Aikyam-Lab/Synoptic-Bench huggingface dataset:
Much drier air has developed across our forecast area in the wake of a deep-layer cold front.
Some sites have seen an increase in visibility and HRRR does slide lower vsbys eastward while the GLAMP25 guidance improves things gradually in the current area but does not advect the lower vsbys eastward. Only change to ongoing forecast will be to re-run ForecastBuilder to yield snow over freezing drizzle given presence of ice aloft. With weak cold advection temperatures will be cooler than previous nights with minimums blo freezing overnight so any wet roadways may get slick. Monday should be mainly quiet with temperatures generally at or blo freezing.
20Z water vapor imagery shows the upper low now over the lower MS river valley and continuing to move east. Another upper low was seen just off the Pacific northwest coast with upper ridging moving over the Rockies. For tonight and Monday, low level moisture remains the main headache as models have not handled the low level stratus very well.
A ridge of high pressure will build over the area in the wake of the trough with light winds and clearing skies. This will lead to good radiational cooling as wind speeds drop off with lows falling into the low to mid 20s for some locations. A mid/upper ridge will build over the central CONUS on Mon while another vigorous trough builds into the Central Great Basin/Southwest states. Low pressure is progged to deepen over the Central High Plains resulting in breezy southeast winds across much of Kansas on Mon into early Tue.
Due to thinning in the clouds and showers, temperatures recovered quite nicely, and by 2 pm were mainly in the lower and middle 60s. As upper low pulls east tonight and Monday, look for north winds to increase and become gusty.
This activity is along a couple of lines is in advance of a cold front moving rapidly eastward through the southeastern Gulf of Mexico. The cold front will blow through the Keys in the predawn hours.
938 PM EST Sun Jan 22 2017 Numerous showers are expected overnight associated with strong area of low pressure. The low will begin to lift north of the region Monday.
404 PM MST Sun Jan 22 2017 Upper level ridging is in place over the SW US and building east into the Central Rockies. Subsidence and a deep dry air mass within the eastern extend of this ridge extends across our CWA. A strong upper low is off the Pacific Northwest coast with diffluent flow between these upper level features over the Great Basin. WAA increases with south- southwest low level flow (east of lee trough), and this will result in above normal high temperatures.
Expect heavy snow in Pocatello to Blackfoot region behind cold frontal passage as all indications show it to be heavy snow pattern post frontal passage and local convergence pattern in the lower Snake River Plain.
This trend will gradually continue ewd after midnight, as both the sfc and upper low move well e of the local area. No changes were needed to the current Wind Advisory xpcted to begin at 3 AM CST, as sfc winds out of the nw begin to increase with the influx of cooler air. The high resolution guidance indicates a 10 millibar surface gradient from west/east across the state and 925 millibar winds approaching 50 knots.
/issued 246 PM CST Sun Jan 22 2017/ Current sfc observations show winds continuing to decrease across West Texas and Southeast New Mexico, w/strongest activity over the Big Bend/lwr Trans Pecos as the tail-end of strong winds rounding the base of the upper trough leaves the region. WV imagery shows the upper trough now over the Arklamiss, and subsidence on the backside of this feature has resulted in CAVU conditions across the region under NW flow aloft. To the west, an upper ridge will briefly build into the area Monday, w/thicknesses increasing and downslope warming pumping temps into the 70s most locations.
900 PM CST Sun Jan 22 2017 A low pressure system, centered over eastern TN and northern GA, continues to track east this evening. Upper low continues to track east-southeast and had entered west central Mississippi this afternoon, with the fringes of the associated precipitation echoes down near the Ohio River. Not really looking for much with this feature, except to linger the clouds a bit longer, until a narrow high pressure ridge builds east into the Mississippi Valley and breaks the clouds up a bit in the afternoon. While temperatures on Monday will still reach the mid 40s, northwest winds of 10-20 mph will make it feel cooler.
327 PM MST Sun Jan 22 2017 Upper level ridging is in place over the SW US and building east into the Central Rockies. Subsidence and a deep dry air mass within the eastern extend of this ridge extends across our CWA. A strong upper low is off the Pacific Northwest coast with diffluent flow between these upper level features over the Great Basin. WAA increases with south- southwest low level flow (east of lee trough), and this will result in above normal high temperatures.
/issued 306 PM CST Sun Jan 22 2017/ The upper level low pressure system responsible for our winds and showers/virga yesterday has pulled well east, and is now creating a massive severe weather outbreak across the southeastern U. Tomorrow will see brief upper ridging pass over the region which will turn winds aloft and at the surface southwesterly. As such, we will see the warmest day of the week with highs well above normal in the lower 70s for all but the southwestern TX Panhandle, which may hang on to the upper 60s.
/issued 248 PM CST Sun Jan 22 2017/ SHORT TERM (Tonight through Monday Night): North northwest winds will weaken through the night as a storm system over the lower Miss.
648 PM EST Sun Jan 22 2017 High pressure will build north of the area tonight.
The lower visibility will likely be in northwest Wisconsin, the Iron Range, and interior (away from the Lake) Arrowhead. There could be periods of drizzle and snow overnight into early Monday, primarily over northern Minnesota, thanks in part to some lift generated by an upper trough that will move into the region. Surface temperatures are expected to dip to near or just below the freezing mark, so there could be some icing on area roads. Upper level and surface ridging will cover the forecast area Monday night.
531 PM CST Sun Jan 22 2017 Updated for 00Z aviation discussion 00Z TAF discussion: Expect showers and areas of light rain across the region well into the night in association with an upper low overhead. Monday wills start out cloudy, but the clouds will clear from west to east through the late morning into the afternoon hours as upper ridging begins to build in over the area. Highs will range from the mid 50s in the north to the low 60s in the south.
535 PM CST Sun Jan 22 2017 Upper low continues to track east-southeast and had entered west central Mississippi this afternoon, with the fringes of the associated precipitation echoes down near the Ohio River. Not really looking for much with this feature, except to linger the clouds a bit longer, until a narrow high pressure ridge builds east into the Mississippi Valley and breaks the clouds up a bit in the afternoon. While temperatures on Monday will still reach the mid 40s, northwest winds of 10-20 mph will make it feel cooler.
Gale warning remains in effect as frequent gusts to Gale Force will occur behind convection and strong cold front expected to move over the waters overnight.
Rain chances will linger into the morning hours and possibly into the early afternoon but mainly be confined to the east as the upper low moves towards the coast. Strong upper level low to the SE of Middle TN is going to continue to affect our mid-state terminals throughout the night.
1022 PM EST Sun Jan 22 2017 High pressure will build north of the area tonight.
This low will slowly push eastward through Monday.
The upper low currently behind the deadly storm system impacting the southeastern U.
942 PM EST Sun Jan 22 2017 Low pressure tracking east through the southern U.
This will by while the main area of high pressure shifts across eastern NE/KS. This ridge focusing more over our eastern counties should help scour out at least some of the lower clouds and fog over our east.
Winds at around 10 mph will gradually shift to the south southwest late tonight as a trough of low pressure at the surface begins to develop along the lee of the Rockies. Given a westerly component to the winds overnight initially am leaning towards temperatures slightly warmer than what the 12z guidance suggested in far western Kansas.
/Issued 329 PM CST Sun Jan 22 2017/ The rain is diminishing quickly across far eastern Oklahoma and northwest Arkansas as the upper low over Mississippi continues to move quickly east away from the area.
WSR-88D radar trends show an expansive and nearly stationary area of light to moderate rain over much of north Mississippi and Eastern Arkansas associated with a surface boundary and upper level low. Latest water vapor imagery shows an impressive 540mb upper level low centered over the ArkLaMiss. Within our regime, on the northern periphery of the low, mostly stratiform rain and cloudy conditions are occurring over the Mid- South. As the upper level low departs off to our southeast this evening, a cold front will swing through.
The storm will weaken and move south along the west coast and then south of the area as an open trough on Monday.
Weak cold air advection and mid- level troffing may generate some patchy drizzle overnight. Medium Surface ridging amplifies into wrn WI during the afternoon.
Southwest winds will increase and become gusty again by mid to late Monday morning and remain that way through the afternoon hours as a surface trof of low pressure develops over ern CO extending southward into ern NM. /Issued 327 PM CST Sun Jan 22 2017/ An upper closed low has moved out of Texas and into the lower MS Valley while an upper level ridge builds into the southern Plains per water vapor imagery. The upper level ridge will lead to large scale subsidence across the Panhandles Monday. Winds will be breezy to windy Monday afternoon as the ridge begins to break down under southwesterly flow aloft.
418 PM CST Sun Jan 22 2017 Upper level closed low pressure system continued to spin over extreme Northeast Louisiana and Southeast Arkansas with its center over Central Mississippi. Temperatures will also warm into the week as the surface and ridge of high pressure move East allowing more southerly winds.
Widespread showers will continue to move through the area through the night as a low pressure moves to the SE. Chattanooga Airport, TN 50 55 40 59 / 90 50 0 0 Knoxville McGhee Tyson Airport, TN 51 55 43 55 / 90 80 30 0 Oak Ridge, TN 50 53 42 56 / 90 80 20 0 Tri Cities Airport, TN 47 52 41 51 / 100 90 60 10.
Skies should then clear during the day on Monday, as upper level ridging builds into the area. Temperatures will remain on the cooler side, though still above average for the time of year.
Lows tonight will likely be warmer than last night with the extensive cloud cover, so freezing fog should not be much of an issue in terms of slick roads.
Upper level high pressure will build over the state through Monday and result in a mostly clear sky. The surface pressure gradient will weaken through the night as a strong low pressure system moves towards the East Coast. These gusty northwesterly winds are the result a strong pressure gradient from an intense low pressure system that had moved into the southeastern United States as of 3 PM.
Another round of showers and thunderstorms today as an upper low over Texas tracks eastward across Alabama this evening. This is a very dynamic system and widespread showers and elevated thunderstorms expected on the north and west side of the upper low. Temperatures near the center of the 500mb upper low will be near -25 celsius, and steep lapse rates could produce some large hail across the southeast counties in the more vigorous convection, with small hail as far north as I-20. Cooler and more stable air will overspread all of central Alabama this evening. Scattered to numerous showers will continue across central Alabama tonight as the upper low center moves across the area.
533 PM CST Sun Jan 22 2017 Quite the uneventful next 24 hours over this region as there's deep upper level troughs over each CONUS coast with weak ridging over the central states along with weak high pressure moving in from the west. After daybreak Monday, the rate of clearing will improve as drier air will be advected in from the west, aiding in visibility first then scouring out the low clouds. With some clearing and drier air in western MN, lows will be a bit cooler, dropping to the mid 20s to lower 30s.
Upper level ridging is in place over the SW US and building east into the Central Rockies. Subsidence and a deep dry air mass within the eastern extend of this ridge extends across our CWA. A strong upper low is off the Pacific Northwest coast with diffluent flow between these upper level features over the Great Basin. WAA increases with south- southwest low level flow (east of lee trough), and this will result in above normal high temperatures.
Low levels remain on the dry side so main affect will be scattered snow showers over the higher terrain.
Snow levels will lower to valley bottoms as the associate cold front moves through Monday night.
544 PM CST Sun Jan 22 2017 Wound up low pressure system over the Deep South continues to sling moisture back up into the Mid Mississippi Valley. A weak ridge will build over the area on Monday ahead of the next storm system over the Great Plains. With stubborn clouds and northwest flow, temperatures will be a little cooler than they've been recently, but still well above normal in the mid and upper 40s.
Models have been enjoying the impressive inverted low level trough and associated high moisture/low level convergence by generating light QPF tonight.
623 PM EST Sun Jan 22 2017 Low pressure over the Southern Plains will move to the middle Atlantic Coast by Monday afternoon.
Sent an update tonight to more accurately reflect the risk area for freezing fog tonight. BMickelson Previous short term discussion: Low pressure will continue to lift northeast of the CWA today, with expected clearing skies tonight. Low clouds/patchy freezing fog have continued today and see little reason to remove it at least for this evening. Eventually, as a trough deepens across the Western U.
433 PM MST Sun Jan 22 2017 Deep upper low will fracture and eject toward the region in the period, supporting cyclogenesis over the central plains and increasing chances for accumulating snow across the region. Forecast models continue to struggle with the details of this system given a fracturing wave and tendencies to close an upper low over the northern plains, not to mention the track of this potential closing upper low. There are a few model members indicating the potential for some light freezing drizzle there, late tonight into the Monday morning.
Regional radars show a well defined MCV/QLCS structure on the east/northeast flank of this low from near BHM to Troy. The high resolution guidance indicates a 10 millibar surface gradient from west/east across the state and 925 millibar winds approaching 50 knots.
628 PM EST Sun Jan 22 2017 Low pressure over the Southern Plains will move to the middle Atlantic Coast by Monday afternoon.
639 PM EST Sun Jan 22 2017 Numerous showers and thunderstorms, some severe, are expected into this evening associated with strong low pressure. The low will begin to lift north of the region Monday.
Glass A cold front will move southward into the region Thursday night.
Major league convective episode this evening with more showers and thunderstorms developing upstream across the Lower Ohio Valley in association with the Midwest short wave trough.
-Stalley A cluster of thunderstorms, which developed earlier this afternoon over the Texas Panhandle has advanced through the Low Rolling Plains and into southwestern Oklahoma this evening. While the July ridge remains overhead, we do expect it to weaken slightly over the next few days.
Inland temperatures were much warmer than coastal temperatures averaging in the mid 70s to mid 80s. A fairly persistent weather pattern will stick around through the weekend, with cooler than normal temperatures for many locations around the forecast area.
Stacked ridging overhead producing significant subsidence for early July in a light wind flow regime. Hot and humid conditions will continue as deep layer ridging holds over the region. These temperatures combined with the high dew points will cause heat indices to once again approach the Heat Advisory criteria of 108 or higher, but like today not expecting these high values to be widespread so will not be issuing an advisory at this time. A light wind flow is expected through the weekend as ridging aloft remains centered over the state. There will remain enough moisture in place for isolated to low-end scattered storm coverage through the weekend but mid-level ridge will suppress overall convective coverage compared to normal for early/mid July.
While the July ridge remains overhead, we do expect it to weaken slightly over the next few days.
The potential for this repeat round of morning convection means that tomorrow's temperatures could again be much cooler than models indicate during the morning through early afternoon hours, so have trended below guidance in both high temperatures and in dewpoints to better reflect this morning's evolution. A cold front will begin sinking southward through the forecast area by late tomorrow evening; however, the environment will likely be capped and convection along the front may be spotty at best, especially if boundary layer mixing is limited during the morning and early afternoon.
The 500mb upper ridge is situated just to our west. /issued 338 pm cdt Wed Jul 6 2016/ Latest RAP analysis and satellite imagery showed the ArkLaMiss under flat upper ridging which was centered over the Southern Plains. Mid afternoon temps were running into the lower to middle 90s with heat indexes from 102 to 107. Flat upper ridging will rebuild during the short term.
Elsewhere, showers and an isolated thunderstorms will be possible as an upper low over north central Montana slowly shifts east this evening and overnight. Cooler and drier air will move into the forecast area late tonight into tomorrow.
Indiana will stay between high pressure over to the south and east and a front over the Great Lakes into Thursday.
At the surface, low pressure is located across Northeast Wyoming and southeast Montana, with a warm frontal boundary into the Nebraska panhandle. Upper level trof over the Northern Rockies will slowly shifting east late this afternoon, with southwest upper flow over the forecast area. Between the incoming high and departing low pressure systems, breezy northwest winds will develop, mainly across the South Dakota plains. High temperatures will be cooler, in the 70s to around 80 degrees.
Lows will be in the low/mid 70s once again. Will therefore transition the higher POPs of the rest of the afternoon into slight chance POPs for the first couple hours after 00z.
Rain chances taper off over the next several days as the ridge builds aloft.
Dewpoints are forecast to range from the lower to possibly middle 70s in the east, while upper 60s to near 70 is more realistic over central KS. Strong upper wave will move across the Upper Midwest pushing a cold front across the area Thu night.
Given this uncertainty will keep POPs in the high chancy category. Again the high level of uncertainty portends to continued chancy pops during the afternoon hours. Thursday Night Through Wednesday Active weather pattern relaxes a bit as upper level ridge temporarily builds into the region. Upper low slowly moves east across northern Wisconsin and U.
852 PM EDT WED JUL 6 2016 Deep layer high pressure is in control of the environment over south Florida and the Florida Keys this evening. The deep layer ridging has provided an unusually dry vertical column in the evening sounding. The low temperature so far today at Key West International Airport is 84 degrees.
And yet the lowering RH will lower the HX toward air temps over time. The process of feels like can be descrided by knowing that the perspiration which was meant to cool your skin from evaporation does not evaporate in the higher afternoon RH.
A cold front will shift winds north at KGUY after 00Z, and thunderstorms are possible across the Panhandles Thursday evening - though expected coverage is too low to mention in TAFs at this time.
Surface winds will remain out of the south to south-southeast at 10-15 kt with gusts to the low 20 kt range this afternoon. A mid-to-upper level subtropical ridge remains centered over the Big Bend region with an H850-700 ridge over Florida. Temperatures are currently in the mid to upper 90s over much of the region with dewpoints in the lower to mid 70s along and east of I-35. Heat indices today should be 1-2 degrees below what they were yesterday, and this trend is expected to continue tomorrow as well as the ridge gradually weakens due to upper level troughs passing along its northern periphery in the Central Plains and Midwest.
An upper trof will continue across the Dakotas into Thursday. Aside from some wrap around shower activity as the upper trof continues east late Thursday the rest of the short term is expected to be dry.
Westerly winds west of the dryline on Thursday likely to help boost temperatures once again into the 103-106 degree range as the thermal ridge remains in place.
Convection has continued to develop over far southern Illinois down into western Kentucky this evening as upper low now centered over far southern illinois near Carbondale with 50 knot mid level speed max just south of low center.
Meanwhile many of the meso models show that as the short trough moves east out of the central Dakotas, a cluster of showers and thunderstorms will move east toward the area. On Thursday night, another short wave trough will move through the area.
The upper trough is moving across central Montana this evening and should slowly work it's way east to the North Dakota border by morning. Proton This afternoon and evening: Forecast is rapidly evolving as a trough to the east moves into Montana. This is generating low pressure aloft and pulling surface moisture into far eastern Montana which is feeding a developing MCS moving across the Yellowstone Valley. These showers will last through the evening as the low twists across the area but the most severe elements should be out of the area by 8AM.
826 PM EDT WED JUL 6 2016 A weak trough of low pressure will cross the eastern Great Lakes early tonight.
Showers and storms, albeit much weaker, should continue off and on through tonight as the upper level waver moves across the northern rockies and high plains, and the cold front slides south across the plains. Tomorrow will be cooler and more stable across the plains in the post frontal environment, so convection will be minimal. Across the west, will see a return of dry and breezy west winds with gusts of 20 to 30 mph likely over the high country.
Ridge extending aloft wl inhibit convective potential and the best chance for storm development will be over the inland counties where boundaries interact.
1048 PM EDT WED JUL 6 2016 A weak trough of low pressure will cross the eastern Great Lakes early tonight.
Overview: Afternoon surface analysis reveals low pressure traversing northern Michigan with an ill-defined front meandering back through eastern Wisconsin and down into Iowa. Even so, temperatures have made it into the lower 80s in many locations with MLCAPE values ranging between 500 and 1000 J/KG per SPC mesoanalysis page.
breezy SWLY sfc winds push the mercury into the lower and mid 90s. with highs Thu aftn in the lower and mid 90s.
The weak front will remain stalled across central Utah through Thursday, allowing for slightly cooler air across northern Utah while the south remains dry.
840 PM PDT WED JUL 6 2016 An upper-level trough along the West Coast will bring cooler than average weather through the weekend.
Warm, humid air mass over the area will result in above avg lows tonight, ranging from the m60s ovr the nw mtns, to the l70s across the Lower Susq Valley.