Aikyam-Lab/Synoptic-Bench huggingface dataset:
1) A pleasant day is in store for our area today, with sunshine and dry conditions expected After the ongoing showers and thunderstorms across our far southern and northern forecast area diminishes early this morning, an area of high pressure and mid-level ridging will build into the Upper Midwest region. This will lead to a pretty pleasant day, with plenty of sunshine due to dry air and high temperatures warming to the lower to middle 80s. Despite some deep boundary layer mixing to around 850 to 800 mb, winds will hover only around 10 to 15 mph from the north to northwesterly direction after a weak cold front passes through this morning. The dry conditions will continue through tonight, with lows dipping to the lower to middle 60s.
This is due to a closed upper low along the California Coast currently near Point Conception which is forecast to slowly work its way toward Los Angeles by this afternoon and park through Sunday. The air mass will be sufficiently moist and unstable today (mean CAPE values 500-700 J/kg) to support another round of scattered afternoon thunderstorms primarily initiating over the higher mountains of our region then moving slowly toward the north- northwest with the potential for training cells leading to isolated heavy rainfall.
These low clouds should diminish before midday as mixing increases in the low levels of the atmosphere. Lows should be near or a little cooler than normal. Sunday will have increasing clouds as an upper trough approaches from the Northern Plains.
The northern storms are the forming along combined outflow and cold frontal boundaries. Temperatures this afternoon should stay a couple to few degrees cooler than previously forecast due to remnant cloud cover and rainfall. For tonight, another round of showers and storms is expected as the cold front making its way south today will move back north as a warm front. The big question for the day is how long will precip and cloud cover persist and how unstable will be become before the warm front lifting through the area comes back through as a cold front later in the day.
Light SW/WSW winds as high pressure lingers over the local area will once again usher in hot temperatures and high humidity this afternoon. This will be the focus for the highest coverage, though overall PoPs peak at around 50% today.
Key Messages: * Cooler today with more cloud cover and a chance for afternoon rain showers.
Generally, VFR conditions prevail; however, this afternoon and evening, a surface cold front passing from north to south across the region causes periods of MVFR conditions in rain showers at our north central and central Montana airfields. The California upper level lower heights move southward, and the upper level higher heights slide northeastward, with the associated ridge building toward The Hudson Bay. A deepening trof is found downstream from the ridge.
The California upper level lower heights move southward, and the upper level higher heights slide northeastward, with the associated ridge building toward The Hudson Bay. A deepening trof is found downstream from the ridge.
73 inches is just above the 20th percentile for this time of year, the freezing level is very high at 17508 feet, and 500 mb temps are hot at approximately -3. A weakness will develop over Florida in the deep- layered ridge of high pressure which will allow for increased convective coverage later today into tonight. As the trough moves through the region tonight into Sunday, convection will linger beyond the normal diurnal cycle with coverage that will peak from southeast to northwest.
426 AM CDT Sat Aug 12 2023 Key Messages: * Cooler today with more cloud cover and a chance for afternoon rain showers.
Upper ridging has been the predominant influence on our day to day weather and should continue to be in the short term. Abnormally dry conditions are favoring deep mixing which is allowing much of the area to reach the low 100s daily.
For Today: Ample monsoon moisture will remain along with relatively cold mid-level temperatures at around -7 to -9 Celsius, about 1 to 3 degrees cooler than normal.
618 AM CDT Sat Aug 12 2023 (Today through Sunday Night ) Overall setup looks to remain generally the same today and tomorrow across the state as H500 ridging situated just to the south persists.
The main pattern across the northern Rockies will buckle, with high pressure shifting northward along the Pacific coast, while a trough drop southward across Montana into the Northern Plains. This will sweep a cold front through the state tonight. Areas behind the front to the north of the Divide will note cooler temperatures on Sunday, a good 10 to 15 degrees lower than today. Shower activity with this front and trough will be minimal, limited to far southern Wyoming the rest of this afternoon, and the Bighorn range and downwind areas of Johnson County on Sunday. This cooler and breezy (almost fall-like) weather will not last, as the high pressure ridge builds quickly back across the Rockies, and will dominate the region for the majority of the upcoming week.
307 PM CDT Sat Aug 12 2023 Weak ridging, reduced moisture, and minimal convergence following the passage of a cold front earlier today should keep a lid on any additional shower and thunderstorm chances until at least late Sunday.
The ridge will remain in control of our weather, with mainly clear skies through Sunday.
As a result of this, overnight lows are forecasted to drop down into the upper 70s, with a few spots potentially reaching the low 80s. Similar conditions are expected tomorrow with afternoon highs forecast to peak in the low 100s across central Mississippi.
Another chance for a few strong to marginally severe storms Sunday as a cold front moves through the region.
1209 PM CDT Sat Aug 12 2023 Hot and dry conditions will be the main focus for today as both the GFS and the Euro continue to show the upper ridge in a stationary position across the southeastern United States. With the high pressure system across the southern Gulf Coast limiting any build up of sufficient moisture flow, rain chances are forecasted to remain low through the afternoon toady. 12Z sounding observations indicate a very dry and stable environment due to thermal profiles showing drier air mixing in the lower levels (around 925 mb). Upper ridging has been the predominant influence on our day to day weather and should continue to be in the short term. Abnormally dry conditions are favoring deep mixing which is allowing much of the area to reach the low 100s daily.
1148 AM EDT Sat Aug 12 2023 Update A band of showers and storms out ahead of the cold front has streamed through South west Michigan this morning.
Afternoon convection is ongoing over the higher terrain along with a convergence/moisture boundary setup from northern CO into the southern NE Panhandle that CAMs have been highlighting for CI this afternoon. For both of these areas, there is the potential for marginal severe thunderstorms as 0-6 km shear sits around 35-40 kt with 1500 J/kg of MLCAPE east of the lee trough. Looking farther north at this time, a surface cold front positioned up in eastern MT will push south tonight brining cooler temperatures and strong northerly winds to the area for Sunday. Could also see light rain/drizzle along the Pine Ridge with the frontal passage early Sunday morning, but otherwise looking at a clearing skies and drier conditions Sunday behind the front.
(This evening through Sunday night) Subtropical moisture will continue to be brought northward over the Panhandles through Sunday night between high pressure to our east and low pressure to our west. On Sunday, an upper level disturbance on the bottom side of an upper level low moving through the northern plains will help to form more showers and thunderstorms across our area. Showers and thunderstorms are expected to continue into Sunday night aided by a southward moving cold front.
211 PM MDT Sat Aug 12 2023 For the rest of this afternoon and evening, radar this afternoon shows the best is along and south of I-76, but scattered showers and storms developing over the higher terrain may spread onto the adjacent plains by this evening. On Sunday, a cold front associated with a passing short wave trough will push into Denver around 9 AM. The models show little if any shower development across the plains as the lower levels become increasingly stable.
Depending on cloud cover this evening, temperatures may stay in the 70s north of the Red River, and in the low 80s by western north Texas. A stronger synoptic cold front will start to push through beginning later in the afternoon. As the cold front moves across the area, severe storms are expected along this boundary, especially across northern Oklahoma.
In addition to bringing some chances for precipitation, the low will push a cold front over the Divide, resulting in a shift to easterly winds overnight tonight and Sunday morning. This high-over-low blocking pattern will lock the atmosphere in place through at least midweek. High pressure will dominate the Northern Rockies, keeping temperatures well above normal.
An upper level high pressure ridge is centered just off the west coast today, with northwest flow aloft over the northwest states. The ridge will migrate inland and strengthen, becoming centered over Washington and Oregon by Sunday night.
A few light showers noted on radar this afternoon along an inverted trough from the Bayfield Peninsula to north central MN.
301 PM EDT Sat Aug 12 2023 Short Term/Aviation The weak cold front moved through earlier bringing a line of showers and storms through the region. While the cooler air will only slightly reduce Daytime highs today. Cooler temps in the upper 50s, calming winds and skies that should be clear through at least mid evening should allow for shallow patchy fog tonight into tomorrow morning. A layer of clouds could build in tomorrow morning in the wake of the exiting mid level low with the positively tilted trough. Weak high pressure will dominate the weather Sunday leading to fair weather.
Ludwig 1150 AM MDT Sat Aug 12 2023 (12/18Z TAF Period) VFR conditions are expected to prevail today, though clouds will be on the increase as a weak cold front pushes into the area. The California upper level lower heights move southward, and the upper level higher heights slide northeastward, with the associated ridge building toward The Hudson Bay. A deepening trof is found downstream from the ridge.
105 PM MDT Sat Aug 12 2023 Embedded impulses in the flow around the upper ridge centered over Texas will provide synoptic scale lift for showers and thunderstorms this afternoon and tonight. On Sunday, cold front on track to move through western areas Sunday morning and eastern areas Sunday afternoon.
Strong cold front will move S into the area this evening with strong wind gusts especially around Judith Gap due to good cold advection and mixing. It will get more interesting late tonight when a trough drops down from the northwest and brings a cold front through the region. This will lead to precipitation chances ranging from 20-50% mainly from Billings and east with the highest chances near the border with the Dakotas. Temperatures cool significantly Sunday into the low to high 70s after the trough and cold front passage.
The closed low off SoCal continues to flex its muscles, but that will be changing over the next couple of days as a strong ridge builds over the Pacific NW. That ridge will retrograde the lower latitude ridge currently parked over east Texas much closer, so expect a good warm up. Satellite imagery depicts a cumulus field developing along the ridges of the Sierra this morning. Given the lower mid-level moisture in place and steep lapse rates, convective initiation won't be too far behind. Steering flow is light so these storms should blow off the ridges quickly and bring localized flood potential. Also, tomorrow the cooling influences of the closed low will wane, so expect temperatures to begin to climb back into the triple digits. The warming trend will continue for several days as the aforementioned ridge across Texas retrogrades midweek.
(Rest of today through Sunday) A summertime pattern continues with a ridge of high pressure over the western Atlantic, keeping a south-to-southeast flow across South Florida. With the advection of this low-level moisture, POPs are scattered across the east metro, with heightened POPs over Miami- Dade County. Tempestuous thunderstorms seem unlikely at this time due to very warm 500 mb temperatures and an unfavorable tall freezing level. The pattern looks similar tomorrow, with the advecting moisture from the trough axis providing additional lift and moisture for diurnally driven storms.
(Tonight through Sunday night) No significant change to the upper pattern over the region during the period, as deterministic runs predict the upper level high pressure system, extending across the south central/southwestern CONUS, and northern Gulf of Mexico, to persist during the period (although an upper level disturbance develops/moves southeastward across the Northern Plains, which will affect the Extended).
Hot and dry conditions will be the main focus for today as both the GFS and the Euro continue to show the upper ridge in a stationary position across the southeastern United States. With the high pressure system across the southern Gulf Coast limiting any build up of sufficient moisture flow, rain chances are forecasted to remain low through the afternoon toady. 12Z sounding observations indicate a very dry and stable environment due to thermal profiles showing drier air mixing in the lower levels (around 925 mb). Upper ridging has been the predominant influence on our day to day weather and should continue to be in the short term. Abnormally dry conditions are favoring deep mixing which is allowing much of the area to reach the low 100s daily.
The upper level ridge continues building in from the west, resulting in rising heights across the forecast area. The highest heat indices will be across coastal portions of AL and the FL panhandle with lowest heat indices over southeastern MS and interior southwestern AL where some more appreciable afternoon mixing can occur. Sunday appears to be a rinse and repeat of today, with afternoon temperatures perhaps a degree cooler.
(Tonight through Sunday night) High pressure continues to be the dominate feature for the short term keeping temperatures abnormally hot, and the forecast rain free.
1243 PM CDT Sat Aug 12 2023 (Today and tonight) Little change has occurred in the synoptic pattern over the past 24 hours as a blocking pattern persists over the southern CONUS, with upper level ridging anchored over the western Gulf Coast and an upper level cutoff low remaining off the CA coast. With 500mb heights very similar to or only a bit lower than yesterday have sided with the higher end of guidance for high temperatures today, especially off the Caprock.
Most of tomorrow should be rather mundane with weak high pressure building in behind the front.
There is an area of low pressure organizing over southern Alberta that will begin extending influence over this region later tonight. Some portion of this low level moisture is going to feed up into the southwestern/southern portion of South Dakota this afternoon through later this evening to give that needed low level moisture for strong storms a boost. Later tonight into Sunday morning, as the brunt of the main dynamic lift of this approaching/strengthening low pressure system reaches north central South Dakota, there should be a pretty good WAA zone establishing, and some fairly efficient rain-producing showers and thunderstorms getting going.
High temperatures so far range from the low to mid 90s near/along the coast (92 degrees at Galveston at 3 PM) to the lower 100s inland (105 degrees at College Station at 3 PM). With a majority of area dew points in the low to mid 70s, heat index values are generally in a 108 to 115 degree range. With the ridge still holding across the area as expected over the weekend, see no reason to make any significant changes to the forecast package which basically means a repeat of today's/tonight's weather for tomorrow/tomorrow night.
Low amplitude ridge keeps dangerous heat in the forecast through the period. About the only thing that could seemingly preclude the need for an Excessive Heat Warning is if some lower dewpoints mix down and looking at the low level lapse rates forecast, this doesn't seem too likely.
249 PM EDT Sat Aug 12 2023 Severe thunderstorms with potential for large hail, damaging winds, heavy rainfall, and isolated tornadoes are expected ahead of a cold front this evening.
A sharp trough axis stretches north-northeast through central Cuba into the Straits of Florida. Although there are no observations along the eastern flank, feature tracking of the low level cumulus suggests 15 to 20 knots a BL flow.
Weather map shows high pressure ridging across the Northern Gulf of Mexico, with southwest winds prevailing across the area. Afternoon highs in the mid 100s across Inland Southeast Texas & Central Louisiana, near 100/lower 100s along the I-10 corridor, and mid to upper 90s across the lower portions of the coastal parishes and counties.
A cold front is stretched from roughly the base of Lake Michigan southwestward toward Macomb, as noted on satellite imagery. A few storms may fire ahead of the cold front this afternoon mainly in eastern and southeast IL. Dewpoints hang around in the low-to-mid 70s.
145 PM MDT Sat Aug 12 2023 Most recent Water Vapor and upper air analysis shows northwest flow over our region, with an upper low over Ontario and mild ridging over the West coast. Sunday will be much cooler, with highs only in the 60s and 70s. Compact upper trough moving across the northern Plains will continue to bring chances for showers and possibly a few thundershowers through much of the day.
Clouds will increase on Sunday ahead of an approaching upper level trough from the northern Plains. Mostly cloudy skies and northeasterly flow will keep temperatures cooler than normal Sunday afternoon. Highs are expected to range from the lower 70s across the north and along the lakeshore to the middle 70s across central and east- central Wisconsin away from Lake Michigan.
1004 PM EDT Sat Aug 12 2023 Showers and thunderstorms will end tonight with the passage of a cold front.
712 PM EDT Sat Aug 12 2023 (Rest of today through Sunday) A summertime pattern continues with a ridge of high pressure over the western Atlantic, keeping a south-to-southeast flow across South Florida. With the advection of this low-level moisture, POPs are scattered across the east metro, with heightened POPs over Miami- Dade County. Tempestuous thunderstorms seem unlikely at this time due to very warm 500 mb temperatures and an unfavorable tall freezing level. The pattern looks similar tomorrow, with the advecting moisture from the trough axis providing additional lift and moisture for diurnally driven storms.
500 PM MDT Sat Aug 12 2023 Most recent Water Vapor and upper air analysis shows northwest flow over our region, with an upper low over Ontario and mild ridging over the West coast. Sunday will be much cooler, with highs only in the 60s and 70s. Compact upper trough moving across the northern Plains will continue to bring chances for showers and possibly a few thundershowers through much of the day.
The lows tonight will be slightly warmer by a few degrees compared to last night with most lows in the 50s and 60s.
The highest readings are possible across the coastal counties east of the sea breeze, where dewpoints should be highest. Low amplitude ridge keeps dangerous heat in the forecast through the period. About the only thing that could seemingly preclude the need for an Excessive Heat Warning is if some lower dewpoints mix down and looking at the low level lapse rates forecast, this doesn't seem too likely.
(The rest of tonight) Shower and thunderstorms to our west across Kansas, Oklahoma and Texas will continue to spread east into the area overnight as the low level jet strengthens.
A cold front will move across nern CO late tonight thru Sun morning with gusty north winds behind it. For the rest of this afternoon and evening, radar this afternoon shows the best is along and south of I-76, but scattered showers and storms developing over the higher terrain may spread onto the adjacent plains by this evening. On Sunday, a cold front associated with a passing short wave trough will push into Denver around 9 AM. The models show little if any shower development across the plains as the lower levels become increasingly stable.
The pattern for most of the upcoming week still looks dominated by hot and dry conditions on the northern end of a ridge building across the western part of the country.
641 PM CDT Sat Aug 12 2023 (Tonight through Sunday night) High pressure continues to be the dominate feature for the short term keeping temperatures abnormally hot, and the forecast rain free.
Convection was no more than isolated once again this aftn due largely to the strength of the overhead ridge.
653 PM CDT Sat Aug 12 2023 (This evening through Sunday night) Subtropical moisture will continue to be brought northward over the Panhandles through Sunday night between high pressure to our east and low pressure to our west. On Sunday, an upper level disturbance on the bottom side of an upper level low moving through the northern plains will help to form more showers and thunderstorms across our area. Showers and thunderstorms are expected to continue into Sunday night aided by a southward moving cold front.
509 PM MDT Sat Aug 12 2023 For the rest of this afternoon and evening, radar this afternoon shows the best is along and south of I-76, but scattered showers and storms developing over the higher terrain may spread onto the adjacent plains by this evening. On Sunday, a cold front associated with a passing short wave trough will push into Denver around 9 AM. The models show little if any shower development across the plains as the lower levels become increasingly stable.
Dry, northerly flow continues to dominate aloft as high pressure strengthens over the Pacific Northwest. Temperatures should remain below normal for one more day (Sunday), before heating up to 5-10 degrees above normal this coming week due to the strengthening ridge.
733 PM CDT Sat Aug 12 2023 Weak ridging, reduced moisture, and minimal convergence following the passage of a cold front earlier today should keep a lid on any additional shower and thunderstorm chances until at least late Sunday.
821 PM EDT Sat Aug 12 2023 Upper ridging builds over the region this weekend resulting in hot and mainly dry weather conditions.
722 PM EDT Sat Aug 12 2023 Aviation The weak cold front moved through earlier bringing a line of showers and storms through the region. While the cooler air will only slightly reduce Daytime highs today. Cooler temps in the upper 50s, calming winds and skies that should be clear through at least mid evening should allow for shallow patchy fog tonight into tomorrow morning. A layer of clouds could build in tomorrow morning in the wake of the exiting mid level low with the positively tilted trough. Weak high pressure will dominate the weather Sunday leading to fair weather.
634 PM CDT Sat Aug 12 2023 (Tonight through Sunday night) No significant change to the upper pattern over the region during the period, as deterministic runs predict the upper level high pressure system, extending across the south central/southwestern CONUS, and northern Gulf of Mexico, to persist during the period (although an upper level disturbance develops/moves southeastward across the Northern Plains, which will affect the Extended).
643 PM MDT Sat Aug 12 2023 520PM UPDATE: Pressure gradient along the cold frontal passage coming in from the north has bumped up the winds high enough to becomes a threat to wave heights across Fort Peck Lake. The pattern for most of the upcoming week still looks dominated by hot and dry conditions on the northern end of a ridge building across the western part of the country.