Severe Weather - SkyWarn:


 
Knots to MPH Conversion Chart

 
5 Knots = 5.8 MPH
10 Knots = 11.5 MPH
15 Knots = 17.3 MPH
20 Knots = 23.0 MPH
25 Knots = 28.8 MPH
30 Knots = 34.6 MPH
35 Knots = 40.3 MPH
40 Knots = 46.1 MPH
45 Knots = 51.8 MPH
50 Knots = 57.6 MPH
55 Knots = 63.4 MPH
60 Knots = 69.1 MPH
65 Knots = 74.9 MPH
70 Knots = 80.6 MPH
75 Knots = 86.4 MPH
80 Knots = 92.2 MPH
85 Knots = 97.9 MPH
90 Knots = 103.7 MPH
95 Knots = 109.4 MPH
100 Knots = 115.2 MPH
105 Knots = 121.0 MPH
110 Knots = 126.7 MPH
115 Knots = 132.5 MPH
120 Knots = 138.2 MPH
125 Knots = 144.0 MPH
130 Knots = 149.8 MPH
135 Knots = 155.5 MPH
140 Knots = 161.3 MPH
145 Knots = 167.0 MPH
150 Knots = 172.8 MPH
Beaufort Wind Scale
 
Beaufort Scale
Speed MPH
Description
0
below 1
Calm: smoke rises vertically
1
1-3
Light Air: Smoke drifts; leaves barely move
2
4-7
Light Breeze: Leaves rustle; wind can be felt
3
8-12
Gentle Breeze: Leaves and twigs move; debris and dust raised from ground
4
13 -18
Moderate Breeze: Small branches move; debris and dust raised from ground
5
19 - 24
Fresh Breeze: Small trees sway and large branches in motion; dust clouds raised
6
25 - 31
Strong Breeze: Large branches continuously move; wind whistles; difficulty using and umbrella
7
32 - 38
Moderate Gale: Large trees sway; difficulty walking
8
39 - 46
Fresh Gale: Twigs and small branches break; walking very difficult
9
47 - 54
Strong Gale: Slight damage to buildings; shingles blow off roof
10
55 - 63
Whole Gale: Large trees uprooted; heavy damage to buildings
11
64 - 72
Storm: Widespread damage
12
above 73
Hurricane: Severe damage and destruction

DHS is mandating that by 30 Sept 2006, all individuals who interact with any government agency or organizations that interact with a government agency and receive federal funding (including federal, state, territorial, local, tribal, private, and NGOs) must have two federal certifications or lose federal funding.  

This includes volunteers and spotters, and affects EMAs, ESDAs, Red Cross most but NWS and anyone else as well.  A list of all individuals involved with respective entities must be maintained with their certifications,
which DHS will check (probably a 10% spot check or something similar). 

This must be done before any transaction occurs, in the case of spotting, making a report.  I leave the implications for you all. 

The following are what is required:
* "ICS-100 Introduction to ICS"
* "IS-700 NIMS: An Introduction"


Fujita Scale to be revised

ATLANTA --The government is changing how it categorizes tornadoes after finding that it doesn't take 300 mph winds to disintegrate homes and turn cars into missiles -- a 200 mph twister can do just as much damage.

The National Weather Service said Thursday it had changed the Fujita Scale, a three-decade- old system of ranking a tornado's strength, to align wind speeds more closely with actual damage.

"It was apparent that many of the speeds used in the estimates were too large, said Joe Schaefer, director of the service's Storm Prediction Center. "The scale guiding wind speeds wasn't in tune with reality."

The change was introduced at the American Meteorological Society meeting in Atlanta. However, the new system will not fully go into effect until February 2007, giving weather scientists time to adjust to it.

Under the old system, created in 1971, an F-5 tornado -- considered the most powerful of tornadoes -- was capable of destroying a typical frame house, with wind speeds estimated at 261 mph to 318 mph. Since then, engineering studies have shown that much slower winds could cause the same damage.

"It doesn't take 300 mph winds to totally destroy an ordinary frame house," said Greg Forbes, a former member of Penn State's meteorology department who studied tornadoes under Theodore Fujita, the University of Chicago professor who created the scale. Forbes now works for The Weather Channel.

Under the new system, an F-5 tornado -- which can disintegrate a strong frame house after lifting it off its foundation or badly damage reinforced concrete buildings -- has wind speeds of at least 200 mph.

Because the new system still uses actual tornado damage to estimate wind speeds, officials said it is not likely that the new system's lower wind speed rating for the F-5 tornado will result in more tornadoes being classified with the nation's top tornado rating.

The old system rated tornadoes only based on damage to homes. The new system classifies tornadoes based on damage to 28 other types of structures, including trees, mobile homes and other types of buildings.

"If a tornado went over a row of trees and didn't hit a house, there was no way to estimate the scale," Schaefer said.

 

 

NOAA NATIONAL WEATHER SERVICE’S IMPROVED

TORNADO RATING SYSTEM NOW OPERATIONAL

NOAA’s National Weather Service fully implemented the Enhanced Fujita (EF) on Thursday , February 1, 2007, to rate tornadoes, replacing the original Fujita Scale. The EF scale will continue to rate tornadoes on a scale from zero to five, but ranges in wind speed will be more accurate with the improved rating scale.

"The EF scale provides more detailed guidelines that will allow the National Weather Service to more accurately rate tornadoes that strike the ,” said Brig. Gen. David L. Johnson, U.S. Air Force (Ret.), director of NOAA’s National Weather Service. “The EF scale still estimates wind speeds but more precisely takes into account the materials affected and the construction of the structures damaged by the tornado."

The Fujita scale was developed in 1971 by T. Theodore Fujita, Ph.D., to rate tornadoes and estimate associated wind speed based on the damage they cause. The EF scale refines and improves the original scale. It was developed by the Texas Tech University Wind Science and Engineering Research Center , along with a forum of wind engineers, universities, private companies, government organizations, private sector meteorologists, and NOAA meteorologists from across the country.

Limitations of the original Fujita scale may have led to inconsistent ratings, including possible overestimates of associated wind speeds. The EF scale incorporates more damage indicators and degrees of damage than the original Fujita scale, allowing more detailed analysis and better correlation between damage and wind speed. The original Fujita scale historical data base will not change. An F5 tornado rated years ago is still an F5, but the wind speed associated with the tornado may have been somewhat less than previously estimated. A correlation between the original Fujita scale and the EF scale has been developed. This makes it possible to express ratings in terms of one scale to the other, preserving the historical database.

The Texas Tech University Wind Science and Engineering (WISE) Center, along with a forum of nationally renowned meteorologists and wind engineers from across the country, developed the EF Scale. The forum began their work in March of 2001 and included participants from several government organizations, universities, and private companies.

The EF Scale will still rate tornado categories from zero to five, but the ranges of wind speed in each category are now more accurate.  The EF Scale takes into account more variables than the original F Scale did when assigning a wind speed rating to a tornado.  The EF Scale incorporates 28 damage indicators (DIs) such as building type, structures, and trees.  For each damage indicator, there are 8 degrees of damage (DOD) ranging from the beginning of visible damage to complete destruction of the damage indicator.  The original F Scale did not take these details into account.

 


Original F Scale
 

Enhanced F Scale
 
Rating 3 second gust (mph) Rating 3 second gust speed (mph)
F0 45-78 EF0 65-85
F1 79-117 EF1 86-110
F2 118-161 EF2 111-135
F3 162-209 EF3 136-165
F4 210-261 EF4 166-200
F5 262-317 EF5 >200

WeatherTAP

ILCHASE WEBSITE / Storm Chasers of America

W5DG's Stormchaser-MARS-Ham Homepage

N9KYQ's Weather Page / VORTEX ST Louis, MO

Central Illinois SkyWarn Site Home Page

Illinois WX IWIN Data / I Want you for SkyWarn

US Advanced Warning Storm Spotters - Chasers

National SKYWARN Page / St. Clair County IL ARES-RACES

The Fujita Scale of Tornado Intensity / Storm Spotter's Reference Guide

Computerized Hurricane Tracking Chart / BOLINGBROOK SKYWARN

HAMWEATHER / ECHOLINK VoIP SKYWARN/HURRICANE NET

Convection Obsession


Illinois road conditions ....... 1-800-425-4368

Missouri road conditions  ..... 1-800-222-6400

Weather for Alton (IL)

Current Weather - St. Louis, Lambert International Airport

NOAA / National Weather Service / NWS - ST. Louis, MO

321Weather.Com / The Weather Channel / UCAR Weather Page


 

SPC Activity Chart
Showing a 1 hour radar loop, the current Day1 convective outlook, and all active watches/warnings

(updated every 15 min.) - click on the image to go to the SPC Hourly Mesoscale Analysis site


QRZ Ham Database / ARRL / National RACES Page


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Last revised: 13 May 2008.