Wednesday, May 25, 2011

The Typhoon Rule signals the coming of cooler weather

I am realizing this week that it is better to be hot and uncomfortable than to be under the repeat threats of tornadoes and severe thunderstorms. Please be in prayer for those suffering in the Midwest and others who are threatened even as I write this article.

Out in the Far East , Typhoon Songda, is providing some hope of a break in the summer heat.  If she follows her predicted path then sometime late Friday or Saturday she will turn east in advance of a trough closing in on Japan.  That would signal the coming of a trough and cooler air to the eastern US either next weekend or early the following week.

Typhoon Songda is forecast to recurve late Friday or Saturday
Image Source: Univ of Wisconsin SSEC

It would not surprise me at all to see out first tropical storm or hurricane of the Atlantic Season in the 6-10 day time frame.  The strong departing heat ridge if it were a summer pattern would have a risk of a tropical system on its SW quadrant. 

Regardless, a break in the worst sustained heat of the entire summer 2011 is coming.

Nightmare storm continues the menace the midwest

The unbelievable storm which has spawned an EF-5 Tornado that destroyed Joplin, MO on Sunday killing 123 people continues to rage in its 3rd day.  So far this year 501 people have lost their lives this year placing the number of deaths at #7 and the year is only half over!  The NOAA estimates that 1,000 tornadoes have occurred so far.  Read more about this horrific season.

A cold pool of air in the upper levels and a huge temperature contrast with the heat that is dominating the east is fueling the storm system which looks like an inland hurricane at times.

East of the menacing swirl are 2 sources of heat that will
dominate through next week. 
Image Source: Univ of Wisconsin SSEC
As of this evening it appears that the storm will weaken Friday as it crosses the Appalachians and leaves its cold upper level support.  Conceptually, I would have a hard time with the idea that the storm could maintain it's strength and organization for that long.  That being said... we need to watch its progression eastward. 

Tomorrow will be a long day west of the mountains as more tornadoes and severe storms threaten lives and property.  Be in prayer for the people who are recovering from the tragic losses and those who are being threatened.

Saturday, May 21, 2011

Special Report: Iceland Volcanic Eruption

The Grimsvotn Volcano in Iceland is erupting.  Plumes of ash have been blasted about 8.5 miles into the atmosphere.  

Eruptions by Grimsvotn are not uncommon.  Further activity which leads to ash and sulfur dioxide being added to the stratosphere may have winter consequences.  High latitude volcanic activity is correlated with increased blocking during the winter.

No one is interested in another negative Arctic/North Atlantic Oscillation winter.  Hopefully Grimsvotn will be consistent with past activity and finish it's eruption quickly. 

Summer heat on the way! Tropical Concerns, and Garden tips.

For a while I wondered if the alignment of convection in the tropics called the Madden-Julian Oscillation (MJO) was going to override the coming of 90 degree+ heat to our region.  It has decided to die out instead of progress through the cool phases!  Therefore here comes summer heat!

The good news is that I expect the worst heat of the whole summer during the next few weeks.  On a bad note:  with the coming of a more moderate to even cool at times regime will come serious hurricane threats to the SE US and eventually even to New England.   Please read a TERRIFIC summary of what to expect this hurricane season by Greg Nordstrom.   Greg is an Instructor or Meteorology at Mississippi State University.

As the heat moves in your gardens will need to be tended in a way that minimizes the stress to your plants.  Here are some guidelines:
  • Water lettuce, salad greens, and anything else every day.  Pick those crops ASAP because time is up!  Eat your salads and give away what you cannot use.
  • It never helps a plant to flood it with water.  Limit watering to 2-4 cups per tomato, pepper, or other summer plant every other day that it does not rain. Water directly to the base of the plants.  Do not water weeds.
  • Zucchini, Squash, Pumpkins, and Cucumbers will wilt some in the afternoon heat.  It is normal.  If the plants fail to recover by 5 PM then give them 2 cups of water to the roots.  Begin to inspect your squash, zucchini, and pumpkins for squash bugs.  Remove the ones that you find and either squash them (phew!!!) or drop them and any eggs you scrape off into soapy water.
  • Mulch summer plants with grass clippings, ground leaves, or other organic matter to maintain moisture.  
  • If your soil is drying out to quickly then gently mix in some compost but do not disturb the roots.  Compost adds spongy matter called humus which will absorb more water.
  • Please avoid spraying tomato vines with water.  It increases the chance of disease
Have no fear that this summer will repeat last years inferno.  It is expected that the heat will come early.  Most of summer will be quite nice!

Tuesday, May 10, 2011

Summer/Tropical Outlook, Abridged version

If I wait until I have 2 hours to compose a full version then it will be autumn.  Here is an brief summer and tropical outlook.  More details will follow mixed into upcoming articles.

Important pattern details:
  • Weakening La Nina/generally rising AAM through much of the summer: This combination favors a general trough in the eastern US which will contrast greatly with last summers mega-ridge that roasted the region.
Cold anomalies are warming in all zones
Source: NOAA Climate Prediction Center

  • Resurgent Madden-Julian Oscillation:  The 40 day wave through the tropics correlates well with temperature and precipitation patterns when it is observed correctly.  It can also be useful when combined with other tools with forecasting bias in the paths and strength of tropical systems.
MJO has strengthened into a trackable feature
Source: The Center of Australian Weather Research

  • Inland Upper Tropospheric Trough: I hesitate to call it a TUTT (Tropical Upper Tropospheric Trough) but the abnormally high rainfall storms and clash of cold and warm between the Mississippi River and Appalachians this spring will lead to an upper level cool pool reminiscent of recent years like 1996, 1999, and to some extent 2003.  Most of us know what happened when the hurricanes came during those years.  The orientation and positioning of that feature will be huge in regards to who takes the 1-3 serious storms that will be coming.
What to expect:
  • Cool to Moderate Temperatures:  This is the summer that we have been waiting for!  Yes, NC and VA summers even when near average are hot ... BUT ...  I will accept this one over the fiery furnace of last year.  My instinct tells me that the biggest heat will  be in the midsummer near July 4th.
  • Regular Precipitation but... :  Rising AAM means more frequent frontal passages.  Therefore rain will be in regular intervals.   The big but...  comes in August/September as falling AAM brings the tropical moisture plume and storms to menace the eastern seaboard.
  • Hurricanes:  If I may continue my winning streak into a 3rd year.  Careful study has led me to believe that average hurricane path will yield landfalls from the FL Panhandle to New England.  If correct, the winter implications would be for real winter storms to menace the same region....
Some details will follow in future  articles.  Enjoy the summer!  Except for drama at the end most of it will be great!

      Monday, May 9, 2011

      Cool to Moderate temperatures will contine for next 10-14 days

      The weather amazes me because of how it can defy millions of dollars in computing power and an army of professionals and enthusiasts.  There are many tools that can be used to attempt to get an angle of what God's tremendous weather machine is trying to accomplish.

      As spring progresses toward it's inevitable conclusion I find the Global Synoptic Dynamic Model (GSDM) to be very useful.  It attempts to integrate atmospheric angular momentum (AAM), MJO activity, and the AAM trend to produce yet another tool called the Global Wind Oscillation (GWO).   Weather is full of acronyms!

      I find the GSDM useful as a means to explain where the weather pattern has been an IN GENERAL where it is headed.  It is not useful in forecasting local or regional events but can be used to support or debunk other long range models. Here is the past 40 days of the Global Wind Oscillation:
      Notice how the Historic tornado outbreak marked a recent bottom in
      global AAM.  The reluctant tight spiral up featured further severe weather
      and a repetitive weather pattern that is leading to massive midwest flooding.
      Source: NOAA Earth Science Research Laboratory, Physical Sciences Division
           Where might the general weather pattern be headed here in NC and VA? The GWO is probably already in Phase 5.  Based on trends in the tropics I believe that phases 5, 6, and 8 will best describe the next 10-14 days.  See below how temperatures correlate to these phases.
      Therefore we can expect moderate to cool temperatures on average.  I am expecting the Phase 6 trough to bring storms on Thursday and a cool weekend.

      Sunday, May 8, 2011

      Concerns for this week, Severe Outbreak and Cold

      Sorry for the delay in getting the next entry.

      A couple of areas of concern for this week:
      1. Severe thunderstorm and tornado outbreak:  A strong cold front is expected to strengthen as it digs SE during the week.  Here in the southeast the biggest threat will be from southern VA through SC,  Right now it appears that the front passes through late Thursday.
      2. Weekend Cold:  More a nuisance than a problem.  As the trough digs into the east a substantial cold pool of air is expected to develop.  This will lead to substantially lower than normal temperatures and probably an unstable atmosphere.