Aikyam-Lab/Synoptic-Bench huggingface dataset:
These showers are bringing snow to the higher terrain, while precipitation type is more complicated in the valleys of west central Montana. The inverted valleys are experiencing a wintry mix with the main impact being freezing rain. The models are still indicating yet another weak cold front pushing through the Northern Rockies on Sunday. This front will drop a few inches of new snow in the higher terrain. Those aforementioned valley inversions could create another round of freezing rain.
500mb RAP analysis and water vapor imagery showed an upper closed low over northern Indiana overnight, with northwest flow behind it across the tri-state region as a ridge built along the west coast. Sunny skies return by the afternoon as the disturbance passes and ridging amplifies across the Great Basin. The ridge advances to the Rockies tonight as temperatures fall into the 20s. An upper trough digs towards the desert southwest, weakening the ridge progressing to the High Plains ahead of it. There continue to be a couple upper level short wave troughs that will move through the forecast area.
High pressure over the central Gulf coast region this morning will track eastward and move across the Sunshine State on Sunday.
By afternoon, the snow will be in far eastern Illinois with only a dusting expected since temperatures will remain above freezing during the day. The clouds will keep temps above freezing today, but below freezing temps will return tonight as slightly colder air moves into the area. However, with the eastern half of the US still in a broad trough, a short wave drops through the area early in the week. Will bring ceilings to MVFR at KSPI in a couple hours, but will be more pessimistic with the improvement elsewhere due to proximity of the low and residual light snow.
This low level moisture was associated with the aforementioned low and has helped keep temperatures nearly steady overnight in this area. Patchy freezing fog has developed in a few locations, however is not expected to become widespread. Freezing fog could develop near/over bridges and overpasses creating slick conditions before the sun has a chance to warm road surfaces. At the surface, high pressure will quickly move across the state. Winds will become southerly this afternoon as the high moves east and the low moves closer. On Sunday/Sunday afternoon, the secondary surge of precipitation will move across the state just ahead of a weak Pacific cold front. This cold front will be lacking significant baroclinicity thus the only forcing will be low level convergence of wind fields.
An area of showers is currently moving across the area associated with the upper low that has provided the rain the last two days. That upper low is lifting northeastward out of the Midwest toward the Great Lakes. Temperatures remain above freezing even on the plateau at the moment. LAPS soundings from the plateau show the lowest 250-500 meters still above freezing. With that said, as temperatures continue to cool a couple degrees and the entire column drops below freezing, a few snow flakes may mix in before moisture moves off the plateau this morning. The entire area should drop below freezing tonight with some breaks in the cloud cover.
Elsewhere, dry conditions and quiet weather are expected today as a ridge of high pressure builds overhead.
By Sunday, subsidence behind the weak trough will allow for clearing skies, warming temperatures into the mid and upper 40s for much of the region.
Overnight into Sunday morning, visibilities may drop due to possible patchy fog development before the approaching weak cold front. The upper level pattern will support a strengthening pressure gradient between the high pressure over the Southeast and low pressure developing over northeastern Mexico and the Texas Panhandle, leading to an increased southeasterly surface flow over our CWA today. The low forming over the Texas Panhandle will drag this front through deep south Texas Sunday morning, bringing a brief wind shift and drier air, but no noticeable cold air advection.
A weak surface front extended from eastern MT to northeast CO, and a trough over central/southwest WY. As the trough tracks east across MT this afternoon, 850 mb CAG-CPR height gradients increase to 50-60 mtrs. Upgraded the High Wind Watch to a Warning for the North Snowy Range Foothills including Arlington/Elk Mountain for gusts near 60 mph. Winds will diminish Sunday as the upper trough approaches the Upper Midwest and the low-level height gradients relax.
418 AM MST Sat Jan 25 2020 Upper trough across CO has brought light snow showers to the central mountains overnight. Temperatures aloft cool behind the trough today, but breezy northerly winds provide sufficient mixing to offset this somewhat and should still see temperatures climb into the 50s across the plains, with 30s and 40s for the valleys and lower mountain communities, and 20s and 30s across the higher terrain. Meanwhile, lee troughing across the plains will keep temperatures in the upper 20s and 30s for the better draining locations in and near the eastern slopes of the southeast mountains.
High pressure is shifting east of the region and setting up southwest flow across eastern North Dakota. A warm frontal boundary moves across the northern tier today, and a band of precipitation is expected to form along and ahead of the boundary, entering the Devils Lake basin mid-afternoon. Soundings support freezing drizzle (very dry air aloft) however increased forcing could lift the parcel into the DGZ enough to allow some light snow to fall as ice is introduced into the cloud. Although QPF values will be light, any freezing drizzle on untreated surfaces will likely result in travel-related impacts. We also can't rule out smaller scale patterns that support fog or brief freezing drizzle development, but these are always hard to anticipated there isn't a specific period in the extended I am confident in highlighting.
The overarching stratus deck however, looks to be stubbornly hanging on for most of the CWA and models indicate saturation in the low levels for most of the day. Even with the continued cloud cover, highs are still expected to be several degrees warmer than the past several days ranging from the low to mid 40s in the west and southwest to the low to mid 30s in the northeast. Tonight winds will shift back to the northwest as a weak surface trof moves over the Dakotas and could usher in some midlevel clouds just as the lower stratus deck starts to clear out. This added insulation along with the warmer daytime temps should help keep lows from dropping too far.
612 AM MST Sat Jan 25 2020 Mostly sunny skies expected this morning with windy conditions over the ridge tops with low pressure over southern Saskatchewan. A weak cold front extending from the low will dip into the northeast corner of the state today with another chance for light mixed precipitation during the afternoon and evening.
Brief upper level ridging has built over NorCal overnight. Because of the higher snow levels during the time of heaviest precipitation, snow amounts are not likely to be very high and snow accumulation is not expected until late Saturday night/early Sunday morning. Precipitation from this system is expected to move out of the area by Sunday night and the upper trough moves east into the Great Basin region.
216 AM MST Sat Jan 25 2020 500mb RAP analysis and water vapor imagery showed an upper closed low over northern Indiana overnight, with northwest flow behind it across the tri-state region as a ridge built along the west coast. Sunny skies return by the afternoon as the disturbance passes and ridging amplifies across the Great Basin. The ridge advances to the Rockies tonight as temperatures fall into the 20s. An upper trough digs towards the desert southwest, weakening the ridge progressing to the High Plains ahead of it. There continue to be a couple upper level short wave troughs that will move through the forecast area.
The upper level pattern will support a strengthening pressure gradient between the high pressure over the Southeast and low pressure developing over northeastern Mexico and the Texas Panhandle, leading to an increased southeasterly surface flow over our CWA today. The low forming over the Texas Panhandle will drag this front through deep south Texas Sunday morning, bringing a brief wind shift and drier air, but no noticeable cold air advection.
428 AM CST Sat Jan 25 2020 Today through tonight: A stratus deck associated with cyclonic flow around a slowly departing closed low has been tenacious over north central MS.
600 AM CST Sat Jan 25 2020 (12Z TAFS) MVFR conditions are possible after 00Z as ceilings lower from a progressive low pressure system crossing overhead.
GOES satellite imagery shows a broad, stacked mid-latitude cyclone over the midwest, centered near the southern tip of Lake Michigan. The exception being in the high elevations of the Allegheny Front and north of I- 80 where light accumulating snow is possible. Showers will generally decrease through the night, though upsloping will maintain light snow in the ridges. The large scale trough responsible for this weekend's wet weather will progress northeast on Sunday.
The most impactful being the upper low now across Indiana, moving to the northeast. Cloud cover will slowly erode from southwest to northeast today and have gone on the cooler side of guidance for highs, generally following the HREF given snow on the ground in the northern CWA and cloud cover as additional high clouds will also be streaming in during the afternoon.
224 AM MST Sat Jan 25 2020 Areas of dense freezing fog over the eastern parts of the forecast will gradually dissipate early this morning as a weak surface boundary pushes the low level moisture off to the east. Breezy to windy northwest winds will develop as a weak surface from moves through in association with the upper trough. Quiet weather and slightly warmer than average temperatures will continue on Sunday.
/issued 421 AM CST Sat Jan 25 2020/ High pressure centered overhead is yielding clear skies and calm winds this morning.
611 AM EST Sat Jan 25 2020 Very moist low level conditions will remain entrenched over the southeast Michigan airspace today, as a low pressure system slowly tracks across the region. A window for light snow and a meaningful reduction in visibility centers this evening /00z-05z/ as the low exits the region. Feasible that patchy fog could hang on along the glacial ridge or in the northern reaches of the Thumb until that time. As the resident closed low is ushered east late tonight into Sunday, moist cyclonic flow will be aided by modest lake enhancement warranting high chc pops for scattered snow showers. Southeasterly winds will continue to slowly veer to west-northwest during the day today as the center of the low crosses the lower peninsula and central Lake Huron.
541 AM CST Sat Jan 25 2020 For aviation section The deep upper level low pressure system that has plagued the region for quite some time will slowly draw off to the northeast today, taking precip chances with it. A weak mid level short wave will slide east from the southern plains into the lower MS River Valley on Sunday.
There are areas of fog/mist/freezing drizzle to note including the Lost River Valley, Upper Snake Valley and Bear Lake Region. As such, snow amounts during this event are not particularly high for the lower Snake River Plain and are 1/2 an inch or less and in some cases with no snow forecast at all.
Surface reflection of the passing wave will be cyclone development over the southern Texas Panhandle this afternoon and eastward progression along the Red River tonight. This will create a southerly to northerly wind shift as the low passes, but little in the way of change in airmass.
A glaze of freezing rain is possible over the highest elevations of the North Central Mountains this morning. Across the far north, temperatures are just cold enough for the higher ridges to see a glaze of ice this morning in parts of the North Central Mountains. Orographic enhancement could result in higher totals of around 2 inches on the ridgetops of southeast Pa. Scattered showers associated with arrival of upper low will produce lingering scattered rain showers into the afternoon hours. However, accumulations appear unlikely due to surface ridging, low inversion heights and surface temperatures remaining above freezing.
To the east this trough low-level moisture continues to persist with widespread low clouds and fog. Downslope west to northwest winds will develop as the trough advances east, and this will help boost highs into the upper 40s and lower 50s across western and southwest Nebraska.
/EC/ Today through tonight: A stratus deck associated with cyclonic flow around a slowly departing closed low has been tenacious over north central MS.
A large upper level trough with a massive cloud shield extended from the Great Lakes down across the Ohio Valley and Tn Valley. Locations southwest of BNA will have the best chance for some breaks in the clouds this afternoon and early evening as the trough starts to lift. Highs will be mainly in the lower 40s.
Sounding profiles suggest a warm nose at low to mid-level, while temperatures remain below freezing at the surface. This could result in light wintry mix (light freezing drizzle/flurries) with better chances north of I-90. A mid-upper level trough dives southeast from Alberta region by Sunday evening.
433 AM MST Sat Jan 25 2020 Areas of dense freezing fog over the eastern parts of the forecast will gradually dissipate early this morning as a weak surface boundary pushes the low level moisture off to the east. Breezy to windy northwest winds will develop as a weak surface from moves through in association with the upper trough. Quiet weather and slightly warmer than average temperatures will continue on Sunday.
Dry weather then returns as another ridge of high pressure builds over the region. High clouds and moisture are streaming south and east across central CA over the top of a Pacific high pressure ridge. Today will be generally mild under the amplifying ridge ahead of an approaching low pressure trough. Current progs show the trough and associated precipitation pushing southward into northern portions of central CA later tonight and continuing into Sunday afternoon. The passing trough will also bring increasing northwesterly winds Sunday afternoon into the evening, mainly through and below the Kern County mountain passes.
400 AM CST Sat Jan 25 2020 The deep upper level low pressure system that has plagued the region for quite some time will slowly draw off to the northeast today, taking precip chances with it. A weak mid level short wave will slide east from the southern plains into the lower MS River Valley on Sunday.
335 AM CST Sat Jan 25 2020 Cyclonic flow will continue today in the wake of the upper low departing the OH Valley. All in all the highs today will be on the order of 3 to 10 degrees below average. However the low clouds will be chased by increasing mid- high clouds spreading in from the west-northwest in advance of several northwest flow short wave trofs with the progressive split flow pattern. All the models are now in rather good agreement keeping any precipitation south of the CWA, more in line with the better forcing across the lower MS and western TN Valleys.
There is one hole in the lower cloud layer that has opened up in southern middle TN into far northern Madison and Jackson Counties. Also, as the upper jet axis shifts northeast and 8h trough and cold pocket aloft pull to the east and northeast, there will be a better chance for erosion of the clouds from southwest to northeast. Tonight will remain partly cloudy and a few degrees cooler than this morning, bottoming out in the upper 20s/lower 30s in the E, and the lower 30s W.
606 AM CST Sat Jan 25 2020 For the 25/12z TAFs, patchy fog and patchy freezing fog will be possible across Southwest Arkansas and North Central Louisiana for the first couple of hours of the period, but conditions should quickly improve back into the VFR range at all terminals.
The overarching stratus deck however, looks to be stubbornly hanging on for most of the CWA, and models indicate saturation in the low levels for most of the day. Even with the continued cloud cover, highs are still expected to be several degrees warmer than the past several days. ranging from the low to mid 40s in the west and southwest, to the low to mid 30s in the northeast. Tonight winds will shift back to the northwest as a weak surface trof moves over the Dakotas and could usher in some midlevel clouds just as the lower stratus deck starts to clear out. This added insulation along with the warmer daytime temps should help keep lows from dropping too far.
258 AM PST Sat Jan 25 2020 Low pressure will move through northeast California, the Sierra, and western Nevada tonight and Sunday.
Several hours ago the lowest visibilities were near I-94, now that area is largely north of I-96 and it continues to shift north with time. Temperatures area mostly near or just above freezing so there could be some icy patches on less traveled roads. A quasi-cold front moves south across the area Sunday and that will turn winds to a more northerly direction and also end most of the light snow showers that will be happening during the mid morning hours.
555 AM CST Sat Jan 25 2020 Cyclonic flow will continue today in the wake of the upper low departing the OH Valley. All in all the highs today will be on the order of 3 to 10 degrees below average. However the low clouds will be chased by increasing mid- high clouds spreading in from the west-northwest in advance of several northwest flow short wave trofs with the progressive split flow pattern. All the models are now in rather good agreement keeping any precipitation south of the CWA, more in line with the better forcing across the lower MS and western TN Valleys.
256 AM PST Sat Jan 25 2020 Low pressure will move through northeast California, the Sierra, and western Nevada tonight and Sunday.
Expect readings to reach the lower 50s over most of the plains, with 20s to lower 30s over most of the mountains. Winds will increase across the plains (mostly east of the I-25 Corridor) behind the trough passage this morning. Sunday will be a mild day across the forecast area as an upper ridge builds over the state. The plains should see high temperatures in the lower to mid 50s while the mountains top out in the 20s to mid 30s under mostly sunny to partly cloudy skies.
723 AM EST Sat Jan 25 2020 Low pressure and its associated cold front will move through this morning. High pressure then builds in behind the front for the second half of the weekend.
421 AM CST Sat Jan 25 2020 High pressure centered overhead is yielding clear skies and calm winds this morning.
926 AM EST Sat Jan 25 2020 The cold front that moved through overnight and this morning has left much cooler and drier air in its wake. Skies are also rapidly clearing out as high pressure is building in along the Gulf Coast states. Glancing at 9 am surface observations, most of east central Florida has temperatures in the mid-upper 50s with dewpoints running in the low-mid 50s. The lower dewpoints and WNW/NW winds around 10 mph should make for a very comfortable day outside.
Went with MAV/MEX for forecast highs instead of NBM as the NBM is typically too cool on the return of warmer air. Showers and a few thunderstorms should be returning to the local area mid week as a slightly more amplified trough moves right in the path of the one before it. A gradual weakening in wind speeds is likely as well as the center of the ridge closes in on the local area.
Tomorrow will be a beautiful Winter day, with light winds under a building ridge to the west, plenty of sunshine and temperatures approaching 70 in many locations.
1125 AM CST Sat Jan 25 2020 High clouds will continue to increase this afternoon as upper trough over northeast Mexico continues to shift eastward. /issued 1008 AM CST Sat Jan 25 2020/ Mild and dry through the rest of the day with increasing clouds from west to east ahead of an approaching upper trof. /issued 421 AM CST Sat Jan 25 2020/ High pressure centered overhead is yielding clear skies and calm winds this morning.
Expect dry weather and warmer than average daytime temperatures through Sunday.
In the mean time, temperatures will likely rise well into the 50s for many this afternoon thanks to a good amount of solar radiation reaching the surface despite the high clouds and light southeasterly winds.
19z/1pm surface analysis shows a 1007mb low over the Upper Peninsula of Michigan with a trough extending into northeast Illinois. While the steady light snow associated with the low has shifted into northern Indiana/Michigan, a few snow flurries or light snow-showers persist north of the I-74 corridor. Since the low will only make very slow progress northeastward, have opted to include slight chance PoPs for light snow northeast of a Bloomington to Paris line through this evening. Elsewhere around central Illinois, cloudy and cool conditions will prevail with overnight lows dropping into the lower to middle 20s. End result will be a continuation of overcast conditions with highs in the lower to middle 30s on Sunday.
1021 AM MST Sat Jan 25 2020 Upper trough across CO has brought light snow showers to the central mountains overnight. Temperatures aloft cool behind the trough today, but breezy northerly winds provide sufficient mixing to offset this somewhat and should still see temperatures climb into the 50s across the plains, with 30s and 40s for the valleys and lower mountain communities, and 20s and 30s across the higher terrain. Meanwhile, lee troughing across the plains will keep temperatures in the upper 20s and 30s for the better draining locations in and near the eastern slopes of the southeast mountains.
Tonight and Sunday Slow moving, vertically stacked low pressure continues to track across the Great Lakes. Limited mid-level moisture will lead to patchy drizzle and freezing drizzle as well. Lack of mid-level moisture could produce patchy drizzle and freezing drizzle as well.
1010 AM EST Sat Jan 25 2020 A weak cold front is now making its way through the deep Gulf waters northwest of Key West.
1229 PM EST Sat Jan 25 2020 Aviation Low pressure will move through Lower Michigan today with scattered snow showers continuing through Sunday. Several hours ago the lowest visibilities were near I-94, now that area is largely north of I-96 and it continues to shift north with time. Temperatures area mostly near or just above freezing so there could be some icy patches on less traveled roads. A quasi-cold front moves south across the area Sunday and that will turn winds to a more northerly direction and also end most of the light snow showers that will be happening during the mid morning hours.
A large upper level trough with a massive cloud shield extended from the Great Lakes down across the Ohio Valley and Tn Valley. Locations southwest of BNA will have the best chance for some breaks in the clouds this afternoon and early evening as the trough starts to lift. Highs will be mainly in the lower 40s. The upper level trough will keep the low/middle clouds over Middle TN through the TAF period. Once the low clouds break it will be back to MVFR.
A transitory ridge will build over the northern Great Basin and Northern Rockies today, keeping northwest flow over the region into Sunday. This ridge will shift eastward over the forecast area during the day Sunday, backing the upper level winds to the southwest.
KSOA should have ceilings on the low end, around 1000 ft. The low cloud field should shift east and south out of our area early Sunday morning, with VFR conditions expected at all of our TAF sites by or just before 13Z.
There will be a warmer than 0C warm nose out ahead of this forcing, which will bring the threat of a freezing rain/snow mix depending on how long this warm nose can hold out.
231 PM EST Sat Jan 25 2020 High pressure will build south of the area through Sunday.
NEAR TERM [Through Tonight] High pressure will continue to build in tonight.