Aikyam-Lab/Synoptic-Bench huggingface dataset:
Deep layer ridging will persist to our east today. Summery temperatures (highs in the low-mid 90s and heat indices in the mid-upper 90s) should lead to the development of both a Gulf and Atlantic coast seabreeze front, but with 1000-700 mb steering flow from the east at 10-15 kts, the east coast seabreeze will push further inland and pin storms near I-75 and the Suwannee Valley, keeping the highest coverage storms in that area.
Storms should start initiating over the Laramie Range around 1 to 2 PM, and then move off into the High Plains around 3 PM. Looking for a quiet, coll night in the wake of this system and its associated cold front. Cool and showery conditions expected Sunday as the upper trough moves across the area with most of the showers occurring over the southeast part of the CWA.
145 AM EDT Sat May 23 2020 Aviation - Mostly Cloudy Tonight - Increasingly Warm and Humid; Thunderstorms Saturday Night - Chance of Showers And Storms Early to Midweek - Mostly Cloudy Tonight - The upper low will continue to bring fairly extensive cloud cover tonight. - Increasingly Warm and Humid; Thunderstorms Saturday Night - Fair wx is forecast for most of the day tomorrow with weak ridging in place. A warm front combined with an upper level disturbance will bring showers and storms Saturday night into early Sunday. Due to persistent deep southwest flow waa high temperatures will reach the lower 80s by Memorial Day with dew points rising well into the 60s by then.
Looking at satellite imagery this afternoon, a large trough is noted to our west, with its axis swinging onshore across the Pacific northwest earlier today. The activity we end up with will be dependent on how temperatures recover late this afternoon, with warmer temperatures pointing at stronger storms. Otherwise, we will need to watch in general for storms rotating under the trough this evening as they might reach as far south as northern Kansas City.
Closed upper low of last few days has now moved over New England, with very weak ridging building over the mid-south. Despite this ridge, moisture remains fairly deep, and a warm frontal boundary currently to our south will lift into southwest middle TN in a few hours. Short of it, blocking ridge remains strong across the eastern US 1/3, while a cutoff upper lows drops into the southern plains and wobbles around there well into late week. SW winds increase some tomorrow afternoon as a warm front lifts north through the Mid State.
Weak instability just south of the upper low over north central Kansas will support a few showers as well until early this evening. However, periodic chances for showers and storms will increase over the remainder of the holiday weekend as deeper moisture/higher PWAT values advect across the area in the south-southwest flow ahead of the advancing upper trof from the western CONUS. Somewhat better chances then on Sunday afternoon/evening along a cold front moving into central Kansas.
No major troughs are expected to transverse the flow this weekend but a few weak pieces of energy will make their way across the area providing adequate lift for precip development. Surface pattern will be fairly stagnant with ridging over much of the area and a warm front well to the north. Temps across southern Arkansas on Saturday may approach 90 F and with Td values in the upper 60s, heat indices may climb into the lower to mid 90s.
East of the Cascades, fog/freezing fog could form, but confidence is low. Our confidence is high that there will be a sustained period of highs in the high 80s and even mid 90s for some west side valleys.
Temperatures may be a bit warmer on Saturday given more sunshine vs what was expected earlier. By 12Z Sunday the elongated area of low pressure at the surface should be along or just east of the Missouri River, and stretch down through the eastern half of NE.
347 AM CDT Sat May 23 2020 Upper trough centered over the Intermountain West this morning will stretch down to Mexico as the parent low moves up into MT tonight.
1052 PM MDT Fri May 22 2020 Deep NW Pac upper trough will remain in place across the NW CONUS through the weekend supporting another round of unsettled conditions by tomorrow. Advecting upper trough across southern Canada will force a cold front into the region tonight, which will stall toward morning as a potent southern periphery impulse ejects NE. This has also shifted QPF totals east as well, with the highest numbers over NW SD between Buffalo and Faith. Further west, NE WY is expected to see the lower pops given main convective forcing over western SD with the upper level dry slot crossing that area. Breezy day expected Sunday with much cooler conds.
Upper ridge will build over the southeastern states through the weekend as a trough digs into the Rocky Mountains and High Plains. Temperatures will be quite warm, reaching the lower to mid 90s each day, with heat indices approaching 100 (and a little above 100 in some spots).
Chances remain for potentially strong to severe thunderstorms Sunday afternoon in association with a rather strong theta-e gradient boundary that will accompany the upper low.
The Evening Update: Less Nly wind and warmer temps expected on Sat as the upper low over the ID/NV border moves Ewd and the Pacific ridge builds into the area. RDD RBL DTS SAC SCK MOD 25 98(2014) 105(1982) 100(1951) 100(1951) 102(1979) 99(1979) Rdd City 103(1982) RDD 34% 1% n/a 19% 6% 20% 26 98 (2009) 102(1951) 102(1974) 101(1976) 101(1974) 102(1951) Rdd City 101(1974) RDD 83% 33% n/a 54% 66% 51% 27 100(2009) 102(1984) 104(1984) 100(1984) 102(1984) 100(1984) Rdd City 108(1919) RDD 83% 73% n/a 98% 76% 95% 28 100(2009) 108(1984) 107(1984) 105(1984) 107(1984) 105(1984) Rdd City 108(1984) RDD 86% 8% n/a 20% 12% 39% An upper level trough is currently making its way through NorCal this afternoon. Upper level ridging will then be building in Saturday and for the weekend.
On Saturday, after some showers and storms lingering from the overnight into the morning hours, cloud cover will slowly decrease through the day as a result of a ridge in the lower to middle Mississippi River Valleys. A low pressure system in the Central Plains will be diverted towards the Great Lakes as a result of the ridge, keeping precip chances lower for the afternoon. At this time, the time-lagged RAP guidance appears to be doing the best resolving the short term expansion of a mid-cloud deck ahead of the thunderstorm complex in western Arkansas, as well as the departure of clouds in southwest Indiana moving along the vorticity axis to the low near northwest MO this evening.
Our confidence is high that there will be a sustained period of highs in the high 80s and even mid 90s for some west side valleys. East of the Cascades, fog/freezing fog could form, but confidence is low.
A fairly sharp upper level low pressure trough will dig through the intermountain west into the southern Rockies and high plains Sunday.
1108 PM CDT Fri May 22 2020 Pesky anchored closed low over the Ohio River Valley continues to spread moisture in the form of low clouds into our area. This will result from a closed low rotating northeast from the Central Plains. Look for this closed low to continue lifting northeast across the area Saturday for increased shower/isolated thunder activity.
Some weak upper level ridging builds in late tonight through Saturday and should for the most part should squelch much in the way of showers and storms. Saturday looks to be a warm and humid day with highs in the lower to middle 80s and dewpoints in the upper 60s. At this point it looks as though upper ridging will hang on into Sunday morning before pushing off to the east Sunday afternoon.
Shower and storm chances return on Sunday as a broad upper trough approaches from the west, and the forecast just gets downright messy after that. Energy in the base of the upper trough closes off and becomes cutoff from the westerlies, which will leave it behind as they retreat north closer to the Canadian border in a more summer like pattern.
The closed low to the northeast continues to move east tonight as mid/upper level ridge builds up from the south. Increase of showers possible late tonight across the northeast part of the area as 850MB warm front shifts north. RG Chattanooga Airport, TN 85 66 89 67 87 / 30 20 40 10 50 Knoxville McGhee Tyson Airport, TN 84 64 87 66 87 / 40 20 50 10 60 Oak Ridge, TN 84 64 87 65 87 / 60 30 50 10 60 Tri Cities Airport, TN 79 61 83 61 84 / 40 20 60 10 50.
Outflow from convection and northeasterly flow leave a boundary generally north of I70 that initially also acts to keep temperatures cooler, but washes out through the day as the ridging moves in and mixing of the boundary layer increases. Late afternoon thunderstorms could develop out over the high plains, with trajectories that could clip our western counties in the evening hours, and with plenty of instability, could bring a wind or hail threat if they develop. The larger scale upper trof continues to approach the plains states on Sunday, bringing a deep fetch of moisture off the southern plains and an unstable atmosphere. With the morning hours likely bringing a lull in activity and a chance for instability to increase with daytime heating, the increased lift with the approaching trof may bring strong to severe storms by the middle afternoon hours.
Skies were partly to mostly cloudy with temperatures in the low-mid 60s. With the trough axis moving northward this morning, we expect some shower and thunderstorms to pop up. Temps should bottom out in the low-mid 60s. Overall severe threat looks fairly low and isolated given the low shear values, but the strongest of any storms may produce some near-severe gusty winds.
210 AM EDT Sat May 23 2020 Mid level ridging will build in over the next several days, bringing an overall decrease in precipitation, along with a significant increase in temperatures. Lows will vary from the low/mid 50s in central Ohio to the low 60s toward the Tri-State area. After quick fog/stratus dissipation in the morning, likely to see a dry period through most of Saturday as high pressure builds in. Mid level ridge will build and then close off over the central Appalachians. This will result in warm and humid conditions, but do not expect to be capped off, especially with the center of the high east of the region.
331 AM EDT Sat May 23 2020 Localized afternoon and evening showers and thunderstorms will be focused by a trough of low pressure lying across the area today through Sunday. A cold front will drop south late Sunday, followed by relatively cooler and dry high pressure building down from the north early to mid week.
This continues to draw warmth and moisture over the region today under south and southwest flow aloft lee of the trough. Temps will again be in the 70s for most with some in eastern North Dakota getting into the lower 80s. Elsewhere, today will be mostly dry and even feature sunshine save some sprinkles in the lakes country of Minnesota associated with another upper low moving through the Upper Mississippi Valley. While somewhat unclear, a surface feature is expected to move east with the trough bringing the chance for additional showers and thunderstorms Sunday, particularly within eastern North Dakota closer to the center of the trough.
The center of this low system will remain south of the forecast area but its external bands will impact areas east of I-29 as the low moves east-northeast this morning. First, a strong cold front over western Dakota is expected to spark convection late this afternoon/early evening, with clusters of storms beign the most likely initial storm mode.
304 AM MDT Sat May 23 2020 Overnight WV imagery showed upper low pressure centers over western IA and northwest UT. The forecast concern today will be convective coverage and intensity with influence from the upper trough to the west and surface front slowly moving through the CWA. Difluence aloft will increase through the day, with scattered showers and thunderstorms developing along the front and moving into the high plains where instability (SBCAPE 1000-1500 j/kg) and 0-6 km shear (35-40 kt) favor discrete supercells capable of producing hail up to 1. Cool and unsettled weather will prevail Sunday and Memorial Day with the passage of a upper level low pressure trough.
High pressure to our east. Storms will increase tomorrow as an upper level low to our west and the moisture off the gulf will enhance showers and thunderstorms through the day.
518 AM MDT Sat May 23 2020 Overnight WV imagery showed upper low pressure centers over western IA and northwest UT. The forecast concern today will be convective coverage and intensity with influence from the upper trough to the west and surface front slowly moving through the CWA. Difluence aloft will increase through the day, with scattered showers and thunderstorms developing along the front and moving into the high plains where instability (SBCAPE 1000-1500 j/kg) and 0-6 km shear (35-40 kt) favor discrete supercells capable of producing hail up to 1. Cool and unsettled weather will prevail Sunday and Memorial Day with the passage of a upper level low pressure trough.
Showers to drop off in coverage throughout the day with mid level ridging building into region. Fair and dry tonight with ridge. Warm front approaches Sunday. Showers more widespread Sunday night with warm frontal passage. On Memorial Day, a sharpening mid-level ridge should keep the region mainly dry.
/issued 347 AM CDT Sat May 23 2020/ Upper trough centered over the Intermountain West this morning will stretch down to Mexico as the parent low moves up into MT tonight.
At this time, the higher chances for severe storms would remain south across Iowa, but a lot will depend on the weather from the previous 12 hours.
The VAD wind profile from KBYX also suggests that the low-levels are already beginning to couple with the mid- to upper-levels in a veer-back-veer configuration.
Closed upper low of last few days has now moved over New England, with very weak ridging building over the mid-south. Despite this ridge, moisture remains fairly deep, and a warm frontal boundary currently to our south will lift into southwest middle TN in a few hours. Short of it, blocking ridge remains strong across the eastern US 1/3, while a cutoff upper lows drops into the southern plains and wobbles around there well into late week. SW winds may gust around 15 kts as a warm front lifts north.
419 AM CDT Sat May 23 2020 The upper low that has been pestering the region for the last few days continues to churn across Iowa this morning. Initial instability will quickly fade as cooler, more stable post frontal air moves in.
/issued 401 AM CDT Sat May 23 2020/ Early morning GOES water vapor imagery showed a closed upper low centered over southwest IA. This feature will lift into the upper MS River valley this morning, allowing an upper ridge over the southeast U.
Generally dry weather is expected today and tonight, but a transition to a more active pattern emerges by Sunday into much of the upcoming week, as a highly amplified upper trough slowly moves into the Plains states. This upper trough may become closed off by mid/late week, drifting over the Southern Plains with a frontal boundary extending northeastward near/across the forecast area.
401 AM CDT Sat May 23 2020 Early morning GOES water vapor imagery showed a closed upper low centered over southwest IA. This feature will lift into the upper MS River valley this morning, allowing an upper ridge over the southeast U.
The track of the upper low will dictate where the bands of precip will be the heaviest today into this evening.
338 AM MDT Sat May 23 2020 A trough of low pressure aloft will keep an unsettled weather pattern over most of the region today through Sunday. Temperatures will be a bit cool in this low pressure trough, with highs reaching only into the 60s and lows dropping down into the 40s.
254 AM PDT Sat May 23 2020 An upper level trough of low pressure over the Great Basin will result in cooler weather today.
628 AM CDT Sat May 23 2020 The upper low that has been pestering the region for the last few days continues to churn across Iowa this morning. Initial instability will quickly fade as cooler, more stable post frontal air moves in.
An upper trough continues to move to the east and away from the forecast area and it will be replaced by a northwest flow aloft ahead of an upper ridge that is moving across the eastern Pacific. Some moisture will move over the top of the ridge and across the Cascades, but it will mostly dissipate due to adiabatic downslope warming and drying on the Cascade east slopes.
Still expect at least isolated/scattered thunderstorm thunderstorms over the area this morning as there will be some weak low level moisture convergence across the CWA underneath a trough rotating around the south side of the upper low in Iowa. Models are showing the upper flow becoming increasing south-southwesterly as a upper low moves into the High Plains. With current temperatures in the mid 60s, expect highs to reach the lower to mid 80s today given some late afternoon May sunshine.
(previous) Atlantic ridge axis will extend across north FL and produce SE wind flow.
649 AM EDT Sat May 23 2020 Upper level low pressure will keep showers in the forecast through the day today with scattered afternoon thunderstorms across the eastern half of the state.
The upper level low pressure system over northern Utah this morning will lift northeast away from the area later today. The unseasonably cold temperatures behind yesterdays cold front will begin to moderate Sunday. A significant warming trend will begin early in the week as high pressure aloft strengthens across the Great Basin. Portions of the southwest valleys have a low cloud deck this morning behind the cold front but after a few hours these clouds should burn off.
253 AM PDT Sat May 23 2020 After a cool start this morning, warmer conditions are expected each day through Memorial Day weekend, with dry weather and light winds prevailing.
Will start the southern area TAFs with TEMPO groups for the MVFR ceilings due to the numerous large breaks in the low cloud shield. upper level trough will not move much today, it will edge eastward a bit, weakening the ridge slightly in our area.
North winds will continue to increase today as a thermal trough develops along the coast.
An upper level ridge is building into the area today. The upper level ridge will remain in place through the weekend with a thermal trough along the coast. This will bring a trend towards warmer temperatures.
High pressure will maintain east-southeast winds around 10 knots with seas of 2 feet or less over the Gulf waters the remainder of today with an enhanced onshore sea breeze component developing along the coast during the afternoon.
The higher moisture values was bring picked up by our forecast builder, as patchy to areas of fog after midnight tonight.
636 AM EDT Sat May 23 2020 Localized afternoon and evening showers and thunderstorms will be focused by a trough of low pressure lying across the area today through Sunday. A cold front will drop south late Sunday, followed by relatively cooler and dry high pressure building down from the north early to mid week.
307 AM MDT Sat May 23 2020 Overnight WV imagery showed upper low pressure centers over western IA and northwest UT. The forecast concern today will be convective coverage and intensity with influence from the upper trough to the west and surface front slowly moving through the CWA. Difluence aloft will increase through the day, with scattered showers and thunderstorms developing along the front and moving into the high plains where instability (SBCAPE 1000-1500 j/kg) and 0-6 km shear (35-40 kt) favor discrete supercells capable of producing hail up to 1. Cool and unsettled weather will prevail Sunday and Memorial Day with the passage of a upper level low pressure trough.
upper level trough will not move much today, it will edge eastward a bit, weakening the ridge slightly in our area.
257 PM MDT Sat May 23 2020 Our upper low was spinning over western Wyoming this afternoon, and is expected to drift northeast into southeast Montana by Sunday morning. We are looking for the best precipitation coverage to shift east overnight into Sunday, and then slowly wind down as the upper low shifts east of Montana Sunday night. By the end of the weak with the ridging, temperatures will be getting into the 80s if not approaching the 90s.
Temperatures have reached into the lower 90s this afternoon but have cooled into the 70s in and around thunderstorms. Another day in the lower 90s is expected tomorrow. Downstream of a broad mid/upper trough, a rather moist airmass will remain in place across the region with PW ranging between 1. By mid/late week, an mid/upper low will cut off from this deep trough and meander around Texas through the end of the week.
Highs on Sunday continue to look hot, mainly from near 90 to the lower 90s at all locations except immediate coast we will be looking at mid 80s. Primarily VFR conditions through the period, although localized instances of IFR in and near convection this afternoon, mostly over far interior regions of the forecast area (along and north of the Highway 84 corridor).
With weak pressure gradients, variable low level winds will transition to easterly overnight as we settle in on the southern side of the high, regaining a southerly component by late morning as the high shifts to the NE.
SW winds may gust around 15 kts as a warm front lifts north.
A warm front approaching the region on Sunday will increase the risk for showers and storms over the western counties Sunday afternoon with more widespread coverage Sunday night. Fair and dry tonight with ridge. Warm front approaches Sunday. Showers more widespread Sunday night with warm frontal passage.
The upper ridge axis should continue to build across much of the SE states Sun/Mon, with afternoon highs both days climbing well into the mid/upper 80s.
upper low will glance by to the northwest as it moves into western WY today. Winds should mix down into the lower elevations by afternoon with RHs dropping below critical thresholds resulting in widespread Red Flag Conditions across much of southern CO. Higher elevation areas may not quite meet RH criteria, but noticed yesterday that RHs overachieved on the drier side of guidance, even across the higher elevations, so it is likely to happen again today. Otherwise, no other changes to the highlights as the rest of the package looked on target. Cold front will make a southward surge through southern Colorado late this evening through the overnight hours. Should see low clouds spread across the plains towards sunrise, mainly along the Palmer Divide and northern slopes of the Raton Ridge towards morning.
213 PM MDT Sat May 23 2020 Upper level analysis has the forecast area in southwest flow, with an upper low over western Wyoming/eastern Idaho and another low further north over Canada. Both of these upper lows are creating a long wave trough down the Rockies, allowing Pacific moisture to stream up from the southwest. Sunday will be breezy and cooler with some showers possible due to cold advection aloft.
An upper trough will moves into Colorado on Sunday, with its axis progged just of the western CWA border by 00Z Sunday afternoon. A cold front will move southward across the forecast area this evening.
1146 AM MDT Sat May 23 2020 Overnight WV imagery showed upper low pressure centers over western IA and northwest UT. The forecast concern today will be convective coverage and intensity with influence from the upper trough to the west and surface front slowly moving through the CWA. Difluence aloft will increase through the day, with scattered showers and thunderstorms developing along the front and moving into the high plains where instability (SBCAPE 1000-1500 j/kg) and 0-6 km shear (35-40 kt) favor discrete supercells capable of producing hail up to 1. Cool and unsettled weather will prevail Sunday and Memorial Day with the passage of a upper level low pressure trough.