Aikyam-Lab/Synoptic-Bench huggingface dataset:
Southwest flow aloft around an upper level ridge will bring another hot day to northeast Colorado Friday. A seasonally strong cold front will move southward out of Nebraska/Wyoming across the eastern plains of Colorado on Friday night. This will keep temperatures much cooler so highs in Denver were lowered to the low 80s.
The region will be between high pressure to the east southeast and a trough to the northwest this period.
Highs should climb into the lower and mid 90s with dewpoints running about as high as possible. To get into southern Wisconsin would mean really penetrating the capping thermal ridge in place, so wouldn't be surprised if the storms remain mostly north of Milwaukee and Madison tonight.
246 AM MDT Fri Jul 19 2019 Synoptic Setup: To the south hot high pressure lies bottled up over the Four Corners. North of this a series of troughs and ridges of relatively cooler air run from the Pacific Northwest and British Columbia through northern Montana and the Canadian Prairies.
328 AM CDT Fri Jul 19 2019 The heat remains front and center today and tomorrow as a hot, mid- summer upper ridge continues to dominate much of the southern and central CONUS.
400 AM CDT Fri Jul 19 2019 Water vapor loop indicate an upper low over the southern ALTA/SASK border and a second upper low was over nw WA. An mid level trough over se MT will move across the southern Red River Valley this afternoon. Warm frontal boundary over SD and southern MN will move north into central MN this afternoon. Model soundings indicate some cooling occurs in the lower layers while some warming occurs aloft. Not so in the far southern Red River Valley where moisture increases in the lower layers and some drying occurs aloft.
Temperatures will again to surge into the low- to- mid 90s across the region as 850- mb temperatures in the 21-24 degree Celsius range mix down to the surface. The high heat combined with mid-70s surface dewpoints will yield heat index values between 100-108.
The Northern Plains is situated under zonal flow this afternoon, with upper level lows parked over the Canadian Rockies and near Hudson Bay. Temperatures will be cooler this weekend, with highs mainly in the 70s. At midnight CDT/05z a cold frontal boundary extended from low pressure in Alberta/saskatchewan south through central North Dakota into northwest South Dakota.
1213 AM CDT Fri Jul 19 2019 Temperatures continue to warm this afternoon and with the dew points in the lower to mid 70s, the heat index values continue to be a few degrees either side of 100 already this afternoon.
An upper level ridge will bring dangerously hot and humid conditions to central Indiana into the weekend.
An upper ridge of high pressure will bring dangerously hot and humid conditions to central Indiana into the weekend.
A warm front will be lined up approximately between the I-90/94 corridors. High heat and humidity (CAPE of 5000+ Kj/Kg) + warm frontal boundary + ample bulk shear (35-50kt) will lead to an enhanced risk of severe thunderstorms by this evening into the overnight hours. The highest severe threat looks to be north of the I-90 corridor where that warm front will be hanging out.
1049 PM CDT Thu Jul 18 2019 High pressure, southerly winds, and clear skies will remain over the area through Friday. Models are in decent agreement that a cold front will be approaching northeast Nebraska Friday night.
353 AM CDT Fri Jul 19 2019 Similar temperatures are expected for today under the upper ridge.
We may see a few high clouds push into portions of the lower Colorado River Valley overnight, but overall mainly clear skies are expected area wide.
350 AM CDT Fri Jul 19 2019 Today will see another day of extreme heat under the influence of an expansive upper ridge of high pressure encompassing the southern two thirds of the CONUS. The heat is expected to peak this afternoon/evening with even hotter temps and heat indices forecast as the the airmass warms ahead of an approaching cold front moving into northern Nebraska. The cold front will be the focus for showers/storms across portions of northern/western Nebraska tonight, but models are in decent agreement that this activity should remain to our north and have removed our small precip chances for tonight. The weather pattern undergoes changes over the weekend a strong upper jet drives a series of waves south across northern/central plains and shunts the upper ridge axis to the south/west.
The stacked ridging will keep warm and somewhat stable conditions in place, but deep moisture advecting into the area under southeasterly surface flow will lead to scattered thunderstorms developing each afternoon, propagating along sea breeze and outflow boundaries through the early evening hours.
Where there was more sunshine in southeast Missouri and southern Illinois, temperatures managed to reach the lower 90s and heat index readings topped 105.
Many locations are reporting temperatures in the mid to upper 70s, with the exception of the Louisville metro which sits in the low 80s at this hour due to the urban heat island effect. The well advertised heat wave will be in full effect today, and temperatures should steadily climb into the low to mid 90s by mid afternoon as the core of the ridge builds in aloft. Overnight lows generally in the mid 70s with urban areas slightly warmer.
Friday will be breezy and several degrees cooler than today.
High pressure has been pushed a bit further southeast than was previously anticipated, due to persistent westerlies over the Great Basin.
Position of the ridge, and timing off the wave will be crucial to placement of late afternoon convection.
High pressure at the surface is centered over the Atlantic this morning and stretches into the northern gulf coast. Aloft, a ridge is also in place.
Upper level high pressure will remain overhead through Sat.
Best chances of convection will likely be across southern counties mainly south of I-40 but slight chance PoPs do extend to the north across the higher terrain. Chattanooga Airport, TN 91 74 91 74 / 30 30 70 30 Knoxville McGhee Tyson Airport, TN 91 73 91 73 / 30 20 50 30 Oak Ridge, TN 91 74 92 73 / 30 20 50 30 Tri Cities Airport, TN 90 70 90 71 / 20 20 40 30.
For today, used persistence for dewpoints with temperatures a degree or two warmer than yesterday based on slightly higher 1000-500 mb thickness values.
A warm front will be lined up approximately between the I-90/94 corridors. High heat and humidity (CAPE of 5000+ Kj/Kg) + warm frontal boundary + ample bulk shear (35-50kt) will lead to an enhanced risk of severe thunderstorms by this evening into the overnight hours. The highest severe threat looks to be north of the I-90 corridor where that warm front will be hanging out. Will be monitoring this situation closely! Likelihood of thunderstorm continue into Saturday/Saturday night as a mid-level trough crossing the Northern Plains begins to drive a surface cold frontal boundary southward into the area.
A strong mid- summer cold front will be advancing south late at night, bringing with it much cooler air.
Temperatures will again to surge into the low- to- mid 90s across the region as 850- mb temperatures in the 21-24 degree Celsius range mix down to the surface. The high heat combined with mid-70s surface dewpoints will yield heat index values between 100-108. With the mid/upper ridge firmly in place, and no real change in the presiding air mass, persistence is the forecast for Saturday.
With an upper level trough remaining over the west coast, westerly flow into the region continues below normal temperatures. The upper level trough then transitions to a weak ridge into Saturday with southerly flow beginning to feed into the area.
A broad ridge will exist over the Southern Plains and Southeast through Saturday with with 500mb geopotential heights maxing out around 593 dam.
A flat cool westerly flow will continue over the area for the next 24 hours resulting in cooler than normal temperatures.
Moisture will begin to increase over the eastern portions of the area as the upper ridge breaks down and a weak upper trough rotates around the ridge. 0 inches in the east, and this combined with weak upper troughing will kick off a few showers and thunderstorms. Afternoon highs will climb into the low 90s once again and this combined with dewpoints in the low/mid 70s, will create heat index values ranging from 100-105.
401 AM CDT Fri Jul 19 2019 WV imagery shows a broad upper ridge extending across the srn CONUS and beyond, that will continue to dominate the weather over West Texas and Southeast New Mexico the next few days. The upper pattern and low-lvl thermal ridge on tap for today looks similar to yesterday's, and should yield similar temps. As has been the case the past few days, any chances of convection will be confined to the higher terrain out west, initiated in upslope return flow each day. Over the weekend, a trough out of the PacNW will ride over the top of the ridge, and dig SE down into the MS Valley, splitting the ridge in two.
The 500mb ridge will remain in place through the period. High temperatures today and Saturday will range from the low to mid 90s near the coast to around 105 across the Rio Grande Plains.
Water vapor loop indicate an upper low over the southern ALTA/SASK border and a second upper low was over nw WA. An mid level trough over se MT will move across the southern Red River Valley this afternoon. Warm frontal boundary over SD and southern MN will move north into central MN this afternoon. Model soundings indicate some cooling occurs in the lower layers while some warming occurs aloft. Not so in the far southern Red River Valley where moisture increases in the lower layers and some drying occurs aloft.
/issued 328 AM CDT Fri Jul 19 2019/ The heat remains front and center today and tomorrow as a hot, mid- summer upper ridge continues to dominate much of the southern and central CONUS. The upper level pattern will begin to change by the second half of the weekend as a deepening closed low over the northeast Pacific cause the ridge to build in amplitude over the Rockies and a trough to sharpen across the eastern CONUS. This will cause the mid-level flow over West Texas to turn more northerly while at the same time driving a Canadian cold front southward through the center of the nation.
For tonight, a cold front will approach the far northeast corner later tonight as winds shift northerly and a chance of stratus deck developing towards daybreak across the far northeast corner. It will be significantly cooler over the weekend. A much cooler airmass will spread in from Wyoming Saturday morning. Overall scenario will be similar but with even cooler temperatures expected across the northeast plains.
253 AM PDT Fri Jul 19 2019 A weak trough near the California coast will continue the slow deepening of the marine layer into Saturday. Warmer after Saturday as high pressure to the east builds, with an influx of monsoonal moisture.
917 AM EDT Fri Jul 19 2019 High pressure in the Atlantic continues to ridge west over the Florida peninsula producing light southeast winds this morning. Daytime high temps will reach the low to mid 90's with heat indices between 100-103 degrees. High pressure continues to ridge over the area producing pleasant boating conditions over the coastal waters.
As the calendar moves into late July, the change from cooling troughs of low pressure pushing into Central California to much more persistent high pressure will commence. So, how the forecast models bring us to this change? For today and Saturday, the forecast area will remain under a weak trough of low pressure.
Temps this afternoon will be near normal in the low to mid 90s; warmest spots in west Volusia/Lake counties where temps could climb to the mid 90s. Overnight lows in the low to mid 70s, upper 70s for some coastal sites. Weak surface pressure ridging remains over the area.
After sunrise, and warming of the low levels, these clouds should quickly dissipate, bringing abundant sunshine to the Midwest again today. As High pressure continues to remain over the southern US, this will hold a flattened 500mb contour pattern across the northern half of the US. As Low pressure systems slide through Canada, any developing weather systems are expected to remain north of the lower Midwest into the weekend.
Thunderstorms are also possible this afternoon/evening, though should remain confined mainly to the higher terrain west of area terminals. /issued 401 AM CDT Fri Jul 19 2019/ WV imagery shows a broad upper ridge extending across the srn CONUS and beyond, that will continue to dominate the weather over West Texas and Southeast New Mexico the next few days. The upper pattern and low-lvl thermal ridge on tap for today looks similar to yesterday's, and should yield similar temps. As has been the case the past few days, any chances of convection will be confined to the higher terrain out west, initiated in upslope return flow each day. Over the weekend, a trough out of the PacNW will ride over the top of the ridge, and dig SE down into the MS Valley, splitting the ridge in two.
High pressure and a little less moisture over the area will limit thunderstorm development trough Saturday with temperatures remaining a couple of degrees warmer than normal.
Cooler air begins to settle in tonight, with lows in the low 60s.
Offshore flow near Brookings will be the weather feature today with highs in the lower 80's along the southern Oregon coastline. A mix of VFR, MVFR, and IFR ceilings exist this morning across the interior, with the lowest ceilings likely along the Umpqua Divide and western foothills of the Cascades. The thermal trough along the coast will peak in strength this afternoon and evening.
241 PM CDT Fri Jul 19 2019 The upper level ridge of high pressure will remain in place across the region through Saturday while a cold front settles southward across the Northern and into the Central Plains states. Maintained low pops across a sliver of our central KS counties on Saturday evening as a cold front approaches late in the period.
/issued 917 AM EDT Fri Jul 19 2019/ High pressure in the Atlantic continues to ridge west over the Florida peninsula producing light southeast winds this morning. Daytime high temps will reach the low to mid 90's with heat indices between 100-103 degrees. High pressure continues to ridge over the area producing pleasant boating conditions over the coastal waters.
Locations around Seeley Lake, Ovando, and Georgetown Lake will likely drop to near freezing by tomorrow morning.
244 PM CDT Fri Jul 19 2019 (Tonight and Saturday) Hot, dry, and breezy conditions will continue across West Central Texas through the next 24 hours as an upper level ridge dominates the weather.
329 PM CDT Fri Jul 19 2019 Cold front is in the process of moving into the northern Red River Valley, with drier air mass advecting in with northwest BL flow. Regarding temperatures: Cooler air mass will support cooler temps Saturday (highs near 80), and lows tonight and saturday below 60.
A warm front will be lined up approximately between the I-90/94 corridors. High heat and humidity (CAPE of 5000+ J/Kg) + warm frontal boundary + ample bulk shear (35-50kt) will lead to an enhanced risk of severe thunderstorms by this evening into the overnight hours. The highest severe threat looks to be north of the I-90 corridor where that warm front will be hanging out. Will be monitoring this situation closely! Likelihood of thunderstorm continue into Saturday/Saturday night as a mid-level trough crossing the Northern Plains begins to drive a surface cold frontal boundary southward into the area.
345 PM CDT Fri Jul 19 2019 The excessive Heat Warning will remain in effect as very hot and humid conditions continue into the weekend as the upper ridge remains in place.
Otherwise, guidance hits at possibility for some convection along and near the trough axis, however, thinking inhibition will be difficult to overcome. Tomorrow, highs will be about 20 degrees cooler tomorrow compared to today. Meanwhile, a surface cold front will lie from northern IL to western KS to southeast CO.
Area temps ranging in the high 90s to low 100s. relief from the heat arrives during the afternoon hours as a slow moving cold front drops from the north. Tight gradient on either side of the cold front will have gusty winds accompanying it up to 30 mph in spots.
Issued by National Weather Service Grand Junction CO 243 PM MDT Fri Jul 19 2019 Hot and dry conditions will be giving way to cooler and wetter weather over the next 12 to 18 hours as a strong summer front drops south. Next up will be the strong cold front that will be driving south Saturday morning, reaching our far northern zones between 5 to 7 am exiting south of Castle Rock, Kiowa and Limon between 8 and 10 am.
322 PM CDT Fri Jul 19 2019 Fairly typical Summer day across the region today with temperatures in the low to mid 90s along with some scattered thunderstorms popping up, especially around the Atchafalaya Basin and into Lower Acadiana. Surface observations show high pressure over the SE CONUS leading to continued southerly flow over SE TX and S LA.
Tonight, a 40-45 kt southerly LLJ will develop and produce some turbulence in the low-levels, but surface winds should remain elevated, with the 0-2000 ft AGL shear falling short of LLWS criteria. /issued 328 AM CDT Fri Jul 19 2019/ The heat remains front and center today and tomorrow as a hot, mid- summer upper ridge continues to dominate much of the southern and central CONUS. The upper level pattern will begin to change by the second half of the weekend as a deepening closed low over the northeast Pacific cause the ridge to build in amplitude over the Rockies and a trough to sharpen across the eastern CONUS. This will cause the mid-level flow over West Texas to turn more northerly while at the same time driving a Canadian cold front southward through the center of the nation.
Hot Weekend Followed By A Cooler Week Ahead. The ridge will camp out for one more day before starting to slide westward.
Models still noting a weak back-door cold front overnight tonight, which will finally knock down the gusty westerly winds, bringing weak north winds for the day Saturday.
A cold front to the north of the area will allow for the winds to continue from the south. On Saturday, the transition to cooler temperatures will begin. The cold front will move into the area during the morning and should be most of the way through the forecast area by early afternoon. The temperatures to the south of the front will continue to be quite warm and the humidity will continue to bring heat index values to around 100 degrees along the Kansas/Nebraska state line, and to the south, even warmer.
Heights are rising overnight as an upper ridge axis builds into Lower Michigan and warm mid level temperatures are expected to cap strong convection through Saturday morning. A better indication for severe weather is on Saturday afternoon and evening as heights fall and a cold front pushes south into the very unstable and most air.
/issued 401 AM CDT Fri Jul 19 2019/ WV imagery shows a broad upper ridge extending across the srn CONUS and beyond, that will continue to dominate the weather over West Texas and Southeast New Mexico the next few days. The upper pattern and low-lvl thermal ridge on tap for today looks similar to yesterday's, and should yield similar temps. As has been the case the past few days, any chances of convection will be confined to the higher terrain out west, initiated in upslope return flow each day. Over the weekend, a trough out of the PacNW will ride over the top of the ridge, and dig SE down into the MS Valley, splitting the ridge in two.
Current temperatures are running about 1-2 degrees warmer than this time yesterday so adjusted highs so only a degree or two higher than yesterday.
Temperatures are still on track to reach the low to mid 90s today with dewpoints in the mid to upper 70s.
850 mb winds increase to 45-50 kts combining with around 30 (C) 850 temps should keep overnight lows around the lower to mid 70s. Saturday should be our last day of 100 degree weather in southwest Kansas for a while as a strong cold front will be entering the northwest part of the state through the mid afternoon. Thunderstorms will develop most likely post frontal as the cold front moves through western Kansas during the evening.
Temperatures a few degrees cooler than yesterday in most areas. Less wind and warmer temperatures - back to near normal - on Saturday.
Closer to home, a generally drier and cooler air mass is in place at the surface behind a trough that was reinforced by this morning's convection, consistent with generally clear skies over much of the area.
The best chance for a heat advisory will be for areas along and west of the Mississippi River, where the ridge will remain strongest. An upper level low, currently located over the Alabama, will continue to drift eastward into our area tomorrow. Expect highs around 90, with heat indices in the lower 100s.
113 PM PDT Fri Jul 19 2019 Weak low pressure continuing off the west coast remains the dominant weather feature as the monsoonal high pressure in the interior remains well east of Southern California. This has kept temperatures moderated and the trough has also kept the mountains and deserts dry. Little change and seasonable conditions are expected to prevail over the next couple of days as weak low pressure off the west coast continues the onshore flow into Southern California.
The air mass that settles in behind the wave will be characterized by weak surface flow and slightly cooler temperatures. An elongated west-to-east oriented 500 mb trough with strong curvature vorticity is forecast to sag down from Canada Saturday afternoon. Some CAMs suggest that this trough may produce isolated afternoon showers or weak thunderstorms across far north central North Dakota.
227 PM EDT Fri Jul 19 2019 Weak inverted upper trough remains over forecast area between ridges further east and west. For Saturday, upper-level inverted trough shifts a bit westward. Maybe slightly less coverage compared to Today with upper trough further west.
Lows as cool as the low 50s in northern Minnesota as drier air moves in, in the low 60s in northwest Wisconsin.
Did lean toward cooler guidance but may have to keep trending downward. The expansion of the ridge across the Rockies into central Canada remain consistent with progs which keep up hot and out of the main plume of mositure to start the week. Another strong northern stream system moves out of the high Pacific and plows into the ridge by midweek.
310 PM CDT Fri Jul 19 2019 Mid level ridging will begin to slowly shift northwest through the weekend. At the surface, the CWA is located between low pressure centered over the Texas and Oklahoma panhandles and high pressure over the northeastern Gulf of Mexico. While temperatures will be slightly cooler on Saturday than today, heat index values will still be 100-107.
The high dew points combined with temperatures in the low to mid 90s have push heat index values into the 105 to 110 degree range.
---BMickelson Previous discussion: Synoptic Setup: To the south hot high pressure lies bottled up over the Four Corners. North of this a series of troughs and ridges of relatively cooler air run from the Pacific Northwest and British Columbia through northern Montana and the Canadian Prairies. Saturday through Saturday night: A dip in the flow will briefly bring cooler conditions and an isolated chance for showers across the northwest zones. Meanwhile, the the hot air to the south will bulge northward over Nevada into Idaho and place northeast Montana under northwest flow with an increasing ridge influence.
A welcomed change is on tap for the beginning of next work week with cooler temperatures and increased rain chances expected. We will remain under a broad upper ridge through Saturday with a fairly strong mid-level thermal ridge anchored near the region.
913 AM PDT Fri Jul 19 2019 Seasonable conditions are expected to prevail over the next couple of days as weak low pressure off the west coast continues the onshore flow into Southern California.