Friday, April 19, 2013

Wind, Rain, Thunder This Evening

We're not officially in any threat level for severe weather as of this morning but the prospect for strong thunderstorms (at least heavy rain and gusty wind) is definitely there for this evening as the front approaches and then passes through tonight.  There's a very low (two percent) chance for an isolated tornado within 25 miles of any point, five percent chance of damaging wind.

The Storm Prediction Center may (and past performance suggests they could) upgrade parts of the region into a slight risk. Slight does not mean certainty from a damage standpoint -- the thunderstorm threat is high but the threat for severe weather is relatively low today.

Better dynamics and instability exist to the south -- more sunshine to our south will help enhance the line later on today as it pushes on east. While we will warm into the 70's this afternoon, the amount of sun ahead of the front may be limited today.  As a result, we probably don't get as much of a severe weather threat.  That said, we will have a heavy rain and wind threat this evening as the front pushes in.

Timing still suggests the front approaches the city from the west after 6 PM -- we should get through the day without much in the way of rainfall.  Rain and thunder enters from the west, moves through during the evening and overnight hours, and exits off the coast by Saturday morning. We probably see a two to three hour window of rain, with the first 30-45 minutes probably the heaviest and windiest of the evening as the front pushes through tonight.

Rainfall could reach an inch in some spots, perhaps exceed that in a few locations as well.  With the bulk of that falling in the first 30 to 45 minutes, some road ponding and drainage flooding is possible.

We'll keep an eye on things through the day and provide another update this evening on the thunder threat.