Aikyam-Lab/Synoptic-Bench huggingface dataset:
Continued increases in onshore winds should solidify the low cloud deck for much of the day with VFR conditions not expected to return until late afternoon. Upper air analysis this morning showed a low amplitude ridge over West Texas with west-northwesterly flow over the region. At the surface, high pressure was centered over us and winds were generally light and variable. The upper level ridge will flatten during this period.
555 PM CST Sat Dec 7 2019 Latest 20z surface analysis shows high pressure over the Ohio River Valley. With southerly winds on the backside of the high pressure over forecast area. Southerly winds aloft on the backside of the surface/upper level ridge will advect warmer airmass into the forecast area.
536 PM CST Sat Dec 7 2019 Impacts/Highlights and Confidence: Highs 5-15 degrees above seasonable temperatures Sunday will be followed by a cold front and chances for snow. Water vapor imagery shows zonal flow aloft overhead with an upper-level trough upstream offshore the West coast. Upper trough will evolve and advance to Northern High Plains to the Central Great Basin by late Sunday. Northern positive PV anomaly is expected to move from MT into the region Sunday night, along with associated strong cold front crossing the area.
526 PM CST Sat Dec 7 2019 Under the influence of a retreating high pressure winds have turned southerly, allowing temperatures to warm today to near normal. How much warming occurs depends on whether lingering low stratus in the Lower Mississippi Valley today will expand tonight and build north into our southern CWA. By Sunday afternoon rain is starting to build into the northwest part of the CWA ahead of the approaching cold front.
354 PM CST Sat Dec 7 2019 Impacts/Highlights and Confidence: Highs 5-15 degrees above seasonable temperatures Sunday will be followed by a cold front and chances for snow. Water vapor imagery shows zonal flow aloft overhead with an upper-level trough upstream offshore the West coast. Upper trough will evolve and advance to Northern High Plains to the Central Great Basin by late Sunday. Northern positive PV anomaly is expected to move from MT into the region Sunday night, along with associated strong cold front crossing the area.
731 PM MST Sat Dec 7 2019 For end users: it will warmer in the morning at sunrise than it will be at sunset for all locations as the front moves through the area. With warmer temperatures in place and over-running cold air from the north, some concern exists for the chance of some freezing drizzle on the leading edge of the precipitation tonight.
326 PM CST Sat Dec 7 2019 Under the influence of a retreating high pressure winds have turned southerly, allowing temperatures to warm today to near normal. How much warming occurs depends on whether lingering low stratus in the Lower Mississippi Valley today will expand tonight and build north into our southern CWA. By Sunday afternoon rain is starting to build into the northwest part of the CWA ahead of the approaching cold front.
Turbulent mixing in the pbl should help limit fog formation and with temperatures above freezing, minimal impacts are anticipated. The good news is that temperatures will remain above freezing limiting impacts in far southeast KS.
Southerly low level flow will increase to around 30 knots by Sunday night and bring in higher moisture in the lower levels. Patchy fog will be possible over the Brush Country as the low level flow will be less there.
High pressure moving to the east of the terminals should allow for some improvement late in the period.
cirrus clouds thicken during the day ahead of an approaching upper trough and cold front. The rather thick cloud cover may impact the high temperature forecast by several degrees. The upper trough and cold front are expected to move through the area by midnight with north to northwest winds increasing into the 20 to 30 mph range with higher gusts. Low temperatures in the low to mid 20s.
Chattanooga Airport, TN 42 56 49 65 / 0 10 60 70 Knoxville McGhee Tyson Airport, TN 38 57 46 63 / 0 10 60 80 Oak Ridge, TN 38 56 46 62 / 0 10 70 80 Tri Cities Airport, TN 33 53 41 61 / 0 0 50 80.
401 PM CST Sat Dec 7 2019 Large extensive stratus deck situated over the Lower Mississippi Valley across the central gulf coast region today will likely remain in place overnight with some breaks at times, but not fully clearing out.
The southerly wind on Sunday will result in high temperatures becoming a few degrees warmer than today, but the skies will be more partly cloudy.
KPNC will have the higher likelihood for fog/stratus development. /issued 348 PM CST Sat Dec 7 2019/ High pressure draped across the southern plains and eastern CONUS is generating southerly winds and moisture advection over our area. The upper level ridge will push eastward ahead of a longwave trough that is currently located off the west coast. Subsequently, NW-ly flow aloft will back WSW-ly tomorrow as the trough axis reaches the western Rockies.
912 PM EST Sat Dec 7 2019 High pressure should maintain dry weather through Sunday.
616 PM EST Sat Dec 7 2019 Dry high pressure will continue to build into the region tonight. The high will shift eastward and a warm front will develop along the Southeast Coast Sunday.
348 PM CST Sat Dec 7 2019 High pressure draped across the southern plains and eastern CONUS is generating southerly winds and moisture advection over our area. The upper level ridge will push eastward ahead of a longwave trough that is currently located off the west coast. Subsequently, NW-ly flow aloft will back WSW-ly tomorrow as the trough axis reaches the western Rockies.
With warmer temperatures in place and over-running cold air from the north, some concern exists for the chance of some freezing drizzle on the leading edge of the precipitation tonight.
Fog and visibility restrictions are a possibility depending on how the low stratus decks redevelop tonight. This may change with the 06 UTC TAF package depending on how the low clouds develop.
As a thermal trough across the area pulls out, the low stratus deck should quickly mix out by 18z.
1253 AM EST Sun Dec 8 2019 High pressure will maintain dry weather today.
1035 PM EST Sat Dec 7 2019 High pressure building south across the area will produce a NE wind flow, bringing isolated to scattered showers across the coast overnight into Sunday morning. Temps have fallen into the lower 60s near the coast with a light offshore flow but considerable mid cloudiness will slow the temp fall and then a switch to onshore (NE) flow overnight should allow temps to rise a bit. High pressure building south across FL will produce a NE wind 10-15 knots overnight.
Upper level analysis shows a ridge axis translating eastward as warm air advection becomes further displaced to the east. Moist, upslope flow will result in a mixture of fog, freezing drizzle, and flurries by Sunday afternoon.
1239 AM EST Sun Dec 8 2019 High pressure will maintain dry weather today.
High pressure will hold over the area tonight, then move off to the east on Sunday.
After the upper trough moves through our CWA overnight, showers will come in from the northwest and continue through mid-morning Sunday then clear from west to east.
Continued increases in onshore winds should solidify the low cloud deck for much of the day with VFR conditions not expected to return until late afternoon.
1031 PM EST Sat Dec 7 2019 Currently - High pressure aligned along the Atlantic coast is producing light mainly northeast breezes across Keys waters this evening. While there has been some moistening through the lower levels, there is still ample warm and dry air above the inversion. Short Term Update - Surface winds will strengthen a little overnight due to the ridge to our north building a bit further south. A ridge to our north will generally produce light northeast breezes across the Keys.
1123 PM CST Sat Dec 7 2019 Impacts/Highlights and Confidence: Highs 5-15 degrees above seasonable temperatures Sunday will be followed by a cold front and chances for snow. Water vapor imagery shows zonal flow aloft overhead with an upper-level trough upstream offshore the West coast. Upper trough will evolve and advance to Northern High Plains to the Central Great Basin by late Sunday. Northern positive PV anomaly is expected to move from MT into the region Sunday night, along with associated strong cold front crossing the area.
Quick zonal pattern across the CONUS early this afternoon with next upper trough entering the west coast. At the surface we have high pressure over western NY and low pressure in the northern plains, with southerly winds in between across the forecast area.
The eastern Ozarks should experience the best coverage, which is where the highest precipitation chances will reside.
949 PM CST Sat Dec 7 2019 Latest 20z surface analysis shows high pressure over the Ohio River Valley. With southerly winds on the backside of the high pressure over forecast area. Southerly winds aloft on the backside of the surface/upper level ridge will advect warmer airmass into the forecast area.
1257 AM EST Sun Dec 8 2019 Dry high pressure will continue to build into the region tonight. The high will shift eastward and a warm front will develop along the Southeast Coast Sunday.
Due to southerly return flow and light/calm winds, fog has begun to develop in addition to the low stratus.
308 AM EST Sun Dec 8 2019 High amplitude U/L pattern over much of North America with a sharp ridge along the west coast of the U. /Canada will induce a deep trough downstream.
An upper trough will shift inland tonight with decreasing showers and drizzle.
352 AM EST Sun Dec 8 2019 High pressure will maintain dry weather today.
The airmass across our region will remain similar to yesterday in fairly zonal flow aloft over the plains ahead of a upper trough extending from Canada to the western CONUS. The weather pattern undergoes changes tonight as an upper trough translating southeast from Alberta across the northern/central Plains drives a strong cold front thru our area.
1107 PM CST Sat Dec 7 2019 Under the influence of a retreating high pressure winds have turned southerly, allowing temperatures to warm today to near normal. How much warming occurs depends on whether lingering low stratus in the Lower Mississippi Valley today will expand tonight and build north into our southern CWA. By Sunday afternoon rain is starting to build into the northwest part of the CWA ahead of the approaching cold front.
411 AM MST Sun Dec 8 2019 Several weak disturbances aloft move across the forecast area today into this evening ahead of the main upper trough moving east of the Rockies and across the northern and central High Plains.
Abundant moisture will continue to bring cloudy skies with isolated showers across the lower deserts today. After a likely lull in shower activity tonight, scattered convective type showers will be possible through Monday afternoon as the low center tracks through southern Arizona. Additional rainfall amounts should be fairly light across the lower deserts, but may approach another half an inch in higher terrain areas. By Monday night, the low will have pushed well southeast of Arizona with increasing subsidence and drier air moving in with an upper level ridge coming in from the west.
South of this is relatively warmer air extending from Wyoming to the Desert Southwest. to the west this warmer airmass forms a trough over the Pacific Northwest and then a ridge off the North American Coast. Today into Tonight: Cold air will find a free ride filling in the top of the Pacific Northwest trough as it moves into Wyoming.
High pressure aloft will return to the region early in the upcoming week, with another system possible by midweek.
Where surface temperatures are below freezing (broadly along and north of I-90), could see some drizzle freezing on untreated surfaces. Although ice amounts are expected to be only a few hundredths, the freezing drizzle could make for a bit of a messy commute Monday morning in some spots. Freezing drizzle/drizzle will continue until the main wave approaches and full saturation occurs during the morning Monday. As for snow amounts, expecting a dusting to around 3 inches, with the higher amounts north of I-90.
531 AM CST Sun Dec 8 2019 The two primary concerns for this forecast period continue to be the possibility for some light precipitation starting later today with low chances continuing into Monday, and the arrival of much colder air behind the strong cold front that will push through the region tomorrow. Temperatures will be fairly mild under the influence of warmer southwesterly flow and despite increasing cloud cover, we should see most areas reach highs this afternoon in the 50s. This will be the last mild day until about midweek as we will see temperatures drop quickly behind a strong cold front that will push through the region through the morning hours on Monday.
Global models are in good agreement bringing an h500 trough across the northern plains today and tonight, bringing snow across northwest North Dakota first, spreading southeast through the day into Tonight. In addition to the broad scale lift expected with the h500 trough passage, CAM models are showing east-west oriented frontogenetic forcing around 700 mb across central North Dakota beginning at 18z and continuing for about 3 to 4 hours. So overall we expect a swath of 4 to 6 inch snow amounts from the northwest to the southeast today, with the highest amounts generally along and and north of I94 over western North dakota and along and south of i94 across the east.
A trough of low pressure along with a cold front will pass through the region today bringing a mixture of rain and snow to the state.
Light snow spreads across the region this morning into afternoon from north to south behind a passing cold front, with the highest snowfall rates expected from around sunrise to noon today. Higher snow accumulations outside the mountains will most favor the northeast parts of north-central Montana, which have already been experiencing snow since last evening, and north- and northwest- facing slopes where temporary blocking of low-level flow will allow for a bit more concentrated areas of higher snowfall.
Quiet weather is in store for today with high pressure over us. Things begin to change on Monday as a cold front approaches the region.
317 AM MST Sun Dec 8 2019 Abundant moisture will continue to bring cloudy skies with isolated showers across the lower deserts today. After a likely lull in shower activity tonight, scattered convective type showers will be possible through Monday afternoon as the low center tracks through southern Arizona. Additional rainfall amounts should be fairly light across the lower deserts, but may approach another half an inch in higher terrain areas. By Monday night, the low will have pushed well southeast of Arizona with increasing subsidence and drier air moving in with an upper level ridge coming in from the west.
502 AM MST Sun Dec 8 2019 Several weak disturbances aloft move across the forecast area today into this evening ahead of the main upper trough moving east of the Rockies and across the northern and central High Plains.
Much cooler temperatures and strong/gusty northwest winds will return by late tonight and Monday, as a strong cold front drives south across the Heartland in response to a deepening longwave trough across central-eastern North America. Below normal temperatures should linger for Tue, as medium range ensemble consensus supports a persistent sharp upper ridge across far western North America, and a deep longwave trough across central- eastern portions of the Continent. Per ensemble consensus, the sharp ridge/trough pattern dampens by mid-late week, supporting moderating temperatures by Wed-Thu and into the weekend. Despite much cooler temperatures and modest humidity values, strong/gusty northwest winds behind a strong cold front will support low-end very high grassland fire danger across much of the forecast area Monday.
The eastern Ozarks should experience the best coverage, which is where the highest precipitation chances will reside. A cold front surges across southern Missouri on Monday, which will bring a dry continental airmass through. Rain will quickly exit east early Monday morning, while temperatures through the day Monday get cooler. Overnight lows Monday night will fall into the low to mid 20s.
The good news is temperatures are several degrees above freezing. Over the next couple of days the synoptic pattern will shift from zonal to Southwesterly as a deep trough deepens over the Southwestern US and Mexico.
A low pressure system will then lift into the region with periods of rain and drizzle tonight into Monday night.
409 AM MST Sun Dec 8 2019 Upper level analysis has zonal flow across the central CONUS with upper trof crossing the Pacific Northwest at the moment. At the surface, cold high pressure resides across southwest and south central Canada with cold frontal boundary slipping south across southern North Dakota. Behind the front, cool and moist air will move in, with areas of patchy freezing drizzle and fog possible across northwest SD.
637 AM EST Sun Dec 8 2019 Southerly winds will develop in the low levels above the surface and then work their way down to the surface beginning this afternoon.
549 AM CST Sun Dec 8 2019 12Z TAFS Light surface winds this morning resulting from high pressure centered over the region has allowed for the development of patchy dense fog. VFR conditions expected to prevail through the remainder of the day with variable winds early this morning becoming moderate out of the south by late this morning as high pressure shifts east of the region. Quiet weather is in store for today with high pressure over us. Things begin to change on Monday as a cold front approaches the region.
As another cold front approaches, winds tonight will come more from the west, and this will help create lows tonight well above usual early December lows.
410 AM CST Sun Dec 8 2019 One more warm day is in store for the region before a cold front sweeps through late tonight and heralds the arrival of colder weather. By tonight, a sharpening cold front should race southeastward from the High Plains, pushing through the forecast area by sunrise Monday morning. Given the fast-moving and low- impact nature of the precipitation band to begin with, along with the low-level dry airmass it will need to overcome, did not mention any threat of freezing drizzle as some of the blended guidance would suggest.
High pressure builds over the region on Monday, which will lead to a period of dry conditions and near average temperatures. These conditions will continue as the upper low gradually exits the region. Once the low exits the region, high pressure and drier weather returns to interior NorCal.
Showers will end late tonight after a cold front moves south across the region.
A low pressure system will then lift into the region with periods of rain and drizzle tonight through Monday night.
820 AM EST Sun Dec 8 2019 High pressure will maintain dry weather today. Rain returns late tonight and Monday with approaching low pressure. Moisture will increase with the warmer air, and clouds will move in from the southwest throughout the day.
The airmass across our region will remain similar to yesterday in fairly zonal flow aloft over the plains ahead of a upper trough extending from Canada to the western CONUS.
High temperatures today should range from the mid 40s in northern Nebraska to the low 50s in southeastern Nebraska.
506 AM EST Sun Dec 8 2019 Water vapor imagery and CIMMS mean-layer analyses place a deep ridge complex over Central America and the extreme eastern North Pacific. Temperatures range from 65 to 70 along the island chain with dewpoints in the lower to mid 60s. The ridge complex centered near the Baja Peninsula will slide quickly east over the next 24 hours, bumped from its Baja vacation by long wave energy digging south through California and the Four Corners.
With high pressure in control expect another very nice day across the forecast area under partly cloudy skies.
317 AM CST Sun Dec 8 2019 The two primary concerns for this forecast period continue to be the possibility for some light precipitation starting later today with low chances continuing into Monday, and the arrival of much colder air behind the strong cold front that will push through the region tomorrow. Temperatures will be fairly mild under the influence of warmer southwesterly flow and despite increasing cloud cover, we should see most areas reach highs this afternoon in the 50s. This will be the last mild day until about midweek as we will see temperatures drop quickly behind a strong cold front that will push through the region through the morning hours on Monday.
One more warm day is in store for the region before a cold front sweeps through late tonight and heralds the arrival of colder weather. By tonight, a sharpening cold front should race southeastward from the High Plains, pushing through the forecast area by sunrise Monday morning. Given the fast-moving and low- impact nature of the precipitation band to begin with, along with the low-level dry airmass it will need to overcome, did not mention any threat of freezing drizzle as some of the blended guidance would suggest.
/issued 308 AM EST Sun Dec 8 2019/ High amplitude U/L pattern over much of North America with a sharp ridge along the west coast of the U. /Canada will induce a deep trough downstream.
414 AM MST Sun Dec 8 2019 Upper level analysis has zonal flow across the central CONUS with upper trof crossing the Pacific Northwest at the moment. At the surface, cold high pressure resides across southwest and south central Canada with cold frontal boundary slipping south across southern North Dakota. Behind the front, cool and moist air will move in, with areas of patchy freezing drizzle and fog possible across northwest SD.
Cold front and stratus moving southwards out of North Dakota is just a few miles from the border and will be in here by sunrise, and continue to track south through the day. Reports of light freezing drizzle are coming in from the northern tier of North Dakota, lending credence to BUFKIT profiles that suggest the stratus will thicken up just enough for some freezing drizzle before saturation of the dendritic growth zone (about 2-3 hours before changeover). As such, will broaden area of freezing drizzle mention, though still expect it will limited in impacts with just a hundredth or two of QPF. Otherwise, fairly good forcing is expected with the passage of the upper trough, centered around 700mb, but is relatively progressive, though at the same time with such cold air, snow ratios will be high.
1036 AM MST Sun Dec 8 2019 Upper level analysis has zonal flow across the central CONUS with upper trof crossing the Pacific Northwest at the moment. At the surface, cold high pressure resides across southwest and south central Canada with cold frontal boundary slipping south across southern North Dakota. Behind the front, cool and moist air will move in, with areas of patchy freezing drizzle and fog possible across northwest SD.
Fog this morning and thicker cloud cover this afternoon have kept temperatures cooler out east. Main focus in the short term will be with rain chances and then with a strong cold front moving through on Monday. Scattered light rain over central MO and in the eastern Ozarks will be the best bet tonight ahead of a cold front, which will push into the western CWA by 12z Mon.
/issued 549 AM CST Sun Dec 8 2019/ 12Z TAFS Light surface winds this morning resulting from high pressure centered over the region has allowed for the development of patchy dense fog. VFR conditions expected to prevail through the remainder of the day with variable winds early this morning becoming moderate out of the south by late this morning as high pressure shifts east of the region. Quiet weather is in store for today with high pressure over us. Things begin to change on Monday as a cold front approaches the region.