Aikyam-Lab/Synoptic-Bench huggingface dataset:
1138 PM CDT THU AUG 25 2016 At 20z the synoptic setup was highlighted by a broad upper level trough over much of the western two-thirds of the conus, and a strong but low amplitude ridge of high pressure centered over the southeast US. At the surface a slow moving frontal boundary extended from the Great Lakes region through the Ozarks and into Oklahoma/Texas, with a weak low pressure center analyzed in northwest Missouri. Increasing DPVA aloft will slowly aid in the development of a lee side low over eastern Colorado, which will turn our winds southeasterly as the low level mass fields begin to adjust. In addition, both the GFS and the NAM advertise upper level clouds streaming into the area overnight, which may keep temperatures a few degrees warmer than previously thought.
Temperatures today were a few degrees cooler than yesterday in most areas, and were as much as ten degrees cooler than normal in the North Bay Valleys.
822 PM EDT THU AUG 25 2016 High pressure across the Southeastern United States is keeping an east to northeast flow over South Florida. The National Hurricane Center gives this tropical disturbance a medium chance of tropical cyclone formation over the next two days and high chance over the next 5 days.
Meanwhile a trough of low pressure over northern Minnesota associated widespread clouds and isolated to scattered showers was slowly drifting toward the northern Great Lakes region this afternoon. Cloud trends and affect on max/min temperatures may continue to provide challenges into Friday even though high pressure drifting over area. The lower level clouds may be persistent across the north, along with a few sprinkles or light rain showers, especially during the morning hours.
An upper trough encompasses the northern Rockies this evening inducing a cyclonic westerly flow across the forecast area. A stalled surface boundary associated with this trough stretches across the forecast area roughly along a Roosevelt- Nephi-Ibapah line. North of this boundary a stable and relatively cool airmass resides across northern Utah, while to the south a moist unstable airmass is in place with dew points running in the 40s (low 50s in the lowest elevations) and PW values near 1 inch.
Isolated showers across across central Alabama this afternoon should dissipate by early evening due subsidence under strong upper ridge. Deeper moisture will pool across north Alabama on Friday as the center of the upper high shifts eastward. The lowering of 500mb heights and pooling of moisture should result in higher coverage of convective activity across north Alabama on Friday than today. Beyond Friday the overall upper air pattern does not change much across Alabama with a large scale ridge over the Gulf Coast region. This ridge will make it difficult for any tropical system to make a poleward movement.
A upper level trough from Montana through Nevada this afternoon is forecast to propagate into the Northern Plains on Friday.
1249 AM EDT FRI AUG 26 2016 Dry and less humid conditions can be expected today as high pressure shifts into the Great Lakes. Highs this afternoon are forecast to reach the low to mid 80s, with lows Friday night into the 60s.
1224 AM EDT Fri Aug 26 2016 High pressure remains off the coast through tonight. A cold front will cross the region early Friday. High pressure will return for the weekend. A light southerly flow will allow for noticeably warmer and more humid conditions overnight compared to recent nights. A cluster of showers and thunderstorms have developed ahead of a cold front over Pennsylvania this evening. Current feeling is that the activity will weaken as it approaches our area due to the fact that it will be outrunning the cold front that will not get here until after sunrise. Not only is the timing out of synch with favored diurnal trends, but west/northwest winds will promote subsidence, and at all levels above the surface ridging will reinforce that subsidence.
Models have been trending a bit slower with the advancement of this wave, and thus have slowed down the higher PoPs until around midnight and later and persisting into Friday morning. These overnight storms will be further supported by the low-level jet and decent isentropic lift, but expect them to be more elevated.
Manual 12z upper-air analysis revealed a positively tilted long-wave trough from central Canada to the southwestern U. A few strong to severe storms will be possible during afternoon into evening, with the highest probability of occurrence over southeast Nebraska and southwest Iowa where a favorable overlap of "sufficient" shear and instability is forecast to reside.
The 594dam subtropical ridge that has dominated our weather over the last few days has shifted NE out of the Deep South and is now centered over E TN. Convection was more widespread this afternoon in the west as an area of tropical air (2+ inch PWs) was advected around the nose of the ridge and juxtaposed with 3500-4000+ J/kg of SBCAPE.
However, an upper ridge building back over the weekend will keep temperatures above normal. Some isolated convection has popped in central Ohio in the heat of the day under the H5 ridge. It now looks like the majority of the convection associated with an H5 s/w lifting ne through the flow on the nrn edge of the ridge will stay north of the fa. Along the Ohio River lows will be on the lower 70s. On Friday, high pressure will be trying to build in. Highs on Friday will be slightly cooler, ranging from the mid 80s in the north to around 90 along the Ohio River.
Chattanooga Airport, TN 74 94 73 94 / 10 40 10 20 Knoxville McGhee Tyson Airport, TN 73 94 72 92 / 10 20 10 20 Oak Ridge, TN 73 95 72 93 / 10 10 10 20 Tri Cities Airport, TN 68 92 66 93 / 10 10 20 20.
1116 PM CDT THU AUG 25 2016 The synoptic pattern this afternoon features a strong subtropical ridge holding strong across the Southeast, with a trough amplifying across the Rockies. In its wake, the cold front along which it was traveling has slowly sagged into portions of west-central IL and northern MO. This convection will move/develop east northeast along and north of the boundary early Friday morning as the low-level jet veers and increases isentropic ascent across central and eastern MO. Deitsch Stalled frontal boundary to begin lifting back north as a warm front on Friday.
The National Hurricane Center gives this tropical disturbance a medium chance of tropical cyclone formation over the next two days and high chance over the next 5 days.
/issued 409 PM CDT THU AUG 25 2016/ Latest water vapor loops clearly show a rich plume of tropical moisture streaming northwest into the area from the Gulf of Mexico and around the western periphery of an upper ridge centered over the Southeast U.
An eastward moving short wave trough moving across the eastern Great Lakes with best mid and upper level support well north of the region. Upper ridge of high pressure centered over the Mid-Atlantic will continue to build through the weekend.
Warm temperatures will continue across the region Friday as high pressure remains over the region, with a thermal trough of low pressure over the Willamette Valley.
At the surface, weak Canadian high pressure resides across the area.
1143 PM EDT THU AUG 25 2016 Quiet evening across the area, with weak surface ridging controlling the weather. Not much change expected through the overnight, with just some passing mid clouds, especially for areas north of the big bridge. High pressure continues to build into Northern Michigan this afternoon. Thick layer of mid cloud is gradually thinning with the departure of the cold front. Tonight will be noticeably cooler with ongoing CAA behind the cold front. Afternoon highs will range form the lower 70s in Eastern Upper and far NW Lower Michigan to around 80 degrees near Saginaw Bay.
646 PM CDT THU AUG 25 2016 Upper level high pressure continues over Tennessee. A short wave on the west side of this high is bringing showers and thunderstorms to Arkansas, mainly central and south. Rest of the night should be dry but another short wave rotates around the high Friday for more showers and thunderstorms.
Otherwise, for Friday, there will be low pops across N Alabama as a weak disturbance goes around the EC Conus upper ridge, but too low of a chance to mention at C Alabama terminals at this time.
Surface wise, an expansive but weakening western Atlantic ridge extends into the southeast United States and down the Florida peninsula. Winds are northeast to east at 10 to 15 knots with the higher winds on the Florida Straits.
819 PM EDT THU AUG 25 2016 High pressure surface and aloft to the north of the state combined with lower pressure over the southeastern Bahamas (Invest 99L) is supporting a 4mb gradient from KMFL north to KJAX this evening. High pressure north of the waters and lower pressure over the southeastern Bahamas will maintain moderate northeast to east winds in the 10 to 15 knot range near shore, and 15 to 20 knots offshore the remainder of tonight along with seas of 2 to 4 feet with choppy bay and inland waterways.
(ISSUED 646 PM CDT THU AUG 25 2016 ) Upper level high pressure continues over Tennessee. A short wave on the west side of this high is bringing showers and thunderstorms to Arkansas, mainly central and south. Rest of the night should be dry but another short wave rotates around the high Friday for more showers and thunderstorms.
714 PM EDT Thu Aug 25 2016 Deep moisture along with a weak wave of low pressure aloft will produce variable clouds along with the chance of a passing shower, mainly south tonight into Friday morning.
However, still expecting thunderstorm chances to gradually increase from the south overnight, as the frontal zone begins to shift north across the region in response to the approaching upper trough across the southern Rockies.
Winds and waves will remain light through Friday afternoon thanks to high pressure passing the area.
Model data indicates this, with increasing moisture, especially later in the afternoon, as the H5 ridge shifts to the east, allowing broad southeast flow to increase.
With the subtropical ridge being located over the southeast U. , deeper moisture and a series of mid level disturbances have continued to stream into southwest Texas and southeast New Mexico along the western periphery of the ridge. With this ridge edging slightly further westward today, the best chances for rain today should be over southwest Texas across the Davis and Guadalupe Mountains, extending up into southeast New Mexico and the northwest Texas Permian Basin. There could be a slight lull in precipitation this weekend as the subtropical ridge slides further east.
754 PM EDT THU AUG 25 2016 Aviation A weak cold front moving across Lower Michigan will result in scattered storms south of a Lansing to Kalamazoo line late this afternoon.
950 PM CDT THU AUG 25 2016 Upper ridge centered over East Tennessee this evening. Temperatures in between the convective activity have reached the low and mid 90s for most folks.
An unsettled weather pattern remains in place this afternoon as mid- level troughing dominates the flow aloft, along with several smaller scale waves rounding the base of the trough.
with short wave trough digging into Utah and Nevada. At the sfc 1024 mb ridge was centered over the Nebraska panhandle with easterly sfc flow ongoing across the CWA. Fairly good signal that instability will rise prior to passage of trough and expect decent coverage of precipitation given timing of the forcing.
838 PM CDT THU AUG 25 2016 The dominance of the ridge is showing up as convective elements over the WFO PAH CWA and southward are decaying rapidly this evening in the presence of drier air is advected into the area at low to middle levels from the southwest.
Upper ridge of high pressure centered over the Mid-Atlantic will continue to build through the weekend.
Have gone a degree or so cooler than today's highs however considering there may be a bit more moisture and cloud cover. Model data indicates this, with increasing moisture, especially later in the afternoon, as the H5 ridge shifts to the east, allowing broad southeast flow to increase.
Radar imagery does show the weak cold front stretching southwest to northeast across much of central Montana and which is about to move through Great Falls. A cold front will move south of the Canadian border and sweep across the area overnight.
Upper trough in Montana is oriented to the southwest across Idaho and Oregon. Bulk of the moisture with the trough remains too far to the northeast for showers, but there is just enough moisture/instability for cloud buildups over the far northern mountains. The trough will push east by late Friday. Temperatures will be slightly warmer, with highs within a few degrees of normal.
However, an upper ridge building back over the weekend will keep temperatures above normal. Expect lows tonight ranging from the mid to upper 60s northwest to the lower 70s in the south. On Friday, high pressure will be trying to build in. Highs on Friday will be slightly cooler, ranging from the mid 80s in the north to around 90 along the Ohio River.
1001 PM EDT THU AUG 25 2016 Quiet evening across the area, with weak surface ridging controlling the weather. Not much change expected through the overnight, with just some passing mid clouds, especially for areas north of the big bridge. High pressure continues to build into Northern Michigan this afternoon. Thick layer of mid cloud is gradually thinning with the departure of the cold front. Tonight will be noticeably cooler with ongoing CAA behind the cold front. Afternoon highs will range form the lower 70s in Eastern Upper and far NW Lower Michigan to around 80 degrees near Saginaw Bay.
934 PM PDT THU AUG 25 2016 A strong ridge of upper level high pressure over the north central Pacific will dominate the weather for Friday.
The dominance of the ridge is showing up as convective elements over the WFO PAH CWA and southward are decaying rapidly this evening in the presence of drier air is advected into the area at low to middle levels from the southwest.
At the surface, a strong cold front stretches from eastern SD into western Nebraska and is quickly pushing southeast. Cold front is expected to push through the forecast area tonight as the upper energy over the Rockies lifts across the northern Plains and into the northern Mississippi Valley. Any precip associated with the upper low lifting over TX is expected to stay southeast of the forecast area. A strong cold front currently pushing into NW KS-North Central KS will continue to push south-southeast across the forecast area for the evening and overnight hours. This strong cold front will shift the winds around to the NW with some gusty winds for a few hours after the front moves through. Some of the Hi-Rez model solutions show some stratus developing just ahead of the cold front for areas along and east of the KS Turnpike.
Southern stream trough currently skirting just to the south of Oklahoma in Texas. Surface cold front associated with northern stream trough has currently moved into northwest Kansas and will move into the local area by mid to late morning. A cold front will push into the region from northwest to southeast on Tuesday in the wake of the exiting system, finally bringing a return to VFR conditions to all sites by afternoon. /Issued 247 PM CST Mon Dec 5 2016/ Upper low currently across south central Texas will continue lifting northeast and weaken as it moves through southern Arkansas overnight. Initial push of cooler air will move into the area overnight.
646 PM EST Mon Dec 5 2016 VFR conditions this evening will deteriorate overnight as a cold front approaches, with MVFR cigs expected for much of Tuesday. The surface cold front will move across the southeast and over Florida tonight and into Tuesday. The next trough will then move across the central and eastern U.
Latest water vapor imagery shows low pressure system centered over southwest Texas will travel east-northeast across southeast plains tonight into Tuesday.
Ceilings and visibilities will improve overnight into Tuesday as a cold front moves across the area bringing drier air and gusty N winds to the region. /issued 320 PM CST Mon Dec 5 2016/ A mid-level low/trough will continue northeast across southern and eastern Texas this afternoon and evening. However, some model soundings suggest very low clouds and some fog may develop this evening as winds decrease ahead of a cold front. As the initial cold air arrives tonight and early Tuesday, any dense fog will dissipate, but low clouds may linger for several hours behind the cold front. As another trough moves across the northern Rockies on Tuesday, some of this air will move quickly southward into the northern part of the country.
As the parent low pres will lift NE into the TN Valley thru daybreak, it will drag its attendant frontal trof into the ern GOMex. Steady S/SW flow will prevail thru the column as the trof plows into the wrn flank of an H100-H70 anticyclone centered NE of the Bahama Bank. pulling its attendant frontal trof from the wrn GOMex ewd. Lcl pgrad will tighten as the trof presses into the wrn flank of a deep anticyclone centered NE of the Bahama Bank.
441 PM MST Mon Dec 5 2016 Current surface analysis shows arctic cold front now southeast of the forecast area, with gusty northwest winds and slowly falling temperatures behind it. Upper level analysis shows low over south central Canada, with broad trof sweeping across the northern high plains right now.
1008 PM EST Mon Dec 5 2016 Low pressure crosses Tuesday.
526 PM CST Mon Dec 5 2016 Surface cold front was approaching northeast Nebraska at 20Z stretching from eastern South Dakota through the southwest corner of Nebraska into northeast Colorado.
A cold front will move through the terminals after midnight local time resulting in a gusty north wind. /issued 256 PM CST Mon Dec 5 2016/ The upper level low that brought rain to the area to start the weekend is on the move this afternoon, crossing the Rio Grande around Del Rio/Eagle Pass and will track toward East Texas this evening. In addition, an upper low will dig southeastward over the Dakotas.
1033 PM EST Mon Dec 5 2016 Low pressure crosses Tuesday.
930 PM CST Mon Dec 5 2016 Surface winds behind cold front moving southward across the forecast area this evening are stronger than earlier grids and text forecasts had going. /Issued 615 PM CST Mon Dec 5 2016/ For the 00Z TAFs, a cold front will move across the terminal sites this evening with gusty north winds in its wake.
705 PM EST Mon Dec 5 2016 Low pressure crosses Tuesday.
537 PM CST Mon Dec 5 2016 Arctic cold front continues to push across the area this afternoon. Even strong winds just to the west in the western panhandle of Nebraska due to the higher elevation.
/issued 323 PM CST Mon Dec 5 2016/ Deep closed upper low over south TX movg ne into east TX this eve, and then becmg an open wave and quickly movg thru cwa late tonight, bringing one more shot of rain into the area. No thunder activity currently over central TX in assoc with this low. Therefore have left tstm out of fcst for overnight hours as stg low lvl inversion in place, despite modest elevated instability with the low. Upper flow becmg zonal in wake of this low and will continue as such for next svrl days.
513 PM CST Mon Dec 5 2016 /00Z TAFS/ Conditions will continue to improve this evening and through the night as the upper low and associated rain chances passes to the east of West Central Texas. Another cold front will move south across the area tomorrow morning, with northerly winds and some redevelopment of MVFR ceilings and reduced visibilities through the morning hours. /issued 326 PM CST Mon Dec 5 2016/ (Tonight and Tuesday) The upper level low is shifting east into Central Texas late this afternoon and is taking the rain chances with it. Cold front moves through West Central Texas on Tuesday.
A large low pressure system moving slowly across the Great Lakes into New England will send a cold front, and more seasonal temperatures across the region late in the week. High pressure will be over the region throughout the night. However, high clouds will increase out ahead of a low pressure in the gulf states this evening into the Overnight. This low will bring another round of precip to the area from sw to ne.
A strong cold front is forecast to move into Arizona from the north on Tuesday with a few light showers late possible over the high terrain.
Given the persistent low cloud cover, have opted to remove freezing fog overnight, even though it can't be completely ruled out for some areas. Cold upper level trough will remain over the region for moist northwest flow aloft. Occasional flurries and areas of light snow will cause MVFR/IFR conditions at times with patchy freezing fog potentially producing local LIFR conditions between 06Z and 15Z Tuesday.
/issued 513 PM CST Mon Dec 5 2016/ /00Z TAFS/ Conditions will continue to improve this evening and through the night as the upper low and associated rain chances passes to the east of West Central Texas. Another cold front will move south across the area tomorrow morning, with northerly winds and some redevelopment of MVFR ceilings and reduced visibilities through the morning hours. /issued 326 PM CST Mon Dec 5 2016/ (Tonight and Tuesday) The upper level low is shifting east into Central Texas late this afternoon and is taking the rain chances with it. Cold front moves through West Central Texas on Tuesday.
609 PM EST Mon Dec 5 2016 Low pressure is expected to spread precipitation across the region Tuesday.
A cold front will push into the region from northwest to southeast on Tuesday in the wake of the exiting system, finally bringing a return to VFR conditions to all sites by afternoon. /Issued 247 PM CST Mon Dec 5 2016/ Upper low currently across south central Texas will continue lifting northeast and weaken as it moves through southern Arkansas overnight. Initial push of cooler air will move into the area overnight.
910 PM EST Mon Dec 5 2016 High pressure will briefly build over the region tonight.
442 PM CST Mon Dec 5 2016 Strong cold front moving through the area this evening.
With this being the first day of the season that Medford has gone below freezing, road temperatures on the west side are still relatively warm and with less than an inch of precipitation is expected any snow that does fall should melt very quickly on road surfaces with snow only sticking on lawns or trees.
522 PM CST Mon Dec 5 2016 An upper low will move through the Lower Mississippi Valley overnight, but influence will be limited to high clouds moving through the area as precipitation will remain well to the south and east of the CWA. A cold front currently located over central Nebraska will make steady progress and move through the forecast area tonight, beginning a markedly colder period for the remainder of the week. If this does occur, surface temperatures should still be a few degrees above freezing, so no impacts would be expected. Highs will be cooler in the middle 30s to lower 40s, even with mostly sunny skies.
Southeast winds will continue to veer more southerly tonight advecting warmer air into South Florida tonight. Latest water vapor imagery shows low pressure system centered over southwest Texas will travel east-northeast across southeast plains tonight into Tuesday.
537 PM CST Mon Dec 5 2016 231 PM CST We remain between a departing high pressure ridge and low pressure over the plains. Low temps will be at or just below freezing. Confidence is low in widespread freezing fog and slick conditions. Freezing rain is possible given forecast soundings and forecast low temps. Ice accumulation will mostly be a light glaze as temps will climb above freezing by mid to late morning. Fog dissipates in the late morning as the cold front moves through and west winds pick up.