Aikyam-Lab/Synoptic-Bench huggingface dataset:
Surface analysis reveals a weak NE-SW oriented cold front extending from lower MI down through western AR.
Weak high pressure with drier air remains situated over the TN Valley this evening between a stalled boundary to the southeast and an approaching cold front to the northwest. An isolated shower or thunderstorm will be possible overnight, as subsidence is not as strong underneath the longwave trough settling over the Mid-MS Valley. Dew points in the low 60s will progress into the region overnight, causing dew point depressions to remain too large for fog development.
303 AM CDT Mon Aug 3 2020 Upper ridge still centered over AZ this morning will build east becoming centered over NM/TX midweek as upper trough over eastern US moves off. Looking out over the coming week a series of upper troughs moving along the US/Canada border will flatten the ridge but even out 240hrs it is still around.
1035 PM CDT Sun Aug 2 2020 We've worked our way to the west side of a positively tilted h5 trough that extends from Hudson Bay southwest into east TX. It will be a little warmer in MN, so STC and MSP lows look very safe both mornings. Given the cool morning temperatures expected, anywhere near a warmer body of water will see fog develop both nights, but dryness of the atmosphere looks to keep any widespread fog from occurring.
Upper trough will sneak eastward overnight, and with the tropical storm working its way up the eastern coast, chances for showers will increase in the northwest and eastern zones by late morning and spread across the area during the afternoon. Later today an upper trough will bring a few shower/storms to the area, especially CKV, with a small chance BNA,MQY.
Temperatures will be cooler across the eastern Big Country and northern Heartland with highs in the lower 90s.
An upper-level trough continues to set up across the region.
Clouds will increase due to a combination of diurnal heating and upper level support from the 500-mb trough that will continue to slowly pivot through eastern parts of the Northland. Temperature-wise, weak northeasterly cool air advection along with some developing clouds will keep the high temperatures down in the low 70s for most areas this afternoon.
144 AM EDT Mon Aug 3 2020 Aviation - Several chances for showers over the next couple of days and then again for the weekend - Cooler than normal temperatures through mid week then warming - Several chances for rain over the next couple of days and then again for the weekend This evening there will be some showers and thunderstorms around.
A dry cold front, currently crossing the Cascade Mountains in Washington, is still expected to pass through the Northern Rockies later this afternoon. It will bring widespread winds gusting to between 20 and 30 mph and cooler, more seasonable temperatures. There will be some thunderstorms activity in southwest Montana ahead of the cold front.
A weak cold front stretches from the Northeast down to the Red River Valley. Combine the lower dewpoints and even cooler temps today behind the front and you get a very comfortable early August afternoon in store. As was mentioned yesterday, a transition from this cooler regime to more typical summer time weather will be complete by week's end.
338 AM CDT Mon Aug 3 2020 Cooler temperatures return today, as a weak boundary lingers across southern Illinois.
Trends keep the convection advancing slowly east before weakening over the highway 283 corridor in the post sunrise hours. With the mid level frontogenetic zone/morning convective potential, the additional cloud cover will lend itself to a cooler temperatures for today in this already cool anomaly mid summer setup. The direct model output from the more convectively active solutions relegate the highs to the lower 70s.
1208 AM CDT Mon Aug 3 2020 Temperatures will remain below early August climo through early this week within the northerly flow regime on the back side of the eastern CONUS longwave upper trof.
Mid level ridging pinched between TS Isaias to the east and broad troughing to the west will weaken as the trough moves eastward into our area.
/ISSUED 1036 PM CDT Sun Aug 2 2020/ Daytime heating, higher moisture levels, a stronger spoke of vorticity passing across the back side of the mid level trof, and outflow/seabreeze interactions led to higher precip coverage and stronger storms than earlier anticipated. High pressure building in keeping most thunderstorm activity at a minimum and light onshore flow.
A low pressure system remains centered about 200 miles west of the mouth of the Columbia River this evening, with an associated front approaching the Pacific NW coastline. An upper trough will move inland this evening, resulting in some light rain along the coast and over the Olympic Peninsula this evening and tonight. This prospect for rain will spread further inland early Monday as the trough crosses the area.
Otherwise, skies are partly cloudy along the island chain, with temperatures hovering in the lower to mid 80s and dewpoints in the upper 70s. This may promote cloud line development, although the vertical extent will be challenged due to the dry air aloft, especially over the Lower Keys.
With upper level trough moving east to the forecast area keeping mainly a dry northwest flow aloft, expecting mainly VFR conditions to prevail into Monday with limited if any convection during daytime heating. /issued 335 PM CDT Sun Aug 2 2020/ Latest sfc analysis shows a rather diffuse front lying along the coast this afternoon, while high pressure remains centered over the cntl/wrn Gulf. Water vapor imagery shows mid/upper-level trof axis in place just west of the forecast area.
1100 PM CDT Sun Aug 2 2020 The cold front has shifted through the area and the broad line of showers, and a few isolated thunderstorms has shifted into eastern WI. Upper level troughing dominates this period with SCT-BKN cumulus in ~2kft layer of instability under the mid-level cap. Low-level ridging will provide at least a few thousand feet of light winds to allow for the possibility of valley fog for Tue/Wed mornings. This period is characterized by a bit more zonal-to-ridging pattern as the longwave amplitude across North America decrease.
The high-res guidance shows that some of the activity that is currently ongoing over extreme southwestern NE and into western Kansas could slowly move eastward with time today and impact the western portions of the area. Models indicate a similar pattern tonight with convection developing along the High Plains and moving eastward with time. Lows tonight should be slightly warmer.
309 AM CDT Mon Aug 3 2020 Currently have an unseasonably deep upper trough extending from the Great Lakes region into the Lower Mississippi Valley. Meanwhile we have strong upper ridging over the Desert Southwest. At the surface, high pressure extends through the northern and central Plains. Not much of a warm-up is forecast by mid week, with highs Wed only topping out in the low 80s. The main theme through these extended periods will be for building upper ridging across the Southern Plains into the lower Mississippi Valley. Confidence is high that we will be seeing a warm-up through these periods with highs for the weekend back to seasonal normals in the low to mid 90s.
Meanwhile, an upper trough axis across the mid to lower MS valley has an associated cold front from southern IL through central AR which will slowly push southeast. The trough will track into the central TN valley this afternoon, aiding convective development thru this evening along and near the first front. Will keep the low PoP in our northwest counties for this, although it is still debatable whether the activity will continue into northwest AL by this evening with loss of heating. Consensus model guidance suggests that the axis of the longwave trough will slowly cross the region this evening, with flow aloft temporarily veering to WNW and subsiding in its wake. Conditions could become a bit more favorable for convection on Tuesday, as another weak mid-level trough and surface cold front approach the region from the northwest.
/issued 457 AM CDT Mon Aug 3 2020/ Below normal temps remain on track through mid/late week, influenced by an upper level trof over the eastern third of U. A rather-ill defined surface cold front will pass through at least the I-40 corridor during the afternoon.
Will continue with a chance showers and thunderstorms as the trough moves through today into early this evening. The the latest runs of the HREF shows that the longwave trough axis will shift east of the region tonight before starting to lift out of the Midwest tomorrow. Britt EPS and GEFS means continue to show that northwesterly flow aloft will set up over the area by mid-late week as both the EPS/GEFS mean are showing a large upper high building over the Central Plains.
1044 AM EDT Mon Aug 3 2020 Periodic rain chances will continue through Tuesday under upper troughing, with drier air supported by building high pressure filtering back into the region by midweek. One exception should be the southeastern ridges, where precipitation chances should increase as a quasi- stationary boundary draped across MD and VA serves as a mechanism for increased convection this afternoon. A digging trough near the Pac. NW should amplify ridging centered near Manitoba, Canada. This should provide balanced jet support with an amplifying ridging on the eastern flank of the deepening Great Lakes low Tuesday, causing it to become cut off by Tuesday evening. The result will be a slow, eastward progression of the aforementioned cold front, with periods of showers and some tstms expected from west to east through the day Tuesday.
Consequently the temps by this afternoon and Tuesday morning are cooler at H850 in the GFS compared to the Euro. Today we should still make it into the lower 70s north to the mid to upper 70s south. There continues to be a 2C difference in afternoon H850 temps between the GFS/Euro with the Euro warmer.
Temperatures are trending generally in the low to mid 70s over the southern part of the area, around 70 across central Louisiana into interior southeast Texas.
Broad troughiness. across the eastern Gulf and high pressure building into the western Gulf will result in north and west winds for the next day or so.
As for the thunderstorms, most of the activity will be in the north and central zones this afternoon and tonight as the weather system moves through and the cold front pushes into the north this evening. A little cooler Tuesday with highs mainly in the 80s across the region.
628 AM CDT Mon Aug 3 2020 The next 48 hours will be dry with light winds and temperatures slightly cooler than the seasonal average for early August. Early morning satellite data with RAP13 surface analysis showed an area of high pressure centered along the Red River Valley. Today temperatures will rebound into the low 70s, and scattered clouds will develop.
508 AM MDT Mon Aug 3 2020 Synopsis: A persistent upper ridge over the Intermountain West was flanked by upper troughs over the MS Valley and Pacific Northwest. Short range models/ensembles indicate little change in the synoptic pattern with the upper ridge and surface front making slow eastward progress through Tuesday. The Pacific trough will track east across MT this afternoon and tonight, flattening the upper ridge. The axis of better instability and shear will shift east into the high plains east of I-25 Tuesday afternoon.
457 AM CDT Mon Aug 3 2020 Below normal temps remain on track through mid/late week, influenced by an upper level trof over the eastern third of U. A rather-ill defined surface cold front will pass through at least the I-40 corridor during the afternoon.
/issued 303 AM CDT Mon Aug 3 2020/ Upper ridge still centered over AZ this morning will build east becoming centered over NM/TX midweek as upper trough over eastern US moves off. Looking out over the coming week a series of upper troughs moving along the US/Canada border will flatten the ridge but even out 240hrs it is still around.
Trends keep the convection advancing slowly east before weakening over the highway 283 corridor in the post sunrise hours. With the mid level frontogenetic zone/morning convective potential, the additional cloud cover will lend itself to a cooler temperatures for today in this already cool anomaly mid summer setup. The direct model output from the more convectively active solutions relegate the highs to the lower 70s. The GFS and ECMWF would indicate a better setup for storms to advance farther east onto the lower plains Tuesday night, as the low level 850 mb upslope flow increases. Tuesday night continues to be the highest precipitation probabilities in the extended.
Another cool day with chances for showers or a thunderstorm is expected today as a weak area of low pressure and an accompanying cold front cross Indiana. High pressure is expected to build across Indiana tonight. Expect this trend to continue and increase over the next few hours as the upper trough axis moves into the region and interacts with a modestly unstable airmass over central Indiana. Isolated to scattered convection will linger this evening but end from west to east towards midnight as the upper trough axis moves away to the east. GFS and NAM shows the large trough axis pushing east of Indiana tonight. as deep low pressure remains aloft over Ontario.
Another cool day with chances for showers or a thunderstorm is expected today as a weak area of low pressure and an accompanying cold front cross Indiana. High pressure is expected to build across Indiana tonight. Surface analysis early this morning shows a weak cold front stretching from Lower Michigan. water vapor showed a large trough in place across the Great Lakes to the Mississippi delta. Water Vapor showed strong subsidence behind the trough axis. The GFS and NAM finally suggest the upper trough axis to our west will progress east of Indiana by late today. This will be aided by the previously mentioned cold front that is expected to push across Indiana this afternoon.
Today Through Tuesday Night Cold front will continue progressing south/east and out of Arkansas by this evening. Once the front exits the region, northwest flow aloft will drive an area of high pressure toward us.
The strong ridge of high pressure responsible for our hotter than average temperatures will gradually weaken in the coming days, although the hotter than normal temperatures will continue through the week. The high pressure ridge aloft centered over the region will continue to weaken and shift south and east of the area by the end of the week. The deeper moisture needed to support daily shower and thunderstorm activity will also shift farther east as a trough of low pressure approaches the West Coast.
Early this morning, an upper ridge axis was placed over southern Saskatchewan, with northwest flow over the Northern Plains. A deep trough was located over the eastern half of CONUS, with low- amplitude troughing over the northwest. At the surface, high pressure was centered over eastern North Dakota, with a few high clouds streaming over western North Dakota from an impulse moving through the upper flow. The chance of showers begins in our far west late tonight as the trough approaches, but bulk of the precipitation is expected Tuesday. Overnight lows should generally be in the lower 50s east to upper 50s west where cloud cover will be increasing tonight.
924 AM CDT Mon Aug 3 2020 Very quiet today with high pressure over the region.
647 AM CDT Mon Aug 3 2020 Currently have an unseasonably deep upper trough extending from the Great Lakes region into the Lower Mississippi Valley. Meanwhile we have strong upper ridging over the Desert Southwest. At the surface, high pressure extends through the northern and central Plains. Not much of a warm-up is forecast by mid week, with highs Wed only topping out in the low 80s. The main theme through these extended periods will be for building upper ridging across the Southern Plains into the lower Mississippi Valley. Confidence is high that we will be seeing a warm-up through these periods with highs for the weekend back to seasonal normals in the low to mid 90s.
Main concern over the next 24 hours is the low potential for thunderstorms at all sites. While south- southeasterly flow in the low levels should help to keep moisture and potential instability - progged MLCAPE values late this afternoon are around 1000 J/kg - in place, convective inhibition remains a concern with skinny CAPE profiles and absolute MLCIN values of 50 to 100 J/kg. Tuesday, flow aloft gains a bit more of a westerly component as south-southeasterly flow in the low levels continues.
501 AM EDT Mon Aug 3 2020 An upper level system will move across the area today in tandem with a cold front and will bring showers and a few thunderstorms.
559 AM MDT Mon Aug 3 2020 Hot weather will once again dominate the forecast headlines to start the week as a ridge of high pressure remains in place over central Arizona and southern Utah. Eastern Utah and western Colorado will remain on the northern periphery of this ridge, resulting in general westerly flow aloft. This light westerly flow will help push our lingering monsoon moisture east of the Divide for today and tomorrow, resulting in a lower chance for afternoon showers and thunderstorms in the higher terrain. Still, a few isolated areas of convection are possible over the higher terrain of the Sawatch and San Juan ranges this afternoon. The southwestern ridge will break down slightly, resulting in a northwest component to upper-level winds.
338 AM MDT Mon Aug 3 2020 Synopsis: A persistent upper ridge over the Intermountain West was flanked by upper troughs over the MS Valley and Pacific Northwest. Short range models/ensembles indicate little change in the synoptic pattern with the upper ridge and surface front making slow eastward progress through Tuesday. The Pacific trough will track east across MT this afternoon and tonight, flattening the upper ridge. The axis of better instability and shear will shift east into the high plains east of I-25 Tuesday afternoon.
In the upper levels, a large scale trough will move across E Conus. This will eventually allow it to be absorbed into the longwave trough. No significant cooler air is expected behind the first boundary for today with low to mid 90s for highs.
615 AM CDT Mon Aug 3 2020 High pressure and northwest flow dominate the next 3 days bringing unseasonably cool but welcome conditions for the area.
748 AM EDT Mon Aug 3 2020 Rain chances will continue through Tuesday with persistent upper troughing over the region. A return to seasonable temperature is anticipated under ridging and swly flow aloft. Precipitation chances should generally be confined to the southeastern ridges and along the western periphery of the forecast area this afternoon and evening. A large portion of the area will be in between the stalled trough to the west and the atmospheric impacts surrounding TS Isaias to the southeast, as it begins to move northeastward along the SE US coast. The far southeast ridges, in WV and MD, could see a shower this afternoon, but most of the rain in that neck of the woods will be confined to the aforementioned front over the Mid-Atlantic region.
Shower and thunderstorm activity will first start over the west this afternoon, eventually shifting east overnight, with showers and thunderstorms lingering perhaps along the Dakotas border and the higher terrain on Tuesday. Otherwise, Tuesday will be cooler behind the front with northwest winds. With easterly low level winds over the area out ahead of the approaching trough, PWATs will be around an inch today. Ample moisture, along with good instability and shear, and forcing from the approaching trough will combine to produce a risk of strong to severe storms over western and central areas (including Billings) later this afternoon and evening.
Western locales are seeing a SSE fetch ahead of the ridge, with eastern areas near calm due to the proximity of the ridge. The focus for the remainder of the day and on into the midweek timeframe shifts back to the strong H5 ridge. At the surface, high pressure remains to the east of the CWA, with weak troughing west over the Front Range.
Aloft the upper level ridge extended from the desert southwest into the northern Rockies with a trough from Hudson Bay into the lower Mississippi River Valley. Precipitation chances return late Tuesday night as storms move off the high Plains into western and central Kansas.
Surface analysis reveals a weak NE-SW oriented cold front extending from lower MI down through western AR. High temperatures today will once again reach into the upper 70s to mid 80s, with overnight lows then dipping into the lower to mid 60s. Eastern CONUS upper trof will be the predominant feature through the middle part of the week. Tuesday will be the most unsettled day as a weak cold front pushes through the Ohio Valley.
The mid level pattern remains very meridional for early August, with a ridge from off the southern CA coast through UT, MT and up into the southern part of the Nunavut territory in Canada. A trough stretched from northern Quebec down to AR and LA. Normal lows are in the lower and mid 60s.
341 AM MDT Mon Aug 3 2020 Upper ridge over eastern Montana with trof pushing through southern BC. Lee trof strengthening in central Montana with fairly strong low level jet into eastern Montana.
524 AM MDT Mon Aug 3 2020 Current surface analysis shows nearly stationary frontal boundary still west and southwest of the area, with high pressure centered over eastern ND. Upper level analysis shows ridge axis centered over the northern Rockies, with a trough along the Pacific NW coast. Skies are clear to partly cloudy with temps mostly in the mid 50s to mid 60s, cooler over the higher Black Hills and some valley locations on the plains. Today will be a bit warmer than yesterday, but still near to slightly below average, with highs in the upper 70s and 80s.
High pressure over the southwest United States will continue to provide dry and warm conditions today. High pressure will be breaking down this week as a low pressure area slowly encroaches upon Nevada. The ridge of high pressure that brought extraordinary heat to the Great Basin has moved east. The ridge axis is now aligning through eastern Utah and Arizona, allowing a few clouds to dirty up the sky over northeast Nevada.
An upper level trough is making its arrival onshore early this morning, resulting in some light rain along the coast and in the northern CWA today. Inland locations may also see some light rain as the trough moves across the area.
505 AM MDT Mon Aug 3 2020 Hot weather will once again dominate the forecast headlines to start the week as a ridge of high pressure remains in place over central Arizona and southern Utah. Eastern Utah and western Colorado will remain on the northern periphery of this ridge, resulting in general westerly flow aloft. This light westerly flow will help push our lingering monsoon moisture east of the Divide for today and tomorrow, resulting in a lower chance for afternoon showers and thunderstorms in the higher terrain. Still, a few isolated areas of convection are possible over the higher terrain of the Sawatch and San Juan ranges this afternoon. The southwestern ridge will break down slightly, resulting in a northwest component to upper-level winds.
Most of this activity has been in response to deep synoptic scale lift in association with deep mid-upper level troughing across the eastern US. Slightly cooler mid level temperatures spreading across a warm boundary layer will increase lapse rates and yield CAPE values in excess of 1500-2000 j/kg by the afternoon. MA Chattanooga Airport, TN 88 69 89 67 91 / 40 30 30 20 20 Knoxville McGhee Tyson Airport, TN 85 67 87 66 89 / 50 40 40 30 20 Oak Ridge, TN 85 66 86 65 88 / 40 40 40 30 20 Tri Cities Airport, TN 79 63 84 62 85 / 80 40 50 40 40.
556 AM CDT Mon Aug 3 2020 Cooler temperatures return today, as a weak boundary lingers across southern Illinois.
As high pressure weakens in response to an area of low pressure developing across California and the Great Basin we can expect to see decreasing temperatures through the week.