URGENT – IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 19
NWS STORM PREDICTION CENTER NORMAN OK
810 AM CST WED MAR 10 2010

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

 NORTHERN AND CENTRAL TEXAS

EFFECTIVE THIS WEDNESDAY MORNING AND AFTERNOON FROM 810 AM UNTIL
300 PM CST.

HAIL TO 1 INCH IN DIAMETER…THUNDERSTORM WIND GUSTS TO 70
MPH…AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 75
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 15 MILES SOUTHWEST
OF STEPHENVILLE TEXAS TO 65 MILES NORTHEAST OF CORSICANA TEXAS.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU9).

REMEMBER…A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

DISCUSSION…TSTMS HAVE FORMED IN THE PAST HOUR OVER NW TX…ALONG
LEADING EDGE OF STRONG FORCING FOR ASCENT ASSOCIATED WITH ERN NM UPR
VORT.  AS UPR VORT CONTINUES ENEWD…AND BOUNDARY LAYER WARMS AND
MOISTENS AHEAD OF IT…STORMS MAY BUILD SWD INTO CNTRL TX…AND
POSSIBLY NWD TO THE RED RVR.  POTENTIAL MAY DEVELOP FOR SVR SFC
WINDS AND HAIL AS 700 MB FLOW INCREASES TO AOA 50 KTS.

AVIATION…A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.
A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. MEAN STORM MOTION
VECTOR 25050.

…CORFIDI

Another batch of thunderstorms is set to pass through on Wednesday, with severe storms possible. Thunderstorms are likely anywhere from I-35 eastward on Wednesday afternoon, as a dryline slowly moves eastward. This dryline will act as a focus for storm development throughout the afternoon hours. The dryline is expected to stall out across the metroplex just east of I-35, and thunderstorms will develop along this boundary, and just to the east. This means areas like western Tarrant county may not receive any storms, while Collin and eastern Dallas counties could become inundated with heavy rains, winds, and hail. The highest risk of severe storms will exist over much of Arkansas on Wednesday, but severe storm chances stretch from the Gulf Coast, through southern Iowa. Tornado risk across Arkansas will be quite notable on Wednesday, and any parties in this area would need to pay attention to weather forecasts. For north Texas, tornado risks are much lower at this time, but if this changes I will send out an update.

Wednesday brings an elevated fire danger to the western parts of the region, due to very dry air and high winds.

Lastly in support of our countries retail shopping industry, the United States government has decided that this Sunday March 14, we will shift our clocks ahead one hour and become Central Daylight Time (GMT -5). The shift to Daylight Slavings Time (did i say that wrong?) is also a great time to check batteries in your weather radio! I suggest activating it to make sure it still has a signal as well. Since we are now entering our severe weather season, this would be a great precaution to take!

As always, if any notable forecast changes occur then I will do my best to send some updates.

Only one tornado recorded across the country in February 2010… the year is off to a slow start.
http://www.norman.noaa.gov/2010/03/no-tornadoes-in-february-2010/

Winter 2010 North Texas Thunderbolt Newsletter by the Fort Worth NWS, including a mention of the 10th anniversary of the Downtown Fort Worth March 28, 2000 tornado.
http://www.srh.noaa.gov/images/fwd/pdf/ThunderboldWinter2010.pdf

New GOES satellite launches successfully.
http://www.noaanews.noaa.gov/stories2010/20100304_satellite.html

Snowfall for our region will begin around 3am, and last through until 6pm. Temperatures will sit near or at freezing, so accumulations will be light to moderate. Icing will be possible on bridges during the day, while well traveled roadways may not be too adversely affected. Temperatures overnight will reach the high 20s so icing on bridges and untraveled roadways will become likely and hinder travel for Wednesday morning. Temps for Wednesday will reach the mid 40s so accumulations will likely melt clear away.

Some additional things to mention here however… I'm sure alot of you have noticed that this season's snowfall forecasts have been somewhat inaccurate. December 24th's forecast was 1-2 inches, with 3.0 inches actually falling; February 11's forecast was less than 1 inch only 24 hours before the snow began falling, with the end result being 12.5 inches. So, take snowfall estimates with a grain of salt as they tend to be subject to huge errors, and anticipate the worst.

Secondly, DFW airport's winter season snowfall record could easily be broken with this Tuesday's snowfall event. Currently the 2009-2010 season sits at 15.7 inches of snowfall total placing us in the number 2 spot. With just an additional 2.0 inches of snow we would become the snowiest year in Dallas' history!

Finally I will close with a comment from the most recent forecast discussion provided by the National Weather Service: EL NINO WINTERS…YOU GOTTA LOVE THEM.

Thursday’s snowfall has brought our seasonal snowfall total to 14.4 inches, the 3rd snowiest winter on record for DFW. Had there been no other snowfall events this entire season, our winter would have still made the top five snowiest, wow! Below are snowfall totals reported as of 11:30pm 2/11/10.

The impacts from this snowfall will be felt quite heavily the morning of Friday February 12th with heavy snowfall accumulations on area roads, plus icing on roadways and bridges. Afternoon temperatures for Friday have been revised downward to 38 degrees. This means snow will melt significantly but not all of it will melt before re-freezing overnight through Saturday. Expect icing conditions Saturday morning as well. Saturday high temps will reach the 50s and any remaining snow will melt off.

Additionally, I walked around and snapped some great pictures with my camera this evening. I have attached the updated gallery below.

[Show as slideshow]

[View with PicLens]

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Public Information Statement issued by the National Weather Service as of Midnight 2/12/10:

...Snow event one for the record books...

At midnight...dfw Airport had recorded 11.2 inches of snow today.
This breaks the previous daily record for February 11 of 1.4 inches
set in 1988. This also breaks the previous 24-hour record for
February...7.5 inches on February 17, 1978 and February 25, 1924.

This is the greatest calendar-day snowfall total on record for
Dallas/Fort Worth. The previous record was 7.8 inches on January 15,
1964 and January 14, 1917.

This brings the seasonal snowfall total to 14.4 inches...which is
the 3rd highest seasonal total on record for Dallas/Fort Worth. This
is the snowiest winter in 32 seasons (since 1977-1978).

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Dallas/Fort Worth - snowiest seasons

   1   17.6   1977-78
   2   15.3   1963-64
   3   14.4   2009-10*
   4   13.5   1923-24
   5   10.4   1976-77
   6    9.5   1909-10
   7    9.2   1916-17
   8    8.8   1947-48
   9    8.1   1937-38
  10    7.3   1965-66
        7.3   1941-42

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Dallas/Fort Worth - most snow in February

   1   13.5   1978
   2   11.2   2010*
   3    7.5   1924

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Dallas/Fort Worth - greatest 24-hour snowfall totals

   1   12.1   January 15-16, 1964
   2   11.2   February 12, 2010*
   3    8.2   January 14-15, 1917
   4    7.5   February 17, 1978
        7.5   February 25, 1924
   6    6.0   March 13, 1924
   7    5.5   December 9, 1898
   8    5.0   November 22, 1937
        5.0   January 5, 1910
  10    4.7   November 13, 1976

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...Snow event one for the record books...

At 7 PM...dfw Airport had recorded 7.9 inches of snow today. This
breaks the previous daily record for February 11 of 1.4 inches set
in 1988. This also breaks the previous 24-hour record for
February...7.5 inches on February 17, 1978 and February 25, 1924.

This is the greatest calendar-day snowfall total on record for
Dallas/Fort Worth. The previous record was 7.8 inches on January 15,
1964 and January 14, 1917.

This brings the seasonal snowfall total to 11.1 inches...which is
the 4th highest seasonal total on record for Dallas/Fort Worth. This
is the snowiest winter in 32 seasons (since 1977-1978).

--------------------------------------------------------------------

Dallas/Fort Worth - snowiest seasons

   1   17.6   1977-78
   2   15.3   1963-64
   3   13.5   1923-24
   4   11.1   2009-10*
   5   10.4   1976-77
   6    9.5   1909-10
   7    9.2   1916-17
   8    8.8   1947-48
   9    8.1   1937-38
  10    7.3   1965-66
        7.3   1941-42

--------------------------------------------------------------------

Dallas/Fort Worth - most snow in February

   1   13.5   1978
   2    7.9   2010*
   3    7.5   1924

--------------------------------------------------------------------

Dallas/Fort Worth - greatest 24-hour snowfall totals

   1   12.1   January 15-16, 1964
   2    8.2   January 14-15, 1917
   3    7.9   February 11, 2010*
   4    7.5   February 17, 1978
        7.5   February 25, 1924
   6    6.0   March 13, 1924
   7    5.5   December 9, 1898
   8    5.0   November 22, 1937
        5.0   January 5, 1910
  10    4.7   November 13, 1976

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Temperatures at surface level will hover at or above freezing, so initial snowfall will melt, and possibly create a minor slush issue. As the snowfall progresses however, accumulation will begin and roads will become hazardous. Thursday evening commute home will be difficult. Temperatures will drop below freezing after sunset, and all the water and slush will quickly freeze, icing over roads. Friday morning commutes will likely be extremely difficult with area roads likely to be completely iced over. Temperatures during the day Friday will increase to 43 degrees, and likely melt any accumulated snow or ice.

Currently the area is under a Winter Weather Advisory for this event, but there is a possibility if conditions degrade beyond the current forecast, that a Winter Storm Warning would be issued. I will send out updates as I can for this…