Overview: Week 2, Day 3

10 AM

Wednesday presented a '7-10 split' of severe potential, with thunderstorms expected in the Great Basin and Mid-Atlantic regions. Most of this was driven by a Slight Risk from the 13 Z SPC Convective outlook, driven by 15% CIG1 wind probabilities. Timing and moisture were a little less certain out west, while convection was more certain in the east but had limited deep instability and subsequent severe weather potential. After some discussion, we localized to the Pittsburgh, PA (PBZ) and Pocatello, ID (PIH) offices.

During the morning discussion we played the same comparison game between the SZA and traditional imagery, but this time for the upper great lakes region around sunset on Tuesday, using archived imagery from CIRA-SLIDER. Forecasters were asked when the imagery no longer became useful to them, and here's their reported times when looking at the same loop between 21 Z and 02 Z.

• Traditional: 2156 Z, 0001 Z, 0001 Z, 0021 Z
• SZA: 0111 Z, 0111 Z, 0111 Z, 0111 Z

Here's the loops so you can play along at home! (Sorry these are really big GIFs, the blog didn't like the when I converted them to MP4 format)

Traditional Day Cloud Phase Distinction RGB

SZZ Day Cloud Phase Distinction RGB

1 PM

Forecasters in the PBZ office were thrown into a situation where convection was already developing in the western side of their CWA, and they began issuing warnings, investigating OCTANE, and sending DSS messages to their mock-events. 

In the PIH office storms were slow to get going, so we looked at some imagery from the FCI and the synthetic GXI imagery from the HRRR. One target we casually watched throughout the day was a dry line in the TX panhandle, and we compared them to moisture boundaries in Europe and north Africa.

3 PM

PIH was issuing warnings by this time, and frequently relied on radar imagery and knowledge of the environment when making warning decisions. When looking at the OCTANE CTC product and other satellite imagery, the presentation of most storms were not impressive.

In the PBZ office, the forecasters noted that the OCTANE CTC product was limited in its application due to dense cirrus and anvil debris obscuring cooling signals in the ABI infrared bands. In the OCTANE Speed Sandwich however, the forecasters found the speed values and textures from visible imagery easier to view new and intensifying updrafts. This resulted in some discussion about how to 'train' for this.

By the end of the day, a number of severe wind reports appeared across the PIH CWA from their mesonet, while in PBZ a single hail report was featured. More reports may come in tonight or tomorrow?

-Kevin