Aikyam-Lab/Synoptic-Bench huggingface dataset:
An upper level trough will track east through Nebraska over the next couple of days, which will provide some upper level forcing for cloud formation. Overnight precipitation is expected to be in the form of snow, becoming rainfall on Saturday morning as temperatures warm up past freezing. Temperatures tonight should be somewhat warmer due to cloud cover over the area, with lows in the upper 20s to low 30s. The troughing pattern is replaced by an eastward moving ridge on Sunday. Building high pressure means clear skies and high temperatures in the 40s.
830 PM MST Fri Nov 20 2020 Satellite imagery showing thin band of high clouds associated with a weak trough moving into central Idaho this evening. Sunday night a Pacific trough will come inland with enough cooling aloft, surface wind, and vertical mixing to break up the weak inversion. The trough will bring a slight chance of snow to eastern Oregon Sunday evening, spreading into Valley County/ID late Sunday night.
Surface analysis depicts a strong high pressure ridge extending from the western Atlantic into the Southeastern states, with the Keys lying in a fairly tight pressure gradient along the southern flank of this high. Aloft, lower/mid level ridging remains dominant over our region.
Upper level ridge is building over the area and the primary weather concern for the next day or so will be fog and stratus. This should aid in the formation of patchy freezing fog in the Columbia Basin below 1500-2000 feet and also in the Kittitas valley and along I-90 toward Snoqualmie pass. It's possible that a dense or freezing fog advisory could be needed for the Kittitas Valley later tonight depending on the the fog trends this evening. Ridging building into the region will allow a return and expansion of fog/low stratus tonight and Saturday. Freezing Fog Advisory until noon PST Saturday for WAZ026-520.
155 AM MST Sat Nov 21 2020 MORNING DISCUSSION: Synoptic Setup: Forecast begins with northeast Montana under a slight trough with high clouds spilling off of the Front Range. Over the Pacific Northwest a ridge runs north into British Columbia and is progressing forward. Behind this a series of sub- synoptic ridges and troughs lie in the flow over the Pacific bringing a very progressive pattern to the area, but surprisingly limited moisture. Today into Sunday night: Trough will exit to the east tonight allowing the ridge to move on through.
Temperatures tonight have begun to fall down into the lower 50s to upper 40s and will continue to drop into the low to mid 40s by early tomorrow morning. However, this is still 5 to 10 degrees warmer than the previous chilly mornings from earlier this week. A quasi-zonal pattern present at the start of Saturday will gradually evolve into a more amplified longwave pattern as a trough in western Canada digs southward into the central and eastern CONUS. The stronger forcing/dynamics associated with the trough will lie mainly to our north as the trough axis moves into the region by late Sunday.
1140 PM EST Fri Nov 20 2020 Dry and warm weather will continue before rain chances return on Sunday with a cold front. Moisture will increase once again on Sunday in advance of an approaching cold front. Stratiform rain is expected by morning as a warm front develops northward. More substantial rainfall is expected with the afternoon and evening cold front.
02Z Surface analysis places a 1032 mb ridge of high pressure over East Tennessee, Northern Georgia, and the Carolinas. As of 8 PM CST, temperatures across the Mid-South are in the 50s to lower 60s on the back side of high pressure. Our next chance for showers will be on Sunday when a cold front pushes through the region.
A short upper ridge will then begin to move by late Sunday with the cool front slipping back east late in the day.
At the surface, high pressure over the far northern plains and a weak low over north- central OK has brought moderate north winds to southwest KS, and these winds will weaken and turn northeasterly after sunset. Sunday morning lows will range from at or below freezing in our northwestern zones to the upper 30s near Medicine Lodge as the zone of strongest ascent and associated precipitation exits our area to the southeast.
the cold front was located from Southwest Oklahoma to near a line from Oilton to Grove in Northeast Oklahoma and then extended eastward into Southern Missouri. the cold front is expected to continue to slowly sag southward reaching near a line from Okemah to the northwest corner of Benton co in Northwest Arkansas around 12z Saturday. though with the low confidence will keep any thunder mention out of the grids at this time.
Broad area of high pressure over the region today brought cooler temperatures into the CWA with current readings in the 30s. An area of low pressure and upper level trough will approach the region from northern Montana late tonight into the morning hours on Saturday. This area is where good WAA will intersect the upper level trough and mid level frontogenesis. The decent forcing should over come the low level dry air around 0Z or after. Snowfall amounts of a dusting to an inch will be possible, with the higher amounts occurring in western MN. High pressure will slide across the area Sunday and return slightly cooler conditions compared to the first half of the weekend.
1113 PM CST Fri Nov 20 2020 A weak cold front passed through the region this morning bringing cloudy skies and cooler temperatures. This cold front has stalled out along the I-44 corridor.
Today through Sunday Temperatures today are about 10 to 15 degrees cooler than yesterday.
High pressure will keep Saturday quiet with mostly clear skies, light south winds, and highs at or just above freezing for the region. An upper level trough coming out of the Rockies will move across the Dakotas late Saturday night into Sunday morning forcing a surface pressure minimum and associated cold front that should be able to pull in some mid-level moisture and deliver some light accumulations of 1 to 3 inches of snow to the area, with a final track yet to be determined.
Upper level high pressure over the western Atlantic adjacent to Georgia and South Carolina will weaken and shift eastward today and tonight, with weak upper troughing shifting into the Florida Panhandle by Sunday morning. Strong high pressure to the north of the area this morning will weaken and be replaced by high pressure to the north as a weak frontal boundary shifts southward across the Tennessee Valley and across the Mid Atlantic this afternoon before stalling. Northeast low level flow will continue through tonight, with a series of coastal troughs developing and moving inland. Lows will be in the mid to upper 50s across interior southeast Georgia and the Suwannee Valley, the lower 60s across interior northeast Florida and the southeast Georgia beaches, and the mid to upper 60s at the northeast Florida beaches.
Overall coverage of onshore-streaming showers is slightly lower this evening compared to nights past, mainly due to drier air filtering into the lowest levels of the atmosphere. Overnight lows fall to the low 60s across the interior to upper 60s/low 70s at coastal areas.
Widespread rainfall will return Sunday morning with a crossing cold front. Additional rainfall is expected midweek with crossing low pressure. Latest sfc analysis shows a weak and fairly dry cold front currently sagging south across the Ohio Valley. Moisture will increase once again late tonight as a warm front lifts north. Stratiform rain is progged by Sunday morning with the warm front, then more substantial rainfall is expected Sunday afternoon and evening with the crossing cold front.
Some snowflakes could possibly mix in at the north edge of the rain, but it seems a low chance, and probably will not happen, as dewpoint are not expected to be able to wetbulb low levels to near freezing, and precipitation intensity should be quite light.
Weak upper ridging continues to persist over the region through Saturday night. High temps Saturday will be a couple degrees warmer than Fridays, reaching the middle 70's north of I-65 and the upper 70's nearer the coast.
As high pressure centered over the Dakotas spreads east tonight into Saturday morning, this will allow skies to clear out and winds to drop to near calm, setting up fairly good radiational cooling conditions. As the high pressure center shifts to the east of the WFO MPX coverage area by daybreak, this will allow for warmer return flow on the backside of the high into the area. A deep pre-cold- frontal trough will swing through the area Saturday night, helping spread precipitation from west to east across the area Saturday night into Sunday morning. The cold front of the aforementioned Canadian frontal system drops southeast through MN/WI Sunday morning, making for mainly -SN in the eastern half of the WFO MPX during the morning.
1258 AM EST Sat Nov 21 2020 High pressure will prevail across the area through the weekend, as a weak coastal trough remains nearby.
408 AM MST Sat Nov 21 2020 Current surface analysis shows a nearly stationary frontal boundary to the north of the region, with an area of high pressure centered to the east. A developing trough is located to the lee of the Rockies. Weak cold front passages in west-northwest flow will help to produce gusty winds at times, but little in the way of moisture for most areas.
A weak cold front will stall across the northern Big Country this morning. Very minimal effects are expected from this front, with light north winds behind it and slightly cooler temperatures. Expect highs today to range from the low to mid 70s across the Big Country to the mid to upper 70s elsewhere. A cold front will slowly move through the Big Country early Sunday morning, approaching the Interstate 20 corridor by daybreak.
Sunday night, a cold front approaches the area, giving us our first shot of pops in a few days.
519 AM EST Sat Nov 21 2020 A rather strong high pressure remains anchored over the Appalachians this morning. Meanwhile, an inverted trough is beginning to move into the far southeastern Bahamas and pivoting northwest. This along with the convergence between the high to our north and the inverted trough to our southeast is creating widely scattered showers. Breezy conditions expected today as the aforementioned high and inverted trough keep an enhanced gradient over the area. The inverted trough will swing out to the northeast.
Additional cooling is likely into Thanksgiving Day as a broader trough digs over the west, with chilly weather expected in the mountains, and periods of gusty west winds also likely, but no precipitation is expected.
/issued 351 AM CST Sat Nov 21 2020/ A cold front is currently moving into southern Missouri and western Kentucky early this morning while high pressure covers the southeast states. Expect the cold front to become stationary just north of the forecast area today due to a blocking ridge to the southeast. The frontal boundary will become a cold front again tonight as it progresses through the forecast area on Sunday.
Water vapor imagery shows high pressure beginning to build over Central California ahead of an upper level low spinning near 35 North and 134. In fact, the coldest spots in the North Bay are already nearing the freezing mark. The trough over the North Pacific will kick the upper level low near 35 North and 134. As the trough moves inland on Sunday and Sunday night, it will bring rain to the Pacific Northwest.
Sunday will see a period of steady/gusty winds for the first part of the day until the surface gradient relaxes in the aftn as high pressure settles in.
415 AM CST Sat Nov 21 2020 Early morning sfc analysis shows high pressure centered over the TN Valley ridging wwd across the forecast area at this time, maintaining a light erly low-level flow. Elsewhere, a weak cold front is noted to our north, extending from the OH Valley wswwd through the Ozarks/Red River Valley to the TX Big Bend Region. Water vapor imagery the area caught between ridges while a generally zonal flow aloft remains in place to our north.
405 AM EST Sat Nov 21 2020 Cooler and mainly dry conditions are expected today with precipitation moving back in tonight into Sunday. Precip will start as rain for the entire area, with wet bulb zeros dropping late tonight into Sunday morning to near freezing. Thermal profiles have suggested that temperatures may be just warm enough across the southeast to limit snow accumulation on mainly grassy surfaces with better potential a bit further north where lows near/below freezing expected. Temperatures are expected to climb back well above freezing on Sunday so any slick spots will quickly improve. High pressure will briefly build in with increasing upper level heights into the start of the work week.
A ridge extending from the northern Atlantic to the mid-Atlantic states and SE US will begin to lift NE tonight. Shower are expected to continue this afternoon and evening, with the highest coverage being from KTIX southward this afternoon and then shifting to KVRB southward this evening.
As high pressure builds into the Central Plains, expect skies to clear.
High temperatures will range from the lower 40s west to lower 50s east. It will be cooler tonight with overnight lows in the teens. A ridge of high pressure will shift east of the CWA Sunday night with light southwesterly winds.
Shower activity will decrease by the afternoon hours as a ridge of high pressure amplifies across the Pacific Northwest. The upper level ridge axis will shift across the Northern Rockies Saturday night into Sunday morning.
By sunrise, widespread 30s will be likely across the Sacramento and northern San Joaquin Valleys with some communities in wind-sheltered areas near the freezing mark. Conversely, locations with breezy conditions will be a bit warmer at sunrise. Tranquil weather will prevail on Saturday as weak ridging develops from the Pacific Northwest through northern California. A stronger trough will approach the Pacific Northwest during the day on Sunday. If anything, this system will likely provide us with increased high clouds, slightly cooler afternoon temperatures, and slightly warmer overnight temperatures.
We expect increasing clouds as the trough moves east, and satellite data continues to show a broad shield of mid to high clouds moving into northwest ND. Warm advection preceding the low should help temperatures rise into the low to mid 40s across the southern half of the state, remaining in the 30s across the north. Clouds will decrease tonight, but probably not clear, after the low exits.
635 AM EST Sat Nov 21 2020 High pressure to the north will weaken today and tonight before a coastal trough moves through on Sunday.
906 AM EST Sat Nov 21 2020 High pressure to the north of the area will maintain a northeast to easterly wind flow across the forecast area the remainder of today. Adequate low level moisture below a subsidence inversion around 825MB (via 12Z Raob data) will support intervals of clouds and possibly a few sprinkles or isolated showers the remainder of today, mainly from the I-4 corridor south where the best moisture will reside, otherwise breezy and warm conditions with afternoon temperatures climbing into the lower 80s can be expected. High pressure northeast of the waters will maintain a 5-6Mb gradient over the Gulf waters the remainder of today.
Then a cold front will slide across the area on Sunday evening bringing slightly cooler temps and a westerly wind shift.
950 AM EST Sat Nov 21 2020 High pressure to the north will weaken today and tonight before a coastal trough moves through on Sunday.
This trend is a hair warmer than the previous forecast, which takes into account some late day clearing and a period of downsloping winds in the west. The progressive upper trough pushes into the Great Lakes and is replaced by a quick building ridge over the High Plains. At the surface, high pressure settles right over the central Conus. Highs should be a few degrees cooler than Saturday, ranging from mid 40s in the north to near 50 far south.
351 AM CST Sat Nov 21 2020 A cold front is currently moving into southern Missouri and western Kentucky early this morning while high pressure covers the southeast states. Expect the cold front to become stationary just north of the forecast area today due to a blocking ridge to the southeast. The frontal boundary will become a cold front again tonight as it progresses through the forecast area on Sunday.
329 AM CST Sat Nov 21 2020 Overnight the surface cold front made its way out of Kansas and into Oklahoma with few scattered post frontal showers evident over southeast KS early this morning. The latest model runs are much more progressive with the trough and blows it through by tonight, thus thinking we shut off the rain showers early in the tonight period with only a few areas of residual drizzle possible early tomorrow morning.
Heading into Sun, the upr flow pattern wl begin to amplify as a long wv trof drops Sewd thru the Plains and eventually passes thru the MS River Valley region Sun aftn/early Sun ngt. Drier and cooler air wl advect into the FA Sun ngt.
Warm advection preceding the low should help temperatures rise into the low to mid 40s across the southern half of the state, remaining in the 30s across the north. Clouds will decrease tonight, but probably not clear, after the low exits.
The first of these is a cold front which is expected to be in southeast KY and about to exit into Virginia as the period starts.
A surface cold front is currently parked across the IL/KY border and will slowly sag southward through the day today. Into tomorrow we are expecting showers associated with a cold front to swing through the area.
651 AM EST Sat Nov 21 2020 Cooler and mainly dry conditions are expected today with precipitation moving back in tonight into Sunday. Precip will start as rain for the entire area, with wet bulb zeros dropping late tonight into Sunday morning to near freezing. Thermal profiles have suggested that temperatures may be just warm enough across the southeast to limit snow accumulation on mainly grassy surfaces with better potential a bit further north where lows near/below freezing expected. Temperatures are expected to climb back well above freezing on Sunday so any slick spots will quickly improve. High pressure will briefly build in with increasing upper level heights into the start of the work week.
240 AM MST Sat Nov 21 2020 Current surface analysis shows a nearly stationary frontal boundary to the north of the region, with an area of high pressure centered to the east. A developing trough is located to the lee of the Rockies. Weak cold front passages in west-northwest flow will help to produce gusty winds at times, but little in the way of moisture for most areas.
528 AM CST Sat Nov 21 2020 Overnight the surface cold front made its way out of Kansas and into Oklahoma with few scattered post frontal showers evident over southeast KS early this morning. The latest model runs are much more progressive with the trough and blows it through by tonight, thus thinking we shut off the rain showers early in the tonight period with only a few areas of residual drizzle possible early tomorrow morning.
There will be increasing high clouds as the upper trough approaches, but at least some sunshine today. A lot of the soundings are right at the zero mark in the low levels, so it will take very little change in temps to make a bit difference in precip type.
/issued 246 AM EST Sat Nov 21 2020/ Mid level ridging will continue to hold over northern Florida today and tonight before pushing east into the Atlantic on Sunday as a broad trough swings through the central and eastern CONUS. A series of weak impulses on the southern edge of this mid level ridge will translate to periods of sprinkles and light showers continuing through the rest of the weekend, but significant downpours are not expected. At the surface, a ridge of high pressure to the north of Florida will keep moderate northeast to east winds in place through the rest of the weekend.
257 PM EST Sat Nov 21 2020 Another nice day expected across the area with high pressure at the surface and aloft. Mid-level high pressure across the area is expected to weaken and shift east as a trough develops across much of the eastern US.
As this low pushes east, staying north of the International Border, the cold front will drag south through the forecast area, bringing a chance of precipitation to portions of the north.
913 AM PST Sat Nov 21 2020 Cooler weather is in store this week with temperatures mostly near to slightly below normal for most days.
Early risers may have dealt with some frost on their cars or on the ground as morning temperatures are generally running around 2-6 degrees cooler than yesterday morning. Despite the chilly start, there will be some weak ridging this afternoon which should give us our warmest daytime highs for the weekend. The trough over the North Pacific will kick the upper level low near 35 North and 134. As the trough moves inland on Sunday and Sunday night, it will bring rain to the Pacific Northwest.
Along with the southwest winds just to the west of the Valley, this has been enough to provide the warmer boost. The timing of precipitation into west central Minnesota by mid to late evening, along with the higher elevation there, would favor this as the best area for 1-2 inches of snow. Since it appears to be a fast moving system, and temperatures have been warmer than anticipated, will not mention any higher end amounts. Sunday should be a cooler day, with northwest winds becoming rather breezy.
VFR to continue with high pressure overhead. /issued 920 AM CST Sat Nov 21 2020/ Early morning fog has dissipated over the lower Acadiana region.
Decent looking mid-level trof/pv anomaly will work its way across the region through tonight. An addition, a nice, sharp H700 thetae ridge is progged to move over the forecast area under a jet streak aloft. For the most part it'll be rain, but with some snow toward mid-evening, and mainly over the higher elevations of the Coteau/Sisseton Hills. Ridging aloft then builds into the region for Sunday and Sunday night with generally dry conditions anticipated.
1134 AM CST Sat Nov 21 2020 Overnight the surface cold front made its way out of Kansas and into Oklahoma with few scattered post frontal showers evident over southeast KS early this morning. The latest model runs are much more progressive with the trough and blows it through by tonight, thus thinking we shut off the rain showers early in the tonight period with only a few areas of residual drizzle possible early tomorrow morning.
1240 PM EST Sat Nov 21 2020 High pressure to the north will weaken today and tonight before a coastal trough moves through on Sunday.
Weak upper ridging continues to persist over the region through tonight. High temps today will be a couple degrees warmer than yesterday, reaching the middle 70's north of I-65 and the upper 70's closer to the coast. Lows tonight will range from the low to mid 50s over most of our interior counties to the low to mid 60s closer to and along the immediate coast.
Only other item this weekend will be the persistent north wind within the lower Colorado River Valley. Any impacts from these systems still looks minimal and will come in stints of gusty north winds and cooler/seasonable temperatures.
116 PM MST Sat Nov 21 2020 Progressive westerly flow will become a little more active as passing upper troughs trend more amplified.
152 PM CST Sat Nov 21 2020 A cold front stretched from extreme northwest AR to south of Okmulgee early this afternoon, with cloudy, cool, drizzly and showery weather observed north of the boundary. Considerably warmer conditions noted south of the front, along with some breaks/thinning of the cloud cover. A few strong/marginally severe storms aren't out of the question, although updrafts will likely get undercut by the southward moving cold front during the evening hours.