Wednesday, February 19, 2014

Severe Weather Likely Thursday

The sunshine today will help to warm us to near 60 degrees for the second day in a row! Tomorrow we may be looking at highs in the low 70s. But the warm air comes with a price as severe storms will begin to roll in late in the afternoon.

What can we expect?
Rain showers will sweep through the area periodically throughout your Thursday, so make sure and pack an umbrella if you will be heading to work or class tomorrow.
Isolated Super cells may form out ahead of the main line of storms during the mid to late afternoon. If this does happen, tornadoes would become a threat. Later in the evening, a squall line will swing through, delivering heavy rain, lightning, and strong winds.

Here is the SPC day 2 outlook:



Bowling Green is included in the 30% risk for severe storms as well as the thatched area. The thatched area is an area where an upgraded risk (to moderate) is possible.
The 4 km NAM shows super cells out in front of the main line to be a real possibility.



Based on the NAM, isolated storms could arrive mid afternoon, bringing an enhanced tornado threat to the region.

Severe storm ingredients:
Plenty of moisture and warm air will be in the area tomorrow. Surface winds will be strong throughout the day. An intense negatively tilted trough will be shifting east out of the plains Thursday, meanwhile a surface low will rapidly intensify and push Northeast toward the Great Lakes. Storms will intensify in this region out ahead of the cold front.

 CAPE (convective available potential energy) is the fuel for storms. The NAM and GFS have continued to increase the instability for later tomorrow.


 The NAM shows CAPE values between 750-1000 at 6pm, more than sufficient for fueling severe storms.
Low level helicity values of over 300 J/kg will be in place around the 6pm time frame. Low level helicity values over 300 J/kg are favorable for super cell development.


Here is a look at the super cell composite for 6pm and significant tornado parameter at the same time.




The super cell composite points toward favorable conditions for super cells to develop after 5pm in our area. The significant tornado parameter  shows values near 4 just to the west of the area and heading east. This puts Bowling Green at a low end moderate risk for an EF2 tornado or greater.

The wind shear tomorrow will be very strong. Wind shear is crucial for the development of rotating updrafts. The more sheared an environment is, the higher the likelihood of tornado development is. Shear also helps keep storms isolated instead of forming a squall line.
Here is the bulk shear for 6pm tomorrow:



My thoughts:
This system will impact our area during the late afternoon and evening hours Thursday. The main concern tomorrow will be how many super cells can form out ahead of the main line. If isolated cells do develop, the chance for tornadoes increases. A squall line will likely move through the area during the evening in addition to the isolated storms out in front. While isolated cells will not affect everyone, if the squall line develops this far west, it will effect everyone. Wind damage is the greatest risk with these storms, along with heavy rain. An isolated tornado can not be ruled out, especially if storms can stay isolated through the entire region.

Timing:
Super cells will begin to develop after 5pm.
A squall line may organize after 8pm.

Note: These timing of this event along with the specifications of the storms are not set in stone and can change between today and tomorrow night. Stay alert as tomorrow afternoon draws closer and keep up to date with local weather reports.

Weather Links:
Twitter: @WarrenCountyWX
Facebook: Warren County WX


Weekly Outlook:
Today: Mostly sunny, with a high near 57. Calm wind.
Tonight: Scattered showers and thunderstorms, mainly after midnight. Mostly cloudy, with a low around 48. Light and variable wind becoming south 5 to 9 mph in the evening. Chance of precipitation is 40%.

Thursday: Showers and thunderstorms likely, mainly after 5pm. Some of the storms could be severe. Mostly cloudy, with a high near 72. Breezy, with a south wind 10 to 15 mph increasing to 20 to 25 mph in the afternoon. Winds could gust as high as 40 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday Night: Showers and thunderstorms, mainly before 1am. Some of the storms could be severe. Low around 37. Breezy, with a south wind 19 to 24 mph becoming west 10 to 15 mph in the evening. Winds could gust as high as 40 mph. Chance of precipitation is 100%. New rainfall amounts between three quarters and one inch possible.

Friday: Sunny, with a high near 55. West wind 6 to 11 mph.
Friday Night: Mostly clear, with a low around 34.

Saturday: A 20 percent chance of showers after 7am. Mostly sunny, with a high near 56.
Saturday Night: A 20 percent chance of showers. Partly cloudy, with a low around 32.

Sunday: A 20 percent chance of showers. Mostly sunny, with a high near 47.
Sunday Night: Partly cloudy, with a low around 27.

Monday: Mostly sunny, with a high near 45.
Monday Night: A 30 percent chance of snow. Mostly cloudy, with a low around 29.

Tuesday: A chance of rain and snow. Mostly cloudy, with a high near 42. Chance of precipitation is 30%.

Forecaster: Tyler Smith

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.