Aikyam-Lab/Synoptic-Bench huggingface dataset:
1000 AM PDT Thu Mar 22 2018 A weakening low pressure trough will interact with deep tropical moisture today to produce light to moderate rain that will sweep across the region, starting across Orange and San Bernardino Counties early in the day, then spreading south.
As the high pressure moves in, the flow from the northwest will bring in cool air that will keep high temps near mid 40s today. The ridges could get down near 30, whereas the valleys could drop into the mid to low 20s.
The rest of the day should be fairly cloudy but quiet with upper ridging building over the western Plains. Some of the high res models have a few blips of QPF so will have to watch for flurries, but not seeing much upstream currently so will hold off any mention for now. The upper ridge will move east tonight and the band of precip will begin to approach our far southwestern counties. Upper level trough will move into the area by Sat morning and essentially shut down the precipitation.
Today Through Friday Night 08z subjective surface analysis indicates a ridge axis from southeast Arkansas, to western Illinois. A few light rain showers will be possible late in the period, weakly focused by a developing warm front across northern Arkansas.
926 AM EDT Thu Mar 22 2018 High pressure slowly builds in today and tonight. Another low pressure system this weekend. A northwest wind flow will persist today, although moisture in the lower atmosphere will be rather limited. A high pressure system will then briefly move over the area tonight.
At that point, a low pressure system will exit the plains and bring in initially chances for rain in the southwest, and then a wintry precipitation mix and some heavy snow potential across central and northern parts of the area with rain remaining across the south.
Temperatures should end up near the high side of the guidance similar to last few days. Little change expected Friday night as the upper low meanders off to the east. 500 mb closed low passes across the area late tonight and on Friday bringing deeper moisture, increased instability, and eventually scattered snow showers, especially over the NY zones.
This will lead to quite a temperatures spread across the area with temperatures only reaching the lower 50s across northeastern Kansas and the low to mid 60s elsewhere. Friday afternoon, a warm front will lift into the CWA as a southwesterly LLJ noses into the area. This will allow showers to develop along and north of the warm front across northern and central Missouri. The warm front bisecting the CWA will also lead to a similar temperature spread to today with highs in the low to mid 50s across northeastern Missouri to the low to mid 60s across the rest of the CWA. This will force a cold front into the area. Thunderstorms will be possible as the cold front moves through the area however, they are not expected to be severe with weak instability.
Northwest flow aloft holds through tonight btwn plains ridging and upper trough bringing Noreaster to Mid Atlantic and New England. At the sfc, weak high pressure ridge across the Upper Great Lakes today will be replaced by ridge extending from stronger high pressure over 1045mb expanding over Hudson Bay late tonight into Friday. NNW gradient wind out of the high to the north of Lk Superior will keep Lk Superior shore from Copper Harbor, Big Bay and Marquette to Grand Marais coolest with highs near 30 degrees. Should see readings only into the lower 30s over the rest of the east forecast area, including at Newberry.
Also made a slight upward adjustment to dewpoints through the day as morning observations were 2-3 degrees warmer than the forecast, and the latest guidance didn't seem to support quite as much mixing out of dewpoints this afternoon.
Some location have already dropped below freezing and more locations should drop to or below freezing before sunrise so will leave current Freeze Warning and Frost Advisory alone. High pressure currently covers much of the Mississippi Valley at this time.
/BB/ Prior discussion below: Today through Tonight: Latest rap and satellite imagery showed an amplified ridge over the Rockies which was providing northwest flow to the region. On the surface a ridge of high pressure was centered over the Midsouth region. Expect areas of frost across the northeast and eastern counties early where some readings were approaching the lower 30s. Otherwise high pressure will bring another day of mostly sunny skies with highs a little more seasonable with readings from the lower 60s northeast to near 70 southwest. With dewpoints mainly in the 30s minimum humidity will dip down into the lower 30s.
Temperatures dropped below freezing across much of our counties located along and north of the Interstate 20 corridor. With full sunshine, temperatures have quickly risen above freezing over the past hour across much of our forecast area. A pleasant day is expected with mostly sunny skies and highs warming into the mid 60s across our southwest counties while cooler reading will be found across our northeast counties with highs in the upper 50's. Lows tonight will be slightly warmer compared to this morning so patchy fog will remain possible across the the normally colder locations in our northeast counties.
A cold front will move through Western Washington this morning followed by a trough axis this afternoon. A deep upper level low will keep the air mass cool and unstable through Friday with isolated thunderstorms possible.
1139 AM EDT Thu Mar 22 2018 An approaching pressure ridge will extend through the forecast area tonight.
/issued 320 AM CDT Thu Mar 22 2018/ Breezy south winds and warmer temperatures expected today with afternoon highs climbing into the 70s and 80s.
/Today through Tonight/ Confidence: Medium to High Weak surface warm front and warm air advection aloft continue to result in a narrow band of light precipitation from west central Iowa southeast to near Lamoni at 0645z. Will monitor for any possible light freezing precip if temperatures on the leading edge of the cloud cover dont warm fast enough. Temperatures immediately behind the warm front continue to warm into the mid to upper 30s already this morning. Temperatures tonight will be warmer with east winds increasing during the night.
Snow levels will begin lowering today with significant accumulations at the higher elevations into the weekend. The large area of rain is expected to slowly edge east out of the valley this morning as the cold front approaches, though orographics will keep precipitation going in the foothills and northern Sierra.
A second cold upper level trough off the Pacific Northwest coast will move east and impact mainly northern and western Utah and southwest Wyoming this weekend. Strengthening flow aloft coupled with a tightening pressure gradient today should also allow winds across western Utah as well as the higher terrain to increase.
/issued 415 AM CDT Thu Mar 22 2018/ (Today and Tonight) High pressure across the region will leave quiet weather in place for today and tonight. Temperatures will be a bit warmer than yesterday in the mid 70s to lower 80s with sunny skies. Then for tonight, winds are expected to drop off little bit and low temperatures should drop into the lower 50s.
The upper level trough axis will edge eastward today with the area in deep-layer northwesterly flow.
Main concern right now is an upper level low with some associated moisture that may cover northern Michigan in clouds. Pattern synopsis/forecast: Dry northwest flow prevails aloft, while extensive area of high pressure dominates the surface. Wave and reinforcing area of high pressure work in tandem to keep cool northerly flow in-place, with the actual low level thermal environment changing little from that which was observed yesterday.
A cold front will move across the area this morning followed by fairly low rain and snow chances this afternoon.
Early this morning the region was under northwesterly flow aloft due to a broad mid-level trough stretched across the eastern U. and a mid-level ridge over the Rockies gradually advancing eastward into the central U. During the evening areas near the NE/KS state line will be closer to the trough and the associated forcing as the wave tracks over NE.
For comparison, the low temperature this morning at our office in Key West was 64.
High pressure at the surface will be impinged on by a weak disturbance moving southeast along a warm front to our southwest today. Low temperatures will bottom out in the lower to middle 30s.
Southerly lower level flow has resulted in warmer temperatures and increased moisture early this morning versus yesterday.
746 AM EDT Thu Mar 22 2018 Building high pressure should maintain mainly dry weather through Friday.
Strong low level jet will precede the low and may support isolated showers across far NE OK / NW AR, however the primary axis of precip will remain well north and east of the forecast area.
Still cooler than normal for the afternoon but moderated from Wed with highs in the mid to upper 50s North to lower 60s for Central Ga. High progresses over the area through Friday morning but increasing clouds should keep temps above freezing and preclude the need for any additional warnings.
827 AM EDT Thu Mar 22 2018 An approaching pressure ridge will extend through the forecast area tonight.
Surface analysis this morning places a 1030 mb ridge of high pressure over portions of the Middle and Lower Mississippi Valleys. GOES-16 Satellite trends indicate some mid/high level clouds spilling over the eastern periphery of an upper level ridge axis. Some location have already dropped below freezing and more locations should drop to or below freezing before sunrise so will leave current Freeze Warning and Frost Advisory alone. High pressure currently covers much of the Mississippi Valley at this time.
Otherwise sunny ridge-dominated day with rather brisk conditions given enhanced NW flow. Still cooler than normal for the afternoon but moderated from Wed with highs in the mid to upper 50s North to lower 60s for Central Ga. High progresses over the area through Friday morning but increasing clouds should keep temps above freezing and preclude the need for any additional warnings.
A few lingering rain/snow showers may persist across the coast into early afternoon but temperatures will be rising well above freezing. Upper low pressure lingers over the Maritimes through the weekend with potential for clouds and scattered rain/snow showers. High temps should recover into the lower to middle 40s in many locations. Coastal low pressure pulls further away from the region and winds will continue to diminish tonight.
and Friday Persistent Hudson Bay high pressure will keep clear to partly cloudy skies over the region through Friday. Mixing through about 850 mb should support highs in the upper 30s to middle 40s, with slightly cooler readings near Lake Michigan as east to northeast winds increase on Friday. Lows tonight are tough, as there are large discrepencies between the cooler MET and milder MAV.
For today, the upper ridge across the Rockies will gradually slide over the high Plains by this evening.
The interaction between lower pressure across west Texas and high pressure across the Gulf of Mexico will increase the pressure gradient. High temperatures today will be in the low to mid 80s, except for the 70s near the coast. Above normal temperatures will continue into Friday with high temperatures in the 80s near the coast to the lower 90s inland under a mix of sun and clouds.
The only real change from today will be temperatures that are a few degrees warmer.
This dry punch and slightly cooler air aloft, as well as potentially much cooler if saturated, might allow development closer to the 925mb boundary.
Weather features as of Tuesday afternoon include a cold frontal boundary extending from low pressure across Minnesota through South Dakota.
855 PM EDT Tue Apr 18 2017 Weather pattern will become more active beginning Wednesday and continuing through the rest of the week thanks to a series of low pressure systems.
A cold front will push southward into central Kansas by late afternoon with the surface pressure gradient tightening up ahead of the front creating strong south winds.
634 PM CDT Tue Apr 18 2017 A busy weather day today with a low pressure system screaming east through central MN. The tough part of the forecast is whether or not the low clouds hang around as high pressure builds in from the northwest. This next system will lift northeast out of Colorado with the warm front advancing through much of Iowa.
This front will lift back northward on Wednesday as an upper level trough moves eastward into the northern Plains and another surface wave develops along the front ahead of it. Warmer temperatures can be expected tonight and Wednesday with southerly surface winds in the warm sector.
/issued 328 PM CDT Tue Apr 18 2017/ An upper level high pressure ridge will pass overhead tonight with mostly thin cirrus. Fog and stratus seems most plausible again over the Rolling Plains in-line with short-range solutions, but also not impossible again over the eastern and central parts of the High Plains, though only in a very thin layer near the ground. On Wednesday, an upper level trough will eject from the Rockies to our north but will flatten and increase mid level flow just a bit.
A weak trough over the southeastern Gulf of Mexico will move westward and dissipate overnight. A large-scale high pressure cell centered over the western North Atlantic currently is being fortified as it coalesces with a southward-building continental anticyclone.
A cold front extended southwest of this low into southwest Minnesota. The main severe weather threats will be large hail and maybe damaging winds near the warm front. In addition with the nose of the low level jet, a coupled jet overhead, and precipitable water values up to 1. After midnight on Wednesday night, the low level jet veers into eastern Wisconsin.
A weak cold front will move east across the forecast area through 12Z with associated scattered showers.
1050 PM CDT Tue Apr 18 2017 A busy weather day today with a low pressure system screaming east through central MN. The tough part of the forecast is whether or not the low clouds hang around as high pressure builds in from the northwest. This next system will lift northeast out of Colorado with the warm front advancing through much of Iowa.
No rain expected with upper ridging over the region.
919 PM EDT Tue Apr 18 2017 High pressure will move east of our region tonight.
1102 PM EDT Tue Apr 18 2017 Update/Marine A weak cold front will bring scattered rain showers tonight.
Most areas will remain dry with highs in the low/mid 80s. A weak mid level trough is situated across West Tennessee and North Mississippi along with some deeper moisture. As the mid level trough and deeper moisture shifts east expect some clearing with patchy fog developing later tonight.
Mid level ridge axis comes through overnight, allowing for skies to clear over good portion of the region.
740 PM EDT Tue Apr 18 2017 Aviation A weak cold front will bring scattered rain showers tonight.
542 PM MDT Tue Apr 18 2017 Southwest flow has developed aloft across the western half of the CONUS including over the northern plains ahead of a longwave trough slowly moving onshore the Pac NW coast. except across parts of the higher Black Hills. Temps will be cold enough late tonight for rain to mix with or change to snow across the higher Black Hills.
A frontal boundary will move into the lower Great Lakes region late tonight into Wednesday and stall, perhaps sparking a few showers and thunderstorms over mainly northern portions of the region from Wednesday afternoon into Wednesday night.
/issued 233 PM CDT Tue Apr 18 2017/ Upper ridging takes over today and tomorrow, leading to warming temperatures and hindering any thunderstorm development.
For the time being, left fog mention out of the forecast given the low confidence, but something to monitor this evening for sure.
846 PM MDT Tue Apr 18 2017 Lobe of instability (800-700 mb layer) associated with approaching trough is producing some decent showers to our west. An upper low and trough off the Pacific Northwest coast will continue to provide a southwest flow aloft across our forecast area this evening through Wednesday. High pressure ridging will begin to build once again during the afternoon and overnight Wednesday. This will be short-lived as the upper low and trough off the Pacific Coast move onshore across the Great Basin area.
Southwest flow has developed aloft across the western half of the CONUS including over the northern plains ahead of a longwave trough slowly moving onshore the Pac NW coast. except across parts of the higher Black Hills. Temps will be cold enough late tonight for rain to mix with or change to snow across the higher Black Hills.
As this trough passes, a cold front will move into central Kansas late Wednesday afternoon and intersect a dryline.
Mixing has allowed temps to increase into the lower to mid 70s. The NAM and ARW solutions suggest more suggest a stronger push from the cold front once it becomes activated than some other solutions. Thunderstorms should be ongoing along a cold front bisecting the CWA from NE to SW at the onset of the period Wednesday evening.
For Wednesday, the weakness aloft and trough axis is expected to move slower eastward than previously expected, which could lead to increased afternoon convection. Going 20-30% right now, but could see higher chances in updates later overnight if position of trough axis still over SE TX/W LA and if enough energy and instability continues into Wednesday afternoon.
A weak upper ridge will move in late tonight. The ridge will be accompanied by mostly clear skies and light winds, and thus an opportunity for patchy valley fog late tonight and early Wednesday morning. The ridge will shift east and transition to a southwest flow aloft on Wednesday.
915 PM EDT Tue Apr 18 2017 A weak low pressure system will track north of Pa tonight and Wednesday.
Stationary front north of the Altamaha river will gradually dissipate as high pressure builds over the Carolinas on Wednesday.
Associated trailing cold front extends from the Wisconsin low southwest into an area of low pressure over far southwest Kansas. Southerly low level flow across the Southern Plains has kept moisture in place across the region with stratus/fog noted across much of OK this morning and surface dewpoints in the low 60s to the south of the boundary. Hail and wind look to be the primary threats however within backed sfc flow near and just north of the warm front, we could see some tornadic potential by mid/late afternoon.
A weak mid level trough is situated across West Tennessee and North Mississippi along with some deeper moisture. As the mid level trough and deeper moisture shifts east expect some clearing with patchy fog developing later tonight.
Expect the ern convection to eventually dissipate with loss of heating, but combo of our very moist airmass and the pesky mid/upper-level trof over ern TX could continue to produce some rainfall through the overnight hours. For Wednesday, the weakness aloft and trough axis is expected to move slower eastward than previously expected, which could lead to increased afternoon convection. Going 20-30% right now, but could see higher chances in updates later overnight if position of trough axis still over SE TX/W LA and if enough energy and instability continues into Wednesday afternoon.
This will effectively lift the old front north as a warm front, while a dry line develops southward from the low. Models indicate the warm front will make it as far north as southwest Nebraska after midnight, which is where any elevated thunderstorm may develop. Might see some fog develop along and north of the warm front as well with moist upslope low levels. A cold front pushes through the region Wednesday night with subsidence filtering in behind.
Dew points over the plains are in the lower 30s to lower 40s F in most areas. Models show a weak upper trough axis to push across the CWa after 06Z tonight with downsloping low level wins over the plains by 12Z. In the low levels, moisture will increase across the northeast plains in southeasterly flow. On Wednesday, the flow is strong and well mixed, so the subsident post-trough environment should bring gusty winds to all of the forecast area including the plains.
The remnant warm front has lifted off to the north, with dew points now recovering to the mid and upper 50s across the entire area. At the same time, a weak warm front will continue to lift north across the area. Some showers from this trough may linger into Wednesday afternoon, mainly in the east. Colder and drier air will quickly invade the region as the trough exits, dropping temperatures into the low and mid 30s Wednesday night.
A trough over the eastern Pacific will move inland across California tonight and Wednesday bringing gusty afternoon and evening winds to the mountains and deserts.
Despite partial clearing, afternoon highs will be cooler on Wednesday, especially north of the stalled front in the vicinity of the I-70 corridor. A shallow transient ridge forms over the region Wednesday night while drying continues. Overnight lows will be colder but do not pose a threat of freezing temperatures in the lower valleys.
1223 AM EDT Wed Apr 19 2017 A series of low pressure systems will keep periodic rain chances in the forecast through late week. A weak boundary will splay west to east across the area, stalling out due to the broad ridge resident over the southeast CONUS.
920 PM MDT Tue Apr 18 2017 Critical fire weather conditions have eased up this evening as relative humidity values climb back above 15 percent in the lower valleys. Still expect periods of gusty winds through late tonight as we see the cold front to our northwest push across the area. Despite partial clearing, afternoon highs will be cooler on Wednesday, especially north of the stalled front in the vicinity of the I-70 corridor. A shallow transient ridge forms over the region Wednesday night while drying continues. Overnight lows will be colder but do not pose a threat of freezing temperatures in the lower valleys.
643 PM CDT Tue Apr 18 2017 Skies will remain partly cloudy this evening, but an increase is expected late tonight in the northwest as a cold frontal boundary slowly drifts into the area. reaching into the lower 80s across most of the area.
Clear skies under dry west to southwesterly flow aloft this evening with a ridge axis now off to our east. Even warmer temperatures for this weekend with stronger ridging aloft building in.
913 PM EDT Tue Apr 18 2017 High pressure will build over the area through early Wednesday.
A weak cold front will continue moving east across the forecast area east of Interstate 15 through 12Z with associated scattered showers and periods of MVFR ceilings.
715 PM EDT Tue Apr 18 2017 High pressure will move east of our region tonight.
743 PM EDT Tue Apr 18 2017 A ridge of high pressure will move off the New England coast overnight. A slow moving cold front will move slowly east from the Great Lakes on Wednesday and will bring rain showers to the north country late Wednesday afternoon and Wednesday night.
A wave which crossed the plains overnight brought a cool front into our northern zones this morning, while to the south a warm front was lifting north from Kansas. Given the frontal position, orientation of the low level jet and track of the wave, our Nebraska zones (especially the eastern and northern zones) have the better chances for precipitation overnight. Chances for convection linger into Wednesday until a cold frontal boundary moves through and scours the low level moisture. Our southeast zones remain in a SPC Day 2 slight risk, for storm development along the cold front in the late afternoon/eve.
Despite the eastward propagation of a deamplified UA ridge tomorrow, can not rule out diurnally driven precip during the aftn tomorrow with a quick demise after sunset, all thanks to the nearby shear axis and a moist low level atmosphere /PWATS of 1.