Aikyam-Lab/Synoptic-Bench huggingface dataset:
1229 AM EST Thu Nov 28 2019 Issued at 648M EST Wed Nov 27 2019 The high winds will gradually diminish by daybreak as a deep low pressure over Lake Huron lifts northeast into Ontario.
A dry cold front will continue to pass south of the area this morning. The fog and low stratus will move south of these areas as the cold front pushes southward with light WSW winds shifting to the NNW later this morning after sunrise. Clearing skies and cooler high temperatures with lower humidity values are expected as high pressure builds in from the NW. Winds will remain light from the north and veer to the NE overnight as high pressure moves north of the area over the southern Appalachian mountains.
228 AM EST Thu Nov 28 2019 A weak cold front extends southwest from an area of low pressure over the New England states.
Surface analysis depicts a weak high pressure ridge extending from the western Atlantic across South Florida into the eastern Gulf of Mexico. A cold front lies along the Eastern Seaboard and northern Gulf coast, with a large continental high pressure building into the Plains states behind the front. Aloft, a strong deep layered ridge is centered over the southeastern Gulf, and continues to dominate our local weather. The 00Z Key West sounding clearly shows the suppressing influence of this ridge, with a strong inversion based at 5000 feet and a very dry airmass above, with PW of only 0. Overnight, expect mostly clear skies to continue, with the strong ridge aloft and resulting low inversion preventing even isolated showers from developing. Temperatures appear to be on track to reach the lower 70s by morning.
Weak ridging and subsidence has helped to clear out the mid and high level clouds but a moist onshore flow continues to bring widespread low clouds to the UP. Upper air pattern consists of a 500 mb ridge across the central U. with a deep trough in the wrn U. This trough moves northeast into the northern plains 12z Sat and into the upper Great Lakes region Sat night. In the extended, GFS and ECMWF show a closed 500 mb low and trough over the upper Great Lakes 12z Sun that moves into the lower Great Lakes 12z Mon. Ridging then back in for Thu.
Snow has turned into rain/freezing rain across these areas and is evident by winds turning calm at many mesonets.
401 AM CST Thu Nov 28 2019 Today into Friday: A large upper low pressure system over the western U. This should produce widespread, albeit fairly light, precipitation across the area with freezing drizzle possible Thursday night/Friday morning before temperatures warm and turn all precipitation over to rain.
Upper ridging at the surface and aloft will prevail across the area today.
823 AM EST Thu Nov 28 2019 Rain and snow showers should end this morning with the passage of a low pressure trough.
Meanwhile, southerly flow will be increasing above the surface pushing moisture over the warm front and into the forecast area.
Due to this increased moisture, there will also be the potential for patchy fog and/or drizzle across the area as the low levels become saturated.
09Z surface analysis places a ridge of high pressure from Manitoba south through the Lower Mississippi Valley. GOES-16 satellite trends indicate a deep upper level trough over the West Coast of the United States and a warm conveyor belt of moisture and southwest flow aloft across the Southern Plains and western sections of the Lower Mississippi Valley.
325 AM CST Thu Nov 28 2019 Cooler and dry weather is on tap for Thanksgiving Day with mostly to partly cloudy skies prevailing. Temperatures will begin to rebound on Friday as ridging aloft builds over the eastern U.
Today into Friday: A large upper low pressure system over the western U. This should produce widespread, albeit fairly light, precipitation across the area with freezing drizzle possible Thursday night/Friday morning before temperatures warm and turn all precipitation over to rain.
547 AM CST Thu Nov 28 2019 Current area of synoptic scale lift spreading light rain and freezing rain across the area should pass mostly east by mid or late morning. Afterwards, a very moist low level atmosphere will remain with solutions pointing toward possibility of either LIFR or very low IFR ceilings and perhaps areas of fog holding into the afternoon and overnight though surface temperatures lifting above freezing at all locations. Also did not yet add a mention of possible shower or even thunder chances for early Friday morning, but solutions seem trending that way as the next and perhaps final portion of lift from this upper trough crosses the area. Snow has turned into rain/freezing rain across these areas and is evident by winds turning calm at many mesonets.
A weak disturbance associated with the upper level trough will enhance the snow over Lemhi county and southwest Montana later this morning. Then the upper level low begins to lift and move eastward on Friday.
Upper air analysis last evening showed a deep trough over the western third of the country with southwesterly flow over Texas. At the surface, there was low pressure centered along the Deep South Texas coast with frontal boundaries extending to the east and south. Temperatures were around 15 degrees cooler and dewpoints were 10 to 30 degrees cooler than 24 hours ago. The upper trough will slowly move to the east during this period and the flow will remain southwesterly. The low level flow will turn easterly today and then southeasterly by Friday.
Looking at the satellite images it does not look likely that the low cloud deck will clear out before sunrise to allow temperatures to drop more than 2 to 4 degrees from the current temperatures. The latest MOS guidance is indicating just this and will leave the high temperatures in roughly the same range that they were indicating previously with this in mind. Thursday into Friday morning an upper low swings up from Southern California into north central Nevada bring some light warp around showers that will brush Lake and Modoc counties.
506 AM CST Thu Nov 28 2019 Large synoptic low pressure system was located along the California coast with deep southwesterly flow ahead of the low across the plains and Mississippi valley region. Good southerly flow in the lower levels bringing moisture back into the region. Some area that drop below freezing at the surface may see some light freezing rain, but with rising temperatures above freezing by the late morning and for the remainder of the day, it should not create any major issues. The upper low will begin to shift eastward into the Rockies on Friday with a strong southerly low level jet setting up over the plains during the day.
547 AM EST Thu Nov 28 2019 Rain and snow showers should end this morning with the passage of a low pressure trough.
Only a few mesonet station have wet-bulb temperatures at or below freezing, so freezing rain chances will continue to dwindle through the early morning. On Friday, a negatively tilted trough will lift across the southern and central Rockies and then the central and northern Plains.
As the precipitation continues and saturates the lower atmosphere, visibility and ceiling conditions are expected to worsen, with widespread IFR conditions expected through the morning and widespread LIFR ceilings in the late afternoon and early evening. Only a few mesonet station have wet-bulb temperatures at or below freezing, so freezing rain chances will continue to dwindle through the early morning. On Friday, a negatively tilted trough will lift across the southern and central Rockies and then the central and northern Plains.
Deeper low level moisture will begin to surge north into far southeast Oklahoma by Friday evening as strong upper jet streak lifts into the Central Plains in association with larger scale upper low moving over the Intermountain West. Models have trended a little slower with cold front, which should allow limited/moderate elevated instability to develop Friday evening into the overnight hours across eastern Oklahoma. If warm front can lift north into far southeast Oklahoma, could see a brief window for a slightly enhanced severe weather threat.
A weak low pressure system located along the coast will maintain overcast skies through much of the forecast period with ceilings improving to MVFR this morning and afternoon. /issued 422 AM CST Thu Nov 28 2019/ SHORT TERM (Now through Friday): A weak area of low pressure along the lower Texas coast has helped keep us socked in with overcast skies overnight. So, have maintained highs in the mid 70s today, but some areas could end up being a few degrees warmer if we see any break in clouds. Temperatures will also quickly warm back up into the lower 80s.
Early this morning, a stratus deck had settled into the area as high pressure built into the area. This high pressure will lead to quiet weather for Thanksgiving. Any precip that does fall will be facing rather dry conditions in the low levels.
SHORT TERM (Now through Friday): A weak area of low pressure along the lower Texas coast has helped keep us socked in with overcast skies overnight. So, have maintained highs in the mid 70s today, but some areas could end up being a few degrees warmer if we see any break in clouds. Temperatures will also quickly warm back up into the lower 80s.
High pressure builds in during today then slides east with winds veering and diminishing.
Lows generally in the M50s, though normally cooler locations may realize L50s or even U40s in a few spots. NW/N winds 14-17 kts, opposing the warmer Gulf Stream, over the open Atlc with some higher gusts as the pgrad tightens.
Steadily increasing moisture, instability, and deep-layer shear will bring better support for tstms Friday night across our far nwrn areas, as the cold front approaches.
320 AM PST Thu Nov 28 2019 A cold storm system will bring snow to the higher terrain and rain showers in the lowest elevations through Friday.
210 PM CST Thu Nov 28 2019 Increasing clouds tonight, but high pressure over the Tennessee Valley means no precipitation. High pressure over the Tennessee Valley holds through Friday, but a dynamic low pressure system starts to eject out of the Rockies and move into the Central Plains.
208 PM EST Thu Nov 28 2019 High pressure into Friday.
/EC/ An anomalously strong upper level anticyclone over the Gulf of Mexico is ensuring a dry Thanksgiving Day for the ArkLaMiss, but west-southwest flow aloft is helping to increase mid level cloudiness, and this combined with northeasterly surface flow will make keep temperatures from climbing much as we go into the afternoon.
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.
Current temperatures range from the lower to mid 40s and with lower values in northeast Arkansas and northern Tennessee. 09Z surface analysis places a ridge of high pressure from Manitoba south through the Lower Mississippi Valley. GOES-16 satellite trends indicate a deep upper level trough over the West Coast of the United States and a warm conveyor belt of moisture and southwest flow aloft across the Southern Plains and western sections of the Lower Mississippi Valley.
1221 PM EST Thu Nov 28 2019 High pressure will bring VFR conditions at KCHA, KTYS, and KTRI for the next 24 hours.
Freezing drizzle is possible across portions of far northwestern and northern Missouri after 7 PM through Midnight.
A few patchy areas of freezing drizzle may still be possible over the next hour or so. Snow has turned into rain/freezing rain across these areas and is evident by winds turning calm at many mesonets.
An anomalously strong upper level anticyclone over the Gulf of Mexico is ensuring a dry Thanksgiving Day for the ArkLaMiss, but west-southwest flow aloft is helping to increase mid level cloudiness, and this combined with northeasterly surface flow will make keep temperatures from climbing much as we go into the afternoon.
A large upper low extends across most of the far western U. Southerly flow ahead of the low, centered in northern California, will send moisture and weak upper disturbances to support snow showers today. Mostly VFR with areas of local IFR/LIFR in freezing fog and snow showers across higher elevations.
239 PM CST Thu Nov 28 2019 (Tonight and Friday) Warm front will continue to move through tonight and Friday morning. Fog and drizzle should end mid to late Friday morning as lee trough brings breezy south winds to the region.
Pops will remain on the low side, however. Then, another chance of some shower activity will begin on Friday afternoon as a warm front lifts across the area.
High pressure will continue to build into the area along with mostly clear skies through Friday. Temperatures will be cooler tonight with lows in the mid 40s inland to the lower 50s coast. Temperatures on Friday will also be a little cooler than today as winds veer to the northeast.
Dew points are in the lower to mid 30s to our south, so think this moisture will get advected this way and it will help with fog formation and possibly drizzle. Temperatures should stay around or above freezing in all areas tonight, so will go with all liquid on the drizzle. The GFS wants to clear the clouds out and is more aggressive with bringing in some showers to the area as the lower levels become more unstable due to the added sunshine. The NAM is not as agressive with the precipitation as it keeps the low clouds in most of the day. The models do agree that an upper level short wave trough will graze our northwest CWA during the afternoon, so this may provide enough lift for a shower or thunderstorm whether it stays cloudy or it clears out.
High pressure and dry air at lower levels will prohibit any precipitation with these clouds. An increase in cloud cover tonight will help keep overnight temperatures in the lower 40s, which is several degrees warmer than the previous night. Winds Friday night shift to the southeast ahead of the advancing cold front.
257 PM EST Thu Nov 28 2019 High pressure continues to control the weather over the area through tomorrow. Temperatures are seasonable, to perhaps a little above during the day, to near normal at night, perhaps a tad cooler in some locations. An area of high pressure will dominate the weather pattern throughout the upcoming weekend. Winds throughout the weekend will veer from easterly to more southerly then southwesterly component ahead of an approaching cold front.
A high amplitude trough over the Pacific Coast, will maintain a damp forecast through Friday night.
High pressure at the surface will bring pleasant weather conditions for the rest of today. Chattanooga Airport, TN 56 41 60 45 / 0 0 0 20 Knoxville McGhee Tyson Airport, TN 51 37 56 44 / 0 0 10 40 Oak Ridge, TN 52 37 56 42 / 0 0 10 40 Tri Cities Airport, TN 48 32 54 39 / 0 10 10 40.
1026 AM EST Thu Nov 28 2019 Currently - A ridge axis arcing south and southeastward across the United States is responsible for gentle to moderate breezes across the Keys. Deep layered ridging prevails and is responsible for a hefty subsidence inversion based around 925 mb. Short Term Update - Ridging will continue to dominate the area this afternoon. The combination of the east northeast flow to our east and backed north to northeast flow over warm waters upstream of the western islands should be sufficient to get temperatures into the lower 80s. Weak ridging across the area will result in winds being light to gentle out of the northeast.
104 PM EST Thu Nov 28 2019 High pressure prevails into Friday.
1233 PM EST Thu Nov 28 2019 High pressure continues to control the weather over the area through tomorrow. Temperatures are seasonable, to perhaps a little above during the day, to near normal at night, perhaps a tad cooler in some locations. High pressure over the area should keep the weather quiet through the weekend. Then a cold front is forecast to move through the area by the beginning of the week, bringing the next chance for any shower activity. However, a low pressure system off the New England coast should eventually send a northeast swell to the area, which may bring hazardous marine conditions to the Atlantic waters over the weekend. High pressure is set to control the weather through the TAF period with mostly clear skies and quiet weather.
A modest increase in upper level moisture and lift could provide isolated to scattered shower chances late tonight into Friday as the large western upper low begins its eastward journey. Southerly to southwesterly flow aloft will intensify with the approach of the system, though exactly how fast this can translate to the surface (and dislodge the cool, moist surface ridging) remains in question.
As the ridge shifts farther east across the central sections of the country the flow will shift more east and southeast today and Friday, but no significant weather is expected through tomorrow. Meanwhile, southerly flow will be increasing above the surface pushing moisture over the warm front and into the forecast area.
200 PM CST Thu Nov 28 2019 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.
Lows tonight will drop into the lower 30s, with highs on Friday near 40 degrees.
235 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.
433 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.
/issued 257 PM EST Thu Nov 28 2019/ High pressure continues to control the weather over the area through tomorrow. Temperatures are seasonable, to perhaps a little above during the day, to near normal at night, perhaps a tad cooler in some locations. An area of high pressure will dominate the weather pattern throughout the upcoming weekend. Winds throughout the weekend will veer from easterly to more southerly then southwesterly component ahead of an approaching cold front.
10", but could see a bit more ice accumulation across southwest Minnesota where temperatures will take the longest to warm and cold air becomes trapped on the east side of the Buffalo Ridge. Will need to keep a close eye on how quickly locations on the east side of the Buffalo Ridge warm. Strong area of low pressure moves into the western plains on Friday, and slowly shifts east through the weekend.
Only expect some passing high cirrus tonight spilling over an upper ridge across the southern GOMEX. Lows temperatures will range from the lower 40s across SE GA and the Suwannee River Valley tonight to the low/mid 50s toward the FL Atlantic coast where NNE flow will advect warmer temps. NNW winds 10-15 kts will increase over the outer waters tonight to 15-20 kts (Small Craft Exercise Caution criteria) as a wake trough slides offshore of South Carolina with a brief tightening of the local pressure gradient over the local waters. High pressure will continue to build into the area along with mostly clear skies through Friday. Temperatures will be cooler tonight with lows in the mid 40s inland to the lower 50s coast. Temperatures on Friday will also be a little cooler than today as winds veer to the northeast.
652 PM EST Thu Nov 28 2019 High pressure will build into the region for Friday.
With high pressure in place, dry weather is expected through the night and into the early morning hours for those wanting to venture out and enjoy some shopping. Temperatures will fall into the lower 40s across the east to the upper 40s in the west. /28/ Prior discussion below: Tonight through Friday: Thinking is unchanged for the near term as an anomalous ridge axis (+2 to 3 SD) centered over the ArkLaMiss region is expected to keep the area rain free while a shallow continental airmass maintains seasonable temperatures. West- southwest flow around the low/mid level anticyclone is sufficient for some increase in cloud cover, but deeper moisture transport and precipitation remain well northwest of the forecast area.
Elsewhere, cloud cover and a southeast wind will keep temperatures cooler during Thanksgiving dinner time. A high amplitude trof that is now over the Western CONUS will move closer to the region tomorrow.
A warm front is expected to lift north over Arkansas on Friday bringing more sustained rain and drizzle from central to north Arkansas for much of the day on Friday.
333 PM CST Thu Nov 28 2019 Tonight through Friday: Thinking is unchanged for the near term as an anomalous ridge axis (+2 to 3 SD) centered over the ArkLaMiss region is expected to keep the area rain free while a shallow continental airmass maintains seasonable temperatures. West- southwest flow around the low/mid level anticyclone is sufficient for some increase in cloud cover, but deeper moisture transport and precipitation remain well northwest of the forecast area.
/issued 239 PM CST Thu Nov 28 2019/ (Tonight and Friday) Warm front will continue to move through tonight and Friday morning. Fog and drizzle should end mid to late Friday morning as lee trough brings breezy south winds to the region.
445 PM CST Thu Nov 28 2019 Several NDDOT webcams across western North Dakota show glazes of ice on the lenses from freezing drizzle. With the overall low level thermodynamic, moisture and lift profiles not expected to change much tonight and Friday before the snow arrives, issued a Winter Weather Advisory for the freezing drizzle threat. We still anticipate a period of light freezing drizzle tonight and Friday, with accumulations amounting to a light glaze.
Overnight temps will be a tad cooler than last night, in the mid to upper 50s, except near 60 degrees along the barrier islands. A dry cold front has pushed through the local waters and winds behind it have increased to around 20 knots, mostly in the offshore waters.
High pressure at the surface is moving across the eastern third of the country while a weakening frontal boundary has stalled across the northern gulf. The front trails back into a weak area of low pressure along the central Texas coast. A few light showers are associated with the area of low pressure near and west of the Houston Metro. Aloft a strong upper level disturbance is moving across the western sections of the country while a ridge is centered near the FL Keys. Tonight and Friday the upper trough over the west will continue toward the plains.
Increasing clouds tonight, but high pressure over the Tennessee Valley means no precipitation. High pressure over the Tennessee Valley holds through Friday, but a dynamic low pressure system starts to eject out of the Rockies and move into the Central Plains.
We still anticipate a period of light freezing drizzle tonight and Friday, with accumulations amounting to a light glaze.
/28/ Tonight through Friday: Thinking is unchanged for the near term as an anomalous ridge axis (+2 to 3 SD) centered over the ArkLaMiss region is expected to keep the area rain free while a shallow continental airmass maintains seasonable temperatures. West- southwest flow around the low/mid level anticyclone is sufficient for some increase in cloud cover, but deeper moisture transport and precipitation remain well northwest of the forecast area.
Chattanooga Airport, TN 42 58 46 64 / 10 0 10 60 Knoxville McGhee Tyson Airport, TN 39 55 44 61 / 10 0 30 70 Oak Ridge, TN 38 55 43 59 / 10 10 30 80 Tri Cities Airport, TN 32 54 39 55 / 10 0 40 80.
The highest snowfall amount that we have heard about was near 5 inches west of Anaconda and also 8 miles south of Butte.