Aikyam-Lab/Synoptic-Bench huggingface dataset:
Water vapor imagery shows an upper level ridge roughly across the Central Great Basin-Central Rockies into central Saskatchewan progressing eastward as an upper level trough advances across British Columbia to northern Alberta. Modest 500 hPa height rises are expected to continue overhead in tandem with northwest flow tonight as the mid-level ridge moves over the Central High Plains. Thereafter the ridge will move to eastern NEB-Upper Mississippi Valley by tomorrow afternoon with zonal flow in place by tomorrow morning that will continue through the day. Best chances in vicinity and east of trough, thus covering the areas of southwest NEB to central and north central NEB.
1017 PM EDT Fri Aug 18 2017 Upper trough Saturday brings more showers to northern areas.
/issued 245 PM CDT Fri Aug 18 2017/ WV imagery shows an upper-lvl ridge extending from New Mexico east thru Texas and the Gulf Coast states out into the Atlantic, bordered to the west by a trough just off the SoCal coast. As mentioned above, the trough will remain in place thru the weekend and into midweek, so best chances for convection will remain out west.
Will return to more Aug like temps for Sat as the upper flow flattens out, allowing for warmer temps to spread north. There is good agreement between the GFS and ECMWF in a robust upper trough tracking out of Manitoba and into the Great Lakes region by Tue night. This feature will push a cold front across the Plains lat Mon night through Tue evening.
The few evening showers have ending across the Southern Appalachian Region this evening as a weakening cold front slides through the area. slightly cooler and slightly drier air will move in. Chattanooga Airport, TN 69 91 70 92 / 0 0 0 10 Knoxville McGhee Tyson Airport, TN 67 89 67 91 / 0 0 0 10 Oak Ridge, TN 67 89 67 90 / 0 0 0 10 Tri Cities Airport, TN 64 88 61 89 / 10 0 0 10.
Look for one more day of minor warming this afternoon as a ridge of high pressure continues to build into our region. High pressure continued to strengthen today resulting in one last day of warming across the region. While coastal areas cooled slightly as a result of slow clearing low clouds along the immediate coast, inland areas saw significantly warmer afternoon highs from 24 hours ago. Over the weekend an upper level low will develop just off the coast of Point Conception.
Weak upper level trough pushing southeastward through the area this afternoon, allowing drier air to spread southward. An upper trough moves eastward through the Midwestern states on Saturday as a broad upper-level low retrogrades westward through the Gulf of Mexico. Low-level ridging is in place across the Southeastern US with northerly flow making its way into Central AL.
Upper level ridge will hold over the region through the period as the TUTT low continues to move to the west.
Upper level trough/wave over the upper Mississippi River valley to arrive early Saturday morning. Narrow/short lived 850-700 MB theta-e Ridge will attempt to slide in overnight, with PW values around 1. Fairly cold 500 mb temps of -13 to -15 C Saturday morning will lead to a brief opportunity for a thunderstorm or two to develop before trough/thermal axis slides east. Upper level northwest confluent flow becoming established Saturday afternoon will allow high pressure to build into the southern Great Lakes, with dry and pleasantly warm conditions around for the rest of the weekend.
Highs this afternoon in the low to mid 90s. Lee trough strengthens across eastern Colorado into NW Kansas during the afternoon, with south winds increasing in response. NAM forecasts decent convergence and modest CAPE along the lee trough axis near the NW zones by late afternoon.
Will return to more Aug like temps for Sat as the upper flow flattens out, allowing for warmer temps to spread north. There is good agreement between the GFS and ECMWF in a robust upper trough tracking out of Manitoba and into the Great Lakes region by Tue night. This feature will push a cold front across the Plains lat Mon night through Tue evening. Cannot rule out an isolated thunderstorm or two this evening across the eastern half of KS, as a weak cold front sinks south.
Weak surface front will merge with the lee side trough and drift into central/south Georgia. Weak high pressure will build into the Tennessee Valley keeping the drier and more stable air across north Georgia Saturday while proximity to the front will keep low pops across central Georgia Saturday afternoon. With the drier air will come slightly warmer daytime temps Saturday with most areas outside of the mountains seeing low to mid 90s.
Visible satellite and observations indicate the development of cumulus over the higher terrain mainly south of I-70 due to steeper lapse rates, but no precipitation detected on radar at all this afternoon. High pressure is sitting to our south with the ridge building over the area, keeping the best moisture south of the U. Some isolated shower and thunderstorm activity is possible over the higher terrain by afternoon with cumulus development once again.
729 PM EDT Fri Aug 18 2017 A few showers or thunderstorms, could linger into this evening, as a cold front passes through the region.
/ISSUED 356 PM CDT Fri Aug 18 2017/ Temperatures as of 3 PM CDT were in the lower to mid 90s across most of Southeast Texas and this heat, combined with some deeper moisture that pushed into the region from the Gulf today, was resulting in heat index values in the 105 to 110 degree range along the coast. Afternoon water vapor imagery depicts an upper low (TUTT) near Florida and this feature is expected to slowly translate west across the Gulf over the next few days.
20z Water vapor imagery clearly shows an upper low pushing through eastern Minnesota into northwestern Wisconsin.
1100 PM EDT Fri Aug 18 2017 A cold front will move slowly east across the area late tonight, then stall just east of Long Island on Saturday.
Having said that, abundant moisture and weak troughing across southern GA and northern FL may spark additional isolated showers later tonight.
There is no mention of thunder at any of the TAF sites due to the low confidence in occurrence and location of any storm that does develop.
Further north, agitated CU is noted just north of the Iowa border, with this activity occurring directly in advance of a cold front that is forecast to track south across our region later this evening. Storm activity to quickly come to an end after midnight with clear sky development expected during the predawn hours as high pressure starts building into the area. Despite the passage of a cold front, southerly flow will return fast enough by Saturday afternoon to allow temps to warm into the upper 80s to lower 90s across much of the area.
A few showers may linger over the Southern Appalachian Region this evening as a weakening cold front slides through the area. slightly cooler and slightly drier air will move in.
Weak low pressure over southern California is bringing up modest moisture to the region, especially over the Sierra and western Nevada.
We are still expecting high pressure to be the dominate force though the weekend which will keep light winds and small seas in the Gulf.
Bermuda Ridge axis just south of Sebastian Inlet will maintain a loose pgrad over the lcl Atlc overnight.
1253 AM EDT Sat Aug 19 2017 A cold front will move into the area late tonight and stall through the weekend.
The only wrench that could be thrown into the forecast tonight is the high cloud cover being seen upstream.
932 PM EDT Fri Aug 18 2017 A cold front will move slowly east across the area late tonight, then stall just east of Long Island on Saturday.
High pressure will continue to build over the region, and winds will be generally from a south direction at 10 mph or less. Lows tonight, mainly in the lower to mid 70s, look likely. Plus, models shift the upper pattern to position high pressure centers in such a way (west and east of our area) to create a shear zone aloft over Texas, during that time frame.
Latest surface analysis reveals a stationary boundary just north of the region, while H5 analysis depicts the region beneath southwest flow aloft with a trough axis to the northwest of the FA. Saturday highs will be warm, reaching the low to mid 90s in southernmost counties, with upper 80s in northern counties.
Ridging then sets up and will be dominant through the day Saturday. The remainder of the period will be dry as high pressure settles in tonight and Saturday. High temperatures on Saturday will range from the lower 80s in west central Minnesota, to the lower 90s west of the Missouri River.
Lee trough/dryline develops or moves to near the Colorado border during the mid and late afternoon hours. However, guidance over all and especially the high resolution guidance differs on where initiation will be with convective feedback issues causing problems with the Nam.
Still looks like some very patchy MVFR CIGS may develop over the north but guidance trending drier in the low levels so MVFR conditions may be very brief or even further north and outside the CWA. Not expecting much to come of this at this time, given the time of day and high pressure over the region.
Fairly sharp upper trof diving out of the Upper Midwest is supporting some strong convection across northern Missouri into western Illinois. The low-level environment is less favorable under our less humid bubble of high pressure, so this activity will weaken as it heads our way. Drier air has advected into the region, with afternoon dewpoints in the low to mid 60s. Mid-level cloud cover is expected to increase early Saturday as an upper trough swings in. Low pressure over Iowa this afternoon is forecast to track east across IL/IN tonight, dragging a weak boundary with it. Ridging Saturday night will bring continued fair weather with lows in the mid 60s.
A dry cold front will cross the area Saturday morning shifting winds to the northwest.
Convective clouds over the higher terrain will dissipate as the airmass stabilizes. There is limited convective cloudiness over the mountains, foothills and Palmer ridge. Models have an upper ridge flattening with weak zonal flow aloft tonight and Saturday. For temperatures, Saturday's highs will be 0-3 C warmer than today's highs. Forecast area under zonal flow aloft Sat night and Sun with lowering PW values with downsloping flow off the Front Range and Cheyenne Ridge. T-storm chances remain low on Sun, with convection mainly confined to the high terrain during the afternoon, with a bit more t- storm activity across southwest sections of the CWA during the evening hours with the arrival of moisture up from the Desert Southwest.
The upper level flow pattern will transition from southwesterly flow this weekend to northwesterly flow aloft for the middle of the week with upper level ridging moving over the area by the end of the week.
West to northwest winds 5 to 10 knots will persist tonight as high pressure edges closer to Lake Michigan. As the high pressure passes through the area on Saturday, light west winds will turn onshore late in the morning and remain south to southeast through the afternoon. A few light showers have developed around KDLL moving east in response to mid-level short wave trof moving through central WI.
929 PM EDT Fri Aug 18 2017 A cold front will pass east of the area tonight. An upper trough will move across the region Saturday afternoon and evening.
713 PM EDT Fri Aug 18 2017 A few showers or thunderstorms, could linger into this evening, as a cold front passes through the region.
724 PM EDT Fri Aug 18 2017 Weak high pressure will slide across the Ohio Valley this this evening and early tonight. Towards morning, weak low pressure associated with a disturbance aloft will drop across the lower Great Lakes and Ohio Valley on Saturday.
An upper level trough was over the region this afternoon with a weak low level trough near or just west of our CWA. High pressure will move in later tonight along with an upper level ridge.
Overnight lows will drop into the lower to middle 60s. A mostly sunny and dry day is anticipated on Saturday, with afternoon highs topping out in the lower to middle 80s.
The synoptic scale pattern for the Desert Southwest remains largely unchanged from recent days with dry southwesterly flow aloft in place due to troughing centered west of the California coast. Meanwhile a belt of subtropical high pressure remains centered over the Gulf Coast. The big picture synoptic pattern evolution remains the same for the coming several days with the development of more southerly steering flow over Arizona and southeast California between the California trough/closed low and a consolidation of subtropical anticylonic flow becoming centered further west.
912 PM EDT Fri Aug 18 2017 A cold front will move slowly east across the area late tonight, then stall just east of Long Island on Saturday.
1035 PM EDT Fri Aug 18 2017 An upper-level composite analysis this evening revealed a rather large and vigorous tropical upper-tropospheric trough (TUTT) cell ambling westward across the service area. So, storms likely will proliferate over the zones north of the lower Keys for the next few hours.
This surface feature is enhanced by the northwestern quadrant of a tropical upper-tropospheric trough (TUTT).
/issued 250 PM CDT Fri Aug 18 2017/ Upper level trough axis seen on current water vapor image is essentially centered north to south down our longitude. Some scattered convection toward the I20 corridor has initiated in monsoon moisture shunted south by early morning outflow from MCS in western Oklahoma, while an upper level low squeezes moisture northward out of Big Bend and Central Texas. Though there is still a slight chance of some convection moving off the higher terrain of New Mexico later tonight int the early morning hours, but should remain in vicinity of the state line. As the upper level low currently to our south shifts west and southward, we'll see high pressure build in farther westward which will keep us mostly dry through the weekend.
515 PM MDT Fri Aug 18 2017 Upper trough is sitting across the eastern half of the CONUS with weak ridging across the northern Rockies into the northern High Plains. At the low levels. northwest flow on the backside of the low pressure across Great Lakes. Upper ridge will weaken Saturday but remain over the northern plains. Cooler temps will then return as the frontal boundary crosses the area late Saturday into the evening.
Look for one more day of minor warming this afternoon as a ridge of high pressure continues to build into our region. Synoptically-speaking, there is an upper level ridge centered near 38N 135W that has gradually strengthened over the past 24 hours. Over the weekend an upper level low will develop just off the coast of Point Conception.
Latest water vapor imagery shows an upper level low over eastern Minnesota, with the upper trough extending southward and through the Central Plains. Across the local area, skies have become mostly clear over the last couple of hours, as high pressure settles in at the surface. The upper trough will push eastward tonight, with its axis swinging through the TN Valley early Saturday morning. Winds will briefly shift to the southwest, filtering in moisture and leading to overnight lows in the lower 70s. The upper trough axis will move east of the forecast area by the afternoon hours on Saturday. Meanwhile, a cold front to our north will shift through the area, bringing a reinforcing shot of drier air across the region.
Not expecting much to come of this at this time, given the time of day and high pressure over the region.
A few light showers have developed around KDLL moving east in response to mid-level short wave trof moving through central WI.
On Saturday morning, a weak cold front will move south into the Big Country, shifting winds to the northeast for a few hours at KABI. This will keep temperatures in the low to mid 70s.
937 PM EDT Fri Mar 16 2018 High pressure will settle over the area tonight through the weekend while low pressure tracks up the Lower Ohio Valley Saturday.
709 PM EDT Fri Mar 16 2018 High pressure through tonight. Low pressure system brings a bag of wintry mixed pcpn late overnight tonight into Saturday morning.
1121 PM CDT Fri Mar 16 2018 A negatively-tilted mid to upper-level trough will cross overhead the local area during the afternoon hours. There is still some uncertainty on whether or not the lower levels can destabilize sufficiently to produce surface based convection this afternoon. Aside from this risk, there is also the potential for elevated storms to produce marginally severe hail as MUCAPE values approach 700 to 800 j/kg, with freezing heights beneath 8000 ft. Saturday afternoon highs will peak in the mid 40s to low 50s, with overnight lows slightly cooler than tonight.
/issued 325 PM CDT Fri Mar 16 2018/ Latest surface analysis shows a ridge extending from the western Atlantic across Florida into the forecast area. At the upper levels, mid latitude cyclone over the Central Plains becoming elongated, while southern stream is located at the base of the trough from the cyclone and stretches from the East Pac through northern Old Mexico and Texas, then across the Gulf South. A second upper level low is moving off the Pacific into northern California. Convective indices remain on the marginal side, and thus any showers that can tap into the highest instability may have enough updraft strength for storm growth to produce cloud to ground lightning and gusty winds, although any organization of the storms seems limited.
A cold front will pass across the region Saturday along with some snow showers and possibly a few squalls. Low pressure is expected to pass to the south midweek but the track is very uncertain at this time. Funny that cold advection is ongoing ahead of the cold front that arrives tomorrow morning! Snow showers are still occurring in some areas, but coverage is very sparse and with drier air moving in it should get even sparser. A cold front will approach from the northwest early on Saturday and is expected to sweep across the region through midday.
1244 AM EDT Sat Mar 17 2018 Low pressure will remain northeast of the region through the weekend.
Winds will start southeast to southwest at 5 to 15 mph with some gusts to near 20 mph, then become more southwest to west as a low pressure trough moves through AR this evening and into the overnight.
909 PM CDT Fri Mar 16 2018 Cold front currently moving into northeast Oklahoma this evening, resulting in a wind shift more towards the north along with cooler air. Less wind tomorrow and slightly cooler temperatures will improve fire danger over the critical conditions observed Friday afternoon.
722 PM EDT Fri Mar 16 2018 High pressure will settle over the area tonight through the weekend while low pressure tracks up the Lower Ohio Valley Saturday.
This precipitation should also fall mostly in the form of rain, but a few hours of near freezing temperatures across the far northern portion of the forecast area late tonight/early Saturday could produce a light glaze of freezing rain. Even so, the temperatures after midnight, mainly north of a line from Galesburg to Danville, will drop to near or just below freezing. However, the NAM has a deeper layer of freezing temps below that to about 1000 ft, leaning towards sleet. GFS is a bit warmer. and both models are right at the freezing mark at the surface. Weak ridging moves back into place through the remainder of the weekend.
One result is that the low temperatures may end up a degree or two higher than previously forecasted with most spots in the 10's to low 20's. Highs will likely only top out in the upper 20s to the low 30's north and into the 30s to the south.
Warm frontal clouds moving very little across the Midsouth early this evening. This low is expected to slowly lift east across central Illinois through Saturday morning. As it does, a weak cold front will push through the Mid-South through tomorrow morning.
However, temperatures look to remain safely above freezing, as even the coldest guidance maintains lows above 40 degrees. Areas of the Nature Coast and interior northern Florida will see the coldest temperatures, generally in the lower 40s, while the remainder of the peninsula will fall into the mid to upper 40s. Areas along the coast will be a bit warmer, with 50s. Pleasant marine conditions will continue into the weekend with high pressure in control.
Periods of light freezing drizzle are possible through the overnight hours, but additional accumulations are expected to be minimal. Active forecast in the short term with band of precipitation lifting to the northwest across the forecast area wrapping around a low pressure center across eastern Nebraska. As the upper level low weakens and shifts east, atmosphere dries out from aloft. With residual lift through deep saturated layer could see some light drizzle/freezing drizzle through the evening hours.
The surface warm front is poised just to the south/west of the FA, starting to nub into/across the southern SEMO border. Things change tonight as the Low moves into Missouri, and the surface warm front is ultimately drawn northward into/across our area. The ridge is shunted east and the modeled soundings show the inversion breaks down, allowing the ample warm/moist advection to begin to precipitate. It looks to be mainly with the lift of the warm front as an assisted lifting force, so from about 00z-09z is the convective (slight) chance mention. Most of the pcpn chance is with the warm front tonight. A lingering pop in our north/east is carried tmrw, until the Low itself passes with the trailing cold fropa.
A clear to mostly clear sky is expected with low temperatures in the low to mid 20s. Afternoon temperatures look to reach the upper 50s northeast to the low/mid 60s across the rest of the area under just a few high clouds. For Saturday night am expecting low temperatures in the low to mid 30s under slowly increasing cloudiness.
a dry line that extended more or less southward from the low and a cold front lagging behind into the Texas Panhandle. with south winds shifting westerly as first the dry line and eventually the cold front moves through the region. Saturday will then be dry but 10 to 15 degrees cooler on the back side of the cold front which will reach the AR/LA border before stalling out.
1225 AM EDT Sat Mar 17 2018 Crossing low pressure will spread a light wintry mix of precipitation along and south of Interstate 70 this morning. Filling low pressure emerging from the mid west is still expected to generate a wintry precip. amounts are expected to remain light (<1/4 inch as per RFC), concern for a glaze of ice via freezing rain continues with strong warm advection is indicated above the boundary layer, although that potential will at least initially be inhibited by wet-bulbing.
623 PM CDT Fri Mar 16 2018 A negatively-tilted mid to upper-level trough will cross overhead the local area during the afternoon hours. There is still some uncertainty on whether or not the lower levels can destabilize sufficiently to produce surface based convection this afternoon. Aside from this risk, there is also the potential for elevated storms to produce marginally severe hail as MUCAPE values approach 700 to 800 j/kg, with freezing heights beneath 8000 ft. Saturday afternoon highs will peak in the mid 40s to low 50s, with overnight lows slightly cooler than tonight.
The WAA associated with this low will maintain low chances for rain tonight and into Saturday but weaken Saturday as the low weakens. Temperatures through the period will be warmer than normal. Despite the clouds and rain chances, highs Saturday will reach the lower 80s and many locations.
The warm start to Saturday coupled with warm 850 mb temps should yield high temperatures in the lower and middle 80s. Fcst soundings show a weak capping inversion in place but the cap could erode between 21-00z once temps warm into the lower 80s.