Aikyam-Lab/Synoptic-Bench huggingface dataset:
Weak low pressure will move in tonight, but prior to that stronger northwest flow aloft will be the only dominant feature. Northerly breezes will usher in Canadian high pressure on Thursday and some slightly cooler, but still seasonable, highs.
Some high level clouds were streaming southeast across southeast Iowa and west cental Illinois early this morning in the wake of the passage of a low pressure trough now in Indiana. A ridge of high pressure was seen building in the plains. Otherwise, a pleasant early December day is expected with plenty of sunshine and high temperatures in the lower 40s along Highway 20 to the upper 40 to lower 50s in SE Iowa, NW Missouri, and west central Illinois. Tonight, the ridge of high pressure will move across the area resulting in mostly clear and calm conditions.
/issued 335 AM CST Wed Dec 4 2019/ An upper trough is just off the California coast with upper ridging over West Texas and southeast New Mexico. Temperatures across the area will be cooler than yesterday but still above normal. The upper trough from the west coast will move toward the region and weaken on Thursday. Strong winds from the base of the upper trough will mix down to the surface across the area. A cold front associated with the previously mentioned upper trough will push into the area Thursday night.
Temperatures will be a bit cooler today however with downsloping southwest winds low 60's should still be reached which is slightly warmer than what guidance was producing. The trough axis will pass the area on Thursday and models have collectively backed off on the precipitation chances across the area. Wind speeds on Thursday will remain breezy as a tight surface pressure gradient develops in response to a developing low pressure system. A cold front will move across the area late Thursday night which will spread seasonably cooler air across the region.
A trough is currently moving north to south along the Florida peninsula and will continue to do so through the evening. The biggest impact from this trough will be falling dewpoints behind it and some breezy offshore winds. Expect temperatures in the mid 60s north and along the I-4 corridor, warming to the low 70s for southern sections.
An area of light rain has developed this morning in response to a plume of moisture moving northward ahead of a Pacific low pressure system off the central California coast. Temperatures have struggled to reach freezing in the high country this morning keeping snow levels mainly above 8,000 ft. Colder air accompanying the trough will bring lowering snow levels overnight, bottoming out around 6,500 - 7,000 ft from Flagstaff westward and 7,000 - 7,500 ft southeast of Flagstaff.
/issued 234 AM CST Wed Dec 4 2019/ High pressure remains over the Gulf Coast this morning. High pressure will continue to dominate the weather through Thursday which will keep conditions dry. Take advantage of the sunshine today as clouds will begin to increase tonight ahead of the next low pressure system. Highs today will be a tad warmer than yesterday with readings in the mid to upper 50s.
451 AM MST Wed Dec 4 2019 Moisture will continue to stream across northwest Montana through at least Thursday, as a ridge of high pressure amplifies along the Pacific Northwest coast. There are still a few narrow valleys that are still receptive to freezing rain on roadways, including the Highway 200 corridor west of Thompson Falls to the Idaho border and Highway 93 between Eureka and Whitefish.
523 AM CST Wed Dec 4 2019 Even though a trough of low pressure moved across Minnesota late evening, gusty westerly winds were still quite mild. Temperatures were still above freezing over west central, and parts of southern Minnesota as of 2 am.
Upper air analysis last evening showed a ridge to the west of Texas with west-northwesterly flow over us. The upper flow will become westerly as the ridge moves to the east and flattens.
With high pressure building in quickly behind this morning's frontal passage, expect just light nrly flow through the day before winds go calm again with sunset.
A ridge of high pressure will then move through the area on Thursday, bringing the threat of valley fog. An incoming low pressure system is spreading rain and higher elevation snow across central CA this morning. The system is progged to swing inland by this afternoon and as the cooler air aloft moves overhead the atmosphere will be destabilized sufficiently for the possibility of thunderstorms over much of our area. Amounts climb to over an inch in the higher terrain, and with snow levels expected around 7000 feet, a Winter Weather Advisory is in effect for the mountains above 7000 feet from Kings Canyon to the Lake Isabella region. By Thursday, an amplifying ridge will move inland across our area in advance of another developing system approaching from the northeast Pacific.
646 AM EST Wed Dec 4 2019 High pressure will direct a dry westerly flow into the forecast area through tonight.
Temperatures will be warmer this afternoon under mostly clear skies as the upper level trough that brought cooler conditions over the last few days pushes east. While the eastern CONUS trough will remain overhead today a combination of warming low-level temps and deeper mixing will result in high temperatures reaching the 60s region-wide. Though we won't quite reach the seasonal normals in the upper 60s, it will be much warmer than yesterday.
1212 PM CST Wed Dec 4 2019 Even though a trough of low pressure moved across Minnesota late evening, gusty westerly winds were still quite mild. Temperatures were still above freezing over west central, and parts of southern Minnesota as of 2 am.
Northwest flow aloft ushers in a weak area of low pressure on Thursday, and although a mid to low-level cloud deck will build in during the morning, the area will stay dry. CAA and the lack of daytime heating will result in slightly cooler temperatures Thursday, with highs near 30 degrees.
1224 PM EST Wed Dec 4 2019 Dry high pressure will continue through Thursday.
CDG Chattanooga Airport, TN 35 59 41 55 38 / 0 0 10 40 10 Knoxville McGhee Tyson Airport, TN 33 56 39 53 36 / 0 0 10 30 10 Oak Ridge, TN 32 55 39 53 34 / 0 0 10 30 0 Tri Cities Airport, TN 31 50 34 49 31 / 0 0 10 30 10.
and temps should peak a little warmer than they did yesterday as well. A cold front will move into the area Thursday as a disturbance dives into the Great Lakes region and the upper low to the southwest approaches the southern Plains.
A cold front will pass across the area in association with the upper wave through the day. A push of low to mid-level cold advection will follow behind the front Thursday evening ahead of Canadian high pressure building south.
High pressure will continue to build from the west Tonight, as low pressure departs to the northeast. The high will settle overhead during the day on Thursday. Readings will be a little lower near the coast Thursday, as the flow turns more onshore in the afternoon bringing in cooler air off the coastal waters.
248 PM CST Wed Dec 4 2019 High pressure centered over southern NOAM extends north into the central-northern Plains this afternoon, with virtually no clouds over MN/WI down through the mid-Mississippi River Valley. High pressure will be suppressed to the southeast through tonight as a weak area of low pressure approaches from the Dakotas.
At the surface, south to southeasterly flow was bringing good recovery of temperatures following last night's weak cold front, with 1 pm temperatures in the upper 60s to low 70s being reported across most of West Central Texas. As we go into tonight, the southerly low level flow will continue, bringing increasing moisture and warmer than usual air. This, in addition to continued high clouds moving over our area, will result in warmer overnight lows tonight in the mid to upper 40s. This low will move east- southeast through the late afternoon across the TX/OK border, dragging a weak front across the Big Country and Concho Valley. (Tomorrow Night through Next Wednesday) A stronger cold front will push through the region Thursday night, bringing northerly winds and much cooler temperatures, although these should only be slightly below normal.
1043 AM EST Wed Dec 4 2019 Currently - Water vapor satellite along with analysis continues to show a broad but weakening upper level trough over the region. Upstream is an equally deep ridge that extends from central Mexico poleward into Alberta.
Tomorrow, this ridge of high pressure will shift to our east to make way for the next active weather system.
This will force a cold front through the area Thursday night.
TFJ An upper ridge over the area today will bring a dry and mild day to the forecast area. Temperatures will be 10 to 15 degrees colder behind the cold front on Thursday.
The low pressure system and associated front will quickly cross the region late this afternoon into tonight, bringing a band of moderate to heavy precipitation. The only minor change made was to add patchy fog this morning, especially over the higher elevations. An area of light rain has developed this morning in response to a plume of moisture moving northward ahead of a Pacific low pressure system off the central California coast. Temperatures have struggled to reach freezing in the high country this morning keeping snow levels mainly above 8,000 ft. Colder air accompanying the trough will bring lowering snow levels overnight, bottoming out around 6,500 - 7,000 ft from Flagstaff westward and 7,000 - 7,500 ft southeast of Flagstaff.
121 PM MST Wed Dec 4 2019 Current upper air analysis shows trough centered off the central California coast with weak ridging and subsequent northwest flow across the northern US. A weak cold front will push through the region late day Thursday and bring with it a moist, cold airmass.
MA Chattanooga Airport, TN 58 35 59 41 55 / 0 0 0 10 40 Knoxville McGhee Tyson Airport, TN 54 33 56 39 53 / 0 0 0 10 30 Oak Ridge, TN 54 32 55 39 53 / 0 0 0 10 30 Tri Cities Airport, TN 49 31 50 34 49 / 0 0 0 10 30.
We'll see higher level clouds move into the region tonight as a low pressure system moves through Utah. We could be battling the low clouds and fog through the rest of the week.
A weak upper level ridge is moving through the southern plains while a river of high to mid level moisture from the Pacific is producing mainly a band of cirrostratus clouds from southwest Kansas back to much of New Mexico and Texas. Mainly light winds and clear skies tonight with overnight lows ranging from the mid 20s west to the low to mid 30s east. A band of light rain is forecast to develop in eastern Colorado along a cold front and move southeast into western Kansas by late afternoon.
Most areas will be around 10 degrees warmer than climatological normals for Thursday afternoon.
158 PM CST Wed Dec 4 2019 Cloud cover will increase this evening with skies becoming overcast across nearly all of western and central North Dakota tonight as a surface cold front begins moving southward through the area. Some patchy fog is possible across central North Dakota this evening/tonight before the cold front passes. Cold air advection associated with this front will help temperatures drop into the mid teens across northern North Dakota tonight with warmer temperatures in the 20s expected south.
/28/ Quiet weather is expected today as the region transitions from northwest flow aloft to ridging. High pressure will also remain at the surface. This will allow for sunny skies and warmer temperatures than was the case yesterday. We are already running around 5 to 10 degrees warmer than this time yesterday. Increasing cirrus tonight should help keep temperatures from falling below freezing.
257 PM CST Wed Dec 4 2019 As of this afternoon, upper level ridging is present over the Plains with a deep trough downstream over the East Coast and an upper low just off the West Coast. This upper low will slowly weaken as it approaches the area tomorrow. While overall moisture and forcing for ascent will be low, weak frontogenesis may still lead to a few showers in the afternoon and evening, especially along and south of I-35 closer to the track of the decaying upper low.
The upper pattern this afternoon is highlighted by broad troughing over the eastern CONUS and ridging out west, which combines to favor deep nwly flow across the OH/TN valley region. At the surface, weak high pressure centered over the ArkLaTex beneath confluent flow aloft will continue to strengthen as it shifts east through the period. On Thursday the upper pattern looks to flatten a bit suggesting less entrenched/deep nwly flow, while the surface anticyclone shifts east across the FL/GA coastline. High temperatures will warm by a few degrees, generally topping out in the mid/upper 50s in the lower valley, low/mid 50s in the central/northern valley, and 40s across the mountains.
VFR conditions will prevail next 24 hours, as sfc flow veers to the west and becomes gusty near the end of the forecast period, when an upper trough passes north. /issued 335 AM CST Wed Dec 4 2019/ An upper trough is just off the California coast with upper ridging over West Texas and southeast New Mexico. Temperatures across the area will be cooler than yesterday but still above normal. The upper trough from the west coast will move toward the region and weaken on Thursday. Strong winds from the base of the upper trough will mix down to the surface across the area. A cold front associated with the previously mentioned upper trough will push into the area Thursday night.
Meanwhile, a shift to southerly winds beginning early Thursday morning will bring a return of some limited moisture into the region ahead of a cutoff low pressure system that will be crossing the Rocky Mountains into the southern High Plains throughout the day.
Quiet weather is expected today as the region transitions from northwest flow aloft to ridging. High pressure will also remain at the surface. This will allow for sunny skies and warmer temperatures than was the case yesterday. We are already running around 5 to 10 degrees warmer than this time yesterday. Increasing cirrus tonight should help keep temperatures from falling below freezing.
At the surface, a high pressure center is approaching the CWA from the west, ending the period centered over western/central Alabama depending on which model you trust. Today temperatures will be warmer than they have been the last few days, peaking in the mid 60s this afternoon.
Given tendency for temperatures to climb toward the higher end of guidance the past couple of days, have trended in this direction again Thursday, especially in our southeast counties where snow cover is lacking, and where the cold front will pass through later.
223 PM CST Wed Dec 4 2019 Water vapor imagery depicts a longwave trough at 500 mb enveloping the Eastern Seaboard and ridging over the Southern Plains. At the surface, high pressure over the Western Gulf will push into the Deep South and keep overnight winds light. Lows overnight should stay above freezing, bottoming out in the mid 30s. Weak ridging currently over the Central Plains will translate eastward into the Tennessee Valley through the short term period. Therefore, slightly above average temperatures for December are expected with highs tomorrow in the low 60s and lows tomorrow night in the mid 40s.
Toward the end of the forecast period an East Coast trough digs into the Southeast as a result of cold air moving south out of Canada.
Some low to mid clouds were present across parts of western and north-central Wisconsin this afternoon associated with a large scale upper trough located to the east of the region. On Thursday a weak cold front will move across the area, bringing light precipitation chances mainly to north-central Wisconsin from late Thursday morning into the afternoon hours. High pressure builds in Thursday night with clearing overnight.
Winds will taper off and shift to the north and northwest at around 5-10mph, with temperatures falling into the lower 30s as clear skies and light winds enhance radiative cooling effects.
Afternoon temperatures are a few degrees cooler today but the roller coaster of temps continue tomorrow as breezy west winds push highs back into the 70s for most locations. Increased winds across the region will be the result of a passing upper trough to the north. This trough will be far enough north that speeds will remain below Wind Advisory criteria for most areas however high winds (40mph sustained or greater) will likely develop in the Guadalupe and Delaware Mountains.
Weak synoptic forcing and cold front will pass through the area early Thursday morning, bringing about a brief dip in temperatures, with highs only in the 30s. Weak lee-side troughing helps to bring a small chance for snow showers to areas at and north/northwest of Billings. Freezing drizzle is not expected, but cannot be ruled out.
Water vapor imagery depicts a longwave trough at 500 mb enveloping the Eastern Seaboard and ridging over the Southern Plains. At the surface, high pressure over the Western Gulf will push into the Deep South and keep overnight winds light. Lows overnight should stay above freezing, bottoming out in the mid 30s. Weak ridging currently over the Central Plains will translate eastward into the Tennessee Valley through the short term period. Therefore, slightly above average temperatures for December are expected with highs tomorrow in the low 60s and lows tomorrow night in the mid 40s.
A ridge of high pressure will then move through the area on Thursday, bringing the threat of valley fog. The trough exits the district by 09z tonight allowing a ridge to start building over central CA overnight. By Thursday, an amplifying ridge will move inland across our area in advance of another developing system approaching from the northeast Pacific.
Temperatures will bottom out around 30, maybe a little cooler in the some lowering lying areas as radiational cooling takes affect before sunrise.
A Winter Weather Advisory is in effect for the ridges due to moderate, accumulating snowfall. Cooling should allow for sub-advisory accumulations for areas outside of the ridges. For the ridges, advisory level accumulation is anticipated as enhanced upslope occurs with support from a strong, 500 mb jet. With cold air aloft and an increase to the wind, windy conditions (gusts of 20-25mph low elevations/30-35mph in the ridges) will linger into the overnight period. Snow showers will gradually taper off across the region as the upper-level trough advances into New England and dry advection commences. Forecast soundings suggest enough residual, low-level moisture in the ridges to maintain mention of snow, but lack of moisture within the dendritic growth zone should prohibit significant, additional accumulation.
915 PM EST Wed Dec 4 2019 Broad troffing pattern centered over the eastern seaboard will push into the W Atlc as a ridge axis over the central/srn plains advances toward the MS Valley.
611 PM EST Wed Dec 4 2019 Dry high pressure will continue through Thursday.
The warming trend continues, once again we are a bit warmer than we were at this time last night. High pressure is situated over the Red River Valley with mostly sunny skies and pleasant weather across the Mid-South.
Mostly cloudy skies tonight will limit the rate of radiation this evening with temperatures generally in the low to mid 40s expected by tomorrow morning. The Wister, OK mesonet recently recorded 39 degrees with other nearby stations in the low to mid 40s.
Clouds expected to increase from north to south during the afternoon following the passage of a cold front.
These echos in most areas should remain as virga, as the lower atmosphere is too dry for the precip to reach the ground.
Recent WV imagery shows a 500 mb trough moving onshore Central California with ample moisture and widespread cloud cover extending over much of Nevada. This trough will continue to push east over the Great Basin tonight bringing moist southwesterly flow aloft to western portions of the CWA. 12z model suite analyzed the trough farther south then WV imagery depicted.
The location of the low pressure with respect to the CWA will determine how much moisture and additional forcing is available for rain generation. Guidance is indicating the low moving through the Ark-La-Tex region, which will keep the light rain largely confined to south of I-70, as a result have increased pops in the southern CWA to likely category.
high clouds will slowly increase once again across parts of the area late tonight ahead of an approaching 500mb trough. This trough is expected to weaken a bit Thursday as it moves southeast into the four corners area. Precipitation chances look to come to an end during the evening as the upper trough moves away from the area. However, will have to watch for the possibility of stratus, freezing fog and freezing drizzle Thursday night as boundary layer saturates. Low temperatures tonight in the low to upper 20s. High temperatures Thursday range from the low 40s northwest to low 50s from Hill City to Tribune and points south.
Pockets of light freezing drizzle are possible in the valleys which could make for slippery roads and sidewalks Thursday morning.
A modest ridge/valley split was beginning to take shape as well, with the exception of urban/water locations where temps were cooling at a slower pace. Weak ridging currently over the Central Plains will translate eastward into the Tennessee Valley through the short term period. Therefore, slightly above average temperatures for December are expected with highs tomorrow in the low 60s and lows tomorrow night in the mid 40s.
758 PM EST Wed Dec 4 2019 While slightly warmer than yesterday, temperatures held below normal this afternoon with mid 60s to low 70s recorded across the area. High pressure building in across the Southeast will result in generally light offshore winds through the weekend along with rain free conditions. Winds then become southerly ahead of an approaching cold front which is expected to move through by the middle of the week.
Increasing high clouds will gradually work their way into the area later this evening and overnight as moisture from an upper trof out west hitches a ride on the generally zonal mid level flow across the southern U.
High pressure is situated over the Red River Valley with mostly sunny skies and pleasant weather across the Mid-South.
However this will be short-lived as a cold front over southern Alberta has been drifting south with temperatures in the 20s just behind the front. With ground temperatures being above freezing, freezing precip is not a concern till the morning if at all. Thursday will be much cooler and cloudy with the cold front to our south.
BY the late afternoon, the next upper level low will be approaching from the northwest, which may bring a few showers to KGUY and KDHT before the end of the TAF period. The higher chances for showers will occur after 00Z on Thursday, yet even those may be few and far between.
Warm temperatures expected again Thursday, generally in the same range as today if not slightly warmer. Quality moisture will be hard to come by due to recent frontal intrusion into the Gulf, but given fairly strong forcing expect some areas of light rain to develop near the low Thursday night, along with a slim chance of thunder mainly south of I-40.
Medium Lingering influence of trough will ease into this evening. The stratocu associated with the low level thermal trough should gradually diminish however some renewed development from WC through SC WI may delay the clearing a bit this evening. A southerly wind flow will be in place ahead of an approaching cold front.
156 PM PST Wed Dec 4 2019 A low pressure system will continue to move east across central and southern California through tonight.
432 PM MST Wed Dec 4 2019 Current upper air analysis shows trough centered off the central California coast with weak ridging and subsequent northwest flow across the northern US. A weak cold front will push through the region late day Thursday and bring with it a moist, cold airmass.