Aikyam-Lab/Synoptic-Bench huggingface dataset:
352 AM EDT Thu May 1 2025 Dry conditions persist through most of today as high pressure slowly departs to the east. Weak upper level ridging will remain overhead into this afternoon resulting in continued dry conditions under a partly cloudy sky. Surface flow turning southerly will allow for a warmer afternoon with highs reaching the 60s and 70s. On Friday, the warm front will lift to the north placing our region within the warm sector. A pressure trough will approach from the west during the afternoon hours. While upper level forcing weakens during the day, a warmer and more humid air mass (precipiable water values increasing to +1 to +2 STDEV) combined with some weak instability (MUCAPE between 500-1000 J/kg) could be enough to generate at least scattered rain showers and isolated thunderstorms, mainly during the afternoon hours.
1200 AM CDT Thu May 1 2025 To begin the period, an upper level trough continues to push east and northeast from the Central Plains bringing with it the chance for strong to severe thunderstorms.
Advertised warm up this weekend is still on tap as 500 mb ridging builds north of an eastward moving 500 mb low over the southwestern U. and north of an upper low stalled out over the Ohio Valley.
1248 AM EDT Thu May 1 2025 * Scattered thunderstorms with gusty winds and locally heavy downpours Thursday afternoon and evening * Periods of showers on Friday followed by growing confidence in an increasingly wet pattern through the first week of May Mainly clear now with only the high clouds, but some lower clouds nudging into the far NW and will likely slide along the nrn border. Upper ridging will begin to erode on Thursday as a trough over the High Plains moves into the northeast US.
At the same time a synoptic cold frontal boundary will approach our northern counties later tonight.
A broad area of high pressure centered just west of Bermuda continues to flex its influences across the region. This is due to an upper level trough impinging on a deep layer ridge that is parked across the western North Atlantic and the eastern half of the Gulf. This will be the only effects we will see in the short term from this feature as the ridge will hold firm for now. First, the low level flow will break down and we will go into a col regime. An upper level trough will become quasi-stationary across the eastern half of the U.
A upper trough moving down the central plains will bring another round of precipitation tonight (primarily after 10pm), lingering into Friday morning.
Overnight tonight, an upper level trof axis is progged to push east northeast through the region which could spark a few showers/storms across the CWA.
Upper flow remains out of the southwest with ridging over the Atlantic. Stalled frontal boundary over our region will also push north today as a warm front. Highest confidence of storms will be across the mountains west of the Blue Ridge, with coverage of storms decreasing east of the mountains.
1111 PM EDT Wed Apr 30 2025 * Scattered thunderstorms with gusty winds and locally heavy downpours Thursday afternoon and evening * Periods of showers on Friday followed by growing confidence in an increasingly wet pattern through the first week of May Mainly clear now with only the high clouds, but some lower clouds nudging into the far NW and will likely slide along the nrn border. Upper ridging will begin to erode on Thursday as a trough over the High Plains moves into the northeast US.
114 AM EDT Thu May 1 2025 High pressure will build in from the west tonight and crest over the area Thursday. Low pressure approaches on Friday and will remain over the state through the weekend. High pressure building in tonight will continue to bring dry air through the region. By later tonight, the tightened gradient from the retreating low pressure system will have relaxed and winds will decrease. Thursday night, low pressure will approach from the west and increase the chance for showers. Friday afternoon, low pressure will move northward along the western state border, and by Friday night the first round of precipitation will be over with.
Assuming the overall environment can recover from early morning precipitation and the prevailing cloud shield can dissipate, diurnal mixing should be sufficient to allow for shower and thunderstorm development during the late afternoon hours with damaging winds and large hail being the highest threat with some storms. Conditions forecast to improve with the loss of daytime heating this evening, with showers and thunderstorms again returning from the northwest late tonight into Friday as an upper-trough swings southeast across the midwest. A lingering surface boundary across the region will serve as the focus for convection on Friday afternoon and evening as lapse rates steepen with the approach of the upper trough. /05/ (Friday Night through Thursday) Northwest flow to increase aloft ahead of building upper-level ridge from the west.
19Z water vapor imagery showed an upper trough over west TX with an MCV moving east along the Red River Valley. Another upper trough was noted along the northern high plains with a narrow upper ridge off the west coast. Surface obs showed a trough of low pressure along the lee of the Rockies with a local mesoscale high over north central KS thanks to clouds and precip. The first of these waves moves east overnight as the west TX trough moves into MO. Looks like there could be a brake from the forcing during the day Thursday as a surface cold front moves southeast and some dry air advects in from the northwest. Concerns for severe weather remain on the low side.
* A spring low pressure system will provide cooler temperatures, breezy winds, and rain/mountain snow showers this weekend. In Mono County, enough lingering moisture may remain to support a few afternoon rain showers, with around a 15% chance of an isolated thunderstorm, mainly along the Sierra crest south of Bridgeport. Conditions will deteriorate over the weekend as another spring low pressure system moves across the Sierra and western Nevada.
Some small rain/thunder probs will exist near the KS/MO borders closer to the central CONUS upper trough and colder temps aloft. Ridging centered over the Pac NW coast currently will shift east over the northwest CONUS. Rising surface pressures down the High Plains will force a cold front south into OK tonight.
An U/L ridge will hold over the Florida peninsula for the next couple days. The overall L/W pattern across the CONUS will gradually transition through the period from a high amplitude pattern to a blocking pattern.
1243 AM EDT Thu May 1 2025 High pressure will build in from the west tonight and crest over the area Thursday. Low pressure approaches on Friday and will remain over the state through the weekend. High pressure building in tonight will continue to bring dry air through the region. By later tonight, the tightened gradient from the retreating low pressure system will have relaxed and winds will decrease. Thursday night, low pressure will approach from the west and increase the chance for showers. Friday afternoon, low pressure will move northward along the western state border, and by Friday night the first round of precipitation will be over with.
- Warmer this weekend with highs reaching the 70s. High pressure was located off the eastern coast of Florida. Ridging extended north into the Mid- Atlantic states. North of this feature, ridging was present from just off the coast of Oregon, north into northern British Columbia. At the surface tonight, a cold front had passed through the forecast area and was oriented from around Norfolk to Concordia. Temperatures will be cooler behind the exiting system Friday with highs in the lower 60s. Looking forward over the next 7 to 10 days, Friday night appears to be the last opportunity for freezing temperatures across the area.
First along a cold front from Aberdeen to Pierre and points east this afternoon (40-70% chance for showers). Otherwise, will freshen up sky/wind details through 12Z, while generally letting the lows in the 40s ride in the current forecast. Flow ahead of this feature is southwesterly allowing for temperatures to overachieve, and also bringing in some "higher" dewpoints in the low to mid 40s. When the period opens Friday morning, a highly amplified positive PNA blocking pattern (upper ridge west/upper trof east) is over the CONUS, with this CWA starting off in northwest flow aloft.
1258 AM CDT Thu May 1 2025 The upper ridge shifts eastward through tonight in response to a medium amplified upper trough exiting the southern Rockies and out over the southern Plains. The upper trough exiting the southern Plains late tonight will pass over the lower Mississippi River region and southeast states on Thursday while deamplifying. High temperatures look to mostly be in the lower to mid 80s Thursday.
1214 AM CDT Thu May 1 2025 Updated at 1213 AM CDT Thu May 1 2025 - After a warm and dry Thursday, a cold front brings the return of cooler temperatures and rain chances to end the week. Stay tuned for updates! (This afternoon through Thursday night) WV imagery this afternoon shows an upper trough entering our CWA, for another round of convection this afternoon. 12Z KMAF raob came in w/deep-layer shear of almost 70 kts, and CAMs keep this going this afternoon w/40-60 kts rounding the base of the trough.
In the low and mid-levels, ample moisture resides. CAPE looks very limited with this system but the combination of cooler air aloft and modest heating should yield several hundred to perhaps 500 J/kg of SBCAPE. At the surface, high pressure will move through the region and in the upper-levels, ridging will spread east into the middle of the country.
Earlier this morning, an upper level trough was positioned over central Kansas and Oklahoma, while a northern branch upper-level trough was moving south across the Northern Plains. At the surface, a cold front was crossing southwest Kansas, with scattered thunderstorms developing along the boundary. This cold front will move into Oklahoma and central Kansas by daybreak. This dry weather however will be short lived as increasing cloud cover and a renewed chance for showers and thunderstorms are expected by early evening, coinciding with the approach of the northern branch upper trough into the Central Plains. Thunderstorms will be likely (60-70%) early tonight west and south of the Dodge City area, as the upper level trough crosses the west central High Plains.
- Sharply cooler Friday through the weekend. Departing high pressure over Lake Huron still has our dew points in the upper-30s to near 40. The best corridor of low- and mid-level RH values is confined to primarily the western half of the forecast area, likely due to the lingering influence of the aformentioned high pressure. The cold front moves through around sunset resulting in decreasing POPs thereafter. A secondary trough rotates through Friday bringing a reinforcing dose of showers and cold air.
Temperatures will trend warmer and rise to several degrees above seasonal averages until late this week. An upper-level disturbance will provide at least a slight chance of showers and thunderstorms to mainly the higher terrain, including the West Side Hills, Kern County mountains, and the Sierra Nevada today and Thursday. We'll likely get some more buildups today as well as a slight chance for showers and thunderstorms by this afternoon for the higher peaks of the West Side Hills (such as towards Santa Rita Peak and Joaquin Ridge near Coalinga) and parts of the Sierra Nevada. 50 inch of precipitation in the Sierra Nevada and adjacent foothills and several inches of snow in the higher elevations of the Sierra Nevada.
341 AM EDT Thu May 1 2025 High pressure across the region will continue to bring dry conditions through much of the day. Will have increasing chances for precipitation overnight as warm front moves into the area. Still looks like we could have a break in the precipitation Friday morning, especially across Vermont, but as cold front approaches the area will have additional showers with possible thunderstorms later in the day Friday especially across southern Vermont. Low temperatures will be tricky and highly dependent on where the front stalls, but thinking it will be cooler for northern New York on the cold side of the front with lows in the mid to upper 40s, and warmer for much of Vermont with lows in the upper 40s to mid 50s.
Slightly cooler overnight low temperatures are expected tonight, mainly in the 50s. By Thursday, high temperatures will look to only reach into the 80s across the Big Country, with elsewhere seeing high temperatures in the low to mid 90s.
Flow pattern will then briefly transition to western CONUS ridging, with a warming/drying trend through the weekend. Showers will shift east and end tonight with dry air advecting into the region under sfc ridging. Long wave upper trough will then build into western NOAM this weekend with the thermal ridge shifting east.
206 AM EDT Thu May 1 2025 (Today through Friday) Mid level ridge centered over FL and just off the SE Coast continues to be suppressed as energy swings through the base of the trof to the west of the area over the southern plains. While much of the main energy lifts northeast into the Great Lakes, there is enough of a push to drag a boundary/pre-frontal trof into NW GA by late afternoon Thursday.
Fairly standard weather continues through Friday with warm inland temperatures and cooler, cloudy weather in the marine layer.
735 AM EDT Thu May 1 2025 High pressure across the region will continue to bring dry conditions through much of the day. Will have increasing chances for precipitation overnight as warm front moves into the area. Still looks like we could have a break in the precipitation Friday morning, especially across Vermont, but as cold front approaches the area will have additional showers with possible thunderstorms later in the day Friday especially across southern Vermont. Low temperatures will be tricky and highly dependent on where the front stalls, but thinking it will be cooler for northern New York on the cold side of the front with lows in the mid to upper 40s, and warmer for much of Vermont with lows in the upper 40s to mid 50s.
A potent weather system will then affect the Desert Southwest by this weekend, bringing increased winds, much cooler temperatures, and even some rain chances across portions of the area. Early morning water vapor satellite imagery shows a weak upper-level low situated near the southern CA coastline with upper-level ridging building over the Pacific northwest. However, it will not result in any noticeable weather impacts other than keeping upper-level height fields from rising as a result of the ridging pattern across the Pacific Northwest and Intermountain West Region. Therefore, temperatures through the next couple of days will remain steady state as afternoon highs hover in the low to mid 90s across the lower deserts.
This may also lead to slightly cooler temperatures in the Fox Valley and lakeshore than previously forecast (not reaching the 70s).
High pressure over the region today will promote warm and dry conditions across western Washington.
Moisture begins to increase tomorrow into the weekend as a weak cold front works its way over FL.
- A warmup is expected this weekend, with high temperatures in the low 80s, 10-15 degrees above normal. These showers move south on Friday as the upper trough digs deeper into the Plains.
(Today through Friday) Mid level ridge centered over FL and just off the SE Coast continues to be suppressed as energy swings through the base of the trof to the west of the area over the southern plains. While much of the main energy lifts northeast into the Great Lakes, there is enough of a push to drag a boundary/pre-frontal trof into NW GA by late afternoon Thursday.
The end of the work week will be pleasant for the Silver State as high pressure builds over the area Thursday into Friday. Warmer temperatures through Friday thanks to southerly winds are in store for the region, but change is coming in the form of a strong weather system that will be precipitation back to Nevada this weekend.
A cold front approaches late Friday into Friday evening with a chance of showers and slight chance of thunderstorms near the Cascades and eastward, including northern California.
- Warmer and pleasant weekend for most of the area. As the cold front moves in from the west, fog is expected to dissipate. The cold front will continue to track across the area this morning causing winds to become northwesterly. A pattern change comes in for the weekend, with upper level ridging building in. This will bring warmer return flow to the area.
A few showers will continue across southern Utah today where a cold front has stalled.
Overnight, winds managed to briefly surge to breezy conditions across the Lower and Middle Keys, but are slackening back down to near 15 mph. The conclusion for the day is persistence with little change to the forecast; dry, occasionally breezy, and highs in the low to mid 80s. From synopsis, a broad high pressure located west of Bermuda will continue to influence our winds through the next couple of days. An approaching low pressure system moving through the Great Lakes region this weekend will weaken the pressure gradient across our area and lead to a brief lull in winds.
Chances for rainfall will increase Friday and Friday night ahead of an approaching cold front/boundary.
254 PM EDT Thu May 1 2025 High pressure offshore will continue to bring dry weather and above normal temperatures through Friday.
352 PM EDT Thu May 1 2025 Low pressure will approach tonight then track north of Maine Friday.
Will have increasing chances for precipitation overnight as warm front moves into the area. Still looks like we could have a break in the precipitation Friday morning, especially across Vermont, but as cold front approaches the area will have additional showers with possible thunderstorms later in the day Friday especially across southern Vermont. Low temperatures will be tricky and highly dependent on where the front stalls, but thinking it will be cooler for northern New York on the cold side of the front with lows in the mid to upper 40s, and warmer for much of Vermont with lows in the upper 40s to mid 50s.
Models indicate the center of this low will be over ND/MN border by 00Z Friday, with the cold front draping horizontally from it through ND into MT. Through the overnight, the center of the low will track east/southeast through MN and over northern WI by 12Z Friday. Its cold front will push southeast through the CWA and exit the area by the late morning or so.
(This evening through Friday night) Looking at the upper levels, troughing in a general sense is in place from the Great Lakes to the Rockies in the northern half of the Country. The effects on local weather mainly comes from lack of ridging subsidence, moisture increase from southerly flow and daytime highs in the mid 80s.
Temperatures across the island chain are in the low to mid 80s with dew points in the upper 60s. Over the Great Lakes, a mature low pressure system is making its way towards eastern Canada. Tonight, the Great Lakes low will suppress the high and allow it to further weaken and shift eastward. Synoptic scale troughing will develop over the eastern CONUS and slacken breezes to gentle over the CWA.
Cloud cover and northwest flow will keep temperatures cooler tomorrow in the 60s for highs.
154 PM PDT Thu May 1 2025 A weak low pressure system moving through southern California will bring a slight chance of showers and thunderstorms for this afternoon for southwestern San Bernardino County. A low pressure system from the northwest will move into southern California this weekend, bringing gusty winds, scattered showers and much cooler weather.
Weak flow throughout the night has kept warm saturated air around the area as a weak cold front approaches. Another trough moves through the region Friday. However, the more dynamic nature of this low coupled with a stronger kinematic front enables more widespread precipitation starting across northern KS tonight and reaching the western parts of our region around sunrise tomorrow. As the center of this low progresses along the MO/IA border during the afternoon residual showers and thunderstorms linger through the day, especially north of I-70. Ridging and northwest flow across the central CONUS and an omega block to the west brings seasonable and dry conditions for the weekend. As troughs and ridges progress over the cut off CONUS lows, they create small blocking patterns which interrupt the overall east to west rhythm across the CONUS.
Skies were mostly clear across the area this morning as upper level ridging builds in from the west.
Dry conditions today comes to end tonight as an approaching low pressure system arrives to the Great Lakes region bringing 40 to 60 percent chances of rain showers to eastern NY and western New England throughout the overnight hours.
- Warmer and pleasant weekend for most of the area. Otherwise, it'll be another cooler day with highs in the lower to mid 60s.
Down at the surface this approaching system is pushing a cold front currently across northern and western Oklahoma. Meanwhile yesterdays cold front stalled across northern Texas but is slowly lifting as a warm front increasing surface moisture back into our area. However, will expect convective initiation on the high plains of the northern panhandles later this evening as deep layer shear increases developing into an MCS with this complex tracking into northwest Oklahoma late in the evening toward midnight. Although the tornado potential will be low, will need to keep an eye southcentral & southeast Oklahoma near the jet where the low-level shear may be strongest.
FRIDAY: The broad upper trough will slowly pivot southeast overhead of the Tri-State area on Friday.
* A spring low pressure system this weekend will bring cooler temperatures, breezy winds, increased chances for showers and thunderstorms, and light rain/mountain snow showers. Friday will be the warmest day of the week before a low pressure system drops into the area from off the coast of Northern California. As the low pushes southward, the greatest precipitation chances shift to W NV Basin and Range through the rest of the weekend.
248 PM CDT Thu May 1 2025 - Rain ends overnight with clouds and cooler temperatures sticking around through Friday. It's been a dreary start to May with a cold front half way across Minnesota this afternoon. Sunshine and warmer temperatures return just in time for the weekend.
High pressure over the region with warm and dry conditions across western Washington.
An active weather day is expected tomorrow with the potential for severe storms increasing as a surface cold front pushes slowly into the region. Highs tomorrow should again reach the mid/upper 80s, with overnight lows dropping a few degrees as mild northerly winds behind the front bring in slightly cooler and drier air.
A low pressure system moving from the Great Lakes into Ontario and Quebec will weaken the aforementioned high and allow winds to diminish to gentle to moderate breezes late this weekend.
636 PM CDT Thu May 1 2025 (This evening through Friday night) Looking at the upper levels, troughing in a general sense is in place from the Great Lakes to the Rockies in the northern half of the Country. The effects on local weather mainly comes from lack of ridging subsidence, moisture increase from southerly flow and daytime highs in the mid 80s.
At the surface, a weak cold front is making its way across southeast KS and currently extends from Central MO into Central OK. At the same time, upper trough is forecast to dig off of the CA Coast and by Sun morning will be closing off over far Southern CA/Northern Baja. Confidence beyond the weekend still remains low with both ECMWF and GFS struggling with consistency with the two closed-off upper lows. Latest run of the GFS is more progressive with the western CONUS upper low and now swings across a vort lobe on Tue, producing fairly widespread rainfall. For now will go ahead and leave modest precip chances in for Tue-Thu as the upper low slowly migrates across the Plains.