Aikyam-Lab/Synoptic-Bench huggingface dataset:
Closed low system, presently over Missouri/Illinois, will continue to meander northeast into lower Michigan by 06Z, introducing the chance to see areas of fog as the occluded front sets up over the state. A deep plume of low level moisture will accompany a low pressure system into the region this taf period. The likelihood for LIFR restrictions will increase late afternoon or evening as the low advances in lower Michigan. Closed low over southern Missouri will modulate Southeast Michigan weather through the weekend. Upper low will then meander toward Lower Michigan tonight through Saturday, much of this period on the drier side for most areas given the degree of dry air that has already wrapped into the core of the circulation.
A fast-moving (but weak) trough will impact northern Utah and southwest Wyoming today, with high pressure returning for the bulk of the weekend.
Weak mid level ridging overhead will break down as a southern High Plains short wave trough moves across Oklahoma during the period, while another weakly connected short wave trough over Baja moves similarly east over Central Mexico.
Regional radars show precipitation overspreading the region as moisture and lift increases ahead of advancing low pressure. If the ingredients line up just right, areas to the west of the Somerset County border (Ligonier- Donegal- Ohiopyle) and areas west of the westernmost ridge (Blairsville- Latrobe-Mt. Farther south, into Western MD and WV, the ridgeline is higher and likely above the inversion. A wind advisory has been issued for the ridges to account for both situations. A very brief period of freezing rain is possible for Garrett County MD if any precip manages to fall before noon today. Cooler, drier air will filter in behind the frontal boundary Saturday morning.
Recent surface observations in the higher terrain supports this, specifically near Seven Springs, with wind gusts in the low 30s kts observed. The wind threat will be confined only for the next couple of hours as rain continues to cool the boundary layer through wet bulbing and effectively erodes the inversion ahead of advancing low pressure. As for precipitation type, persistent warm advection and overall surface temperature above freezing will support widespread rain through the remainder of the period. Cooler, drier air will filter in behind the frontal boundary Saturday morning.
A deep upper low is situated just north of the Mid- South. Any threat of rain will end by early this evening as the upper low starts to pull away. Lows will be in the lower 30s with a diminishing west wind. Mean upper trough will remain over the eastern U.
1002 AM MST Fri Jan 24 2020 09Z upper level analysis has very amplified flow across the CONUS with ridge to the west of the Northern Plains, and trof to the east. Thin high clouds are spilling over the western ridge across northeastern WY with low stratus present across the SD plains. At the surface, high pressure is present across the eastern Dakotas with weak lee trof across eastern Montana into northeastern WY. Some areas of fog are present across the SD plains under the low stratus. Temperatures overnight will be a bit warmer, especially across western areas. Little accumulation is expected except for minor amounts across the higher Black Hills.
(This afternoon through Saturday) Large upper low over the Midwest/Great Lakes region continues to move eastward and away from our area. Ware (Saturday night through Friday) As a progressive s/wv trough moves over the region late Saturday, lapse rates will be sufficient to support brief elevated storms, mainly Saturday evening into the overnight hours over southeast parts of Oklahoma.
154 PM EST Fri Jan 24 2020 An upper-level low continues to move through the midwest with an associated cold front working its way toward the region. High pressure will quickly build in behind it, with cooler, drier, and sunnier conditions for Saturday.
130 PM MST Fri Jan 24 2020 The upper low center lifting out of the eastern plains will leave a dirty northwest flow pattern in place over the central Rockies and central High Plains region through the weekend with several short wave troughs either skirting around or shearing out across the forecast area for periodic increases and decreases in cloud cover. This will move the cooler airmass out of the region and bring a warming trend to the central High Plains through the weekend.
Conditions will continue to clear up through the morning as a ridge moves over the area. -Mottice Low cloud and fog over the eastern zones for most of the night, beginning to break up as upper ridge pushes over the state. With the low level inversion, could also see some valley fog overnight. Weak cold front dips into the northeast corner of the state on Saturday with another chance for light precipitation.
1134 AM MST Fri Jan 24 2020 Only minor changes at this point to match current cloud cover and a little more wind in the high mountains. Forecast temps in the low 50s look good, we may get a degree or two warmer if the shift to easterly winds is a bit slower. Thin layer of low clouds coming up against the Front Range from the west, but the deeper moisture with the trough won't be until late evening. For tonight, an upper level trough will move across the area. A developing downslope component just off the deck should also promote late day warming, but not sure we'll see the lower 50s suggested by the latest model averages.
222 PM EST Fri Jan 24 2020 A cold front expected to push through the area tonight.
/27/ Prior discussion below: Today through tonight: as a closed low crosses the Middle MS Valley today, cyclonic flow and weak low level cold advection will support gusty west winds and stratus persisting for locations mainly north of the I-20 corridor. For tonight, the low will pull away allowing skies to clear. Lows tonight should drop to near or just below freezing for the majority of the forecast area, so there may need to be some consideration given to the possibility of freezing fog where fog becomes dense enough.
1235 PM EST Fri Jan 24 2020 Periods of light rain will continue into this evening, before becoming mixed with snow as temperatures slowly fall into the lower 30s.
1257 PM EST Fri Jan 24 2020 A warm front is moving northward through the forecast area early this afternoon, with a cold front expected to push through the area tonight.
129 PM CST Fri Jan 24 2020 Low pressure system centered over Missouri and Illinois will continue slowly drifting north and east this evening. A brief break in cloud cover into the early evening is expected to continue over the eastern forecast area before more clouds along the southern side of the low push in from the west. Dry and cool weather returns on Saturday as high pressure moves back into the region. Highs in the mid to upper 40s and overnight lows in the lower 30s with partly clouds skies.
1228 PM CST Fri Jan 24 2020 Updated temperatures today a couple times for a faster rise and raised the highs a bit to reflect the latest observational trends.
1139 AM CST Fri Jan 24 2020 Predominant VFR conditions over this TAF period, with brief drops into MVFR possible at KTXK, KELD, and KMLU as the cloud desk associated with the passing low pressure continues to move east. MVFR ceilings associated with clouds wrapping around a departing upper trough will affect portions of Southeast Oklahoma and Southwest Arkansas before exiting the area by early afternoon. Some low-level clouds wrapping around the back side of the departing trough will affect Southeast Oklahoma and portions of Southwest Arkansas today, but the clouds will gradually exit with the trough. Clear skies and light winds should lead to another chilly night across the forecast area, especially across Southeast Oklahoma and Southwest Arkansas where overnight low temperatures are expected to fall below freezing. Warmer temperatures are expected for Saturday.
1031 AM EST Fri Jan 24 2020 The cold front that will cross central Florida tonight into Saturday morning is currently entering the FL panhandle. After more stubborn low stratus this morning, conditions have improved to VFR and are expected to remain through the remainder of today with multiple cloud layers ahead of a cold front. Isolated showers are expected to develop this afternoon as the cold front approaches the area with coverage too low for TAF mention. Southeasterly winds of 10-15 kts will veer south then southwesterly this afternoon ahead of an approaching weak cold front. much drier air is expected to move into central Florida behind a cold front.
We'll eventually lose the low clouds as the upper low that brought the snow this morning to NE OK/NW AR moves away.
/issued 437 AM CST Fri Jan 24 2020/ (Today and Tonight) As an upper trough continues to move east, high pressure will build over Texas, and a warm-up will begin. Then, winds from the south will continue to pull warmer air from the south, into West Central Texas.
Temps across favored downsloping areas running warmer than previous hourly temps. NAM soundings and CC values show the freezing level between 5,500 and 6000 feet. Upper level low rotating into the area now. Low CIGs persist through the end of the period as low level moisture remains locked in at the lowest levels. Chattanooga Airport, TN 35 45 31 50 37 / 10 10 0 20 30 Knoxville McGhee Tyson Airport, TN 36 42 33 48 36 / 20 10 10 10 30 Oak Ridge, TN 35 42 32 48 35 / 20 10 10 10 30 Tri Cities Airport, TN 35 40 33 43 34 / 30 30 20 10 20 TN.
MVFR ceilings associated with clouds wrapping around a departing upper trough will affect portions of Southeast Oklahoma and Southwest Arkansas before exiting the area by early afternoon. Some low-level clouds wrapping around the back side of the departing trough will affect Southeast Oklahoma and portions of Southwest Arkansas today, but the clouds will gradually exit with the trough. Clear skies and light winds should lead to another chilly night across the forecast area, especially across Southeast Oklahoma and Southwest Arkansas where overnight low temperatures are expected to fall below freezing. Warmer temperatures are expected for Saturday.
A low deck of clouds along with occasionally gusty winds associated with an upper low persists over all TAF sites at this time. The cloud deck will generally lift and erode from west to east today as the upper low continues to move away from the area. Skies should slowly clear from southwest to northeast through the day as the upper low associated with these clouds moves away.
An upper low now over southern MO will shift away from the area today. Light rain/drizzle has been giving way to a band of snow pivoting around the low.
Tonight and Saturday Vertically stacked low pressure continues to slowly work its way toward the area. But dewpoints at or above freezing and not a lot of cold air to transfer down could limit things. It will be a pretty wet snow, plus ground temps near freezing will promote some melting and compaction. On Saturday, the low pressure will slowly track toward Lake Huron. Periods of light snow, drizzle and freezing drizzle is expected to continue. There will still be some mid-level energy wrapping around the departing low pressure system, keeping a chance of light pcpn in the forecast through Saturday night, especially across eastern and northeast Wisconsin. Boundary layer temps near Lake Michigan may also be just above freezing, then fall below freezing after midnight, which could also affect p-types.
1205 PM EST Fri Jan 24 2020 Ongoing moisture transport associated with the upper low over the Mid Mississippi Valley will sustain intervals of rain and drizzle through the afternoon and into the evening hours. Closed low system, presently over Missouri/Illinois, will continue to meander northeast into lower Michigan by 06Z, introducing the chance to see areas of fog as the occluded front sets up over the state. Closed low over southern Missouri will modulate Southeast Michigan weather through the weekend. Upper low will then meander toward Lower Michigan tonight through Saturday, much of this period on the drier side for most areas given the degree of dry air that has already wrapped into the core of the circulation.
1017 AM MST Fri Jan 24 2020 Overnight WV/IR imagery loop showed a potent upper low centered over the Mid-MS Valley and a upper ridge across the Intermountain West. Short range models are in good agreement with the steady northeast track of the upper low through the OH Valley and eastern Great Lakes. Meanwhile, the upper ridge to the west weakens as it translates east through the Rockies and High Plains.
1047 AM MST Fri Jan 24 2020 500 mb RAP analysis and water vapor imagery showed an upper closed low over the Ozarks of southern Missouri and northern Arkansas overnight. To the west, a ridge built over the Great Basin, placing the tri-state region under northwest flow. Dry conditions are expected to prevail, with high temperatures in the low 40s to low 50s from east to west. Ridging rebuilds over the Great Basin on Saturday and advances to the Rockies by Saturday night. High pressure tries to slide into the area Saturday night as temperatures fall into the 20s. A couple upper level short wave troughs will move through the northwest flow during this period.
1121 AM CST Fri Jan 24 2020 A strong upper level low centered across southern Missouri this morning will shift eastward into southeast Illinois by early this evening. Meanwhile upper level ridging will translate east through the Rockies toward the western High Plains. At the surface a nearly stationary arctic cold front will bisect our immediate area from northwest to southeast. Light westerly downslope flow and sunshine will boost highs into the lower and mid 40s. warm air spreading east of the higher terrain to the west via downslope flow will push highs well into the 40s across western and southwest Nebraska. Some of this air will spread into north central Nebraska with highs in the lower to mid 30s. The lower levels below 700mb will be quite dry however, so probably more virga than anything.
High pressure over the area tonight will move east and allow for southeast winds to develop tomorrow. High and mid level clouds will increase tomorrow afternoon over the area with the approach of the next trough.
435 PM MST Fri Jan 24 2020 The upper low center lifting out of the eastern plains will leave a dirty northwest flow pattern in place over the central Rockies and central High Plains region through the weekend with several short wave troughs either skirting around or shearing out across the forecast area for periodic increases and decreases in cloud cover. This will move the cooler airmass out of the region and bring a warming trend to the central High Plains through the weekend.
Large closed upper low over the Ohio Valley has sent several waves of showers through the region early this afternoon and this will continue into the evening hours until the primary upper wave axis finally exits the region to the northeast overnight. Most shower activity will be confined to areas along and north of I-40 in closer proximity to the upper low but could reach as far south as the AL line at times. Shallow low-level instability will allow for some brief downpours with this activity, and this combined with very low freezing levels has even resulted in some small hail in the heavier showers. Small hail will remain a possibility with the stronger showers this afternoon, and then later this evening there could be some snow/graupel mixed in as the freezing level drops further.
Temperatures are on track to reach the low 30s in many places tonight. An upper low will continue to swing showers through Middle Tennessee this evening.
726 PM EST Fri Jan 24 2020 A cold front expected to push through the area tonight.
Weak cold front dips into the northeast corner of the state on Saturday with another chance for light precipitation.
953 PM EST Fri Jan 24 2020 A cold front will push offshore tonight followed by high pressure. The surface frontal trough was sagging into the region at this hour, with the cold fropa soon to follow on it's way through the forecast area overnight. Cooler and drier air will move in by daybreak, although some low clouds and shallow fog could linger much of the night, especially across SC. Low temps should range from near 40 toward the CSRA to the lower 50s along the central SC coast.
Last night's trof is moving across the Great Basin and 5H heights are recovering over Norcal. This is leading to high cloudiness passing through the W Coast ridge. Although the stratus/patchy F+ has eroded/dissipated, the low SC (stratocumulus) deck over the Nrn Sac Vly and surrounding foothills has not, and the moisture profiles for that area suggest it won't mix out with more moisture spreading into the area through the overnite. Behind this trof, upper ridging strengthens over Norcal Friday night into early Saturday, and morning dense valley fog is possible, especially over the Nrn SJV, as indicated by the HREF probability of <1 mile VSBY. Forecast soundings indicate very shallow and weak CAPE Sun afternoon, although there are likely to be some high REF echoes on the radar given the lowering freezing levels Sun afternoon.
Diegan Chattanooga Airport, TN 35 45 31 49 39 / 10 10 0 20 40 Knoxville McGhee Tyson Airport, TN 36 42 31 48 38 / 20 10 0 10 40 Oak Ridge, TN 35 42 30 48 38 / 20 10 0 10 40 Tri Cities Airport, TN 35 40 31 45 35 / 40 20 20 10 40.
With the freezing level within the first several hundred feet in MO and the far western IL, most of this precipitation is falling as snow. The low is slowly but steadily crawling east out of the CWA and lingering precipitation is forecast to diminish southwest to northeast overnight. Overcast skies will stick around through much of the day Saturday before the influence of the low will have moved east of the bi-state region and westerly winds advect dry air into the area. MRM The current mid level trough over the central US will expand to cover the eastern half of the CONUS by the end of the weekend.
648 PM EST Fri Jan 24 2020 Early evening water vapor satellite imagery is showing drier air aloft filling into northern Florida behind a cold front that is on track to move through the forecast area overnight through Saturday morning. A cold front will pass through the area during the overnight and early morning hours, with winds turning to northwesterly behind the front. A cold front will move southeast through the coastal waters overnight, with isolated to scattered showers gradually diminishing by Saturday morning.
The deep closed low is currently centered over southern Illinois with the moist low level jet flowing north over eastern Kentucky. West of the low level jet, precipitable water values drop to under an inch, but pockets near the center of circulation are seeing values over 0. Not expecting many issues tonight other than wet roadways as temperatures stay slightly above freezing.
343 PM CST Fri Jan 24 2020 The weather tonight through Saturday night will be dominated by a large, slow moving upper low pressure system that is over southern IL this afternoon.
Low clouds and light showers will clear this evening, with high pressure returning for the bulk of the weekend.
308 PM MST Fri Jan 24 2020 Temperatures had warmed into the 40s and 50s over the area today with downslope flow in place and ridging overhead. Ridge axis will slide east tonight with a weak wave moving into the region increasing snow chances over the western mountains. While they look to be mainly a mix of rain and snow, there is a very small chance that there could be some freezing rain over northeastern areas if a shallow layer of colder air near the surface develops. Low pressure system over northeast Montana slides east into North Dakota on Saturday with mainly dry conditions for most places, outside of continued snow chances over the southwest mountains.
212 PM MST Fri Jan 24 2020 The upper low center lifting out of the eastern plains will leave a dirty northwest flow pattern in place over the central Rockies and central High Plains region through the weekend with several short wave troughs either skirting around or shearing out across the forecast area for periodic increases and decreases in cloud cover. This will move the cooler airmass out of the region and bring a warming trend to the central High Plains through the weekend.
A plume of moisture, on the eastern flank of the northeastward moving upper low, will keep in widespread rain showers through the evening hours. As for precipitation type, persistent warm advection and overall surface temperature above freezing will support widespread rain through the remainder of the period. Cooler, drier air will filter in behind the frontal boundary Saturday morning.
Similar to recent weather observed in the region, light snowfall at high elevations and a wintry mix of rain, snow, and freezing rain at low elevations are anticipated. The locations favored for freezing rain will shift around as each storm system evolves, however valleys of northwest and west central Montana, as well as portions of Lemhi County (inclusive of Salmon, North Fork, Shoup) are the most likely areas to be impacted by freezing rain. Much of the freezing rain impact will be to sidewalks, driveways, and parking lots. Temperatures will continue to be warmer than the seasonal average throughout the region.
734 PM CST Fri Jan 24 2020 A strong, occluded cyclone continues to move to the east across the OH Valley this evening. West winds around 10 mph will gradually diminish late, with temperatures eventually falling into the lower 30s. A deep upper low is situated just north of the Mid- South. Any threat of rain will end by early this evening as the upper low starts to pull away. Lows will be in the lower 30s with a diminishing west wind. Mean upper trough will remain over the eastern U.
302 PM CST Fri Jan 24 2020 Upper level low over the far northeast zones was spinning and is forecast to slowly shift east as short wavelength upper ridge over the MT/ND border moves east. Water vapor loop indicated an upper low off the Pacific Northwest coast. Upper low will move into central ND by 12Z Sun. Warm advection east of the low will produce some light precip mainly over eastern ND. Warm air aloft may produce the potential for freezing precip in the far western zones Sat afternoon and evening. Given the trend towards warmer temperatures and calm wind conditions, there is a risk for fog especially during overnight periods. Ridging will begin to build into the northern plains into the start of the workweek resulting in dry calm conditions.
Low pressure system centered over Missouri and Illinois will continue slowly drifting north and east this evening. A brief break in cloud cover into the early evening is expected to continue over the eastern forecast area before more clouds along the southern side of the low push in from the west. Dry and cool weather returns on Saturday as high pressure moves back into the region. Highs in the mid to upper 40s and overnight lows in the lower 30s with partly clouds skies.
437 PM MST Fri Jan 24 2020 Upper ridging is building across the northern Rockies to the northern Plains.
308 PM CST Fri Jan 24 2020 Expect clearing skies tonight as the low moves away from the area, and high pressure builds in. Lows tonight should drop to near or just below freezing for the majority of the forecast area, so there may be the possibility of some freezing fog where fog becomes dense enough. Expect dry weather Saturday as high pressure remains in control.
559 PM CST Fri Jan 24 2020 Large low pressure system over north central IL this afternoon will lift northeast into Lake Huron by sunset Saturday. This will bring another round of light rain and snow to the area tonight into Saturday as some cooler air filters into central IL.