Aikyam-Lab/Synoptic-Bench huggingface dataset:
1101 PM MDT Mon Sep 20 2021 Mean ridging can be expected through most of the period, although an increasingly active northern stream will support periodic cold fronts into the region, the next being Thurs. Upper level trough and associated cold pool will continue to support sct to isold showers into the evening, being heavily diurnally driven. The next cold front will arrive Thurs with cooler and breezy conds Fri.
A ridge of high pressure will build into the area on Tuesday providing sunshine, dry conditions and some increase in temperatures for at least a couple of days. An area of low pressure will move into the region later this week and linger through the weekend. 1250 PM PDT Mon Sep 20 2021 The primary weather of note today has been some cooler temperatures and gusty north winds, especially down the Colorado River Valley. Temperatures in many locations are 5 to 10 degrees cooler at noon today than they were yesterday at the same time. An area of high pressure will build into the Desert Southwest on Tuesday and then move east on Wednesday with the ridge axis centered over the four corners region by Wednesday afternoon.
Highs will be held in the lower 70s for valleys, and upper 60s atop the highest Cumberland Plateau areas, if clouds can clear off. If a low strato-cu deck holds, wouldn't be shocked if temperatures were cooler.
Expecting PoPs to increase once more moving into Wednesday, with Likely PoPs across north and east-central GA as surface front and associated digging mid-lvl trough push through.
302 AM CDT Tue Sep 21 2021 Surface cold front has now pushed entirely out of the state and is draped over MO into OK, leaving behind a refreshing air mass with 08Z readings showing temps in the 50s and 60s and dew points in the 40s and 50s. As the upper trough axis swings across the Plains, mid- level clouds move across the area with light precip in central KS. With dry air in the low levels, this is expected to be largely limited to sprinkles for areas that see any of it reach the surface. Highs are forecast in the low to mid 70s today and tomorrow with lows falling back to the 40s each night. As the upper trough pushes east, northwest flow develops over the area with ridging to the west.
Lows will hover around 70F this evening before the cold front moves through tomorrow. A deep trough will shift out of the Plains tonight and east of the Mississippi river by Wednesday night. A fairly strong early season cold front associated with the trough will move quickly across the Midsouth late tomorrow into early Wednesday. Abundant moisture is already in place ahead of the surface front and midlevel trough. Conditions should improve abruptly behind the cold front. Behind the front a cooler and drier Fall-like airmass will move into the Midsouth.
While the cold front has pushed eastward out of our area, a fairly expansive stratus deck still remains overhead. Heading into Wednesday, expect upper level ridging to briefly build over the region.
Precipitation chances could return by the latter half of the week along with cooler temperatures. Some high country basins above 6500 feet that see those winds cut off and remain calm will see temperatures at or near freezing by early Tuesday morning. Models have the trough continuing to move off to the east as the ridge moves in off the Pacific today and tomorrow bringing a very dry air mass with it.
Tonight should be dry until near daybreak Tuesday morning when convection developing on the approaching cold front will attempt to move into the area. The cold front will enter the area 12Z to 15Z and will exit the area by 23Z. The upper trough will be getting better organized as it begins to impact the area in the late afternoon. There is still some disagreement amongst the models as to how progressive the trough will be.
There remains some decent mid-level moisture and perhaps enough lift with the approaching mid-level trough and/or some frontogenesis around the 800 mb later to support the elevated convection. It still appears there is some potential for a few storms to develop along a cold front late this afternoon (~5 pm) through the early evening hours (~7-8 pm). As a trough approaches and moves across the region late tonight into early Tuesday, better forcing should support higher chances across the northern half of Oklahoma.
239 AM CDT Tue Sep 21 2021 Today the main upper trough axis moves across Kansas leaving weak ridging overhead by tonight/tomorrow morning. In the lower levels, cold air advection will continue this morning through this afternoon.
Lower heights associated with a passing upper trough will promote below average high temperatures as well, in the mid 60s across and east of the Prairie Coteau to the mid 60s and lower 70s along and west of the James River Valley. The big picture steering flow pattern appears to want to favor upper level ridging (or some derivation thereof) across the western half of the CONUS throughout the period, interrupted only a couple of times by energy working into western NoAm off of the Pacific Ocean. These systems would knock down or flatten the ridge some before moving across southern Canada or along the Canada/U.
Tranquil conditions will continue today into tonight as weak ridging aloft fills in across the Intermountain West behind an upper level trough shifting east across the Central Plains. High pressure spreading south-southeast through the Western High Plains will reinforce a much cooler air mass across western Kansas, holding H85 temperatures around 12-15C. Longwave pattern sets up another upper level ridge across much of the western states and Rockies giving way to quiet northwest flow for the high plains. Return of southerly flow and a leeside trough over eastern Colorado will give way to south winds becoming gusty late week.
232 AM CDT Tue Sep 21 2021 With the cold front well south of the area, it has begun to feel a lot nicer already in terms of moisture levels. The breezy conditions should persist much of the day finally tapering around sunset as high pressure moves into the region. High temps should range from the lower 70s west to lower 80s in the Rolling Plains. Wednesday will see upper level ridging beginning to expand across the Desert Southwest although height rises will only be modest.
Then with daytime heating on Wednesday and a low level west to northwest flow we should see another day of scattered to numerous convection with the highest chances over the interior and eastern half of the Florida peninsula during the afternoon and evening. This lead system will push an associated cold front across north Florida late Wednesday.
As an upper level trough passes by, some cooling of the interior is expected on Wednesday and coastal areas may see a few more marine layer clouds. High pressure continue building into the the Great Basin today. An upper level trough will move into the Pacific Northwest on Wednesday, which will cool down by 10 to 15 degrees the coast.
Northwestern MN will however see cu develop early afternoon as upper level thermal trough moves across southern Manitoba, bringing H500 temps in the -22 to -26 range to northeastern zones. Did go along with MPX/DLH and so more 25 percentile NBM temps for lows in my east, 2-4 degrees cooler than straight blended model guidance.
3 inches across central FL, light southeast flow in the H9-H8 layer and a trof near the east coast will continue high rain prospects again for east central FL this afternoon. An elongated inverted trough will remain parked near the east coast and become more diffuse this afternoon. High coverage of showers/storms across the Atlantic this morning will become more numerous onshore in the afternoon, though the trof axis aloft is still expected to keep shower/storm chances high across the waters.
433 AM PDT Tue Sep 21 2021 High pressure will keep the Inland Northwest warm and dry Tuesday.
630 AM CDT Tue Sep 21 2021 (Today and tonight) A strong cold front has started to work it's way through the northern portions of our area from northwest to southeast, bringing a shift from warm southerly winds, to cool and gusty northeasterly winds this morning and afternoon. Expect cooler and mostly dry conditions today with high temperatures in the upper 70s to lower 80s, and overnight lows in the 50s.
An upper level ridge of high pressure will begin to build into the Cowboy State today, and will be across the area on Wednesday.
Windy conditions will bring a few challenges on terminal operations especially early this morning as the low- level jet keeps winds up around 50KT at 5kft AMSL. Conditions should slowly improve this afternoon as high pressure settles into the region. /issued 232 AM CDT Tue Sep 21 2021/ With the cold front well south of the area, it has begun to feel a lot nicer already in terms of moisture levels. The breezy conditions should persist much of the day finally tapering around sunset as high pressure moves into the region. High temps should range from the lower 70s west to lower 80s in the Rolling Plains. Wednesday will see upper level ridging beginning to expand across the Desert Southwest although height rises will only be modest.
411 AM CDT Tue Sep 21 2021 As of 0830z, an effective surface cold front stretches approximately from KDEC to KUNO and continues to press eastward. Ongoing showers and elevated thunderstorms continue to lag the cold front and have become more aligned with the position of the front at 850-hPa early this morning. These showers and thunderstorms will continue eastward through the morning with gradually decreasing coverage and intensity as they outpace the lift associated with an approaching upper-level trough and MLCAPE initially around 500 to 1000 J/kg wanes. By this afternoon, the surface cold front is forecast to clear the CWA. However, the aforementioned upper-level trough is expected to begin deepening as it traverses the Midwest leading to increasingly vigorous lift overspreading the region.
With calm, clear conditions and dewpoints in the 30s for much of the area it is possible for temperatures to be a few degrees cooler than currently forecast. Dry conditions are expected on Wednesday as the region sits firmly under the ridge. eventually separating from the westerlies and transitioning into a cut-off low that meanders southwestward through the 4-Corners and Desert Southwest -- along the eastern fringe of an upper level ridge offshore the southern Pacific Coast. Modest ridging aloft over the Central Plains (Thu) will transition to cyclonic flow aloft (Thu night) as a SW-NE oriented shear axis (extending from the 4-Corners to the Northern Plains) approaches.
This should clear once the upper level trough axis passes east by this afternoon. Main story for the week will be the lack of any deep layer moisture after today as we remain mainly within northwest flow aloft with a mean ridge over the western United States. Lingering sprinkles in our far south should quickly move off and dissipate this morning as the upper level trough axis passes to the east and quickly provides enough subsidence to quell the sprinkle activity potential.
345 AM PDT Tue Sep 21 2021 Much warmer weather is in store for Central California Today.
High pressure over the southeastern Gulf of Mexico will weaken this afternoon through Wednesday, as a mid- latitude trough pushes in from the east, before stalling over north-central Florida.
615 AM CDT Tue Sep 21 2021 Early morning satellite imagery shows the upper level trough continuing to swing through the region, as evident by upper level clouds off to the east streaming northwards while areas out west have them moving southeastwards. With no strong WAA or CAA to alter our airmass, temperatures today will remain on the cooler side with highs in the mid to upper 60s. With calm winds and clear skies, radiational cooling should bring temperatures down into the lower 40s. Weak ridging aloft further attempts to help warm temperatures up, but alas we'll likely only get to the lower 70s for areas east of I-29, while areas out west in central SD will get into the upper 70s where conditions will be a touch breezier.
These winds should decrease throughout the morning as the low pressure system moves off to the east and pressure gradients relax. Skies will clear this morning as the system departs, but the upper level trough will linger and cause diurnal cumulus to develop across portions of northeastern Minnesota and northwestern Wisconsin.
As the cold front and rain continue to push eastward expect a cloudy and cool fall day with temperatures only in the 60s. We'll remain in this cool pattern as a closed upper level low will develop Wednesday from the trough that is slowly moving through the Great Lakes region. This will sock us into breezy northerly flow and blocking the return of any warmer air mass over the next few days. There is a slight chance for some lake effect showers tonight into Wednesday in far southeast Wisconsin as cooler air is advected over the warmer lakes and some reinforcing positive vorticity advection moves overhead.
Huston This morning does appear to be the last really cold morning before things start to moderate throughout the week as high pressure will serve as the dominant feature in the forecast.
By tomorrow, low pressure will bring an increase in winds plus a few more degrees of warming. An upper level ridge will move through today with the axis passing across northern and central Nevada. Afternoon high temperatures will warm today with readings in the low 70s to low 80s. By later tonight, the ridge axis will have shifted off to the east. Southwest flow will develop behind the ridge due to an incoming upper trough in the Pacific Northwest. For Wednesday, the aforementioned trough will slide to the east. A cold front will make its way east.
620 AM CDT Tue Sep 21 2021 Today the main upper trough axis moves across Kansas leaving weak ridging overhead by tonight/tomorrow morning. In the lower levels, cold air advection will continue this morning through this afternoon.
Surface cold front has now pushed entirely out of the state and is draped over MO into OK, leaving behind a refreshing air mass with 08Z readings showing temps in the 50s and 60s and dew points in the 40s and 50s. As the upper trough axis swings across the Plains, mid- level clouds move across the area with light precip in central KS. With dry air in the low levels, this is expected to be largely limited to sprinkles for areas that see any of it reach the surface. Highs are forecast in the low to mid 70s today and tomorrow with lows falling back to the 40s each night. As the upper trough pushes east, northwest flow develops over the area with ridging to the west.
228 AM PDT Tue Sep 21 2021 High pressure will keep the Inland Northwest warm and dry Tuesday.
More widespread showers and possible thunderstorms can be expected for Wednesday as a cold front approaches and crosses the region. The upper Midwest trough will continue to deepen and dig eastward into Wednesday as the warm moist southwest flow strengthens. A surface cold front, ahead of the occluding system will also cross the region Wednesday afternoon.
A warm ridge of high pressure over the West Coast will move eastward and over Arizona through Wednesday continuing the dry and warm weather pattern. Cool temperatures will start off the day today, with perhaps a few cold spots in the high country reaching freezing this morning. Temperatures will quickly rebound this afternoon topping out a couple of degrees warmer than average.
Upper ridge will dominate our forecast today and tomorrow bringing clear/sunny skies and near normal to slightly above normal high temperatures.
423 AM MDT Tue Sep 21 2021 Upper ridging over the western U. will extend into the Northern High Plains for a warmer and drier weather pattern over the next couple of days. As the ridge slides east in response to a trough entering the Pacific Northwest, a surface cold front will approach the CWA Wednesday afternoon and evening.
The long forecast cold front to start this week had finally moved completely through the area this morning. Quiet weather is expected today as the cooler air moves into the area. Clouds are expected to remain across parts of the area through the morning, leading to potentially cooler day across the area. Guidance is spread on temps today as raw models say go colder, especially the CAMs, and the BC models and NBM say go warmer.
A ridge of high pressure building over the area today will allow for dry conditions and temperatures to warm a few degrees above Mondays readings. Today and Wednesday High pressure will continue to build over the desert southwest today, and then shift east towards the four corners region on Wednesday.
Water vapor shows upper trof shifting from the Northern Plains into the Upper Midwest, with upper ridge building from the Pac NW into the Northern Rockies. Upper ridge building in will dominate our weather through midweek, with dry and warming conditions.
Drier air will continue to filter in late this morning and into the afternoon limiting rain chances before rain associated with a cold front approaches overnight. DGS Chattanooga Airport, TN 81 63 71 52 71 / 30 80 80 10 0 Knoxville McGhee Tyson Airport, TN 81 64 71 50 69 / 40 60 90 10 10 Oak Ridge, TN 81 62 70 49 68 / 40 80 80 10 10 Tri Cities Airport, TN 75 62 72 49 67 / 80 40 90 40 10.
A dry and warm Tuesday will give way to cloudier and cooler conditions for the start of fall on Wednesday.
The highly touted, much anticipated longwave trough and it's associated cold front will finally arrive in our area late tonight into Wednesday. Unfortunately, this feature will likely kick off one more final round of showers and thunderstorms along and ahead of the surface cold front. In its wake, a much drier and cooler air mass will filter into the region. We'll begin to notice the difference by Wednesday afternoon as RH values lower and northerly winds help to keep temperatures in the lower 70s despite the clearing sky.
401 AM CDT Tue Sep 21 2021 Main story for the week will be the lack of any deep layer moisture after today as we remain mainly within northwest flow aloft with a mean ridge over the western United States. Lingering sprinkles in our far south should quickly move off and dissipate this morning as the upper level trough axis passes to the east and quickly provides enough subsidence to quell the sprinkle activity potential.
642 AM CDT Tue Sep 21 2021 (12Z TAFS) A cold front is moving through the area shifting winds from the northeast and causing them to increase and become gusty. Hennig (Today through Wednesday afternoon) Currently, a cold front has moved through southeastern New Mexico and is located along a line from Guadalupe Pass to McCamey and Big Lake. Yesterday was almost certainly our last hundred degree day of the year here at MAF with this cold front bringing in temperatures that will struggle this afternoon to reach 80 degrees in most locations north of I-10.
The corresponding cold front, currently approaching North Central Texas (per MSAS), is expected to move across the CWA 00-06z Wednesday (NAM/GFS deterministic runs). Significantly cooler conditions expected tonight. Drier and cooler Wednesday.
Outside of rain areas, current air temperatures in Keys island communities are in the lower 80s, with dewpoint temperatures in the mid 70s. The large-scale pattern features weak ridging in the lower troposphere northeast of the Florida Keys over the western North Atlantic. An upper-tropospheric anticyclone was centered over the Gulf of Mexico, providing a favorable outflow pattern aloft for deep convection.
Warmer & drier for Wednesday with upper-level ridging building back into the region.
(Today and tonight) The cold front has moved through all of the forecast area except Atoka and Bryan Counties this morning. Although temperatures are cooler and humidity is somewhat marginal this afternoon, the drying vegetation and strong winds are sufficient to produce RFTI values showing elevated fire weather conditions across southwest Oklahoma and western north Texas this afternoon. Otherwise, cooler weather is expected today and tonight behind this cold front. The high temperature forecast will be the coolest highs that we have seen since early June and forecast low temperatures will be the coolest temperatures since mid May in many areas.
337 AM PDT Tue Sep 21 2021 Dry and warmer weather this week. Locally gusty north to east winds over the higher terrain will be decreasing this morning.
Skies will continue to clear through the morning as the trough exits and remain mostly sunny through Tuesday.
Temperatures are steady in the lower 70s with a light south wind. To our west, two MCSs are ongoing along the leading edge of a longwave trough. Both systems will move into the Mid-South this morning and afternoon, as the main trough pivots into the Mississippi Valley. The main push of showers and storms will be this afternoon, as the main trough begins to push into the Mid-South. Highs will be comfortably cool on Wednesday, with readings only in the lower 70s with a northwest breeze.
Clear skies with cool temps in the low lying locations will be warming today with sunshine and a west/southwest wind. Upper ridging over the western U. will extend into the Northern High Plains for a warmer and drier weather pattern over the next couple of days. As the ridge slides east in response to a trough entering the Pacific Northwest, a surface cold front will approach the CWA Wednesday afternoon and evening.
Today will be a fairly normal last full day of summer (Fall begins at 1:21 pm MDT tomorrow), and it will warm up a few degrees tomorrow as we get into southwest flow just ahead of an upper level trough that will move through tomorrow afternoon and evening.
518 AM MDT Tue Sep 21 2021 Water vapor shows upper trof shifting from the Northern Plains into the Upper Midwest, with upper ridge building from the Pac NW into the Northern Rockies. Upper ridge building in will dominate our weather through midweek, with dry and warming conditions.
1151 AM CDT Tue Sep 21 2021 Today the main upper trough axis moves across Kansas leaving weak ridging overhead by tonight/tomorrow morning. In the lower levels, cold air advection will continue this morning through this afternoon.
902 AM MDT Tue Sep 21 2021 Temperatures have rebounded above freezing after sunrise, allowing the freeze warnings in the upper Colorado and Yampa River Valleys to expire.
251 PM CDT Tue Sep 21 2021 Occasional showers will continue across portions of east central Illinois tonight and Wednesday as an upper low moves across the region. This afternoon, a slow moving cold front has pushed east of central Illinois into Indiana. This feature is expected to deepen into a closed mid/upper low Wednesday as it cuts east across the mid Mississippi Valley. The greatest chance will again be across portions of east central Illinois which will be immediately ahead of the upper low during peak heating. Would not rule out a funnel cloud or two associated with any showers forming under the upper low.
Upper ridging dominated the weather pattern through Wednesday night, increasing temperatures to the low 80s on Wednesday and some winds 10-15 mph mixing down across the area, with locally higher amounts possible along the foothills west of Billings.
/issued 232 AM CDT Tue Sep 21 2021/ With the cold front well south of the area, it has begun to feel a lot nicer already in terms of moisture levels. The breezy conditions should persist much of the day finally tapering around sunset as high pressure moves into the region. High temps should range from the lower 70s west to lower 80s in the Rolling Plains. Wednesday will see upper level ridging beginning to expand across the Desert Southwest although height rises will only be modest.
High pressure brings dry conditions and warming temperatures through the middle of the week. A changing weather pattern toward the end of week will bring slightly cooler temperatures and slight chance of some showers across most of the area over the weekend. High pressure is firmly in place over the western U. In a previous forecast discussions we noted the potential for a cutoff low pressure system forming off the California coast over the coming weekend.