Tuesday, March 27, 2012

3 comments:
The Invisible Weather Danger...continues
 Advisor Brad Lear

9 April 2012

Again today, Red Flag Warnings are posted. 
This time in 22 States.


Red Flags, Monday, 9 April
 See the Saturday and Sunday posts below for Red Flag info and cautions.



The Invisible Weather Danger
 Advisor Brad Lear

8 April 2012

Again today, as many celebrate Easter, 17 States are under posted
Red Flag Warnings.
As discussed yesterday, Red Flag Warnings indicate that critical fire weather conditions are, or soon will be, occurring.  Those of you who follow the weather have come to associate Fire Dangers in the drought strickren areas (NOAA SITE) of our country, like our Southwest.  While this certainly is true, residents of heavily populated areas, like the Mid-Atlantic, are not used to fire-related weather statements.  High winds coupled with low humidity and low fire fuel moisture can lead to surprise flare-ups if the area is ignited.  Caution must therefore be taken in the areas shown in Red below:
Red Flag Warnings- Easter Sunday

 People are cautioned to be aware of the obvious, like open burning, BBQ's, campfires, tossed cigarettes, or any fireworks, but there are other dangers that people often overlook.  Hot exhaust systems of motor vehicles, ATV's, tractors, or even gasoline-powered tools can produce enough heat to ignite dry vegetation.  Windblown sparks or embers from a carefully controlled fire can also create conflagrations.
Enjoy your Sunday, your cookout, your campfire...but do so with a serious care about The Invisible Weather Danger.
More Information at NWS Fire Weather



Fire is a Concern for Today
 Advisor Brad Lear

7 April 2012

On this first full day of Passover, 16 States are under posted Red Flag Warnings.
The NWS defines Red Flag criteria: whenever a geographical area has been in a dry spell for a week or two, or for a shorter period, if before spring green-up or after fall color...and the following forecast weather parameters are forecasted to be met:
1) a sustained wind average 15 mph or greater
2) relative humidity less than or equal to 25 percent and
3) a temperature of greater than 75 degrees F.
... A Fire Weather Watch may be issued prior to the Red Flag Warning...
Red Flag Warnings in...Red
 The Good News is that for Easter much of the Country will have nice weather.  The exceptions being thew SW (rain and thunderstorms), the Upper Ohio Valley and the NE (rain), and Northern New England (snow!).

Easter Sunday
   Happy Holiday Weekend to All!



    


TGIF and Happy Good Friday.
Meteorologist Shundra Stewart
6 April 2012
As we head into the Easter weekend, some states could see some snow and cold temperatures. Some could see rain while others will see nice dry weather for Good Friday.  Let's take a look across the US.
Saturday
Winter still in the Northwest?  It looks like Mother Nature has forgotten what season it is in the Northwest. Parts of the northwest will see rain and even some snow mixed in. 
South: Texas, Oklahoma and Arkansas and Mississippi will finally dry out after days of heavy rain and severe weather, but will continue to see above normal temperatures for this time of the year.  A low pressure system off the coast of the Carolinas will be rain to Georgia, Florida, The Carolinas and Virginia and should start to dry out for the weekend.
Great Plains: Party cloudy skies with a few thunderstorms popping up in the afternoon.
MS/OH Valley: High pressure in Canada will bring nice dry weather to the MS/Oh Valley.
Mid-Atlantic and Northeast: High pressure will be dominating the northeast bringing beautiful weather.  Temperatures will be between the 50s to 60s.
Mountain States:  A cold front will be pushing through Idaho, Montana, and Utah bringing some snow showers.
Sunday AM

The Cause of Wind
 Jolene Wagner
5 April 2012

          Have you ever wondered what makes the wind blow…or not blow? Have you ever wondered why the wind blows at different speeds? Well, the answer lies in a rather simple concept. The sun in the center of our galaxy that the Earth revolves around is the culprit.
          Have you ever been in a warm room when a door to an adjacent cold room opens? If you have been in a similar situation as this you can feel the cold air rush into the warm room. Likewise the warm air rushes into the cold room. This event is caused to create equilibrium between both rooms (or in other words constant temperature). A similar situation exists on a global scale.
















The sun’s solar energy heats the surface of the earth. The amount of heating depends upon the angle of the sun with reference to the earth (see FIGURE 1 (above). Already this angle difference will cause surface temperatures to vary from location to location also known as temperature gradient. The atmosphere then acts just like the two rooms in the earlier example. Since the sun never stops giving off radiation and the earth never stops turning, there will always be a temperature gradient somewhere.
When the temperature gradient (difference in temperature) between two locations is small the resulting wind will be at a slow speed. When the temperature gradient between two locations is large the resulting wind will be at a high speed. A temperature gradient can be found within just a short distance between two locations and it is possible that there is no temperature gradient. However, the distance between the two locations must be small just because of the fact that the Earth’s surface does not heat evenly.
Once the wind is created the state of equilibrium is broken and weather systems and events begin to develop to strive to restore the equilibrium. It is, however, at this point that the wind is no longer simple and many other factors in the atmosphere come into play such as topography and ground cover; see FIGURE 2 below.
Works Cited



Figure 2: “Fly High For Smoother Rides” http://overtheairwaves.com/vol5-6final.html


TORNADOES RIP THROUGH DALLAS-FORT WORTH YESTERDAY  4 April    (see yesterday's article below)

NWS- Yesterday, over 200 reports of severe weather were received including 18 tornado reports from northeastern Texas. Wind and hail reports were scattered over eastern Texas, Louisiana, Mississippi, Arkansas, Oklahoma, Florida, Georgia, Tennessee, Kentucky, North Carolina and South Carolina. 

Source- Texas Foot's Forecast follower Stacy
(CNN) -- Rescuers plan to search the Dallas area again Wednesday for anyone trapped after violent tornadoes flattened homes, sucked up tractor-trailers and sent debris swirling in the air.
Between six and 13 tornadoes may have touched down in north Texas on Tuesday, the National Weather Service in Dallas-Fort Worth said. The number is an estimate pending a survey and damage assessment.
There are no reports of deaths so far, according to the mayors of Dallas and Arlington.
Three people were taken to a hospital in Arlington and at least 150 homes were destroyed, said Mayor Robert Cluck.

This article was late...and shortened...due to this editor's travel, and an internet problem at his hotel.  Apologies



Weather 101 – Coming to terms with the new tornado warning terminology

H. Michael Mogil

A contribution to National Weather Examiner (4/3/12); this version a lead story for Foot’s Forecast


The National Weather Service (NWS) is testing the way it alerts the media and emergency managers about imminent tornado risk.  The change is being foisted because so many people died last year at the hands of several major tornado events and outbreaks, especially Joplin, MO.  Five NWS offices will participate in the test (Fig. 1)


However, with warnings easily available on the Internet and social media, the new advice wording will quickly be in the hands of everyone.  From my initial assessment of what is proposed for this 6-month test, I am very concerned about unintended consequences that could actually lead to a further decrease in the desired public response.

Let me explain.

Although the 2011 death toll reached 550 (a tragic number under any circumstances), this was the highest annual total since 1936 (552 fatalities).  Let’s be honest; a lot of strong tornadoes struck larger cities in 2011.  When normalized for population (Fig. 2), 1936 showed 4.3 deaths per 1 million people, while 2011 showed only 1.8 deaths per 1 million.  The large numbers in 2011 could easily be viewed as a single-year spike in an otherwise effective (albeit not perfect) tornado warning system.
 
Anyone involved in weather safety recognizes that far too many tornado warnings sound alike.  Part of the issue is that most are based on “Doppler radar indicates.”  Many of these circulations remain aloft or may become brief, weak tornado touchdowns.

Hence, the issue became how to tell people that a Joplin, MO event was unfolding rather than just a “run of the mill” situation.

Instead of working to hone how Doppler warnings are issued (i.e., reduce the excessive false alarm rate), the meteorological approach, the NWS has taken a social science approach and tried to push this into a geographical setting. 

You can read the complete story at … examiner.com


© 2012 H. Michael Mogil

March Madness: 
Fire, Wind, Lightning, and Ice? 

5:30 PM EDT 3/27/12  (Forecaster Mike) This week is proving that we don't need a big storm to have crazy weather from coast to coast! It's almost April, but severe weather is relatively quiet, and winter has been in the backseat all winter long. Still, the big changes around the country are making for some major weather headlines!

Today's featured zone in Facebook has been the Foot's Forecast | Potomac Ridge & Valley because of the cold temperatures which made a return across the region early Tuesday morning.

Fire - There are two key areas of fire danger around the country, indicated by the pink areas on the map. Red Flag Warnings have been issued for much of New Mexico, Colorado, Nebraska, and bordering states, but another unexpected area also has some fire danger: New York City! For NYC this is because of the strong N winds digging in the trough. Further west, these warnings are because of a potent S to W wind coming dry off the mountains. 

Wind - While much of the fire danger is because of the wind, I thought it deserved its own headline because of the huge portion of the Plains States with High Wind Warnings (Gold/Brown) or Wind Advisories (Light Brown) without Red Flag Warnings. Strong winds in Colorado on Monday will shift north into Montana, and N/S Dakota for Tuesday before pulling out of the plains Wednesday. 

Lightning - The storm threat is not very large, but still must be mentioned. The primary threat for severe weather on Tuesday is across N Missouri, N Illinois, SE Iowa, and S Wisconsin, with a few rumbles of thunder elsewhere around the Great Lakes and Plains. 

Ice - While winter was a no show for most of the actual winter season, the extended early spring is taking a break for Freeze Warnings (Blue) across a huge portion of the Mid-Atlantic, Great Lakes, and Ohio Valley. This will make a danger for the early planters across the region with the freeze risking some of the plant life.