Aikyam-Lab/Synoptic-Bench huggingface dataset:
1152 AM CDT Sat Mar 14 2020 The closed low off the California coast yesterday at this time has opened up and shifted eastward into the high plains early this morning. A low level jet at 850 mb was also in place from the south-southwest which was pumping in some moisture in the lower levels above the surface. This moisture was overrunning cooler and drier air at the surface and so the precipitation over the area has been light initially. 6 inches will be possible with the higher amounts southeast of I44. The cooler air mass at the surface will remain in place with an east to northeast surface wind and with clouds and rain all day, the temperatures will be quite chilly with readings from the upper 30s in central MO to the low 50s in the southwest corner of MO.
The upper level wave that brought rain and snow to central Indiana today will exit the area tonight with high pressure moving in afterwards.
246 PM CDT Sat Mar 14 2020 Snow showers continue over much of the area this afternoon, as an upper trough pushes east through the region.
Overnight, we remain saturated through the lower levels across the area. Temperatures in central KS tomorrow morning will be at or near freezing, which means this area could see patchy drizzle mix with or change to freezing drizzle. This should also mean minimal impacts, but we know barely a trace of freezing drizzle can sometimes cause issues.
TFJ/Rux Previous Discussion: Radar imagery and area wind observations suggest that this late- season snow storm has begun across northeast Montana, but the onset of snowfall may have been delayed a few hours while the lower levels of the atmosphere have taken a while to completely saturate. As of early today, the lower reflectivity values forming a large open hole in the radar imagery over Glasgow have nearly filled in. Beginning on Sunday, the upper level low pressure center completely separates from the Canadian low pressure trough.
so did add areas of Freezing Fog across much of the Panhandle and southeast Wyoming plains. Evening shift may need to issue a Freezing Fog Advisory once we see where the denser fog sets up.
Expect plenty of sun however it will remain chilly with highs only in the lower to mid 30s which is about 15 degrees below normal.
Temperatures are already at or just above freezing, so expect freezing fog and freezing drizzle to quickly become predominant. Roads are already slick and the freezing fog/drizzle will only exacerbate the situation. Temperatures are forecast to remain in the lower to middle 30s, which may minimize the chances of freezing fog, but it depends on how much warming actually takes place during the day.
Warm and humid conditions continue as high pressure remains stretched from the Atlantic into the northern gulf coast. A cold front is stalled from North Texas, across North Louisiana, and into Georgia. South of the front, the onshore flow around the edge of the Atlantic ridge continues pushing in a warm and humid air mass. Aloft, a ridge remains centered over the Gulf of Mexico which is keeping most precip north of the local area.
An upper low continues to churn off the PacNW coast this morning, and it is expected to drift south to the NorCal coast tonight. Ahead of this low, Utah remains under a mild southwesterly flow aloft. Weak disturbances ejecting out of the low will continue to graze northern Utah today, maintaining a weak boundary over far northwest Utah and into southeast Idaho. Expect showers to expand this afternoon across the higher terrain of Utah as instability increases with daytime heating. Otherwise, still looking at more of a midweek timeframe before the low finally ejects across Utah, bringing a better chance of widespread precipitation to the area.
128 PM EDT Sat Mar 14 2020 Rain and snow chances return late today and tonight with a low pressure trough. Dry weather returns Sunday under building high pressure. A Winter Weather Advisory for at least a couple of the ridge zones remains a possibility. Dry weather is expected through early afternoon under high pressure. Rain chances are expected to increase from the southwest towards the northeast this afternoon/early evening as moist advection and ascent increase with the approach of the trough. Warm ground temperatures should help limit snow accumulation for much of the area, though the higher elevation of WV, MD and the Laurel Highlands should see one to three inches of accumulation.
Spotty freezing drizzle is possible, mainly the southeast zones. Freezing rain was reported earlier today from Livingston to Big Timber that caused lots of traffic accidents with reports of black ice. TFJ Previous Discussion: This evening through tonight, wind speeds will drop to around 12 to 15 mph as the snowfall becomes more erratic and scattered in nature, mainly along and south of Highway 2 Beginning on Sunday, the upper level low pressure center completely separates from the Canadian low pressure trough. Spotty freezing drizzle cannot be ruled out later tonight into Sunday, especially near Glendive.
ABM Chattanooga Airport, TN 54 64 49 63 50 / 70 40 20 40 50 Knoxville McGhee Tyson Airport, TN 46 58 45 63 51 / 80 40 20 30 50 Oak Ridge, TN 45 58 45 62 50 / 80 30 20 30 50 Tri Cities Airport, TN 42 55 42 59 46 / 80 40 20 20 40.
321 PM EDT Sat Mar 14 2020 Cooler resident conditions marking the front end of the weekend period thanks to a combination of prevailing low level northerly flow and a steady influx of high based cloud cover. This will present a limited opportunity for light precipitation to emerge within the 01z-05z period, wet bulb temperatures sufficiently below freezing supporting very light snow or flurries. A subtly cooler environment offset by full insolation, yielding a standard diurnal temperature response with highs peaking in the 40s most inland locations. The prevailing flow will leave areas immediate downstream of the larger bodies of water noticeably colder, afternoon readings held within the low-mid 30s range in some locations across the thumb.
There may be some potential for patchy drizzle given near saturation in the lowest 1 to 1. For this reason, we have gone on the cooler side of guidance for expected high temperatures.
Exception has been across the I-10 corridor just ahead of the nearly stationary cold front. This front will probably sag a little farther south this evening before pulling up stationary and shifting slowly north as a warm front on Sunday.
Temperatures today have ranged from the mid 70s north to the lower 80s south with south to southwest winds bringing in moisture across the region. However, this front will also run into ridging over the northern Gulf Coast. Quite the temperature gradient will occur across the area with highs in the 50s possible across the Delta compared to the lower 80s in the Pine Belt.
Latest sfc analysis places a cold front sw-ne across the mid state. By Sunday morning the cold front will be placed well south of the mid state with the shower activity ending.
Cold front will push back into tonight and IFR CIGS/MVFR VSBY are expected to redevelop and then persist thru much of the day Sun.
Dominant high pressure today and tonight with a stalled frontal boundary a little north of the area.
Precipitation chances are expected to increase in the Sierra overnight tonight as the upper low continues to dig south.
A dry weather pattern will persist through Sunday afternoon as upper ridging remains over the northern gulf and deep south. Lows tonight primarily in the upper 50s across the area, with a few locations in the lower 60s. Highs on Sunday should again reach into the lower to mid 80s over the interior, and in the upper 70s along the beaches.
Very weak warm air advection as the high shifts to east will allow highs to climb into the middle 30s to lower 40s for most spots.
However, upper level trough over the Southern Rockies/Plains this morning will move east and significantly increase moisture across our region as today wears on. Rains should decrease after 06Z-09Z as cold front moves from northern counties toward the southern counties.
High level moisture (cirrus) still flowing overhead with southwesterly flow aloft while in the lower levels the southeasterly flow dominates and continues to pull in Gulf moisture. Will need to monitor this as it may boost chances for some advection fog but of note it is drier aloft above this low level surge. The wave along the front moving through the Dallas area may give the cold front a small nudge southward but it probably won't get as far south as the 12z NAM is progging so overnight rain chances will probably be low and limited to the far northern areas.
255 PM CDT Sat Mar 14 2020 Satellite and radar reveal that the majority of the precipitation has shifted to the south with the low level warm frontal forcing. Winds will stay out of the east keeping us cool again tomorrow with lows near freezing and highs only in the lower 40s with cloudy skies.
Overnight, the low level jet is not projected to be as strong so surface winds should be able to weaken more compared to 24 hours prior. The approach of a mid-level trough and late-season cold front should help keep winds from increasing too much, but the thermal gradient (temps near 70 across the waters to lower 90s across the Rio Grande Plains) should still reside, keeping slightly breezy conditions. Models continue to keep the front well north of the area, but will need to monitor elevated convection within the SW-NE flow of the trough for portions of the western Brush Country. Being on the subsident side of the trough, any rain that does develop should remain in the form of showers, but an isolated thunderstorm or two will be possible.
241 PM MDT Sat Mar 14 2020 The latest water vapor images and upper-air analysis places a trough across the western CONUS and a ridge over the eastern CONUS.
Stout mid to upper tropospheric ridging centered over the Gulf of Mexico will remain our dominant weather influencer. The 594 dm mid- level high will provide for plenty of subsidence and drying aloft, while supporting the westward extension of low-level subtropical Atlantic ridging into our area. With the easterly wind flow off the relatively cooler Atlantic waters the eastern coastal areas should remain mainly in the lower 80s, with mid 80s expected farther inland. Lows tonight will range from the lower 70s along the east coast to the mid to upper 60s elsewhere. A similar pattern for temperatures and weather should persist into Sunday with high pressure in control.
These showers are associated with a frontal boundary that is sliding a bit northward as a warm front. The models have shown this warm front moving northward today giving way to a cold front that will push south into the area tonight. The cold front will push south through the state Sunday with precip also moving south through the area. There will be some instability developing across central GA ahead of the sinking cold front so introduced a mention of isolated thunder to the forecast for Sunday afternoon. As the cold front pushes southward Sunday. a weak wedge of high pressure begins to push into NE GA bringing temps down a bit for Sunday night.
253 PM CDT Sat Mar 14 2020 Increasing potential for accumulating snow highlight the short term forecast period with a chance of freezing drizzle across portions of southwest North Dakota. Expect snow to become more widespread late this evening as a mid- level impulse is forecast to advance east through the ridge axis. A widespread area of light snow will be possible, though the highest potential for accumulation should in an area along an area north of Highway 200 through the International Border. An additional hazard is the potential for freezing drizzle, generally across the southern counties where there some low level omega and moisture may overlap. Temperatures across the south should struggle to make it above the low 30s while high temps across the north stay in the upper 20s to 30.
Snow showers continue over much of the area this afternoon, as an upper trough pushes east through the region.
514 PM MDT Sat Mar 14 2020 Plenty of low and mid clouds remain today under southwest flow as one system exits onto the Plains and another larger low pressure system spins off the Pacific Northwest coast. Some isolated showers have popped up over the high terrain this afternoon due to lingering instability but due to drier low levels, do not anticipate much in the way of precipitation accumulation with light showers over the mountains and sprinkles over the lower valley locations. The broken cloud cover is causing temperatures to be a bit cooler than yesterday but it does look like highs will be close to normal.
Decided to go ahead with a Freezing Fog Advisory through 9AM Sunday as winds stay out of the south and southeast overnight. so did add areas of Freezing Fog across much of the Panhandle and southeast Wyoming plains. Evening shift may need to issue a Freezing Fog Advisory once we see where the denser fog sets up.
A closed upper low was positioned just offshore the SW Oregon coast this afternoon. Lobes of ascent were rotating around the low and aiding in numerous showers over northwestern CA. A cold mid-level airmass was also associated with the low, leading to steepening lapse rates and weak CAPE values. Snow levels have generally been running around 2000-2500 feet through the day, with some brief lower snow levels as heavier showers drag cooler air aloft toward the surface.
This precipitation is occurring in response to the Ohio Valley short wave trough, as well as some upper level divergence, associated with a passing jet streak to our north. A very busy start to the weekend, as an area of low pressure and a frontal boundary aloft will move through the Ohio and Tennessee valley regions today and tonight.
Stable conditions exist for deep convection with ample ridging aloft and attendant warm dry air. Short Term Update - Ridging will remain intact to our north, keeping local winds light to gentle out of the northeast to east. The lower level inhibition is expected to dull overnight. Expect overnight lows to bottom out broadly in the lower 70s. Ridging to our north is maintaining mostly gentle to moderate northeast to east breezes across Keys waters.
619 PM CDT Sat Mar 14 2020 There has been some patchy light freezing drizzle across the area this afternoon and have kept the Winter Weather Advisory in place. Sounding profiles are not overly impressive for freezing drizzle tonight, with the mid-levels only modestly dry and lift weak.
Lows overnight will range from the lower 50s in the north to the lower 60s in the south. Temperatures today have ranged from the mid 70s north to the lower 80s south with south to southwest winds bringing in moisture across the region. However, this front will also run into ridging over the northern Gulf Coast. Quite the temperature gradient will occur across the area with highs in the 50s possible across the Delta compared to the lower 80s in the Pine Belt.
502 PM EDT Sat Mar 14 2020 A very busy start to the weekend, as an area of low pressure and a frontal boundary aloft will move through the Ohio and Tennessee valley regions today and tonight.
Normally cooler rural, inland locations may realize U50s. The mid-level ridge does weaken as it gets nudged a bit further south and flow aloft becomes more zonal. Weak surface ridging will exist over the area with very weak pressure gradient in place.
603 PM MDT Sat Mar 14 2020 The latest water vapor images and upper-air analysis places a trough across the western CONUS and a ridge over the eastern CONUS.
Model guidance is mixed on the chances and extent of fog through early Sunday morning, but dew points slightly warmer than last night should allow for at least a few patches forming after midnight, with the highest chances over the interior and across southwest Florida. High pressure will build back in to the north of the waters through the next couple days.
A very busy start to the weekend, as an area of low pressure and a frontal boundary aloft will move through the Ohio and Tennessee valley regions today and tonight.
712 PM CDT Sat Mar 14 2020 Satellite and radar reveal that the majority of the precipitation has shifted to the south with the low level warm frontal forcing. Winds will stay out of the east keeping us cool again tomorrow with lows near freezing and highs only in the lower 40s with cloudy skies.
628 PM CDT Sat Mar 14 2020 Updated for 00Z aviation discussion 00Z TAF discussion: VFR ceilings will prevail through much of the evening, but a weak cold front moving in from the north at late evening will bring a northerly wind shift, MVFR ceilings and isolated showers. Temperatures today have ranged from the mid 70s north to the lower 80s south with south to southwest winds bringing in moisture across the region. However, this front will also run into ridging over the northern Gulf Coast. Quite the temperature gradient will occur across the area with highs in the 50s possible across the Delta compared to the lower 80s in the Pine Belt.
This has prompted the expansion of the Freezing Fog Advisory to include the Southern Laramie Range. One thing we will continue to monitor is the possible expansion of low visibilty/freezing fog potential into the Kimball and Cheyenne County areas of the Nebraska Panhandle. If this occurs, an additional expansion of the current Freezing Fog Advisory will need to be done to incorporate those areas. Current observations in those areas show 7 to 10 mile visibility, despite the low cloud ceilings under 1000 feet presently. Decided to go ahead with a Freezing Fog Advisory through 9AM Sunday as winds stay out of the south and southeast overnight. so did add areas of Freezing Fog across much of the Panhandle and southeast Wyoming plains. Evening shift may need to issue a Freezing Fog Advisory once we see where the denser fog sets up.
Dry and warmer weather return for the early part of the new week. Despite some grassy accumulation, impact off the ridges will remain minimal as road temperatures are in the 35 to 40 degree range. The winter weather advisory for the ridges remains in place with accumulating snow possibly finished off toward morning with some freezing drizzle in the higher elevations where surface temps are below freezing as per road sensors. Otherwise, expect rapid improvement through Sunday via building high pressure.
1241 AM CDT Sun Mar 15 2020 There has been some patchy light freezing drizzle across the area this afternoon and have kept the Winter Weather Advisory in place. Sounding profiles are not overly impressive for freezing drizzle tonight, with the mid-levels only modestly dry and lift weak.
As the aforementioned upper high moves closer, subsidence should keep things a bit dry outside perhaps an uptick in cloud and a spotty shower or two along the Gulf breeze this afternoon across interior areas.
/Today through Tonight/ Confidence: Medium to High Weak ridge of high pressure settling into the area tonight continues to bring some clearing to northern and northeast Iowa where patchy fog has developed. As the high slides east this afternoon, low pressure to the west should help increase winds aloft and at the surface - enough to partially break up the clouds across the region and bring some sunshine back to the area this afternoon. Temperatures at H850 continue to warm slightly south and west today which should help the temperatures warm into the lower to mid 40s by late day. Lows tonight will drop into the lower 30s northeast to the lower to mid 30s south.
344 AM CDT Sun Mar 15 2020 An omega blocking pattern over the eastern Pacific is here to stay for quite some time, at least the next 2 weeks. One upper low after another is ejected into the Plains from the southwest CONUS in that southern stream flow, bringing multiple rounds of showers and storms.
343 AM EDT Sun Mar 15 2020 Synopsis/Discussion/Marine - Mostly sunny today - Cold front brings light precipitation Monday night - A significant precipitation event likely late week --Mostly sunny today-- I expect skies to be mostly sunny today and tonight. -- Cold front brings light precipitation Monday night-- Our next precipitation event comes to us thanks to the northern branch of the polar jet.
344 AM EDT Sun Mar 15 2020 High pressure builds over the region today and Monday with fair weather and seasonable temperatures.
352 AM EDT Sun Mar 15 2020 Quiet weekend continues with high pressure to the north mostly in control. Expect that as heights continue to rise and subsidence continues, these clouds will continue to clear out, hanging on the longest over the higher terrain of western Upper Michigan where the upslope nature of the flow will keep enough moisture around longer. With sunshine through at least midday on Sunday, temps should rebound back into the low to mid 30s for highs, coolest along the lakeshores. Northern stream disturbance will push into far northern Ontario on Monday pushing a cold front southward across Lake Superior and the U. Most of the precipitation will fall in the form of light snow but as low level temperatures climb above freezing by late morning.
Surface analysis depicts weak high pressure extending from the western Atlantic across central and north Florida into the eastern Gulf of Mexico, with the Keys lying within moderate easterly flow to the south of this high. Aloft, water vapor imagery shows a strong deep layered ridge centered over the Gulf of Mexico. This ridge continues to dominate our local weather regime. The 00Z Key West sounding reflected the strong ridging aloft, with a substantial subsidence inversion based at 7500 feet. High temps will be several degrees above normal again today, topping out in the lower to mid 80s.
/issued 157 PM EDT Sat Mar 14 2020/ Stout mid to upper tropospheric ridging centered over the Gulf of Mexico will remain our dominant weather influencer. The 594 dm mid- level high will provide for plenty of subsidence and drying aloft, while supporting the westward extension of low-level subtropical Atlantic ridging into our area. With the easterly wind flow off the relatively cooler Atlantic waters the eastern coastal areas should remain mainly in the lower 80s, with mid 80s expected farther inland. Lows tonight will range from the lower 70s along the east coast to the mid to upper 60s elsewhere. A similar pattern for temperatures and weather should persist into Sunday with high pressure in control.
348 AM CDT Sun Mar 15 2020 Patchy freezing drizzle and fog will continue mainly near and south of Highway 2 through mid-morning. This will remain conducive for patchy freezing drizzle and fog to continue through mid-morning. A system moving across the Southern Plains northward into Kansas and southern Nebraska will bring a slight chance for drizzle or freezing drizzle to far southeast areas after midnight. A cold front will move through during the day, to actually bring slightly warmer temperatures from the lower 40s north to the mid and upper 40s south.
Mid level high pressure centered over the southern Gulf of Mexico with a ridge axis extending across FL and the Bahamas will keep our weather warm and dry. Light and variable winds this morning in vicinity of the low level Atlc ridge axis will turn onshore in a sea breeze by afternoon along the coast, spreading inland during the afternoon. Another mild night with lows in the low to mid 60s, except near 60 over southern interior sections (Okeechobee and the interior Treasure coast counties).
Trajectory over cooler waters may again generate intermittent periods of dense sea fog.
High pressure over far northern Ontario will build toward the lower St Lawrence Valley thru tonight. Ridging will cross northern MI today, with return flow getting underway in its wake tonight.
There will be an increase in high clouds today from the subtropics in between mid level ridging across the Gulf of Mexico and an upper low moving down the west coast. Highs today will be in the 80s and lows tonight will be in the low 60s.
This reinforces some of the higher PoP values suggested in the guidances, but today may still wind up being a low QPF day with only some isolated pockets of deeper convection.