Sunday, May 28, 2017

Work week 4 for Taney County!


Some relief is on the way as a surface high will remain in control of the region's weather through Memorial Day with temperatures around 80 degrees and mostly sunny skies. Overall, Monday looks to be a great day for outdoor activities.


The upper level flow for Tuesday looks to be northwesterly. This is in response to a ridge that builds just east of the Rockies. Several reinforcing surface highs will slide out of Canada and across the Plains which should help to keep rain chances limited. A persistent cut-off upper low over the Great Lakes may swing pieces of energy through the upper level flow and bring slight chances for showers and storms between the surface highs in the form of weak cold fronts. None of this activity looks severe at this time.


As we head into this afternoon and early this evening, low level convergence and temperatures warming into the lower to middle 80s will likely initiate more scattered thunderstorms from northeastern Kansas into central Missouri. We may then see widely scattered thunderstorm activity begin to shift towards the U.S. 60 corridor in the evening as cold pools become established and that
low level jet begins to redevelop.

The setup for large hail looks good today given steep mid-level lapse rates, moderate deep layer shear, and good CAPE/speed shear in the hail growth zone (-10 to -30 Celsius layer). Inspection of
forecast soundings also indicates quite a few matches for large hail with the SARS Sounding Analogue System. With support from indices such as the Large Hail Parameter, we will include a mention of ping pong ball sized hail in the Hazardous Weather Outlook.

Given steep low level lapse rates and relatively high cloud bases, damaging straight line winds also appear possible in areas where cold pools conglomerate and we get bowing segments. At this time,
it appears that the greatest threat for severe storms this afternoon and this evening will be west of U.S. 65 and north of U.S. 60.


Remnants of that MCS may then persist across portions of the central and eastern Missouri Ozarks Thursday morning. Thunderstorm chances in the afternoon will then be dictated by convective outflow from morning storms and where that low level convergence zone ends up. Thursday night and early Friday then look fairly dry at this point.


Friday night into Sunday night, an upper level trough will dive south towards and into the region sending a front through the area. This will result in better widespread shower/storm chances across the region as better lift will occur.


Behind the system surface high pressure and dry conditions will build over the area Sunday into early next week as highs warm into the 70s each afternoon during this time....

Saturday, May 20, 2017

Taney County work week #3 for May!


A high amplitude pattern continues to be expected over the CONUS with a long wave trough over the Plains and Midwest. An approaching shortwave will bring the next chance of showers/tstms late Mon-Tue, but amounts are expected to be fairly light with better moisture down toward the Gulf of Mexico.


The upper level long wave trough axis passes through the day Wednesday. Clouds, maybe some light precipitation will linger into Wed, but hazardous weather impact is expected to be nil/very low.


Thursday looks dry again with surface high pressure. In general there is decent agreement with global models of the pattern trying to become more zonal late in the week. We have some rain chances by Fri with an approaching relatively weak approaching system.


Surface low pressure moving east over the plains, an approaching upper level trough, a 30 mph low level jet nosing into the region, surface dew points in the upper 60s to middle 70s, CAPE values in
excess of 4000 J/kg and steep lapse rates will all contribute to the potential for a significant severe weather outbreak across the Ozarks and southeastern Kansas this afternoon and into this evening.

The amount of instability and expected updraft strengths are conducive to very large to giant hail production. Current thoughts are for baseball size or larger hail with the strongest storms.
Thunderstorm wind gusts in excess of 60 mph and a few tornadoes will also be possible.

The convection early this morning will likely leave boundaries across the area, which will potentially act to enhance storms and rotation this afternoon. Another concern would be the development of a significant cold pool with this system. It would not be out of the question that at some point this system develops a derecho-like nature (squall line with widespread wind damage potential) that would move across the region, taking advantage of the instability in place across the area today. Additionally, 0-3 km bulk shear vectors orientated towards the east at 30-40 knots would support mesovortex tornado potential with any portions of the line bowing towards the east.

The Moderate Risk area from SPC was expanded to the west this morning and now includes all of the Missouri Ozarks and southeastern Kansas through tonight.

Saturday, May 13, 2017

Taney County MO Wx for work week #3!


Warmer conditions will occur as highs in the 80's will occur each afternoon from Sunday to Wednesday. Monday and Tuesday will be the warmest days as highs in the middle to possibly upper 80s occur.

Southerly winds will also increase Sunday into mid week and could see gust up to 30 mph during the afternoon each day especially across the southeastern Kansas and western Missouri.


A more activity weather pattern will setup during the middle of the week into next week. An upper level trough will slide south across the west coast today and Monday then kick east on Tuesday
pushing into the Plains by Wednesday. This will push the ridge off to the east and allow the front to sag to the southeast into the area Tuesday night into Thursday. Scattered showers and storms will be possible Tuesday night and Wednesday as the better upper level support will remain west and north of the area with the upper level trough path. With the timing expected to be Tuesday night into Wednesday morning and that instability will be on the weak side should help to limit the overall severe risk Wednesday.

An upper level low will move onto the west coast early this week and dig to the southeast into the Middle of the week. Medium range models then differ on how the the upper levels behaves regarding track and timing to the east after it digs into the southeastern U.S. Therefore, there remains uncertainty on the exact details for the end of the week into next week. What is known is that the low will be to the west and will be able to pull better gulf moisture north ahead of it helping to increase instability across the area. As the low moves to the east, showers and storms will develop and we could see a couple rounds depending on the exact track of the system. There could be the potential for severe weather but when and where we be dependent on the track/timing of the the system and also a flooding risk given the very wet spring so far but there is a lot of uncertainty with when and where. We will likely need to wait for the low to make it on to the west coast and be sampled by the upper air network to get a better handle on the exact track and timing.

Highs around 80 will occur Wednesday and Thursday, then slightly cooler conditions will build over the region as highs in the 70s are expected Friday into the weekend.


A rather wet start to the weekend.


Clouds to beging this day and sun to end it. Look for improving conditions. Some chances for showers and some scattered storms are expected, but we are not looking at high impact weather during this period.


 Looks quiet/dry with surface high pressure moving into MO.

Friday, May 12, 2017

Hail strikes again!

Forsyth MO - Normally, hail falling from the skies is a pretty rare event. Part of the reason is the conditions required to it to form. (Hail forms when thunderstorm updrafts are strong enough to carry water droplets well above the freezing level. This freezing process forms a hailstone, which can grow as additional water freezes onto it. Eventually, the hailstone becomes too heavy for the updrafts to support it and it falls to the ground.) The other reason is that when it does fall, it tends to fall in rather narrow strips and only for short periods of time. It's not unusual for a person in a car to be in dry conditions one minute, a driving rain with hail the next and then back out of the whole deal a few minutes later. Lastly, hail in southwest Missouri is much more likely early into the spring season when enough cold air can be scrounged up!

So, it was amazing to me to see similar hail events, one on March 9 and the other May 11 happened so darn close together. The picture at right was a hailstone that greeted me at my front door. And yes, it was made in the good ol US of A!

Sunday, May 7, 2017

Taney county work week #2!

A slight upper level ridge will be over the southern U.S. And Lower Mississippi River Valley Region to start off this week. Southwesterly winds will be a little breezy on Monday and Tuesday. Mostly sunny to partly cloudy skies will be joined by warmer temperatures with most locations getting up into the lower 80s both Monday and Tuesday. We might even see a few middle 80's.


A moist and unstable air mass is in place across the area and this will aid in the development of additional showers and storms through Tonight. While the main synoptic front is located across Northern Missouri west into Northern Kansas, an effective front/trough is located further south from Central Missouri back into West Central Oklahoma. Impulses riding up from the south have contributed to pockets of storm development, most remaining just to our north and west thus far. Will be watching the evolution of storms across Southern and Central Oklahoma this afternoon and evening as they approach the area ahead of a lead impulse over the Red River Valley. The atmosphere is ripe for organized storms with 1500j/kg of ML cape along with 40-50kts of effective bulk shear. If storms can get organized then large hail and damaging winds will be possible. Locations along and north of Interstate 44 are most favored for this activity.

Most model guidance thus far has struggled with the evolution of showers and storms and thus caution must be used with them. There is a signal that the heavier axis of showers and storms may be pushed further south into our area tonight vs locations to our north given a strong low level jet developing and interacting with this trough/effective boundary. While uncertainty in this scenario is high, it would have implications on our qpf amounts overnight and this will need to be monitored. A severe threat will exist for most of the night as the environment will not change much. Shear profiles will actually become more favorable for storms heading into the overnight hours.

There will likely be ongoing showers and storms Thursday morning across the area and this will be key as to what it does with the true synoptic front. Models have the front along the Interstate 44 corridor Thursday afternoon. Forecast soundings off the GFS reveal a class splitting super cell profile with large hail being the most prominent threat. Mid level lapse rates will be steep and CAPE will be plentiful especially in the hail growth zone. Thinking that robust thunderstorm development is possible along the front in the afternoon with hail to the size of golf balls possible. There is a conditional threat for a tornado if storms can ride the front and increase effective helicities. This will be evaluated more closer to tomorrow. A Slight risk for severe storms is across most of the area for Thursday with locations along and south of Interstate 44 most likely to be affected.


Slightly cooler weather returns for the end of the week.