Aikyam-Lab/Synoptic-Bench huggingface dataset:
This is thanks to a low level thermal ridge overhead boasting 30-31C combined with downsloping westerly flow developing this afternoon. Meanwhile, an upper trough currently set to eject into the northern Plains through the next 12-18 hours is going to help drag a cold front down through the Texas panhandle on Sunday. Diurnal heating should limit the front's southward progress, allowing much of our CWA to heat up well into the upper 90s with 100s expected in the lower elevations.
As western US closed low accelerates eastward into the northern Plains today, surface cyclogenesis will lead to isallobaric backed/easterly low level flow across Indiana. Temperatures should peak in the low 80s most areas, or about 5-7 degrees above mid-late September climo. The northern Plains closed low decelerates and dampens into the weekend.
233 AM MDT Sat Sep 23 2023 An upper low is centered over northeastern WY and moving eastward early this morning, with clouds and showers rotating around the low. If you are headed for the high country please be prepared for winter conditions. Tonight, upper ridging will move eastward into the area and cause much of the remaining shower activity over southeast MT to diminish during the evening. Sunday into Sunday night, upper ridging will dominate our weather with mostly clear to partly cloudy skies.
Temperatures will continue to seasonal with lows in the low to mid 60s across the region.
(Today through Sunday) With a tropical system to our east and a cold front well to our west, high pressure will remain in control through the weekend.
Current temperatures seem to be trending cooler, so took tonight's lows down a couple of degrees. Early afternoon temperatures are generally in the lower 80s. Through the upcoming short term period, an upper ridge axis is set to build from the Arklatex region northeastward. This feature will be somewhat moisture starved and as a result, shower chances will be on the low side. However, moisture levels in the lower levels are unimpressive and hence, the low pops. The upper levels though do feature some ridging/higher heights.
1235 AM CDT Sat Sep 23 2023 (This evening through Saturday night) A building ridge across the panhandles will continue to cause dry and fair weather for the rest of today and again on Saturday. Temperatures will be hot again under the ridge with highs in the 90s with the hottest spots having a small chance of even hitting 100.
306 AM EDT Sat Sep 23 2023 We'll have a very nice first day of fall today with surface ridging overhead between Ophelia to our east and low pressure crossing the Plains to our west. For temperatures today, forecasts over the past couple of days have shown a cool bias of 1-3 degrees, and NBM is a couple degrees cooler than the model consensus, so went a head and bumped MaxT up a bit for today, resulting in highs generally in the lower 80s. The ridging over the Ohio Valley will strengthen slightly tonight with dry air giving us clear skies.
1225 AM CDT Sat Sep 23 2023 (The rest of tonight) Overall, a quiet night is expected for the region as upper level ridge axis moves overhead.
The second, associated with a weak upper level low near Point Conception, was mid and high level clouds spreading over Inyo and western San Bernardino counties. Despite all the mid and high level moisture present, the low levels had moistened very little. As the morning goes on and the upper low draws closer, there could be a little better forcing to wring out a few hundredths of an inch, with northern Mohave and northeast Clark counties being the most likely area. Dry southwest flow between high pressure over Mexico and low pressure over the Gulf of Alaska takes over on Sunday, bringing a quiet weather day with warmer temperatures thanks to full sunshine.
(Today and tonight) Hot temperatures are forecast across West Central Texas, as an upper level ridge centered across northern Mexico continues to dominate our weather. Otherwise, expect overnight lows to remain mild, in the low to mid 70s.
The strong upper low we've been watching for the last few days is currently over the Great Basin region and beginning to move east towards the Plains. Some hail and gusty winds could occur with these storms, but more importantly they would reduce the instability for mid/late afternoon storms along the cold front. If the early storms are weak or don't occur, diurnal heating, rich low-level moisture, and steep mid-level lapse rates would result in 2500-3000 J/kg of ML CAPE developing ahead of the cold front. By Sunday morning, the cold front will have pushed through the entire area, helping clear out any lingering overnight showers and storms. Northwest flow will be in place aloft, with ridging to our west and our old upper low slowly moving over the Midwest.
(Today) While Tropical Storm Ophelia makes its way over the Carolinas today, brief upper ridging is expected to nose into the Tennessee Valley.
Ridge axis extending from Mexico through the middle Mississippi Valley combined with dry air moving down the back side of the upper low associated with TS Ophelia (located off the east coast) will keep rain chances shunted to the west of the local area. Going into Sunday, an upper low moving into the Great Lakes region will push a cold front into the middle and lower Mississippi Valley. However, if the front speeds up a bit, some of the higher POPs could be earlier than currently indicated.
1147 PM CDT Fri Sep 22 2023 A pleasant but warm end to the week is in store as height rises begin to occur with an upper level ridge.
The ridge sits over northern ALberta while the trough is stationed over Idaho, Montana and Wyoming. Behind this a cold core trough is developing off the coast of British Columbia. To the south hot high pressure over the Desert Southwest and southern Plains has been bottled up. Today into tonight: Split flow looks to be transitory through the day with the trough Wandering into the Dakotas and the ridge into northern Manitoba. Remaining rain showers will flow with the trough towards the east.
As upper low shifts east into the northern Plains, a mid/upper level jet streak will overspread the region with strong diffluent flow aloft. Strong to severe thunderstorm are expected to rapidly develop near approaching cold front across far northeast Oklahoma by late afternoon.
In its wake, a cold front will sweep across southwestern Kansas this morning. Drier air will arrive along with cooler temperatures today, with north winds at 10-20 mph. Expect afternoon highs from 80 to the mid 80s, with the warmer readings at the lower elevations of south central Kansas. With drier air in place tonight, along with light winds, strong radiational cooling will allow temperatures to fall into the lower to mid 50s.
The official first day of fall is being ushered in with drier air and slightly cooler temperatures. High temperatures will top out just below 90 for most, with some still reaching the lower 90s. However, with the lower humidity, it will still make for a pleasant day. Humidity begins to creep up throughout the week as an upper level trough and associated frontal boundary pull more moisture over the area.
208 AM EDT Sat Sep 23 2023 Dry high pressure will continue to ridge down across the area from the north through this evening.
1204 AM CDT Sat Sep 23 2023 (Tonight through Saturday night) Midday RAP analysis depicts a 594 dm subtropical ridge centered over northern Mexico, providing a NW flow aloft over south-central TX.
254 AM CDT Sat Sep 23 2023 Mostly sunny, warm, and dry today, with high temperatures in the low 80s.
PoPs will gradually ramp up from west to east as the surface cold front approaches. High temperatures Sunday will be cooler due to more cloud cover and precipitation coverage, but most areas will still reach the upper 70s to lower 80s.
Sheared off remnants of post-tropical cyclone Kenneth continue to stream into the Mojave Desert this evening with widespread dense mid and high cloud cover across all of Clark, San Bernardino, and Mohave Counties this evening. While moistening will continue overnight from the top down, lower desert elevations will be hard pressed to see much more than sprinkles by early morning, as surface dewpoints are only expected to recover into the lower 40s at best. Remnant moisture from post-tropical cyclone Kenneth moving over southern California will brush southern Nevada tonight as it spreads across northwest Arizona through Saturday morning. These features will move across northern Arizona Saturday afternoon followed by dry and mild conditions under ridge Sunday with high temperatures climbing 5-6 degrees and readings in the lower to mid 90s across the desert zones.
Thus, have undercut blended guidance by a few degrees with lows in the lower 60s, except mid 60s near the coast. Some upper 50s are possible in the normally cooler spots.
Highs on Saturday will top out in the lower to middle 80s. Shower chances increase again from late Saturday night into Sunday, with cooler weather expected thereafter. to the lower 60s west. Thanks to ample sunshine, afternoon highs will climb into the lower to middle 80s. As this system approaches, it will push a cold front into Illinois by Sunday.
Once these elevated storms move farther east towards sunrise the low to mid level instability will be closing in on the Missouri River and storms should strengthen a bit. The system wraps up tonight scattered showers and storms will remain possible, mainly north of I-90 and east of the Buffalo Ridge.
Mostly sunny on Saturday in the Northwest flow with Max temps rebounding close to normal values with highs in the mid/upper 80s while the lower humidity values remain in place. As Tropical Storm Ophelia to the east northeast, continues to track northward toward the Carolinas, high pressure will build from the northwest. Between these two features the wind will come from the north then northwest, helping to drive a cooler and drier airmass across the area. (Saturday through Sunday night) A trailing trough will extend southwest across the southeastern US Saturday through Sunday morning from tropical system. Otherwise, weak high pressure will be over the area through Sunday night.
Main concern will be the continued threat of some stronger winds across the region as the strong westerlies will be impinging across the mountains and this will lead to some strong gusty winds at ridgetops through mid day tomorrow. Could see lows getting to around freezing across the San Luis valley, but a widespread hard freeze does not appear likely.
It is progged that a line of storms will organize/strengthen from the low near Watertown east-southeast into SW Minnesota to west of Mankato 22-23z today.
112 AM PDT Sat Sep 23 2023 Currently, temperatures are around five degrees cooler than what is normally seen at this time of year. A low pressure system just north of our forecast area is tracking eastward across the western United States, bringing cooler temperatures in its wake. These temperatures are around five degrees cooler than what we normally see at this time of year and will continue through the weekend. Long range ensemble guidance favors another low pressure system moving into the area a week from now, lowering temperatures again as it moves onto land.
337 AM EDT Sat Sep 23 2023 High pressure remains largely in control over northern New England while Ophelia remains well to the south as the system moves inland over the Mid Atlantic.
Aloft a ridge axis is shown to stretch from the southern plains across the mid-Mississippi Valley, acros jhgjhs Indiana to the Great Lakes. Surface analysis this morning shows strong low pressure off the Carolina coast, a ridge axis of high pressure over the Great Lakes stretching south to the deep south and another area of low pressure over western plains. As western US closed low accelerates eastward into the northern Plains today, surface cyclogenesis will lead to isallobaric backed/easterly low level flow across Indiana. Temperatures should peak in the low 80s most areas, or about 5-7 degrees above mid-late September climo. The northern Plains closed low decelerates and dampens into the weekend.
411 AM MDT Sat Sep 23 2023 An upper level trough moving over central WY this morning and its associated cold front triggered a couple of strong storms over Weld and Sedgwick counties earlier this morning, but that has shifted to the east of the forecast area. For today, moderate downward QG descent will be over the region, but the subsidence will weaken as the trough lifts to the northeast. A little cooler today as well with temperatures near normal for this time of year. This week will be dominated by ridging over the area with warm air aloft and dry air throughout.
Dry and quiet weather has settled in, and temperatures trend warmer over the weekend with some help from sunny, clear skies.
(Rest of Today) A large area of high pressure centered over eastern Canada extends SSW into the western portions of the Tennessee Valley. As Tropical Storm Ophelia continues to move north across the North Carolina and Virgina coast, the upper level ridging should amplify over much of northern Alabama.
Today: As of 3 AM, a cluster of storms is building across the Nebraska Panhandle and extreme northeast Colorado, with GOES water vapor imagery displaying the main trough trailing behind it.
(Today through Sunday) Mid-level ridging parked over northern Mexico will continue to provide subsidence across Deep South Texas through the weekend. Low temperatures are expected to be in the 70s with a few places in the lower 80s for tonight.
334 AM MDT Sat Sep 23 2023 The recent wet weather will come to an end today as weak high pressure builds across the Greater Yellowstone region. As we start the new week, we will find ourselves sort of in between a weak upper level ridge to our east and a strong upper level low sitting over the eastern Pacific Ocean, which will result in deep southwesterly flow across the area.
341 AM MDT Sat Sep 23 2023 Key Messages: 1) Calm, slightly cooler weather today. High temperatures today will be a bit cooler than yesterday post-front, hitting 70s to low-80s over most of the area. Secondary trough moves eastward behind the main trough over the northern High Plains.
726 AM EDT Sat Sep 23 2023 High pressure remains largely in control over northern New England while Ophelia remains well to the south as the system moves inland over the Mid Atlantic.
We'll have a very nice first day of fall today with surface ridging overhead between Ophelia to our east and low pressure crossing the Plains to our west. For temperatures today, forecasts over the past couple of days have shown a cool bias of 1-3 degrees, and NBM is a couple degrees cooler than the model consensus, so went a head and bumped MaxT up a bit for today, resulting in highs generally in the lower 80s. The ridging over the Ohio Valley will strengthen slightly tonight with dry air giving us clear skies.
605 AM CDT Sat Sep 23 2023 (Today and tonight) Hot temperatures are forecast across West Central Texas, as an upper level ridge centered across northern Mexico continues to dominate our weather. Otherwise, expect overnight lows to remain mild, in the low to mid 70s.
High clouds from tropical cyclone Ophelia remain just east of KY. Temperatures were a bit cooler this morning than 24 hours ago. Readings ranged from the lower 60s in the Bluegrass to the upper 60s to near 70 out in the I-65 corridor and points west. A cooler NE wind flow pattern will remain in place today while ridging aloft continues to build.
557 AM CDT Sat Sep 23 2023 Mostly sunny, warm, and dry today, with high temperatures in the low 80s.
629 AM CDT Sat Sep 23 2023 (Today through Sunday) Mid-level ridging parked over northern Mexico will continue to provide subsidence across Deep South Texas through the weekend. Low temperatures are expected to be in the 70s with a few places in the lower 80s for tonight.
605 AM CDT Sat Sep 23 2023 (Today) While Tropical Storm Ophelia makes its way over the Carolinas today, brief upper ridging is expected to nose into the Tennessee Valley.
A few clouds, a bit of a breeze and highs in the low to mid 80s -- unless you're on the Cumberland Plateau, where highs will be in the mid 70s. Otherwise expecting dry conditions during the day with highs getting into the low to mid 80s.
644 AM CDT Sat Sep 23 2023 (Today through Sunday) With a tropical system to our east and a cold front well to our west, high pressure will remain in control through the weekend.
(Now through Sunday) Upper level flow becomes northerly today as the area is between a trough over the east coast and an upper ridge to the west.
Today is shaping up to be another sunny and quiet day, with just some increased westerly winds along ridgelines. Be aware that depending on your elevation, the temperature may drop below freezing overnight, so make sure to protect any sensitive plants.
609 AM CDT Sat Sep 23 2023 (Today and tonight) Hot and dry conditions are in store once again today as the CWA remains beneath the northern periphery of the subtropical ridge that is currently centered over north-central Mexico.
545 AM MDT Sat Sep 23 2023 The recent wet weather will come to an end today as weak high pressure builds across the Greater Yellowstone region. As we start the new week, we will find ourselves sort of in between a weak upper level ridge to our east and a strong upper level low sitting over the eastern Pacific Ocean, which will result in deep southwesterly flow across the area.
The mean-layer ridge remains centered over Mexico, although the 12Z RAOBs sampled falling heights within the core of the ridge as it loses some strength. The deep-layer cyclone over the southeastern US which contains Tropical Storm Ophelia is beginning to split. Meanwhile, a weak and disorganized trough axis will develop near and west of the Florida Keys.
Bands of precipitation will bring rain chances to western PA and northern WV this afternoon and tonight before Ophelia departs far enough east to suppress most precipitation east of the ridges. Original thinking was precipitation would struggle to measure outside of the terrain due to the potential for downsloping and dry air in the low-mid levels. Continued ascent, and deep layer moisture on the northern/western side of the low, will maintain rain chances Saturday night and Sunday, again with the highest POPS east and south of Pittsburgh. In addition to the rain, wind gusts could approach 35 mph on the ridge tops across WV and the Laurel Highlands tonight with a tightening pressure gradient in advance of the low.
300 PM EDT Sat Sep 23 2023 A weak cold front will dissipate across the Central Highlands into southeastern Aroostook County tonight. Another weak cold front will approach from the north late Sunday.
1106 AM EDT Sat Sep 23 2023 High pressure remains largely in control over northern New England while Ophelia remains well to the south as the system moves inland over the Mid Atlantic.
A break in the steady rain has pushed into the Lower Susq Valley, but more rain is on the way later today. A breezy northeasterly wind is expected this afternoon, and we could see max gusts reach the 30+ mph across the Lower Susq Valley. Model consensus and NHC track is for the low center of the (expectedly) downgraded depression to inch north-northeastward, only reaching central Delaware by Sun evening. Rainfall totals of >2" are still expected across the Lower Susq Valley. Winds will be less than remarkable for Central PA, even in the Lower Susq. The higher gusts into the L-M30s will be S/E of Harrisburg.
07/mb (Now through Sunday) Upper level flow becomes northerly today as the area is between a trough over the east coast and an upper ridge to the west.
Although it is classified as tropical, its roots were not, and it is uncharacteristically associated with a sizable mid/upper level low. Well to the northwest there is another mid/upper level low over the northern plains, and in between there's a weak ridge or col over the Midwest and lower Great lakes. At the surface, a blocking high pressure system is situated to the north of Ophelia. Much of this period will be determined by a slow-moving upper low moving east across the northern tier of the United States.
- Warmer and sunnier in the latter half of the coming week. The synoptic cold front remains well to our west over eastern Nebraska, and as it approaches this afternoon and evening we should see additional thunderstorms develop in our western counties and progress steadily eastward into tonight, carrying a renewed severe weather threat as previously anticipated. Overnight tonight the showers and storms will push just east of our area along with the front, stalling over eastern Iowa and western Illinois/Wisconsin as the parent cyclone parks near the North Dakota/South Dakota/Minnesota triple-point and wobbles around there on Sunday.
1143 AM MDT Sat Sep 23 2023 Key Messages: 1) Calm, slightly cooler weather today. High temperatures today will be a bit cooler than yesterday post-front, hitting 70s to low-80s over most of the area. Secondary trough moves eastward behind the main trough over the northern High Plains.
(Rest of today through Sunday) Overview: Longwave troughing remains in place over the SE CONUS with Tropical Storm Ophelia currently located over North Carolina and another impulse pivoting south into the GOM. At the lower- lvls a NE-SW oriented boundary was noted in satellite WV imagery and satellite PWATs, with PWATs currently ranging from 1. As although temperatures aloft are relatively cool, cooler temperatures lower in the atmosphere will keep lapse rates modest, likely limiting the strong storm threat. High temperatures should remain in the 80s, as the airmass remains on the cooler side.
Tennessee is located between two low pressure systems - one in southeast Texas and one off the North Carolina coast. Daytime highs will be a tad warmer than today, generally in the 70s and 80s.
The upper and mid level low pressure centers have pushed into northwest SD this afternoon. The associated warm front and associated convection has pushed up into northeastern SD. But, more unstable conditions could develop as there is some clearing occurring behind the warm front convection. As the low complex moves east through SD tonight, it will stall and retrograde a bit in ND on Sunday bringing some wraparound showers through Sunday night. The main challenge that will continue to present some uncertainty into this portion of the forecast revolves around the timing and movement of this closed upper level low pressure system that looks to remain in the vicinity of our area at the beginning of this period.
For Sunday, an upper level ridge builds over the Central Rockies. Winds will be weaker with a weak pressure gradient and ridging across the area.
159 PM MDT Sat Sep 23 2023 Upper low continues to move eastward thru SD and we are now seeing building heights and drying/clearing in our west. It should noted that as we see clearing on satellite imagery the high peaks of the Beartooths stand out as snow-covered. Otherwise, aforementioned building ridge will bring dry and warmer conditions through the remainder of the short-term period.
310 PM EDT Sat Sep 23 2023 Three weather systems of note in the short term: tropical storm Ophelia moving up the Mid-Atlantic region, a developing area of low pressure over the northern Plains, and a ridge of high pressure squished between the two over the Ohio and Tennessee Valleys and Great Lakes. Once Ophelia moves away from us on Sunday, the Plains trough will begin moving our way, which will lead to increasing cloud cover from the west during the day on Sunday. The ridge that is currently in place will gradually break down and move off to our east as the trough moves in from the west.