Aikyam-Lab/Synoptic-Bench huggingface dataset:
As the low begins to pull away this evening showers will gradually come to an end with most areas expected to be dry by midnight. Warmer conditions will begin to filter into the area on Tuesday as the low continues to push eastward, but temperatures will still be roughly 10 degrees below normal for early May with highs forecast to be in the low to mid-50s. However, the clearing skies will allow temperatures to cool into the lower to mid 30s with some locations across far northern Illinois possibly dipping below freezing Tuesday night.
136 PM EDT Mon May 1 2023 (Through tonight) The tri-state region is under the influence of a large upper- level troughing pattern that will continue to hold, with deep west-northwest flow. Lows tonight will be in the low 50s north of I-10, mid 50s to the south, and upper 50s along the coast.
337 PM EDT Mon May 1 2023 Discussion/Marine -- Rain and snow expected tonight into Tuesday -- No major changes are expected to the forecast for tonight into Tuesday as an upper low slowly moves to the east through the Great Lakes region. Cellular rain showers are moving off to the southeast that popped up in a zone of partial clearing within the upper low circulation. Temperatures will be at or slightly above freezing tonight (32 to 38) so not expecting travel issues even where the snow will be more dominant. The zone of higher accumulations (1-3 inches with a few higher totals possible) will be on the higher ground across Central Lower Michigan near U.
145 PM EDT Mon May 1 2023 Low pressure tracks north of the area today then meanders over the Great Lakes before slowing moving over the northeast through the middle of the week. An upper level low then lingers over the area through the end of the week. High pressure begins to build in over the weekend.
Temperatures have climbed above freezing this morning and the freeze warning for today has been cancelled. Sub-freezing temperatures are expected to return to a majority of the local area tonight, and a Freeze Warning remains in effect from 1 AM through 9 AM CDT Tuesday. Key Messages: * Freezing temperatures this morning and again Tuesday morning.
Isolated showers and storms have developed this afternoon along the low level forcing near the weak frontal boundary draped across the FL/GA state border. Overnight lows will be around seasonable in the low 50s to low 60s.
* Sub-freezing are temperatures expected across much of the area overnight.
1240 PM CDT Mon May 1 2023 High pressure in control at the surface and dry, Northwesterly flow aloft yielding plenty of sunshine and very pleasant temperatures on this first day of May.
--Temperatures trend warmer to end the week. Temperatures remain on the cooler side this afternoon with highs only in the 50s to low 60s, despite the ample sunshine, thanks to the continued northwest flow/cold air advection with our mid to upper level flow still controlled by the expansive low over the eastern Great Lakes.
Not too far to the west, high pressure stretched across the northern Great Plains and western Mississippi River Valley. Unfortunately, not much movement in the upper level low is expected through tomorrow due to an omega block located over the Rockies, meaning a near repeat of today is expected tomorrow. Winds will remain rather breezy out of the northwest thanks to a tight pressure gradient between the low and high, but values will remain below advisory criteria with waning low to mid level winds.
Issued by National Weather Service Green Bay WI 257 PM CDT Mon May 1 2023 (Issued 256 PM CDT Mon May 1 2023) Tonight and Tuesday: The latest RAP analysis and satellite/radar imagery show the large cyclone continues to spin over the central and eastern Great Lakes. The center of the upper cyclone will shift slightly to the northeast over the next 24 hours. Cyclonic flow combined with thermal troughing will lead to a mostly cloudy and blustery day on Tuesday.
Overnight lows are expected to be a touch warmer tonight compared to last night. The upper low over the Great Lakes, and broad upper trough over the eastern CONUS, will gradually lift out in the coming days as features in the pattern shift east.
Quiet weather is expected through the work week as the upper level trough over the eastern U.
Our area is dominated by northwest flow from the troughing off to our east. This is causing gusty conditions along will cooler than normal high temperatures this afternoon. Otherwise we can expect sunny skies this afternoon with highs topping out in the low to mid 60s across the area.
314 PM CDT Mon May 1 2023 Currently, windy conditions are in place east of the Missouri River, particularly where the pressure gradient between high and low pressure has been tightest, mainly along and east of the James River Valley (observed 35 to 45 mph northerly gusts). An upper-level ridge will finally gain ground on the large and slow- moving stacked low over the Great Plains, and provide a period of much warmer temperatures across the Northern Plains.
1247 PM CDT Mon May 1 2023 (Rest of Today) A mid/upper-level cyclone centered across Lower MI this morning will shift slowly northeastward into adjacent portions of southern Ontario today, maintaining strong (75-80 knot) west-northwest flow aloft across the TN Valley.
Ridge then begins to progress eastward late Tuesday and winds to shift from the north to the south, helping to keep overnight lows more mild for Tuesday night. Confidence is high winds will remain light as winds above the sfc, around 850mb are also very light, around 10 to 15 mph, thus did not issue any fire weather headlines for Tuesday despite the low min RH. By mid-week the ridge axis will move over the High Plains, bringing above normal temperatures both Wed.
Light east winds this afternoon should become more southeaster- ly overnight/tomorrow as this high slowly shifts east with time. Lows tonight to range from the mid 50s over the far northern counties to the lower and mid 60s elsewhere. increased clouds with this system should help keep highs tomorrow in the low- er 80s. Even with the persistent onshore winds in place for much of the day tomorrow, the drier air aloft mixing down to the surface is going to help keep lows tomorrow night in the lower and mid 60s.
(Now through Tuesday) A large, closed upper level low over the northeast will remain nearly stationary through Tuesday. Meanwhile, an upper level ridge will amplify over the central states. The central Gulf coast will remain between these two features, with an upper level northwest flow pattern and building high pressure at the surface.
1213 PM CDT Mon May 1 2023 (Today and tonight) The forecast area is under northwest mid to upper level flow this morning between an omega block ridge over the Rocky Mountain states and a deep low over the Great Lakes. The ridge will move slowly eastward through tonight with some upstream cirrus spilling over the ridge overnight with some increasing cloud cover over the forecast area. Cooler air behind the front will see temperatures peak in the 70s to near 80 this afternoon.
Key Messages: - Temperatures again drop to around freezing in northeast Nebraska tonight, and we will issue another freeze warning for that area.
1231 PM CDT Mon May 1 2023 KEY MESSAGES: - Warmer and drier for the week ahead.
118 PM MDT Mon May 1 2023 Omega block ridge has established itself over the area today and will last through most of the week. Eventually as the week progresses the west coast trough will slowly track to the northeast bringing rain chances a little bit closer each day.
The large upper low over the East Coast continues to influence the weather over large portion of the nation this afternoon. The Omega blocking pattern in place will ensure its influence continues into Tuesday before it begins to shear out midweek. May see values drop into the low teens. The pattern will become less dominated by the deep trough across the east mid to late week and milder air will be allowed to build in from the Plains.
1220 PM CDT Mon May 1 2023 (Today through Tuesday Night) Today, an upper level ridge over the Rockies/Great Basin will find itself caught between two troughs (centered over the West coast and Northeast CONUS respectively).
1125 AM EDT Mon May 1 2023 Low pressure tracks north of the area today then meanders over the Great Lakes before slowing moving over the northeast through the middle of the week. An upper level low then lingers over the area through the end of the week. High pressure begins to build in over the weekend.
Strong and broad upper trough will bring dry air and below normal temperatures to the region through mid week.
A trough to our west will bring cooler temperatures, gusty winds, and increasing moisture this week.
An amplified mid/upper flow regime was in place across the CONUS with a deep trough over the Great Lakes area and an amplified ridge over the Rockies with another trough over the Pacific Northwest/west coast. north/northwest mid/upper flow will help steer a ridge of high pressure at the sfc over the Northern Plains southward across the area tonight. As this ridge builds in, dry air, clear conditions and light winds will allow for a period of radiational cooling. Low-lying areas may approach freezing with some scattered frost possible. Afternoon highs are expected to top out in the lower 70s.
There was plenty of virga and only a few sprinkles associated with the higher reflectivity returns this evening. Lows will be around 10 degrees below normal with readings expected to be in the lower 40s NW and mid to upper 40s SE.
512 PM EDT Mon May 1 2023 Low pressure will remain west of the region tonight. An upper level low will then slowly cross the region Tuesday through the end of the week. Vertically stacked surface/upper level low pressure will remain across the Great Lakes tonight through Tuesday. A disturbance rotating around the upper level low will lift toward the region Tuesday afternoon. Low temperatures tonight will range from around 40 to the lower 40s north, to the lower 40s Downeast. High temperatures Tuesday will generally range from the lower to mid 50s across the forecast area. Cold air with NE flow could drop dew points below freezing, thus scattered snow showers are possible in North Woods and higher terrain.
305 PM MDT Mon May 1 2023 Key messages: 1) Increased shower/thunderstorm chances Tuesday Mainly isolated convection firing over the higher terrain this afternoon in response to slight increase in low level moisture/instability, though storm strength is still rather weak as surface CAPE is only a few hundred J/KG, and t/td spreads are rather large. On Tuesday, low level moisture continues to increase along and east of the mountains, while mid level wave works through the ridge and crosses srn Colorado in the afternoon.
This activity stems from a lobe of vorticity that is moving around the parent closed low over the Great Lakes. The large upper low over the East Coast continues to influence the weather over large portion of the nation this afternoon. The Omega blocking pattern in place will ensure its influence continues into Tuesday before it begins to shear out midweek. May see values drop into the low teens. The pattern will become less dominated by the deep trough across the east mid to late week and milder air will be allowed to build in from the Plains.
As a result, the High Rip Current Risk will be allowed to expire at 8 pm for area beaches. High pressure over the southern Gulf of Mexico and strong low pressure well to the north will continue to support west to northwest winds tonight and Tuesday, with Small Craft Exercise Caution headlines continuing overnight over the northeastern Gulf of Mexico before subsiding by Tuesday morning. Winds will turn to more northerly during the second half of the week as high pressure builds in north of the waters.
757 PM EDT Mon May 1 2023 Aviation -- Rain and snow expected tonight into Tuesday -- No major changes are expected to the forecast for tonight into Tuesday as an upper low slowly moves to the east through the Great Lakes region. Cellular rain showers are moving off to the southeast that popped up in a zone of partial clearing within the upper low circulation. Temperatures will be at or slightly above freezing tonight (32 to 38) so not expecting travel issues even where the snow will be more dominant. The zone of higher accumulations (1-3 inches with a few higher totals possible) will be on the higher ground across Central Lower Michigan near U.
732 PM EDT Mon May 1 2023 Low pressure will remain west of the region tonight. An upper level low will then slowly cross the region Tuesday through the end of the week. Winds are beginning to relax over eastern areas, though the higher terrain is still gusting above 30kts. Vertically stacked surface/upper level low pressure will remain across the Great Lakes tonight through Tuesday. A disturbance rotating around the upper level low will lift toward the region Tuesday afternoon. Low temperatures tonight will range from around 40 to the lower 40s north, to the lower 40s Downeast. High temperatures Tuesday will generally range from the lower to mid 50s across the forecast area. Cold air with NE flow could drop dew points below freezing, thus scattered snow showers are possible in North Woods and higher terrain.
Temperatures will not fall quite as much as this morning tonight, generally in the lower to mid-60s across the area. However, a feel normally cooler, rural spots could dip into the upper 50s.
204 PM PDT Mon May 1 2023 Much cooler temperatures this week with afternoon highs 10 to 15 degrees below normal for early May. A low to medium chance of precipitation through the week with the higher chances over the mountains. Upper trough is deepening over the west coast today with a much cooler and unsettled week in store. Model ensembles show good agreement with the upper low tracking south tonight to over the San Francisco Bay area on Tuesday.
604 PM CDT Mon May 1 2023 Currently, windy conditions are in place east of the Missouri River, particularly where the pressure gradient between high and low pressure has been tightest, mainly along and east of the James River Valley (observed 35 to 45 mph northerly gusts). An upper-level ridge will finally gain ground on the large and slow- moving stacked low over the Great Plains, and provide a period of much warmer temperatures across the Northern Plains.
The lower heights across the region courtesy of the upper low will also keep temperatures below normal tonight, with lows generally in the 40s.
657 PM CDT Mon May 1 2023 Tonight and Tuesday: Cooler than normal temperatures and dry weather will continue through the period. Mid afternoon surface analysis had a stalled frontal boundary just off the central Gulf coast with a ridge of high pressure nosing into our CWA from the northwest. Mid afternoon satellite imagery/RAP analysis showed our CWA on the southwest periphery of a large closed low spinning over the eastern Great lakes region. This closed low was the eastern low of an omega block across the CONUS. Morning lows will range from the mid 40s northeast to the lower 50s southwest. A lighter wind is expected Tuesday but the wind will still be out of the northwest and hold afternoon highs from the lower 70s northeast to the lower 80s southeast.
A low pressure system off the coast of California will bring gusty southwesterly winds to the region this week.
Anderson (Issued 256 PM CDT Mon May 1 2023) Tonight and Tuesday: The latest RAP analysis and satellite/radar imagery show the large cyclone continues to spin over the central and eastern Great Lakes. The center of the upper cyclone will shift slightly to the northeast over the next 24 hours. Cyclonic flow combined with thermal troughing will lead to a mostly cloudy and blustery day on Tuesday.
Latest water vapor imagery overlaid with 500mb heights shows a large closed low slowly moving east towards the New England States.
Combined with dewpoints in the lower 60s, effective radiational cooling is possible overnight tonight, especially in the typically favored locations of the Upper Keys and the larger islands, including Big Pine.
The urban corridor and plains trend near upper 30s to low 40s tonight; the mountains and foothills trend near the low 30s to low 40s. 40 inches mainly in the higher terrain.
Currently, windy conditions are in place east of the Missouri River, particularly where the pressure gradient between high and low pressure has been tightest, mainly along and east of the James River Valley (observed 35 to 45 mph northerly gusts). An upper-level ridge will finally gain ground on the large and slow- moving stacked low over the Great Plains, and provide a period of much warmer temperatures across the Northern Plains.
655 PM EDT Mon May 1 2023 A large area of low pressure will bring unseasonably cold high temperatures, scattered to widespread rain showers, and breezy conditions to our forecast area through Tuesday.
This activity is occurring in association with the main upper level trough axis moving overhead, which can be seen really well on water vapor imagery.
(The rest of tonight) Central CONUS remains under high pressure at the surface, which will result in light winds overnight with just a few high clouds. The upper low over the Great Lakes, and broad upper trough over the eastern CONUS, will gradually lift out in the coming days as features in the pattern shift east.
A relatively cooler/drier and mostly cloud-free evening across South Florida, with near-zero precipitation chances continuing through the evening. (Rest of today through Tuesday) Dry and benign weather will persist through early week over the southern Florida peninsula with the lack of any significant surface features and the establishment of the Omega Block synoptic upper level pattern across the CONUS (ridging over the central US while troughing flanks the ridge along the Pacific West Coast and across the Northeast).
An upper low will continue to slide southward along the Oregon and California coast for continued clouds and some at times through early Tuesday morning.
1010 PM EDT Mon May 1 2023 Low pressure will remain west of the region tonight. An upper level low will then slowly cross the region Tuesday through the end of the week. Vertically stacked surface/upper level low pressure will remain across the Great Lakes tonight through Tuesday. A disturbance rotating around the upper level low will lift toward the region Tuesday afternoon. Low temperatures tonight will range from around 40 to the lower 40s north, to the lower 40s Downeast. High temperatures Tuesday will generally range from the lower to mid 50s across the forecast area. Cold air with NE flow could drop dew points below freezing, thus scattered snow showers are possible in North Woods and higher terrain.
518 PM MDT Mon May 1 2023 Synoptic Overview: An omega block -- characterized by an upper level trough/low along the Pacific Coast, an upper level ridge over the Rockies and High Plains, and an expansive upper trough/low over the eastern CONUS (east of the MS River Valley) -- will prevail through the short term period. Today-Tonight: Synoptic subsidence on the eastern periphery of the aforementioned ridge / western periphery of the east CONUS trough. along the western periphery of a persistent low-level (surface to 850 mb) ridge extending NNW from the Lower MS River Valley/Gulf Coast to the Dakotas. with afternoon highs in the lower-mid 70s and overnight lows in the mid-upper 40s. Trough entrenched along the west coast will be slow to lift out due to a blocky upper pattern.
Weakening low pressure will continue to spin over the Great Lakes through the Short Term. Lows Tuesday morning should mostly be in the lower 40s, but sheltered rural locations will dip into the upper 30s. Those west winds will continue tomorrow but not quite a gusty as the past couple of days as the low to our north deamplifies.
636 PM CDT Mon May 1 2023 (Tonight through Tuesday night) Upper level ridge along the Rio Grande into the southern Rockies will move eastward to an axis from the southern high plains down to deep south Texas Tuesday and Tuesday night. The low level flow will be weaker for Tuesday night but low clouds will remain over the region.
A general troughing pattern will bring cloudy skies and wet weather to the area through the week. A closed upper low tracking southward across the NERN PAC is approaching Northwest California this afternoon. The aforementioned closed low will continue to drop toward CNTRL California overnight and into Tuesday morning, with showers rotating westward across the region. However, rainfall amounts are expected to be light, ranging from a tenth to half of an inch, with locally up to an inch over the higher terrain. Cluster suggest that general troughiness will lingering over the Western U. An upper level low, centered off of west coast, is the catalyst for todays's aviation weather concerns.
939 PM EDT Mon May 1 2023 A strong upper level low pressure system over the eastern Great Lakes will continue to influence our weather through midweek. Several pieces of energy will pivot around the low bringing gusty winds, below normal temperatures, and mountain snow.
The first one is to the reflect an earlier relaxation time of the wind gusts given current observations and the trends in the high resolution model guidance. Weakening low pressure will continue to spin over the Great Lakes through the Short Term. Lows Tuesday morning should mostly be in the lower 40s, but sheltered rural locations will dip into the upper 30s. Those west winds will continue tomorrow but not quite a gusty as the past couple of days as the low to our north deamplifies.
Key Points: - Very high fire danger this afternoon area-wide - Chilly Tuesday morning especially in north central KS - Increasing chances for showers and thunderstorms latter half of this week 19Z water vapor imagery depicts an upper low encompassing the eastern half of the CONUS, still centered over lower MI. Another upper trough is off the Pacific coast with an amplified ridge over the Rockies, which leaves the area solidly in a northwest flow regime. That said, if dew points were to increase slightly or temperatures trend slightly cooler, then Republic and Washington Counties could see frost/freeze conditions, so trends will need to be watched this evening for any deviations from the forecast.
-Enriquez PREVIOUS DISCUSSION: Omega block ridge has established itself over the area today and will last through most of the week. Eventually as the week progresses the west coast trough will slowly track to the northeast bringing rain chances a little bit closer each day.
Low-level southerly flow across the ArkLaTex will bring increased moisture as well as a warmer airmass to the region.
1222 AM CDT Tue May 2 2023 (The rest of tonight) Central CONUS remains under high pressure at the surface, which will result in light winds overnight with just a few high clouds.
1146 PM CDT Mon May 1 2023 An amplified mid/upper flow regime was in place across the CONUS with a deep trough over the Great Lakes area and an amplified ridge over the Rockies with another trough over the Pacific Northwest/west coast. north/northwest mid/upper flow will help steer a ridge of high pressure at the sfc over the Northern Plains southward across the area tonight. As this ridge builds in, dry air, clear conditions and light winds will allow for a period of radiational cooling. Low-lying areas may approach freezing with some scattered frost possible. Afternoon highs are expected to top out in the lower 70s.
There is some potential for patchy fog with the higher dewpoints over lower southeast Texas and the coastal marshes of southern Louisiana.
Key Messages: - Temperatures again drop to around freezing in northeast Nebraska tonight, and we will issue another freeze warning for that area. Breezy northwesterly winds with gusts 30-35 mph continue this afternoon, with humidity dropping into the lower-mid 20 percent range. This is producing very high fire danger, and mostly north of I-80 where percent green values remain the lowest. And then similar concerns are expected for Wednesday when high temperatures boost in to the lower to mid 70s.