Aikyam-Lab/Synoptic-Bench huggingface dataset:
621 AM EDT Thu Jul 21 2022 A very weak cold front will pass through the state today, accompanied by isolated to scattered showers and thunderstorms over mainly the eastern third of the state.
The high pressure ridge remains stretched across the central part of the Florida peninsula this morning. High pressure ridging across the Florida peninsula will keep a SE through SW wind flow around 10-15 knots over the gulf waters through the end of the week and into the weekend.
The upper level high over the southwestern states will be centered over northern Arizona today, and then shift a bit east over the Four Corners area by Friday morning. This high will weaken slightly. A couple of disturbances will move around the east side of this high and into our area, in weak northerly flow aloft. With a weakening 850mb thermal ridge, an increase in cloud cover and the development of convection, temperatures will not be as hot today.
701 AM EDT Thu Jul 21 2022 Satellite imagery shows the low over northern Ontario continuing to pull away early this morning. As dry air behind the low continues to cycle over the region, expect any remaining cloud cover to leave this morning. Thus, lows should be in the low to mid 60s early this morning. In its wake, a cold front will track through the UP today, but it will be dry with limited moisture and surface ridging.
407 AM MDT Thu Jul 21 2022 A robust upper-level ridge will remain over the region today and Friday, keeping temperatures warm and above average. There is not a large amount of instability, and the lower atmosphere remains quite dry, so don't expect widespread soaking rain from these storms/showers.
A slow moving cold front stretching across central Arkansas is spreading scattered showers down through northern Louisiana this morning.
Discussion: A complex of showers and storms is drifting south out of KY and into the east TN valley ahead of a cold front across the Ohio River Valley. The aforementioned cold front will move into east TN during the afternoon hours and then stall along the TN/NC/GA line late afternoon into the evening hours.
Similar to the last couple of days, CAMs are in good agreement for both today and Friday developing showers and thunderstorms in afternoon hours across the higher terrain mainly south and east of Tucson and in the White Mountains. This is occurring as the subtropical high weakens slightly but more importantly becomes aligned from east to west from the Four Corners into the Lower Mississippi Valley.
Based on the latest short-term guidance from several CAMs, dewpoints will end up with a sharp gradient from the low 60s to 75F+ right around the southern border of our CWA this afternoon. A warm front lifts north by tomorrow and an upper ridge builds in, making for hot and humid days with warm and balmy nights for the next several days. The next decent chance for rain looks to be next Thursday as a cold front trails down from a deep occluded low over eastern Ontario. Wind SSW 8-12kts decreasing overnight and becoming northerly behind a cold front Thursday.
Weak upper trough remains over the E CONUS. A weak upper trough axis will be over the area, although the stronger westerly flow will be retreating further north. Highs will be in the low 90s.
Even with a bit lower temperature in the cloudier regions of central and southern Oklahoma, the higher surface moisture will lead to heat advisory criteria in north central and east central and southeastern Oklahoma this afternoon.
The strong trough that helped drop dewpoints and temperatures yesterday is beginning to lose its influence on eastern Nebraska and southeast Iowa as it spins away across southeastern Canada. Behind it sits a strong mid/upper ridge centered over the desert southwest, that will slowly move eastward over the next few days. Along the stalled out boundary, a corridor of locally increased dewpoints will develop and by around midnight and with the development of the low-level jet, nocturnal storms will likely develop at its nose. CAMs seem to indicate vertical profiles that are pretty dry in the low levels, indicating that some stronger wind gusts could develop with these storms.
A cold front is currently draped along the KY/TN border with cooler and less humid air filtering into the region behind it. Northerly flow will allow significantly lower humidity into the region with dewpoints dipping into the low to mid 60s by afternoon. So while high temperatures will only be 2 to 5 degrees cooler than yesterday, it will feel remarkably nicer with the lower humidity.
/issued 242 AM CDT Thu Jul 21 2022/ SHORT TERM (Now through Friday): 500 mb high pressure centered over the Four Corners area will continue to dominate over the BRO CWFA, even though a weak inverted mid-level trough will develop over the central Gulf of Mexico and slowly approach from the east.
Eastern Utah and western Colorado are in for another hot one today as the dome of high pressure over the Southwest remains in control. PWATs continue to run at or a bit above normal as moisture trapped under the ridge gets recycled each day. Today will be no different, as diurnal heating will act on that moisture and break out convection over the higher terrain during the afternoon hours. Friday will be similar to Thursday, with enough moisture sticking around to fire off convection over the higher terrain.
1055 AM EDT Thu Jul 21 2022 Observations from soundings across the state this morning show that the low-level ridge remains over mainland Florida promoting gentle east to southeast breezes across our waters. High pressure centered to the east of Bermuda and extending westward across Florida will maintain gentle to moderate east to southeast breezes across the Florida Keys coastal waters through Friday, with breezes becoming moderate to occasionally fresh during the weekend.
Weak high pressure moves across the area in the wake of the aforementioned wave Friday with sunny skies and light winds.
625 AM CDT Thu Jul 21 2022 (Today through Friday) Approaching cold front continues to support showers and thunderstorms just to the north of the mid state, but will work their way into the area over the next hour or two. Very high CAPE values of 3000 J/kg and higher in some areas will support some strong to severe thunderstorms capable of producing damaging wind gusts, but the high moisture/PWAT values are more concerning for flooding potential, especially for the eastern half/northeast part of the area. This should keep more widespread heat index values from getting above 100 degrees, but temperatures will still be in the low to mid 90s for most areas. Drier conditions will move in Friday with high pressure building in aloft, and high temps back into the mid to upper 90s.
615 AM CDT Thu Jul 21 2022 The long wave pattern overall continues to indicate a mid-level ridge over the Rockies, and mean troffing over the eastern CONUS. During the short range, the ridge flattens some as energy flows in off the Pacific Ocean. Initial thunderstorm development may be over NC SD where the low level thermal and theta-e ridge will be strongest.
An upper level trough will bring dry and windy conditions across southwest Montana and Lemhi County Friday where wind gusts will range between 25 and 40 mph. The trough will initiate showers and thunderstorms Thursday night through Friday, mainly across northwest Montana.
VRB winds wl be noted through the day as high pressure cont to dominate the pattern. Nevertheless, hazardous heat conditions are expected around the state again today, w/ the highest air temps across Nrn AR, and the greatest heat index values over Cntrl and Srn AR.
526 AM MDT Thu Jul 21 2022 A robust upper-level ridge will remain over the region today and Friday, keeping temperatures warm and above average. There is not a large amount of instability, and the lower atmosphere remains quite dry, so don't expect widespread soaking rain from these storms/showers.
442 AM CDT Thu Jul 21 2022 Temperatures will be on the increase the next couple of days as high pressure aloft shifts east. eventually flattening late in the weekend and allowing a cold front to cross the local area.
610 AM EDT Thu Jul 21 2022 Left over patches of stratus aligned along/in immediate wake of trough axis will shift east early this morning as this features shifts out of the region and the mid/upper flow flattens. Strong mixing in the wake of passing trough should yield westerly wind gusts near 25 knots by midday. Last vestiges of vorticity tied to the upper low now over far northeastern Ontario have generated a few isolated showers/drizzle overnight into early this morning.
323 AM PDT Thu Jul 21 2022 Strong high pressure over the southwest states will continue the seasonally hot weather for inland areas through Friday while the marine layer keeps coastal areas cooler with areas of night and morning low clouds and fog.
Northwest flow aloft remains over the Northern/Central Plains with an upper high centered over the Desert Southwest. At the surface, a very weak stationary front stretches just south of the KS/OK border with weak high pressure situated over east/central KS. Additional storms will develop out over the High Plains of northwest KS as a weak upper impulse slides across Northern CO. This will allow a weak cold front to push south and setup generally along the KS/NE border for Sat night through Sun and will provide some small storm chances to areas generally along and north of I-70. Not much is expected to change for Mon into Tue as a cold front remains positioned across the northern portion of the forecast area.
Based on the latest short-term guidance from several CAMs, dewpoints will end up with a sharp gradient from the low 60s to 75F+ right around the southern border of our CWA this afternoon. A warm front lifts north by tomorrow and an upper ridge builds in, making for hot and humid days with warm and balmy nights for the next several days. The next decent chance for rain looks to be next Thursday as a cold front trails down from a deep occluded low over eastern Ontario. Wind will be variable as a cold front moves across much of the Midsouth likely stalling across north Mississippi.
Isolated showers and thunderstorms will develop near CHA late this afternoon as a cold front approaches the region. McD Chattanooga Airport, TN 72 95 72 96 73 / 30 10 10 20 10 Knoxville McGhee Tyson Airport, TN 71 93 71 95 72 / 10 10 0 10 0 Oak Ridge, TN 70 93 70 94 71 / 10 10 0 10 0 Tri Cities Airport, TN 67 90 66 93 67 / 10 0 0 10 10.
Finally, a third potential solution is more activity developing with the low level jet/850mb warm advection in the mid to late evening, mainly along and south of the Interstate 94 corridor. This time the wave should be stronger, with better surface boundaries, and the low level jet.
1230 PM CDT Thu Jul 21 2022 Northwest flow aloft remains over the Northern/Central Plains with an upper high centered over the Desert Southwest. At the surface, a very weak stationary front stretches just south of the KS/OK border with weak high pressure situated over east/central KS. Additional storms will develop out over the High Plains of northwest KS as a weak upper impulse slides across Northern CO. This will allow a weak cold front to push south and setup generally along the KS/NE border for Sat night through Sun and will provide some small storm chances to areas generally along and north of I-70. Not much is expected to change for Mon into Tue as a cold front remains positioned across the northern portion of the forecast area.
328 PM EDT Thu Jul 21 2022 Warm conditions are expected today through Friday before even warmer, more humid air builds back into the region for this weekend. Northwesterly upper level flow and upper level troughing weakens on Friday giving way to height rises. At the surface, high pressure may start nudging in from the southwest modestly. Friday night starts off quiet due to high pressure building in from the south. Sub tropical ridge to extend from the Southern Plains across the Gulf states with a west-northwest flow across the Ohio Valley and Great Lakes.
The upper ridge helping to give us soaring heat for the next couple of days is forecast to flatten in both ensemble and deterministic models.
245 PM CDT Thu Jul 21 2022 Upper ridge remains in place over the southwest CONUS with modest northwest flow over the central Plains. Surface pressure pattern was rather nebulous with weak high pressure to the north and east, keeping winds modest. Latest suite of models on various scales keep nearly all precip north of eastern Kansas tonight, with little semblance of an upper wave and the low-level jet focused north.
With the impact of cloud cover, forecasted high temperatures have been decreased, ranging from the mid 90s to the low 100s.
122 PM PDT Thu Jul 21 2022 High pressure will continue to bring hot weather to the deserts through Friday. An Excessive Heat Warning will be in effect today and Friday for the lower deserts. The high pressure will weaken and push northeast later this weekend, putting SoCal back into a monsoonal pattern and decreasing temperatures in the deserts.
The region will be between high pressure to the southeast, and a stalled cold front to the north through Tonight. Temperatures aloft are cooler Today, so could still get strong storms, with an isolated severe possible.
216 PM EDT Thu Jul 21 2022 High pressure builds across the area through the start of the weekend. Shower activity diminishes by late evening as ridging builds from the west.
127 PM EDT Thu Jul 21 2022 Satellite imagery shows the low over northern Ontario continuing to pull away early this morning. As dry air behind the low continues to cycle over the region, expect any remaining cloud cover to leave this morning. Thus, lows should be in the low to mid 60s early this morning. In its wake, a cold front will track through the UP today, but it will be dry with limited moisture and surface ridging.
250 PM CDT Thu Jul 21 2022 The upper ridge over the southwestern CONUS remains strong today. As a dynamic upper trough exits the Great Lakes region, this upper ridge will begin to build eastward across the central plains late this week and into the weekend. With the upper ridge expected to expand across the central plains on Friday, it will also begin to flatten out allowing for zonal flow across the northern plains.
227 PM EDT Thu Jul 21 2022 A cold front is slowly crossing Eastern KY this afternoon from NW to SE. The high will shift to the east overnight and settle over the central Appalachians through Friday night. Overnight lows will be in the lower to middle 60s, with some river valley fog developing late tonight. We start ramping up the heat on Friday as the low level flow returns to the W/SW.
221 PM EDT Thu Jul 21 2022 Northwesterly flow behind a now departed low is keeping cooler onshore flow for the northeastern U. In its wake, a cold front will track through the UP today, but it will be dry with limited moisture and surface ridging.
Most CAMs have elevated thunderstorms developing through the lower MO river corridor around 06Z, then expanding to the east through parts of southeastern SD, northwestern IA, and southwestern MN during the later overnight hours. Model instability continues to vary quite a bit among model soundings, with the GFS on the lower end with MUCAPE less than 1000 j/kg, while the HRRR/RAP are closer to 1200 j/kg, and lastly the NAM continuing to be the most aggressive with MUCAPE of 1500 j/kg or slightly higher. Convection then tapers off by mid morning on Friday as the low level jet weakens and veers eastward. This will lead to a a very warm day with NAEFS ensembles pointing toward 700/850 mb temperatures in the the 90th percentile with respect to climatology, and highs are looking to reach the lower to mid 90s.
High pressure over the Four Corners area remains in place with South Texas on the eastern periphery. There will be little change to H5 heights as small perturbations occur in the high as it remains mainly anchored in place over the Desert Southwest. Heat indices tomorrow will range from 105-109 degrees but it is not expected to be as widespread as today with air temperatures a few degrees cooler with a slight uptick in cloud cover.
If you become concerned about yourself or someone else, immediately move the person to a cooler area and provide cool water.
Mainly dry conditions will be in place today as high pressure builds in from the west. Going into the afternoon and the evening, the relatively dry conditions will be interrupted with a post frontal trough passing through. This may have enough forcing to pop a few thunderstorms into the afternoon and evening especially with assisted lift from the ridges to the east. Locations that do not receive precip will experience warmer temperatures with Heat Index values into the lower to mid 90s.
101 PM CDT Thu Jul 21 2022 Temperatures will be on the increase the next couple of days as high pressure aloft shifts east. eventually flattening late in the weekend and allowing a cold front to cross the local area.
Dew points consist of the low to upper 50s and are expected to diminish a bit more with afternoon mixing. Tomorrow an upper level ridge will build over the region brining an increased heights aloft. Therefore, a strengthened low-level thermal ridge will increase temperatures into the upper 90s across the southwest part of the state.
252 PM EDT Thu Jul 21 2022 A cold front is slowly crossing Eastern KY this afternoon from NW to SE. The high will shift to the east overnight and settle over the central Appalachians through Friday night. Overnight lows will be in the lower to middle 60s, with some river valley fog developing late tonight. We start ramping up the heat on Friday as the low level flow returns to the W/SW.
The long wave pattern overall continues to indicate a mid-level ridge over the Rockies, and mean troffing over the eastern CONUS. During the short range, the ridge flattens some as energy flows in off the Pacific Ocean. Initial thunderstorm development may be over NC SD where the low level thermal and theta-e ridge will be strongest.
926 AM PDT Thu Jul 21 2022 High pressure will continue to bring hot weather to the deserts through Friday. An Excessive Heat Warning will be in effect today and Friday for the lower deserts. The high pressure will weaken and push northeast later this weekend, putting SoCal back into a monsoonal pattern and decreasing temperatures in the deserts.
The mid level ridge center has shifted farther west away from the region today, so there is a window of opportunity for storm development.
The ridge will slowly lift northward through the end of the week and into the weekend putting the entire state in an ESE wind flow. Daytime highs in the low to mid 90s expected with heat indices around 100-105 degrees. High pressure ridging across the Florida peninsula will keep a SE through SW wind flow around 10-15 knots over the gulf waters through the end of the week and into the weekend.
A 850/700 mb trough dropping southeastward through WI is forecast to track through the CWA this evening. This is where we will feature the highest POPs. The low level jet and stronger instability is shown to be aimed in those locations. Close monitoring will be needed going forward as a northward shift of the low level jet and instability could lead to an increase in the storm coverage for the CWA.
Hot and dry again today, about a degree warmer than yesterday, but Friday will be 5 degrees cooler as weak cold front and supporting upper trough come in from the north Pacific.
1014 AM CDT Thu Jul 21 2022 Shower activity has made its way into central Louisiana with a lead disturbance moving around the upper level ridge. Also, showers and thunderstorms are developing across the lower Atchafalaya Basin with an increase in moisture and daytime heating. A slow moving cold front stretching across central Arkansas is spreading scattered showers down through northern Louisiana this morning.
At the surface, dry air and high pressure are building in which are allowing for clear skies today. Lows tomorrow night will be slightly warmer than tonight, dropping to near 70.
Dry weather contiues across the area this afternoon as upper level ridging continues its hold on the weather pattern regionally. The upper level ridging will lose its strangle hold over the area tomorrow, as a weak disturbance moves through the area.
216 PM MDT Thu Jul 21 2022 Hot and dry are the 2 buzzwords that define today and tomorrow, being under prominent upper ridging an downsloping is allowing temperatures to climb into the mid to upper 90s and humidities dropping into the single digits to upper teens, quite different conditions that what we are use to this summer.
Gulf high pressure is interacting with lower pressure to the west and northwest. /issued 242 AM CDT Thu Jul 21 2022/ SHORT TERM (Now through Friday): 500 mb high pressure centered over the Four Corners area will continue to dominate over the BRO CWFA, even though a weak inverted mid-level trough will develop over the central Gulf of Mexico and slowly approach from the east.
1142 AM MDT Thu Jul 21 2022 A robust upper-level ridge will remain over the region today and Friday, keeping temperatures warm and above average. There is not a large amount of instability, and the lower atmosphere remains quite dry, so don't expect widespread soaking rain from these storms/showers.
Temperatures will begin to trend cooler over the weekend as monsoonal moisture returns to the region.
1145 AM MDT Thu Jul 21 2022 A robust upper-level ridge will remain over the region today and Friday, keeping temperatures warm and above average. There is not a large amount of instability, and the lower atmosphere remains quite dry, so don't expect widespread soaking rain from these storms/showers.
That said, there will be a weak 25 kt llj that develops ahead of the low after 3z, so can't completely rule out some thunderstorm development with the jet. Above normal highs are forecast again on Friday as heights rise slightly with a minor amplification/shift of the upper ridge. A low pressure system will move off the Rockies and into SD Friday night.
---BMickelson Previous discussion: Synoptic Setup: Forecast begins with hot high pressure over the western half of the CONUS with a ridge spur running north over the Front range of central Alberta and British Columbia. Just north of this a strong closed low is making its way down the down the Yukon into northern British Columbia and slamming up against the ridge crest. the cold air behind this is expected to smash against the ridge and move it east rapidly with a surface cold front pushing down the High Plains. Today through Friday: Highs pressure will remain in place for today and tonight as the ridge's influence continues to hang over the region. By Friday the cold front will push to the Canadian border int eh afternoon hours.
A cold front is slowly crossing Eastern KY this afternoon from NW to SE. The high will shift to the east overnight and settle over the central Appalachians through Friday night. Overnight lows will be in the lower to middle 60s, with some river valley fog developing late tonight. We start ramping up the heat on Friday as the low level flow returns to the W/SW.
A strong high pressure system was centered over Arizona during the morning hours and is expected to remain in place through Friday with hot temperatures continuing. Normally under such a strong high pressure system we can see activity completely shut down over Arizona.
1037 PM EDT Thu Jul 21 2022 High pressure builds across the area through the start of the weekend. Shower activity diminishes by late evening as ridging builds from the west.
This is in part due to a trough moving into NorCal, which will lower temperatures around 2 to 4 degrees from today's readings. This trough will also ramp up pressure gradients across the region to around 15mb between SFO to LAS.
/ISSUED 454 PM MDT Thu Jul 21 2022/ Dry weather contiues across the area this afternoon as upper level ridging continues its hold on the weather pattern regionally. The upper level ridging will lose its strangle hold over the area tomorrow, as a weak disturbance moves through the area.