Aikyam-Lab/Synoptic-Bench huggingface dataset:
If low clouds can partially clear out by early afternoon, which is starting to appear possible, temperatures have a good shot at warming into the low to mid 70s. Better chances for redevelopment of showers and thunderstorms will occur this evening and overnight, as the low level jet strengthens and isentropic ascent increases along and north of the stationary front to our south.
315 AM MDT Sat May 15 2021 Upper low was situated over northern CA with weak ridging over the central and southern Rockies. The emphasis for strong to marginally severe storms shifts south and east of a Laramie-Torrington-Scottsbluff-Bridgeport line Sunday afternoon where 0-6 km shear is 25-30 kt with surface-based CAPE of 1000-1500 j/kg.
For 12Z Aviation discussion below As the trough moves east today precipitation chances will dry up in western Minnesota.
405 AM CDT Sat May 15 2021 As the trough moves east today precipitation chances will dry up in western Minnesota.
The closed upper low that brought good moisture feed into the region, as well as strong dynamics, continues to move south through the day today. As expected however, thunderstorm development in the Cascades, and in Siskiyou county where the strongest ridge level theta-e convergence was indicated. The upper low will move down to central California by this afternoon, bringing the bulk of the instability to the southern fringes of the forecast area in northern California by max heating. The upper low migrates east into southern Nevada Sunday, and the area if instability moves with it, leaving just a sliver in southeast Modoc county, but the northerly steering flow should push any cells out of the area before they develop into showers, let alone lightning.
Daily occurrences of afternoon showers and thunderstorms will be possible the next couple of days in the Sierra Nevada and foothills as the trough of low pressure moves overhead.
735 AM EDT Sat May 15 2021 High pressure will move slowly east across the area today and tonight. The high will move off the Mid-Atlantic Coast Sunday morning while maintaining a ridge across the eastern Great Lakes through mid-week.
Will have to monitor trends through the day, but right now the highest chances for storms based on short term consensus would be across SE MN/NE IA through far western WI. The region will be in between a trough digging into the southwest US and a trough passing to the north over northern Ontario.
357 AM MDT Sat May 15 2021 A rather weak overall flow pattern will continue over our region today while an upper low sits over the west coast. Temperatures will gradually warm over the next couple of days, with highs in the upper 60s to mid 70s today, and generally about five degrees warmer for Sunday.
Shower and thunderstorm chances will begin to increase this evening across portions of southwestern OK and western north TX as activity moves off the high plains of TX again.
308 AM MDT Sat May 15 2021 A low pressure system will move through northern California today. Some gusty winds and small hail are possible once again, although the additional cloud cover will keep temperatures a little cooler today which will hold the instability back as well. On Sunday the low will move into the Great Basin. But the high-res models are supporting isolated convection reaching out into the Snake Plain and central mountains as well. Cloud cover is a little less on Sunday, which will allow for warmer temps once again.
Cloudy skies and warmer conditions were seen early this morning, with scattered showers across our Iowa and Missouri counties. Expect coverage to increase some this morning, especially over the southern half of the forecast area, with the highest likely PoPs along and south of a line from Sigourney,IA to Sterling, IL.
Models consistency remains with this low moving to the southern tip of Nevada by tomorrow evening.
527 AM MDT Sat May 15 2021 Upper low was situated over northern CA with weak ridging over the central and southern Rockies. The emphasis for strong to marginally severe storms shifts south and east of a Laramie-Torrington-Scottsbluff-Bridgeport line Sunday afternoon where 0-6 km shear is 25-30 kt with surface-based CAPE of 1000-1500 j/kg.
Temps will be a bit warmer with some 80s possible and southwesterly winds will increase to the 15 to 20 mph range. Will have to monitor for near critical fire weather conditions as a few spots could see RH values drop into the lower 20s. A ridge dominates the synoptic pattern early in the week, with increased fire weather concerns due to low relative humidities, breezy conditions, and warm temperatures across the region.
A series of 500 mb vortices will be ejecting out from the closed low that is settling in over the Desert SW today and Sun.
549 AM MDT Sat May 15 2021 Upper low along northern CA coast is sinking southward with band of moisture streaming northeastward ahead of it as broad ridging over the Rockies/Plains. Weak surface trof extends north-south across central Dakotas-eastern MT.
Mid- level clouds will be on the increase for our Saturday ahead of a low pressure system to our west. With the return flow in place, temps are expected to reach the low to mid 70s. As mentioned earlier, the persistent high pressure that provided the below normal temps is scheduled to depart today. With increased mid-level moisture, a few radar returns will be possible starting this afternoon, but with model soundings showing a deep dry layer in the low levels, expect to see more of a virga scenario until the low levels saturate by tonight. Better precip chances arrive around 00z and continue through tonight and into Sunday morning as a east-west oriented warm front lifts north out of TN and sits across KY by 12z Sunday.
A few complexes of thunderstorms have developed across Kansas in response to the low level jet (LLJ) interacting with the warm front extending eastward from the low. This convection may also lay out an outflow boundary somewhere across SW MO this evening, essentially extending an effective warm front from western KS into southern MO. As the low level jet ramps up this evening, enhanced convergence along the effective front will result in another round of convection.
The shower activity is being supported by short wave rotating around a closed low currently located over Butte and Plumas counties northeast California. That low will continue to move southeast, and a ridge flopped over the top of the low will gradually move south as well. Once that activity ends this evening, it will be dry through Sunday with the ridge over the area. It will also be warmer, as the drying and stabilization of the air mass will allow more sunshine and subsidence.
246 PM EDT Sat May 15 2021 Latest surface analysis reveals high pressure slowly retreating eastward as lower pressure edges in from the west with a couple tendrils of weak boundaries crawling toward the OH Valley. Rainfall chances will continue throughout the day Sunday as isentropic lift along a warm frontal boundary sets up over the region. Sunday morning mins will likely range in the low to mid 50s with afternoon highs in the upper 60s to low 70s.
An upper ridge over the Great Plains will shift east of the Mississippi River by late Sunday afternoon. But, increasing upper subsidence from the approaching upper ridge will limit rain chances, with temperatures approaching seasonal norms. High temperatures today remain on track to top out in the lower 80s inland, with upper 70s along the immediate coast. Highs on Sunday about the same, but perhaps slightly warmer over the interior, where low to mid 80s are expected. Low temperatures tonight will range from the mid 50s north of the I-10 corridor to the lower 60s for areas closer to the coast.
Temperatures Sunday should be even warmer than today with 80s likley in the RRV. While mixed layer Td values aren't particularly low the warmer temperatures will still result in minimum RH values in the teens to lower 20s. The first half of the workweek will be quiet, as an upper level ridge holds tightly to the region.
This will allow a warm front to approach our western door step tonight, but should remain just west of the mountains. Lows will be mostly in the lower 50s tonight, in the 50s, except for some mid to upper 40s across the NE where latest arrival of cloud cover will allow for better/longer radiational cooling. Finally, a backdoor cold front will shift south from VA into NC Sunday night. As this occurs, the warm front aloft will focus shower chances over KY/WVA and into western VA. Highs Sunday will be a bit cooler due to the clouds.
AC Chattanooga Airport, TN 56 81 57 82 62 / 0 10 10 10 20 Knoxville McGhee Tyson Airport, TN 56 75 56 80 60 / 10 20 20 10 30 Oak Ridge, TN 55 75 55 79 59 / 10 20 20 20 30 Tri Cities Airport, TN 52 70 54 76 56 / 20 40 30 30 30.
As the trough moves east today precipitation chances will dry up in western Minnesota.
/Tonight through Sunday Night/ The flow aloft will become increasingly southwesterly as the next in a series of upper troughs moves across the Southern Plains and towards the Lower Mississippi Valley. Ascent from the upper trough combined with some instability should be enough to sustain the showers and thunderstorms as they begin to move into our area, mostly likely during Sunday afternoon.
(This evening through Sunday) A general moistening of the lower layers will continue through the weekend.
Tonight, a weak upper level trough will push across the area. The mentioned wave moves out of the state Sunday morning, with weak ridging building in for Sunday.
Tomorrow will see the high pressure around the Great Lakes region slide off the eastern seaboard and an area of lower pressure developing along the eastern slopes of the rockies. What looks to happen for the week ahead is the high pressure to the east remains off the east coast blocking the low pressure from moving to east and the frontal boundary remains stalled.
229 PM MDT Sat May 15 2021 20z surface analysis had two troughs across the CWA, one from central ND into central NE, and another from central MT into southeast WY. Water vapour loop had splitting upper trough from AB to CA with northern stream energy heading toward the northern plains and upper low over southwest central CA.
/issued 1021 AM CDT Sat May 15 2021/ We remain under the influence of high pressure to the east. Look for temperatures around the low 80s with cooler temps along the beaches for aftn highs.
1200 PM EDT Sat May 15 2021 High pressure will remain over the area through tonight.
1158 AM MDT Sat May 15 2021 Upper low was situated over northern CA with weak ridging over the central and southern Rockies. The emphasis for strong to marginally severe storms shifts south and east of a Laramie-Torrington-Scottsbluff-Bridgeport line Sunday afternoon where 0-6 km shear is 25-30 kt with surface-based CAPE of 1000-1500 j/kg.
Broad ridging was positioned over the Southern Plains while residual troughing aloft was located just offshore of the Mid Atlantic Coastline. Expect low and mid level ridging to continue build over the area. Highs today will range from the upper 70s north and northeast to readings in the lower 80s south and west.
408 PM EDT Sat May 15 2021 High pressure briefly builds over the region through tonight before shifting offshore into the western Atlantic on Sunday.
This low will be dragged behind the current system, and provide lift. Behind this system is an upper level low that is currently centered over northern California/ eastern NV. This low will be the main feature in more precipitation tomorrow. Therefore, can expect daytime highs to be cooler, and overnight lows to be warmer than if clouds were not present. With 850 temps around 9-11C, expecting lows tonight to be in the lower 50s.
1257 PM PDT Sat May 15 2021 An unseasonably cool upper level trough will push through Southern California on Sunday.
The favored areas where measurable rain will occur will be across the higher terrain of SW VA and NE TN mountains.
Drier air and quiet weather is expected on Sunday as a ridge builds into the area. Warmer temperatures are expected on Sunday with highs in the low 70s expected across much of southern Wisconsin. Areas near the lakeshore will be slightly cooler with the onshore flow.
As a warm front lifts north into/across the area this weekend, it will begin a trend toward bringing warmer and more moist air to the region. Dew points today in the 40s, will make their way into the lower 60s Sunday.
Large-scale subsidence within a very dry airmass will contribute plentiful sunshine and high temperatures in the low 80s.
With low pressure developing over the Intermountain W & frontal zone off to the N, light winds are possible overnight. Lows will be near normal in the low 60s in the NW Delta while cooler than normal in the mid 50s in the E. Low-level thermal warmth will climb, helping highs climb near normal in the low-mid 80s. The best chances for activity look to be across western portions of the area as high pressure ridging will still remain off to the east. High temperatures through the period will be seasonal, ranging from the lower to middle 80s with southerly winds.
Satellite imagery showing a mid-level closed low over north-central CA this morning.
1202 PM EDT Sat May 15 2021 High pressure will remain over the area through tonight.
This may be aided by a surface warm front lifting north tonight and into Sunday. As a result, the trend will remain toward a warmer and more moist airmass across the region.
151 PM CDT Sat May 15 2021 An upper trough is centered over California and Nevada with westerly flow over West Texas and Southeast New Mexico. The upper low moves over Southern California/Southern Nevada on Sunday with another dryline across West Texas and Southeast New Mexico.
Until then a few isolated to widely scattered thunderstorms will be possible late day near a surface boundary/warm front that will be located just north of the Garden City and Dodge City area.
Lowered the chances for showers through the rest of the late morning and early afternoon hours to reflect the lower chance in showers across southern Wisconsin. Overall trend is for things to start moistening up here ahead of surface/850 trough. The drying trend should last into Sunday with ridging building in from the east and mid levels showing more of an anticyclonic regime.
Highs will be a little warmer today with temperatures reaching near 80F this afternoon. /issued 354 AM CDT Sat May 15 2021/ A rather low-amplitude longwave trough is affecting much of the CONUS this morning. Lows will generally range from the mid 50s in the east to the lower 60s along/west of the MS River. A few showers and/or thunderstorms will again be possible near the MO/KY lines Sunday, but much of the area will continue to see the affects of the ridge aloft with dry and warm conditions.
12z upper air/surface analysis indicate mid-level ridging over W. Blended in the op HRRR dewpoints & more mixed afternoon highs, which was a touch warmer. Broad upper ridging will also keep conditions on the dry and sunny side for us today. Temperatures will be a little warmer today into the 80s with plenty of sunshine.
The shower activity is being supported by short waves rotating around a closed low currently located over Butte and Plumas counties in northeast California. That low will continue to move southeast, and a ridge flopped over the top of the low will gradually move south as well. Once that activity ends this evening, it will be dry through Sunday with the ridge over the area. It will also be warmer, as the drying and stabilization of the air mass will allow more sunshine and subsidence.
Overnight, the low level jet will ramp up and interact with this boundary, with convection developing at the nose of the jet across eastern Kansas.
Northern portions of the forecast area will see the highest PoP's through early evening. Temperatures should reach the lower 70s across the northern CWA, but a wedge of upper 60s is likely south of I-70 where rain chances are higher.
258 PM CDT Sat May 15 2021 18Z surface data has high pressure over the Ohio Valley with a stationary front across Oklahoma.
1213 PM MDT Sat May 15 2021 Upper low along northern CA coast is sinking southward with band of moisture streaming northeastward ahead of it as broad ridging over the Rockies/Plains. Weak surface trof extends north-south across central Dakotas-eastern MT.
High pressure will be located off the Carolina coast with easterly winds tonight becoming southeasterly Sunday. Lows tonight will fall to the mid and upper 50s with highs Sunday in the low to mid 80s.
Otherwise, enjoy the sunshine and even warmer temps this afternoon.
1021 AM CDT Sat May 15 2021 We remain under the influence of high pressure to the east. Look for temperatures around the low 80s with cooler temps along the beaches for aftn highs.
209 PM CDT Sat May 15 2021 Another picture perfect day continues, although it is noticeably warmer than what we have been experiencing as of late.
Due to low clouds and persistent fog through the morning hours, temperatures across portions of Laramie, Platte, Goshen and Albany Counties have struggled to reach into the mid 50s while other places across the area have warmed into the low to middle 60s. Lows tonight from the lower 40s to low 50s for many. Sunday will be very similar to today as the low deepens into Arizona with vorticity advection ahead of main low and a stationary front providing ample moisture once more for showers and thunderstorm activity.
Surface analysis shows high pressure centered near West Virginia and sprawling across the entire eastern CONUS, with the Keys lying within a moderate pressure gradient along the southern flank of this high. Aloft, water vapor imagery shows a trough exiting from the U. East Coast, with an upstream ridge building into the western Gulf region, and another trough digging southward through California.
105 PM EDT Sat May 15 2021 High pressure over the upper Ohio River Valley will drift eastward through tonight. The high will reach the Mid-Atlantic Coast Sunday morning while maintaining a ridge across the eastern Great Lakes through mid-week.
238 PM CDT Sat May 15 2021 A beautiful day across the Tennessee Valley with temperatures early this afternoon in the low to mid 70s. There are some showers associated with this trough currently across northern Arkansas and Missouri. This light southerly flow coupled with cloud cover overnight will lead to warmer overnight lows. Expect lows tonight will be in the low to mid 50s.
Complex area of low pressure continues to take shape over the Northern and Central Plains. Associated warm front is holding from the Central Plains thru Mid Mississippi Valley. High Impact Weather Potential: Low Pattern Synopsis: A closed low will dip down into Baja California while ridging in the main upper-level flow progresses across southern Canada on Sunday.
Very warm temperatures will remain throughout the Northern Rockies for the next few days while under high pressure. Low pressure south of the region will bring just enough moisture into Lemhi County and southwest Montana for isolated showers and thunderstorms.
159 PM MDT Sat May 15 2021 The influences of a northern stream trough pulling across the area, as well as support from a right-entrance region of an upper jet will support convection across the entire area this afternoon and evening. The northern stream trough and associated upper jet exits the area tonight, with the main focus shifting to an upper low currently over central California. This upper low will slowly shift southward into S.
An upper ridge over the Great Plains will shift east of the Mississippi River by late Sunday afternoon. But, increasing upper subsidence from the approaching upper ridge will limit rain chances, with temperatures approaching seasonal norms. Low temperatures tonight will range from the mid 50s north of the I- 10 corridor to the lower 60s along the coast. Highs on Sunday will top out in the low to mid 80s inland, with upper 70s along the immediate coast.
Temperatures continue to trend warmer, with some locations reaching near 80 on Sunday. All activity ends this evening with ridging aloft.
An upper level trough of low pressure over central California will send pcpn chances into the region this afternoon through Sunday. This pattern will favor a nearly cutoff upper low over the southwest CONUS, with ridging aloft over the Northern Plains. That ridging aloft should suppress most activity across the forecast area until about mid-week. At that time, the upper low to the south will start shearing out in pieces to the north as another low digs into the far western CONUS.
433 PM EDT Sat May 15 2021 Upper level pattern today per water vapor imagery and RAP model heights features a blocking ridge over the eastern Pacific stretching British Columbia with a cutoff low over northern California. Overnight, a mid level warm front will continue to push through the U. The low clouds and any fog that develops should mix out through the mid to late morning hours.
918 AM PDT Sat May 15 2021 An unseasonably cool upper level trough will push through Southern California through Sunday.
Blend of models backed off on pops as did several other models, warranting a trimming of the higher pops in the south.
This will allow a warm front to approach our western door step tonight, but should remain just west of the mountains. Lows will be mostly in the lower 50s tonight, except for some mid to upper 40s across the NE where latest arrival of cloud cover will allow for better/longer radiational cooling.
Very active upper level pattern with a closed low over California and open wave over the southern plains which is undercutting a ridge axis. At the surface, a warm front was located over northern Arkansas with temperatures in the 70s south of the front. The warm front will also start to lift northward this evening. The low level jet will increase later tonight and overrun the warm front which will set up in the northern CWA.
208 PM MDT Sat May 15 2021 A rather weak overall flow pattern will continue over our region while an upper low over the west coast drifts toward Arizona. Temperatures will be warmer on Sunday, with highs in the 70s.
SHORT TERM (Tonight through Sunday Night):Convective cluster that initiated over Nuevo Leon prior to sunrise is nearing the Lower Texas coast as of this writing.
341 PM EDT Sat May 15 2021 High pressure over the upper Ohio River Valley will drift eastward through tonight. The high will reach the Mid-Atlantic Coast Sunday morning while maintaining a ridge across the eastern Great Lakes through mid-week.
213 PM EDT Sat May 15 2021 High pressure will remain over the area through tonight.
/issued 151 PM CDT Sat May 15 2021/ An upper trough is centered over California and Nevada with westerly flow over West Texas and Southeast New Mexico. The upper low moves over Southern California/Southern Nevada on Sunday with another dryline across West Texas and Southeast New Mexico.
Cooler than normal temperatures are forecast this weekend. Still a slight chance of showers and T-storms in the northern reaches of our CWA, as the upper low over CA may wrap around some convective activity firing over the Sierra. The upper low overhead will drift slowly south and east overnight. Marine layer will likely compress Sunday evening as some weak ridging builds in from the Pacific.
720 PM EDT Sat May 15 2021 High pressure will remain just south of Long Island through Sunday.
946 PM EDT Sat May 15 2021 High pressure over the upper Ohio River Valley will drift eastward through tonight. The high will reach the Mid-Atlantic Coast Sunday morning while maintaining a ridge across the eastern Great Lakes through mid-week.
The warm front is expected to become a little more defined after midnight and the low levels will become more moist.
Larger scale pattern for the upcoming week will amplify with a trough through the western U. and ridge over the Plains/Great Lakes. Upper low across the southwestern U.
640 PM CDT Sat May 15 2021 (This evening through Sunday) A general moistening of the lower layers will continue through the weekend.