Aikyam-Lab/Synoptic-Bench huggingface dataset:
152 PM PDT Tue Apr 25 2023 Patchy cloud cover will persist across portions of the coast and western valleys this afternoon, but the marine layer will weaken slowly as a building ridge centers over the West Coast this week. Warmer across inland areas today, with noticeable warming for all areas on Wednesday.
Broad troughing will continue across the area with quasi-zonal flow aloft.
201 PM EDT Tue Apr 25 2023 A nearly stationary upper level low pressure remains over the region today and Wednesday, bringing chilly conditions and scattered showers. Brief high pressure and drier conditions builds in towards the end of the week, but another upper level disturbance will bring showers back into the region this weekend. Upper level low will keep its grip over the region through the period. 330 AM Update: The upper level low finally exits the area Wednesday night as a ridge starts to build in. With light winds and high pressure moving overhead, radiational cooling will allow for seasonably chilly temperatures, with lows expected to be in the upper 20s to mid 30s.
351 PM CDT Tue Apr 25 2023 The Northern Plains sit under weak northwest flow aloft this afternoon, with high pressure from the northern Red River Valley into southwest Ontario maintaining a cool and dry east-southeasterly surface flow. The resulting southerly breeze across western and central North Dakota will keep overnight temperatures slightly warmer, with most of the western half of the state remaining above freezing. A few hundred J/kg of CAPE is forecast over southeast North Dakota during the afternoon, where a stronger storm or two cannot be ruled out given a low freezing level just slightly above the LFC, inverted-v soundings, and modest effective shear. A more well mixed boundary layer will actually allow for warmer temperatures on Wednesday, with highs in the mid 50s to mid 60s.
The main reason for additional lines is due to wind direction changes expected as high pressure moves out of the region. Tonight into Wednesday morning, expect lows to range mainly in the low to upper 50s north of I-10, with upper 50s to low 60s south. Highs on Wednesday will range in the low to mid 80s inland, with mid to upper 70s at the immediate coast.
1224 PM PDT Tue Apr 25 2023 A significant warming trend will occur through the weekend as high pressure builds, taking afternoon highs well above normal. The upper-level ridge of high pressure remains centered offshore but has nudged closer to the coast. This ridge will begin to push further eastward by Wednesday, and temperatures will continue on an upward trend. Much warmer temperatures are expected later this week as the high pressure ridge moves inland.
201 PM CDT Tue Apr 25 2023 (Issued 201 PM CDT Tue Apr 25 2023) Tonight through Wednesday night: The troughing pattern will hang on across the area through Wednesday.
At the surface widespread southeasterly flow was in place as low pressure continued to develop over the Rockies. Weak subsidence/short wave ridging has likely inhibited much of today's rainfall as forcing not able to overcome inversion due to aforementioned ridge.
335 PM EDT Tue Apr 25 2023 A nearly stationary upper level low pressure remains over the region today and Wednesday, bringing chilly conditions and scattered showers. Brief high pressure and drier conditions builds in towards the end of the week, but another upper level disturbance will bring showers back into the region this weekend. Upper level low will keep its grip over the region through the period.
/Tonight through Tuesday/ Key messaging highlights: * Another round of Frost/Freeze headlines in susceptible areas overnight * Dry and warmer midweek * Late week rain chances, then turning cooler The main weather story initially will be another round of cool temperatures with overnight lows either side of freezing. With mostly clear skies overnight, and light winds associated with western Great Lakes high pressure, conditions will be fairly good for efficient radiational cooling overnight. Thus for susceptible areas where the growing season as progressed sufficiently (generally Highway 20 and south) have issued a Freezing Warning where much of the county will see <=32F and a buffer of Frost Advisory where mins should be several degrees higher.
249 PM CDT Tue Apr 25 2023 Broad upper level trough extends from the Upper Midwest eastward through New England. Otherwise, at the surface a weak cold front, just north of I-70, will continue to slowly sink south across the region exiting the forecast area by daybreak on Wednesday. On the backside of the system, weak CAA will build in with lows a bit cooler than last night, in the upper 30s to mid 40s. On Wednesday, the upper level trough will slide off to the east allowing an upper level ridge to build over the western CONUS.
With skies clearing, calm winds, and high pressure centered over eastern Kentucky, it is a good bet temperatures will make it low enough for frost to develop late tonight into early Wednesday morning. Consequently, our typically colder valley locations are expected to fall into the low to mid 30s late tonight into early Wednesday morning. A surface boundary (cold front) will sink southeast during the short term as well, reaching into eastern Kentucky by the end of the period.
404 PM EDT Tue Apr 25 2023 A nearly stationary upper level low pressure remains over the region this evening into Wednesday, bringing cooler conditions and scattered showers. Brief high pressure and drier conditions builds in towards the end of the week, but another upper level disturbance will bring showers back into the region this weekend. Upper level low over Canada keeps conditions cooler over the region. Moisture associated with the low will continue to support scattered rain showers this afternoon. Southerly winds advect warmer air resulting in a slight increase of temperatures tomorrow. Wednesday night will be dry and slightly cooler.
Instability is generally weak across the region with the exception of the lower CSRA and far southeastern Midlands where some thunder is possible. Overnight lows expected to be in the lower to mid 50s. Northeasterly flow will keep temperatures below normal for late April with forecast highs in the lower to mid 70s. Overnight lows will generally be in the lower to mid 50s.
Snow showers have ended this morning in southwest Montana and Global Models are showing signs of a blocking pattern developing in the Northern Hemisphere.
247 PM CDT Tue Apr 25 2023 Broad upper level trough extends from the Upper Midwest eastward through New England. Otherwise, at the surface a weak cold front, just north of I-70, will continue to slowly sink south across the region exiting the forecast area by daybreak on Wednesday. On the backside of the system, weak CAA will build in with lows a bit cooler than last night, in the upper 30s to mid 40s. On Wednesday, the upper level trough will slide off to the east allowing an upper level ridge to build over the western CONUS.
As the upper low that brought yesterday's active weather continues to track southeastward, a ridge of high pressure will build in over Idaho through the duration of the short-term period. Widespread morning lows tomorrow will remain above freezing, with mountains reaching as low as the 20s and mountain valleys running a few degrees below freezing.
A ridge will bring warming temperatures to the area through this weekend. Today and Wednesday North to northwest winds will continue into tomorrow evening as a ridge of high pressure slowly moves onshore.
Many Valley locations will reach the low 90s beginning mid-week.
Wednesday, high pressure will be over the area with plenty of sunshine and light winds.
252 PM CDT Tue Apr 25 2023 Models show an upper level low sitting over Colorado today, moving over the Oklahoma/Texas panhandles by Wednesday afternoon.
At the surface, weak surface ridging was beginning to lose its influence to a stronger pressure gradient building in from the northeast as high pressure builds into the Great Lakes. This is typically a cooler regime and in this case, with 1000-850mb heights slightly lower, we'll probably see similar to slightly cooler temperatures tomorrow compared to today.
Pattern Synopsis/Forecast: Upper troughing continues to pinwheel across the region this afternoon through tonight. Combination of enhanced moisture convergence along this trough and passing mid- level energy helped to produce morning rain/snow showers, with additional afternoon scattered to numerous showers driven largely by solar insolation, steep low-level lapse rates and secondary passing mid-level perturbation. Quick loss of low-level instability and building high pressure will bring a return of dry conditions tonight. As was alluded to above, quick loss of diurnally driven instability and upstream high pressure further building into the area will bring a return to dry conditions heading into at least the first half of tonight (perhaps some isolated flurries/sprinkles return late overnight?). If clouds are able to clear more aggressively, lows likely to fall a few degrees farther than this, especially across the typically cooler/interior locales.
There will also be some tornado risk in the vicinity of the warm front. Again, tornadoes will be possible in the vicinity of the warm front tomorrow--the biggest question is where that front will be.
Clouds will filter in from west to east and keep lows a touch warmer than the previous forecast, in the mid to upper 30s. WAA at the 850 mb level supports the warmer air at the surface, as it increases into the 2 to 4 degrees C range. Winds turn southerly while a weak upper ridge moves overhead Wednesday. With the low temperatures for Wednesday night in the 40s, that precipitation should remain liquid.
(Tonight) Cloud cover will steadily increase this evening and especially overnight as an area of low pressure approaches the Tennessee Valley.
The showers will be caused by subtle conditions, including an inverted trough that extends N into the area from WY, areas of jet divergence, and energy moving through the SE zones. Arthur Upper level low over SE Idaho early this morning will take a more southerly track today into UT/CO, meaning less precipitation today compared to previous forecasts and a quicker end to precipitation in general. With less precipitation and cloud cover expect temperatures to be a bit warmer as well.
Dry and much warmer weather is forecast late in the week and into the weekend, with high temperatures 10 to 15 degrees above normal. For the remainder of the week high pressure will build over the area with warming temperatures, breezy winds and dry conditions. The shower threat will end by mid evening as the current trough head eastwards. During the course of the night look for winds, behind the trough, winds will shift to northerly at 5 to 15 mph over much of the area but become locally gusty to 10 to 20 mph with gusts to 30 mph from the Mogollon Rim southward.
607 PM CDT Tue Apr 25 2023 Broad upper level trough extends from the Upper Midwest eastward through New England. Otherwise, at the surface a weak cold front, just north of I-70, will continue to slowly sink south across the region exiting the forecast area by daybreak on Wednesday. On the backside of the system, weak CAA will build in with lows a bit cooler than last night, in the upper 30s to mid 40s. On Wednesday, the upper level trough will slide off to the east allowing an upper level ridge to build over the western CONUS.
Another zone of heavier precipitation with possibly some thunderstorms mixed in is expected to reinvigorate tonight across parts of southeast Oklahoma within the warm advection regime as the low level jet intensifies. Instability remains rather meager as the primary warm front remains along and south of the Red River, but some elevated instability could lead to a few stronger storms with the possibility of some isolated small hail south of I-40 with the stronger cores.
Surface dewpoints have warmed from the 30s to the lower 50s, as the sub-cloud column has moistened.
Given the increase in cloud cover coupled with the veering winds, lows will also trend around 10F warmer compared to this past morning, with temps falling mainly into the upper 40s/near 50F for most spots.
MH (Issued 201 PM CDT Tue Apr 25 2023) Tonight through Wednesday night: The troughing pattern will hang on across the area through Wednesday.
715 PM EDT Tue Apr 25 2023 High pressure will be overhead today, followed by a series of upper level disturbances that will pass across the region for the second half of the week.
Strong ridging has begun to build over the area, brining clear skies throughout the interior with highs in the mid 80s.
The Northern Plains sit under weak northwest flow aloft this afternoon, with high pressure from the northern Red River Valley into southwest Ontario maintaining a cool and dry east-southeasterly surface flow. The resulting southerly breeze across western and central North Dakota will keep overnight temperatures slightly warmer, with most of the western half of the state remaining above freezing. A few hundred J/kg of CAPE is forecast over southeast North Dakota during the afternoon, where a stronger storm or two cannot be ruled out given a low freezing level just slightly above the LFC, inverted-v soundings, and modest effective shear. A more well mixed boundary layer will actually allow for warmer temperatures on Wednesday, with highs in the mid 50s to mid 60s.
Expect temperatures to drop to near freezing north of I-74, with areas of frost expected over much of central Illinois.
640 PM CDT Tue Apr 25 2023 (Tonight) Cloud cover will steadily increase this evening and especially overnight as an area of low pressure approaches the Tennessee Valley.
The variability in flow appears to extend upwards to 850 mb with broad and transitions to broad weak ridging by 700 mb.
440 PM MDT Tue Apr 25 2023 Current Water Vapor and upper air models show an upper Low sitting over the four corners region.
Dry and sunny conditions will persist over western Washington this afternoon as a ridge resides over the Pacific Northwest.
Occluded troughing to our north remains quasi-stationary and we have remained under fairly zonal flow from 250mb down to 700mb; a broad moisture gradient seen in the PWAT fields continues to align across the deep south. Temps overnight will broadly fall to where they have been the last few nights, in the low 50's. Northeasterly flow will keep temperatures below normal for late April with forecast highs in the lower to mid 70s. Overnight lows will generally be in the lower to mid 50s.
The lower high temps are expected over western portions of the state, where precipitation and cloud cover has been more persistent. A closed upper low will dig southeastward into the south-central states Wednesday, where a surface cyclone will become more organized. High temps by Thursday will be in the lower 60s to the mid 70s, with lows that morning in the upper 40s to upper 50s.
248 AM CDT Wed Apr 26 2023 Low pressure is organizing in Northwest Texas early this morning while an upper low is positioned to the northwest in New Mexico. The narrow Midwest ridging will steer the low northeastward through the Quad State tomorrow afternoon and evening, with shower chances peaking in the categorical range.
314 AM EDT Wed Apr 26 2023 A very weak east-west cold front will slowly slip southward across Kentucky today, accompanied by partly cloudy skies and light breezes from the north and northeast.
1036 PM CDT Tue Apr 25 2023 Broad upper level trough extends from the Upper Midwest eastward through New England. Otherwise, at the surface a weak cold front, just north of I-70, will continue to slowly sink south across the region exiting the forecast area by daybreak on Wednesday. On the backside of the system, weak CAA will build in with lows a bit cooler than last night, in the upper 30s to mid 40s. On Wednesday, the upper level trough will slide off to the east allowing an upper level ridge to build over the western CONUS. Then as the initial system exits into the Ohio Valley, the weakening upper level trough will lift northeast through the region with another round of rain Thursday evening, before tapering off late Thursday night.
Temperatures were responding with rises into the pleasant but cooler than normal 60s. Temperatures will be cooler than normal tonight, although not as cool as the past couple of nights. Highs tomorrow will be similar to today, or a little warmer, just depending on the thickness of the clouds and how many showers impact a given location. Generally, our north counties will be on the warmer side with very low rain chances as the frontal zone stays over our southern counties. For Wednesday night, the low pressure system will move east to the Mid Ms Valley, lifting a slug of deep moisture into Middle Tennessee. Showers will be likely throughout Thursday as the low pressure system moves into Tennessee. Showers and a few thunderstorms will linger into Thursday night as the broad, weakening low pressure system completes its path across the area.
340 AM EDT Wed Apr 26 2023 A couple of mid and upper-level disturbances will move east across NC this afternoon and evening, while high pressure will otherwise extend across the state through Thursday. A closed mid/upper level low over the Southern Rockies will advance eastward into the Southern US Plains by Thursday morning. Downstairs, weak high pressure will remain in place. The closed low over the Southern Plains is forecast to open up as it lifts north into the Mid-MS Valley Thursday night. Rain chances look quite low as available forcing and instability across central NC remain weak, with low-amplitude s/w ridging through the region. Under mostly cloudy skies, highs in the lower 70s north to mid 70s south.
After a brief respite, a compact closed low wl be apchg AR fm the west heading into tngt. By Thu/Thu night, the aforementioned upper low is progged to bcm an open wave as it passes acrs AR.
Given a drier trend, have temperatures a tad warmer, with highs ranging from the mid 60s east to around 70 west, with easterly winds of 5-10 mph.
1034 PM MDT Tue Apr 25 2023 Current Water Vapor and upper air models show an upper Low sitting over the four corners region.
Would expect this activity to persist through the remainder of the night and into morning hours in some form as the low level jet impinges on the area.
to the south a warm ridge rises out of the Baja along the California coast into southern Oregon. Today: As the first disturbance exits weak meso-ridging will bring partly cloudy skies to region through the afternoon hours. Tonight through Thursday: The second disturbance will arrive and kick out the meso ridge by the late evening. A low pressure system, will spin up over southern Alberta and northern Montana and drag a cold front along behind it.
One more night of lows near freezing is anticipated tonight.
1236 AM PDT Wed Apr 26 2023 A significant warming trend will occur through the weekend as high pressure builds, taking afternoon highs well above normal. Clear skies and warm temperatures will be the story this week as a ridge of high pressure will build over the west coast. The higher elevations of the Sierra Nevada, even above 8,000 feet, will also be above freezing throughout later this week into the weekend, and this will enable more snowmelt. Temperatures are expected to dip back to below average for this time of year as our ridge of high pressure moves eastward and a trough pushes inland. With the cooler air comes gusty surface winds, especially for our Kern County zones.
[Key Messages] 1) Freeze Warning and Frost Advisory continue through mid-morning 2) Quiet with below normal temperatures today and tonight [Discussion] Freeze Warning and Frost Advisory will expire at 800 AM this morning, with most site dropping into the low to mid 30s. On Thursday, southerly flow will make a return to the area behind the high thanks to a northward moving warm front.
243 AM MDT Wed Apr 26 2023 Current Water Vapor and upper air models show an upper Low sitting over the four corners region.
As the upper low dips further south, the overall the brunt of the forcing will continue to shift into southeast Colorado and away from northern Colorado. Models have upper ridging over the CWA early on Thursday, then northwesterly flow aloft through the day.
249 AM MDT Wed Apr 26 2023 There is currently a low pressure located over the CO/NM state line, which is expected to continue tracking southeastward today. In the wake of the low pressure northeasterly flow and residual moisture have kept snow showers going most of the evening. This will result in slightly warmer highs compared to yesterday. Tomorrow attention turns to a potent trough that will drop out of southern Canada. A sharp cold front will accompany this system. Showers and storms will develop along and behind the cold front, which does not move in from Wyoming until around sunset. The last several model runs have nudged this trough further west as it drops over eastern Utah and western Colorado.
400 AM EDT Wed Apr 26 2023 High pressure will build into the Ohio Valley today, providing dry conditions and below normal temperatures.
An upper level low will move south out of southern Colorado and into northern New Mexico this morning, then swing eastward through the TX/OK panhandles this afternoon. Winds then shift back to the southeast by tomorrow afternoon as lee troughing develops across eastern Colorado.
The higher coverage of activity will likely occur north and east of the CWA where mid level jet energy will play more of a roll. All this energy aloft will eventually result in a deep eastern upper CONUS trof, but somewhat delayed from previous forecasts.
Temperatures this afternoon could reach the 60s along the Buffalo Ridge, with low to mid 50s generally expected elsewhere.
(Today through Thursday afternoon) Current observations show a cold pool enhanced cold front is moving into southeastern New Mexico with very gusty winds along the leading edge of the front. Winds backing around from the west will downslope off the higher terrain causing a quick rebound in temps with highs tomorrow actually being similar to today despite the cool morning.
157 AM EDT Wed Apr 26 2023 A couple of mid and upper-level disturbances will move east across NC this evening and again Wednesday afternoon and evening, while high pressure will otherwise extend across the state through Thursday. Another short wave trough is expected to cross the region Wednesday. Expect cloud coverage for most of the day with highs in the low 70s, and lows hovering around 50.
Precipitation will begin tapering off after sunset, and should mostly end by midnight as the closed low moves farther south into northern New Mexico. Transitory ridging will take over for Wednesday, leading to clearer skies and near seasonal temperatures for the majority of the area. However, this brief ridging will be followed by a quick-hitting Canadian trough on Thursday. A strong cold front and widespread precipitation will accompany the system as it digs into the northern Great Plains.
1232 AM CDT Wed Apr 26 2023 Key Messages: - A cold front will bring showers and thunderstorms to Nebraska Thursday afternoon into Thursday night.
Discussion: Quasi-zonal flow aloft over the region will begin to transition as low amplitude short wave ridging ahead of an approaching upper low will build over the region late today into tonight. Temperatures will be warmer north than south today given the precipitation coverage further south.
Chances may also be locally higher along the ridges with the aid of orographic influences. Daytime highs will remain around 10 degrees below climatological normals with a pesky upper low continuing to reinforce cooler air aloft in west- northwest flow. Sub-freezing dewpoints and effective radiative cooling may allow much of the region to drop near or below freezing during the overnight period. Late Thursday night, rain will be possible with warm frontal forcing as the gulf low enters the area. Southeast flow orthogonal of the ridges will be supportive of mountain wave development.