Eastern   Pacific   Zulu  


STORMcast alert notifications are also pushed out through Twitter.  Click the icon to follow. 
STORMcast Advisory 2018-14

Issued: 05May18

Time:  1245 EDT

The STORMcasts shown here are intended for the students of UDHS's AGS and AES geoscience programs and are for educational/informational purposes only.  They frequently combine scientific concepts along with a sense of humor that often pokes fun at our behavior during weather events. While intended to be informative, the STORMcasts should never be used to make life and death decisions during severe weather events.  Follow the appropriate bulletins posted by the National Weather Service for appropriate actions during these events.


Current National Weather Service advisory map as of STORMcast issuance...

SEVERE THUNDERSTORM WATCH - For interior PA until 8 PM.  Strong to severe thunderstorms with lightning, large hail, damaging winds and isolated tornadoes possible.

FLASH FLOOD WATCH
- For the Philly metro area, most of NJ, DE and MD from 4 PM through this evening.  Short-lived but very heavy rains possible in expected severe weather this evening that could produce rapid flooding with little to no warning.

(Map courtesy of NWS)
Severe Weather Potential Growing

Hi everyone.  Just a quick heads up for severe storm potential this afternoon and evening in case you had outdoor activities planned. 

Tonight

A frontal boundary is expected to pass through the region this evening that will mechanically lift very warm, unstable air out ahead of it and produce organized thunderstorms.  As of 1:15 PM, numerous severe storms were beginning to organize in the western part of the state heading east.  Large hail, damaging winds and rotation have already been detected in these storms.  Thought still a ways off, the storms should continue to organize and benefit from maximum daytime heating as they approach Philly early this evening.  A mesoscale convective system (MCS) is also possible later today.  These long-lived features frequently bring very high wind gusts and hail although the tornado threat is not particularly high at this time.

At this point, the best estimate for passage of the storms should be between 6-8 PM tonight.  Further east, NJ might benefit a bit from coastal cooling and the start of night before the storms hit but the likelihood of a wild evening is still pretty high.

Outdoor interests taking place (especially) this evening should take careful heed and plan for rapidly deteriorating conditions.  The potential for severe weather is noticeably higher toinight than it was last Thurs. under similar conditions.

Watch for the expansion of the Severe Thunderstorm Watch issuance within the next 1-2 hours as instability continues to increase in eastern PA and NJ. 

      

IGeneralized view of severe weather potential for later this afternoon.  Philly is not in the sweet spot but sunny skies have added considerable instability to the atmosphere so the potential for severe weather is still fairly high.  On the right is a current stability map as of 1245 EDT.  By the numbers, anything above 1000 is worth keeping an eye on.  As the afternoon progresses, numbers near Philadelphia should be in the 2500-3000 range which is ripe for the formation of strong to severe thunderstorms.

rs
1324