Aikyam-Lab/Synoptic-Bench huggingface dataset:
(This evening through Thursday) At the time of this writing, a wedge of high pressure remains in place along the lee side of the Appalachians and expanding into much of the forecast area. Cooler temperatures and a stable airmass have served to limit chances for thunderstorms thus far, although an isolated thunderstorms cannot be ruled out through the remainder of the afternoon. As a low pressure system swings through the Midwest and towards the Great Lakes, an elongated front extending from the low is anticipated to drop towards the Tennessee Valley. After starting the morning in the low 60s, high temperatures are forecast to be slightly warmer than today, rising into the upper 70s and low 80s in the afternoon.
524 PM MDT Wed Sep 27 2023 The trough over to our northwest will continue to slowly advance and the low to our northeast may do so as well. There will be an increasing southwesterly flow aloft ahead of the trough, probably pushing into northwest Colorado but likely not into our area yet, so weak flow aloft to persist. Yet warmer everywhere, generally 10 to 15 F warmer than normal across the plains and valleys, to near normal in sparse areas above 9000 feet.
Mostly clear skies, light afternoon breezes, and temperatures slightly above-average are expected for another day before gusty winds, much cooler temperatures, and chances for precipitation enter the forecast this weekend.
1044 PM EDT Wed Sep 27 2023 Low and mid level clouds continue to spread back northwest on north side of mid level low pressure currently centered along the Indiana/Michigan border. Those clouds will keep temperatures a bit elevated, with lows only in the lower and middle 50s. More of the same tonight with the upper level low to our south continuing to send low level moisture northward into northern Michigan.
612 PM CDT Wed Sep 27 2023 (This evening through Thursday) Water vapor imagery shows an upper level low pressure system over the Great Lakes and a ridge of high pressure extending back to far West Texas giving way to north-westerly flow aloft. The upper low and weak ridge over the Great Plains will move eastward while the high seems to dissipate. Wind speeds tomorrow will remain southerly but will ramp up in speed to 15 to 20 mph on the Caprock due to flow around a mid to upper level trough to the northwest of the region.
819 PM EDT Wed Sep 27 2023 High pressure will build in from the north tonight, then hold on through the remainder of the forecast period. Strong pressure ridge centered over New England extending southwest across the Carolinas into Georgia. Due to this, prefer to lean heavily on the warmer side of guidance for temperatures, with lows in the upper 50s across the northern/western Midlands and upper CSRA, and in the lower 60s elsewhere. Guidance still indicating that surface ridging will be in place across the area in association with a strong high pressure system centered over southeastern Canada. We'll have a 500 hPa trough axis slowly moving east and through the area on Thursday; despite this, no precipitation is expected.
830 PM EDT Wed Sep 27 2023 Low and mid level clouds continue to spread back northwest on north side of mid level low pressure currently centered along the Indiana/Michigan border. Those clouds will keep temperatures a bit elevated, with lows only in the lower and middle 50s. More of the same tonight with the upper level low to our south continuing to send low level moisture northward into northern Michigan.
At the upper levels, a ridge axis currently extends from southwest North Dakota, northeast into the vicinity of the Turtle Mountains with a broad western CONUS trough to the west of the state. At the surface, a weak low pressure center is located over southeast Montana with a weak frontal boundary extending to the north. Thursday's highs will be similar to today, just a touch cooler in the west and a touch warmer in the east, ranging from the mid 60s to mid 70s.
734 PM EDT Wed Sep 27 2023 More of the same tonight with the upper level low to our south continuing to send low level moisture northward into northern Michigan.
928 PM CDT Wed Sep 27 2023 Weak high pressure centered across the Tenn Valley into the Southeast U. is resulting in a very weak pressure gradient observed across the Lower Miss Valley, into the Southern Plains. Most locations have already made it into the lower 90s, and will likely top out in the mid and possibly upper 90s today. Expect mostly clear skies and light winds tonight, as high pressure will settle over the region. Overnight lows will once again fall into the mid to upper 60s, with a few isolated locations in the lower 60s.
734 PM EDT Wed Sep 27 2023 Variably cloudy and warmer today with no rainfall expected through tonight.
The models have handled the wedge poorly but the higher-res models have finally caught on. (This evening through Thursday) At the time of this writing, a wedge of high pressure remains in place along the lee side of the Appalachians and expanding into much of the forecast area. Cooler temperatures and a stable airmass have served to limit chances for thunderstorms thus far, although an isolated thunderstorms cannot be ruled out through the remainder of the afternoon. As a low pressure system swings through the Midwest and towards the Great Lakes, an elongated front extending from the low is anticipated to drop towards the Tennessee Valley. After starting the morning in the low 60s, high temperatures are forecast to be slightly warmer than today, rising into the upper 70s and low 80s in the afternoon.
714 PM EDT Wed Sep 27 2023 Cloudy skies with below normal temperatures will persist through the end of the week as a strong area of high pressure remains to our north. While temps are a bit warmer to the south, the Sandhills and southern Coastal Plain are still running about 10 degrees below normal for late September. Temps tonight will fall into the low 50s in the north. Temps will be warmer than today although still below normal with highs ranging from the upper 60s in the north to the mid 70s in the south.
923 PM EDT Wed Sep 27 2023 Cloudy skies with below normal temperatures will persist through the end of the week as a strong area of high pressure remains to our north. The 00Z surface analysis shows the ridge still extending southwest through central NC from a 1030mb high over Quebec. Aloft, the H25 and H5 lows remain roughly over southern Lake Michigan/northern IL/IN, with the trough extending southward through the MS Valley. Temps will be warmer than today although still below normal with highs ranging from the upper 60s in the north to the mid 70s in the south.
At the same time showers and storms were moving across the lower Ohio Valley late this evening with an upper level impulse in the cyclonic flow around the upper low now over Lake Michigan and Indiana/Illinois. Discussion: An upper low continues to rotate across Illinois this afternoon placing the region within diffluent upper flow. The upper low moves into the Great Lakes tonight and on Thursday with the region still within cyclonic flow. Discussion: We begin the period with a closed low to our north across the Ohio River Valley and a trough axis centered through our area.
Will be a warm one once again, with highs in the mid to upper 80's for the lower elevations. The trough over to our northwest will continue to slowly advance and the low to our northeast may do so as well. There will be an increasing southwesterly flow aloft ahead of the trough, probably pushing into northwest Colorado but likely not into our area yet, so weak flow aloft to persist. Yet warmer everywhere, generally 10 to 15 F warmer than normal across the plains and valleys, to near normal in sparse areas above 9000 feet.
255 AM CDT Thu Sep 28 2023 (Issued 255 AM CDT Thu Sep 28 2023) Today and Tonight: The upper low that has loitered near the region for the past 3-4 days continues a Midwest Goodbye, slowly exiting stage east.
Highs will once again be above normal in the low to mid 90s. A few of the high res models are showing an isolated thunderstorm near our southeastern counties, but they are keeping them out of our area for now.
231 AM EDT Thu Sep 28 2023 Cloudy skies with below normal temperatures will persist through the end of the week as a strong area of high pressure remains to our north. The 00Z surface analysis shows the ridge still extending southwest through central NC from a 1030mb high over Quebec. Aloft, the H25 and H5 lows remain roughly over southern Lake Michigan/northern IL/IN, with the trough extending southward through the MS Valley. Temps will be warmer than today although still below normal with highs ranging from the upper 60s in the north to the mid 70s in the south.
235 AM EDT Thu Sep 28 2023 High pressure remains largely in control over northern New England through the end of week.
401 AM EDT Thu Sep 28 2023 High pressure will continue to bring dry weather and seasonable temperatures today.
323 AM EDT Thu Sep 28 2023 High pressure will be in control of the region for the next several days.
314 AM CDT Thu Sep 28 2023 All of the short term models are showing a rapid warm-up this morning as an east-west stationary boundary lifts northward across the I-70 region as a warm front, and widespread vertical mixing occurs across the area.
This is associated with an upper level low that is departing to the east of the region this morning. Today-Tonight: By later today, an upper level ridge and a warm airmass build back into the region. Overnight lows fall into the lower to middle 60s.
233 AM CDT Thu Sep 28 2023 An upper level low will move east across the Great Lakes region causing a weak sfc frontal boundary to sag south of the FA by this evening.
The presence of subtle vorticity maxima rotating around the closed mid-upper low just to our northeast, convergence associated with its lower tropospheric circulation, and a small amount of instability through diabatic surface heating may be enough for isolated showers to continue across portions of central Indiana today.
400 AM EDT Thu Sep 28 2023 Cloudy skies with below normal temperatures will persist through the end of the week as a strong area of high pressure remains to our north. The 00Z surface analysis shows the ridge still extending southwest through central NC from a 1030mb high over Quebec. Aloft, the H25 and H5 lows remain roughly over southern Lake Michigan/northern IL/IN, with the trough extending southward through the MS Valley. A closed mid/upper-level cyclone will drift east and offshore the nrn middle Atlantic this period, while maintaining cyclonic flow aloft over cntl NC. An omega blocking ridge will develop from the lwr MS Valley newd and across the Great Lakes.
214 AM CDT Thu Sep 28 2023 The upper level low that brought the rain the last two days is slowly spinning eastward away from Chicago. A few of the high-res models are still suggesting that isolated cells could pop up over the lake and move westward as the last outstretched reach of the low.
403 AM EDT Thu Sep 28 2023 Light to moderate rainfall will continue through morning hours as the slow moving mid/upper level closed low moves directly over Michigan at 12Z. The mid/upper closed low translates slowly to the east throughout today with the surface reflection extending through IN/OH during the afternoon.
Mostly clear skies, light afternoon breezes, and temperatures slightly above-average are expected for another day before gusty winds, much cooler temperatures, and chances for precipitation enter the forecast this weekend. Looks like relatively uneventful weather across our region for the overnight period as longwave troughing to our north inches closer.
This will support another afternoon of temperatures in the low to mid 80s, with values on the cooler side of that range being over Illinois thanks to cooler mid-level temperatures. As a result, surface winds will become increasingly southerly to southeasterly, advecting warmer air into the CWA.
251 AM EDT Thu Sep 28 2023 High pressure will be in control of the region for the next several days.
Rain chances will diminish in the evening to overnight hours as the upper trough axis moves eastward away from our area.
1252 AM CDT Thu Sep 28 2023 Weak high pressure centered across the Tenn Valley into the Southeast U. is resulting in a very weak pressure gradient observed across the Lower Miss Valley, into the Southern Plains. Most locations have already made it into the lower 90s, and will likely top out in the mid and possibly upper 90s today. Expect mostly clear skies and light winds tonight, as high pressure will settle over the region. Overnight lows will once again fall into the mid to upper 60s, with a few isolated locations in the lower 60s.
137 AM EDT Thu Sep 28 2023 Aviation Have increased PoPs substantially (to 80-100%) south and east of GRR where showers continue to blossom related to a well-defined spoke of vorticity pivoting n/nw around the upper low. Some question as to how much farther north and west this rain area makes it overnight as the upper low over nw Indiana tracks slowly east-northeast, but for now will go with about GRR to MOP as the westernmost edge of the more widespread rain. As the upper level low slowly tracks to the east we move back into northwest flow, chances for showers diminish through Thursday morning.
Overnight lows trend in the low to mid 70s for most while the island will bottom out closer to 80 degrees.
1200 AM CDT Thu Sep 28 2023 (This evening through Thursday) Water vapor imagery shows an upper level low pressure system over the Great Lakes and a ridge of high pressure extending back to far West Texas giving way to north-westerly flow aloft. The upper low and weak ridge over the Great Plains will move eastward while the high seems to dissipate. Wind speeds tomorrow will remain southerly but will ramp up in speed to 15 to 20 mph on the Caprock due to flow around a mid to upper level trough to the northwest of the region.
(Today through Wednesday) A decaying MCS is currently trekking across the Ohio Valley associated with an upper low digging from the Great Lakes region. As this upper low spins nearly stationary over Ohio today, showers and thunderstorms will be possible in our northeastern counties on the trailing edge of the frontal boundary. As the upper low drifts off to New England this afternoon, convection is expected to gradually taper off.
203 AM MDT Thu Sep 28 2023 Water vapor imagery was showing a broad upper trough over the Pacific Northwest, stretching east into the Northern Rockies. This trough has replaced the upper ridge was over the area a few days ago. Cooler temperatures have accompanied the trough, with highs generally in the mid 70s yesterday. Highs today will be even cooler, with maxes in the mid to upper 60s, courtesy of a cold front ripping through the forecast area overnight. Broad troughing will continue tonight.
The chance for convection across northwest Oklahoma appears a little higher (10-15%) late tonight/early tomorrow morning with the low-level jet axis farther to the east with sufficient elevated instability (MUCAPE ~500 J/kg).
358 AM EDT Thu Sep 28 2023 High pressure will continue to bring dry weather and seasonable temperatures today.
The weak troughing above South Texas that has maintained unsettled weather on our southeast doorstep will push offshore today, which will be the first of several consecutive rain-free days for North and Central Texas.
Ridging aloft will steadily build east into the region through the period. This, as high pressure at the surface remains wedged into the forecast area from the northeast.
Stronger winds aloft associated with a disturbance rounding the base of the upper trof will support more vigorous convection into Thursday morning, mainly across southern Kentucky. Forcing diminishes as the day progresses, but even with the trof axis to our east there remains enough cold pool influence to support isolated to scattered afternoon storms.
Upper ridge axis centers over the Mid-Missouri Valley today, spelling a dry and hot day ahead. In fact, high temperatures this afternoon will feel more like summer, with readings nearly ten degrees above normal in the lower 80s over NE MO to the lower 90s south and west of the KC Metro. Upper ridge will generally remain in place over the area through the weekend as the initial wave over the northern US Rockies quickly ejects into Canada ahead of the next larger trough taking shape over the Intermountain West this weekend.
1159 PM EDT Wed Sep 27 2023 High pressure remains largely in control over northern New England through the end of week.
The axis of a weak upper trough is to the east of the region today, and with onshore flow at the ridge level and above a cool air mass below normal temperatures will continue today. Models remain on track showing a low approaching the area from the west on tonight with an upper trough moving over the region Friday. Models are showing a trend of increased instability as the upper trough moves in from the west in central Siskiyou county, and a slight chance of thunderstorms has been added to mainly the Mt Shasta area Friday afternoon.
Consensus model solutions have been consistent in their propagation of a broad upper level trough across mid state region in association with a closed upper level low currently across southern Great Lakes Region. That upper level low will move slowly northeastward into Eastern Great Lakes Region as Friday progresses resulting in upper level troughing pushing eastward of our area as Friday morning hours progress. Upper level ridging developing across MS River Valley as Friday progresses will then begin to usher in a dry airmass to our entire area as Friday afternoon progresses. Temperatures will continue their slightly warmer than normal trend through Friday afternoon.
(Today through Friday) A wedge of high pressure still remains in place across the forecast area and has resulted in some areas of low cloud cover. Current temperatures are a little cooler than this time yesterday as a result of some breaks in the clouds. A low pressure system and associated surface front will continue to track south towards the TN Valley Region today. Dry conditions and partly cloudy skies are expected for Friday as well as high pressure remains present. Forecast high temperatures will be in the mid 70s to low 80s today and slightly warmer on Friday with highs in the 80s.
617 AM CDT Thu Sep 28 2023 An upper level low will move east across the Great Lakes region causing a weak sfc frontal boundary to sag south of the FA by this evening. Otherwise, clearing skies are in store for Friday as an upper level ridge axis begins to build over the Mississippi. Above normal temperatures remain in store with maxTs in the low to mid 80s on Thursday and mid to upper 80s on Friday.
Clouds will be on the decrease later this afternoon as high pressure builds into the area. Under partly sunny skies, high temperatures on Friday will be a few degrees warmer with readings in the upper 60s to middle 70s.
1024 AM EDT Thu Sep 28 2023 High pressure will continue to bring dry weather and seasonable temperatures today. A low pressure system off the Mid-Atlantic coast is expected to bring some rain on Friday to parts of Northeast PA and Central NY, especially across the Poconos and Catskills.
An upper low will crawl into NW Ohio today. Better eastward progression of the upper low is expected Thursday night and Friday, keeping scattered showers in the forecast through the overnight into Friday morning. Weak warm advection ahead of the trough will warm temperatures several degrees on Friday.
Afternoon temperatures will be cooler than they have been, but only a few degrees below normal.
626 AM CDT Thu Sep 28 2023 (Today through Friday) Closed and weak 500 mb low pressure will linger along the Texas coastline today. Convection is likely to be limited to the lower Texas coastal waters, with the best chance over the Gulf of Mexico waters from 0 to 60 nautical miles offshore.
Isolated showers associated with an upper low currently centered over southern Michigan and slowly transitioning east will result in isolated to scattered showers today. Better eastward progression of the upper low is expected Thursday night and Friday, keeping scattered showers in the forecast through the overnight into Friday morning. Weak warm advection ahead of the trough will warm temperatures several degrees on Friday.
Today-Tonight: The stubborn slow-moving low pressure system that has impacted the region over the past several days continues to spin across the Great Lakes this morning. However, it will move away today as the blocking ridge across eastern Canada finally gets kicked eastward. GOES nighttime microphysics imagery shows plenty of stratus across the area early today and another cloudier day with seasonable temps is expected before higher chances of some clearing occur into tonight with the arrival of mid-level ridging.
Tighter gradient between this boundary and ridge to the north is producing a stronger N/NE flow just north of the region along the NE FL coast, but could see some breezy conditions develop by this afternoon across coastal Volusia County as the front slowly slides southward through the day.
WV imagery shows the upper ridge parked off the coast of Baja del Sur, leaving northwest flow aloft over West Texas and Southeast New Mexico. Friday, flow aloft transitions to southwest as the next trough makes landfall on the west coast.
701 AM EDT Thu Sep 28 2023 Center of upper level low pressure will slowly meander across southern Lower Michigan during the next 12 to 18 hours. Light to moderate rainfall will continue through morning hours as the slow moving mid/upper level closed low moves directly over Michigan at 12Z. The mid/upper closed low translates slowly to the east throughout today with the surface reflection extending through IN/OH during the afternoon. Ridging builds into the western Great Lakes in the wake of the trough on Friday and quickly amplified into the central Great Lakes into the beginning of the weekend. Clouds will be slow to clear on Friday as the low level easterly feed of moisture gradually gives way to deeper dry air moving into the region while mid and upper level flow turns northerly.
631 AM EDT Thu Sep 28 2023 High pressure will be in control of the region for the next several days. Wedge- like conditions will continue today with model soundings indicating a strong inversion in the low levels. North to northeasterly flow will also keep cooler air in place across the region helping to ensure the inversion persists through the day and aids in trapping moisture in the low levels. Low temperatures will again be in the upper 50s in the western portions to the low 60s in the east. An upper level trough will be shifting east from the Great Lakes into the Northeast on Friday. Cloud cover should decrease through the day as the trough axis moves further east of the forecast area and drier air pushes into the region.
A cooler air mass will settle over the region lowering snow levels to 6000-6500 feet.
Synoptic pattern does not change much by Friday as the upper-ridge remains over the Central/Southern Plains.
The wind should progress eastward the rest of the morning and into the afternoon hours with peak gusts of 30-35 mph possible over the higher terrain area of the Prairie Coteau.
Slightly cooler temperatures will settle into northern Utah today behind a cold front.
Isolated to scattered light showers continue crossing the area today as the upper level low slowly shifts east. Better eastward progression of the upper low is expected tonight and Friday, keeping scattered showers in the forecast into Friday morning. Weak warm advection ahead of the trough will warm temperatures several degrees on Friday.
Stronger winds aloft associated with a disturbance rounding the base of the upper trof will support more vigorous convection into Thursday morning, mainly across southern Kentucky.
A closed low will move across the Great Lakes today, with troughing and northwesterly winds extending southward into the Deep South. A surface front/trough will remain to our north as its southward progression is prevented by the influence of the surface wedge and increasing heights/ridging aloft.