EWP Blog

I had been scouring through some of the satellite and radar images in East Central Wyoming. WV/IR was showing some of the higher cloud tops through Southeast Wyoming. At one point a small area was depicted on the OTD. At this time, there was no activity on radar through southeast Wyoming.

On visible satellite, clouds began to develop in East Central Wyoming. This is where some of the first radar returns were coming in at 40+ dbz. When referring to the Nearcast the vertical Theta-e Diff was showing as much as -10.6K. It was on the edge of this difference (gradient) where convection was taking place, as seen below.

21:45 Z…had an area of 60% CI in NE TN (Claiborne Co.) on Cu developing in conjunction with a little disturbance and perhaps some outflow from convection farther west.  No storms an hour later.  A reminder to use these tools in conjunction with all your other tools and be aware of the overall set-up.   Minima in theta-e and precip. water were trending that direction as well.

The CI product is deemed most useful leading up to a severe weather event. As intended, it seems that it can provide at least an idea where convection will occur. There are two things that came to mind when looking at this tool.

On quieter days this tool can become noisy. By editing the colors in the RGB color model, I was able to black out all probabilities below 50% and to clean up the product. This will bring attention to the higher probabilities, as opposed to cluttering the field with lower end probabilities. The threshold (<20%, <30%, <40% etc) a person chooses to ignore is up to the user. To do this, though, you must continually edit the color model. This isn’t difficult, but  takes time. It would be nice if a default button existed that allows you to black out a specified range. Below is a result between the two (normal view 1-100% and 50-100% probabilities, respectively):

The second thought pertains to what application this could have during lake effect snow events. In the proper environment, convective snow banding could lead to heavy, consistent snowfall of greater than 35 Dbz. This may be a useful tool for updates to geographical locations of higher intensity snowfalls in these events.

GOES-R CI product shows low chances for convection in EC Wyoming

Isolated weak storms formed just north of the Black Hills with no probability

of CI (could be a thin cirrus issue).

Bthoren

CI indicated 83% chance for a cell in Claiborne, Co., TN as of 21:45Z.  Subtle impulse and perhaps outflow from old convection to the east may be puffing up the Cu…we’ll see how it develops over the next hour.—DB

Day one of our Big Spring Experiment and operations are already well underway.

The focus for today is primarily hands-on training.  The forecasters have been asked to examine all the experimental products and issue occasional blog posts as they see interesting or note-worthy items.  The goal is to develop a familiarity with both the new products and blogging process.

Two forecasters (Thoren / Maples) are localized to the Sterling, VA (LWX) WFO and watching ongoing convection there and areas south including the Blackburg, VA WFO.  The other forecasters (Rudge / Bickford) are localized to the Cheyenne, WY (CYS) WFO, monitoring the region for CI.

As the week continues, are focus will become a little more defined and move to writing mesoscale / forecast discussions and warnings.  Expectations are that the probability for severe convection will increase with each day of operations this week.

-Kristin Calhoun, Week 1 Coordinator

A storm developed in Western Virginia around Long Spur, just west of Pulaski. In early stages of development, probabilities of severe weather occurring were low. Radar reflectivity was generally between 50-60 Dbz. Severe probability quickly increased from 11% to 96% within 18 minutes. In the same time span reflectivity of up to 71 Dbz was detected. MRMS MESH maximum was 1.74 inches, while there was a notable increase in MUCAPE and EBSHEAR.

Not really our area today, but prob severe model indicated

a 56% chance this storm would produce severe weather

at 1950Z .  At 2012Z prob was up to 96%.  Model has

low probabilities with other storms in area.

b thoren