 500 mb trough with embedded closed low will gradually retrograde towards and over the BRO CWFA during the period.
638 AM EDT Sun Jun 27 2021 High pressure will extend from north of Bermuda westward into the Southeast and southern middle Atlantic, with associated easterly flow off the Atlantic, through early this week. Water vapor satellite showed an upper-level ridge off the Delmarva coast, and an upper-level trough across Plains. Surface observations showed high pressure centered NE of Bermuda, with ridging across the Southeast. Dewpoints in the low 70s this morning will lower to the upper 60s this afternoon as mixing occurs, however the heat index will still make it feel like the low to mid 90s this afternoon. The upper ridge to our northeast will continue to build Monday, increasing high temperatures a degree or two for most areas compared to highs today.
/22/ Today and tonight: Early morning water vapor imagery showed the circulation around an upper level low spinning in the northwest Gulf and around a mid level ridge to the northeast that will remain dominant over our region through tonight. Early morning surface analysis still had a >1016mb ridge nosing across our CWA from the east. The combined affects of ridging surface and aloft our our northeast is expected to inhibit convection there again today but afternoon heating and the increase in moisture across the south is expected to lead to at least scattered coverage south of Interstate 20. Highs today should reach into the lower 90s at most sites and most sites tonight will bottom out in the lower 70s again.
We would have gone lower, except for the noted height falls at 12Z, the deep cyclonic flow encroaching from the northeast, and the expected backing of the low-level winds to the northeast to east this afternoon, all mechanisms for in-situ development. From synopsis, high pressure centered over the western North Atlantic will maintain moderate east to southeast breezes over the next few days. Breezes will lull briefly on Monday as an inverted trough moves into the southeastern United States and dissipates.
However, the high pressure dominating the Pacific NW continues to compress our marine layer. With the rest of the west focused on that dominant high pressure system to the north. how's our heat looking? Well, we've got an upper level low that is spinning offshore due west of the Bay Area and that will slightly weaken the local impact of that high pressure to our north. Areas near the coast are still looking fairly seasonal or slightly cooler than average (mid 50s to mid 70s).
501 AM EDT Sun Jun 27 2021 Currently - An Atlantic ridge extend southwestward of the Atlantic Coast and into the southeastern United States and Gulf of Mexico. A ribbon of moisture rich lower level air is wrapping around the ridge axis. Meanwhile, another upper level low and associated lower level inverted trough is rolling westward towards the northern Bahamas. The previously mentioned upper level low and lower level trough approaching the northern Bahamas will be nearing the southeast Atlantic coast on Monday. As the trough moves north of our area, it will cut into the pressure gradient, causing local winds to trend downwards on Monday.
Upper trough over the Plains and the boundary extending from the southern Plains towards the Great Lakes continues to keep most of the showers and thunderstorms off to our northwest. The upper high which has kept us mainly dry over the past few days will start to lose its grip today, and we may see some isolated showers and thunderstorms especially east of I-65 in the afternoon, largely diurnally forced.
Central CONUS troughing and east coast ridging remain largely unchanged throughout the short term, though the 5H ridge is progged to build slightly over the OH Valley. CAMs do show a chance of very isolated showers over the CWA this afternoon, but aforementioned building high pressure aloft should keep most areas dry. Thickness values slightly increase from yesterday, so expect afternoon max temperatures will be a degree or two warmer today. Another quiet night is expected with Monday morning min temperatures in the low 70s. Large Atlantic ridge that has kept our weather dry the past few days will slowly get squeezed by an upper low moving in from the northern Gulf coast and an trough dropping into the Midwest.
The beginning of the upcoming work week will feature a rinse and repeat pattern, with mid level southwesterly flow between a weak ridge over the southeastern CONUS and a weak low over the Canadian prairie. The higher amounts would be focused, again, south/east of the I-35 corridor, and perhaps even more likely between the I-70 corridor and the I-44 corridor.
There is a cold front somewhere in the area whose presence is masked by numerous outflow boundaries present from recent convection.
With our Canadian friends to our north experiencing warm temperatures, today's northerly winds advect warmer weather southward across central Montana. - Fogleman As we head into the work week, a strong, slow moving upper level ridge pushes into the area, leading to a prolonged heat wave across the state.
Lower shower and thunderstorm chances today, with drier air in place in the mid and upper levels thanks to high pressure off of the eastern US. Overall, PoPs around 20-30% area-wide into early evening, with the highest chances (~35%) across Lake and far western Osceola Counties.
In terms of synoptic lift, we are under a right entrance region of a jet streak (enhancing synoptic lift), we also have the main trof axis just to the west of the area and slight vorticity increase that slides around the trof. At the midlevels there is a small perturbation that moves through around the trof. Finally, at the surface we have a weak sfc trof and diffuse weak boundary over the middle of the area that will serve as a focus for lift as air runs up and over the boundary.
A strong ridge over the far NW United States will allow s/wv energy over the central plains to dig into New Mexico and Texas over the next few days. Why this matters is that the attendant "backdoor" cold front will enhance convection over New Mexico, pushing higher dewpoints toward Arizona.
through Monday Night Features we are monitoring in the short term are the anomalously strong high center positioned over the Pacific Northwest and British Columbia as well as a trough over low pressure over the central and southern Rocky Mountain states. The ridge axis does extend south from the Pac NW through western Nevada and California which will bring a bout of well above normal temperatures through Monday.
917 AM EDT Sun Jun 27 2021 The area will remain in warm, humid air for the next few days on the western periphery of Atlantic High Pressure.
541 AM EDT Sun Jun 27 2021 The area will remain in warm, humid air for several days on the western periphery of Atlantic High Pressure.
Did adjust the high temps today and tomorrow, to ensure that each day is at least a bit warmer than the previous day. With our Canadian friends to our north experiencing warm temperatures, today's northerly winds advect warmer weather southward across central Montana. - Fogleman As we head into the work week, a strong, slow moving upper level ridge pushes into the area, leading to a prolonged heat wave across the state.
Monday looks to be mostly a rinse and repeat of today, although with the upper trough finally beginning to make some eastward progress, more activity may stick around into the overnight hours tomorrow night. High precipitable water values and seasonably high freezing levels will continue to combine to produce high precipitation efficiency and an attendant heavy rain/isolated flood threat along with the pulse severe threat. An upper trough will gradually dig into the area mid to late week.
High pressure centered over the coastal Pacific Northwest will slowly drift eastward through the middle of the coming week, increasing temperatures toward record warmth.
1228 PM EDT Sun Jun 27 2021 Update - Marginal risk for severe weather this afternoon - Potential for more heavy rain especially Mon Aftn-Tue A cold front is situated from Northern Lake Michigan southwest into portions of Northern Illinois. Dew points ahead of the cold front remain in the upper 60s to lower 70s. The low level jet remains quite stout at midday on the order of 35-40 knots at this point, but it should continue to diminish as we move through the afternoon and evening. However the low level jet is centered off to the east of the CWA and our area is generally in the divergent part of that feature.
The highest coverage is over the mountains and foothills from the divide eastward. WIll keep the highest pops going there. For convection on Monday, the highest CAPE, by far is over the mountains foothills again, especially south of I-70. It will be a bit warmer on Monday and there will be a bit more moisture over the plains on the precipitable water fields. Ensemble guidance has shown general agreement with the gradual breakdown of the blocking upper level ridge to the west and trough over Colorado.
(This evening through Monday) A mid-level trough axis will continue to be positioned along the Rockies this evening and into tomorrow, with southwest flow aloft over the area.
248 PM MDT Sun Jun 27 2021 Isolated to scattered showers and a few thunderstorms are expected each of the next couple of days along with cooler than average temperatures.
Most of this activity should end around midnight, although a few showers may linger through early Monday morning along the higher terrain. Temperatures will be slightly warmer in most places, with isolated to scattered showers and thunderstorms again expected east of the Divide - mainly Johnson and Natrona counties. The hot ridge remains to the northwest, while weak troughing stretches across the state and to the east.
Monday forecast to be slightly warmer with a slight chance for afternoon convection, mainly across higher elevations. Upper ridge continues to strengthen on Monday with model guidance showing 500mb heights increasing from about 592 dam to 594 dam across the forecast area. This will result in continued warm temperatures on Monday with max temperatures in the low 90s for many areas. A few afternoon showers will be possible, but PoPs are forecast to be lower than on Sunday and primarily limited to the higher terrain of the mountains.
A broad upper level trough over the region will continue producing pockets of showers and thunderstorms through this evening.
Excessive Heat Warning remains in effect today and tomorrow for the lower elevations west of Las Vegas in Nevada and into portions of southeast California. through Monday Night Features we are monitoring in the short term are the anomalously strong high center positioned over the Pacific Northwest and British Columbia as well as a trough over low pressure over the central and southern Rocky Mountain states. The ridge axis does extend south from the Pac NW through western Nevada and California which will bring a bout of well above normal temperatures through Monday.
The mean trough axis over the central CONUS continued to yield light winds and temperatures in the 80s during the afternoon. These showers and storms were wandering aimlessly for the most part given much of eastern Colorado and far western Kansas were positioned in the middle of the mid tropospheric trough axis. More of the same is expected on Monday, although even a bit cooler with more cloud cover as mid level RH's will be higher. The Pacific Northwest upper ridge responsible for the record- breaking heatwave will transition east over the course of the week with the mean trough axis breaking down only to redevelop a bit farther east across the Great Lakes into the Ohio Valley.
313 PM EDT Sun Jun 27 2021 Latest analysis shows an upper level trough to the west over the center part of the country and upper level high pressure off the east coast. Overnight low temps will range from the lower 60s in the sheltered valleys to near 70 near the ridge tops.
The upper level pattern is rather amplified for late June with a ridge centered on both coasts of the CONUS. One centered over the Mid-Atlantic and another over the Pacific Northwest with troughing extending across the Great Plains. Upper level heights will also be slightly higher as the ridge across the Mid-Atlantic tries to expand southwestward.
Chance of thunder is low with ridging resulting in poor mid-level lapse rates, but chance of thunder is higher than yesterday with some added instability due to the higher low-level moisture. In the upper levels, strong ridging remains over the East Coast and Southeast states. A trough is over the Central U. High pressure remains over the region today and tonight with light southerly low level winds. McD Chattanooga Airport, TN 71 91 71 90 71 / 10 20 10 40 20 Knoxville McGhee Tyson Airport, TN 70 91 69 90 70 / 10 20 10 30 20 Oak Ridge, TN 69 91 69 90 70 / 10 20 10 30 20 Tri Cities Airport, TN 66 90 65 89 66 / 10 20 10 20 10.
Otherwise, expect fairly quick clearing late this evening through the night as a surface area of high pressure moves across the region and the upper-level ridge begins to more fully nose into the CWA from the Pac NW and SW Canada. As the region remains in the grips of the ridge of high pressure centered just west of the CWA, each day is expected to get progressively warmer through mid-week.
Tonight: A quiet night is in store as sfc ridging builds in & convection begins to wane shortly after sunset. With abundant low-level moisture, near to slightly above normal lows are expected in the low 70s.
Afternoon satellite images depict the forecast area near or just east of the center line axis of a weakening upper trough/shear axis extending down from the Northern Plains. the trend toward somewhat more wet and possibly a touch cooler weather was initiated yesterday in the the models and to some degree in the forecast. This stems from the upper axis of the trough shifting/moving out, though it is weakening with time.
There will be a decrease in any shower/thunderstorm activity later in the evening as the heating of the day is lost, though cannot rule out a few isolated showers overnight with an upper level trough axis remaining just to our west. Not much change for Monday with the upper level trough continuing to exert influence on our area. Highs will generally run in the lower 80s.
The upper trough just to our west will retrogade west as an upper ridge to our east also retrogrades west. By late week, a significant upper trough will develop to our east, which should drive a weak cold front south through the area.
A cold front will move through the region late in the week. It will be warm and muggy with lows in the upper 60s to the lower 70s.
The first is the leading edge of the tropical moisture, ahead of the upper level low across the northwest Gulf of Mexico, that has arrived into the region. The upper level low across the northwest Gulf of Mexico will continue west and inland tonight into South and Deep South Texas, then open into an inverted trough along the Rio Grande.
Cooler and less humid conditions return by the end of the week. Midlevel heights continue to slowly build through the evening as Upper Midwest trough finally lifts NE and Midatlantic subtropical ridge nudges westward. Better shear will be focused in our far NW associated with stronger midlevel WSW flow on periphery of retrograding ridge but instability is expected to be lower here. We will reside in warm and humid airmass on northwest periphery of strong subtropical ridge. More formidable trough/upper low still slated to arrive by late week and finally shunt moist airmass to our SE. showers will remain possible at times depending on track and evolution of upper low which models are still struggling with.
This trof lies downstream/east of a highly anomalous ridge over the wrn CONUS, which is contributing to record- breaking heat across the Pac NW. Over the next few days, there is relatively high confidence in this ridge slowly but steadily shifting ewd, transitioning our region away from the recent cooler, unsettled stretch of weather and toward another warm, dry week.
An omega block remains in place over the western CONUS with a large trough/southwest flow positioned over the Midwest states. SPC mesoanalysis as of 3 PM depicts MLCAPE of 1500+ J/kg across a good chunk of the CWA, though values quickly drop off closer to the aforementioned quasi-stationary cold front where a CAP is in place. The best shear is located across our northwest counties and points north/west of there, nearest to the upper trough.
300 PM EDT Sun Jun 27 2021 High pressure will remain centered off the Mid-Atlantic coast through midweek. Aloft, an upper-level ridge off the Delmarva/lower mid-Atlantic coast continues to slowly retrograde or build westward across the lower mid-Atlantic coast. west of a Danville- Farmville-Ashland line early this afternoon, embedded in moist llvl airmass along a weak piedmont trough. Will need to watch weak area of low pressure along the Carolina coast.
To the right of the front, dewpoints in the low to middle 70s are present with winds out of the south. A strong ridge of high pressure still dominates the western US while a positively tilted trough remains relatively stagnant over central parts of the country. Ahead of the front, the moist airmass remains with dewpoints in the low 70s. Tonight, the stalled boundary begins modifying into a warm front, returning southerly winds for all except the northernmost parts of the CWA.
The Sea Breeze is coming on line now in our area with the high res model indicating best time frame late day for I-20 TSs ending up toward KTXK by night fall.
Latest CAM guidance shows POPs for the remainder of the day may be a bit on the high side, especially given our 12z sounding came in a little drier than expected (PWAT 1. Aloft, an fairly tight upper level low continues to move westward across the Northwest Gulf this morning. For today, the upper level low will continue to move westward, bring additional moisture and lift later this morning and afternoon across most of the region.