Watching the Skies

Severe thunderstorms still on track for Friday afternoon and evening. Strong forcing, plentiful moisture, and favorable low level wind shear will be supportive of severe thunderstorms. Tornado chances will be enhanced on Friday with the low level wind shearing forecast. However instability may be limited by a persistent cloud deck limiting afternoon heating. If a gap in clouds can develop and heating can initiate instability, then strong storms with tornadoes are a distinct possibility.

As I like to say here, keep watching the skies folks.

-- Weather in Frisco, TX when posted --
Temp: 60.8 °F, Humidity: 38%
Wind: 150° at 10km/hr
Sky: Clear

Strong winds and a fire hazard exist for Saturday across north Texas. Additionally, a slight chance of thunderstorms exists across the eastern parts of north Texas on Saturday afternoon.

A strong low pressure system currently located over the Texas panhandle will send a dryline through the region Saturday mid-day, increasing winds and posing a fire weather hazard. This dryline will act as a focus for some isolated thunderstorms that may develop in the afternoon east of I-35. These storms are likely to form just east of the immediate DFW Metroplex, so most of us will likely experience just dry and windy conditions in the afternoon. However storms that do develop will rest in an environment that could be supportive of strong to severe storms, and would be worth keeping an eye on.

Weather Saturday morning may be mostly cloudy or overcast, but quickly switch to clear skies after the dryline passes around noon. The rest of the day should remain clear, dry, and windy. The next 5 days including Sunday appear to remain dry and finally bring about a warming trend, with temps finally reaching 80 degrees by Thursday.

However Friday brings around our next significant storm system, with computer models already picking up on a good shot of severe weather for Friday afternoon or evening. Exact timing or locations of severe weather is hard to determine this far out, but computer models are all in good agreement that with plentiful moisture available, this storm system has alot of severe potential already. I will keep an eye on this developing situation and send updates as needed.

-- Weather in Frisco, TX when posted --
Temp: 62.6 °F, Humidity: 45%
Wind: 140° at 13km/hr
Sky: Clear

Current forecasts from the Storm Prediction Center and our local weather forecast office have mentioned a severe storm risk for Wednesday late afternoon through evening.

Currently the computer models agree on the location for storm initiation across the western parts of north Texas near Wichita Falls through Breckenridge at 4 to 6pm. The storms will progress eastward throughout the evening, switching from a ’surface’ based storm to a more ‘elevated’ structure. What this means for us is that tornado risk decreases, while hail and wind risk remains the same. Computer models differ in regards to timing of these storms moving through the metroplex, but current thinking suggests approximately midnight. The environment will still remain supportive of severe thunderstorms at this time, so I would plan for some potentially severe weather in the form of hail and winds. The storms will continue eastward throughout all of north Texas and clear the region by sunrise Thursday.

Clearing skies with slightly cooler temps will spread over the area for Thursday and Friday. The next storm system will move through the region Saturday afternoon and evening, with a very similar setup as Wednesday. However there will be less moisture available Saturday, so storms will likely be less intense.

-- Weather in Frisco, TX when posted --
Temp: 62.6 °F, Humidity: 56%
Wind: 190° at 12km/hr
Sky: Partly Cloudy

I thought Winter was over… but it apparently has one last bite before fading away. Snowfall is possible across the northern areas of the region on Saturday evening. Accumulations will be light, if any. Areas around the Red River could receive up to 1 inch of accumulation on exposed areas. Prior to the snow however a very strong cold front will move through the area, bringing a line of thunderstorms with it. The timing on these storms right now is probably in the overnight hours tonight, into early Saturday morning. Expect very windy and cold conditions immediately after the front moves through, with the snow following several hours afterward.

The last freeze of the season is expected for the region Saturday night, so take action on Saturday to protect any sensitive vegetation since the growing season has already begun.

Below is a diagram detailing the average date of last freezes across the region… It looks like we are right around average here.

I will send more details as needed later…

Severe Thunderstorm Watch has been issued for nearly all of North Texas, until 3:00pm today. A developing line of thunderstorms is approaching from the west, currently located from Mineral Wells through Wichita Falls. This line already has embedded severe thunderstorms, and will continue to gain intensity as it travels twards the DFW Metroplex. Today's primary risks are large hail and winds, the tornado threat today is very low and will likely not be an issue for our area. Timing on these storms, best guess i can make right now will be anywhere from 10:00am to noon for arrival in DFW.

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

Hey Texans, it’s been a bit since I sent out the last e-mails. However, being a severe weather enthusiast, my days brighten when your days darken.(maybe a new catch phrase?) Anyways, our first batch of spring time storms moved through the area Sunday and Monday. They even produced the first two spring time tornadoes of the year in western Oklahoma.

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.

-- Weather in Frisco, TX when posted --
Temp: 59 °F, Humidity: 48%
Wind: 170° at 8km/hr
Sky: Clear

Brief weather news update on a few assorted items… weather in north Texas the past few days has been beautiful and Saturday will continue that pattern. First batch of springtime storms arrive Sunday evening and Monday across the region. Isolated severe is possible, but more likely towards the south.

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

Hey folks, looks like all of north Texas will receive some snowfall yet again on Tuesday Feb 23. Counties south of I-20 are currently under a Winter Storm Watch with forecasts estimating 4+ inches of snow, while counties in and north of the metroplex are forecast to receive 1-3 inches. Isolated areas of the southern metroplex could receive 4-5 inches, while areas south of I-20 could receive up to 8 inches! Expect additional Winter Storm Watches and Warnings to be issued Monday morning as this event approaches.

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.

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

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

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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Hey folks, a significant arctic cold air blast will impact the area beginning tonight around midnight and last through Sunday at least. Air temperatures will fall as low as 11 to 14 degrees around the metroplex, with wind chills below zero! Freezing rain is also possible Wednesday night thru very early Thursday morning.

The arctic cold front originating from as far away as Siberia will plunge through the area late tonight around midnight, sending winds of 10-15mph and temperatures dropping to 22 degrees by sunrise. Freezing rain is possible in a narrow window overnight from maybe midnight to 3am? This could make for some patchy areas of ice on the roadways for Thursday. Temps will struggle to increase during the day, never exceeding 27 degrees. Overnight clear skies will promote strong radiational cooling and temperatures will drop as low as around 11 degrees to the north, 14 in and just south of the metroplex. Winds at this time will create very hazardous wind chill values below zero!

This cold air will persist on Friday as well, with highs once again not exceeding the freezing mark.Temperatures on Saturday will struggle to reach freezing, and very well could remain below freezing for the entire day on Saturday as well. Sunday will begin to warm up a bit with lows around 27, highs of 45.

Bundle up everyone, this is likely to be the coldest weather in the metroplex since January 2005!