Aikyam-Lab/Synoptic-Bench huggingface dataset:
Models and ensembles in good agreement regarding longwave mid- level trof over western CONUS for the next several days, with a slow eastward translation. The low-level jet is expected to develop overnight for the next several days, with speeds of 30 to 55 knots nightly.
Friday, flow aloft will be weak with mean broad ridging affecting South Texas, however isolated showers and storms will be possible along the seabreeze in the morning and afternoon.
A upper level ridge residing just east of the area will retrograde back west bringing the local area under its influence.
215 PM EDT Thu Sep 21 2017 An upper level trough will drift south of our region today, then linger while weakening through the end of the week. A weak upper low/concentric vort max across eastern NC will drift slowly eastward throughout the day and will eventually feed into the broad upper trough extending SW from TC Jose off of the southern New England Coast. This feature coupled with steep low-level lapse rates associated with strong insolation will support scattered showers and thunderstorms, mainly south of the Triangle within the upper trough Dpva axis. H8 temps and low-level thickness are forecast to drop off ever so slightly, so perhaps a degree or two cooler than yesterday, but still in the same ballpark with afternoon highs in the 85-90 degree range.
141 PM MDT Thu Sep 21 2017 A large trough across the western CONUS will influence our weather through the upcoming weekend. At 19z a cold front had pushed through over 1/2 of the CWA and was from roughly KD07 to KIEN. Aloft, southwest flow will prevail with periodic short- wave troughs ejecting out of the western CONUS trough about every 24 hours.
Strong upper ridging becomes a bit better established over the Ohio River Valley today.
In addition to the increasing chances for rain, the change in the upper-air pattern will also bring cooler weather to the southern Plains.
Latest RAP satellite imagery showed the area showed the region under an upper ridge which extended through the Lower Mississippi Valley as well as under a shear axis over the southern areas which extended from an upper trough over the eastern seaboard. Highs will be in the lower 90s. There will only be slight changes in the upper level pattern over the weekend with the deep troughing over the western CONUS and ridging over the east.
The upper disturbance weakens heading into Friday as upper level ridging will build back over the area.
353 PM CDT Thu Sep 21 2017 An upper level trough over the western U. Most of the CWA will be cooler on Friday (50s and 60s) but the southern James River Valley could see some readings near 80. A cold front will move through central ND this afternoon and evening.
Although it appears the surface dew point depressions will not be as low as previous nights, ground fog should develop and be thickest near water bodies and in the normally cooler spots. The upper trough shifts slightly southward on Friday.
Satellite imagery early this afternoon shows an elongated trough extending from southern Canada down into northern California/Nevada. An area of low pressure was beginning to form over eastern Oregon/western Idaho.
248 PM MDT Thu Sep 21 2017 Southwest flow aloft will increase over Colorado tonight and Friday as an upper level trough over the western states slowly progresses eastward.
157 PM EDT Thu Sep 21 2017 An upper level trough will drift south of our region today, then linger while weakening through the end of the week. A weak upper low/concentric vort max across eastern NC will drift slowly eastward throughout the day and will eventually feed into the broad upper trough extending SW from TC Jose off of the southern New England Coast. This feature coupled with steep low-level lapse rates associated with strong insolation will support scattered showers and thunderstorms, mainly south of the Triangle within the upper trough Dpva axis. H8 temps and low-level thickness are forecast to drop off ever so slightly, so perhaps a degree or two cooler than yesterday, but still in the same ballpark with afternoon highs in the 85-90 degree range.
542 PM EDT Thu Sep 21 2017 High pressure will prevail through this weekend. The high will weaken and shift inland as Hurricane Maria tracks northward off the Southeast U. Weak high pressure and diminishing cloud cover should support decoupling winds and another fair radiational cooling night. A weak upper trough pattern and lingering low-level moisture on Friday will support isolated showers/tstms mainly in the afternoon associated with the sea breeze.
Deep upper trough in place over Western US. East Idaho remains ahead of main trough in line with deepest moisture field. Moisture and cloud cover appear to be sufficient tonight to keep overnight lows in the Snake Plain a few degrees above freezing.
Minimum temperatures will remain mild overnight over all but the far nw with thermal ridge axis in place, warm advection and low level moisture flux.
410 PM CDT Thu Sep 21 2017 Expansive area of high pressure dominates the eastern half of the CONUS this afternoon as southwesterly flow stretches from the southern California coast into the Upper Midwest. The ridge is compressed slightly as it starts to break down. Another deep wave moves across southern Canada, bringing slightly cooler air behind a weak cold front midweek. Central IL then comes under the influence of the deep SWrly flow as the ridge shifts to the east coast and breaks down.
148 PM EDT Thu Sep 21 2017 High pressure will continue to bring sunny skies and warm temperatures to NY and PA. Warm high pressure will yield a continuation of mostly clear skies and mild temperatures. A large dome of high pressure along with a very warm air mass.
At the surface the flow has turned southerly and low level moisture and the effective warm front has surged north of the area into central MN and N Wisconsin. Through the short term, high pressure will be the primary weather driver. Highly amplified longwave upper trough-ridge pattern over the contiguous U.
/issued 204 PM CDT Thu Sep 21 2017/ Mid level flow across the desert SW continues to back in response to an approaching trough. By Fri PM SW mid level flow will have pulled up a theta-e ridge axis which will become increasingly rich. Into the Sat the mid level flow/theta-e ridge will have an especially long fetch while edging farther e to encompass much more of the Trans Pecos/SE NM, which will be the favored area for rain, again some heavy rain even thru thru Sat night.
/issued 308 AM CDT Thu Sep 21 2017/ A more diffuse dryline will set up across the area today with backing flow aloft in advance of a trough digging into the western CONUS. A deep long wave trough will still cover the entire western CONUS.
Snow will bring hazardous travel conditions to the to the passes along I-80 and US-50, and possibly the highest passes on US-6.
Turning warmer and drier this weekend. A winter like trough will continue to move across interior northern California and exit early tonight. Trough will shift east into northern Nevada with cut-off low developing on Friday. Drier weather is expected this weekend as the trough shifts eastward.
Ridging aloft stretching from the southern plains into the Great Lakes region along with sfc ridging will build into the region on Friday.
High temperatures are expected to be only in the 40s but warmer and drier conditions return for the weekend.
Through Tonight At 2 PM, visible satellite and surface obs indicated a surface warm front draped across the western MN/IA border, then extending southeastward toward northern Illinois. The northward advancement of the warm front over eastern Iowa was somewhat hampered by an MCS this morning, which has since dissipated. The big question is whether any TS/SHRA will be able to develop along the warm front this afternoon. However, given the strong moisture transport signal and 1000 to 2000 J/kg of CAPE, will keep a slight chance of showers and storms along the northward advancing warm front into tonight.
Dense fog is not expected at this time as some degree of cirrus arcs over area within upper level ridge. High amplitude upper ridging will govern conditions across the great lakes right through the upcoming weekend.
348 PM CDT Thu Sep 21 2017 Jose and Maria still to the east underneath ridge. Deep trough extends from upper Hudson Bay through central Canada into Northern California. Transition continues with the upper pattern and deep trough through the western Conus. Much warmer over night lows forecast with lows ranging from 70 at Oneill to 45 at Gordon to 55 at Imperial. As upper trough approaches from the west and increased moisture advection into central plains through the weekend a prolonged period of moderate to heavy rain through southwest into North central Nebraska expected.
A cool, upper level trough will dominate the western portion of the country through the workweek maintaining cooler than average temperatures and breezy conditions. The cold front that passed through overnight was able to sufficiently mix-out the marine layer with mostly clear skies extending over the waters as well. On Friday we'll begin to see a gradual and continuous warming trend as an upper level ridge begins to build in the eastern Pacific. Expect Friday's highs to be about 2 to 5 degrees warmer than today with some communities in the interior East Bay climbing to the upper 70s.
Convection started to fire late this morning along the eastern edge of the ridge axis. Expect this trend to continue as we head through the short term with high pressure in charge for the most part.
As discussed this morning, showers and thunderstorms are developing along and east of a trough axis/deep layer moisture gradient from near Panama City northeast through Tifton.
/17/ Latest satellite imagery and rap analysis showed the region under an upper ridge which extended through the Lower Mississippi Valley as well as under a shear axis over the southern areas which extended from an upper trough over the eastern seaboard. Left afternoon highs in the lower 90s. Warm and humid conditions will continue across the forecast area today as high pressure at the surface strengthens a bit from the northeast into the region. Aloft, the forecast area will be fixed between high pressure wedging southwest from the Mid- Mississippi River Valley through the Mid-South region, and increased troughing from the East Coast, southwest into the Deep South. With dew points remaining in the low and middle 70s, afternoon heat indices will hover around the century mark across much of the area.
A strong upper level trough and surface cold front will move into the Great Basin today.
208 PM EDT Thu Sep 21 2017 Warm temperatures and dry conditions will persist through the remainder of the week and the weekend with high pressure holding in place across the region. A seasonably strong 588dm mid-level ridge along with 850mb temps running near +17C will continue our summer-like pattern into this weekend despite the arrival of Autumn on Friday. Ideal radiational cooling will again support temperatures again dipping down into the mid 50s inland to the low 60s near the lakes. The weather will remain status-quo through the weekend as a strong and dominant ridge of high pressure surface and aloft remains parked over the Ohio Valley and eastern Great Lakes.
204 PM CDT Thu Sep 21 2017 Mid level flow across the desert SW continues to back in response to an approaching trough. By Fri PM SW mid level flow will have pulled up a theta-e ridge axis which will become increasingly rich. Into the Sat the mid level flow/theta-e ridge will have an especially long fetch while edging farther e to encompass much more of the Trans Pecos/SE NM, which will be the favored area for rain, again some heavy rain even thru thru Sat night.
400 PM EDT Thu Sep 21 2017 High pressure will prevail through this weekend. The high will weaken and shift inland as Hurricane Maria tracks northward off the Southeast U. Strong sfc heating seen earlier today will continue to support a few showers and/or thunderstorms this evening while a mid/upper lvl trough of low pressure extends northeast to southwest across much of the area. Weak high pressure and diminishing cloud cover should support decoupling winds and another fair radiational cooling night. A weak upper trough pattern and lingering low-level moisture on Friday will support isolated showers/tstms mainly in the afternoon associated with the sea breeze.
The convection is being steered around the perimeter of an upper ridge that extends to near the northern gulf coast. The aforementioned upper ridge will remain in place across the region over the next several days allowing for only isolated to scattered diurnally driven showers and thunderstorms that will likely follow a similar overall evolution (which is to say a general northwestward motion) as we have seen today.
Early this morning, isolated showers and storms continue to diminish over southeast Wisconsin as a cold front drops southeastward. Bufkit data shows an increasing cap today due to the warmer air 850 flow turns southwest during the morning. MU cape values start low today but elevated cape levels increase by tonight and a surface warm front lifts back north for a focus of convection. Will keep the small chance pops tonight and Friday morning as the warm front lifts northward. Its possible the precipitation chances will start later this afternoon if the instability and surface warm front make a quicker return.
240 PM EDT Fri Apr 6 2018 We will continue to stay under the influence of high pressure tonight as a cold front starts to approach the area. The cold front will switch the winds to the south overnight and increase them slightly, but overall it will be a quiet and mild night with lows staying in the mid 60's. The line of showers and thunderstorms out ahead of the cold front will start to make its way through the Nature Coast by the early afternoon hours.
Around sunrise, a strong cold front will sweep south across the region with strong Nrly flow and overcast MVFR CIGs prevailing in its wake. Slight chance areas of FG may dvlp late in the night before pre frontal trough pushes through, but for now I have elected to go with lower CIGs.
Skies should clear this evening with the loss of sun and weakening of the low level lapse rates. Saturday should be a cool, but dry day, with highs in the low 30s.
As the cold front rolls through the region early Saturday expect another gloomy day with winds shifting northerly and becoming gusty. at this time based on what happened earlier this week with a similar set up decided to go somewhat on the cooler side behind the front.
Low pressure will move inland over the weekend spreading strong gusty winds across the southern Great Basin and Mojave Desert along with increasing rain and snow chances for the Sierra.
315 PM MDT Fri Apr 6 2018 Current surface analysis shows cold front well south of the area, with high pressure centered over far northeast MT. Another cold night is on tap for the area, with lows mainly in the 5 to 15 degree range, as high pressure to the north slides southeast across the Northern Plains. Some milder air will return on the back side of the high Saturday as winds turn to the south and southeast.
Temperatures have reached the low to mid 80s across the Keys today with winds from the southeast at around 10 mph. A high pressure will continue to move to the east and away from the eastern coast of United States. Its western ridge will extend towards the Florida peninsula tonight and move away as well on Saturday.
251 PM CDT Fri Apr 6 2018 Dry and strong cold front currently in the Texas Panhandle will plunge quickly south tonight and should be in Mexico by sunrise Saturday. In addition freezing temperatures currently across the northern and central plains will likely infiltrate the extreme northern Permian Basin late tonight through mid Saturday morning despite abundant cloud cover and the wind.
The cold front extends along the Ohio Valley across southern Missouri and into northwest Texas. Rain will continue throughout much of the day as the cold front continues to push slowly south. /issued 330 AM CDT Fri Apr 6 2018/ An upper level trough will continue to dig across the central and eastern half of the U. A strong cold front will be dropping south out of the Central Plains today and push across the Mid South tonight. Showers and thunderstorms should continue to blossom across the region today in response to the approaching upper trough. As the cold front drops south tonight, much colder air will filter into the area. In these areas, some light accumulations will be possible, mainly on grassy surfaces, although some slick spots could develop on elevated road surfaces such as bridges and overpasses.
Models have missed quite significantly on the high temperatures today as they soared into the mid 60s today. Would not expect freezing rain during this transition. Thus, will expect around 1 to 2 inches in most locations, especially the ridges. A local 3 inch is possible but mainly on the highest ridges. Heading into the day on Saturday, the colder air filters more into the area but the slightly warmer daytime temps will lead to a mix with snow and rain in the afternoon. Saturday night, the cloud cover clears out quickly as high pressure moves back into the area. This will lead to temps plummeting into the lower 20s.
136 PM CDT Fri Apr 6 2018 Cold front is situated along the Ohio River as of this writing, and showers are already spreading northeastward into Middle Tennessee. Much colder air will advect into the mid state behind the front, so that by tomorrow morning, readings will be at or close to freezing most areas. Some of this precipitation will fall as snow or a snow/sleet mixture, and light accumulation is possible along the Highland Rim and near the KY/TN state line, mainly after 12Z. At this time, it appears that freezing rain is unlikely, despite the presence of a steep low- level inversion tomorrow morning that resembles a classic freezing rain sounding.
Dry cool weather will be in place then for the weekend under high pressure.
Brief transition from rain to snow will move across the area, but any sleet and/or light freezing rain should be light and transient.
High pressure will then remain in place through Saturday night.
230 PM EDT Fri Apr 6 2018 High pressure will shift offshore today, allowing a warmer SW flow to develop. A low pressure area and associated cold front will move through our region Saturday.
Some breezy conditions are expected throughout the afternoon in advance of an approaching cold front tonight. Late this evening a strong cold front arrives with good convergence expected to generate a broken line of showers and storms at least over areas along and east of Highway 281. Farther west the consensus is for scattered clouds for much of the day, leading to warmer maxes in the low 70s.
But temperatures warm gradually as a weakening upper ridge moves east into the area.
We've seen temperatures struggle through the low 50s elsewhere due to thick and persistent cloud cover over the southern half of the mid state. Expect showers to increase in coverage this afternoon with a few rumbles of thunder possible through this evening before a cold front arrives from the northwest later. Have addressed the cooler temperatures in the updated forecast package. Light south winds this morning will veer to southwesterly this afternoon then northerly this evening/tonight as a cold front sinks southward across the area.
Though ground temperatures are well above freezing (46F soil temperature at the 4-inch depth in Goodland this morning), 1-2" of snow accumulation cannot be ruled out if precipitation of moderate intensity develops and persists for several hours this afternoon and evening as the air temperature falls into the 20s. Highs today will be tempered by cold advection, cloud cover, and evaporative cooling assoc/w precipitation, remaining near steady in the low- mid 30s this morning, then gradually falling into the mid-upper 20s from NNE-SSW this afternoon and evening. Expect overnight lows ranging from the low teens (north/northeast) to upper teens or low 20s south/southwest where cloud cover may linger the entire night.
340 PM CDT Fri Apr 6 2018 An impressive early April cold front will bring gusty northeasterly winds, blowing dust and sub-freezing temperatures to the region later this afternoon into tonight. Cold near surface air coupled with a warm nose aloft could support anything from freezing rain to sleet and perhaps even snow, though any amounts should be very light and of little/no impact given the warm ground too.
404 PM EDT Fri Apr 6 2018 WV imagery and RAP analysis indicated a deep mid/upper level trough from New Foundland into nrn Ontario resulting in cyclonic nw flow into the nrn Great Lake. Expect enough clearing and diminishing winds for temps to drop toward the lower end of guidance inland west to the low single digits but remain in the teens where LES/clouds persist. Saturday, sfc ridging and drying will move in more strongly over the west with lingering LES in the morning diminishing by afternoon with little additional accumulation.
Half an inch to an inch of snowfall accumulations in the lower elevations is expected. 1 to 3 inches in the ridges.
Cold, Canadian high pressure will remain in place over the area on Saturday with highs in the mid 30s to around 40.
235 PM EDT Fri Apr 6 2018 High pressure will move farther off the Southeast Coast ahead of an approaching front. Low pressure tracking eastward along the front will move into the forecast area Saturday. The low will lift northeast of the area Saturday night.
The 19z MSAS surface analysis showed an area of low pressure over extreme southeast Ontario with a cold front extended southwest into the Mid-MS Valley. A ridge of high pressure stretched from the Canadian Prairie southeast into the northern Plains. The high pressure is forecast to extend from the northern Plains south into the central Plains, and southeast toward southern sections of the Great Lakes tonight. The high pressure moves east and will extend from the Upper MS Valley to the southern Plains, and east into southern sections of the Great Lakes on Saturday.
An area of light precipitation north of the areas, now across Nebraska will slide south as the cold front does which will bring the cold air to the area. Despite that, have trended towards more of a light snow event as models bring the cold front and cold air into the area with up to an inch of snow fall possible for most locations. The Freeze Warning remains in effect as temperatures will fall solidly into the lower 20s by sunrise Saturday. Cloud cover should tapper off through the morning on Saturday allowing some sun to help bring afternoon highs into the lower 40s.
300 PM CDT Fri Apr 6 2018 Seeing an increase in shower development this afternoon (moving generally off to the northeast) as temperatures warm into the lower 80s. Cannot rule out some thunder- storm development later this afternoon, but still looking for much higher rain chances for our area later this evening and on through the overnight hours as a cold front and associated storms move into the area from the north. Behind the front, it will be turning much cooler (Satur- day's temperatures will hold steady or even fall during the day, generally into the 50s inland and in the lower 60s at the coast), it will become breezy (wind advisories might be needed) and rain chances will decrease as the day progresses.
Minnesota and the Dakotas are holding in the lower to mid teens in full sun today, with wind chills around -10 as of 2 PM. Through modification with full sunshine Saturday, highs will climb back to the lower 30s north to upper 30s central and south.
1248 PM CDT Fri Apr 6 2018 Early this morning a cold front has moved through the CWA however, the better cold air advection has lagged behind the front. High pressure should begin to build into the area from the northern Plains tonight ushering in another round of dry air and shunting precipitation south of the area. A unseasonably cool day is then expected on Saturday with highs in the upper 30s to lower 40s as high pressure dominates.