Aikyam-Lab/Synoptic-Bench huggingface dataset:
Cooler temperatures expected today and overnight. Freeze watch for the higher mountain elevations Monday morning. Discussion: Currently the cooler pattern has set up as broad mid-level troughing remains over the eastern United States and colder air from the north/northwest filters into the southern Appalachian region. Overnight there is the possibility of some patchy frost along the higher elevations of the Cumberland Plateau and southwest Virginia. The freeze watch along the east TN mountains will be upgraded to a freeze warning with temperatures in the higher elevations likely to dip down into the 20s based on current guidance.
Sunday night, a small 500 hPa ridge builds over ahead of disturbance moving in from the Gulf of Alaska. This disturbance will become a closed low on Monday and move through the Pacific Northwest.
With temps being above freezing for the most part though, no snowfall accumulations are expected. Meanwhile, lake- effect snowfall moves over the rest of the NW snow belts over the eastern half tonight; with lows getting into the mid 20s out west and around freezing out east, a dusting to an inch of snowfall could be seen across most of the NW snow belts.
Farther north, mid-level clouds will remain but may thin or decrease enough to allow temperatures to approach freezing by early Sunday morning. More sunshine is expected across the northern half of Oklahoma, so daytime highs should reach the 60s with cooler temperatures expected farther south.
Showers and isolated thunderstorms are expected today along with warmer temperatures. A cold front passage on Monday afternoon and evening will bring gusty northwest winds to northern and central Nevada and some showers to northeast Elko County.
An upper level low continues to pivot in place over southern Ontario providing continued cyclonic flow aloft.
Temperatures barely go above freezing just in the lowest 1-2kft, which is why we should see the snow/graupel still even if our surface temperatures are in the low 40s (enough downward momentum to get to the ground before melting in this convective environment).
Some dinural shower activity looks possible across the south-central late this afternoon, but they should have a hard time overcoming the low level dry air. Tonight, surface ridging and dry air continue, allowing for some clear to partly cloudy skies. Key Messages: -Monday showers, early in the east, late in the interior west -Dry and warming midweek under high pressure -Watching tracks of Canada clipper, Texas low, and Hudson high for end of week into weekend PoPs The Monday forecast period begins with showers in the east as lingering troughing will support a band of precip.
(Today through Monday) Large upper low spinning over the western Great Lakes with ridging near the west Coast. At 3 AM CDT, temperatures were generally in the 50s, but in the New Orleans area, winds blowing across the warmer (lower 70s) waters of Lake Pontchartrain were holding temperatures in the 60s.
Gusty winds will decrease this evening as the low continues east. After Sunday, an upper level ridge sets up over the Northern Plains, strengthening a high pressure in Canada.
Some dinural shower activity looks possible across the south-central late this afternoon, but they should have a hard time overcoming the low level dry air. Tonight, surface ridging and dry air continue, allowing for some clear to partly cloudy skies.
142 AM EDT Sun Apr 23 2023 An upper level trough will persist across the Great Lakes and Ohio Valley into Sunday. The high will linger across the Great Lakes into midweek. Upper level trough to persist across our region into Sunday. The upper level trough is forecast to shift a little east Sunday night into Monday. And with lighter winds, frost and/or freezing conditions will be possible. After lows in the lower to mid 30s, highs on Monday will mostly be in the 50s, which is still cool for late April. A trough in the upper atmosphere positioned over the Eastern CONUS will lead to below normal temperatures, while a lack of major weather systems and weak instability will allow little if any severe weather.
131 AM EDT Sun Apr 23 2023 A slow moving upper level low pressure system and frontal system will bring widespread moderate rainfall to the region tonight through at least Monday along with cooler temperatures. Previous forecast remains on track with little change for the overnight with rain additionally stabilizing the low levels allowing gusty southeasterly winds to subside to generally below 25 mph.
147 AM EDT Sun Apr 23 2023 Cooler temperatures and unsettled weather will occur today into midweek. Showers will linger well behind the cold front, and expect plenty of low clouds areas of fog through the night. Clouds will linger through Sunday, along with cooler temperatures in the 50s. An upper level low will be the main feature impacting the weather for our area during this period. A blocking pattern to over eastern Canada will keep an upper level low spinning mostly stationary over the northern Great Lakes.
1146 PM EDT Sat Apr 22 2023 Southeast Michigan will remain within the moist/cool cyclonic flow maintained within an expansive upper level low pressure system easing into Ontario through Sunday. The end result has been a convective line of showers along the cold front that has easily produced some small graupel and even some lightning strikes. Showers taper off this evening with the loss of daytime heating and as the trough axis begins to move out. The thermal trough axis (around -7C at 850mb) passes over the region Sunday night into Monday, resulting in another cold night with lows flirting with the freezing mark. Another cold night follows with lows likely dipping into the lower 30s away from the lakeshore.
Overall not much happening with cooler than normal temps. This is driven by an upper low sliding down the Rockies and the low currently over the region.
Complex area of low pressure remains centered between the Great Lakes region and James Bay early this morning. Upper level low remains centered from Western Ontario thru all of Michigan. while the parent upper low remains parked over Western Ontario thru tonight. Synopsis/Forecast: The cut-off low over southwestern Ontario will become more elongated through early week, making only very slow progress eastward (and finally out of our area by the end of the week) thanks to a blocking area of high pressure over Greenland. This will keep us cooler than normal and more cloudy than not through the first half of the week.
Low temperatures tonight will range from the lower 50s to mid 60s with winds shifting to northeasterly. (Sunday through Monday night) Sunday will be dry in the wake of the cold front, with slightly cooler temperatures expected, with highs ranging from the mid 70s to mid 80s and northeasterly winds.
Another trough will move into the area Sunday afternoon. The combination of the trough, cool air aloft and daytime heating should kick off some more rain and snow showers, with the greatest concentration of precipitation in the afternoon.
(Today and Tonight) Drier airmass filtering into the region behind cold frontal passage on gusty North winds this morning that will shift Northeast through the remainder of the day. Temps slightly cooler and closer to seasonal averages today with lower to middle 80s inland and mid/upper 70s in the breezy onshore flow along the Atlantic Coast. High pressure settles in just north of the region tonight and expect seasonable temps to continue as high clouds slowly increase through the overnight hours and lows will fall in to the mid/upper 50s inland and likely bottom out during the late evening/around midnight time frame due to the increasing clouds overnight with generally steady temps through morning. Onshore flow will keep lows in the lower to middle 60s along the Atlantic Coast.
The 1 PM surface map continued to show chilly surface ridging wedging south through the TX Panhandle with a cold front draped near the I-20 corridor. Elsewhere, models have trended drier due to deeper and drier NE winds in the lowest several thousand feet effectively closing the window sooner on precip hopes, so PoPs were lowered mostly in sync with the HREF mean to reflect this trend.
Temperatures are falling into the 50s at this hour, on their way to lows in the lower 40s for most areas.
Some clearing will occur later across parts of northeast Oklahoma and northwest Arkansas, allowing temperatures to fall into the low to mid 30s, so will maintain the frost advisory as is.
959 PM MDT Sat Apr 22 2023 Latest upper air analysis shows a closed low over the Great Lakes area. Circulating around the closed low was drier, cooler air. Tonight another weak upper level short wave trough will move over the southwest corner of the forecast area. WAA will return with the south winds, causing temperatures to be warmer than today. Sunday night an upper level short wave ridge will move in from the west. The continued WAA will keep lows a few degrees warmer than tonight. This will translate down to the surface as a slow moving inverted trough along the Colorado border. This trough will slowly slide south and east going into the evening hours. Some instability as well towards sunset, so can't rule out a rumble of thunder along the east side of the trough.
With the lighter winds it will be a cooler night with lows in the mid 20s.
North of there, the main cold front is pushing south across the Big Country where the mesonet at Weinert is already down to 59 degrees. Cold front will also continue south and as it overtakes the stationary front we expect storms to blossom and become more widespread. Cold front continues south thru the area this evening and we may see a brief lull in the precipitation before isentropic lift up and over the frontal boundary starts to generate more widespread showers and a few storms. This will continue into Sunday and help produce much cooler temperatures.
(Today) Cloud cover has increased overnight throughout the TN Valley and is forecast to continue to increase through the day today-- contributing to cooler post-frontal temperatures due to lack of sunshine.
315 AM EDT Sun Apr 23 2023 In the wake of the exiting cold front, high pressure will settle over the area today bringing cooler temperatures to the region.
This will maintain unsettled conditions with widely scattered to scattered light rain showers over the next several days as several vorticity lobes rotate around the upper low through the region.
1243 AM CDT Sun Apr 23 2023 A weak cold front positioned just north of the region will help reinforce lingering low-level moisture resulting in very light showers across our extreme northwestern zones. Temperatures this evening will be on the cooler side for areas north of the I-20 corridor where lows will drop to the upper 40s while everywhere else can expect temperatures in the lower 50s. A weak polar stream cold front, currently pushing south toward northern portions of the area, will not do much other than to reinforce the baroclinic zone currently in place across the Gulf Coast region and drop temperatures just a bit more.
103 AM CDT Sun Apr 23 2023 (This afternoon through Sunday Night) Cloud coverage has begun to increase slightly this afternoon ahead of a cold front moving through the area. Much cooler temps will follow the front, knocking temps into the 30s to 40s overnight. If you are curious about the daytime tomorrow, it looks pretty similar to today but cooler.
Key Messages: - Freezing, near or record cold temperatures this morning.
(Today and tonight) A cold front has pushed south of West Central Texas early this morning, with the severe threat shifting south of the area. Expect highs this afternoon in the low to mid 50s for most locations.
1037 PM MDT Sat Apr 22 2023 19Z upper level analysis has deep trof across the north central CONUS with ridging along the West Coast. Cold northerly boundary layer flow in place as Canadian high pressure settles over the area. Upper trof over the north central CONUS will gradually shift east overnight as western ridge builds over the Northern Rockies. Upper ridge will continue to build across the Rockies on Sunday and into the Plains on Monday with quiet weather expected.
208 AM EDT Sun Apr 23 2023 Cyclonic flow under an elongated trough aloft has supported some snow showers downwind of Lake Superior overnight. Some dinural shower activity looks possible across the south-central late this afternoon, but they should have a hard time overcoming the low level dry air. Tonight, surface ridging and dry air continue, allowing for some clear to partly cloudy skies.
Temperatures are expected to dip into the 30s overnight as a cold front continues sinking south into central MS/AL.
Confidence in freezing temps is considerably higher than for this morning, with widespread frost also on tap.
333 AM CDT Sun Apr 23 2023 Low clouds across eastern Iowa and northwest Illinois have held temperatures in the low to mid 30s for most locations so far tonight. There is still time for temps to drop a few more degrees, but many locations may not reach freezing or below.
Frost with temperatures in the lower 30s is not expected to be damaging to most agriculture in their current stage.
Key Messages: - Near or record cold freezing temperatures Sunday morning. Near freezing temperatures for extreme northeast Nebraska and northwest Iowa Monday morning.
Frost is also possible in this pattern, especially early Monday morning when temperatures may dip below freezing. Shower coverage has increased as expected this afternoon in response to steepening low level lapse rates and a vorticity maxima pivoting through on the southern periphery of a broad northern/western Great Lakes upper low. Weak low level instability and a deep sub freezing layer aloft has supported a mix in with graupel/sleet in more robust convection. Low temps are forecast to drop into the mid 30s early Sunday morning as elevated winds and lingering cloud cover likely curtail sub freezing sfc temps and more widespread frost development.
411 AM EDT Sun Apr 23 2023 (Today through Monday) A dry cold front will drop south across the CWA today and tonight. High pressure will build in from the north overnight and Monday.
Large upper low remains stalled just north of the MN/Canada border. There is a wave of energy that looks to rotate through from the stalled upper low this afternoon and evening. High temperatures today will be slightly warmer yet below normal and generally in the 40s. Winds close to the high will go light and variable, yet turn southeasterly behind this high mainly across the west. A weak ridge will keep Monday mainly dry.
Clearing skies across the north has already allowed temps to drop off into the mid 30s near the KS border, so a frost and possibly a freeze at the typical cooler valley spots is most likely there. This will yield warmer high temps for most. As such, another frost advisory was posted and it's not out of the question that the colder valley sites, such as KFYV and KBVO, dip down to freezing.
58/rose Previous short-term discussion: (This afternoon through Sunday) Only a few light showers remain across Barbour County as the cold front continues to move eastward into Georgia. Drier and cooler air has filtered into Central Alabama, with plentiful sunshine. A reinforcing shot of cooler and drier air will move into the region tonight, as most of the eastern CONUS remains under the influence of the longwave trough. A 1031mb ridge centered north of Montana will continue to filter a continental polar airmass southeastward through the short-term period which will lead to below-normal temperatures for this time of the year.
355 AM EDT Sun Apr 23 2023 Cooler temperatures and unsettled weather will occur today into midweek. A large upper level trough is over the Midwest and upper Great Lakes. Closed off upper low will continue to influence our weather through the period as it spins nearly stationary over the Great Lakes. Several weak perturbations pivot around the the upper low and will bring increased chances for showers as they push through.
324 AM EDT Sun Apr 23 2023 An upper level trough will park over the Great Lakes and New England into at least the middle of the new week. Upper level troughing and a fair amount of cloud cover should result in chilly day for late April. GEFS 2m temp anomalies are 8-12 degrees below climo, ranging from the upper 40s over the Alleghenies, to the low 60s across the Lower Susq Valley.
This will provide for a few hours of additional cooling across northern parts of the state, allowing temperatures to fall into the lower to mid 30s F around daybreak. Precip will be confined to far southern Arkansas by this afternoon as sfc ridging continues to expand southward across the region. Temperatures will rebound a bit closer to normal on Monday as sfc ridging begins to shift east of the area.
Updated Aviation Warm temperatures will continue into Sunday with most lower desert locations reaching the lower to middle 90s with just a bit of high level cloudiness into Sunday morning.
Clouds will gradually clear from north to south as high pressure begins to slide in and provides another re-enforcing shot of cold air.
(Today through Monday afternoon) Our strong cold front has cleared the region early this morning. A thick cloud layer looms across much of the area keeping much of the lower elevations in the 50s! The record cold high temperatures is 55 this afternoon at Midland International.
321 AM EDT Sun Apr 23 2023 Cooler temperatures and unsettled weather will occur today into midweek. Showers will linger well behind the cold front, and expect plenty of low clouds areas of fog through the night. Clouds will linger through Sunday, along with cooler temperatures in the 50s. Closed off upper low will continue to influence our weather through the period as it spins nearly stationary over the Great Lakes. Several weak perturbations pivot around the the upper low and will bring increased chances for showers as they push through.
Deep layer moisture is lacking, though at least isolated showers are expected as this trough crosses. Isolated snow showers are expected across the highest elevations as 850mb temperatures fall below freezing. Some snow should mix in Monday morning across portions of the area, continuing through the day across the highest elevations.
Lingering showers over central and east central WI should taper off by mid-evening, as the weak trough shifts south and daytime instability weakens. Temperatures should be a few degrees warmer, with highs in the 40s to around 50.
Due to the lower relative humidity there is a potential for fire weather concerns across the southern half of the state.
141 AM MDT Sun Apr 23 2023 Quick moving upper level ridge will move across the area Sunday and Monday.
952 PM MDT Sat Apr 22 2023 The northwest flow loosens up a bit today into Sunday, as weak ridging builds across the northern Rockies, pushing the broad Great Lakes trough to the east. Ridge isn't particularly sharp, and doesn't dislodge the cooler air in place, so temperatures will struggle to reach back to the western Wyoming April normals of the 50s.
(Today and tonight) Flow aloft has become more zonal this morning as upper troughing over the Great Lakes region begins retreating northeastward ahead of flat upper ridging over the northern Rockies. Have still opted to side with the cooler guidance considering the continuation of upslope flow, but temperatures may need to be adjusted upward if drier air ends up winning out this afternoon.
617 AM EDT Sun Apr 23 2023 In the wake of the exiting cold front, high pressure will settle over the area today bringing cooler temperatures to the region.
558 AM EDT Sun Apr 23 2023 Upper level low remains over the region holding plenty of low level moisture across the region that will amount to an expanding stratocu field later today, and a slight chance of showers this afternoon. Initially, there is widely varying conditions as a trough axis is producing IFR/MVFR conditions northwest and west of SE MI, clear skies over parts of lower MI, and VFR stratus lifting north out of Ohio. This will maintain unsettled conditions with widely scattered to scattered light rain showers over the next several days as several vorticity lobes rotate around the upper low through the region.
636 AM EDT Sun Apr 23 2023 Drier air filters into the region with slightly cooler, dry weather expected today and Monday.
Cooler temperatures today and Monday, followed by a warming and dry trend for the reminder of the week. High temperatures are expected to be 5 to 10 degrees cooler in the interior valleys compared with yesterday's readings.
345 AM PDT Sun Apr 23 2023 A Pacific trough moving inland will bring cooling today and Monday along with a deeper marine layer and gusty mountain and desert winds.
High pressure at the surface will build into the region through the day behind this front, with northerly winds filtering in some cooler drier air into the region. Highs today will range from the upper 50 across the Delta region, to the middle 70s across the Pine Belt region, which lies ahead of the cold front.
631 AM CDT Sun Apr 23 2023 (Today and tonight) Flow aloft has become more zonal this morning as upper troughing over the Great Lakes region begins retreating northeastward ahead of flat upper ridging over the northern Rockies. Have still opted to side with the cooler guidance considering the continuation of upslope flow, but temperatures may need to be adjusted upward if drier air ends up winning out this afternoon.
524 AM EDT Sun Apr 23 2023 Drier air filters into the region with slightly cooler, dry weather expected today and Monday.
330 AM MDT Sun Apr 23 2023 Upper air analysis shows low pressure sitting across the Great Lakes region, with northwest flow persisting across the northern Great Plains. Low amplitude upper ridging is approaching from the west, ahead of the next storm system moving onto the Pacific NW coast. On the surface, a broad area of high pressure stretches across the northern to central Plains. Temperatures have dropped into the 20s across the plains across the forecast area, and teens across the higher Black Hills. Warmer temps are expected today but still slightly below the seasonal average.
Thus, highs today in the lower 80s along the coast and mid to upper 80s west of I-95. Lows in the mid to upper 60s, though normally cooler areas of northern Lake and Volusia Counties could see lower 60s or even upper 50s.
Low clouds across eastern Iowa and northwest Illinois have held temperatures in the low to mid 30s for most locations so far tonight. There is still time for temps to drop a few more degrees, but many locations may not reach freezing or below.
(Today through Monday) A dry cold front will drop south across the CWA today and tonight. High pressure will build in from the north overnight and Monday.
638 AM CDT Sun Apr 23 2023 (Today) Cloud cover has increased overnight throughout the TN Valley and is forecast to continue to increase through the day today-- contributing to cooler post-frontal temperatures due to lack of sunshine.
656 AM CDT Sun Apr 23 2023 (Sunday through Monday) At 08z, a surface cold front was located across our southernmost counties/parishes of Deep East Texas eastward into Central Louisiana. No precip is expected during the day Monday as we'll be in a brief break between upper level troughs.
Rest of today's forecast remains on track with slightly warmer temperatures and perhaps a few showers in the east. Large upper low remains stalled just north of the MN/Canada border. There is a wave of energy that looks to rotate through from the stalled upper low this afternoon and evening. High temperatures today will be slightly warmer yet below normal and generally in the 40s. Winds close to the high will go light and variable, yet turn southeasterly behind this high mainly across the west. A weak ridge will keep Monday mainly dry.
Monday appears like a rather benign day as Colorado remains under modest west to northwest flow aloft but with a weak trof passage to bring some showers.