Aikyam-Lab/Synoptic-Bench huggingface dataset:
(Today and tonight) 06Z upper air analysis depicts an occluding cyclone over the northern Great Plains and a subtropical ridge that was slowly retrograding westward over the Sea of Cortez. The cold front associated with the occluding cyclone has crossed through the CWA, delineated along a line from HOB-GNC-LUV-SNK before bending northeastward into the Big Country and towards SPS as per regional METAR and West Texas Mesonet data. The movement of the front continues to slow as it moves beneath an increasingly barotropic airmass beneath the expansive subtropical ridge that was analyzed at 595 dam on the 24/00Z objectively analyzed maps last evening. Temperatures today will be approximately 10 degrees cooler than yesterday across the entire CWA, with the coolest temperatures across the extreme southwestern TX PH.
229 AM MDT Sun Sep 24 2023 MORNING DISCUSSION: Synoptic Setup: Forecast begins with Hot high pressure over the Four Corners and a ridge rising up through Wyoming, central Montana and southern Saskatchewan. To the west semi zonal to southwest flow resides over the Pacific Northwest with a ridge trough couplet developing right off the coastline.
High pressure and dry westerly flow will be in control of our weather this week. This will result in mostly clear conditions this week with temperatures generally running a few degrees above normal, peaking mid-week at 5 to 10 degrees warmer than normal.
Lines of showers will continue to swing north and west of the low, which will keep much of western PA and northern WV under the threat of occasional showers. Model ensembles indicate a trough will persist across the Northeastern CONUS through much of the upcoming week.
Dry air at the lower and middle layers of the atmosphere will limit any potential shower that might develop. Convective models do show support for some upper level clouds that might keep temperatures a bit cooler across portions of south-central and southeast Kansas.
307 AM EDT Sun Sep 24 2023 High pressure will remain in place across the region today. Chances for rain will increase into this week as an upper level low slowly moves east across the Great Lakes and Ohio Valley. High pressure at the surface and aloft will extend from the central Great Lakes into the middle Ohio Valley today. Meanwhile, the remnants of tropical cyclone Ophelia will drift northeast into eastern Pennsylvania. Low level flow between the high and the overall circulation from the low to our east will funnel lower and mid clouds west/southwest across the forecast area. This will have an effect on highs which will range from the lower 70s east to the upper 70s to near 80 west.
138 AM EDT Sun Sep 24 2023 (Through Tonight) Weak high pressure will remain over area through Tonight with dry airmass in place. Another cooler than normal night is expected, with lows in the lower 60s inland, 65 to 70 coast.
(Today and tonight) Weak high pressure over the southeast US will lead to another sunny day with low humidity. Highs will be in the lower 90s.
) a weakening closed mid-upper low over the northern Plains, and 2. Peripheral to eastern Canada ridge, dry easterly flow will continue. We again adjusted RH downward today given character of the lower tropospheric moisture profile and mixing depth. Meanwhile, to our west, a closed low over the northern Plains should weaken through tomorrow.
Moisture increases as throughout the week as an upper level trough and associated frontal boundary move over the area.
Lines of showers will continue to swing north and west of the low, which will keep much of the region under the threat of occasional showers. Model ensembles indicate a trough will persist across the Northeastern CONUS through much of the upcoming week.
Upper level low pressure will drift east and then north through the day, allowing cyclonic flow to remain in place. Model soundings indicate a deep west to northwest flow with marginally cooler temperatures aloft. Continued northwest flow will keep cooler, but seasonally mild temperatures in place with lows in the lower to mid 50s.
1146 PM MDT Sat Sep 23 2023 Upper level Low centered over northwest South Dakota continues to trek eastward tonight.
A combination of moisture pooling along a slowly advancing cold front, cool advection into that moisture behind the front, and overall light winds is leading to areas of fog in northeastern KS and northwestern MO. But this will likely result in some lower cloud cover that tracks east this morning with the cold front. Water vapor imagery shows a strong/ deep cutoff upper low spinning over the eastern Dakotas. The closed upper low will slowly track eastward which will help push the cold front through the area today.
High pressure over Quebec will then support mainly fair dry weather through the upcoming week. the ever weakening tropical remnants still centered near the Delmarva Peninsula will start to lose its battle with high pressure over Quebec.
1120 PM MDT Sat Sep 23 2023 20Z upper level analysis has deep upper low over western South Dakota, slowly shifting to the east. At the surface, low pressure is located across eastern Nebraska, with inverted trof extending back into the western Dakotas. Deep upper low will continue to shift slowly east through the overnight hours, with western ridge gradually sliding into western portions of the area by morning. Upper low shifts into far northeastern South Dakota by Sunday, with some lingering light showers possible across central South Dakota. Ridging to the west will make further inroads across the remainder of the forecast area, with dry and mild conditions expected.
230 AM MDT Sun Sep 24 2023 Key points: - Upper low continues to depart the region today, with only a few sprinkles or light showers possible across our far east. - Dry and warmer conditions return today and tomorrow from west to east, then persist through much of the week. Synopsis: Satellite and radar imagery tonight show an upper low continuing to spin across the eastern Dakotas, with bands of deep moisture streaming into western SD. Forecast: Upper low will continue to slowly drift northeastward away from our area today. Otherwise, rising heights from west to east should bring mostly clear skies as low- level thermal ridging noses into the northern High Plains.
1236 AM EDT Sun Sep 24 2023 A weak cold front will dissipate across central portions of the region overnight.
(Today and tonight) The cold front has moved through much of the area, much drier air is filtering into northwest Oklahoma, and the overnight convection has generally shifted east of the forecast area this morning. This low will translate slowly east today allowing the front to shift south across western north Texas today to the west of the low, but likely keep the front stalled near the Red River of south central and southeastern Oklahoma.
109 AM EDT Sun Sep 24 2023 (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.
Warmer today with the rain having moved out. Highs will be much warmer without the rain and NE flow.
Currently - A highly amplified southern stream trough aloft stretches from the Atlantic coast states down well into the northwestern Caribbean Sea. This trough is deep and an associated surface reflection is aligned in the far southeastern Gulf of Mexico and the northwestern Caribbean Sea. Forecast - Over the next few days lower level Atlantic ridging stretching southwestward into the Caribbean Sea will rotate northward into our area as a weakening Ophelia moves further northward into New England and the southern end of the previously mentioned amplified deep layered trough retrogrades westward into Central America and the Gulf of Mexico. Over the course of the week the remnants of the amplified trough will be absorbed into another passing souther stream trough. Lower level ridging should remain dominant across our broader region. Meanwhile, Atlantic ridging will build westward across Florida.
(Today and tonight) Early this morning, a warm and humid airmass was located across west central Texas, while a cold front was located just south of the Panhandle. A strong upper-level ridge was located over northern Mexico. By tonight, the ridge will start to become suppressed by increasing northwest flow aloft.
252 AM CDT Sun Sep 24 2023 Key Messages * nearly stationary closed low circulation generates pockets of rain shower activity over the next 24 hours. As of 2 AM CDT, multiple areas of rain shower activity rotating south and east around the backside of the upper low circulation. Occluded/closed low circulation over Groton, SD will continue to churn while slowly meandering toward Fargo, ND by 00Z this evening. Continuing, at minimum, chance to likely PoPs today for showers working down over the CWA on the backside of the low.
The ridge tops/east-facing slopes are picking up slightly more than the valleys are. The best chance for periods of heavy rain will occur from the pre-dawn hours into Sunday over the Lower Susquehanna Valley. Rainfall totals of >2" are still expected across the Lower Susq Valley.
1220 AM CDT Sun Sep 24 2023 (This evening through Sunday) With the upper-level ridge over West Central Texas influencing our overall weather patter to remain drier and warmer through much of the weekend, overnight lows tonight are only expected to fall into the mid to upper 70s.
A large area of low pressure will drop from the Pacific Northwest into the Great Basin toward the end of the week, leading to increasing winds and another cooling trend.
346 AM EDT Sun Sep 24 2023 Quiet weather will continue through the weekend with scattered to overcast highs clouds associated with Post-Tropical Cyclone Ophelia as it moves northward into the Mid Atlantic.
A sprawling high pressure system will remain entrenched across southeast Canada and the northeast CONUS. Tropical Storm Ophelia will continue to weaken along the mid Atlantic coast with the remnants eventually shearing east along the southern periphery of this high with no impact on southern MI weather. Another low pressure system will lift from the central plains into the upper midwest late this weekend where it will stall and weaken as it encounters the subsidence and dry air associated with the high pressure system. A weak backdoor cold front will settle into the region late Sunday as this high strengthens to our northeast.
111 AM EDT Sun Sep 24 2023 Forecast is on track this evening with northerly flow across our region around the western periphery of the tropical cyclone across eastern NC and VA. Otherwise, we expect to remain dry and mostly clear across our area tonight with subsidence aloft noted in the low and mid-level WV satellite imagery. 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.
Areas west of the Kansas turnpike will not likely see much fog development as dewpoints have already begun to dip in the low 50s and upper 40s. Today should shape up to be a pleasant day with highs topping out in the low to mid 80s and minimal humidity.
1237 AM CDT Sun Sep 24 2023 (Tonight through Sunday night) The upper ridge will remain in place over the region during the period, while an upper disturbance moves across the Southern Plains Sunday/Sunday night.
Ahead of the front, very warm and humid conditions present with dewpoint temperatures in the low 70s over central/southern Oklahoma. Severe storms (producing very large hail) are expected to develop by late afternoon or early evening, initially firing over north- central / east-central Oklahoma as a mid-level wave exits the high plains. With satellite showing a line of cumulus clouds currently developing over Grady County, this may indicate storm development could also occur near the trough axis/psuedo dryline (though this is less certain). As the LLJ/WAA ramps up tonight near/east of I-44, storms could become more widespread ahead of the cold front, though most models suggest activity remains in Tulsa's FA.
351 AM EDT Sun Sep 24 2023 A blocked upper level pattern exists over eastern North America involving two closed low circulations and a tenuous ridge located between them directly over the central Great Lakes. The ridge has been locally accentuated by radial subsidence occuring at the periphery of each of the closed lows. closed low weakens further and the wavelength of the circulation broadens into the state. Models show residual stability holding in the low to midlevels so no concern whatsoever on any rain shower activity today.
1150 PM MDT Sat Sep 23 2023 Aviation Section Updated Drier, along with warmer afternoon temperatures are expected for the next few days.
Otherwise, expect another warm/dry day as high pressure remains the primary influence of the weather.
Further east, dry air advecting around post-tropical cyclone Ophelia will keep any rain at bay, though cloud cover will gradually increase. High temperatures will be quite warm, in the lower to middle 80s. Tonight's low temperatures will dip into the lower to middle 60s.
253 AM MDT Sun Sep 24 2023 Models are in good agreement with satellite imagery placing the low that passed to the north yesterday now over central eastern South Dakota, ridging along the Rocky Mountains and a trough descending south out of the Gulf of Alaska to a point well off the Pacific Northwest Coast. The cool airmass over the region and clear skies to the north will drop the morning lows today to the freezing mark in the northern valleys of Craig, Steamboat Springs and the upper Colorado River.
High temperatures will trend a little warmer today with highs reaching the upper 80s to low 90s across the region. High temperatures will trend warmer on Monday with temperatures in the low 90s across the majority of our area.
(Now through Monday) Upper level ridging continues today with a continued dry airmass. The pattern breaks down on Monday with a trough developing over the area.
622 AM EDT Sun Sep 24 2023 Upper air pattern consists of a 500 mb closed low over SD with another closed low over VA and a ridge across Hudson Bay and Ontario. The closed low over SD heads slowly northeast to near Fargo by 00z Mon. Another round of pops will move into the far west today as the low remains off to the west of the area with some moisture and 850-500 mb q-vector convergence across the west which weakens by 00z Mon. Key Messages: -Weakening low pressure system provides slight chances for precip in the western U. Starting tonight, a mid-level closed low over the North Dakota and Minnesota state line slowly shifts east through Minnesota and then southeast on Monday. Meanwhile, ridging over Ontario and the Hudson Bay keeps this low from advancing further east.
411 AM MDT Sun Sep 24 2023 Drier, along with warmer afternoon temperatures are expected for the next few days.
Aloft, 500mb troughing has shifted ever so slightly eastward though remains elongated across portions of the eastern CONUS. With upper troughing associated with the remnant tropical system continuing to lift northeastward and a potential cut-off low forming in the Gulf, upper level flow across the southeast will become a little more zonal going into Monday.
607 AM CDT Sun Sep 24 2023 (Today and tonight) Early this morning, a warm and humid airmass was located across west central Texas, while a cold front was located just south of the Panhandle. A strong upper-level ridge was located over northern Mexico. By tonight, the ridge will start to become suppressed by increasing northwest flow aloft.
408 AM MDT Sun Sep 24 2023 A ridge of high pressure over UT/CO will provide plenty of sunshine with a dry northwesterly flow aloft. There's better model agreement on the larger scale pattern for later in the week into the weekend as a western trough sags towards us with dry southwest flow aloft over Colorado.
(Rest of Today) High pressure remains in place over central Tennessee southward into northern Alabama. This is helping to keep the MCS that developed over Arkansas and northern Louisiana well southwest of the area along a warm front.
Cloud cover associated with post tropical cyclone Ophelia still plaguing the area so far this morning, with no signs of dissipating as of yet. There is another weak trough aloft which will head into our area from the west on Monday. The approach of the mid/upper level trough will bring in higher clouds from the west Sunday night and Monday.
Upper level low pressure will drift east and then north through the day, allowing cyclonic flow to remain in place. Model soundings indicate a deep west to northwest flow with marginally cooler temperatures aloft. Continued northwest flow will keep cooler, but seasonally mild temperatures in place with lows in the lower to mid 50s. Continued northwest flow on Monday along with cooler temperatures aloft will again allow some diurnally driven showers to develop, with model soundings indicating that this would mainly be east of I- 29.
Afternoon highs are still on track to climb up into the low 90s.
This activity was associated with a closed upper low tracking NEwrd over the Nrn Plains. The second wave of precipitation could develop just ahead of a slow moving cold front.
Upper level analysis places low over northeast South Dakota, with ridge building into central Montana. Rain showers continue to wrap around the upper low, passing through eastern and central North Dakota. For today, upper low meanders to the northeast into southeast North Dakota and western Minnesota. In the meantime, aforementioned central Montana ridge builds easterly into eastern Montana, which will end up gradually shutting down any rain showers over much of western North Dakota, especially towards the border. For tonight, low meanders slightly east, but ridging will continue to build to our west. Upper ridge will keep dry conditions over our area into mid-week along with a modest warming trend.
High pressure over Utah and southwest Wyoming will shift east beginning Monday, but dry conditions will continue for much of the upcoming week.
1051 AM EDT Sun Sep 24 2023 High pressure will remain in place across the region today. Chances for rain will increase into this week as an upper level low slowly moves east across the Great Lakes and Ohio Valley. High pressure will extend from the Great Lakes into the Upper Ohio Valley today, while the remnants of Ophelia affect the Mid-Atlantic. Highs will range from the lower 70s north and east to the upper 70s southwest. Moisture still somewhat limited despite increasing in advance of the lumbering upper level low that pivots toward the region.
The low clouds will gradually mix out over the next several hours. Building ridge will bring dry and warmer weather today w/ temps reaching the upper 60s to mid 70s. JKL This morning, there will be patchy fog in northern Rosebud, Custer, Fallon, and northern Carter Counties as the lower levels of the atmosphere reach saturation from recent rainfall, light winds, and clearing skies overhead. Otherwise, upper ridging will move eastward into the Northern Rockies through Monday night. This ridge will bring dry conditions under mostly clear to partly cloudy skies much of the time, and a warming trend. RMS The extended will start warm and dry, then become cooler with an increasing chance of showers through end of the week. A broad upper trough will set up over the Pacific Northwest.
620 AM EDT Sun Sep 24 2023 (Today and tonight) Weak high pressure over the southeast US will lead to another sunny day with low humidity. Highs will be in the lower 90s.
A bit uncertain as to whether the temperature will fall below freezing at KLAR given the presence of weak WAA aloft and surface winds near 10 MPH, but the potential is still there through daybreak. Upper-level ridging will result in large scale subsidence & plentiful sunshine through Monday. Minimum RHs falling into the lower to middle teens may support critical fire weather conditions. Highs could return to the lower 80s for portions of the NE Panhandle by Monday afternoon. Above normal temperatures and dry weather expected through the early portion of the work week, with an upper level ridge pushing eastward across the Intermountain West and stalling out across the Great Plains by midweek.
It will keep temperatures cooler in the 70s as compared to the more sunny areas of central east and southeast Tennessee where lower to possible mid 80s will occur. The remnants of the now Post-Tropical Cyclone Ophelia should continue to provide increased cloud coverage over northeast Tennessee and southwest Virginia through at least the first half of Sunday.
Another quiet day ahead of us as high pressure and an upper ridge start to build in across our area. upper trough developing. Upper level ridge builds over the Rockies Mon-Wed, then shifts eastward into the Mississippi Valley by late week into the weekend as deep western U. trough develops. Temps Mon-Wed will climb as mid level heights/temps rise, and portions of the southeast plains will likely see maxes back into the lower 90s by mid-week. Thu-Fri will feature increasing swly flow across the area as wrn trough deepens, though still some model differences on strength/timing of stronger flow across CO and thus any potential fire weather impacts. Bigger impacts may not arrive until after the weekend, especially if 24/00z deterministic solutions of energy cutting off in the base of the trough over CO are realized.
1027 AM EDT Sun Sep 24 2023 Low pressure is currently situated across west central SC with a trough extending into central GA. The low pressure should push off to the northeast, but the trough will linger through early tomorrow. The trough will not be a weather-maker and clear/dry conditions are expected to continue. Aloft, 500mb troughing has shifted ever so slightly eastward though remains elongated across portions of the eastern CONUS. With upper troughing associated with the remnant tropical system continuing to lift northeastward and a potential cut-off low forming in the Gulf, upper level flow across the southeast will become a little more zonal going into Monday.
Otherwise expecting another dry day today with highs in the low to mid 80s as upper level ridging moves overhead.
More widespread activity will occur late tonight as a cold front pushes south.
An approaching trough on Monday will lead to strong winds in the Sierra, northeast CA, and western NV.
624 AM CDT Sun Sep 24 2023 (Today through Monday) Mid-level ridging parked over northern Mexico will continue to provide subsidence across Deep South Texas through Monday. The subsidence from the mid-level ridge should allow for drier air to mix down and keep the humidity down. Low temperatures are expected to be in the 70s with a few places in the lower 80s for tonight.
A blocked upper level pattern exists over eastern North America involving two closed low circulations and a tenuous ridge located between them directly over the central Great Lakes. The ridge has been locally accentuated by radial subsidence occuring at the periphery of each of the closed lows. closed low weakens further and the wavelength of the circulation broadens into the state. Models show residual stability holding in the low to midlevels so no concern whatsoever on any rain shower activity today. 5 kft agl and that westerlies finally undercut the ridge through the Ohio River Valley.