Aikyam-Lab/Synoptic-Bench huggingface dataset:
518 AM MDT Mon Jul 20 2020 Counter-clockwise flow around the high, centered over the Four Corners, will continue to pump in drier air to the region. The same can't be said down south but even then, coverage and intensity of any convection will be on the low side and very isolated at that.
419 AM CDT Mon Jul 20 2020 For today and tonight, the weakness in the broad upper level ridge of high pressure which covers the southern half of the United States will persist through tonight. This weakness in the upper level ridge is expected to result in northwest flow aloft across the OK and TX Panhandles, which is a more favorable steering flow for brining showers and tstms into our region from the higher terrain of southeast CO and eastern NM.
Expect cooler-than-average conditions to continue through the middle of the week, especially over the interior. These factors, along with the expected development of a weak upper low off the northern California coast by this afternoon, will mean temperatures across the area will remain slightly below normal today. Models agree that the weak upper low developing offshore today will gradually deepen and approach the San Francisco Bay over the next 36 hours.
643 AM EDT Mon Jul 20 2020 Clouds will diminish today as a ridge of high pressure shifts across the Great Lakes region. This high pressure will bring less humid conditions today.
/Today through Tuesday/ A weak disturbance across the northwest Gulf of Mexico on the western periphery of an upper-ridge centered across the southeast CONUS will support scattered showers and thunderstorms along and south of Interstate 20 this afternoon. Due to increased instability across the region, sufficient mixing of the column will take the edge off of the heat with afternoon highs forecast to climb into the lower to middle 90s. An upper-trough across central Texas will again bring another chance of scattered to numerous showers and thunderstorms across the region on Tuesday. Afternoon high temperatures forecast to climb into the lower 90s. Upper-level ridging will hold strong over the course of the workweek across the southeast, with most of our weather continuing to be diurnally driven.
633 AM 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.
104 PM CDT Mon Jul 20 2020 Low pressure system located over the northwestern Gulf of Mexico will continue to produce disorganized SH/TS activity throughout the TAF period.
Once the low clouds depart, the daytime on Tuesday is shaping up to be a fairly nice summer day with fairly light winds. The stalled boundary will be the focus for another round of convection Tuesday night aided by a weak low level jet, with additional development possible along the high plains in eastern CO/western KS which could organize and move into our region overnight.
146 PM PDT Mon Jul 20 2020 Warm weather will prevail through early this week as high pressure weakens.
As the high pressure over SE MT builds, the boundary along the divide will push southwestward into Sweetwater County to bring an end to the west wind by 9-10 pm.
Expect cooler-than-average conditions to continue through the middle of the week, especially over the interior. Extensive low clouds this morning due to onshore flow and a weak low pressure area approaching from the west. Temperatures were several degrees cooler and humidities higher compared to yesterday with the exception of higher peaks above the inversion where conditions were actually a little drier. Models agree that the weak upper low developing offshore today will gradually deepen and approach the San Francisco Bay over the next 36 hours.
131 PM EDT Mon Jul 20 2020 The upper ridge will continue to dominate the weather early this week before weakening later in the week as an upper trough moves into the Ohio Valley and Mid Atlantic region. High pressure aloft remains in control of the weather pattern for The Midlands and CSRA with heat indices between 101 and 106 degrees. The CAMs initiate convection over the higher terrain of SC/NC and move it into the Northern Midlands this evening. Focused the highest POPs across the Northern Midlands. High pressure aloft will dominate the weather pattern during the middle of this week. Subsidence underneath this feature will limit thunderstorm activity to the afternoon and evening hours with initiation in the favored areas of the higher terrain of SC/NC and along the sea breeze front.
The Southeast United States and subsequently our region is still enveloped in a deep upper level ridge.
1221 PM CDT Mon Jul 20 2020 A broad low amplitude trough over Canada will lead to relatively zonal upper-level flow over the Northern Plains for the next 36 hours. Warmer more moist mid-level air resides to the south and southwest of Siouxland, with a relatively cool air mass in place.
As skies clear and winds remain light, radiational cooling will allow temps to fall into the lower 70s by daybreak on Tuesday. Mid level ridging will weaken on Tuesday, as a weak trough moves into the Upper/Mid Mississippi Valley. This trough will quickly swing through the Ohio Valley, with the weakness in the ridge allowing for a greater coverage of showers and thunderstorms during the afternoon.
135 PM EDT Mon Jul 20 2020 VFR flying conditions will prevail through the TAF period as weak high pressure continues to build across the central Great Lakes. Westerly winds around 10 knots, occasionally gusting 15-20 knots at times especially for the southern TAF sites, will gradually shift more northeasterly overnight as the high drifts further eastward towards Georgian Bay. Dewpoints will fall with passage during the day as high pressure moves across the region. Highs today will range from the low 80s north to the upper 80s Detroit area as lower dewpoints will allow for good diurnal warming with plenty solar insulation through some CU and high cirrus. Highs will continue seasonable in the low to mid 80s with dewpoints slowly increasing as surface flow veers more southeasterly.
This means today may feel slightly more humid and the highs will likely be a couple degrees cooler than yesterday.
Possibility remains for lightning fire starts in the western forecast area where min RH values will remain from the low teens into low 20 percents this week coupled with temps into the 80s and 90s.
941 AM PDT Mon Jul 20 2020 High temperatures will begin to cool slightly early in the week as high pressure weakens.
129 PM EDT Mon Jul 20 2020 Clouds will diminish today as a ridge of high pressure shifts across the Great Lakes region. This high pressure will bring less humid conditions today.
But in some areas there could be significant rainfall amounts as the activity lines up right over the area along the boundary, and given the high amount of instability. The upper level flow pattern during the period will be influenced by an upper high from the southern Plains into the Southeast, which will keep the bulk of the stronger wind flow across the northern third of the U.
With this cooler air aloft we will see scattered showers and thunderstorms continue across eastern Montana through this evening before tapering off around sunset. Weak ridging begins to build in Tuesday and will then intensify as we head into the middle of the week.
Overnight lows in the lower to mid 60s are expected.
1230 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.
Expect cooler-than-average conditions to continue through the middle of the week with even a little drizzle near the ocean at times. Warmer conditions will slowly return later in the week. A few things are at play for the slightly cooler temperatures. Additionally, the ridge of high pressure over the region has shifted eastward. In its wake, an upper low offshore is deepening and slowly tracking eastward. Northwest winds, onshore flow and approaching upper low led to the slight cool down today. The upstream upper low will continue to move over the region through midweek. Given the lowering 500mb heights would not be surprised to see the marine layer depth actually deepen over the next few days. As the upper low moves eastward flow aloft will become more southerly.
1200 PM MDT Mon Jul 20 2020 Counter-clockwise flow around the high, centered over the Four Corners, will continue to pump in drier air to the region. The same can't be said down south but even then, coverage and intensity of any convection will be on the low side and very isolated at that.
318 PM EDT Mon Jul 20 2020 High pressure will persist this week. Seeing a bit more convective coverage this afternoon compared to yesterday, although mostly outside of our forecast area closer to the Midlands near the lee side trough.
0" with the greatest moisture depth over the Victoria Crossroads and the inverted trough to our west. A bit warmer temperatures Tuesday will induce possible SPS conditions during the afternoon, with heat indices approaching 107.
We could see a few sprinkles toward the IL border, but we are mainly just being affected by the high clouds which will linger through much of the night. The effective warm front will remain to our south. An upper trough will track across the MN/Canada border Tue morning and continue to weaken as it reaches Lake Superior in the afternoon and evening. These two features will nudge the warm front into southern WI and we could see a round of showers and thunderstorms during the afternoon and evening hours. Clouds and afternoon precip chances will limit our heating despite where the warm front lies, so highs will be very similar to today.
Chances for showers and storms increase mid-week before high pressure and seasonable temperature arrive for the weekend. Ultimately, any noteworthy convection today will be along and south of the frontal boundary, with greatest chance in nrn WV into the ridges of WV/MD, where best moisture and convergence will be focused. Deep-layer quasi-zonal flow will be in place Wed as the region remains on the nrn side of sern-CONUS high pressure and to the south of the nrn-stream mid-level jet. With increased cloud cover and the prior day's widespread showers and storms, temperature on Thu will be considerably cooler than prior days. Troughing is expected to persist across the Great Lakes late in the week. High pressure will then build across the region Fri/Sat downstream of a mid-level ridge. VFR will prevail into tomorrow morning despite high pressure eroding across the region.
This feature will maintain dry weather into Tuesday evening with very comfortable temperatures in the lower 80s (upper 70s Thumb) and not particularly humid conditions. Southwesterly flow in advance of this wave will push a warm front northeast into the area overnight Tuesday night with shower/thunderstorm chances increasing with time as lift from this front increases during the course of the night.
A low pressure feature over the NW Gulf is expected to move onshore into the Coastal Bend tonight.
Elsewhere, additional storms will be seen along the higher terrain near the Virginia border, with another cluster off the Cumberland Plateau into the Lake Cumberland region.
SHORT TERM (Now through Tuesday Night): The latest 500 mb pattern shows a general weakness in the ridge pattern over the state as a weak disturbance concentrates along the upper Texas coastline. The NHC is tracking this disturbance, and has given a low chance for tropical cyclone formation. At the surface, sub-tropical high pressure centered near Bermuda continues to stretch from the western Atlantic into the eastern Gulf of Mexico.
The focusing mechanism here would be a weak boundary that is attendant to low pressure that is slated to propagate across northern Minnesota through the day Tuesday. Upper ridge still driver of precip as overall pattern looks to feature numerous impulses that propagate across its northern edge. Fairly simplistic in that where there is clouds/precip during the afternoon, temperatures will be comparably cooler than where there is sunshine.
Clear skies over the region this morning with upper ridge and dry northwest flow aloft. Upper level trough approaching the Pacific northwest Tuesday.
Convection along a diffuse warm front was oriented north- south and moving through central North Dakota. However the "destabilizing" portion of that statement will be the big fly in the ointment following this morning's convection and the less than ideal surface dew points in the low to upper 50s currently in place.
By Tuesday, the disturbance is expected to continue moving inland across Texas, with the highest chances of showers and thunderstorms across all of SE TX and W/SW LA, still healthy chances for the remainder of the area.
Convective cloud debris and the weakening influence of the departing upper ridge to taper temperatures on Tuesday back toward climatological norms.
The mid-level ridging to the north does break further on Thu as troughing slides across the Great Lakes and down toward the mid Atlc coast, but the ridging is reinforced by high pressure building from the central CONUS toward the Ohio/Tennessee Valleys into the weekend. The persistent pattern continues with the Atlantic ridge axis north of the local waters.
213 PM MDT Mon Jul 20 2020 Water vapor shows robust upper trof crossing the Northern Plains.
153 PM MDT Mon Jul 20 2020 A cold front moved through the forecast area this morning, with northwest winds and below seasonal temperatures today. Heights build for Tuesday and warmer temperatures will take over. Model clusters were in decent agreement with a SW flow over the area ahead of a western split trough until Monday, when solutions were all over the place.
The upper level ridge continues to be the main features in the near-term forecast. The ridge is forecast to flatten somewhat today as an upper level trough passes to the north across the Great Lakes and Ohio River Valley. At the surface, there is a cold front to the north stretching across the Great Lakes and Ohio River Valley. With elevated upper level heights, temperatures will once again top out in the low to mid 90s for most locations. Current visible satellite imagery indicates some cu developing across the higher terrain long the TN/NC line and across the Cumberland Plateau. Latest CAM guidance is not very impressive with the coverage of showers/storms this afternoon with best chances along the higher elevations.
/Tonight through Tuesday Night/ Weak flow aloft continues, as the upper ridge remains centered over the sern CONUS and a trof axis lingers across the Central Plains. Cloud cover/convection will keep our temps across much of the region cooler than in the past several days, especially where coverage is greater.
344 PM CDT Mon Jul 20 2020 High pressure will continue to dominate the weather pattern this evening, leading to dry weather and calm winds. MUCAPE values are getting closer to 2000 J/kg, but this is assuming that the stratus associated with the low is able to clear out in the afternoon to coincide with peak daytime heating.
232 PM CDT Mon Jul 20 2020 High pressure is to continue to dominate the area with slightly lower heights, around 580 decameters.
239 PM EDT Mon Jul 20 2020 The upper ridge will continue to dominate the weather early this week before weakening later in the week as an upper trough moves into the Ohio Valley and Mid Atlantic region. High pressure aloft remains in control of the weather pattern for The Midlands and CSRA with heat indices between 101 and 106 degrees. The CAMs initiate convection over the higher terrain of SC/NC and move it into the Northern Midlands this evening. Focused the highest POPs across the Northern Midlands. High pressure aloft will dominate the weather pattern during the middle of this week. Subsidence underneath this feature will limit thunderstorm activity to the afternoon and evening hours with initiation in the favored areas of the higher terrain of SC/NC and along the sea breeze front.
337 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.
309 PM EDT Mon Jul 20 2020 Dry and more pleasant, seasonable weather returns tonight into Tuesday night as high pressure settles south across the area.
322 PM EDT Mon Jul 20 2020 A subtropical ridge over the southern half of the CONUS and a broad Bermuda High will continue to provide PA with hot and humid weather for the next few days.
In the meantime, before then, WPC has analyzed a weak warm front that bisects the area, and a few spotty thundershowers can't be ruled out to the in the vicinity and north of this boundary through the evening as the low level jet develops.
/Issued 720 AM EDT Mon Jul 20 2020/ General pattern remains largely unchanged across the region today through tomorrow as flat upper ridging persists. Mid and upper level ridge axis holds in a little longer a shunts any potential frontal incursions well to the north.
A warm front was located south of the area while an upper level wave was found across the N CONUS. As the MCV approaches the area, deep layer shear will increase and the proximity of the warm front will also lead to llvl shear, especially across the highway 20 corridor. However, with lower CAPE across this area the best chance for storms may be further south with the lower deep layer shear.
As the upper low translates eastward shower/thunder chances will end from from west to east on Tuesday. We will go from high temperatures in the 70s early this week up to the low to mid 90s by the end of the week.
As the trough moves across the area on Tuesday we expect showers and thunderstorms to continue. We remain in a marginal risk for severe storms on Tuesday, which seems appropriate given the high shear/low CAPE scenario conditional on diurnal destabilization. Fairly extensive stratus cloud cover will be the limiting factor to instability, however, but models do indicate some scattering of the low clouds during the afternoon hours which could instigate stronger storms.
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.
An Excessive Heat Warning remains in effect through Monday for the lower Grand Canyon. Cooler temperatures beginning Tuesday will last through the weekend. The high resolution models have picked up on these showers and have them continue through the morning. The mid- level trough has eroded the cap enough to generate lightning in the Las Vegas area.
342 PM CDT Mon Jul 20 2020 An upper trough in the northern stream will push a disturbance through the area tonight. A weak cold front, and likely outflow boundaries from thunderstorms will also move through. Slightly warmer in the mid 80s, with upper 80s far southwest.
Upper ridging will continue to slowly shift east with weak westerlies prevailing across the Mid-South through at least mid- week.
Lows overnight will again be in the lower 70s, with highs in the lower to mid 90s Tuesday.
Elsewhere, additional storms will be seen along the higher terrain near the Virginia border, with another cluster off the Cumberland Plateau into the Lake Cumberland region. Upper level ridging will be present over the southeast CONUS at the start of the period, while a trough ripples eastward through the prevailing westerlies across the northern tier of the CONUS. It will temporarily suppress the aforementioned ridging, and allow a surface cold front to approach and possibly move through the local area.
325 PM EDT Mon Jul 20 2020 Lower tropospheric ridging centered near Bermuda stretches west across the southeastern United States. Water vapor imagery highlights a stretched mid- upper tropospheric trough from north of the northern Bahamas, southwest to the Yucatan Peninsula.
329 PM EDT Mon Jul 20 2020 A subtropical ridge over the southern half of the CONUS and a broad Bermuda High will continue to provide PA with hot and humid weather for the next few days.
Additional isolated convection was also occurring this afternoon within the higher terrain of Southeast Oklahoma from the instability associated with daytime heating. dewpoints were upper 60s to upper 70s with the highest values pooling near the outflow boundary across Northeast Oklahoma. low temps in the low to mid 70s are expected. with the ridge of high pressure retreating to the southeast. highs temps look to be slightly cooler compared to previous days.
Once the wave moves west and away into the Gulf on Tue night, the Keys will continue to be on the southern periphery of a strong, deep-layer high pressure ridge extending from near Bermuda westward across the Southeast States.
732 PM EDT Mon Jul 20 2020 The upper ridge will continue to dominate the weather early this week before weakening later in the week as an upper trough moves into the Ohio Valley and Mid Atlantic region. Overnight lows will be in the low to mid 70s. High pressure aloft will dominate the weather pattern during the middle of this week. Subsidence underneath this feature will limit thunderstorm activity to the afternoon and evening hours with initiation in the favored areas of the higher terrain of SC/NC and along the sea breeze front.
Water vapor shows robust upper trof crossing the Northern Plains.
715 PM EDT Mon Jul 20 2020 The upper ridge will continue to dominate the weather early this week before weakening later in the week as an upper trough moves into the Ohio Valley and Mid Atlantic region. Overnight lows will be in the low to mid 70s. High pressure aloft will dominate the weather pattern during the middle of this week. Subsidence underneath this feature will limit thunderstorm activity to the afternoon and evening hours with initiation in the favored areas of the higher terrain of SC/NC and along the sea breeze front.
724 PM EDT Mon Jul 20 2020 High pressure will persist this week. Deep layered ridging will prevail across the entire forecast area, resulting in large scale subsidence and putting a damper on any lingering isolated showers/t-storms after about 9 pm.
Outside of that, rain and storms have ended elsewhere in the region and we can expect partly cloudy skies with lows in the lower to mid 70s. Active troughiness with deep moisture around the periphery of the persistent mid level ridge over the MidSouth will continue to weaken the ridge through tomorrow.
717 PM EDT Mon Jul 20 2020 High pressure will persist this week. Deep layered ridging will prevail across the entire forecast area, resulting in large scale subsidence and putting a damper on any lingering isolated showers/t-storms after about 9 pm.
Clear skies and generally light winds to prevail through the evening and much of tomorrow under E-W elongated ridge centered off the coast. Tuesday likely to be our warmest day under the ridge, with a good swath of the lower Columbia Basin in the triple digits and mountains in the mid to upper 80s. From broader view, weak disturbance passes to our N tomorrow before a more potent trough phases somewhat with California low Wed and sweeps over the region by late Thu.
818 PM EDT Mon Jul 20 2020 A subtropical ridge over the southern half of the CONUS and a broad Bermuda High will continue to provide PA with hot and humid weather for the next few days.
644 PM CDT Mon Jul 20 2020 High pressure will continue to dominate the weather pattern this evening, leading to dry weather and calm winds. MUCAPE values are getting closer to 2000 J/kg, but this is assuming that the stratus associated with the low is able to clear out in the afternoon to coincide with peak daytime heating.