Aikyam-Lab/Synoptic-Bench huggingface dataset:
A very strong and stacked upper low continues to churn over the region. Very strong cyclonic low-level flow is occurring on the western side of the low, putting eastern KS and western MO in the path of very strong winds. As the low moves further away from the area later today and overnight, the pressure gradient over the area will weaken. The forcing associated with the upper low will also diminish so we'll see precipitation winding down as well and generally from west to east. During this exiting phase, cloud ice begins to be lost and there could be some periods of freezing drizzle mixed with the snow.
Some snow is expected today in the higher terrain, but accumulations will be quite light (1 to 3 inches) as the weak storm slides across the Northern Rockies.
/issued 417 AM CST Fri Jan 15 2021/ SHORT TERM (Now through Saturday): Tranquil weather is expected across deep south Texas with high pressure aloft and at the surface through the period. A few locations may drop briefly to around freezing late tonight into Saturday morning across the northern ranchlands but not enough to warrant a freeze warning at this time. Mild temperatures are expected on Saturday with highs ranging from the upper 60s near the coast to the low to mid 70s inland.
517 AM CST Fri Jan 15 2021 (Today and tonight) Early this morning, water vapor satellite showed a strong and large upper low over the Midwest, with northwest flow aloft over our region. At the surface, winds have weakened significantly, with high pressure from the northwest building into the area. Expect cooler highs today in the mid to upper 50s.
Light snow across thea area and reports of freezing drizzle as well. From water vapor, it does appear that the northern 500 mb system in Manitoba is now completely absorbed into the upper low in eastern Iowa.
322 AM CST Fri Jan 15 2021 Powerful upper level low, with circulation center currently located over Iowa, will continue to drift slowly southeast today into Saturday. Overall impacts should be minimal given temperatures will likely remain above freezing during this time period.
Other than gusty afternoon winds developing at VCT, light winds will prevail through tonight as high pressure draws closer. Surface ridging from a 1025 mb high near Clovis, NM will continue to amplify across South Texas today while keeping keep dry and light northerly winds intact. As the high slowly departs into the Gulf by Saturday afternoon, light southerly flow unfolds along with rising thicknesses.
525 AM CST Fri Jan 15 2021 A deep closed low was currently centered in southeast Iowa. A lobe extending from the upper low center in southeast IA extends northwest into nctrl SD. Regarding the high winds, the GFS bufkit sounding at BBW shows 65KT winds at the top of the mixed layer (near 775 mb) at 7am cst. As the upper low advances east into the Ohio Valley and Great Lakes tonight, northwest flow will exist across the Rockies and High Plains. Highs slightly warmer from the mid 30s to mid 40s.
Following the progression of the low, precip chances will be greatest in the west in the morning, then expand eastward by the afternoon.
442 AM MST Fri Jan 15 2021 Deep low pressure and associated winds continue to affect most of the FA, with warning level winds ongoing across much of the SD plains.
A weak upper level disturbance is serving to temporarily flatten the ridge this morning as it moves across the Oregon Coast, with an associated surface cold front decaying as it approaches the area from the northwest. Ridging will quickly rebuild overhead tonight, yielding dry and mild conditions across NW California heading into the weekend. Temperatures aloft will gradually warm through Saturday, particularly across the southern half of the area where 850 mb temps of 15-17 degrees Celsius will correspond to afternoon highs in the low to mid 70s in the interior valleys of Mendocino and Lake County this weekend.
A tight pressure gradient between the Midwest low and ridge to the west continued to generate strong northwest winds with gusts meeting high wind criteria (sustained 40 mph or higher and peak gusts of 58 mph or higher) over the South Laramie Range and Foothills, east-central WY plains and NE Panhandle. As the Midwest low pressure system moves east during the next 12 to 24 hours, northwesterly winds aloft will gradually decrease. Short wave ridging aloft will quickly give way to a Pacific short wave trough later tonight and Saturday.
322 AM CST Fri Jan 15 2021 From water vapor, it does appear that the northern 500 mb system in Manitoba is now completely absorbed into the upper low in eastern Iowa.
/Today through Saturday/ A strong upper level low is proceeding through the Midwest, with strong wind speeds in its wake. By Saturday, winds gradually slacken as the strong upper low shifts east.
226 AM MST Fri Jan 15 2021 Deep low pressure and associated winds continue to affect most of the FA, with warning level winds ongoing across much of the SD plains.
Upper level analysis places low over southeast Iowa into northwest Illinois, with ridge from the Bay Area of California through the Northern Rockies. Therefore, have dropped the high wind warning and replaced with wind advisory over much of the area.
WV imagery shows a broad trough over the MS Valley, nudged along by a highly-amplified ridge over the western CONUS, leaving West Texas and Southeast New Mexico under NW flow aloft. Thicknesses increase Saturday, with highs rebounding to a couple of degrees above normal, but a dry, weak trough moving through the region will drop another cold front into the area Saturday night.
525 AM CST Fri Jan 15 2021 For the 15/12Z TAF update, a strong upper level low over the Midwest will keep winds out of the west elevated above 15-20KT through most of the period. /Today through Saturday/ A strong upper level low is proceeding through the Midwest, with strong wind speeds in its wake. By Saturday, winds gradually slacken as the strong upper low shifts east.
Surface ridging from a 1025 mb high near Clovis, NM will continue to amplify across South Texas today while keeping keep dry and light northerly winds intact. As the high slowly departs into the Gulf by Saturday afternoon, light southerly flow unfolds along with rising thicknesses.
Models handling the low well and continue to expect the occluded system to track south southwest with time early this morning. As it does, the low will continue to fill as warmer air aloft gets pulled into the storm from the northeast. At 130 am, winds are gusting from 40 to 50 mph at Estherville southwest to Harlan with the highest gust at this time at Sioux City at 57 mph. The lowest visibility continues to be tied to the higher winds over the west with 1/4 to 3/4 most common. Both the HRRR and synoptic models support a gradual lessening in winds speeds back toward the west after 13z this morning as the low continues to push south into Missouri this morning. By 12z Saturday the low will have weakened considerably with modest northwest winds and more clouds expected through tomorrow.
SHORT TERM (Now through Saturday): Tranquil weather is expected across deep south Texas with high pressure aloft and at the surface through the period. A few locations may drop briefly to around freezing late tonight into Saturday morning across the northern ranchlands but not enough to warrant a freeze warning at this time. Mild temperatures are expected on Saturday with highs ranging from the upper 60s near the coast to the low to mid 70s inland.
A broad upper level ridge parked about 400 miles west of Santa Barbara will promote another afternoon with temperatures well- above January normals. The offshore ridge is forecast to amplify over the weekend, leading to further warming across much of the Golden State.
Northwest winds will taper off today across much of the area with passing high clouds and slightly warmer temperatures.
A cold frontal band was making progress east through north AL and southern TN early this morning. The large nearly stacked upper low over IA will drop southeast into the eastern corn belt this afternoon. Before the SC/CU field develops in response to the steepening lapse rates, sunshine should push temperatures back into the upper 40s in valleys/lower 40s atop the higher eastern plateau regions. The upper low will shift east into northeast KY and OH overnight. 5 inch atop the higher plateau locations in Franklin and northern Jackson Counties. Max temperatures will be held in the lower 40s for valleys and middle to upper 30s atop the higher plateau regions.
Warmer temps aloft today, so the mixed areas and the mountains will be milder today.
334 AM CST Fri Jan 15 2021 A cold front moving through this morning is bringing the clouds and what rain it could develop away from the area. High pressure builds in over the weekend with some light freezing temps during the overnight mainly for northshore areas.
Friday Details: As of this morning water vapor imagery shows an elongated trough dipping down to near the Iowa/ Missouri border. During the morning hours, expect the upper level trough to remain nearly stationary over central Iowa, as the system attempts to cut off. As this happens, expect a tightening gradient upstream of the trough basin. At the same time, a deformation zone has develop along the northern and western sides of the low pressure. As the cut off upper level low bobbles over Iowa, the low at the surface will slide to the west brining more moderate snow rates through about 10 AM.
601 AM CST Fri Jan 15 2021 319 AM CST Currently, a large 990 mb low pressure system is located in far northeastern Iowa leading to impressively strong winds across the northern Plains and a blizzard across parts of Minnesota and Iowa. Accordingly, an increase in snow shower coverage is expected this afternoon with the highest concentration generally along and south of I-88. As the parent upper- level trough finally starts to pull away Saturday morning, the deformation zone of the secondary low (manifested as a band of snow) will swing through northern Illinois.
556 AM CST Fri Jan 15 2021 From water vapor, it does appear that the northern 500 mb system in Manitoba is now completely absorbed into the upper low in eastern Iowa.
With the approach and passing of a weak cold front, we should see breezy conditions again Saturday afternoon and evening, but little in the way of precipitation. Either way, the cooler temperatures will be the story through tomorrow night, even though it's still above seasonal norms.
426 AM CST Fri Jan 15 2021 Cold front has pushed well east of the area and will be exiting far SE LA shortly. The latest WV imagery and UA analysis shows large and deep low pres over the midwest that is producing winter storm and blizzard conditions acrs much of the N cntl CONUS, while ridging builds over the wrn US.
413 AM CST Fri Jan 15 2021 A strong upper low over the Midwest will be the driver of the forecast for today into Saturday. A cold front passed through last night and winds will be elevated today across portions of the Mid South. As that upper low spins some energy will rotate through the region this afternoon into the evening hours. The upper low pushes east and we dry out over the region.
230 AM MST Fri Jan 15 2021 High pressure ridging will be in place through this morning but another disturbance across the Pacific northwest will flatten the ridge as it approaches south central Montana this afternoon.
Surface analysis depicts a stalled frontal boundary in the Straits, with another cold front extending from near Mobile across the central and western Gulf of Mexico. Aloft, water vapor imagery shows a massive gyre spinning over eastern Iowa, and anchoring a full latitude trough which extends southward into the Gulf. This low level moisture should tend to mix out in the afternoon, allowing for some peeks of sunshine and high temps to climb into the lower 70s. The next cold front remains on track to push through the Keys late tonight, as the supporting longwave trough progresses slowly eastward into the eastern CONUS. We will not see as much sunshine as we normally would behind a cold front, as mid/high level moisture will continue to stream overhead through the weekend.
320 AM PST Fri Jan 15 2021 High pressure will remain overhead through the weekend with mainly light winds, weak to moderate inversions, and mild temperatures. Besides the increased cloud cover and breezy Sierra ridge winds, this wave of low pressure should not do much else in terms of impacts to western Nevada and the Sierra due to lack of energy and overall moisture. The high pressure ridge off the California coast continues to be the dominant synoptic feature at least through this weekend resulting in weak to moderate valley inversions, light winds, and above average temperatures.
403 AM CST Fri Jan 15 2021 A deep closed low was currently centered in southeast Iowa. A lobe extending from the upper low center in southeast IA extends northwest into nctrl SD. Regarding the high winds, the GFS bufkit sounding at BBW shows 65KT winds at the top of the mixed layer (near 775 mb) at 7am cst. As the upper low advances east into the Ohio Valley and Great Lakes tonight, northwest flow will exist across the Rockies and High Plains. Highs slightly warmer from the mid 30s to mid 40s.
/issued 413 AM CST Fri Jan 15 2021/ A strong upper low over the Midwest will be the driver of the forecast for today into Saturday. A cold front passed through last night and winds will be elevated today across portions of the Mid South. As that upper low spins some energy will rotate through the region this afternoon into the evening hours. The upper low pushes east and we dry out over the region.
A closed upper level low pressure system approaching the Northeast and its associated cold front pushing into the Gulf of Mexico the afternoon and into Saturday. The highest chances of rain will be across the Big Bend given that the frontal boundary is expected to weaken as it moves across the Peninsula.
Surface temperatures were mostly in the low-mid 30s, where skies were cloudy; however temps have fallen into the 20s in portions of southeast Missouri where skies were clear. The strong broadscale lift associated with this feature is expected to track principally through the western forecast area, through northeast and central MO and into portions of southeast MO, and this is where the highest confidence in snowfall accumulations will be.
1157 AM EST Fri Jan 15 2021 Rain, and then snow showers return to the region today and continue over the weekend as a low pressure system advances into western Pennsylvania. A strong low pressure system situated in eastern Iowa will continue to slowly advance southeast today. Strong frontogenesis over the ridges of West Virginia early this afternoon has been consistent in the last few Hi-Res model runs.
This is due to the low pressure system that has been spitting out rain and snow over us since yesterday. The stacked low over western IL will develop another area of low pressure over Lake Michigan this evening before shifting east. Snow ratios should be around 10 to 1 with temperatures around freezing.
1038 AM MST Fri Jan 15 2021 Deep low pressure and associated winds continue to affect most of the FA, with warning level winds ongoing across much of the SD plains.
1251 PM EST Fri Jan 15 2021 A strong cold front will cross the area today, bringing showers.
Currently, low pressure was centered over northeast Missouri.
Given the gusty winds of 15 to 20 mph and the low humidity values in place, there will be an increased fire danger risk for today. /issued 334 AM CST Fri Jan 15 2021/ A cold front moving through this morning is bringing the clouds and what rain it could develop away from the area. High pressure builds in over the weekend with some light freezing temps during the overnight mainly for northshore areas.
Large upper low over the Central Mississippi valley continues to promote gusty winds over much of TX. Winds will die down fast with the setting of the sun; this, combined with the very low dew points will lead to most of the area reaching near or below freezing for Saturday morning. A more gentle NW flow aloft over TX is expected Saturday into Saturday night, with the low level CAA ending by midday.
RMS High pressure ridging will be in place through this morning but another disturbance across the Pacific northwest will flatten the ridge as it approaches south central Montana this afternoon.
Snow within the blizzard warning areas is also on a steady decrease, with some locations seeing freezing drizzle over snow. The biggest change to the forecast is the addition of freezing drizzle for the James River valley and points east. Visibility at Watertown, Wheaton and Ortonville has been around 2 mile or greater, so there is some concern the blizzard warning is really only relevant for the higher terrain (not that locations outside the hills aren't seeing blizzard, it would just be more intermittent).
As the upper low continues to fill over the Mississippi Valley and push southeast tonight, precipitation and wind gusts will wind down gradually into the night. The loss of moisture aloft with a fairly deep moist layer in the low levels could allow for some patchy freezing drizzle while temperatures fall through the 20s. Not expecting much of an additional impact beyond what may already refreeze as temperatures finally drop below freezing. Although the spread in the ensembles are not as noticeable from yesterdays model runs, there remains large enough differences to lean toward a warmer than normal scenario.
Light snow across the area and reports of freezing drizzle as well. From water vapor, it does appear that the northern 500 mb system in Manitoba is now completely absorbed into the upper low in eastern Iowa.
CD Chattanooga Airport, TN 31 41 31 46 30 / 20 20 0 0 10 Knoxville McGhee Tyson Airport, TN 30 36 30 42 30 / 30 40 0 10 20 Oak Ridge, TN 29 37 30 42 29 / 30 30 10 10 30 Tri Cities Airport, TN 28 34 28 39 27 / 40 50 20 10 40.
1146 AM CST Fri Jan 15 2021 (Today and tonight) Early this morning, water vapor satellite showed a strong and large upper low over the Midwest, with northwest flow aloft over our region. At the surface, winds have weakened significantly, with high pressure from the northwest building into the area. Expect cooler highs today in the mid to upper 50s.
Cold front actively marching across the region. SR Chattanooga Airport, TN 48 31 41 31 46 / 20 20 20 0 0 Knoxville McGhee Tyson Airport, TN 46 30 36 30 42 / 70 30 40 0 10 Oak Ridge, TN 46 29 37 30 42 / 60 30 30 10 10 Tri Cities Airport, TN 42 28 34 28 39 / 70 40 50 20 10.
Classic deep occluded upper low with a plume of dry air wrapped all the way up into its center. There has been some patchy drizzle at times, but with most observing stations reporting temperatures above freezing, haven't had any persistent freezing drizzle reported.
231 PM EST Fri Jan 15 2021 Rain, and then snow showers return to the region today and continue over the weekend as a low pressure system advances into western Pennsylvania. Given warm sfc temperatures accumulations will be limited to the higher terrain which could see an inch or two. Scattered snow showers will once again develop in eastern Ohio later in the morning before expanding in coverage to the northeast during the afternoon as the upper low and cold air aloft moves overhead.
251 PM CST Fri Jan 15 2021 The stacked low pressure system over the Mid Mississippi Valley will pull away slowly to the east tonight. The eastern edge of the dry slot will move through the remainder of Missouri into Illinois tonight as the low drifts eastward.
245 PM CST Fri Jan 15 2021 A compact upper low will continue to shift southeastward across IL this afternoon, with the combination of strong west-southwesterly flow aloft and a deep mixing layer enhancing the magnitude of gradient flow at the surface. We expect sustained winds to remain in the 15-20 MPH range with frequent gusts of 25-30 MPH for the rest of the afternoon, and although sufficient insolation has occurred to allow temps to reach the lower 50s, an increase in cloud cover from the west should result in progressively cooler readings from this point forward. The only exception to this may be in the higher terrain of northeast AL/southern TN, where accumulations up to 0.
346 PM EST Fri Jan 15 2021 Currently - An advancing prefrontal trough in the Gulf of Mexico has forced a narrow weakening ridge axis across the Keys. Temperatures range broadly from the upper 60s to the mid 70s with dew point temperatures in the lower to mid 60s. Forecast - Light and variable winds will give way to gentle to moderate southwest to west breezes this evening as the prefrontal trough nears the Keys. Winds will freshen out of the northwest after midnight in wake of the prefrontal trough passage. This will usher in a cooler and drier air mass. Northwest breezes will diminish significantly and shift more northerly Saturday and Saturday night as high pressure builds eastwards from the gulf.
Temps will climb from the lower-mid 40s to the lower 70s this afternoon. A line of showers that will be pushed towards the local area by a dropping cold front will reach Lake and Volusia counties a little after sunset today. Accumulations are not expected to be high, actually averaging no more than a few hundredths before passage of the cold front tonight. A cold front will approach later tonight, pushing a line of light to moderate showers, reaching first KLEE and KDAB around 16/00z.
The vertically stacked low pressure center continues migrating southeastward this evening, causing a relaxation in the pressure gradient and therefore decreasing winds. One additional issue that may be introduced this evening through midnight is freezing drizzle. Continued modest lift in the lowest saturated levels may cause liquid drizzle to fall while surface temperatures remain below freezing.
Pattern synopsis and forecast: Deep slow moving low pressure continues to pinwheel southeast into the western Ohio Valley region early this afternoon. Marginal temperatures through the boundary layer has resulted in a rain/snow mixture, with most of the snow confined to the higher elevations. Mid/upper level low pressure will be a slow mover, gradually shifting east across the Ohio Valley tonight through Saturday. Troughing/associated moisture hangs back across northern Michigan to start the period as our low pressure system continues to crawl away to the east.
117 PM CST Fri Jan 15 2021 Today has a weak upper ridge building in from the west. after that high pressure will return.
Temperatures will remain around freezing or several degrees above, especially towards Lake Michigan. RAH (Issued 441 AM CST Fri Jan 15 2021) Today through Saturday: Patchy drizzle and light snow showers will be possible today as moisture circulates around the meandering low pressure system to our west and a reservoir of cold air lingers aloft. Tonight, as the low slides off to our west, easterly fetch will increase off the lake allowing for better low level moisture and the lingering tail of a jet aloft will allow for upper level divergence. Light snow will linger through early Saturday morning before the low finally exits to our east and light snow subsides.
The main upper level low pressure system centered over the mid Mississippi River Valley will will continue to move east across the Ohio River. As the center of the low does so, height gradient will begin to wane with winds subsiding to 10-15 MPH out of the northwest as we go past midnight.
221 PM CST Fri Jan 15 2021 Powerful upper level low that has been anchored over the Midwest the last couple of days is finally beginning to move off to the east this afternoon. A dusting to a couple tenths of an inch accumulation could be possible for some areas, but little to no impacts expected through the evening as temperature remain well above freezing. These will continue through the afternoon and begin to slowly wind down this evening and tonight as the upper low moves off to the east.
1221 PM EST Fri Jan 15 2021 A strong cold front will cross the area today, bringing showers.
122 PM CST Fri Jan 15 2021 Today has a weak upper ridge building in from the west. after that high pressure will return.