Aikyam-Lab/Synoptic-Bench huggingface dataset:
The marine layer is being suppressed by strengthening high pressure over the region (profilers show the depth has lowered below 1k ft). Current temperatures are milder compared to 24 hours ago with most locations running about 2-6 degrees warmer. At the lower elevations, readings range from the mid 60s in the Delta to around 80 in some spots across the northern Sacramento Valley. Heat will continue to build over NorCal, peaking today and Saturday, as high pressure builds up from the southeast.
A warm front is now approaching the I-94 corridor in MI while a cold front is between Milwaukee and Chicago. Though, discrete storms toward the warm front would have the greatest tornado potential due to enhanced helicity there. Cooler and not as humid on Friday with dry weather.
High pressure over Arizona will continue to bring very hot conditions into the weekend. Expect cloud cover over southern Apache/Navajo counties to gradually dissipate this evening with warmer than average overnight lows again expected. An elongated and very strong high pressure system stretches along the southern tier of states including Arizona. The flow around the high pressure system is unfavorable for monsoon moisture today, with just some very limited moisture in the White Mountains where isolated showers have developed. Elsewhere, it is mostly sunny with some flat cumulus development over the higher terrain.
Hot and mostly dry weather continues through this weekend as a strong ridge of high pressure dominates the Northern Rockies. Although increased subsidence occurs today, high resolution models still show isolated showers and thunderstorms this afternoon and evening across the higher terrain of Lemhi County and Southwest Montana.
High temps are probably overdone with the amount of cloud cover and rainfall expected, but regardless with dewpoints this high in the mid/upper 70s muggy conditions are expected thus a heat index around 100 will be felt across the board. As for Saturday's daytime highs, they will only be in the mid 80s thanks to the passage of the cold front and the lingering cloud cover and earlier rainfall. High pressure will build in behind the front and help drier air filter in, keeping conditions dry into Saturday night.
The upper-level ridge of high pressure will be moving from the Desert Southwest and strengthening over our forecast area over the next couple of days.
However, we can't completely let down our guard with a cold front to our north positioned to make passage tonight. This combined with the northerly flow into the region will help limit our high temperatures to only the lower 80s. Dewpoints will only be in the low to mid 60s which will feel quite nice compared to what we've experienced of late! Fantastic weather greets us for the beginning of the coming weekend. High pressure overheads allows for plenty of sunshine, lower humidity (dewpoints upper 50s to lower 60s), and below normal temperatures (highs low to mid 80s) on Saturday. Lows both mornings will fall into the lower half of the 60s. The large scale pattern features a ridge centered across the southwest U. and troughing across the eastern U.
(Tonight through Friday night) Key Messages: - Dangerous heat continues Models have backed off the solution of the ridge retreating and beginning to erode Friday into Saturday, instead, models now show the ridge holding strong through Friday night.
1239 AM CDT Fri Jul 21 2023 (This evening through Friday) Subtropical ridging persists across the southwestern U. Moderate baroclinity should exist along the quasi-stationary front tomorrow, and the trend towards cooler temperatures has been maintained for the afternoon prognostication.
Heights will continue to rise today as ridging builds over the Cowboy State. What this spells is a day of warmer temperatures and more sparse coverage of afternoon convection.
202 AM EDT Fri Jul 21 2023 High pressure brings a change to drier and less humid weather today into the weekend. Tonight should continue to be dry, but with high pressure overhead, expecting areas of fog to form. With high pressure building into the region, mainly dry conditions are expected throughout the first half of the weekend amid pleasant temperatures. High temperatures on Saturday will be approximately 5 degrees below normal, translating into upper 70s and low 80s for the lowlands, with mid 60s and 70s for the higher terrain. Low temperatures will also be pleasant, with upper 50s and low 60s for the lowlands, while the higher terrain bottoms out in the low to mid 50s. A ridge that has been parked over the southwestern United States will gradually shift eastward to begin the next work week.
Waves will slowly subside this evening as winds become light with weak high pressure moving across the area. Much of the 00z guidance has dewpoints only in the lower/mid 50s. Opted to make no changes to current 30-40 pops, but if trends continue, the highest pops can eventually be focused near the lake. However, despite a narrow layer of low-mid level moisture advection Friday night, the atmosphere may be too dry for widespread thunderstorm activity with surface dewpoints progged in the lower 60s and afternoon temperatures in the lower and middle 80s.
Convection has already developed over the high terrain, but it may struggle to move over the valleys. With the ridge of high pressure still centered over New Mexico temperatures will again be above normal. The CWA remains entrenched under dry northwest flow on Saturday, with the center of high pressure displaced to the southwest of the Four Corners region.
(Today through Saturday Night) The mid to upper level ridge will continue to shift westward and build over the the Desert SW today into the weekend.
A much cooler day is on tap with highs some 8 to 12 degrees below climo.
(Today and tonight) The upper high currently over the Desert Southwest will push westward today with the resulting upper ridge amplifying across the West Coast. This, along with a slow moving cold front, will help cool highs across the region with upper 80s across the far southern Texas Panhandle to upper 90s across our southern counties. The cold front, as of 2 AM CDT, is beginning to make its way into the northern Texas Panhandle. Convection is still expected to develop across the Rotan Mesa this afternoon and will be aided by upsloping flow due to the cold front. With the upper high being located to our west resulting in a northwesterly steering flow, storms should be able to make it at least into our northwestern zones by this evening before gusting out.
Nice Weekend: A cooler and much drier air mass has filtered into the region in the wake of yesterday's frontal passage.
930 PM PDT Thu Jul 20 2023 Strengthening high pressure over the Great Basin and Southwestern US will bring warming into the weekend, with dangerous heat continuing inland.
CONUS longwave pattern continues to feature strong ridging over the west and mean troughing over the east. The latest in this series, responsible for shower and thunderstorm activity yesterday, will move off to the east, allowing high pressure to briefly build into the area today and Saturday. At the surface, weak low pressure centered near southern Ontario will likewise continue to move east, while weak high pressure over the northern Plains up into the Canadian prairies moves in, bringing drier air and subsidence with it.
1245 AM CDT Fri Jul 21 2023 Persistence continues to be the main forecast tool concerning the heat across our region even though subtle changes will arrive late tomorrow through Saturday in the form of a rare late July cold front.
At the surface, a ridge axis stretched across the Northern Bahamas has slowly been sliding down the Florida Peninsula overnight, and winds along the Florida Reef have dropped a few knots since yesterday morning. The subtropical ridge will slide southward today, dragging the ridge axis over South Florida and the Keys, which will cause winds to decrease.
141 AM MDT Fri Jul 21 2023 Energy moving through the upper level ridge will bring a 10-15% chance of isolated showers to the Absaroka/Beartooths, northeastern Bighorns, and far southeastern Montana this afternoon and evening. Saturday looks to be a quiet weather day as the ridge axis continues to inch east and become more centered over the forecast area. The lows for tonight and tomorrow are expected in the low to mid 60s. Archer Ridge builds over the area this weekend bringing the hottest air of the year so far.
The surface cold front is now south of the region, with high temperatures a little below normal anticipated this afternoon.
421 AM EDT Fri Jul 21 2023 A trough will linger over the region Friday followed by weak high pressure through the weekend.
Otherwise, a cold front will continue to push south through southern Oklahoma into north Texas this morning with a nice cool down in its wake across much of the area today.
101 AM PDT Fri Jul 21 2023 Drier and warmer conditions with typical westerly afternoon breezes will persist through the weekend. High pressure has returned across much of the West bringing warmer, drier, and more stable conditions. Temperatures will soar back towards the triple digit mark for much of the lower valleys with forecast highs between 100-106 degrees for western Nevada. For northeastern CA, highs will be in the upper 90s to 100, while Sierra communities will be in the low 90s. This may contribute to warmer morning lows, but also cooler afternoon highs.
Details: It's a quiet and very nice early morning, as high pressure continues building into the region accompanied by light northerly winds. Regional radar mosaic shows an MCS progressing E/SE across far southern Kansas and northern Oklahoma aided by the right entrance region of an upper level jet atop a surface cold front.
Temperatures fall back into the normal range this weekend as a cold front sags into the Southeast providing support for increased cloud cover and rain chances. Low to mid level troughing is beginning to shift east and winds aloft will weaken through morning.
413 AM EDT Fri Jul 21 2023 High pressure will offer cooler and drier weather today.
109 AM EDT Fri Jul 21 2023 Aviation The cold front has moved through the cwa and the severe wx has moved east. Radar shows a line of showers and thunderstorms accompanying a cold front as it moves across Lower MI.
Over the next few hours, coverage of these storms will increase as a cold front currently situated over the northern portions of the Mid-South moves further into the region.
(Today and tonight) Weak cold front will make an appearance this afternoon across the Big Country, and slide a little farther south tonight.
Otherwise, lows early Fri will again fall mainly into the lower/mid 70s for most spots.
Ensembles still strongly agree in large upper ridging over the western two thirds of the country.
124 AM EDT Fri Jul 21 2023 Showers and thunderstorms are expected this afternoon and evening ahead of a cold front.
(Today through Saturday) The Subtropical Ridge remains over our area today. Subsidence under the Ridge will keep POPs out of the forecast for one more day. The Subtropical Ridge shifts to the west allowing a northwesterly flow aloft to develop over our area on Saturday and bring a "cold" front into our area in the afternoon. This combined with heating and weaker subsidence as the Ridge shifts west should allow for showers and thunderstorms to develop late in the afternoon.
Pressure gradient weakens as a high pressure system builds into the region on Friday. Low level anticyclonic flow becomes a weak trough. Focus for convection could be the lake breeze and further west in closer proximity to thr low level trough axis.
1215 AM CDT Fri Jul 21 2023 (Tonight through Friday night) The very persistent subtropical ridge axis extending from the Desert Southwest into the Northeast Gulf of Mexico will retreat slightly northwest through the short-term period.
Their departure pulls cooler air into Lower Mi in the trailing NW low level wind. Ongoing convection will continue to congeal into a solid line of thunderstorms as cold front progresses through the area late this afternoon with activity sweeping east and southeast of the region during the early evening.
High pressure over Arizona will continue to bring very hot conditions into the weekend. The center of the high pressure has moved far enough northward this morning to allow moisture to increase over north- central and northern Arizona. The high pressure will continue to bring hot to record breaking temperatures across northern Arizona today.
556 AM EDT Fri Jul 21 2023 A trough will linger over the region Friday followed by weak high pressure through the weekend.
743 AM EDT Fri Jul 21 2023 A trough of relatively cool air aloft will combine with a cold front, that was located along the South Shore of Lake Erie early this morning, to bring the chance of a few showers or perhaps an afternoon thunderstorm today, especially over the eastern part of the state. The weekend should be drier, as high pressure builds overhead.
The overhead ridge responsible for this week's hot temperatures will strengthen as we head into the weekend, bringing persistent dangerous temperatures to the region.
As for Saturday's daytime highs, they will only be in the mid 80s thanks to the passage of the cold front and the lingering cloud cover and earlier rainfall. High pressure will build in behind the front and help drier air filter in, keeping conditions dry into Saturday night.
639 AM CDT Fri Jul 21 2023 (Today through Saturday Night) The mid to upper level ridge will continue to shift westward and build over the the Desert SW today into the weekend.
530 AM MDT Fri Jul 21 2023 High pressure remains locked in across the region this morning. The flat, elongated high pressure area continues to push the strongest moisture plume westward over Baja Mexico. Some weaker moisture remains trapped under the high from the Four Corners southward to the Mexican Border. Dry air has begun to infiltrate the Great Basin to the south of the approaching Pacific Northwest trough. Ample sunshine will push temperatures 5-10 degrees above normal values, as the ridge builds over the Intermountain West. The amplitude of the ridge will strengthen Saturday, thus high temperatures on Saturday are expected to add a few degrees to Friday afternoon's highs.
945 AM EDT Fri Jul 21 2023 A trough of relatively cool air aloft will combine with a cold front, that was located along the South Shore of Lake Erie early this morning, to bring the chance of a few showers or perhaps an afternoon thunderstorm today, especially over the eastern part of the state. The weekend should be drier, as high pressure builds overhead.
510 AM MDT Fri Jul 21 2023 Updated Aviation Discussion An upper level ridge of high pressure will strengthen through the upcoming weekend for increasingly hot and mainly dry conditions.
905 AM EDT Fri Jul 21 2023 A trough of low pressure will maintain the risk of some showers and thunderstorms today and tonight. High pressure will then build back into the Great Lakes this weekend, with mainly dry weather outside of a few lingering showers east of Lake Ontario on Saturday. A sharp mid-level trough will be crossing southern Ontario and Quebec today and tonight. However, a surface cold front will move across the region today, and this along with limited instability will produce some additional showers and thunderstorms today. By tonight, expect mainly dry weather across Western NY as trough axis shifts eastward into southern Quebec. A mid level trough axis across southern Quebec on Saturday may support a few lingering showers east of Lake Ontario.
901 AM EDT Fri Jul 21 2023 High pressure will offer cooler and drier weather today.
523 AM CDT Fri Jul 21 2023 (Today through Saturday Night ) H500 ridging will persist to the S/W of the state today which will continue to provide NW flow over the region. A cold front will be making progress into the state from the north and is expected to be near the AR/LA border by tonight.
Low level moisture will take more time to scour out so with the upper level trough axis overhead, instability will redevelop late morning into the early afternoon. High pressure across the region should result in a mostly clear Saturday night with light winds across the region.
In the meantime, upper level ridge will continue to build over the western CONUS with trough over the eastern seaboard. It will interact with the cold front which is currently along the MO/AR border. However with weak lift and enough moisture lingering in the low levels across far southern portions of the forecast area, will see isolated/scattered showers develop through this afternoon. Byrd For the remainder of the forecast period, a majority of the members of the LREF ensemble are in agreement with the upper level ridge sliding east into the region. However, there are a few members indicating that the eastern trough will deepen a bit more, slowing down the progress of the upper level ridge. Thus this would keep us in northwest flow aloft a bit longer and a bit cooler.
With the drier air from the high, most of the cu that develops in the afternoon will struggle to produce anything. Temperatures will be a bit warmer on Saturday as heights rise aloft with upper ridging attempting to transition farther east.
454 AM MDT Fri Jul 21 2023 High pressure remains locked in across the region this morning. The flat, elongated high pressure area continues to push the strongest moisture plume westward over Baja Mexico. Some weaker moisture remains trapped under the high from the Four Corners southward to the Mexican Border. Dry air has begun to infiltrate the Great Basin to the south of the approaching Pacific Northwest trough. Ample sunshine will push temperatures 5-10 degrees above normal values, as the ridge builds over the Intermountain West. The amplitude of the ridge will strengthen Saturday, thus high temperatures on Saturday are expected to add a few degrees to Friday afternoon's highs.
416 AM MDT Fri Jul 21 2023 An upper level ridge of high pressure will strengthen through the upcoming weekend for increasingly hot and mainly dry conditions.
454 AM PDT Fri Jul 21 2023 High pressure causes peak temperatures of the forecast today and tomorrow.
Temperatures will be a bit warmer south of I-40, in the upper 80s to low 90s, where precipitation was more minimal.
925 AM EDT Fri Jul 21 2023 A trough will linger over the region Friday followed by weak high pressure through the weekend.
RMS Energy moving through the upper level ridge will bring a 10-15% chance of isolated showers to the Absaroka/Beartooths, northeastern Bighorns, and far southeastern Montana this afternoon and evening. Saturday looks to be a quiet weather day as the ridge axis continues to inch east and become more centered over the forecast area. The low for tonight and tomorrow are expected in the low to mid 60s. Archer Ridge builds over the area this weekend bringing the hottest air of the year so far.
Surface observations at 945 AM show temperatures in the low 70s across the board with dewpoints in the low 60s - much more pleasant than yesterday in the wake of the front. Guidance suggests we'll jump another 10 degrees or so today before hitting our high temperatures which NBM suggests have only around a 10% chance of reaching 85 degF, thanks to the northerly flow behind the low and mid-high clouds spreading in from the west to inhibit incoming solar radiation. Nice Weekend: A cooler and much drier air mass has filtered into the region in the wake of yesterday's frontal passage.
638 AM EDT Fri Jul 21 2023 A trough of low pressure will maintain the risk of some showers and thunderstorms today and tonight. High pressure will then build back into the Great Lakes this weekend, with mainly dry weather outside of a few lingering showers east of Lake Ontario on Saturday. A sharp mid-level trough will be crossing southern Ontario and Quebec today and tonight. However, a surface cold front will move across the region today, and this along with limited instability will produce some additional showers and thunderstorms today. By tonight, expect mainly dry weather across Western NY as trough axis shifts eastward into southern Quebec. A mid level trough axis across southern Quebec on Saturday may support a few lingering showers east of Lake Ontario.
630 AM CDT Fri Jul 21 2023 (Today through Saturday) The Subtropical Ridge remains over our area today. Subsidence under the Ridge will keep POPs out of the forecast for one more day. The Subtropical Ridge shifts to the west allowing a northwesterly flow aloft to develop over our area on Saturday and bring a "cold" front into our area in the afternoon. This combined with heating and weaker subsidence as the Ridge shifts west should allow for showers and thunderstorms to develop late in the afternoon.
659 AM CDT Fri Jul 21 2023 (Today through Saturday) Upper levels this morning show ridging across much of the southern CONUS and amplified northward along the Rockies. A trough is moving eastward out of the Great Lakes and in to New England. Central Alabama is influenced by the ridge and warm temperatures across the south and northwesterly flow around the trough in the north. Cooler air behind the front will keep highs on Saturday in the mid 80s to lower 90s.
616 AM CDT Fri Jul 21 2023 (Today and tonight) Weak cold front will make an appearance this afternoon across the Big Country, and slide a little farther south tonight.
High pressure causes peak temperatures of the forecast today and tomorrow.
Triple digit heat with highs in the upper 90s to lower 100s are expected over the weekend in many valley locations as high pressure strengthens over the region. Upper level high pressure will continue to build over southern Nevada today with the axis shifting eastward tomorrow. Highs today will be warmer with readings in the 90s to low 100s. By Saturday, model solutions are showing a weak impulse moving northward from the western edge of the ridge.
633 AM EDT Fri Jul 21 2023 High pressure will offer cooler and drier weather today.
604 AM CDT Fri Jul 21 2023 (Today and tonight) The upper high currently over the Desert Southwest will push westward today with the resulting upper ridge amplifying across the West Coast. This, along with a slow moving cold front, will help cool highs across the region with upper 80s across the far southern Texas Panhandle to upper 90s across our southern counties. The cold front, as of 2 AM CDT, is beginning to make its way into the northern Texas Panhandle. Convection is still expected to develop across the Rotan Mesa this afternoon and will be aided by upsloping flow due to the cold front. With the upper high being located to our west resulting in a northwesterly steering flow, storms should be able to make it at least into our northwestern zones by this evening before gusting out.
520 AM EDT Fri Jul 21 2023 A trough of relatively cool air aloft will combine with a cold front, that was located along the South Shore of Lake Erie early this morning, to bring the chance of a few showers or perhaps an afternoon thunderstorm today, especially over the eastern part of the state. The weekend should be drier, as high pressure builds overhead.
The light winds will continue into Saturday, although they will pick up a little bit in magnitude by afternoon as a leeside trough slowly develops near the Front Range leading to a light MSLP gradient. Northwest flow will be continuing aloft with the upper ridge still well to our west, so it is certainly something to watch. After Saturday Night, the summer subtropical ridge will expand its reach across the Rockies and adjacent High Plains.