Sandy the Troublemaker, pt 4: the phasing begins!

Growing up on the Jersey shore, I would wonder whether it was ever possible for a hurricane to come in off the ocean and hit NJ head-on. Oh, my naive youth! I guess Sandy is about to show us that anything is possible!

Today’s post is more to show you some of the great tools we are using to help analyze the large-scale pattern interactions with Sandy. Please note that even though the latest NHC forecast philosophy calls for Sandy to become post-tropical (no longer considered a hurricane) about 120 miles off the NJ coastline, there will be winds close to hurricane strength near the NJ coastline, while farther inland hurricane force gusts are certain a good possibility!

GOES-14 visible imagery in super rapid scan operations (SRSO) with 1-min lightning overlaid courtesy of the Vaisala GLD-360.

The animation above (click on the image to open in a larger screen) shows us a special GOES-14 super rapid scan of Hurricane Sandy on 10/27/12 with 1-min lightning overlaid. Notice there is very little lightning and much of it is in the arcing band to the north and east of Sandy’s center. This imagery is being used at HPC and the Ocean Prediction Center (OPC) during this entire event to showcase future capabilities of GOES-R. This helps forecasters monitor convective trends near the core and outer bands as Sandy transitions to a hybrid storm.

For a longer loop, minus the lightning: Thank you to Timothy Schmidt from NESDIS STAR for providing the animation!

GOES-Sounder RGB Air Mass product with features highlighted valid at 20z on 10/27/12.

The GOES-Sounder RGB Air Mass product above continues the story-line I started a few days ago. The shortwave (upper-level low circled in red) that is responsible to tangling Sandy with the Mid-Atlantic is now diving southeast at a rapid clip. This low (red “L”) will continue east-southeast overnight and you can see the effects of its influence on Sandy by the fanning out of the upper-level clouds to the west-northwest. As this occurs, Sandy (black “L”) will first move north-northeast into tomorrow, before being captured by the aforementioned shortwave. I highlighted in the yellow-circle some obvious dry air (red-shading) in the Sandy’s eastern quadrant. This is indicative of significant drying at upper-levels, most likely associated with a stratospheric intrusion, which has assisted in the hybrid nature of Sandy.

Although not shown today, the blocking in the Atlantic is already causing a significant atmospheric traffic jam. The large ocean storm is still moving southeast and the upper ridge will block any possible escape of Sandy, therefore allowing this highly unusual northwest-west track into either DE or NJ.

The MODIS RGB Air Mass product valid at 1828z on 10/27/12.

The final image today is courtesy of the MODIS instrument on NASA’s AQUA satellite. This version of the RGB Air Mass product is much higher resolution than the GOES-Sounder version, but it is a polar orbiter, therefore you only get a few images a day. Notice the amount of red-shading wrapping around the eastern quadrant of Sandy (yellow-circle). This shows us that the tropical to extratropical transition is underway and with the added energy coming in from the west, we will likely see Sandy deepen further from its current 961 mb pressure. This means the winds could actually increase despite the classification!

Hopefully everyone along the Mid-Atlantic and southern New England have made their preparations. Conditions will go downhill starting tomorrow. Again, the main impacts will be high wind, heavy rainfall, severe coastal flooding (4-8 feet in spots along the Delmarva and NJ), and mountain snows! What a storm!

I will try to update the blog on Sunday morning. Thanks for reading!

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