Aikyam-Lab/Synoptic-Bench huggingface dataset:
556 PM MDT Sun Sep 19 2021 Fast southwesterly flow aloft is located over the forecast area this afternoon ahead of an upper trough approaching from the west. Low pressure exists at the surface, currently centered over western South Dakota with a cold front moving into the area from southeastern Montana. The cold front will sweep into northeastern Wyoming and far northwestern SD late this afternoon, then will quickly cross the rest of western SD this evening. There remains a good chance of showers and a few thunderstorms during the rest of the night and through the day on Monday due to cyclonic flow and cold advection aloft increasing the instability as the upper trough crosses the northern plains.
652 PM EDT Sun Sep 19 2021 High pressure at the surface and aloft over the Northeast U.
/issued 250 PM CDT Sun Sep 19 2021/ SHORT TERM (Tonight through Monday Night): Subsidence is expected through the short term due to a 500mb trough across eastern Texas into the Lower Mississippi Valley and northwesterly winds aloft.
Weak trough in the western Gulf of Mexico with weak 500 MB westerly flow aloft over area. Weak high pressure to build into coastal waters during the week with building in during the week with easterly winds prevailing.
A weak mid/upper-level trough will slowly be drawn northward across our region into increasing southwest flow aloft through Monday. However, forcing with the trough, along with increasing moisture through the column will lead to numerous showers streaming north or northeast over our region through the period. The greatest coverage will be over the Pennyrile and southwest Indiana, but the best chances of thunderstorms may be on the western periphery of that area where presumably temperatures will be a bit warmer. Monday night our attention turns back to the west as a much more substantial trough pushes through the Plains and Upper Midwest.
BT A trough will continue to transit the area tonight. Tomorrow will remain cooler with scattered showers as the area will remain the northwest flow aloft.
941 PM EDT Sun Sep 19 2021 Isolated showers dotted the coastal waters this evening, with the cloud line over the lower Keys having settled. A drifting outflow boundary from afternoon thunderstorms over the southwest portion of the Everglades was currently moving through the lower Keys. The low-to-mid level col will shift slightly northward, putting the Keys and especially the Straits into the lower, weakly-cyclonic easterly flow. Continuing from earlier synopsis, high pressure centered over the Northeast will slowly pivot eastward off the coast of the United States this week.
The convection allowing models have for the last 24 hours or more suggested thunderstorms developing in the higher terrain and advecting eastward with the westerly momentum this afternoon. 5-8 C/km are in place as far east as the highway 283 corridor. There may be a relative weakening of the surface winds briefly as a cold front approaches in the morning, however as winds turn north behind the cold front, windy conditions will continue for much of Monday.
Temperatures remain on track to reach the lower 70s area wide with light southerly winds (and low dew point depression values possible just before sunrise) boosting the chance for patchy fog, especially near Lufkin and in the Ouachita River Valley.
732 PM EDT Sun Sep 19 2021 High pressure at the surface and aloft over the Northeast U.
Also, with the wind gusts occurring out west with the passage of the cold front, will increase winds some through the night for the cwa. There have been some radar returns visible all day, but nothing is reaching the surface in the trough. The forcing in the upper trough coalesces a bit more after 0z so did leave pops in for that time period. The cold front will push east tonight with the trailing upper trough. Continuing showers will remain over the region on Monday under the trough. Temperatures will be considerably cooler with the clouds and rain behind the front.
Otherwise, a partly cloudy night is in store for the ArkLaMiss region, with overnight lows in the high 60s to low 70s. Persistent cyclonic flow over the Lower MS Valley region will continue to combine with very moist air to bring scattered diurnally driven showers and a few thunderstorms to much of the ArkLaMiss.
Dry on Monday with temperatures beginning to trend warmer, however lows Monday night will also be near or below freezing in many valley locations. Air quality has improved drastically following the passage of the cold front thus the Air Quality Alert is cancelled. Dry on Monday with temperatures beginning to trend warmer, however lows Monday night will also be near or below freezing in many valley locations.
An upper trough will move out of the Rockies and across the northern into the central Plains on Monday. Associated cold front will push south across the Texas Panhandle and northern Oklahoma in the afternoon. With ample sunshine and a pronounced 850mb thermal ridge (850mb temperatures 27-29 deg C across the northwest half of our area), afternoon temperatures will soar into the triple digits across a good portion of our area.
Another unseasonably hot day expected ahead of the much anticipated cold front which will move into northeast Oklahoma by late afternoon. As mentioned previously, areas with ongoing drought conditions/cured fine fuels will likely see the highest fire weather concerns. Still expect showers with embedded thunderstorms to increase in coverage behind the front as stronger forcing develops in association with upper trough axis. Finally a break in the heat with significantly cooler conditions expected behind the cold front with breezy north winds.
As much cooler air continues to filter in tonight and tomorrow, it will finally feel like fall.
Persistent U/L low over the Lower Mississippi Valley will be absorbed by a digging U/L trough through the Plains over the next couple of days.
216 AM CDT Mon Sep 20 2021 H5 trof and embedded energy will lift northeast across the area today, with scattered showers and a few thunderstorms anticipated, especially east of the MS River. The chance of showers and maybe a rumble of thunder will continue behind the surface front Tuesday night as the parent upper trof moves toward the area from the west.
The better chance for precipitation comes tonight as a cold front will help usher in a line of thunderstorms. High temperatures will be in the low to mid 80s today, dropping to the low to mid 70s for Tuesday. At the surface, high pressure exists over New England and low pressure over the central U. However, the better chance for showers and thunderstorms will come late tonight and early Tuesday morning as a cold front associated with the approaching upper wave pushes southeast across the region.
SHORT TERM (Now through Tuesday): A 500mb trough axis over the northwest Gulf of Mexico and northwest flow aloft will continue to provide subsidence across deep south Texas through much of the period. A strong 500mb trough will swing eastward over the High Plains tonight into Tuesday. The associated cold front will push into north Texas tonight and into central Texas on Tuesday.
Warmer temperatures return Tuesday and will likely continue into the weekend. Ridging builds back in for Tuesday and southerly flow returns with warmer temps expected. High temps will be 5-12+ degrees warmer than Monday, in the upper 60s to low 80s.
246 AM CDT Mon Sep 20 2021 A strong cold front has moved through most of the area overnight with much cooler air now in place. The mid level trough and upper level trough are a bit slow to move east of the area, so the chances for showers and isolated thunderstorms will linger into the early evening, although by late afternoon the activity should be more isolated to scattered. As for temperatures, much cooler than yesterday with highs in the 60s, maybe some lower 70s in northwest IA this morning before falling during the day.
229 AM MDT Mon Sep 20 2021 MORNING DISCUSSION: Synoptic Setup: As of early this morning, a large trough runs down the High Plains of Alberta, Montana, and Wyoming. To the west a large ridge is developing just off the coast of the Pacific Northwest and British Columbia. Behind this another trough/ridge couplet is developing over the Gulf of Alaska and farther toward the west in a very progressive fall pattern. Today into Tonight: Convection will develop on the backside of the trough across our southwestern zones NAM forecast soundings are showing CAPE around 300-600 with some of it rising above 20*C for possible light lightning.
At 2 AM CDT, a cold front (over the Prairie Coteau) continues to move east across the CWA. Behind it, temperatures have cooled into the low 50s, with dewpoints in the upper 40s to lower 50s.
1133 PM CDT Sun Sep 19 2021 No big changes have been made to the forecast with a cold frontal passage and a chance for showers/thunderstorms expected late Monday-Monday night.
A disturbance was slowing moving away from the region while a ridge of high pressure builds into the two state area tomorrow. Otherwise low temps are expected to fall into the 40s with 30s in the higher elevations and the present short term forecast appears on track.
100 AM EDT Mon Sep 20 2021 Dry and warm weather is expected today under a ridge of high pressure. Rain chances will increase through mid week with the approach of a cold front. A developing trough will deepen across the central Rockies today, causing a corresponding amplification of the eastern CONUS ridge. Increasingly warm, moist southerly flow aloft will develop over the region as we rest under the impressive ridge. High cirrus clouds will cross the region today as the ridge drifts eastward.
The highs will be mainly 100 to 104. A strong cold front will move south across the Big Country late tonight, with gusty north winds behind the front.
1124 PM EDT Sun Sep 19 2021 High pressure at the surface and aloft over the Northeast U. Clouds will increase on Tuesday, and by the middle of the upcoming week, a strong cold front and sharpening trough aloft will bring a widespread soaking rain to Pennsylvania. Following the frontal passage towards the end of the week, temperatures will be noticeably cooler for the first few days of fall. 5 of an inch will support efficient radiational cooling with lows ranging from the upper 40s in the cooler valleys of northern Pa to the mid 50s across the southern counties. By Tuesday, the trough will begin to deepen over the midwest which will be the primary weather producer for the middle and end of the week.
Aloft, phasing of the closed upper low with an approaching trough will commence today as the trough ejects into the Plains from the Rockies. At the surface, high pressure will remain to the E of the state resulting in S/SWrly winds this afternoon. On Tuesday, the aforementioned trough will approach the state from the N as a surface cold front sweeps across AR. Showers and thunderstorms are expected to develop invof of the cold front, with better coverage over the Nrn half of the state. Much drier and colder air will advect into the region Tuesday Night and as a result, lows should dip into the low 50s N to the near 60 over the S.
319 AM CDT Mon Sep 20 2021 A strong cold front continues to push southeast this morning at approximately 30-35 kts. Also of interest on the KLBF VAD this morning was a northerly 50kts 850mb wind speed just behind the cold front.
With the colder air, an inch or two of snowfall is likely in the highest elevations of the Park Range. As previously mentioned, cloud cover will likely keep the coldest ares from bottoming out below freezing tonight. Nearby valleys along the Yampa and upper Colorado Rivers could also see sub-freezing temperatures as low as the upper 20s. After a cold morning on Tuesday, temperatures will remain unseasonably cool on Tuesday under a dry northwesterly flow as the ridge of high pressure builds over the western states.
With the dominant upper trough axis continuing to shift further northeast, precipitation coverage will continue its decreasing trend. 500mb trof axis should be situated further east tomorrow.
An opening upper level low over the eastern Plains continues to open and stretch northeast on the west side of an upper ridge stretching north over the East Coast. With the richest airmass shifting east, the higher chance of water issues shifts east, but only a bit. By Tuesday evening, a cold front begins to move across the Mississippi Delta region. Tonight and Monday night, low temperatures the low to mid 70s well inland, upper 70s along the coast are expected.
333 AM CDT Mon Sep 20 2021 A strong cold front remains on track to move across the CWA this afternoon, bringing a chance of storms to far eastern KS with much drier and cooler air behind it for the rest of this week. Closer to home, a subtle mid-level perturbation within the upper trough along with isentropic lift on the warm side of the boundary has generated scattered elevated storms through central KS/NE. The cold front should move through north central KS late this morning and be through the CWA by 00Z, which has been consistent in the model guidance for the past few days. By tonight, CAA will bring in much cooler temperatures and drier dew points behind the front, leaving more fall-like conditions in its wake.
842 PM PDT Sun Sep 19 2021 After a cool, wet, and breezy weekend, the Inland Northwest will become warmer and drier. Monday will be cooler than average with high temperatures mainly in the 60s. KSFF/KGEG will have some potential as well but for now kept conditions VFR with BL moisture progs showing these areas on the edge of the highest BL moisture content.
1134 PM EDT Sun Sep 19 2021 High pressure at the surface and aloft over the Northeast U. Clouds will increase on Tuesday, and by the middle of the upcoming week, a strong cold front and sharpening trough aloft will bring a widespread soaking rain to Pennsylvania. Following the frontal passage towards the end of the week, temperatures will be noticeably cooler for the first few days of fall. 5 of an inch will support efficient radiational cooling with lows ranging from the upper 40s in the cooler valleys of northern Pa to the mid 50s across the southern counties. By Tuesday, the trough will begin to deepen over the midwest which will be the primary weather producer for the middle and end of the week.
Drier and warmer conditions expected on through Tuesday before another system brings showers and cooler temperatures to the region midweek.
To the west of the low getting a period of gusty NW winds in the 25-40 kt range in SE ND into parts of WC MN. This low will track ENE toward Grand Rapids MN by 18z. Rain showers with the upper trough moving from south central into northeastern ND currently leaving 0. The rain in NE ND will exit this early morning, while another wave coming out of the eastward moving 500 mb trough will spread showers from South Dakota into SE ND and MN today, moving out this afternoon except the far east/southeast which will keep showers around til early evening. Cooler and breezy day all areas with temps in the low 60s.
953 PM PDT Sun Sep 19 2021 After a cool, wet, and breezy weekend, the Inland Northwest will become warmer and drier. Monday will be cooler than average with high temperatures mainly in the 60s. KGEG will have some potential as well but for now kept conditions VFR with BL moisture progs showing this area on the edge of the highest BL moisture content.
353 AM CDT Mon Sep 20 2021 A weakening trough axis remains across Arkansas and Louisiana this morning. A deepening upper trough extended from the Canadian Prairie Provinces southward to the Four Corners area. At the surface, low pressure and an associated cold front extended from western Ontario Canada southwestward to Colorado. Temperatures and dew points were in the low and mid 70s.
Short range models indicate an amplified upper level trough shifting east across the Dakotas today, ushering a relatively strong attendant cold front through western Kansas by early afternoon. Precip chances will be limited through much of the day as drier air begins to overspread much of the high plains. With cooler air beginning to filter into extreme western Kansas by late morning, look for highs only up into the 70s(F) in west central Kansas with temperatures still expected to reach the 80s(F) in south central Kansas. Much cooler temperatures are likely tonight with lows dropping down into the 50s(F). A relatively tranquil pattern is forecast through the end of the week as a much drier air mass overspreads the Western High Plains in conjunction with ridging aloft building in across the Central and Southern Rockies.
242 AM MDT Mon Sep 20 2021 Broad trough was over the area this morning, with chilly air aloft and even down to the surface with temperatures early this morning in the 40s despite cloud cover. Snow level has fallen to around 6500 feet with periods of snow showers over the higher terrain putting a dusting, or light accumulation, down. The trough will swing east today, but the cold air aloft will linger and thus the atmosphere will be unstable for showers to develop. Heights rise tonight and Tuesday for drier and warmer weather ahead. Highs on Tuesday will rebound into the lower to mid 70s with much more sunshine. TWH Upper ridging will dominate our weather during the middle and latter part of the week with dry and near to above normal temperatures.
400 AM EDT Mon Sep 20 2021 Dry and warm weather is expected today under a ridge of high pressure. Rain chances will increase through mid week with the approach of a cold front. A developing trough will deepen across the central Rockies today, causing a corresponding amplification of the eastern CONUS ridge. Increasingly warm, moist southerly flow aloft will develop over the region as we rest under the impressive ridge. High cirrus clouds will cross the region today as the ridge drifts eastward.
229 AM MDT Mon Sep 20 2021 Water vapor shows deep upper trof over the Northern Rockies/Northern Plains. At the surface, cold front is well east of our zones, with some gusty winds across south central SD early this morning. The rest of the week and weekend will be dry and warmer with generally west/northwest flow aloft.
The 19Z MSAS surface analysis showed high pressure over the eastern Great Lakes, an area of low pressure just north of Lake Winnipeg and another low pressure over the northern Plains. A cold front connected the lows from southern Manitoba southwest through the northern Plains into the central High Plains. The second precipitation event would approach central WI late in the afternoon as a cold front moves into western WI. Most of the models show showers/thunderstorms to be along the cold front, however cannot rule out some precipitation developing ahead of the boundary.
DGS Chattanooga Airport, TN 76 69 81 65 74 / 90 50 60 70 70 Knoxville McGhee Tyson Airport, TN 78 67 81 66 76 / 60 60 60 70 70 Oak Ridge, TN 77 67 81 65 74 / 60 50 70 70 70 Tri Cities Airport, TN 84 65 77 64 78 / 40 60 60 70 80 TN.
As an upper ridge builds in from the west, a thermal trough deepens along the coast, with east winds spreading to cover the entire forecast area by late morning. The thermal trough deepens up to the northern coast of Oregon by Tuesday morning, and with the continued offshore flow temperatures will be 5 to 10 degrees above normal as the thermal trough moves inland Tuesday afternoon.
A strong cold front continues to push southeast this morning at approximately 30-35 kts. Also of interest on the KLBF VAD this morning was a northerly 50kts 850mb wind speed just behind the cold front.
725 AM EDT Mon Sep 20 2021 Dry and warm weather is expected today under a ridge of high pressure. Rain chances will increase through mid week with the approach of a cold front. A developing trough will deepen across the central Rockies today, causing a corresponding amplification of the eastern CONUS ridge. Increasingly warm, moist southerly flow aloft will develop over the region as we rest under the impressive ridge. High cirrus clouds will cross the region today as the ridge drifts eastward.
434 AM MDT Mon Sep 20 2021 A band of showers along w/ a few embedded thunderstorms associated with the 700 hpa cold front is expected to continue progressing to the east across the western Neb Panhandle over the next few hours, likely exiting the CWA around 12z. Freezing temperatures will be most likely in our zones along/west of the Laramie Range, but we have trended up-ward slightly with overnight lows given greater boundary layer moisture in place.
A strong cold front remains on track to move across the CWA this afternoon, bringing a chance of storms to far eastern KS with much drier and cooler air behind it for the rest of this week. Closer to home, a subtle mid-level perturbation within the upper trough along with isentropic lift on the warm side of the boundary has generated scattered elevated storms through central KS/NE. The cold front should move through north central KS late this morning and be through the CWA by 00Z, which has been consistent in the model guidance for the past few days. By tonight, CAA will bring in much cooler temperatures and drier dew points behind the front, leaving more fall-like conditions in its wake.
Today through Tuesday The trough axis associated with the storm continues to exit eastward and is expected be out of the state by daybreak this morning. Lows will be near the freezing mark in the Wind River Basin. Tuesday will be dry and warmer, under mostly clear skies and light winds.
305 AM PDT Mon Sep 20 2021 After a chilly start today along with below average highs this afternoon, high pressure will bring warming temperatures with dry conditions this week.
436 AM PDT Mon Sep 20 2021 After a cool, wet, and breezy weekend, the Inland Northwest will become warmer and drier. Monday will be cooler than average with high temperatures mainly in the 60s. High pressure will build back into the region through Tuesday, and daytime temps will be about 6-11 degrees warmer than today.
510 AM EDT Mon Sep 20 2021 High pressure at the surface and aloft will result in low humidity and dry weather today. By the middle of the upcoming week, a strong cold front and sharpening trough aloft will bring a widespread soaking rain to Pennsylvania. Following the frontal passage towards the end of the week, temperatures will be noticeably cooler for the first few days of fall. The clouds will be thickest over the Ridge-and-Valley region/central mtns. There will probably be patchy drizzle where the orographic lift is best (windward slopes/ridges), but enough mixing should occur Tues to poke some holes. The trough will deepen over the midwest which will be the primary weather producer for the middle and end of the week.
605 AM CDT Mon Sep 20 2021 A strong cold front has moved through most of the area overnight with much cooler air now in place. The mid level trough and upper level trough are a bit slow to move east of the area, so the chances for showers and isolated thunderstorms will linger into the early evening, although by late afternoon the activity should be more isolated to scattered. As for temperatures, much cooler than yesterday with highs in the 60s, maybe some lower 70s in northwest IA this morning before falling during the day.
647 AM EDT Mon Sep 20 2021 High pressure at the surface and aloft will result in low humidity and dry weather today. By the middle of the upcoming week, a strong cold front and sharpening trough aloft will bring a widespread soaking rain to Pennsylvania. Following the frontal passage towards the end of the week, temperatures will be noticeably cooler for the first few days of fall. The clouds will be thickest over the Ridge-and-Valley region/central mtns. There will probably be patchy drizzle where the orographic lift is best (windward slopes/ridges), but enough mixing should occur Tues to poke some holes. The trough will deepen over the midwest which will be the primary weather producer for the middle and end of the week.