Weather Blog: NWS Conference Call 7-19-18
NWS Louisville is held a conference call today to discuss Friday's severe weather setup with emergency management, government officials, and the media. Timestamped notes from the call are below.
3:00pm - The call is starting shortly. Ted Funk will be leading the call.
3:03pm - This is an anomalous type of system for this time of year due to the strong winds aloft. Typically winds are calmer aloft in the summer.
3:04pm - Couple rounds of storms tomorrow. The first will be in the morning. Severe weather is not likely in the morning, but an isolated severe storm is possible. Not everyone sees thunderstorms in the morning, they'll be scattered. Heavy rain and hail are the main risks from these storms, with the hail being smaller than 1" in diameter.
3:05pm - The main round of storms is in the afternoon and evening, but how the morning round of storms plays out will affect how the afternoon/evening round plays out. General time frame for the main round of storms is 5pm to 2am EDT. That's a broad range, but the confidence on timing is low, especially if there is more than one line of storms.
3:06pm - Wind and hail are the main threats with these storms. Hail will be a fairly high risk because of supercell storm potential, possibly up to golf ball size or slightly higher. That's very large hail. (Editor's note: Instability values will be VERY high, hence the big hail)
3:07pm - The aforementioned supercell storms will quickly merge into one or more lines of storms, taking the hail threat to more of a wind damage threat, the highest of the threats. There is a tornado threat, but it's not the main concern. Flooding is also not a main concern, but storms will produce high rainfall rates.
3:08pm - There will be a break in storm activity in the afternoon. It'll be quite warm and humid, helping spark development later in the day.
3:09pm - SPC's latest outlook has our area in an Enhanced Risk of severe weather, a 3 out of 5 on their ranking.
3:10pm - Timing is going to be really tough with these storms. Greatest risk of severe weather would be Southern IN and Louisville after 5pm, south of Louisville after 8pm, and in extreme Southern Kentucky after 11pm. With multiple rounds of storms possible after these times, it's impossible to go into more detail at this time.
3:11pm - Western Kentucky and Tennessee has the highest potential for wind damage. (Editor's note: This is because of the location of the strong winds aloft. We talked about that potential on this very weather blog earlier this week.)
3:12pm - The call has opened up to questions from emergency managers, media, and government officials.
3:12pm - Will Saturday be severe too? These storms will not be as intense on Saturday, but a few could be strong. Generally those storms will be sub-severe.
3:15pm - Will we see a Moderate Risk upgrade? A derecho tomorrow? SPC will make the decision on the risk area tomorrow. They bumped up the risk today, but it's hard to say if they will. Ted Funk, leader of the call, sees Western KY and West TN as being at risk of an upgrade to a Moderate Risk. This type of pattern "does suggest" a derecho potential. A derecho is a widespread wind damage event that fits a specific set of criteria. Highest risk for that would be Western KY & TN.
3:19pm - The cloud-to-ground lightning threat with these storms is prolific, especially late in the day into the evening. Lightning doesn't make a storm "severe" but obviously the impact from it is high.
3:20pm - Saturday, when will the storms hit Frankfort? There may be a shower or storm around noon, but after 2-3pm numerous showers and storms will form. They don't look severe at this time, but some stronger ones aren't out of the question. (Editor's note: This timing applies to most of WAVE Country too.)
3:21pm - Will flooding be bad? Flooding is in the low to medium category. Storms will be moving quick enough to prevent flash flooding on a widespread scale, but some localized issues on creeks and streams may develop.
3:24pm - Any river flooding with this? Rivers will be fine, just some small creek and stream issues. Larger rivers won't have significant rises.
3:25pm - The conference call has concluded. Another conference call is likely tomorrow in the early afternoon.