Aikyam-Lab/Synoptic-Bench huggingface dataset:
H5 upper pattern was high amplitude with lows off the New England coast, and over the northern California coast, and a broad ridge over the nation's mid section.
This will also keep effective boundary (warm front) to our south through much of the day, limiting convection as instability will struggle to develop northward. Main upper trough begins to shift east/northeast out of the southern Rockies late today into tonight.
943 PM PST Thu Nov 28 2019 Much cooler temperatures and dry weather will be in place tonight and Friday.
Weak upper level ridging is in place over the eastern CONUS with a deep trough dug into the western half of the CONUS. Most of the upper trough will begin to eject out of the west this afternoon with lee cyclogenesis occuring over NE Colorado. Closer to home another weak disturbance will ride along upper ridging allowing for a few light showers this afternoon mainly in the northwest. As the cold front approaches Saturday night, there is a narrow tongue of instability that could lead to a few rumbles of thunder.
The models rmn consistent in keeping the highest PoPs ovr the NW part of the FA tngt and Fri. Upper ridging ovr SE AR wl actually result in little in the way or organized rainfall. South winds ahead of this storm sys wl bring warmer air NWD into the region.
325 AM EST Fri Nov 29 2019 Mainly dry but cloudy weather is expected through tonight under high pressure. Precipitation chances return with weekend low pressure. Some erosion of the lower clouds are expected by afternoon as high pressure builds across the region, though mid level clouds should quickly increase in warm advection aloft keeping skies mostly cloudy. Expect mainly rain for most areas S of Route 422 outside of the higher terrain. Areas near and N of Route 422, the Laurel Highlands, and the WV/MD ridges should see a period of freezing rain, though some snow is possible at the onset later Saturday and Saturday evening until the warm advection aloft intensifies as sfc temps stay near or below freezing. SE upslope flow in Garrett County MD should also keep temperatures near/below freezing, resulting in a more prolonged period of freezing rain.
Deep layer ridging will remain in place over the area today and begin to shift eastward overnight.
1226 AM EST Fri Nov 29 2019 Mainly dry weather is expected through Friday night under high pressure. Precipitation chances return with weekend low pressure. Dry weather and some clearing of the stratocu is expected Friday and Friday night, however, mid level clouds will be on the increase in warm advection ahead of the next low pressure system approaching from the west.
1036 PM EST Thu Nov 28 2019 High pressure will build into the region for Friday.
1116 PM EST Thu Nov 28 2019 Mainly dry weather is expected through Friday night under high pressure. Precipitation chances return with weekend low pressure. Dry weather and some clearing of the stratocu is expected Friday and Friday night, however, mid level clouds will be on the increase in warm advection ahead of the next low pressure system approaching from the west.
This is likely some light snow or freezing drizzle, and have adjusted POPs accordingly. It is expected that this early precipitation will begin to lose most of its ice in the DGZ over the next few hours and light snow will mostly turn to freezing drizzle. Precipitation type will remain mostly drizzle and freezing drizzle tonight through Friday afternoon before saturation returns to the DGZ and snow begins mixing in towards at the end of the period. But, that said the operational GFS is still too aggressive with LL thermal fields and is much warmer than all other guidance for much of the Friday night through Saturday night time period.
1019 PM EST Thu Nov 28 2019 High pressure will build into the region for Friday.
/issued 934 PM CST Thu Nov 28 2019/ The upper level disturbance that has produced steady light rain across NE AR, the MO Bootheel and NW TN is weakening as it pushes into the broad upper ridge extending from the Gulf into the Great Lakes.
These conditions will continue through mid-morning with chances of showers and thunderstorms increasing by late morning and continuing through Saturday morning as isentropic lift increases in advance of a cold front that is slated to move through the region late Tonight into Saturday morning. There is the potential that some of the thunderstorms that develop in the vicinity of the cold front could become strong to marginally severe with hail the main concern. However, temperatures are expected to slowly rise Tonight in advance of the Saturday cold front with high temperatures on Saturday expected to be above normal for this time of year.
1030 PM MST Thu Nov 28 2019 Water vapor shows upper ridge axis shifting east of the northern plains with upper low digging along the CA coast. Surface trof deepening along the lee of the central Rockies, with gusty southeast winds across the cwfa, especially northeast WY into northwest SD. Low stratus covers most of the region, with fog and even some spotty freezing drizzle around the southern hills and Rapid City area. Low stratus with expanding fog expected tonight, with some pockets of freezing drizzle. Closed upper low forms over the NEB panhandle around midnight Friday night and slowly slides east along or just south of the NEB/SD border Saturday, then across IA Saturday night.
High pressure will prevail across the area today with a dry airmass in place.
A dry upper level trough will remain over the area tonight, while high pressure continues to build in over British Columbia. Clear skies will make for a chilly evening, with lows dipping down into the low to mid 20s across the region.
100 AM EST Fri Nov 29 2019 Cool high pressure will build in and settle across the region today, joined by variable high clouds.
Most locations will receive an additional inch of rain between Friday and Saturday in advance of the cold front. Temperatures on Friday will range between the mid 40s and lower 50s, while overnight lows only drop a few degrees from the high. The main forecasting concern during this period remains the possibility for strong-to-severe storms late Friday into Saturday morning along and ahead of a strongly forced cold front.
ABM Chattanooga Airport, TN 58 46 64 52 62 / 0 10 60 90 20 Knoxville McGhee Tyson Airport, TN 55 44 61 51 61 / 0 30 70 90 60 Oak Ridge, TN 55 43 59 50 60 / 10 30 80 90 50 Tri Cities Airport, TN 54 39 55 47 58 / 0 40 80 90 80.
332 AM EST Fri Nov 29 2019 High pressure will prevail with dry weather through Saturday.
1006 PM EST Thu Nov 28 2019 Cool high pressure will build in and settle across the area through Saturday.
Some good news is that temperatures have been holding above freezing, so am not anticipating icy concerns as it stands right now. Will of course watch for the rest of the morning, but even dewpoints are running above freezing as well. Lows tonight are expected to be in the 30s, a little warmer due to the continued elevated winds. Will let the High Wind Watch ride out for now as confidence is not high enough to upgrade to a warning at this point in time.
For the most part, the convection will be rooted above cooler air near the ground, but the near-surface cool air will become very thin or be mixed out in far southeast Oklahoma later on Friday night.
Mid level clouds and a few lingering radar returns are still moving along the periphery of the ridge currently situated over the Eastern half of the United States. Clouds will remain in the vicinity moving in from the west, but some sun should be able to make it to the ground helping temperatures be slightly warmer than what we saw yesterday. Isentropic lift will begin to strengthen tonight into tomorrow morning ahead of an approaching cold front.
314 AM EST Fri Nov 29 2019 Broad upper level ridging extends from the Gulf of Mexico northward through the Ohio River Valley and into Ontario Canada.
After a dry, but kind of cloudy Friday, the low will move over the Plains Saturday. We should see snow develop along the warm front ahead of the low. There will be a transition of mixed freezing rain and sleet before a change over to rain occurs. Light rain will continue Saturday night south of I-96 and mixed rain/snow north of there as the low moves closer.
Water vapor imagery still shows a large upper low along the west coast with broad southwest flow aloft bringing Pacific moisture into the plains and central U.
A broad upper low centered near Reno NV will work northeastward overnight with light snow developing in advance of the low. In the Snake Plain areas east of Mountain Home will see the highest totals, though will have to watch for accumulation from the wrap around snow Friday afternoon in the lower Treasure Valley.
934 PM CST Thu Nov 28 2019 The upper level disturbance that has produced steady light rain across NE AR, the MO Bootheel and NW TN is weakening as it pushes into the broad upper ridge extending from the Gulf into the Great Lakes.
High pressure to encompass much of the eastern CONUS with precip chances remaining absent from the forecast. High pressure in control with VFR conds. High pressure building into the area after yesterday's weak front.
The dryline/Pacific front will push through early Saturday, ending any lingering precipitation and ushering in minimum RH values as low as the low to mid 30s across central KS by Saturday afternoon. Winds will also strengthen as the upper low currently over the western CONUS pushes north of the forecast area, bringing the strong upper jet directly over the area.
/issued 334 AM CST Fri Nov 29 2019/ SHORT TERM (Now through Saturday): KBRO Doppler radar currently shows patches of light rain and drizzle over the lower Texas coastal waters and the immediate three coastal counties. The proximity of a stationary front along the Lower Texas Coast will produce additional isolated convection over Deep South Texas and the Rio Grande Valley today. Tonight and Saturday, dry weather will become established and prevail as the stationary front dissipates and mid-level high pressure becomes more prominent over the BRO CWFA.
For today expect light precipitation at times, with a mix between freezing drizzle and light snow.
An impressively deep upper level low (5250m at 500mb) will lift into the eastern Nebraska by midday Saturday. For the Midsouth, the main impact will be a marginal risk of severe storms south and west of Memphis, along and just ahead of a surface cold front Saturday afternoon and evening. Best chances for surface-based convection is expected near a marine warm front, extending from southern AR into central MS Saturday afternoon. The midlevel dry slot will sweep through the Midsouth Saturday night, abruptly ending rain chances behind the cold front.
/issued 314 AM EST Fri Nov 29 2019/ Broad upper level ridging extends from the Gulf of Mexico northward through the Ohio River Valley and into Ontario Canada.
We've opted favoring slightly cooler guidance for the center and eastern parts of our area more deeply entrenched in the cool, damp airmass with our forecast highs mainly lower to middle 50s. While on the western and southern fringes there should be a better chance for mixing and drying a bit later today enough to warm perhaps even into the lower to middle 60s. Saturday will see much more veered west-northwesterly flow as a deep low pressure system steers fairly far north through the central plains but strong layered flow passes overhead. Temperatures will be a bit below normal with passage of a Pacific Cold Front early in the day so a windy and brisk day looks on the way.
403 AM CST Fri Nov 29 2019 Another quiet weather day is in store for the forecast area today with ridging aloft and high pressure at the surface prevailing across the eastern conus. This ridge will shift to the east on Saturday as a deep mid/upper level low pressure system moves out of the western U.
726 AM EST Fri Nov 29 2019 High pressure will prevail with dry weather through Saturday.
SHORT TERM (Now through Saturday): KBRO Doppler radar currently shows patches of light rain and drizzle over the lower Texas coastal waters and the immediate three coastal counties. The proximity of a stationary front along the Lower Texas Coast will produce additional isolated convection over Deep South Texas and the Rio Grande Valley today. Tonight and Saturday, dry weather will become established and prevail as the stationary front dissipates and mid-level high pressure becomes more prominent over the BRO CWFA.
617 AM EST Fri Nov 29 2019 High pressure will prevail with dry weather through Saturday.
Upper air analysis last evening showed a deep trough along the west coast with southwesterly flow over Texas. At the surface, the low pressure center has moved onshore near Palacios with a warm front extending to the east and a cold front to the south. Our CWA, on the western side of the low, has winds from the north through northeast. The upper level flow will remain southwesterly as the trough begins to move toward the east today and tonight. At the same time the warm front will move farther inland and bring southeasterly surface winds to our CWA. Isentropic lift across the warm front will bring chances for rain, mainly across the eastern half of the area, today.
Late Friday night a front will approach the area, shifting winds to the west and beginning to clear out the low ceilings. This will also keep effective boundary (warm front) to our south through much of the day, limiting convection as instability will struggle to develop northward. Main upper trough begins to shift east/northeast out of the southern Rockies late today into tonight.
Snow will taper to flurries this afternoon as the upper low weakens over our area. The low is still forecast to split this evening with the main part going into Wyoming and the weaker part going back into the Pacific where it will join up with another low already in the Pacific.
Poor flight conditions can be expected thru much if not all of the forecast period due to a saturated boundary layer ahead of a cold front. These conditions will continue through mid-morning with chances of showers and thunderstorms increasing by late morning and continuing through Saturday morning as isentropic lift increases in advance of a cold front that is slated to move through the region late Tonight into Saturday morning. There is the potential that some of the thunderstorms that develop in the vicinity of the cold front could become strong to marginally severe with hail the main concern. However, temperatures are expected to slowly rise Tonight in advance of the Saturday cold front with high temperatures on Saturday expected to be above normal for this time of year.
Upper ridging at the surface and aloft will continue to prevail across the area today. The ridge will begin to shift to the east tonight as a strong storm system deepens over the plains.
As low pressure rapidly deepens over eastern Colorado and lifts northeastward into Nebraska, a surge of WAA precip will arrive across central Illinois tonight. Showers and a few thunderstorms will continue on Saturday as a warm front lifts northward through central Illinois.
427 AM CST Fri Nov 29 2019 (Today and Tonight) Warm front still south of the area early this morning and leaving West Central Texas in cool conditions with widespread fog and drizzle. This looks like it will be the main area of rain for the day so will keep the highest POPs across the eastern half of the area. Even the NAM, which has handled the warm front better than the other models, eventually lifts the warm front into the central portions of the area by noon and into the northern Big Country by sunset. Will follow this general idea and allow warmer temperatures to spread north during the day. Main upper level trough passes tonight. Overnight lows in the 50s for most areas, although a little warmer east where the increased low level moisture will keep readings warmer.
These increasing clouds are due to the large low pressure system lifting and moving off to the east today. The path of the low will bring wrap around precipitation to portions of the Northern Rockies. The current forecasted path of the low will cause upslope flow across portions of north central Idaho by this afternoon and evening. A low amplitude ridge of high pressure builds over the Northern Rockies. This ridge will bring a period of dry conditions to the region with the exception of a low probability of light snow on the eastern edge of Flathead Lake. This ridge will keep cold air locked in the valleys, so temperature readings will remain well below normal for this time of year.
Widespread low stratus located across the forecast area, with some areas of fog/freezing drizzle. Lack of mid level seeding will be favorable for drizzle/freezing drizzle for much of today. Large scale ascent increases across the area this evening as upper low begins to close off over the Nebraska Panhandle.
815 AM EST Fri Nov 29 2019 Mainly dry but cloudy weather is expected through tonight under high pressure. Precipitation chances return with weekend low pressure. Some erosion of the lower clouds are expected by afternoon as high pressure builds across the region, though mid level clouds should quickly increase in warm advection aloft keeping skies mostly cloudy. Expect mainly rain for most areas S of Route 422 outside of the higher terrain. Areas near and N of Route 422, the Laurel Highlands, and the WV/MD ridges should see a period of freezing rain, though some snow is possible at the onset later Saturday and Saturday evening until the warm advection aloft intensifies as sfc temps stay near or below freezing. SE upslope flow in Garrett County MD should also keep temperatures near/below freezing, resulting in a more prolonged period of freezing rain.
517 AM EST Fri Nov 29 2019 Mainly dry but cloudy weather is expected through tonight under high pressure. Precipitation chances return with weekend low pressure. Some erosion of the lower clouds are expected by afternoon as high pressure builds across the region, though mid level clouds should quickly increase in warm advection aloft keeping skies mostly cloudy. Expect mainly rain for most areas S of Route 422 outside of the higher terrain. Areas near and N of Route 422, the Laurel Highlands, and the WV/MD ridges should see a period of freezing rain, though some snow is possible at the onset later Saturday and Saturday evening until the warm advection aloft intensifies as sfc temps stay near or below freezing. SE upslope flow in Garrett County MD should also keep temperatures near/below freezing, resulting in a more prolonged period of freezing rain.
1002 AM CST Fri Nov 29 2019 Boundary layer moisture convergence situated along the coastal counties in close proximity to the returning warm front has continued to produce scattered showers in a narrow band this morning. This band of showers is expected to slowly diminish by late morning/early afternoon as the warm front lifts north of the CWA and boundary layer convergence weakens. Likely less fog tonight due to the warmer temps and stronger gradient flow from the S/SE. SCEC conditions are expected to develop by the afternoon across most of the coastal waters as the gradient continues to tighten with the warm front lifting rapidly northward.
Expect some freezing drizzle and freezing fog to make for slick travel across the Yellowstone River Valley this evening before an eventual change over to all snow later tonight. Lows will range from possibly below zero west to the low teens east.
218 PM CST Fri Nov 29 2019 As expected, surface ridging held firm today with dense fog persisting until the early afternoon. However, winds will quickly turn to the southwest and then to the west early Saturday morning due to a Pacific cold front moving through the region. The upper level trough axis will pass overhead during the day on Saturday which will bring strong subsidence to the region. The aforementioned Pacific cold front may keep us from mixing up to 700mb but winds between 800 and 750mb are still around 50kt.
An upper level ridge remains over the Midwest, Mississippi Valley, and Ohio Valley early this morning, but the core of the upper anticyclone is centered over the Gulf of Mexico. Upstream, a deep upper low is spinning over CA/NV. Abundant mid-level moisture continues to stream over the ridge, resulting in a cloudy forecast today. Highs are expected to be in the low to mid 40s in the north and mid to upper 40s in southern KY. Numerous light to moderate showers are expected to spread east into the area north of the sfc warm front.
250 PM CST Fri Nov 29 2019 High pressure will continue to move east of the area. We will see a warm front develop to our south, and move into the area late tonight.
Surface pressure falls to our northwest will induce a warm front to progress northward into TN Saturday morning.
The lowest visibilities around 1/2 mile currently extend from Hebbronville to Alice just ahead of the primary surge of dewpoints that have since risen to as high as 75 degrees at Corpus Christi.
Temperatures are in the lower 80s in most island communities with dewpoints recovering into the middle to upper 60s, so at least it still feels more autumnal for the Florida Keys.
1036 AM PST Fri Nov 29 2019 Much cooler temperatures and dry weather will be in place through Saturday.
1207 PM EST Fri Nov 29 2019 The very deep longwave trough along the West Coast and south into Baja will fill and rotate eastward as a series of new troughs dig into the West Coast. This will create a more zonal flow across the CONUS and break down the ridge over the Gulf of Mexico or at least push it South into the Caribbean. This pattern shift will usher in a little cooler air but nothing too cold.
227 PM CST Fri Nov 29 2019 Wet and cloudy conditions will persist through Saturday morning as a low pressure system deepening over the eastern Rockies and central high Plains moves into our region. At the surface a warm front will advance northward from eastern Oklahoma into the MO Ozarks during the overnight hours, raising temperatures and dewpoints into the 50s. Rain should end during the mid to late morning hours on Saturday as the cold front moves across the region.
Cold front coming in Saturday early afternoon near CLL and IAH/HOU area 23z-ish.
Areas of MVFR and IFR/LIFR in snow and freezing fog. Winds aloft at 10k ft MSL: variable 10-20 kts around the low pressure system, becoming NW 15-25 kts after 30/00z.
Looks like upper ridge will tend to keep KCHA drier as precip stays mainly north during this period.
243 PM EST Fri Nov 29 2019 Mainly dry but cloudy weather is expected before precipitation chances return with weekend low pressure. Dry conditions will be maintained the remainder of the afternoon and overnight as ridging transitions across the region. During the evening areas near and N of Route 422, the Laurel Highlands, and the WV/MD ridges should see a changeover to freezing rain as surface temperatures drop to and slightly below freezing.
112 PM EST Fri Nov 29 2019 High pressure will prevail with dry weather through Saturday.
A low pressure system will move through the region tonight.
No rain is expected in the near term thanks to persistent ridging aloft.
Given the cooler model solutions today, have backed off some on temperatures through Saturday.
The warm front is still slowly moving further inland from the Coastal Plains. With warm air advection behind the warm front, paired with overcast skies, overnight temperatures will increase slightly before staying almost constant overnight. Tomorrow will be quiet warm as we heat up before the next cold front has a chance to clear everything out Saturday afternoon.
945 AM PST Fri Nov 29 2019 Much cooler temperatures and dry weather will be in place through Saturday.