Fall 2010

School once again has started, and work is subsiding just a bit. I am excited about this Fall Semester at NIU. I get to do some Research for Hintzsche Fertilizer, Inc. which is based out of Maple Park, IL. I really like how Met 431 brings a real life situation into play, and Dr. Changnon gives a chance to really run with it.

Besides that, I'll be doing some research on year to year weather patterns (Synoptically), and ENSO; to see how they change the Mesoscale Weather (severe, snowstorms, etc.). I find it quite that the synoptic events really seem to control the type of weather that the Continental U.S receives.

Besides this, the weather here in Chicago has been pleasant. Right now, we're sitting under a large ridge of high pressure after the latest cold front came through. We have actually had seasonable temperatures for the past few days, in comparison to the warmer than average temperatures we had for most of the summer. But, its to be expected that the temperatures will increase, as will the moisture as the High moves off to the east, and we will soon get a Southerly wind component. I wouldn't expect anything weather wise, till the middle of next week, or so.

Its been a while!

Its been a while since I have posted anything to my blog, so I figure I would throw up some pictures from tonight as a weak Bow Echo passed near my house in Yorkville. It had a nice looking shelf cloud associated with it, so I took full advantage of the photo opportunities.

Ongoing severe weather

A little late to the topic, but I had to finish studying a bit over the weekend! Currently there are several tornado warnings in the Southern Plains, and quite a few storms have already produced tornadoes. These storms are moving extremely fast, but the atmosphere is VERY unstable. NWS launched another weather balloon in Oklahoma City because of the severe weather situation (close to 4000 J/kg of ML CAPE). This morning this area was held in check by the low lying clouds, and with atmospheric warming this afternoon and a progressing Low Pressure system coming out of the rockies; warm, moist air was pushed northward. A dryline developed, and is now about 40-50 miles (rough guess) west of Oklahoma City. The 22Z dewpoints were approaching 70 degrees at Oklahoma City as well. The wind shear could be described as amazing. This enhanced southerly flow thanks to our friend the Low Level Jet, is producing a SSE wind at the surface, and with heights winds turn to the west. The storms that pop, do so quickly, and they become severe warned a very short time afterwards. These storms will tend to be long track supercells because of the "rich" environment, and the tornadoes could be very strong. I want to take a special look at the OKC sounding; the Lifted Index is very unstable, and the lapse rates are steep. As well, look at the amount of positive area on the right side of the environment's temperature. With such a small cap, it doesn't take much to break this cap, and if convergence is strong enough (which it is), then the storms will explode once they rise above that cap. This is the type of day that storm chasers live for!

Little Rock Skew-t

This was from the 0000Z sounding (7pm CDT), can you say explosive thunderstorms!!??

Active Night in Arkansas!!

Here are some radar shots from a confirmed tornadic supercell east of Little Rock, AR. Note the comma shape, and Base Velocities, as well as the Storm Relative Velocity. Its quite and amazing storm! Look at the last picture, of the Base Velocity, note the max wind speeds (124 knots), thats over 142mph. In the first two pictures, just look at the evolution of this tornado, that pinkish hue in the doppler picture is most likely debris associated with this tornado. The the Base Velocity is very impressive!

Possible Conway County Tornado

Almost on the same line as the Pottsville, AR tornado; this supercell developed. I caught it about 5 minutes before the NWS out of Little Rock Tor Warned it. It too has a well defined inflow notch.

Radar Indicated Tornado (Near Pottsville, AR)

Well, things are shaping up for a good set of severe storms this afternoon in Kansas and Nebraska; possibly even Iowa or Missouri. I want to keep a close eye on the dewpoints to see if they progress northward, and if they're high enough. All other "keys" are there for a tornado outbreak. We always like to see this (above) put out by the SPC, as well!

Update for Severe Weather

NWS currently has a hatched area of probability for NE Kansas, SE Nebraska, SW Iowa, and NW Missouri. Instability looks like it will be slightly higher than what I originally thought; couple that with the continued forecast of strong wind shear, and decent low level moisture, we could be looking at a greater possible chance of tornadic supercells. Storms will progress through the evening, but will become more linear with time.

There is a possible chance of severe weather here in Northern IL, but I believe it will be associated more with an advancing cold front, rather than an established dryline. Even though wind shear should still remain strong; I'd tend to say that the storms will be more linear, with wind and hail as the main threat. There could be an isolated tornado if the storms become suface based with isolated cells.

We will see the outcome as we progress towards Friday.

Possible Severe Weather 4/30

Keep a close eye on current Low Pressure system centered in the Northwest U.S.  With this system moving slowly into the Plains, I hope to see a return of moisture to the Central U.S.  If low level moisture can work its way north; Ensembles and WRF would indicate possible tornadic supercells.  ML Cape values from 1000 J/kg-1500 J/kg are projected across Central-Eastern Kansas, even into SE Nebraska.  With very good bulk shear in that area, and a small cap, which will increase instability; storms that fire would develop fast.  Dewpoints are projected to be in the low 60's as well.  I want to lean towards the possibility of good surface moisture, but even at this time, that would only be a best "possible" scenario.  Theoretically, the primary issues that would arrise from this convection would be strong winds and hail, if the surface moisture isn't sufficient enough for tornado development.  Not only is the moisture a concern, but a deep Boundary Layer is expected to be present as well.  Those two combined could very well limit the threat of tornadoes with these storms.

No matter what, I sure do wish I was chasing; instead of preparing for Finals.

I was in Carbondale, IL this past weekend (visiting the better half), and was surrounded by moderatedly severe weather.  I am in the process of getting my new laptop, so unfortunately, I didn't have access to GR Level yet.  But, I kept close tabs on the developing situation in Yazoo City, MS, as well as developing storms near the Carbondale area.  I was treated with a nice cell, with a pronounced Bow Echo during the mid-afternoon on Saturday, as the shortwave had ejected from the SW U.S. ahead of the main Low Pressure system.  With good low level moisture in place in the South, and very favorable instability, as well good wind shear, everything seemed in place for a tornado outbreak in the south, and it sure didn't disappoint.  It was unfortunate that the limited severe weather that we have had this year, that the best day had to take so many lives in Mississippi.

On my way home Sunday afternoon, I was driving West on IL-24, outside of Forrest, IL.  I was intrigued by what looked to be a little bit of forcing/lift to the west of me.  Without having access to any type of Visible Satellite, or Radar; I would tend to say that the small towers that were going up was done by an outflow boundary/cold air boundary left over as remnants of the exiting Low Pressure system.  I noticed a pronounced wind shift to the NE, and a drop in temperature with that Cold Air Advection.  The south side of the small cumulo formed clouds were nicely lit by the sun that was breaking through the higher deck of stratiformed clouds.