Aikyam-Lab/Synoptic-Bench huggingface dataset:
The large closed low over the Central Plains continues to expand in its spatial footprint as it continues to mature and occlude. However, as upper low meanders north-northeastward out of the Central Plains into the Upper Midwest, it weakens and breaks up into one or more pieces of vorticity into the Dakotas and Minnesota through Tuesday. By tonight, the weakening process of the low cuts off the warm conveyor and assoc moisture ending snow chances. As synoptically driven northern plains split flow pushes east and upper ridging takes hold across the region the predominantly dry weather will persist across the area.
549 AM EDT Mon Mar 15 2021 Dry, cool weather is expected before a low pressure system brings light rain to the area tonight and Tuesday.
Part of the trough that was responsible for bringing the snowstorm to Colorado will break off across the Nebraska panhandle today. Fog should be quite dense across much of the urban corridor and eastern plains excluding the Cheyenne Ridge and Palmer Divide. There may be patches of black ice that develop especially on bridges and overpasses so travel conditions could become poor for the morning commute Tuesday.
The upper flow will be replaced by short wave ridging with an upper low entering the western CONUS. A fairly small but strong upper level low was currently moving onshore in northern California early this morning. This low will continue to drop into southern California this evening and track into Arizona tonight. We will see weak lee surface cyclogenesis and pressure troughing in eastern New Mexico this afternoon. As mentioned above the upper level low in Arizona in will continue to move towards the region on Tuesday.
A north to northeast flow will develop elsewhere, keeping temperatures a few degrees cooler from what has been experienced the past couple of days. Temperatures will rebound to a few degrees above normal by mid- week as another high pressure builds over the Northern Rockies. Lowering snow levels behind a cold front tonight may bring light snow or a rain/snow mix to the valleys south of I-90, but no accumulations are expected for area terminals.
607 AM EDT Mon Mar 15 2021 High pressure wedges in from the north today, bringing a return to below normal temperatures. Rain chance will begin to arrive later tonight as low pressure system moves northeast from the Plains.
232 AM PDT Mon Mar 15 2021 Temperatures will be cooler today, and there will be a chance for light rain.
During this afternoon, a negatively tilted upper-level trough manifested from an an deformed upper-level closed low over the Central Plains will pivot across the Midwest. These features will provide a focus for showers and thunderstorms developing during the late afternoon into evening as strong surface heating in breaks of cloud cover south of the front promote surface heating beneath steepening mid-level lapse rates associated with the trough. Even ordinary cell thunderstorms could produce small hail, given a freezing level depressed to near 800 hPa. Broad upper-level ridging will dominate the forecast area with dry conditions on Tuesday.
616 AM CDT Mon Mar 15 2021 A large upper low to our west over the central U.
/Issued 308 AM CDT Mon Mar 15 2021/ Large upper level low spinning over southwest Kansas this morning will lift northward into the northern Plains by late this afternoon. Meanwhile another vigorous upper level closed low will move southeast to the central valley of California by late this afternoon. This upper level low is then expected to make a turn to the east across Arizona and New Mexico and then it will move across the Texas Panhandle Tuesday night. A few thunderstorms may develop ahead of the dryline and north of the warm front Tuesday evening before they move off to the east of our area.
Stratcu expected to spread south and east around Kansas low pressure system. (Today and tonight) A deep surface cyclone centered over western Kansas this morning will drift slowly east/northeast, while weakening. Oklahoma and north Texas will be sitting underneath a weak short- wave ridge tonight, resulting in light winds and no precipitation, as we await the arrival of the next storm system on Tuesday.
Another windy day is in store today ahead of a quick moving cold front. This system will bring another round of showers with accumulating snow across much of the high country from late tonight into Tuesday morning.
536 AM EDT Mon Mar 15 2021 Dry, cool weather is expected before a low pressure system brings light rain to the area tonight and Tuesday.
Upper low spinning over western KS, with main lift focusing on the northeast quadrant as deformation zone breaks down over the western half of the CWA. Rest of today through Tuesday, moist cyclonic flow will continue as main upper low shifts northeast breaking off a couple of weaker circulations over the northern plains.
We may be able to cancel that early, however there was some concern that the precip could end as a period of freezing drizzle. The upper low responsible for the precipitation is in the process of cutting off a piece of energy that will remain across the Black Hills.
Tuesdayâs highs will be several degrees warmer then Monday, especially in the central and western Rio Grande Valley where highs in the low to middle 90s are expected.
631 AM CDT Mon Mar 15 2021 (Today and tonight) A deep surface cyclone centered over western Kansas this morning will drift slowly east/northeast, while weakening. Oklahoma and north Texas will be sitting underneath a weak short- wave ridge tonight, resulting in light winds and no precipitation, as we await the arrival of the next storm system on Tuesday.
(Today and tonight) Warmer temperatures and dry conditions will be the main story for today.
534 AM EDT Mon Mar 15 2021 Dry, cool weather is expected before a low pressure system brings light rain to the area tonight and Tuesday.
735 AM EDT Mon Mar 15 2021 Approaching low pressure should support light rain across the area tonight and Tuesday.
910 AM EDT Mon Mar 15 2021 High pressure in control today will bring sunny, but cold conditions.
559 AM EDT Mon Mar 15 2021 Canadian high pressure will build into the region today. The core of coldest air associated with upper trough will be shifting east of Pa today. Mixing to near 850mb supports high temperatures in the low to mid 40s over much of the region, but as cold as the low and mid 30s over the mountains north of KIPT. However, will keep POPs low due to some very dry air in the lowest 2km. However, southeast flow and low level moisture could result in lingering drizzle with freezing drizzle possible over the high terrain of northeast Pa.
This boundary will retreat inland as a warm front today, bringing a southerly warm/moist airmass.
A strong area of low pressure was located over western Kansas this morning with rain and snow north of a warm front stretching from Iowa into eastern South Dakota and southwestern Minnesota. Strong high pressure was centered just northeast of Lake Superior and stretched westward across the Northland. As the low in the Central Plains lifts northeast today, precip will run into the high pressure and dry air and have trouble spreading into the region. Overnight lows will fall below freezing, helping to mitigate runoff issues from melting snowpack.
523 AM PDT Mon Mar 15 2021 Temperatures will be cooler today, and there will be a chance for light rain.
Slightly warmer conditions/profiles would suggest rain would be the more dominant ptype, however, can't rule out some light snow mixed in there as well. One last item that I had been monitoring early this morning, is some possible drizzle/freezing drizzle development.
But these will warm up again this afternoon to the lower 80s along the coast and mid 80s (an possibly 87 degrees in some locations) across the interior.
Still expecting moisture to eventually saturate the lower layer given continued moisture feed, but it will be a battle of the two air masses this morning. The large closed low over the Central Plains continues to expand in its spatial footprint as it continues to mature and occlude. However, as upper low meanders north-northeastward out of the Central Plains into the Upper Midwest, it weakens and breaks up into one or more pieces of vorticity into the Dakotas and Minnesota through Tuesday. By tonight, the weakening process of the low cuts off the warm conveyor and assoc moisture ending snow chances. As synoptically driven northern plains split flow pushes east and upper ridging takes hold across the region the predominantly dry weather will persist across the area.
/issued 314 AM CDT Mon Mar 15 2021/ We get to enjoy a break in the windy conditions today as an upper level low ejects off to the northeast. The quick arrival of the second upper low also means that moisture will not have a chance to return this far west so rainfall will most likely remain to the east of our CWA.
A nearly vertically stacked system continues to spin across the High Plains this morning with an occluded front draped across the CWA along a CNK to MHK to LWC line. The better chances for any of these storms to become severe is expected to be east of the forecast area where instability and low-level shear is maximized ahead of the upper low. The upper low departs early on Tuesday setting up a dry and seasonable day with highs in the 50s.
This is associated with a remnant piece of the departing upper low. After another cool and cloudy day on Tuesday, attention switches to another cutoff upper low moving out of the southwestern CONUS and through the southern/central Plains.
634 AM CDT Mon Mar 15 2021 (Today and tonight) Warmer temperatures and dry conditions will be the main story for today.
This is a little cooler than the deterministic blend. The cooler temperatures seem appropriate given afternoon temperatures are in the 30s. The temperature forecast Tuesday and Tuesday night also uses the guidance blend plus bias correction which in on the cooler side of the forecast envelop.
153 PM MDT Mon Mar 15 2021 A powerful low pressure system over the midwest will exert its influence over our region tonight and Tuesday as an upper low associated with the midwest system forms over SW South Dakota this evening. The band appears to have a steep precipitation gradient on either side and combined with fact temperatures will hover near freezing late tonight and early Tuesday, snow amounts will vary dependent on where band sets up and on elevation with hilly areas picking up more than river bottoms. Rain showers at the lower elevations should switch over to snow after midnight for most areas. Slushy or slick roads are possible over these areas, especially over bridges by tomorrow morning.
122 PM EDT Mon Mar 15 2021 A light wintry mix of sleet, snow, freezing rain, and rain is expected to spread in from southwest to northeast late this morning into this evening.
There will however be some freezing drizzle on the back end of the band as the air aloft dries out.
An upper low will move south across the region today, with some lingering showers moving through the southern half of the area this morning.
/Issued 1040 AM CDT Mon Mar 15 2021/ Fire weather is the main concern today as drier air is expected to surge into southeast Oklahoma this afternoon in the wake of another Pacific cold front moving through the region.
155 PM MDT Mon Mar 15 2021 An elongated low pressure is moving north into the area today. Southeast flow at the low levels has brought cool moist air in with virga in most areas this afternoon. An upper ridge will then be building in and bring another round of warm and dry conditions to the area.
The showers will spread into southern Malheur and Owyhee Counties this afternoon as an upper low moves through Nevada. A cold front accompanying the low will move through southeast Oregon this morning and southwest Idaho this afternoon and evening, accompanied by breezy to locally windy conditions. Temperatures will be cooler today, especially in southeast Oregon. Isolated IFR/MVFR showers through the day as a trough of low pressure passes through especially across SE Oregon and along the Nevada border.
316 PM EDT Mon Mar 15 2021 Approaching low pressure should support light precipitation across the area tonight and Tuesday.
The region will experience a break in the action this afternoon and into the evening as a transient ridge lingers overhead. However, another closed mid-level low pressure trough was circulating over central Colorado at mid afternoon. As the low tracks over Arizona and New Mexico on Tuesday, moisture and lift in concert with orographic forcing begins to favor the south-central and southern mountains and snow begins to accumulate in earnest during the day and into the evening.
Review of 12z regional sounding data indicates the presence of a capping inversion associated with an elevated mixed layer aloft emanating from the high terrain of west Texas and northern Mexico. Latest visible satellite imagery is showing several breaks in the low level stratus across all of interior southeast Mississippi into southwest Alabama.
1040 AM CDT Mon Mar 15 2021 Fire weather is the main concern today as drier air is expected to surge into southeast Oklahoma this afternoon in the wake of another Pacific cold front moving through the region.
1124 AM EDT Mon Mar 15 2021 High pressure wedges in from the north today, bringing a return to below normal temperatures. Rain chance will begin to arrive later tonight as low pressure system moves northeast from the Plains.
This has allowed temperatures to climb into the lower 80s, about five degrees above the climatological average high temperature for the middle of March. Mid and upper- level analysis reveals the center of a deep synoptic ridge is almost directly over the Florida Keys.
Ahead of the aforementioned low, a surface cyclone will intensify across the Texas panhandle, resulting in increased southerly winds and the development of a low-level thermal ridge. By Tuesday night, the surface cyclone is forecast to accelerate eastward with an attendant Pacific front/dry line and a warm front lifting northward toward the Kansas/Oklahoma border.
Looks like freezing potential is small as temps should be rising today, more so to the east over ND. TFJ An upper low that is currently over Colorado and Kansas will drift north today and will be over South Dakota tonight and Tuesday. Eastern Montana will continue to see mid and high clouds and somewhat cooler temperatures move into the area today with increasing moisture. A cold front moves into the area this evening with surface convergence that allow precipitation to develop over the forecast area. Precipitation will begin as rain this evening and change to snow late tonight as temperatures cool below freezing.
The northern edge should continue to erode southward expecting IAH/HOU/SGR to go VFR this afternoon and persist through early evening then as warm front intrudes inland lowering ceilings. Trends in the short term guidance also looking more favorable for some showers this afternoon as the warm front backs up into the area.
Cannot rule out some light snow or patchy freezing drizzle still occurring, especially across the eastern part of the area, but expect any further impacts to be minimal. The low splits with one portion of the energy headed north into western SD, the other piece of energy shears off to the east toward the Mississippi River valley. With temps likely near or above freezing this afternoon, feel impacts from fzdz/dz will be minimal. Lingering upper energy could bring some light pcpn to the northeast CWA this evening, while meandering upper low out west could provide for some light pcpn on Tuesday, mainly over southern 1/4 of the state. The pattern starts out with an upper low overhead but dissipating/washing out with weak upper flow and an anemic low level pressure pattern.
A splitting upper level trough continues to move over the region today. The southern portion of the trough is passing to the south while the northern portion moves over the Pacific Northwest. A small closed low is forming over western Washington that will drop south over eastern Oregon tonight. There will be some showers mainly over the eastern portion of the forecast area today and overall temperatures will be cooler. The trough will move off to the east on Tuesday with showers ending and a ridge of high pressure building in from the west for a return of warm dry conditions through midweek.
206 PM CDT Mon Mar 15 2021 GOES water showing a closed low over NE with a large conveyor belt of moisture rotating ahead of into our area. However, as this main band of snow exits, some freezing drizzle is possible on the backside this evening into the overnight hours. Will leave snow amounts/headlines alone for now (ending at 6 pm) but will be in monitor mode with that freezing drizzle potential and impacts.
A strong Pacific cold front will surge through the forecast area late tomorrow evening, shifting winds to the west at around 20-25 mph and remaining quite breezy overnight.
This next closed low system will track a little farther south than its predecessor and will be more centered over KS and OK.
(This evening through Tuesday) Overnight low temperatures will be 5 to 10 degrees above normal, in the lower 50s. An upper level low will track across the Desert Southwest on Tuesday. High temperatures will be 10 to 15 degrees above normal, in the lower 80s.
1137 AM MDT Mon Mar 15 2021 An area of light snow is currently heading back westward across western South Dakota as moisture and lift wrap around the north side of the upper low. Upper low spinning over western KS, with main lift focusing on the northeast quadrant as deformation zone breaks down over the western half of the CWA. Rest of today through Tuesday, moist cyclonic flow will continue as main upper low shifts northeast breaking off a couple of weaker circulations over the northern plains.
1214 PM CDT Mon Mar 15 2021 (Today and tonight) Warmer temperatures and dry conditions will be the main story for today.
907 AM MDT Mon Mar 15 2021 An area of light snow is currently heading back westward across western South Dakota as moisture and lift wrap around the north side of the upper low. Upper low spinning over western KS, with main lift focusing on the northeast quadrant as deformation zone breaks down over the western half of the CWA. Rest of today through Tuesday, moist cyclonic flow will continue as main upper low shifts northeast breaking off a couple of weaker circulations over the northern plains.
Ahead of the low pressure system currently over eastern KS, a warm front is draped across central MO. Increasing mid level lapse rates and instability resulting from the low approaching the area and surface warming has resulted in a few showers popping up near SGF.
1106 AM EDT Mon Mar 15 2021 A light wintry mix of sleet, snow, freezing rain, and rain is expected to spread in from southwest to northeast late this morning into this evening.
245 PM EDT Mon Mar 15 2021 A wintry mix will track through this afternoon into early this evening, with patchy rain and freezing drizzle possible tonight.
The upper level ridge will weaken through the day today into tonight. The cold front associated with it will move into the Tennessee river valley and extend south to Mississippi and Alabama. Temperatures for today and tomorrow are expected to reach the upper 70s/ low 80s and start off in the low 60s Tuesday morning with slightly warmer temps along the western panhandle coast.
322 PM CDT Mon Mar 15 2021 An upper level low currently over the Northern Plains will remain there tonight and through the day Tuesday before slowly getting pushed eastward Tuesday night. At the surface, weak high pressure will build back in as a low pressure system to the south slides eastward, then will remain the main weather feature through the short term period. The main result will be a prolonged period of low cloud cover, and occasional periods of light snow/drizzle/freezing drizzle, along with overnight and early morning fog. As the upper low finally begins to push east late Tuesday night, may see the ceilings rise enough to bring an end to any light precipitation.
Earlier this morning, regional radar trends kept precipitation fairly stationary, as dry air in the lower layers throughout much of Wisconsin kept precipitation out of the state. Cloud layers aloft kept temperatures steady in the 30s but still above freezing. The precipitation will likely be snow upon onset, although there may be a brief window for rain to be included before evaporative cooling brings temps below freezing. This will mark the transition from light snow to freezing drizzle over much of the area, likely sometime around or shortly after midnight for portions of central to east-central WI. Impacts from the freezing precipitation will hopefully be somewhat mitigated by falling into the fresh snow, but still expect raised and exposed surface to become icy.
124 PM EDT Mon Mar 15 2021 Approaching low pressure should support light precipitation across the area tonight and Tuesday.
The atmosphere has destabilized south of this warm front due to daytime heating where the sky has cleared out. Although the stratus cloud deck has hindered the diurnal heating north of the warm front, lessening the instability, there still may be at least small hail from storms in parts of central and east central MO late this afternoon and early this evening with a relatively low freezing level.
1059 AM PDT Mon Mar 15 2021 Temperatures will be cooler today, and there will be a chance for light rain.
Areas of light rain or showers and patchy drizzle continue over parts of the area as a lobe of lift moves north up into the area to the northeast of the closed low over KS. We may be able to cancel that early, however there was some concern that the precip could end as a period of freezing drizzle. The upper low responsible for the precipitation is in the process of cutting off a piece of energy that will remain across the Black Hills.
SHORT TERM (Tonight through Tuesday Night): The stalled front along the lower Texas coast gradually works north into Tonight, dragging the chance of showers and fog back inland into tomorrow. Expect temperatures to bottom out in the mid to upper 60s tonight with patchy to areas of fog forming, especially across the northern ranchlands and along the lower Texas coast.
Onshore flow on both coasts will act to keep temperatures a little cooler, with maximum temperatures in the lower to mid 80s. High temperatures on Tuesday will once again reach the upper 80s along southwest and western portions of the interior, with cooler temperatures along the coast due to moderating onshore flow. Out ahead of this storm system, high pressure will be in control with mostly dry conditions expected.
With the loss of cloud ice some light freezing rain/drizzle will be possible before ending early Tuesday morning. Ice accumulations of a light glaze will be possible with the light freezing rain and drizzle as temperatures will be around freezing. Quieter conditions set up for Tuesday as a weak high pressure sits over the area.
Water temperatures remain in the low to mid 60s for the lakes and eastern coastal waters, thus expecting another round of fog overnight as the front beings to lift back to the north. As the next system approaches the western plains on tomorrow, the warm front will lift north across the area as a warm front and showers and thunderstorms are likely along and north of the front.
248 PM MDT Mon Mar 15 2021 Latest analysis shows an upper low centered over the South Dakota side of the forecast area, which will very gradually shift eastward over the next couple of days. Due to the placement of the upper low, moist cyclonic flow will continue over the forecast area. Some weak disturbances rotating around the upper low will bring periods of light snow, or snow showers, tonight through Tuesday Tuesday night.
/issued 456 PM CDT Mon Mar 15 2021/ Upper level ridge will continue to move off to our east over the next 24 to 36 hours. An occluding low pressure system will track along the upper midwest tonight.
545 PM MDT Mon Mar 15 2021 Aviation Section Updated A cold front will continue to push eastward through the region tonight.