Aikyam-Lab/Synoptic-Bench huggingface dataset:
There is little change in forecast thinking today as stout high pressure continues to promote hot and dry conditions across NW California.
High temperatures this afternoon and Wednesday are expected to be slightly cooler than previous days due to increased cloud cover and precipitation, peaking in the mid 80s to low 90s across central Georgia. The upper trough extending from the Great Lakes into the southern Appalachians persists at the start of the period. This trough gradually drifts off the Atlantic Coast by the weekend as the upper ridge builds across the southeast.
Otherwise, the surface subtropical ridge will remain the dominant feature controlling the weather pattern through the forecast period. This ridge axis will remain across southern Florida today and Wednesday, with light and generally west and southwest flow continuing across the forecast area. Apart from the storms, high temperatures in the low to mid 90s and dew points in the mid 70s will lead to heat indexes topping out in the low to mid 100s each afternoon, with conditions borderline for heat advisories.
Models have weakened the large scale ascension associated with this feature, so expect most of the convection today to be driven by low-level forcing along a surface cold front. Cold front will move east of the area late this evening, bringing an end to the showers and storms. Drier air will quickly overspread the region tonight, as well as cooler temperatures.
1000 AM EDT Tue Jun 23 2020 Ridging aloft will maintain warm temperatures today.
Wed could see the highest of the 3 day tallies in rainfall as storm motion and propagation vectors are opposite in vector and equal in magnitude although not exact but close enough to see some locations get higher rainfall than others. The central Gulf coast area will be under the influence of a weak upper level trough midweek. The trough will weaken towards the end of the week and this will greatly reduce the amount of showers and thunderstorms as a result.
413 AM CDT Tue Jun 23 2020 Today and Tonight: Early morning water vapor imagery showed our region at the base of a large upper level trough around a low centered over the northern Great Lakes region.
443 AM CDT Tue Jun 23 2020 Cyclonic flow aloft continues today with the upper level pattern slowly shifting as ridge builds over the Intermountain West. A few degrees warmer then the previous day will create slightly steeper low level lapse rates. Wednesday will see the high pressure slowly moving into MN. Drier conditions at the surface as the high moves will keep showers to our south.
Where sun breaks occur during peak heating, it's very likely temperatures will jump up into the low to mid 80s. DGS Chattanooga Airport, TN 84 68 85 66 86 / 90 20 30 10 10 Knoxville McGhee Tyson Airport, TN 81 67 84 64 85 / 80 20 20 10 10 Oak Ridge, TN 80 64 84 63 85 / 80 10 30 10 10 Tri Cities Airport, TN 78 62 80 60 81 / 60 30 30 20 10.
1032 AM EDT Tue Jun 23 2020 Currently - A surface atlantic ridge extends westward across South Florida resulting in light east southeast breezes across the Keys. The lower level ridge is aligned a bit further south across the Keys. Consequently, this mornings sounding indicated a good amount of dry air through the lower troposphere and some inhibition. The over all ridging and vertical structure has resulted in a fairly inhospitable environment for shower development despite the warm humid surface conditions. Short Term Update - Overall ridging will continue to dominate Keys weather through this afternoon. Given the high theta-e and the weak inhibition, a few showers cannot be absolutely ruled out. A ridge across South Florida will maintain light east to southeast breezes on Keys waters through the afternoon.
Synoptically, high pressure continues to ridge over southern Florida keeping us in a very warm and muggy environment. Temperatures are already in the low to mid 80's with heat indices in the 90's. Temps will continue to rapidly warm up under mostly sunny skies through the afternoon topping out in the low to mid 90's, which combined with high humidities correlates to heat indices in the 102-107 degree range by mid-afternoon. High pressure east of the Bahamas continues to ridge across Florida and into the Gulf of Mexico through the week.
341 AM MST Tue Jun 23 2020 High pressure will predominate across the Desert Southwest, resulting in above normal temperatures into the weekend.
624 AM EDT Tue Jun 23 2020 Upper air pattern has a 500 mb ridge in the western U. and a deep 500 mb trough across the central U. The trough axis is across the upper Great Lakes this morning and slowly moves east through 12z Thu into the lower Great Lakes.
H5/H7 flow continues out of the north to northwest, influenced by a rather strong upper low situated well to our east. Instability will build through the late morning and early afternoon; however, the low to mid level shear profile is only conditionally supportive of stronger storms. For Wednesday, look for quiet and dry weather with warmer temperatures in the upper 70s to low 80s across the forecast area.
The short term will be dominated by an upper level trough centered over the Great Lakes region. A secondary zone of isolated showers are possible late this afternoon and early evening as weak energy rotates down around the upper trough.
223 PM MDT Tue Jun 23 2020 An upper ridge over the region through Wednesday will bring continued dry weather with hot temperatures. A cold front will approach the region Wednesday night.
1220 PM EDT Tue Jun 23 2020 Ridging aloft will maintain warm temperatures today.
1117 AM MDT Tue Jun 23 2020 Upper level analysis shows northwest flow with gradually rising heights across the northern Plains with a ridge axis centered from central Alberta/Saskatchewan SD into ID/OR.
348 PM EDT Tue Jun 23 2020 Currently - A surface atlantic ridge extends westward across South Florida resulting in light east southeast breezes across the Keys this afternoon. The lower level ridge is aligned a bit further south across the Keys. This mornings sounding indicated a good amount of dry air through the lower troposphere and some inhibition. Surface dew point temperatures have been fairly gross in the high upper 70s to near 80 with temperatures near 90. The over all ridging and vertical structure has resulted in a fairly inhospitable environment for shower development despite the warm humid surface conditions. Forecast - Large scale ridging will remain the dominant feature near our area through the week. The lower level ridges will meander slowly northward over the next several days.
Issued by National Weather Service St Louis MO 1223 PM CDT Tue Jun 23 2020 Northwest flow aloft and weak high pressure at the surface will build into the region today and remain overhead tonight. Quiet and cooler air will filter into the region through the period and be most noticeable tonight. High pressure slowly shifts off to the east on Wednesday and Wednesday night with winds coming around to the south.
246 PM MDT Tue Jun 23 2020 Ridging will continue into tomorrow, but a trough will start to shift the pattern tomorrow afternoon. Wednesday will be another warm day, with highs a few degrees warmer today, with much of the area in to the lower 90s. During the afternoon, as the trough start to push into the area, showers and scattered thunderstorms will develop mostly west of Billings. The GFS is still a little more sharp with the trough, but there is still a little better agreement between it and the ECMWF.
Behind the cold front, with dry air advecting into the area, and a severe lack of forcing within the northwest flow aloft there will not be much (if any) chance for precipitation in the next day or so.
An upper trof over the eastern states broadens somewhat through Wednesday but otherwise remains in place. Southwesterly winds 10 to 15 knots this afternoon, with the higher values near the coast, diminish to 5 knots or less overnight then increase to 5 to 10 knots Wednesday morning.
335 PM CDT Tue Jun 23 2020 Early this afternoon a broad upper level trough was located across the east central US.
An upper low over eastern Canada will continue influencing weather for the area through the forecast period. Another system will move in as the high moves off to the east leading to better rain chances for the latter half of the forecast. This evening and early tonight there is another slight chance of rain prompted by a brief surge of energy on the back side of the low. An upper level low will continue slowly tracking over the Great Lakes and into SE Canada through the short term period. A couple of short waves off of this low will bring periods of slight rain chances in what will otherwise be a mostly dry mid-week.
216 PM CDT Tue Jun 23 2020 The short term will be dominated by a large and cool upper low dumbelling around the Great Lakes region.
226 PM CDT Tue Jun 23 2020 The FA is currently sandwiched between a trough over the Great Lakes region and a ridge over western CONUS. The ridge to our west is bringing NW flow aloft to the FA. It looks like temperatures will be seasonable and the weather will be pretty quiet overall from mid to late week as a broad, but not overly strong, upper-level ridge extends eastward from the Desert SW into the Southern Plains. However, a continuing weakness in the northeast flank of the ridge with modest NW flow may steer convective activity developing across NE NM Wed afternoon southeast through the evening hours, and possibly into the far southwest TX Panhandle and NW South Plains before dissipating Wednesday night.
Low level moisture transport will again return to western KS by this evening or tonight which will lead to renewed convection over the high plains, as a weak impulse drops SE out of the Rockies. Max temps on Wed may be a bit tricky, as widespread storms suggest temps staying in the 80s, while a less widespread storm solution may lead to temps climbing back into the lower 90s. Ketcham A return to zonal flow will lead to warmer temps for both Thu and Fri, especially for Fri, as a gradual shift to SW flow will lead to breezy SW downslope flow. Ketcham Weakening surface flow as ridge axis moves across central and eastern Kansas by early evening.
1139 AM MDT Tue Jun 23 2020 Eastern CONUS troughing and ridging in the West is becoming more defined today leaving us in a northwest flow pattern. With the building ridge in the West temperatures will continue an upward trend by a degree or two and forecast here remains on track.
156 PM CDT Tue Jun 23 2020 Latest analysis showing weak cold front moving across the mid-state this afternoon. as long-wave upper trough axis finally moves to our east. On Fri, upper ridge is building but boundary is expected to retreat northward, as well as some deeper moisture, which remains through the weekend. This boundary does look to wash out Sat, and upper ridging will be the main theme into early Mon. On Tues it brings an upper low down toward the MS river valley as upper ridge breaks down. The EURO has also come around to a similar solution, however is not quite as aggressive with southward movement of upper low. A cold front moving across the region will produce isolated showers or thunderstorms this afternoon.
310 PM EDT Tue Jun 23 2020 Surface cold front has pushed east of the forecast area this afternoon. As expected, temperatures have warmed back into the upper 70s to the lower 80s across the region. For Wednesday, we'll be within the base of an upper level trough axis. Highs will range from the upper 70s to the lower 80s region wide. Issued at 250 PM Tue Jun 23 2020 A 5H closed low over the Great Lakes will slowly meander northward from midweek through the weekend. By Wednesday night, the upper level trough axis will lie N-S over the Ohio Valley with high pressure building in the lower level.
A broad mid-level trough continues to lift slowly across the eastern CONUS and will serve as the main source of forcing throughout the day and into tonight. 5-2" supports isolated storm development, especially in the southern portion of the CWA, which is located towards the higher end of the moisture gradient. An area of confluence over central AL associated with the mid-level trough axis will further increase chances of showers and storms in the southern portion of the CWA. The upper low just north of the Great Lakes region will continue to move extremely slowly tonight through Wednesday afternoon. Slightly cooler temperatures are expected on Wednesday. Some drier air should move into the area on Wednesday night, as the front associated with the upper low finally kicks east in earnest.
Some gusty winds will persist with some developing high waves along the eastern shore of Lake Michigan today due to northwesterly winds behind a cold front.
1236 PM CDT Tue Jun 23 2020 Central Illinois is on store for breezy and cooler conditions today. Upper air and moisture channel satellite imagery depicts the upper level trough from the western Great Lakes into northern MO. This feature is rotating to the east, bringing cooler conditions for the region today. A few isolated showers will be possible later this afternoon, with some marginal instability caused by the cooler air aloft. 08z/3am surface analysis shows a cold front pushing across the I-57 corridor. Breezy and cooler conditions will be left in its wake, resulting in afternoon high temperatures remaining in the 70s. Upper troughing will dominate the weather across the Midwest/Ohio River Valley over the next couple of days.
148 PM EDT Tue Jun 23 2020 A cold front will cross the Mid-Atlantic tonight into Wednesday, bringing numerous showers and thunderstorms.
259 PM CDT Tue Jun 23 2020 A vort max is descending south across Minnesota this afternoon on the back end of a mid level trough centered over the Great Lakes. The trough will lift out late week with heights building behind it.
The moist airmass combined with heating and the presence of a lee- side trough will allow isolated to scattered showers and thunderstorms to develop early this afternoon. Radar shows the convection associated with the trough as of 1630Z extending through the western Carolinas into northern GA.
229 PM CDT Tue Jun 23 2020 229 PM CDT The trough and upper low over the western Great Lakes region today will gradually lift north into eastern Canada this week, but not before a couple more small perturbations pivot around the upper low. With slightly cooler air aloft and slight warmer air near the surface allowing for some modest SBCAPE.
141 PM CDT Tue Jun 23 2020 Cyclonic flow aloft continues today with the upper level pattern slowly shifting as ridge builds over the Intermountain West. A few degrees warmer then the previous day will create slightly steeper low level lapse rates. Wednesday will see the high pressure slowly moving into MN. Drier conditions at the surface as the high moves will keep showers to our south.
Instability is quite different from yesterday, while we are still moist in the low levels, we did have a weak cold front come through yesterday, and that brings us cooler highs for today. Wednesday flow will shift more northwesterly and warmer temperatures will be in play.
/issued 957 AM CDT Tue Jun 23 2020/ Skies mostly clear this am as temperatures have moved into the low to mid 80s.
A cold front moving across the region will produce isolated showers or thunderstorms this afternoon.
322 PM EDT Tue Jun 23 2020 Deepening low pressure (998 mb at 19z) exiting northeast out northern Lake Huron this afternoon with gusty westerly winds of 35+ MPH ushering in cooler and drier air to southeast Michigan, allowing surface dew pts to fall into the 50s early this evening, and likely dipping into the upper 40s tomorrow. Impressive for temperatures to significantly fall in the middle of the afternoon during late June without precipitation, indicative of the low level cold advection ongoing. Large upper level low closing off over Ontario tonight (556 DAM at 500 MB), with the trough extending south of the Ohio River.
Where sun breaks occur during peak heating, it's very likely temperatures will jump up into the low to mid 80s. CD Chattanooga Airport, TN 68 85 66 86 68 / 20 30 30 10 10 Knoxville McGhee Tyson Airport, TN 67 84 64 85 66 / 20 30 30 10 10 Oak Ridge, TN 64 84 63 85 65 / 10 20 20 10 10 Tri Cities Airport, TN 62 80 60 81 61 / 30 20 20 10 10.
200 PM EDT Tue Jun 23 2020 Upper air pattern has a 500 mb ridge in the western U. and a deep 500 mb trough across the central U. The trough axis is across the upper Great Lakes this morning and slowly moves east through 12z Thu into the lower Great Lakes.
A weak cold front passes late Tuesday night into Wednesday, with some risk of showers and thunderstorms.
249 PM CDT Tue Jun 23 2020 Considerable cloud cover persists across the region this afternoon on the backside of a large upper trough over the Great Lakes.
Upper level ridge will strengthen over the region today bringing warmer conditions through Wednesday. An impressive plume of moisture off the Pacific NW coast will weaken and move across our region on Wednesday afternoon and evening, bringing a cold front with showers and thunderstorms to the region.
1003 AM CDT Tue Jun 23 2020 Cyclonic flow aloft continues today with the upper level pattern slowly shifting as ridge builds over the Intermountain West. A few degrees warmer then the previous day will create slightly steeper low level lapse rates. Wednesday will see the high pressure slowly moving into MN. Drier conditions at the surface as the high moves will keep showers to our south.
242 PM CDT Tue Jun 23 2020 Cooler conditions can be expected with northwesterly upper level flow behind the deep upper level trough centered over the Great Lakes region. The better threat for typical diurnal convection should shift east of the forecast area for Wednesday afternoon as the upper level trough moves slowly eastward.
337 PM EDT Tue Jun 23 2020 Cooler and less humid conditions will arrive for a few days.
No significant weather expected this evening and overnight as temps will be slightly cooler than last night as clear skies, light wind and H85 temps around 12 to 14C will be over southwest MO tonight. Wednesday high temps will be slighly below normal by a few degrees, in the lower to middle 80s. To the west of this low, ridging edges into the northern plains. On Wednesday night, H85 southwest low level jet increases in central and eastern Kansas with a resultant weak surface warm front.
A ridge over the region today breaks down tomorrow leading to more active weather. These storms will need the lift and natural instability that comes along with the cold front.
Though MUCAPE in northwest North Dakota is on the low side due to surface dew points around 50 and warm low to mid level temperatures, the 20Z NUCAPS pass suggests mid- level lapse rates may be slightly steeper than what guidance is depicting. Deep layer shear increases with the approaching mid-level speed max, though with the low-end instability we will hold off on severe messaging at this time. The short term will be dominated by a large and cool upper low dumbelling around the Great Lakes region.
629 PM CDT Tue Jun 23 2020 Considerable cloud cover persists across the region this afternoon on the backside of a large upper trough over the Great Lakes.
723 PM EDT Tue Jun 23 2020 Cooler and less humid conditions will arrive for a few days.
Latest analysis showing weak cold front moving across the mid-state this afternoon. as long-wave upper trough axis finally moves to our east. On Fri, upper ridge is building but boundary is expected to retreat northward, as well as some deeper moisture, which remains through the weekend. This boundary does look to wash out Sat, and upper ridging will be the main theme into early Mon. On Tues it brings an upper low down toward the MS river valley as upper ridge breaks down. The EURO has also come around to a similar solution, however is not quite as aggressive with southward movement of upper low.
1010 PM EDT Tue Jun 23 2020 A slightly cooler airmass will move into the region, bringing seasonable temperatures.
940 PM EDT Tue Jun 23 2020 A cold front will cross the Mid-Atlantic tonight into Wednesday, bringing numerous showers and thunderstorms.
Deep ridging will continue across the area for the next several days, with little change to the forecast. W/SW flow will be in place for the next few days under high pressure. Ridging continues across the waters with winds shifting to the E/SE late in the week and for the weekend.
Clouds will increase this evening and tonight as an upper trough approaches. Wednesday, a weak cold front will reinforce clouds. bring cooler temperatures, and possibly produce light rain showers, mainly far north.
646 PM CDT Tue Jun 23 2020 229 PM CDT The trough and upper low over the western Great Lakes region today will gradually lift north into eastern Canada this week, but not before a couple more small perturbations pivot around the upper low. With slightly cooler air aloft and slight warmer air near the surface allowing for some modest SBCAPE.
Ridge axis has moved off to the east as an upper level trough approaches the region. Current temps 5-10 degrees warmer than this time yesterday. Upper trough will move across the Pacific northwest Wednesday along with a weak cold front. Partly cloudy and cooler with increasing westerly winds.
706 PM CDT Tue Jun 23 2020 Cooler conditions can be expected with northwesterly upper level flow behind the deep upper level trough centered over the Great Lakes region. The better threat for typical diurnal convection should shift east of the forecast area for Wednesday afternoon as the upper level trough moves slowly eastward.
An impressive surge of cooler and less humid air drives the improving cloud trend which leaves just some pockets of high based convective debris by midnight. Deepening low pressure (998 mb at 19z) exiting northeast out northern Lake Huron this afternoon with gusty westerly winds of 35+ MPH ushering in cooler and drier air to southeast Michigan, allowing surface dew pts to fall into the 50s early this evening, and likely dipping into the upper 40s tomorrow. Impressive for temperatures to significantly fall in the middle of the afternoon during late June without precipitation, indicative of the low level cold advection ongoing. Large upper level low closing off over Ontario tonight (556 DAM at 500 MB), with the trough extending south of the Ohio River.
A ridge of high pressure over the region today will break down Wednesday, leading to a return of active weather. A surface cold front will strengthen as it moves across central Idaho and southwest Montana Wednesday. Widespread cloud cover could reduce atmospheric instability along the cold frontal boundary, which would limit the coverage and strength of thunderstorm activity.
A western Atlantic ridge axis stretches west across south-central Florida. East to southeast breezes are light to gentle, but should freshen a little overnight as Florida cools and the ridge reconstitutes across the peninsula. Overnight lows will struggle to fall into the lower 80s, a welcome reprieve from today's heat.
/issued 245 PM CDT Mon Jul 20 2020/ WV imagery shows an elongated trough covering the srn CONUS from coast to coast, bifurcated over Texas by a tropical disturbance just off the Gulf coast near Houston. An upper trough is forecast to make landfall on the west coast near the Bay Area by midweek, re-centering the ridge over the Gulf Coast states. Isolated chances of convection are still in the mix over the higher terrain each day, mainly due to upslope flow, but chances will increase after midweek as the ridge is shunted east.
950 PM EDT Mon Jul 20 2020 Hot, subtropical high pressure will remain near the region through the middle of the week. The persistent upper-level ridge will transition eastward to the mid-Atlantic coast on Tuesday, lowering high temperatures a degree or two. With the moist, southwesterly flow continuing in the lower levels, it will be another dangerously hot and muggy day across the region.
1009 PM EDT Mon Jul 20 2020 High pressure will persist this week.
743 PM EDT Mon Jul 20 2020 High pressure at the surface and aloft will linger over the Southeast for much of the week ahead, with high heat and humidity, along with isolated thunderstorms.