Aikyam-Lab/Synoptic-Bench huggingface dataset:
410 AM CDT Mon May 18 2020 The main weather feature in the near term will be the Midwest mid/upper low (and its surface reflection). Meanwhile, the mid/upper low, motivated by a building ridge over the central CONUS, will continue to dive toward our region. The presence of the low will continue to generate isolated to scattered showers for Tue and Wed, mostly during the daylight hours, with the highest PoPs on Wed in the Pennyrile region as the low stalls temporarily in TN. The upper low over the Ohio/TN valley regions at the beginning of the period will move east and weaken. Meanwhile out west, a trof will develop and gradually move east with time. Ridging should develop between the two systems.
Water vapor loop indicated ridge building over ID and MT as upstream trough shortens in wavelength. Easterly low level flow will bring drier air into the area today with a high pressure system over James Bay. Ridge building will continue over the Northern Plains today through Tue.
However, there should be enough daytime heating/instability, combined with sufficient lift from approaching vigorous mid level S/W trough to allow storms and areas of rain to continue pushing through the area with additional scattered to numerous storms development ahead of this activity through the afternoon.
Water vapor imagery this morning shows a long conveyor belt of Gulf moisture spreading across the TN Valley to the Great Lakes ahead of two low pressure systems, one over LA/MS and the other over IL/MO/IA. The line of showers near the cold front will sweep NE across our area tonight, and with high PW values and efficient warm cloud processes, locally heavy rainfall can be expected.
The main weather feature in the near term will be the Midwest mid/upper low (and its surface reflection). Meanwhile, the mid/upper low, motivated by a building ridge over the central CONUS, will continue to dive toward our region. The presence of the low will continue to generate isolated to scattered showers for Tue and Wed, mostly during the daylight hours, with the highest PoPs on Wed in the Pennyrile region as the low stalls temporarily in TN. The upper low over the Ohio/TN valley regions at the beginning of the period will move east and weaken. Meanwhile out west, a trof will develop and gradually move east with time. Ridging should develop between the two systems.
The closed upper low continues to rotate over the Midwest region while a secondary upper trough is just off the northwest coastline. Ridging is continuing to build over the Intermountain West, bringing a welcome break from rain chances the next few days in the area. Expect the cloud deck to once again mix out by mid afternoon, allowing pleasant temps in the low and middle 70s to return to northeast Kansas. The upper ridge begins to elongate into the plains this evening, slowing the cutoff low as it's blocked by Tropical Storm Arthur in the Atlantic.
High pressure will allow dry weather to return for tomorrow with plenty of sunshine. A large closed off upper level low is located over the mid-Mississippi Valley. Clearing is starting to slowly move in from the north, as an area of Canadian high pressure builds southward towards the area. The remainder of the short term period will be dry with seasonable temperatures and mostly sunny skies as Canadian high pressure dominates.
358 PM EDT Mon May 18 2020 High pressure pushes in from the north over the next few days while Tropical Storm Arthur turns east over the Atlantic. Expect mostly sunny weather for most of the week with temperatures starting off cool but getting warmer as the week goes on. High pressure continues to shove its way southward this evening with much drier air noted as winds shift to the north. Thus expect some radiational cooling especially up north where temperatures near the freezing mark are possible in northern valleys.
1024 AM CDT Mon May 18 2020 Weak sfc ridging remains setup across our western third this morning with this feature expected to slowly nudge eastward through tonight. Some mid level moisture exists above this ridge in northwesterly flow aloft from the Upper Red River Basin into the Piney Woods of NE TX that should begin showing up later today but it should not hamper temperatures from reaching forecast max values this afternoon.
Modest moisture advection is confined to below stronger/warmer flow aloft in veering wind profile, and this should cap off development of convection. We'll carry a ~10-20 probability across our southeast counties where confluences is strongest and where capping warm layer is weakest further east from the mid-upper ridge. This has confined deeper moisture return to a relatively narrow corridor up through southern Texas into the High Plains. Ridging and subsidence will keep our area dry, with convection confined to the high terrain of eastern New Mexico down through west Texas.
/issued 635 AM CDT Mon May 18 2020/ 12Z TAFS The upper level ridge responsible for the disturbed weather over the last couple of days continues to depart to the east with ridging beginning to build across the region this morning. Sfc analysis shows an associated area of low pressure over nern MS providing a nrly low-level flow over the forecast area, while weak high pressure is noted over the wrn Gulf. Obs indicate cooler conditions behind the weak cool front with temps mainly in the 60s (roughly 5-10 degrees below this time yesterday) at this time. As thicknesses creep upward, will see temps warm a bit for tomorrow with highs progged in the lower 90s for a good portion of the forecast area tomorrow.
The 12Z BRO sounding shows a very dry and stable airmass in place over the RGV today as 500 mb ridging strengthens over the state. /issued 444 AM CDT Mon May 18 2020/ SHORT TERM (Now through Tuesday): Hot and rain-free conditions will rule the short term as mid to upper-level high pressure builds and remains wedged across our region. At the surface, high pressure is centered just off the lower Texas coast this morning, resulting in light winds at 5 MPH or less. Rain chances are near zero due to very dry air in the low-levels.
With the axis of the ridge over eastern New Mexico along with very light south to southeast winds and H850 temps of 26C to 29C being advected into the area, temperatures this afternoon have rebounded quickly with high temperatures still expected to range from the upper 80s in the northeast to mid 90s in the southwest TX Panhandle. Southeasterly flow has brought Td's this afternoon in the lower 50s all the way into the NW Panhandles. As the low level moisture interacts with the high terrain in NE NM, this could produce a shower or storm for the high terrain of NM with better lift and near a weak sfc boundary. With H500 temperatures warmer than -10C, it will be a challenge for thunderstorms to form tall updrafts.
Upper level troughing remains in place over the northern US Rockies and Canadian Rockies through the work week. Upstream of the trough is ridging over north-central CONUS into central Canada coupled with a cut off low over the southeast CONUS. While warmest temperatures aloft will continue to advect over the High Plains, cloud cover and modified cooler air stripped away will collide with warmer temps to its west.
1245 PM CDT Mon May 18 2020 Upper level ridging builds across the region today ahead of a large upper trough that will be moving onshore the west coast. Meanwhile another upper low will be slowly moving southeast across the Mississippi Valley region. Upper level ridging will remain in place across the central U.
/issued 156 PM CDT Mon May 18 2020/ Upper ridge over the area will continue Tuesday but will begin to be squeezed between a strong low over the Eastern US and a trough over the Western US.
232 PM MDT Mon May 18 2020 A upper ridge axis reached from the central Dakotas to the southern Rockies and a upper low pressure trough moving onshore into the Pacific coast states. A 700 mb thermal ridge centered west of the Laramie Range and ample insolation allowed temperatures to warm quickly through the late morning and early afternoon with readings in the 70s to middle 80s.
Under sunny skies temperatures are generally running in the low to mid 80s, while dewpoints remain modest near 60 degrees.
The cooler temperatures could allow for snowfall in the mountains by mid week as well. Overall, the Rocky Mountain Front continues to favor the highest precipitation amounts.
Water vapor shows amplifying ridge over the plains with upper low digging along the west coast. At the surface, ridge is located over the eastern Dakotas with gusty south/southeast winds from northeast WY into northwest SD. Warm and dry weather expected through Tuesday with upper ridge largely in control over the northern plains.
325 PM EDT Mon May 18 2020 An upper level low pressure system will move across the Ohio Valley tonight through Tuesday, bringing occasional showers and the possibility of heavy rain to the region. A chance for showers will then linger through much of the week as the upper level low slowly drifts across the Tennessee Valley. The upper level low will drift slowly south into the southern Ohio Valley through tonight. Fairly widespread shower activity rotating around the low will continue to affect our fa through the overnight hours. This will help keep us cool through the day with highs on Tuesday in the low to mid 60s.
254 PM CDT Mon May 18 2020 Closed low pressure system. The backside of this low was spreading scattered to broken cumulus clouds across far Northeast Oklahoma and far Northwest Arkansas. Closed low is progged to continue to move south southeast to near the Ohio River valley Tuesday morning and into the Southeast U.
240 PM EDT Mon May 18 2020 High pressure will continue to build into the North Country for mid week, providing our region with plenty of sunshine and pleasant temperatures. Expect temps will range from the upper 20s dacks/nek to l/m 40s warmer CPV.
Tilly The main focus thru this period will be the stacked upper low currently impacting the region. Model solns generally suggest this low will lift to the NE out of the Ohio Valley. Tilly Upper low over region will spread showers with MVFR cigs across the region this afternoon and evening.
As the upper low lifts out and the cold front passes, much drier air advects in from the west and overnight lows will fall into the upper 50s deg F over the interior to the lower 60s along the coast. The surface front becomes a weak pressure trough and frontolyzes along the coast tonight.
The eastern portion of the CWA is still seeing lighter winds due to the proximity of the ridge axis to the east of the CWA. Through the midweek timeframe, the entire region is still looking at above normal temperatures as an upper ridge will shift east over the area.
Issued by National Weather Service Duluth MN 104 PM CDT Mon May 18 2020 Issued at 434 AM Mon May 18 2020 Large-scale upper low responsible for this past weekend's precip continues to slowly inch to the east this morning. Otherwise, cooler temperatures will prevail in the east thanks to continued cloud cover and rain chances (mid/upper 50s), while western zones see gradual warming under clearing skies (mid/upper 60s). Dry conditions will return area wide this evening as high pressure begins building in aloft. This should result in a gradual clearing trend as a ridge of high pressure noses in from the northeast. Upper-level ridging to become more entrenched over the upper Midwest on Tuesday as omega blocking pattern sets up over the CONUS.
Showers continue to move through the area, with the cold front advancing into the Magic Valley. The area of low pressure associated with this activity will continue to advance eastward today, with an increased pressure gradient noted across the area.
241 PM EDT Mon May 18 2020 High pressure will continue to build into the North Country for mid week, providing our region with plenty of sunshine and pleasant temperatures. Expect temps will range from the upper 20s dacks/nek to l/m 40s warmer CPV.
400 PM EDT Mon May 18 2020 An upper level low will continue to rotate across the Lower Ohio and Tennessee Valleys.
/Tonight through Monday/ The upper low was centered over Illinois per latest satellite imagery and it was nearly stationary or drifting very slowly south. The cloud cover resulting in warmer low temperatures and a smaller diurnal range. The upper low fills and drifts around the lower Ohio Valley Tue-Wed before lifting slowly northeast late this week.
Cyclonic flow around back side of upper low in the Mississippi valley, which continues to meander slowly to the south, resulting in lower ceilings spreading south into far northeast OK and northwest AR this morning. Could see broken low clouds develop over northwest Arkansas today as upper low drops southeast into the mid Mississippi river valley. Otherwise, dry/mild conditions expected for the next few days as weak ridging at the surface persists.
246 PM CDT Mon May 18 2020 An upper level omega blocking pattern will keep the weather fairly status quo through Tuesday with cool and cloudy conditions. An upper low over IL will move south into TN by Tuesday.
1249 PM CDT Mon May 18 2020 Low level clouds/moisture was moving back into the region from the north early this morning as an upper level low centered across eastern Iowa moves south-southeast. 850mb-925mb moisture looks to remain above 80% for most of the day and evening therefore a cloudy day is in store, which will keep high temperatures about 10-15 degrees below average, in the lower-middle 60s. Clouds tonight will keep temps in the lower 50s. By Tuesday morning the upper low will be across western Kentucky with several lobes of energy spinning around it. Highs should be a few degrees warmer in the middle to upper 60s however will be highly dependent on how thick the cloud cover is as the low level flow will still be northerly.
250 PM MDT Mon May 18 2020 Current surface analysis shows low pressure over central MT, with warm front stretching southeast into eastern WY. Upper level analysis shows ridge axis over the high plains, with low pressure just off the northern CA coast. Nearly stalled warm front will creep into far western SD on Tuesday, bringing warmer air into the forecast area. Highs should reach into the 80s across much of the plains, with some upper 70s over the higher Black Hills and toward central SD. As upper low moves onshore and tracks slowly east- northeast into the Great Basin by late Tuesday, stronger energy aloft will shift further east into our region and will likely be strong enough to break the cap late in the day, especially over the higher terrain in WY.
Look for stratus to loiter through much of Tuesday before skies clear as high pressure builds.
Temperatures are already in the low to mid 60s, on the way into the mid 70s. Water vapor loop indicated ridge building over ID and MT as upstream trough shortens in wavelength. Easterly low level flow will bring drier air into the area today with a high pressure system over James Bay. Ridge building will continue over the Northern Plains today through Tue.
238 PM CDT Mon May 18 2020 A surface cold front continues to progress across the Tennessee Valley region this afternoon. The cold front will continue to progress east and through the region by late this evening, as winds shift to the NW and dry air begins to move in. This will bring in end to precipitation chances and should help to scatter out some of the lower clouds for at least part of the night.
Afternoon showers and storms will continue into the evening ahead of a cold front moving in from out of the west, with convection developing primarily over southeast Georgia with conditions having become more stable over northeastern Florida.
Tilly The GEFS H500 mean shows a high-amplitude longwave upper RIDGE over central and eastern North America at the start of this period and this RIDGE is forecast to be maintained through the entirety of this period.
A quiet start to the work week as an upper level ridge is in place overhead. Otherwise, tonight will be mild with lows in the low to mid 70s. Tuesday will be a few degrees warmer than today with temperatures in the mid 80s along the coast to around 100 degrees out west.
SHORT TERM (Tonight through Tuesday Night): 500 mb ridging will control conditions over Deep South TX and the RGV throughout the short term period. The NAM and ECMWF are warmer throughout the short term versus the GFS for the RGV sites. Prefer the warmer numbers indicated the NAM/ECMWF considering the strength of the 500 mb ridging.
A backdoor cold front may sag south of the Red River toward our far northern counties overnight, but this boundary is expected to stay north of KABI. For tonight, overnight lows will also be warmer than usual mid May lows.
1233 PM EDT Mon May 18 2020 An upper low will remain over the region through the middle of the week and bring cool weather and rounds of rain, especially through Tuesday. The center of an upper low was drifting east and moving into northwest Illinois. The cold front was well east of the low over Indiana where the front was occluding. The upper low will be completely blocked off with out anywhere to move, making for a very challenging forecast. Given model consensus with the low dropping south of the Ohio River, deformation zones rains are expected south of Highway 30 tonight.
Upper level ridge right over the area on Tuesday, with the low level thermal ridge reaching its peak.
Strong northeast to easterly winds across the Northland will continue into the early evening north of deep low pressure across Illinois. The 12 UTC global suite favors an upper level ridge building across the central CONUS into mid week, transitioning to a high over low blocking pattern, and eventual southwest flow aloft across the Upper Midwest late this weekend and weekend.
Water vapor imagery was showing flow aloft consisting of a deep trough/closed circulation situated off the the west coast with a well amplified ridge over the central CONUS. Another deep upper trough downstream was covering the eastern half of the CONUS.
1154 AM CDT Mon May 18 2020 (Today and tonight) The short term forecast looks dry as we'll remain under a building ridge of high pressure with seasonably average temperatures. Clear night skies and light variable winds will continue to enhance radiational cooling through the morning, making it feel slightly cooler than our previous morning. Skies should remain mostly clear today, with just a few high clouds coming down the upper ridge from the Central High Plains. Expect a light east breeze for tonight under mostly clear skies, with just enough wind keeping low temperatures for Tuesday just a little bit warmer.
217 PM EDT Mon May 18 2020 High pressure will continue to build into the North Country for mid week, providing our region with plenty of sunshine and pleasant temperatures. Expect temps will range from the upper 20s dacks/nek to l/m 40s warmer CPV. High pressure will remain draped across the Northeast through the short term, keeping the weather dry with a few passing clouds.
313 PM CDT Mon May 18 2020 Upper ridging continues to build over the northern plains today. Southeast winds ahead of a lee side trough are expected to develop again on Tuesday after gusts diminish tonight. With the ridge and good mixing, temps have climbed into the 60s and 70s today, though hampered in some places by cirrus. Went with a cooler solution for now, but if the stratus clears by noon, daytime heating will be sufficient that warmer highs in the 70s will be probable.
330 PM EDT Mon May 18 2020 Synopsis/Discussion/Marine/Hydro -Rain ends Tuesday; river flooding persists through the week -Dry with a warming trend mid to late week -Holiday weekend looking summer-like -Rain ends Tuesday; river flooding persists through the week Illinois upper low still slinging showers our way tonight, but latest radar trends are encouraging showing axis of heavier rain/thunder trying to nudge toward eastern Lwr MI. Rain threat gradually winds down on Tuesday as the upper low sinks farther south, especially in the afternoon, but considerable cloud cover likely remains. Unfortunately the widespread 2-4 inch rainfall totals left behind by the upper low will result in river flooding continuing through much of the rest of the week.
A cold front continues to march into the Tennessee Valley region this morning as an upper-low slowly pivots south into the lower Ohio Valley. The upper low will be dropping into western KY by early Tuesday morning, then drop into the middle TN on Tuesday. The cold pocket in mid levels will produce modest lapse rates and CAPE that will lead to showers and perhaps a few low-topped thunderstorms, especially closer to the upper low in TN. The clouds and rain will keep high temperatures in the u60s-a70 in valleys and m60s atop the higher plateau areas. The showers will continue through Tuesday night, especially near the upper low that slows down over eastern portions of middle TN.
Water vapor satellite imagery, heights, and lightning highlight the closed low pressure area over Illinois. Cyclonic flow around the low spreads moisture into the county warning forecast area from the east. Moisture will continue to be drawn into the area from the east as the area of h5 low pressure gradually drops south through Tuesday. RAP/HRRR/other short term forecast soundings remain saturated in the low levels.
Three distinct areas of low pressure can be seen spinning east of the Mississippi River. Across the Deep South, the slowly moving low pressure system that brought our latest round of clouds and rain continues to drift eastward. And across the Midwest, a much deeper low pressure system is about to begin drifting southeast toward the Ohio River Valley.
Mid range models continue to the upper level low diving south southeast over Tennessee Valley by Tuesday afternoon and Tuesday evening.
156 PM CDT Mon May 18 2020 Upper ridge over the area will continue Tuesday but will begin to be squeezed between a strong low over the Eastern US and a trough over the Western US.
/issued 1024 AM CDT Mon May 18 2020/ Weak sfc ridging remains setup across our western third this morning with this feature expected to slowly nudge eastward through tonight. Some mid level moisture exists above this ridge in northwesterly flow aloft from the Upper Red River Basin into the Piney Woods of NE TX that should begin showing up later today but it should not hamper temperatures from reaching forecast max values this afternoon.
332 PM CDT Mon May 18 2020 An area of low pressure in central Illinois Monday afternoon will slowly drift toward the southeast tonight, reaching southern Indiana by Tuesday afternoon.
This system will also bring a notable increase in winds and fire danger, especially across parts of southeast California and the lower Colorado River Valley.
These clouds will be dissipating quickly by mid-morning as temperatures climb into the lower 90s by noon time. Both GFS and NAM forecast soundings for Tuesday afternoon show an area of very dry airmass between 6 and 8 Kft with even a bit of a south southwest component and that could be enough for the airmass to mix down for a few degrees warmer than expected.
As the upper low lifts out and the cold front passes tonight, much drier air advects in from the west. Overnight lows then fall into the upper 50s deg F over the interior to the lower 60s along the coast. The surface front basically evolves into a weak pressure trough along the coast tomorrow.
For midweek a mid/upper level low will meander over the southeast U. Meanwhile at the surface weak high pressure will begin to ridge in from the southeast during the week setting up across the Florida peninsula this weekend.
Similar conditions to Monday are likely Tuesday as a ridge axis aloft shifts only slightly to the east giving way to a southwesterly flow developing across the high plains of western Kansas late in the day.
Seeing a few differences mainly in that the system has a little better instability to work with today (MLCAPE ~1000 J/kg) but less shear in the lower levels with 0-1/0-3 km SRH is generally less around 100 m2/s2 or less. Cold frontal zone associated with the low over IL/IN stretches southward and basically bisects the Commonwealth. An upper level low will continue to rotate across the Lower Ohio and Tennessee Valleys.