Heavy Rain at times this Weekend Followed by major Pattern Change

The weekend will not be a total wash out but heavy rain will once again threaten the Washington Region on Saturday and Sunday afternoon/evening.

NAM_4PM-SAT_1AM-SUN

The image above (courtesy Tropicaltidbits.com) shows heavy thunderstorms developing during the mid to late afternoon hours and continuing through Saturday evening before tapering off around midnight.

Continue reading “Heavy Rain at times this Weekend Followed by major Pattern Change”

Timing Today’s Potential Widespread Severe Weather Outbreak

Many ingredients are coming together for a possible widespread severe weather outbreak this afternoon through the late evening hours.  While pinning down the exact timing is difficult, the latest HRRR (High Resolution Rapid Refresh) and High Resolution NAM (North American Model) are currently in agreement that this afternoon & evening may feature very rough weather.

Latest HRRR (High Resolution Rapid Refresh) model 4PM to 8PM: 

  • The image below (courtesy tropical tidbits.com) shows the potential for super cells (individual severe thunderstorms) breaking out in the mid-afternoon hours. With wind shear values running moderately high, any super cell thunderstorm would have the potential risk of dropping an isolated tornado.
  • The model also suggests that an organized squall line may push through between 5 and 8PM.  The main threat with squall lines of course is widespread wind damage.

HRRR_4PM-8PM

 

Next up is the latest NAM (North American Model) showing the a similar set up.  This image below shows what the potential radar may look like from 4PM to midnight: Notice the entire Metro Area gets absolutely hammered with what could be a dangerous squall line.

NAM_4PM-Midnight

Please stay tuned to local media outlets should the Storm Prediction Center issue Tornado or Severe Thunderstorm Watches this afternoon.

Also of concern will be flash flooding as some of these storms will have the potential to drop 1 to 3″ of rain in a very short period of time!