Aikyam-Lab/Synoptic-Bench huggingface dataset:
At the surface, cold front has pushed down into central TX into eastern AR. By Fri morning, GFS and ECMWF agree on an open wave trough moving into the Mississippi Valley, pushing the better precip chances east of the forecast area. Upper trough is then expected to dig over the West Coast by Mon morning which will continue the warming trend, with 80s on tap for Mon. Tue looks like the time frame when the upper trough will bring storm chances to the area and will likely provide our next chance for severe storms across the Southern Plains.
Two upper troughs will be a factor over the next 48 hours.
/issued 300 AM CDT Tue Apr 20 2021/ The advertised cold front was currently plowing through the region early this Tuesday morning. Surface ridging will be in place Wednesday which will keep temperatures cool with light southeasterly surface winds.
Currently situated across the central Plains and upper Midwest (as evident by the 40 degree afternoon temperatures across a large swath of this area), this air mass will follow a cold front due in here tonight. Light post-frontal rain will follow the passage of this cold front and the problem then becomes the cold air pushing in with the precipitation.
1147 AM MDT Tue Apr 20 2021 This morning, the upper-level trough axis will move across the area. On the backside of the trough, the winds will shift to the NW as high pressure moves into the area from the west. It is expected to be warmer today, with highs in the upper 30s to upper 40s. Dry conditions are expected tonight with overnight lows in the lower 20s and wind chills in the teens. Wednesday a weak ridge will move over the area during the first half of the day as an cut-off trough moves across the Great Basin into the Four Corners region. Temperatures on Wednesday are expected to reach the lower 40s to lower 50s for highs and cool to the mid 20s and lower 30s overnight.
204 PM MDT Tue Apr 20 2021 This morning, the upper-level trough axis will move across the area. On the backside of the trough, the winds will shift to the NW as high pressure moves into the area from the west. It is expected to be warmer today, with highs in the upper 30s to upper 40s. Dry conditions are expected tonight with overnight lows in the lower 20s and wind chills in the teens. Wednesday a weak ridge will move over the area during the first half of the day as an cut-off trough moves across the Great Basin into the Four Corners region. Temperatures on Wednesday are expected to reach the lower 40s to lower 50s for highs and cool to the mid 20s and lower 30s overnight.
Dry weather through Wednesday with an upper ridge over the area.
Winds will shift to the west northwest tomorrow morning as an area of high pressure builds across the southeast U.
Overnight lows are still expected to drop below freezing across the board. Cold air mass remains over central IL Wednesday night with high pressure beginning to build in from the west. Additional freezing temperatures are expected, with lows upper 20s to around 30.
637 PM CDT Tue Apr 20 2021 (This evening through Wednesday) As of 2pm, a strong cold front is progressing southward and has reached the I-10 corridor. The front will continue pushing southward this evening, as a 1025mb high pressure center moves into southern Oklahoma and north Texas. Overnight, the high will shift southward and settle over the Big Country by sunrise. Fairly light winds and mostly clear skies for most of the night will allow for decent radiative cooling conditions, which may drop temperatures down to around freezing, especially in low-lying areas. Tomorrow, the high pressure center is progged to drift further south over the Concho Valley before finally starting to move eastward late in the afternoon. Between potential cloud cover and the cold high pressure centered directly overhead, high temperatures for Wednesday are expected to stay well below seasonal normals.
The highest rain chances (PoP 30-50 percent) will be across the Treasure Coast and Okeechobee counties with everywhere else having 20 percent or less. Rain chances will lower overnight, especially across the north, with the highest chance for scattered showers and storms being from KVRB southward overnight. Rain chances will decrease tomorrow from what they were the last few days, with the highest chances for showers and storms being from Brevard county southward.
The actual surface cold front is already half way through Middle TN, but the moisture is lagging behind the front. Windy conditions expected overnight and into the morning knocking wind chills to below freezing. A strong cold front will move across the terminals this evening.
No changes were needed for the late eve update as increased swly flow on the van of deepening, Great Lakes low pressure should support warm, moist advection and an overall increase in cloud cover ahead of a developing cold front. The developing cold front is supported by anticipated cyclogenesis, which should occur west of the region tonight. This should then support a fairly rapid increase to categorical PoPs after midnight, from west to east, as the cold front quickly advances eastward. Categorical precipitation, mainly in the form of rain showers should be ongoing Wednesday morning, but a changeover to a mix/snow is expected as upper troughing and sfc nwly flow continue to cool the column.
VFR conditions will continue overnight as a weak cold front moves through the area, reaching the coast near dawn. Winds will be light to moderate northeast behind the front as high pressure over the southern Plains shifts east. /issued Issued by National Weather Service San Juan PR/ SHORT TERM (Tonight through Wednesday Night): Low temperatures tonight will range from the upper 50s in the ranchlands to lower 60s in the lower Rio Grande Valley. A weak cold front will drop through the CWFA late this evening and early Wednesday morning, with the primary impact being slightly cooler temperatures for Wednesday afternoon. Look for partly to mostly cloudy skies on Wednesday with highs generally in the middle to upper 70s for much of the CWFA, while the typical warmer spots out west reach the lower 80s.
Clear and cool again tonight, then sunny and warmer Wednesday.
This should keep lows a few degrees warmer than last night, which was accounted for in the forecast. The piece from the north will help reinforce the cooler air in place. Don't expect any accumulation across the lower elevations.
212 PM PDT Tue Apr 20 2021 Cooler today with the chance of mainly mountain showers and thunderstorms. Otherwise dry and warmer weather returns through the end of the week. Showers and a few thunderstorms will be possible even in the Valley given the CAPE as the vort max pushes over the region but the best chances will remain over the higher elevations. With more moist low levels over the higher elevations that is where the heavy rain threat will be greatest. The upper level trough will push into NV during the morning tomorrow and we will see some CAPE build in over the Sierra from I-80 south.
Meanwhile, the cold front continues marching southeast across KY into the Middle TN, generally just west of the I65 corridor. A cold front continues to approach from the west which will sweep through the region overnight. CDG Chattanooga Airport, TN 42 54 36 64 42 / 10 0 0 0 10 Knoxville McGhee Tyson Airport, TN 42 50 33 59 38 / 50 40 0 0 10 Oak Ridge, TN 40 51 33 60 38 / 50 10 0 0 10 Tri Cities Airport, TN 42 47 30 54 32 / 30 50 10 0 0 NC.
/issued 200 PM CDT Tue Apr 20 2021/ Winds are showing signs of decreasing in wake of this morning's strong cold front as low clouds erode west to east. We will opt to issue freeze warning from Hobbs northward and east to Borden Co as these are where the lightest winds will be with the highest surface pressure, and where high clouds will arrive the latest.
737 PM CDT Tue Apr 20 2021 Strong and tight upper level low pressure area spinning in eastern sd was bringing some intense snow showers to the region with visibilities to less than a quarter mile. Dry conditions then return and will continue through the remainder of the short term period as high pressure settles in over the area late tonight and Wednesday before tracking off to the south Wednesday night. Low temperatures tonight will range from the upper teens west to the lower 20s east, with highs on Wednesday ranging from the upper 40s east to the lower 50s west.
243 PM PDT Tue Apr 20 2021 Dry and warmer temperatures will continue through Wednesday before our next round of active weather.
641 PM CDT Tue Apr 20 2021 A cold front, currently located along a line from LFK to ELD, will continue to push eastward across the region this evening. So cold in fact, we've issued a Freeze Warning for a chunk of the CWA, as overnight lows may get to at, or below freezing.
With the sun down and temperatures falling to below freezing. Thermal profiles are cold enough for p type to be all snow as the column saturates, even this afternoon with sfc temps in the lower to mid 30s where it is snowing. We tweaked amounts to be in the 1 to 2 inch range as there will be some melting due to above freezing skin temps. - Cold High Brings Freeze tonight and Wednesday night Sharp upper trough and northerly flow will transport cold air into Lower Michigan. Temperatures were in the lower to mid 20s across our northern zones this morning and we expect them to be about 5 degrees colder tonight, with some upper teens in the colder spots. Widespread freeze both nights with several hours of sub- freezing temperatures potentially doing significant damage to fruit buds and blossoms.
An upper ridge over the area through Wednesday for dry weather.
Cooler and breezier conditions today ahead of a trough of low pressure that will reach the area tomorrow. As the trough reaches the area tomorrow, isolated showers and thunderstorms will be possible across the Sierra Nevada with cool dry weather in the valley.
Attention turns to the sub-freezing temperatures in the forecast tonight. Latest short-range guidance continues to show widespread subfreezing temperatures tonight. Forecast soundings show fairly dry air in the low levels though, which is why I didn't go with even higher PoPs.
With clouds cleared out, the overnight temps will drop below freezing with all but the southeast looking for Hard Freeze Warning criteria. The blanket of clouds won't stop the area from sinking into the mid and upper 20s overnight, but it may prevent us from seeing even lower temps in the low 20s as a good amount of radiational cooling can still take place through the late evening hours.
352 AM CDT Wed Apr 21 2021 The frontal boundary has pushed offshore early this morning as cooler, drier air advects into the region on brisk northerly winds. High pressure will settle nearly overhead tonight allowing winds to calm and providing a nearly ideal radiational cooling environment that will allow lows to drop into the lower 40s across central Louisiana and upper 40s along and south of the I-10 corridor.
Unseasonably cool air will move into the region in wake of a cold front, which has finally moved through the entire region this evening. Overnight lows will range from the low 30s north to near 40 in our southern zones. A Freeze Warning remains for areas near and north of the Interstate 30 corridor overnight, as temperatures in these locations will possibly fall to or just below freezing by tomorrow morning. /issued 641 PM CDT Tue Apr 20 2021/ A cold front, currently located along a line from LFK to ELD, will continue to push eastward across the region this evening. So cold in fact, we've issued a Freeze Warning for a chunk of the CWA, as overnight lows may get to at, or below freezing.
320 AM CDT Wed Apr 21 2021 Freezing temperatures were widespread across the region this morning, likely having some very damaging impacts to vegetation.
Early morning temperatures are in the 30s, but some areas will get to around or just below freezing by sunrise. By tonight, areas near the Tennessee river will see close to freezing temperatures, or even at freezing.
1011 PM PDT Tue Apr 20 2021 Dry and warmer temperatures will continue through Wednesday before our next round of active weather.
120 AM CDT Wed Apr 21 2021 For the ArkLaTex terminals, Canadian high pressure has blown in with N winds still peaking to 28KT at KMLU.
/Today through Tuesday/ The primary weather highlights through the period will be quite changeable starting with snow early this morning, continued freezing temperatures through tomorrow night, and then warmer conditions and possibly the return of thunder and more appreciable rainfall toward the end of the period and just beyond. At onset, a deep PV trough will pass through Iowa this morning which has resulted in scattered snow showers, which have been briefly intense with Spencer dropping to a half mile visibility at times. Although temps may bottom out and become steady before sunrise as low level warm advection finally returns, overnight lows should still dip into the 20s, approaching the low end of the guidance suite based on recent history, and needing another Freeze Warning where applicable.
233 AM CDT Wed Apr 21 2021 Light NE flow continues over much of the area in wake of our cold front that cruised through this morning. Borderline freezing criteria in the neighboring counties to the south in TX, so perhaps they sneak in a freezing temp, but the prospects are lower than further north, especially considering high clouds peeking in from the west at this hour. Quasi- zonal flow will transpire tonight and tomorrow with temps really warming up thanks to return flow and SW flow aloft ahead of our next trough.
With that said, due to the drier air in the low and mid levels, what precipitation was present evaporates and has transfered momentum down to the surface.
A plume of low level moisture looks to move up from the south today as the 850 mb ridge pushes east, resulting in mostly cloudy skies today. These clouds, in addition to the cool air mass, should result in highs that are much cooler than normal (low 50s to low 60s). Tonight, warming of the air mass should result in warmer lows in the 40s.
Meanwhile, upper ridge moves in which will warm temperatures across the region under mostly clear skies. The ridge will keep skies clear through tonight.
Temperature gradient associated with the front is stronger as well, with warmer temps ahead of the cold front as well. Mid 30s will be the majority for low temps this morning, but some areas will get to around or just below freezing by sunrise. Tonight, the eastern half of the area will see freezing temps, and even some upper 20s possible on the Plateau.
The 19Z MSAS surface analysis showed one area of low pressure moving up the OH Valley, thereby keeping accumulating snow to our south. Otherwise, several very weak areas of low pressure were over the Great Lakes under a broad upper-level trough aloft.
229 AM MDT Wed Apr 21 2021 Weak ridging will build into the area on today, bringing clearer conditions and warmer temperatures to the area but still remain below normal for this time of year.
320 AM CDT Wed Apr 21 2021 Temperatures below freezing this morning will give way to afternoon highs in the upper 40s to around 50. Temperatures are expected to fall below freezing for most of central Illinois again tonight.
Weak high pressure will persist through the evening. A series of ill-defined storm systems will bring unsettled weather for the middle to latter part of the work week before high pressure brings a warming and drying trend for the weekend. All of the high resolution models show this band of showers moving across northern Utah from Provo to Ogden between 0300 and 0600 tomorrow morning. Current forecast of gusts over 30-35 mph looks reasonable, and may even be on the low side.
The actual surface cold front is already half way through Middle TN, but the moisture is lagging behind the front. Windy conditions expected overnight and into the morning knocking wind chills to below freezing.
1213 AM CDT Wed Apr 21 2021 (This evening through Wednesday) As of 2pm, a strong cold front is progressing southward and has reached the I-10 corridor. The front will continue pushing southward this evening, as a 1025mb high pressure center moves into southern Oklahoma and north Texas. Overnight, the high will shift southward and settle over the Big Country by sunrise. Fairly light winds and mostly clear skies for most of the night will allow for decent radiative cooling conditions, which may drop temperatures down to around freezing, especially in low-lying areas. Tomorrow, the high pressure center is progged to drift further south over the Concho Valley before finally starting to move eastward late in the afternoon. Between potential cloud cover and the cold high pressure centered directly overhead, high temperatures for Wednesday are expected to stay well below seasonal normals.
1223 AM CDT Wed Apr 21 2021 Strong and tight upper level low pressure area spinning in eastern sd was bringing some intense snow showers to the region with visibilities to less than a quarter mile. Dry conditions then return and will continue through the remainder of the short term period as high pressure settles in over the area late tonight and Wednesday before tracking off to the south Wednesday night. Low temperatures tonight will range from the upper teens west to the lower 20s east, with highs on Wednesday ranging from the upper 40s east to the lower 50s west.
500 AM EDT Wed Apr 21 2021 A trough deepening over the eastern half of the country was helping to push a cold front into northwest GA this morning. Lows near freezing still look reasonable for the far northeast and the Freeze Watch has been upgraded to a Freeze Warning.
It will also be cold this morning with low temperatures well below freezing, thus the existing freeze warning will remain in place through 9 am.
Temperatures had dipped below freezing over all of the forecast area tonight. Still, temperatures are hovering at or a few degrees above freezing and could still drop a little more before sunrise. Have adjusted max temperatures down to around or a few degrees below the cooler MET MOS guidance. With considerable cloud cover over the region, temperatures should stay above freezing in most areas tonight.
We've got one more day under the influence of a cold trough. The last lobe of vorticity we'll have to deal with with this trough is currently up over northern MN and will slide through southern MN and western WI this afternoon. There will be some moderation in 850mb temps today, so we'll be a couple of degrees warmer than yesterday, with highs not reaching 40 possible in western WI. Tonight, we finally get on the back side of the trough and into a region of rising heights.
Today will be a chilly one while high pressure nudges its way in, with peak afternoon temps in the lower to middle 50s and a west- northwesterly breeze. Thu will be mostly sunny and a little warmer under high surface pressure, as the pattern aloft over us begins to transition to more of a flat ridge. As the dome of high pressure begins to retreat to the east Thu night, models show a southwesterly low level flow starting up from the west, increasing available moisture.
314 AM CDT Wed Apr 21 2021 Unseasonably cold airmass coupled with light wind and clear skies has resulted in sub-freezing temps at virtually all reporting sites across the area early this morning. At this point the current expiration time of 14z for the Freeze Warning appears valid as most if not all areas should quickly rise above freezing by then. The most likely area to see enough breaks to allow for freezing temps will be across NW AR and extreme NE OK and, as such, will issue a Frost Advisory for those areas tonight as expect duration of sub- freezing temps to be brief.
Meanwhile, the cold front continues marching southeast across KY into the Middle TN, generally just west of the I65 corridor. A strong cold front will move through early this morning leading to winds shifting to W and NW at all TAF sites and a period of MVFR cigs with widely scattered, light showers for a few hours. Garuckas Chattanooga Airport, TN 54 36 64 42 68 / 20 0 0 10 10 Knoxville McGhee Tyson Airport, TN 50 33 59 38 65 / 60 0 0 10 10 Oak Ridge, TN 51 33 60 38 65 / 20 0 0 10 10 Tri Cities Airport, TN 47 30 54 32 63 / 60 10 0 0 0 NC.
Generally, however, a drier and milder day is expected as broader trof axis shifts to our south and low-to-midlevel ridge axis becomes centered over the High Plains.
257 AM CDT Wed Apr 21 2021 The broad upper level trough that has been over a good portion of Canada and the CONUS will finally begin to move to the east. Continued southerly low level flow overnight, but overall the cool air mass will hang on tightly for just a little longer with overnight lows once again down into the 30s, although with freezing temperatures likely confined to the northwestern zones which remain right at the climatological average for last freeze date.
Winds mainly southwesterly 5 to 10 knots this evening, but will be shifting to the west and northwest late tonight and early Wednesday morning as a dry cold front moves south across the area.
/issued 257 AM CDT Wed Apr 21 2021/ The broad upper level trough that has been over a good portion of Canada and the CONUS will finally begin to move to the east. Continued southerly low level flow overnight, but overall the cool air mass will hang on tightly for just a little longer with overnight lows once again down into the 30s, although with freezing temperatures likely confined to the northwestern zones which remain right at the climatological average for last freeze date. This low will help sharpen the dryline and lead to southwesterly surface winds across the western South Plains and southwestern Panhandle.
The disturbance will lift a warm front into swrn Nebraska by Thursday morning. The warm front will lift slowly north through wrn and ncntl Nebraska during the day and is the basis for a chance of rain or snow showers throughout the day.
657 AM CDT Wed Apr 21 2021 Morning conditions across the forecast area characterized by a chilly airmass in place with temperatures in the lower to middle 30s. It's still pretty likely that many areas will still see sub-freezing temperatures, and it will be very plausible that as the mid level clouds move out there could be a quick drop of a few degrees. So will maintain the freeze warning for the area as temperatures are still pretty close to freezing even with the passing cloud cover. The mid level trough located generally over the Great Lakes region will remain mostly in place through the next couple days.
High pressure over the Northern Plains will continue to build into the forecast area today. This will provide dry conditions in the low levels with just some passing high level cloudiness. /issued 352 AM CDT Wed Apr 21 2021/ The frontal boundary has pushed offshore early this morning as cooler, drier air advects into the region on brisk northerly winds. High pressure will settle nearly overhead tonight allowing winds to calm and providing a nearly ideal radiational cooling environment that will allow lows to drop into the lower 40s across central Louisiana and upper 40s along and south of the I-10 corridor. As the high slides east of the region Thursday, temperatures will begin to moderate as southeasterly flow becomes reestablished.
541 AM CDT Wed Apr 21 2021 Temperatures below freezing this morning will give way to afternoon highs in the upper 40s to around 50. Temperatures are expected to fall below freezing for most of central Illinois again tonight.
502 AM CDT Wed Apr 21 2021 Gusty northerly winds behind a dry cold frontal passage will continue this morning, as high pressure builds back into the region. A much cooler and drier airmass is moving in, resulting in todays highs only climbing into the upper 50s/lower 60s. The pressure gradient behind the cold front will slowly loosen as the day progresses. The narrow band of clouds on sat imagery will also diminish later this morning with general subsidence as high pressure builds back in. Overnight, the ridge axis moves into the forecast area and winds drop off considerably, becoming light and variable if not completely calm. Areas without cloud cover will radiate out efficiently in a cooler, drier airmass with no wind.