Aikyam-Lab/Synoptic-Bench huggingface dataset:
As the main mid level trough ejects into the area for Sunday, and impressive low level jet along the E/NE quadrant of the H85 low will impact mainly the northern half of Missouri, into Iowa and Nebraska. Mixing will be at a premium, so it's possible we have a hard time mixing down the beef of the low level jet, but that would result in 70 mph winds at the surface, so even a forecast of around 40-50 mph gusts is somewhat conservative and taking into account the rather shallow mixing. After a lull in the action for the early to middle part of the week another potent trough moves through with another dose of light to moderate rain. Did not include them in the official forecast as surface winds are expected to remain adequately strong to minimize the low level shear.
301 AM MST Sat Mar 13 2021 09z surface analysis had high over Lake Michigan with weak ridge back into the CWA bringing clear skies over the northern 4/5ths of the area. Water vapour showed upper low spinning into southwest UT with trough into WY. Upper low is main concern this forecast. Today through Sunday, models are generally converging on a similar solution for the upper low, but NAM is still the farthest north.
This will let temperatures rise into the low to mid 70s by afternoon for most places, with the possible exception of far northeast Oklahoma where the front will reach later in the day.
SHORT TERM (Now through Sunday): The main event in this portion of the full forecast will be the Sunday morning passage of a cold front. The front will serve to bring temperatures to more near normal values, with dry weather and well above normal temperatures expected in advance of the cold front.
205 AM PST Sat Mar 13 2021 Temperatures will trend warmer through Sunday under dry conditions.
Through the day s/wv mid level ridging will strengthen across the region and serve to diminish precipitation chances, with the focus turning to areas to our west ahead of a large upper low that will centered over east CO by 18z Sunday.
Like all other areas with winter impacts, snow will be most impactful at higher elevations first because of warmer road conditions. What snow does fall across the region is likely not to last too long in the lower elevations, as the higher sun angle and warmer temperatures of early to mid March should bring temperatures up quickly once the sun rises.
Gusty southeasterly winds return this afternoon and will continue through the evening hours ahead of an approaching cold front. Upper trough over the Desert Southwest will continue to develop a tight sfc pressure gradient and gusty southerly winds this afternoon and evening. Speaking of this strong upper-level trough.
The front is expected to resume its northward movement as a warm front later this morning. Meanwhile, a cold front will develop over west Texas this afternoon.
Meanwhile a combination of strong daytime heating in the clearing zone, and very cold temperatures aloft associated with closed upper level low is something we will need to keep an eye on.
331 AM MST Sat Mar 13 2021 A Rex block over the western half of the US is responsible for the ridge of high pressure currently over the region and large cut off low over the southwestern US. An eastern Gulf of Alaska low with an associated high amplitude trough is nearing the western US coast.
400 AM CST Sat Mar 13 2021 Non-impactful weather is forecast today and Sunday as a blocking ridge is expected to hold firm north of a large cutoff low impacting portions of the central Rockies and Plains. This ridge aloft will promote dry conditions and clear skies save some thin upper level cirrus coming out of Canada today, and eventually striped away from the expanding cloud shield of the cutoff low Sunday. The high temp record for Grand Forks has a very good chance at breaking the record of 59 as NBM's 50th to 75th percentile currently stands at 57 and 62, respectively. Sunday will be a little cooler than today as a backdoor cold front slides into the area from the northeast.
/issued 309 AM CST Sat Mar 13 2021/ SHORT TERM (Now through Sunday): The main event in this portion of the full forecast will be the Sunday morning passage of a cold front. The front will serve to bring temperatures to more near normal values, with dry weather and well above normal temperatures expected in advance of the cold front.
Today and Tonight High pressure remains in control today leading to light winds and well above normal temps into the mid/upper 50s. Mid-level moisture advection on the eastern fringe of a large upper low over Colorado will begin to reach the southwest forecast area late tonight. Sunday Cooler conditions in the upper 40s to low 50s are expected due to widespread cloud cover and a strengthening east wind (gusting up to 30 mph).
As this happens, a strong cold front will slowly progress through the region bringing additional showers and thunderstorms.
332 AM CST Sat Mar 13 2021 Another warm and dry day can be expected for today as the region remains in between systems and sees ridging aloft. A developing low to our south will provide a slightly cooler easterly flow pattern across the state on Sunday. This will bring still dry conditions, some breezy winds at times, and slightly cooler temperatures in the upper 40s to lower 50s.
845 AM EST Sat Mar 13 2021 Some patchy ground fog this morning has dissipated, and mostly clear skies will be in place through the rest of the day as we warm into the lower to mid 80s with high pressure firmly in place across the area at the surface and aloft. E/SE winds under high pressure for the next several days with winds turning onshore each afternoon.
(previous) A weak pressure gradient with high pressure nearby will keep winds generally below 10 kts through the period.
Clouds may linger along the coast for much of the day, with sunny skies and warmer temperatures inland.
Another warm and dry day can be expected for today as the region remains in between systems and sees ridging aloft. A developing low to our south will provide a slightly cooler easterly flow pattern across the state on Sunday. This will bring still dry conditions, some breezy winds at times, and slightly cooler temperatures in the upper 40s to lower 50s.
Upper trough over the Desert Southwest will continue to develop a tight sfc pressure gradient and gusty southerly winds this afternoon and evening. Speaking of this strong upper-level trough.
An area of low pressure will continue to bring rain and snow to much of the area today. Dry and warmer conditions are expected to return Sunday with gusty west to northwest winds.
Upper level high pressure will remain over the region for continued mostly clear to partly cloudy skies with warm temperatures and relatively light winds.
653 AM EST Sat Mar 13 2021 High pressure will provide dry and cool weather over the weekend.
610 AM CST Sat Mar 13 2021 Non-impactful weather is forecast today and Sunday as a blocking ridge is expected to hold firm north of a large cutoff low impacting portions of the central Rockies and Plains. This ridge aloft will promote dry conditions and clear skies save some thin upper level cirrus coming out of Canada today, and eventually striped away from the expanding cloud shield of the cutoff low Sunday. The high temp record for Grand Forks has a very good chance at breaking the record of 59 as NBM's 50th to 75th percentile currently stands at 57 and 62, respectively. Sunday will be a little cooler than today as a backdoor cold front slides into the area from the northeast.
Non-impactful weather is forecast today and Sunday as a blocking ridge is expected to hold firm north of a large cutoff low impacting portions of the central Rockies and Plains. This ridge aloft will promote dry conditions and clear skies save some thin upper level cirrus coming out of Canada today, and eventually striped away from the expanding cloud shield of the cutoff low Sunday. The high temp record for Grand Forks has a very good chance at breaking the record of 59 as NBM's 50th to 75th percentile currently stands at 57 and 62, respectively. Sunday will be a little cooler than today as a backdoor cold front slides into the area from the northeast.
546 AM EST Sat Mar 13 2021 Dry and stable environment under high pressure will bring VFR conditions as skies remain clear this forecast period. * None A strong 1033 high pressure system centered directly over southern Michigan with a moisture-starved atmospheric column (PW values under a tenth of an inch) will bring another round of mostly sunny skies to Southeast Michigan today. Daytime highs in the lower 50s remain achievable. Otherwise, a strengthening pressure gradient will coincide with peak diurnal heating later this afternoon as the center of high pressure sags south into the Ohio Valley.
616 AM EST Sat Mar 13 2021 High pressure will provide dry and cool weather over the weekend.
The cold front has dipped a little further south than previously expected and stretches across north MS attm. Temps range from the lower 50s north to around 60 south. Showers and thunderstorms across the north will diminish this morning as the low level jet breaks down and an upper ridge starts to build across the region in advance of the upper low pushing across the Four corners region. The stalled front will lift a little further north on Sunday as the deep upper low moves into the southern plains and a cold/occluded front pushes east toward the lower MS valley. In advance of the front, southerly low level winds will transport moisture north with surface dewpoints reaching the lower 60s across the Delta.
Temperatures to start out above freezing across enough of the profile for rain, though it will be tricky thereafter. GEFS probabilities are helpful to some extent here, with most members leaning towards liquid/above freezing through the day Sunday before a shift to snow from members.
251 AM MST Sat Mar 13 2021 09z surface analysis had high over Lake Michigan with weak ridge back into the CWA bringing clear skies over the northern 4/5ths of the area. Water vapour showed upper low spinning into southwest UT with trough into WY. Upper low is main concern this forecast. Today through Sunday, models are generally converging on a similar solution for the upper low, but NAM is still the farthest north.
449 AM CST Sat Mar 13 2021 Another very nice March day in store today courtesy of high pressure. Some rain is possible briefly at the onset, but surface temperatures should quickly drop below freezing as the heavy band continues to move in and encounters drier air in the low levels. These two factors, despite surface temperatures that will be a few degrees below freezing, the snow will be wet and heavy with ratios in the neighborhood of 8-10:1.
328 AM MST Sat Mar 13 2021 Upper level high pressure will remain over the region for continued mostly clear to partly cloudy skies with warm temperatures and relatively light winds.
410 AM MST Sat Mar 13 2021 09z surface analysis had high over Lake Michigan with weak ridge back into the CWA bringing clear skies over the northern 4/5ths of the area. Water vapour showed upper low spinning into southwest UT with trough into WY. Upper low is main concern this forecast. Today through Sunday, models are generally converging on a similar solution for the upper low, but NAM is still the farthest north.
The showery nature of the precipitation with this low is brought out by the low confidence in where the precipitation falls over the forecast area. This intense low tracks farther eastward compared to the previous (and current) upper level low, but still digs southward and the center passes to the south. The overall northerly surface flow with all the low pressure to the south makes afternoon temperature forecasts a little more uncertain, depending on cloud cover and how much cold air is able to cross the continental divide.
As the main mid level trough ejects into the area for Sunday, and impressive low level jet along the E/NE quadrant of the H85 low will impact mainly the northern half of Missouri, into Iowa and Nebraska. Mixing will be at a premium, so it's possible we have a hard time mixing down the beef of the low level jet, but that would result in 70 mph winds at the surface, so even a forecast of around 40-50 mph gusts is somewhat conservative and taking into account the rather shallow mixing. After a lull in the action for the early to middle part of the week another potent trough moves through with another dose of light to moderate rain.
411 AM EST Sat Mar 13 2021 Currently - Surface through lower level high pressure centered over the far southeastern United States is responsible for moderate northeast to east breezes across the Keys and surrounding waters. This high is aligned under a fairly sharp ridge aloft over the Gulf of Mexico. Through this period the mid and upper level ridges will be aligned over Florida. The flow aloft will become zonal by mid week and the lower level ridge will become aligned over and east of the Bahamas.
1048 AM MST Sat Mar 13 2021 09z surface analysis had high over Lake Michigan with weak ridge back into the CWA bringing clear skies over the northern 4/5ths of the area. Water vapour showed upper low spinning into southwest UT with trough into WY. Upper low is main concern this forecast. Today through Sunday, models are generally converging on a similar solution for the upper low, but NAM is still the farthest north.
High pressure currently analyzed over north central FL has maintained light and variable winds across the region today, with a small indication of the east coast sea breeze forming east of I-95 as winds shift onshore this afternoon. Highs will reach the lower 80s this afternoon. Temperatures will be even warmer than today, with highs at the coast reaching the upper 70s to lower 80s and the mid 80s over the interior. High pressure extending swd along much of the eastern US Seaboard will provide mild onshore flow with stable dry conditions.
Still seeing sfc dewpoint temperatures in the lower teens along the Missouri River from Williston to Garrison, and don't expect much improvement today so lowered min RH values there down into the upper teens. Another warm and dry day can be expected for today as the region remains in between systems and sees ridging aloft. A developing low to our south will provide a slightly cooler easterly flow pattern across the state on Sunday. This will bring still dry conditions, some breezy winds at times, and slightly cooler temperatures in the upper 40s to lower 50s.
Currently, weak northwest flow aloft remains with an upper level ridge axis extending into western Montana and a large area of low pressure moving east out of the Desert Southwest and into the southern Rockies. Large upper level low will slowly push east into the Central Plains tonight into Sunday, spreading clouds northward into our region along with cooler temperatures aloft. Cooler highs for Sunday, but still mild with forecast highs from the mid 40s to mid 50s.
224 PM EST Sat Mar 13 2021 High pressure will maintain dry and cool weather through Sunday.
A ridge of high pressure will remain over the region through early Sunday. Today will again be warm with light winds while tonight will be cool but a little warmer with continued light wind.
The resulting height falls will drive an associated cold front across Lake Huron and into Se Mi. Northerly flow across Lake Huron into Se Mi associated with this high will sustain dry and cold air advection through the day Sunday. Despite full mid March sun, the cold air will keep highs across metro Detroit and points south in the low to mid 40s with low 30s expected over the northern Thumb.
143 PM CST Sat Mar 13 2021 Latest 18z surface analysis shows high pressure extending from southern Michigan into northern Iowa/southern Minnesota.
104 PM EST Sat Mar 13 2021 High pressure will provide dry and cool weather over the weekend.
Overnight, quiet and cloudy weather is expected as weak high pressure cell to will suppress rain chances to our south and west. Sunday night, a stacked low pressure system near the Oklahoma panhandle will begin to break apart. The mid-level low will get displaced to the north by a sharply amplified trough dropping south along the West Coast.
High pressure aloft remains over the region today, for another day of mild conditions.
A large low pressure system will gradually shift eastward through the weekend.
1220 PM EST Sat Mar 13 2021 High pressure is centered over the southern MI border holding a very dry airmass in place across the region resulting in only a few cirrus above 20kft today. * None A strong 1033 high pressure system centered directly over southern Michigan with a moisture-starved atmospheric column (PW values under a tenth of an inch) will bring another round of mostly sunny skies to Southeast Michigan today. Daytime highs in the lower 50s remain achievable. Otherwise, a strengthening pressure gradient will coincide with peak diurnal heating later this afternoon as the center of high pressure sags south into the Ohio Valley.
The daytime heating and strengthening southerly low level flow are mixing out the low ceilings from earlier this morning allowing for a return to VFR levels. A cold front will approach the RGV late in the current TAF period pushing through the region tomorrow morning resulting in the surface flow starting to swing around from the SW-NW. /issued 309 AM CST Sat Mar 13 2021/ SHORT TERM (Now through Sunday): The main event in this portion of the full forecast will be the Sunday morning passage of a cold front. The front will serve to bring temperatures to more near normal values, with dry weather and well above normal temperatures expected in advance of the cold front.
A narrow upper ridge over the PacNW, situated between an upper trough off the coast and a large upper low near the Four Corners, will be accompanied by clear skies and light winds across southeast Oregon and southwest Idaho today.
A weak cold front brings a wind shift later this evening, with northerly, then northeasterly winds bringing in drier and slightly cooler air for tonight into Sunday. A rather potent upper low continues pushing across the High Plains into the Midwest Sunday afternoon and evening.
Meanwhile, deep and well- stacked ridging remains entrenched across the Western Caribbean and Central America. High pressure centered over northern Florida supports moderate easterly breezes across the Florida Keys. Temperatures are in the lower 80s with dewpoints ranging from 60 to 66. The storm system over the Four Corners will slide east over the next couple of days, eroding the northern flank of the mean layer ridging.
1038 AM EST Sat Mar 13 2021 High pressure will provide dry and cool weather over the weekend.
945 AM PST Sat Mar 13 2021 Temperatures will trend warmer through Sunday under dry conditions.
The strong upper level low over the intermountain west will shift east into western KS tomorrow. There is an outside shot of some severe storms along the Missouri/Arkansas border in the afternoon and evening if the warm front can make it farther north, but current projections keep the front south of the area.
Vigorous and large upper level storm system over the Four-Corners of the Desert Southwest results in down- stream amplification of Gulf ridge which keeps the near-term weather over our area on the quiet side. The high to our east maintains a light southeast to southerly component in the wind, resulting in sufficient boundary layer moisture to support the re-development of fog overnight.
High pressure over the Northern Rockies is forecast to transition eastward on Sunday as the next trough moves into the Pacific Northwest. What this means for Sunday is, warmer temperatures are expected as a mild southwesterly flow sets up over central Idaho and western Montana. The approaching trough is forecast to split and model consensus maintains that the main low will drop well south of the region, leaving only weak lift and a slight increase in available moisture.
GAH MORNING DISCUSSION: A Rex block over the western half of the US is responsible for the ridge of high pressure currently over the region and large cut off low over the southwestern US. An eastern Gulf of Alaska low with an associated high amplitude trough is nearing the western US coast.
Chattanooga Airport, TN 66 53 74 52 65 / 30 20 0 20 80 Knoxville McGhee Tyson Airport, TN 61 51 60 48 64 / 40 40 20 20 80 Oak Ridge, TN 61 50 60 47 63 / 40 50 20 20 80 Tri Cities Airport, TN 62 45 57 43 57 / 20 20 50 20 80.
As we move into late afternoon and early evening, very strong forcing will spread over the area in conjunction with a jet streak on the east side of the upper low and a Pacific-type front will overtake the dryline across the central South Plains. As the upper low moves curls northeast into eastern Colorado, the mid-level trough axis will swing over the South Plains, which should keep winds somewhat elevated overnight. The drier and cooler airmass with the trough's passage will bring cooler overnight lows. The upper level low will continue to drift northeast of the area on Sunday with broad cyclonic circulation around it producing deep westerly flow across the CWA.
Mid and upper level moisture flowing around an upper ridge will keep skies partly to mostly cloudy. On Sunday, the area will be under an upper ridge, and high pressure will remain in control at the surface. At the surface, high pressure will remain anchored off to the northeast, keeping a dry east to northeast flow across the area. Temperatures aloft will be warm, but the evaporative cooling in the lower levels will allow the possibility for some sleet to mix in with the rain across the northeast fringe of the precipitation area late Sunday night.
CDG Chattanooga Airport, TN 53 74 52 65 51 / 20 20 20 80 60 Knoxville McGhee Tyson Airport, TN 51 60 48 64 48 / 30 30 20 80 60 Oak Ridge, TN 50 60 47 63 48 / 30 30 20 80 60 Tri Cities Airport, TN 45 57 43 57 41 / 20 20 20 80 70.
254 PM CST Sat Mar 13 2021 Mid level ridging will build into the region tonight into Sunday. It will likely be a fairly dirty ridge with a good deal of cloud cover, but should keep things fairly quiet except for a stray shower here and there with near seasonal temps in the mid 50s to near 60. Yet another round of showers and isolated thunderstorms is expected to move from west to east across the region later Sunday afternoon and Sunday night as a mid level short wave and associated sfc warm front approach.
Meanwhile, deep and well-stacked ridging remains entrenched across the Western Caribbean and Central America. High pressure centered over northern Florida supports moderate easterly breezes across the Florida Keys. High pressure will persist over the western North Atlantic for the next several days, maintaining moderate to occasionally fresh breezes.
441 PM MST Sat Mar 13 2021 The strong upper low is now centered across the Four Corners region, and is slowly making it way eastward. high pressure is extending from the Midwest into MN/ND. The northern end of warning criteria totals could suffer if temperatures tomorrow are warmer than expected and dry air within the high pressure to the north hinders the moisture. From the highest elevations to the leeward SW Black Hills, models are suggesting very strong downsloping combined with 60kt winds down to about 1000 feet, which would support gusts to 60 mph at the surface. The strongest winds would be limited to west of Hill City in Pennington, in Custer County, from the higher foothills into the southern Black Hills, and down into Fall River County.
520 PM CST Sat Mar 13 2021 We are monitoring the clearing over southwest parts of Oklahoma where sufficient warming into the lower 70s is eroding the cap. Overall convergence in the warm sector and near warm front is weak at the moment, but convergence appears to be increasing some from near Erick, eastward toward Anadarko. Even if this occurs, they could quickly cross the front into the cooler air mass.