Aikyam-Lab/Synoptic-Bench huggingface dataset:
As an upper ridge axis moves across western and central North Dakota this afternoon, expect mild temperatures. Ahead of this trough, clouds will be on the increase through the afternoon which may limit how high temperatures can reach across the west. Therefore, while we do have an outside shot at highs near the 60 degree mark somewhere across the far west, highs in the low to mid 50s is the most likely outcome. The cold front continues to sweep through the area on Sunday, bringing breezy to windy conditions and cooler temperatures to the region, with highs in the low to mid 30s. Areas across the north and James River Valley will see the highest winds and may reach borderline Wind Advisory criteria with sustained speeds up to 30 mph and gusts to 45 mph by Sunday afternoon.
The main story will be warmer temperatures. The deep upper trof centered through the eastern U. will continue to shift east today, while the surface/low level anticyclone currently centered through the CWA also retreats eastward. Glass A weak disturbance in the quasi-zonal flow aloft and continued forcing via the southwesterly LLJ should result in a big uptick in coverage of showers and even a few thunderstorms Sunday night along and ahead of the advancing cold front.
Westerly flow aloft brings temperatures into the lower teens at the 850 hPa layer today; therefore, have leaned surface temperatures closer to the 75th percentile of guidance. 2016-> 42F 2012-> 35F 2008-> 42F 2004-> 43F 2000-> 55F Tonight, winds will gradually shift to the west-northwest as a cold front moves through. Flow aloft turns to the west on Sunday as an upper trough moves north of the region, along the International Border.
Sub-freezing temperatures are expected east of the Cascades, and in Siskiyou, Modoc, Jackson, and Josephine County both Saturday and Sunday night. However, north winds will increase as a thermal trough develops along the coast.
Ridging will extend through the area tonight and Sunday.
355 AM MST Sat Feb 29 2020 Upper level analysis has large ridge over the Rockies and Great Plains with mid to high clouds streaming across the region. At the surface, high pressure resides across much of the area with weak trof developing in the lee of the Northern Rockies. Upper ridge will bring another mostly sunny and dry day to the area, with temperatures climbing into the upper 40s to upper 50s. Lee trof will move through the area tonight with winds becoming more west to northwesterly. Upper ridge shifts east on Sunday as northern stream trof slides across the Northern Plains. Surface cold front moves through the forecast area early Sunday with winds becoming very breezy out of the northwest. Northwest South Dakota will see the highest winds of 20 to 30 mph with some gusts to 40 mph.
/issued 240 AM CST Sat Feb 29 2020/ Zonal flow today and Sunday will promote lee surface cyclogenesis today across southeastern Colorado with the low moving eastward Sunday. Increased heights and thicknesses point to warmer temperatures today while veering winds to a more direct westerly direction on Sunday will add on a healthy downslope warming component.
Updated the forecast to allow the winter weather advisory to expire at 7 am est while extending the advisory for Southwest Virginia and Northeast Tennessee through 11 am est while doing the same for the highest elevations in the Smoky Mountains. The upper level trough is gradually shifting east of the region however, still some snow showers across Southwest Virginia and Northeast Tennessee with some mvfr ceilings around tri. The remainder of the forecast should be vfr as high pressure and drier air envelopes the area.
Some mountain snow showers will continue for today into tonight as upper level trough is slow to push eastward. During the second half of the overnight and headed into Sunday, surface and upper level ridges build over our area. The first half of the night will be dry, but a warm front will be moving into the region during the overnight hours and this will bring light snow to the area.
Flow aloft and at the lower levels remains from the northwest which is bringing moisture off of Lake Michigan. Tonight the high pressure ridge axis will cross the region. Flatten upper level ridge will allow an increase in upper level moisture.
/issued 433 AM CST Sat Feb 29 2020/ GOES water vapor imagery showed an upper level trof centered over Appalachians early this morning.
535 AM CST Sat Feb 29 2020 219 AM CST It is a chilly start to the morning across the area thanks in large part to an area of high pressure moving across the area. Temperatures are then expected to drop back off into the upper 20s early this evening, before rising back into the lower 30s later tonight as warm air advection continues to increase over the region. Forecast guidance continues to support the likelihood of a cold frontal passage over the area Sunday night.
321 AM MST Sat Feb 29 2020 Upper level analysis has large ridge over the Rockies and Great Plains with mid to high clouds streaming across the region. At the surface, high pressure resides across much of the area with weak trof developing in the lee of the Northern Rockies. Upper ridge will bring another mostly sunny and dry day to the area, with temperatures climbing into the upper 40s to upper 50s. Lee trof will move through the area tonight with winds becoming more west to northwesterly. Upper ridge shifts east on Sunday as northern stream trof slides across the Northern Plains. Surface cold front moves through the forecast area early Sunday with winds becoming very breezy out of the northwest. Northwest South Dakota will see the highest winds of 20 to 30 mph with some gusts to 40 mph.
Clear skies across the lowest 5000 ft for tonight, with simply a thickening high based cloud deck as warmer air enters the region. Otherwise, clear skies across the lowest 5000 ft through tonight. Upper level ridge over the Rockies this morning will slide over the Central Great Lakes by Sunday, allowing for a significant warmup. Even today, with the developing insolation we should be able to reach into the low/mid 30s per latest MAV/MET/EURO mos. Warm front lifts through late tonight with nothing more than some mid/high clouds, setting us up for a mild Sunday with increasing southerly winds, as gusts likely reach 25 mph (per local probabilistic guidance).
Still a couple more bands of light snow with some moderate snow at times expected in the higher terrain along the North Carolina border as an upper trough and associated cold front grind their way across the Southern Appalachians this morning. Temperatures are still above freezing across much of the Great Valley ahead of the cold front just edging into Tennessee at the current hour. Lighter winds and clear skies allow for efficient radiation tonight as high pressure shifts steadily east toward the Eastern Seaboard.
433 AM CST Sat Feb 29 2020 GOES water vapor imagery showed an upper level trof centered over Appalachians early this morning.
308 AM MST Sat Feb 29 2020 Ridging continues to be the main upper level feature over Northeast Montana for now, but an upper level trough and surface cold front will move through the region later today and tonight bringing a return to cooler (and closer to seasonal normal) temperatures.
A storm system will bring showers and a change to much cooler weather by later tonight and Sunday.
Based on visible satellite imagery and winds still out of the southwest in Rutland, cold front has yet to make it south of our forecast area. Some mountain snow showers will continue for today into tonight as upper level trough is slow to push eastward. During the second half of the overnight and headed into Sunday, surface and upper level ridges build over our area. The first half of the night will be dry, but a warm front will be moving into the region during the overnight hours and this will bring light snow to the area.
As of 2 am satellite, radar and surface analysis place the approaching cold front near the Idaho panhandle and on the cusp of entering NW Montana. So overall we believe today's cold frontal passage across Idaho and Montana will come with little fanfare. And aside from a brief period of moderate intensity snow as the cold front passes, the mountains will see periodic light snow showers today accumulating 1 to 4 new inches of snow throughout the terrain.
559 AM CST Sat Feb 29 2020 Widespread VFR conditions will prevail through the period as high pressure both aloft and on the surface dominate.
828 AM CST Sat Feb 29 2020 High pressure will continue to slide to the east today, allowing southwest winds to return to Illinois. Even warmer conditions are expected for Sunday, as strong southerly winds boost temperatures into the upper 50s and lower 60s. High pressure will dominate the weather across central Illinois today, providing light winds and plenty of sunshine. As the high shifts into the Ohio River Valley, southerly return flow on its back side will signal the beginning of a major warming trend. As the pressure gradient between the departing high and an approaching cold front tightens, southerly winds will increase. The cold front will push into central Illinois Sunday night, eventually tapping into increasing Gulf of Mexico moisture and triggering widespread showers.
Southerly winds will be weaker tomorrow as a pre-frontal trough moves over northern and western parts of Oklahoma ahead of our next cold front.
Occasionally visibility has dropped to a quarter mile or less, more notably within the Sheyenne River Valley as well as in the higher elevation lakes country of west-central Minnesota, where Dense Fog Advisories remain in effect until 9 AM. This widespread area of fog combined within steady winds out of the south and temps below freezing is making for riming frost depositing on elevated structures. By early Sunday, a cold front moves through the area as a system moves through southern Manitoba. This cold front will increase winds out of the west 20-30 mph gusting 45+ mph Sunday afternoon. Despite the cold front, temperatures do not plummet much as temps are expected to remain in the 20s above zero.
224 PM EST Sat Feb 29 2020 High pressure over the forecast area Sunday morning will shift off the coast during the afternoon.
Elevated low level northwest winds behind reinforcing cold front, will lead to breezy conditions across much of the area today, with winds speeds up to 15 to 20 mph. Cooler and drier conditions will continue across the area with sunny skies expected and highs below normal in the mid to upper 60s. All things considered, and after input from JAX (much appreciated!) will be issuing an RFW for Volusia/Orange/Seminole, given the high likelihood of critical wind/RH being met, and just in case that ERCs wind up a little higher than forecast.
234 PM CST Sat Feb 29 2020 Saturday afternoon, a warm front extended across central North Dakota and will move east through the region during the evening. A cold front will then move southeast through the region late tonight and Sunday. Short term forecast concerns are gusty winds associated with the cold frontal passage and some marginal precipitation chances. VFR conditions will prevail across the region until a cold front from Canada enters the picture late tonight.
A cold front will move into northern Oklahoma Sunday afternoon, and the pressure gradient will relax in northwestern Oklahoma keeping the wind speeds a bit lower in the northwest.
252 PM CST Sat Feb 29 2020 18Z surface data has high pressure over the Ohio Valley with areas of low pressure along the front range of the Rockies. After 18z/01 a weak cold front will move through eastern Iowa with it near the Mississippi river by 00z/02.
1045 AM EST Sat Feb 29 2020 Currently - Visible satellite along with surface analysis shows a subtle reinforcing cold front moving south across the Sunshine State and heading towards the keys. Along and ahead of this front are some lingering strato-cu which continues to stream across the Lower Keys at times. Overnight lows dropped into the lower 50s across the Upper Keys, with upper 50s in the Middle Keys and lower 60s in the Upper Keys. High pressure cell to our west will move across the Gulf and emerge over the western North Atlantic by Sunday afternoon.
This front will also help cool lower and mid level temperatures over today's climatologically high values and therefore result in a cooler, although still above normal day.
With a dry air mass in place and clear skies, temperatures will fall into the 30s across much of the area, with below freezing temperatures confined to east Alabama.
Have also introduced some MVFR CIGs at our southern sites for a few hours tomorrow morning as moisture will increase tonight in the low levels.
145 PM CST Sat Feb 29 2020 Upper air analysis shows a large ridge over the rockies this afternoon, shifting eastward as we move into Sunday. Prior to the cold front, we could see the development of patchy fog similar to this morning if the upper cloud cover remains light. Kept with MOS guidance for winds Sunday to better capture the higher post frontal gusts expected. Despite the passing cold front and wind shift, temps only drop slightly for Sunday, with highs still expected to reach into the upper 30s and low 40s. Upper level ridging is forecast to be over the western CONUS at the start of the period. By Saturday morning, the ridge has migrated to being over the central part of the CONUS, with west-southwest flow developing over this CWA.
Despite scattered to broken high clouds across the area, temperatures are in the lower to mid 60s, with Imperial the warmest at 69. Light southwest winds this evening will become west, then northwest after midnight as a cold front moves in. On Sunday, cooler air will move in behind the cold front. Highs from the low 40s northwest Sandhills to the lowers 50s across the southeastern zones. Meanwhile, a positively tilted upper trough will move across most of the Great Basin on Sunday. Pacific moisture will increase on the downstream side of the trough.
946 AM MST Sat Feb 29 2020 Upper level analysis has large ridge over the Rockies and Great Plains with mid to high clouds streaming across the region. At the surface, high pressure resides across much of the area with weak trof developing in the lee of the Northern Rockies. Upper ridge will bring another mostly sunny and dry day to the area, with temperatures climbing into the upper 40s to upper 50s. Lee trof will move through the area tonight with winds becoming more west to northwesterly. Upper ridge shifts east on Sunday as northern stream trof slides across the Northern Plains. Surface cold front moves through the forecast area early Sunday with winds becoming very breezy out of the northwest. Northwest South Dakota will see the highest winds of 20 to 30 mph with some gusts to 40 mph.
A prefrontal trof will move through during the overnight with a wind shift. A backdoor cold front will also move through tomorrow, with a stiff northerly wind in its wake. Highs tomorrow will obviously be cooler in the wake of the fropa with widespread 60s.
The dry airmass coupled with high pressure, light winds, and clear skies will lead to ideal radiational cooling conditions tonight. Temperatures will drop down into the low to mid 20s across most of the area before daybreak on Sunday.
239 PM EST Sat Feb 29 2020 High pressure builds towards the local area tonight then continues offshore Sunday into Sunday night.
Fire weather concerns will be the highlight today, as well above normal temperatures, low relative humidities, and increasing southerly winds are expected this afternoon, especially in parts of northeast Oklahoma.
224 PM CST Sat Feb 29 2020 At 2 PM, southerly winds are bringing warmer air into the region. Due to this, the high temperatures were warmed by 3 to 6F.
Models have trended the track of this upper low toward the deep south, and have now suppressed the zone of baroclinicity in that area as well.
After a dry and pleasant Sunday, warmer weather with periods of rain can be expected through the first half of the next work week. By this evening, the low-level wind profile will gradually back to a more westerly direction, quickly ending any snow showers. Sunday will feature quite pleasant weather for the forecast area as the day begins with the axis of the low-level ridge bisecting the CWA. However, the ridge will prograde eastward through the day, allowing for southerly flow (and thus warm advection) in the low/mid-levels to commence. By Sunday evening, cloud cover will gradually overspread the region as upper-level divergence combined with the arrival of comparatively warm, moist air on the nose of the low-level jet. Temperatures will be warmer than previous nights due to the warmer air and cloud cover.
Temperatures currently range from the lower 40s to the mid 50s. Expect highs to range from the upper 40s to the lower 60s this afternoon. The warmest temperatures will occur across East-Central Arkansas and Northwest Mississippi as winds will begin to turn around to the south later this afternoon as the high begins to shift east. /issued 433 AM CST Sat Feb 29 2020/ GOES water vapor imagery showed an upper level trof centered over Appalachians early this morning.
Clear conditions, with the latest moisture channel satellite data depicting upper ridge having moved to the east, now extending from the Dakotas into northern TX.
1234 PM EST Sat Feb 29 2020 A ridge of high pressure is providing dry conditions across the terminals today as the anticyclonic flow field produces WNW winds for this afternoon before gradually backing S through the overnight hours as the circulation tracks southeastward into the lower Mississippi Valley. * None Upper level ridge over the Rockies this morning will slide over the Central Great Lakes by Sunday, allowing for a significant warmup. Even today, with the developing insolation we should be able to reach into the low/mid 30s per latest MAV/MET/EURO mos. Warm front lifts through late tonight with nothing more than some mid/high clouds, setting us up for a mild Sunday with increasing southerly winds, as gusts likely reach 25 mph (per local probabilistic guidance).
Upper level trof axis aligned over the east coast moves steadily off into the west Atlantic with flow aloft flattening over the southeast US by Sunday into Sunday night. At the surface, ridge of high pressure analyzed over the central and northern Gulf will also translate eastward, moving off the southeast US coast Sunday where it remains positioned over the southwest Atlantic through Sunday night. With the surface and low level pressure ridge to the east, a more established southerly flow off the Gulf allows environmental moisture to slowly improve. By Sunday night, clouds begin to thicken with the passage of embedded weak mid level impulses/ascent in the higher level westerlies operating on better moisture. Temperatures moderate tonight with overnight lows in the lower to mid 40s north of the coast closer to climatology.
1249 PM CST Sat Feb 29 2020 1248 PM CST Sunny but cool conditions are in place across the lower Great Lakes this final day of meteorological winter, and outside of the Pacific Northwest and the northeast conditions are fairly quiet across the continental United States. High pressure is centered across southern Illinois into the Ohio Valley and will shift through the Ohio valley, with weak upper level ridging across the plains. Warm advection will ramp up in earnest behind the high, resulting in an increase in lower level southwest flow. A northward flux of moisture will occur Sunday evening ahead of a cold front Sunday night, and this will result in an area of showers over eastern IL and IN Sunday evening and night.
219 PM EST Sat Feb 29 2020 An upper level trough over southeast Canada and the northeast will lift out of the region late tonight and Sunday. With the departing trough, milder air will return to the region beginning tomorrow with above average temperatures once again for much of the upcoming week.
Lows tonight will be 8-15 degrees warmer than last night as a result.
Trough and associated cold front to swing through the region today.
232 PM CST Sat Feb 29 2020 South winds prevail this afternoon with temperatures on track to reach the lower to middle 30s. The H5 upper ridge continues moving eastward, bringing continued warmth to the region through the remainder of the day and into evening. Heading into the overnight period, winds will become westerly in response to an upper low that will bring a cold front through the area on Sunday. This will be mainly for portions of the region west of the Red River Valley; however, there remains some uncertainty with how far east we will see the higher wind gusts.
119 PM MST Sat Feb 29 2020 Upper level ridge axis centered from Saskatchewan southward into the Central Plains will continue to move eastward tonight. Southern stream vort max centered along trough axis extending off the CA/OR coast will slowly meander through the southwest US this weekend. A cold front will push southward later tonight, crossing from NW to SE after 03z and will usher in a slight chance for some light snow/rain showers, mainly across NE WY and SW SD through Sunday.
259 PM EST Sat Feb 29 2020 An upper level trough over southeast Canada and the northeast will lift out of the region late tonight and Sunday. With the departing trough, milder air will return to the region beginning tomorrow with above average temperatures once again for much of the upcoming week.
Winds will gradually shift from westerly to southerly overnight as high pressure drifts east of the region. Temperatures tomorrow morning will start cool, but expect them to warm up considerably by the afternoon as a warm front advances toward the Great Lakes region. Highs tomorrow will approach the low to mid 60s in many locations.
325 PM EST Sat Feb 29 2020 Dry and chilly high pressure will build over the Southeast states through Sunday.
Temps will be much warmer on Sunday despite increasing high clouds as the eastern U. S low moves away and a weak upper level ridge moves across our region.
Overnight lows should remain mild with thermal ridge along the frontal boundary. We were able to reach the upper 40s to the lee of the Buffalo Ridge this afternoon, so we should be able to see similar readings into a portion of west central WI Sunday afternoon as the front moves in. Winds will be a bit breezy as well as the cooler air arrives.
The forecast is on track for this afternoon with the upper low now beginning to shift east of our area. Some mountain snow showers will continue for today into tonight as upper level trough is slow to push eastward. During the second half of the overnight and headed into Sunday, surface and upper level ridges build over our area. The first half of the night will be dry, but a warm front will be moving into the region during the overnight hours and this will bring light snow to the area.
1128 AM CST Sat Feb 29 2020 219 AM CST It is a chilly start to the morning across the area thanks in large part to an area of high pressure moving across the area. Temperatures are then expected to drop back off into the upper 20s early this evening, before rising back into the lower 30s later tonight as warm air advection continues to increase over the region. Forecast guidance continues to support the likelihood of a cold frontal passage over the area Sunday night.
Widespread VFR conditions will prevail through the period as high pressure both aloft and on the surface dominate.
616 PM EST Sat Feb 29 2020 High pressure builds towards the local area tonight then continues offshore Sunday into Sunday night.
Bigelbach PREVIOUS DISCUSSION: Ridging continues to be the main upper level feature over Northeast Montana for now, but an upper level trough and surface cold front will move through the region later today and tonight bringing a return to cooler (and closer to seasonal normal) temperatures.
321 PM CST Sat Feb 29 2020 High pressure over the Mid-South will begin shifting east tonight. Lows will be warmer with readings in the upper 30s to upper 40s.
457 PM EST Sat Feb 29 2020 High pressure over the forecast area Sunday morning will shift off the coast during the afternoon.