Aikyam-Lab/Synoptic-Bench huggingface dataset:
High pressure is centered over the SW half of TX today, further prolonging the long dry spell and elevated heat indices. We're expecting to see a westward shift of the H5 level ridge tonight into Monday, and this could more Gulf modified air into the I-35 Corridor areas with some isolated convection Monday afternoon over parts of the Coastal Prairies.
This has helped keep temps in the lower to middle 70s across much of south central Nebraska where the clouds have persisted. With this latest guidance coming in cooler. but kept generally above guidance as a warmer airmass will be in place and anticipate most areas will end up being partly cloudy by afternoon.
It will be much cooler and less humid with lows in the middle to upper 40s north and in the lower to middle 50s south.
For tonight and Monday, upper level high pressure will continue to slowly build northward over the srn Rockies, with dry air remaining in place over the mountains and interior valleys into Mon afternoon. While humidity will again drop below 15 percent over much of the higher terrain, winds will be fairy light under building high pressure, so no fire weather highlights needed.
So far, they are staying just to the west of this cwa but may briefly cross into central SD early this morning before dissipating under building high pressure. However, as the high exits to the east return flow will set up. Southerly winds will increase Monday afternoon to 15 to 25 mph, ushering up warmer air.
For the next 48 hours southwest winds aloft will remain as high pressure consolidated over Texas and low pressure develops off the west coast.
Model soundings still look to be on the dry side for the short term period, and expect diurnal convection to be mostly limited to the higher terrain. Hot and humid weather will persist into mid week as a strong 595 dam mid level ridge centered in the southern Plains extends over the TN valley.
Winds will begin to transition to the south this evening into the overnight hours, as the high moves southeast. Overnight lows will range from the lower 50s to lower 60s.
/issued 417 AM CDT Sun Aug 18 2019/ Trough boundary can be seen fairly well in satellite imagery along the east coast through FL into the gulf south of near Apalachee Bay. Some of these thunderstorms that are forming along the trough axis toward the west may develop over the coastal waters this morning. There is a marginal risk of excessive rainfall that is aligned mainly where the trough axis is located. Southerly onshore flow will dominate through the next 7 days as surface 1019 MB high pressure sits over the northeastern and northcentral Gulf.
116 PM CDT Sun Aug 18 2019 Early morning satellite imagery shows a bit of a flat pattern in place across the center of the Nation, with a synoptic level trough axis swinging into the Northern Plains, focusing another round of stormy activity across the Central Plains with the help of the nocturnal jet. Otherwise, expectations are that this activity will continue to spread southeast slowly as the cold pool behind these storms continues to interact with the low level jet through sunrise, with storms eventually congealing into a broad area of storms across central and southern Missouri later this morning.
350 PM CDT Sun Aug 18 2019 Mid-afternoon sfc analysis shows the area remaining under the influence of high pressure centered over the wrn Atlantic, ridging wwd across the nrn Gulf, and maintaining a very moist srly low- level flow across the region. Water vapor imagery shows ridging aloft remaining to our west while weak troffing is noted over the ern 1/3 of the country. As we move through the mid-week time frame, the ridge axis to our west begins pushing back somewhat ewd to a more wswrly-enerly plane.
High res guidance is a little all over the map this morning as far as convective coverage for the afternoon, but given the high moisture content noted in area 12z soundings as well as the increased coverage already mentioned, nudged POPs up for the remainder of the day which is in line with local ARW guidance. Area will remain on the eastern periphery of mid and upper level high limiting capping and allowing for a daily chance of late morning and afternoon thunderstorms. High pressure continuing to ridge west across the northern Gulf will maintain a light to occasional moderate onshore flow.
WV imagery shows an upper ridge centered over the lwr Rio Grande Valley, resulting in yet another day of hot temperatures for West Texas and Southeast New Mexico. Over the next few days, the ridge will generally drift NW, w/thicknesses gradually decreasing across the area.
Upper flow shifts to the west-southwest today bringing warmer air to the region. Winds will be light, except it will become breezy in the higher elevations this afternoon.
Overnight the cold front to the north will move into our region providing a solid low cloud deck that may just keep our temperatures at bay for most of the region on Monday.
These winds will be bringing in much warmer air to mainly central South Dakota with highs in the upper 80s to the lower 90s. The models show a short wave trough coming in from the northwest Monday night along with a surface front. At this time, have in some slight chances of showers/storms for part of the north and east Monday night with this trough and front.
A ridge of high pressure will remain over the Western Atlantic waters extending westward into the Florida Peninsula for early to middle part of this week.
With a ridge of high pressure over the region, expect temperatures to remain on the warm side. Otherwise, m id and upper flow across the region is transitioning southwesterly today as a low pressure trough moves away from Montana. At the same time, a broad high pressure ridge is strengthening from the Desert SW to the southern Plains while a low pressure trough forms over/just west of British Columbia.
243 PM CDT Sun Aug 18 2019 WV imagery shows the upper high moving slowly overhead while building.
CIN continuing to erode over eastern CWA this afternoon as surface trof moves through the region. However the boundary layer winds will subside later tonight in the west due to approaching ridge. A pleasant and less humid day lies ahead for Monday with high pressure settling over the area. A lake breeze will keep lakeshore areas slightly cooler in the afternoon.
Will see temperatures soar into the lower 90s with heat index values likely ranging from 95 to 107, with the warmest values over southeast Kansas and western Missouri.
The transition begins as upper level ridging extending from Bermuda southwestward over the Bahamas and southern Florida starts to shift northward as the trough that has been over the east coast weakens and moves north.
Scattered thunderstorms expected through mid afternoon as convection begins to fire off with a focus along the observed sfc theta-e ridge where dewpoints are in the upper 60s to low 70s with mid 80/low 90 sfc temperatures. A fairly significant layer of warmer air should be moving in between 700mb and 850mb continuing into the afternoon which may put a lid on additional activity from mid-afternoon on. With somewhat less instability from near PIT and south, and weak ridging, continued with lower/isolated POPs in this area, with slightly higher POPs/scattered coverage north.
Otherwise, the forecast remains on track with temperatures warming into the low to mid 70s across the northern Valley where daytime heating and adiabatic downsloping are helping temperatures climb faster than elsewhere in the region. High temperatures will stay on the cooler side however and west winds will get a little gusty by afternoon.
With the upper ridge building into the western portions of the CWA, best chance for storms would be across eastern portions of the CWA during the afternoon hours. Tilly Upper ridge builds further west into the area on Tues with 850 mb temps in the 22-26C range. This should result in the warmest day of the week with temps in the lower to mid 90s across the region. Would expect warmer dewpoints as well as a warm front lifts into the region. Terminals should remain dry overnight with a potential for redevelopment Mon morning around sunrise as the cold front lingers in the region.
Atlantic high pressure and an inland trough will then prevail into late week before a cold front approaches but likely stalls before reaching the area.
1048 AM MDT Sun Aug 18 2019 Dry and hot conditions will continue today and Monday across the western slope with no thunderstorm activity expected as the upper level trough responsible has moved far enough east into the northern Great Lakes to lose its influence over the area. High pressure will build back over the region and much of the west with a westerly flow today shifting to southwest by this evening. Temperatures will remain above normal during the afternoon with perhaps some cooler nights due to the presence of drier air and clear skies, leading to efficient radiational cooling.
A ridge of high pressure will remain over the Western Atlantic waters extending westward into the Florida Peninsula for the early to middle part of this week.
Low pressure will continue east into Ontario tonight, with winds remaining gusty from the west across the northern half of the lake. High pressure will build in tonight into early Monday, bringing quiet conditions.
With somewhat less instability from near PIT and south, and weak ridging, continued with lower/isolated POPs in this area, with slightly higher POPs/scattered coverage north.
Below normal temperatures continue across interior NorCal, with afternoon temperatures running 3 to 10 degrees cooler than 24 hours ago.
An area of light rain is located over the northern nature coast which is associated with a trough of low pressure. Transition has begun over the central and southern forecast area as high pressure surface and aloft is building over the region. The northern nature coast will be along the periphery of the trough with scattered showers and isolated thunderstorms again possible. Scattered mid/late afternoon showers and thunderstorms will develop across the region with high temperatures around 90 to the lower 90s.
A few showers and thunderstorms are still going along the Highway 190 corridor and between the northern and southern terminals. /issued 350 PM CDT Sun Aug 18 2019/ Mid-afternoon sfc analysis shows the area remaining under the influence of high pressure centered over the wrn Atlantic, ridging wwd across the nrn Gulf, and maintaining a very moist srly low- level flow across the region. Water vapor imagery shows ridging aloft remaining to our west while weak troffing is noted over the ern 1/3 of the country. As we move through the mid-week time frame, the ridge axis to our west begins pushing back somewhat ewd to a more wswrly-enerly plane.
Scattered thunderstorms expected to continue for areas west of a DUJ to ZZV line as per trough encroachment. With somewhat less instability from near PIT and south, and weak ridging, continued with lower/isolated POPs in this area, with slightly higher POPs/scattered coverage north.
The upper level ridge is predicted to remain quasi-stationary over the SCNTRL/SWRN CONUS during the period. The upper level ridge notwithstanding, anticipate isolated convection over mainly the NERN CWA Monday.
449 PM MDT Sun Aug 18 2019 Upper ridging continues to build across the western to central CONUS bringing dry and quiet weather to the region. Highs tomorrow will be much warmer.
We'll continue to monitor our far northwest counties through the peak heating of afternoon, but strong subsidence associated with the mid level ridge will likely squash any convective attempts. Farther east, puffy cumulus are spreading through East Texas with the effects of the upper ridge likely to keep a lid on things in this area as well. Deeper mixing west of I-35 has allowed dewpoints to fall into the lower 60s. The beginning of the work week will continue to be hot with highs near 100 and little chance for rainfall as the persistent upper ridge remains in place. As we get into the middle and latter part of the week, there continues to be signs that the ridge will flatten some and retreat westward. This will result in high temperatures being 1-3 degrees cooler than they currently are.
It's enough of a concern to lower highs a few degrees into the lower 80s across those areas.
High pressure over the region will result in continued warm and dry conditions over the next few days.
648 PM CDT Sun Aug 18 2019 154 PM CDT In the near term, focus revolves around the low potential for additional isolated to widely scattered showers and/or storms this afternoon and evening. High pressure centered to our north Monday evening/overnight should be plenty close to aid in bringing tranquil conditions to the region for much of Monday night. Partly to mainly clear skies should allow temperatures to fall several degrees cooler than they have been the previous several nights with lows ranging from the low 60s north and west to the mid-upper 60s elsewhere.
18Z surface data had the cold front from KLSE to KOMA with a pre- frontal trof from northeast Illinois back through KOTM.
911 PM EDT Sun Aug 18 2019 High pressure in the Atlantic will direct a moist flow into the forecast area through much of the week. Weak troughing will linger locally. Persisted with overnight temperatures with lows in the low to mid 70s. Persistent upper trough over the area with ridge out west and offshore. Continued forecast of scattered afternoon and evening thunderstorms both days with temperatures remaining above normal in the low to mid 90s. The surface southerly flow is forecast to continue on the backside of high pressure off the Southeast Coast. The models depict a weakness in upper ridging over the forecast area.
352 PM MDT Sun Aug 18 2019 Upper ridging continues to build across the western to central CONUS bringing dry and quiet weather to the region. Highs tomorrow will be much warmer.
Most of the convergence was across the eastern Fl Panhandle and Big Bend between the wave and a ridge building in across cntl Fl. models indicate the wave of low pressure will start to track more east later tonight as a short wave moves across Se Ga which may produce scattered showers/isolated storms there before dawn which will continue at least into Monday morning.
Slightly cooler air has moved into much of the forecast area behind this boundary such that the Heat Advisory issued earlier has been cancelled for all counties except Palo Duro Canyon State Park. Convergence along the trough may be just enough to spark ISO TSTMs across the far SE corner late this aftn and evening and just now beginning to see some CU developing in this area. An upper level ridge of high pressure will continue to migrate west to a position near the four corners region by the middle of this week.
Winds will be light and variable with high pressure over the region.
/issued 243 PM CDT Sun Aug 18 2019/ WV imagery shows the upper high moving slowly overhead while building.
645 PM EDT Sun Aug 18 2019 High pressure in the Atlantic will direct a moist flow into the forecast area through much of the week. Weak troughing will linger locally. Persistence with overnight temperatures with lows in the low to mid 70s. Persistent upper trough over the area with ridge out west and offshore. Continued forecast of scattered afternoon and evening thunderstorms both days with temperatures remaining above normal in the low to mid 90s. The surface southerly flow is forecast to continue on the backside of high pressure off the Southeast Coast. The models depict a weakness in upper ridging over the forecast area.
605 PM EDT Sun Aug 18 2019 It will remain very warm and humid into early this coming week and a meandering trough of low pressure will keep the mention of mainly afternoon and evening showers and thunderstorms in the forecast.
1024 PM EDT Sun Aug 18 2019 Water vapor imagery highlights a well-formed, mean-layer anticyclone centered over southern Texas. A mid to upper-level weakness in the ridge complex stretches southwest from the Bahamas to the extreme Western Caribbean. Deep northeasterlies sampled by the KKEY RAOB have begun to paint the northwestern fringes of the inverted trough over the Bahamas.
Troughing off the Pac NW Coast will keep dry and stable southwest flow over the Sierra through this week.
Following a few streamer showers this morning, the best precip chances today should reside on the eastern periphery of this ridge along the Texas Upper Coast closer to an axis of better 700-500 mb moisture, but some of this activity may graze our NE zones this afternoon where slight chance PoPs exist. As the upper high moves even farther northwest of the region tomorrow, spotty showers and storms should expand west to the I-37 corridor. Models are in fair agreement with the mid level high shifting northward as an inverted trough slides west across S TX by mid week.
310 AM EDT Mon Aug 19 2019 Synopsis/Discussion/Marine - Fair weather today and tonight - Showers and storms possible Tuesday afternoon and night - Cooler late in the week A high pressure ridge will build in and bring fair wx today through tonight with seasonable temps for this time of year. A strong cold front will bring some showers and storms Tuesday night.
An upper level ridge will build into the area Monday with warmer temperatures and more sun into Tuesday. A front will move through Western Washington the middle of the week with a chance for showers and cooler temperatures.
329 AM CDT Mon Aug 19 2019 The subtropical ridge that had brought record heat to the area will remain centered over W TX and E NM today.
Temps range from the lower to mid 70s. Surface dewpoints have climbed a bit more in the last 24 hrs and are mainly in the lower 70s.
Hot weather expected to continue in the short term as upper high remains in place over W TX. Two disturbances, one over NE AZ and one just south of NM, should continue to ride the northwestern side of the upper high.
Later today, we heat up into the low to mid 90s across the area as upper ridge begins to build into the area. Heat index values will range from around 100 to 107 with the highest readings over the western CWA.
Current surface dewpoints are in the low to mid 70s along the Arkansas River valley up through Tulsa and do not expect this to mix out this afternoon.
304 AM CDT Mon Aug 19 2019 High pressure will exit to the east today. Return flow will set up on the back side of the high. Breezy southerly winds will usher in warmer, more humid air. Low pressure moves in from the west by this evening bringing some showers and thunderstorms. Canadian high pressure builds back in on Tuesday with dry conditions expected.
Heat indices are likely to approach if not meet the low 100's to 105 F area for heat indices along the Oklahoma line. The better opportunity for severe might be with the northern storms as the area will be moving into better surface moisture pooling near a warm front, so a wind and isolated hail risk is possible but those storms may remain out of our forecast area altogether. The higher probability appears associated with storms in the south which could also produce gusty winds close to severe limits.
For now, expect the upper ridge will continue to limit the coverage of afternoon showers/storms and have kept things dry for now.
Winds will begin to transition to the south this evening into the overnight hours, as the high moves southeast. Overnight lows will range from the lower 50s to lower 60s. Upper ridge will be centered over the Four Points/Southern Plains. Warm and humid conditions continue on Tuesday with highs slightly warmer than Monday. Thunderstorm chances increase across the Central Plains, ahead of an upper trough moving north into NE/IA.
Weak upper wave passing by this morning will be followed by weak ridging today but LL moisture is on the upswing. Upper ridge breaks down and that will allow weak upper troughing and several bits of energy to cross the region.
This will allow southerly winds to bring a warmer/moist airmass back into the region overnight tonight and into the day Monday. As warmer air returns to the region tomorrow, temperatures will climb into the low to mid 80s with dewpoints in the 60s spreading northward through the day. The continued eastward advection of a mid level thermal ridge will help build a capping inversion over the region that will maintain dry weather for the day Monday. Have POPs mostly in the north and west Monday night, with some lingering showers in the northeast into Tuesday morning as the cold front pushes through.
For tonight and Monday, upper level high pressure will continue to slowly build northward over the srn Rockies, with dry air remaining in place over the mountains and interior valleys into Mon afternoon. While humidity will again drop below 15 percent over much of the higher terrain, winds will be fairy light under building high pressure, so no fire weather highlights needed. high pressure will continue to spin across the region with dry weather expected to continue Monday night.
These winds will be bringing in much warmer air to mainly central South Dakota with highs in the upper 80s to the lower 90s. The models show a short wave trough coming in from the northwest Monday night along with a surface front. At this time, have in some slight chances of showers/storms for part of the north and east Monday night with this trough and front. Cooler high pressure moves into the region Tuesday and we'll see a less active pattern this week with mostly dry conditions expected.
The low level moisture together with steeper mid-level lapse rates will lead to MUCAPE values in excess of 2000 J/kg Monday night along the Minnesota/Dakota border.
Confidence remains high that excessive heat will be in place for both today and Tuesday as upper ridging continues to build over the southern Plains. There is good model agreement that a fairly impressive upper trough will dig across Ontario into the Great Lakes for Tue night through Wed. This will allow a cold front to migrate south across the Central Plains.
High pressure over the region will result in continued warm and dry conditions over the next few days. High pressure will continue to build across the southern Rockies through southern Great Plains area through midweek, keeping a dry southwest flow across the forecast area.
The ridge will continue to build into the area continuing the dry and above normal temperatures across the area. Todays's RH values will be the lowest, dropping into the lower teens today and increasing into the low to mid 20s tomorrow.
311 AM EDT Mon Aug 19 2019 Mid level ridging centered over the southern high plains sprawls to southwest Canada. weak troughiness stretches down the eastern seaboard. and ridging nudges into FL from the Atlantic through Tue night. At the surface a frontal trough along the northern Gulf coast and through northern Fl eases northward as broad Atlantic high pressure across south-central FL to the Gulf lifts into northern FL Tue. Wed-Sun: Atlantic high pressure ridging west along 30 North Latitude to the central Gulf coast provides a prevailing southeast flow but with an onshore shift near the Gulf coast in the afternoons. Gentle to moderate winds generally from the southeast except during afternoon seas breezes as relaxed high pressure dominates the waters.
As these previously mentioned features continue to slide east toward the I-29 corridor and eventually SW MN/NW IA, better focus of the low level jet should allow for better chances/coverage of thunderstorms and thus have adjusted POPs appropriately. Mid level ridging builds in to the west by the middle of the week and will allow for quiet weather across the region.
Will see temperatures soar into the lower 90s with heat index values likely ranging from 95 to 107, with the warmest values over southeast Kansas and western Missouri. Tuesday will be dominated by the strong upper level ridge overhead and a continuation of the hot and humid weather.
212 AM MDT Mon Aug 19 2019 Upper flow over the northern plains is nearly zonal, with slight ridging to the west. Temperatures will rise into the lower 90s, beneath sunny skies. Highs will be cooler - but still warm - in the 80s.