Aikyam-Lab/Synoptic-Bench huggingface dataset:
The low-level moisture and very weak forcing/low- level instability may lead to some light drizzle or a few rain showers, mainly over east-central and far northeast WI.
A cold front is currently draped across a line from Del Rio to just south of Victoria. Highs today and Tuesday will be in the upper 80s along the coast and in the low to mid 90s elsewhere. Dry air and high pressure will settle in behind the front, causing a decrease in cloud cover as the day progresses.
1214 AM CDT Mon Oct 4 2021 The mid level low has made its way to Chicago, and cloud cover on the back side of the low is slowly thinning and moving off to the southeast.
Conditions are generally expected to improve by around mid-morning, but the low stratus deck may be slow to dissipate in some areas. /EC/ Prior discussion below: A weak cold front remains just to the northwest this afternoon and GLH wind came around to more northwesterly on the last ob. In the trough associated with the front.
Expect the weather to remain active today as the longwave trough currently over the area begins to orient itself from the SW to NE ahead of a closed low developing across the Mississippi Valley. During the early portions of the day weaknesses in the longwave trough will help kick off periods of rain showers and isolated thunderstorms. Hi-res models suggest storms will first develop north of the Fall Line and then increase in coverage this afternoon as the aforementioned closed low becomes well established over the region. Outside of the precipitation temperatures will be cooler than yesterday with light SW winds. Tonight into tomorrow with the closed low to our west and subtropical ridging to our east persistent moisture influx will occur over GA.
350 AM CDT Mon Oct 4 2021 A low pressure system over the Great Lakes region will produce a west to northwest wind flow across our region today. The high- res nam and 06z hrrr are among the models that generate some isolated to scattered showers along this secondary front this afternoon. Tonight will be partly cloudy and a bit cooler. A rather strong 500 mb closed low is forecast to form over the lower Mississippi Valley by 12z Tuesday.
With an upper level ridge aloft, temperatures on Monday will rise and should be near to above normal area wide.
Meanwhile, a surface cold front is expected to slowly move across the Lower Mississippi Valley region thoughout the day, approaching our northwestern zones by Monday evening. Although, portions of southeast Mississippi may reach the low 80s as they remain behind the front.
Moisture return starts up Monday night as low pressure off the coast of Southern California spreads Pacific moisture inland. As the day progresses, an upstream kicker wave over the eastern Pacific will cause the SoCal closed low to gradually lift to the northeast before transitioning to a strong, negatively tilted open wave. South to southwesterly moist upslope flow will initially favor the San Juans with precipitation becoming steady and persisting through Tuesday night (with snow likely at the highest ridgetops).
Quick update to lower rain chances over the coastal counties where the seabreeze collided with the prefrontal trough producing storms earlier this evening but have since pushed into the coastal waters and weakened. Upper troughing to the west will keep the high level moisture streaming overhead tonight and at least through late morning Monday. Drying in the low levels though will continue as the cold front pushes through the coastal counties this evening and into the Gulf A pleasant and dry day expected Monday with northerly flow of around 10 mph with gusts of 15 to 20 mph at times.
Very pleasant weather will continue through most of the week as the area remains sandwiched between a closed upper low over Missouri and a deeper West Coast trough.
Seasonable and dry weather conditions will persist into mid-week as high pressure builds in from the west and an upper-level ridge tilts over the northern Great Lakes Region. A stacked low then shifts into the Lower Mississippi River Region becoming cut off from the main upper-level stream. This forms a rex block with the high pressure system to the north spilling over into the northeast CONUS. There is some discrepancy between model guidance with exactly when and where this cut-off low pressure system reunites with the upper- level jet and moves through the local region. Current model guidance and ensembles have precipitation chances returning to the area as the low lifts through the region.
WV imagery, in particular, indicates a building ridge over the Great Basin region extending into the nrn Rockies, with the ern periphery of the ridge over the nrn Plains.
1117 PM MDT Sun Oct 3 2021 Continued drying of the air mass in place as well as a lack of support/focus with anticipated upper ridging, will provide dry weather during the period. Seasonably cool overnight lows, with some near freezing temps possible in the mountains valleys early Monday morning. A ridge of high pressure will continue to be the main influence over the area throughout the day as it pushes east. Given the synoptically sinking air associated with the high pressure, and low moisture content, precipitation chances are expected to remain low and the forecast area to stay dry. Though with the ridging still in place, high temperatures for the day are expected to warm above average across the southern Colorado region.
Nonetheless, should see any development quickly dissipate after daybreak as strong upper level ridging builds overhead.
Steadiest showers have pushed eastward and extend from the Pocono Plateau to the Lower Susq River Valley late this evening. A southerly breeze and influx of low level moisture will result in a much milder night than those recently, with lows in the lower 60s over much of the region. Diurnal heating and approach of a weak upper trough will bring another round of scattered convection Tuesday PM.
Ridging extends northward through the Rockies/High Plains, while low pressure spins over the Great Lakes region, with an embedded weaker disturbance sliding through eastern KS/OK. At the sfc, the current light/variable winds are expected to become more northeasterly, esp during the second half of today, thanks to high pressure becoming a bit more organized over the western Great Lakes and its southward extending ridge axis.
CD Chattanooga Airport, TN 77 64 74 65 74 / 40 40 90 80 90 Knoxville McGhee Tyson Airport, TN 77 62 76 64 76 / 40 30 80 80 90 Oak Ridge, TN 77 61 75 63 75 / 30 20 80 70 90 Tri Cities Airport, TN 76 58 76 60 76 / 40 20 70 60 80.
Zonal flow will persist during the day Monday and will help keep rain chances on the lower side; however, isolated to scattered showers and thunderstorms are possible. As the cut off low settles into the Lower Mississippi Valley on Monday night, flow aloft will once again shift to the southwest. With the strong synoptic lift associated with the upper low and the abundance of moisture, numerous to widespread showers will impact the region on Tuesday.
1024 PM MDT Sun Oct 3 2021 Upper ridge is building over the northern Rockies and high plains with clear skies across the entire forecast area. Most of the week will be warm and dry as the upper ridge builds, then shifts to the east as an upper trof deepens along the west coast, keeping southwest flow over the northern Plains.
Tonight Through Tuesday This afternoon and evening, a cold front will continue to move southeast/east and out of Arkansas. Behind the front, clouds associated with a digging trough in the mid Mississippi Valley will move back into the state. Monday and Tuesday should be slightly cooler, as surface flow remains northwest/northerly behind the front, and the aforementioned upper trough forms a closed low, bringing up moisture into the region, keeping some clouds over us.
The main trough axis now east of the region will keep showers relegated to the far eastern portions of the Ozarks region through this evening and cloud cover over the area into tonight. Northerly winds will continue as the trough shifts east. A second trough will round the top of the amplifying ridge over the plains and slide into the region overnight. The second trough will make its was through the Ozarks during the day Monday, while todays trough develops into a cutoff upper level low, with little fanfare as skies look to be mostly sunny with continued light northerly winds, A few gusts to 15 mph may occur during the afternoon, but otherwise it will be a nice day with highs in the middle 70s. The upper level cutoff low will migrate south and over the lower Mississippi valley by Tuesday morning.
355 AM CDT Mon Oct 4 2021 (Issued 355 AM CDT Mon Oct 4 2021) Today through Tuesday: Clouds will hang on today into Tuesday as low pressure departs and high pressure gradually builds in from the northwest. There's a better chance for some peeks of sun Tuesday, especially in the north towards the high.
903 PM MDT Sun Oct 3 2021 With high pressure overhead, there are no weather concerns tonight. Models keep upper ridging over the CWA tonight and Monday with weak flow aloft and benign synoptic scale forcing. For temperatures, tonight's lows will be a bit warmer than this morning's. Monday's highs will be a tad warmer than today's highs at well. Quiet weather will persist on Tuesday as the ridge axis slowly moves east of the area. For the urban corridor, temperatures will again be in the upper 70s to near 80F, with a very slight chance a shower or two sneaks off the higher terrain and into the urban corridor.
Overnight strong 500 mb ridging leans over into the Lake Superior/Upper Michigan by 06z/Tue, spreading dry air into N Lower at least in the mid level (700-500 mb layer). High impact weather potential: None expected Synopsis/Forecast: Troughing exists from the Great Lakes down through the southern Plains with ridging once again building through the center of the CONUS.
359 AM CDT Mon Oct 4 2021 The short term remains quiet across the cwa as the models show upper level high pressure ridging building over our region today and to our east on Tuesday. The upper level high pressure ridge then closes off over the Great Lakes by Tuesday evening. A ridge of high pressure aloft will maintain quiet conditions through midweek as it is projected to be set up from the western Great Lakes westward across our area. An upper trough is progged to push into the Pacific Northwest by midweek. The aforementioned trough is expected to slide out into the northern High Plains and central Rockies toward the end of the week.
400 AM EDT Mon Oct 4 2021 Upper level ridge will build over the region through mid week. Ridge starts breaking down by the end of the week as an upper level low lifts from the mid Mississippi Valley to the Great Lakes. Lows dropping into the lower 60s, mild for this time in October. Elsewhere should endure a brief break in any showers until later Tuesday afternoon and evening as energy arrives from the southwest around an upper level low pressure system.
248 AM MDT Mon Oct 4 2021 A ridge of high pressure will stretch from New Mexico into the Upper Midwest today. The fire danger will be elevated due to the low rh values across the plains which will drop below 15 percent this afternoon, but this will be offset by mostly light and variable surface winds. The upper level ridge axis remains in place across eastern Colorado Tuesday leading to another warm and dry day.
An area of high pressure at the surface will move out of western Kansas and into Oklahoma today as a trough of low pressure moves into northwest Kansas.
(Today and tonight) The axis of a positively tilted upper trough will shift east of our forecast area, with the upper low expected to eventually cut-off over the Mississippi Delta Region overnight. With another cut-off low already in place in the Pacific Ocean off Southern California and a blocking ridge inbetween, the upper flow across much of the CONUS will configure into an Omega Block Pattern. For today, our forecast area should stay under the far eastern extent of the blocking upper ridge, resulting in one more day of unseasonably warmer temperatures. Adjusted the MaxT for today only slightly warmer than the NBM and closer to MAV guidance.
As high pressure slowly shifts eastward and warm, dry southwesterly flow begins to dominate central Idaho into western Montana, temperatures could approach the low to mid 80s on Tuesday with continued dry conditions.
252 AM CDT Mon Oct 4 2021 Temperatures this morning will start off cool in the lower 50s with some areas in northern MO seeing temps in the lower 40s. Weather today will be dry and pleasant as an upper level trough slides to our east, bringing in northerly winds at all levels and keeping temps in the mid to upper 70s.
346 AM CDT Mon Oct 4 2021 Very strong upper level ridging is expected to remain in place across the central US through the short term. Nighttime temperatures will drop into the low to mid 40s with the warmest temperatures across northern Nebraska (north of US-20). Dry conditions remain in place through the end of the week as the upper level ridge slowly slides eastward.
A narrow upper level high pressure ridge will sharpen over New Mexico while low pressure digs into the lower Mississippi Valley. A weak backdoor surface cold front Tuesday will only serve to cool Wednesdays highs slightly below normal.
341 AM CDT Mon Oct 4 2021 The synoptic pattern has flipped over the past few days with a deep trough now residing over the eastern CONUS and a fairly broad ridge over the west. The ridge to our west is progged to build northeast over the top of this low, resulting in a classic Rex Block from the Great Lakes into the Lower MS Valley.
At 3 PM, upper level ridging was building over the region, resulting in abundant sunshine. Exceptionally Quiet Weather this Week (Probably): The main question in our forecast this week looks to be the track of a closed upper low forecast to develop over the Tennessee Valley by Tuesday.
Warm weather continues for Monday, with much cooler temperatures and widespread rainfall due on Tuesday.
137 AM MDT Mon Oct 4 2021 Across the region this morning, high pressure over the central Plains is providing clear skies area-wide. The latest RAP40 500mb analysis, along with the current mid level water vapor imagery, is showing a building amplified ridge over the Rockies making a slow shift eastward towards the Plains region. There is an upper low over the Great Lakes region, and another off Baja California. Latest guidance for the short term period keeps the upper ridge in place over the Tri-State area.
High pressure has begun to move into the region, though low level moisture has lingered and dense fog is widespread with zero-value dewpoint depressions across much of the area. Fog should dissipate by mid morning as the low levels mix out. Upper level ridging will push into the upper Midwest through much of this week, squeezing its way over a cut-off low spinning over the lower Mississippi Valley. With the cut- off low to our south, WAA directly into the Northland will be somewhat restrained, but high temperatures in the low 70s are still possible for many, which is well above normal. Thankfully, we should not have to suffer the same temperatures as the folks in western North Dakota, who may see high temperatures in the low 90s before the week is over.
/Issued 1257 AM CDT Mon Oct 4 2021/ /Through Tuesday/ The quiet and warm trend will continue in the near term with North & Central Texas situated between upper level ridging to the west, and a closed low shifting southward to our east. The upper level clouds across Central Texas currently will continue to taper off in the overnight hours as the upper level flow transitions from the southwest to drier, more northwesterly winds as the upper low shifts south. /NEW/ /Tuesday Night Onward/ Dry and warm weather conditions are forecast to continue the rest of the week and most of the following weekend as ridging builds over the southern Plains.
Otherwise, mostly sunny skies and unseasonably warm temperatures are expected today as high pressure prevails. An upper level low is set to take shape across the Lower Mississippi Valley tonight into Tuesday and gradually lift to the north.
(Today through Tuesday afternoon) An upper level trough is centered over the Midwest and an upper ridge is over the Rocky Mountains. West Texas and Southeast New Mexico are in between the upper ridge and trough with mostly westerly flow aloft. Temperatures today will be similar or slightly warmer than yesterday with highs mostly in the 80s. A portion of the upper trough gets cutoff from the upper flow and develops a cutoff low over the Arkansas/Mississippi border on Tuesday. Another upper low will be over Southern California with West Texas and Southeast New Mexico remaining in the middle of these two features. Temperatures on Tuesday will be similar or slightly warmer than today.
217 AM EDT Mon Oct 4 2021 Rain showers will continue overnight, with with isolated embedded thunderstorms tomorrow due to a weakening low pressure system. Aforementioned low pressure positioned over southern Michigan will continue to erode within the upper level flow on Monday.
The southern branch of energy will slide from the Ozarks to the Mississippi Delta and develop into an closed low overnight. This low will assist a slug of deep moisture to lift into our area during the day on Tuesday allowing for widespread showers and storms.
320 AM EDT Mon Oct 4 2021 Upper air pattern consists of a 500 mb trough over the Great Lakes region this morning and a ridge in the Rockies. The ridge moves east into the upper Great Lakes by 12z Tue with the trough moving into the eastern U. Will go with more persistent clouds today into tonight than previous forecast had due to dry air being slower to move in and will change low temperatures in the far west to a bit warmer than previous forecast had in there because of the clouds.
As a result, focused the highest POPs across the Pee Dee and LBT areas during Monday. The cold front will barely move into western Alabama at the surface as the cutoff low is stationary. Along the coast, the high pressure will remain with a southerly flow. Highs in the lower to middle 80s and lows upper 60s.
/NEW/ /Through Tuesday/ The quiet and warm trend will continue in the near term with North & Central Texas situated between upper level ridging to the west, and a closed low shifting southward to our east. The upper level clouds across Central Texas currently will continue to taper off in the overnight hours as the upper level flow transitions from the southwest to drier, more northwesterly winds as the upper low shifts south. /Issued 247 PM CDT Sun Oct 3 2021/ /Tuesday onward/ The week ahead will feature warm but tranquil weather as mid- level ridging builds across the region.
'Warm With Isolated Convection' may describe the near term period, as slight upper ridge amplification unfolds ahead of an upper trough that transitions to a closed low over the lower Mississippi Valley. Meanwhile, a weak offshore ridge amplifies back towards the mid-Atlantic states.
208 AM MDT Mon Oct 4 2021 A ridge of high pressure will prevail over the region today with a very dry air mass in place over the inter-Rockies and high plains. BT Cooler and unsettled weather will be the main story across the region through forecast period.
155 AM MDT Mon Oct 4 2021 It'll be a warm and dry start to the work week as a ridge of high pressure settles overhead. Its axis, currently situated directly over the Western Slope, will shift east towards the Northern Plains later this afternoon in response to an approaching closed low off the coast of southern California. Before the high exits the region, high temperatures today will climb to 3 to 6 degrees above normal for most sites under sunny skies.
A mild and dry forecast remains in place as a mid-level ridge builds across the Northern Plains through the first half of this week. As the ridge builds, a cutoff low forms over the lower Mississippi River valley.
Today will be slightly warmer than tomorrow with temperatures in the low to mid 80s compared to tomorrow's upper 70s to low 80s. Further Details: An H5 trough will continue to dig south over the southern Gulf States eventually becoming cutoff by tomorrow. Looks like this cut off low will meander over the lower Mississippi Valley region for a couple days and it does appear a Rex Block could form by tomorrow night. This will likely block the next oncoming trough swinging through the west coast tomorrow and force it to go north of the Panhandles.
430 AM EDT Mon Oct 4 2021 High pressure is in place over the area today with a front stalling across the deep south. An upper low will stall over the AR/MS/TN region through mid-week as upper ridging remains over the state, before the low finally lifts out to the north by the end of the week, then through the state through the weekend. A front will then move into the area or push through over the weekend with the upper trough.
However additional moisture will eventually wrap around the back side of the occluding cyclone and into the the CWA this afternoon. Meanwhile the upper pattern will amplify with a ridge building across the eastern two-thirds of the CONUS. This moisture, coupled with cyclonic flow on the northern flank of the low, will likely result in isolated to scattered showers and perhaps a few storms on Tuesday, mainly in the afternoon when instability is maximized.
Models show a long wave mid level trough advancing into the eastern CONUS while pushing the ridge over the eastern seaboard further into the west Atlantic. The southern periphery of the ridge becomes flatter during the short term with winds across SoFlo gradually veering from NE to E.
Current conditions and trends were blended into the forecast, which did force the overnight low temperature forecast a few degrees cooler over parts of central and southwest North Dakota.
729 AM EDT Mon Oct 4 2021 Scattered showers and isolated thunderstorm chances will continue this week within a warm, humid airmass ahead of low pressure. Recent radar mosaic depicts scattered showers and a few, isolated thunderstorms impacting the region within deep, moist swly flow on the eastern flank of an upper trough. The digging upper trough will continue to deepen on Tuesday, eventually cutting off over the Lower Mississippi Valley. This feature will linger through the short term while upper ridging develops across Manitoba and Ontario.
510 AM PDT Mon Oct 4 2021 An upper level low pressure system well off the northern Baja coast will weaken and move slowly inland across the area through Tuesday.
A transition to cooler weather is forecast to occur across northwest California during the middle of the week. The large-scale pattern has changed very little during the past 24 hours, as a cut off low remains positioned offshore from SRN CA, and a positive tilt trough was located over SERN AK.
555 AM CDT Mon Oct 4 2021 Updated aviation section for 12z taf issuance A low pressure system over the Great Lakes region will produce a west to northwest wind flow across our region today. The high- res nam and 06z hrrr are among the models that generate some isolated to scattered showers along this secondary front this afternoon. Tonight will be partly cloudy and a bit cooler. A rather strong 500 mb closed low is forecast to form over the lower Mississippi Valley by 12z Tuesday.
The short term remains quiet across the cwa as the models show upper level high pressure ridging building over our region today and to our east on Tuesday. The upper level high pressure ridge then closes off over the Great Lakes by Tuesday evening. A ridge of high pressure aloft will maintain quiet conditions through midweek as it is projected to be set up from the western Great Lakes westward across our area. An upper trough is progged to push into the Pacific Northwest by midweek. The aforementioned trough is expected to slide out into the northern High Plains and central Rockies toward the end of the week.