Aikyam-Lab/Synoptic-Bench huggingface dataset:
Thunderstorm chances will increase late tonight, as an 850-700mb theta-e boundary surges north-eastward into Minnesota advecting warmer air and more low-level moisture. Friday night is marked by a cold frontal passage in this forecast area.
A cold front currently extending from southern Lake Michigan to central Iowa will sag southward late tonight. High temperatures will once again top out in the lower to middle 90s, with peak afternoon heat index values reaching the 105 to 110 degree range.
952 PM EDT Thu Jul 20 2017 A cold front will approach the area tonight and cross through by Friday morning.
947 PM CDT Thu Jul 20 2017 Much of the afternoon cu field and very isolated -SHRA have diminished this evening with the loss of heating, with weak H850-700 ridging expected to linger over the region overnight through Friday.
A weak upper level trough will transition to a zonal flow pattern Friday.
516 PM MDT Thu Jul 20 2017 Latest analysis shows low pressure centered over eastern Montana. A warm front extends eastward from the low into northern North Dakota and a dry line extends southward from the low into eastern Wyoming. The dry line will push into western South Dakota this evening followed by a weak cold front that will push southeastward across the region overnight. Thunderstorms have already developed in southeastern Montana and along the warm front in North Dakota. Might see some breezy areas in the area of the tighter sfc pressure gradient to the west of the low especially during the morning. Drier air will flow into the region as high pressure moves in behind the departing low.
High pressure is expected to hold over the waters through the remainder of the week and into the weekend.
Locations that received heavier rainfall today have already cooled to their forecast lows for tonight, with minimum temperatures in the low to mid 70s for most locations. Bermuda ridge axis will remain surpressed over south FL and the north Bahamas as a weak sfc/low lvl trough over north FL and the SE coast weakens and fills in.
1144 PM CDT Thu Jul 20 2017 /06Z TAFs/ VFR conditions will prevail as ridging aloft persists across the Southern Plains. While most of this Cu is quite flat thanks to the influence of mid-level high pressure just to our north, some slightly more robust puffs are apparent on visible satellite imagery. /Issued 306 PM CDT Thu Jul 20 2017/ The upper level ridge will still be in control of our region on Friday but be centered to our northeast where the Midwest and Southeast regions meet.
If storms develop here, there is a small chance for one or two to become strong or perhaps briefly severe although wind shear is on the low end to support any long-duration severe activity and it should remain fairly isolated and relatively short lived. Friday will be hot once again, and likely very similar conditions to today although with a better chance for the entire area to remain primarily cloud free and hot with the thermal ridge building back into northeast Nebraska.
A cold front will move through overnight and should be to around Miles City by 6 AM tomorrow.
Water Vapor Satellite trends this afternoon place an upper level ridge of high pressure over the Lower Mississippi Valley. A very hot airmass with temperatures in 90s combined with surface dewpoints in the 70s have resulted in heat index values between 105 to 112 degrees with the highest values across portions of Northeast Arkansas and the Missouri Bootheel. Not much change in the overall forecast is expected through Friday evening as the very hot airmass combined with the high low level moisture will produce conditions conducive for a heat advisory across the Mid-South.
Temperatures across the area are cooling off reasonably well despite this impediment, with most spots now within a few degrees of the lower 80s. Tonight should stay fairly quiet as a weak upper low centered off the southeast Atlantic coast begins retrograding south of the upper high, placing the high right over the Tennessee Valley. High pressure is xpcted to be layered across the mid/srn Atlantic states while the upper ridge axis gradually translates ewd across the SE region. Slightly cooler conditions/higher rain chances are then xpcted going into the weekend period, as Gulf moisture begins to increase into the area and a weak cold front approaches from the NW.
Thudnerstorms occurring along cold front and expect isolated storms late this afternoon and early evening mainly in zones 411 and 413.
Strong theta-e advection ahead of a low pressure system in the high plains will likely begin producing precipitation after midnight in extreme southern and western Minnesota. Dew points will rise above 70 degrees during the day as the warm front draped east from the high plains low inches northward through Iowa.
The 16C h700mb thermal ridge will move overhead, ahead of a cold front during the afternoon, and this should present deep vertical mixing and super adiabatic lapse rates near the SFC. The models forecast midlevel clouds which will take a few degrees off the high temperature forecast. The 16C thermal ridge should move in late tonight and hold up lows to the upper 60s to lower 70s for a warm start Friday morning. Whatever convection develops Friday afternoon is expected to grow upscale Friday night as a significant cold front moves through Swrn Neb.
Also adjusted PoPs a bit over southeast Montana to focus the higher PoPs over the far southeast. A cold front will move through overnight and should be to around Miles City by 6 AM tomorrow.
Temperatures are as expected in the lower to mid 90s. Dewpoints mainly in the lower to mid 70s, yielding heat index values in the 103-107 range. With high pressure aloft expected to stay over the region through Friday, afternoon shower and thunderstorm chances expected to remain 20-30% over SE Texas & Western Louisiana. The western edge of an approaching upper level low pressure moving across the northern Gulf will increase moisture and instability from the east. This combined with afternoon temperatures in the mid 90s, could ignite increased thunderstorms by late afternoon over MS/SE LA and move westward into Central and South Central Louisiana by late afternoon, thus the higher chances there.
952 PM EDT Thu Jul 20 2017 The upper level ridge is centered to the west across the Central CONUS. At the surface, high pressure extends across the Southern Appalachians. The upper level high will shift to the east tomorrow making for the hottest day of the forecast period. Chattanooga Airport, TN 75 95 75 93 / 10 20 10 30 Knoxville McGhee Tyson Airport, TN 73 93 73 92 / 10 20 10 30 Oak Ridge, TN 74 93 73 92 / 10 20 10 30 Tri Cities Airport, TN 67 91 70 91 / 10 40 20 30.
The center of a 500 mb ridge will move east, parking itself directly over the Kentucky-Missouri border on Friday.
High pressure and drier air will return Friday. High pressure builds in for tonight, and low level moisture will likely result in valley fog development once again. High pressure and drier air returns for Friday into Friday night. A series of embedded short waves will rotate around the base of the upper trough and act in phase with multiple surface features to produce periods of showers and thunderstorms.
Expansive upper ridge dominates the southern CONUS this afternoon. By Friday night the persistent mid-level ridge over the central US begins to break down and zonal flow returns over the northern CONUS.
As is largely the case this time of year, the upper level high and its orientation and strength will be the governing factor for our upcoming weather. When combining proximity with strength, the influence of the upper high will peak on Friday afternoon.
/issued 947 PM CDT Thu Jul 20 2017/ Much of the afternoon cu field and very isolated -SHRA have diminished this evening with the loss of heating, with weak H850-700 ridging expected to linger over the region overnight through Friday.
Upper ridge currently overhead begins to break down by Sat which will hopefully allow a cdfnt to drop into the area Sat evening and into Sun. With good upper air support, expect at least sct TSRA to develop along what appears to be a pre-frontal trof of sorts while the actual cdfnt hangs up over IA. Slightly cooler 850mb temps are expected on Sun, tho if convection is limited, the going forecast may be too cool by a few degrees. The actual cdfnt shud push thru the area early Mon morning allowing for a couple of days of cooler and drier weather before the next warmup on Wed. Have overall trended aoa the warmer guidance thru the period.
Area 00z soundings showing very unstable conditions beneath upper low.
1125 PM CDT Thu Jul 20 2017 The main challenge is timing of the weekend "cold frontal" passage and affect on temperatures and trends in precip/convective chances.
Just some marine stratus over the coastal valleys and some dissipating cumulus over the ridges.
Latest analysis shows low pressure centered over eastern Montana. A warm front extends eastward from the low into northern North Dakota and a dry line extends southward from the low into eastern Wyoming. The dry line will push into western South Dakota this evening followed by a weak cold front that will push southeastward across the region overnight. Thunderstorms have already developed in southeastern Montana and along the warm front in North Dakota. Might see some breezy areas in the area of the tighter sfc pressure gradient to the west of the low especially during the morning. Drier air will flow into the region as high pressure moves in behind the departing low.
Mainly due to warmer temperatures at H85 around 20-23C which tends to inhibit convection. Temperatures will remain hot, with temperatures ranging from the low 90s along the immediate coast, to mid to upper 90s across the Coastal Plains.
An H5 upper low off the GA/Carolina coast will move inland tonight and open into a weak wave.
Mostly clear skies will take over tonight with high pressure over the Gulf supporting light southeast winds, and with low temperatures in the mid 70s to near 80 degrees. Mid-level ridging centered over the Southern High Plains with extend south over the area, limiting significant weather in the short term. High temperatures Friday may inch a degree or two higher under the persistent mid- level ridging, ranging from the lower to mid 90s near the coast to just above the century mark inland west.
Upper level ridge continues to build over the area on Friday with high temps similar to Today if not a degree higher.
510 PM MDT Thu Jul 20 2017 Latest upper air analysis shows the ridge nearly stationary. There were a few weak disturbances in the upper level flow rotating around the ridge. At the surface a warm front was moving north into Nebraska. During the evening a weak upper level short wave trough will move over the west edge of the forecast area. Isolated to scattered storm coverage may accompany this short wave trough. The majority of the storm activity will remain west and north of the forecast area, rotating around the upper level ridge over KS. During the afternoon an upper level short wave trough will approach from the west. Accompanying the trough will be a weak cold front and isolated to scattered storm activity.
814 PM PDT Thu Jul 20 2017 A high pressure ridge will bring seasonally hot inland weather through the weekend.
/issued 242 PM CDT Thu Jul 20 2017/ The focus remains on thunderstorm potential this weekend as upper level ridging and dry mid to upper levels are replaced by a weakness in the ridge and the return of some monsoonal deeper moisture arriving from the west.
Isolated to scattered storms will continue into this evening, mainly across the higher terrain and the adjacent plains. Easterly flow aloft will continue into this weekend as the upper high shifts eastward, and while 850mb temperatures will increase, heights will fall in response to a disturbance that will progress westward across Texas. Thus, temperatures will remain near to just above normal, with rain chances expanding eastward from the higher terrain across the Trans Pecos and Permian Basin.
Otherwise, Water vapor showing moisture stream reaching the CWA and combined with the upper low moving into Alberta, isolated- scattered showers/storms look good overnight. TFJ With a ridge in place temperatures continue warm. Cold air advection and tighter pressure gradient will result in stronger northwest winds along with cooler or more seasonal temperatures.
714 PM CDT Thu Jul 20 2017 /00Z TAFs/ VFR conditions will prevail as ridging aloft persists across the Southern Plains. While most of this Cu is quite flat thanks to the influence of mid-level high pressure just to our north, some slightly more robust puffs are apparent on visible satellite imagery. /Issued 306 PM CDT Thu Jul 20 2017/ The upper level ridge will still be in control of our region on Friday but be centered to our northeast where the Midwest and Southeast regions meet.
300 AM CDT Sat May 6 2017 Still under the influence of upper level low and and associated trough over the Appalachians. Before it leaves us, a piece of energy, currently over north central Illinois will slide south on the backside of the trough. A decent gradient will exist on the west and northwest side of the low and thus will have a lake wind advisory out for a good part of the CWA. Ridging will move into the area tonight and keep us dry through Sunday. A second upper level low will form/move into the desert southwest Sunday and will send pieces of energy up over the ridge which will be centered over the Plains states.
/Issued 321 AM CDT Sat May 6 2017/ Highly amplified pattern currently in place across the CONUS will be slow to evolve and with ridging aloft to dominate conditions across the Southern Plains for the next several days.
Max temps should be a couple of degrees warmer than Fri as H85 temps warm slightly.
429 AM EDT Sat May 6 2017 Fairly quiet weather is expected for the short-term portion of the forecast as high pressure system remains nearly stationary across Hudson Bay. Nam shows a closed 500 mb low over Lake Huron 00z Sun with a trough in the western U. and a ridge over the plains. In the extended, ECMWF and GFS show a 500 mb closed low over New England 12z Tue with a ridge over the plains and a closed low and trough over the desert sw. By 12z Thu, 500 mb troughing will be over the upper Great Lakes with a closed low over the southern plains. By 12z Fri, ridging is over the Rockies with troughing in the Pacific NW and troughing over the eastern U.
443 AM EDT Sat May 6 2017 Low pressure will maintain rain chances through the weekend. Temperatures will be much cooler today.
Satellite imagery shows the closed upper low spinning over the Ohio Valley into the Great Lakes region while our area is under cold air advection and northwest flow aloft. This pattern will bring down another dry cold front later tonight into our area. 925mb temperatures will reach ~4+ deg C, which will support high temperatures about 5-6 degrees warmer than yesterday, near the upper 70s to near 80 degrees in the west, which are still below normal high temperatures. The best pressure gradient for gusty winds will remain in the Delta, Highway 82 corridor and near Meridian as the cold front moves down later today. With some wind around, we won't radiate as efficiently but still will fall below normals low temperatures Sunday morning into the low-mid 50s areawide.
A cold front will move through the region this afternoon/evening and temperatures in most locations will run 5 to 10 degrees below seasonal averages on Sunday. Showery conditions will persist on Sunday especially over the higher terrain near the Continental Divide.
Upper ridge over eastern Montana will slide into North Dakota by this evening.
/DC/ The closed low over TN that has been plaguing our weather for the last few days has finally moved off to our East as an open wave within the main East Coast trough. The tight surface pressure gradient responsible for our breezy winds has also moved off to the east and relaxed, so most locations are already observing light to calm winds as ridging begins to build in across the area. Ridging at the surface and aloft will get underway Saturday and begin a warming trend over the area. While cooler low to middle 70s will be common in the east, the increased ridging in the west will result in lower 80s being achieved.
/Issued 320 PM EDT Fri May 5 2017/ Thanks to the closed upper low currently residing over the southern Appalachians, the weather today has been damp and chilly. While some light showers will linger into the evening, the overall coverage will diminish greatly overnight tonight as the low begins to pull away from the area.
WV imagery shows a highly- amplified upper ridge over the western CONUS, which is slowly moving eastward into West Texas and Southeast New Mexico. As a result, temperatures have been on the uptick, and will peak for this forecast Saturday as the ridge axis passes thru the region.
19Z water vapor imagery shows an upper level ridge over the Rockies and into the Canadian plains with an upper trough just off the Pacific Northwest coast line. At the surface, weak ridging was noted throughout the southern and central plains with a weak low pressure system moved across northern MN. Northwest flow aloft and the weak surface ridging should maintain a relatively dry airmass with little in the way of forcing for ascent. So with favorable conditions for radiational cooling, have lows a few degrees cooler than MOS guidance especially in the river valleys.
A developing omega block will continue to take shape with the central ridge axis located through the Great Plains. The influence of this upper ridge over the next few days will result in a general persistence forecast.
418 AM CDT Sat May 6 2017 Another quiet day in store for the area Saturday as surface and mid/upper ridging overspread the area. As the ridge slides off to the east southerly return flow will commence.
An upper level trough will maintain seasonally cool temperatures today with occasional light rain.
553 AM EDT Sat May 6 2017 Low pressure will maintain rain chances through the weekend. Temperatures will be much cooler today.
A deep upper level long wave trough is now moving into the west coast. then diminish Saturday evening as a long wave ridge noses into the area between the residual trough and the cutoff low.
215 AM MDT Sat May 6 2017 Upper ridge axis over the Rockies today will shift eastward to the High Plains on Saturday.
The low will move well southeast of our region by Saturday evening, taking any shower chances with it. High pressure will build southward out of Canada for the remainder of the weekend. Highs Saturday and Sunday will be in the lower 70s along and west of the Mississippi River, to the middle 60s to around 70 degrees east. Sunday will be the cooler of the two days.
The low pressure system will move up to the northeast through the period as high pressure builds over the local area at the lower levels. Lows will be in the low 50s Saturday night and Sunday night.
Amplified high pressure ridge along the spine of Rockies is delivering one of the nicest days of the year this afternoon. High pressure ridge axis inches eastward onto the high plains on Saturday, delivering a continued clear sunny sky.
1258 AM CDT Sat May 6 2017 A fantastic weekend awaits as a strong ridge of high pressure builds over the region.
325 AM CDT Sat May 6 2017 An upper level ridge will slowly progress across the central plains through Sunday. Highs today will be in the lower to middle 80s. South winds at 10 to 15 mph along with increasing dewpoints into the upper 40s will lead to warmer lows lows in the lower to mid 50s tonight.
321 AM CDT Sat May 6 2017 Highly amplified pattern currently in place across the CONUS will be slow to evolve and with ridging aloft to dominate conditions across the Southern Plains for the next several days.
/ISSUED 637 PM CDT Fri May 5 2017/ With a pair of high pressures over the Central Plains and off the Texas coast clear skies and VFR conditions will prevail through the period at all terminals. Moisture levels will remain low in part to an upper level ridge slowly moving closer to the central plains with two deep low-pressure systems on either side of the amplified ridge (Omega Block).
An upper level ridge of high pressure will continue to build throughout the central CONUS through the day on Sunday.
Pattern is dominated by deep troughs over the Ohio Valley and off the west coast. In between is a large upper ridge stretching from far west Texas northward to Montana. A compact upper level impulse will travel down the eastern periphery of the upper ridge today and push a back door cold front through the region. Front will only bring a wind shift, a few clouds and some slightly cooler and drier air to the region. Otherwise the upper ridge will begin to build over the area as yet another upper low develops and moves into southern California.
One more day of record or near record highs across our CWA as high pressure dominates the high plains. The split flow trough over the west coast will gradually move inland over the weekend. There is some indication we could see some of this roll off the higher terrain into the plains. Dewpoints have climbed slightly at the lower elevations over the past 24hrs. But we feel it is still just a slight chance of convection for the lower elevations late today. An increasing chance of scattered showers should expand eastward to the Billings area very late tonight and into Sunday morning as upper trough slides east. This along with increasing clouds and height falls will result in cooler afternoon highs for all but the furthest southeastern zones.
High pressure noses south through Wisconsin today in the wake of the departing low pressure system to the south. We should still manage to get temps in the low-mid 50s east to the lower 60s west of Madison. We still see lots of temps in the lower and mid 30s. Dewpoints really fall off and this lowers our humidity and that may keep frost from forming.
107 AM EDT Sat May 6 2017 Low pressure will maintain rain chances and colder temperatures through the weekend. Temperatures will be much cooler today.
Beyond some clouds with the secondary boundaries this morning, mostly sunny skies and dry conditions are expected through the weekend as high pressure builds across the state from the Gulf of Mexico. Daytime highs will be on the cooler side today under occasionally breezy west/northwest flow, in the upper 70s and low 80s.
The Texas high pressure will move slowly east and be centered from the Ohio River Valley to the Florida Panhandle.
Overall moisture is expected to decrease as the main upper low and trough cycle to the northeast toward the Great Lakes and New England through tonight. Also, we could still see a few showers and maybe even a thunderstorm in the far northeast as another bit of energy passes through the base of the exiting trough.
Highs will range from around 40 near Lake Superior to the low 50s south-central. Nam shows a closed 500 mb low over Lake Huron 00z Sun with a trough in the western U. and a ridge over the plains. In the extended, ECMWF and GFS show a 500 mb closed low over New England 12z Tue with a ridge over the plains and a closed low and trough over the desert sw. By 12z Thu, 500 mb troughing will be over the upper Great Lakes with a closed low over the southern plains. By 12z Fri, ridging is over the Rockies with troughing in the Pacific NW and troughing over the eastern U.
A few cooler spots, especially in the northeast may approach the upper 30s.
Skies were clear over most of the region except over the mtn ridges were a few cumulus were noted. Things start to change as moisture associated with a large trough off the CA coast begins to get advected into the region. Overall this pattern will bring increasing moisture into the high country and expect we will see a few scattered showers and storms over the mtns by mid to late afternoon. It will be another warm day with highs well into the 80s across the lower ark rvr valley, with L80s res of plains.