Aikyam-Lab/Synoptic-Bench huggingface dataset:
The extensive cloud cover/drizzle to the south will keep temperatures cooler today, while the partial sunshine to the north will bring warmer temperatures. Although still cannot rule out some lingering drizzle/isolated light showers across Northeast PA Tuesday morning, Tuesday will feature mainly dry weather along with gradual clearing skies as high pressure across southern Quebec starts to drift southward into our region. Temperatures will remain seasonably cool with highs expected to be in the lower to mid 60s. As of now, chances of a widespread frost is low but in the higher valleys of the Catskills as well as up on the Tug Hill, lows could fall into the mid 30s so patchy frost is possible in those locations.
High pressure nosing down from eastern Canada will provide a brief dry period during mid-week. An upper level trough will then move across the area later in the week. A short wave trough rolling in from the west will slide across OH/PA tonight. Will continue to hold maxes like we had them Sun and Mon without much hope for sun/mixing and slight cold advection in the lower atmos. Latest guidance supports a gradual trend toward drier/brighter weather Tue-Wed, as expansive high pressure over Quebec nudges south. By late week the focus shifts to an upstream trough over the Grt Lks.
At the surface, a boundary persists to our south, with high pressure over the Appalachians and a cold front to our northwest over Missouri. Otherwise, highs are forecast to top out in the lower to mid 80s, with perhaps slightly cooler temperatures over elevated terrain.
Temperatures on Monday should be a couple of degrees above normal, but a few degrees cooler than today with that cloud cover expected over the area.
500 AM EDT Mon Sep 25 2023 A cold front will exit across the Gulf of Maine today.
126 AM EDT Mon Sep 25 2023 High pressure will remain in place across the region through tonight. Chances for rain will increase into this week as an upper level low slowly moves east across the Great Lakes and Ohio Valley. High pressure remains northeast of the Ohio Valley overnight while the remnants of a tropical system spin over the Mid Atlantic. Northeasterly flow around the high will help usher in some low level moisture from the tropical remnants through the night.
Warmer than normal temperatures and dry weather will persist for most of the week.
1215 AM EDT Mon Sep 25 2023 A cold front will approach from the north this evening and cross the region tonight.
Cooler temperatures and increasing southwest to west winds of 25 to 40 mph are anticipated. The strongest winds are likely to occur along and east of the Highway 93 corridor through western Montana and Lemhi County, Idaho. Wet, cool and breezy conditions will continue for the remainder of the week as the low pressure trough moves inland off the PacNW Coast.
By tonight, activity will have settled further south of the I-10 corridor, thanks to the cold front shifting southward.
High pressure will prevail across the greater region tonight. These conditions should lead to the overall cooler lows. For Monday, high pressure will continue to prevail across the FA. For Monday night, weak lee troughing will eventually resume. This will lead to slightly warmer lows heading into Tuesday morning with more 50s rather than 40s.
In its wake, high pressure will build into the region and dominate for the remainder of the short term period, keeping dry conditions in place. Upper level low pressure over the upper midwest this morning will help amplify upper riding to our west keeping northwest flow aloft over the region.
While it will be difficult to realize the passage of a cold front with all the shifting boundaries, there should be a modified air mass in place over the region by late Tuesday morning.
The 19Z MSAS surface analysis indicated an area of low pressure over southeast ND with a trough extended east-northeast into Upper MI and an occluded frontal boundary over southwest MN into central IA. A large Canadian high pressure remained over eastern Ontario. There may be a push farther east toward east-central WI (toward the Fox Valley), but the dry air mass from that strong Canadian high pressure will likely have any precipitation fall as sprinkles. Min temperatures should be similar to last night with readings in the lower to middle 50s north (coolest far northeast), middle to upper 50s south. For eastern WI, the battle between incoming moisture and dry low-levels from the high pressure will continue for another day.
Did update the forecast to lower pops to high chance for the far Nrn zones, while also delaying the higher end likely/categorical pops farther E where the convection development has yet to occur. Also added heavy rainfall mention for much of E TX/Wrn and Cntrl LA where the stronger convection continues to develop and spread SE along the higher PW/sfc theta-e axis. 15 (06Z TAFS) For the 25/06Z TAF period, active convection persists at/invof most terminals early this morning as a cold front and upper-level trough continue to shift across our airspace.
The trough over the Ohio Valley is moving slower each model run I see. The temperatures at 925mb are near 80 degrees, so that translates to mid to upper 80s at the surface for Monday and Tuesday with overnight lows in the low 60s. (Tuesday Night through next Monday) For the extended, we're still watching this cut-off upper low slowly trek to the SE.
411 AM EDT Mon Sep 25 2023 Upper air pattern consists of a 500 mb closed low over western MN with a ridge across Hudson Bay and Ontario. The closed low over MN heads slowly northeast to central MN by 00z Tue. Another round of pops will continue in the far west today as the low remains off to the west of the area with some moisture and 850-500 mb q-vector convergence across the far west. Key Messages: -A weakening low pressure system provides slight chances for precip in the western U. A mid-level closed low over southeastern Minnesota swings southeast through Iowa tonight and Tuesday, then moves eastward into northern Illinois Tuesday night. Meanwhile, high pressure over Hudson Bay gradually settles south over James Bay through Tuesday, moving into Ontario Tuesday night and keeping the low away from the U.
312 AM EDT Mon Sep 25 2023 Southeast Michigan will be influenced by both pervasive easterly gradient flow to the south of strong northern Canadian high pressure and slowly developing mid to upper level deformation on the eastern flank of northern Mississippi River Valley low pressure. The net result of this action will be to broaden the wavelength of the upper level trough over the Northeast United States.
1111 PM MDT Sun Sep 24 2023 20Z upper level analysis has deep closed low across western Minnesota, large trof off the West Coast, with ridging in between across the northern Rockies. At the surface, high pressure resides across the northern Rockies. Closed upper low over western Minnesota will continue to slowly shift east, as the ridge over the Rockies builds into the forecast area. Persistent ridge builds across the central CONUS for Monday through late in the week, with dry and warm conditions expected. As upper ridge shifts a little further east late in the week, and the Northern Plains falls under southwest upper flow, chances for precipitation will increase as weak disturbances eject out of the developing western trof into the Northern Plains.
Upper low continues to spin with the center between KFAR and KFFM. A slow moving upper level low will continue to meander around the ND/SD/MN border. This period will begin Tuesday with still just a slight chance for a couple of showers hanging on in our far eastern zones as this pesky upper level low continues to slowly drift southeast and away from our area.
123 AM EDT Mon Sep 25 2023 The remnants of Tropical Storm Ophelia will exit tonight but flow will transition towards the next upper level trough through the end of the week. Monday will see the region nestled between an upper Mississippi River Valley trough and the Ophelia remnants under weak flow. Remnant moisture trapped under that ridge may be enough to fuel a few isolated afternoon showers, otherwise the subsidence the ridge creates should foster dry weather Tuesday. Cooler east wind will persist based on surface gradient and likely will reinforce the dichotomy of seasonably cool temperature for eastern zones with more near normal temperature for western zones.
Biggest thing to note for today compared to the past few days will be increasing cloud cover and isolated rain chances (largely confined to areas north of I-20) in association with a passing 500mb trough. The forecast area will be briefly situated in a quasi-zonal type pattern with a developing upper low to the NW eventually to dive southward and a weak trough along the northern Gulf States.
253 AM EDT Mon Sep 25 2023 Although low pressure over New Jersey is expected to pull away from the area, lingering moisture will allow for showers this afternoon and tonight.
Did update the forecast to lower pops to high chance for the far Nrn zones, while also delaying the higher end likely/categorical pops farther E where the convection development has yet to occur. Also added heavy rainfall mention for much of E TX/Wrn and Cntrl LA where the stronger convection continues to develop and spread SE along the higher PW/sfc theta-e axis.
1142 PM EDT Sun Sep 24 2023 The low to mid level easterly winds have advected a little more moisture into Se Mi this evening, resulting in a 4-6k foot cloud deck now covering much of the area. Stacked low pressure over Minnesota will slowly migrate southeast through the upper midwest region and eventually into the northern Ohio Valley and far southern lower MI by midweek as it is steered around blocking high pressure centered over Quebec.
Highs clouds are expected to increase as the system gets closer so will likely be partly to mostly cloudy overnight and lows a little warmer in the upper 50s/low 60s. We will be partly to mostly sunny and highs still above normal in the low to mid 80s. An upper low is forecast to rotate SSE from southern MN across IA, before reaching IL by Tuesday night. Modest destabilization looks possible Tuesday afternoon and evening as the wave of low pressure approaches from the northwest. Afternoon highs should reach the low to mid 80s.
Visibilities will be reduced below 1/4 mile in some locations, especially in the lower valleys and near the larger lakes. A drier air-mass will filter into the region behind weak cold front.
Temperatures will at least be cooler than late last week thanks to the front that moved to our south.
Weather across southeast Colorado will be quiet and dry again today as the upper-level ridge continues to build in overhead.
Clearing skies and warmer temperatures this afternoon are still on track, no changed to the going forecast at this time. Therefore, clear skies will lead to warmer high temperatures. High temperatures are expected to be in the low-mid 80s.
The CIMSS mean layer winds currently indicate the presence of an upper level trough over the Yucatan Peninsula. The trough has resulted in the weakening of the ridge, which has created an opportunity for abundant tropical moisture from the Caribbean to move beneath the weakening ridge. However, the Lower Keys have not received any rainfall due to the convection from overnight, which has suppressed the formation of storms in the atmosphere. A trough near the Yucatan Channel will slide westward over the next several day as the Atlantic ridge builds back into the region.
This would tend to favor daytime highs near the 75th/90th %iles of the NBM, so did go ahead and blend these warmer values into the official grids. Highs should return to the lower to middle 80s for most areas along/east of I-25 by Tuesday. Models have remained consistent with prolonged upper level ridging pushing eastward across the Intermountain West and stalling out across the Great Plains by midweek.
As the low propagates southeasterly a weak cold front stretching southwestward across central and west Texas will slowly move southeast, likely reaching the northern portion of our CWA Monday night. The cold front will likely weaken as it continues south Tuesday, slowly washing out as it moves through the central portion of the CWA. While the main feature of this forecast is a cold front, it doesn't do much for our temperatures. The Highs today are expected to reach around 100 degrees, and after the front moves into the air and dissipates Tuesday the highs are only forecast to drop into the upper 90s.
The north-south oriented axis of clouds / showers / thunderstorms has gradually shifted from our western CWA to our central CWA overnight, though the CAMs expect a brief reversal of this propagation today, putting the highest afternoon and evening POPs (50%) back in our western CWA. For tonight, rain becomes likely (80%) for the southwestern half of our CWA thanks to the PVA from the approaching low pressure.
Looks like the higher amounts will be limited to the mountains of Shasta County where 0. Dry weather returns by Tuesday afternoon, and milder temperatures are expected through mid-week with valley highs returning to the lower to mid 80s.
838 AM MDT Mon Sep 25 2023 Satellite imagery this morning shows varying amounts of mid and high level clouds streaming northeast across the Northern Rockies and and western/central portions of MT in between an upper level ridge with axis across eastern MT and a deep upper level low offshore of the Pacific NW. Hoenisch Pleasant weather will accompany the start of the work week today as upper level high pressure slides over the region.
525 AM MDT Mon Sep 25 2023 Aviation Section Updated Pleasant weather will accompany the start of the work week today as upper level high pressure slides over the region.
343 AM MDT Mon Sep 25 2023 Pleasant weather will accompany the start of the work week today as upper level high pressure slides over the region.
Southeast Michigan will be influenced by both pervasive easterly gradient flow to the south of strong northern Canadian high pressure and slowly developing mid to upper level deformation on the eastern flank of northern Mississippi River Valley low pressure. The net result of this action will be to broaden the wavelength of the upper level trough over the Northeast United States.
611 AM EDT Mon Sep 25 2023 A cold front will exit across the Gulf of Maine today.
(Now through Tuesday) Upper level ridging will continue to weaken as a broad trough develops across the eastern states. Meanwhile, on Tuesday, an inverted trough over the eastern Gulf will slide east and bring a surge of moisture into the coastal and marine locations. This leads to a challenging POP forecast with the higher rain chances today across northwest areas. On Tuesday the highest rain chances will be across coastal areas and offshore as precipitable water values around 2 inches move northwest into the area.
634 AM CDT Mon Sep 25 2023 (Today through Tuesday afternoon) After yesterday's initial cold front diffused out, we've been tracking a secondary, back-door front pushing through the Permian Basin early this morning. With continued easterly flow into tomorrow, storm chances shift to the western high terrain as moisture pooling against the higher elevations provides a local axis of maximum moisture.
A ridge of high pressure will bring another sunny afternoon to the region. It will be warm and dry under the ridge through midweek leading into southwest flow aloft ahead of the upstream trough by the weekend.
634 AM CDT Mon Sep 25 2023 (Today and tonight) Northwest flow aloft will continue over the region with WV imagery showing the upper level low over the upper Midwest and the upper level high over Mexico. Tonight a cooler air mass will remain locked in place with overnight lows expected in the upper 50s to low 60s.
A pattern change possibly closes out the week, with cooler temperatures and active weather returning. Lows will be in the 40s for most, with cooler mountain passes and summits dropping into the 30s. Lows will be in the 40s with most, with cooler mountain passes and summits dropping into the 30s.
920 AM EDT Mon Sep 25 2023 A cold front will exit across the Gulf of Maine today.
602 AM CDT Mon Sep 25 2023 (Today through Tuesday night) High pressure is building back across the panhandles which coupled with drier air that has intruded into the area last night will yield sunny and fair weather conditions. The building of the ridge will cause the winds to shift to a southerly direction today and then a southwesterly direction during the overnight. The position of the ridge will also not be dominant which will allow weak troughs to pass across the panhandles on Tuesday. Temperatures under the ridge will see a small increase for most areas with highs mainly in the 80s to low 90s.
321 AM MDT Mon Sep 25 2023 Across the region this afternoon, sunny skies area-wide as high pressure dominates the weather over the Plains. With a ridge axis nosing across the region, areas mainly north of the Interstate are seeing W/NW flow with gusts up to 15-20 mph at times. Upper ridge currently over the Rockies will make a slow trudge east through Tuesday, as the system is blocked by an upper low over the northern Mississippi Valley. On monday, low pressure begins to work into the Front Range setting up southerly flow, the ridge shifts a bit northward on Tuesday, setting up a surface flow to more easterly through the day. For temps, looking for daytime highs on Monday to range into the lower to mid 80s, with slightly warmer conditions for Tuesday, with 80s area-wide, warmest south of the Interstate.
High temperatures will be on the lower side today due to cloud cover; although there may be pockets in southwestern Wisconsin that rise into the lower to mid-70s due to a lack of constant cloud cover. The north-south oriented axis of clouds / showers / thunderstorms has gradually shifted from our western CWA to our central CWA overnight, though the CAMs expect a brief reversal of this propagation today, putting the highest afternoon and evening POPs (50%) back in our western CWA. For tonight, rain becomes likely (80%) for the southwestern half of our CWA thanks to the PVA from the approaching low pressure.
619 AM EDT Mon Sep 25 2023 Upper air pattern consists of a 500 mb closed low over western MN with a ridge across Hudson Bay and Ontario. The closed low over MN heads slowly northeast to central MN by 00z Tue. Another round of pops will continue in the far west today as the low remains off to the west of the area with some moisture and 850-500 mb q-vector convergence across the far west. Key Messages: -A weakening low pressure system provides slight chances for precip in the western U. A mid-level closed low over southeastern Minnesota swings southeast through Iowa tonight and Tuesday, then moves eastward into northern Illinois Tuesday night. Meanwhile, high pressure over Hudson Bay gradually settles south over James Bay through Tuesday, moving into Ontario Tuesday night and keeping the low away from the U.
3am discussion: Upper level ridge will be over the area today and Tuesday. This will bring dry weather with warmer temperatures.
337 PM EDT Mon Sep 25 2023 A backdoor cold front will move south through the area tonight. Strong high pressure will follow, and ridge from eastern Canada southward through the Carolinas through the work week. Latest model guidance is showing areas of light showers later tonight, mainly across the NE Coastal Plain due to saturation increasing in the low levels along with a shift to a more northeasterly onshore flow.
147 PM MDT Mon Sep 25 2023 An upper low spins over MN, while another one sits off the Pac NW. Upper ridging between the two lows will keep weather mild and dry through much of this week. Highs will be in the 70s to lower 80s, which is near to above average (average highs for this time of year are in the low to mid 70s).
200 PM EDT Mon Sep 25 2023 Cloud trends remain the primary focus for the 18Z cycle as Southeast Michigan lies within low-level confluent flow between low pressure over the Upper Mississippi Valley and retrograding high pressure over eastern Canada. Southeast Michigan will be influenced by both pervasive easterly gradient flow to the south of strong northern Canadian high pressure and slowly developing mid to upper level deformation on the eastern flank of northern Mississippi River Valley low pressure. The net result of this action will be to broaden the wavelength of the upper level trough over the Northeast United States.
1124 AM MDT Mon Sep 25 2023 Aviation Section Updated Satellite imagery this morning shows varying amounts of mid and high level clouds streaming northeast across the Northern Rockies and and western/central portions of MT in between an upper level ridge with axis across eastern MT and a deep upper level low offshore of the Pacific NW. Hoenisch Pleasant weather will accompany the start of the work week today as upper level high pressure slides over the region.
This Afternoon through Next Monday Abundant sun shines across the forecast area Monday as a ridge of high pressure builds over the region. A clear and calm night on tap Monday night as the ridge axis only shifts to eastern Wyoming.
A ridge is positioned behind the low, which is bringing drier air from 500-700mb, per soundings/GFS RH model. With this low, abundant moisture continues at 850/925mb in the form of clouds/LL moisture.
On Tuesday, an upper low will slowly move southeastward through the Midwest, helping develop weak troughing over the Southeast.
The 19Z MSAS surface analysis showed a weak area of low pressure over southeast MN with an occluded frontal boundary extended south-southeast through eastern IA into western IL. High pressure remained parked over eastern Ontario/western Quebec. Visible satellite imagery clearly showed clouds rotating around an upper- level low pressure area over west-central MN with radar indicating several bands of showers and isolated thunderstorms impacting the Upper MS Valley and western Great Lakes.
Tomorrow, high pressure builds in with the low clouds clearing and low chances of precipitation for the rest of the week. Some of the NAM was blended in though the NAM was an outlier with overnight lows falling into the low 30s and upper 20s across the Catskills into the Twin Tiers. Surface moisture will likely be a bit too high and fog and dew formation will most likely keep temperatures from falling into the low 30s. Some patchy frost is likely in some of the higher valleys of the Catskills.
(This evening through Tuesday Night) An upper trough axis moving southeast across Northern Louisiana and Northeast Texas is providing additional forcing for ascent along a stationary front just south of the forecast area. The convection should continue to increase in coverage and intensity over the next few hours before gradually diminishing and exiting the area after sunset as the upper trough axis moves southeast out of the area by midnight.
221 PM MDT Mon Sep 25 2023 Upper ridge will continue sliding east across Montana tonight and Tuesday, while a deep low spins slowly toward the coast of British Columbia. Warm and dry weather continue on Tuesday with a strengthening lee trof. Tightening pressure gradient will fuel the low level jet over eastern Montana for increasing winds. Current models suggest that the strongest winds will be over the higher terrain areas north of Highway 2, with a weaker pressure gradient over Fort Peck Lake but winds should be close enough to criteria to issue a Lake Wind Advisory. The lee trof will move across eastern Montana Tuesday night as a cold front. This will bring to an end the warmer weather, with temperatures dropping back to near normal for late September.
An upper trof in the easterlies over the central Gulf progresses slowly westward through Tuesday, while an upper trof over the northeastern Plains/western Great Lakes spreads eastward to include the central Great Lakes to Ohio/Mississippi River confluence region. Lows tonight range from the mid to upper 60s inland to the lower 70s near the coast.