Aikyam-Lab/Synoptic-Bench huggingface dataset:
A decelerating mid-level trough across the Pacific Northwest along with ample atmospheric moisture will bring increasing showers and thunderstorm coverage to much of central and northeastern Nevada late this morning into the afternoon. The slow movement of the low once it gets into Oregon through today will keep showers and thunderstorms in the state Wednesday although overall intensity will be lower. Temperatures will be cooler overall with cloud cover and precipitation with highs today and Wednesday generally in the 70s.
1005 AM EDT Tue May 23 2023 High pressure will keep conditions dry across the Mid Atlantic through the middle of this week.
635 AM CDT Tue May 23 2023 (Today through Wednesday Night) The primary story today will be an amplifying upper trough over the Southeast U. and an approaching weak backdoor cold frontal boundary due into our region later this afternoon and evening. With the cooler upper levels and amplifying trough, expect a continuation of lower end POPs despite being on the drier side with upper level flow becoming more northwesterly/drier. The lower heights should allow for a bit steeper lapse rates (albeit modest in nature) so think this will be where the best potential for convection will reside especially along the surface boundary or any sea breeze that develops along the MS Gulf Coast.
Low pressure tracking southward along the coast today will bring a cooling trend and the potential for isolated showers and thunderstorms over the interior mountains each afternoon through the end of the week.
1006 AM EDT Tue May 23 2023 High pressure will allow warm and dry weather to persist today through Wednesday.
442 AM PDT Tue May 23 2023 A cooling trend will begin on Tuesday and persist through the remainder of the week in response to an upper level trough over the West Coast. (Today and tonight) A band of mid/high level clouds dropping southward into the North Bay early this morning are associated with a long-wave trough aloft. The aforementioned trough will sweep through the entire region by this afternoon and will allow for decent mixing of the boundary layer. In response to the cooling air mass aloft, temperatures across the interior will be slightly cooler today compared to previous days. While this troughing pattern supports the potential for convection across the northern and interior portions of the state, the probability of any development over the Bay Area/Central Coast remains low (<10%).
There should be considerable multi-layered cloudiness which will limit heating/sfc based instability holding max temps to the lower 80s Orlando northward and mid 80s south. Low pressure is forecast to lift slowly N/NE away from the FL Atlc coast Thu-Fri which will scour out the deepest moisture. Starting in the low 80s north and mid 80s south Thu-Fri, warming to the upper 80s/near 90 interior by Mon and mid 80s immediate coast.
High pressure generally remains in control of our weather. Not much going on in the short term across eastern Kentucky, as a strong ridge of high pressure is firmly entrenched over the region.
Otherwise, upper level ridging remains in place today with a warm air mass over the Northern Plains. 850 mb temps are similar or maybe just a touch warmer than yesterday.
635 AM EDT Tue May 23 2023 High pressure will keep conditions dry across the Mid Atlantic through the middle of this week.
629 AM CDT Tue May 23 2023 (Today through Wednesday) 500mb ridge builds over South Texas with subsidence and drying of the atmosphere increasing through Wednesday.
547 AM MDT Tue May 23 2023 08Z analysis shows an upper trough over the western CONUS with an upper ridge over the Great Plains. The upper trough will remain anchored in place, while the upper ridge gradually shifts eastward. Due to the upper ridge and subsidence over the eastern parts of the forecast area, the bulk of convection over the next few days will be over northeastern Wyoming and far western South Dakota. Warmer than average temperatures will continue through the forecast period.
Upper low pressure over region forecast to meander over the region over the next several days. But there is a still quite a bit of uncertainty on the course this low will take.
And, the remainder of the morning will remain inactive until a cold front drops down from the north later today. Southwesterly surface flow will result in strong WAA ahead of the aforementioned cold front, pushing today's highs into the upper 70s/low 80s over most of the forecast area.
Main forecast item will be a cold front dropping south early tomorrow morning roughly between 09-12Z. A late spring temperature roller-coaster starts today as readings climb into the lower 80s this afternoon. The warmer air develops within diffuse high pressure allowing nearly full sun through patchy high clouds and the lingering high altitude smoke layer. Mild temperatures then hold tonight before taking a downward slide with the passage of a strong cold front early Wednesday. Rainfall is supported in this phase of the system by mid afternoon peak heating, strong 850-700mb Fgen, and strong DCVA within the mid level trough.
531 AM MDT Tue May 23 2023 The overall general flow pattern remains from the southwest or south with a trof digging across the western states.
The deeper moisture begins to move farther south and offshore Wednesday with high pressure and dry weather expected for the end of the week. There remains potential for an offshore low pressure system to bring another chance of rain to the region over the holiday weekend. Quite a nice range in dewpoint temperatures from the Pee Dee, around 50 degrees, to the CSRA where dewpoint temperatures are in the lower 60s this morning. As for temperatures today, expect warmer across the northern and central Midlands and slightly cooler across the CSRA with thicker cloudiness and low chance pops. Tonight, high pressure will continue to hold in across the area with surface winds from the northeast. High pressure over the Great Lakes will begin to build south over the east coast with broad troughing in the upper levels.
621 AM CDT Tue May 23 2023 (Today through Wednesday) An inverted trough is currently situated to our immediate west, and this will provide the focus for isolated showers and perhaps a storm or two later this afternoon and early evening. After tonight, high pressure will expand across Middle Tennessee, keeping the atmosphere relatively dry and rain chances non- existent.
An upper level low situated over the Pacific Northwest will maintain showers and near-normal temperatures across western Washington today.
653 AM EDT Tue May 23 2023 High pressure over the region will move east on Wednesday as a dry cold front crosses south during the afternoon and early evening.
639 AM CDT Tue May 23 2023 (Today through Wednesday Night) The primary story today will be an amplifying upper trough over the Southeast U. and an approaching weak backdoor cold frontal boundary due into our region later this afternoon and evening. With the cooler upper levels and amplifying trough, expect a continuation of lower end POPs despite being on the drier side with upper level flow becoming more northwesterly/drier. The lower heights should allow for a bit steeper lapse rates (albeit modest in nature) so think this will be where the best potential for convection will reside especially along the surface boundary or any sea breeze that develops along the MS Gulf Coast.
306 AM MDT Tue May 23 2023 08Z analysis shows an upper trough over the western CONUS with an upper ridge over the Great Plains. The upper trough will remain anchored in place, while the upper ridge gradually shifts eastward. Due to the upper ridge and subsidence over the eastern parts of the forecast area, the bulk of convection over the next few days will be over northeastern Wyoming and far western South Dakota. Warmer than average temperatures will continue through the forecast period.
217 AM PDT Tue May 23 2023 Relatively warm temps today will trend cooler to slightly below seasonal standards through the week. A developing area of low pressure centered along the US-southwest Canadian border and upper troughing deepening south along the West Coast will bring daily chances for showers and thunderstorms across the region through the extended holiday weekend. The main system will eject a closed low that will swing into the Pacific Northwest today before briefly stalling and then slowly drifting south into the base of the now persistent trough. Before the upper trough become more established along the western US, a drier southwest upper flow will limit convection across the region today.
At the surface, a backdoor cold front associated with a weakening CAD wedge across the Carolinas continues to approach the area from the northeast through tonight. Any chance for stronger storms wanes quickly after sunset, particularly as the cold front progresses to the southwest of the area by mid to late evening, although some guidance is suggesting the front may not fully move out of the area until tonight into Wednesday. Regardless, cooler and drier air will slowly move into the region through the period in its wake. For temps, lows tonight are forecast to be cooler with upper 50s over the far north increasing to the low/mid 60s as you move south towards the coast. Some guidance remains on the warmer end with upper 70s further north to mid 80s further south, while others have mainly upper 70s across the entire area.
The low chance for rainfall over the northern Coastal Plains and Victoria Crossroads from late tonight through tomorrow afternoon will be contingent on if enough mid- level moisture will be in place for convection that develop across central and southeast Texas to maintain strength to reach South Texas.
(This evening through Wednesday night) Issued at 237 PM EDT Tue May 23 2023 The high pressure that has dominated the last few days will shift westward as a upper level trough swings through.
101 PM CDT Tue May 23 2023 A litte weak low level warm advection is incoming on near surface southeasterlies, with dew points running in the lower 60s. Weak pva from nearby low pressure aloft may coexist at times and combine with diurnal instability to touch off an isolated shower or storm during the heat of the pm today-tmrw. trof drags a cold front across the Ohio valley. High pressure builds across the Great Lakes in its wake, and will begin to push this refreshingly cooler/drier air our direction. The aforementioned high will firm its grip as it settles over the Great Lakes and influences the lower Ohio river valley with its cool/dry northeasterly near surface flow.
157 PM CDT Tue May 23 2023 Upper level ridging remains in place tonight into Wednesday which means continued warm with southerly breezes. By Wednesday afternoon a weak wave will drop south into Wisconsin which will allow slightly cooler air to try to back westward towards the Buffalo Ridge in southwest MN. Maybe a couple of degrees cooler in southwest MN where the better chance for enhanced cumulus exists.
Low pressure to our west near Elko Nevada with a cold front extending from southern Montana.
Radar is picking up on some returns in southeast Modoc, but nothing is reaching the ground and given the returns are far away from the radar and dewpoints are on the low side, therefore most likely any precip is evaporating before reaching the ground. This afternoon, the rick for isolated thunderstorms remain, but fine tuned some of the details there to match up with some of the high res guidance and HREF reflectivity.
/ISSUED 527 AM MDT Tue May 23 2023/ The upper-level low situated over the Pacific Northwest corner splits, with the bulk of the energy associated with the low retrograding back north and east into Canada. The remainder of the energy propagates southwestward, leading to the development of a quasi-stationary, positively-tilted trough over western CONUS, which remains in place through the work week.
As of now, KBYX is only detecting isolated showers south of the Lower Keys as most other activity in the forecast area has dissipated. To our north, a frontal boundary is stalled across the Florida Panhandle, with a weak area of low pressure situated along this boundary producing showers and thunderstorms. Temperatures along the island chain are in the upper 80s and dew points are in the lower 70s, making for quite a muggy afternoon. This trough is going to be one of the main drivers of the unsettled weather over the next few days. As of now, model guidance has pinpointed the next three periods as having the highest chance for rain, so have bumped each of these periods PoPs up.
12Z morning sounding observations support mixing in the lower levels (particularly around 850 mb). The increasing cloud cover combined with the limited insolation should help keep afternoon highs in the low 80s across much of our forecast area. /DL/ A dry pattern will continue for much of the forecast period as persistent troughing aids in northerly flow across the area, wrapping dry air around the base of the trough.
Meanwhile, an upper level trough of low pressure is dropping south through the Pacific Northwest. Near the surface, a weak lee side trough of low pressure is anchored in eastern Colorado. With decreasing cloud cover allowing mid-level lapse rates to steepen, thunderstorm development is likely this afternoon in vicinity of an convergence axis associated with the lee side trough, with storms then spreading east-southeast into the panhandles of OK/TX this evening. Look for lows mainly in the 50s(F) with the lower 60s(F) possible in south central Kansas.
1218 PM CDT Tue May 23 2023 (Today through Wednesday) 500mb ridge builds over South Texas with subsidence and drying of the atmosphere increasing through Wednesday.
206 PM CDT Tue May 23 2023 18z surface data has high pressure from the Great Lakes and Ohio Valley west into the Plains. A cold front was along the international border moving south. A back door cold front will push into the area Wednesday leading to quite a contrast in temperatures.
313 PM EDT Tue May 23 2023 Warm and mainly dry weather is likely to persist through Wednesday under high pressure.
Forecast temperatures for Wed afternoon are in the low 80s across the area, but wouldn't be surprised to see them surpass this a little, with less cloud cover expected. A cold front pushed by the aforementioned low will be approaching from the north shortly after the end of the short term.
Winds will initially diminish quickly overnight, with a backdoor cold front pushing southwestward late tonight into Wednesday morning. Generally cloudy skies are expected throughout the day, with high temperatures ranging from the upper 60s in southwestern Wisconsin to the lower 50s close to the lakeshore.
As for the remainder of the week, anticipate a benign weather pattern across Arizona due to the development of a weak, longwave trough positioning itself over the West Coast states.
138 PM PDT Tue May 23 2023 Warm temperatures will trend cooler to near seasonal averages through the week.
(This evening through Wednesday Night) Ridging spanning across the Plains should keep conditions mostly benign today, save for a few showers and storms. Highs are progged to be a tad cooler, but still in the mid to upper 80s area-wide.
In the short term, a cold front moving through on Wednesday will drop highs from the upper 70s to low 80s into the upper 60s to low 70s by the end of the work week. An Omega blocking pattern sets up by late in the week, leading to continuing dry, mild, and pleasant conditions through Memorial Day weekend. High pressure remains over the CWA through late tonight, leading to continued dry, clear conditions overnight. Throughout the day Wednesday, a cold front arrives from the north.
At the surface, a backdoor cold front associated with a weakening CAD wedge across the Carolinas continues to approach the area from the northeast through tonight. Any chance for stronger storms wanes quickly after sunset, particularly as the cold front progresses to the southwest of the area by mid to late evening, although some guidance is suggesting the front may not fully move out of the area until tonight into Wednesday. Regardless, cooler and drier air will slowly move into the region through the period in its wake. For temps, lows tonight are forecast to be cooler with upper 50s over the far north increasing to the low/mid 60s as you move south towards the coast. Some guidance remains on the warmer end with upper 70s further north to mid 80s further south, whilest others have mainly upper 70s across the entire area.
Meanwhile, a weak inverted trough across the Lower and Mid-MS Valley is expected to serve as an additional focus for isolated to widely scattered convection by late this afternoon into the early evening hours. As a result, expect convection to develop along the eastern periphery of the upper-level ridge with decent coverage across our western zones. Farther east of the I-49 corridor, we will likely remain dry with slightly warmer temperatures across these areas compared to our western zones with a range of lower to mid 80s. Otherwise, expect cloud cover to gradually decrease in coverage as well with overnight low temperatures dropping back into the lower to mid 60s.
Otherwise, the warm conditions today will change markedly tomorrow as a strong cold front moves southward across the forecast area. This cold front is currently located over Lake Superior. The amplification of a mid level trough diving from northern Ontario into upstate New York tonight into Wednesday will drive this cold front southward across Se Mi Wednesday morning. Deep layer frontogenesis across the associated cold front is forecast to essentially fall apart as the cold front pushes across cntl/southern Lower Mi, leaving only a low level shallow frontal circulation by the time it advances south of roughly the Interstate 69 corridor.
As of 17Z, GOES18 satellite showed thunderstorms developing just north of Lincoln county with increasing cumulus development over the high terrain areas north of the I-40 corridor. This should serve to further lessen convective potential across southern Nevada, perhaps staying just as cumulus across higher terrain with a very low end chance for a shower or storm south of the Highway 6 corridor.
1208 PM CDT Tue May 23 2023 (Today through Wednesday) An inverted trough is currently situated to our immediate west, and this will provide the focus for isolated showers and perhaps a storm or two later this afternoon and early evening. After tonight, high pressure will expand across Middle Tennessee, keeping the atmosphere relatively dry and rain chances non- existent.
136 PM MDT Tue May 23 2023 Satellite imagery shows S-SW flow ahead of an amplified Pacific coast trof. Air mass in our region stabilized this morning behind last night's cold front, but we are starting to see some convection develop over the mountains and Rosebud County eastward. Mesoanalysis shows no cape over our western lower elevations, courtesy of cooler easterly winds, and up to 500 j/kg of MLCape in our east remains capped. hottest along surface trof east of Billings.
Tonight and Wednesday Forecast concerns: Precip chances and winds as a strong cold front dives south across the region tonight. This cold front will shift south across northern Wisconsin from about mid-evening through early overnight. Winds: Gusty northeast winds will develop behind the the cold front from late tonight thru Wednesday. Gusts will be the highest down the Fox Valley and along the Lakeshore where gusts to 30 mph are possible. Fire Weather/Humidity: Despite a cooler airmass arriving on Wednesday, the airmass will also be very dry. Temps: Much cooler temps are expected on Wednesday with highs only in the 50s along the Lakeshore.
So far there hasn't been much showing up on RADAR, probably due to weak upper level ridging over the Mid Mississippi Valley producing broad scale subsidence. This boundary will be the first manifestation of an east-to-west moving cold front which will move through the Mid Mississippi Valley.
130 PM EDT Tue May 23 2023 High pressure will allow warm and dry weather to persist today through Wednesday.
A cooling trend begins today due a disturbance of low pressure aloft moving over the area. A trend to slightly cooler than normal temperatures is forecast by the end of the week. The ridge of high pressure that has been bringing afternoon highs 10-12 degrees above normal is breaking down today as a trough of low pressure moves over Central California. Some onshore gradient/marine cooled air is expected to push through today, leading to much cooler conditions in Merced County with a westerly breeze. This cooler air will spread southward through the evening and lead to much cooler temperatures across the entire valley tomorrow. Global ensembles show the trough pattern remaining in place for at least a few days after Wednesday, reinforcing the cooler airmass in the valley.
156 PM PDT Tue May 23 2023 An upper trough dominating the U. This is due to an onshore flow pattern associated with an upper trough over the U. Temps over the coast and valleys are running cooler than forecast, so adjusted temps down through the remainder of the day based on current obs. The upper trough will not be going anywhere anytime soon, so persistence is forecast this week with little in the way of day- to-day changes anticipated. Temperatures will remain below normal through the upcoming holiday weekend with most places running 5-10 degrees below normal with the highest departures over inland areas.
152 PM EDT Tue May 23 2023 High pressure will keep conditions dry across the Mid Atlantic through the middle of this week.
204 PM EDT Tue May 23 2023 High pressure will keep conditions dry across the Mid Atlantic through the middle of this week.
The upper level pattern through the end of the week will remain nearly similar to what we've seen so far this week, with weak short wave ridging over West Texas, downstream from a western CONUS upper trough. This pattern will remain favorable for thunderstorm development to our west and northwest each afternoon, as disturbances in the flow aloft rotate around the ridge axis.
216 PM EDT Tue May 23 2023 We'll have another tranquil night tonight with surface ridging to our east and upper ridging to our west. Tomorrow a cold front will approach from the north. Afternoon highs will again be in the lower and middle 80s. about five degrees warmer than normal. The mid-week synoptic view will feature an Omega pattern over the lower 48, with extensive ridging over the central Plains stretching from the Mexican border to the Canadian border, and troughs over both coasts.
257 PM MDT Tue May 23 2023 Pattern through the short term period will not change, with an upper trough stuck over the Great Basin and southwest flow aloft ahead of it over the Rockies and plains.
The mid/upper ridge portion of this block will be anchored to our west and provide a subsident dry airmass.
(This evening through Wednesday night) Tonight through Wednesday night, a backdoor cold front boundary will arrive and linger over the area.
After today though, that trend will start to come to an end as a stationary front pushes north and high pressure over the eastern great lakes finally moves along.
256 PM CDT Tue May 23 2023 Currently have upper troughing extending from British Columbia down into the Pacific Northwest with a broad area of upper ridging across the Plains. At the surface, some weak Lee troughing is in place with a broad area of high pressure from the Great Lakes into the Northeast CONUS.
Upper level troughing will allow for a cooling trend to return to the region this week. As of 1230 PM PDT, temperatures are currently trending 5 to 15 degrees cooler than this time yesterday. Instability and forcing with the trough will bring isolated showers and thunderstorms back today with the best chances over Shasta County, Coastal Range, and Southern Cascades. Thunderstorm chances will spread southward over the higher elevations of the Sierra Nevada the rest of this week.
Water vapor satellite imagery this morning is showing a pair of well defined upper lows along the West Coast with moist southerly flow over the Great Basin.