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Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 6:54 am
by ticka1
Will the rain start progressing southward or is the majority of it going to be to our north?

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 7:01 am
by srainhoutx
ticka1 wrote:Will the rain start progressing southward or is the majority of it going to be to our north?
There is some short wave energy moving ENE in the SW flow near the Baja Region this morning. I suspect that feature will be a 'trigger' for showers and embedded storm development later today for areas N of the frontal boundary beginning in S Central TX and then traversing up the Coast. We will see. Thankfully the Hill Country is getting some much needed rain to replenish the Lakes where it is sorely needed.

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DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0633 AM CST FRI MAR 09 2012

VALID 091300Z - 101200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
SPLIT FLOW WILL PREVAIL OVER THE CONUS...WITH THE MAIN BELT OF THE
WLYS PERSISTING FROM BC ACROSS S CNTRL CANADA INTO THE NERN U.S. A
FAIRLY STRONG SHORTWAVE TROUGH IN THIS FLOW WILL PROGRESS FROM THE
CNTRL GRT LKS TO OFF THE NEW ENGLAND CST BY THE END OF THE PERIOD.
IN THE WEAKER SRN STREAM...NM UPR LOW SHOULD RETROGRESS TO SE
AZ...ALLOWING HEIGHTS TO REBOUND ACROSS THE SRN PLNS/LWR MS VLY.

AT THE SFC...COLD FRONT ATTENDANT TO BOTH THE NM LOW AND THE NERN
TROUGH IS EXPECTED TO CONTINUE ADVANCING SE ACROSS THE NWRN GULF OF
MEXICO AND THE SERN STATES. THE BOUNDARY SHOULD WEAKEN AS IT
REACHES CNTRL FL EARLY SAT.

...FL AND ADJACENT SERN STATES TODAY...
EMBEDDED ELEVATED TSTMS WILL PERSIST THROUGH LATER THIS MORNING
NORTH OF COLD FRONT OVER THE NWRN GULF...SRN LA...AND SRN MS.
OTHERWISE...DIURNAL DESTABILIZATION COULD SUPPORT DEVELOPMENT OF
WDLY SCTD SFC-BASED SHOWERS/STORMS ALONG THE FRONT EWD TO THE S
ATLANTIC CST. HOWEVER...GREATER COVERAGE OF DIURNAL STORMS IS
EXPECTED FARTHER S OVER THE FL PENINSULA...WHERE MORE SIGNIFICANT
CONVERGENCE WILL EXIST ALONG SEA BREEZE BOUNDARIES. COMBINATION OF
SEASONABLY MOIST AIR /PW AOA 1.25 INCHES/ AND STRONG SFC HEATING
SHOULD BOOST SBCAPE TO AOA 1500 J/KG. WEAK SHEAR SHOULD LIMIT
UPDRAFT ORGANIZATION/STRENGTH.

...TX THROUGH EARLY SAT...
IT WILL REMAIN RELATIVELY MOIST AND UNSTABLE ATOP SHALLOW FRONTAL
INVERSION OVER CNTRL AND S TX THROUGH SAT. HEIGHTS WILL RISE
ALOFT...BUT UPR DIFFLUENCE WILL PERSIST E OF RETROGRESSING UPR LOW.
THIS SETUP MAY YIELD PERIODIC BOUTS OF ELEVATED CONVECTION/TSTMS.
WHILE A FEW UPDRAFTS MAY BECOME STRONG ENOUGH TO PRODUCE
HAIL...CLOUD LAYER SHEAR AND INSTABILITY EXPECTED TO REMAIN TOO WEAK
TO SUPPORT A RISK FOR SUSTAINED SVR STORMS.


Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 9:50 am
by Snowman
Alright I am tired of these little showers when is the big stuff moving in?

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 10:08 am
by Ptarmigan
srainhoutx wrote:The over night guidance suggests and bit more close core upper low will remain well to our W with embedded short wave energy rotating beneath that U/L in the SW flow aloft for the next 48 to 60 hours. Over running showers with a chance of some stronger elevated storms look to increase mid day Friday near SE TX before another break in the action on Saturday. The 'heavier rains Saturday appear to be focused further W over Central TX and the Hill Country Lakes where the past events have missed and should benefit that region of our drought parched State, and that is a good thing.

The guidance had suggested that heavier storms/rains of Thursday, with the cold front passage, would remain to our N and E and that has be exactly what has happened and where Flood Advisories are in effect near Lufkin and on N and E. The NAM (WRF/NMM) continues to advertise a round of heavier elevated storms moving near the Houston Metro area Friday as short wave energy swings across the region heading ENE along the boundary. On Saturday, a surface wave of low pressure looks to develop near Rock Port and traverse NNE as the U/L creeps slowly E toward the Texas Panhandle. Additional short wave energy streams in from the W with over running showers developing again Saturday night into Sunday. As the U/L finally begins to trek NE across N TX/OK, a line of heavier showers/elevated storms appears to swing through as the frontal boundary begins retreating N decreasing aerial coverage of rains by Sunday evening, if guidance is correct. All in all things are unfolding as generally expected and we'll need to watch radar trends later today to see if training cells set up mainly along and W of the HWY 59 corridor.
Let'em have the rain. They need it. 8-)

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 10:08 am
by srainhoutx
Snowman wrote:Alright I am tired of these little showers when is the big stuff moving in?

The 12Z GFS suggests Saturday afternoon through Sunday... ;)

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 10:14 am
by Snowman
srainhoutx wrote:
Snowman wrote:Alright I am tired of these little showers when is the big stuff moving in?

The 12Z GFS suggests Saturday afternoon through Sunday... ;)
Will it be one round of heavy rain or multiple rounds?

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 1:42 pm
by wxman57
Snowman wrote:Alright I am tired of these little showers when is the big stuff moving in?
Sunday looks like the best chance for heavy rain. The rain Saturday afternoon/evening may stay mostly to our north.

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 2:59 pm
by ticka1
Its 49 degrees and I got THUNDER here at the house! Didn't know we were going to have storms today!!!! And love this cold weather!!!!

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 3:07 pm
by svrwx0503
Decent amount of lightning associated with the shower and thunderstorm activity moving in from the west. There could be some small hail with with the stronger activity.

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 3:10 pm
by srainhoutx
svrwx0503 wrote:Decent amount of lightning associated with the shower and thunderstorm activity moving in from the west. There could be some small hail with with the stronger activity.
The HPC is now mentioning SE TX in particular in their updated short term forecast discussions concerning heavy rainfall as well...

SHORT RANGE FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
328 PM EST FRI MAR 09 2012

VALID 00Z SAT MAR 10 2012 - 00Z MON MAR 12 2012

...ADDITIONAL MODERATE TO HEAVY RAINFALL IS EXPECTED ACROSS
SOUTHEAST TEXAS AND INTO THE ARKLATEX...


...AN ACTIVE PACIFIC TROUGH WILL KEEP UNSETTLED WEATHER IN THE
FORECAST FOR MUCH OF THE NORTHWESTERN U.S...


A MEANDERING UPPER LOW CENTERED OVER NORTH-CENTRAL MEXICO WILL
BRING ANOTHER BATCH OF SNOW TO MUCH OF NEW MEXICO THROUGH SATURDAY
EVENING. UNDERNEATH THIS LOW CENTER...BELOW NORMAL TEMPERATURES
WILL BE IN PLACE AS HIGHS IN THE 40S WILL BE COMMONPLACE ON
SATURDAY ACROSS A LARGE PORTION OF TEXAS. BY THE CONCLUSION OF THE
WEEKEND...A SYSTEM TO THE WEST WILL FINALLY HELP PUSH OUT THIS
STAGNANT DISTURBANCE WHERE IT SHOULD EVENTUALLY REACH THE CENTRAL
PLAINS BY LATE SUNDAY. BESIDES THE CHILLY CONDITIONS IN
PLACE...ENHANCED LOW-LEVEL MOISTURE EMANATING FROM THE GULF OF
MEXICO WILL KEEP A THREAT FOR MODERATE TO HEAVY RAINFALL IN THE
FORECAST OVER THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY.
THE HIGHEST RAINFALL AMOUNTS ARE EXPECTED FROM SOUTHEAST TEXAS UP
TOWARD THE ARKLATEX WHERE A POSSIBILITY OF FLOODING EXISTS FOR
SATURDAY EVENING INTO MUCH OF SUNDAY.


Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 3:32 pm
by mckinne63
Nice rain coming down in Stafford right now. Ahhh...I love the sound of rain.

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 3:39 pm
by svrwx0503
Pretty strong storm moving toward the Copperfield area. Harris county rain gauge at Bear Creek and FM 529 has recorded almost 1'' of rain in 30 min. Could also have some pea sized hail.

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 3:48 pm
by srainhoutx
svrwx0503 wrote:Pretty strong storm moving toward the Copperfield area. Harris county rain gauge at Bear Creek and FM 529 has recorded almost 1'' of rain in 30 min. Could also have some pea sized hail.
Yeah, Matt. Just received a quick inch up here with frequent CG lightening.

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 3:52 pm
by svrwx0503
srainhoutx wrote:
svrwx0503 wrote:Pretty strong storm moving toward the Copperfield area. Harris county rain gauge at Bear Creek and FM 529 has recorded almost 1'' of rain in 30 min. Could also have some pea sized hail.
Yeah, Matt. Just received a quick inch up here with frequent CG lightening.
Any hail?

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 3:53 pm
by PaulEInHouston
Definite shortwave impulse approaching from W/SW area as storm increasing in coverage and strength. Radar indicated hail poss to .5" diam in cell to N/NE of Katy http://wx.apxsolutionsinc.com/wxradarbaseref.php. Gusty winds here in League City to 25 mph.

It also appears a previously mentioned coastal low may be trying to spin up to the NE of BRO and S of CRP area as indicated by radar returns...hard to say for sure.

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 4:05 pm
by srainhoutx
svrwx0503 wrote:
srainhoutx wrote:
svrwx0503 wrote:Pretty strong storm moving toward the Copperfield area. Harris county rain gauge at Bear Creek and FM 529 has recorded almost 1'' of rain in 30 min. Could also have some pea sized hail.
Yeah, Matt. Just received a quick inch up here with frequent CG lightening.
Any hail?
No. But Gene reports small hail in Jersey Village.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
339 PM CST FRI MAR 9 2012

TXZ199-213-092245-
HARRIS-MONTGOMERY-
339 PM CST FRI MAR 9 2012

...ELEVATED STORM PRODUCING SMALL HAIL IN HARRIS COUNTY...

AT 330 PM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 8 MILES SOUTHWEST OF JERSEY VILLAGE...MOVING EAST
AT 30 MPH.

ONE HALF INCH DIAMETER HAIL WAS REPORTED BY A STORM SPOTTER NEAR FRY
ROAD AS THIS STORM PUSHED THROUGH.

LOCATIONS IN THE PATH OF THIS STORM INCLUDE...PORTER...NEW CANEY...
LAKE HOUSTON DAM...ADDICKS...SPRING VALLEY...SPRING...KINGWOOD...
JERSEY VILLAGE...HUMBLE...HILSHIRE VILLAGE...BARRETT AND ALDINE

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 4:06 pm
by mckinne63
Hearing some thunder. Hope my husband is inside at the Rodeo. :D

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 4:09 pm
by srainhoutx
Near 1.75 inches of rain in the past 45 minutes at my location.

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 4:12 pm
by PaulEInHouston
srainhoutx wrote:Near 1.75 inches of rain in the past 45 minutes at my location.
Where located? That's a Texas size dumping!

Re: March 8th-11th: Significant Heavy Rainfall/Flooding Even

Posted: Fri Mar 09, 2012 4:18 pm
by srainhoutx
PaulEInHouston wrote:
srainhoutx wrote:Near 1.75 inches of rain in the past 45 minutes at my location.
Where located? That's a Texas size dumping!
Near 290 @ HWY 6 N. HGX is monitoring rainfall rates for Urban/Small Stream Flood Advisory. We'll see.