Aikyam-Lab/Synoptic-Bench huggingface dataset:
A surface cold front is moving eastward across the forecast area this afternoon. Surface ridging will commence following fropa, and winds will quickly relax by this evening.
Heat relief is on the way however in the form of a cold front that extends from northern Missouri into northwest Oklahoma at this time.
Going into Tuesday, NW flow aloft becomes anti-cyclonic, and high pressure will build into eastern Montana.
605 PM CDT Mon Aug 26 2019 The August 27-28 00 UTC TAF discussion follows: Isolated to scattered showers and thunderstorms may develop along a cold front that will move southward through the evening hours. /issued 245 PM CDT Mon Aug 26 2019/ Very warm temperatures around 700mb (+15-18) will likely delay and limit thunderstorm coverage late this afternoon/early evening, despite a cold front moving into northern/western Oklahoma.
The 500mb trough that entered the region today has weakened and will move off to the east this evening. On Tuesday a cold front will approach from the west and move through the middle Ohio Valley during the late afternoon/evening hours. Sfc cold front is forecast to push east of the area Tuesday night.
Chattanooga Airport, TN 69 85 72 87 / 60 60 60 20 Knoxville McGhee Tyson Airport, TN 66 84 71 86 / 50 50 50 20 Oak Ridge, TN 66 84 70 86 / 50 60 60 20 Tri Cities Airport, TN 63 82 67 83 / 40 40 50 40.
552 PM EDT Mon Aug 26 2019 Expect periods of rain tonight as a warm front lifts north across the area. Additional, widespread showers are anticipated Tuesday night with the passage of a cold front.
230 PM PDT Mon Aug 26 2019 Slightly warmer temperatures expected by Tuesday as the upper ridge of high pressure remains in place.
Clearing skies tonight will help temperatures drop into the upper 40s west to the low 50s central, before the chance of showers returns in the morning, primarily in the north-central part of the state. Gusty northwest winds behind the cold front continue this afternoon with peak wind gusts around 30 mph. A reinforcing cold front will sweep across North Dakota late Monday night and Tuesday morning.
/issued 344 PM CDT Mon Aug 26 2019/ An unseasonably deep upper low will lift from southern Manitoba to northern Quebec this week. This feature will remain sufficiently broad to result in northwest aloft across the Midsouth, which will aid in a surface cold frontal passage late tonight. The drier air will allow for overnight lows to cool as the low as the upper 50s in the valleys near the TN River. This secondary MCS would have a synoptic cold front on which to focus convection initially.
633 PM CDT Mon Aug 26 2019 A closed upper low will remain across southern Manitoba Canada tonight. Lows tonight will be on the cool side ranging from the upper 40s western Sandhills to the lower 50s elsewhere. On Tuesday, a disturbance will rotate through the upstream side of the upper trough. A reinforcing cold front during the day and considerable cloud cover will limit highs to the low 70s.
808 PM CDT Mon Aug 26 2019 With the H850 trough having passed through the area, the threat for thunderstorms has shifted south and east of the forecast area. A surface cold front is moving eastward across the forecast area this afternoon. Surface ridging will commence following fropa, and winds will quickly relax by this evening.
A weak cold front north of the area will try to sag into the area tonight so looking for a weak wind shift to the north. Relief will arrive in the form of a cold front later tonight. Models show the front backdooring into the northwestern CWA and funneling down through the higher terrain and western mountain areas by early tomorrow. Models are all over the place with regards to high temperatures tomorrow afternoon, but the good news is the new guidance has come in with cooler temperatures across the Permian Basin and southeast New Mexico.
The large low pressure system, currently straddling Manitoba and Ontario, will be drifting east through Tuesday. Cooler temps aloft and diurnal heating have allowed for relatively steep low level lapse rates, and instability showers/storms have developed this afternoon in response.
901 PM CDT Mon Aug 26 2019 Severe thunderstorms continue to develop in the vicinity of the cold front that is advancing into northeast Oklahoma at this hour. The airmass just in advance of the cold front is still uncapped with surface based cape running in the vicinity of 5000 J/kg. As the cap strengthens over the next few hours the activity will become more elevated as the cold front spreads south. Still expecting a cluster of storms to develop overnight across southern portions of the area as the low level jet increases.
548 PM MDT Mon Aug 26 2019 The Tri-State area remains under northwest flow aloft this afternoon as an upper ridge is situated over the western U. and an upper trough digs southward into the Dakotas. The cold front moved through the area earlier this morning and winds have not mixed down as much as anticipated.
Gusty northwest winds behind the cold front continue this afternoon with peak wind gusts around 30 mph. A reinforcing cold front will sweep across North Dakota late Monday night and Tuesday morning.
1007 PM EDT Mon Aug 26 2019 High pressure will gradually loosen its grip on the region as a weakening front approaches from the west.
A cold front will move through the region this evening and into the early morning hours.
Focus for next 2 to 4 hours will be across NW Indiana where pre- frontal trough and approaching upper level wave from central Illinois as allowed for broken line of showers to form from southern Lake Michigan into extreme west central Indiana. This activity is oriented along a 1000-1500 J/kg MLCAPE axis with some locally enhanced shear associated with stronger westerly flow accompanying the pre-frontal trough. Localized effective shear values of 30-40 knots are noted per latest HRRR analyses along the pre-frontal trough axis. The above combination of shear/instability along with near sfc vorticity source associated with pre-frontal trough could support isolated instances of funnels or brief weak tornadoes through around 01Z across northwest Indiana. Otherwise more concerted secondary band of rainfall expected to develop late tonight along trailing height fall axis of departing wave and ahead of incoming cold front.
Flying conditions are set to worsen over the next couple of hours as thunderstorms develop in the vicinity of an advancing cold front and spread to the east-southeast across the area. Heat relief is on the way however in the form of a cold front that extends from northern Missouri into northwest Oklahoma at this time.
731 PM EDT Mon Aug 26 2019 High pressure will gradually loosen its grip on the region as a weakening front approaches from the west.
523 PM MDT Mon Aug 26 2019 An upper trough covers the northern plains, with a 100 kt jet moving over the region. The upper trough will shift east on Tuesday, as a ridge builds over the western CONUS.
Satellite imagery this afternoon shows scattered cirrus drifting across northern Arizona, and scattered flat cumulus across across the higher terrain. A ridge of high pressure covers the desert southwest this afternoon, its axis along a line from Sacramento-Prescott-El Paso. With the ridge overhead, expect fair weather across northern AZ tonight. Very hot temperatures are forecast again for Tuesday, likely a degree or 2 warmer than today across areas below 6000 feet.
Slightly warmer temperatures expected by Tuesday as the upper ridge of high pressure remains in place.
Winds becoming light to moderate through the week as high pressure remains situated over the region with mainly a slight chance of showers and thunderstorms expected. 45 A weak cold front will move into the NE half of the CWA. Convective temperatures are in the lower 90's and weak capping in the 850-700 layer erodes in the afternoon.
1237 AM CDT Tue Aug 27 2019 A closed upper low will remain across southern Manitoba Canada tonight. Lows tonight will be on the cool side ranging from the upper 40s western Sandhills to the lower 50s elsewhere. On Tuesday, a disturbance will rotate through the upstream side of the upper trough. A reinforcing cold front during the day and considerable cloud cover will limit highs to the low 70s.
A strong upper trough was present over the northern plains and up into the central Canadian provinces this morning. The much talked about cold front stretched south from the Great Lakes into Indiana and southwestward into Missouri and Oklahoma. Further southeast into eastern Tennessee, the remnant influence of a warm front can be seen thanks to a weak CAD setup east of the Appalachians and northerly surface flow down the TN valley. Increased lift across the remnant warm frontal boundary will likely cause another uptick in shower activity, albeit with only light rain expected. Temperatures today should be notably warmer than yesterday. Couple this with a lack of rain and we should see highs in the low 80s in many areas. As mentioned, convection along the cold front arrives over the plateau during the evening hours.
Additional widespread showers are anticipated tonight with the passage of a cold front.
These showers are a result of a weak ribbon of mid level frontogenesis and instability, as main upper trof drops into the northern plains (ie to our east). Cloud cover has kept temps a bit warmer than previously expected, with most areas still in the low-mid 50s, and 40s up in Wheatland County.
358 AM CDT Tue Aug 27 2019 The much advertised, much anticipated (especially after yesterday's record breaking heat!) cold front has pushed into northern portions of the area early this morning. The front is expected to stall out today in the vicinity of the I-20 corridor, with locations to the north of the boundary experiencing northeasterly winds and high temperatures today 15-20 degrees cooler than yesterday, in the upper 80s to lower 90s. While still hot, these temperatures will still be over 10 degrees cooler than yesterday for most.
These storms have exited the Ozarks while a drier and cooler airmass begins to spread in from the northwest. Very ideal conditions for outdoor activities will be observed this afternoon with highs in the low 80s.
1146 PM EDT Mon Aug 26 2019 High pressure will gradually loosen its grip on the region as a weakening front approaches from the west.
244 AM CDT Tue Aug 27 2019 Cold front continues to slowly sink to the south across the forecast area early this morning with scattered showers and storms ahead of it. Activity will diminish as cold front exits region by 15z Tuesday.
1235 AM CDT Tue Aug 27 2019 Cooler and increasingly moist air will continue to build into the region on breezy northeasterly winds. Once the low clouds overspread the terminals, they should hold tough through the remainder of the forecast.
818 PM PDT Mon Aug 26 2019 High pressure over the Southwest will bring warm days and mild nights this week.
245 AM MDT Tue Aug 27 2019 Upper level analysis depicts fast northwest flow aloft with deep upper trough centered over Manitoba/western Ontario. Tight pressure gradient at the surface with low pressure over western Ontario and high pressure gradually building into the northern Plains.
/Issued 901 PM CDT Mon Aug 26 2019/ Severe thunderstorms continue to develop in the vicinity of the cold front that is advancing into northeast Oklahoma at this hour. The airmass just in advance of the cold front is still uncapped with surface based cape running in the vicinity of 5000 J/kg. As the cap strengthens over the next few hours the activity will become more elevated as the cold front spreads south. Still expecting a cluster of storms to develop overnight across southern portions of the area as the low level jet increases.
313 AM CDT Tue Aug 27 2019 The much anticipated cold front was still pushing its way through our far southeastern counties early this morning. As a potent upper level low over Ontario lifts north, the ridge to our west will begin to build back east, cutting off moisture and the northwest flow. Temperatures will also rapidly heat under the influence of the ridge. Models continue to hint at a backdoor front for the weekend with the possibility of precip chances, but model to model run inconsistency also continues on the position of the ridge, which could make or break those chances. We have again backed off the high PoPs of the Blend but have included some chance category PoPs this forecast package.
Otw, High temps will generally be in the low to mid 80s for today.
1154 PM CDT Mon Aug 26 2019 With the H850 trough having passed through the area, the threat for thunderstorms has shifted south and east of the forecast area. A surface cold front is moving eastward across the forecast area this afternoon. Surface ridging will commence following fropa, and winds will quickly relax by this evening.
1106 PM MDT Mon Aug 26 2019 The Tri-State area remains under northwest flow aloft this afternoon as an upper ridge is situated over the western U. and an upper trough digs southward into the Dakotas. The cold front moved through the area earlier this morning and winds have not mixed down as much as anticipated.
The combination of a cooler airmass in place with remnant mid level cloud should result in temperatures likely only topping out in the upper 70s to lower 80s for highs.
A cold front was moving through the region early this morning. Cooler air will move across the area behind the front brining low IFR stratus to the area for a few hours around sunrise.
/issued 605 PM CDT Mon Aug 26 2019/ The August 27-28 00 UTC TAF discussion follows: Isolated to scattered showers and thunderstorms may develop along a cold front that will move southward through the evening hours. /issued 245 PM CDT Mon Aug 26 2019/ Very warm temperatures around 700mb (+15-18) will likely delay and limit thunderstorm coverage late this afternoon/early evening, despite a cold front moving into northern/western Oklahoma.
1201 AM EDT Tue Aug 27 2019 Expect periods of rain tonight as a warm front lifts north across the area. Additional, widespread showers are anticipated Tuesday night with the passage of a cold front.
Less humid and a bit cooler weather can be expected to settle in by Tuesday night with lows dropping into the middle and upper 50s.
1246 AM CDT Tue Aug 27 2019 For the 06Z TAFs, northeast winds behind the latest cold frontal passage will become more easterly throughout the course of today.
1208 AM EDT Tue Aug 27 2019 Expect periods of rain overnight as a warm front lifts north across the area. Additional widespread showers are anticipated Tuesday night with the passage of a cold front.
For today, a closed upper low will move across southern Manitoba and into Ontario with a strong short wave rotating around the system and into Minnesota. High temperatures today will range from the low to mid 70s north to the upper 70s south.
423 AM EDT Tue Aug 27 2019 A dying warm front will fizzle before it reaches PA this morning.
112 AM EDT Tue Aug 27 2019 High pressure will gradually loosen its grip on the region as a weakening front approaches from the west.
Ongoing rain should end by 08z, with another round in the 10z to 15z range, and the last round with the approaching cold front this afternoon and evening.
343 AM CDT Tue Aug 27 2019 (Today and Tonight) Cold front continues to sag south from the northern Permian Basin northeast into the Red River Valley early this morning. As for temperatures, all areas will be at least a little cooler than the record breaking heat from Monday. Coolest conditions across the northern Big Country where highs may remain in the lower 90s in a few areas.
1041 PM MDT Mon Aug 26 2019 An upper trough covers the northern plains, with a 100 kt jet moving over the region. The upper trough will shift east on Tuesday, as a ridge builds over the western CONUS.
Had two showers pop up near the White Mountains briefly late this afternoon, but the cap under the ridge limited activity in the area to just the two showers. Satellite imagery this afternoon shows scattered cirrus drifting across northern Arizona, and scattered flat cumulus across across the higher terrain. A ridge of high pressure covers the desert southwest this afternoon, its axis along a line from Sacramento- Prescott-El Paso. With the ridge overhead, expect fair weather across northern AZ tonight. Very hot temperatures are forecast again for Tuesday, likely a degree or 2 warmer than today across areas below 6000 feet.
154 AM EDT Tue Aug 27 2019 A dying warm front will fizzle before it reaches PA this morning.
SHORT TERM (Now through Wednesday): Mid level ridging over west Texas will continue to provide subsidence across Deep South Texas through the period. The pressure gradient strengthens this afternoon due to the interaction between the thermal trough over west Texas and high pressure across the eastern Gulf of Mexico. Hot and humid conditions are expected Today and Wednesday with afternoon high temperatures ranging from the low to mid 90s near the coast and 100 to 105 degrees inland. Muggy conditions continue overnight tonight and Wednesday night with low temperatures in upper 70s to the lower 80s.
Otw, High temps will generally be in the low to mid 80s for today. Thermal troughing will prevail with 850 mb temps down to 13C or so.
Chances will continue mainly along the high terrain through the holiday weekend.
Main development however, will be this afternoon into early evening as diurnal instability maximizes as the upper trough passes.
Upper ridge axis extended from northern California southeastward into the Texas Big Bend early this morning.
Otherwise, with high pressure to our west and low pressure to our east, there will be some enhancement to the pressure gradient, and with winds at the top of the mixed layer running around 40 kts, will have gusts of 30 to 35 mph during the afternoon. Highs will be in the lower to mid 70s. For tonight, winds will die off as surface ridging exerts a greater influence, and with mostly clear skies it will be a cool night as lows drop into the lower 50s. Dew points will still be comfortable however - in the lower 50s - and with less wind it will be a really nice day with highs in the mid to upper 70s.
Lower humidity for inland areas and a little warmer for late in the week.
As influence of central/northern Plains trough lessens and midlevel heights build into Wednesday, drier conditions are expected.
Expect VFR conditions for the next 24 hours as the 500mb ridge over west Texas continues to provide subsidence across the area. /issued 433 AM CDT Tue Aug 27 2019/ SHORT TERM (Now through Wednesday): Mid level ridging over west Texas will continue to provide subsidence across Deep South Texas through the period. The pressure gradient strengthens this afternoon due to the interaction between the thermal trough over west Texas and high pressure across the eastern Gulf of Mexico. Hot and humid conditions are expected Today and Wednesday with afternoon high temperatures ranging from the low to mid 90s near the coast and 100 to 105 degrees inland. Muggy conditions continue overnight tonight and Wednesday night with low temperatures in upper 70s to the lower 80s.
For temperatures, today will be the coolest day of the week as considerable cloudiness will help keep temperatures down as the airmass is already anomalously cool to begin with behind the strong cold front passage from yesterday.
655 AM EDT Tue Aug 27 2019 A dying warm front will fizzle before it reaches PA this morning. A weak and moisture-poor cold front will approach from the west and move through on Wednesday morning. High pressure will then be centered over the Ohio Valley through the end of the week and keep PA dry. The weak/shearing short wave trough will still end up generating a few hundreths of an inch through the morning and early aftn over the west and central counties. Will hold them where prev shift nudged them down to, but they could easily be another deg or two cooler. The cold front driving the rain/showers could make enough lift over the west to spark a TSRA later tonight, but am more tempted to remove all mentions of thunder from the forecast.
An approaching cold front and several outflow boundaries may reach as far south as KABI (Abilene) to shift winds around to the northeast at least briefly, but remainder of the area will keep south to southeast winds, gusty at times, through the afternoon. /issued 343 AM CDT Tue Aug 27 2019/ (Today and Tonight) Cold front continues to sag south from the northern Permian Basin northeast into the Red River Valley early this morning.
Additional widespread showers are anticipated tonight with the passage of a cold front. increased morning PoPs across the ridges where light rain continues and is evident current radar imagery. Showers are expected to again overspread the area from west to east later this afternoon and evening with the approach of a cold front. Given expansive cloud cover through today and cooler mean guidance, have adjusted this afternoon's high temperatures down a couple degrees or so.
Closed upper low over Manitoba will make its way into Upper Ontario, with its trailing trof axis moving into the Lower Ohio Valley by early Wednesday morning. In the process it will push a sfc cold front through the area by this evening. Dewpoints will drop sharply into the lower 60s and even some upper 50s by Wednesday morning. This will bring sunshine and keep a northerly component to the winds helping to limit highs to the low to mid 80s.
537 AM EDT Tue Aug 27 2019 A dying warm front will fizzle before it reaches PA this morning. A weak and moisture-poor cold front will approach from the west and move through on Wednesday morning. High pressure will then be centered over the Ohio Valley through the end of the week and keep PA dry. The weak/shearing short wave trough will still end up generating a few hundreths of an inch for the west. Will hold them where prev shift nudged them down to, but they could easily be another deg or two cooler. The cold front driving the rain/showers could make enough lift over the west to spark a TSRA later tonight, but am more tempted to remove all mentions of thunder from the forecast.
930 AM EDT Tue Aug 27 2019 Deep lyr trof btwn Bermuda and the Carolinas has severed the wrn flank of the Bermuda Ridge into an independent anticyclone currently centered over the FL Straits.
Another cold front just north of Casper at 08z will continue to make its way south into the northeast plains by late this morning. Temperatures today will be 2-4 degrees cooler than yesterday. A ridge will start to develop Wednesday behind today's system.
Warm and dry weather will continue through Wednesday as a ridge of high pressure builds across the western U.
/issued 313 AM CDT Tue Aug 27 2019/ The much anticipated cold front was still pushing its way through our far southeastern counties early this morning. As a potent upper level low over Ontario lifts north, the ridge to our west will begin to build back east, cutting off moisture and the northwest flow. Temperatures will also rapidly heat under the influence of the ridge. Models continue to hint at a backdoor front for the weekend with the possibility of precip chances, but model to model run inconsistency also continues on the position of the ridge, which could make or break those chances. We have again backed off the high PoPs of the Blend but have included some chance category PoPs this forecast package.
505 AM MDT Tue Aug 27 2019 Updated Aviation Discussion High pressure will strengthen over the Northern Rockies and Montana for dry conditions with near average temperatures today, warming to above seasonal averages on Wednesday.