Aikyam-Lab/Synoptic-Bench huggingface dataset:
401 AM MDT Mon Jul 27 2020 An upper level ridge of high pressure will reside over the northern Rockies this week. For this afternoon, expect some monsoonal moisture to start to work its way up into Southwest MT, as upper level disturbances rotate around the Great Basin area of high pressure. As a result, afternoon temperatures over Southwest MT will be a touch cooler on Tue, while hot temperatures continue over North Central MT.
1036 AM EDT Mon Jul 27 2020 The area will remain between high pressure to the east and low pressure inland through the week. Lows should bottom out in the low to mid 70s for most locations, with areas at the beaches hovering around 80.
High pressure aloft will strengthen over the interior west beginning midweek, bringing hot and dry conditions through the end of the week.
417 AM CDT Mon Jul 27 2020 Scattered showers and storms are developing and moving through northeast and central MO and west central IL early this morning south of a cold front extending from WI southwest through southern portions of Nebraska and Iowa. This cold front will drop southward through our forecast area today and tonight as the upper level trough over the Northern Plains deepens as it moves eastward through the Great Lakes region. By 12Z Tuesday the cold front should be near the MO and AR border with slightly below normal low temperatures for northeast and central MO and west central IL tonight along with much lower humidity/surface dew points.
Upper level heights will continue to decrease today as a ridge of high pressure breaks down due to a trough moving off the northern plains. A cold front attendant the upper level trough remains well to the north today. Thunderstorms should begin to fire over the next couple of hours mainly off the Plateau area and in the higher terrain of the southern Appalachians. DGS Chattanooga Airport, TN 93 72 92 73 87 / 40 20 60 30 70 Knoxville McGhee Tyson Airport, TN 92 70 90 72 87 / 50 20 70 40 70 Oak Ridge, TN 91 70 89 71 87 / 50 20 60 40 60 Tri Cities Airport, TN 89 67 87 68 86 / 40 30 60 40 60.
756 AM EDT Mon Jul 27 2020 As the low level ridge axis sinks south into south central Florida today the rather light and variable winds early this morning will become southerly late this morning and then southwesterly this afternoon. High pressure will hold over the waters through the period with rather benign conditions across the eastern Gulf. /issued 302 AM EDT Mon Jul 27 2020/ An U/L ridge will hold over the Gulf of Mexico and Florida through the period creating broad large scale subsidence across the region.
609 AM CDT Mon Jul 27 2020 A pleasant start to the work week today, with high pressure working across the Tri-State area. Light and variable winds continue through the day, thanks to the aforementioned high pressure. However, some areas along and near the Buffalo Ridge could see some gusts around 20 knots this afternoon with slightly better mixing potential.
High pressure building over the desert southwest by the midweek will bring much warmer temperatures and a downturn in monsoon activity. A high amplitude ridge will begin building in across the southwest on Tuesday.
423 AM MDT Mon Jul 27 2020 Weak ridging will be building across central WY today, which will continue to produce warm and dry conditions for the central third of the state. Temperatures Tuesday will be noticeably cooler and more comfortable for all but the lower elevations of Johnson County.
511 AM EDT Mon Jul 27 2020 Chances for showers and thunderstorms return this afternoon and evening with a crossing cold front. Slightly cooler temperatures are expected after today, with periodic rain chances through the week. Today signals a pattern shift as the east US ridging flattens and is replaced by upper troughing across the Great Lakes. The main concern for the near term will be an advancing sfc cold front, expected to cross the Upper Ohio Valley tonight through Tuesday.
1240 PM CDT Mon Jul 27 2020 Cooler and less humid conditions return to the Northland today and Tuesday. However, there will be some diurnally-driven scattered showers and isolated thunderstorms as a large upper-level trough slowly traverses the region. An upper-level low associated with this trough will help bring a few embedded impulses of positive vorticity advection this afternoon and again late Tuesday morning into afternoon. There will be some lingering mid-level troughing over the region, which may keep some cloud cover over the Minnesota Arrowhead, but chances of showers should diminish Tuesday evening.
Tomorrow will be similar conditions with the higher chances for rain south and east of I-35.
218 PM CDT Mon Jul 27 2020 Quiet weather with high pressure continues through the short term forecast period. With a ridge continuing to build in, temperatures should continue to increase tomorrow (especially west).
231 PM CDT Mon Jul 27 2020 Scattered showers and thunderstorms already going up along a cold front that extends from Clovis to Tulia to Wheeler, particularly on the eastern end of that line in an area that got quite a bit warmer than forecast. The combination of temperatures of 95-100 and dew point temperatures in the low to mid 60s is resulting in a band of surface-based CAPE of around 1500 J/kg and weak inhibition that these storms are developing in. The cold front is expected to undergo frontolysis with a return to a general southerly low level flow across the area. Strengthening of the mid- and upper-level ridge across the Desert Southwest will veer winds aloft, resulting in west-to-northwesterly flow above the boundary-layer while southerly flow persists beneath.
215 PM EDT Mon Jul 27 2020 The area will remain between high pressure to the east and low pressure inland through the week. Lows should bottom out in the low to mid 70s for most locations, with areas at the beaches hovering around 80.
1150 AM EDT Mon Jul 27 2020 Showers and thunderstorms return this afternoon and evening with a crossing cold front. Slightly cooler temperatures are expected after Monday, with periodic rain chances through the week. Warm and moist advection is occurring ahead of a cold frontal passage. More widespread coverage of thunderstorms is expected later this afternoon and evening when upper frontogenesis and jet divergence accompany a cold frontal passage. As the cold front propagates to the SE, some diurnal enhancement of thunderstorms along the front is expected Tuesday afternoon in West Virginia and Maryland counties. Temperature on Tuesday will be much more comfortable after cold frontal passage.
148 PM MDT Mon Jul 27 2020 500mb RAP analysis and satellite imagery showed a trough spanning the northern Plains and Upper Midwest early this morning. Behind the trough, ridging continued over the Four Corners region to the Pacific Northwest. This placed the region under northwest flow aloft, with an area of high pressure across western New Mexico. Northwest flow persists on Monday with the upper trough sliding east and high pressure over the southern Plains and Desert Southwest. High temperatures will be slightly cooler, in the upper 70s to low 80s.
Will maintain scattered pops into early evening as some convergence on the northern edge of better focus over the northern Ohio Valley yields some activity perhaps as far north as I-94 and additional focus works into mainly northern areas (I-69 north) with synoptic scale cold front. A big pattern change occurs as upper troughing becomes established from Tuesday into the end of the week as an upper low settles into southern Ontario/northern Great Lakes and then gradually shifts to Quebec with time. This will bring notably lower humidity levels as well as high temperatures generally ranging in the lower 80s for the remainder of the forecast.
230 PM EDT Mon Jul 27 2020 An upper ridge will suppress widespread convection through tonight. Broad upper ridging will weaken over the region tonight as it shifts eastward with an upper trough moving into the Great Lakes region. Overnight lows in the lower 70s.
Northwest flow will dominate as we reside between a southeastward meandering upper low over Ontario and upper ridging across the northern Plains.
1053 AM MDT Mon Jul 27 2020 Weak ridging will be building across central WY today, which will continue to produce warm and dry conditions for the central third of the state. Temperatures Tuesday will be noticeably cooler and more comfortable for all but the lower elevations of Johnson County.
228 PM MDT Mon Jul 27 2020 Upper ridging continues across much of the western CONUS, with quiet and weak northwest flow across the CWA. A broad upper low is sitting across the central to southern Pac coast. The upper low will drift northeastward overnight and through Tuesday, reaching the region by the afternoon.
Otherwise, partly to mostly cloudy skies can be expected during the overnight hours, as lows fall into the low and middle 70s. The once cutoff low aloft over the region will steadily weaken during the period, thus eventually becoming an open trough late in the day.
Otherwise, we are watching the Panhandle and Oklahoma where a cold front has sagged to south of Amarillo. Decent remnant cloud cover will help slow the temperature climb for Tuesday with highs mainly in the low to mid 90s.
Developing SHRA may hang over KHRO for much of the night tonight as a weak cold front drops into AR from MO. The upper lvl flow pattern acrs the Mid-South wl cont to transition to NWLY in the coming days, as upper ridging gradually blds acrs the WRN States.
247 PM CDT Mon Jul 27 2020 Lingering showers and thunderstorms will diminish this evening, as a cold front pushes south across our area. The cold front is making some headway into the northwest corner of the CWA now, with dew points dropping from the low 70s to the mid 60s between Galesburg and Moline. With the drier air arriving, lows in the lower 60s are expected over much of central Illinois. While temperatures reach the mid 80s on Tuesday, the lower dew points will make it feel much more comfortable. Longer range models continue to build the upper ridge just west of the Rockies late this week, keeping more of a northwest flow feeding the Midwest states.
248 PM EDT Mon Jul 27 2020 Showers and thunderstorms have returned for tonight and early tomorrow with a passing cold front. Slightly cooler temperature and periodic rain chance can be expected for the rest of the week. Warm and moist advection is occurring ahead of a cold frontal passage. More widespread coverage of thunderstorms is expected later this afternoon and evening when upper frontogenesis and jet divergence accompany a cold frontal passage. As the cold front propagates to the SE, some diurnal enhancement of thunderstorms along the front is expected Tuesday afternoon in West Virginia and Maryland counties. Temperature on Tuesday will be much more comfortable after cold frontal passage.
235 PM MDT Mon Jul 27 2020 Early afternoon VIS imagery showed CU building over the higher terrain. Showers will increase in coverage west of the Laramie Range Tuesday morning, becoming more numerous with scattered thunderstorms during the afternoon as copious moisture streams northward ahead of an approaching upper trough from the northwest.
High pressure will continue over the region for another very hot day and slightly warmer temperatures overnight.
337 PM EDT Mon Jul 27 2020 The area will remain between high pressure to the east and low pressure inland through the week. Some more showers and storms are possible near the coast and over the Atlantic late closer to the upper low where instability will be better. Weak upper level disturbances will be moving across the area during this time period as strong upper level ridging remains in place across much of the central and western Atlantic and an upper level low remains anchored north of the Great Lakes.
A longwave trough is deepening over the Northern Plains, Great Lakes and Midwest setting up Northwest flow across the Midsouth. Most of the area should warm another degree or two this afternoon resulting in highs in the low to middle 90s. A rare midsummer cold front is pushing through Missouri and is expected to stall tonight just before reaching the Midsouth. Outflow from ongoing showers and thunderstorms across Northern portions of the Midsouth may eventually become the effective front by midweek, masking any trace of the original cold front.
123 PM PDT Mon Jul 27 2020 The influence of the weak trough on our weather will dwindle over the next few days, as the stage is set for building high pressure and rising temperatures through late week.
334 PM EDT Mon Jul 27 2020 Low level ridge axis will remain across south central Florida through Tuesday with the south to southwest flow persisting. During midweek the low level ridge drifts north into central Florida with a rather light flow allowing the east and west coast sea breezes to develop and move well inland with scattered showers and thunderstorms developing mainly during the afternoon and evening.
As we move into Tuesday, high pressure with the ridge axis across the Florida peninsula. Temperatures will be in the low to mid 90s once again with heat indices into the triple digits.
Primary feature of note is a mid-level trough over the Lower MS Valley which is producing extensive cloud cover and rain showers over southern Louisiana and Mississippi. As the trough slowly lifts northward through tomorrow, deep moisture will stream into Central AL from the Gulf. 2 inch range tomorrow as the trough begins to lift into northern Mississippi.
For tonight into Tuesday, a large Canadian low with an associated trough over the Great Lakes will move very little while an upper level ridge builds over the Rockies.
Highs Tuesday and through the end of the week will be in the low to mid 80s.
Clear skies, mild temperatures and light winds will dominate today as high pressure moves in. High pressure continues through the short term forecast period. Broad closed cyclone will slowly shift into southern Ontario with mid-level heights beginning to rise over the Northern Plains as an upstream ridge builds. With a ridge building, temperatures should be slightly warmer than yesterday in the west with highs in upper 70s north to upper 80s southwest. Lows going into Tuesday morning should again be mostly in the low to mid 50s with a few spots reaching the upper 40s possible. Conditions stay dry on Tuesday during the day as the aforementioned ridge drifts over the region.
A sfc cold front over east central KS into central MO will shift south into our area.
Montana is under the influence of an upper level ridge that is flattening as monsoonal moisture drifts into it from the southwest. Tuesday the dissipating ridge axis reaches the Montana Dakota border with allows deeper moisture to move into southwest and south central Montana and Sheridan County Wyoming. Overnight Tuesday night an upper level low begins to form over northern Wyoming and this develops a deep southeasterly flow aloft into southeast Montana.
An upper low centered over the lower Mississippi River valley gradually devolves to an upper level weakness while an upper ridge remains over the northeastern Gulf. Have also lowered daytime highs mainly over southeast Mississippi into the far western Florida panhandle where the high coverage of rain and abundant cloud cover will make it difficult for temperatures to climb much. Lows tonight range from the lower 70s inland to the mid/upper 70s at the coast.
We will experience above-average high temperatures this afternoon as a ridge of high pressure moves east from its current position over Northern Rockies.
1216 PM CDT Mon Jul 27 2020 A pleasant start to the work week today, with high pressure working across the Tri-State area. Light and variable winds continue through the day, thanks to the aforementioned high pressure. However, some areas along and near the Buffalo Ridge could see some gusts around 20 knots this afternoon with slightly better mixing potential.
A cold front and trough of low pressure will approach the area by midweek and linger over the region into the weekend. Very little in way of convection with continued strong ridging in place. Then, as a large upper trough and surface front move into the region, and a period of unsettled weather is expected from mid week into the weekend.
Weak upper ridge currently breaking down, as weak upper trough approaches. This weak upper trough/wave expected to swing across the area later tonight, and that will bring a weak frontal boundary down into our north by early Tue. Behind this passing upper wave on Wed, there is a bit of very weak ridging and that may bring a brief period of ML/UL drying early in the day, but that will be very short-lived. Secondary jet max looks to spin up SFC/LL low ahead of a trough axis late Fri night, and those lows will pass northwest/north of the mid-state through Sun.
Northwest flow aloft will persist through the majority of the week between upper ridging over the Intermountain West and upper troughing/Rex block over the Hudson Bay and Great Lakes region. Temperatures will be seasonable, ie highs in the low to mid 80s and lows in the mid to upper 50s.
As of 15z, temperatures have warmed into the low to mid 80s, and expect a similar day to yesterday with the mercury peaking in the low to mid 90s for most valley locations.
221 PM EDT Mon Jul 27 2020 Upper air pattern consists of a 500 mb trough over the upper Great Lakes this morning with a closed low over northern Ontario and both digs to the southeast this forecast period.
borsum It's been a rare cloudless night across the state of Montana as prominent upper ridging continues to build into the area, which combined with dry low-levels is helping to produce another cool night. Going into today, ridging will persist. Temperatures will rise back into the lower 90s, and relatively low dewpoints possibly dropping into the upper 30 will bring about humidities in the mid teens by the late afternoon.
A weak area of low pressure along the LA/MS coast will slowly begin to lift to the northeast, bringing with it a deeper, tropical air mass into the Mid South and Tennessee Valley regions. Expect a redevelopment of scattered showers and thunderstorms by late Tuesday morning which will become more numerous in nature by the afternoon as moisture and lift from the aforementioned low pressure system increases.
The orientation/location of convection currently in Southwest KS and Southeast CO appears to be best correlated with a weak H7 trough/wind shift progressing southward into TX/OK.
1127 AM MDT Mon Jul 27 2020 500mb RAP analysis and satellite imagery showed a trough spanning the northern Plains and Upper Midwest early this morning. Behind the trough, ridging continued over the Four Corners region to the Pacific Northwest. This placed the region under northwest flow aloft, with an area of high pressure across western New Mexico. Northwest flow persists on Monday with the upper trough sliding east and high pressure over the southern Plains and Desert Southwest. High temperatures will be slightly cooler, in the upper 70s to low 80s.
At 333 PM, in the wake of yesterdays cold front, the region was enjoying fair skies and mild temperatures.
241 PM CDT Mon Jul 27 2020 18Z surface data has the main cold front from southeast lower Michigan into central Kansas with high pressure in the Plains. Decreasing humidity and quiet conditions will be seen late this afternoon and tonight as high pressure moves through the area.
A longwave trough is deepening over the Northern Plains, Great Lakes and Midwest setting up Northwest Flow across the Midsouth. Current temperatures are in the middle to upper 80s with highs expected in the low 90s. Will maintain slight chance to low chance pops this afternoon with the highest chance in North Mississippi just before sunset. Expect one more day of a typical summertime weather before a cold front starts to work its way into the region Tuesday.
To start the extended, deep upper level low pressure sits over southeastern Canada with upper level high pressure over the Desert Southwest.
122 PM CDT Mon Jul 27 2020 Diurnal CU field is increasing north of I-94 this afternoon as an upper low continues to spin north of Minnesota. Elsewhere, it's sunny and in the lower 80s. An area of troughing over eastern Canada and the Great Lakes will remain in place as ridging shifts back to the desert southwest.
Forecast Confidence Medium Upper low will slowly slide through Quebec tonight and tomorrow keeping Wisconsin in northwest flow. 5 and the storm motion is parallel to the front, in addition to the low level jet impinging flow into the front, so heavy downpours are expected with any storms. There will be north winds across northern/central Wisconsin due to low pressure over southeast Canada, high pressure sagging south into Minnesota and high pressure to our south.
252 PM MDT Mon Jul 27 2020 Weak ridging will be across central WY this afternoon, which will continue to produce warm and dry conditions for the central third of the state. Temperatures Tuesday will be noticeably cooler and more comfortable for all but the lower elevations of Johnson County.
325 PM EDT Mon Jul 27 2020 The afternoon surface analysis shows a cold front pushing into portions of the Ohio Valley and a pre-frontal trough axis ahead of this. These features will be the focus for convection over the period as it sags into the lower Ohio Valley and heights fall with a mid level trough.
A few storms may be severe especially early in the evening when instability is expected to be the highest.
322 PM EDT Mon Jul 27 2020 An upper ridge will suppress widespread convection through tonight. Broad upper ridging will weaken over the region tonight as it shifts eastward with an upper trough moving into the Great Lakes region. Overnight lows in the lower 70s.
Temperatures will fall into the low to mid 70s tonight. Ridge axis of high pressure over the west Atlantic will remain near Lake Okeechobee into tomorrow, with a generally weak S/SW wind flow persisting across the region. Highs will reach the low 90s for most locations before convection and cloud cover increases into mid to late afternoon.
Meanwhile, a cold front dropping south and east from the Ohio River Valley is expected to stall near the Tennessee/Kentucky border, which will provide a focus for showers and thunderstorms across the northern portion of the forecast area.
This was embedded in a large area of upper level low pressure over northern parts of Manitoba and Ontario. We expect lows in the lower to middle fifties for most areas but some mid to upper forties will occur across the Iron Range into the Borderland.
213 PM CDT Mon Jul 27 2020 GOES Visible this afternoon showing mostly sunny skies across the area thanks to high pressure building in from the Northern Plains. Cooler and a bit less humid today as well with temperatures at 1 pm in the mid-70s to lower 80s and dewpoints in the upper 50s to lower 60s. This was within a broader/longwave trough carved out across the Dakotas/Upper Mississippi River valley/Great Lakes regions. This trough along with mid-level frontogenesis, close proximity to right entrance region of 300mb jet and 850-500mb MUCAPE in the 500-1100J/kg range, will combine to produce scattered showers and storms over the area -mainly in the afternoon during peak heating.
MORNING DISCUSSION: Synoptic Setup: Forecast begins with a hot high pressure ridge developing into a large heart dome ridge over the western third of the CONUS. An extension of this ridge juts north into southern British Columbia and Alberta. On either side, sit large troughs over Manitoba and the Alaskan Panhandle. Northeast Montana lies in between air masses on the warmer side of northwest flow aloft. Today through Tuesday: Ridge pressing in from the west will generate hot dry conditions as the ridge axis topples east across the region.