Aikyam-Lab/Synoptic-Bench huggingface dataset:
240 AM CDT Thu Aug 26 2021 Another clear and mild night across the TN Valley, with 2 AM temps in the lower to mid 70s. This higher moisture, with PWs approaching 2 inches, will make the chance for thunderstorms a bit higher this afternoon, but with little in the way of forcing the coverage should remain isolated to scattered.
Discussion: Ridging continues across the area with 500mb heights around 592 to 593 dam across the region. Our forecast area is between two upper 594 dam 500mb ridge axes with slightly lower heights and weaker subsidence. Differential heating along the higher elevations will result in scattered convection developing across the mountains and plateau between 16z and 19z early in the afternoon.
The exception will be across the SRN and ERN counties where dewpts may remain in the low to mid 70s. Temps for Fri afternoon will be a bit cooler than Thu as heights aloft and 850mb temps decrease further.
345 AM CDT Thu Aug 26 2021 The dome of high pressure that had been over the region the past several days is expected to begin its eastward trek this afternoon toward the East Coast for Friday. afternoon temps today look to be a degree or so cooler compared to yesterday with highs in the mid 90s to near 100 degrees for most of Eastern Oklahoma and Northwest Arkansas. As the ridge moves off to the east.
347 AM CDT Thu Aug 26 2021 Upper level ridging will continue to exert its influence on West Texas today, though mid-level heights are progged to decrease slightly as the center of the high shifts toward the middle Mississippi River Valley. The net result should be slightly cooler temperatures versus yesterday. Highs in the lower 90s will be common on the Caprock, while the southeastern Texas Panhandle and Rolling Plains will peak in the middle to upper 90s. Broad upper level ridging centered over Oklahoma will have begun the process of splitting early Friday, with 500mb heights progged to fall slightly as two distinct anticyclonic centers shift both eastward and westward away from the area.
/issued 347 AM CDT Thu Aug 26 2021/ Upper level ridging will continue to exert its influence on West Texas today, though mid-level heights are progged to decrease slightly as the center of the high shifts toward the middle Mississippi River Valley. The net result should be slightly cooler temperatures versus yesterday. Highs in the lower 90s will be common on the Caprock, while the southeastern Texas Panhandle and Rolling Plains will peak in the middle to upper 90s. Broad upper level ridging centered over Oklahoma will have begun the process of splitting early Friday, with 500mb heights progged to fall slightly as two distinct anticyclonic centers shift both eastward and westward away from the area.
831 AM CDT Thu Aug 26 2021 An upper trough located over the Pacific Northwest will begin to dig and erode a ridge that is parked over the Central and Southern Plains. By early this morning the trough located over the Pacific Northwest should begin to slowly erode the ridge and the ridge begins to lose its influence over the area.
High pressure in place at the sfc/aloft will again translate into seasonably hot and humid weather conditions this afternoon, as highs climb mainly into the lower 90s/near 90F.
/TW/ Today and tonight: An inverted trough associated with the remnants of a Tropical Upper Tropospheric Trough (TUTT) is forecast to slide from the Florida Panhandle and into the Lower Mississippi River Valley. This moisture in conjunction with the aforementioned inverted trough will help foster scattered afternoon showers and thunderstorms with the highest rain chances along the Highway 84 corridor. Otherwise, fair to partly cloudy skies are expected tonight with overnight temperatures in the low 70s.
On Friday, an upper level trof will move through the area. As a result, expect much cooler temperatures, with afternoon highs about 10 degrees below normal.
Friday through the weekend, showers and thunderstorms will develop along the high terrain before shifting onto lower elevations along an axis from west central to northeast New Mexico.
610 AM CDT Thu Aug 26 2021 (Today and tonight) The mid-level ridge overhead begins to break down today, and hot/humid conditions are expected to continue with highs in the mid- to upper-90s.
Water vapor satellite loop this morning shows upper high pressure centered over eastern Kansas at 0730Z while a trough was moving eastward across the Pacific Northwest. Temperatures at 07Z were in the upper 70s to around 80 degrees with dewpoints in the lower 70s. Today the upper high remains over eastern Kansas with another day of hot temperatures and heat indices in the 102 to 107 degree range this afternoon. On Friday the upper high moves gradually eastward as the upper trough moves into the northern PLains. Slightly lower heights are expected over eastern Kansas, but highs will only be a few degrees cooler with mid to upper 90s common.
438 AM CDT Thu Aug 26 2021 Today and tonight: An inverted trough associated with the remnants of a Tropical Upper Tropospheric Trough (TUTT) is forecast to slide from the Florida Panhandle and into the Lower Mississippi River Valley. This moisture in conjunction with the aforementioned inverted trough will help foster scattered afternoon showers and thunderstorms with the highest rain chances along the Highway 84 corridor. Otherwise, fair to partly cloudy skies are expected tonight with overnight temperatures in the low 70s.
Only isolated coverage in the morning due to ridging aloft continuing to build in. However, as we approach midday, the ridge aloft weakens, shifts off to the northeast, and inverted surface to mid-level troughs begin to develop over South Texas from northeast Mexico and the Gulf of Mexico, respectively. These troughs, along with above normal PWATs and a stronger sea breeze, will lead to scattered showers and thunderstorms mainly east of the Brush Country. Activity will decrease in coverage in the early evening as we lose daytime heating and a surface lifting mechanism, however kept slight chances due to the sufficient moisture and nearby mid-level troughs in place. The increase in rain and cloud cover will cause highs to drop a few degrees, ranging from the low to mid 90s.
(Today and tonight) The upper level ridge will be weaker today and centered north of the area. Otherwise, expected dry conditions with some afternoon CU developing, with highs in the lower to middle 90s. Clear to partly cloudy skies are expected tonight, with lows in the low to mid 70s.
The southeast ridge will creep slowly northward through the weekend in response to a trough dipping into the northern Great Plains. Drier and cooler conditions should develop eventually with a strong enough trough passage and attendant cold front. The better chc for tsra is at MGW, HLG, and LBE where a crossing shrtwv trough wl likely promote coverage via forcing for ascent, albeit weak in the aftn warmth and humidity.
618 AM CDT Thu Aug 26 2021 An upper trough located over the Pacific Northwest will begin to dig and erode a ridge that is parked over the Central and Southern Plains. The cold front that is associated with this system is expected to retreat northward as the ridge flexes its muscles over the state during the day today. By this evening the trough located over the Pacific Northwest should begin to slowly erode the ridge and the ridge begins to lose its influence over the area.
Another clear and mild night across the TN Valley, with 2 AM temps in the lower to mid 70s. This higher moisture, with PWs approaching 2 inches, will make the chance for thunderstorms a bit higher this afternoon, but with little in the way of forcing the coverage should remain isolated to scattered.
VFR conditions will prevail beneath high pressure aloft. /Issued 345 AM CDT Thu Aug 26 2021/ The dome of high pressure that had been over the region the past several days is expected to begin its eastward trek this afternoon toward the East Coast for Friday. afternoon temps today look to be a degree or so cooler compared to yesterday with highs in the mid 90s to near 100 degrees for most of Eastern Oklahoma and Northwest Arkansas. As the ridge moves off to the east.
This feature should cause scattered showers with cooler temperatures.
423 AM MDT Thu Aug 26 2021 Broad upper ridging covers the eastern 2/3 of the CONUS, while an upper trough is over the west coast. Some low ceilings may linger across northwestern/central SD through the day, and temperatures there are expected to be noticeably cooler (70s) than areas farther south (80s). As the main trough crosses the region, most of its energy will be to our north.
Heat indices will reach into the low 100s for most of the area. As always please take the necessary precautions when heat indices are this high. The upper level ridge will continue to influence the weather through the weekend.
Scattered to numerous showers and thunderstorms possible through the early afternoon hours today, with the highest chances from KMLB northward.
A weak upper-level trough will continue to eject eastward away from the west coast today.
307 AM MDT Thu Aug 26 2021 Satellite imagery shows broad troffing over the northern intermountain west and WSW flow aloft over our region. This wave will be associated with a cold front and the onset of breezy NW winds during the day. There is potential for a brief period of severe storms in our far east along inverted surface trof. Skies will remain hazy from smoke today, but we should see improvement on Friday w/ the cold front and veering winds.
647 AM CDT Thu Aug 26 2021 (Today and tonight) The upper level ridge will be weaker today and centered north of the area. Otherwise, expected dry conditions with some afternoon CU developing, with highs in the lower to middle 90s. Clear to partly cloudy skies are expected tonight, with lows in the low to mid 70s.
The main player in the short term forecast will be mid-/upper- level high pressure positioned just off the NC/SC coast. Over the last 24 hours or so, a disturbance riding along the periphery of this high passed over the CWA from southeast to northwest. Models indicate another mid-/upper-level wave drifting northwestward around the high and across the CWA through the day Friday, bringing with it another surge of tropical moisture.
Deep ridging continues to dominate with latest sat imagery finally indicating cu development across the higher terrain, which is expected to expand regionally through morning. JB Chattanooga Airport, TN 92 71 90 72 90 / 40 20 20 10 30 Knoxville McGhee Tyson Airport, TN 92 69 92 70 91 / 50 20 20 10 20 Oak Ridge, TN 92 69 90 70 91 / 40 20 20 10 20 Tri Cities Airport, TN 91 68 90 66 91 / 50 30 30 10 20.
Lowered temps and cancelled the Heat Advisory as a result with afternoon peak heat indices now expected to reach the low-mid 90s. Mid level ridge retrogrades to Carolinas this weekend in deference to strong northern stream wave progressing eastward through southern Canada.
Otherwise, rain free conditions and mostly sunny skies prevail across the Mid-South this afternoon with temperatures as of 3 PM CDT in the lower to middle 90s at most locations. Few changes from earlier forecasts, as a broad upper level high pressure ridge brings clear skies and light winds. With little change in the upper ridge position and strength, 850mb temps and precipitable water values will change little on Friday.
Greatest coverage is expected to be mainly along the high terrain, especially along the Mogollon Rim into the White Mountains, Kaibab Plateau, Black Mesa, Chuska Mountains. Ridge remains in place over the Southern Plains, extending westward into the desert southwest to allow for monsoonal moisture to slowly creep northward into Arizona. Though the ridge's westward build is hampered by a series of weak troughs passing through the Great Basin just to the north of Arizona through the weekend. Daily afternoon showers and thunderstorms are also expected to continue, however coverage will remain isolated to scattered at best and mostly over the high terrain through the weekend with the bulk of the moisture still remaining just south of the region.
Broad ridging remains over much of the Southeast while lower-level ridging remains to our east and northeast.
The HRRR continues to be on the more aggressive/farther north solution, with the potential of storms mainly near the Missouri River around 05-06Z (mainly south of Mobridge).
This afternoon, flow aloft was turning southwesterly across the Northern Plains as a shallow trough was based over the western CONUS. Broad high pressure was centered to the northeast of the forecast area, with a moderate pressure gradient between the high and relative low pressure over northeast Wyoming. The highest chance for a strong to severe storm would be in the southwest, where there is the best overlap of shear and instability.
Upper level high pressure remains over the coast of the Carolinas and into the Atlantic. At the surface, high pressure will persist over the Appalachians and over the coast of North Carolina through the short term. Therefore, the higher chances of showers and storms are most likely over southeast Mississippi and far southwest Alabama. Finally, high temperatures are expected to be ever so slightly cooler, in the upper 80s to around 90 degrees.
1127 AM MDT Thu Aug 26 2021 Broad upper ridging covers the eastern 2/3 of the CONUS, while an upper trough is over the west coast. Some low ceilings may linger across northwestern/central SD through the day, and temperatures there are expected to be noticeably cooler (70s) than areas farther south (80s). As the main trough crosses the region, most of its energy will be to our north.
1240 PM CDT Thu Aug 26 2021 (Today and tonight) The upper level ridge will be weaker today and centered north of the area. Otherwise, expected dry conditions with some afternoon CU developing, with highs in the lower to middle 90s. Clear to partly cloudy skies are expected tonight, with lows in the low to mid 70s.
Discussion: Broad H5 ridging continues to dominate across the southeast CONUS with the southern Appalachians between two centers of anticyclonic flow, one over the southern plains, another centered off the Western Atlantic. Ample daytime heating induced instability will continue to foster CI through the afternoon hours with fcst pops highest over the higher terrain (high chance to low likely), slightly lower in the valley (mid/high chance). On Friday the eastern CONUS ridge looks to dominate with mean flow shifting sly/sely with profiles continuing to support deep instability albeit with some low/mid CIN and slightly lower pwats.
205 PM EDT Thu Aug 26 2021 An upper level low keeps a chance of showers and thunderstorms tonight, mainly over northeast WV. Heat and storm chances continue as an upper level ridge builds Friday into the weekend. An upper level low will continue to drift eastward across the area this afternoon and tonight.
(This evening through Friday) The upper level ridge from the southwestern states across the southern Plains is on a weakening trend.
SHORT TERM (Now through Friday Night): Seabreeze-induced convection continues develop along the coastal counties while midlevel ridging over the Southern and Central Plains slowly lifts northward. A similar setup for seabreeze convection can be expected on Friday, especially with the midlevel ridge weaker and moving farther northeast away from the BRO CWA.
Temperature have been a bit cooler than yesterday with mid 80s and a few upper 80s in the upper Keys.
1016 AM CDT Thu Aug 26 2021 Upper ridge has flattened a little bit for the end of the work week. VFR conditions will prevail beneath high pressure aloft. /Issued 345 AM CDT Thu Aug 26 2021/ The dome of high pressure that had been over the region the past several days is expected to begin its eastward trek this afternoon toward the East Coast for Friday. afternoon temps today look to be a degree or so cooler compared to yesterday with highs in the mid 90s to near 100 degrees for most of Eastern Oklahoma and Northwest Arkansas. As the ridge moves off to the east.
1224 PM CDT Thu Aug 26 2021 An upper trough located over the Pacific Northwest will begin to dig and erode a ridge that is parked over the Central and Southern Plains. By early this morning the trough located over the Pacific Northwest should begin to slowly erode the ridge and the ridge begins to lose its influence over the area.
At the upper levels, the ridge to our west is starting to weaken while the high off the SE coast becomes more dominant. There is a subtle weak trough passing by to the north this afternoon which may try to provide some support for convection, but otherwise looking at mostly diurnally driven thunderstorms this afternoon into the early evening. On Friday the high currently to our north moves well to the east, with high pressure remaining in vicinity of the Appalachians. Overall a similar pattern to today with mostly diurnally driven convection although with the low level flow becoming S/SW expect convection to start near the mountains during the afternoon and the focus of additional convection should drift north by late afternoon into the early evening.
Cloud cover around the Tri-Cities through much of the day has kept our temperatures just a few degrees cooler, but these clouds have finally started to erode and lift northeast.
The high pressure over the area will continue to give surface temperatures that are slightly warmer than normal over the next couple of days. With H7 to H5 temperatures continuing to be very warm across the area, thunderstorms will be limited to the far northwest combined Panhandles up against eastern NM further away from the center of the upper high pressure.
Two separate upper level ridge centers will be to our east and west placing West Texas under a relative weakness in the heights overhead.
Deep ridging continues to dominate with latest sat imagery finally indicating cu development across the higher terrain, which is expected to expand regionally through morning. VFR to dominate through the taf cycle as high pressure prevails. CDG Chattanooga Airport, TN 71 90 72 90 72 / 20 20 10 30 10 Knoxville McGhee Tyson Airport, TN 69 92 70 91 70 / 20 20 10 20 10 Oak Ridge, TN 69 90 70 91 70 / 20 20 10 20 10 Tri Cities Airport, TN 68 90 66 91 67 / 30 20 10 20 10.
306 PM EDT Thu Aug 26 2021 An upper level low has moved northwest and continues to exit the region and into the Gulf of Mexico. As we move into Friday, high pressure will remain across the region with breezy easterly winds. High temperatures will be seasonable today around 90 degrees, with temperatures tomorrow in the low to mid 90s.
Slightly lower mid level heights are expected on Friday with the center of the ridge shifting eastward. This and other factors may result in daytime high temperatures a few degree cooler.
Lows tonight will range from the 60s to 70s with highs Friday in the lower 80s north to the lower 90s south.
Expect this will enhance convergence along synoptic scale warm front to serve as a focus for vigorous convection this evening into tonight. Storms are expected to move into eastern Nebraska with some lingering showers/thunder in elevated instability though the low level jet axis will be shifting to our east.
While areas along I-74 should also have a heat index around 100, the cooler conditions there today has interrupted the duration string that is one of the issuance criteria. Upper level high pressure will be centered over the Carolinas this weekend, which should help drive much of the convective activity northward into the western Great Lakes.
157 PM CDT Thu Aug 26 2021 Upper high that was firmly entrenched across the central plains yesterday has weakened considerably. Meanwhile, upper high development is now commencing off the southern Atlantic coast. A ridge weakness is now more apparent across the mid state and we are seeing some isol to sct convection across the Plateau area at this time. On Friday, that upper high off the Atlantic coast will strengthen with ridging stretching westward toward the mid state by afternoon.
122 PM EDT Thu Aug 26 2021 An upper level low keeps a chance of showers and thunderstorms tonight, mainly over northeast WV. Heat and storm chances continue as an upper level ridge builds Friday into the weekend. An upper level low will continue to drift eastward across the area this afternoon and tonight. Building ridge along the east coast Friday into the weekend, with hot and humid conditions continuing. Going into the new work week, ridging continues to weaken as an upper level trough develops to the north and pushes a cold front towards the area.
For Friday, additional showers and thunderstorms are in the forecast along a pre-frontal trough and associated theta-e gradient boundary. Periods of heavier rain are possible during the overnight hours as PW values continue increasing ahead of the main cold front.
Then a Pacific cold front moves through the region and brings more scattered showers and west to northwesterly breezes on Friday. On Friday, an upper level trof will move through the area. As a result, expect much cooler temperatures, with afternoon highs about 10 degrees below normal.
A pacific trough will move across the Pacific Northwest into the Northern Rockies overnight into Friday morning. Temperatures will trend cooler Friday, with highs only reaching into the 60s across western Montana and into the 70s across north central Idaho.
An upper trough approaching the area will be sending a couple upper disturbances through.
Cooler weather can be expected for Sat with perhaps an isolated shra over the Black Hills.
Lows will bottom out in the low to mid 70s. Tomorrow, a midlevel anticyclonic ridge centered just off the coast of the Carolinas will continue to generate moist, southerly flow into the SE region.
Another hot and humid day across the area with early afternoon temperatures in the lower to middle 90s with heat index values between 100 and 105. Mid level heights lower slightly on Friday as the upper level trough moves through the northern US.
Still can't rule out isolated convection, primarily diurnally driven, near any outflows from upstream convection as sfc dewpoints linger in the low-mid 70s.
/Issued 1016 AM CDT Thu Aug 26 2021/ Upper ridge has flattened a little bit for the end of the work week. VFR conditions will prevail beneath high pressure aloft. /Issued 345 AM CDT Thu Aug 26 2021/ The dome of high pressure that had been over the region the past several days is expected to begin its eastward trek this afternoon toward the East Coast for Friday. afternoon temps today look to be a degree or so cooler compared to yesterday with highs in the mid 90s to near 100 degrees for most of Eastern Oklahoma and Northwest Arkansas. As the ridge moves off to the east.
Meanwhile, a surface warm front and warm/unstable airmass was gradually advancing northward, but exactly how far it gets is uncertain, owing to the aforementioned ongoing convection.
SHRA/TS already developing on the higher terrain will spread into nearby highlands and valleys on strong outflow boundaries. Friday through the weekend, showers and thunderstorms will develop along the high terrain before shifting onto lower elevations along an axis from west central to northeast New Mexico.
The Heat Advisory will remain in effect through 8 PM tonight for temperatures in the low to mid 90s resulting in heat index values of around 100 to 107 degrees. In addition, several storms have popped up along this boundary which will help to reinforce the cooler temperatures for a lucky few counties across northern Missouri. Temperatures on Friday will also be warm with air temperatures only slightly cooler then today's afternoon highs.
Another challenging forecast day with a wide range of solutions amongst the high-res models. Regarding the heat advisory, there are some concerns that areas along and north of I-74 may not reach the duration criteria of 100+ degrees over 4 days, as dew points are a few degrees cooler than they have been as of late.
TFJ Southwest flow aloft will prevail over the region today as an upper trough approaches the area from the west. The upper trough moves into the area on Friday with widespread showers along with some thunderstorms especially in the afternoon.