Aikyam-Lab/Synoptic-Bench huggingface dataset:
This activity appears to be related to frontogenetic forcing near the 700 millibar level, well north of the surface front, and southwest of the main upper trough and jet activity. /issued 225 AM CDT Tue Sep 5 2017/ The long-awaited cold front is on the doorstep early this morning, south of I-40 at the time of writing. The front should be south of the forecast area by 9 AM, and with high pressure building in behind the front northeast winds will become breezy. Surface ridging will shift east of the area during the day Wednesday with return flow setting up during the afternoon and temperatures at or a bit above those expected for today.
157 PM EDT Tue Sep 5 2017 Numerous showers and storms have blossomed over KY over the past few hours both along and just behind the cold front. North-south band of light rain roughly along I- 65 is producing only trace amounts, and convection along the effective boundary ahead of the cold front is quite isolated. Strong cold front dropping SE into the Ohio Valley overnight.
Models still indicating that the remnants of Lidia will be caught- up in a deep trof and carried into Northern California by Wednesday night.
Digging east CONUS trough is quickly pushing the cold front south and at 3pm was located from central KY to northern MS to northeastern TX. The trough axis will swing through tomorrow and remain east of the area through the end of the work week. The cold front will push into the Gulf and eventually stall in the Gulf of Mexico. Cooler and much drier air will move in behind the front Wednesday but it will be delayed, even though the wind shift will be through the region quickly tomorrow the actual cooler and drier air will move in later in day Wednesday if not Wednesday evening.
This puts the ridge axis over the western CWA. Tonight with ridge axis in place. expecting temps to drop to the lower to mid 40s by Wednesday morning. main wx features for the region during this time will be an amplifying H5 ridge over the western portion of the country that works into the western portion of the Plains region by the end of the week.
130 PM EDT Tue Sep 5 2017 Showery weather and well below normal temperatures can be expected through the week until high pressure returns this weekend.
A cold front stretches from Muscle Shoals AL to just south of Tupelo to Cleveland MS. Chances for showers and thunderstorms will taper off from NW to SE this evening as the cold front moves well south and high pressure quickly builds in. Dry air and cooler temps will advect in overnight and temps will fall well into the 50s.
259 PM MDT Tue Sep 5 2017 A quiet weather pattern will prevail over the next several days as the CWA remains in dry northwest flow aloft, on the eastern fringe of upper-level ridging over the western US.
144 PM EDT Tue Sep 5 2017 High pressure will remain well off the coast this afternoon, while a cold front approaches from the northwest.
This will continue through the day as the upper level ridge axis remains over eastern Oregon and eastern Washington.
1104 AM MDT Tue Sep 5 2017 Imagery shows large, broad amplified ridge centered over the western CONUS (nrn UT) over a minor low off the srn California coast. The SFC has weak low pressure across much of the wrn CONUS with a back door front siding s/sw through WY with strong high pressure building to the north behind the front. Today will be post frontal, cooler, drier, with generally sunny skies over eastern and central WY. RH values look to bottom out across the lower elevations in the mid to upper teens.
338 PM CDT Tue Sep 5 2017 255 PM CDT Unseasonably cool weather will continue through tomorrow and beyond as a deep upper trough slowly moves across the upper midwest and Great Lakes regions. Any showers and much of the cloud cover will dissipate with sunset and temperatures should drop into the 40s across much of the CWA away from the Chicago metro urban heat island, where lows should remain in the lower 50s. Temperatures Wednesday should be even lower than Tuesday, with highs only in the lower to middle 60s. 315 PM CDT The deep trough responsible for the cool weather to start the period (highs in 60s and lows in 40s for many areas) will exit east by the weekend, enabling moderation in high temperatures back to near/around normal for early to mid September.
240 PM CDT Tue Sep 5 2017 Today's cold front has almost exited the area this afternoon. Thanks to the cold front winds are out of the north and northwest and temperatures have dropped into the 60s in several counties. Lingering showers may continue into the evening hours tonight, but conditions should be dry and noticeably cooler by Wednesday morning.
Our present unseasonally cool regime will remain in place through late Wednesday until the passage of the low level ridge. There will be some weak short waves embedded within the long wave trough but the phasing of sufficient moisture and lift will not be there for appreciable large scale precip, at least this far south and west.
350 PM EDT Tue Sep 5 2017 A cold front will progress very slowly across the region this evening and practically stall overhead tonight.
As mentioned in the morning update, the smaller scale circulation within the cold pool of the upper level trough together continue to provide weak to moderate convective potential over the Great Lakes. Hourly mesoanalysis depicts surface based CAPE hanging around 500 J/kg which remains adequate for a brief thunderstorm capable of some pea size hail in the low freezing level environment. The upper level trough axis is moving eastward but will remain over the western Great Lakes overnight into Wednesday morning. Otherwise, expect a repeat performance of diurnally enhanced convection over lower Michigan Wednesday afternoon with the added support of deformation forcing within the upper level trough axis.
238 PM CDT Tue Sep 5 2017 Low amplitude short wave continuing to slide by well to the east with cooler and drier air will be our dominant features through Wednesday. Upper level ridge over much of the intermountain west will elongate to our south and then edge more overhead late in the week and into the weekend, allowing slow warming trend.
252 PM CDT Tue Sep 5 2017 Aloft: 12Z upr-air data/WV imagery/aircraft winds showed a highly amplified Wrn ridge with an embedded subtropical high. and a trof over the Cntrl/Ern USA. The only minor change thru tomorrow will be further deepening of the Ern trof. Heights will then build around it as the Wrn ridge shifts E. This will isolated the trof from the flow and rotation will bundle. Depending on how this low evolves. So this low will not have much moisture to work with.
Anomalously deep trough continues to dig into the western Great Lakes with attending pocket of +2C 850 mb/-23C 500 mb air descending into the region. Trough axis slowly slips across the western Great Lakes tonight and much of Wednesday maintaining broader scale forcing for ascent across the region. upper trough axis does get just east of the region with a bit more subsidence building into the region through the day.
In addition, a cold front currently in north central Texas will move south, slightly a head of schedule, arriving in our northern CWA this evening and pushing south to Matagorda by sunrise Wednesday. Hennig The cold front is still on schedule to move off the coast and through the coastal waters late tonight through early tomorrow morning. Elevated winds and seas will then persist for the remainder of the week and probably into the weekend as high pressure ridges into the area from the north and northeast. Little movement is expected over the next few days as a cold front moving off the Texas coast Wednesday prevents this system from moving north.
Currently, the ridge off to our west has continued to dominate our area. Expecting a slightly cooler and dryer trend for the area due to an airmass being brought in today from the north.
High pressure will be building into the region from the west to promote that clearing. There will be lighter northerly flow Wednesday, and the high will continue building into the region. Highs should be in the upper 50s and low 60s in the Arrowhead and northwest Wisconsin, to the lower 60s across the rest of the Northland. The massive long wave trough that will dominate the weather over the entire Great Lakes region for much of this week, will gradually migrate to the eastern part of the country by late in the work week.
Currently, strong north-northwest flow remains aloft between a persistent ridge of high pressure across the western U. and a deep trough over the east.
A little cooler outside the Red River Valley proper. Expecting CU development late this morning with convective temps in the low 60s.
Strong high pressure ridge entrenched across the region will nudge slightly eastward on Wednesday. A few showers/ thunderstorms are possible in far southwest Harney County (along the leading edge of moisture ahead of a trough near the west coast), otherwise expect dry conditions through Wednesday.
A cold front has pushed into northwest Alabama this afternoon. The strongest storms were located in a band just ahead of the cold front. The cold front should reach the I-20 corridor around 7 pm and the near the I-85 corridor around 3 am Wednesday. Much cooler temperatures on Wednesday with highs in the middle to upper 70s across the north and lower 80s south.
By late tonight, an early season cold front will move south through the RGV with light and variable winds taking on a northerly component by daybreak. An early season cold front arrives late tonight but any significant change in wind speed and direction is expected after this TAF cycle. /issued 454 AM CDT Tue Sep 5 2017/ SHORT TERM (Now through Wednesday): Attention continues to focus on a trough of low pressure located over the southwestern Gulf of Mexico, east of Tampico, for signs of further development. The National Hurricane center is giving a 50- 60 percent chance of a possible tropical cyclone developing in this vicinity in the next 2-5 days.
316 PM EDT Tue Sep 5 2017 Cold front has passed through the area, although a few post-frontal showers are still lingering over Lake Cumberland. Overnight lows will be much cooler than last night, dropping into the low and mid 50s in most spots. One more vort lobe rotates through the parent trough tomorrow, and could bring some isolated showers or sprinkles with it. Trough axis swings through with high pressure building in Wednesday night.
Highs on Wednesday will barely reach the lower 60s in most locations.
Otherwise, we're looking at a quiet short term period with pleasant conditions setting up for Wednesday as high pressure remains in control.
Upper level ridge over western Northern America will slowly shift east and roll over the Northern Plains/south central Canada by Fri afternoon. Upper level trough over WI will move away from the area. For tonight high pressure will shift over the ND side by 12Z Wed. Some mid level moisture over southern Canada will drift south and may keep western zones warmer than expected. Upper level disturbance is forecast to roll over the ridge and into western Ontario by late Wed. A little warmer air is forecast to shift into the western zones for Wed. Cold front will back door the area Thu as short wave moves past the area.
A big upper level trough is digging across the Great Lake Region into the Midwest. The center of the high moves over the region late on Wednesday with another seasonable cool day with mostly sunny skies and highs in the lower 70s.
242 PM EDT Tue Sep 5 2017 Moisture will begin to increase today ahead of an approaching cold front today.
502 PM CDT Tue Sep 5 2017 Isolated showers and thunderstorms have formed ahead of the cold front. Additional showers and storms have developed along a pre- frontal trough in Kinney and Uvalde counties. Partly to mostly cloudy skies are in place across the region with temperatures in the lower 90s. The cold front associated with a large trough east of the plains is located to our north but a pre-frontal wind shift is already knocking on the door of the northern Hill Country. Additional chances for showers and storms will be possible overnight as the main cold front moves through the area. Overall, chances of precip will remain low due to lack of forcing as the main trough remains well to the east. Dewpoints in the 40s and 50s will allow for this cooler night time temperatures.
416 PM CDT Tue Sep 5 2017 Scattered convection is quickly developing along a cold front that is located from near Mount Vernon, to De Queen, and east-northeast into Central Arkansas.
/issued 211 PM CDT Tue Sep 5 2017/ An upper trough is over the Great Lakes region with an upper ridge over the western half of the country. There is a cold front moving through the area with gusty northerly winds behind it. Temperatures today will be cooler than yesterday with highs slightly below normal. The hi-res models indicate precipitation is possible across the Lower Trans Pecos, Davis Mountains, and Big Bend area this afternoon and evening.
317 PM CDT Tue Sep 5 2017 (Tonight and Wednesday) A weak cold front has moved through all but far southern portions of the CWA this afternoon. Lows tonight will be in the upper 50s and lower 60s, with highs on Wednesday in the lower and middle 80s.
Isolated to scattered SHRA/TSRA are expected to develop this afternoon over interior southeast MS and southwest AL ahead of an approaching cold front. A large upper trough will dig over the north-central CONUS today and tonight. This will send a strong sfc cold front southward toward the area this afternoon and tonight.
High pressure will build into the region during the day tomorrow.
The flow aloft remains out of the southwest with a ridge to our south and an amplifying trough to the north. For tonight into Wednesday, the mid/upper-level trough will amplify a bit more, with flow over Florida becoming more southwest as ridging gets shunted south and east. The period will begin a mid/upper level trough moving across the eastern U.
Latest satellite imagery shows an amplified mid and upper-level ridge across the western US with a deep trough extending from eastern Canada southwest across the Great Lakes region and into the Mississippi River valley. At the surface, cool high pressure extended from south-central Canada into the High Plains. For our area, the coldest temps we have forecast are in the low 40s around the Columbus and Wayne areas. Another cool day expected Wednesday as high pressure continues to move overhead. Return flow will set up across the region by late in the week allowing warmer temperatures to move into the area.
The depression is expected to remain nearly stationary through Wednesday then begin a slow south to southwest motion, away from the Lower Texas Coastal waters, as high pressure builds into the northwest Gulf of Mexico behind a cold front. With the current National Hurricane Center forecast keeping the tropical cyclone well south of the coastal waters no direct impact is expected however, the combination of the cyclone and the high pressure building over the NW gulf will increase northeast winds and allow for swells to build to small craft advisory levels.
251 PM EDT Tue Sep 5 2017 Strong cold front exits tonight. High pressure with drier and cooler weather behind front for the remainder of the week. Rather tricky forecast as models have a couple of waves of low pressure riding up along a cold front moving eastward across the area tonight. Right now with all the low level moisture hanging around, will go for some fog later tonight, especially over central and eastern WV. For Wednesday, we look for fog to dissipate by mid morning with high pressure to build in with cooler and drier air, but lots of clouds will remain in the cold advection. A sharp upper level trough will have a sfc reflection crossing the area Wednesday.
321 PM CDT Tue Sep 5 2017 /Tonight/ A pre-frontal trough extended south of a Quitman to Hillsboro to Gatesville line as of 20z with the cold front 75 to 100 miles to the northwest. High temperatures on Wednesday look to be some 7 to 10 degrees below normal-- topping out in the lower to middle 80s area-wide.
A relatively cool air mass is expected to remain in place across the forecast area as a strong upper level ridge resides upstream over the far western U. A Great Lakes upper trough is expected to shift eastward on Wednesday while the ridge to the west remains in place. This will drive rising heights and warmer temperatures into the area.
A cold front will slowly cross parts of the area early this evening and move slowly east of the Chesapeake Bay Wednesday evening. High pressure will then build to the north of the area over the weekend. Additional showers will likely develop Wed morning over wrn areas as right entrance jet dynamics increase as upper level trough amplifies across the Great Lks.
High pressure will follow and build from the mid MS Valley east to the middle Atlantic states Thu and Fri. A warm and muggy night expected with minimum temperatures in the upper 60s nw to the low-mid 70s east-se. A mid level s/w and attendant sfc cold front will enter the western Piedmont Wednesday morning, then drift slowly east through the day. This should limit the ability of the lower half of the atmosphere to destabilize, and prevent storms from reaching severe criteria. Cooler drier air will infiltrate behind the boundary, leading to partial clearing across the Piedmont overnight.
A broad upper level trough will persist across the eastern CONUS through this period, with a modest mid-level jet streak gradually intensifying over our area. However, a cold front moving in from the northwest will provide sufficient forcing for a slight chance of showers/storms through the overnight hours, especially across SE Alabama and the FL Panhandle. After highs in the upper 80s to lower 90s this afternoon, lows will be in the lower- mid 70s inland with upper 70s along the Gulf Coast.
This is likely due to the showers/storms outrunning the trough. The first will be storms associated with mesoscale boundaries/pre-frontal trough late this morning. The second will be with the stronger to possible severe storms attached close to the cold front itself. This second scenario has the highest potential for strong storms within the predicted 1500-2500 J/kg CAPE between 19Z-22Z (2PM-5PM) time frame. A strong push of cooler, drier air will filter into the area by Wednesday morning, bringing a swift end to precipitation thereafter and help to diminish cloud cover over much of Northern Alabama by 12z Wednesday.
The large scale synoptic pattern was characterized by mean troughing centered from the western Great Lakes to the mid Mississippi Valley. and mean ridging in the upper troposphere across the Great Basin and Pacific Northwest. Surface ridging behind the eastern trough continued to expand across Nebraska and Kansas. This ridge will remain in place through Wednesday. A fresh airmass in place from northern latitudes will help temperatures tonight fall to the coldest readings since May 24th for most locations -- in the lower to mid 40s. This, coupled with clearing sky and dewpoints in the lower 30s most locations should allow temperatures to fall fairly quickly through the 50s and into the 40s.
High pressure continues to build over the region this afternoon and will remain established over the area through Wednesday. Stable air associated with the high pressure system will effectively trap wildfire smoke near the surface. Temperatures will be tricky over the next couple days as smoke filled valleys will remain cooler than otherwise anticipated.
A ridge of high pressure was positioned across the west early this afternoon as a deep low pressure trough shifted slowly east through the Gulf of Alaska and a sub-tropical low lifted north off the California coast.
Cold front currently bisects the CWA with ongoing convection across the mid section of the area. as a large upper trough digs deeper into the deep south today. We will see highs at least 10 degrees cooler today than yesterday with readings mainly in the mid to upper 70s. Light winds and mostly clear skies will result in lows plummeting into the lower 50s tonight. Any cloudiness will also help keep temperatures down as well, which will struggle to get out of the lower to mid 70s as it is. Cooler readings will be found in the eastern sections with southeast MO being the warmest.
211 PM CDT Tue Sep 5 2017 An upper trough is over the Great Lakes region with an upper ridge over the western half of the country. There is a cold front moving through the area with gusty northerly winds behind it. Temperatures today will be cooler than yesterday with highs slightly below normal. The hi-res models indicate precipitation is possible across the Lower Trans Pecos, Davis Mountains, and Big Bend area this afternoon and evening.
315 PM CDT Tue Sep 5 2017 High pressure across MT will settle south across Wrn Nebraska overnight.
Mid/upper level high pressure draped along the western U. The northwesterly flow aloft will help push a cold front, currently movg across north TX, toward S TX tonight. Light and variable winds this evening are expected to become more northerly overnight, but the cooler drier air and slightly stronger winds are not expected until during the day Wed into Wed evening. Did not go any higher than 20 percent due to increasing CIN overnight and the high pressure aloft. Instability does increase Wed ahead of the main surge of drier air, but the moisture is limited to the lower levels, therefore only went 30 pops across the southern CWA, but a tad higher over the waters where deeper moisture and better instability will be located. Much drier and cooler air will be more noticeable by Wed night.
313 PM CDT Tue Sep 5 2017 At 2 PM, a short wave trough was moving through southwest Wisconsin and northeast Iowa and another short wave trough was located over the Minnesota Arrowhead. For late tonight and Wednesday, a trough currently located over Hudson Bay, is expected to move south through Wisconsin.
336 PM EDT Tue Sep 5 2017 A cold front will progress very slowly across the region this evening and practically stall overhead tonight.
Strong cold front that swept through Mon afternoon/evening is now situated from northern AR into the TX Panhandle. By 12z Thu, sharp upper trough will extend from the Great Lakes through the Ohio Valley with lee troughing strengthening over the high Plains.
1207 PM CDT Tue Sep 5 2017 Cold front currently located across southern Arkansas will continue to advance southward and out of the region this afternoon. Precipitation will be around a cold front advancing southward through the state. Today Through Wednesday Night A cold front was pushing into Arkansas from the north early this morning. Much cooler air will be noted behind the front.
149 PM EDT Tue Sep 5 2017 Aviation Much cooler temperatures are expected the rest of the week with highs in the 60s. With these cooler temperatures will be scattered rain showers especially near Lake Michigan.
1209 PM CDT Tue Sep 5 2017 Cold front that brought storms to the area last evening has moved well south of the region. With ample insolation and deep mixing to above 800mb, have trended temps at or just above the warmer guidance. However, mdls show the upper trof digging into the area late tonight, which shud bring along patches of clouds. In the end, have gone aob the cooler guidance for tonight, but this still may not be cold enuf in some areas.
Meanwhile, an outflow boundary from convection earlier this morning over the Gulf waters south of here has worked to stabilize portion of Deep South Texas this afternoon given the overall lack of activity over the Lower and Mid Valley areas. Temperatures will continue to be in the 90s for highs, with lows by Wednesday night more noticeably cooler across the northern areas.