Saturday Morning, March 25, 2017
Forecaster: Scott Martin
AN ACTIVE, STORMY SATURDAY: As of 10:40 PM on Friday night, when this post was made, the Storm Prediction Center still has roughly the western half of Alabama in a slight risk for severe storms throughout the day, with a marginal risk for the eastern counties.
THE SETUP: A surface low will be over parts of Missouri, with a surface front trailing to the south and southwest. We will have warm, moist air advecting across Central Alabama ahead of the system, and this will make our airmass unstable. Highs will mainly be up in the mid to upper 70s, with lower 70s for the extreme northern parts of Central Alabama. Dewpoints will be in the upper 50s to the lower 60s. We'll have surface based CAPE values up to near 1,500 J/kg by the afternoon hours, along with a little better alignment of the higher shear values and higher instability values over the western parts of the state near the Mississippi border.
TIMING: We will have the possibility of a few showers and storms developing during the morning, and some of these could be strong, but the primary risk for severe weather will be from noon until roughly 9PM Saturday night. It is very likely that it will not rain for the entire nine-hour time frame, but strong to severe storms will be very possible.
THREATS: The main threat will be from damaging straight-line thunderstorm winds. Large, damaging hail will also be possible, and based on the latest model output, an isolated tornado or two could be possible especially over the western counties. Flooding will not be a threat, as rain amounts will range from 1/2 to 1 inch.
WORD OF ADVICE: Be sure to be in a position to hear severe weather watches and warnings throughout the afternoon and evening hours if they are needed. Have your NOAA Weather Radio handy and your smart phone charged and nearby.
UNSTABLE AGAIN ON SUNDAY: The airmass over Central Alabama will once again be unstable, and the possibility for scattered showers and storms will be there mainly during the afternoon and evening hours. The SPC has defined the extreme northeastern part of the state in a marginal risk for severe storms on Sunday. Where these storms do form, they could be strong, and the main threat will be from hail. Afternoon highs will be up in the mid 70s to the mid 80s across the area, and dewpoints will mainly be in the lower 60s.
A BRIEF LOOK AHEAD TO THE UPCOMING WEEK: We will be in the middle of a very active pattern that has set up over the southeast, and we may actually have two more shots at strong to severe storms during the work week. The first as of now appears to be on Monday, as CAPE values are expected to reach 1000-2000 J/kg with steep lapse rates. Good news is that low-level shear rates are marginal so the tornado threat looks low, but damaging straight-line winds and hail will be possible with this system. The next system will move across the state on Thursday, but it is too early to be specific on exactly what to expect at this point. This is just a great reminder that we are in the active point of our spring severe weather season, so these kind of events are pretty common for this time of the year.
STORM SPOTTER TRAINING: We will be on the road through early April offering free storm spotter classes. We need more trained spotters in Alabama; by attending you can make the severe weather warning process better. No need to register; just come with a curious mind. And, there is no age limit... kids that love weather will enjoy it. You will never look at a storm the same again. Next week we are at Oxford Tuesday (at the Oxford Civic Center) and Jasper Thursday (at the Jasper Civic Center).
Today's Record Temperatures