SPC Outlooks for Wednesday – All Hazards
All types of severe weather hazards are on the table for tomorrow, Wednesday. A cold front will pass by on Thursday morning, but before it does, we have to deal with the potential for strong to severe thunderstorms. Timing is looking like Wednesday evening through the overnight into early Thursday morning. I’ll have more details on timing in the Tomorrow section down below.
Looking at the SPC outlook, almost all of our region is under a Slight Risk or Marginal Risk of severe weather. There’s currently a 5-9% probability of a tornado in the brown areas shown in the top-right figure and a 2-4% chance in the green areas. Most of those shaded areas are also under CIG 1 intensity, as indicated by the single tick marks, meaning conditions are favorable for tornadoes to reach EF-2 strength if they form.
Severe wind is also a possibility during severe storms, as we have a 15-29% chance in the yellow areas in the bottom-left figure and a 5-14% chance in the brown areas. No CIG intensity tic marks for wind, so any severe gusts should remain below 75 mph. Lastly, severe hail is possible, with a 5-14% chance in those brown areas.
Tonight’s Forecast
We’ll see a very mild night tonight as our storm fuel is pumping in from the south (aka warm/moist southerly flow). We’ll see a low temperature in the upper 60s or near 70 degrees.
Tomorrow’s Forecast: Wednesday, March 11
Tomorrow is going to start off with a mix of sun and clouds. As we know, the more sunshine you get during the day, the more instability there will be for storms to tap into, so we will see tomorrow just how much sun we see in the morning and afternoon before the storms begin to fire up in the evening. Also, we will have temperatures in the upper 70s to 80s, as well as extremely high dew points in the 70s, which add to the storm fuel. Models currently show about 1000 or so J/kg of CAPE, or Convective Available Potential Energy, during the afternoon and into the evening, which is not extreme, but certainly enough to get storms going. There’s also a noticeable amount of speed and directional wind shear, which could support the formation of supercells and tornadoes.
Looking at the HRRR solution for tomorrow, some early boomers are possible anytime from noon to dinnertime, and then the rest of the heavy downpours and potential severe-embeded storms will push through into the overnight. It’s very possible that the early boomers hold off, and you don’t see any storms until 12-4 am on Thursday, but when it does come through, that’s when we could see the damaging wind threat and tornado threat.
Since this will be mostly a nocturnal event, ensure that your phones are charged when you go to sleep tomorrow night, just in case you receive a severe alert, and that you can reach your safe place before the warning expires.
This is not a widespread severe weather event, so there is no need to panic… but it’s important to take all necessary precautions when severe weather approaches.
Thursday’s Forecast: March 12
Any storms or rain will be offshore by 8-10 am on Thursday, and that is when we will officially be behind the cold front. It will be a beautiful day with temperatures topping out in the 60s and dew points only in the 30s! That is very dry and a huge change from the recent humidity and hot weather we’ve had.
Extended Local Outlook
The low humidity will only be temporary, unfortunately. By Friday, humidity will creep up slightly, and by Saturday and Sunday, we’re back to hot and humid. If we take a look at the 500 mb height pattern, we are currently under a large ridge aloft, which is allowing warm, moist southerly flow around the Gulf high-pressure system. By early next week, models are picking up on a dip in the jet stream, or a trough, which will shift our winds to blow from the north. This looks like it will bring us to slightly below-average temperatures for Monday-Wednesday next week and very low humidity! Definitely something to look forward to!
