Aikyam-Lab/Synoptic-Bench huggingface dataset:
In the mid and upper levels, a trough extended down from the Great Lakes Region down into Oklahoma and Texas, with another one from the Dakotas to the southern Rockies. As the first trough shifts southeastward today, the warm front will move back to the northeast. I'll detail All modes of severe weather will be possible today, with the highest likelihood over the western half of Arkansas this afternoon and evening. But, if this gets going and moves out early enough, it would be ample time for the low levels to recharge, as warm advection will be pretty strong, and 60+ dewpoints will extend well up into the warm sector. it's more of the high precipitable water/efficient rainfall producer setup. High pressure will follow the front, with precip moving out of eastern Arkansas during the morning as cooler, drier air advects in.
Warm inland today as high pressure passes over the region. A noted cooling trend develops as early as Wednesday as a dry cold front moves across Northern California with increasing onshore winds and a deepening marine layer lasting into the weekend.
A cold front will approach from CO/KS this morning, leading to gusty northerly winds at all sites late this morning into this afternoon. /Issued 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.
317 AM MDT Tue Apr 28 2020 Synoptic Setup: Desert Southwest contains hot high pressure that is constantly attempting to spring board north as a ridge into the least resistant pathway. The northwest quarter of the CONUS including northeast Montana has zonal flow aloft bringing ridge/trough couplets across in a fairly progressive pattern. Along with this gusty winds are expected to have enough mixing to drop RH down to near 15 percent behind the trough by the afternoon. Tonight through Wednesday: As the PGF slackens and high pressure takes hold, winds will rapidly decrease after dark with fairly light southern winds lasting through Wednesday afternoon. Ridge overhead should also keep things clear to partly cloudy for awhile.
The next wave and cold front will come in late tonight through Wednesday. The first will be late tonight in our far western counties and the second will be Wednesday morning as the cold front moves across our eastern counties.
/issued 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.
Building high pressure brings steadily warming temperatures and dry conditions with record highs in many locations on Wednesday. A few thunderstorms are possible across Elko county for the latter part of Wednesday, which signals the start of a slightly more active and cooler weather pattern for the remainder of the week.
A cold front will backdoor the area after sunset, w/fropa at KMAF/KHOB around 05Z. 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.
Chattanooga Airport, TN 77 59 69 50 64 / 20 40 100 30 30 Knoxville McGhee Tyson Airport, TN 74 59 71 51 61 / 30 20 100 60 60 Oak Ridge, TN 73 57 69 50 62 / 40 20 100 50 60 Tri Cities Airport, TN 70 54 73 50 59 / 20 10 90 90 70.
325 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.
A weak warm front will clip the area today with rain mainly on the Olympic peninsula.
A cold front will move through KABI this evening and the rest of the terminals overnight, shifting winds to the northeast. 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.
/issued 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.
Upper level ridge axis moves across the region today, the hottest temperatures of the week expected this afternoon. The good news is the heat will be short lived, with onshore flow developing by early evening as the ridge axis shifts eastward. Lows in the Delta and Sacramento metro area are expected to be in the upper 50s, in the lower 60s elsewhere in the Valley, mid 60s in the foothills. The area will see more widespread cooling on Wednesday, with highs about 4 to 8 degrees cooler than those of today, in the mid to upper 80s.
Midafternoon GOES water vapor imagery showed a double-centered upper low over the western Dakotas, and another upper low near Duluth MN. These three low pressure centers will combine into one deep upper low dropping into the mid-MS River valley by Wednesday morning. Main directed cold pool push will likely occur to the west and south of the Midsouth, toward the Red and Sabine River valleys, into the low level instability axis. One axis of the multi-lobe upper low will drop through the Midsouth toward midday Wednesday. That said, 925-850mb winds are depicted 25 to 30 knots, less strong than with the previous couple of upper low pressure systems.
An upper level trough over the Northern Plains today will deepen into the Southeast on Wednesday. An associated cold front will enter our western zones during the afternoon and push gradually eastward.
1119 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.
259 PM 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. It looks like a fairly decent slug of mid and upper level clouds will stream over the region on the back side of the ridge axis. Attention then turns to increasing afternoon breezes late week, as the ridge moves off to the east and leaves the region sandwiched in southwest flow.
A mid tropospheric trough extends from the Dakotas and MN down into NE, with several vort maxes embedded. High temperatures will be cooler, in the 60s.
Short range models indicate a strong upper level trough of low pressure digging southeast out of the Dakotas into the Central Plains tonight, then turning eastward across the Mississippi River Valley Wednesday all while ridging aloft moves in across the Intermountain West. Near normal temperatures are likely tonight as cooler air spreads into western Kansas behind today's frontal passage. Should see highs only up into the 70s(F) Wednesday with cooler air settled across the high 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.
Surface winds will back off a bit this evening, but will pick back up after midnight thanks to stronger winds aloft on the backside of the upper trough. Skies will also clear out as high pressure moves in, allowing for good radiational cooling.
The remainder of the night should be mostly quiet, with dry weather favored along with dropping temperatures behind the cold front. Rain showers are likely across the area beneath the amplifying trough on Wednesday. The trough axis attendant from the closed low across the Great Lakes is expected to move far enough eastward Wednesday night.
143 PM PDT Tue Apr 28 2020 High pressure will continue to strengthen today resulting temperatures 15 to 20 degrees above normal in the mountains and deserts and 5 to 10 degrees above normal west of the mountains.
310 PM CDT Tue Apr 28 2020 A cold front will trigger thunderstorms across central Illinois this evening. 19z/2pm surface analysis shows a 1004mb low over southeast Minnesota with a cold front extending southwestward to near the Kansas City metro.
VFR conditions likely overnight with gusty northwest winds behind cold front into Wednesday morning.
However, with the upper level low parked to our north, wrap around showers and isolated thunderstorms will spread back into the region by the afternoon tomorrow.
co- located with the highest dewpoints and sfc/elevated CAPE values in excess of 3000 J/Kg. Ongoing convection along the southeastward moving cold front in Central Kansas is expected to continue to build back westward along the front with additional storm initiation forecast over the next couple of hours as the front reaches the higher moisture/instability plume. as thunderstorms fill the line along the cold front as it pushes south southeast through the CWA. Majority of the storms should be exiting the CWA around 5-6z with the exiting cold front. Behind the cold front. northwesterly winds transporting a drier and cooler airmass into the region will continue into Wednesday while the main upper level trof axis moves through and exits the Plains. There may be a few light rain showers across Northwest Arkansas Wednesday afternoon as the trof axis moves through the CWA.
147 PM CDT Tue Apr 28 2020 An upper ridge centered over the West Coast will slide east today as a trough moves down from the Northern Plains to the Mississippi River Valley.
The trailing boundary is now moving east of Interstate 35 with the pre-frontal trough even further east and about to move out of the county warning area. Temperatures on Wednesday will be cooler with highs in the 50s and 60s but obviously the chill from the wind will keep apparent temperatures much lower than that.
Previous Discussion: Synoptic Setup: Desert Southwest contains hot high pressure that is constantly attempting to spring board north as a ridge into the least resistant pathway. The northwest quarter of the CONUS including northeast Montana has zonal flow aloft bringing ridge/trough couplets across in a fairly progressive pattern. Along with this gusty winds are expected to have enough mixing to drop RH down to near 15 percent behind the trough by the afternoon. Tonight through Wednesday: As the PGF slackens and high pressure takes hold, winds will rapidly decrease after dark with fairly light southern winds lasting through Wednesday afternoon. Ridge overhead should also keep things clear to partly cloudy for awhile.
Strong ridge building across the region will bring the warmest day yet of the year on Wednesday. The high at Billings so far in 2020 has been 72 degrees, and we will eclipse that easily.
Mostly clear skies tonight with temperatures a few degrees warmer than last night as south to se winds increase the low level moisture. Winds will increase and become breezy on Wednesday as the pressure gradient tightens ahead of the frontal system moving east across the lower Ms River Valley.
As high pressure moves east of the region, high clouds will increase from the west and winds will veer to the south around 10-12 knots towards 00Z. Winds will relax after 00Z to 4-6 knots and then increase by 14Z from the south 10-12 knots inland and 12-14 knots at the coast terminals with some gusts up to 18-22 knots at those locations as the pressure gradient increases ahead of a low pressure system approaching the region from the west late in the day Wednesday well after the end of the 18Z TAF period.
/NEW/ /Through Wednesday/ An upper trough currently located over the Dakotas will deepen as it drops southeast through the Plains tonight and into the Mississippi Valley Wednesday. Strong ascent associated with the system will lead to rapid thunderstorm development across Oklahoma late this afternoon, with convection being focused along a southward moving cold front. Gusty north winds will advect a drier and cooler airmass across the region behind the cold front, keeping high temperatures comfortably in the 70s for Wednesday.
1133 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.
The next wave and cold front will come in late tonight through Wednesday. The first will be late tonight in our far western counties and the second will be Wednesday morning as the cold front moves across our eastern counties. An approaching low pressure system and front will keep winds gusty out of the southwest throughout the TAF period.
That said, can't rule out small, sub-severe hail (with freezing heights around 7000 ft) and brief gusts up to 55 mph. With the deepening upper level trough and tightening surface pressure gradient, expect windy conditions through Wednesday night. Some late runs today hi-res models have started to hint at some afternoon showers Wednesday, mainly across the Buffalo Ridge. The latter half of the week looks quiet, with a fairly robust ridge and return to mid- and upper level northwest flow.
Inland, stratus still persists in the valleys and northern ridges of Coos, Curry, Douglas and Josephine Counties. Some high cloud moving into the area may slow the decay of this low cloud, but it is still expected to gradually dissolve as the high clouds shift north. The lower conditions should improve to VFR later this morning and this afternoon, though IFR stratus will likely return to coastal areas in the evening and last most of the night.
This low level instability, 0 to 3km MLCAPE of up to 150j/kg, per latest mesoanalysis, combined with short wave forcing and cold pool aloft will create the possibility of enhanced low level stretching. Precip ends tonight as cold front turns winds to the north.
A weak warm front will pass by and bring rain mainly to the Olympic peninsula.
CDG Chattanooga Airport, TN 59 69 50 64 47 / 20 90 30 30 20 Knoxville McGhee Tyson Airport, TN 59 72 51 61 46 / 10 100 60 60 30 Oak Ridge, TN 58 71 50 62 45 / 10 90 50 60 20 Tri Cities Airport, TN 55 74 50 59 44 / 10 70 90 70 60.
Current forecast is on track expecting sunny and warmer weather today, then very warm Wednesday followed by showers and thunderstorms late Wednesday in eastern Oregon and Wednesday night in western Idaho.
Convection associated with a weak short wave trough was moving away from the region into the upper Texas coast. Some of the hi-res models show convection may develop over northeast Mexico as a weak short wave trough moves southeast out of Coahuila.
A cold front with gusty north to northeast winds will begin moving into the area tonight. 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.
The evening will set up with much of the area recovered and ready for action as the cold front dives our way. The front will shift the winds before daybreak, but lows in the low to mid 60s will become much cooler tomorrow night as highs keep to seasonal.
243 PM CDT Tue Apr 28 2020 A line of storms was rapidly developing along a cold front this afternoon in southeast Minnesota.
A cold front will move down through North Texas tonight bringing showers and thunderstorms into the eastern half of South Central Texas.
Another question is how much low level moisture can work north into the area ahead of the cold front. Currently have dew points in the lower and mid-50s. It still looks like some will develop, so thinking we will see some large hail and damaging winds along and just ahead of the cold front. There is still a possibility of isolated tornadoes near the warm front which be located near the Interstate 90 and 94 corridors.
While severe storms will be possible across the area, the higher chances will be north of I-10 with increasing threat the further north you go. Fowler A deep upper trough over the southern Great Lakes will allow upper level ridging to expand over Texas.
Farther west, the surface boundary is being influenced by what appears to be a secondary 850 low and a subtle 500mb short wave trough moving into northeastern Kansas.
130 PM EDT Tue Apr 28 2020 High pressure will remain across the region today with mostly sunny skies and warmer temperatures.
Overnight lows will also be milder and above freezing up to mid mountain levels.
Short range models indicate a strong upper level trough of low pressure digging southeast out of the Dakotas into the Central Plains tonight, then turning eastward across the Mississippi River Valley Wednesday all while ridging aloft moves in across the Intermountain West. Near normal temperatures are likely tonight as cooler air spreads into western Kansas behind today's frontal passage. Should see highs only up into the 70s(F) Wednesday with cooler air settled across the high plains.
The aforementioned cold front will pass through the region late this evening, resulting in a wind shift to the north and northeast. Winds will begin to taper off after dark as cooler air filters into the CWA. During the early morning hours, a secondary surge of cooler air will move through the region causing lows to bottom out into the upper 40s across the extreme southern Texas Panhandle and into the lower 50s in the South and Rolling Plains. Relatively milder temperatures are in store for Wednesday, as highs build into the upper 70s on the Caprock and into the lower 80s in the Rolling Plains due to the light, northerly winds.
338 PM CDT Tue Apr 28 2020 18Z surface data has has low pressure in southeast Minnesota just west of KRST. A warm front extended east southeast from the low across southern Wisconsin into lower Michigan. A cold front and a pre-frontal boundary ran south from the low through central Iowa and into eastern Kansas. Dew points south of the warm front and ahead of the cold front were in the 50s and 60s. Behind the cold front dew points were in the 30s and 40s. The question becomes what will occur with the cold front. Satellite trends through mid-afternoon indicate a stable atmosphere below the higher altocumulus and cirrus over the area.
A pair of upper lows over the north central U. this hour will merge into one closed low by daybreak Wednesday somewhere near the MO/IA/IL border. By late morning, convective temperatures look to be low enough to see additional showers/some storms develop closer to the actual cold front pushing eastward through the region. Given the cold dome of air coming with the upper level low passing by just to our north, would not be surprised to see some gusty conditions.
This system will drive a cold front southeastward, passing through Middle Tennessee on Wednesday. At the same time, a low pressure system will close off and sit over the Ohio Valley. By late morning, instability ahead of the incoming cold front may help storms perk up again for areas east of I-65. The deep and cold upper level low will help generate scattered showers through the afternoon.
The window for the potential of SVR storms is still from 5-9pm when the low pressure area and cold front moves from sw WI ewd to srn or central Lake MI by 06Z. Sfc based CAPE of 500-1200 J/KG is now present along the cold front over ne IA. The low pressure area will then occlude over lower MI for Wed-Wed nt with brisk nly winds, cool temps, and showery conditions for srn WI.
The cold front that approaches the area on Wednesday, moves across the area Wednesday night with shower and storm chances diminishing. Storm total rainfall for Wednesday/Wednesday Night is ranging in the 1 to 2 inch range for most areas with the highest amounts favoring the mountains.
254 PM EDT Tue Apr 28 2020 High pressure centered near South Carolina supports moderate northeast to east breezes across the Florida Keys. Temperatures are in the lower to mid 80s with dewpoints in the mid to upper 60s. Meanwhile, the high pressure system near the Carolinas will spread east into the western North Atlantic.
High pressure aloft will strengthen across the interior west through Wednesday.
Farther upstream over the northern High Plains, an upper jet streak is digging southeast across the central Plains states, with a trough expected to rapidly deepen over the eastern Plains and MS Valley as a result tonight into Wednesday. CAMs also indicate some redevelopment occurring in the wake of this line along the cold front itself over southwest Alabama late Wednesday afternoon as the boundary layer recovers under peak daytime heating. These thunderstorms, both along the leading line and the cold front, will carry potential for damaging wind gusts.
A cold front will move through the area overnight, resulting in north to northeast winds of 12 to 20 knots, with higher gusts. A cold front will move through KABI this evening and the rest of the terminals overnight, shifting winds to the northeast. 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.
245 PM CDT Tue Apr 28 2020 An upper ridge centered over the West Coast will slide east today as a trough moves down from the Northern Plains to the Mississippi River Valley. This trough will move off to the east then flatten out by the weekend.
With upper level ridging working in from the west tomorrow, expect the warming trend to continue resulting in lower relative humidity values tomorrow, but with less wind.
Upper trof very evident in wave imagery is diving quickly southeast through western SD this afternoon.
We clear out in the west, behind the exiting system, with high pressure settling over the far west by 12 UTC Wednesday. Much less wind and dry on Wednesday with highs in the 60s east to lower 70s west as upper ridging builds over the area.
909 AM PDT Tue Apr 28 2020 High pressure will continue to strengthen today resulting temperatures 15 to 20 degrees above normal in the mountains and deserts and 5 to 10 degrees above normal west of the mountains.