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.

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

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

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).

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

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

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

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.

Severe Thunderstorm Warning issued for Denton County. Currently the storm is over far western Denton County, but moving east at about 35 knots. If the storm holds its severity, it will reach Frisco within 45-55 minutes, or around 1:45pm. Currently the storm looks marginally severe due to hail, along with strong winds but they dont appear to be severe. I will send updates as needed.

BULLETIN – EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FORT WORTH TX
1254 PM CDT TUE OCT 6 2009

THE NATIONAL WEATHER SERVICE IN FORT WORTH HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR…
DENTON COUNTY IN NORTH CENTRAL TEXAS…

* UNTIL 200 PM CDT

* AT 1254 PM CDT…NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL…AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 9 MILES
WEST OF JUSTIN…AND MOVING EAST AT 45 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR…
JUSTIN BY 105 PM
CORRAL CITY…NORTHLAKE…ROANOKE AND KRUM BY 110 PM
BARTONVILLE…ARGYLE AND SANGER BY 115 PM
COPPER CANYON AND DOUBLE OAK BY 120 PM

PRECAUTIONARY/PREPAREDNESS ACTIONS…

FOR YOUR PROTECTION MOVE TO A STURDY SHELTER UNTIL THE STORM HAS
PASSED.

IF YOU ARE CAUGHT OUTSIDE…SEEK SHELTER IN A STRONG BUILDING AND
STAY INSIDE…AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

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.

This likely affects very few of us, but probably set off the weather radios for those who have them. While composing this email, a second Severe Thunderstorm Warning was issued for Denton County, covering the southern half including The Colony and the Denton county portion of Frisco. These storms are warned mainly due to severe hail. The angle and direction these storms are traveling make it difficult to properly see wind velocities but there is a good chance of severe winds in these storms as well. Now is a good time to bring in any lightweight patio furnature.

BULLETIN – EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FORT WORTH TX
436 PM CDT THU OCT 1 2009

THE NATIONAL WEATHER SERVICE IN FORT WORTH HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR…
NORTHERN DENTON COUNTY IN NORTH CENTRAL TEXAS…

* UNTIL 515 PM CDT

* AT 436 PM CDT…NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL…AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 7 MILES
NORTHWEST OF SANGER…AND MOVING EAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR…
SANGER AND KRUM BY 455 PM
RAY ROBERTS PARK JOHNSON BRANCH AND DENTON BY 510 PM
RAY ROBERTS PARK ISLE DU BOIS…AUBREY…PILOT POINT AND
KRUGERVILLE BY 515 PM

PRECAUTIONARY/PREPAREDNESS ACTIONS…

FOR YOUR PROTECTION MOVE TO A STURDY SHELTER UNTIL THE STORM HAS
PASSED.

IF YOU ARE CAUGHT OUTSIDE…SEEK SHELTER IN A STRONG BUILDING AND
STAY INSIDE…AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

Main threats here are high winds… hail is still a possibility however.

BULLETIN – EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FORT WORTH TX
539 PM CDT THU OCT 1 2009

THE NATIONAL WEATHER SERVICE IN FORT WORTH HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR…
NORTHERN DALLAS COUNTY IN NORTH CENTRAL TEXAS…
SOUTHERN DENTON COUNTY IN NORTH CENTRAL TEXAS…
NORTHEASTERN TARRANT COUNTY IN NORTH CENTRAL TEXAS…

* UNTIL 645 PM CDT

* AT 539 PM CDT…NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL…AND
DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED NEAR
FLOWER MOUND…AND MOVING SOUTHEAST AT 25 MPH. THIS STORM WAS PART
OF A LINE OF STRONG TO SEVERE THUNDERSTORMS.

* THE SEVERE THUNDERSTORM WILL BE NEAR…
BEDFORD AND HURST BY 545 PM
GRAPEVINE…LEWISVILLE…LAKE LEWISVILLE AND HACKBERRY BY 550 PM
COPPELL AND EULESS BY 555 PM
HEBRON AND THE COLONY BY 600 PM

PRECAUTIONARY/PREPAREDNESS ACTIONS…

FOR YOUR PROTECTION MOVE TO A STURDY SHELTER UNTIL THE STORM HAS
PASSED.

IF YOU ARE CAUGHT OUTSIDE…SEEK SHELTER IN A STRONG BUILDING AND
STAY INSIDE…AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

The SPC in Oklahoma has gone ahead and issued a Severe Thunderstorm Watch for our area, expiring at 11pm local time. Today’s threats have changed and has become mainly a hail and wind threat, while the tornado threat is now reduced to near-zero. Severe storms have developed over south central Oklahoma dumping severe-sized hail (larger than 0.75″) along a pre-frontal trough. The cold front is expected to overtake this trough later todayand shift the storm threat from large hail to more of a high wind event. Not sure on exact timing, but previous estimates of 6 to 7pm for ETA around Frisco still seems to hold up. Ill send more updates as I can.

URGENT – IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 752
NWS STORM PREDICTION CENTER NORMAN OK
350 PM CDT THU OCT 1 2009

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

SMALL PART OF SOUTHEAST OKLAHOMA
LARGE PART OF NORTH CENTRAL AND NORTHEAST TEXAS

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 350 PM UNTIL
1100 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 85
STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH
NORTHWEST OF PARIS TEXAS TO 20 MILES SOUTH OF TEMPLE TEXAS.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU2).

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 751…

DISCUSSION…COLD FRONT MOVING SEWD INTO NRN TX ENCOUNTERING AN AIR
MASS THAT HAS BECOME MDTLY UNSTABLE.  WITH MLCAPES AOA 2000 J/KG AND
DEEP LAYER SHEAR OF 30-40 KT…SEVERE THUNDERSTORMS ARE EXPECTED TO
DEVELOP ALONG AND E OF COLD FRONT AS IT CONTINUES SEWD ACROSS THE
WATCH.

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 550. MEAN STORM
MOTION VECTOR 27025.