Aikyam-Lab/Synoptic-Bench huggingface dataset:
For the start of this new week, a cooler change is in the works, as abnormally deep troughing for late June becomes established across the eastern half of North America. Another disturbance was forming on the western half of this trough across northern Saskatchewan and Northwest Territories.
401 AM CDT Sun Jun 25 2017 06Z has a weak front/boundary running from lower Michigan into northern Missouri with high pressure over the northern Plains. The area that appears to be favored for any rain is mainly the highway 20 corridor.
454 AM CDT Sun Jun 25 2017 Water vapor imagery shows persistent upper high and broad anti- cyclonic flow over the desert southwest. As of 09z, scattered showers and thunderstorms are developing over the higher elevations in eastern NM with more isolated development in the TX Panhandle. Short and medium range guidance show 500mb feature rounding base of upper high to our west, with area of PVA shifting from west to east between now and about 18z.
346 AM MDT Sun Jun 25 2017 Northwesterly flow aloft over Montana diminishes today as an upper level high pressure ridge builds over the region.
Otherwise, high pressure building in from the north will keep temperatures down below normal again today and on Monday as well.
With much drier airmass in place in the low lvls, plan to not mention any POPS tngt ATTM, but wl let evening shift monitor later model data. We will see a NWLY flow aloft cont as well thanks to a broad upr trof ovr the ERN half of the nations, with an upr rdg persisting ovr the Rockies.
Meanwhile, upper level disturbances will continue to move from west to east over the forecast area in the base of a large upper trough over the the central and eastern conus. Patchy morning fog along the coastal sections will dissipate by mid morning, but the low to mid levels clouds will persist today and tonight. Low temperatures tonight will be in the low to mid 60s inland areas, with upper 60s to lower 70s along the coast.
The last day of the oppressive ridge through the desert southwest bringing excessive heat will be tempered a little by the moisture increase, especially in eastern areas. As the ridge weakens and shifts south to southwest of our area, a drier westerly flow will start to push some of the moisture back out of our area this week.
452 AM MDT Sun Jun 25 2017 A 90 kt jet is moving through northwest flow over the northern plains, as the upper ridge builds over the western CONUS.
These clouds will produce partly sunny conditions this morning, but model soundings shows the higher level moisture moving out this afternoon/evening. Surface ridging will also be the main feature with low dewpoints advecting into the region allowing temperatures to drop into the 50s Sunday night.
This evening, chances will begin to wind down but will maintain slight chances across the north as a weak cold front sags into southern AL/GA by sunrise Sunday. A +PV anomaly aloft of Quebec will swing off the Newfoundland coast Sunday night, dragging a cold front across the southeastern states.
Ahead of this activity, there is a small area of southwest ND (Hazen to Glen Ullin and Hettinger) that has fallen into the low to mid 30s.
At the surface, cool high pressure remains in place over the high plains with light easterly to southeasterly flow developing today and continuing through Monday. Forcing mechanisms remain negligible other than heating over the higher terrain and upstream soundings show a subsidence inversion aloft which will probably inhibit much in the way of convection.
Lows tonight will remain on the cool side from the low to mid 40s north central, where skies will remain clear to partly cloudy, with mid 40s to near 50 southwest, where cloudy skies develop. For Sunday night, a warm front at 850 mb will lift northeast in conjunction with a weak disturbance in northwest flow aloft. On Monday, a broad trough will extend across the Great Lakes Region and Midwest with upper ridging moving east into the Great Basin. A weak backdoor cool front will bring an east to northeast wind, limiting any warmup in the east to the mid and upper 70s, while parts of the southwest reach the lower 80s.
156 AM MDT Sun Jun 25 2017 A 90 kt jet is moving through northwest flow over the northern plains, as the upper ridge builds over the western CONUS.
121 AM EDT Sun Jun 25 2017 A cold front will move southeast across the western Carolinas and northeast Georgia this evening and then settle southeast of the region overnight. Drier and cooler air will start to spread in from the northwest through the day on Sunday, with these conditions persisting through much of the week. Moisture will slowly return around an offshore ridge of high pressure toward the end of the week.
This is based on an amplified ridge over the western states. This ridge is anchored by hot desert air spread over the entire Southwest, and extending north through western Canada into the Arctic Ocean. Off to the east is a broad, long-wave trough with much cooler air. The boundary between these two air masses runs through Montana, with the local region on the cooler side of the boundary.
However, preferred the warmer side of model guidance highs thinking some sun will occur, especially early in the day.
However, the challenge for precipitation coverage lies with the evolution of the sharpening trough rotating around the Great Lakes low during the aforementioned time period. Given the sharpening of the baroclinic zone ahead of the middle/upper level trough, had to consider raising PoP chances across a broader area Monday evening, closer to the Canadian model solution.
High pressure aloft will persist for another day today with hot and dry conditions. Ridgetop wind. Ridgetop wind. Ridgetop wind.
548 AM CDT Sun Jun 25 2017 Broad trough at 500 mb dominates the CONUS aloft. with a ridge axis all the way over on the Pacific Coast. Northwesterly winds as high pressure continues to spread over the Plains to the west. The northwesterly flow breaks down as the 850mb thermal ridge shifts to the east.
Water vapour had upper ridge from AB/SK into CO and upper trough just off the northwest CONUS. Today, upper/thermal ridge peak over the CWA with spring-like temperatures and plenty of sunshine as aforementioned frontal boundary shifts northeast as a warm front. Tonight, upper ridge starts to breakdown as upper trough moves onshore over the northwest CONUS. Warm front stalls and becomes a back door cold front in response to pressure falls ahead of upper trough over MT/WY. Temperatures will be quite varied, staying up over the higher terrain and dropping off on the SD plains. Thursday, back door cold front sinks southwest across western SD and will hangup on the southern edge of the snowpack.
VFR will prevail through the entire TAF cycle as high pressure will slowly shift east of the area. Very light winds in the lowest 5,000 feet of the atmosphere combined with clear skies and the low dewpoints will result in excellent radiational cooling tonight. Some of the traditionally cooler spots in valleys may flirt with freezing around sunrise. /Issued 315 PM CDT Tue Mar 13 2018/ Water vapor imagery continues to show a couple of weak disturbances moving down the back side of the trough this afternoon, with one currently over Oklahoma and the other moving into Kansas. Temperatures are also trending a few degrees warmer than this time yesterday afternoon, with most locations expected to top out in the mid to upper 60s today. Dry conditions will continue to prevail the next several days, as high pressure builds back across the region.
An upper level low is off the coast of British Columbia with a trough along the west coast. There will be a short break from the precip Wednesday night as the upper low starts to drop south.
402 AM EDT Wed Mar 14 2018 High pressure in the Lower Mississippi River Valley today will be in the northeast Gulf of Mexico Thursday.
Expect temperatures to fall into the low to mid 20s by daybreak Thursday.
Northwest flow aloft will transition to near-zonal Wednesday night as a mid-level ridge translates east across the Texas and Oklahoma Panhandles. Pacific cold front passes Thursday night, scouring out any low- to mid- level moisture.
151 AM CDT Wed Mar 14 2018 GOES_East water vapor imagery early this morning showing a mid-level trough dropping south along the Manitoba/Ontario border. Warm air advection kicks in this morning across the region ahead of that mid-level trough/surface cold front dropping south out of Canada. High pressure builds in behind the departing mid-level wave/surface cold front tonight with overnight lows falling into the teens to middle 20s. Sunny and a bit cooler for Thursday as high pressure continues to build into the region. Plan on highs in the 30s to the lower 40s.
High pressure will drift across the Gulf Coast states and Southeast states this afternoon through Thursday.
Should still be able to achieve highs in the low/mid 40s across most of the area, with possibly the exception of the northwest near Alexandria where the front passes not too long after daybreak.
A ridge of high pressure will build in and bring fair weather mid to late week and into the weekend. The light snow showers will taper off overnight as h8 temps moderate a bit toward daybreak and a mid level ridge begins to build in from the northwest. Fair weather will return Wednesday as ridging takes hold of the wx pattern. A cold front will come through dry across the vast majority of our fcst area Wednesday evening.
1143 PM MDT Tue Mar 13 2018 Cooler day across the area with light winds and higher humidity readings behind yesterday's cold front. With ridge axis shifting over the area on Wednesday this should help keep winds relatively light once again. Southeast corner of the state will see some afternoon breezes as southerly winds pick up ahead of the deepening lee side surface trof. and 30s and 40s for the higher mountains.
Upper trough will swing southeast across the Southern Appalachians through the first part of the forecast period generating some snow showers.
However, breezy west-southwesterly winds are expected to develop over the area this afternoon in advance of an approaching cold frontal trough. As the surface pressure gradient strengthens between this feature and an area of high pressure over the Lower Mississippi Valley, the surface winds will become gusty up around 30 mph this afternoon, but will abate by early this evening as the surface frontal trough shifts overhead. These westerly winds will result in a warmer day, with highs likely to warm well into the 40s across the area. Following the cold frontal passage early this evening, expect winds to shift back out of the northwest, with temperatures falling back into the 20s for overnight lows.
Otherwise, winds are moderating from the north across the service area, with temperatures in the lower 60s. Large high pressure area will continue to settle southward from the central portion of the country, and be centered in the northern Gulf tonight through Thursday night.
359 AM MDT Wed Mar 14 2018 An upper level ridge of high pressure will be over the region this morning, but this ridge will move eastward by tonight, as a strong upper level disturbance moves into the region. On Thursday, expect colder air to move into the region, allowing for the potential for a period of freezing rain, sleet or snow to fall over much of North Central MT. There is also the potential for a mix of freezing rain/snow/sleet over much of the eastern half of North Central MT.
114 AM EDT Wed Mar 14 2018 Periodic snow showers and cold temperatures are expected most of the week under upper level low pressure. Upper low shift northeast today. Another cold front will swing through early Thursday morning with a reinforcing shot of cold air. This will invigorate snow showers for a majority of the lower elevations, but could lead to appreciable accumulations in the highest elevations of Tucker and Garrett Counties.
The result is a light southerly wind with temps ranging mainly in the lower to mid 30s. Weak trough shifts off the Front Range during the day.
While a back-door cold front will move across the CWA this afternoon, temperatures will warm into the 30s and 40s. An area of low pressure approaching the region from the southwest will bring easterly winds to the CWA tonight. Low level moisture from snow melt today, could combine with the easterly winds to produce fog over the higher terrain areas in western South Dakota.
A weak dry cold front will push through the area during the morning hours. All this cold front will do is reinforce the cold that has already settled over the area. A freeze watch has been issued for Levy county where some places will see below freezing temperatures for up the 4 hours. Freezing temperatures right before sunrise could be possible as far south as Hernando county with most interior area getting down into mid to upper 30's. High pressure will be dominating with sunny skies and temperatures slightly warmer with most of us getting to around 70 degrees in the afternoon.
Clouds will start to spread across the divide by late this afternoon as upper low off the Pacific coast starts to pump moisture northward into Montana as it moves onshore. Best chances will be over the western zones Thursday morning, and with warm temperatures aloft could result in freezing rain.
A ridge of high pressure at mid and upper levels remains over the forecast area resulting in sinking dry air, no rain and light winds.
The high pressure ridge that has been over the forecast area the past several days will shift east today and Thursday. This is a result of a large upper low and trough moving into the Pacific northwest. This upper low will bring a divergent southwest flow aloft across our forecast area through the period. The upper low will remain fairly stationary over the Pacific northwest through Thursday. However, several vort disturbances will rotate northward from this low bringing rain and snow to our forecast area. Colder air will then get pulled south behind the low resulting in the rain/snow mix to change to all snow across the area.
This will push temperatures up into the low to mid 60s across much of Iowa, roughly south of Highway 20 and west of Highway 218.
With the warmer temperatures today and low-level moisture of significance off the Texas coast (with current offshore flow), we will also see low humidity this afternoon, especially west. Have initialized the dewpoints closer toward the lower ECMWF over the next few days which tends to do better in these environments than the model blends.
Ridging over the central CONUS will spell warm temperatures today and Thursday, as well as quiet weather conditions. Winds may actually remain a bit lighter on Thursday as a weak warm front/inverted trough develops over the forecast area, which will combine with increasing low- level moisture to possibly lessen fire weather concerns a bit for Thursday afternoon. Higher QPF and coverage are expected in northern MO where the warm front will linger and provide more focus for showers to develop, especially from HWY 36 northward.
328 AM EDT Wed Mar 14 2018 High pressure in the Lower Mississippi River Valley today will be in the northeast Gulf of Mexico Thursday.
As high pressure drifts off to the east, NE winds around 5 KTs will turn to SE at 5 to 10 KTs most areas by early Wednesday afternoon with 10 to 15 KTs and gusty out west. SPC upper air analysis from this morning showed a large upper level low across the Great Lakes region with another upper trough approaching the Pacific NW. 500 mb west northwesterly flow was in place over south central Texas with surface pressure ridging continuing to build over our area and light surface winds out of the east northeast. Wednesday will be mostly sunny and mild with Wednesday night much warmer than tonight.
114 AM EDT Wed Mar 14 2018 Scattered snow showers have formed across the area today thanks to a potent upper level low.
An area of clouds were located from just north of the Manitoba Lakes east into northern Ontario early this morning, behind a cold front. How much of the lower clouds over Manitoba/Ontario will make it into the Northland remain one of the forecast challenges today. However, forecast soundings reveal the moist layer is quite thin with very dry air above the low level moist layer. High pressure will nose into the region on Thursday with mostly sunny skies expected for most areas.
416 AM CDT Wed Mar 14 2018 High pressure over eastern Kansas will move south today toward the Southern Plains providing a period of dry weather through the short term. A broad trough over the eastern one third of the country will slowly continue to move to the east today. Winds will switch from the northwest to the southwest after sunrise today over the area in response to high pressure moving south this morning.
High Pressure is expected to build across Indiana today. followed by a second high pressure system on Thursday. This will bring dry and warmer weather for the rest of the work week.
01 UTC surface analysis shows an area of high pressure still well back to the NW of the region, however the local pressure gradient is much more relaxed than this time last night and accordingly many stations within the last hour are now reporting calm or nearly calm winds. Though it is unlikely for winds to go completely calm areawide overnight, the lighter winds will be supportive of better radiational cooling conditions, which should help low temperatures get into the low to mid 30s. Dry weather will prevail through the short term with high pressure and a cool airmass in place. Warmer conditions are expected for Thursday night, although some frost may still occur across the southeast big bend. High temperatures are expected to range from the upper 50s to mid 60s on Wednesday with warmer temperatures on Thursday.
After a brief warm air advection period this morning, a series of cold fronts will drop over the area. The first cold front will be associated with a wind shift from southwest to northwest during this afternoon.
A cold front associated with a storm system will move through the state today brining showers and a few thunderstorms to much of the state.
The low pressure will form somewhere near Dillon and then take a northerly track east of the Divide towards Alberta, Canada by late Thursday morning. Any jog to the east would dramatically reduce the higher impact heavy snowfall threat for our area. If the low tracks closer to the Divide, then travel could become difficult at times between Helmville/Highway 200 and MacDonald Pass/Highway 12 and also between Marias Pass and West Glacier.
allowing for a minor surge of slightly cooler/drier air to filter into the region this morning. Light NNE winds in the morning will gradually become more easterly, and eventually southeasterly through the day as the area of high pressure starts to shift into the N Central Gulf by late today. Rather persistent mid/upper level cloudiness is likely to prevail today as the H25 jet remains nearly overhead and mid level vort maxes ride east over the weak ridge axis, which is currently west of the CWA. Continued unseasonably cool temps will occur again with max temps briefly warming into the low 70s this afternoon. Thicker cloud cover should also negate significant diurnal warming despite a warmer southerly flow.
325 AM CDT Wed Mar 14 2018 Low pressure off the New England coast this morning. High pressure is centered over Oklahoma, with another low pressure off the British Columbia coast.
355 AM CDT Wed Mar 14 2018 Strong 519 dm 500 mb low over eastern NY/PA will move off the MA coast by sunset, while upper level ridging into the high plains and IL in a nw upper level flow. 1028 mb Canadian high pressure along the eastern KS/OK border to settle into the southern MS river valley by sunset while a weak front drops southward into nw IL by early evening. Upper level ridge weakens/flattens some as it shifts into the eastern plains by sunset Thu. Low pressure emerging over the central plains by Fri morning to develop light waa mixed precipitation ahead of a warm front over sw MO and mid MS river valley.
Northwest flow continues this morning with an upper level trough across the eastern U. The northwest flow will allow for the cooler and drier conditions to continue and a Frost Advisory is in effect this morning for all of the area, except the extreme coastline.
Aloft, NW flow will persist today around a trof over the ERN CONUS, though this feature is progged to slowly lift out with weak/flat ridging sliding overhead on THU. Consensus is for it to remain stalled north of the area, thus warm and humid weather with periodic rain chances will continue through the weekend until this second upper trof drives a front through the area MON into TUE. Southerly winds will increase and become modest through the day Thursday as an area low pressure moves into the Plains.
1224 AM CDT Wed Mar 14 2018 High pressure will slide south over the state by Wed morning. Tonight Through Thursday A northwest wind flow aloft will start the period, with high pressure over Arkansas at the surface. Under the high, another freeze is expected tonight over much of the Ozark and Ouachita Mountains of the north and west. The high will remain in place on Wednesday, but will shift toward the southeast United States Wednesday night/Thursday. Looking aloft, some ridging will occur locally, with a warming trend during the remainder of the near term. The fly in the ointment will be a back door cold front pushing southward through the mid-Mississippi Valley on Thursday.
Otherwise, skies will be sunny on Wednesday with warmer conditions with better mixing northeast winds.
A thermal ridge pushes onto the northern Plains overnight with decent downslope flow (25-30kts at H85). Trended max temps up toward the warmer MAV/MET guidance to account for abundant sunshine, southerly low level flow right up the High Plains, and H85 temps exceeding 10C.
Although the cloud cover will increase by dawn Wednesday morning, the high pressure should bring a period of mostly clear skies, which should set up some good radiational cooling coupled with fairly weak winds overnight. Overnight lows should drop into the lower to middle teens, with the warmest temperatures near the Brainerd Lakes eastward over the South Shore of Lake Superior. For Wednesday morning, expected partly to mostly cloudy skies to linger along Lake Superior where higher relative humidity air will become situated as the cold front passes through. High temperatures will range from the lower 30s over the tip of the Minnesota Arrowhead, into the upper 30s and lower 40s further inland. Very dry low- level air will dive southward into the region along-side the western fringe of the trough as mid-level ridging over the Intermountain West states will slowly translates eastward.
This will serve to moisten the low levels and allow a more efficient stratiform onset in a few more hours.
320 AM CDT Wed Mar 14 2018 Large trough over the eastern U. However, it will be on the cool side as the trough is not expected to begin relinquishing its grip until tonight and Thursday. Warmer Thursday as heights rise considerably and a southerly return flow sets up.
High pressure will keep winds generally less than 10 kts for most sites.
Northwest flow continues to usher a drier and cooler air mass into the area, with today expected to be the coldest day for the remainder of the week. A Freeze Warning remains in place for much of north Georgia for this morning given the expected sub-freezing temperatures. High pressure will shift to over the Florida peninsula early on in the forecast period, while a backdoor front begins to approach northern portions of GA.