Aikyam-Lab/Synoptic-Bench huggingface dataset:
In the wake of this system, H500 flow will be steeply out of the north and surface ridging will plunge south. Sunny skies will accompany cool temperatures on Tuesday as surface and upper ridging build in briefly.
232 PM MST Mon Jan 20 2020 A backdoor cold front has been moving west across the CWA today. As of 21Z, the cold front was situated diagonally across the center of the GLD CWA. This occurs ahead of an approaching 500 mb trough. Expect temperatures to drop into the lower teens to 20s tonight. There is potential for some fog/freezing fog tonight/tomorrow morning in the southwest corner of the CWA.
High pressure over Texas will move east tomorrow with an upstream upper level ridge axis expected to move over the area tomorrow afternoon/evening. Approach jet streak behind the ridge axis will help stream high clouds into the area and cloud cover should continue to increase Tuesday night.
726 PM EST Mon Jan 20 2020 High pressure will slowly build into the area through mid week.
Brought tomorrows highs over Havre down a bit given how they have been having a hard time moderating to the warmer airmass that is right on their doorstep.
225 PM MST Mon Jan 20 2020 Thanks to an upper ridge, main challenge over the next few days will be temperatures with elevation playing the main role. Snowcover in the northern valleys will keep them colder than adjacent ridges.
This system will be warmer than last weeks storm with snow level generally above 5000 feet. The higher snow levels and low snowfall rates should decrease travel impacts, although still could see chain controls.
534 PM CST Mon Jan 20 2020 VFR will dominate the next 18-21 hours or so, with an upper ridge axis currently transitioning east, and increasing high clouds overnight. A fast moving upper trough currently nearing the southwest US coastline will race across the area late Tuesday spreading light rain through the area. Temps at the surface are expected to remain above freezing as CAA will be non-existent as surface winds remain out of the south to southeast with cooling coming in the form of web bulbing. Surface WAA should help keep temps mostly above freezing rain threshold.
1021 PM MST Mon Jan 20 2020 Warmer air is flowing into the region this afternoon as the upper ridge builds over the region from the west.
338 AM EST Tue Jan 21 2020 High pressure builds into the region today and crests over the region tomorrow with mainly clear skies.
920 PM PST Mon Jan 20 2020 A weak Pacific trough will spread high clouds over southern California tonight with sprinkles or light showers at times through early Tuesday.
Tuesday and Tuesday night will be warmer than today as an upper- level ridge axis builds across the Central CONUS.
1017 PM EST Mon Jan 20 2020 High pressure will slowly build into the area through mid week.
At the surface, high pressure will result in northeasterly winds transporting an airmass sourced from the Eastern Seaboard. Lighter winds are expected overnight, which will allow temperatures to fall a couple degrees cooler than this morning.
150 AM MST Tue Jan 21 2020 A backdoor cold front has been moving west across the CWA today. As of 21Z, the cold front was situated diagonally across the center of the GLD CWA. This occurs ahead of an approaching 500 mb trough. Expect temperatures to drop into the lower teens to 20s tonight. There is potential for some fog/freezing fog tonight/tomorrow morning in the southwest corner of the CWA.
Aloft, GOES east shows a cutoff low pressure system churning over Kentucky. Enhanced lift, associated with this low, has resulted in light snow developing across portions of eastern Arkansas. As this low pivots southeast overnight, snow flurries will likely continue across much of the forecast area through early morning. Low temperatures are expected to fall into the low to mid 20s areawide by Tuesday morning.
Latest forecast models call for slightlywarmer temperatures overnight and Tuesday morning. Overall, a warming trend is expected with highs expected to reach the low 40s by mid week. FGC Previous discussion: Thanks to an upper ridge, main challenge over the next few days will be temperatures with elevation playing the main role. Snowcover in the northern valleys will keep them colder than adjacent ridges.
By mid to late morning, although the inversion remains in place, high pressure at 850mb will be moving into Indiana, cutting off the moisture supply from Lake Michigan. Also at that time the strong high at the surface will be entering the lower Ohio Valley, introducing a much drier air mass. Went on the cool side of guidance for highs today given the expected morning clouds, with temperatures peaking around the freezing mark this afternoon.
High pressure will be in place today with skies clearing through the morning hours.
Lows will be in the lower 20s for most of the forecast area, with early morning wind chills in the 8-12 degree range based on a northerly wind of 10-15 MPH (and occasional gusts of 15-20 MPH). Ridging over the Plains slowly pushes eastward as high pressure over the mid-atlantic weakens.
The next robust low pressure system is forecast to approach Tuesday morning and afternoon, bringing a quick moving wave of widespread precipitation across the area. The cold front passage will move through late Tuesday afternoon and evening, and showers will quickly diminish thereafter as snow levels lower to valley floors.
825 PM MST Mon Jan 20 2020 Much warmer temperatures this evening than then last few. The east was cooler with 20s. High pressure ridging will hold over the forecast area today into tonight. A zonal flow aloft will prevail Tuesday as the ridge gets flattened in response to an upper low and trough that moves onto the Washington and B. Temperatures are expected to warm a few degrees more with readings ranging from the lower 40s along the Dakota borders to upper 40s along the foothills.
Low clouds and flurries are finally beginning to diminish across the area, and this trend will continue into today as the upper trough over the area gives way to an upper ridge building in from the west and the low level cold advection dissipates.
1052 PM CST Mon Jan 20 2020 Upper level ridge axis passing overhead early this morning with increasing high clouds and scattered low-base mid clouds dominating the next 15-18 hours. /issued 534 PM CST Mon Jan 20 2020/ VFR will dominate the next 18-21 hours or so, with an upper ridge axis currently transitioning east, and increasing high clouds overnight. A fast moving upper trough currently nearing the southwest US coastline will race across the area late Tuesday spreading light rain through the area. Temps at the surface are expected to remain above freezing as CAA will be non-existent as surface winds remain out of the south to southeast with cooling coming in the form of web bulbing. Surface WAA should help keep temps mostly above freezing rain threshold.
936 PM CST Mon Jan 20 2020 We increased the winds along the higher terrain across north central North Dakota and the far south central, Wishek area, to match current observations, where winds have been gusting to 35 mph. This corresponds fairly well with the lowering (to 800 agl) low level jet forecast by the CAM models.
Southwest winds will increase on Tuesday has high pressure moves southeast of the lake.
241 AM CST Tue Jan 21 2020 Latest water vapor imagery shows a closed low and amplified trough digging southward into the TN Valley, with ridging building over the Plains. Despite this, with highs yesterday only warming into the upper 20s, temps were still in the lower to mid 20s, as of 2 am. The ridge is expected to further amplify and move eastward today, shifting the low to our south and east. Upper ridging will generally dominate the short term period, keeping dry and warming conditions over the TN Valley.
1112 PM CST Mon Jan 20 2020 High pressure will drift across the Midwest through Tuesday, with lingering clouds moving out and temperatures warmer than on Monday.
1248 AM EST Tue Jan 21 2020 High pressure will slowly build into the area through mid week.
The highest winds have been focused over Ward County. We increased the winds along the higher terrain across north central North Dakota and the far south central, Wishek area, to match current observations, where winds have been gusting to 35 mph. This corresponds fairly well with the lowering (to 800 agl) low level jet forecast by the CAM models.
VFR conditions should prevail for most of the forecast period, but cigs should begin coming down Tue afternoon as the upper trough moves into the region. Leeside troughing ahead of the system will induce gusty south winds over the NE CWA into the evening hours. /issued 203 PM CST Mon Jan 20 2020/ Surface ridging finally starts to wane Tue.
306 AM EST Tue Jan 21 2020 High pressure will cross the region today.
widespread freezing fog has developed from Goodland and Burlington south with visibilities as low as 3/4sm in Goodland. The freezing fog will continue for another few hours before dissipating. The high temperature forecast will be difficult as some arctic air may still be in place in the east, precipitation possibilities and extensive cloud cover. For the overnight hours precipitation chances slowly decrease from west to east as the upper trough moves through. Low temperatures in the low to upper 20s.
Conditions will trend warmer and drier with high temperatures reaching the low 70s by the latter half of the week. The GOES-17 IR channel shows a deep plume of moisture stretching from west of Guadalupe Island in the Pacific into the Four Corners region ahead of a weak trough. Radar trends and short-range ensemble guidance suggest shower activity will increase in the Phoenix area over the next hour or two as the lowest atmosphere becomes saturated. 10" while the higher terrain north and east of Phoenix may see up to 0. After that, dryer conditions with a gradual warming trend start on Wednesday and continue for the second half of the week as the next ridge of strong high pressure builds across the W CONUS.
Initial thought without diving into the data too deep from yesterday morning is that some weak lift was able to squeeze out some larger flakes in the snow growth zone which just happened to coincide with the moisture in the low cloud deck. Since the models not only did not have the low clouds, and did not have clouds in the afternoon, they were not able to resolve the snow/flurries potential yesterday morning. Upper low is currently working its way southeastward, and some breaks in the clouds are already evident this morning as NVA follows behind the upper low. It appears that we will get the sun today as ridging follows behind the upper low and helps clear skies by the afternoon.
Surface temperatures, here, will drop to at or below freezing around daybreak which will allow for a few hours of freezing rain to be possible with light accumulations.
Latest water vapor imagery shows a closed low and amplified trough digging southward into the TN Valley, with ridging building over the Plains. Despite this, with highs yesterday only warming into the upper 20s, temps were still in the lower to mid 20s, as of 2 am. The ridge is expected to further amplify and move eastward today, shifting the low to our south and east. Upper ridging will generally dominate the short term period, keeping dry and warming conditions over the TN Valley. The axis of the ridge will move overhead on Wednesday, and then shift east of the area Wednesday night as a trough moves into the Plains. Southwesterly flow will strengthen as the ridge moves east, with moisture quickly filtering into the region.
/issued 427 AM CST Tue Jan 21 2020/ (Today and Tonight) An upper level ridge will move east of the area today as an upper level short wave tracks east across the Southern Rockies.
Another area of rain/snow showers should break out in the next few hours, ahead of the mid-level s/wv trough. Activity ends from west to east tonight, with high pressure developing later on Wednesday and for the rest of this week and into the weekend.
Guidance suggests the strongest winds will be in the northern valley and across SE North Dakota from the Sisseton hills northward to the Valley City area and across the higher terrain in the Fergus Falls area with sustained speeds 25 to 30mph. Probabilities indicate that the lowest visibilities will be in the 1 to 3 mile range, above any headline criteria. These south winds will eventually mix out the colder air and late afternoon highs should reach into the low to mid 20s with some cirrus filtered sun.
Latest surface analysis shows an upper low currently moving southeastward, allowing for some breaks in the clouds, this morning as negative vorticity advection follows behind the upper low. By Wednesday, ridging over the region will warm temperatures. By Wednesday a strong, mid-level jet over the central Rockies will dive southeast and deepen a trough just west of our area.
Otherwise, short and medium range guidance in generally good agreement of building a ridge aloft over the region, with the western limb of the ridge moving into the western sections of the WFO PAH forecast area by 09z (3 am CST) Wednesday. Despite the return of southeast-southerly flow around the vertically stacked ridge around 12z Wednesday, warm air advection will be slowed, as low to mid-level thickness change little. Opaque middle and high cloud cover with the approaching trough behind the ridge early Wednesday will severely limit insolation, helping to hinder any significant rise in temperatures.
310 AM CST Tue Jan 21 2020 The upper ridge that has brought dry weather to the region the last few days will move east and exit as an upper level trough across the west coast moves quickly east into the Rocky Mountains by late this afternoon. Large scale Lift will increase significantly today as the trough/upper jet approach the forecast area.
The cooler air mass that continues over the eastern half of Oklahoma will provide a short window for rain mixed with snow over northern and possibly central Oklahoma tonight. However, moderate lower layer south winds and modest positive temperature advection in the lower layers should terminate any snow by sunrise over northern OKlahoma.
As for temperatures, a much milder airmass will continue to advect off the High Plains and east into the region. The current forecast highs for today remain on the high side of the model spread, and pretty close to the model blend.
A cold front will bring widespread rain and high elevation snow this morning, followed by showers this afternoon.
850mb temperatures start out the day above freezing, but cool from the latent heat of melting and by evaporation as precipitation begins.
213 AM MST Tue Jan 21 2020 Water vapor shows dirty ridge building into the plains with next upper trof just offshore the Pac NW. At the surface, lee trof is deepening along the Rocky Mountain front. Thermal ridge overhead today and advancing surface trof will likely result in the warmest day of the week, with readings in the 50s west to 40 east. Upper trof/surface front works into the northern plains Wednesday and will bring a good chance of rain/snow to the area, especially in the afternoon and evening hours.
At the same time due to wet bulbing effects temperatures at the surface should cool but all model guidance now indicates that temperatures should remain at or above freezing. Due to the very close temperatures near freezing at the surface did maintain a mention of the potential for snow across the northern South Plains and southwestern Panhandle.
605 AM EST Tue Jan 21 2020 High pressure builds into the region today and crests over the region tomorrow with mainly clear skies.
continued with cooler than modeled temps for this afternoon. the latest NAMnest is indicating freezing precip across the majority of the area by mid evening. ridging to our west is forecast to slide across the region over the upcoming weekend resulting in a return to above normal temperatures and dry conditions over the upcoming weekend.
creating the potential for a light wintry mix of rain/snow/sleet/freezing rain to develop as the low levels saturate. a developing warm layer aloft will bring about the greater potential for wintry mix/freezing rain during the morning hours across far Eastern Oklahoma and Northwest Arkansas. with a light wintry mix potential remaining within the higher terrain locations of Northwest Arkansas.
P-type will be hard to pin down with temperatures close to freezing at times and snowfall expectations reliant on those temps and that p-type. Warming of temperatures, however, will outpace the past few days as WAA associated with ridge axis building in from Rockies. Along with the warmer air, the southerly winds -quickest along the SD state line- will pull in some moisture. The NAM does keep things much cooler and produces an extra 4" of snow for many locations, but it is the outlier and has been relegated to the sidelines.
Front will continue to weaken as it shifts inland across NorCal today as stronger upper support with the trough lifts north of the area into the PacNW. A few inches of snowfall accumulation will be possible across the higher northern Sierra passes from mid-afternoon into the overnight hours tonight and could lead to some travel impacts. Precipitation chances retreat to the far northern portion of the state during the second half of the week as ridging from the eastern Pacific moves in. Even weaker systems riding over the ridge will bring occasional cloudiness, but showers will mainly remain up by the OR/CA border.
The cooler air mass that continues over the eastern half of Oklahoma will provide a short window for rain mixed with snow over northern and possibly central Oklahoma tonight. However, moderate lower layer south winds and modest positive temperature advection in the lower layers should terminate any snow by sunrise over northern OKlahoma. Moisture advection in the breezy southerly winds will be increasing the dew points (lower to mid 40s), as all models are trending much warmer than the previous forecast. Warm air ascent and a strong low level jet in a mostly stable environment will keep POPs in the forecast for light rain all day Wednesday, with the POPs increasing from west to east where the low level jet is displaced.
250 AM MST Tue Jan 21 2020 Upper ridge currently over eastern Montana will move to the east today. The inversions will be the strongest along and north of US 2 which will also have snow cover to keep temperatures cooler. Will mention patchy freezing fog tonight in some valley areas. There may be enough moisture for a chance of light rain, light snow, or light freezing rain on Wednesday.
Another cool day in store with some freezing temps once again tonight mainly over northshore locations.
Otherwise downslope winds will keep the lower elevations dry with a good deal of mid to high level cloud cover around. A weak Pacific cold front pushes through from the west late tonight into the day Wednesday. Mountain locations will see the highest potential for measurable snow. Any precipitation that does fall in the lower elevations will be light, and a mix of snow and rain.
Elevated low level northerly winds across the area today will continue to strengthen across the area into tonight as high pressure builds across the eastern U. and low pressure develops offshore the east coast of Florida. Highs expected to only reach the mid to upper 50s from Volusia/Lake Counties southward through Osceola/N Brevard counties this afternoon, with max temps in the low 60s farther south through Okeechobee County and the Treasure Coast. The Freeze Watch has been upgraded to a Freeze Warning for Lake and inland Volusia counties tonight as as sub-freezing temperatures as low as 30 degrees are expected late tonight.
Precip amts is these areas are still expected to be on the light side, as the higher QPF totals are fcst ovr cntrl and srn AR.
600 AM CST Tue Jan 21 2020 This morning have VFR conditions areawide but expect these to worsen by late afternoon/evening as rain chances increase from west to east ahead of the trough. /issued 310 AM CST Tue Jan 21 2020/ The upper ridge that has brought dry weather to the region the last few days will move east and exit as an upper level trough across the west coast moves quickly east into the Rocky Mountains by late this afternoon. Large scale Lift will increase significantly today as the trough/upper jet approach the forecast area.
Cooler today with isolated to scattered showers persisting into Wednesday as a storm system moves across the area.
Temperatures will climb above the freezing mark across the region today, though the warmest temperatures will be in far southwestern Missouri where around 40 degrees for highs are expected. Precipitation during the morning will transition from snow to rain as temperatures climb above freezing.
351 AM MST Tue Jan 21 2020 Water vapor shows dirty ridge building into the plains with next upper trof just offshore the Pac NW. At the surface, lee trof is deepening along the Rocky Mountain front. Thermal ridge overhead today and advancing surface trof will likely result in the warmest day of the week, with readings in the 50s west to 40 east. Upper trof/surface front works into the northern plains Wednesday and will bring a good chance of rain/snow to the area, especially in the afternoon and evening hours.
400 AM CST Tue Jan 21 2020 High pressure slides on out to the east and southerly flow returns across the region. With mid-level ridging in place, quiet weather is in store for today with mostly sunny skies. An active weather pattern returns for the middle of the week as a short wave trough begins to slide in across the region. There are some hints that the onset of the event could start out as some spotty freezing rain. This would be possible if ground temperatures remain below freezing, but after Tuesday night temperatures will be on the increase. Daily high temperatures will warm above freezing for most of the area.
658 AM EST Tue Jan 21 2020 High pressure will track east and cross the Ohio Valley early on Wednesday.
These showers may struggle to reach the ground initially, especially in the valleys, given the low level dry air present as evident in the GJT 00z sounding. As of now there are indications that there is a potential for a few inches in these areas, but temperatures are expected to warm above freezing later today. Some other valleys could receive snow as well, but even the lowest guidance for temperatures hint at highs reaching at least freezing under the warm advection. The trough crosses the Divide this evening leaving westerly flow in it's wake, which will support orographic lift through most of the overnight. The main energy associated with this trough will pass north of the area, but the southern extent looks to clip the northern and central mountains Wednesday morning.
By mid to late morning, although the inversion remains in place, high pressure at 850mb will be moving into Indiana, cutting off the moisture supply from Lake Michigan. Also at that time the strong high at the surface will be entering the lower Ohio Valley, introducing a much drier air mass. Went on the cool side of guidance for highs today given the expected morning clouds, with temperatures peaking around the freezing mark this afternoon. As we move into more southerly flow, expect high temperatures Wednesday to warm to near normals into the lower 40s.
A surface lee-side trough will strengthen today which should help to kick the cold air out of the Panhandles today. Mid level cooling in association with the arrival of the mid level trough will help to switch some of the rain over to snow occasionally.
Heading into the evening hours temperatures will begin to drop and more of freezing precipitation type is possible. Decided to go with a wintry mix instead of freezing drizzle as moisture advection brings in mid- level moisture with frozen droplets in the mid-levels instead of a low cloud stratus type of setup that would be more indicative of drizzle. As for temperatures today, did raise a few degrees with a model blend across portions of southwest Nebraska and the Sandhills, kept temperatures cooler across north central Nebraska where snow cover still remains.