Aikyam-Lab/Synoptic-Bench huggingface dataset:
The low clouds have had a hard time spreading southward as the NAM has forecast, due to the strong northerly downslope sfc winds that are occurring over El Paso and Pueblo counties. An upper level trof will be moving over CO today and tonight, from northwest to southeast. The NAM12 show the highest area of CAPE this afternoon (800-1200 J/kg) from near the Wet mtns to the KTAD area and eastward acrs Las Animas and Baca counties. Slightly cooler air will remain in place, while somewhat limited moisture will keep convection chances mainly tied to the higher terrain.
While this seems plausible given the expected influx of warm, moist air in the lower levels from the Gulf of Mexico and dry air aloft, sometimes the numerical guidance can be too aggressive with these scenarios.
An upper level low pressure area spinning over the Rockies late this afternoon already spreading clouds and some rainfall into southwest SD. With northerly flow aloft remaining through Sunday night, another short wave trough dropping in straight from the north will clip the eastern part of our region Sunday afternoon and night bringing some more chances of showers/storms in the far eastern cwa as weak instability will again be available.
354 AM CDT Sat May 27 2017 Surface and upper level ridging will continue across the area today before gradually shifting eastward tonight. Another dry day expected with the upper ridge overhead and strong subsidence continuing.
Look for warmer temperatures and generally light winds this Memorial Day weekend as high pressure builds over Arizona.
/12/ Prior discussion below: Latest satellite imagery showed a general west southwest zonal pattern the the mid to upper levels and southwest flow in the low levels. A front with low pressure was observed across the Southern Plains which brought a tight pressure gradient for some breezy conditions across the delta region. With the extra low level moisture and anomalous low level temps expect highs to be from the upper 80s to the lower 90s. /17/ There will be a warm, muggy start to Saturday night as moisture continues to pool south of an approaching cold front. A deep upper trough associated with a closed low over Canada will continue to trek across the Plains Saturday night.
354 AM CDT Sat May 27 2017 Mid level trough continues to dig across central North Dakota into southeast Wyoming early this morning. Will leave the highest chances for measurable rain near our southern border/Missouri Valley and into northwest Iowa with the initial band of rain this morning. Early week conditions will be courtesy of the influence from closed low over the western Great Lakes along with various impulses on the merry-go-round through the Northern Plains. First, temperatures will become cooler than normal once again to start the week, and have hedged temps a bit lower than climatologically impacted guidance.
Areas of fog are likely to form across the higher terrain overnight. Scattered showers continue within a cool, northwest flow and weak upward motion around the western periphery of closed low over New England coastal waters. By Sat afternoon the mid-lvl ridge will have shifted eastward across the midwest and weak WAA will occur. Anticyclonic flow aloft will continue Saturday night and high pressure at the sfc will build across NY and PA. Sfc temps will fall into the low 50s by Sunrise on Sunday. Current trends with latest model runs indicate the upper level ridge will remain over the region late enough on Sunday for a dry day for most if not the entire forecast area. Highs will range in the lower to middle 70s under partly sunny skies.
1018 PM PDT Fri May 26 2017 High pressure builds over the region this weekend.
A cold front will move across northern Oklahoma today and into central and southern sections this evening. Other, more widespread thunderstorms, also likely severe, will move southeast into northern and central Oklahoma this evening along a cold front.
106 AM EDT Sat May 27 2017 A period of showers and thunderstorms is expected mainly this evening across the area along and north of a warm front and area of low pressure area tracking east. A cold front will move through by Sunday bringing another round of showers and storms followed by cooler and less humid conditions into Memorial Day. Hi res models show mcv working east and warm front slowly working north to set the stage for at least a period of showers and storms across much of the area. An unstable airmass should reside across parts of the area Sat ngt into early Sunday as a cold front sweeps through. Chance to likely pops warranted in the period followed by cooler and less humid conditions. Upper low will settle across the Great Lakes and linger through at least mid week.
259 AM EDT Sat May 27 2017 Advancing low pressure will return rain to the region tonight.
Low temperatures tonight to fall into the low to mid 70s.
Relaxed high pressure continues across the waters through midweek with light winds and an onshore shift during afternoon sea breezes. High pressure will remain in place across the state for the next few days.
A cold front will move through the GUY and DHT TAF sites around mid day Saturday switching the winds around to the north. AMA should remain gusty out of the west as the cold front may not make it there until just beyond this forecast. Localized region of higher instability with trof may support isolated thunderstorms this evening in northeast part of forecast area. On Saturday, surface wave expected to develop, with cold developing cold front dropping into northern sections. Sunday and Sunday night expected to remain dry as cold front moves well south of forecast area.
Other, more widespread thunderstorms, also likely severe, will move southeast into northern and central Oklahoma this evening along a cold front.
347 AM CDT Sat May 27 2017 Large scale lift out ahead of the approaching trough is bringing a large area of precipitation from far south central SD southward into KS.
142 AM EDT Sat May 27 2017 A weak cold front will approach from the west tonight, and will slowly sink south through the region late Saturday afternoon through Saturday night, bringing scattered showers and thunderstorms. The front will dissipate on Sunday, with another cold front moving in from the west on Memorial Day. Lows overnight will avg in the mid/upper 50s to around 60F inland to the lower 60s near the coast in VA/NE NC. Weak ridge aloft nudges into the region from the WSW through Sat morning. A cold front will be crossing the mountains Mon morning. A frontal boundary will push south of the area Tue morning, with weak high pressure providing mainly dry wx for Tue aftn thru Wed.
504 AM EDT Sat May 27 2017 High pressure will build across the area today then slide south of the region Saturday night. A cold front will move into the area Sunday and stall.
We expect one more day of unlimited cigs and unrestricted Vis with a dry airmass and high pressure in place. Expect mid-level ridging to begin increasing from the west by the end of the period. High pressure will dominate over the weekend with an upper level ridge strengthening across the CWA as the center of the ridge slides across the area on Sunday. Highs will reach into the lower 90s with 80s along the coast with lows in the upper 50s to lower 60s tomorrow morning increasing to the upper 60s to lower 70s with the increasing cloud coverage for Sunday morning.
A warm surge aloft later tonight is still indicated in the high res models, which will push the rain-snow line to our far northern CWA between 4-7am. That track still supports a persistent NW to SE band of snowfall across our far northern counties, aided by dry NE flow to keep wetbulb temps just below freezing through the precipitating layer in our warning area and northern advisory area. Low pressure center at surface starting to move now and seen in surface data over western KS. Lift remains significant through the day on Saturday, with temperatures around freezing over the northern CWA. Winds will also increase overnight and remain easterly at mainly 20 gusting to 30 to 35 through day as the low center moves south of region.
A cold front will move through Saturday morning shifting winds to the north then becoming easterly around 10 knots in the afternoon. /issued 244 PM CDT Fri Mar 23 2018/ Tonight, the upper level ridge that has kept the area warm and dry the past few days will continue to translate east as a Pacific trough starts to dig southward across the Pacific coast. Tomorrow, a weak backdoor cold front will move across the area. Backing winds and weak CAA will result in temperatures about 10 to 15 degrees cooler than today and calmer winds.
1157 PM EDT Fri Mar 23 2018 High pressure anchored over northern Ontario will sustain northeast flow across the area throughout the TAF period. Omega blocking will take root throughout the weekend with geopotential heights ballooning to the northeast through Hudson Bay. This will keep the low track and precipitation over southern Indiana. Highs will range in the lower 40s for much of the area, lower 30s in the Thumb.
These echoes northeast of Huron will have to be monitored, as several of the high resolution models show this approaching the far southern Red River Valley around midnight, before shifting it southward again.
803 PM EDT Fri Mar 23 2018 The ridge will move off the Southeast Coast Saturday with a warm front and showers moving in to the north.
907 PM EDT Fri Mar 23 2018 High pressure will build in from the west through Saturday. Low pressure will move from the mid-Mississippi valley Saturday to the southern Mid-Atlantic Saturday night.
A warm front moving through the area overnight will keep plenty of mid and low level moisture over the area.
Scattered thunderstorm activity is continuing around the region resulting in brief periods of heavy rain with periods of snow at the higher elevations when they pass. Overnight lows tonight will be slightly cooler as skies clear, but will remain unseasonably warm. Clouds will be on the increase again starting in the late afternoon tomorrow ahead of a slowly digging trough across Nevada and western Utah.
1045 PM EDT Fri Mar 23 2018 High pressure will continue across the area tonight. Temperatures will not be as cold as previous nights, with values mostly in the 40s outside of the higher elevations.
Another night of above normal temps expected tonight as southerly flow out ahead of a low pressure system centered over the Great Plains slowly makes its way east. This will continue to feed warmer and more moist air (PWs ~1 inch) into the region, which will help low-mid level clouds to increase from the west overnight. This will help lows be considerably warmer (~10-15 degrees above normal) in the mid-upper 50s in the east to low 60s in the west. Winds could gust as high as 20-25mph or so, with some of the higher gusts in the Delta. As better moisture moves in, expect there to be enough lift and surface convergence, especially in the Highway 82 corridor, for some showers to develop.
831 PM CDT Fri Mar 23 2018 Snow north central, and a mix of snow sleet and freezing drizzle south central, continue to move east this evening. Also starting to see some freezing rain and sleet where a ice crystals in are lacking.
As of 20Z Friday afternoon a cutoff mid/upper low continues to spin off of the Pacific northwest coast. Within the warm sector surface temperatures have reached the low to middle 70s.
It's this low that will open up a chance for the thunder.
735 PM EDT Fri Mar 23 2018 VFR conditions under high pressure. /issued 334 PM EDT Fri Mar 23 2018/ A large area of high pressure will continue to dominate the weather across South Florida bringing dry conditions to the region tonight and into the weekend. Low temperatures tonight will not be as cool as the last couple of nights as they will drop into the upper 40s across the northwestern interior to the lower 60s across the east coast areas. The winds will begin to shift to a more east southeasterly direction Saturday which will allow for warmer temperatures during the afternoon. High temperatures on Saturday will range from the upper 70s across the east coast metro areas to the lower 80s across the interior.
An upper level trough over Colorado and the left exit region of the jet will continue to bring scattered showers, isolated thunderstorms and windy periods through early evening. Eventually subsidence and drying will move in behind the trough late this evening bringing mostly clear skies. A weak ridge moving across the state will result in mostly clear skies Saturday morning. An upper level trough digging south over the Pacific Northwest will increase Pacific moisture resulting in high clouds moving in late in the day.
606 PM CDT Fri Mar 23 2018 With the warm front perched just to the south, mid clouds/returns were still falling into high (td) depression air/mostly evaporating before reaching the ground. Best chances for heavier/focused rain showers will be along the warm front itself, across our north, although perhaps better thunder chances in the max instability field, will be across the south. Backwash/instability shower activity will persist into/thru the overnight hours, as last bit energy rotates around the mean upper trof/across the Ohio river valley. Critical boundary layer temps later Saturday night temper a flirtation with changeover pcpn, but it appears such occurrences will be mainly just north and east of our FA and even if it does occur, negligible QPF means it will be a nil impact changeover as surface temps (lows) remain above freezing Sat night, even in the north.
The cold upper level trough along the northwest coast will send another band of snow showers our way on Saturday, but they will be mainly over the higher terrain.
The other thing that looks like it will occur is some fog/freezing drizzle after the snow moves out, especially in areas west of the Red River Valley.
652 PM CDT Fri Mar 23 2018 A warm front is currently position near the Highway 54 corridor and down into the eastern Ozarks. Temperatures were in the lower 50s north of the warm front and the lower 70s across far southeast Kansas and southwest Missouri. Models show scattered showers and isolated storms will develop later this evening and overnight ahead of an advancing cold front. Saturday will be cooler and breezy with clouds decreasing from west to east during the day. Canadian high pressure will build in for Saturday night with most temperatures falling into the lower and middle 30s.
Some quick moving showers, associated with a weak impulse, were noted on radar mainly near the Tennessee River on the north side of a surface warm front. Short term Hi-res models are in good agreement with showers residing near the warm front through the overnight hours. Surface analysis this afternoon places a warm front over portions of Central Arkansas and into Central and Southern Mississippi. A warm front is expected to move north across the Mid-South tonight bringing isolated to scattered rain chances to the area. Short term models indicate some rain showers with perhaps an embedded thunderstorm or two will be possible during the day Saturday with the potential for additional showers and thunderstorms along a trailing cold front Saturday evening.
526 PM MDT Fri Mar 23 2018 Area of mainly showers expected to progress over the Panhandle/far se Wy into this evening as a cold front moves across the area.
One of the highest reflectivity echoes passed over KALB last hour, with only sprinkles reported. Expect partly to mostly cloudy skies with widely scattered rain or snow showers as a trough of low pressure starts to dive southeast from the eastern Great Lakes and southern Quebec. For Saturday and Saturday night there will be mainly widely scattered rain or snow showers as another trough of low pressure moves across the region.
701 PM CDT Fri Mar 23 2018 Low pressure center at surface starting to move now and seen in surface data over western KS. Lift remains significant through the day on Saturday, with temperatures around freezing over the northern CWA. Winds will also increase overnight and remain easterly at mainly 20 gusting to 30 to 35 through day as the low center moves south of region.
MVFR CIGS and IFR VSBYS could move into areas well southwest of Madison between 09-18z Saturday as low pressure brings a swath of heavy snow to areas mainly west of Wisconsin. This agreement generally holds through the forecast period, although the GFS develops a strong pressure rise/fall couplet north of the low which appears to result from convective feedback.
In the low levels of the atmosphere, an area of high pressure will be centered over North Florida overnight. In the mid levels of the atmosphere, a trough of low pressure will be located over the Bahamas tonight. In the upper levels of the atmosphere, a trough of low pressure will progress eastward over the Florida peninsula overnight.
Winds should again lower in speed by Saturday evening as an area of low pressure shifts east of the region, weakening the pressure gradient over SE TX.
With the return of onshore flow in the lower levels, moisture content has increased with a precipitable water value of 0. The freezing level was at 12,600 feet tonight with the -20C level at 23,400 feet. /issued 516 PM CDT Fri Mar 23 2018/ A large area of high pressure over the northeastern gulf continues to bring dry and seasonably mild conditions to the area. A light return flow will take place tonight as the high slowly slides eastward.
1151 PM CDT Fri Mar 23 2018 This afternoon a warm front exist over the southwestern CWA and south of the front temperature have crept up into the upper 60s. This evening a southwesterly LLJ will increase and over ride the warm front.
Mid to high level clouds have been slowly eroding this afternoon as the upper level ridge begins to flatten out and become more zonal. Another impulse will sweep down the east side of the ridge axis later tonight, and a few showers could move across the northeast counties. Overall, much warmer temperatures tonight with mainly high level clouds.
A weak cold front will move across the fcst area later tonight with some cooling seen for Saturday.
Any snow is expected to change to rain by late morning as temperatures warm to above freezing. Chattanooga Airport, TN 44 63 55 64 / 50 70 60 30 Knoxville McGhee Tyson Airport, TN 41 54 45 59 / 90 90 80 40 Oak Ridge, TN 40 53 45 60 / 100 90 80 30 Tri Cities Airport, TN 34 44 38 52 / 70 100 90 40.
1005 PM EDT Fri Mar 23 2018 High pressure will keep the area dry, but cool through the weekend.
The second is an upper level ceiling streaming out of the northwest within a very broad upper ridge. /issued 340 PM CDT Fri Mar 23 2018/ Current sfc analysis shows high pressure centered over the nern Gulf and lower pressures over the srn Plains providing an elevated srly low-level flow over the forecast area this afternoon. Water vapor imagery shows deep troffing along the East Coast with weak ridging developing up the Plains. Despite the increasing low-level moisture, the ridging aloft is maintaining at least some capping and regional 88Ds remain quiet. Max temps tomorrow are progged to reach into the lower 80s across the nwrn 1/2 of the area. A storm system coming ashore along the Pacific coast will push ewd, helping flatten the cntl CONUS ridge.
Expect a few showers to develop tonight ahead of a weak cold front that will move through on Saturday.
Tried to adjust weather types a bit to reflect the wintry mix, but ice should have little impact over the next hour or two as sfc temps remain above freezing. These kind of rates should overcome the warm ground and surface temps in the lower 30s. Still expecting 3 to 6 inches of snow tonight, mainly over the higher terrain areas of the Prairie Coteau. Generally a trace to up to an inch of snow is possible there, and if p-type is changed over to light drizzle/freezing drizzle type precipitation, generally a trace of precipitation is expected at this point.
1133 PM CDT Fri Mar 23 2018 A warm front is currently position near the Highway 54 corridor and down into the eastern Ozarks. Temperatures were in the lower 50s north of the warm front and the lower 70s across far southeast Kansas and southwest Missouri. Models show scattered showers and isolated storms will develop later this evening and overnight ahead of an advancing cold front. Saturday will be cooler and breezy with clouds decreasing from west to east during the day. Canadian high pressure will build in for Saturday night with most temperatures falling into the lower and middle 30s.
A cold, showery upper low off the coast will weaken on Saturday with the remnant trough axis moving across Western Washington Saturday night.
An area of low pressure will bring accumulating snow to central Indiana Saturday with rain elsewhere. Air temperatures will not be that cold with lows only in the upper 20s northeast to around freezing near I-74. With the uncertainty and the low changes needed in the atmosphere to make a big impact, changes to the forecast at any one location are likely as trends become clearer.
Soundings also indicate that there could be some sleet mixed in with the rainfall under the higher reflectivity returns this evening.
1019 PM EDT Fri Mar 23 2018 The ridge will move off the Southeast Coast Saturday with a warm front and showers moving in to the north.
757 PM EDT Fri Mar 23 2018 High pressure anchored over northern Ontario will sustain northeast flow across the area throughout the TAF period. Omega blocking will take root throughout the weekend with geopotential heights ballooning to the northeast through Hudson Bay. This will keep the low track and precipitation over southern Indiana. Highs will range in the lower 40s for much of the area, lower 30s in the Thumb.
High pressure will settle across north/central FL and produce light winds. A high pressure ridge has been gradually building out of the southeast states into the Florida peninsula. All model guidance shifts the ridge into the waters overnight, so these winds will diminish to 10 knots or less and become south/southeast on Sat as the ridge continues to push eastward.
928 PM CDT Fri Mar 23 2018 A cold front will move across the northern half of Oklahoma after midnight. Slightly cooler and drier air can be expected behind the front.
Near the surface, a cold front is pushing southeast across west central into southwest Kansas. Saturday, weak upper level ridging moves into the Central Plains allowing high pressure to move in western Kansas. Temperatures will range from the lower 60s toward central Kansas to the lower 70s toward the Kansas/Oklahoma border.
707 PM CDT Fri Mar 23 2018 This afternoon a warm front exist over the southwestern CWA and south of the front temperature have crept up into the upper 60s. This evening a southwesterly LLJ will increase and over ride the warm front.
Given the air moving in is cooler, a return of more abundant sunshine this afternoon will be tempered by the airmass. The eastern flank of a highly amplified upper ridge will begin to affect the TN Valley tonight.
After a fairly quiet period of weather tonight, a low pressure system moving into the Pacific Northwest will result in below normal temperatures and fairly widespread gusty southwest winds across the area on Sunday.
356 PM CDT Sat May 13 2017 High pressure moves into the area and should last through most of the forecast period.
308 PM CDT Sat May 13 2017 Thickness ridging will allow tomorrow to be hot with highs reaching into the low/mid 90s area wide. Upper ridging will be kicked to the east tomorrow as an upper trough digs along the west coast. Overall chances for convection will be low tomorrow evening/night as dewpoints are only expected to, at best, recover into the low 50s.
232 PM CDT Sat May 13 2017 High pressure aloft ridging all the way from the northern Gulf of Mexico northward into Canada will work its way slowly east through the MS River Valley during the period.