Aikyam-Lab/Synoptic-Bench huggingface dataset:
The main topic of interest today is shower and thunderstorm development this afternoon as an upper level wave across the Mississippi river valley meanders atop a ridge of high pressure across the southern plains. The lack of appreciable upper support means that the main forcing mechanism to initiate convection will be differential heating along the higher terrain. Diurnal convection is beginning to develop off the higher terrain early this afternoon with further development expected into the later afternoon and early evening. Diegan Chattanooga Airport, TN 73 87 72 87 70 / 40 80 60 60 30 Knoxville McGhee Tyson Airport, TN 72 86 71 84 69 / 40 70 50 80 40 Oak Ridge, TN 71 86 70 85 68 / 30 80 50 70 40 Tri Cities Airport, TN 68 85 68 82 66 / 40 70 50 90 50.
212 PM CDT Thu Aug 13 2020 131 PM CDT Quiescent pattern continues through the end of the week here with the region hanging out in the more subsident regime immediately north of a slow-moving upper low across southern Illinois. Can't rule out some light/patchy fog tonight, but this would mainly be for locales west of Chicago where dewpoints remain the highest. Tomorrow looks much the same as today, with high temperatures around a degree or two warmer than today. Can't rule out a stray shower developing in our far southeastern locales as the upper low starts to jog a bit more northeastward, but any chances seem to be under 10% or so with no mention in the gridded forecast.
313 PM EDT Thu Aug 13 2020 High pressure across the western Atlantic will maintain southerly winds, along with seasonably warm and humid conditions. Weak low pressure tracking northward will produce greater coverage of storms into the weekend. Low pressure along the NC coast will continue to track northward tonight into Friday. A trough is trailing from this low cutting through our forecast area from NE to SW. The low should continue to lift northeastward toward Delmarva coast through Fri but trough will linger as mid to upper trough west of the area deepens and slowly migrates eastward. Mid level trough axis will be to our west through the period. Activity might be concentrated inland first under the lowered heights/cooler mid level air at first.
Winds aren't as strong on Friday as a strong area of high pressure begins to emerge across the Great Basin.
1242 PM CDT Thu Aug 13 2020 (Today and tonight) Oklahoma and north Texas will continue to feel the effects of the upper level ridge today as heat indices rise to 103-110 degrees Fahrenheit this afternoon.
205 PM EDT Thu Aug 13 2020 The ridge axis both aloft and at the surface continues to extend through central Florida.
Otherwise, upper ridging remains in firm control through the period with PWATs holding 1/3 to 1/2 inch below normal across South Texas.
/Tonight through Thursday/ A warm, humid and moderately unstable air mass is in place across Iowa this afternoon as the area is sandwiched between high pressure to the east and low pressure to the west. The resultant return flow has led to dew point values in the low to mid 70s and in turn surface based CAPE values near 3000 J/kg. The high pressure to the east will funnel drier air into eastern Iowa tonight with dew points dropping into the 60s. A strong short wave will approach the area by mid to late afternoon along with an attendant cold front.
CDT Thu Aug 13 2020 Looks like at least one more day of dealing with the pesky, nearly stationary, mid level trof that has been plaguing much of the region the past few days. The trof should be far enough east by Friday to affect mainly areas east of the MS River with scattered showers/thunderstorms. Most of the activity will shift east of the forecast area Friday night as the mid level trof finally exits.
Currently the surface pattern is conducive for the moist air mass responsible for the lower to middle 70s dewpoints to remain in place for the next couple days. In the mid levels, weak ridging aloft should prevent much in the way of any discernible mid level support for ascent, despite the unstable airmass.
JKL Upper trough will be tracking across the northern Rockies and our region today. There will be favorable upper dynamics over our region as well with a reinforcing short wave making its around the bottom of the trough by evening. Otherwise look for a cooler day with some breezy conditions locally. Friday has the trough moving east of the region and building 500 mb heights. BT Upper ridging will prevail over the western U.
Upper trough over the region will deepen later, and that will keep a good amount of showers/storms around well into tonight as well.
1226 PM CDT Thu Aug 13 2020 Clear skies will continue today and much of tonight with high pressure in control. Given temperatures from yesterday along with some strengthening of the low- level thermal ridge, we will go ahead and issue a Heat Advisory for today and tomorrow for counties along and east of the Interstate 35/Interstate 37 corridors. Exactly how efficient the low-level moisture can mix out will determine whether we hit criterion based on the heat index or air temperature.
For Friday, the advancing upper trough will push a cold front into the region. Models have also trended cooler for Friday night, with lows now expected to be in the 50s for most of central Nebraska.
135 PM EDT Thu Aug 13 2020 A quiet night is in store for then region with lows in the low to mid 60s.
The models are in good agreement that a mid to upper level trough will move into Central TN tonight and into northwest Georgia by tomorrow night. Proximity of trough will provide enough lift to support thunderstorm activity this afternoon and evening to continue into the overnight hours. AS trough moves closer to the area tomorrow will once again see an increase coverage and intensity of afternoon and evening convection, with storms again continuing into the overnight hours.
As of 2 pm, a ridge of high pressure remained over the area, but was moving off to the northeast. A warm front was nearly still from north central Iowa to southeast Iowa. Temperatures were in the lower 80s north to upper 80s south. Tonight, a ridge of high pressure will remain stretched from the Great Lakes through eastern Iowa, but will slowly continue to move off to the northeast. Temperatures look to be on track with lows in the lower 60s NE to upper 60s south. Friday, dry conditions will continue as the ridge moves further east and the warm front remains stationary. With the high humidity levels, heat indices will push into the upper 80s to low 90s.
Looks like at least one more day of dealing with the pesky, nearly stationary, mid level trof that has been plaguing much of the region the past few days. The trof should be far enough east by Friday to affect mainly areas east of the MS River with scattered showers/thunderstorms. Most of the activity will shift east of the forecast area Friday night as the mid level trof finally exits.
Showers and scattered thunderstorms remain near and south of Olney/Lawrenceville as a weak upper wave moves into the lower Ohio Valley. Not much change expected across this region overnight, while the northern CWA remains under the influence of high pressure centered north of the Great Lakes.
418 PM MDT Thu Aug 13 2020 With a ridge of high pressure building over the Great Basin, temperatures will warm significantly heading into the weekend.
720 PM EDT Thu Aug 13 2020 A trough of low pressure will persist inland, while high pressure remains over the Atlantic through Friday.
828 PM EDT Thu Aug 13 2020 With the Bermuda high offshore and a persistent upper level trough in the Lower Mississippi Valley, a moist and unstable air mass will remain across the area into this weekend. Overnight lows will again be in the low to mid 70s.
As the trough moves east of the area later tonight, a northwesterly flow aloft will develop. This will result in clearing skies and temperatures cooling into the 40s for most locations, with cooler 30s over the normally cooler higher valleys. Dry northwesterly flow aloft will continue through the first half of the weekend as high pressure ridging begins to work its way into the region.
/issued 249 PM CDT Thu Aug 13 2020/ Heat will be the word for the next couple of days as high pressure aloft holds fast over west Texas and southeastern New Mexico.
68 inches, once again scraping the low-end of the interquartile range (25th percentile) with regards to the sounding climatology. That is to say convection should have a harder time becoming robust as the low to mid levels of the troposphere have dried considerably compared to last night. From synopsis: A western Atlantic ridge axis will extend across the Florida Peninsula overnight through Friday night, resulting in gentle to moderate easterly breezes across the coastal waters of the Florida Keys.
As of 200 PM EDT Thursday: A mid level trof will traverse the area this weekend.
718 PM EDT Thu Aug 13 2020 Dry and pleasant conditions with near seasonable temperatures will be the rule the next several days as high pressure dominates.
Unsettled conditions with cooler temperatures are forecast for the upcoming weekend. Quite an airmass change heading into the northern 1/2 of the CWA with a mainly clear sky and comfy dewpoints in the low-mid 50s. Temps stay muggy across the south central/southeast zones with lows around 70F in the lower Susquehanna Valley metro areas. One change may be that the storms may actually creep more to the north on Friday with an upper level trough developing in the OH Valley. By Friday evening, split flow produces a weak broad upper trough over the lingering frontal boundary to our south.
944 PM EDT Thu Aug 13 2020 A trough of low pressure will persist inland, while high pressure remains over the Atlantic through Friday.
627 PM CDT Thu Aug 13 2020 131 PM CDT Quiescent pattern continues through the end of the week here with the region hanging out in the more subsident regime immediately north of a slow-moving upper low across southern Illinois. Can't rule out some light/patchy fog tonight, but this would mainly be for locales west of Chicago where dewpoints remain the highest. Tomorrow looks much the same as today, with high temperatures around a degree or two warmer than today. Can't rule out a stray shower developing in our far southeastern locales as the upper low starts to jog a bit more northeastward, but any chances seem to be under 10% or so with no mention in the gridded forecast.
Upper level ridge will continue to limit rain development across the CWA, nevertheless, an ISO SHRA could develop along the seabreeze boundary Friday afternoon. Look for a repeat of today's weather tomorrow with little changes in the weather pattern (ridging aloft in control, warm southwest surface winds in the morning becoming south in the afternoon, warm temperatures with highs once again in the upper 90s to around 100 inland and in the low to mid 90s at the coast).
729 PM EDT Thu Aug 13 2020 A trough of low pressure across the area, will result in numerous showers and and thunderstorms through Friday. A cold front pushes south into Virginia Friday night, then stalls near the Virginia North Carolina border over the weekend.
A weakening mid level short wave feature over northern Lower Mi will hold generally stationary tonight into Friday night as it has become orphaned from the mean flow and embedded within an amplifying longer wavelength ridge. There is a little broader mid level trough now located over south-central Illinois, forecast to drift into Indiana and Ohio Fri/Fri night.
/issued 231 PM CDT Thu Aug 13 2020/ SHORT TERM (Tonight through Friday Night): 500 mb high pressure centered over the Desert Southwest will remain extended over Deep South Texas and the Rio Grande Valley during the period. After holding at near to below normal levels in the wake of Hurricane Hanna, temperatures are beginning to creep into above normal levels due to the presence of the 500 mb ridge and the steady drying of previously-soaked and flooded soils from Hanna rains.
A warm upper ridge will nose into the area with much warmer weather on tap for the weekend.
Low temperatures are expected to be in the low to mid 60s. A cold front enters the northwest portion of the area in the morning steadily moving through the remainder of the area through the rest of the day. High temperatures are expected to reach the low to mid 90s.
534 PM EDT Thu Aug 13 2020 A trough of low pressure will persist inland, while high pressure remains over the Atlantic through Friday.
1042 PM EDT Thu Aug 13 2020 Dry and pleasant conditions with near seasonable temperatures will be the rule the next several days as high pressure dominates.
1058 PM EDT Thu Aug 13 2020 With the Bermuda high offshore and a persistent upper level trough in the Lower Mississippi Valley, a moist and unstable air mass will remain across the area into this weekend. Overnight lows will again be in the low to mid 70s.
The forecast area remains in northwest flow aloft between a ridge over the Desert Southwest and a large-scale trough covering southwestern Canada and the northern Rockies. What may be a slightly better area to watch is the convection developing in southwest NE/northwest KS within the lee trough and along the dryline. As the aforementioned trough translates eastward Friday, it will drag a cold front across NE and eventually into KS later in the day.
715 PM EDT Thu Aug 13 2020 A quiet night is in store for then region with lows in the lower to mid 60s.
1039 PM EDT Thu Aug 13 2020 A trough of low pressure will persist inland, while high pressure remains over the Atlantic through Friday.
810 PM EDT Thu Aug 13 2020 A trough of low pressure across the area, will result in numerous showers and and thunderstorms through Friday. A cold front pushes south into Virginia Friday night, then stalls near the Virginia North Carolina border over the weekend.
244 AM EDT Fri Aug 14 2020 With the Bermuda high offshore and a persistent upper level trough in the Lower Mississippi Valley, a moist and unstable air mass will remain across the area into this weekend. Morning lows will again be in the low to mid 70s. Today: Main upper trough axis will still be off to the west of the area through the day. Overnight lows in the lower to mid 70s. Both the GFS and ECMWF agree on pushing the trough axis to the coast over the weekend.
318 AM CDT Fri Aug 14 2020 High pressure was in control over the Great Lakes into portions of the Mid to Upper Mississippi Valley. Light ESE to SE winds should advect in slightly less humid air compared to yesterday, with dewpoints in the low to mid 60s east and upper 60s west. Convection is expected to develop this afternoon along a cold front draped across Southwest Minnesota and Northwest Iowa.
High pressure remains in control providing light winds and dry atmosphere. /issued 231 PM CDT Thu Aug 13 2020/ SHORT TERM (Tonight through Friday Night): 500 mb high pressure centered over the Desert Southwest will remain extended over Deep South Texas and the Rio Grande Valley during the period. After holding at near to below normal levels in the wake of Hurricane Hanna, temperatures are beginning to creep into above normal levels due to the presence of the 500 mb ridge and the steady drying of previously-soaked and flooded soils from Hanna rains.
Unsettled conditions with cooler temperatures are forecast for the upcoming weekend. Recent sat trends and model data suggest a fair amount of mid-high clouds drifting over the area which could limit radiational valley fog beneath the high clouds to some extent. Temps stay muggy across the south central/southeast zones with lows around 70F in the lower Susquehanna Valley metro areas. One change may be that the storms may actually creep more to the north on Friday with an upper level trough developing in the OH Valley. Split flow produces a weak broad upper trough over the lingering frontal boundary to our south.
254 AM MDT Fri Aug 14 2020 Combination of a strong trough moving through E MT on water vapor imagery and a coupled jet, produced bowing segments of thunderstorms across northern areas overnight. Axis of the trough was progged to be right along the MT/Dakotas border at 12Z and jet divergence will be in the Dakotas.
114 AM EDT Fri Aug 14 2020 A quiet night is in store for the region with lows in the lower to mid 60s.
MOS guidance suggests significantly cooler temps behind the front for this afternoon with highs near 90 at PVW. While temps may be a few degrees cooler, cooling on the order of 10+ degrees doesn't seem extremely likely. Even highs yesterday behind the front in the northern Texas Panhandle were much warmer. The one thing that could keep highs on the cooler side would be convection. Convection is possible this afternoon into the evening as a weakness rotates around the upper high that is currently to our west.
A weak blocking pattern remains positioned over the great lakes and Midwest. This Rex block will begin to break down through the day as a strong 500mb short wave trough lifts across the Dakotas into northern Minnesota through midday.
We're beginning to see a bit of cloud cover develop as the low-lvl jet increases. Convective chances later today will be driven by an advancing cold front moving southeast by the mid-day hours. The area with the highest potential for development will be in SW Minnesota where PVA is maximized.
351 AM EDT Fri Aug 14 2020 Dry and pleasant conditions with near seasonable temperatures will be the rule the next several days as high pressure dominates.
By early this evening, the main upper trough will be east of the area, as a weakening upper level ridge moves southeast into the area. The deeper moisture will move out as the trough moves east, so any lingering showers and thunderstorms during the evening hours will be in our far eastern sections.
Widespread scattered showers and thunderstorms are expected late Friday afternoon and Friday evening associated with an upper low impacting each TAF site. JB Chattanooga Airport, TN 87 73 87 69 90 / 80 70 70 30 30 Knoxville McGhee Tyson Airport, TN 86 71 85 69 88 / 70 60 70 50 40 Oak Ridge, TN 85 71 86 68 88 / 70 60 70 40 40 Tri Cities Airport, TN 84 69 82 66 83 / 70 50 80 70 50.
329 AM EDT Fri Aug 14 2020 Dry and pleasant conditions with near seasonable temperatures will be the rule the next several days as high pressure dominates.
248 AM EDT Fri Aug 14 2020 An area of high pressure will build by to our north through the weekend. A developing onshore flow will bring noticeably cooler weather to the region for the weekend. A weak secondary cold front stretched from the Bay of Fundy through central New England accompanied by scattered mid and high clouds. Highs today will be in the lower and mid 80s. we're sandwiched between the high centered to our north and low pressure passing well to our south.
Upper trough remains across the Tennessee Valley and Southern Appalachians. While scattered showers and thunderstorms are forecast across the entire area on Friday, most widespread coverage is forecast across the higher elevations as well as southeast TN. Instability is expected to be marginal with MLCAPE between 1000 to 2000 J/Kg, but with the very moist atmosphere and high freezing levels, risks of damaging winds and hail will be low.
However, we will see more in the way of stacking in terms of the lower and mid level trough patterns across the area today. Upper low over IN will deepen a bit more this afternoon as compared to yesterday. Height values and mid level temps will be a touch cooler as well. We finally see some form of pattern progressiveness tonight as the trough axis shifts eastward.
Generally, the higher the maximum temperature, the lower the dew point temperature. In any case, it appears that the highest heat indices will be in the existing Heat Advisory area.
A Gulf airmass was stuck beneath northwest flow aloft, as summertime high pressure remained west of the region. Dry conditions will continue into tonight with lows mainly in the low 70s.
138 AM EDT Fri Aug 14 2020 A trough of low pressure across the area, will result in numerous showers and and thunderstorms through Friday. A cold front pushes south into Virginia Friday night, then stalls near the Virginia North Carolina border over the weekend.
1210 AM CDT Fri Aug 14 2020 131 PM CDT Quiescent pattern continues through the end of the week here with the region hanging out in the more subsident regime immediately north of a slow-moving upper low across southern Illinois. Can't rule out some light/patchy fog tonight, but this would mainly be for locales west of Chicago where dewpoints remain the highest. Tomorrow looks much the same as today, with high temperatures around a degree or two warmer than today. Can't rule out a stray shower developing in our far southeastern locales as the upper low starts to jog a bit more northeastward, but any chances seem to be under 10% or so with no mention in the gridded forecast.
133 AM EDT Fri Aug 14 2020 Dry and pleasant conditions with near seasonable temperatures will be the rule the next several days as high pressure dominates.
239 AM CDT Fri Aug 14 2020 131 PM CDT Quiescent pattern continues through the end of the week here with the region hanging out in the more subsident regime immediately north of a slow-moving upper low across southern Illinois. Can't rule out some light/patchy fog tonight, but this would mainly be for locales west of Chicago where dewpoints remain the highest. Tomorrow looks much the same as today, with high temperatures around a degree or two warmer than today. Can't rule out a stray shower developing in our far southeastern locales as the upper low starts to jog a bit more northeastward, but any chances seem to be under 10% or so with no mention in the gridded forecast.
205 AM EDT Fri Aug 14 2020 A weak upper level trough to our west and surface boundary nearby will allow for better coverage of showers and storms over the next several days with heavy rainfall possible. However, instability is limited by cooler than usual surface temperatures, so storms aren't getting particularly tall, just big enough to produce some CG.
413 AM EDT Fri Aug 14 2020 Under mostly clear skies and east to southeast winds of around 10 mph, temperatures are in the lower to mid 80s along the island chain.
An upper trough extends from the Great Lakes into the Mid-South this morning. Temps are generally in the lower to mid 70s across the Mid-South. The 500 mb trough axis will gradually shift east today with afternoon convection most prevalent east of the MS River and especially toward the TN River. Convection will diminish this evening with loss of heating and lows overnight will remain mild, in the lower 70s.
1245 AM EDT Fri Aug 14 2020 A trough of low pressure will persist inland, while high pressure remains over the Atlantic through Friday.
339 AM CDT Fri Aug 14 2020 An upper level high continues to exert its influence as sunny skies and subsidence create another day of oppressive heat. Today will be the hottest day of the week with temperatures exceeding 100 degrees across all but the highest elevations in the CWA; 105 will be exceeded across the Permian Basin and southeastern New Mexico so a Heat Advisory continues. Tomorrow may be a little cooler, though still quite hot, as the high and subsidence weakens and temperatures drop a few degrees.
Dewpoints should approach the low 70s across southeast MN/northeast Iowa, making for a warm and humid August afternoon.
318 AM CDT Fri Aug 14 2020 The primary forecast concern will be thunderstorm potential associated with a cold front moving through the area this afternoon and evening. The cold front moves into northeast NE by 18z, then south of the area by about midnight tonight. Highs should reach 87 to 90, with dewpoints still in the lower 70s producing heat index values well into the middle to upper 90s.
Storms continue to fire along a cold front that is ever so slowly sagging southeast across North Dakota.