Aikyam-Lab/Synoptic-Bench huggingface dataset:
Upper trough will move south and east of the area by this evening ending any precipitation over the eastern mountains this afternoon. A ridge of high pressure will build over the area tonight so expect the fog and stratus to redevelop. Upper level ridge will keep weather calm through the period, but fog likely will develop again overnight across the area with ifr conditions expected everywhere except KRDM/KBDN.
High pressure aloft will return to the region early in the upcoming week, with another system possible by midweek. The splitting trough remains across the West this morning.
Morning satellite imagery showing upper trough axis tracking southeastward with precipitation in advance.
156 PM CST Sun Dec 8 2019 An upper level trough moving southward down the Califoria coast this afternoon will move eastward along the Arizona/Sonora border on Monday with increasing mid level ascent across mainly the southern half of West Texas. Meanwhile, a sharp upper level trough will move across the northern Plains on Monday, driving a cold front southward through the southern High Plains.
Otherwise our skies will be partly sunny with the warm front in the Gulf now approaching the coastline. Overall, we can expect a warmer day with just the shift in the wind direction from E to SE. Tomorrow we will start off warmer and windy with no fog and a range of mid to upper 50s. Highs to start the week will soar another 10 degrees with gusty SW winds, the cold front will be more than knocking on the door in I-30 by late Monday afternoon shifting the winds to W/NW.
945 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.
At the surface, high pressure to the east and strengthening low pressure over southeast CO is resulting in a decently strong pressure gradient, causing gusty southwesterly winds of 15 mph with gusts of 20-25 mph. Increasing cloud cover and a continued increase in dewpoints will result in a warmer night tonight, with lows in the low to mid 50s. Meanwhile, cooler conditions expected in the Big Country (highs mainly in the low to mid 60s) where a cold front will be moving through that region by late afternoon. Increasing lift with the approaching trough in the afternoon will combine with increasingly deep moisture to bring chances for showers by late afternoon along and west of an Ozona to Cross Plains line.
At the surface, high pressure is centered to the east of our CWA and winds are from the south to southwest. Southerly low level flow will continue tonight bringing warmer air. A cold front will approach South Central Texas Monday and ahead of the front temperatures will be well above normal. The cold front will move through the region Monday night bringing likely rain.
In the wake of this system, high pressure is expected for most of the rest of the week. Model data suggest cold frontal passage will occur late Monday afternoon through the evening hours.
1140 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.
Upper trough will move south and east of the area by this evening ending any precipitation over the eastern mountains this afternoon. A ridge of high pressure will build over the area tonight so expect the fog and stratus to redevelop.
1127 AM CST Sun Dec 8 2019 Westerly flow aloft with considerable high clouds will transition to southwest flow tonight and Monday ahead of an approaching upper level low pressure trough.
Mid-level frontogenesis/thetae ridging and omega values all support decent lift across the northeast CWA later this evening, and into the early post-midnight hours.
158 PM CST Sun Dec 8 2019 Low level southerly flow will strengthen overnight, ahead of a northern branch upper trof approaching from the central plains.
This wave will race across the central plains during the day on Monday with a strong cold front pushing across Kansas.
Despite the cold front, we should remain precipitation free, with only VFR ceilings remaining across the Panhandles.
Temperatures are also above normal, despite increasing high clouds, courtesy of a surface lee trough and low level thermal ridging. The High Wind Warning will remain in effect until 2 am MST tonight for the Guadalupe and Delaware Mountains.
Widespread mountain obscuration from the lower cloud ceilings are also expected to persist throughout the day today. -TP /ISSUED 408 AM MST Sun Dec 8 2019/ 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.
Areas along the foothills of the eastern mountains are currently warmer than most valley locations. The low-level inversion keeps the surface winds much slower than the the winds aloft. Chattanooga Airport, TN 49 64 58 59 32 / 40 30 70 80 60 Knoxville McGhee Tyson Airport, TN 46 63 58 58 32 / 50 40 70 80 70 Oak Ridge, TN 46 61 56 57 29 / 50 40 70 80 60 Tri Cities Airport, TN 41 61 55 56 30 / 60 40 50 80 60.
This will be accompanied by some light scattered precipitation as well as a strong cold front. It's during this time that light precipitation will be possible, with the higher chances across northern Neb. Model soundings indicate about a 3 hour window for some light drizzle or light freezing drizzle immediately after the frontal passage. Highs will struggle to get out of the lower 20s across portions of north central Nebraska.
1250 PM 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.
This high clouds will linger through much of the evening hours and likely into the overnight. Meanwhile, a long wave trof will be moving across the Northern Plains late tonight. This feature will usher in the passage of a cold front across SW Kansas by morning. Highs will be much cooler tomorrow with values peaking mainly in the 30s and 40s.
Main surface cold front extends from western IA through SD and into WY. Cold front will move toward Oklahoma overnight and arrive in northeast Oklahoma Monday morning and into northwest Arkansas by afternoon.
Stout return flow as the onshore pressure gradient tightens ahead of the arrival of a late Monday cold front. Moisture levels will be on the rise as dew points increase into the low to mid 60s. Pattern change on the way for the middle of the new week as a pair of potent mid level lows (one currently over the nrn Rockies and the other off the CA coast) carves out a large trough over the eastern half of the U. This will allow associated cold front to surge southward across southeast Texas starting Monday evening.
Temperatures trend gradually warmer through the week ahead.
The Canadian cold front which briefly brought winter like conditions along the Continental Divide and into the Flathead valley this morning is gradually retreating back to the east this afternoon. Light snow, possibly mixing with freezing rain, could develop tonight into Monday for areas that do see stratus.
Otherwise, the cold arctic airmass and high pressure will have moved over the region and cutoff the moisture supply from NW to SE.
426 PM MST Sun Dec 8 2019 Mean eastern PAC and western NOAM ridging will prevail in the period, with the region being on the edge of this feature under the NW flow track. A cold front will exit the CWA early this evening with gusty northerly winds behind it.
High pressure builds over the region on Monday, which will lead to a period of dry conditions and near average temperatures. Water vapor imagery and mid-level height fields show a positively-tilted trough slipping southward through central California. Across the higher terrain, generally above 5,500 feet, any such snow shower may briefly reduce visibilities. All of this activity should wind down by the evening hours as the upper low shifts farther south along with the loss of diurnal heating. Heights will continue to build on Monday as an offshore ridge moves through.
The expectation is that these showers will diminish this evening with dry weather after that as an upper ridge builds over the area.
An upper level ridge is building into the region with some clearing this afternoon. With dew points in the 40s west of the Cascades and in the lower 30s over the east side, high pressure building in will bring fog and low clouds in the valleys by sunrise.
The low pressure system that brought some valley rain and mountain snow this weekend, will be exiting the region tonight. You may have to deal with some fog issues during the Monday morning commute, however improving conditions are expected to start the week as high pressure spreads across the Great Basin.
Ground surfaces across much of the area are wet, not from falling precipitation but likely due to the ground temperatures being cooler than the lower to middle 40 dewpoints present across the area. The higher cloud deck around 10 to 15 kft resides above a very dry layer between roughly 03 and 10 kft. The lower cloud deck is in the form of a low stratus, which doesn't appear to be producing much rain, but as we go into the overnight hours may produce some light drizzle. Along and just behind the cold front expect some light rain and perhaps some very light snow.
/issued 158 PM CST Sun Dec 8 2019/ Low level southerly flow will strengthen overnight, ahead of a northern branch upper trof approaching from the central plains.
The low stratus and fog are expected to gradually erode 16Z-19Z, with VFR conditions in the afternoon. A cold front is forecast to move into the region Monday night, reaching AUS 03Z-05Z Tue and SAT 05Z-07Z Tue. At the surface, high pressure is centered to the east of our CWA and winds are from the south to southwest. Southerly low level flow will continue tonight bringing warmer air. A cold front will approach South Central Texas Monday and ahead of the front temperatures will be well above normal. The cold front will move through the region Monday night bringing likely rain.
302 PM CST Sun Dec 8 2019 Area is coming in transition from moderating high pressure influence to onshore marine layer advection this evening.
A cold front is expected to move through late Monday morning into the afternoon shifting winds to the north to northeast. /issued 156 PM CST Sun Dec 8 2019/ An upper level trough moving southward down the California coast this afternoon will move eastward along the Arizona/Sonora border on Monday with increasing mid level ascent across mainly the southern half of West Texas. Meanwhile, a sharp upper level trough will move across the northern Plains on Monday, driving a cold front southward through the southern High Plains.
then will persist into Monday before a strong cold front pushes through the region.
Chattanooga Airport, TN 49 65 53 62 / 40 30 80 80 Knoxville McGhee Tyson Airport, TN 47 63 52 59 / 40 20 80 80 Oak Ridge, TN 47 63 49 58 / 50 20 90 80 Tri Cities Airport, TN 42 62 51 58 / 50 20 80 80 TN.
Will keep mention of MVFR cigs at KPNC behind cold front tomorrow morning, otherwise VFR conditions expected.
A cold front moving south across the region will focus shower and isolated thundershowers through this evening. The focus for the short term remains upper-level trough and attendant cold front. As the cold front dives south this evening, expect this activity to work its way south, beginning to impact the Las Vegas Valley around 00Z-02Z, then starting to dissipate as it continues further south.
an upper level trough and associated cold front remain on track to move through the area from around midnight tonight through mid morning Monday. Low temperatures tonight range from the low 20s in the northwest to the mid/upper 20s far east through south. High temperatures Monday in the low to upper 30s.
Much cooler temperatures will also occur Monday followed by cold temperatures Monday night behind the departing system.
Shower activity has been most widespread along the higher terrain, with even a lightning strike detected over the Kaibab Plateau.
204 PM MST Sun Dec 8 2019 Mean eastern PAC and western NOAM ridging will prevail in the period, with the region being on the edge of this feature under the NW flow track. A cold front is currently dropping through northwest South Dakota this morning, and will then slip south through the rest of the area this afternoon. Area area of IFR/LIFR ceilings will spread across the area behind the front, with the lowest conditions around the Black Hills.
210 PM MST Sun Dec 8 2019 An upper level trough over the northern Rockies and Great Basin will move east tonight and cross the region by Monday morning. Moisture in excess of 150 percent of normal ahead of this trough has been streaming over the area all day and has resulted in steady mountain snow and valley rain for areas along and south of I-70. Behind the upper level trough, some lingering moisture will result in continued light snow showers for the northern and central mountains and close to the Divide through Monday morning.
Cold front will move through terminals mid-late morning Monday with MVFR conditions in its wake for a few hours. Main surface cold front extends from western IA through SD and into WY. Cold front will move toward Oklahoma overnight and arrive in northeast Oklahoma Monday morning and into northwest Arkansas by afternoon.
449 PM MST Sun Dec 8 2019 An upper level trough over the northern Rockies and Great Basin will move east tonight and cross the region by Monday morning. Moisture in excess of 150 percent of normal ahead of this trough has been streaming over the area all day and has resulted in steady mountain snow and valley rain for areas along and south of I-70. Behind the upper level trough, some lingering moisture will result in continued light snow showers for the northern and central mountains and close to the Divide through Monday morning.
912 PM CST Sun Dec 8 2019 Considerable cloudiness at various levels will persist through the night ahead of a cold front, which will enter the area early Monday morning.
Upper trough mas moved off to our east and drier, colder nnwly flow aloft is now coming in. Due to recent pcpn, moist air remains in the lower atmospheric levels and fog is expected the next two nights/mornings.
/Issued 912 PM CST Sun Dec 8 2019/ Considerable cloudiness at various levels will persist through the night ahead of a cold front, which will enter the area early Monday morning.
Guidance suggests the inversion will weaken further overnight and profiles indicate a veering flow will set up through the lower levels as the high retreats further away. A ridge to our north will maintain gentle to moderate mostly easterly breezes on Keys waters overnight.
On Monday, warm southerly flow will produce above normal temperatures in the lower 80s but likely shy of any record highs.
This widespread shower activity should translate more into the lower to mid Ohio Valley Monday morning along with the strongest low-level forcing. Behind this activity, isolated-scattered showers are possible ahead of the approaching cold front. Deterministic model guidance is in good agreement on the timing of this aforementioned cold front, nearly bisecting the CWA around midday and then clearing the CWA by early evening on Monday.
Ahead of the front, warmer temperatures in the middle to upper 50s will be found along and south of Interstate 44 through the late morning hours.
950 PM PST Sun Dec 8 2019 A cold front will move across Southern California overnight.
The cold front is crossing into northern Arizona this evening having made its way onto the Kaibab Plateau at this time. Shower activity has been most widespread along the higher terrain, with even a lightning strike detected over the Kaibab Plateau.
1023 PM MST Sun Dec 8 2019 03z surface analysis showed initial cold front into NE. Mean eastern PAC and western NOAM ridging will prevail in the period, with the region being on the edge of this feature under the NW flow track. Drier air arrives Monday scouring out the lower clouds as VFR conditions dominate by afternoon.
828 PM MST Sun Dec 8 2019 03z surface analysis showed initial cold front into NE. Mean eastern PAC and western NOAM ridging will prevail in the period, with the region being on the edge of this feature under the NW flow track. A cold front will exit the CWA early this evening with gusty northerly winds behind it.
256 AM EST Mon Dec 9 2019 High amplitude U/L pattern to begin the period with a sharp ridge along the west coast of western North America and a deepening trough over central Canada and the central U.
Cold front should move into the CLL area around 03z and temperatures to fall quickly.
Temperatures east of the Cascades should drop to below freezing if they haven't already, so freezing fog is likely there. Weak high pressure will be in control with light winds through Monday.
248 AM CST Mon Dec 9 2019 Precipitation and mid level trough continues to roll east across the eastern CWA with rapid weakening in the James valley. With the high being off to the southeast, winds likely won't completely settle down and some cloud cover is possible.
An upper level trough over the northern Rockies and Great Basin will move east tonight and cross the region by Monday morning. Moisture in excess of 150 percent of normal ahead of this trough has been streaming over the area all day and has resulted in steady mountain snow and valley rain for areas along and south of I-70. Behind the upper level trough, some lingering moisture will result in continued light snow showers for the northern and central mountains and close to the Divide through Monday morning.
A cold front moving south across the region will focus shower and isolated thundershowers through this evening. The focus for the short term remains an upper-level trough and attendant cold front. As the cold front dives south this evening, expect this activity to work its way south, beginning to impact the Las Vegas Valley around 00Z-02Z, then starting to dissipate as it continues further south.
1043 PM MST Sun Dec 8 2019 An upper level trough over the northern Rockies and Great Basin will move east tonight and cross the region by Monday morning. Moisture in excess of 150 percent of normal ahead of this trough has been streaming over the area all day and has resulted in steady mountain snow and valley rain for areas along and south of I-70. Behind the upper level trough, some lingering moisture will result in continued light snow showers for the northern and central mountains and close to the Divide through Monday morning.
Also seeing some fog and freezing drizzle over southern parts of the area. Mid-level frontogenesis/thetae ridging and omega values all support decent lift across the northeast CWA later this evening, and into the early post-midnight hours.
A strong cold front will push through early Monday morning before sunrise turning winds out of the north and gusting up to 35-40 mph shortly after sunup due to strong cold air advection behind it. Morning low temperatures will be in the low to upper 30s across the CWA and only warming into the mid 30s to low 40s north to south during the afternoon hours. After sunset Monday evening, winds will diminish behind the front as high pressure builds in across the CWA with decreasing clouds aiding in strong radiational cooling and an inversion near the surface.
The highest concentration of showers are over southwest/south central Illinois where the strongest low level moisture advection is.
High pressure aloft will return to the region early in the upcoming week, with another system possible by midweek. The split upper level trough continues to cross the area this evening, with the mean trough axis nearly bisecting Utah from southwest to northeast. The surface cold front has moved through the area, with the back edge of the frontal band across southeast Utah.
Expect some clearing in the northeast as high pressure slided into the northern plains, and with temperatures dropping into the teens below zero, may need a wind chill advisory. Limiting factor will be the lack of wind under the high pressure.
especially up along the MO/IA border where moisture is pooling ahead of the front and temperatures are a bit cooler. If these echoes are associated with the higher cloud cover, any precipitation will evaporate as it falls through a significant dry layer between 850-600 mb. We could possibly see some light drizzle and/or some light rain develop later this morning as lift increase ahead of the incoming trough. As of 3 AM, the cold front generally extended from central Iowa to east-central Nebraska to north-central Kansas. Winds will decrease slightly as the front works south, but will still see gusts of 30 to 35 mph throughout much of the day before dropping off later this evening as high pressure settles in. Temperatures will rapidly fall behind the front with the high temperature for today having occurred just after midnight.
Low pressure is centered over southeastern California and is pushing a cold front across north-central Arizona. The low has moved further southwest than previously anticipated, which has resulted in precipitation developing further south and west along the Colorado River. Isolated to scattered light showers will remain possible through the daytime as the cold front moves through the area, but the latest trends are pointing toward less coverage of showers.
Thanks to increasing SSW winds, we have more cloud cover and warmer temps than yesterday at this time. Looking at the bigger picture, a longwave trough is getting its act together across the western U. As a cold front approaches from the west tonight, rain will turn from scattered in nature to more widespread after dark.
/issued 256 AM EST Mon Dec 9 2019/ High amplitude U/L pattern to begin the period with a sharp ridge along the west coast of western North America and a deepening trough over central Canada and the central U.
Dry conditions under a ridge of high pressure are expected across the area today and Tuesday.
404 AM MST Mon Dec 9 2019 Upper level analysis has trof axis swinging through the Dakotas at the moment with ridging along the West Coast. Temperatures at 3am across the forecast area have fallen into the single digits and teens, with 20s holding out across the higher elevations of the Black Hills. Winds will drop off a little this morning, but return to breezy levels by the afternoon as a weak surface trof slides across the Dakotas.
313 AM CST Mon Dec 9 2019 Overnight temperatures have warmed a bit as strong warm advection pumps a warmer, moist airmass across the Midsouth. A strong cold front will move across the region overnight.
449 AM MST Mon Dec 9 2019 The upper trough axis swings east of the region today with the overall pattern shifting to the east through the middle of the week. This will bring northwest flow aloft and upper short wave ridging to the the region Tuesday and Tuesday night.