Tuesday, May 31, 2011

Flu update: mostly in Southern Hemisphere

No more (well, almost no more) flu in Northern Hemisphere, but the Southern Hemisphere is cooling down. 
Flu activity is low throughout  the US and Canada. The only country in Europe reporting moderate flu levels is Armenia. Google trends shows slightly increased activity in Norway, but this may be an artifact of searches. 

According to the Pan American Health Organization (PAHO)/WHO, respiratory illness activity in Chile and Argentina was increasing between Week 12 (March 21-27) and Week 18 (May 2-8). However, almost all of this activity was attributed to non-influenza viruses. Google trends predicts increased activity in Brazil.

Influenza activity was low in tropical regions, Australia and New Zealand. According to the Australia Department of Health and Ageing, the number of laboratory-confirmed influenza cases decreased in recent weeks, although it remains higher than during the same period in 2010.

South Africa National Institute for Communicable Diseases reported low influenza activity as of May 1. According to Google flu trends, however, flu levels increased in the end of May. 

Saturday, May 14, 2011

How cold is cold enough? How humid is really humid?

How cold is too cold? How windy is really windy? It depends on where you live. If you are from the South you will need a blanket if it's below 50 degrees Fahrenheit (10 °C). If you are accustomed to cold weather, 70 (20+ C) is too hot.  For residents of Oymyakon in Eastern Siberia with average winter temperature of -49°F (−45°C) and record low -90°F (-67.7°C), -30°F (−34.4°C)  is pretty pleasant. If you live in Cold Bay, Alaska, 15 miles per hour is not really windy, while in Oak Ridge, Tennessee average wind blows at only 4 miles per hour.

In general,
110 Fahrenheit is considered dangerously hot
100° F may be hazardous
90° F is uncomfortably hot
80-40 is considered a relatively comfortable range - the average surface temperature of the Earth is 59° F
30° F is uncomfortably cold
15° F is very cold (although for avid runners cold is below 10 F with winds over 15 mph)
0° F is bitter cold with significant risk of frostbite

But let's take a closer look at the world's climate, mostly defined by long-term (30 years) patterns in temperature and precipitation:

Purple regions (A) in this map are hot and rainy year around. Orange areas (B) are dry with little rain and a large range of daily temperatures. Green areas are two-season climates with warm, dry summers and cool, wet winters. Blue regions (C) have continental climates with distinct four seasons and moderate precipitation. E denote cold areas with permanent ice and tundra. Only about four out of twelve months temperature in these areas raises above freezing.

3 most windy cities in US (seasonal wind averages are given in miles per hour):
City                JAN    FEB    MAR    APR    MAY    JUN    JUL    AUG    SEP    OCT    NOV    DEC    ANN
MT. WASHINGTON, NH  46.1   44.3   41.4   35.8   29.7   27.3   25.3   24.7   28.8   33.8   39.5   44.5   35.1
ST. PAUL ISLAND, AK 19.9   20.0   18.8   17.4   14.9   13.6   12.1   13.7   15.4   17.4   20.0   20.1   16.9
COLD BAY,AK         17.5   17.9   17.4   17.5   16.2   15.8   15.6   16.2   16.2   16.6   17.5   17.5   16.8

10 most humid cities in US:
No. 10: Olympia, WA
Average relative humidity: 78%
Average annual precipitation days: 163
Highest precipitation month: November
No. 9: Houston, TX
Average relative humidity: 78%
Average annual precipitation days: 105
Highest precipitation month: June
No. 8: Brownsville, TX
Average relative humidity: 78%
Average annual precipitation days: 73
Highest precipitation month: September
No. 7: Victoria, TX
Average relative humidity: 78.5%
Average annual precipitation days: 91
Highest precipitation month: May

Average relative humidity: 78.5%
Average annual precipitation days: 77
Highest precipitation month: September
Average relative humidity: 79.5%
Average annual precipitation days: 104
Highest precipitation month: June
Average relative humidity: 78.5%
Average annual precipitation days: 77
Highest precipitation month: September
Average relative humidity: 81%
Average annual precipitation days: 193
Highest precipitation month: November
Average relative humidity: 83%
Average annual precipitation days: 209
Highest precipitation month: November
No. 1: Quillayute, WA
Average relative humidity: 83.5%
Average annual precipitation days: 209
Highest precipitation month: November 

Highest Average Annual Precipitation Extremes in the World

Continent Highest
Place Elevation

South America 523.6 * Lloro, Colombia 520 29

Asia 467.4 * Mawsynram, India 4597 38

Oceania 460.0 * Mt. Waialeale, Kauai, HI 5148 30

Africa 405.0 Debundscha, Cameroon 30 32

South America 354.0  Quibdo, Colombia 120 16

Australia 340.0 Bellenden Ker, Queensland 5102 9

North America 256.0 Henderson Lake, British Colombia 12 14

Europe 183.0 Crkvica, Bosnia-Hercegovina 3337 22
* The value given is continent's highest and possibly the world's depending on measurement practices, procedures and period of record variations.  

Saturday, May 7, 2011

Allergy Seasons in Alaska

Internet  offers many allergy resources for US States. Examples are pollen.com providing allergy forecasts for US zip codes and American Academy of Allergy sources of allergy levels reported by certified counting stations. Weather.com features pollen maps too.  Neither of these sites, however, tells anything about Alaska and Hawaii.

Actually Alaska's Aerobiology is similar to Northern Europe, with some tree patterns resembling northern states of US. Pollination of poplar  - food for honey bees - starts in April - as in Michigan. Birch is very high in May - as in Russia and Scandinavia. Grass is active in June and July. A core pollen season of prophylactic and clinical urgency in Fairbanks and Anchorage is defined from May 10 to June 5.

You may want to visit Anchorage Daily news site  and Anchorage Pollen and Mold Reporting or Fairbanks area report to find today' allergy information for Alaska, or check Dr. Anderson's calendar below.  It is based on the observations made for six seasons: 1982-1987, from three sample locations in Fairbanks area, but represents a good prototype for other parts of Alaska.

This pollen calendar shows the range of possible atmospheric pollen concentrations for late April through July, assuming the weather is relatively warm, dry, and breezy.
pollen calendar
Reference: James H. Anderson, MLIS, PhD, Institute of Arctic Biology and BioSciences Library, University of Alaska Fairbanks