Fast Flat Flow Is a Delicate Balance

It's not as if we have no storms around, it's just our (the Northeastern USA's) turn for a break. Super storm Sandy was just 4 weeks ago, and her super sequel 3 weeks ago. We have watched storms miss to the southeast and northwest for the 3 weeks since. So now all the sudden we could use some rain & snow.
The ocean storm last week was great for surfing, just too bad that northeast wind would not quit. Here is a shot of Surf in Scituate from Friday November 23. (yes, there were many surfers on Thanksgiving Day too.)

Also on the day after Thanksgiving, a front arrived in Vermont with rain that changed to snow before sunrise Saturday the 24th. The cold air racing in on northwest wind (to 101 mph on Mt.Washington) caused lake effect and up-slope snow in much of Vermont, and flurries at most of our New England Mountains. That cold front was with a storm that tracked over northern Ontario.
Mount Mansfield Vemont has a new 5" snow cover.

Those two storms are now joining together and will work to steer the next storm out to sea south and east of New England. The way this happens is with the development  of another 'Super-Storm' over the Labrador Sea. That storm, in combination with a huge storm south of Alaska, will generate a Fast, fairly flat, flow in the Jet Stream across the lower 48. Though we do have a major trough off California, and a slight ridge west, trough east, we can see the flow is fast and flat, here is the Wednesday steering current forecast.


The North Atlantic surface analysis from Sunday November 25, 2012 shows Powerful storms in the northwest and northeast Atlantic Ocean. Between those storms is a strong high pressure system, all part of North Atlantic blocking that may hold for a 'very interesting' winter to come.


See the word 'merge' in the Labrador Sea? That is where a 974 millibar low (the one responsible for weekend cold and snow here in the northeast) and a 969 millibar low (the one responsible for 20 foot waves this weekend at George's Bank Buoy) are merging. We also call this phasing. Phasing of northern and southern atmospheric energy centers cause the most powerful storms, like Sandy a few weeks ago. Sandy is one that hit, but previous to 947 millibar Sandy, we had another 955 super storm in the Labrador Sea. That 955 low was on October 13th and resulted on the coldest Columbus Day Weekend for us since 1993. So to have another similar set up we have to watch for potential record cold in eastern Canada. Summit Greenland is close to -60 degrees this week. But this cold is butting up against an incredibly strong flow from the Pacific Ocean all the way across the lower 48. It is a tenuous balance of Pacific low pressure systems racing the tight rope of a Fast Flat Flow across the Untied States. All the ingredients are in place for extreme weather (for example, the record floods in England from low on the right on map above).
Last week we just missed a major storm. With this set up it's only a matter of time before more extremes show up. Though the Tuesday storm is too far out, we have a series of fronts form Canada with snow squalls possible every 36 to 48 hours before the heart of this cold outbreak arrives Friday the 30th. By then we have a 1036 millibar (very heavy cold) arriving in Quebec. At the same time, a warmer storm will push from the West Coast to the Mid West. A Major warm front will move into New York Saturday. Warm air is light, cold air is heavy, the stage is set for a significant over running winter storm in New England next weekend. Snow, then ice, then rain is likely next weekend. A mini thaw may follow for Dec 3-5, before more extremes (leaning cold) will show up in the second week of December.

Contact Us