Watching the Skies

A Severe Thunderstorm Watch has been issued for parts of north central Texas, including the DFW metroplex, expiring at 10pm.
Thunderstorms are developing inside a destabilizing air mass along a cold front moving eastward. The storms arrival now brings it through the region within the next 2 or so hours, or before 5:30 to 6:00pm. Hail remains the primary risk, but severe winds are also a possibility. Tornado threats still remain low.

URGENT – IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 34
NWS STORM PREDICTION CENTER NORMAN OK
320 PM CDT WED MAR 24 2010

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

PART OF WEST CENTRAL  AND NORTH CENTRAL TEXAS

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 320 PM UNTIL
1000 PM CDT.

HAIL TO 2 INCHES 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 60
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES SOUTH
SOUTHWEST OF SAN ANGELO TEXAS TO 65 MILES EAST NORTHEAST OF
DALLAS TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).

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…STORMS ARE DEVELOPING ALONG AND AHEAD OF THE COLD FRONT
MOVING EWD ACROSS NWRN TX.  AIR MASS HAS SUFFICIENTLY DESTABILIZED
WITH HEATING TO SUPPORT STRONG UPDRAFTS. WITH THE 40-50KT OF DEEP
LAYER SHEAR AND STEEP MID LEVEL LAPSE RATES A FEW OF THE STORMS ARE
EXPECTED TO BECOME SEVERE AS THEY CONTINUE E/NE INTO THE EVENING
HOURS.  PRIMARY THREAT WILL BE LARGE HAIL…HOWEVER THERE IS THE
POSSIBILITY OF A COUPLE OF SUPERCELLS GIVEN THE IMPROVING LOW LEVEL
SHEAR LATER THIS AFTERNOON…ACCOMPANIED BY A DAMAGING WIND THREAT
AS WELL AS LARGE HAIL.

AVIATION…A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 24030.

This is post number 500 for Watching the Skies, an exciting achievement!
The pictures here were taken in Frisco, TX during the afternoon of March 21, 2010 after our spring snow storm.

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February 11, 2010 broke the all-time snowfall record for any calendar day and any 24-hour period with 11.2 inches of snow, as of midnight. This surpasses the previous daily record of 1.4 inches on Feb 11, 1988. This also exceeds our 24-hour record of 7.5 inches on Feb 17, 1978 and Feb 25, 1924. Lastly this breaks our greatest calendar-day snowfall total of 7.8 inches from January 15, 1964 and January 14, 1917.

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.

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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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The latest from the National Weather Service, snowfall today now shatters the previous record at DFW Airport. A whopping 7.9 inches 11.2 inches of snow has fallen today 2/11/10, surpassing the previous single calendar day record of 7.8 inches set on 1/15/1964 and 1/14/1917.  The real kicker, snowfall is set to continue for a few more hours! This makes February 11th the snowiest calendar day, and snowiest 24 hour period in the history of DFW Airport. This winter season is now the 4th 3rd snowiest winter on record at 11.1 14.4 inches total. Details below…

...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).

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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

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Dallas/Fort Worth - most snow in February

   1   13.5   1978
   2    7.9   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    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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Some images from my Flickr of this record breaking snowfall for the Dallas/Fort Worth Metroplex.

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A Tornado Watch has been issued for Collin, Dallas, Tarrant counties as well as several others across central, east, and north Texas as well as eastern Oklahoma. The SPC has bumped this watch area up to a 10% tornado risk which is certainly worth paying attention to. While most of the metroplex is under a Tornado Watch, the cold front has mostly passed through the metroplex already so the threat is quite low, if not gone. There is currently a Severe Thunderstorm Warning for eastern Dallas county, but that storm has weakened and moved out of the warned area so I would expect this to expire shortly. Areas directly to the east and south of the Metroplex however should absolutely keep an eye on this situation since the severe weather threat and tornado potential is moderate.

Temperatures behind the front are 20 degrees lower, dropping temps from 75 down to 55 immediately behind.

URGENT – IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 781
NWS STORM PREDICTION CENTER NORMAN OK
1155 AM CDT THU OCT 29 2009

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

SOUTHEAST OKLAHOMA
NORTHEAST TEXAS

EFFECTIVE THIS THURSDAY MORNING AND EVENING FROM 1155 AM UNTIL
600 PM CDT.

TORNADOES…HAIL TO 1 INCH IN DIAMETER…THUNDERSTORM WIND GUSTS
TO 80 MPH…AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE
MILES EAST AND WEST OF A LINE FROM 15 MILES EAST NORTHEAST OF
MUSKOGEE OKLAHOMA TO 40 MILES EAST SOUTHEAST OF TEMPLE TEXAS.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU1).

REMEMBER…A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.

OTHER WATCH INFORMATION…CONTINUE…WW 780…

DISCUSSION…THUNDERSTORMS ARE EXPECTED TO CONTINUE TO INTENSIFY
ALONG SLOW EWD-MOVING COLD FRONT THIS AFTERNOON. RICH BOUNDARY LAYER
MOISTURE AND STRONG TO INTENSE LOW THROUGH MID-LEVEL WIND FIELDS
WILL SUPPORT INCREASINGLY ORGANIZED STORMS/CELLS. WHILE ACTIVITY MAY
EVENTUALLY CONSOLIDATE INTO A SQUALL LINE WITH DAMAGING
WINDS…INITIAL/DISCRETE STORMS WILL EXISTS WITHIN VERY SUPPORTIVE
ENVIRONMENT FOR PERSISTENT LOW-LEVEL ROTATION AND POSSIBLE
TORNADOES.

AVIATION…TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 21045.

Several Flash Flood Warnings are issued for Tarrant, Denton, Collin, Grayson, Cooke and other counties around the area. A band of very heavy rainfall has fallen creating flooding conditions most notably around Fort Worth where several high water rescues have been taking place after motorists get stranded in high waters. Additionally the Trinity river at Dallas is surpassing flood stage at this time, and is forecast to exceed flood stage by 4 feet. At 34 feet several low water crossings will flood. This heavy rainfall will continue for a few more hours at least until the cold front passes through Thursday before sunrise. The rain will likely come to an end sometime around 3am to 5am I am thinking. Until then, plan for continuous heavy rain and flash flooding potential.

Here is the storm total rainfall amounts so far, this is since 1:21am Wednesday morning. Blue areas are reaching up to 5.8 inches of rainfall. The green polygons indicate current Flash Flood Warnings, the green and blue FFL icons indicate reports of Flash Flooding including road closures and high water rescues.

The National Weather Service has issued a Flash Flood Watch for the DFW Metroplex including Frisco, from 1pm Thursday through 7pm Friday. The area’s waterways and soil is already very saturated, plus when you factor in the upcoming forecasts, conditions begin to scream Flash Flood. The weather service compared the forecast event to events that happened October 14-15 2007 and October 18-19 2002. Both events saw abnormally high amounts of rainfall resulting in flooding, high water rescues, stranded vehicles etc. The weather service is forecasting a possibility of 4 inches of rainfall accumulation over our area.

The SPC in Oklahoma has issued a Severe Thunderstorm Watch for the entire DFW Metroplex including Frisco. This watch expires at 6:00pm today, the main threat will be large hail, with a small possibility of severe wind gusts. Tornados are very unlikely today.

URGENT – IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 757
NWS STORM PREDICTION CENTER NORMAN OK
1155 AM CDT TUE OCT 6 2009

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

CENTRAL AND NORTH CENTRAL TEXAS

EFFECTIVE THIS TUESDAY MORNING AND EVENING FROM 1155 AM UNTIL 600
PM CDT.

HAIL TO 2 INCHES 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 50
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES NORTH
NORTHWEST OF SAN ANGELO TEXAS TO 15 MILES SOUTH SOUTHEAST OF
PARIS TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).

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.

OTHER WATCH INFORMATION…CONTINUE…WW 756…

DISCUSSION…ELEVATED TSTM DEVELOPMENT /INCLUDING A SUPERCELL OR
TWO/ WILL CONTINUE WITHIN FEED OF MODERATE MUCAPE BEHIND SHALLOW
SURFACE COLD FRONT SAGGING SSEWD INTO CENTRAL TX THIS AFTERNOON.
GIVEN EFFECTIVE SHEAR AROUND 40-50 KT AND MODEST LAPSE
RATES…POTENTIAL FOR ISOLATED LARGE HAIL AND PERHAPS A
STRONG/SEVERE WIND REPORT REMAINS WITH THE STRONGER CORES.

AVIATION…A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 25020.

Took these using my G1… not the best camera, but with beautiful shots like these its hard not to see the beauty. The first three are about 40 minutes before the store arrived, the last one is 30 minutes after the storm passed by.