Aikyam-Lab/Synoptic-Bench huggingface dataset:
438 PM MDT Fri Sep 11 2020 The last vintages of the rainfall from the wrap around moisture of the exiting low pressure center (which is now centered over the western South Dakota/Nebraska border) continues to stream south across Johnson and Natrona counties this afternoon. A chilly night tonight is expected with temperatures freezing or below in the west tonight, and 30s and 40s expected east. The warming trend will continue Saturday with highs mainly 75 to 80 as the flat ridge builds in from the west.
532 PM MDT Fri Sep 11 2020 Lingering low and mid-level cloud cover continues to steadily clear out this afternoon in the wake of our departing low pressure system. Warm-air advection aloft and sunny skies will result in a much warmer day. with afternoon highs 8-10 degrees warmer on Saturday than on Friday.
937 PM EDT Fri Sep 11 2020 High pressure will bring dry weather to NY and PA through Saturday.
1000 PM EDT Fri Sep 11 2020 High pressure over the Great Lakes will slide eastward tonight and off of the New England coast on Saturday.
654 PM CDT Fri Sep 11 2020 Upper low centered across far southwest SD and the northern NE Panhandle early this afternoon. The low is slowly drifting to the east. The center of the upper low will drift east along the NE/SD border overnight and be centered near Yankton in southeast SD by sunrise Saturday morning. The lift and moisture will be located east of the area by then with Saturday expected to be a dry and warmer day. Winds will increase some from the northwest, with a warmer Pacific airmass and downslope wind component bringing highs back into the 70s. Upper level ridging builds east and northeast across the central and southern plains for the first half of the coming week.
/Issued 1201 AM CDT Sat Sep 12 2020/ /Overnight through Sunday/ A period of tranquil weather will continue through the weekend as we will remain on the eastern periphery of stronger mid level ridging through Sunday. The subtropical jet will continue to feed into deeper troughing over the Midwest and Great Lakes resulting in intermittent high clouds through the weekend, but otherwise it should be fairly quiet with temperatures continuing to recover to near seasonal norms.
326 AM CDT Sat Sep 12 2020 (Today through Sunday) Clearing skies and light winds along with plenty of ground moisture and warm moist winds in the low levels should result in patchy areas of fog this morning across the area. Upper level winds were from the west as the upper low tracks across the Northern Plains today.
High pressure aloft along the west coast will move east into the Great Basin this weekend.
Meanwhile, an upper low ovr wl cont to track acrs the Nrn MS River Valley later today, and eventually thru the Great Lakes region tngt into Sun.
335 AM EDT Sat Sep 12 2020 High pressure east of the area will bring dry weather to NY and PA today. Showers are expected late tonight and Sunday as a cold front approaches from the west.
Going forward, as the H500 low continues to lift north across the Great Lakes region a cold front will approach and move across the state from the northwest into Sunday morning.
1042 PM MDT Fri Sep 11 2020 The last vintages of the rainfall from the wrap around moisture of the exiting low pressure center (which is now centered over the western South Dakota/Nebraska border) continues to stream south across Johnson and Natrona counties this afternoon. A chilly night tonight is expected with temperatures freezing or below in the west tonight, and 30s and 40s expected east. The warming trend will continue Saturday with highs mainly 75 to 80 as the flat ridge builds in from the west. The models are consistent with an upper level ridge axis and a mid to upper level northwest flow moving across the area through Sunday. A slow increase in high temperatures are expected, as temps may climb into the low-mid 80s across much the area and in the mid-upper 70s in northwest sections and higher elevations.
1108 PM MDT Fri Sep 11 2020 An upper level low will continue moving away from the area tonight and Sat, while an upper ridge moves into the Great Basin. This will lead to dry weather over the area, and even warmer temps on Sat. Tonight's low temps are expected to mostly be in the 40s across the southeast plains, with upper 20s and lower 30s in the high valleys, with is below average. On Saturday, highs should be in the upper 70s to lower 80s along the I-25 corridor, in the lower to mid 80s over the far southeast plains and mostly in the 60s in the high valleys. These highs are around average for the plains, and slightly below average for the high valleys.
232 AM EDT Sat Sep 12 2020 The dry period will end with the arrival of a cold front bringing some soaking rain tonight and through Sunday.
1204 AM CDT Sat Sep 12 2020 Upper low centered across far southwest SD and the northern NE Panhandle early this afternoon. The low is slowly drifting to the east. The center of the upper low will drift east along the NE/SD border overnight and be centered near Yankton in southeast SD by sunrise Saturday morning. The lift and moisture will be located east of the area by then with Saturday expected to be a dry and warmer day. Winds will increase some from the northwest, with a warmer Pacific airmass and downslope wind component bringing highs back into the 70s. Upper level ridging builds east and northeast across the central and southern plains for the first half of the coming week.
The persistent upper level low over the Southern Dakotas early this morning will finally become absorbed in the prevailing westerlies later today and exit the Great Plains. For today, an increase in lower tropospheric downslope momentum, along with a clear sky all day (after local fog burns off in the southeast), will allow temperatures to shoot up into the lower 80s for afternoon highs. Wind speeds behind the trough axis will most likely remain at or below 15 MPH later on in the afternoon. A weak leeside trough will attempt to become established to our northwest later in the week, but the pressure gradient will not be all that strong. Daily temperatures will be quite steady much of the week, with highs in the lower to mid 80s for the most part.
414 AM EDT Sat Sep 12 2020 Satellite imagery early this morning shows an upper level low centered over South Dakota slowly moving northeast towards the region. The upper level low will open up as it heads into the northern Great Lakes by tonight and merge with a trough moving through central Canada. Tonight models show a strengthening upper level jet as the system merges with the Canadian trough. This combined with an advancing cold front will be sufficient to set off another round of showers overnight, especially for western and northern portions of the U. With the southerly moisture transport and upslope flow expect fog to develop over the highlands and southern counties. Fog will overspread much of the area this evening but will diminish from west to east as the cold front sweeps through.
That area of rain showers should wrap around the upper low as it moves into southern MN later today, shifting eastward. Think there should be enough clearing later in the day to get into the low to mid 70s across the northwestern counties, with the southeast stuck near 60 degrees under clouds and drizzle. This will help push a weak cold front down from Canada overnight, and could produce a bit of light precip.
/NEW/ /Overnight through Sunday/ A period of tranquil weather will continue through the weekend as we will remain on the eastern periphery of stronger mid level ridging through Sunday. The subtropical jet will continue to feed into deeper troughing over the Midwest and Great Lakes resulting in intermittent high clouds through the weekend, but otherwise it should be fairly quiet with temperatures continuing to recover to near seasonal norms. But after a second consecutive summery weekend, a reinforcing cold front will drop temperatures back below normal where they will remain throughout the upcoming workweek.
Upper ridge remains essentially in place over the region this afternoon and tonight, but begins shifting east tomorrow. Meanwhile, a cold front will make progress southeastward toward to region on Sunday as an upper trough traverses the Great Lakes.
411 AM EDT Sat Sep 12 2020 The upper ridge is in the process of drifting east with a moist easterly flow pattern continuing across the area today.
Water vapor imagery this morning shows the upper level closed low slowly moving northeast through NE and SD. The upper level low will move east through the upper Midwest today, pushing a weak cold front south and east across our area. The cold front will be the focus point for storm chances. Right now it looks like it will be a thin, broken line of storms that moves through with the cold front, not impacting any one area for too long.
The Td depression at TRI is currently only 1 degree, indicating saturation in the lower levels. BW Chattanooga Airport, TN 87 72 85 71 87 / 60 40 60 50 60 Knoxville McGhee Tyson Airport, TN 87 70 85 70 84 / 50 30 60 50 60 Oak Ridge, TN 87 70 84 70 84 / 60 40 70 50 40 Tri Cities Airport, TN 83 66 83 67 82 / 40 30 60 50 50.
1121 PM CDT Fri Sep 11 2020 The upper level closed low will continue to weaken as it lifts through the central and northern Plains tonight into the upper Mississippi River Valley by Saturday afternoon. A trough associated with this feature will traverse the region tonight. Enough instability and lift looks to exists for some showers/storms to continue ahead of this trough. The upper level system continues to push into the Great Lakes region Saturday night as high pressure at the surface begins to build southeastward into the area from Nebraska and Kansas. Overnight lows are expected to range from the upper 50s to the lower 60s.
Today's elongated ridging at 5h will gradually give way to the development of a broad mid-level weakness as the remnants of a low drift nwd out of MX and as a mid-level low cutoffs off from the mean nw flow well to the n. The net result will be noticeably warmer temps today and lower heights Sun-Mon when the high temps will cool slightly.
342 AM CDT Sat Sep 12 2020 Upper level low pressure presently located over south central South Dakota will meander off to the east through the day today. One more day of below average temperatures remains for today, especially east of the Missouri (low to mid 60s east, mid 70s west), before becoming above average Sunday (upper 70s to mid 80s) as a ridge builds into the region. The period starts out with a high pressure ridge over the western U.
412 AM EDT Sat Sep 12 2020 High pressure east of the area will bring dry weather to NY and PA today. Showers are expected on Sunday as a cold front approaches from the west.
Winds will switch around to the north behind this trough, but speeds will still remain around 15 mph or less. Winds will be light and generally from the east and southeast in the wake of the trough on Sunday.
354 AM CDT Sat Sep 12 2020 For today, the upper level low currently over eastern South Dakota will gradually move east and out of the region by evening. We suspect this is the reason for some increase in showers around the western edge of the upper low in south central North Dakota this morning. We expect the warmest temperatures today across the west central, in the lower 80s, to the mid to upper 60s across the southern James RV. Tonight, h500 flow will allow a weak cold front to sag south into the state. The cold front will sink south through the state on Sunday, and this will bring a brief period of cooler temperatures for the region as the center of high pressure moves over Manitoba.
High temps this afternoon will still remain a few degrees below average but climb into the low to upper 80s area wide.
Highs today will range from the upper 70s near Lake Michigan to the lower 80s inland. Chances for showers and thunderstorms will increase from west to east starting this afternoon and continuing into tonight as a cold front moves through the area. As southern South Dakota cyclone shifts eastward into western Wisconsin late this evening, expect southern periphery of strong mid level height falls, right rear quadrant 100 knot 3H jet axis over CWA should aid in ample shower/isolated thunderstorm activity late evening into overnight.
Warm and dry conditions persist today under a broad ridge of high pressure.
1254 AM EDT Sat Sep 12 2020 The dry period will end with the arrival of a cold front bringing some soaking rain tonight and through Sunday.
At 222 AM, a closed low was spinning along the Nebraska/South Dakota border, resulting in a few light showers over northeast Nebraska. Elsewhere we were seeing widespread low clouds, along with patchy fog where the low clouds had cleared briefly. Winds were light out of the south and temperatures were in the lower 50s. What To Expect Today: Rain showers and a couple isolated thunderstorms are possible today as the core of a closed low drifts along the Nebraska/South Dakota border, then into southern Minnesota. A couple strikes of lightning may occur between Noon and 6 PM over mainly western Iowa, where diurnal heating will increase instability ahead of a weak cold front. Tonight & Sunday: Peaks of sunshine this evening should give way to clearing skies overnight as low pressure shifts east.
The pattern of high pressure and calm weather is ending, as southerly flow and a cold front move toward the area. A stationary boundary, currently draped across the TN Valley, will lift north as a warm front this afternoon. However, it will not be long before forcing along the aforementioned cold front increases, promoting additional storm development pre-dawn Sunday.
This trough will shift the winds around to the north behind. A closed low moving over western SD will eventually merge with main northern stream flow and shift east across the upper midwest. The low level moisture has also eroded as stratus has dissipated across the area. The southern extension of the main 700mb - 500mb trough axis associated with departing closed low will cross the Panhandles tonight with a trailing surface inflection.
243 AM MDT Sat Sep 12 2020 MORNING DISCUSSION: Synoptic Setup: Forecast begins with a large high pressure ridge setting over the Intermountain West of the CONUS. Today through Sunday: A glancing blow from a dry cold front to the north will move through and then just as quickly get shoved east this morning.
313 AM CDT Sat Sep 12 2020 The center of the well advertised upper level low is presently nudging into the western portion of our CWA very early this morning. Showers have developed over the southeastern flank of the low center where the best vorticity advection resides, and expect this activity to slide eastward through the day collocated with the upper level feature. Model RH time sections would indicate that low clouds will be slow to clear today - probably not until late evening for most places as the upper level low moves into central MN/IA, though may see some sun over south central SD by afternoon. The upper level low will move into the Upper Mississippi Valley tonight with clouds finally clearing out of our area.
Chances for showers and thunderstorms will increase from west to east starting late this afternoon as a cold front moves through the area.
Visible satellite imagery from this earlier this evening showed the massive smoke field over OR/WA expanding eastward as it wrapped around the mid-upper level high centered over s-central Oregon. An upper ridge to our west will slide into our area on Saturday and then shift for southwest flow aloft on Sunday.
426 AM EDT Sat Sep 12 2020 The dry period will end with the arrival of a cold front bringing some soaking rain tonight and through Sunday.
1226 AM CDT Sat Sep 12 2020 An upper level closed low will march across MN/WI Saturday. The system exits Saturday evening into Sunday morning with weak high pressure building afterwards.
This will be a warmer day with afternoon highs in the lower to mid 70s. Tonight: The main trough will swing across the cwa with at least scattered showers, especially this evening. In the wake of the trough, skies should become partly cloudy later tonight. With winds becoming northwest, lows will bottom out in the lower to mid 50s.
239 AM MDT Sat Sep 12 2020 Current IR Satellite loop and KCYS radar imagery shows the well- defined upper level low accelerating eastward near the SD/Nebraska border across central Nebraska early this morning. It will be breezy this afternoon behind the upper level low, with northwest winds gusting up to 30-35 mph at times into early this evening. A prolonged dry period with warmer temperatures will begin this weekend as the upper level high along the western coastline moves eastward through the weekend.
1246 AM CDT Sat Sep 12 2020 (This evening through Saturday) Temperatures remain well-below normal this afternoon, but are 10-15 degrees warmer than yesterday and climbing through the 60s. As the upper low (over the Wyoming/Nebraska border this afternoon) moves east- northeast across parts of far southern South Dakota tonight, the flow aloft over our area will weaken and veer to the west. Mostly sunny to partly cloudy skies and warmer temperatures are in store for Saturday afternoon, with highs expected to be in the mid 80s.
227 AM MDT Sat Sep 12 2020 High pressure will build over the region for the weekend and lead to a warming and drying trend.
Deterministic runs maintain a weak upper ridge over the region during the period.
Meanwhile, aloft, high pressure was centered over the Carolinas, and a sizable closed low was over SD. The high will weaken and drift eastward during the weekend, while the low opens up and gets absorbed into the flow ahead of a trough traversing eastward across southern Canada. The upper low will support a cold front which will approach from the northwest today and move into the area on Sunday. Southerly flow and warm air advection ahead of the cold front will pull the stalled boundary northward through the area as a warm front today. The cold front, combined with support from the right entrance region of an upper level jet will lead to more activity on Sunday. A cold front will continue to push south across the area Sunday night.
710 AM EDT Sat Sep 12 2020 High pressure east of the area will bring dry weather to NY and PA today. Showers are expected on Sunday as a cold front approaches from the west.
Rains were heaviest in the southern 1/3 of the area overnight, which had the highest FF guidance thresholds. This will be a warmer day with afternoon highs in the lower to mid 70s. Tonight: The main trough will swing across the cwa with at least scattered showers, especially this evening. In the wake of the trough, skies should become partly cloudy later tonight. With winds becoming northwest, lows will bottom out in the lower to mid 50s.
320 AM MDT Sat Sep 12 2020 Lingering low and mid-level cloud cover continues to steadily clear out this afternoon in the wake of our departing low pressure system. Warm-air advection aloft and sunny skies will result in a much warmer day.
522 AM MDT Sat Sep 12 2020 Skies were clear over eastern Utah and western Colorado overnight as dry northwest flow continued between the low over the upper Midwest and the ridge of high pressure to the West. Clear skies are expected overnight which will result in cooler than normal overnight lows, but still more moderate than in recent days. The high shifts eastward on Sunday bringing close to 5 degrees of warming to most locations across the forecast area which should result in near normal afternoon highs. Return flow on the eastern edge of the high is expected to bring a modest push of moisture to the San Juan Mountains which, when combined with greater instability associated with increased surface temperatures, should bring isolated thunderstorms.
Temperatures trend warmer through the forecast period staying near normal for the most part.
Meanwhile, aloft, high pressure was centered over the Carolinas, and a sizable closed low was over SD. The high will weaken and drift eastward during the weekend, while the low opens up and gets absorbed into the flow ahead of a trough traversing eastward across southern Canada. The upper low will support a cold front which will approach from the northwest today and move into the area on Sunday. Southerly flow and warm air advection ahead of the cold front will pull the stalled boundary northward through the area as a warm front today. The cold front, combined with support from the right entrance region of an upper level jet, will lead to more activity on Sunday. A cold front will continue to push south across the area Sunday night.
401 AM MDT Sat Sep 12 2020 Skies were clear over eastern Utah and western Colorado overnight as dry northwest flow continued between the low over the upper Midwest and the ridge of high pressure to the West. Clear skies are expected overnight which will result in cooler than normal overnight lows, but still more moderate than in recent days. The high shifts eastward on Sunday bringing close to 5 degrees of warming to most locations across the forecast area which should result in near normal afternoon highs. Return flow on the eastern edge of the high is expected to bring a modest push of moisture to the San Juan Mountains which, when combined with greater instability associated with increased surface temperatures, should bring isolated thunderstorms.
High pressure transitioning eastward across the area this weekend will result in light winds and warmer temperatures. Enhanced fire danger is possible late in the week as troughing increases winds over the southern Great Basin and Desert Southwest. 500 mb ridging over the western US will continue through the weekend with the ridge axis shifting east, returning the region to southwest flow by late in the weekend. Weak easterly flow on the south side of the ridge should be enough to keep smoke from spreading into Nevada from California, but could keep southeast CA from warming as efficiently as the rest of the CWA. A rather benign first half of the week is expected as broad ridging sets up over the western CONUS through mid-week.
Dunn Previous Discussion: /Overnight through Sunday/ A period of tranquil weather will continue through the weekend as we will remain on the eastern periphery of stronger mid level ridging through Sunday. The subtropical jet will continue to feed into deeper troughing over the Midwest and Great Lakes resulting in intermittent high clouds through the weekend, but otherwise it should be fairly quiet with temperatures continuing to recover to near seasonal norms.
For today, the upper level low currently over eastern South Dakota will gradually move east and out of the region by evening. We suspect this is the reason for some increase in showers around the western edge of the upper low in south central North Dakota this morning. We expect the warmest temperatures today across the west central, in the lower 80s, to the mid to upper 60s across the southern James RV. Tonight, h500 flow will allow a weak cold front to sag south into the state. The cold front will sink south through the state on Sunday, and this will bring a brief period of cooler temperatures for the region as the center of high pressure moves over Manitoba.
415 AM CDT Sat Sep 12 2020 The deep, closed upper low over the Northern Plains will continue to move slowly east today as the Southeast ridge gradually weakens and shifts off the Carolina coast. Tropical Depression 19 near the tip of south FL will continue to trek to the WNW on the southern periphery of the ridge and a weaker disturbance is currently located over the north-central Gulf of Mexico. Falling geopotential heights associated with the retreating ridge and approaching trough will continue to cool mid-level temps, increasing instability across the region today. However, a cold front will move through the CWA on Sunday, serving as a focus for additional showers and thunderstorms throughout the day. Expect a pleasant Sunday night as rain ends and slightly cooler air moves into the Mid-South.