Aikyam-Lab/Synoptic-Bench huggingface dataset:
458 AM CDT Wed Oct 30 2019 Current surface analysis shows a cold front across west Tennessee to south central Arkansas. By this afternoon, a brief lull will occur as a longwave trough moves eastward from the central Plains. By Thursday night as the upper trough moves through the area a much cooler airmass will follow.
Cold temperatures to start the morning as a behind a cold front that moved through the area in the overnight hours. Surface observations from across the area shows that the cold front has moved through northern Arizona overnight. This will be most notable in the high elevation basins north of the Mogollon Rim. Despite the cold start to the day Thursday, temperatures will begin to rebound back towards normal values as the airmass begins to moderate out under the influence of a large scale ridge that is beginning to build into the region.
453 AM CDT Wed Oct 30 2019 Today through tonight - Current analyses show very rich moisture influx into central MS with 40kt of flow through 340+ H850 theta-e ridge feeding current heavy rain complex along/north of the I-20 corridor. This current focus for lift will shift eastward through the morning and there should be a relatively lull before the cold front pushes east across the area tonight. Additional rainfall associated with the cold frontal passage should generally range from a half to one inch on average with locally heavier amounts - will hold off on any mention of heavy rain in the HWO graphics.
Upper level trough axis extended from Hudson Bay to UT. A north- south upper level jet was on the west side of the trough. Upper level trough will shift east of the area Wed night. Upper level ridge over southwest Canada and the Pacific Northwest will move over the area Wed night.
Today, the base of the upper trough is forecast to track from Colorado into central Kansas. For Thursday night, increasing clouds across the northwest in the evening as a cold front moves in. An upper trough behind the cold front will move across the Northern Plains.
A weather systems passing north of the area will bring cooler than normal temperatures much of this week.
Otherwise surface dew points across much of Lower Michigan are in the lower to mid 30s and upstream obs suggest there is not much evaporative cooling potential as wet bulb temperatures range from about 36 to 40F which is resulting in rain there. No accums expected on roads except perhaps the high ground of Osceola County but even there it looks marginal.
Water vapor imagery and upper level analysis show a positively tilted longwave trough located from Hudson Bay to the Four Corners region, placing the trough axis through North Dakota from northeast to southwest. At the surface, high pressure was analyzed over northern Wyoming. The upper level trough will slowly progress eastward through the day, with upper level ridging building over the Northern Rockies and associated low level warm air advection commencing downstream into the western Dakotas. This, along with clearing skies will give us slightly warmer temperatures this afternoon, but still well below late October normals. Upper level ridging will nudge into the Northern Plains tonight, with low level warm air advection continuing.
Temperatures are below freezing at KHOB where light icing is possible; all other terminals should remain above freezing. Northeast winds will increase later this morning behind a cold front. /issued 402 AM CDT Wed Oct 30 2019/ An upper trough extends from the Northern Plains/Upper Midwest to Arizona and New Mexico. Another cold front has moved into the area with temperatures at or below freezing across Lea County and the northern Permian Basin. Drizzle is also falling across the area associated with lift from the upper trough. A Winter Weather Advisory is in effect through mid morning for the northern Permian Basin and portions of Lea County where the freezing temperatures and drizzle have combined. The upper trough will move eastward on Thursday with temperatures mostly in the 50s across the CWA.
near zero north of Pierce while across the Camas Prairie, temperatures are in the lower to middle teens. Though we expect some moderation of temperatures today and Thursday, there is a good possibility that highs may continue to struggle because of strong high pressure in place. We have better confidence that the higher elevations, especially along the Continental Divide will see light snow.
508 AM MDT Wed Oct 30 2019 Slow-moving upper trough persists across the central and western CONUS. Temperatures will be slightly warmer than yesterday's, with highs in the mid 20s to mid 30s, and lows 5 to 15 degrees above zero. Northwest flow develops behind the trough, and weak, short-lived ridging will result in a comparatively mild day for Halloween: highs will warm into the 40s. However, a fast-moving wave and its cold front will slide into the region Thursday night, bringing some light snow and breezy winds, mainly after midnight.
333 AM MDT Wed Oct 30 2019 Following a cold start this morning across NE Montana, look for temperature recoveries by this afternoon with many locations expected to see highs approaching or exceeding the freezing mark. A quick moving ridge will also bring lighter winds to the area and dry weather conditions extending through tonight.
An unseasonably cold airmass resides across the forecast area this morning, in the wake of a departing upper low currently spinning across the central Rockies.
402 AM CDT Wed Oct 30 2019 An upper trough extends from the Northern Plains/Upper Midwest to Arizona and New Mexico. Another cold front has moved into the area with temperatures at or below freezing across Lea County and the northern Permian Basin. Drizzle is also falling across the area associated with lift from the upper trough. A Winter Weather Advisory is in effect through mid morning for the northern Permian Basin and portions of Lea County where the freezing temperatures and drizzle have combined. The upper trough will move eastward on Thursday with temperatures mostly in the 50s across the CWA.
Southwest flow ahead of the low was sending scattered-broken deck of mid-cloud/altocumulus over our area. At the surface, a west to east ridge of high pressure was in place from near the SD/NE border into WI. For today, relatively quite conditions with increasing clouds ahead of that low which will be edging out into the high Central Plains. The mid-level low and associated precipitation shifts east of the area by Thursday afternoon with ridging building in from the Plains. Thursday night starts off mostly clear with increasing clouds overnight ahead of a cold front dropping through the Dakotas/MN.
619 AM CDT Wed Oct 30 2019 With high pressure at the sfc, dry conditions are expected through Thursday afternoon. The upper trough will slide east today leaving the region in northwest flow aloft on Thursday. Under the trough, highs will remain well below normal today, by about 15 to 20 degrees. Daytime Thursday will bring somewhat warmer highs, mainly in the lower 40s.
Temperatures will continue to run a few to several degrees below climo for the next couple of days as a result of the passing trough. Thursday morning will bring the coldest temperatures across the area, and the strong cold high pressure will produce lows below 28 degrees in much of the Kern County desert areas. As the trough pulls away to the east, high pressure will build along the west coast.
/issued 458 AM CDT Wed Oct 30 2019/ Current surface analysis shows a cold front across west Tennessee to south central Arkansas. By this afternoon, a brief lull will occur as a longwave trough moves eastward from the central Plains. By Thursday night as the upper trough moves through the area a much cooler airmass will follow.
604 AM CDT Wed Oct 30 2019 Upper level trough axis shifts eastward today with a stretched out vort lobe moving by to our south. Temperatures above the surface 2-3 SD below climatology will keep temperatures near or just a tad above the freezing mark today. While afternoon temperatures may rise into the upper 30s to lower 40s, evening temperatures will fall back into the lower 30s and 20s once the sun goes down.
Latest model data does lean toward some thermal ridging across eastern areas.
Areas that are snow free will stay a few degrees warmer, but still cold in the lower to mid teens.
There will be a break for a few hours this afternoon before the next round starts to develop ahead of the approaching cold front. /issued 458 AM CDT Wed Oct 30 2019/ Current surface analysis shows a cold front across west Tennessee to south central Arkansas. By this afternoon, a brief lull will occur as a longwave trough moves eastward from the central Plains. By Thursday night as the upper trough moves through the area a much cooler airmass will follow.
Cold front beings to push in early tomorrow morning. A narrow band of storms ahead of it is expected and once the cold front moves through winds will rapidly veer around to the northwest and increase in speed.
Chattanooga Airport, TN 72 67 70 33 / 100 70 90 10 Knoxville McGhee Tyson Airport, TN 69 65 71 34 / 100 70 90 20 Oak Ridge, TN 67 65 71 33 / 100 80 90 20 Tri Cities Airport, TN 69 62 74 33 / 100 80 100 50.
High pressure with a very dry and cool post Arctic Front air mass continues over the area.
Breezy northerly winds behind a cold front will decrease as the day goes on.
Highs today are struggling to reach the freezing mark. By trick-or-treat time, we'll see temperatures falling back towards the lower 30s. Light winds will make the wind chill fall below freezing however.
301 PM CDT Wed Oct 30 2019 Low clouds and occasional flurries are slow to leave the forecast area this afternoon as the trough axis is moving east slower than any model run had yesterday afternoon. Halloween looks to see temperatures warm into the 50s for the afternoon, fall to around 50 at sunset, and then by 10 pm range from near freezing along the TX/NM state line to the mid to upper 30s for the rest of the forecast area.
Around sunrise, temps will start out in the mid 40s far northwest, to the lower to mid 60s Plateau. Making it feel even colder will be the wind chills which will be close to freezing at that time.
248 PM CDT Wed Oct 30 2019 The deep upper trough that has brought very cold temperatures and wintry precipitation to the area over the past few days will begin to move out of the Plains states tonight. Continued cold advection on the backside of the trough will allow for very cold (near record) temperatures tonight, with values in the teens across northwest Oklahoma and twenties elsewhere.
An advancing cold front will produce vicitnity showers/thunderstorms at all terminals throughout the afternoon/evening.
Temperatures will continue to range between the low 40s and low 50s.
A weak short wave trough in the flow will send some clouds through Valley County, ID Thursday afternoon but the rest of our CWA will stay clear.
May be a little freezing drizzle across the far northwest zones late this afternoon as colder temperatures filter in, so will keep the mention of -FZDZ. Upper trough to clear the region overnight which will sweep the low level moisture to the east.
A stationary front is situated from Middle Tennessee through Northeast Mississippi into the Lower Mississippi Valley this afternoon. A potent upper trough is swinging into southern plains. More showers and a few thunderstorms are blossoming across Arkansas southwest into the ARLATEX ahead of a developing cold front. If any stronger convection develops as the cold front approaches then this area could see some surface based activity with a threat of damaging winds. Cold front will accelerate east overnight with brisk NW winds by morning. Temps will drop below freezing in most areas with some 20s across NE AR, West TN and the MO Bootheel.
Strong winds expected to develop over southern Platte county by late evening as the low level pressure gradient increases. This should continue through the day Thursday but warmer temps should help to reduce blowing snow as the day progresses. Warmer across the CWA Thursday but snow cover should retard the warming some.
300 PM MDT Wed Oct 30 2019 Snow ending across the plains this afternoon as upper low pulls away into the central plains, and will end snow chances at all locations with new forecast.
242 PM CDT Wed Oct 30 2019 The main concern will be light freezing drizzle and light snow potential tonight. Temperatures look to stay above freezing through the the evening traffic rush. Vertical moisture and temperature profiles in the low level cloud layer would indicate a mix of drizzle/freezing drizzle and light snow possible. All-in-all the fcst database has a light ice (freezing drizzle) accumulation as far south as the KSGF/western Ozarks Highlands area late this evening and into the early overnight hours just after midnight with a mix of light ice and snow accumulation over our northern counties.
As a result, light snow is likely over a much of Central MT, with the highest snow accumulations in the Little Belt Mountains and Big Snowy.
As upper low deepens and moves east snow will increase this afternoon through this evening. There will be a brief period of sleet this afternoon south of I-70, also a very brief period of freezing precipitation possible in same area this evening between 7 PM and midnight but do not expect any significant ice accumulations and impacts will be minimal. The main snow impacts will be to bridges and overpasses tonight, also with leaves on trees if enough snow accumulates there could be scattered areas of broken tree branches potentially causing power outages.
With high pressure at the sfc, dry conditions are expected through Thursday afternoon. The upper trough will slide east today leaving the region in northwest flow aloft on Thursday. Under the trough, highs will remain well below normal today, by about 15 to 20 degrees. Daytime Thursday will bring somewhat warmer highs, mainly in the lower 40s.
1124 AM MDT Wed Oct 30 2019 Slow-moving upper trough persists across the central and western CONUS. Temperatures will be slightly warmer than yesterday's, with highs in the mid 20s to mid 30s, and lows 5 to 15 degrees above zero. Northwest flow develops behind the trough, and weak, short-lived ridging will result in a comparatively mild day for Halloween: highs will warm into the 40s. However, a fast-moving wave and its cold front will slide into the region Thursday night, bringing some light snow and breezy winds, mainly after midnight.
The passage of stronger cold front has managed to keep temperatures in the 40s for most of the area. As colder and drier air continues to filter through with gustier north winds, some parts of the Hill Country will see freezing temperatures overnight. While most of the area will be in the 50s for the high, an additional freeze warning may be necessary for counties along and north of I-10, including a portion of the I-35 corridor, through effective radiational cooling overnight.
That being said, Thursday's high temperatures should begin to get closer to the freezing mark.
Where the airmass mixes with the warmer air aloft, temperatures are expected to rise through the night. Where the airmass remains decoupled from the warmer airmass, temperatures are expected to plummet to around or below zero. It will be warmer Thursday under mostly sunny skies. An upper level trough of low pressure will cover the central and eastern U.
223 PM CDT Wed Oct 30 2019 Cloudy and cold conditions persist across much of the region this afternoon, behind a cold front that moved through overnight. In addition, will see very winds by the early morning hours Thursday, allowing temperatures to drop below freezing for all but areas along the Rio Grande River.
Cloud cover will increase across the west late tonight as a warm front propagates in from Montana. This warm front quickly occludes through the day on Thursday as it continues to propagate east across North Dakota. Given a lack of a strong signal for mesoscale forcing for banding, and meager large scale forcing, did not favor the higher QPF range of the 12 UTC guidance suite.
As skies slowly clear tonight, radiational cooling, along with continued cold air moving into West Central Texas, from the northwest, will help create overnight lows below freezing.
As the positively tilted upper level trough moves east, I expect the snow to continue to move east.
Weak high pressure is over the area bringing clear skies and overall light winds today. With weak high pressure and very cold temperatures, patchy fog may again be possible over reservoirs and rivers tomorrow morning.
Meanwhile, forcing associated with upper low is increasing across the southeast half of the state with precipitation gradually expanding in this area. May see some relatively slick conditions as cooler air pushes in dropping pavement temperatures drop below freezing tonight allowing any moisture on the pavement to ice up. The strong subsidence on dry air on the backside should erode the cloud shield with sunshine in most locations by midday on Thursday as the thermal trof passes through the state.
With a deep longwave trough working through the center of North America, we will remain colder than normal.
A positive tilt upper trof over the central CONUS will continue to advect off to the east tonight, as more energy dives south out of Canada. S/W ridging ahead of that feature will provide for a quiet night across the region.
252 PM CDT Wed Oct 30 2019 Upper trough axis responsible for today's precip is currently centered over eastern Colorado this afternoon. Dry air sampled below 4 kft on the TOP 12Z sounding despite precipitation observed on radar was a good indication that snowfall amounts may be on the lower end, despite the likelihood of light snow continuing through the early evening. Sunny skies return for Halloween with overall light winds veering to the north as a weak cold front passes through. Snow cover should be minimal and not have an impact on temps so have increased highs given the ample sunshine and weak cool air advection with readings in the lower 40s.
141 PM MDT Wed Oct 30 2019 The very cold upper level trough axis has moved east of the area with a genearlly clear sky established over the region. Warming aloft ahead of the next trough will result in considerably warmer highs for the higher elevations.
Low temperatures will be quite cold late tonight into early Thursday morning with widespread overnight lows well below freezing in the Kern County desert areas; coldest lows could drop into the teens. Meanwhile, the coldest SJ Valley locations could briefly reach freezing by early Thursday morning.
Temperatures should bottom out in the upper 20s tonight then only rise to the lower to mid 30s on Halloween, making for one of the coldest Halloween on record. All sites are expected to see IFR conditions for much of tonight due to the low visibilities and ceilings accompanying the snow.
250 PM MDT Wed Oct 30 2019 Current surface analysis shows high pressure centered across eastern ID. Upper level analysis shows positively tilted trough moving across the central Plains, with ridging along the west coast.
1223 PM CDT Wed Oct 30 2019 Upper level trough axis shifts eastward today with a stretched out vort lobe moving by to our south. Temperatures above the surface 2-3 SD below climatology will keep temperatures near or just a tad above the freezing mark today. While afternoon temperatures may rise into the upper 30s to lower 40s, evening temperatures will fall back into the lower 30s and 20s once the sun goes down.
The cold temperatures will be short lived with warm advection on Thursday, the temperatures will warm into the lower to mid 40s for highs. This is still well below normal for this time of year, but warmer than today.
Tomorrow, showers and possibly TS ahead of a cold front will move through in the 12-16Z time frame, followed by a cold front passage after 16Z that will shift winds to the west and become gusty.
The cold front is now off of the upper Texas coast just east of GLS.
Another batch of showers will move in late night with mainly IFR/LIFR cigs/vsbys as a cold front approaches.
To the west it is clear as warm air advection is ongoing, and will continue through Thursday afternoon before cold air advection returns behind a cold front. Cloud cover will increase across the west late tonight as a warm front propagates in from Montana. This warm front quickly occludes through the day on Thursday as it continues to propagate east across North Dakota. Given a lack of a strong signal for mesoscale forcing for banding, and meager large scale forcing, did not favor the higher QPF range of the 12 UTC guidance suite.
The H500 hand analysis map continues to show strong blocking ridges off each coastline of N.
A potent round of showers and thunderstorms is still expected to cross the region Thursday morning ahead of a strong cold front.
A cold front has passed through all area terminals leaving a breezy north wind and clearing skies in its wake. /issued 223 PM CDT Wed Oct 30 2019/ Cloudy and cold conditions persist across much of the region this afternoon, behind a cold front that moved through overnight. In addition, will see very winds by the early morning hours Thursday, allowing temperatures to drop below freezing for all but areas along the Rio Grande River.
413 PM CDT Wed Oct 30 2019 Drizzle may transition to a period of freezing drizzle or light snow across northeast Oklahoma and northwest Arkansas before coming to an end later this evening.
/issued 248 PM CDT Wed Oct 30 2019/ The deep upper trough that has brought very cold temperatures and wintry precipitation to the area over the past few days will begin to move out of the Plains states tonight. Continued cold advection on the backside of the trough will allow for very cold (near record) temperatures tonight, with values in the teens across northwest Oklahoma and twenties elsewhere.
Models continue with agreement and persistence over multiple runs now of maintaining a strong offshore upper level ridge in the eastern Pacific with the inland northwest under the northwesterly flow aloft on the eastern flank of this persistent synoptic feature. but the low level air mass remains very dry and there is a possibility that only virga will be noted as this disturbance transits the area.
The upper level low pressure storm system which brought the light wintry precipitation to the OK and TX Panhandles will continue moving further northeast and away from the region this evening. On Thursday, plenty of sunshine and warmer temperatures are expected along with winds becoming southwest as a leeside sfc trof of low pressure develops over ern CO and ern NM.
As high pressure builds in on top of the existing cold air, mixing conditions will begin to suffer. Other than a slight warming trend as high pressure builds along the West coast.
Scattered to numerous showers will continue in low level warm air advection zone above the cold front through 06Z. Winds will gradually decrease through the day as high pressure builds into south Texas with clear skies expected Thursday afternoon.
Temperatures should bottom out in the upper 20s tonight then only rise to the lower to mid 30s on Halloween, making for one of the coldest Halloween on record.
No snow accumulation is expected, however we could see a few slick spots develop on elevated surfaces from residual moisture at temperatures fall below freezing overnight.
436 PM MDT Wed Oct 30 2019 Current surface analysis shows high pressure centered across eastern ID. Upper level analysis shows positively tilted trough moving across the central Plains, with ridging along the west coast.
/issued 301 PM CDT Wed Oct 30 2019/ Low clouds and occasional flurries are slow to leave the forecast area this afternoon as the trough axis is moving east slower than any model run had yesterday afternoon. Halloween looks to see temperatures warm into the 50s for the afternoon, fall to around 50 at sunset, and then by 10 pm range from near freezing along the TX/NM state line to the mid to upper 30s for the rest of the forecast area.