Weather post by Ryan Maue
Wichita, Kansas was hit with a thunderstorm induced “heat burst” early Thursday morning, with the temperature jumping from the mid-80s up to 102F after midnight!
Wichita has now experienced the earliest string of 7-straight 100F+ days (so far) this June.
What is a heat burst?
From theweatherprediction.com:
A heat burst is a downdraft of hot and dry air that typically occurs in the evening or overnight hours. A heatburst is much more rare than a severe thunderstorm. Thus, the atmospheric conditions have to be just right for a heat burst to occur. Heat bursts usually happen in the evening or at night after thunderstorms are ending. Thus, a thunderstorm has a vital role. Two other characteristics are that the air must start its descent from fairly high up and the environmental air aloft needs to be very dry. Precipitation falling into very dry air aloft will cause the air to cool through latent heat absorption. If the air is very high aloft and the air is much more dense than the surrounding air then it will accelerate toward the surface. In the case of a heat burst, all the precipitation that cooled the air aloft has been vaporized. Therefore, the precipitation can no longer absorb latent heat. As this dense air accelerates toward the surface it rapidly warms at a dry adiabatic lapse rate compression. What must make a heat burst so rare is that this downdraft must reach extremely high velocities. Velocities must be high enough so that the momentum of the sinking air offsets the fact that it is becoming warmer in temperature and thus less dense than the environmental air it is falling into.
Not only is the air in a heat burst anomalously hot but it is also extremely dry. The extremely high temperatures combined with extremely dry air plus the wind can remove all the moisture out of vegetation. Just like any atmospheric phenomena, heat bursts have differing intensities. The worst heat bursts persist for a significant amount of time and have temperatures that go over 120 F, even in the middle of the night. This extremely hot and dry air can remain in place for several hours before temperatures return to normal.
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Bernie Eastlund says:
June 9, 2011 at 5:01 am
> Could instability created by heating a patch of the upper atmosphere with, say, 3 billion watts of radio energy cause such rapid vertical displacement?
No, the heated air would be more buoyant and lift upward.
From Ryan’s description, it took rain to cool a patch of dried air to get it moving downward fast enough to keep going all the way to the ground long after the rain evaporated.
Perhaps if you heated a ring of the lower atmosphere with your 3 Gw for several minutes you might get enough convection to cycle air and have a downward column of air in the center. It would have a dew point much higher than 30, though because there would be no way to dry the air.
44katie says:
June 9, 2011 at 7:40 am
> We live near McConnell AFB, and were right in the midst of the damaging winds associated with the ‘heat burst’.
Oh good. They have a Wunderground station, check out http://www.wunderground.com/history/airport/KIAB/2011/6/9/DailyHistory.html
Looks like an ASOS station, reporting at 0:55 minutes each hour, but apparently triggers on interesting events, i.e. several between 0100 and 0111. Max temp 98.6, min dew point 24.8 (RH of 7%!), pressure drop of 0.10″, peak gust of 62.1 mph, sustained of 40.3 mph.
What was going through your mind during the event?
Please name for me the frequency band(s) of said ‘radio energy’ used to heat ‘air parcel’/the atmosphere and we can get back with you (Hint: it won’t be in the range of 3 to 10 MHz). Said RF energy would be effective on the ionosphere, however, at a range outside the range of ‘weather’ though.
Addenda: A 15 x 12 element planar array mounted on earth’s surface has, at the least, an effective angle above the horizon of about 45 degrees (normally range of +- 30 degrees from boresight). A beam directed at the horizon on any compass bearing is not possible (sin 90 deg (msrd from boresight) = 0).
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Are we sure it isn’t actually caused by a huge VTOL UFO hovering over the area with its jets directed downward?
Bernie Eastlund says:
June 9, 2011 at 5:01 am
> Could instability created by heating a patch of the upper atmosphere with, say, 3 billion watts of radio energy cause such rapid vertical displacement?
My power plant puts 3.9 GW into the local atmosphere, year round. It doesn’t cause much of a disturbance, except from time to time you can see hundreds of buzzards riding the thermal until they are tiny black dots and then finally disappear from naked-eye view.
Bernie Eastlund says:
June 9, 2011 at 5:01 am
Please do not feed the HAARP troll.
Sounds like another verison of LA’s Santa Anna wind.
“.. As it descends, the air not only becomes drier, but also warms adiabatically by compression. The southern California coastal region gets some of its hottest weather of the year during autumn while Santa Ana winds are blowing. During Santa Ana conditions it is typically hotter along the coast than in the deserts..”
Ed Forbes says:
June 9, 2011 at 5:23 pm
> Sounds like another verison of LA’s Santa Anna wind.
Not really – this is vertical transport of warm air. The Santa Ana wind is a low (I think) level wind that follows the surface for hundreds of miles starting with cold, dry (and hence dense) air.
The main common point is that both heat up thanks to adiabatic compression
and heating.
After the past two days of well hyped Eastern US heat it looks like there is quite a rapid cool down in progress now, for all areas except the Southern Plains. Of course here out West, even though storminess is now limited to higher latitudes, cool conditions persist.
Fascinating.
Now….less than 24 hours later…Nature has a way of balancing itself out. Training severe thunderstorms, with 1.25 inch hail, 60 MPH gusts, and over 2 inches of rain….and temps at a comfortable 66 degrees F.
The National Weather Service in Wichita has issued a
* Flash Flood Warning for…
Sedgwick County in south central Kansas…
* until 1230 am CDT.
* At 835 PM CDT… National Weather Service Doppler radar indicated
very heavy rain from a thunderstorm over the warned area.
Doppler radar estimated around 2 inches of rain has fallen across
the Wichita Metro area… with additional rainfall amounts of 1 to
2 inches likely. This will likely cause numerous areas of street
flooding across the Wichita Metro and surrounding communities. Do
not drive into water of unknown depth! Your vehicle could stall
and you will then be stranded!
—————————–
Chris
Norfolk, VA, USA
THX to those who offered insight. I could do without the ad hominem stuff. I am not a troll, just ignorant — which is why I come here. Thanks to the moderator for letting me in.
I pose the question b/c I really don’t understand the phenomenon. The “planar phased array” antenna is said to heat the ionosphere thru resonance effects (?). If the beam can be focused (?), would it create a sort of fireball?. Could this affect the lower atmosphere? Does the heating effect of EMF only occur in the ionosphere? Thanks in advance for any gentle enlightenment on this subject.
Bernie, there are more than just a few reputable sites that address how and what H A A R P is actually used for; those websites would be a good place to start studying that subject.
For instance:
http://www.haarp.alaska.edu/haarp/learn.html
and:
http://en.wikipedia.org/wiki/High_Frequency_Active_Auroral_Research_Program
[Please, no more comments on HAARP. See site Policy. ~dbs, mod.]
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Plse, mods, it is understood the reason for this, but, we can do the public a service by properly addressing the few, low-level inquiries that legitimately arise on occasion (see the reason above why Bernie asked the question; WUWT being one of the few places he could get a proper answer … “I am not a troll, just ignorant — which is why I come here. Thanks to the moderator for letting me in.”). So, I respectfully submit an ever-so-slight revision to this policy when an innocent question arises.
See, that HAA…P thing is a legitimate research facility and not simply the brainchild of the mindless conspiracy-industry types that have invented the most nefarious of ‘uses’ because of SSI (severe science illiteracy) coupled with the opportunity to sell books (‘make money’).
I would submit that only legitimate mentions and cites be allowed through all-the-while continuing to snip at-will the ‘conspiracy’ based posts. Sometime back I made reference to the Riometer that is based as that facility, an instrument that measures ‘ionospheric attenuation’ by observing galactic noise as 30 MHz … at that time I also had to make a ‘special pleading’ to free up a post ‘stuck in spam’ owing to in-effect policy.
To borrow a quote from Walter E. Williams, this is another opportunity to “beat back the frontiers of ignorance” regarding the legitimate uses of that facility.
Respectfully submitted, _Jim
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Thanks to Jim for the mention of the Texas heat burst of the late 50s. It occurred near Lake Whitney S/W of the DFW area on either a Wednesday or Thursday night. I just happened to be going to a technical conference in Dallas that weekend, and the event was the principal subject of conversation all weekend. It was years before the Taft/Godbey book came out and explained what the heck happened to all the crops in the area that night.