Aikyam-Lab/Synoptic-Bench huggingface dataset:
Wed-Wed night: NNW flow aloft will prevail, on the eastern periphery of an amplifying upper level ridge over the Intermountain West/Rockies -- and the western periphery of an amplifying upper level low invof the Great Lakes. Thu-Fri: The ridge aloft will progress east from the Intermountain West/Rockies across the Central Plains in this period. Sat-Tue: Long range guidance suggests that flow aloft will back to the SW as an upper level trough moves ashore the Pacific Coast and the aforementioned ridge progresses east across the Mississippi River Valley. A cold front will move into hte region on Tuesday, with winds expected to pick up in the late morning to early afternoon.
A majority of the high resolution models initially moisten 850MB via lift on front until the front reaches southeast KS, where moisture will have time to return. No big changes to going temperatures, although a bit concerned that western sections could be few/several degrees warmer if flow veers any more than currently forecast in the afternoon.
03z surface analysis showed cold front entering south central SD. Initial band of convection affected northwest SD earlier this evening along cold front tapping into weak MLCAPE. Upper level analysis shows a weak ridge over the northern plains, with a wave pushing in from the northwest. Initial impulse and associated cold front will spark some showers and perhaps a few isolated thunderstorms this evening, as well as some gusty winds behind the front. Behind the cold front, strong northwesterly winds are expected on Tuesday. As the departing upper wave transitions into a longwave trough, strong upper ridging will build over the western CONUS.
Afternoon high temperatures today are expected to be range from the upper 70s along the coast to the low to mid 80s inland with overnight lows ranging from the mid 50s inland to mid 60s along the coast.
Showers and thunderstorms will form along a cold front across northern Texas today. Northwesterly flow aloft forces the front and convectively induced boundaries south while the low level jet maintains the showers and thunderstorms as they track south and southeast.
Marine layer advection ahead of approaching cold front to bring in MVFR ceilings that will be indicated in the 24-30 hour portion of the KMSY TAF and could be anticipated in 12Z TAF package issuance for other locations along with onset of convection associated with cold front mainly after 29/09Z.
1043 PM MDT Mon Apr 27 2020 De-amplification of the robust northeast Pacific ridge is leading to a drier and warmer forecast which really began today and should continue through the forecast. We will still be on the tail end of a system moving out of the northern Rockies into the High Plains this evening. Strong ridging will be setting up across the Intermountain West to the Rockies as tonight's system carves out a trough in the eastern CONUS and heights lower off the Pacific Coast.
A return of ridging will allow warmer and drier conditions Tuesday and Wednesday.
Tuesday is expected to be the warmest day this week as high pressure builds over California.
Surface winds will become more SE Today as High Pressure moves well E of the TAF sites. High pressure building directly over the region tonight along with clear skies, near calm winds and dry airmass in place will set the stage for good radiational cooling conds. On Tuesday, High pressure will slide offshore and surface flow will become Southeast at 10-15 mph with gusts to 20-25 mph at the beaches during the afternoon hours. This milder SE flow will push temps back closer to seasonable late April values with Highs in the lower/middle 80s inland and mid/upper 70s at the coastal areas. Mostly sunny and mild conditions will continue on Tuesday with temperatures a few degrees warmer. Highs will reach the upper 70s coast to the lower 80s inland.
Lows will be in the 50s and highs Tuesday in the low/mid 80s. The cold front will move through our area beginning late Wednesday and Wednesday night. Shear will be better north of the area closer to the low center where the large scale lift is better.
Winds will remain light and southerly until the surface cold front pushes across the area, between 12 and 15 UTC. With 850 mb temps around 15 degrees cooler than 24 hours before, lows tonight could be as low as around 40 degrees on the high plains and warmer near 50 on the lower plains. Sunny Wednesday as the large upper PV anomaly moves through the mid Mississippi valley leaving western KS in deep subsident airmass and amplifying ridge. The large high pressure will continue to build in to the area with steep lapse rates and gusty north surface winds though the day.
CD Chattanooga Airport, TN 77 58 68 50 64 / 0 40 90 20 20 Knoxville McGhee Tyson Airport, TN 75 58 69 51 62 / 0 20 90 40 50 Oak Ridge, TN 74 56 67 49 62 / 0 30 90 40 60 Tri Cities Airport, TN 72 53 71 49 59 / 10 10 90 70 70.
A cold front ran south from the low across northwest Iowa and into Nebraska. The threat for severe weather associated with the low and cold front coming through Tuesday afternoon/evening was discussed in the short term section of this discussion. Breezy NW to N winds will develop behind the front as cooler and drier air advects into the region and temps fall into the 40s. The ECMWF is weaker/further east with the deformation zone and is about 5 F warmer for highs. Our current forecast follows closely to the NBM which has trended a few degrees cooler over the past few days.
The precipitation appears to be the result of mid level isentropic ascent overtop the low level dry airmass. As it does so, its attendant cold front dropping through the mid MS valley will ignite a squall line during the afternoon. Once the cold front comes through Wednesday, dry air will filter in and the ArkLaMiss will see a break from the rain/storms for a few days.
At the surface, low pressure was centered over South Dakota with a trailing cold front extending across central NE and into far northwest KS early this morning. As a result, short-range models suggest afternoon temperatures in east central KS could briefly soar into the low/mid 80s before the frontal passage and associated precipitation quickly drop temperatures back into the 60s/70s. With the deepening mid-level trough diving into the area tonight, an associated vorticity max may help to support the development of some widely scattered showers behind the front this evening. If anything, the increased cloud cover across east central KS along with gusty northwesterly winds on the back-side of the exiting low will keep temperatures cooler on Wednesday with highs only reaching into the mid/upper 60s to low 70s from eastern to central KS, respectively.
Temperatures early this morning range from the mid 50s to the lower 60s. A cold front which is currently moving into the central Plains will move toward the Mid-South today reaching northwest Arkansas by late this afternoon. Temperatures will be a little warmer than yesterday with highs in the mid to upper 70s. The cold front will move into western sections of the Mid-South after midnight tonight. By Wednesday morning, the cold front is expected to cross the Mississippi River and should reach east Tennessee by late afternoon. Temperatures will be cooler on Wednesday with highs from the mid 60s to lower 70s. High pressure will start to build into the region Wednesday night and will continue to influence the weather across the Mid-South into the weekend.
Damaging winds would also be possible given some drier air in the lower levels resulting in higher DCAPE values. After the initial cold front, a secondary vorticity maximum will drop into the area Tuesday night, driving a secondary cold front southeast again. Wednesday into the start of the weekend, a period of dry and increasingly warm weather will take hold as the strong western US ridge shifts eastwards over the Plains.
A strong cold front nears KBVO around 22Z with storms likely. The timing may need to be adjusted an hour early or later depending on how the cold front and storms track.
Southeast winds will pick up this morning as the pressure gradient tightens between high pressure over the northeastern Gulf and low pressure over the Plains. /issued 252 PM CDT Mon Apr 27 2020/ SHORT TERM (Tonight through Tuesday Night): High pressure remains in control this afternoon, supporting moderate to breezy southeast winds and scattered to broken low level cumulus cloud streets. Low clouds will mix out Tuesday morning and breezy to windy conditions will develop across the southeast corner of the lower RGV, including Brownsville and Harlingen, and to a slightly lesser extent, McAllen.
An upper level ridge will build in behind the exited low over the latter half of the week.
155 AM EDT Tue Apr 28 2020 High pressure will remain across the region today with mostly sunny skies and warmer temperatures.
Line of showers and thunderstorms will move through the state this afternoon and into Wednesday morning along a cold front, primarily affecting the northern and western sites during the 00Z- 06Z time frame, and the remainder of the area just beyond. Expect VFR conditions to persist overnight until a warm front lifts north during the morning hrs on Tue. Some low clouds and DZ could be seen along this warm front as moisture lifts north over the area. The more organized TSRA will hold off until late in the period across the NRN terminals as a cold front drops SE into the state.
Heights build quickly behind the system tonight into Wednesday with strong ridge axis overhead.
Dewpoints in the low 60s will move into the region overnight from the SW and eventually into the mid to upper 60s areawide by tomorrow resulting in humid conditions. A deep trough will dig out of the Northern Plains through the Midwest Tuesday evening, dragging a long trailing cold front towards the region. 5 C/km in some areas and freezing levels below 13 kft.
Plume of steep mid level lapse rates along with MLCAPES of 2500 to 3500 J/kg will be common ahead of the front across southeast Kansas and southern Missouri as surface dew points rise into the low to mid 60s. The upper level low closes off over northeast Missouri early Wednesday morning and tracks into Illinois during the day. Wednesday will be a breezy and cooler day, with highs ranging from around 60 in the eastern Ozarks to the upper 60s in southeast Kansas.
A cold front may affect KABI toward 2Z Tuesday evening, shifting winds northeast. In addition, compressional heating ahead of an approaching cold front will result in unusually hot temperatures, especially across the western half of the area. Highs will range from the mid 90s to near 100 degrees across the western half of the area, to the low 90s across our eastern counties.
With that said though winds will be shifting to the south and moisture levels will be on the increase as the trough begins to approach the area.
Moisture return will continue through tonight into tomorrow as the high pressure slides farther east and the system over the Plains deepens. Better chances will hold off until tomorrow evening as a cold front begins to approach. Ahead of this front, expect high temperatures to be a few degrees warmer than today - upper 70s to lower 80s. /NF/ Showers and thunderstorms will be increasing in coverage across the region Tuesday night as a cold front approaches from the west. Showers and thunderstorms will be ending late Wednesday morning into the afternoon as the cold front moves through the region. Expect dry conditions Wednesday night through the weekend as high pressure returns and remains in control.
A cold front will backdoor the area near the end of the forecast period, but only make it to KMAF/KHOB. The dryline will move into the central and eastern Permian Basin south to the lower Trans Pecos by mid to late afternoon as westerly flow aloft continues. A weak disturbance combined with intense heating along the dryline, with help from the higher terrain, should break the cap and generate a few late day thunderstorms just east of the Davis Mountains in the lower Trans Pecos region of west Texas. A dry cold front is forecast to backdoor into the region Tuesday night with cooler temperatures (but still near normal) and windy conditions early Wednesday.
A few stronger echoes moved through Mobridge South Dakota recently, which only produced about a tenth of an inch. Currently, weak high pressure exists across the region with the center of the high in north-central ND. Indications persist for a decent ridge to build over the region for Thu and Fri with temps climbing through the 60s to near 70 Thu and exceeding 70 degrees most places for Fri. On Fri the next boundary approaches, with the main area of low pressure positioned well north in Manitoba province. Pretty much kept with the 00Z set of TAFs, which continue the idea of light winds overnight and even staying on the lower side into Tuesday.
The cold front will be surging southward from late afternoon to early evening and likely induce convective mode transition from dominant supercellular to a mix of linear with embedded supercells. The orientation of the low / mid level speed max in the base of the amplifying trough will align orthogonal to frontal linear features and one or more corridors of intense wind damage appear possible. The upper ridge that aided recent record high temps across the southwestern U. The next cold front moves into the region over the weekend with the next chance of storms and potential severe weather.
/issued 757 PM EDT Mon Apr 27 2020/ High pressure over the region kept us pleasantly drier and relatively cooler today. For tomorrow, high pressure shifts eastward, allowing the air mass to moderate a bit, so we will be a bit more humid and warmer. High pressure over the region will shift east into the Atlantic Ocean tomorrow with winds becoming northeast and then east through Wednesday.
Rain chances will continue along a warm front this afternoon, with briefly dry weather returning south of the front tonight.
A cold front will move into the Big Country this evening, moving south along a San Angelo to Brownwood line around 1 AM, and south of I-10 and Mason county by 4 AM.
Further upstream, trough axis centered across central Montana will clip the northern half of the forecast area this afternoon. Ridging returns Wednesday as thermal ridge builds across the northern plains.
334 AM EDT Tue Apr 28 2020 High pressure will remain across the region today with mostly sunny skies and warmer temperatures.
Dry weather and hot afternoon temperatures expected through mid-week as a ridge of high pressure dominates the region. The ridge of high pressure will weaken in the second half of the week for a gradual decrease in the temperatures and increase in afternoon breezes.
An amplifying upper trough will push eastward from tonight into Wednesday with deeper moisture quickly increasing across the forecast area from Wednesday morning into Wednesday afternoon. RW By Wednesday night the upper-level trough and associated cold front will still be progressing through the forecast area. Most convective allowing guidance shows a line or semi-broken line of storms along or just ahead of the cold front moving through central and eastern GA at 0Z that would expect to continue to push east with the front.
304 AM CDT Tue Apr 28 2020 Current observations reveal a cold front beginning to push south through CO/KS. With the mid level front not arriving until Tuesday evening, still think conditions across the CWA will be warmer than average, with highs mainly in the 80s.
The combination of downslope warming as well as compressional warming ahead of an approaching cold front will result in temperatures today well into the 90s for most of the area, with lower 100s possible across portions of the Permian Basin, Trans Pecos, Stockton Plateau, and through the Rio Grande Valley. The aforementioned cold front will begin to push southward into the area late this evening, and progress to the Rio Grande by early Wednesday morning. Winds will gradually diminish by early afternoon, with much cooler temperatures in the upper 70s to lower 80s expected, and 90s confined to the Rio Grande Valley.
332 AM EDT Tue Apr 28 2020 Upper level ridging will build into the eastern US today as a trough pushes east from the eastern seaboard. At the surface, the ridge of high pressure north of Florida this morning will slowly shift east into the Atlantic through Wednesday, with generally easterly winds turning to southerly. The influence of high pressure at the surface and aloft will support stable conditions, with dry and mostly sunny weather allowing temperatures to gradually warm up today and Wednesday.
The deepening low pressure system will continue to push off to the east Tuesday night into Wednesday, with some showers in a deformation band lingering across the area through at least the morning.
The main forcing with this feature won't arrive until after 7 PM Tuesday, as a cold front pivots southeastward across MO/IL and into our area Tuesday night. We continue to feel like the highest risk for severe storms will be across southeast Missouri, far southwest Illinois, and points further west of our CWA. With a 500mb closed low developing over Illinois on Wednesday, wrap around showers and isolated thunderstorms will pivot down across our area, particularly during the afternoon hours. We're going to see coolish start period temps transition to warmer than normal readings by this weekend, as the Eastern U. long wave trof is replaced by more zonal flow.
Winds, initially south-southeasterly across the forecast area, will veer through the period as a cold front approaches from the north.
SPC has a marginal risk of severe into our far southwest counties, as a warm front attempts to lift into the area this afternoon.
This storm is showing signs of weakening, likely due to the mixing of the low level jet, but small hail and frequent lightning will remain possible as it moves southeast of Corsicana and affects Fairfield and eventually Centerville in the next couple of hours. A lull in convective activity is expected later this morning and this afternoon, but active weather will arrive again this evening as an upper trough deepens across the Plains. Thunderstorms will develop rapidly late this afternoon north of the Red River, then push south through the region tonight along and ahead of a cold front. Otherwise, cooler and drier air will spread in behind the cold front, making for a rather pleasant Wednesday as convection continues south into South/Southeast Texas.
Dry and breezy conditions will take hold this afternoon under a northwest flow as the ridge axis shifts over the Great Basin. Temperatures today will be a few degrees cooler than yesterday due to the passage of yesterday's cool front but still about 10 degrees above normal. Dry conditions continue on Wednesday as the ridge axis shifts overhead.
829 AM MDT Tue Apr 28 2020 Vigorous upper level trough advecting through the region today. Further upstream, trough axis centered across central Montana will clip the northern half of the forecast area this afternoon. Ridging returns Wednesday as thermal ridge builds across the northern plains.
After this time, showers and thunderstorms redevelop across the Pine Ridge region and move across northern Nebraska and into north central Nebraska through the afternoon. Overnight Tuesday, skies will gradually scatter out as high pressure begins to build into the central Plains. Lack of cloud cover will allow temperatures to range from the mid 30s across the west to the low to mid 40s in central Nebraska.
Tonight, after 8 PM, the storms should be out of the east, and our area will dry out initially before the closed upper low moving overhead bring rain showers south of the area after midnight.
521 AM MDT Tue Apr 28 2020 A cold front extended from south-central SD through central KS and CO. This trough will continue its southeastward trek into the northern/central Plains today. Strong subsidence behind the exiting trough will transport these stronger winds aloft to the surface with gusts of 30-40 kt likely.
WV imagery indicates an upper level trough of low pressure digging southeast out of southern Canada into the Dakotas. Near the surface, a cold front is pushing southeast across west central into southwest and central Kansas. Winds will remain light and southerly until the surface cold front pushes across the area, between 12 and 15 UTC. With 850 mb temps around 15 degrees cooler than 24 hours before, lows tonight could be as low as around 40 degrees on the high plains and warmer near 50 on the lower plains. Sunny Wednesday as the large upper PV anomaly moves through the mid Mississippi valley leaving western KS in deep subsident airmass and amplifying ridge. The large high pressure will continue to build in to the area with steep lapse rates and gusty north surface winds though the day.
Building high pressure will result in warming interior temperatures today, with afternoon valley temperatures reaching well into the 80s and perhaps touching 90 degrees in the warmest locations.
A squall line will sweep through the region after midnight ahead of an approaching cold front. The precipitation appears to be the result of mid level isentropic ascent overtop the low level dry airmass. As it does so, its attendant cold front dropping through the mid MS valley will ignite a squall line during the afternoon. Once the cold front comes through Wednesday, dry air will filter in and the ArkLaMiss will see a break from the rain/storms for a few days.
629 AM EDT Tue Apr 28 2020 High pressure will remain across the region today with mostly sunny skies and warmer temperatures.
Light and variable winds will veer to the southeast after 14Z as high pressure moves east of the region today.
437 AM CDT Tue Apr 28 2020 High pressure will move off the Carolina and NE Florida coast by this afternoon eventually bringing dewpoints back up well in the 60s areawide. A deep amplified late season trough with an associated cold front will bring the next chance of showers and thunderstorms to the the forecast area on Wednesday. Given the high latitude track of the system the threat for tornadic severe weather expected to be minimal do to lacking of overall shear. The cold front will push through the area by Wednesday evening brining a return to dry and continued mild conditions.
High pressure aloft will strengthen across the interior west through Wednesday. A weak cold front will move through the northern and central Utah during the latter half of the week.
Main concern is severe weather for late this afternoon into early tonight as a cold front moves into northern and western OK from 18-21Z.
412 AM CDT Tue Apr 28 2020 A slug of mid level moisture associated with a weak upper trof over central Texas is producing a large area of cloud cover that has been gradually working its way into the region over the last few hours. This activity will form well ahead of a strong squall line that will develop along and ahead of a cold front which is expected to dig quickly south across the central U.
952 AM EDT Tue Apr 28 2020 High pressure centered over the southeastern United States supports moderate northeast to east breezes across the Florida Keys. High pressure will expand from North Florida into the Western Atlantic Ocean this afternoon, with the ridge axis dropping southward through Wednesday evening.
Today will be dry and warmer for most inland locations with highs in the upper 70s to lower 80s for many westside valley locations and low to mid 70s east of the Cascades. The lower clouds will break up around mid morning with partly cloudy skies in the afternoon. The upper ridge bringing the dry and warmer weather today will quickly shift east tonight and a moist southwest flow will replace it.
An upper level ridge will build and move inland on Tuesday, allowing for conditions to clear and temperatures to warm. The warming trend will continue into Wednesday as the ridge pushes eastward, forcing southwest flow aloft.
Clear skies, dry and warm conditions for Tuesday as high pressure develops over the area. Wednesday will be 10 to 15 degrees warmer than normal with temperatures in the upper 70s and possibly 80 in some locations.