Aikyam-Lab/Synoptic-Bench huggingface dataset:
Cliff PREVIOUS DISCUSSION: Warm and dry conditions are expected today ahead of an approaching cold front. Cooler conditions and improved fire weather conditions are expected on Thursday as winds decrease over the area. That said, upper ridging is expected to build back across the western U. A cold front will push through the area today with isolated showers and thunderstorms this afternoon and evening. In addition, dry lightning during the expected cold frontal passage this afternoon may add to the overall threat.
The main concern is the timing of the cold front as it sinks southeast across the cwa. Will rely heavily on the high resolution model solutions to get an hourly trend for late this evening and overnight, particularly the HRRR, RAP13, and GFS1hr not only for temperatures and dewpoint trends, but winds. Cooler air and lower dewpoints will move in behind the cold front. The pattern will feature a western CONUS ridge and central/eastern CONUS trof.
428 PM EDT Wed Sep 2 2020 A weakening cold front will push southeast across the area this evening.
206 PM MDT Wed Sep 2 2020 Latest sfc analysis shows warm front has pushed east of SD. with series of weak sfc trofs moving east across SD attm. with cold front now pushing into nwrn MT. Thursday will be a cooler day as 850hpa temps fall back into the teens.
Taking a look at water vapor imagery, we can see the upper level low finally starting to exit the region. Ahead of the low, there is a jet streak at 300 mb, and the left exit region is helping produce just enough ageostrophic circulation to allow divergence aloft and hence lift in the east. As the upper low pushes east, subsidence will be observed on the back side, and we should see skies generally clearing. A cold front will push in from the north tomorrow, and while the front might not make it completely through the area, we should see a northerly wind develop for a majority of the forecast area. With plenty of sunshine tomorrow, highs will be able to reach the mid 80s to mid 90s; cooler temperatures anticipated across the northern half of the area.
128 PM EDT Wed Sep 2 2020 The cold front and assoicated clouds will continue to push off to the east this afternoon. A potent longwave trough with an anomalously strong embedded polar jet streak for early September (+125 kts) will scrape through the UP this morning. The second area of development comes in the form of low-topped showers through the Tri-Cities and Thumb localities after sunrise in response to what remains of the aforementioned stationary front once it transitions into a southeastward propagating cold front. Given the strength of this system and impressive low level convergence, the surface pressure gradient will steadily constrict ahead of an active cold front. Forecast soundings depict mid-level ascent, but given the dryness of the low-levels, the FROPA looks to be rather dry with virga more likely than surface surviving precipitation.
High pressure will remain in place over the region leading to hotter than normal conditions through the evening. Given the instability, warmer column aloft, and storms are expected to be garden variety.
251 PM EDT Wed Sep 2 2020 It will unfortunately remain dry the next several days, despite a cold front passing through on Thursday.
While lingering convection will remain possible across southeast Oklahoma, intensity and coverage should be less being west of the low's center. As a result, warmer to hot temperatures are expected with highs in the upper 80s to mid 90s deg F.
Most of the models families slowly bring this frontal system into the region but tend to keep the POPs to a minimum despite the higher mid level moisture.
239 PM CDT Wed Sep 2 2020 (Tonight and Tomorrow) An upper level low currently just southeast of Lubbock will continue moving southeast into central Texas tonight, then stall and weaken just southeast of our CWA on Thursday. With the low just southeast of our area tomorrow, will keep the highest rain chances concentrated across our eastern half. Look for lows tonight from the upper 60s to lower 70s, and highs on Thursday in the upper 80s to mid 90s, with the cooler temperatures on Thursday across the eastern half of the area, closer to the upper low and cloud cover.
Moisture ahead of the boundary combined with an upper-trough overhead to allow for sufficient instability to generate some descent convection later this afternoon.
Quiet and dry conditions will be seen late this afternoon through tonight as high pressure moves into the Ohio Valley. On Thursday a cold front will sweep through the area during the morning but no precipitation is expected. Windy conditions will develop behind the cold front which will cause humidity levels to drop through the afternoon.
132 PM EDT Wed Sep 2 2020 Warm and humid weather with periodic shower and thunderstorm chances are expected through Thursday with the approach and passage of a cold front. Cooler, more comfortable conditions are expected by late week. Moist swly flow and large scale jet ascent on the van of an advancing cold front will support additional development of showers and thunderstorms through tonight.
A cold front is expected to move northwest to southeast through the region, entering NW Missouri by mid morning and completely through the region by early to mid afternoon. This will create a decent gradient of temperatures for tomorrow, with highs across NW Missouri only expected to reach the low 80s by frontal passage and highs for areas along and south of the Interstate 70 corridor expected to warm up to the mid to even upper 80s tomorrow afternoon prior to frontal passage.
1252 PM CDT Wed Sep 2 2020 (Today and tonight) The upper-level low pressure area is very apparent in the water vapor satellite loop this morning in the Clovis/Portales New Mexico area. Showers and storms will be likely again ahead of this low, although with the current projected path, the highest liklihood of heavy rainfall has shifted a bit farther south into Texas. As the low moves east-southeast, precipitation chances will decrease tonight in central Oklahoma, so will shift the expiration time of the central Oklahoma portion of the flood watch to 00Z this evening.
Hot temperatures will return to much of the region in the coming days as high pressure builds across the Western US.
At 2 PM, skies were crystal clear and winds were light as we await the passage of a weak cold front tonight.
254 PM EDT Wed Sep 2 2020 Main upper level feature impacting the forecast area today is the high pressure centered just to our southeast.
BW Chattanooga Airport, TN 73 91 73 90 69 / 10 30 20 30 0 Knoxville McGhee Tyson Airport, TN 72 89 72 88 66 / 20 40 30 30 0 Oak Ridge, TN 72 89 71 88 64 / 20 50 30 30 0 Tri Cities Airport, TN 69 88 69 84 61 / 30 50 50 30 0.
and NC Gulf and a mid-level trough over the Arklatex region. The deep dry air associated with the ridge continues to dominate the much of the CWA with best moisture trying to leak into the Texas Lakes region and the northern portions of Central LA. A few thunderstorms are possible across the northern and western areas later tonight if additional clusters of thunderstorms develop along the trough axis and drift into the region. Muggy air and a warm southerly flow to maintain warmer then normal overnight lows for tonight.
By Thursday, a digging 500-mb trough moves across the western Great Lakes region. This will help drive a cold front through southwest Missouri by late evening. Afternoon temperatures will surge into the upper 80s for much of the region ahead of this front with surface dewpoints in the low 70s.
306 PM EDT Wed Sep 2 2020 A weakening cold front will push southeast across the area this evening.
519 PM MDT Wed Sep 2 2020 Latest sfc analysis shows warm front has pushed east of SD. with series of weak sfc trofs moving east across SD attm. with cold front now pushing into nwrn MT. Thursday will be a cooler day as 850hpa temps fall back into the teens.
Winds are widespread 30-40 mph sustained winds and gusts are 50-60 mph with the cold front passage. Cliff PREVIOUS DISCUSSION: Warm and dry conditions are expected today ahead of an approaching cold front. Cooler conditions and improved fire weather conditions are expected on Thursday as winds decrease over the area. That said, upper ridging is expected to build back across the western U.
The remainder of the week will see the upper ridge over the western states building back eastward over the central High Plains. This will result in continued dry and warmer weather with highs climbing back into the upper 80s and 90s. The GFS and GEM models keep this pattern as an open wave transitioning east across the central and eastern CONUS while the ECMWF model closes the wave into a deep upper low somewhere over the Rockies or Great Basin. Current light winds will trend light SWly overnight, ahead of an approaching dry cold front. The cold front is expected to reach the airports in the 14-15z Thu time range, follow by a several hour period of strong N/NE winds.
635 PM CDT Wed Sep 2 2020 Weak ridging has brought a quiet day to the region early this afternoon, other than some occasional gusty winds. This system will track eastward along the Canadian border tonight, with an associated cold front extending southward and sliding through the forecast area sometime Thursday morning. closer to the low where stronger forcing will be present. However, model soundings suggest anything that does develop will have to overcome quite a bit of dry air in the low levels, so keeping the forecast dry in areas south of I-94 for now. The gradient should relax a bit by late afternoon, but the persistent northwesterly flow should still keep temperatures about 10 degrees cooler than today, with highs in the mid 60s to mid 70s.
Composite analysis shows the subtropical ridge at the surface and aloft extending from the western Atlantic across central Florida and into the northern Gulf of Mexico. The 00Z Key West sounding showed that the ribbon of stable/dry air in the lower/mid levels which was over the Keys earlier today has now shifted to our west, with PW jumping from 1.
The main concern is the timing of the cold front as it sinks southeast across the CWA. Will rely heavily on the high resolution model solutions to get an hourly trend for late this evening and overnight, particularly the HRRR, RAP13, and GFS1hr, not only for temperatures and dewpoint trends, but winds. Cooler air and lower dewpoints will move in behind the cold front. The pattern will feature a western CONUS ridge and central/eastern CONUS trof.
However, should winds decouple in the low-lying valleys prior to this wind speed increase, the higher winds may be confined to the higher ridge tops and terrain.
Dangerous conditions due to heat will be possible in the lower elevations. Very strong high pressure centered to our northwest will push eastward over the next several days. The position of the high is not conducive for increasing moisture across the Northland. An Excessive Heat Warning is in effect for the lower valleys of Yavapai/Gila counties and the Grand Canyon, but people should be prepared for elevated heat elsewhere as well.
Strong high pressure will bring mostly fair skies, continued dry conditions, light winds, and very warm daytime temperatures through the Labor Day weekend.
608 PM EDT Wed Sep 2 2020 It will unfortunately remain dry the next several days, despite a cold front passing through on Thursday.
An upper ridge will continue to build into the area through Thursday, accompanied by mostly clear skies and temperatures around 10 degrees above normal.
Elongated ridge of high pressure extends across much of the western Great Basin and out across California under a light to moderate northwest flow aloft over Colorado. There is a weak disturbance over the northern plains states which will drop a cold front across northeast Colorado later tonight. For Thursday the airmass will be a little cooler behind the front, but only about 3-6 degrees cooler behind today's readings on the plains.
/issued 302 PM CDT Wed Sep 2 2020/ West TX and SE New Mexico are finally enjoying a reprieve from the heat thanks to a cold front which has worked its way through the region this morning. The upper low will depart to the E of our region and ridging aloft will expand over the forecast area by tomorrow afternoon.
849 PM CDT Wed Sep 2 2020 Fairly benign evening across the Tennessee Valley region as an upper-level ridge of high pressure just to our east has significantly helped to squash any convection, subsequently resulting in a clear and dry evening. Otherwise, expect another warm and muggy night with lows in the low to mid 70s.
Over our area, the subtropical ridge remains the main weather influencer as conditions continue to be hot and muggy. We are now starting to see dewpoints in the lower 70s in the eastern parts of the CWA. Overnight lows will dip into the lower 70s and high temperatures will top out in the low to mid 90s again.
/Issued 254 PM EDT Wed Sep 2 2020/ Main upper level feature impacting the forecast area today is the high pressure centered just to our southeast.
1046 PM EDT Wed Sep 2 2020 A weakening cold front will hang up over the srn tier overnight and may waggle back north slightly as a warm front on Thursday.
The upper low is moving across north central Texas tonight.
853 PM EDT Wed Sep 2 2020 Warm and humid weather with periodic shower and thunderstorm chances are expected through Thursday with the approach and passage of a cold front. Late Evening Update: A few trailing showers will quickly cross over the ridges in the next hour.
More showers are possible tomorrow evening as a cold front moves through the region. Dry and cooler conditions are expected this weekend. Will make some adjustments to the timing of the PoPs this evening, with the higher PoPs beginning after 030400Z. A cold front will move through late Thursday into the overnight hours.
753 PM CDT Wed Sep 2 2020 Winds the primary concern this evening into the overnight as low pressure traverses the CWA. Mixing does increase in the wake of the cold front within the CAA regime and the potential to mix down 850mb winds overnight for the Devils Lake basin down into the Wahpeton area with gusts to 50mph. At the start on Fri, we would look for temps to trend upward into the 70s after a cooler Thu and the trend should continue into a seasonable Sat. Several periods of strong winds will move through the region, with directions shifting from the south to east to northwest as a cold front moves across eastern ND and northwest MN.
/issued 239 PM CDT Wed Sep 2 2020/ (Tonight and Tomorrow) An upper level low currently just southeast of Lubbock will continue moving southeast into central Texas tonight, then stall and weaken just southeast of our CWA on Thursday. With the low just southeast of our area tomorrow, will keep the highest rain chances concentrated across our eastern half. Look for lows tonight from the upper 60s to lower 70s, and highs on Thursday in the upper 80s to mid 90s, with the cooler temperatures on Thursday across the eastern half of the area, closer to the upper low and cloud cover.
512 PM EDT Wed Sep 2 2020 Warm and humid weather with periodic shower and thunderstorm chances are expected through Thursday with the approach and passage of a cold front.
A cold front will push through the area this afternoon, bringing with it gusty winds and an isolated shower along the Hi-Line.
Dangerous conditions due to heat exposure will be possible in the lower elevations. Unseasonably strong high pressure will move into much of the southwestern United States over the next several days, likely peaking over the weekend.
DGS Chattanooga Airport, TN 90 72 90 68 86 / 20 20 30 0 10 Knoxville McGhee Tyson Airport, TN 88 71 87 65 83 / 30 30 30 0 10 Oak Ridge, TN 88 71 86 64 83 / 30 30 30 0 10 Tri Cities Airport, TN 87 68 84 59 80 / 50 50 30 0 10.
A low pressure system tracking up the OH Valley will produce numerous showers and thunderstorms just north of our area through today, with the tail end of this activity expected to clip SW VA this afternoon. Farther south across the TN Valley, coverage will decrease to scattered and isolated, with some convective development expected along a pre-frontal trough/convergence zone and weak instability. The SW winds ahead of the trough will be gusty at times, up to 25 mph. Tonight, the forcing along the low level trough moves to our east, with little left to support overnight convection.
This northern wave will shear apart the southern upper low, pulling it across the Mid-South tonight and tomorrow. A cold front will move into the Mid-South late tomorrow night, continuing south toward the I-20 corridor on Friday. This front will bring cooler and drier air into the Mid-South with rain chances gone by sunset. The GFS/CMC drive a fairly substantial trough down the eastern flank of the west CONUS ridge, spelling cooler temperatures and a return to rain chances. On the other hand, the ECMWF pinches a strong closed low off of this trough and cuts it off over the Great Basin, maintaining a ridge over the Southeast.
1217 AM CDT Thu Sep 3 2020 Dry, subsident northeast flow aloft will dominate on the backside of the upper level low pressure system currently edging southeast through north Texas. Current analysis shows an upper-level trough over the area and an upper-level ridge over southwestern CONUS with an upper low centered over the NUNAVUT and the western Hudson Bay. The trough will begin to move out of the southern Plains by late Thursday. This will allow the ridge over the southwestern CONUS to build/expand to the east. As the ridge begins to build, it will bring northeasterly winds aloft to the area drying the mid-levels and limiting storm chances through the weekend. Late this weekend, the aforementioned upper low over northern Canada will begin to dive south, bringing a cold front with it.
Enough destabilization will allow for a few showers and storms over the Lower Trans-Pecos this afternoon and early evening before fading. Temps will be warmer today with mid to upper 90s for most of the forecast area. Friday and through the weekend will continue to see prevailing easterly winds near the surface, leading to cooler air being brought in from north TX and OK. Friday will see increasing PoPs for the southern and eastern Permian Basin down into the Lower Pecos River valley and adjacent high terrain.
352 AM EDT Thu Sep 3 2020 Mainly dry the next few days, but can't totally rule out a brief sprinkle as a cold front passes through.
Aloft we have a fairly amplified ridge over the western U. This will help in shifting a surface cold front into the area later today. A cold front will move into the area from the northwest during the afternoon (for most of the area it will be the late afternoon or early evening) and we may see some scattered showers develop with the front as it moves through. A slightly cooler and drier air mass is expected with highs from the low to mid 80s.
1112 PM CDT Wed Sep 2 2020 Weak ridging has brought a quiet day to the region early this afternoon, other than some occasional gusty winds. This system will track eastward along the Canadian border tonight, with an associated cold front extending southward and sliding through the forecast area sometime Thursday morning. closer to the low where stronger forcing will be present. However, model soundings suggest anything that does develop will have to overcome quite a bit of dry air in the low levels, so keeping the forecast dry in areas south of I-94 for now. The gradient should relax a bit by late afternoon, but the persistent northwesterly flow should still keep temperatures about 10 degrees cooler than today, with highs in the mid 60s to mid 70s.
At mid levels, the 500 mb ridge maintains its hold over the Southeast, while a positively tilted trough axis settles from the Ohio Valley to the Southern Plains. The cold front will slide underneath the mid and upper level ridge during the day on Friday, and will bring with it scattered convection, despite subsidence from the high aloft. A later frontal passage would mean warmer temperatures. High pressure filters in Friday night, sharply ending any showers or thunderstorms and ushering in a drier airmass. Look for lows Friday night to drop to the low to mid 60s with mostly clear skies.
Most of the model families slowly bring this frontal system into the region but tend to keep the POPs to a minimum despite the higher mid level moisture.
The cold front is still expected to bring some gusty winds and slightly cooler temperatures later tonight. Elongated ridge of high pressure extends across much of the western Great Basin and out across California under a light to moderate northwest flow aloft over Colorado. There is a weak disturbance over the northern plains states which will drop a cold front across northeast Colorado later tonight. For Thursday the airmass will be a little cooler behind the front, but only about 3-6 degrees cooler behind today's readings on the plains.
SHORT TERM (Now through Friday): Mid level trough of low pressure settles south through Texas toward the lower Texas coast between ridges of high pressure across the Desert SW and off the Southeastern US coast through Friday. With a slightly more dominant seabreeze expected today and Friday, high temperatures may reach a couple of degrees cooler today than yesterday, and combined with increased cloud cover and rain chances, potentially a degree or two cooler yet on Friday.
Big changes will arrive on Friday as our first pseudo-Fall cold front pushes through during the day. Much cooler and drier air will filter in behind the front just in time for the holiday weekend, with dewpoints dropping into the 50s for several days.
A cold front is expected to move northwest to southeast through the region, entering NW Missouri by mid morning and completely through the region by early to mid afternoon. This will create a decent gradient of temperatures for tomorrow, with highs across NW Missouri only expected to reach the low 80s by frontal passage and highs for areas along and south of the Interstate 70 corridor expected to warm up to the mid to even upper 80s tomorrow afternoon prior to frontal passage. The frontal passage will give us a shot of some cooler and drier air, with low temperatures on Friday morning in the low to mid 50s across the region before rebounding to the low 80s by Friday afternoon (although low dewpoints will remain, making it a pleasant and comfortable afternoon).
438 AM EDT Thu Sep 3 2020 Under partly cloudy skies and a steady east wind of 10 to 15 mph, temperatures are in the lower to mid 80s along the Florida Keys.
Highs will range from the lower to upper 80s across the state Thursday and Friday, with lows in the lower 70s through Friday morning.
For today and tonight, a dry and subsident airmass will dominate as the upper level low pressure system over north Texas edges slowly southward. Upper level high pressure over the western Great Basin will expand eastward in response with heights rebuilding across the Texas Panhandle and South Plains. Otherwise, the building upper heights will lead to warmer temperatures today several degrees above normal followed by another quiet and mild night tonight. Affects of an upper high building to our west. Anther direct result of the upper high building is a return to warmer temperatures starting Friday.
High pressure aloft will expand east across the Great Basin through the end of the week. This high pressure will maintain dry conditions and bring summer- like temperatures back to all of Utah for Friday through the upcoming weekend. Mean ridging is holding pat across the western Great Basin/central Pac coast, and isn't expected to vary much in position or strength through tomorrow.
Models prog that the upper trough axis will break off from the main flow and begin to move south today. Will show the highest PoPs in the Hill Country in the 18- 21z time frame then transition the higher PoPs to the south and southeast in the 21z-00z time frame and then a bit farther in the early portion of the tonight period.
355 AM EDT Thu Sep 3 2020 Warm and humid weather with periodic shower and thunderstorm chances are expected today with the approach and passage of a cold front.