Aikyam-Lab/Synoptic-Bench huggingface dataset:
An upper ridge extending eastward from the southern plains over the northern gulf region and the state of Florida will build slightly northward over the next 24 hours. Expect less coverage of showers and thunderstorms throughout the day with the upper ridge building northward over the region providing a stronger capping inversion around 800 mb and a slightly drier mid and upper level air mass.
At the surface, low pressure was analyzed over eastern CO and a meso high from this morning's convection was noted over the mid MO river valley. With this in mind, have highs in the lower 90s across northern KS with mid to upper 90s over east central KS. Overnight, the low level jet is progged to be veered to the west southwest so convergence along the boundary would appear to be minimal.
A cold front on Friday will usher in cooler and drier air for the weekend. Have adjusted temperatures a little cooler to account for these clouds.
Have TEMPO groups in for our southern sites through 15Z, after which the low clouds should scatter out to mainly clear skies.
Current thinking is that best upper support to aid in storm development will occur from 18-21z this afternoon with approach of mid level trof. With wave and inverted trof will likely still see areas of rain/T so will maintain relatively higher pops. Friday will be a bit blustery and overall cooler. High pressure will bring diminishing wind to the region.
Low pressure will strengthen in the Plains and should see a decent pressure gradient set up out ahead of the low over our western CWA. Can't rule out some scattered convection tonight along the southeastward moving cold front. It doesn't appear like we will get rid of the higher dewpoints anytime soon as the front stalls out across the area.
1034 AM EDT THU JUL 7 2016 Low pressure will approach the area today then track south of the region tonight.
During the early to mid afternoon hours, mesoscale models and some larger scale models are in fairly good agreement that the upper ridge to the southwest of northern Alabama builds into the area this afternoon. Lowered cloud cover to primarily partly cloudy conditions through much of the day, due to lower level subsidence expected/the upper level ridge building back over the area later today.
Upper level ridging will build over the Central Plains through the weekend.
At the surface, weak trough is now crossing Iowa. Main cold front will sweep through the state tonight to finally bring a break from storm chances as we head into the weekend.
A continuation of hot and mostly dry conditions today under mean layer west to southwest steering flow over the northern edge of the persistent 1000-500 mb ridge axis across south Florida. Wave vapor imagery indicated an upper level and sheared trough axis across NE Fl and SE Ga. but coupled with high low level instability and weak upper level lift per the trough axis aloft.
Showers continued across central and eastern portions of the area early this morning, associated with a weak cold front sweeping across the region. Shower coverage will gradually decrease from west to east through the morning hours as the front and its' parent upper low shift east of the area. High pressure will begin to build over the region today with dry conditions and warming temperatures expected. Heights continue to build into Friday, with the ridge axis eventually shifting east into the Dakotas, and southwest flow aloft progged to develop over the area as an upper low moves onshore into the Pac NW.
Chattanooga Airport, TN 91 73 97 75 / 60 20 20 20 Knoxville McGhee Tyson Airport, TN 83 70 93 74 / 60 30 30 30 Oak Ridge, TN 83 71 93 74 / 60 30 30 30 Tri Cities Airport, TN 82 68 91 70 / 100 30 30 40.
Winds will turn to southerly today into tonight with the arrival of a cold front.
Afternoon temperatures on the lower deserts will not vary much, and range from 107 to 110 degrees. In other words nearly all the southern half of AZ was generally under tradition monsoon moisture, although the low end variety.
Expect the low clouds to mix out by mid to late morning. An upper level ridge will continue to dominate the weather across North and Central Texas but, it will shift slowly southwestward this weekend.
The prospect of severe weather would generally be limited to large hail with cooler air in place.
/issued 305 AM CDT THU JUL 7 2016/ Only changes tonight from last night is temperatures are running a degree or two warmer and winds were stronger from the southwest. the upper level ridge over the ARLATEX and Ozarks will shift east over the Midsouth.
Sunny and warmer today as flat upper ridge moves through from west to east. Cold front ahead of deep upper low in the Gulf of Alaska will reach our nwrn CWA corner Friday morning and stay there Friday as upper flow backs to southwesterly.
It should weaken as the sun rises and cloud tops warm while the low level jet weakens. Residual clouds will slow the rise in temperatures in the western counties this morning and an increasing easterly wind will keep the eastern counties cooler today than yesterday. There isn't too much in the way of support for precipitation this afternoon until a warm front starts to approach from the south. There is a good chance of showers and thunderstorms Friday as a strong upper low drifts across the Upper Peninsula.
Meanwhile, the cold front was beginning to move into extreme northeast NE, and this will be the main show later this afternoon and evening. Upper level ridging will build over the Central Plains through the weekend.
At the same time, low pressure and attendant frontal boundaries over southern Nebraska will lift northward through the morning hours, bringing a triple point into northwestern IA by mid afternoon. As for temperatures today, highs look to be a touch cooler than yesterday - in the lower to mid 80s. Friday looks like a pleasant day as a closed upper low moves across Upper Michigan, giving this area a dry northwest surface flow.
A flat ridge of high pressure over the region is in the process of giving way to an approaching weak cold front. More precipitation and cooler conditions are expected through the weekend.
A weak cold front will remain stalled across central Utah today.
With mid- level temperatures very slowly cooling from north-to-south (and cooler than yesterday), this northern convection may be our initial hint that it won't be as difficult to pop activity during the daylight hours as it was yesterday. but with various models (both deterministic and hi-res) suggesting that at least isolated development could affect mainly the eastern/southern halves of the CWA from late this afternoon into tonight mainly along/just behind an invading weak cold front, wanted to at least cover the small possibility. The same models have an upper level wave that moves through the area today and a cold front moves through the forecast area today.
Otherwise, not a lot of change indicated in the past 24 hours with axis of surface/mid level high pressure ridge extending across south/central Florida. High pressure will ridge across the waters through the weekend with the ridge axis meandering through the period.
Gilchrist Previous discussion: Upper trof moving across eastern Montana early this morning with a few showers lifting into southern Saskatchewan. Scattered showers are possible through the morning as the low moves east. Upper ridge builds into the state behind the departing low pressure.
235 PM CDT WED SEP 28 2016 Current upper level analysis shows cutoff closed low moving into the Ohio Valley while high pressure builds into the southern Plains. A weak front in association with closed low has shifted surface winds to the northeast across the Panhandles.
Light winds will continue, then begin to shift to a north or northeast direction late tonight and Thursday morning as a cold front moves through the area. As high pressure continues to dominate, highs today will range from the lower 80s to the upper 80s. For tonight, another push of cooler air will move into West Central Texas, mainly after midnight.
Would expect coolest temperatures and possible fog development in these areas with lows possibly into the lower 40s in favored cool spots of the cranberry bogs. Thursday will be partly to mostly sunny as high pressure ridge nudges east toward the forecast area.
/issued 411 AM CDT WED SEP 28 2016/ Morning WV satellite imagery shows an upper level trough centered over the Great Lakes extending down into the lower Mississippi River Valley and Southern Plains. The first cold front associated with this trough has already moved offshore resulting in cooler air working into the region this morning. Model guidance indicates that the 500 hPa trough will continue to cut off today and Thursday with the low drifting southward.
338 PM EDT Wed Sep 28 2016 A large, slow moving low pressure system will settle into the Tennessee Valley tonight, then lift through the Northeast this weekend.
Cold front currently extending from Michigan across north central Illinois then back up into South Dakota will dive south today and into northwest Middle Tennessee by mid afternoon and continue to push through the Mid State as we go into the early evening. Air mass behind the front will reinforce the cooler Autumn temps now in place.
220 PM EDT WED SEP 28 2016 A large upper level low brings unsettled weather into the area tonight. A broad and deep upper low over the Great Lakes region will move south over the OH Valley and WV tonight.
Min Temps will range from the lower 60s northwest to the lower 70s southeast and along the coast.
a cold front is dropping southward toward the I-72 corridor. The upper low and its associated surface front will gradually sink southward today, resulting in mostly cloudy and cool conditions. Upper cold pocket directly beneath the low will remain just east of the area across Indiana, where resulting instability parameters will support isolated thunder. High temperatures will range from the lower 60s far north around Galesburg and Lacon. The showers will be diurnally driven, so have dropped PoPs everywhere except the far NE CWA for tonight as low temperatures settle into the lower 50s.
237 PM CDT Wed Sep 28 2016 A cold front has push south through the area and is generally located near the Arkansas Missouri border early this afternoon. A cooler air mass is spreading south into the area behind the front. Lows tonight will drop into the middle 40s with some spots dropping into the lower 40s tonight. Highs on Thursday will again top out in the upper 60s to the lower 70s across the region.
Weak cold front will shift winds from n-ne around 10 kts thu am. This will help to push a reinforcing shot of cooler air into our region tonight into Thursday in the form of a cold front. should see compressional warming across our region which will result in temperatures being warmer than those experienced on Tue with cold air advection resulting in considerably cooler temperatures on Thursday. This cooler and drier airmass will stay with us through the upcoming weekend with the Gulf remaining shut down.
However an amplifying upper level ridge will suppress most convection and keep the area dry through the weekend. A deep low over the southern Great Lakes has north winds over the plains which has brought cooler and drier air into West Texas and eastern New Mexico the past several days. This low will unfortunately move east by the weekend causing south winds and above normal temps to return.
The upper low currently over the OH Valley will more or less remain in place. Tilly Upper level low will continue sit and spin over the Ohio Valley, maybe even retrograde back to the northwest a bit through the end of the work week and into the first part of the weekend.
Turning in the atmosphere has led SPC to put the CWA east of the Blue Ridge at a 5% tornado risk. It is difficult to pick an exact spot where the heaviest rain could fall but two areas of conern appear to be 1) the area between DC and the PA border and 2) the eastern slopes of the Blue Ridge.
A shot of cooler and drier air on the way. Deep low currently positioned over Indiana progged with associated cold front arcing through the mid-Mississippi valley and across the south plains.
/For the 18z TAFs/ A cold front has moved through most of the area shifting winds to northerly. Backdoor cold front is moving into northern Oklahoma and continues on track to bring cooler weather for this evening and tomorrow. Although the high clouds across southern Oklahoma and northern Texas look rather thin on satellite, there is enough to give observations sites a broken cloud layer where obs are supplemented by humans /ksps and kdfw/ and we can see the cirrus out the window to the south.
The cold front should lift northward some later today with highs possibly reaching the mid 70s west river. Further east, partly cloudy skies along with good boundary layer moisture not seen in the past few days should yield cooler temps for the eastern CWA.
A weak backdoor cold front will move through area terminals in the 14Z- 15Z time range, shifting winds to the northeast with speeds up near 10 kts. A weak cold front will ooze into the region Wednesday night. A deep upper low will cut off and sag south over the Ohio River Valley while upper ridging builds in over the Plains this week. The upper low to our east will send a weak backdoor cold front through the area overnight tonight.
455 PM EDT Wed Sep 28 2016 A cold front was located over the far NW portion of the JKL forecast area at mid afternoon, and was moving SE. Showers were occurring near and behind the front, with thunderstorms further northwest over IN where colder air aloft was located near an upper low center. Instability wanes again on Thursday night, and models agree on a dry slot of sorts wrapping around the upper low, with the result being most precip drying up during the night. Very blocky pattern will continue into the upcoming weekend with the upper level low continuing to spin over the Ohio river valley.
231 PM MDT WED SEP 28 2016 Clear skies over almost the entire CWA this afternoon with just some cumulus clouds over the higher mtns. These clouds indicative of a slow increase in moisture advecting from the south ahead of an upper low over the CA/AZ border area. This low will open and eject northeastward on Thursday as an upper ridge over the high plains drifts eastward.
Reinforcing surge of high pressure should lead to breezier Nrly winds just beyond valid TAF period.
231 PM CDT WED SEP 28 2016 Water vapor imagery shows the center of a closed mid-upper low drifting south across northwest Indiana early this afternoon. This has forced another surge of a cooler air into our area. The cold front is seen in surface observations nearing the Red River as of early afternoon. Cooler temperatures and stronger north- northeasterly winds are present behind the front. Mid-upper ridging will be in place for the rest of the week and then gradually deamplify this weekend.
Highs on Thursday should only reach into the lower to middle 70s, or about 10 to 15 degrees cooler than today. Also, there will be a gradual increase in high level cloud cover from the southwest, as upper-level moisture from weakening tropical cyclone Roslyn gets directed toward West Texas by an upper low over southern California.
Cool and showery conditions are expected through the weekend with temperatures 20 degrees cooler than what the region is experiencing now. Cool and showery conditions are expected through the weekend with temperatures 20 degrees cooler than what the region is experiencing now.
238 PM EDT Wed Sep 28 2016 Upper level low pressure will bring rain to our region for the rest of the week. Otherwise, upper low pressure will continue to dig over the Midwest during the near term. Currently-progged rain-supporting dynamics for that period are limited given the lack of convergence/mid level frontogenetical forcing in this mature stage of the low.
A dry cold front will continue to move across the region this afternoon resulting in sfc gusts around 20kts from the N-NE behind the boundary. Dry cold front has pushed in to northeast Oklahoma as indicated by north winds gusting to around 20 mph at this time. cooler and dry conditions to continue through the end of the week.
237 PM CDT WED SEP 28 2016 This afternoon, the prominent upper level low was located over northern Illinois/Indiana and is expected to continue drifting south through tomorrow. High temperatures today have been lowered slightly with very northeast Kansas topping out in the high 60s. Similar day tomorrow as today with dry conditions and cool temperatures expected as the upper level ridge to the west begins to move into western Kansas. Upper ridging dominates much of the region through the week as the closed low remains nearly stationary over the Midwest.
(Issued 1112 AM CDT Wed Sep 28 2016) A weakening surface and upper level ridge continues to remain in place over northern Alabama and Southern Middle Tennessee. Further north, a cold front continues to push southeast from the upper Midwest/Great Lakes region into southern Missouri and Indiana. Some moisture advection ahead of the front should keep dewpoints from dropping below the lower 40s this afternoon. An approaching cold front will swing through the area during the evening hours, with winds gusting up to 15 kts this afternoon ahead of this front.
Light and variable winds overnight then a weak cold front mid morning shifts winds to the NE with speeds generally 10-12kt sustained. However an amplifying upper level ridge will suppress most convection and keep the area dry through the weekend. A deep low over the southern Great Lakes has north winds over the plains which has brought cooler and drier air into West Texas and eastern New Mexico the past several days. This low will unfortunately move east by the weekend causing south winds and above normal temps to return.
Temperatures overnight will be a challenge as winds in the wake of the front will help keep readings up a bit, but also in the wake will be cooler air filtering in. On Thursday, steady cool air advection will bring a noticeably cooler feel to the air.
Upper low continues to spin nearly in place over the Great Lakes today, sending another shot of cooler air southward in the northerly flow behind. Forecast through the end of the week and much of the weekend remains dry and mild with upper ridge aloft remaining intact as the upper low lingers in the Ohio Valley.
The stubborn upper low over southern Lake Michigan should continue to move slowly southeastward through the day, gradually lessening its influence on the Northern Plains with ridging building into the region. The eastern area of clouds is more likely to persist as an upper low across continues to spin across the Great Lakes. Generally uniform high temperatures across the region with readings in the upper 50s/near 60 where the clouds take a bit longer to clear out across the east while reaching the low 60s elsewhere. Clouds should slowly clear in the east by evening as the low dips southward and ridging builds into the Dakotas.
Forecast area is between a ridge of high pressure over the northern Plains and a trough of low pressure in the eastern Pacific.
As we go past 15Z, a weak cold front will work its way through all the TAF sites from north to south. /Issued 226 AM CDT WED SEP 28 2016/ Northerly flow behind a large upper level low over the Great Lakes will help to drive a cold front through the panhandles today.
Upper level low will be dropping into the region. Chattanooga Airport, TN 84 56 72 52 / 0 10 20 10 Knoxville McGhee Tyson Airport, TN 82 56 69 49 / 10 20 40 20 Oak Ridge, TN 82 55 69 51 / 10 30 40 20 Tri Cities Airport, TN 80 52 67 51 / 10 20 60 40.
343 PM EDT Wed Sep 28 2016 A large, slow moving low pressure system will settle into the Tennessee Valley tonight, then lift through the Northeast this weekend.
This air is wrapping counter-clockwise around low pressure that is spinning over northern Indiana. This will keep the low levels more mixed and help to warm the temperatures. Clouds will come and go over far southeast WI overnight as waves of vorticity and corresponding upward motion rotate around the closed upper low.
Cooling trend will continue into the weekend as the marine layer and onshore flow become better established with a trough along the West Coast.
557 PM CDT WED SEP 28 2016 A new cold front is pushing south through the state early this Wed evening.
1111 AM MDT WED SEP 28 2016 Upper low over southern CA and western AZ will lift slowly northward over the next 24 hours spreading mid/high level moisture into the Continental Divide region by this afternoon. Increased mid/high cloud cover should keep min temperatures warmer than past few nights.
An upper level ridge across the Northern Plains will remain in place tonight into Thursday. Under the upper level ridge, slightly above normal temperatures are expected on Thursday.
422 PM EDT Wed Sep 28 2016 Canadian high pressure will continue to build into the region from the north through Thursday. The high will remain parked to our north while low pressure over the midwest drifts slowly north and east.
327 PM CDT WED SEP 28 2016 A cold front is moving south across the Mid-South this afternoon, extending roughly from Little Rock, to just north of Memphis, to Clarksville. Behind the cold front, winds are from the north and northwest at 10-15 mph with temperatures in the mid 70s to lower 80s. Temperatures will largely be in the low/mid 50s by 7AM Thursday. The large, cyclonic vortex associated with this cold front will remain quasi-stationary over the Ohio Valley for the next few days, maintaining northwesterly flow aloft. Enhanced moisture in the lower half of the troposphere will support a small chance for showers, mainly in the area around Paris tomorrow afternoon as a lobe of enhanced vorticity rotates around the low. Temperatures will be cooler on Thursday afternoon, with highs in the upper 60s to mid 70s.
303 PM EDT WED SEP 28 2016 First major vorticity spoke has pivoted north to northwewt into Southeast Lower Michigan around parent upper level low pressure system now dropping gradually south through the Ohio Valley. While the higher resolation model solutions vary considerably in the mesoscale details of the anticipated bands of moderate to locally heavy rainfall, there is a strong consensus of maintaining a rather persistent arc of rain from western Lake Erie/far southeast lower Michigan northwestward through a bulk of the 1/2 to 2/3 of the forecast area. Forecast thinking has not changed much through the rest of the week as the upper low settles south to Kentucky and the feed of moisture back west to northwest into the area remains steady.
This cold pool pocket is modeled to sink south with the Low(s) into/across the middle Ohio river valley, and our Commonwealth, as we close out the workweek. while Lows generally fall into the lower half of the 50s. By the start of the weekend, our pesky upper level low will still be situated over central Indiana.
1241 PM CDT WED SEP 28 2016 Quiet weather conditions will continue today with noticeably cooler high temperatures. A large upper level low continues to drift southeast across the southern Great Lakes region with a strong vort lobe rotating around the back side of the low. This has allowed a cold front to push into the Central Plains and fairly strong 850mb cold air advection will continue to take place today with 850mb temps falling about 10C in 24 hours. Highs today will range from the lower 60s in our western Iowa counties to the mid to upper 60s in our Nebraska counties. This could impact areas along and east of the Missouri River today which would keep temps a few degrees cooler.
240 PM MDT WED SEP 28 2016 The upper level ridge over the area will be shifting a little eastward for tonight and Thursday, as an upper low over southern CA weakens and moves over the Great Basin, and an upper trof approaches the Pacific NW. Most low temps tonight at the lower elevations will be in the 40s, with a few locations in the 30s.