Texas Spring-2015

[Brent]

HRRR being very consistent with a pretty significant line just after daybreak plowing through the metro, the latest run looks like a bow echo at 7-9am. It's currently a line south of Abilene.

[TheProfessor]

interesting, it's rare you see storms strengthen at this time of night.

MESOSCALE DISCUSSION 0580
NWS STORM PREDICTION CENTER NORMAN OK
0420 AM CDT SUN MAY 10 2015

AREAS AFFECTED...N-CNTRL TX / S-CNTRL OK

CONCERNING...SEVERE THUNDERSTORM WATCH 153...

VALID 100920Z - 101015Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 153
CONTINUES.

SUMMARY...ADDITIONAL STORM DEVELOPMENT AND INTENSIFICATION IS
PROBABLE AS STORMS MOVE DOWNSTREAM INTO A MOIST/UNSTABLE AXIS
LOCATED ACROSS N-CNTRL TX INTO S-CNTRL AND SWRN OK.

DISCUSSION...RADAR MOSAIC AND 09Z SUBJECTIVE SURFACE MESOANALYSIS
SHOWS A BOWING SEGMENT MOVING ENEWD ACROSS THE TX BIG COUNTRY AROUND
45 KT AND INTO A MOIST/UNSTABLE AXIS. AN EARLIER OUTFLOW BOUNDARY
LOCATED ACROSS N-CNTRL TX APPEARS MORE DIFFUSE WITH TIME AND AN
INFLUX OF MORE MOIST AIR CHARACTERIZED BY AN AXIS OF UPPER 60S
DEWPOINTS EXTENDS FROM E-CNTRL TX NWWD THROUGH THE METROPLEX AND
INTO SWRN AND INTO S-CNTRL OK. RECENT ADDITIONAL STORM DEVELOPMENT
HAS OCCURRED ACROSS WRN N-CNTRL TX AND BOTH STORM CLUSTERS WILL MOVE
DOWNSTREAM. THE SCTD DEVELOPMENT SW OF SPS IS CAPABLE OF AN ISOLD
LARGE-HAIL THREAT IN ADDITION TO A STRONG WIND GUST. THE PRIMARY
THREAT WITH THE BOW WILL BE POCKETS OF SEVERE WIND GUSTS 60-70 MPH
BUT SMALL HAIL COULD ACCOMPANY THE MORE INTENSE
UPDRAFTS...ESPECIALLY ON THE SRN FLANK OF THE BOW.

..SMITH.. 05/10/2015


ATTN...WFO...TSA...FWD...OUN...SJT...

LAT...LON 33439977 34459895 34959689 34449564 33429541 32629613
32119718 31539908 33439977

[Shoshana]

My sister is in Lewisville

Tornado Warning
Statement as of 6:50 AM CDT on May 10, 2015

... A Tornado Warning remains in effect until 715 am CDT for
southeastern Denton County...

at 649 am CDT... a severe thunderstorm capable of producing a tornado
was located over Lewisville... moving northeast at 55 mph.

Hazard... tornado.

Source... radar indicated rotation.

Impact... flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed. Damage
to roofs... windows and vehicles will occur. Tree damage is
likely.

This dangerous storm will be near...
The Colony around 655 am CDT.
Little Elm and Hackberry around 700 am CDT.
Frisco around 705 am CDT.

Other locations impacted by this tornadic thunderstorm include
Lakewood Village.

This includes Interstate 35e between mile markers 446 and 454.

Precautionary/preparedness actions...

Take cover now! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors... in a
Mobile home... or in a vehicle... move to the closest substantial
shelter and protect yourself from flying debris.


Lat... Lon 3298 9704 3298 9706 3299 9713 3326 9684
3299 9684 3299 9703
time... Mot... loc 1149z 214deg 46kt 3306 9697

Tornado... radar indicated
hail... <.75in


Dunn

[Ntxw]

What a line this morning, not common as theProfessor said for this time of day. Sheets and sheets of blinding rain.

[BrokenGlassRepublicn]

What a line this morning, not common as theProfessor said for this time of day. Sheets and sheets of blinding rain.

Yep. Making my traditional Mother's Day trip for fresh flowers and donuts. It's a mess out here.

[WeatherGuesser]

Tornado on the ground just 2 miles(confirmed by spotters) west from where I live. I can hear the roar of the Tornado and see a rapidly rotating wall cloud.

Is aggiecutter ok? Anyone heard from him?

Update?

[gboudx]

Yeah getting worried about aggiecutter. He would've posted by now.

[Ntxw]

Looks like it's DFW's turn to get the train, redevelopment to the south and southwest moving NNE.

[Ntxw]

Image post! From about a week and a half ago, I think this was a good call I'm going to start looking for WWB's to help with insights this summer got a feeling it will be useful.

Big post today.

Through the weekend the weather will be tranquil, enjoy it. Haven't had a long stretch of sunny days for quite some time but don't think that is it. In motion are much bigger things in the Pacific Ocean. A substantial westerly wind burst event is about to occur, thus leading to the idea the El Nino will in fact get much stronger. If you understand the mechanism of ENSO this is a pretty clear line of thought.

With the eastern Pacific basin rain rates are increasing, the oceanic Kelvin wave is upwelling and convection is firing below us. This is our power source for heavy rain later week 1 and week 2 of May. Models are slowly latching on and the dry maps of the HPC are being replaced slowly with wetter ones. You can see the rainfall cluster slowly move across the globe and I circled the forecast area of it reaching our longitude.

http://i61.tinypic.com/s5wewg.gif

Analogs suggest often in periods like this, May opens up the floodgates and the pattern persists for months. We'll see, certainly haven't seen this kind of progression in a while.

http://i58.tinypic.com/2h51o2p.jpg

These storm systems are well rooted to the subtropical jet. This is clearly the most active the jet has been since the Nino of 2009. This summer from the CFS shows the STJ continues to dominate. You can see it stream from the TX/Old Mexico border and PWATS have remained very high for over a week. All from the Pacific.





This Nino means business, super Typhoon Noul will recurve and have impacts down the road as well as typhoons behind it. Texoma is already 5FT above pool. If this pattern keeps up it's not going to hold.

[TheProfessor]

And that's exactly what FWD is expecting, looks like were going to be hitting the replay button this week. I've also been hearing of a possible wide spread severe outbreak in the Southern, Central, and Northern planes around the 17th-20th.

.DISCUSSION...
AN UPPER LEVEL LOW OVER NORTHEASTERN COLORADO WILL CONTINUE TO
MOVE NORTHEAST INTO THE NORTHERN PLAINS THROUGH TONIGHT AND THEN
EAST ACROSS NORTHERN MINNESOTA AND INTO SOUTHERN ONTARIO BY
TUESDAY MORNING. AS THIS HAPPENS...A COLD FRONT WILL MOVE SOUTH
INTO THE NORTHWESTERN PART OF NORTH TEXAS BY MIDNIGHT TONIGHT.
THIS FRONT WILL MOVE THROUGH THE SOUTHEASTERN ZONES BY MONDAY
EVENING.

BEFORE THE FRONT MOVES THROUGH...WE WILL REMAIN IN A VERY MOIST
AND UNSTABLE AIRMASS. EXPECT THUNDERSTORMS THAT WERE APPROACHING
THE WESTERN PART OF THE FORECAST AREA AT 330 AM...TO MOVE EAST
ACROSS THE REGION THIS MORNING. SOME STRONG TO SEVERE THUNDERSTORMS
ARE EXPECTED...AND LOCALLY HEAVY RAIN WILL SERVE TO ONLY
EXACERBATE FLOODING WHERE THE GROUND IS ALREADY SATURATED FROM
RAINS OVER THE LAST SEVERAL DAYS. THE PRECIPITABLE WATER WILL BE
1.5 TO NEARLY 2 INCHES...WHICH IS APPROACHING THE 99TH PRECENTILE
FOR THIS TIME OF THE YEAR. HAVE DECIDED TO EXPAND THE FLASH FLOOD
WATCH SOUTHWARD TO INCLUDE AREAS ALONG AND NORTH OF A COMANCHE TO
HAMILTON TO HILLSBORO TO TERRELL TO SULPHUR SPRINGS LINE.

UNFORTUNATELY THIS FRONT WILL NOT DRY US OUT...AND WITH
SOUTHWESTERLY FLOW ALOFT....WE WILL CONTINUE TO HAVE CHANCES
OF SHOWERS AND THUNDERSTORMS THROUGH MUCH OF THE COMING WEEK.
SURFACE WINDS WILL BECOME EASTERLY TUESDAY NIGHT AND SOUTHEASTERLY
WEDNESDAY AFTERNOON. AS A SHORTWAVE APPROACHES...WE SHOULD HAVE
WIDESPREAD SHOWERS AND THUNDERSTORMS WEDNESDAY AND THURSDAY.
AFTER THIS SHORTWAVE MOVES TO THE EAST...WE SHOULD SEE ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS FRIDAY AND SATURDAY.

58

[TheProfessor]

Those are some high parameters in the Tornado watch issued.

[Ntxw]

Heads up Rockwall county folks, cell crossing from Dallas county is trying to go supercellur with maybe a hail core and hooking.

[EF-5bigj]

That is a pretty dangerous tornado watch 60% probs and moderate EF-2+ probs.

[Brent]

MDT is back south of the metroplex, for hail... tornado is 10% unhatched

[aggiecutter]

Thanks to all the above for the concerns. Yesterday was a pretty amazing day. Around mid-morning yesterday, a line of Thunderstorms gusted-out a long the Red River just north of Texarkana. The out-flow boundary from the decaying storms to the north came through the Texarkana area around noon and set-up a boundary about 20 miles south of town during the afternoon. Storms started forming a long this boundary around 5:00 in the afternoon and rapidly became rotating super-cells. Around 5:30, one of those super-cells crossed the western part of Texarkana near Lowe's Home Improvement Center.

It was reported at that time that a storm spotter had seen a funnel cloud over Lowe's. That was when I went outside and looked to the west and saw the rotating wall cloud and heard what sounded like a bunch of jet air planes taking off. To my knowledge, the funnel never actually touched down. However, within the next hour, 6 more super-cell tornado warned storms developed a long the out-flow boundary and moved north. 2 of those super-cells came right over the Texarkana metro area. The other 4 went just to the east and west of town.

The saving grace was that the storms that formed a long the out-flow boundary moved into an environment that was somewhat more stable because of the rain cooled air from the morning storms. Had the storms moved a long the out-flow boundary(to the east, instead of north), they would of have had access to 72 dew-points and mid 80 temperatures. Instead, they ran into mid 60 temperatures and mid 60 dew-points. At the time the storms formed, it was 65 in Texarkana with dew-point of 64 and 85 in Shreveport with a dew-point of 72.

[gboudx]

Good to see ur good aggiecutter.

Heads up Rockwall county folks, cell crossing from Dallas county is trying to go supercellur with maybe a hail core and hooking.

I'd be interested in dh's experience from it. It was ur standard lightning, thunder and pouring rain here. Not even high winds.

[gboudx]

From jeff:

Long duration Tornado Watch issued for much of C TX until 900pm this evening.

Air mass over central TX is becoming increasingly unstable as breaks in the overcast warm the surface layer. Mid level capping is starting to weaken and recent radar observations show an increase in convective elements over central and north TX. Pacific cold front is overtaking the dry line and will buckle this feature eastward early this afternoon helping to support thunderstorm formation. Main tornado risk appears over N TX along low level outflow boundary where winds are backed to the east enhancing low level shear along this feature however supercells will be possible across the entire watch area for the next several hours. Given the low level wind shear in place a few strong tornadoes will be possible this afternoon especially across the northern 1/3rd of the tornado watch area including DFW.

Storms will continue to develop in a SW to NE fashion much of the afternoon and into tonight with the threat shifting toward flooding rainfall as a continuous supply of rich Gulf moisture is pumped inland on SE winds. Expect to see the remain of overnight storms approach SE TX on Monday and possibly move into the area with an associated outflow boundary. This boundary then looks to stall across the area and support a very active late Monday into much of Tuesday. High resolution models are showing fairly extensive development of excessive rainfall Tuesday over the region especially west of I-45 and the global models have been suggesting this pattern for several days now so confidence is fairly high that some significant rains will begin late Monday and last into Wednesday.

[cheezyWXguy]

The storm southwest of Ft Worth approaching the area is gaining intensity and looks like it might be starting to rotate

[TheProfessor]

Yeah it looks like a hook echo is trying to form.

[TheProfessor]

Intellicast has put a tornado indicator on the storm, it would be heading straight for me too.