Aikyam-Lab/Synoptic-Bench huggingface dataset:
In the mid and upper levels of the atmosphere, a closed low sits over the Four Corners region, while strong ridging extends westward into the western Atlantic. Meanwhile at the surface, a coastal trough is positioned just off the southeast U. 75 to 2 inches and dew points in the lower to mid 70s. This moisture combined with some short wave energy along the western periphery of the ridge will result in isolated to scattered showers this evening, with high resolution mesoscale models showing coverage diminishing some late this evening and during the overnight hours. Coastal trough/low off the Carolina coasts will continue to move very slowly westward and inland over the next couple of days.
509 PM MDT Wed Sep 9 2020 Latest analysis shows an upper low over the four corners region streaming abundant mid/high level moisture and clouds toward the forecast area from the south. Relatively dry high pressure at the surface, with dewpoints in the lower 20s to lower 30s, is keeping most of the the cloud cover confined to the southern parts of the forecast area with clear skies currently over the north. Temperatures will be relatively cold again tonight, however expect lows to be a few degrees warmer than the various MOS guidance numbers as the models are underestimating the amount of cloud cover for tonight.
/Issued 312 PM CDT Wed Sep 9 2020/ Shallow frontal boundary is hung up in the higher terrain from near Grove to McAlester at this time. An upper low near the four corners will move little until Thursday afternoon when it will finally begin to eject to the northeast.
High pressure will remain in place overnight, keeping conditions dry and winds light and variable. The established ridge across the Southeast will breakdown on Thursday as a trough and a cut off low slide eastward.
Overnight lows will not be as cold with most areas about 5 to 10 degrees warmer than this morning. Hooley Upper ridging will promote clear skies tonight into Thursday across the Northern Rockies.
Temperatures were adjusted to match current observations and trends, which resulted in slightly cooler lows tonight for some locations. Quiet weather and slightly warmer temperatures highlight the short-term. Clear skies and light winds will lead to lows Thursday morning in the 30s and low 40s, with the potential for near or below freezing conditions again in some areas (mainly southwest ND). Thursday will be very similar to Wednesday, though slightly warmer as clear skies and southerly winds continue.
Quiet weather and slightly warmer temperatures highlight the short-term. Clear skies and light winds will lead to lows Thursday morning in the 30s and low 40s, with the potential for near or below freezing conditions again in some areas (mainly southwest ND). Thursday will be very similar to Wednesday, though slightly warmer as clear skies and southerly winds continue.
Rain chances return over the weekend with an approaching low pressure system. Temperatures will remain above average as warm, moist low- level southeast flow will continues on the western flank of the Atlantic ridge. The aforementioned frontal boundary will nudge southward on Thursday, with only slight relief as temperatures are only expected to be a couple degrees cooler than Wednesday. Convergence just south or along the front combined with heating across the Allegheny Mountains may result in a few showers across the higher elevations, but otherwise no precipitation is expected given meager upper-level support.
A quieter weather pattern is expected for the remainder of the week as the upper ridge slowly weakens along the West Coast. Ridge is forecast to begin shifting east over the weekend as an upstream trough over the eastern Pacific approaches bringing stronger onshore flow.
508 PM MDT Wed Sep 9 2020 Overview: A cut-off upper level low meandering invof the 4-Corners (Today-Thu) will eventually be picked up by the westerlies. with precipitation largely confined to areas in close vicinity of the meandering upper low (i. 12Z GFS/ECMWF guidance suggest that the upper level low will lift NNE through north-central CO into eastern WY Thursday evening/night. in a synoptic pattern characterized by a meandering/cut-off upper low transitioning into a more progressive feature, confidence is well below average. Beginning of the forecast period an upper level low will be positioned to the north of the area across the Nebraska panhandle and into Wyoming which will lead to a continuation of northwesterly flow.
821 PM EDT Wed Sep 9 2020 Latest RAP model locates an inverted trough from the southeast Gulf of Mexico to northeast FL that eases westward later tonight and Thu. Deep southeasterly flow moves in behind the trough and helps maintain a moisture rich atmosphere. An inverted trough in the eastern Gulf slowly exits to the west as high pressure.
1000 PM CDT Wed Sep 9 2020 Wind shift associated with shallow cold front is on the doorstep of nw/w parts of the CWA and should be filtering into the Brazos Valley overnight & maybe to a Trinity-Katy-Edna line by morning. Appears the front is a bit ahead of schedule locally, and temps are also on the lower side of available guidance. Cooler air will be most noticeable the further west & northwest one goes. After all this activity winds down, the main issue should be the cold front trying to make its way down from North and Central TX tonight.
338 PM MDT Wed Sep 9 2020 Overview: A cut-off upper level low meandering invof the 4-Corners (Today-Thu) will eventually be picked up by the westerlies. with precipitation largely confined to areas in close vicinity of the meandering upper low (i. 12Z GFS/ECMWF guidance suggest that the upper level low will lift NNE through north-central CO into eastern WY Thursday evening/night. in a synoptic pattern characterized by a meandering/cut-off upper low transitioning into a more progressive feature, confidence is well below average. Beginning of the forecast period an upper level low will be positioned to the north of the area across the Nebraska panhandle and into Wyoming which will lead to a continuation of northwesterly flow.
The cold front continues to slowly move eastward at this time across far eastern Oklahoma. Instability is pretty meager across the area thus why a lack of lightning has been observed tonight but it's just enough to trigger showers and isolated storms across southeast Oklahoma near the cold front. A storm across far southern Muskogee county earlier this evening showed brief weak rotation as it interacted with favorable shear near the cold front. This may occur to a storm or two over the next hour or two with storms in close proximity to the cold front before shear becomes unfavorable a little later tonight. Precipitation chances for northwest Arkansas start to increase late tonight into tomorrow morning as the cold front continues to inch eastward.
High pressure rebuilds over the weekend with a return to warm and dry weather. A cold upper level low pressure system continues to spin near the Four Corners this afternoon. Many of our higher elevation locations will approach the freezing mark by Thursday morning. The low will eject to the northeast on Thursday with high pressure building in for the remainder of the forecast period. Isolated storms cannot be ruled out each afternoon along the higher terrain, but much of the area will remain dry. An upper level low to sit over the Four Corner through tonight then move away by Thursday afternoon.
As the upper low anchored over the four corners region will begin to weaken and reemerge with the main flow stream, the ridge over the eastern U. will also weaken somewhat allowing heights to fall and possibly allow cooler temperatures to overspread the remainder of the forecast area through Friday.
As per the latest ob trends, it looks like the wind shift/weak cold front is about to move into our far NW counties, along with another round of showers and thunderstorms. /ISSUED 1000 PM CDT Wed Sep 9 2020/ Wind shift associated with shallow cold front is on the doorstep of nw/w parts of the CWA and should be filtering into the Brazos Valley overnight & maybe to a Trinity-Katy-Edna line by morning. Appears the front is a bit ahead of schedule locally, and temps are also on the lower side of available guidance. Cooler air will be most noticeable the further west & northwest one goes.
Temperatures were adjusted to match current observations and trends, which resulted in slightly cooler lows tonight for some locations. Quiet weather and slightly warmer temperatures highlight the short-term. Clear skies and light winds will lead to lows Thursday morning in the 30s and low 40s, with the potential for near or below freezing conditions again in some areas (mainly southwest ND).
236 AM CDT Thu Sep 10 2020 An upper ridge will remain over the Mid-South through Friday. The ridge will begin to break down over the weekend allowing for a cold front to move into the area. Models are showing a low pressure system developing near the Gulf Coast with an inverted trof extending northward into the Mid-South. Thus the higher dewpoints would pool on the eastern side of this inverted trof while drier air continues across Northeast Arkansas. The interaction of daytime heating and the higher dewpoints would produce showers and thunderstorms across areas of West Tennessee and Northeast Mississippi. Temperatures may be a tad cooler where convection occurs with readings in the lower to mid 80s. KRM /06z TAFs/ VFR conditions continue at all sites due to high pressure.
ABM Chattanooga Airport, TN 90 71 90 72 86 / 20 10 30 10 60 Knoxville McGhee Tyson Airport, TN 88 70 88 70 86 / 20 10 30 10 60 Oak Ridge, TN 90 69 88 70 86 / 20 10 30 10 60 Tri Cities Airport, TN 86 66 85 67 84 / 20 20 40 20 60.
Upper level flow highlighted this morning by a longwave trough centered over the Great Lakes and a closed low centered over the Four Corners. A warmer 850mb air mass continues to slowly push east over the region.
Overnight tonight, morning low temperatures will cool into the mid 30s to mid 40s across much of the forecast area, while ridging overhead will lead to temperatures warming into the upper 80s and lower 90s tomorrow afternoon. Expect this will continue overnight into Thu as strong upper ridge is over the Pacific northwest. Low level thermal trough over interior Oregon and Washington with light northerly winds. The upper ridge axis will start to move into the Pacific northwest on Friday.
As the almost stationary upper level closed low continues churning over the Four Corners region, another wave can be seen generating thunderstorms over the mountains near the AZ/NM state line. The nearly stationary upper low over the 4-corners will finally lift out onto the northern Plains on Friday.
Today through Friday The upper low continues to rotate over the Four Corners region this morning. By this evening, these showers will continue to spread northward into Johnson and Fremont counties, as the upper low begins to move northeastward over northwestern CO and southern WY. Showers will then become confined from Johnson to eastern Sweetwater counties after midnight, as the low moves over southeast WY. Showers will gradually end by late Friday morning, as the low makes its way over the High Plains. Dry and warmer conditions will be in place over central and western portions, with cool temperatures continuing from Rock Springs to Casper. Gusty winds will develop over southern portions Friday afternoon, as the gradient tightens in response to the proximity of the upper low.
Given the high rainfall rates and slow storm motion, showers and storms can produce a quick 1 to 2 inches or more over a localized area.
Rain chances return over the weekend with an approaching low pressure system. Otherwise, warm and moist low- level southeast flow continues on the western flank of the Atlantic ridge; temperatures will once again stay above the climatological average. Upsloping and lingering moisture in the boundary layer increase the chances for showers along the ridges. The cold front is expected to approach the shores of Lake Erie near sunset and continue to gradually move south overnight. The cold front will continue to advance south early Friday morning. Ongoing northerly flow on the east side of a building high pressure will bring in comparatively cooler, drier conditions. As high pressure advances east into New England, warm, moist air will return to the Ohio River Valley.
200 AM MDT Thu Sep 10 2020 Water vapor shows west/northwest flow along the US/Cndn border, with cut-off low over the Four Corners. Temps will warm into the 60s to around 70 today, with increasing mid/high level clouds from the south as aforementioned cut-off low begins ejecting northeast. Upper low will lift into southeast WY by late tonight and western SD on Friday, spreading fairly widespread showers into the region. High temps on Friday should be a tad cooler than today given abundant cloud cover.
However, an upper speed maximum will lift out across the high Plains Thursday night into early Friday as the upper low begins to lift northeastward into the northern high Plains.
Compared to the guidance blend, these temperatures are warmer at night and cooler by day by at least a few degrees. The upper level low across the Four-Corners region of the wrn U. The long-lived upper level low circulating through the srn Rockies this afternoon will lift through the nrn Plains and exit ncntl Nebraska Friday.
The upper level low pressure positioned near the Four Corners will turn to the northeast and move slowly across western Colorado late Thursday through Thursday night.
211 AM MDT Thu Sep 10 2020 Clear and dry conditions exist across the cwa as we are in a col region, with a four-corners low, strong ridging over the PacNW and southeast CONUS, and troffing to our northeast. This is still a little cooler than normal. This low will keep temps cooler in our east again Friday (around 70F for a high), but a shift to downslope NW winds should push temps to the upper 70s and low 80s in our west. That said, one change in the latest model runs that raises a little concern, is that the low is progged to deepen as it moves into South Dakota, therefore we will continue to keep a close eye on this system as is moves northeast over the next couple of days.
SHORT TERM (Now through Friday): The main story in the short term is the cold front and the challenge of the progression of this front through Deep South Texas. By Friday the 500 mb low located over the four corners begins to retreat to the north and west allowing warmer temperatures to ease back into the area.
An inverted trough remains near the SE coast. Along and east of this trough, a very moist airmass is in place. High pressure from the west will build in across the north tonight and Friday, but a weakness between this ridging and the western Atlantic ridge will continue along the coast through the remainder of the short term period. At the surface, an inverted trough also remains stationary along the SE US coastline. The trough should continue as a focus for convection through the period. Temperatures in the high 80s and lower 90s will be accompanied by widespread dewpoints in the mid 70s.
This evening, the upper low that is currently centered over the Four Corners will start to eject.
Aloft, ridging stretches northeastward from the Gulf, across the eastern CONUS, and into the Atlantic. A large closed cyclone persists over the Four Corners region with mean troughing over the northern Plains and Great Lakes. Through period, the Four Corners upper cyclone will begin to eject northeast while the eastern CONUS ridge will persist. A band of deep moisture sandwiched between these features will support continued convection within and just to the east of the frontal zone with the highest PoP over western AR, although guidance shows the boundary will gradually wash out near and beyond the end of the period with convection waning as a result. Temperatures will remain near average for much of the area with slightly cooler readings where clouds/rain are more widespread, namely across the western third of the state.
Quiet weather remains the theme tonight into tomorrow as ridging aloft continues to influence our weather. The quasi-stationary front across central Indiana will slowly drop south as a weak cold front. Upper ridging over the southeastern CONUS will keep us dry and seasonably warm through Friday night.
1258 AM CDT Thu Sep 10 2020 (Tonight through Thursday) On water vapor satellite, an upper level low was spinning over the Four Corners region, which is continuing to pump plentiful mid and upper level moisture into West Central Texas. Meanwhile, plenty of moisture has come into the surface and low levels from the cold front which has finally pushed through most of the Northwest Hill Country, leaving behind significantly colder air. With the expected overcast skies and cool post- frontal northerly winds continuing, expect another day of much cooler than normal temperatures Thursday with highs in the upper 50s in the northwest counties to mid 60s in the southeast counties.
Shallow cold front will continue to bring forecast and aviation headaches thru the TAF period. The cold front continues to slowly move eastward at this time across far eastern Oklahoma. Instability is pretty meager across the area thus why a lack of lightning has been observed tonight but it's just enough to trigger showers and isolated storms across southeast Oklahoma near the cold front. A storm across far southern Muskogee county earlier this evening showed brief weak rotation as it interacted with favorable shear near the cold front. This may occur to a storm or two over the next hour or two with storms in close proximity to the cold front before shear becomes unfavorable a little later tonight. Precipitation chances for northwest Arkansas start to increase late tonight into tomorrow morning as the cold front continues to inch eastward.
1107 PM CDT Wed Sep 9 2020 (This evening through Thursday) The cold front is expected to slowly move through the remainder of the forecast area this evening, but it may stall southeast of the forecast area again, but there will likely be enough push of the front to bring the temperatures down in Atoka and Bryan Counties for tonight and tomorrow.
as the stalled frontal boundary over our region will be pushed to the south by an approaching area of high pressure. courtesy of a ridging off the east coast. High pressure centered over the Great Lakes Friday morning will spread eastward into the weekend.
Expanding high pressure system moving in from the Midwest this morning and upper-level confluence will act to weaken the baroclinic zone across the state through the afternoon and will end drizzle/light rain chances across the state as drier air filters in. Northeast surface winds will hold ahead of the advancing high pressure which will maintain widespread stratus through the day while capping daytime highs in the 60s (touching 70 across the southern Metro region).
Surface analysis shows the cooler air mass and the quasi- stationary front deceptively close, yet so far away. The cooler and drier air associated with the airmass should remain largely outside of the CWA during the short term forecast period. Above the surface, there is a vigorous closed low associated with the western storm system, located in the vicinity of the 4 corners. The low will remain somewhat stationary for the next 24 hours, and will start to lift into the northern Plains by the end of the forecast period.
Another warm and mostly dry day is in store for us as upper level ridging continues to hold over the mid-Atlantic region. Friday - Friday Night High pressure sliding from the Great Lakes to New England will keep us dry with slightly warmer than normal temperatures.
Rain chances return over the weekend with an approaching low pressure system. Temperatures will remain above average as warm, moist low-level southeast flow continues on the western flank of the Atlantic ridge. Convergence just south or along the front combined with heating across the Allegheny Mountains may result in a few showers across the higher elevations, but otherwise no precipitation is expected given meager upper-level support. Ongoing northerly flow on the east side of a building high pressure in wake of the cold front will bring in comparatively cooler, drier conditions late Thursday night into Friday.
A large closed low centered over the 4 corners region will basically not move for the next 12-18 hours which will keep the clouds and periodic rain showers all across western and central Kansas for tonight. Thursday the center of the upper low slowly starts to move northward and as we go throughout the day the chances of rain should lessen. Thursday night into Friday the upper level low position should be more into the northern plains. the low will continue to exit towards the Great Lakes as an upper level ridge builds in the Rockies.
246 AM MDT Thu Sep 10 2020 Satellite imagery shows deep closed low centered near the Four Corners region while amplified ridge remains off Pacific coast. Frost Advisory remains in effect this morning, though temperatures are still elevated well above freezing as of 2am. With upper ridge gradually shifting east through the remainder of the week, and temperatures trending upwards, believe this will be the last East Idaho will see from this current cold snap.
1155 PM MDT Wed Sep 9 2020 06Z TAF CYCLE An unseasonably strong upper level low pressure system will linger over the Four Corners through early Thursday morning, then eject north northeastward across CO during the afternoon. This system is not done with us yet! Cold easterly upslope flow across central and eastern NM will interact with strong diffluence ahead of the upper low to spread widespread rain and mountain snow over the area again late today. The nose of an 85 kt speed max will round the upper low and keep precip going all night. Precip is expected to end slowly from west to east Thursday with slightly warmer temps.
259 AM CDT Thu Sep 10 2020 The upper low continues to spin near the four corners this morning while a broad area of ascent was noted across the southern and central Plains. As the upper low begins to move northeastward tonight precipitation chances will increase for the late evening and overnight hours as large scale ascent along with some isentropic lift increases across eastern Kansas.
A persistent trough over Florida will continue to move west through today pulling ample tropical moisture (forecasted PWAT values in 2- 2.
The easterly wave was having a tough time progressing westward due to a deep upper trof west of the MS river. Easterly flow and cloud cover will result in mild readings overnight, with lows in the lower to middle 70s.
346 AM CDT Thu Sep 10 2020 Cold front is making slow progress east this morning, presently in the general vicinity if U.
Temperatures have already slid into the lower to middle 70s, on their way to overnight lows in the middle to upper 60s. The established ridge across the Southeast will breakdown on Thursday as a trough and a cut off low slide eastward. Despite the isolated to scattered showers and storms, temps will reach the lower 90s and with a further increase in dewpoints, heat index values will encroach on 100 degrees. Overnight, it will be mild and muggy with temps only reaching the lower 70s.
/issued 428 AM CDT Thu Sep 10 2020/ An upper level low is over the Four Corners Region. The winds at Guadalupe Pass have weakened below high wind criteria and are not expected to increase so the High Wind Warning has been cancelled. The upper low lift northward over the northern Plains on Friday with surface winds across the area becoming southerly. Upper ridging develops over the southern U. Slight chances of precipitation will remain but it will mostly be confined to the higher terrain.
Smoke will continue to cause problems with the daily high forecast the next few days but in general cooler temperatures below seasonal normals will likely continue today.