Aikyam-Lab/Synoptic-Bench huggingface dataset:
An upper trough will remain situated over the eastern CONUS as ridging builds over the MS Valley. Southwesterly flow in the low levels will help keep our airmass very warm and moist.
Southwest flow aloft strengthens considerably ahead of the approaching trough aloft over the Pacific Northwest. Slightly cooler at some locations with more cloud cover.
A little bit greater moisture in the lower/mid levels should still linger in the eastern counties late this afternoon and have kept chance POPs going for mainly Liberty/Polk counties and would rule out a few claps of thunder.
200 PM EDT Sat Jun 27 2020 The axis of the Atlantic ridge is well to our north, cutting through north Florida. The ridge is somewhat segmented vertically due to troughing along the mid and northern Atlantic seaboard, with orphaned ridging above the surface through 500mb over the Keys, south Florida, and the Bahamas. This has allowed for a fairly tight surface pressure gradient between the ridge and lower pressure in the Caribbean.
A broad longwave trough draped across the northwestern US will slowly approach the region and amplify as a blocking pattern sets up across the eastern US. This wave may be accompanied by a complex of strong to marginally severe thunderstorms as it clips the far northwest overnight, interacting with the stationary front/pressure trough.
Isolated showers or possibly a thunderstorm can be expected along the Highway 77 corridor. As the low-level jet develops early Sunday morning, some additional convection may develop farther east toward San Antonio and the remainder of the Hill Country.
1142 AM MDT Sat Jun 27 2020 Another disturbance will move over the region today with some upper level support noted thanks to a weak portion of the jet stream rounding the base of an upper level trough. Strong southwesterly winds look to develop during the day as the deep and tight area of low pressure gets closer to the CWA. Surface winds of 20 to 30 mph with gusts reaching 40 mph, if not higher, will develop Sunday ahead of the low and surface cold front. Temperatures will climb a few degrees thanks to southwesterly flow ushering in a bit warmer air. By Sunday night, the area of low pressure will be over Idaho and instead of continuing to drop to the southeast, models forecast the low moving to the northeast.
High pressure remains centered over FL which is helping pump in an uncomfortable and humid airmass from the southwest with temperatures already in the 80s and dew points in the 70s. Regardless, today will be much warmer as an upper-level ridge builds over the middle part of the country and an Omega Block develops over CONUS. The omega block pattern over the lower 48 will strengthen on Sunday, with the deepening of upper trofs over the Pacific northwest and New England. The intermediate ridge over the MS River valley will amplify, warming Midsouth temps to near normal values, and limiting rainfall potential.
As a result of the clouds, have trimmed highs for a small eastern part of the forecast area to the low to mid 80s, while everyone else should still reach the upper 80s to low 90s with more insolation occurring this afternoon. The broad trough previously mentioned will slowly progress into the western US and then weaken later this week, with embedded waves bringing small precipitation chances on and off throughout the week.
CDG Chattanooga Airport, TN 71 87 71 89 72 / 20 40 30 50 20 Knoxville McGhee Tyson Airport, TN 69 82 70 86 70 / 30 70 50 50 40 Oak Ridge, TN 69 82 69 86 69 / 40 70 40 50 50 Tri Cities Airport, TN 66 78 66 80 67 / 50 80 50 70 60.
The long wave trough will keep a boundary along Michigan's southern border this evening. However the propagation of the upper level low into the northeast will keep any precipitation south of the region. There is good consensus that the Upper level low will stall over the Northeast.
Isolated showers and thunderstorms will develop over the west central Idaho mountains this afternoon and south and east of Boise this evening as a cold front moves through the area.
Temperatures will be noticeably cooler today than previous days, with highs topping off in the low to mid 60s. An upper trough will bring cool showery weather to Western Washington over the weekend.
Freezing levels are 14-15k ft so hail threat appears low.
1235 PM EDT Sat Jun 27 2020 Low pressure over eastern Ontario will move eastward into Quebec today with a weakening cold front sagging southward across the region this evening.
1226 PM CDT Sat Jun 27 2020 Quiet weather under high pressure. Expect more of the same throughout the week as the pattern doesn't really change, and more vort maxes eject from a deep trough to our west. VFR conditions expected through the TAF period as high pressure remains in control. Very quiet conditions expected, with some increasing clouds Sunday morning ahead of a trough of low pressure that will support increasing chances of thunderstorms for Sunday afternoon and evening. High pressure remains in control over the region today through much of the day Sunday.
140 PM EDT Sat Jun 27 2020 Low pressure over eastern Ontario will move eastward into Quebec today with a weakening cold front sagging southward across the region this evening.
The better cloud cover and precipitation will keep temperatures slightly cooler in central MO where some mid 80s will be possible, but further south it looks like upper 80s to around 90 once again. Warm conditions are expected tonight with lows in the low to mid 70s. It looks pretty toasty though with highs into the low 90s just about everywhere and heat index values in the mid to upper 90s.
the afternoon diurnal showers and thunderstorms have had a tougher time initiating across the higher terrain of Southeast Oklahoma.
1229 PM CDT Sat Jun 27 2020 Upper level ridging will amplify over the northern Plains and upper Mississippi Valley today and tonight. This places the CWA on the backside of the ridge axis as a weakening Great Basin low evolves into an open wave to our west. The airmass warms slightly Saturday and Saturday night as we will fall under the influence of the upper ridge. Highs trend warmer on Sunday as increasing southwest flow ushers in warmer and drier air.
Reimer Conditions are priming for a period of showers and strong to severe thunderstorms across our region with the approach of an upper trough from N/NW. The upper trough will be reinforced and strengthen over the Pacific NW Sunday.
BT Conditions are priming for a period of showers and strong to severe thunderstorms across our region with the approach of an upper trough from N/NW. The upper trough will be reinforced and strengthen over the Pacific NW Sunday.
BW Chattanooga Airport, TN 71 90 72 89 72 / 20 40 30 40 20 Knoxville McGhee Tyson Airport, TN 69 85 71 87 71 / 40 60 50 50 30 Oak Ridge, TN 68 86 71 88 71 / 40 70 50 50 40 Tri Cities Airport, TN 66 80 66 84 67 / 60 80 70 70 50.
/issued 200 PM CDT Sat Jun 27 2020/ SHORT TERM (Now through Sunday night): Modest, broad, mid-level ridging will stretch over the area in the short term, leading to relatively benign, seasonal weather.
Even though high amplitude, blocking upper air pattern has mean ridge across our area, ridge is actually on the weaker side and once again we will need to watch the approach of another short wave trough from the southwest. In any event, this feature will likely tap in to very unstable airmass closer to I-80 and help push warm front northward. The rest of the period remains low confidence and messy, as the region becomes caught between upper low to our west and ridge over the Great Lakes. Latest trends also indicate the possibility of a compact closed low oscillating in the Midwest mid-week.
There is an area of increased surface convergence on the cold front slipping south into that area. The long wave trough will keep a boundary along Michigan's southern border this evening. However the propagation of the upper level low into the northeast will keep any precipitation south of the region. There is good consensus that the Upper level low will stall over the Northeast.
A warm front lifted north across the local area this morning.
The slow-moving cold front is now positioned across far southern lower MI. Weak mid-level ridging will move up from the south tonight, so do not expect much more activity other than a few showers.
Isolated showers may still occur overnight with the strengthening of the low level jet, only mentioned for San Antonio sites. Isolated showers or possibly a thunderstorm can be expected along the Highway 77 corridor. As the low-level jet develops early Sunday morning, some additional convection may develop farther east toward San Antonio and the remainder of the Hill Country.
235 PM PDT Sat Jun 27 2020 Heat wave will finally come to an end this evening as a trough of low pressure coming from western Canada approaches the region.
202 PM PDT Sat Jun 27 2020 Significant cooling expected this weekend with a slight chance of showers over the higher Sierra Nevada Sunday night.
This MCV combined with what's left of a cold front is expected to produce another round of thunderstorms later this afternoon and tonight. The area of convection pushes south, likely due to outflow, and then starts drifting north again as the warm front gets pushed northward by the low level jet. There may be some lingering showers/storms along the warm front as it continues moving through Illinois. Upper level pattern becomes highly amplified with large cut off lows over the eastern and western CONUS, and ridge extending from the deep south north through the Mississippi Valley.
814 PM EDT Sat Jun 27 2020 Low pressure is along the Ontario/Quebec border, with a surface cold front crossing OSC and W Branch. We will still scour out the lower clouds in eastern upper MI over the rest of the afternoon and early evening. This occurs as weak high pressure moves overhead. Min temps tonight will be cooler than last night, mainly in the 50s. Also expecting less in the way of cu Sunday, as our low-level airmass is both a little warmer and a little drier. Otherwise mostly sunny and just a little toasty, with highs mainly in the low-mid 80s. The lakeshores will be somewhat cooler as onshore lake breezes develop. An upper level ridge (omega block) is centered across northern Michigan through the period.
Upper low digging into the area about as forecast.
Ridge axis across the area will shift slowly southward, with S/SE winds around 5-10 knots over the waters becoming S/SW late tonight.
Similar to yesterday a dry subsident air mass under deep layered ridging covering the region kept convective development and coverage to a minimum by late June standards with only a few isolated storms being observed. High pressure will maintain light east southeast winds and slight seas over the Gulf waters the remainder of tonight through Sunday with an onshore sea breeze component developing along the coast Sunday afternoon.
1036 PM EDT Sat Jun 27 2020 Currently - A surface pressure ridge extends westward across Central Florida, resulting in gentle to moderate east breezes across the Keys and surrounding waters. Temperatures will likely only fall a few more degrees into the lower 80s. A ridge across Central Florida will result in moderate easterly breezes relaxing some through the overnight period.
Along with the gusty winds, expect much cooler temperatures.
High pressure both aloft and at the surface will continue to keep the stagnant weather pattern across south Florida through the remainder of the weekend and into the start of the new workweek. The upper level ridge will eventually begin to spread westward across the Gulf. With the lower afternoon temperatures along with some slightly drier air mixing down, no heat products today. Low level winds appear to be fairly light as high pressure remains practically over the region limiting gradient somewhat. A weakness in midlevel subtropical ridging is forecast to persist across South Florida through the period. Late in the week into the following weekend, lower/middle-tropospheric flow may attain a more decidedly southwesterly component ahead of a midlevel cyclone potentially advancing southward over the Lower Mississippi and Tennessee Valley regions.
205 AM EDT Sun Jun 28 2020 A weakening cold front will move across Lake Erie early this morning, eventually stalling over central Ohio tonight. This boundary will eventually dissipate over southern Ohio as high pressure ridges into the region from the north and south. A weakening cold front will move across Lake Erie early this morning, eventually stalling over central Ohio tonight. Lows tonight should be slightly cooler in the wake of the cold front with mid 50's inland to mid 60's near the cities. Confidence increasing in omega block pattern setting up over the region with an upper-level ridge over the Midwest/Great Lakes area and an upper-level low situated over the northeast CONUS through the week.
However, no additional shwrs/tstms activity mentioned thru 29/06Z as weak upper level ridging influences build across these locations.
343 AM CDT Sun Jun 28 2020 Will start the day with the sub tropical ridge extending into TX from the Gulf and an upper low located over OR. This low will spin east Monday with its associated trough deepening across the SW US.
High temperatures both today and Monday are expected to be in the mid 80s to the east of the Red River Valley, and in the low 90s along and west of the Valley.
Activity will diminish after sunset with overnight lows in the low to mid 70s. Rising heights means hot temps with highs in the mid to upper 90s and lows in the low to mid 70s.
The issue for this evening and again on Sunday afternoon/evening will be a weak short wave trough slowly making its way east across southern sd and then northeast across northeast sd. Otherwise, through Sunday night, a large upper level low pressure area will develop over the western U. It may be a little warmer with highs in the upper 80s to the mid 90s under mostly sunny skies. Expect warm Sunday night lows in the upper 60s to the lower 70s. Dry, hot and muggy conditions are anticipated Monday, as an upper level ridge holds across the Northern Plains.
Ridging will build westward across the FL peninsula and eastern Gulf of Mexico which will shift more dry air in the mid levels into the southeast. Otherwise, it will be mostly sunny today with highs in the mid to upper 90s and heat indices reaching the low to mid 100s.
400 AM EDT Sun Jun 28 2020 A weakening cold front will move across Lake Erie early this morning, eventually stalling over central Ohio tonight. This boundary will eventually dissipate over southern Ohio as high pressure ridges into the region from the north and south. A weakening cold front will move across Lake Erie early this morning, eventually stalling over central Ohio tonight. Lows tonight should be slightly cooler in the wake of the cold front with mid 50's inland to mid 60's near the cities.
305 AM EDT Sun Jun 28 2020 A upper level area of low pressure will stall over New England for the next few days bringing the chance for mainly afternoon and evening thunderstorms through at least mid week. Best chance will be over the higher terrain of he Catskills nearer the upper low.
436 AM EDT Sun Jun 28 2020 A weak cold front over the Ohio Valley today drops into the Mid Atlantic region on Monday.
Meanwhile, a closed low was tracking south into the Pacific Northwest from Canada as an upper trough extended south along the west coast. The warming trend continues today, as southwest flow develops aloft ahead of the west coast trough. For tonight, a disturbance pushes through the southwest flow on the periphery of the upper trough, generating thunderstorms along the Rockies. On Monday, the closed low is centered over Idaho, then starts to lift northeast. For this part of the forecast the upper level trough over the Great Basin lifts northeast across the Plains mid week as the ridge over Mexico builds north onto the Plains. There look to be minor troughs moving through the 500mb flow over the forecast area during this time.
As the strong upper trough over the Pac NW digs south and becomes established over the West, this pair of lead impulses, which are forecast to eventually merge, will eject northeast over the region over the next 24 to 48 hours. After this wave passes off to the northeast, a low level thermal ridge /850mb/ will strengthen over the High Plains downstream from the western CONUS upper trough. This thermal ridge will expand eastward over the southern Plains, allowing high temps to climb to the warmest readings so far this year.
Southwest flow aloft strengthens considerably ahead of the approaching trough aloft over the Pacific Northwest. Slightly cooler at some locations with more cloud cover. Definitely a cooler overnight across our western counties in the wake of the cold front.
1002 PM PDT Sat Jun 27 2020 Low pressure will move in over the Inland Northwest tonight into Sunday. Much cooler and wetter weather will persist into midweek with a bit of warming and drying by the of the week. Moisture wrapping into this low along with weaker pulses of energy swinging around Northern and Central WA will bring a renewed threat for showers and some thunderstorms.
Temperatures were in the upper 70s to middle 80s, except in the lower to middle 70s near the bay of Green Bay and near Lake Michigan.
151 AM EDT Sun Jun 28 2020 A upper level area of low pressure will stall over New England for the next few days bringing the chance for mainly afternoon and evening thunderstorms through at least mid week. Best chance will be over the higher terrain of he Catskills nearer the upper low.
A broad area of low pressure will otherwise remain over VA and the Carolinas through mid-week. Lows tonight will be a few degrees warmer than this past morning and range around 70. Sunday afternoon and evening should be much more convectively active than recent days as the upper level ridge across the Southeast relaxes and mid-level troughiness across the OH Valley and Northeast slips southward.
JB Chattanooga Airport, TN 90 72 89 72 88 / 50 30 40 20 60 Knoxville McGhee Tyson Airport, TN 85 71 87 71 86 / 60 50 50 30 70 Oak Ridge, TN 86 71 88 71 86 / 70 40 50 40 70 Tri Cities Airport, TN 80 66 84 67 81 / 80 70 70 50 80.
Models depict a strong mid level short wave trough over the Brush Country early Sunday morning that will move northeast to between VCT and SAT in the afternoon.
This activity is associated with a weak upper level low pressure system and a mid level short wave shear axis located over that region. A few lingering showers and an isolated thunderstorm or two over the Hill Country are possible as the short wave departs and high pressure builds and expands westward across our area. High's today to be below normal and in the low to mid 80s most areas due to cloud coverage and the potential for isolated to scattered showers and storms. By Monday, high pressure will be in place high's in the low to mid 90s.
Expect this line to continue to surge eastward over the next few hours as the low level jet increases to around 45 kts from the southwest. Temperatures warm into the low to mid 90s today with dewpoints in the low to mid 70s will yield heat indices around 100- 105 degrees this afternoon. Tonight temperatures will gradually cool into the low to mid 70s with heat indices mainly in the 80s for much of the night before dropping into the 70s late in the night.
However, feel the higher showers and storm chances will be east of our forecast area over southern MO. By Tue morning a sharp upper trough is expected to stretch across the Rockies with the main vort max forecast to lift across far western KS into central NE by Wed, having minimal impact on our forecast area. With increased cloud cover, currently expecting slightly cooler readings for Mon with Tue being one of the hottest days of the year so far. Upper ridging is expected to build over the southern and central Plains through these extended periods.
A strong upper level trough will then dig south across the western US on Monday. High temperatures will range from the low 90s east of US-183 to the mid 100s in southwest Nebraska. At this time, apparent temperatures (heat indices) will remain slightly cooler due to gusty winds up to 25 to 30 mph Monday afternoon.
257 AM CDT Sun Jun 28 2020 The upper low/trough across the West Coast is expected to amplify southward today through tonight placing the FA in a southwesterly flow aloft pattern by tomorrow morning. The upper height gradient for today will be relaxed as the upper trough amplifies. The upper level low pressure trough crossing southwest New Mexico this morning will continue east across our area later tonight and early Monday. This will result in enhanced downslope warming and we have trended several degrees warmer than our blended temperature guidance more in line with thickness and low level temperature trends, historical temperatures and MOS guidance, and the previous forecast.
For the afternoon, CAMs shoe the rain coverage thinning out as the axis of an upper ridge approaches, providing more subsidence across the area and suppressing rain. Muggy conditions will continue through the short term period due to prolonged warm air advection on the backside of a high pressure system. The axis of an upper level ridge will build over the area tonight, suppressing widespread rain. ECMWF keeps a large ridge in place stretching from the SW state to the great lakes to start off the forecast period.
358 AM MDT Sun Jun 28 2020 A vigorous upper-level trough currently over the Pacific Northwest will continue to deepen over the next 12-24 hours as it digs south toward the Great Basin. Deep layer shear remains very modest around 20 knots, so it will be difficult to get organized/long lived convection today, at least until early evening when shear begins to increase in response to strengthening 500 mb flow with the approaching trough. Strong wind gusts will be the primary hazard with deep inverted-V profiles & LCLs well above the freezing level, as well as a belt of 45 to 50 knot 700-500 hpa flow taking shape over our western zones after 00z. The same general synoptic pattern remains in place for Monday as the upper- level trough drifts slowly eastward.
543 AM EDT Sun Jun 28 2020 An upper level trough moving east across the region today will gradually deepen into a closed upper low that will drift slowly south across the New England states through the midweek period.
A closed low pressure circulation is anticipated to swing across southwest Montana this afternoon, drawing a large amount of atmospheric moisture over the Northern Rockies. Rainfall will remain fairly continuous across the Northern Rockies on Monday, as the low pressure circulation over southwest Montana begins to wobble a bit around the region.
701 AM EDT Sun Jun 28 2020 An upper level trough moving east across the region today will gradually deepen into a closed upper low that will drift slowly south across the New England states through the midweek period.
/issued 448 AM CDT Sun Jun 28 2020/ An omega blocking pattern will amplify over the lower 48 states today. The upper ridge in the center of the omega block will build through the MS River valley, bringing likely the warmest and driest conditions of the week to the Midsouth.
/issued 257 AM CDT Sun Jun 28 2020/ The upper low/trough across the West Coast is expected to amplify southward today through tonight placing the FA in a southwesterly flow aloft pattern by tomorrow morning. The upper height gradient for today will be relaxed as the upper trough amplifies. The upper level low pressure trough crossing southwest New Mexico this morning will continue east across our area later tonight and early Monday. This will result in enhanced downslope warming and we have trended several degrees warmer than our blended temperature guidance more in line with thickness and low level temperature trends, historical temperatures and MOS guidance, and the previous forecast.
However, the low-level water vapor channel shows dry air near the surface for much of the peninsula.