Aikyam-Lab/Synoptic-Bench huggingface dataset:
Thunderstorm development will become more widespread on Thursday afternoon and evening as the remnant low circulation gets pulled northwest around an upper level high, sending it further west into Arizona. The presence of the low will advect additional moisture into the forecast area, particularly in northwest Arizona and southern Nevada where PWATs reach 1. That being said, the highest POPs are over Mohave, Lincoln, and Clark Counties, while the greatest rainfall earlier this week and last week was over eastern California.
1123 PM CDT Wed Aug 23 2023 A strong upper level ridge remains parked over MO. We are in for a couple more days of high heat before a cold front moves through this weekend and brings more reasonable temps to the Mid-South. Currently, hot and dry conditions are expected throughout the remainder of the week due to an upper level ridge centered above the Central Plains.
639 AM CDT Thu Aug 24 2023 (Today and tonight) Hot and humid conditions continue with slightly warmer air temperatures today as the center of the upper ridge passes westward across our FA. Despite the slightly lower dewpoint temperatures, the higher dry bulb temperatures will compensate to yield heat indices within the 105 to 115 deg range. However, rain chances are very low due to strong subsidence beneath the ridge and depth of dry air.
Despite the cloud cover, temps have managed to rebound into the lower/mid 80s from their earlier lows in the lower/mid 70s. With the eastern half of a strong upper ridge axis remaining entrenched over the Mid South/TN Valley areas, temps later today should have no prob climbing into the mid/upper 90s for most spots. However, given the drier air/subsidence aloft traversing southward along the eastern fringe of the upper ridge pattern, have maintained a dry forecast for now given current trends.
525 AM MDT Thu Aug 24 2023 Current Water Vapor and upper air analysis shows broad upper ridge over the central and northern plains with a closed upper low over western Canada. At the surface, low pressure and an associated boundary sits over eastern MT. As the upper low slides east across Canada, ridge breaks down and flow over our region becomes more zonal. Monsoonal moisture continues to advect in from the south, however the majority of moisture will stay south of the forecast area as the upper low tracks across Canada.
The main difference between today and the past couple of days, when there was more widespread shower coverage, is weaker speed convergence as the North Atlantic ridge continues to be disrupted by general troughing to the west in the vicinity of the Eastern Seaboard. From synopsis, high pressure over the eastern United States will result in gentle northeast to east breezes. This ridge will weaken with its core moving out into the Atlantic. This along with troughing moving into the waters off the Atlantic coast will relax breezes through the weekend.
It will be interesting to see how this boundary might settle and ripen during the course of the day to possibly serve as a focus for afternoon convection, especially when paired with the expected cold front later today. There is a suggestion of a boundary stretching from Ludington to Saginaw Bay that could perhaps later serve as a prefrontal trough to the main cold front. While it is true the cooler and moister conditions described above will lower the associated risks in the short term, we expect temperatures to rebound very quickly later today and dewpoints should remain extremely elevated as well. The forecast POPs roughly follow the GFS and ECMWF 00Z deterministic runs that show precip blossoming along the cold front this afternoon.
Analysis shows the H5 ridge continuing to dominate the central CONUS. Mid-level clouds will begin push into northeast Nebraska at lunch time as a cold front crosses the SoDak state line. Highs will peak mostly in the low-80s, as the upper level ridge retreats southwest.
635 AM CDT Thu Aug 24 2023 A large area of high pressure will allow hot and dry conditions to remain across the Mid-South through the end of the work week.
625 AM CDT Thu Aug 24 2023 (Today through Friday) High pressure remains the dominant force across the area.
635 AM EDT Thu Aug 24 2023 (Today and tonight) A weak "back door" cold front moving through from the northeast yesterday, allows for drier air to filter in for today.
(Today through Friday night) 07z WV satellite reveals an upper high, with 598dm 500mb peak height as measured by 00z RAOBs, over OK/KS/MO/AK with southerly flow aloft over the Panhandles. Today, guidance in good agreement that upper high will continue to slowly migrate southward over OK, resulting in flow aloft becoming south-southwesterly. Friday, expect another hot day with the upper high located over our southeast.
Models continue to show a large upper ridge over the midwestern United States with an upper trough moving through Arizona. Another upper trough is sitting off the coast of the western United States. Models are keeping the upper ridge remaining around the midwestern United States for Friday and Friday night.
We did 99 for a high yesterday and at 9 am today, we're already 4 degrees warmer than we were at this time yesterday. Models continue to push temperatures close to 100 or more, but with the high pressure that's been responsible for the heat starting to meander farther west on Friday and into the weekend, it seems possible that we remain just below 100 degrees.
* Cooler temperatures and rain/thunderstorm chances return for the Friday and into the weekend, although, the severe risk is low at this time. frontal system will begin to push into northern Nebraska today while upper level ridging remains in place to the southeast. A slightly cooler day (highs in the low to mid 90s) with isolated rain showers should be anticipated across the northwest with a hot (highs in the mid 90s to low 100s, plus heat indices over 100) and mostly dry forecast to the south and east.
556 AM CDT Thu Aug 24 2023 (Today through Friday night) 07z WV satellite reveals an upper high, with 598dm 500mb peak height as measured by 00z RAOBs, over OK/KS/MO/AK with southerly flow aloft over the Panhandles. Today, guidance in good agreement that upper high will continue to slowly migrate southward over OK, resulting in flow aloft becoming south-southwesterly. Friday, expect another hot day with the upper high located over our southeast.
633 AM CDT Thu Aug 24 2023 (Today and tonight) Mid-level high pressure will begin to slide back to the southwest today becoming centered over southern Oklahoma by this afternoon.
614 AM CDT Thu Aug 24 2023 (Today and tonight) The upper-level ridge will build back across the area today and bring back hot and dry conditions to West Central Texas through the end of the week. The "cooler" conditions across the Northern Edwards Plateau can be attributed to some lingering cloud cover this morning, which will limit some daytime heating over that area today.
The center of circulation associated with the remnants of Harold will push northward through Arizona today as it gets pulled into the upper-level flow of the dominating monsoonal high pressure. These areas coincide with where CAMs favor the highest concentration of thunderstorm development, though isolated thunderstorms in Inyo and San Bernardino cannot be ruled out. The highest vulnerability to flash flooding exists in the Spring Mountains where devastating flooding occurred from Hilary last weekend. Chances of precipitation will decrease on Friday as the monsoonal high pressure shifts eastward, creating a dry southwesterly flow over the Desert Southwest.
Models continue to push temperatures close to 100 or more, but with the high pressure that's been responsible for the heat starting to meander farther west on Friday and into the weekend, it seems possible that we remain just below 100 degrees.
Drier and warmer conditions heading into the weekend.
The 12Z SPC upper air map shows a 596 dam upper level ridge over the TX/OK/AR border and is expected to slowly migrate southward over OK, allowing for southerly surface flow to prevail over the CWA. Tomorrow, the hot and dry weather pattern will continue with temperatures expected to be a few degrees warmer as thickness values increase over the FA.
927 AM PDT Thu Aug 24 2023 Dry conditions today, with slightly cooler conditions compared to yesterday.
(This evening through Friday) The upper level high is situating itself closer to our area, centering over Oklahoma and north Texas for the short term.
1212 PM CDT Thu Aug 24 2023 (Today through Friday night) 07z WV satellite reveals an upper high, with 598dm 500mb peak height as measured by 00z RAOBs, over OK/KS/MO/AK with southerly flow aloft over the Panhandles. Today, guidance in good agreement that upper high will continue to slowly migrate southward over OK, resulting in flow aloft becoming south-southwesterly. Friday, expect another hot day with the upper high located over our southeast.
High pressure ridging remains in place tonight for pleasant conditions, although hazy skies will exist from regional smoke sources. A weak disturbance from the southwest displaces the ridge axis further east on Friday with increased instability leading to a chance of showers and thunderstorms in the afternoon/evening.
A lee side trough or frontal boundary situated across the northern High Plains will shift into the western Dakotas later this afternoon and eastward through our forecast area late tonight into early Friday. The 700mb thermal ridge that has been dominant over our area most of the week has shifted farther south with sufficient cooling already in place across most of this CWA. Post-frontal northerly winds will usher in a cooler and drier, more comfortable air mass by Friday afternoon. Mean ridging aloft will waffle back and forth over the Western High Plains and Rockies through the period.
Temperatures are 3-5 degrees cooler this morning than yesterday across southeastern Arizona making overnight lows at or below normal. For us today, expect a 10-30% chance for storms with warmer highs, especially east of Tucson. Low grade monsoon activity over the next 7 days with temperatures heating up as upper ridge aloft builds over the desert southwest this weekend.
The best chance (15-25%) for thunderstorms this afternoon will be in/near Harney County as a weak upper level low moves north through western NV.
However, a boundary will be sagging southward as the H5 ridge aloft retreats westward. This will include a marginal risk of severe as the cold front drops nearer to our FA with some energy to boot late in the night.
As instability builds into the afternoon (SBCAPE near 3000 J/kg south of I-80) along with modest deep layer shear of 30 - 35 kts, scattered storms may redevelop along and slightly north of the surface boundary with the highest coverage during the late afternoon and evening hours.
A weak warm front will lift into the area Friday morning, lingering into the afternoon before cold air advection takes precedence overnight. Expect high temperatures in the lower to middle 80s, with lows in the lower 60s.
On Friday as the upper level ridge retrogrades to the west there will be another chance of afternoon showers and storms on the northeastern and eastern side of the forecast area.
Higher moisture covers the Gulf of Mexico from off the Louisiana coast to east of the Lower Texas coast where scattered convection has developed. Will show slightly warmer temperatures for Friday.
1227 PM CDT Thu Aug 24 2023 (Today and tonight) The upper-level ridge will build back across the area today and bring back hot and dry conditions to West Central Texas through the end of the week. The "cooler" conditions across the Northern Edwards Plateau can be attributed to some lingering cloud cover this morning, which will limit some daytime heating over that area today.
1141 AM CDT Thu Aug 24 2023 Sunny skies continue across the Mid-South this morning with temperatures in the lower 90s.
259 PM CDT Thu Aug 24 2023 A cold front will move into central Kansas by Friday afternoon as a weak disturbance traverses the northern plains.
With the increased cloud cover, temperatures will be cooler on Friday for most locations, with highs generally peaking in the 70s and 80s.
Low grade monsoon activity over the next 7 days with temperatures heating up as an upper ridge aloft builds over the desert southwest this weekend.
With mostly sunny skies (and diurnal heating) returning, locations will see temperatures warm back into the mid to upper 80s across central MN to western WI and the lower 90s across S MN. Relief is on the horizon though as cooler and drier air arrives behind the FROPA Friday afternoon and evening.
Very hot and dry conditions will continue for the next couple of days across the Mid-South as an upper level ridge remains in place across the region.
A few storms could develop farther west over Death Valley, where precipitable water was near an inch, and orographic forcing over the Sierra Nevada could overcome the lower PW there. Sticky surface dewpoints of 50-60F in the lower elevations will continue however, and temperatures will rise a few degrees from today.
(The rest of today ) The dome of high pressure remained the common feature across the region this morning. the high was slightly weaker at the 500-mb level compared to a couple days ago. Underneath the high pressure ridge. the upper level ridge center is progged to slide slightly to the west southwest and be centered over more of Western/Central Oklahoma. This will put far Eastern Oklahoma and Northwest Arkansas on eastern side of the high. Latest short term guidance indicates the greater potential of any isolated convective development being near an elevated theta-e boundary oriented west to east within the higher terrain of Northwest Arkansas. will continue with ongoing slight chance PoPs across these locations as well as the higher terrain of far Southeast Oklahoma from daytime heating. with high pressure in place.
Radar shows isolated thunderstorms bubbling across the higher elevations south of Interstates 84/86. Central mountains have the highest confidence of seeing the greatest coverage in the afternoon.
Showers and thunderstorms are developing across the higher terrain and will remain there through the evening. Upper ridging has built back across the region and will continue to expand into the weekend. This keep temperatures running above normal Friday with maybe an isolated storm in the higher terrain.
1215 PM CDT Thu Aug 24 2023 (Today through Friday) High pressure remains the dominant force across the area.
117 PM MDT Thu Aug 24 2023 Key Messages: -Isolated storms this evening, a few storms may be strong to severe and capable of strong winds and marginally severe hail -Increasingly unsettled conditions through the end of the week into the weekend with a slight cooldown and near daily chances for storms Current upper air analysis and water vapor imagery depicts upper level high centered over the southern plains with upper low associated with remnants of TC Harold centered over the Four Corners region. Lee trough and sfc front crosses the region this afternoon, potentially triggering some elevated convection.
However, given the strength of the upper ridge pattern over the Mid South/TN Valley areas, not expecting much/if any of this associated convection to translate more to the SW, although this will be monitored into the evening hrs. Otherwise, the hot/dry pattern will continue thru the overnight period, as lows again fall mainly into the lower/mid 70s.
1258 PM CDT Thu Aug 24 2023 Sunny skies continue across the Mid-South this morning with temperatures in the lower 90s.
Would expect the fog to remain above dense levels but the low stratus is expected to persist through midday and perhaps early afternoon before it mixed out and breaks up. Low level thermal/mixing progs are a bit cooler today than days past, while weak low level CAA northerly winds persist through mid-day. Later this evening, the next wind-shift/cold front is progged to be entering the western Dakotas. At this point, it appears that Friday sets up as a dry/quiet weather day on north-northwest post-cold frontal winds. Overall, temperatures are going to be trending cooler (back toward climo normal for late August) over the next couple of days. A mostly dry forecast with near seasonal temperatures thanks to northwest flow and upstream ridging.
as a cold front settling southward into central Illinois will trigger scattered thunderstorms across the area Friday afternoon into Friday night. followed by considerably cooler weather by the weekend.
(Through Tonight) Yet another hot and humid day is in progress across eastern Oklahoma and northwest Arkansas, with much of the area running a few degrees warmer than at this same time yesterday, aided by a good westerly component to the low level winds and lower dew points in most spots. The weather tomorrow will not be markedly different from what has been seen today, with the highest heat index values favored in areas along and east of Highway 75 due to expected dew points - except for the climatologically cooler areas of far northwest Arkansas and adjacent areas of northeast Oklahoma.
Models are coming together in showing the 23z to 04z period as the highest potential for storm to develop over or track through the CWA.
1054 AM MDT Thu Aug 24 2023 Current Water Vapor and upper air analysis shows broad upper ridge over the central and northern plains with a closed upper low over western Canada. At the surface, low pressure and an associated boundary sits over eastern MT. As the upper low slides east across Canada, ridge breaks down and flow over our region becomes more zonal. Monsoonal moisture continues to advect in from the south, however the majority of moisture will stay south of the forecast area as the upper low tracks across Canada.
1223 PM CDT Thu Aug 24 2023 (Today and tonight) Hot and humid conditions continue with slightly warmer air temperatures today as the center of the upper ridge passes westward across our FA. Despite the slightly lower dewpoint temperatures, the higher dry bulb temperatures will compensate to yield heat indices within the 105 to 115 deg range. However, rain chances are very low due to strong subsidence beneath the ridge and depth of dry air.
This is leaving dew points in the low 70s, which is likely keeping us from reaching triple digits. Tomorrow is going to be more of the same as the upper ridge holds firm.
(This evening through Friday night) A 594dm ridge is sitting over the central/southern Plains causing large-scale subsidence across the area. The ridge will move west slightly tomorrow and temperatures will be a few degrees warmer, but the afternoon should be dry. However, this threat will progressively lower as the evening progresses and the low-levels become more stable.
After today's high temperatures reach to near and slightly above normal for many locations, a cold front will bring slightly below normal temperatures to the region for the next day or so.
258 PM CDT Thu Aug 24 2023 Key Messages: * Friday will mark a transition day across the region as cooler air begins to filter in across the local area.
1217 PM CDT Thu Aug 24 2023 (Today and tonight) Mid-level high pressure will begin to slide back to the southwest today becoming centered over southern Oklahoma by this afternoon.
301 PM CDT Thu Aug 24 2023 Today and tonight: An upper ridge is finally showing signs of weakening as denoted by observed heights of 595dm, down from 603dm and some high cirrus has been observed across the area this morning. Higher dewpoints should lead to much warmer nights, approaching or exceeding record warm lows (upper 70s to near 80) across the area. The upper ridge begins to retreat west resulting in height falls, especially in the south east. However, much of the north and western areas will still be under the influence of the upper ridge, and hot and dry conditions should still continue.
322 PM CDT Thu Aug 24 2023 A cold front continues to move southeastward as an upper level low moves across southern Saskatchewan. The storms began interacting with the cold front kicking off severe weather this afternoon. Friday temperatures will cool behind the cold front resulting in cooler high temperatures spanning from the upper 60s to upper 70s. An upper level low is forecast to dig across Northern Minnesota bringing northwesterly flow to the Northern Plains. This weekend temperatures are forecast to slightly drop below normal as cooler air moves in from the north.
Tonight and Friday The latest RAP analysis and satellite/radar imagery show a weak wave of low pressure located over southwest Wisconsin and an associated warm front south of Wautoma and Fond Du Lac early this afternoon. Weak high pressure will build toward the western Great Lakes as the cold front drops south of the region. Remained on the warmer side of guidance with lows in the upper 50s to middle 60s.
634 PM CDT Thu Aug 24 2023 (This evening through Friday) The upper level high is situating itself closer to our area, centering over Oklahoma and north Texas for the short term.
Even the clouds should finally dry up for the most part tonight as mid/upper level ridging builds eastward and the remnant circulation moves away to the southeast and weakens. Meanwhile, a wave aloft traveling eastward along the Canadian border will suppress the ridging south southwestward and send a cold front southward in the Midwest tonight and Thursday. Key Point: * Temperatures more typical of late summer follow the passage of a cold front this weekend and continue through the last days of August.
Cooler temperatures expected tomorrow (Friday). As a result, we have seen cooler temperatures today (thanks to marine layer deepening plus cooler temps aloft).
As of 2345 UTC, the surface cold front extends from roughly Rugby southwest to near New Salem and Hettinger. Only minor changes were made with this forecast update, though we did remove some counties that are well behind the cold front from Severe Thunderstorm Watch #654. A cold front continues to move southeastward as an upper level low moves across southern Saskatchewan. The storms began interacting with the cold front kicking off severe weather this afternoon. Friday temperatures will cool behind the cold front resulting in cooler high temperatures spanning from the upper 60s to upper 70s. An upper level low is forecast to dig across Northern Minnesota bringing northwesterly flow to the Northern Plains. This weekend temperatures are forecast to slightly drop below normal as cooler air moves in from the north.
705 PM CDT Thu Aug 24 2023 (This evening through Friday night) A 594dm ridge is sitting over the central/southern Plains causing large-scale subsidence across the area. The ridge will move west slightly tomorrow and temperatures will be a few degrees warmer, but the afternoon should be dry. However, this threat will progressively lower as the evening progresses and the low-levels become more stable.
952 PM CDT Thu Aug 24 2023 Strong ridge over the area brought hot temperatures today and we will see a warm night across the area. This will set us up for what will likely be a slightly warmer day than what we saw today. Highs should be a degree or two warmer and will be close to daily record high territory. This is leaving dew points in the low 70s, which is likely keeping us from reaching triple digits. Tomorrow is going to be more of the same as the upper ridge holds firm.
Overnight temperatures will be in the lower 70s for inland locations, with coastal locations in the mid/upper 70s.
Monsoon moisture will dwindle over the coming days as a high pressure system moves over Arizona. On Friday, high pressure currently centered over Oklahoma, will begin to shift westward toward Arizona. Otherwise, warmer under the building high with generally light and variable winds.
Have removed the low PoP in our eastern counties. Overnight lows will be in the lower to middle 70s.
Long-wave trough and associated upper-level low will park itself off the West Coast late week, allowing for slightly less warm weather on Friday.
A cold front will move into central Kansas by Friday afternoon as a weak disturbance traverses the northern plains.