Woohoo!  A much overdue update to the Personal Weather Station (PWS) project has been released!

http://www.pwsweather.com

Since 2000, HAMweather and WeatherForYou have helped bring the PWS community together by allowing users to post their observations to a central service with the ability to integrate this data into their HAMweather installations.  HAMweather and WeatherForYou have joined forces once again to improve the tools available for the PWS community, with the release of the PWSweather.com website.

PWSweather.com provides a great new feature set for PWS users in a fast, clean and ad free interface. Some of the new features include:

• Improved registration process
• Improved display of a stations latest observations and archived data:
    As seen for Station KORGRANT1 in Grants Pass, OR:
    http://www.pwsweather.com/obs/KORGRANT1.html

  

• New Google Maps Mashup to view and find other Personal Weather Stations.

  

The release of PWSweather.com is only the beginning, as  HAMweather and WeatherForYou are committed to continously expanding and improving PWSweather to bring additional features and tools to the PWS community.

The Storm Prediction Center (SPC) is forecasting a moderate risk for severe weather today and into tonight for portions of the Southern Plains and Southeast. Another tornado outbreak is possible along with large hail and damaging winds. The following is the public discussion released by the SPC this morning at 11:50 CDT:

TORNADOES LARGE HAIL AND DAMAGING WINDS OVER PARTS OF EASTERN
TEXAS NORTHERN AND WESTERN LOUISIANA AS WELL AS SOUTHERN AND EASTERN
ARKANSAS THIS AFTERNOON AND TONIGHT...

THE NWS STORM PREDICTION CENTER IN NORMAN OK IS FORECASTING THE
DEVELOPMENT OF TORNADOES...LARGE HAIL AND DAMAGING WINDS OVER PARTS
OF EASTERN TEXAS...NORTHERN AND WESTERN LOUISIANA AS WELL AS
SOUTHERN AND EASTERN ARKANSAS THIS AFTERNOON AND TONIGHT.

THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE

- EASTERN AND SOUTHERN ARKANSAS
- NORTHERN AND WESTERN LOUISIANA
- EASTERN TEXAS

ALSO...A THREAT FOR OTHER SEVERE THUNDERSTORMS ARE EXPECTED FROM
CENTRAL TEXAS EASTWARD ACROSS THE LOWER MISSISSIPPI VALLEY AND
NORTHWARD INTO THE WESTERN PORTIONS OF TENNESSEE AND KENTUCKY.

A POTENT UPPER LOW AND STRONG JET MAX WILL MOVE EAST ACROSS
TEXAS/LOUISIANA AND ARKANSAS LATER TODAY AND TONIGHT...WITH A
SURFACE LOW AND COLD FRONT SHIFTING FROM EASTERN TEXAS ACROSS THE
LOWER MISSISSIPPI VALLEY TONIGHT. AHEAD OF THIS FRONT...THE
COMBINATION OF A MOIST AIR MASS...DAYTIME HEATING AND COOLING ALOFT
WILL RESULT IN AN UNSTABLE ENVIRONMENT FAVORABLE FOR WIDESPREAD
SEVERE THUNDERSTORMS...ESPECIALLY FROM MID AFTERNOON THROUGH
MIDNIGHT. THE WIND SHEAR WILL BE QUITE STRONG...AND FAVOR
TORNADOES...SOME STRONG...ESPECIALLY ACROSS NORTHEAST TEXAS...
NORTHERN LOUISIANA AND ACROSS PORTIONS OF SOUTHERN AND EASTERN
ARKANSAS. ALTHOUGH TORNADOES ARE ALSO POSSIBLE ACROSS SOUTHEASTERN
TEXAS AND LOUISIANA...A SQUALL LINE IS EXPECTED TO DEVELOP AND MOVE
ACROSS THIS REGION LATE THIS AFTERNOON/EVENING...WITH DAMAGING
STRAIGHT-LINE WINDS MORE LIKELY.

STORMS WILL CONTINUE EASTWARD INTO MISSISSIPPI...WESTERN TENNESSEE
AND WESTERN KENTUCKY OVERNIGHT WITH A THREAT OF DAMAGING WINDS AND
ISOLATED TORNADOES.

THOSE IN THE THREATENED AREA ARE URGED TO REVIEW SEVERE WEATHER
SAFETY RULES AND TO LISTEN TO RADIO...TELEVISION...AND NOAA WEATHER
RADIO FOR POSSIBLE WATCHES...WARNINGS...AND STATEMENTS LATER TODAY.

A severe weather outbreak occurred across the Tennessee Valley, southern Appalachians and into central Georgia/South Carolina, starting Friday, March 14th and continuing into today. One supercell thunderstorm developed west of Atlanta, quickly intensified and drug a tornado directly across downtown Atlanta causing extensive damage to many structures (including high-rises). The following HAMrad II animation shows the storm as it moved through downtown Atlanta and finally weakening after passing to the east of the city. The National Weather Service reported that based on the damage investigation, this tornado was an EF-2 with winds up to 130 mph and a path of about 6 miles.

The following is the official NWS report regarding their damage investigation on the Atlanta tornado:

0938 PM     TORNADO          1 NW ATLANTA            33.77N 84.43W
03/14/2008  F2               FULTON             GA   EMERGENCY MNGR

            NWS DAMAGE SURVEY CONCLUDED AN EF2 TORNADO 6 MILES LONG
            AND 200 YARDS WIDE TUCHED DOWN AT SIMPSON AND BURBANK
            ROAD AT 938 PM. IT MOVED ACROSS DOWNTOWN ATLANTA AND CAME
            UP AT THE CORNER OF BRAEBURN AND JOSEPHINE ROAD IN
            WESTERN DEKALB COUNTY.

Earlier today additional supercell thunderstorms developed across the northern suburbs of Atlanta bringing additional storm damage in the form of very strong winds, large hail and even several tornadoes. Several moved close to the HW offices in Kennesaw, including the storm depicted in the following image which brought up to 3″ diameter hail and a possible tornado near Canton just to the north of our offices.

The following map shows the official NWS storm reports across Georgia since yesterday, the second of which only showing the tornadoes and/or funnel clouds that were reported (click for full-size image).

Expanding on the great success of our HAMrad I service, we have been busily working to create our upcoming HAMrad II service which is now in live beta testing.

http://mapcenter.hamweather.net/radar/ptype/latest/us.html

Some of the great new features of HAMrad II include:

• Greatly improved precipitation type maps.
• Higher resolutions providing for improved quality and details. The following sample image shows how closely related the topographical base map is with the actual precipitation type (rain in the lowlands versus snow in the higher elevations).
  
• Now more than 170 views with the addition of over 120 local views. Click through directly to many of the local views by hovering over the Continental US map and selecting the highlighted areas.
• Optional topographical or flat base maps.
• New capability for overlays which can be applied directly to the image or displayed via Javascript, including: warnings, counties, interstates, rivers, radar summaries and more.
• New radar imagery, including composite reflectivity, 1-hour precipitation totals, storm precipitation totals, vertically integrated liquid and echo tops.
• Animation options of 2, 6, 12 and 24 hours.
• Standard sizes now include 800×600.

As always, and especially during our beta period, we welcome comments and suggestions. No official go-live date has been set but will be determined by the beta testing period.

Is it going to be colder than normal? I’m going on vacation in June, what will the weather be like?
These are common questions that we are often asked. To help answer these questions, we are introducing the new climate area, accessible via:

http://climate.hamweather.com

The new climate area incorporates data from several sources into a user friendly and easily accessible format. Some of the great features of the climate area include:

• Records Events - View the records set over the past couple days, the past week or even a specific date from the past couple years. You can mouse over the map to view individual records or in tabular format below the map.
   
• Normals – HAMweather has created a collection of maps that detail the normal precipitation, highs, lows and mean temperatures for all 365 days of the year, as well as monthly and yearly summaries. Maps are available for the Continental US, 9 regional views, Alaska and Hawaii.One of my favorite maps from this set is the CONUS view of the yearly precipitation. This map allows you to easily depict the drier conditions east of the Rockies and the increased areas of precipitation in the southeast by the Gulf of Mexico.

  Another great feature of the Normals area and many of the other maps is the ability to click on a regional map to view a tooltip of the data near the location clicked on the map:
  
  In the tooltip you can click the “More Details” link to view the normals in tabular form, either a daily view for the month or a monthly view for the year.
   

• Temperature Change – The improved temperature change maps provide the change in temperature as compared to 24 hours ago, as well as 1 hour ago. Like most of the other regional views, clicking on the map will display more information for the location clicked:
  
  The southeast was definitely much cooler the morning of the Feb 27^th than it was the morning of Feb 26^th!
   
• Forecasted Departure from Normal Highs (and Lows) – As part of the short-term outlooks, these maps are providing the forecasted departure from the normal highs and lows for days 1 through 7.
  Here we can see the forecasted highs for the central plains on Feb 28^th, look to be above normal.
  
• Long Term Outlooks – This map set, based on data provided by the NOAA Climate Prediction Center, display the probabilities of the temperatures and precipitation being above or below normal for a specific time range. Available ranges include days 8-14, the next month and for the next year in three month intervals.

Upcoming HWClimate Service
Within the next couple of weeks, HAMweather will begin offering a HWClimate content service. With this service, you will be able to add custom branded map images and data to your websites, visual displays, mobile devices and more. More details to come.

Once the Northeastern storm exists stage right Friday night, a new storm begins affecting the West Coast on Saturday and continuing through Sunday, bringing heavy snows once again to the mountains with heavy rainfall across Oregon and California. The storm center will make landfall farther south than previous systems which will give western Washington and British Columbia a break from the continuous rain and snows of the last week. The country east of the Rockies will get a much needed break for most of the weekend before another storm system begins taking shape later Sunday afternoon and evening across the Southern Plains. As milder Pacific air continues to flood the country next week, many areas will see rain with this next system with the exception being the usual areas where it wants to snow this year–the northern Plains and far northern parts of New England. Severe weather will once again be possible across the Gulf Coast states as the accompanying cold front scours out high levels of moisture engulfing the region from the Gulf and Pacific.

The development of HAMweather 4 (HW4) is going quite smoothly, and several new features have been integrated into its core code base. One such feature is the ability to cache the output of a request so that future requests within a set cache time can simply output the cached page without having to load and process the various modules and data. For high volume access this feature can save a lot of time and resources. HAMweather has been using this feature on our Tropics Center (which uses HW4 alpha code) with great success. Thus, HW3cacher was developed so that HW3 users can benefit from the increase in efficiency as well until HW4 is released.

The HW3cacher script is used as a front end to the HW3php script. When installed, the script will cache HW output on the original request. Then on future requests for the same URL the data in the cache will be used and the HW3 script will not be loaded. If the cached output has expired, then HW3 will be loaded and the output regenerated and cached once more.

During our testing a standard HW3php request for a local forecast used up to 4MB of memory and 1.3 seconds to fetch, parse and output the data. When using HW3cacher, once cached subsequent requests for the same URL used only 0.25-0.5MB of memory and only took 0.02 seconds to output to the web browser. This data shows that subsequent requests for the same URL use up to 94% less memory and are outputted up to 65 times faster than calling HW3 directly. Note that each individual user/server will experience different results based on the available server resources, network speeds and server specifications.

While the HW3cacher script is primarily designed for high volume websites that receive a high number of HW3 requests for the same data within a short amount of time, other sites can benefit from HW3cacher as well. For example, a site can benefit from HW3cacher if weather data is included on the home page via calls to HW3php or when inclement weather occurs in a location and the site receives an abnormally larger number of requests for a specific local forecast etc.

Downloads Via Plugins Area: http://support.hamweather.com/dload.php?action=file&file_id=169

Documentation:
HTML: http://www.hamweather.com/hw3/docs/hw3php/HW3Cacher_php/
PDF: http://www.hamweather.com/hw3/docs/hw3php/HW3Cacher_php/HW3Cacher_php.pdf

Support: http://support.hamweather.com

Not only will a major winter storm be sweeping across the country this weekend, but another very strong storm will slam into the Pacific Northwest by the end of the weekend. Heavy snows will be likely across the northern tier of the US, especially northern sections of the Midwest and Northeast. This system will quickly intensify once it reaches the coast of New England and will threaten to bring blizzard conditions across portions of Maine, Vermont and New Hampshire on Monday and Tuesday. Meanwhile the storm system moving into the Pacific Northwest will bring widespread snow across all of Washington and northern Oregon as modified arctic air filters south central Canada through the Fraser Valley region. However, as the storm approaches the coast on Sunday it will bring very strong southerly winds to the region, increasing temperatures at the surface and upper levels. Precipitation that began as snow will transition to very heavy rain on Sunday and into Monday with much higher snow levels.

The new HAMvid Basic Package allows you to add select HAMvid branded feeds to your website for free! Now you can easily add the HAMvid weather content delivery system to your site.

The select HAMvid feeds available in the HAMvid Basic package currently include:

National Current Conditions - Includes current conditions of the Continental US displayed on animated maps.
US National Summary - Provides current conditions and forecasts for major cities through our the US.
Local Weather Outlook - Displays the local current conditions, shortterm outlook and 7 day forecast for US zip codes.

Integration into a web page is as simple as adding a single <script> tag to the web page or HAMweather template where you would like the HAMvid player to be displayed.

Start using HAMvid basic today and enjoy the benefits of an improved web visitor experience and loyalty.

A strong cold front is sweeping across the country and will continue to do so through the upcoming holiday. The most dramatic changes will occur across the Central and Southern Plains where temperatures will be 30-40 degrees colder on Wednesday than today. Rain and thunderstorms will become more widespread Wednesday along and ahead of the front and will continue into Thanksgiving day from the Gulf Coast into New England. Some of the moisture will overrun the cold front which will bring a chance of snow showers behind it from the Central Plains northeastward into the Great Lakes region. Overall snow amounts will not be extremely impressive behind the front and will only amount to a few inches in most locations, though amounts can be locally heavy where more moisture is available in the colder airmass. Light snow showers will continue across the Front Range of the Rockies in Colorado and southern Wyoming due to upsloping conditions behind the front.

The primary travel headache on Wednesday will be the persistent wet weather and storms along the frontal boundary. For the major cities across the Northeast, this storm will bring a steady rain as warm, moist air is pulled north across the region. Rain will be mixed with or change over to snow across upstate New York and northern Maine. Expect airport delays in many hubs east of the Rockies on Wednesday, especially for Chicago, Kansas City, Denver and Saint Louis where there is a greater threat of accumulating snowfall.

Keep up to date with the latest weather conditions, advisories and airport delays for the following major US cities likely to be affected by this system:

Atlanta, GA
Boston, MA
Chicago, IL
Denver, CO
Kansas City, MO
New York, NY
Philadelphia, PA
Saint Louis, MO