Aikyam-Lab/Synoptic-Bench huggingface dataset:
Latest satellite imagery showed a closed upper low over Western MN. On the surface a warm front was pushing north bringing in a moist unstable airmass in strong low level southerly flow in response to the developing storm system. A cold front was located across the Southern Plains. Latest CAM guidance shows some isolated severe storms for this afternoon and a broken QLCS for tonight along the cold front. High pressure will build into the region from the west during the afternoon. As far as temps are concern lows tonight will be in the upper 40s northwest to the lower 60s southeast.
Our weather through the rest of the week should generally be uneventful as deep closed low moves east and flow aloft is zonal, or at least quasi-zonal.
Currently, under a cloudy sky and northwest winds, temperatures are hovering anywhere from a few degrees below freezing to as much as 5 or 6 degrees above freezing. And, bands of snow continue to march around this parent upper level low pressure circulation centered on central MN. Will watch minimal changes in low level thermal advection yield perhaps 3 to 6 degree cooler lows tonight and highs on Wednesday, compared to last night's lows and today's highs. (Wednesday Night through Tuesday) Issued at 351 PM CST Tue Nov 29 2016 The low pressure that has been over the region the past couple days will continue to move away from the area Wednesday night.
340 PM EST Tue Nov 29 2016 Strong low pressure system over the upper midwest and its associated front will push across the southeast plains this week while ridge of high pressure continues to hold over the southern portion of Florida. High pressure will keep southeasterly flow across the region before weakening as the front gets closer to the area.
Clearing from the west with much cooler temperatures and the coldest lows of the season so far tonight and Wednesday night, with widespread freeze or hard freeze conditions for Southeast Arizona.
A continued tight pressure gradient will bring gusty winds to the area today, with the highest winds across central and east-central Wisconsin. Given the push of cooler air, some snow may mix in at times across the north.
245 PM MST Tue Nov 29 2016 Northerly flow on the back side of upper midwest low pressure system will continue across CO with a lobe of energy exiting eastern CO this afternoon. with only spotty additional snowfall amounts of up to an inch across the higher mtns.
Upper pattern will remain mostly unchanged today and tonight as the large upper low slowly migrates into MN with nw flow aloft remaining over the central Plains. Wintry precip will stay north of the forecast area, closer to the upper low. Even though temps will be a few degrees cooler than Mon, good mixing and downslope will still allow highs to be above normal. Temps on Wed and Thu will be slightly cooler but will still be close to seasonal normals. A cold air advection pattern will continue as the mean northwest flow aloft deepens across central and eastern Kansas tonight thru Wednesday morning behind the passage of a mid/upper level trof.
The models show a 500 mb vort max backing into the Laramie Range and weakening after 18z which should lead to decreasing precipitation chances for the High Plains.
After a brief respite from the rain today, a cold front will cross the region tonight. In the wake of this system, high pressure at the surface and slowly rising H5 heights are expected to keep the region dry through the end of the short term period. Zonal flow aloft will prevail across a good part of the country at the beginning of the forecast period, with a cut-off low developing over AZ.
The surface warm front has pushed to near the I-20 corridor and will push north of central Alabama this evening. The main severe threat will be along a QLCS that will form in northern Mississippi this evening ahead an approaching cold front. The greatest threat for severe storms will be across our northwest counties, where the low level jet will be strongest and veering wind profiles maximized. The tornado threat should decrease after the line moves south of I-59 as the low level flow veers, but isolated tornadoes still possible.
311 PM EST Tue Nov 29 2016 A wave of low pressure moves northeastward tonight, pushing a front through on cold Wednesday. Cooler high pressure to end the week. A cold front comes through on Wednesday with a fairly good line and some instability. Some differences still exist in model timing of the cold front, so although there is a high confidence in showers on Wednesday, confidence is lower in the timing. Expecting post frontal precipitation in the northeast mountains, light, with a trace of snow possible in the highest elevations.
920 AM PST Tue Nov 29 2016 A mid level ridge of high pressure will move rapidly across the area today in advance of a frontal system over the Pacific.
/Tonight through Wednesday/ Upper low that has been impacting the region over the last few days continues to spin across central MN tonight into Wednesday.
140 PM EST Tue Nov 29 2016 A wave of low pressure moves northeastward tonight, pushing a front through on cold Wednesday. Cooler high pressure to end the week. A cold front comes through on Wednesday with a fairly good line and some instability. Some differences still exist in model timing of the cold front, so although there is a high confidence in showers on Wednesday, confidence is lower in the timing. Models are in decent agreement with strong cold front pushing through the region on Wednesday.
Early Wednesday VFR with a (dry) cold frontal passage timed to come through and strengthen northerlies just before noon. Made some adjustments to the afternoon rain chc to shift the higher pops to eastern portions of our area. There is a nearly stationary warm front located across central portions of the area. The cold front will not arrive until tonight.
This should allow temps to drop into the low 30s most places, as winds will be light. Clouds will increase from west to east tomorrow morning as low pressure draws near. Temps are right on the edge for snow though and the NAM is colder in the low levels suggesting mainly snow.
229 PM CST Tue Nov 29 2016 Early afternoon water vapor imagery together with GFS 500mb heights and surface obs show a broad upper level trough across the central Conus, with the center of an upper level low across central Minnesota. Over the next 36 hours this upper level low will slowly meander to the east southeast. we have the Wednesday night upper low to spread east taking the light snow.
A strong upper trough is currently passing through the Central Plains and this feature is expected to send another reinforcing shot of drier and cooler weather to the region by the morning hours. Some outlying locations in protected valleys could reach the freezing mark.
Otherwise a northerly flow is expected to continue through the rest of today and tonight with some passing cloud cover later today ahead of the next trough tomorrow. An upper ridge in the PacNW will weaken and slide into the region tonight. Clouds will increase late tonight ahead of the next upper trough which will reduce the chance for fog, although patchy fog will be possible late tonight in the valleys from Ontario to McCall. The upper trough will bring a chance of valley rain/snow showers and mountain snow showers on Wednesday. Precipitation amounts will be light with up to an inch of snow expected in the higher elevations.
Cooler Weather the Remainder of the Week. A cooler airmass will settle into the region tonight and Wednesday in the wake of a cold front moving across the Ozarks Tuesday afternoon. After a mild day, lows tonight will fall to near the freezing mark. Will likely see intervals of clouds Wednesday within a cold air advection pattern associated with a passing upper level trough. A broad trough will continue over the Great Lakes Region into the Upper Midwest. All models show an upper level low pressure and trough digging into the southwestern portions of the country by the weekend.
The pattern aloft was influenced by an expansive low pressure area across the interior conus with low pressure centered located in Minnesota and New Mexico. A lobe of energy was translating around the back side of the upper midwest low with a cold frontal boundary crossing central and eastern Nebraska and Kansas this afternoon. The upper low pressure system will continue to lift out towards the Great Lakes and we remain on the back side of the trough. The surface pressure gradient remains tight between the departing low to the east and ridging along the Rockies/High Plains and we are looking for another day of windy conditions with northwest wind gusts of 30 to 40 mph.
An area of low pressure located over central Minnesota is the dominant feature in upper levels while a disturbance moving around the back side of it brings flurries to the forecast this afternoon. Slightly warmer temperatures, with highs in the 40s, are forecast on Wednesday. The upper low makes its way into Canada and the region remains under northwest flow both at the surface and aloft.
226 PM CST Tue Nov 29 2016 A broad upper level trough is over most of the country with the CWA at the south end. Temperatures today are expected to be a little cooler than yesterday as lower heights spread across the region due to the upper trough. A cold front will move through the area tonight in association with the upper trough. Overnight lows will likely reach the freezing point or below for much of the area. On Wednesday, the previously mentioned upper trough will begin to move eastward while another upper low moves over the Pacific Northwest. Temperatures on Wednesday will be cooler than normal with highs mostly in the 50s.
Chattanooga Airport, TN 72 61 66 38 / 30 90 100 20 Knoxville McGhee Tyson Airport, TN 71 60 68 41 / 50 90 100 20 Oak Ridge, TN 70 58 66 41 / 40 90 100 20 Tri Cities Airport, TN 67 56 65 39 / 80 50 100 40 TN.
Cold front is currently near a Copan to Spencer line and is expected to move through the majority of the Tulsa Forecast Area this afternoon. /Issued 359 AM CST Tue Nov 29 2016/ Early morning water vapor imagery shows large upper low pressure center now across the upper Midwest. Surface cold front/wind shift extends from Wichita to near Gage. as cold front moves east across the area this afternoon.
Another upper low will bring chances for showers and thunderstorms later this evening and overnight, with KCKV likely seeing impacts first followed by KBNA and then KCSV.
/Today through Tonight/ The upper level low pressure is currently over the tri-state region of the Dakotas and west central Minnesota this morning with the sfc reflection beginning to slowly fill and shift northeast. A few patches of light rain and light snow ongoing over far northern Iowa in response to a short wave lifting northeast around the upper low. With sub freezing temperatures aloft, the precipitation type will be dependent on near surface wet bulb temperatures.
High pressure building over the region will maintain dry weather conditions and temperatures near to slightly below seasonal averages today.
An area of high pressure is moving off the mid Atlantic Coast this afternoon and tilting to a more northeast to southwest orientation. The ridge axis from the high is stretching across the Florida Peninsula ahead of the trough draped along the northern Gulf of Mexico.
Deep upper level circulation now centered over souther Minnesota this afternoon, with positive tilted longwave trough over the Eastern Rockies. This trough axis will become more neutral tilted over the Plains Tomorrow, making for a tough call with respect to rain chances over southeast Michigan with the tightening baroclinic/FGEN zone which looks to be residing in between the Central and Eastern Great Lakes.
Visibilities might be reduced to near 2SM at times, but the lower visibilities should be short lived.
Made some adjustments to the afternoon rain chc to shift the higher pops to eastern portions of our area. There is a nearly stationary warm front located across central portions of the area. The cold front will not arrive until tonight.
Otherwise a cold front will gradually move through AR. Expected some convection this afternoon to evening as the upper system and cold front gradually move through the region. This low stratus along with some SRLY winds. cooler and much drier airmass moving into the region.
a warm frontal boundary is located across central Alabama. Forecast soundings show boundary layer so can not rule out an isolated tornado near the warm frontal boundary (especially for the CHA area).
Location of primary rain band will be dependent on the exact track of the low and the aforementioned deformation zone. Latest NAM/GFS/SREF trend the low further west than the previous forecast, bringing the best rain chances almost directly over Pittsburgh and through the heart of the forecast area. The arrival of the low and associated cold front make Wednesday high temps a little more difficult, but they will remain above average. Likewise, upper troughing starts to move farther eastward into the Great Lakes region with the frontal passage on Wednesday night, low level flow really fails to turn NW immediately.
1100 AM MST Tue Nov 29 2016 18Z TAF CYCLE An upper level low pressure system has closed off over north central New Mexico. A cold week is in store as a deep upper level trough ushers in the coldest air of the season today.
Wednesday will be just a touch warmer with some modification of the polar airmass and also slightly drier with dewpoints falling to the lower to mid teens by afternoon.
This low will pull newd today, keeping the CWA under rather strong WAA thru the afternoon. For tonight, with the cdfnt moving thru the region, have generally trended cooler.
Deep cyclone centered over Minnesota this afternoon with 120 knot upper jet from Texas to Pennsylvania will undergo anticyclonic curvature this afternoon and overnight placing Middle Tennessee in the right rear quadrant for several hours which will aid the development of convection. Surface cool front will begin to push eastward from Oklahoma this evening with strengthening low level jet and a northward surge of moisture along with a warm front currently draped west to east across Mississippi and Alabama that will move northward this evening placing Middle Tennessee in the warm sector by mid evening.
1150 AM CST Tue Nov 29 2016 /18Z TAFS/ VFR through the next 24 hours as a dry cold front moves through the area tonight. A dry cold front moving through the area will be preceded by westerly winds gusting 15-25 knots by mid-day becoming light northwesterly by early evening. /issued 356 AM CST Tue Nov 29 2016/ (Today and Tonight) An upper trough passing eastward across the southern Plains today through tonight will drop a dry cold front through the forecast area today. West winds 10 to 20 mph with higher gusts will precede the cold frontal passage with northwesterly winds dropping to around 10 mph after frontal passage. A few of the more sheltered areas could see temperatures dip to the freezing mark before sunrise.
With north winds in the low levels through tomorrow morning, should avoid any obstructions to terminals for the next 24 hours. For tonight, a cold front will move across the region bringing a reinforcing shot of dry and cool air. Overnight lows will drop into the lower 40s to lower 50s.
313 PM CST Tue Nov 29 2016 Broad upper level trough remains over the central U. Cold front currently passing through northeast OK and shifting wind out of the northwest should lead to a bit cooler temps tonight in most locations along with several degree drop in high temps for Wednesday. There will be some increase in fire danger for Wed afternoon despite cooler temps as wind speeds pick up and very dry air remains in place.
The rain was occurring near a cold front moving east through Kentucky. Its initial cold front trying to pass through at our latitude is becoming oriented nearly parallel to the upper level flow, and is slowing down and losing its identity. Instead, another upper level impulse rotating around the large scale low/trough will support a second cold front moving in from the west tonight. Forecast soundings suggest it will be mainly elevated, but show some potential to become briefly surface based just ahead of the cold front. Lingering precip will probably last into Wednesday morning, but will taper off for the afternoon as the cold front moves east of the area, a much cooler air mass arrives, and most moisture above 850 mb is lost.
Pops will be lower for a bit before ramping them back up late as the closed upper low approaches northwest Wisconsin.
333 PM CST Tue Nov 29 2016 Continental upper level low pressure trough will translate eastward across the area overnight. A weak surface cold front should gain a little momentum overnight with cooler and drier northerly low level flow, though surface winds will weaken later tonight. A chilly morning will start the day Wednesday with sub-freezing conditions most of the area other than perhaps parts of the Rolling Plains. Highs Wednesday will be slightly cooler than today most areas owing to a chilly start, except eventually should climb a little warmer than today across our west or northwest counties.
More seasonably cooler air will infiltrate later this week with highs around 40 and lows around 30. With the cooler air there is a chance of some lake effect rain and snow showers north of highway 6 but little to no snow accumulation is expected at this time.
Water vapor satellite imagery this morning shows the deep trough which brought snow showers across Utah yesterday, sliding southeast into northeast New Mexico this morning with subsident relatively dry air sweeping across western Utah. As the trough axis swings southwest, conditions are unstable enough to allow snow showers this morning across the mountains but will taper off by mid-late afternoon. Winds are breezy over far southwest Utah and down across Castle Country with gusts up to 30 mph, however the gradient should relax later today with the departing trough.
1242 PM EST Tue Nov 29 2016 WV imagery and RAP analysis indicated a broad mid/upper level trough over the Plains with a low centered over the eastern Dakotas. Tonight, Dry slot of mid-upper low moving across the area should ensure dry conditions across much of the forecast area under partly to mostly cloudy skies. Min temps will range from the low 30s over interior west to the mid to upper 30s near the Great Lakes. By that time, cooler air will begin to move in aloft which may allow some snow to mix in with the rain at times over the far west late Wednesday afternoon and especially Wednesday night.
224 PM CST Tue Nov 29 2016 Large vertically stacked low over the Upper Midwest dominating the weather map across the country as the trof stretches from coast to coast. However, cooler air is just to the west on the other side of a sfc trof/secondary cold front. Drier air expected to help scour out some of the higher dwpts in the southeast where cloud cover today trapped some of the ground moisture from yesterdays precip. And whereas the highs tomorrow will be cooler than today. As the large low pressure area continues to move east-northeast, high pressure ridge will build into the middle of the US and bring dry and seasonable temps to the entire CWA for the remainder of the week and the beginning of the weekend.
The upper level low pressure system that has remained relatively stationary over the past 24 to 36 hours bringing record snows to central ND will begin to move east tonight and be centered over western Wisconsin by 18Z Wednesday. Where temps stay closer to freezing the light snow and or drizzle will linger.
Expected some convection this afternoon to evening as the upper system and cold front gradually move through the region. This low stratus along with some SRLY winds. cooler and much drier airmass moving into the region.
Low pressure continues to spin across the Upper Midwest late this afternoon and will start edging eastward into the local area late tonight through Wednesday. However, this may not happen until Wednesday as the the low moves in. The low continues to edge east Wednesday night but we will stay in cyclonic flow providing cloudy skies and perhaps some very light rain or snow.
The system which will have the highest impact on our region is likely the upper low over the Great Lakes region. Flow around the western flank of the upper level low has forced a cold front southward all the way to the upper TX Coastal area. Behind this front, cooler and drier has settled in across the region. For today, we saw more in the way of mid and high clouds than previously expected due to the presence of both an upper low over northwest Mexico and Tropical Storm Roslyn in the Eastern Pacific. However, the upper low is forecast to lift northwestward and weaken tonight and Wednesday.
323 PM CDT Tue Sep 27 2016 High pressure remains over the region with sunny skies and temperatures in the middle 70s to around the 80 degree mark. Clear skies will occur through tonight, but with a light southwesterly wind lows will be slightly warmer tonight than it was last night. Lows tonight will be in the lower to middle 50s. The upper level low will sag south sending a cold front through the area on Wednesday. Winds will shift to the north behind the front and a cooler air mass will spread into the area. Highs on Wednesday are expected to top out in the upper 60s to the lower 70s with lows Wednesday night dropping into the 40s. Cooler conditions will prevail across the area through the end of the week.
314 PM CDT TUE SEP 27 2016 Deep upper low continues to spin over the Great Lakes with ridging over the Great Basin into the Rockies. At the surface, high pressure is situated over the southern Plains. Upper low over the Great Lakes will sink south and will be situated over the Ohio Valley by Wed night. 850mb temps on Thu support highs struggling to get out of the low 70s.
300 PM PDT TUE SEP 27 2016 High pressure will begin to weaken Wednesday with a few showers possible over southern Mono County. The ridge weakens further late week as a trough of low pressure moves into the west coast. This will bring breezy and cooler conditions to northeast California and western Nevada.
/issued 253 AM CDT TUE SEP 27 2016/ Curved upper level ridge extending from Texas to the Great Basin will slowly become more meridional over the next 24 hours. This low is interacting with TC Roslyn in the Pacific and helping to stream upper level moisture into the region. The Baja low will drift NW into SRN California today as the ridge shifts westward.
Another picture perfect early autumn day with ridging aloft keeping it warm and dry. Warmer than yesterday based on thickness changes and 700 mb temperatures near 10 Celsius. Ridging aloft moves overhead and with low level winds becoming upslope (easterly), and 700 mb temperatures cooling to near 8 Celsius, temperatures will be slightly cooler.
/Issued 1116 AM EDT TUE SEP 27 2016/ Latest satellite/obs showing cold front/wind shift pushing across northwest Georgia, beginning to get into northwest portions of Atlanta metro (Cobb/Paulding counties). Low clouds can be seen just behind this boundary with temps in the lower 70s.
And aside from some easterly winds sweeping into NW Montana with the passage of a back door dry cold front, most of the Northern Rockies will yet again be under warm, dry, mostly sunny conditions on Wednesday.
The low levels of the atmosphere still remain relatively dry, which will hinder convective potential again today. Cooler and drier will work into north Alabama this evening with temperatures falling into the 50s across areas along and north of I-20 by Wednesday morning.