FRONT DOOR FRONT

satsfc.gif JULY 21, 2013

(Click map to enlarge)

FRONT DOOR FRONT

Looking at the above map you can see an honest front has slipped down over the Northeast.  It is not a sneaky back door front, which is a glorified sea breeze slipping inland and south from the cold waters off Maine and the Maritime Provinces, but rather is a more typical front from the west, holding polar air from way up in Canada and even the Arctic Ocean.

However it is still high summer. Up at the north pole the sun never sets, and temperatures have slowly risen until now they are around freezing, or above.  If you don’t believe me check out the meltwater pool shown by Camera One, up there: (click images to enlarge.)Arctic Ice npeo_cam2_20130722013404

Looking the other way with Camera Two shows no such pool, but it does look a bit slushy,

Aectic Ice npeo_cam1_20130722021242

When the weather gets really hot down here it can be very restful to check out the views from such North Pole cameras.  You can access all pictures taken clear back to April at http://psc.apl.washington.edu/northpole/NPEO2013/WEBCAM1/ARCHIVE/ for Camera One and at http://psc.apl.washington.edu/northpole/NPEO2013/WEBCAM2/ARCHIVE/ for Camera Two.

The melt at the North Pole occurs every year, and sometimes the camera even tilts, as the foundation thaws.  At times the ice cracks and you can see open water, (“leads,”) and then winds change and the the sides of the leads crush together like jaws and mini-mountain ranges of ice can build, (“pressure ridges.”) It is nice to stay up-to-date on such cool doings, when the temperatures are ninety in your neighborhood. On a whole the melt has been slow, recently, as temperatures have been a little below normal up there this year:

Arctic Temps July 21 meanT_2013 (1)

(I should note most ice-melt up there is caused by warm currents under the ice, and not so much by air temperatures above the ice.)

But even with temperatures below normal the air procuced up there in the summer is not called arctic, but rather polar, because as it starts down towards us it is roughly seventy degrees warmer than it is in the winter.  During the winter, even over that “warm” ocean, the air is at minus forty, but now, in July,  the air that starts south towards us is at plus thirty (F), at its coldest.

Then it travels through midsummer sunshine, across landscapes with midnight sun, and then across tundra with long, long days, and by the time it gets here it really isn’t all that cold.  As that polar air reached New Hampshire temperatures “fell” to eighty, today.  Even the dew points only “fell” from around 73 (F) to around 62 (F).

Still, it made a huge difference, especially in the shade.  Out in the sun you still knew it was midsummer, but in the shade it felt wonderfully cooler and drier.  And how did people respond, with the weather no longer oppressively sultry?  Did they walk with new found vigor in their stride?

Nope.  What I noticed was that everyone seemed to be yawning. It’s a good thing it was a Sunday, and officially “The Day Of Rest,” because vigor was definitely not in sight.

Actually I think this is to be expected, after a heat wave.  When I lived in South Carolina one summer I did see the body makes adjustments, acclimatizing to the heat, but this far north people are not acclimatized, and a heat wave is a true shock to the system.  Furthermore, is is an accumulative shock. Day after day people are beaten down, until both their bodies and minds start to see they need to make some radical changes or they will simply expire. Routines start to change, metabolisms start to change, (and, sadly, some elderly do expire.) All in all, it is exhausting, and the exhaustion shows as bad moods as the hot spell continues, and as a whole lot of yawning when the front passes and the hot spell ends.

Even when I was young, long before I noticed any aching in my joints as pressures fell and relief as pressures rose, I noticed I had my best sleeps on those cool nights after a front passed, when pressures were springing upwards

This is one of those nights, and I would have long since doddered off to bed, but I had my excellent sleep last night just after the front past, and a second excellent nap after church today, so I can stay up just a bit longer to look at the map.

One odd thing I observed was that, as the polar front approached, there was a lot of talk about the big thunderstorms the clash of air masses would create, but it didn’t happen. I heard no thunder. In fact, though a few small showers passed nearby, my vegetable garden didn’t receive a drop. Why didn’t storms form?

Usually the cooler air pushing in, being denser, snouts under the warmer, humid air, which is lighter like a hot air balloon, and rises.  This did happen. Why didn’t thunderstorms occur?

One fuel for the uplift of thunderstorms is the condensation of steam to liquid.  This not only increases uplift by releasing latent  heat, (IE: boiling steam burns worse than boiling water, because steam holds more heat,) but also, because a balloon of steam shrinks down to a drop of water, extra space is created and suction is created (low pressure) and more moist air is sucked in to the storm’s growing uplift.

However it wasn’t all that cold up high, due to the largeness of the Bermuda High south of us.  Whereas arctic and polar high pressure areas can be flat things, slinking close to the surface, warm tropical high pressure areas can stick up higher. It was well over sixty (F) atop Mount Washington, and even up around the 700 mb map level (10,000 feet,) it was fifty-three (F.)  Therefore, because it was so much warmer aloft, less steam condensed to liquid.  Cumulus clouds didn’t get that extra boost that hurls them upwards to thunderheads.

The fact the Bermuda high extended so high up seems to make it high and mighty, to me.  And the fact the cold front was stopped even before it could push south of Pennsylvania and New Jersey seems to suggest the polar powers are wimpy.  Therefore I expect the more-powerful Bermuda High to counter attack, and push the warmth back up over us.

Apparently I am completely wrong about this.  All the forecast maps show the Bermuda High eroding away to nothing in only 48 hours.  This will be interesting to watch and study, as it happens.  And, if it happens, my brains will be bright, for nights will be cool and sleep will be delicious all this week.

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3 thoughts on “FRONT DOOR FRONT

    • I’m glad you liked it. In terms of meteorology, I am unschooled, but have been paying attention all my life. I really enjoy schooled meteorologists who put things in terms laymen can understand. I’ll be watching your site with interest.

      However I confess to being an old grouch and a skeptic, when it comes to Global Warming. Hopefully you won’t find that side of me too objectionable.

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