Aikyam-Lab/Synoptic-Bench huggingface dataset:
An upper ridge over the eastern Pacific will keep a northwesterly upper level flow going over the Pacific Northwest through at least Wednesday. The low level flow will continue to be west to northwest as well, though a period of lighter drainage winds will be possible later tonight into mid morning Wednesday. Low temps should be up 2 to 5 degrees versus this morning due to a warmer start of the cool down.
300 AM CDT Wed Aug 16 2017 Surface analysis early this morning indicated a trough of low pressure across the central high plains with a warm front draped eastward across Nebraska and along the Missouri/Iowa border. Relatively dry low-level air was in place to the north with easterly surface flow under the influence of high pressure. Showers/isolated storms have been lifting northward especially across southeast Minnesota along the 850 mb warm front/moisture gradient. Stronger forcing will arrive late this afternoon with increasing low- level warm/moist advection ahead of the surface warm front. CAMs are in pretty good agreement that one or more bands of convection will lift north and eastward into the area by this afternoon and tonight as forcing from the upper trough increases.
630 AM EDT Wed Aug 16 2017 High pressure brings drier weather on Wednesday but unsettled pattern returns to end the week with another cold front.
This disturbance is loosely tied to a larger/stronger disturbance over the Central Plains which have collectively suppressed ridging aloft over TX and enhanced the low level pressure gradients.
545 AM CDT Wed Aug 16 2017 Developing storm system over western Kansas early this morning will be lifting northeast and strengthening today, with the synoptic models centering the low over southeast Minnesota by late tonight. A line of thunderstorms associated with the cold front itself should begin to take shape by mid afternoon from western Iowa into Kansas. The low will continue to strengthen as it lifts northeast across Wisconsin on Thursday, with the front itself crossing the forecast area Thursday afternoon.
Ridging continues to build in on Wednesday with relatively weak upper-level flow across the area. With ridging in place and weak synoptic scale forcing, believe that showers and thunderstorms should not be widespread and will mainly develop and be confined to the higher elevations with chance PoPs primarily in the afternoon. With ridging in place and sufficient sunshine, expect high temperatures to be several degrees above normal.
Deep layer ridging, above normal moisture levels, and westerly flow will favor an active seabreeze pattern with the best coverage of storms across north Florida over the next few days. Otherwise, highs will be in the lower to middle 90s with heat indices around 105 degrees.
The upper level ridge centered to the east of the region will build back further west during the period as an upper level trough north of the region lifts to the northeast. Upper level ridging will take better hold across the region tonight and Thursday, and with lower PWAT values during this time, a dry forecast will return.
Even with a ridge in place across the area, rain has been abundant and looks to be that way again this afternoon, especially in the west. With plenty of moisture around looks like local effects and thermodynamics will again beat the overall synoptic pattern and the dynamics of the building ridge. The highest chances at seeing the higher heat index readings will be basically south of the I-22 corridor in the west and I-20 in the east. Ridging is in place across the Southeastern US on Thursday. Without any significant lifting mechanisms, expect only scattered afternoon thunderstorms, allowing temperatures to reach the low to mid 90s across the area. Meanwhile, a low pressure system moves through the Upper Midwest and into the Great Lakes region Thursday.
Covection over central Nebraska is associated with a surface cold front and mid level trough from the central Dakotas into northwest Kansas, while eastern Nebraska convection associated with warm advection and overrunning of an outflow boundary across southern Nebraska. IR satellite loops show the colder cloud tops and stronger convection ahead of the surface front and upper trough while cloud tops have in general been warming across eastern Nebraska with isolated colder tops developing now and then. General trend will be for the surface front and upper trough to move east today and tonight with rain chances increases for the forecast area.
Boundary remains draped across northern Missouri into southeast Nebraska but is anticipated to push back north-northeast as a warm front throughout the day today.
400 AM PDT Wed Aug 16 2017 Weak trough across the west will allow for light winds as well as temperatures near to slightly above average through the week. Instability resulting from afternoon heat, lack of a mid-level cap, and a weak trough aloft will aid in increasing the extent of thunderstorm coverage over what was previously forecast. A few lingering showers are occurring mainly in the Basin and Range on the heels of a weak trough that will be slow to exit the region today. General troughing will remain over Nevada and northeast California through the short term forecast. However, a weak extension of the ridge will likely limit convective development south of Alpine County along the higher Sierra for Thursday.
Shower and thunderstorm chances will increase this afternoon and evening as a cold front moves across northern and central Oklahoma. A cold front moving across western Kansas early this morning will be the focus for strong to severe thunderstorms by this afternoon and early evening. The front will likely have a better push southward over the higher terrain to our west. Warmer lower to mid level temperatures over southwest Oklahoma and western north Texas may limit convective potential, however, there should be enough storm organization to keep high chance POPs across this area.
High pressure aloft strengthens over the weekend for continuing dry weather. The region will remain in between two upper level low pressure systems, one dropping south from the Gulf of Alaska and a cut-off low off California.
The Keys area is under the influence of high pressure stretching across the Florida Peninsula and eastward over the central Atlantic. An upper level low is sliding north of Puerto Rico. The ridge will remain in control of the Keys environment for another few days.
Wednesday and Thursday will be more humid than previous days, with noticeably warmer overnight lows. Due to lack of upper level support with mid level ridge over the region, expect this activity to continue to weaken early this morning. Mid level ridge to shift east with flow backing as s/w tracking into the MS VLY tonight. Thunderstorm chances will increase, especially over the nw counties as low level convergence/warm front develops. With increasing moisture and clouds temperatures will be mild tonight with lows generally in the lower 70s. Ongoing storms to start Thursday especially invof of the warm front. Warm temperatures to continue with Thursdays highs from the lower 80s northwest to the upper 80s southeast. Cold front will be moving east Thursday night.
Expect VFR conditions with brief MVFR ceilings to prevail across the Rio Grande valley and northern ranchlands late tonight into Wed morning as 500mb subtropical ridge across the Gulf of Mexico and south Texas provides subsidence across the area. /issued 242 PM CDT Tue Aug 15 2017/ SHORT TERM (Now through Wednesday Night): No significant changes to the short term forecast as a strong H5 ridge remains perched over much of the Southeastern U. While it is doubtful that any precip will form due to the exceedingly dry air aloft and lack of forcing, the moisture could raise dewpoints enough at the surface on Wednesday to be concerned about warmer heat index values.
Overnight fropa will usher in cooler temps for Wednesday with highs dropping into the 70s over lower elevations.
Temperatures will warm through the week as a ridge of high pressure builds into our region. A ridge of high pressure that is slowly building toward our region will help to push temperatures up a few degrees especially well away from the coast. Far eastern spots will go into the lower 90s. Temperatures will trend warmer the next several days as the ridge continues to progress toward our region. Highs will return to warmer than normal levels for far inland spots with mid 80s to upper 90s likely. An upper level low will drop into our region by next work week.
141 AM EDT Wed Aug 16 2017 High pressure across the northern Great Lakes will build eastward providing the North Country with cooler and drier weather conditions Wednesday and Thursday.
Meanwhile, the water vapor imagery depicts a H500-300 low over the Srn Gulf, with its attendant inverted trough extending NE into extreme SE LA/Srn MS and AL.
This will allow for dry and warmer weather over the forecast area. With little or no moisture expected, it looks like it will be a dry cold front. NW winds behind the cold front may be high enough to create critical fire weather conditions.
This system will drag a cold front through the area today and stall out. This cold front will become the focus for additional convection this afternoon into the evening. The center of a sprawling upper level ridge over the southeastern US will begin to move west on Thursday. The cold front that is expected to affect the region today will retreat back north during the day on Thursday allowing the entire region to become unstable.
Early morning temperatures were in the low to mid 70s, while dew point temperatures were just a few degrees less. Aloft, the upper ridge was off to the east of AR, while southwest flow was now into AR, especially western AR. This flow will allow warmer temperatures, and much of any convection mainly over western to northern parts of AR. Thursday night, a lower chance of convection is forecast, with the highest in the north, the lowest in the south.
Current temperatures are pretty similar to 24 hours ago and generally range from the lower 50s in the mountain valleys to around 70 across the warmest portions of the Central Valley. Otherwise, warmer weather returns today with synoptic warming of the airmass and slackening of onshore flow.
Look for a gradual warming trend through late week as high pressure builds over the region.
These storms are developing north of a east-west surface boundary that runs from northern Missouri into south central Nebraska and back to northwestern Kansas where the low level jet is focused. This cold front will be the main player in the potential for severe weather this evening. These storms are expect to progress across the CWA tonight as the cold front will exit the area by tomorrow morning. Temperatures will be near normal again today with highs in the mid to upper 80s however with dewpoints in the low to mid 70s, heat index values will reach into the low to mid 90s. Behind the cold front on Thursday, temperatures will be a couple degrees cooler however, without any cold air advection behind the front, highs will still reach the low to mid 80s.
The SPC mesoanalysis page shows two segments to the low level jet, one feeding into the showers over the northern valley and the other into the convection in Nebraska. Since both these areas did not get the higher end amounts from the past weekend system, it should not result in any ponding/flooding issues. The weekend still looks warmer and dry, owing to building high pressure both at the surface and aloft. High pressure brings tranquil conditions for Tue. Temps will rise to the low and mid 80s for the weekend before easing back just a bit for the beginning of the new week.
141 AM EDT Wed Aug 16 2017 Aviation High pressure will result in dry weather tonight into Wednesday evening. Humid conditions with showers and thunderstorms are then expected Wednesday night into Thursday night, as a low pressure system passes to the north of the region and drags fronts through the area.
Dry and cooler weather is forecast for today and through the weekend.
With cold air continuing to move in aloft, the chances for any freezing rain/sleet should be gone in the next hour or two. Current surface analysis places low over southeastern Manitoba, with trough dipping down into the central plains. Some light spotty precipitation continues to show up on radar over southern portions of the area, as broader area of freezing precipitation has pushed off to the northeast. For today, some light precipitation may continue over southern portions of the area, but the threat for freezing rain and sleet will diminish through the morning as cooler air aloft works in. Temperatures will remain quite chilly to the northeast, warmer to the southwest. Mainly quiet weather is expected tonight with cold temperatures as high pressure settles in. A cooler day is expected on Saturday as high pressure continues to settle through the area.
Dry west winds with surface trof will diminish temporarily this evening, but then ramp up again with the approach and passage of a cold front. Cold front expected to pass through the Texas and Oklahoma Panhandles between 11 PM tonight and 4 AM Saturday. Saturday night will be cold with lows below freezing area-wide.
Expecting one more night of LIFR/IFR BR and CIGs in advance of an approaching cold front which should end this trend of poor flying conditions in the morning hours. Winds will generally be out of the SSW with speeds approaching 20 knots this afternoon ahead of a cold front.
Focus then turns to a fast moving cold front which is currently through far northwest KS. These winds along with temps some 20 to 30 degrees cooler than today will make for raw Saturday.
High pressure aloft will return to the region this weekend. The upper level trough currently positioned across the Pacific Northwest will continue east across the northern Rockies/northern Great Basin this afternoon through early this evening. Trailing this trough will be a low amplitude upper ridge which will encompass most of the western CONUS this weekend. The surface cold front associated with the approaching upper trough is just south of KPVU (Provo) and is moving slowly south at this time. As the Pacific Northwest trough nears Utah the low-level baroclinic zone will become more frontogenic as low-level cold advection increases immediately ahead of the advancing mid-level trough. The low amplitude upper ridge trailing the exiting trough tonight will bring a quick end to any convection during the overnight hours.
Winds will lay down a bit with sunset but will increase again behind a cold front that will move through the area late tonight. An interesting mesoscale feature is noted on the H5 and lower fields suggesting the blocking of some of the flow by the Sandias which looks to let loose this afternoon. The polar trough axis then swings into the region tonight into Saturday.
A warm front has lifted into AR, with elevated south winds at 10 to 20 mph with some gusts. Temperatures have warmed behind the warm front and are from the mid and lower 70s south, around 70 central and 60s north.
Ahead of the low gusty southerly winds are occurring across the area. An upper level trough will sweep east across the Plains tonight and then across the area on Saturday. As the upper level trough moves across the area late tonight into Saturday morning, showers and may be a few rumbles of thunder will be develop and occur behind the front. The better potential for these showers will be across central Missouri closer to the trough axis.
315 PM CST Fri Nov 17 2017 Low pressure was located in northeast Kansas with a warm front into central MO. Low pressure will be tracking across northern MO into central IL, pulling a strong cold front southeast into the dvn cwa after midnight.
949 AM MST Fri Nov 17 2017 Decided to cancel the High Wind Warning through early this afternoon. May need to extend current advisories into the lower elevations since rain has changed to snow a little earlier than expected. Complicated forecast in the short term for today through tonight as a strong cold front approaches the area from the northwest. Cold front lays along a line from central South Dakota to Newcastle to Riverton to near Evanston this morning.
Main feature of interest in the short term will be the strong cold front on Saturday. Overnight lows will fall into the low 70s along the immediate coastal with 60s elsewhere. On Saturday, an upper level trough will swing through the Central and Southern Plains. At the surface, a cold front will be moving southward across the state during the day.
A positively tilted open wave is beginning to translate into the Plains with a surface cold front now just about through our far southeast counties as of 2 pm. Precipitation type this evening should start off as rain before cooler air advecting in could change things over to a mix or snow toward the end of the period. While Saturday will feature more sunshine, it will feel like a fairly raw day with cooler temperatures in the 30s and low 40s and wind chills teens and 20s. The surface cold front from tonight continues to drive south bringing with it any meaningful source of moisture.
This will help a Canadian cold front to move across the forecast area from late Saturday afternoon and early Saturday evening. A much cooler and drier air mass will then move in behind the front for the remainder of the weekend.
Trough starts swinging into the forecast area Friday night, bringing enough weak forcing to produce another shot at light precipitation Friday evening and overnight. The highway 14 corridor should see very little if any precipitation. Cooler air will begin advecting into the region overnight, allowing temperatures to drop into the 20s. Northwesterly winds will keep the area dry and cooler than previous days with highs only reaching the 30s to around 40 along the Missouri River. With breezy winds increasing in the afternoon, wind chill values could drop in the lower 20s.
By Saturday afternoon, much of the snow activity will be confined to the higher terrain, with little to no accumulation anticipated.
This also allows western areas to mix into warmer temperatures into the middle 70s, with the eastern counties getting to near 70 before the better mixing declines later in the afternoon. Temperatures will be slightly cooler this day with CAA funneling into the area, with highs in the low 50s.
317 PM CST Fri Nov 17 2017 Very warm to hot, windy, and dry (in the west) conditions will be replaced tomorrow with much cooler, windier, and less-dry conditions after a cold front sweeps quickly southeast across Oklahoma/north Texas. The remainder of the forecast is for relatively benign and roughly seasonal weather, despite the passage of a couple of weak cold fronts.
A storm system moving through the region will bring a few more showers to the southern Sierra along with the higher elevations of Lincoln and northern Mohave Counties today. Gusty winds will occur ahead of a cold front that will move through the region this afternoon and evening. Much cooler temperatures are expected over the weekend. Otherwise, the rest of the forecast is in good shape with a gusty day for most with a cold front brining gusty northerly winds in its wake in northern portions of the area and southwesterly winds ahead of it in central/southern portions of the area. Generally decreasing clouds expected by the evening with temperatures a few degrees cooler than yesterday.
This trof will cross the CWA tomorrow AM followed by NW flow. Wrn USA high pres will begin building in tonight and a piece of this high will break off and emerge onto the Plns tomorrow afternoon. The incoming trof will have a strong pulse of -divQ/strong upr-lvl forcing/ascent to supplement/ coincide with strong mid-lvl Fgen. That leaves the lowest roughly 1000-1800 ft of slightly above frzg air for melting. Sat: The precip should be done by sunrise as the trof will be E of the CWA. the longwaves will feature a Wrn ridge/Ern trof over the CONUS. Temps: warmer than normal. except for Tue-Wed when temps will be near normal behind a cold front that moves thru Mon night.
This will change early Saturday as a storm system currently moving through the Intermountain West emerges over the High Plains and allows surface ridging to spill southward through the South Plains.
Southwesterly winds will develop by around 15Z as the prefrontal trough moves into the area. High temperatures for your Friday are expected to reach into the low 80s across the region, with upper 70s along the coast. Yesterday's surface ridging tailing down into the region has shifted to MS/AL as the Pineapple Express atmospheric river dumps copious snow/rain over high terrain in CA thanks in large part to the upper trough swinging through the Pacific Northwest. This upper trough will race east swinging a cold front through SETX Saturday afternoon. As the front reaches the Highway 59 corridor the rain chances will be improving getting out from underneath the capping influence.
200 PM MST Fri Nov 17 2017 Strong cold front will sweep through the area tonight bringing windy conditions and a good chance for light rain and light snow. There is the potential for the precipitation to mix down wind gusts of 45-50kts during the overnight hours with a wind max behind the upper trough axis.
Precipitable water values will remain around 1 inch or less with high pressure building over the area.
A cold front is moving east into eastern ND. Warmer air ahead of the front as well. Temperatures in this area should be a bit warmer with more 33-34 and thus a bit lesser risk of icing. Cold front will push though and winds turn west to northwest and temperatures will fall some behind it. Saturday a dry but chilly day as high pressure moves southeast across western ND.
1240 PM EST Fri Nov 17 2017 High pressure will control the region through Saturday when the next cold front will approach from the northwest.
Cold front should arrive near I-70 around sunset. Saturday: Decent lift ahead of main upper trough and deeper moisture in wake of front may lead to scattered rain showers or light rain in central KS.
Strengthening south wind today will help contribute to much warmer than normal temperatures this afternoon. This with mid level ridging will allow for rather warm temperatures across the region as maximums could push 80 over the southwest.
East of the trough axis which also corresponds to the 850mb trough, southerly flow continues providing a continuous supply of saturated air with dewpoints in the mid 30s. As expected for today, temperatures warmed above freezing and no icing issues have been reported. The moisture currently in place will not move much until the arrival of the cold front coming down from North Dakota. When the front eventually moves through, the low stratus will depart but for Saturday we'll see a mix of sun and mid and high clouds moving through.
209 PM EST Fri Nov 17 2017 Clear skies overhead in the lower and middle Keys, with some cumulus over the upper Keys.
Mid/upper level high pressure centered across the western portions of Mexico is progged to move east toward deep S TX today. This will bring drier mid/upper level airmass and warmer temps to S TX today. The high pressure then shifts more southward and flattens out leading to a zonal flow across S TX tonight. A cold front is progged to move across S TX on Saturday with the stronger winds and cooler temps lagging behind the initial windshift 2 to 4 hours.
Through the day, there has been a decent amount of mid level ridging, which is developing a good amount of subsidence, as opposed to lift, and that has likely stymied the production of any notable precipitation. As we go into tonight the mid level trough will move into and through the area, which will provide some mid level support for ascent, which may help produce some organized rainfall. After the precipitation departs the area Saturday/Saturday afternoon the pattern will take on a very benign character with upstream ridging in the mid levels holding firm through the next 7 to 10 days.
Given the push of higher dewpoints across relatively cooler ground, may also see the development of some fog although likely not dense at this time.