April Weather Discussion.

[wxdata]

I was wondering WTH WxData was talking about at 10 am, and then it hit me. It goes a ways to explaining temps in the 70s.

NAM and GFS disagree with fropa timing. GFS showing around sunrise while NAM indicating late morning to near noon Saturday. Past experiences have shown that the front is usually 'ahead of schedule' than not.

[srainhoutx]

Moderate Risk now up for TX/OK Panhandles.

[wxdata]

Great timing-

OUS64 KFWD 211826
FTMGRK
Message Date: Apr 21 2010 18:26:53

The KGRK wsr 88d will down through at least Thursday afternoon and more likely
Friday afternoon. Parts are being ordered.
moore, wfo fwd

[wxdata]

There is always Granger, Dyess, Frederick and OUN, and Shreveport. Should cover most of the CWA. Plus that guy from Oklahoma who armored his Suburban like the TIV and who chases storms and even calls in to local NWS offices.

Not what the message said. Quote-

"The KGRK wsr 88d will down through at least Thursday afternoon and more likely
Friday afternoon. Parts are being ordered.

GRK is Granger. No mention of HGX.

[sleetstorm]

It looks like folks north and east will get in on the "big" action this time. However, that does not mean that we in s.e. Texas will be left out. Just like with the last event when many said we were going to be dry, the same uncertainty remains with this event. If you need a more detailed view of these weather events, follow Jeff's blog. He was right on last go round, and he is with this one as well. Watch for Friday morning's forecast. I would not be surprised, the way things are shaping up now, to see much less confidence in this cap. Still, again, expect bigger things north of Montgomery County as this unfolds Friday night, and on Saturday.

I am not wishing death on anyone, I just think that it would be interesting to get some of that action down here in souhteast Texas. By the way, severe thunderstorms have been forming rapidly out in western Texas and the Texas panhandle.

[sleetstorm]

In case any of you have not noticed, I very closely watched KHOU's dopplar radar and saw not just hues of red, but also shades of deep blue and even some light blue. Needless to say, numerous people are receiving, to my knowledge anyway, very fierce weather from those severe thundestorms. It is like the atmosphere is have an acute case of indigestion, metaphorically speaking.

[weatherguy425]

From Larry Cosgrove, very interesting!

A derecho will start to form in the southern and central portions of Texas Friday night, and roar into E TX sometime after midnight. The vertical velocity and instability profile has a very crazed look to it, the same classic appearance that most intense thunderstorm events have. While I cannot rule out a tornado or two locally, the greatest danger will be from microburst winds and large hail. The computer models suggest that the worst of this barrage will hit around 3 AM to 6 AM, with the chief damage risk being along and north of a line from Rosenberg to Liberty. Rain will be an issue as well, and it appears that the numerical predictors are underdoing total precipitation; most communities above Interstate 10 will see 1 to 3 inches of rainfall by dawn on Saturday.

Trouble is, there may be a second barrage with the surface cold front around noon on April 24. If the sun comes out (and the 18z NAM scheme asserts that is indeed the case), rapid destabilization of the atmosphere (-9 Lifted Index) in conjunction with a potent jet stream maximum (110 knots at 250MB) may create an opportunity for more strong thunderstorms until perhaps 2 PM. The entire system will aim its full fury at the Mississippi, Tennessee, and Ohio Valleys on Saturday afternoon and night; there is a very strong suggestion form the forecast equations that cities such as Memphis TN, Louisville KY and Birmingham AL will take a brutal hits form both tornadoes and torrential rainfall. On Sunday, the system will redevelop off of the Delmarva Peninsula, and in the process become a heavy rainmaker for some of the major cities of PA, NJ, and NY.

[srainhoutx]

35 Tornado reports today so far!

[weatherguy425]

Tornado Warning
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LUBBOCK TX
823 PM CDT THU APR 22 2010

TXC075-101-230145-
/O.CON.KLUB.TO.W.0003.000000T0000Z-100423T0145Z/
CHILDRESS TX-COTTLE TX-
823 PM CDT THU APR 22 2010

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 845 PM CDT FOR NORTHERN
COTTLE AND SOUTHERN CHILDRESS COUNTIES...

AT 818 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR AND STORM
SPOTTERS WERE TRACKING A LARGE AND EXTREMELY DANGEROUS TORNADO. THE
MOST DANGEROUS PART OF THIS STORM WAS LOCATED 8 MILES EAST OF CEE
VEE...OR ABOUT 14 MILES NORTH OF PADUCAH...MOVING EAST AT 20 MPH.

SOME LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE
SWEARINGEN...LAZARE...AND KIRKLAND.

THIS IS AN EXTREMELY DANGEROUS AND POTENTIALLY LIFE THREATENING
SITUATION. IF YOU ARE NEAR THE PATH OF THIS LARGE AND DESTRUCTIVE
TORNADO...TAKE COVER IMMEDIATELY!!

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 PM CDT THURSDAY EVENING
FOR THE PANHANDLE AND NORTHWEST TEXAS.

LAT...LON 3422 10000 3423 10003 3423 10005 3411 10006
3412 10044 3424 10044 3431 10043 3431 10042
3436 10042 3444 10000 3424 9999
TIME...MOT...LOC 0121Z 251DEG 19KT 3422 10029

[Ptarmigan]

From Larry Cosgrove, very interesting!

A derecho will start to form in the southern and central portions of Texas Friday night, and roar into E TX sometime after midnight. The vertical velocity and instability profile has a very crazed look to it, the same classic appearance that most intense thunderstorm events have. While I cannot rule out a tornado or two locally, the greatest danger will be from microburst winds and large hail. The computer models suggest that the worst of this barrage will hit around 3 AM to 6 AM, with the chief damage risk being along and north of a line from Rosenberg to Liberty. Rain will be an issue as well, and it appears that the numerical predictors are underdoing total precipitation; most communities above Interstate 10 will see 1 to 3 inches of rainfall by dawn on Saturday.

Trouble is, there may be a second barrage with the surface cold front around noon on April 24. If the sun comes out (and the 18z NAM scheme asserts that is indeed the case), rapid destabilization of the atmosphere (-9 Lifted Index) in conjunction with a potent jet stream maximum (110 knots at 250MB) may create an opportunity for more strong thunderstorms until perhaps 2 PM. The entire system will aim its full fury at the Mississippi, Tennessee, and Ohio Valleys on Saturday afternoon and night; there is a very strong suggestion form the forecast equations that cities such as Memphis TN, Louisville KY and Birmingham AL will take a brutal hits form both tornadoes and torrential rainfall. On Sunday, the system will redevelop off of the Delmarva Peninsula, and in the process become a heavy rainmaker for some of the major cities of PA, NJ, and NY.

Looks to be a nighttime thunderstorm for us.

[wxdata]

In case any of you have not noticed, I very closely watched KHOU's dopplar radar and saw not just hues of red, but also shades of deep blue and even some light blue. Needless to say, numerous people are receiving, to my knowledge anyway, very fierce weather from those severe thundestorms. It is like the atmosphere is have an acute case of indigestion, metaphorically speaking.

I didn't see it, but any colors on the radar tonight was anomalous propagation- False echos caused an inversion/cap over the area.

http://www.theweatherprediction.com/habyhints/247/

[sleetstorm]

From Larry Cosgrove, very interesting!

A derecho will start to form in the southern and central portions of Texas Friday night, and roar into E TX sometime after midnight. The vertical velocity and instability profile has a very crazed look to it, the same classic appearance that most intense thunderstorm events have. While I cannot rule out a tornado or two locally, the greatest danger will be from microburst winds and large hail. The computer models suggest that the worst of this barrage will hit around 3 AM to 6 AM, with the chief damage risk being along and north of a line from Rosenberg to Liberty. Rain will be an issue as well, and it appears that the numerical predictors are underdoing total precipitation; most communities above Interstate 10 will see 1 to 3 inches of rainfall by dawn on Saturday.

Trouble is, there may be a second barrage with the surface cold front around noon on April 24. If the sun comes out (and the 18z NAM scheme asserts that is indeed the case), rapid destabilization of the atmosphere (-9 Lifted Index) in conjunction with a potent jet stream maximum (110 knots at 250MB) may create an opportunity for more strong thunderstorms until perhaps 2 PM. The entire system will aim its full fury at the Mississippi, Tennessee, and Ohio Valleys on Saturday afternoon and night; there is a very strong suggestion form the forecast equations that cities such as Memphis TN, Louisville KY and Birmingham AL will take a brutal hits form both tornadoes and torrential rainfall. On Sunday, the system will redevelop off of the Delmarva Peninsula, and in the process become a heavy rainmaker for some of the major cities of PA, NJ, and NY.

Wow! A Derecho, something that Texas has not had in I honestly do not know how long. A majority of us in this forum know just how strong, potent, and lethal that type of severe thunderstorm can be by simply reading about them on the intenet, and past experiences.

[Ptarmigan]

Wow! A Derecho, something that Texas has not had in I honestly do not know how long. A majority of us in this forum know just how strong, potent, and lethal that type of severe thunderstorm can be by simply reading about them on the intenet, and past experiences.

A Derecho would be bad for us. There was a Derecho on May 17, 1986, known as "The Texas Boaters' Derecho". Another Derecho occurred on May 4-5, 1989 and that happened at night.

1986 Derecho
http://www.spc.noaa.gov/misc/AbtDerecho ... 86page.htm

1989 Derecho
http://www.spc.noaa.gov/misc/AbtDerecho ... 89page.htm

[biggerbyte]

This is a developing situation, one that we all should watch closely between now and Sunday night. There is potential for some really nasty weather over s.e. Texas if a couple of players come together. More on that on Friday. I think we can forget about the words boring and nothing for this event. Folks up north of the area can count on some fun. Around here, how interesting things get could be anything from marginal, to something to wake this forum up.

Stay tuned for Friday afternoon's updates...

[Ptarmigan]

This is a developing situation, one that we all should watch closely between now and Sunday night. There is potential for some really nasty weather over s.e. Texas if a couple of players come together. More on that on Friday. I think we can forget about the words boring and nothing for this event. Folks up north of the area can count on some fun. Around here, how interesting things get could be anything from marginal, to something to wake this forum up.

Stay tuned for Friday afternoon's updates...

I think a lot could change. I think severe weather is not out of the picture. I think this will likely happen early Saturday morning.

[sambucol]

Tomorrow night, Friday night, we have Relay for Life. Last year during Relay, we were hit with a very heavy rains and high winds and flooding during Relay. It was called off about 10:00pm that night. Are we looking at possibly the same kind of rainmaker tomorrow night? I really don't want to go through that again. Thanks

[wxdata]

Tomorrow night, Friday night, we have Relay for Life. Last year during Relay, we were hit with a very heavy rains and high winds and flooding during Relay. It was called off about 10:00pm that night. Are we looking at possibly the same kind of rainmaker tomorrow night? I really don't want to go through that again. Thanks

Forecast models continue to show showers/thunderstorms today (ending in the afternoon) and another chance Saturday morning. If that forecast trend continues, tonight may be between the rain systems.

[wxdata]

SPC- moderate risk area grows; southern sections of SE TX (and Houston) continue to be on the southern fringe of the severe weather threat. Still can't rule out a rouge strong thunderstorm or two in or around the Houston metro area.

"...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE FROM NEB TO CENTRAL
IL...THEN SWD TO S-CENTRAL/SE TX...LA GULF COAST AND WRN AL..."

http://www.spc.noaa.gov/products/outloo ... 0_prt.html

[srainhoutx]

SPC issues a Public Severe Weather Outlook. While capping appears to be very strong across the Houston Metro Area, past experience has showed us that we need to be mindful that our Area remains in a Slight Risk and thing can and often do change as we cannot predict any Meso scale Convective Complexes beyond 6-12 hours with any certainty. Stay Tuned!


PUBLIC SEVERE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0550 AM CDT FRI APR 23 2010

...SEVERE THUNDERSTORMS EXPECTED OVER PARTS OF THE LOWER MISSISSIPPI
VALLEY THIS AFTERNOON AND TONIGHT...

THE NWS STORM PREDICTION CENTER IN NORMAN OK IS FORECASTING THE
DEVELOPMENT OF A FEW STRONG TORNADOES OVER PARTS OF THE LOWER
MISSISSIPPI VALLEY THIS AFTERNOON AND TONIGHT.

THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE

ARKANSAS
NORTHERN LOUISIANA
NORTHERN AND WESTERN MISSISSIPPI
WESTERN TENNESSEE
NORTHEAST TEXAS

ELSEWHERE...SEVERE STORMS ARE ALSO POSSIBLE FROM...ERN PORTIONS OF
THE SRN PLAINS...THE MID MS VALLEY AND NEB

AN OCCLUDED SURFACE LOW OVER SRN CO WILL MOVE EWD THROUGH WRN AND
NRN KS TODAY AND TONIGHT IN ASSOCIATION WITH UPPER TROUGH MOVING EWD
THROUGH THE SRN AND CNTRL PLAINS. A TRAILING COLD FRONT WILL ADVANCE
THROUGH OK AND TX REACHING THE ERN PARTS OF THESE STATES LATE
TONIGHT. A WARM FRONT WILL LIFT NWD THROUGH ERN NEB...NRN MO AND IA.


INFLUX OF WARM...MOIST AIR WITH UPPER 60S DEWPOINTS WILL SPREAD NWD
THROUGH ERN TX AND THE LOWER MS VALLEY ALONG A STRONG SWLY LOW-LEVEL
JET. THE RAPID INCREASE IN MOISTURE WILL BE THE PRIMARY
DESTABILIZING INFLUENCE...WITH MODERATE INSTABILITY EXPECTED OVER
MUCH OF THIS AREA TODAY. A CAPPING INVERSION WILL INITIALLY SERVE TO
INHIBIT THE DEVELOPMENT OF STRONG STORMS. HOWEVER...A ZONE OF
INCREASING UPPER DIVERGENCE AND LARGE-SCALE ASCENT AHEAD OF EWD
MOVING UPPER TROUGH MAY HELP TO WEAKEN THE CAP ENOUGH FOR STORMS TO
DEVELOP AHEAD OF THE COLD FRONT BY THIS AFTERNOON AND POSSIBLY AS
EARLY AS LATE MORNING. DEEP LAYER VERTICAL SHEAR WILL INCREASE TO IN
EXCESS OF 50 KT AND BECOME SUPPORTIVE OF SUPERCELLS AND BOW ECHOES.
A FEW STRONG TORNADOES...LARGE HAIL AND DAMAGING WIND WILL BE
POSSIBLE AS STORMS DEVELOP NEWD THROUGH THE LOWER MS VALLEY.

A SECOND ROUND OF SEVERE STORMS WILL LIKELY DEVELOP LATE TONIGHT AS
ANOTHER SHORTWAVE TROUGH MOVES EWD THROUGH TX RESULTING IN A
SUBSTANTIAL INCREASE IN FORCING FOR ASCENT ALONG WITH AN INCREASE IN
THE SWLY LOW LEVEL JET. DAMAGING WIND...LARGE HAIL AND TORNADOES
WILL BE POSSIBLE.


..DIAL.. 04/23/2010

[srainhoutx]

Also of note are the comments from the HPC this morning regarding E TX and LA...

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
554 AM EDT FRI APR 23 2010


FINAL DAY 1...DAY 2 AND DAY 3 QPF DISCUSSION
VALID APR 23/1200 UTC THRU APR 26/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


...DAY 1...

...UPDATE...
MAJOR CHNGS ACRS ERN TX/LA LATER TNGT AS MDLS ARE SHOWG AN EVEN
MORE IMPRVS SPLIT IN THE POLAR JET ACRS THE REGION THAT WL PROMOTE
VRY STG UPR DVRG AND ASSOCD DEEP LYRD ASCENT. MDLS ARE SHOWG A RPD
INCRS/BACKG OF THE LOLVL FLOW WITH 50 KTS AT 8H THAT WL SUPPORT
MSTR FLUX ANOMALIES THAT INCRS FM ARND ONE STD TO OVER FIVE STDS
BY THE END OF THE FCST PD. HAVE BEEFED UP QPF...ARND ONE
INCH...THRU THE REGION TO BETTER FIT THE INCRSG MSTR/UPR DYNAMIC
SUPPORT. DID NOT CHNG THE EXCESS IN ERN TX/LA DUE TO VRY HI
FFG...BUT COULD SEE AN UPGRADE LATER TDA.