Aikyam-Lab/Synoptic-Bench huggingface dataset:
501 AM EDT Wed Mar 18 2020 Early this morning, an upper level ridge was centered in the Caribbean/Cuba vicinity and extending into portions of the southeast Conus. Further west, an upper level low/trough is rotating across the western Conus. Today and tonight, the upper level ridge axis should shift to the east though mid level heights should increase across the Gulf Coast states while the upper level trough continues to work into the western Conus. With winds increasing aloft near the northeast lifting warm front, a stronger storm or two cannot be ruled out with locally heavy rain and strong wind gusts possible. The region will remain in the warm sector on Thursday as the warm front lifts even further north as low pressure tracks from the Plains toward the Great Lakes region.
324 AM MDT Wed Mar 18 2020 Snow will continue to press eastward across the CWA this morning, possibly mixed with freezing rain or freezing drizzle for a time in the east this morning. Colder and drier conditions will continue for the second half of the week, but upper ridging will begin to become established over the area by this weekend. There is also a low probability of brief freezing rain or freezing drizzle for a time before 18Z from KGDV to KSDY.
Thursday will be on the dry and windy side with marginally cooler temperatures behind the Pacific front. All guidance has a pronounced mountain wave signature in place for Thursday across the Guadalupe's, so have continued the High Wind Watch beginning late Wednesday evening through much of Thursday. Longwave trough axis will vacate to the east with a zonal flow setup lasting through the weekend.
336 AM MDT Wed Mar 18 2020 The northern part of the low that has been anchored of the California coast has been impacting the area overnight. While previous forecast soundings had shown a chance that some of the showers overnight would have a chance for freezing drizzle, that has not been reported. Also the latest guidance has trended away from showing any significant chance for freezing drizzle. Through the day Thursday where area will see the influences from that northern split in the low, but the low is expected to stay south of the area. With the cloudy conditions and being on the backside of the Canadian front, high temperatures today and Thursday will be in the low to mid 30s.
Large trough continues to evolve along the West Coast with multiple low centers moving about. NorCal is presently between a closed low over northwest Nevada and a vort dropping quickly southward off the coast.
This is primarily influenced by the large mid/upper level low over the Southwest U. and the mid/upper level high over the Gulf.
408 AM MDT Wed Mar 18 2020 A low pressure system will slowly move through the region bringing cooler and unsettled weather through the remainder of the week.
438 AM CDT Wed Mar 18 2020 Today through tonight: Subtropical ridging over the southeast CONUS continues to bring warm and humid weather to the ArkLaMiss region.
1036 AM EDT Wed Mar 18 2020 Weak high pressure will remain over the forecast area today. Daytime heating and a weak warm front to provide a chance of showers and possibly an isolated thunderstorm this afternoon, mainly CSRA and S Midlands. The warm front will traverse the area tonight.
High pressure aloft will keep the region dry through the rest of the week.
Thursday: This will be a day of extremes as the strong trough over the West Coast will finally move over the central Plains. In front of that trough will be strong warm air and moisture advection that will push temperatures over 70 degrees in southeast Nebraska and dew points close to 60 degrees. It will bring with it a cold front that will lead to strong cold air advection. The timing of the cold front will be key to the snow amounts. What I do have confidence in is that there will be strong winds with the cold front.
Dry weather will continue through much of today as high pressure completes a slide across the region. Thursday is forecast to feature the emergence of Great Basin low pressure across the Plains and Great Lakes with phasing into the northern stream. With low pressure passage across the Great Lakes, flood threat again looks to be alleviated via element progression and by better convergence areas which are forecast along frontal boundaries north and west of the area.
Stationary boundary currently sitting to our south poised to to retreat north as a warm front later this morning, eventually setting up just to our north around midday. Warm front moves into the OH valley later this evening, at which point we could see a break for widespread pcpn, but it will come back late tonight. We will then see a return of widespread pcpn late Thu night as a cold front approaches. This cold front is expected to push across the mid-state Fri afternoon. leading to a dry Sat, but a ML/UL trough axis does pass early Mon. Ceilings will drop later this morning and showers along with a couple storms will move in around noon as a warm front lifts north across Middle TN terminals.
Initially we have southerly flow ahead of a weak trough over western MN. Weak upper trough exiting the area taking deeper mid level moisture with it. We expect to retain the lower clouds however. We should warm into the low-mid 40s today, even with the cloud cover and then with the approach of the front tonight, lows should remain in the 30s to some lower 40s possible to the south. Later tonight we see the southern stream trough lift northeast, drawing in deeper moisture. Should see increasing PoP potential as the northern stream trough approaches across the north.
Increasing precip chances will take place across ND, post-frontal and ahead mid level energy while upper level energy rotates out of an upper level low across the central Rockies northeastward into SD. Light rain across our southern zones to start while farther north and west a mix of p-types in the form of freezing drizzle- rain/sleet/snow.
A chance of showers will continue across most areas as an area of low pressure cuts off over northern California/western Nevada today. Showers will linger into Thursday across the southern half of the area as the low slides south and exits the region. Warmer and drier conditions are forecast through the later part of the week before yet another weather system moves into the area bringing rain chances to the district over the weekend. Showers are forecast to continue today as the upper low that brought us rain the last few day splits forming two distinct lows today. The low that will impact the region today will cut off over northern California/ western Nevada later today then gradually slide south through Thursday.
In the lower levels, isentropic ascent was occurring with strong moisture transport north of a surface warm front currently situated over Oklahoma/Arklatex region. A surface warm front will begin to lift northward through the forecast area late in the day/evening, likely residing across portions of northern Missouri by midnight Thursday morning. A strong cold front will pass through the area Thursday night, with significantly colder and drier air advecting into the area.
/issued 323 AM CDT Wed Mar 18 2020/ A warm front stretches across Northern Louisiana to Central Alabama this morning. Chances for showers and thunderstorms will then increase Thursday afternoon into Thursday Night as a cold front approaches the area.
This will allow for the prefrontal heavier precipitation to fall as snow in the higher elevations, with mostly rain occurring below the rim. One complication is that some of the heavier snowfall amounts will be possible this afternoon and early evening, dependent on snowfall rates and temperatures slightly above freezing, accumulations will vary widely. By this evening temperatures are expected to drop well below freezing allowing for a higher confidence in accumulation amounts. After the upper level dynamics move eastward early thursday morning, upslope forcing near the surface will remain, and allow for additional light accumulations of snowfall along the southwestern slopes of the higher terrain, especially the Mogollon Rim and Coconino Plateau through the day Thursday.
724 AM EDT Wed Mar 18 2020 High pressure builds in for today. Weak low pressure passing to our south on Thursday could bring a coating of snow across interior sections before warmer air changes precipitation to all rain by later Thursday.
651 AM CDT Wed Mar 18 2020 A relatively mild day today as highs reach the lower 50s most areas. The 700mb low will move over central CO late tonight with a warm front extending across southwest and central Nebraska. Meanwhile a strong cold front will begin to move into northwest Nebraska. As the 700mb low emerges onto the eastern plains of CO Thursday morning, arctic air will quickly drop southeast behind the advancing cold front. Snow will continue Thursday evening, with the highest accumulation across the southeast. Model differences continue, as the GFS is faster and further north with the upper low than the ECMWF.
A storm system will pass through the region today into Thursday bringing gusty winds, cooler temperatures and showers to the area.
/EC/ Today through tonight: Subtropical ridging over the southeast CONUS continues to bring warm and humid weather to the ArkLaMiss region.
Will have to closely monitor far southwest Wisconsin into the afternoon with some hints for those areas to break into the warm sector as a surface wave slides up a cold front bisecting the local area.
An upper level low pressure system, currently over southeast Oregon, will continue to drift southward today. Weak spokes of energy will break off this low, with one currently producing shower activity from southwest Montana north and westward to near Lolo Pass.
1052 AM EDT Wed Mar 18 2020 High pressure builds in for today. Weak low pressure passing to our south on Thursday could bring a coating of snow across interior sections before warmer air changes precipitation to all rain by later Thursday.
1039 AM EDT Wed Mar 18 2020 High pressure will pull east of the region today, with clouds gradually increasing from west to east.
Sunshine and southwest winds should lead to a much warmer day with most sections rising well into the 70s. All sections have chances for rain tonight, with the higher pops across the south and southeast. Pacific cold front passes Thursday morning, with windy conditions expected, with a wind advisory possibly being needed.
1019 AM EDT Wed Mar 18 2020 High clouds and some developing stratocumulus are likely to be the only evidence of any moisture this afternoon, as high pressure prevents a dissipating boundary north of the panhandle from dropping down into the area and dry conditions continue. Highs today reaching the mid to upper 80s in the interior, while the seabreeze limits temperatures along the coast to the low 80s.
Thursday will be very warm, likely a degree or two warmer than today, with readings well into the 80s away from the Gulf.
This is ahead of a rapidly advancing warm front which is forecast to push into southern Iowa during the morning. By early afternoon on Thursday, the warm front will be situated from near Denison to Waterloo with temperatures in the 60s with even low 70s near the Missouri border. This may be sufficient for a few tornadoes near the track of the low with low topped supercells.
Stationary boundary currently sitting to our south poised to to retreat north as a warm front later this morning, eventually setting up just to our north around midday. Warm front moves into the OH valley later this evening, at which point we could see a break for widespread pcpn, but it will come back late tonight. We will then see a return of widespread pcpn late Thu night as a cold front approaches. This cold front is expected to push across the mid-state Fri afternoon. leading to a dry Sat, but a ML/UL trough axis does pass early Mon.
1132 AM EDT Wed Mar 18 2020 High pressure will pull east of the region today, with clouds gradually increasing from west to east.
Moisture wrapping around low pressure centered over northwest Nevada is expected to shear apart as this low sinks southward over the next 24 hours. With snow levels between 4000 and 5000 feet, the high terrain may experience periods of rain, snow, or graupel.
A trough will be departing the area tonight across New Mexico and West Texas which will maintain a southwesterly flow. With the cold front slowing down a touch, Thursday will be a warm and mostly cloudy day with rain chances near zero.
The warm front has lifted north of the region and the coverage of rain has decreased with some rain showers moving across eastern sections of the Mid-South. The warm front will stall out north of the Mid-South tonight. On Thursday, a cold front will begin to push east across the Plains. The cold front will move into western Arkansas by Thursday evening with more showers and thunderstorms moving across the Mid-South.
146 PM EDT Wed Mar 18 2020 A warm front will traverse the area tonight.
Rux PREVIOUS DISCUSSION: Snow will continue to press eastward across the CWA this morning, possibly mixed with freezing rain or freezing drizzle for a time in the east this morning. Colder and drier conditions will continue for the second half of the week, but upper ridging will begin to become established over the area by this weekend. There is also a low probability of brief freezing rain or freezing drizzle for a time before 18Z from KGDV to KSDY.
Forecast Summary: Strong low pressure system will bring a good chance for widespread precipitation to our region through Thursday night. As upper wave ejects into the Plains on Thursday, strong low level cyclogenesis in eastern Colorado will induce warm frontal boundary from the low into central Iowa. Strong low level theta-e advection is expected during the day as surface dew points over 60F are forecast into southeast Nebraska and southwest Iowa just south of warm front. But also shear vectors parallel to warm front will support splitting cells and linear structures leading to enhanced wind threat. The severe threat will diminish during the evening as the warm front slides southeast and greater theta-e advection shifts into central Iowa.
104 PM CDT Wed Mar 18 2020 A relatively mild day today as highs reach the lower 50s most areas. The 700mb low will move over central CO late tonight with a warm front extending across southwest and central Nebraska. Meanwhile a strong cold front will begin to move into northwest Nebraska. As the 700mb low emerges onto the eastern plains of CO Thursday morning, arctic air will quickly drop southeast behind the advancing cold front. Snow will continue Thursday evening, with the highest accumulation across the southeast. Model differences continue, as the GFS is faster and further north with the upper low than the ECMWF.
128 PM EDT Wed Mar 18 2020 High pressure will pull east of the region today, with clouds gradually increasing from west to east.
The strong upper trough over Baja CA, Mexico will lift newd into the central Great Plains for Thu afternoon.
239 PM MDT Wed Mar 18 2020 A very well defined low pressure center is rotating through Lemhi County and creating and area of rain and snow that is moving from south to north.
231 PM MDT Wed Mar 18 2020 Slow moving upper low across Nevada keeps an upper-level southerly flow in place across the area.
As this upper trough finally moves east, dry and warm conditions will follow Thursday. Surface winds Thursday afternoon will initially be from the south; but, an approaching cold front will create winds more from the south west or west, by Thursday afternoon. Cooler and Wet.
Radar is not picking either one up, but under each we can expect periods of light snow, with isolated areas of freezing drizzle still possible over the southwest. Some pockets of freezing drizzle are possible. An upper level closed low lingers over the California/Nevada border keeping most of the energy from this system to our south, while pumping some moisture up into The Treasure State. Some pockets of freezing drizzle are possible.
Upper level troughing over the eastern Pacific and western U.
Temperatures range from the lower 50s to upper 60s. A warm front is just south of the Mid-South and as it moves north this afternoon, more showers and thunderstorms will develop. Most of the activity will form north of the warm front. /issued 323 AM CDT Wed Mar 18 2020/ A warm front stretches across Northern Louisiana to Central Alabama this morning. Chances for showers and thunderstorms will then increase Thursday afternoon into Thursday Night as a cold front approaches the area.
Deep layer ridging moves northward over the area leading to warm and dry conditions tomorrow. Lows tonight will be in the low to mid 60s. Near record highs tomorrow in the mid to upper 80s with cooler temperatures along the coast.
A low pressure system will slowly move through the region bringing cooler and unsettled weather through the remainder of the week. An upper low spinning over northwest Nevada is maintaining a steady stream of moisture across much of the forecast area midday. Meanwhile further south an upper low rotating around the Nevada feature is lifting through the lower Colorado River Valley, and will continue on a northeastward trajectory through this evening, enhancing precipitation across southern Utah into the overnight hours.
A chance of showers will continue across most areas as an area of low pressure cuts off over northern California/western Nevada today. Showers will linger into Thursday across the southern half of the area as the low slides south and exits the region. Warmer and drier conditions are forecast through the later part of the week before yet another weather system moves into the area bringing rain chances to the district over the weekend. Interesting satellite imagery this afternoon revealing several upper levels lows embedded in a broad trough covering the West. The storm system that brought more widespread rain to the region a day or so ago is swinging through the base of the trough near Baja. A separate upper level low is spinning westward in Western Nevada.
330 PM CDT Wed Mar 18 2020 A warm front will continue to lift north though the area this evening. CAMs are pretty quiet on the convective front this evening, however the RAP does indicate that capping may be relatively weak for parcels lifted from the low-levels of the atmosphere. The potential for severe storms will then increase Thursday afternoon as that low pressure system tracks northeast across the central Plains. A cold front will then sweep through the area later Thursday night.
Here the timing of the switch over will be delayed with the potential for liquid precip to persist into the early morning as temps stay up and road surfaces remain above freezing. Mostly snow is expected elsewhere for the late evening into the overnight with the possibility of some freezing drizzle lingering behind the departing snow as ice nucleation departs with saturated near sfc layer persisting. Winds will be diminishing during the day Fri as pressure gradient eases and a cold area of high pressure builds in. A wintry mix will change to snow tonight for DVL, BJI and GFK with TVF and FAR possibly seeing a mix of snow or freezing drizzle.
After a break in the precipitation tonight, more showers and thunderstorms will move across the area Thursday and Thursday evening, along with much warmer temperatures. Once this passes, drier weather is expected to spread across the region tonight into Thursday morning, before the next large Low pressure system arrives.
High temperatures are on track to top out in the low to mid 80s this afternoon, with upper 70s along the coast. A deep southwesterly wind flow will remain over the region tonight and persist through Thursday ahead of an upper level trough over the western conus. Mild lows are forecast for tonight in the low to mid 60s. High temperatures Thursday will be in the low to mid 80s inland area, with upper 70s along the coast.
An upper level trough in NV will slowly move southwest today into central CA by Thursday. Expect drier and warmer conditions on Thursday as weak ridging builds over the area and the system remains in southern NV and UT.
Ridging centered over the Gulf of Mexico will continue to be the main driver for sensible weather across the area today. This will keep the entire area within the open warm sector with highs climbing into the low 80s. /TW/ Prior discussion below: Today through tonight: Subtropical ridging over the southeast CONUS continues to bring warm and humid weather to the ArkLaMiss region.
147 PM PDT Wed Mar 18 2020 Low pressure will continue to bring periods of snow to the region into tonight with slick roads possible for the commute hours this evening and Thursday morning.
Simultaneously the subtropical moisture plume will continue to draw moisture into the Desert SW and then into our region helping dewpoints slowly climb into the low 60s. As the main upper low moves eastward the associated Pacific cold front will move through the region. The cold front will provide even more lift resulting in the possibility of another round of severe storms early tomorrow morning. The severe weather threat will quickly come to an end after the passage of the cold front tomorrow morning.
Lows tonight will run about 10 degrees above average, only falling into the low to mid 60s across the area.
245 PM CDT Wed Mar 18 2020 WV imagery shows the west coast upper trough has separated in two, w/the southern portion just making landfall at Baja del Norte, leaving progressive SW flow aloft over West Texas and Southeast New Mexico. A secondary cold front late Thu night will then take temps well-blo normal Fri/Sat, w/Sat being the coldest day this forecast.
Expecting snowfall of up to one inch along and south of Interstate 94 tonight along with a chance of light freezing drizzle later tonight. A cold front now over northern North Dakota will begin to slowly shift south overnight. As mentioned above, as low level convergence and frontogenetical forcing increase overnight, expect a mix of snow and light freezing drizzle south, with snow north. A little concerned about the far south overnight where freezing precipitation could last longer with the cold front/cold air advection not reaching the south until closer to 12z Thursday. Think road/surface temperatures may remain above freezing for a good portion of the night. This will be followed by light freezing drizzle late. The surface cold front doesn't actually shift through Bismarck until 09z-12z Thursday.
239 PM MDT Wed Mar 18 2020 20z surface analysis had weak cold front from north central WY into east central SD. Low pressure will developing over eastern CO with a boundary northeast into northern NE. Water vapour had upper low of interest over Baha California with main 130kt jet streak starting ejecting northeast into the desert southwest. Tonight/Thursday, upper low races northeast into southeast NE Thursday and then into the upper Midwest.
400 PM EDT Wed Mar 18 2020 Deep layer ridging remains anchored over the western Atlantic and stretches back across the Sunshine State and Gulf of Mexico. Temperatures have once again risen into the lower 80s with dew points near 70 degrees.
/issued 933 AM EDT Wed Mar 18 2020/ High pressure surface and aloft over the area will maintain dry and unseasonably warm conditions across the entire forecast area the remainder of today with ample sunshine expected.
240 PM EDT Wed Mar 18 2020 A warm front will traverse the area tonight.
TWH The northern part of the low that has been anchored of the California coast has been impacting the area overnight. While previous forecast soundings had shown a chance that some of the showers overnight would have a chance for freezing drizzle, that has not been reported. Also the latest guidance has trended away from showing any significant chance for freezing drizzle. Through the day Thursday where area will see the influences from that northern split in the low, but the low is expected to stay south of the area. With the cloudy conditions and being on the backside of the Canadian front, high temperatures today and Thursday will be in the low to mid 30s.