Texas Spring-2014

[Texas Snowman]

1.5 inch hail in McKinney as per NWS and ham radio operators. Pretty quick flare-up of severe storms. Hope the trend continues this spring (for rain, not hail and twisters).

[WeatherNewbie]

Watched the thunderhead form northwest of us and move across the area while sitting on a patio in Plano. No rain where we were, but a very impressive lightning show.

[dhweather]

Watched the thunderhead form northwest of us and move across the area while sitting on a patio in Plano. No rain where we were, but a very impressive lightning show.

Very much so, nice to watch. I could still see it in Heath when the cell had moved to Greenville.

[dhweather]

FWD discussion. I'm almost to the point of reading blah blah blah cap blah blah blah cap blah blah cap. * Reference to an old Far Side cartoon on what your dog hears when you talk to it.

.PREV DISCUSSION... /ISSUED 424 AM CDT FRI MAR 28 2014/
THE VIGOROUS MID-LEVEL FLOW THAT FORCED A DRYLINE HUNDREDS OF
MILES EAST ACROSS THE LONE STAR STATE ON THURSDAY HAS ABATED...
AND THE BOUNDARY HAS RETREATED BACK TO THE WEST OVERNIGHT IN
TYPICAL DIURNAL FASHION. A BLANKET OF IFR STRATUS ADVECTED WEST
OF THE I-35 CORRIDOR...DESPITE A LLJ ABOVE IT WITH A DISTINCT
WESTERLY COMPONENT. DEW POINTS IN THE 50S AND 60S HAVE ALREADY
RETURNED TO THE CLEAR AREAS FARTHER WEST...BUT ARE UNLIKELY TO
MAKE MUCH FURTHER PROGRESS BEFORE DAYBREAK. A COLD FRONT HAS
MOVED STEADILY SOUTH THROUGH OKLAHOMA OVERNIGHT AND IS NOW
CROSSING THE RED RIVER. A COUPLE OF CONVECTIVE CELLS DEVELOPED
ALONG THE BOUNDARY IN SOUTHEASTERN OKLAHOMA OVERNIGHT. THE
SOLITARY REMAINING STORM HAS MOVED INTO WESTERN ARKANSAS...CLOSER
TO THE AXIS OF THE LLJ. GUSTY NORTHEAST WINDS IN SOUTHERN
OKLAHOMA WILL ASSURE THE FRONT CONTINUES MAKING PROGRESS SOUTH
THIS MORNING. ALTHOUGH THE FRONT IS CURRENTLY QUIET IN NORTH
TEXAS...IT WILL BEGIN PEELING UP A VERY MOIST (THOUGH NOCTURNALLY
STABILIZED) SURFACE LAYER. A FEW SHOWERS/THUNDERSTORMS MAY DEVELOP
BEFORE MIDDAY AS THE FRONT ENCOUNTERS DEEPER MOISTURE TO THE
SOUTH.

A SHORTWAVE CURRENTLY OVER NEW MEXICO WILL ENTER TEXAS THIS
MORNING ON A MUCH MORE SOUTHERLY TRACK THAN THE DISTURBANCE
YESTERDAY. A PATCH OF MID CLOUD OVER THE PECOS VALLEY IS LIKELY
AN INDICATION OF THE INITIAL FORCING FOR ASCENT THAT WILL SPREAD
EASTWARD ACROSS THE STATE TODAY. WHEN THIS LIFT REACHES THE
MOISTURE DISCONTINUITY OVER THE EDWARDS PLATEAU...IT MAY BE ABLE
TO ERODE THE CAPPING INVERSION SUFFICIENTLY TO ALLOW FOR
CONVECTIVE INITIATION ACROSS THE HILL COUNTRY AS EARLY AS
DAYBREAK. AS THE FORCING MOVES FARTHER EAST INTO THE DEEPER
MOISTURE...THIS ACTIVITY WOULD TRANSLATE EASTWARD. GUIDANCE IS
REMARKABLY CONSISTENT WITH SUCH AN EVOLUTION...WITH THE VAST
MAJORITY OF SHORT RANGE QPF OUTPUT SHOWING A COMPLEX SKIRTING THE
SOUTHERN EDGE OF THE FWD CWA TODAY. OUR EVENING DISCUSSION RAISED
THE PROPOSITION THAT THIS CONVECTION COULD DISRUPT DRYLINE/FRONTAL
ACTIVITY LATER IN THE DAY. HOWEVER...THE MODEL CONSENSUS IS THAT
THIS WILL NOT BE AN ISSUE...EVEN WITH SOLUTIONS THAT MAINTAIN AN
AREA OF SIGNIFICANT CONVECTION TO OUR SOUTHEAST INTO THE AFTERNOON
HOURS. THE TTU WRF IS THE LEAST IMPRESSED WITH THE MORNING
ACTIVITY...WHICH MIGHT SUGGEST THAT THE DRYLINE/FRONT WOULD
EXPERIENCE EXPLOSIVE INITIATION LATER IN THE DAY...BUT THE TTU WRF
GENERATES ONLY A FEW ISOLATED CELLS AS THE BOUNDARIES ENTER AN
AREA OF CONSIDERABLE INSTABILITY. AS DISCONCERTING AS THIS IS...
IT IS UNLIKELY THAT THE FRONT WILL REMAIN QUIET AS IT INTERACTS
WITH AN INCREASINGLY DESTABILIZING BOUNDARY LAYER. THIS BUOYANT
AIR HAS REMAINED VIRTUALLY UNTAPPED (A FEW CONVECTIVE CELLS
THURSDAY AFTERNOON NOTWITHSTANDING). WITH ADEQUATE SURFACE
HEATING...MLCAPE VALUES MAY EXCEED 3000J/KG WITHIN THIS AIR MASS.
THE BEST FORCING MAY ARRIVE IN EASTERN ZONES AT PEAK HEATING...AND
CLOUD COVER WILL ONLY BE ABLE TO TEMPER THE INSTABILITY SO MUCH.
THE MAIN LIMITING FACTOR WILL BE THE PERSISTENT CAPPING INVERSION
THAT STIFLED INITIATION ON THURSDAY. LIFT ALONG THE SURFACE
BOUNDARIES COMBINED WITH DYNAMIC LIFTING ALOFT MAY NOT BE ABLE TO
OVERCOME THIS INHIBITION...AND POPS WILL REMAIN IN THE CHANCE
(RATHER THAN LIKELY) CATEGORY. EVEN IF COVERAGE IS LIMITED...
ANY CELLS THAT DEVELOP COULD QUICKLY BECOME SEVERE WITH LARGE HAIL
AND DAMAGING DOWNBURST WINDS. SOME CONVECTION MAY LINGER (OR EVEN
INITIATE) BEHIND THE SURFACE FRONT AS THE UPPER IMPULSE SWINGS
THROUGH LATE IN THE DAY. THE ACTIVITY WILL COME TO AN END AREAWIDE
BY NIGHTFALL AS THE FRONT MOVES THROUGH SOUTHEASTERN ZONES...AND
DOWNGLIDE ENSUES.

[Ntxw]

I've always like the HRRR model regarding severe weather. It's been the superior one the past couple of years. Been awhile since I've analyzed using meso-analysis but could be a few car dingers if this verified. I'm not impressed with the pwats but better keep an eye on it, junk convection to the southwest could hurt or help depending if they break down or not.

[dhweather]

NTXW - I think today boils down to cap erosion - if forcing/lift can get it out of the way AND we get some sun to burn off this low level fog/moisture , we could have an exciting afternoon. Lots of if's there, but it's all we've got.

[dhweather]

Just for my Far Side reference, here's that cartoon. Replace Ginger with Cap.

[Ntxw]

NTXW - I think today boils down to cap erosion - if forcing/lift can get it out of the way AND we get some sun to burn off this low level fog/moisture , we could have an exciting afternoon. Lots of if's there, but it's all we've got.

The cold front will break the cap. But that itself will only create a thin line of storms, but you're right breaking it sooner pre frontal will yield much more thunderstorms and supercells. At least this is our best severe weather day thus far in spring, it's still not all that impressive considering what it could be.

There currently is a complex of rain/storms to our southwest. In the past when something like this breaks down and leaves outflows it creates a focus for new thunderstorms and we overachieve but if they come through early it's junk.

[gboudx]

From McCauley

Severe weather will be possible across parts of north Texas later this afternoon and evening as a cold front/dryline combination works its way across the area. The cap will be breakable today - probably even more than it was Thursday evening - which means there should be more activity.

Yesterday, it looked like the severe weather threat would be just east of the Metroplex today, but now the data suggest it could fire in the Metroplex itself this afternoon. The atmosphere will be more unstable than Thursday, so there will once again be the threat of severe storms in the afternoon, shifting east of the Metroplex after sunset.

[texas1836]

1.5 inch hail in McKinney as per NWS and ham radio operators. Pretty quick flare-up of severe storms. Hope the trend continues this spring (for rain, not hail and twisters).

We received light marble sized hail where I'm at in McKinney (East of 75) with .30 inches of rain. It was a nice rain, which made me realize I need to clean my gutters, lots composting up there.

[TheProfessor]

I just hope that the storms form in northern Denton county so that way the southern half of the county can get some rain.

[TheProfessor]

Wednesday looks interesting, if the cap doesn't get too strong spec says that we could have a high end severe weather threat in DFW and Oklahoma City.

[TexasStorm]

Setup sound familiar. April 3rd, 2013. Outflow boundary draped across the metroplex. Don't think we have quite as much energy to work with this time but who knows.

[aggiecutter]

Looks like the first significant severe weather event of the spring for NE Texas and SW Arkansas this afternoon. This from this mornings Shreveport AFD:

"THE SHORT TERM PROGS ARE IN GENERAL AGREEMENT IN DEVELOPING SCT
CONVECTION AROUND MIDDAY OVER CNTRL TX AND SE OK...WITH A BROAD
DIFFLUENT ZONE SPREADING E ACROSS MUCH OF OUR REGION THIS
AFTERNOON DURING PEAK HEATING. THUS...SCT TO NUMEROUS CONVECTION
IS EXPECTED TO DEVELOP...ADVANCING QUICKLY E OVER THE AREA LATE
THIS AFTERNOON AND EVENING. GIVEN THE VERY UNSTABLE CONDITIONS
EXPECTED THIS AFTERNOON WITHIN A STRONGLY SHEARED
ENVIRONMENT...WILL LIKELY SEE SVR CONVECTION DEVELOP...WITH THE
STEEP LAPSE RATES...COLD TEMPS ALOFT /500MB TEMPS OF -14-(-17C)/
AND 40-50+KTS OF BULK SHEAR CONTRIBUTING TO A SVR HAIL THREAT.
SHOULD THESE STORMS ORGANIZE INTO A MORE ORGANIZED MCS
CLUSTER...DAMAGING WINDS WILL BE A SECONDARY THREAT AS THIS
CONVECTION RACES E OUT OF THE AREA JUST PRIOR TO 06Z SATURDAY. THE
TORNADIC THREAT APPEARS VERY MINIMAL...AS 0-1KM AND 0-3KM WINDS
REMAIN QUITE WEAK /UNDER 15KTS/...AND VERY LITTLE IF ANY BACKING
OF THE WINDS OCCUR S OF THE SFC LOW/WAVE."

[dhweather]

Updated AFD from FWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
1054 AM CDT FRI MAR 28 2014

.UPDATE...
12Z UPPER AIR ANALYSIS SHOWED A WELL DEFINED SHORTWAVE TROUGH
ALONG THE TX/NM BORDER WITH IMPRESSIVE CYCLONIC CURVATURE IN THE
HEIGHT AND WIND FIELDS ALOFT. WATER VAPOR LOOP HAS SINCE INDICATED
THAT THIS TROUGH HAS MOVED INTO WEST TEXAS. SHORT-TERM MODELS AND
EXTRAPOLATION BRING THE BEST FORCING WITH THIS FEATURE ACROSS THE
REGION DURING THE NEXT FEW HOURS. IN FACT THIS FORCING IS ALREADY
LIKELY WORKING TO LIFT AND REMOVE A STRONG CAP THAT WAS EVIDENT ON
THE 12Z FWD RAOB. 500MB TEMPS WILL DROP TO -19C TO -16C ACROSS THE
REGION TODAY WITH STEEP LAPSE RATES EXTENDING THROUGH THE
TROPOSPHERE. WHERE SURFACE TEMPS REACH THE UPPER 70S TO MID 80S
THIS AFTERNOON...SURFACE BASED CAPE WILL INCREASE TO NEAR
2000-3000 J/KG. DEEP LAYER SHEAR WILL BE IN EXCESS OF 40KT...AMPLE
ENOUGH FOR SOME SUPERCELL STORMS. THE HIGH INSTABILITY AND STEEP
LAPSE RATES WILL PROMOTE A RISK FOR VERY LARGE HAIL TODAY...PERHAPS
TENNIS BALL SIZE OR LARGER. DAMAGING WINDS WILL BE A SECONDARY
RISK DUE TO STEEP LOW LEVEL LAPSE RATES. WHILE A TORNADO CANT BE
RULED OUT DUE TO THE PRESENCE OF SUPERCELL STORMS AND HIGH LOW
LEVEL INSTABILITY...WIND FIELDS BELOW 850MB ARE VERY WEAK WHICH
MAKES THIS THREAT MORE CONDITIONAL.

AS FAR AS CONVECTIVE EVOLUTION AND TIMING...THIS EVENT WILL
EVOLVE A LITTLE EARLIER THAN A USUAL SPRING SEVERE WEATHER EVENT.
IN FACT CONVECTION MAY NOT WAIT FOR THE DRYLINE TO BECOME WELL
ESTABLISHED BEFORE INITIATING DUE TO THE STRONG UPPER FORCING
ARRIVING IN THE EARLY AFTERNOON. WE EXPECT SCATTERED STORMS TO
DEVELOP ACROSS THE WESTERN AND SOUTHWESTERN COUNTIES BY
MIDDAY...AND CONTINUE TO MOVE/DEVELOP EASTWARD AND INTENSIFY
DURING THE EARLY AFTERNOON HOURS. STRONG TO SEVERE CONVECTION
SHOULD BE ALONG A DFW TO KILLEEN LINE BY THE EARLY-MID AFTERNOON
HOURS. CONVECTION SHOULD CONTINUE TO MOVE EAST AND WILL LIKELY BE
OUT OF THE CWA BY EARLY-MID EVENING. HIGHEST SEVERE RISK TODAY
WILL BE OVER THE SOUTHEAST HALF OF THE REGION...AND ESPECIALLY THE
SOUTH CENTRAL AND SOUTHEAST ZONES.

FORECAST WAS IN GOOD SHAPE...BUT DID UPDATE TO RAISE POPS OVER THE
EASTERN HALF OF THE AREA...AND TO MAKE SOME CHANGES TO HIGH TEMPS
BASED ON LATEST NAM/RAP TIMING OF COLD FRONT THAT HAS ENTERED THE
NW ZONES.

TR.92

[dhweather]

Severe thunderstorm watch for the metroplex until 7PM.

[TheProfessor]

it would ne ironic if one of these storms spawned a tornado because this is the 14th anniversary of the 2000 Fort Worth tornado, which is probably the main reason why I'm so interested in weather today. I was only three at the time and I was living in Arlington and the whole event was just so thrilling for me to go through

[WeatherNewbie]

Looks like cells are starting to fire. Nasty looking one down by Stephenville.

[TheProfessor]

The latest RAP run shows the Metroplex's CAPE reaching close to 3000 later this afternoon.

[TarrantWx]

The latest RAP run shows the Metroplex's CAPE reaching close to 3000 later this afternoon.

The cold front is already through all of Denton county and most of Tarrant county. You can see it on radar. No way CAPE gets that high now. Unfortunately all of the heavy rains will stay to the south and east