Storm Chances Increasing

Good Evening Folks...

Storm chances are INCREASING across the area ahead of the upcoming Memorial Day Weekend...some of the storms that develop over the coming days, primarily Thursday and Friday will have the potential to become severe, capable of producing large hail, damaging winds and isolated tornadoes. In addition to the threat of severe weather, flash flooding may also become a problem given very high moisture levels across the area. Early indications are that we may receive an additional 1-3 inches of rain, localized areas of 4 inches possible over the next several days.

Lately everybody has been asking me, what's this weather going to do? It feels and looks like it could pour down at anytime, however, all we end up seeing are sprinkles or spotty showers. Not to get too geeky for you, but in order for a thunderstorm to develop we need THREE ingredients to be present:

-Moisture

-Instability (in simple terms, a large difference in temperatures between the surface and aloft...rapidly cooling air with height)

-Lift (the trigger for a parcel of air at the surface to rise, cold fronts and/or the dry line are excellent producers of lift)

The moisture is definitely in place, the instability is in place, however, the lift is not in place, yet...that will be changing over the coming days as a deepening trough, or valley, of low pressure at the mid levels of the atmosphere approaches the area sending disturbances, or atmospheric ripples, across the area providing lift.

Storm chances will begin to increase across the area as early as tomorrow (Wednesday) evening and really increase for Thursday, Thursday Night, and Friday.

Severe Weather Risk Areas over the coming days:
Light Green = General Storms (<5% chance of severe weather)
Dark Green = Marginal Risk (5% chance of severe weather)
Yellow = Slight Risk (15% chance of severe weather)
Orange = Enhanced Risk (30% chance of severe weather)

***probabilities above represent chances of seeing severe weather, not chances for seeing showers and storms***

Wednesday/Wednesday Evening:

Thursday/Thursday Evening:

Friday/Friday Evening:

 

Pattern Change

Forecast Discussion:
TGIF Everybody! This beautiful stretch of spring weather we have been enjoying for the past several days is going to be coming to an end for us over the upcoming weekend. Don't get me wrong, it's still going to be a nice weekend, but you'll definitely notice some changes compared to the near perfect weather we have been enjoying with low humidity and comfortable temperatures.

Weekend Changes:
Clouds and moisture will begin to stream back into the area on returning southerly winds ahead of our next upper level disturbance/storm system that will bring rain chances back into the forecast for the second half of the weekend and into much of next week. You will really begin to notice the increase in humidity by Saturday afternoon and especially during the day Sunday.

The atmosphere will become very unstable over the area by late weekend into early next week, however, a strong capping inversion, or lid on our atmosphere will efficiently work to limit the amount of showers and thunderstorms that are able to develop. With that being said, if a developing storm is able to break through the cap, or layer of warm air over the area, it would have the potential to become severe in a hurry potentially producing large hail and damaging winds.

The heart of the energy associated with our next approaching storm system will be focused generally north of our area, however, disturbances (impulses) of energy in the wind flow above us spinning counter-clockwise around the upper level low will give us increased opportunities for seeing showers and storms...these disturbances (impulses) work to create lift in our atmosphere, essentially forcing the air to rise, condensate and effectively precipitate.

Weekend Summary:
Highs will be in the 80s over the weekend with overnight lows generally warming from the 50s/lower 60s on Saturday morning into the mid 60s Sunday morning as moisture increases across the area effectively doing away with the pleasant cool mornings we have been experiencing.

Weather Pattern Changes Highlighted:
With all of this mentioned, shower and thunderstorm chances will be creeping back into the forecast by the second half of the upcoming weekend and into next week...really a typical May weather pattern for us here in central and south central Texas. We will have to watch the potential for strong/severe storms to form along the dry line in west Texas each afternoon...those storms would then have the potential to organize into a cluster, or line of showers and thunderstorms, that would make a run for the I-35 corridor during the late evening/early morning hours.


Mother's Day (Sunday) Severe Weather Risk Area (categorical): We are NOT under a threat for severe weather in Austin, however, areas west and especially northwest of the area will be)

Light Green = General Thunderstorms Possible
Dark Green = Marginal Risk for Severe Storms (5% chance of severe weather)
Yellow = Slight Risk (15% chance of severe weather)

*severe weather = t'storms capable of producing large hail, damaging winds, isolated tornado)

I want to take a moment to wish all of you moms out there a "Happy Mother's Day"