Aikyam-Lab/Synoptic-Bench huggingface dataset:
It will be a relatively cool day across the forecast area with highs mostly in the low 60's for the plains, and 40's in the high country. Weak ridging will build in from the east, pushing against the closed low that remains due west.
At 4AM, two primary areas of precip are appearing on KOAX with a line of heavy showers along a cold front slipping southeast across south-central Nebraska and some showers that have developed in the warm sector with the aid of the LLJ. Expect the front's line of storms to mostly miss this CWA to the south as it fizzles as it approaches the amplified ridge east of here.
High pressure building into the region, will bring dry and warming conditions through the weekend.
526 AM MDT Thu Sep 30 2021 Water vapor imagery early this morning shows a compact upper low over extreme southwest Wyoming, and adjacent northeast Utah. This low is expected to slowly shift/reform over N.
/issued 358 AM EDT Thu Sep 30 2021/ Upper-level ridging is building in from the west as a deep, negatively-tilted trough axis propagates off to the NE.
520 AM MDT Thu Sep 30 2021 Updated Aviation Discussion High pressure will maintain mainly clear and dry conditions with seasonably mild temperatures this afternoon. Upper level ridge axis extends from off the CA coast NE into the Northern Rockies today for mainly clear and dry conditions with afternoon temperatures warming to near and slightly above seasonal averages in the upper 60s to low 70s. The upper level trough weakens considerably as it progresses east across the Northern Rockies and MT but will bring a period of cloudiness to most of the forecast area with at least a few widely scattered showers moving east across north-central MT Friday afternoon and evening as a weak disturbance embedded within the trough moves across the area.
609 AM CDT Thu Sep 30 2021 (Today and tonight) A cold front continues to move southward across Kansas and the Oklahoma/Texas panhandles this morning. As the cold front continues to move southward (likely being reinforced by the convection), convection will spread south and east this morning. Cooler temperatures are expected in the front's wake. Initially, it appears the highest probabilities for convection will be across northern Oklahoma with gradual propagation to the southeast.
Brownsville radar currently indicates some showers and thunderstorms along the lower Texas coast. Brownsville radar currently indicate isolated to scattered activity across the lower Texas coastal waters.
630 AM EDT Thu Sep 30 2021 High pressure will provide for dry and pleasant conditions today and Friday.
404 AM CDT Thu Sep 30 2021 (Issued 310 AM CDT Thu Sep 30 2021) Today through Friday Night: Fog continues this morning given calm winds and strong high pressure overhead making for good enough conditions for fog despite upper level clouds. The rest of the day looks to remain fairly quiet with the strong surface and upper level ridge dominating the region and keeping the CWA dry.
At 4 AM, two primary areas of precip are appearing on KOAX radar with a line of heavy showers along a cold front slipping southeast across south-central Nebraska and some showers that have developed in the warm sector with the aid of the LLJ. Expect the front's line of storms to mostly miss this CWA to the south as it fizzles as it approaches the amplified ridge east of here.
At 08Z (3 AM), overnight convection is ongoing in central and north- central Kansas along a cold front that runs north to south through the central part of the state.
Deep layer ridge remains in place across the area today, which will keep the weather quiet for the most part. However, an upper trough just to the west is associated with an area of deep moisture and lift.
From synopsis, high pressure anchored over the southeastern United States will maintain northeast to east breezes across the coastal waters of the Florida Keys.
941 AM CDT Thu Sep 30 2021 Updated the forecast to reduce chances of rain and take out thunder for most of the CWA for today and tonight, with the exception of the far eastern CWA along the Highway 81 corridor for today and this evening as it appears just enough instability hangs around there, according to HREF ensembles, to warrant the inclusion of this area. A cold front is moving through the forecast area in the vicinity of the line of thunderstorms. The main upper low/wave continues to move through the area during the day. Temperatures will be a bit warmer on Friday, especially in the west, with highs around 70 degrees.
622 AM EDT Thu Sep 30 2021 Increased ridging across the East Coast with high pressure centered just to our north. The ridge axis will move offshore towards the end of the weekend and moisture will begin to increase from the west.
2) Temperatures will be several degrees cooler today, but still above average for late September. Mid/high-level clouds continue to stream north amidst deep southerly flow in the center of a highly-amplified mid- level ridge. Today will likely be several degrees cooler across most of the CWA thanks to increased cloud cover and a more southeasterly wind direction. Despite more moisture available in the lower half of the atmosphere, the limited forcing will keep precipitation coverage scattered at most. Temperatures will continue their slow march to cooler values, but stay above normal. Guidance continues to show considerable agreement that a change in the upper-level regime is in store this weekend, triggered by the amplified ridge across the central CONUS eroding.
Morning analysis indicated upper level ridge axis stretched south to north from the Gulf coast through the Great Lakes, across central IL. At the surface a low pressure trof extended north to south over the eastern Plains. Southeast winds at 5-10 mph and dewpoints mixing down into the lower 60s will make for nice "July-August" weather. A thick blanket of high clouds will stream across the area today, keeping temperatures a degree or two cooler than they were yesterday in the middle to upper 80s. Dry and mild weather will prevail tonight as lows drop into the lower to middle 60s. Despite the change, the GFS continues to be too bullish driving showers eastward into the prevailing upper ridge axis. Given increased cloud cover, temps will be another degree or two cooler.
1048 AM EDT Thu Sep 30 2021 High pressure will provide for dry and pleasant conditions today and Friday.
High pressure should limit shower development, with the exception being over the western portion of the CWA. Another quiet day is forecast, as high pressure remains the dominant feature. Just to our west, a trough holds, which could push some showers into our western portion of the CWA today. The ridge should keep the area free from precipitation, but a few isolated showers can't be ruled out.
520 AM CDT Thu Sep 30 2021 Hefty upper ridge remains anchored over central North America early this morning, with its axis now sitting just east of the forecast area. This ridge will begin to break down today as an upstream longwave trough transitions to a closed upper low over the Four Corners region. Dewpoints will again climb into the low 60s. Upper flow transitions into a split flow pattern by Friday with the closed low meandering through the Southwest region and a northern stream trough making landfall in the Northwest.
725 AM CDT Thu Sep 30 2021 (Today and tonight) A cold front continues to move southward across Kansas and the Oklahoma/Texas panhandles this morning. As the cold front continues to move southward (likely being reinforced by the convection), convection will spread south and east this morning. Cooler temperatures are expected in the front's wake. Initially, it appears the highest probabilities for convection will be across northern Oklahoma with gradual propagation to the southeast.
1008 AM EDT Thu Sep 30 2021 High pressure brings dry, pleasant Fall weather through the end of the week. Increasing chance for showers and afternoon storms returns by the end of the weekend ahead of a cold front. High pressure continues building slowly southward toward the area through tonight, beneath upper level north to northwest flow. Ridging aloft begins to flatten this weekend as a trough slides eastward.
Brownsville radar currently indicate isolated to scattered activity across the lower Texas coastal waters.
949 AM EDT Thu Sep 30 2021 No changes foreseen to the inherited forecast with lots of sunshine across northern lower Michigan and above normal afternoon temperatures this afternoon as high pressure continues to encompass the region. High pressure extends southward from Hudson Bay toward Lake Huron. The southern part of this ridge breaks off, with a high centered over the eastern lakes by Friday morning. Low pressure will gradually advance into nw Ontario, as the 500mb ridge upstream gets deamplified by energy transiting southern Canada. Highs mainly within near 70f to the lower 70s, a bit cooler near Lk Huron.
332 AM MDT Thu Sep 30 2021 High pressure will maintain mainly clear and dry conditions with seasonably mild temperatures this afternoon. Upper level ridge axis extends from off the CA coast NE into the Northern Rockies today for mainly clear and dry conditions with afternoon temperatures warming to near and slightly above seasonal averages in the upper 60s to low 70s. The upper level trough weakens considerably as it progresses east across the Northern Rockies and MT but will bring a period of cloudiness to most of the forecast area with at least a few widely scattered showers moving east across north-central MT Friday afternoon and evening as a weak disturbance embedded within the trough moves across the area.
401 AM CDT Thu Sep 30 2021 At 08Z (3 AM), overnight convection is ongoing in central and north- central Kansas along a cold front that runs north to south through the central part of the state.
High pressure will bring light winds, dry conditions and warming temperatures to Nevada through the weekend.
This will create hazardous conditions for mariners near the inlets and the high risk of rip currents at the beaches.
Afternoon temperatures will remain cooler than average during much of the forecast.
Weak high pressure will build in Friday through the weekend.
High pressure/upper level ridging will remain in control for the duration of the short-term forecast period.
Today through Friday night Closed upper low over Utah and the Four Corners region will dig south into the southwestern states this afternoon and will then move slowly track east across the southern Rockies Friday. The closed upper low is forecast to lift east and north across southeastern Colorado Friday night. Biggest threat as the column moistens up in the lower and middle levels by 06Z to 09Z Friday and also in the upper levels will be localized very heavy rainfall. Cold front moving rapidly east and south across the Panhandles at this time and should be exiting the forecast area by 12Z today.
Will maintain the low chances for showers through the day, but again it will not be a washout by any means.
With the passage of the associated cold front, the Desert Southwest is left with breezy and (unseasonably) chilly conditions. Today will be the coolest day of the week, with morning lows in the 60s and afternoon highs in the 80s for the lower valleys. For the higher elevations, morning lows will range from the 30s to 50s, so if you're expecting to hike in the mountains this morning, be sure to check the forecast and plan accordingly. The higher elevations including Dyer and locations along the US Route 6 corridor east of Tonopah will experience freezing temperatures this morning, which are likely to kill crops, sensitive vegetation, and potentially damage unprotected outdoor plumbing.
1237 PM CDT Thu Sep 30 2021 Updated the forecast to reduce chances of rain and take out thunder for most of the CWA for today and tonight, with the exception of the far eastern CWA along the Highway 81 corridor for today and this evening as it appears just enough instability hangs around there, according to HREF ensembles, to warrant the inclusion of this area. A cold front is moving through the forecast area in the vicinity of the line of thunderstorms. The main upper low/wave continues to move through the area during the day. Temperatures will be a bit warmer on Friday, especially in the west, with highs around 70 degrees.
(This evening through Friday) A cold front + storm outflow has passed through all but the southeast quarter or so of our forecast area.
338 PM CDT Thu Sep 30 2021 (Issued 302 PM CDT Thu Sep 30 2021) Tonight through Friday night: The influence of broad high pressure centered over the Lower Great Lakes region will linger through tonight and into the day on Friday as it slowly slides east. Tomorrow will be unseasonably warm as a sharp ridge remains aloft, high pressure hangs on, and the sky remains mostly sunny for the first half of the day, with increasing clouds in the afternoon. Highs will be in the low to mid 80s over southern Wisconsin. Winds will become more southerly to SSW- erly and it'll feel more humid during the day as weak winds advect dewpoints in the low 60s into the area.
A subtle H5 ridge resides over much of the Florida peninsula today. On Friday, the signal gradually begins to increase a bit more with the upper high breaking down a bit. Models continue on keeping broad high pressure in control of the SE CONUS during the weekend while a backdoor cold front slowly sagging southward across the western Atlantic waters knocks on South FL's door. Simultaneously, an amplifying mid-upper level trough across the Midwest will become cutoff as an upper-level high builds across the central CONUS. PoPs subtly increase mid-week as a secondary cold front pushes towards South FL.
242 PM CDT Thu Sep 30 2021 Our region is divided between a warm/sunny day underneath upper ridging across the east and a rainy/cloudy day across southeast Missouri associated with an upper disturbance. As the upper low over the southwest U.
/Issued 730 AM EDT Thu Sep 30 2021/ Dry high pressure will persist through the short term. The high amplitude upper ridge will weaken through Friday.
A weak north- south stationary boundary remains draped just west of the I-29 corridor this afternoon, subtly warmer to the east across IA/MN where light south or east winds and warm air advection reside.
This will lead to dry and warm conditions with highs 3 to 5 degrees above normal in the low/mid 80's. Otherwise, VFR will prevail as high pressure remains in control. Garuckas Chattanooga Airport, TN 64 85 65 84 66 / 0 10 10 40 20 Knoxville McGhee Tyson Airport, TN 60 83 62 83 64 / 0 10 0 40 10 Oak Ridge, TN 59 83 62 82 64 / 0 10 0 40 20 Tri Cities Airport, TN 49 81 56 82 60 / 0 0 0 30 10.
1212 PM CDT Thu Sep 30 2021 Have trended the forecast for the next 24-30 hours on the warmer, drier, and clearer side given recent observational trends. Hefty upper ridge remains anchored over central North America early this morning, with its axis now sitting just east of the forecast area. This ridge will begin to break down today as an upstream longwave trough transitions to a closed upper low over the Four Corners region. Dewpoints will again climb into the low 60s. Upper flow transitions into a split flow pattern by Friday with the closed low meandering through the Southwest region and a northern stream trough making landfall in the Northwest.
Narrow high magnitude ridge axis anchored just upstream will ease eastward into the area while dampening with time to finish the week. Pleasant conditions with highs in the low to mid 70s.
Portions of the Laramie Valley could reach the freezing mark once again tonight, but already received their first freeze a few nights last week. Temperatures will be around 10F degrees warmer Friday afternoon as the upper low begins to propagate into the central Plains resulting in gradual height rises headed into the weekend.
Dewpoints were slowly creeping upwards, now in the lower to mid 60s on the low level southeasterly flow. Aloft, the flow was highly amplified with a sharp ridge over the Ohio River Valley and western Great lakes and a deep upper low just west of the Central Rockies. Much cooler air was flanked to the west, where widespread 60s were observed across the plains, while 70s and 80s were common to the east and southeast. Tonight into Friday, the upper level ridge gradually breaks down and shifts eastward. Otherwise, tonight will be another warm night with lows in the lower to mid 60s. While cloud cover will be more extensive than today, temperatures should easily surge back into the lower to mid 80s.
235 PM MDT Thu Sep 30 2021 Water vapor satellite imagery showing a moist southerly flow aloft ahead of a closed low over Utah. Weak ridging in the southerly flow aloft is bringing some drying to the region. Precipitation is expected to be brief and light, so no snow accumulation is expected over the higher peaks. The low clouds along the Front Range will continue to slowly erode from the east. A new upper level low replaces the current one near the Four Corners tonight. This low tracks east-northeast across northern New Mexico Friday. Lift ahead of the low is expected to bring rain to southern Colorado. The cooler temperatures will be found south of I-70 where afternoon cloud cover should slow heating. Models have an upper closed low over southeast Colorado and southwest Kansas Friday night.
* None Upper-level troughing across the Four Corners region will close off this morning while an upper-level closed low system continues to slowly push south around New England. This omega blocking pattern will maintain an amplified ridge across the Midwest and Great Lakes through the day and will result in another day of dry weather. Thinly veiled cirrus and cirro-stratus that is currently parked across the Midwest will filter in through the afternoon as upper- level steering flow back more westerly, but otherwise, mostly sunny skies are expected with temperatures again pushing into the lower 70s -- cooler across the Thumb. Blocking pattern to again hold through Friday as the four corners closed low gradually progresses eastward near the Texas Panhandle, reinforcing seasonally higher heights over Southeast Michigan.
Longwave ridging slowly develops, which will continue to result in mainly clear skies and dry weather across the region. Overall, Friday brings very similar conditions, with highs about 5 to 7 degrees warmer than today.
Cliff PREVIOUS DISCUSSION: Look for warmer temperatures and dry weather conditions across NE Montana over the next couple of days. Upper ridging is expected to strengthen across the wester U. Longer term ensembles eventually show the ridge breaking down or shifting east sometime near the end of the first week in October as a deep Pacific trough sets up. As this results, look for markedly cooler and more fall-like temperatures.
Ridging aloft will keep mostly sunny skies and dry conditions over the area. Temperatures will stay a bit above seasonal levels in the lower to middle 70s.
Issued by National Weather Service Billings MT 1140 AM MDT Thu Sep 30 2021 Water vapor imagery early this morning shows a compact upper low over extreme southwest Wyoming, and adjacent northeast Utah. This low is expected to slowly shift/reform over N.
High pressure will maintain mainly clear and dry conditions with seasonably mild temperatures this afternoon. Upper level ridge axis extends from off the CA coast NE into the Northern Rockies today for mainly clear and dry conditions with afternoon temperatures warming to near and slightly above seasonal averages in the upper 60s to low 70s. The upper level trough weakens considerably as it progresses east across the Northern Rockies and MT but will bring a period of cloudiness to most of the forecast area with at least a few widely scattered showers moving east across north-central MT Friday afternoon and evening as a weak disturbance embedded within the trough moves across the area.
328 PM CDT Thu Sep 30 2021 Scattered showers and thunderstorms have been moving east throughout the day ahead of a slow-moving cold front.
315 PM CDT Thu Sep 30 2021 A cold front is steadily approaching the area bringing with it cloudy skies and increased chances for precipitation. The front attempts to push eastward, but a large high pressure over the SE CONUS stifles its movement.
Rain showers associated with the main low over Nebraska have been tracking northward into portions of central South Dakota most of the day, but have had trouble making it much further north than Highway 12 due to encountering dry air associated with high pressure to the northwest. As the high pushes into the area Friday night, will see the precipitation come to an end over the majority of the region, but may see a few light showers linger over the far eastern CWA.
134 PM EDT Thu Sep 30 2021 High pressure will provide for dry and pleasant conditions today and Friday.
Afternoon temperatures will remain cooler than average during much of the forecast. Latest WV imagery shows the upper low near the UT/AZ border with the longwave trough axis extending southward across the rest of Arizona. These showers continue to move towards the east associated with the synoptic scale lift out ahead of the trough. Given the cold temperatures aloft with the trough and perhaps a weak disturbance or two aloft helping out, we do expect to see some scattered instability showers with perhaps a few embedded thunderstorms mainly from Central Pima County eastward later this morning and especially through the afternoon hours. This showers will diminish this evening with the loss of daytime heating in combination with the low starting to push off to the east.
This squeeze will begin to usher additional moisture across the region Friday, increasing cloud coverage ahead of the next Low pressure system arrival for the weekend. As the High dominates, and holds dry weather in place across the eastern CONUS, precipitation chances should remain west of the Mississippi River Valley through much of Friday night. Overnight temperatures will cool back into the 50s and low 60s across the land CWA, with near 60 lows along the Lake as easterly winds carry the warmer water temps to land. With warm, moist airflow Friday expecting temperatures to climb back into the 80s, while cooler in the 70s over Lake Michigan. 304 PM CDT Heading into the weekend, Low pressure is forecast to overspread the region, bringing widespread rainfall to the Midwest and Great Lakes regions.
Cold front that moved through is well south of the area with showers and storms occurring along the main frontal boundary between San Angelo and Midland.
Precip/clouds will keep readings on the cooler side today, generally speaking.
LV Energy from trof to our south is focused over the central and southern Rockies, leaving us in a dry air mass underneath flat ridging and weak flow aloft.
Thermal instability has proven to be limited north of the surface cold front that tracked south across our CWA during the morning hours. The open wave associated with the upper level low, currently over the Four Corners region, will support weak-elevated convection to pass northeast from the South Plains into western Oklahoma after sunset. Low clouds and light rain will linger through the early morning hours tomorrow, when the primary trough axis associated with the upper level low exiting to the northeast begins its pass across our CWA. We'll cool down nicely in the post frontal environment and thick cloud cover tomorrow, with highs mostly in the low 70s on the Caprock and mid 70s to the east over the Rolling Plains.
Upper level ridging extends from the western Great Lakes into the SE US.