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

Posted: Fri Mar 09, 2012 4:26 pm
by PaulEInHouston
Just had some small dime size hail League City

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

Posted: Fri Mar 09, 2012 4:30 pm
by srainhoutx
Nearing 2.25 inches of rain in the past hour now at my location.

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

Posted: Fri Mar 09, 2012 4:37 pm
by mckinne63
Looks like it is clearing up in Stafford. Not sure on inches, but I know I don't have to put any water in the pool or the pond. :D

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

Posted: Fri Mar 09, 2012 4:37 pm
by Snowman
wow srain! your location may be one of those lucky areas with 5 to 6 inches of rain by the end of sunday!

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

Posted: Fri Mar 09, 2012 4:42 pm
by srainhoutx
Snowman wrote:wow srain! your location may be one of those lucky areas with 5 to 6 inches of rain by the end of sunday!
The NAM (WRF/NMM) did suggest this happening yesterday. We'll see what future guidance offer over night regarding Saturday night/Sunday...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
343 PM CST FRI MAR 9 2012

.DISCUSSION...
PERIODS OF -RA WITH EMBEDDED TSTMS SHOULD PERSIST THRU THE EVENING
HOURS. MOST LOCATIONS SHOULD AVERAGE 1/4-1/3"...BUT LOCALIZED
SWATHS OF 1.25" AMOUNTS ARE POSSIBLE UNDER THE TSTMS. SMALL HAIL
WILL ALSO BE POSSIBLE. THINK MOST ACTIVITY SHOULD GRADUALLY
DECREASE IN AREAL COVERAGE AND MIGRATE BACK WEST AHEAD OF THE NEXT
PIECE OF ENERGY EXPECTED TO MOVE NORTHEASTWARD ACROSS TX ON
SATURDAY. EXACT TRACK OF THIS NEXT ROUND OF THE HEAVIER PRECIP IS
QUESTIONABLE AT THIS TIME BUT CLOSE ENOUGH TO OUR NRN ZONES TO
TAKE NOTICE - ESPECIALLY CONSIDERING THE FAVORABLE DIFFLUENT FLOW
ALOFT. NAM12 & WRF INDICATE IT WILL PASS JUST N OF OUR CWA. THEY
DID THE BEST JOB WITH LAST NIGHT AND TODAYS WX. BUT LOOKING AT W/V
IMAGERY DOWN IN MEXICO...CANNOT RULE OUT THE FURTHER SOUTHWARD
TRACK ADVERTISED BY GFS/ECMWF EITHER - POSSIBLY AFFECTING THE NRN
1/3-1/2 OF THE CWA. HAVE LIKELY POPS GOING ACROSS THE N/NW HALF OF THE
REGION AND NOT PLANNING ON CHANGING THAT.
ALSO DON`T THINK WHATEVER
RAIN FALLS TOMORROW WILL CAUSE ANY WIDESPREAD SIGNIFICANT FLOOD
ISSUES. BUT THE AMOUNTS WILL PLAY A FACTOR IN DETERMINING IF AND
WHERE THE THREAT WILL BE ON SUNDAY WHEN THE MAIN TROF AXIS PUSHES
ACROSS ON SUNDAY.

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

Posted: Fri Mar 09, 2012 4:48 pm
by tireman4
Lightning and Thunder in Humble with moderate to heavy rainfall....

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

Posted: Fri Mar 09, 2012 4:51 pm
by txflagwaver
Rockin and Rollin with thunder and lightning here!!

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

Posted: Fri Mar 09, 2012 5:15 pm
by Katdaddy
Picked up .77". Lots of vivid lightening with CGs. Agree that Srain will be the rainfall lottery winner by Monday morning.

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

Posted: Fri Mar 09, 2012 5:19 pm
by ticka1
Its pouring with thunder and lightning here between Baytown and Mont Belvieu! I think this is setting in....

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

Posted: Fri Mar 09, 2012 5:34 pm
by Andrew
It took me 3 hours to get from college station to Houston and it rained a good hour to hour and a half in NW Houston. I picked up between 1-2 inches of rain and the streets outside were almost flooded. Now the grounds are saturated around here and any large amounts of rain later could provide some issues for flooding. Look out later tonight into Sunday for some more heavy rain. Sunday looks like the best chance as the ULL tracks east.

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

Posted: Fri Mar 09, 2012 5:41 pm
by srainhoutx
Light to moderate rain with rumbles of thunder once again at my location as showers/elevated storms re develop to our W.

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

Posted: Fri Mar 09, 2012 6:54 pm
by Andrew
Water vapor continues to show a flow of moisture from the SW and this should continue to spark more storms overnight:

http://www.ssd.noaa.gov/goes/east/sc/flash-wv.html

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

Posted: Fri Mar 09, 2012 7:43 pm
by JackCruz
According to accuweather it's already 46 here in cypress and feels like 31. Rain steady coming down...been falling for over 2 hours non stop...or at least that's what it seems like.

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

Posted: Fri Mar 09, 2012 10:06 pm
by Ptarmigan
Image

Thunderstorms forming southwest of Houston. I expect to hear thunder later tonight.

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

Posted: Fri Mar 09, 2012 10:52 pm
by Karen
do you think all of the rain down around Victoria will make it up here?

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

Posted: Sat Mar 10, 2012 5:35 am
by djjordan
Nice gentle soaking rains overnight at my house. Definitely going to be taking care of the lawn this coming week. Hoping we can continue the trend of just the right amount of rain per week or every other week through the spring and summer. Good Saturday morning everyone. Hope your weather day is fantastic.

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

Posted: Sat Mar 10, 2012 8:06 am
by Katdaddy
2.02" of soaking well needed rainfall here in League City. Watching more showers develop off the Middle TX Coast headed N toward SE TX.

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

Posted: Sat Mar 10, 2012 8:22 am
by srainhoutx
The over night guidance suggest a general 1-3 inches of rain are possible across the area with areas N of I-10 being the favored areas. At my location, nearly 3 inches of rain have fallen since yesterday afternoon and light showers continue at this hour.

A surface low is developing just S of Rock Port or just SW of Matagorda Bay and is offshore by about 75 miles and slowly drifting N. The upper low is currently spinning near the Arizona/New Mexico border and embedded short wave energy continues to move NE in the SW flow aloft from the Eastern Pacific across Old Mexico. Later today the front should begin to retreat N bringing a southerly to SE low level flow off the Gulf and temps should begin to rebound. Along with the retreating front, increasing instability may begin to fire off stronger storms and weak low level rotation is possible, so an isolated weak tornado or two is not out of the question as the afternoon/evening progresses. While severe storms do not appear to be an issue, heavy training cells with heavy rainfall rates are something that will need to be monitored.

Later tonight and into Sunday the upper trough will begin to trek E as the upper low finally begins to march NE across the Texas Panhandle. Rain chance will continue for Sunday and all depends on just how quickly the upper trough clears our area to the E before rain chances decrease. The HPC QPF forecast suggests some isolated 2-3 inch amounts mainly to our N but that will need to be watched as well. The SPC Day 2 Outlook has outlined a Slight Risk for portions of NE TX/NW LA/SW AR for tomorrow as the upper low ejects NE into the Southern Plains and trough slowly swings E across Texas.

We’ll see what the 12Z shorter range meso models offer a bit later and expect some further ‘fine tuning’ of the forecast in this complex and complicated weather pattern. Unfortunately, wxman57 will not be riding his bike this weekend, but the good thing is our drought situation is improving with every round of rain we receive so all in all there is little to complain about. :P Also, don’t forget to set you set your clocks forward tonight as Daylight Savings Time begins and you’ll need to change your profile settings to DST as well when you log in tomorrow.;)

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

Posted: Sat Mar 10, 2012 9:29 am
by srainhoutx
Morning e-mail from Jeff:

Rainfall event underway across the region.



Strong upper level storm system over the SW US combined with stalled frontal boundary offshore, developing coastal surface trough/low, and weak disturbances in the SW flow aloft all producing periods of rainfall across the region since yesterday afternoon. Rainfall amounts so far have averaged 1-2 inches for many areas with a few locations over 3 inches.



Upper level storm will begin to translate eastward toward the TX/OK panhandle tonight into Sunday and this will bring the greatest chance of widespread heavy rainfall and thunderstorms to the region. Height falls over NW TX this afternoon will continue to force coastal surface low development near the low TX coast which will begin to lift northward tonight. Large swath of strong warm air advection just above the surface will continue to support bands of showers moving NNW off the Gulf into the coastal bend this afternoon and the coastal front and surface cold dome is overrun by warm moist air just above the surface.



As the stronger core of lift with the upper level storm moves eastward tonight, the low level jet will shift into eastern TX with PWS increasing to near 1.5-1.7 inches (2SD above normal for early March). Additionally, the coastal boundary offshore will attempt to retreat northward and may move inland by early Sunday morning adding a good low level focus for thunderstorms/heavy rainfall. Expect thunderstorms to develop tonight across central into north TX in the region of greatest lift and then spread ESE on Sunday. Storm motions will slow with time and training will become more common. With grounds now saturated from previous rainfall flooding/flash flooding will become a bigger threat on Sunday. Not very confident where the greatest rainfall potential will be, and not overly confident that the forecast models have a good handle on the meso scale situation which tends to drive these heavy rainfall events.



Additional rainfall amounts of 1-2 inches is likely with isolated amounts of 3-5 inches possible with storm totals from Thursday-Sunday approaching 3-4 inches and isolated amounts of 5-7 inches across the region.



A few thunderstorms will be possible tonight with the threat increasing on Sunday. At this time any severe threat should be just north of the area, but if the warm front moves inland then there could be a greater threat than current thinking suggest. Will take a closer look at the severe threat this afternoon.



Storm system will push eastward Monday, but air mass does not dry out greatly and moisture along with noisy upper level flow (disturbances aloft) look to keep some amount of rain chances in the forecast for much of next week. Likely a few days will have better chances than others. Temperatures will warm back to March levels of lows in the 60’s and highs in the upper 70’s with scattered afternoon showers.

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

Posted: Sat Mar 10, 2012 10:51 am
by srainhoutx
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1030 AM CST SAT MAR 10 2012

VALID 101630Z - 111200Z

...NO SVR TSTM AREAS FORECAST...

...SRN PLAINS...
EARLIER FORECASTS ON TRACK FOR TODAY AS LARGE SRN STREAM CLOSED
MID-UPPER LOW...NOW CENTERED OVER NRN MEXICO AND THE AZ/NM BORDER
AREAS...EJECTS NEWD TO THE SRN HIGH PLAINS BY EARLY SUNDAY. ZONE OF
QG-ASCENT WITHIN ERN FLANK OF THIS SYSTEM WAS CONTRIBUTING TO AN
EXPANDING PCPN SHIELD DOTTED WITH ISOLD EMBEDDED TSTMS ACROSS TX
THIS MORNING. SHOWERS/STORMS WILL CONTINUE TO SPREAD AND EXPAND
NWD/NEWD ACROSS OK AND INTO KS/AR THROUGH THE PERIOD. WITH THE
POSSIBLE EXCEPTION OF NEAR SURFACE-BASED STORMS TAKING FORM LATE IN
THE PERIOD NEAR THE TX GULF COAST
...MOST STORMS WILL BE ROOTED ABOVE
A STABLE BOUNDARY LAYER AND FUELED BY MEAGER MUCAPE AOB 500 J PER
KG. THE LIMITED INSTABILITY MAY BE BRIEFLY OFFSET BY DYNAMIC ASCENT
AND SUFFICIENT SHEAR FOR UPDRAFT PERSISTENCE THUS CONTRIBUTING TO
THE OUTSIDE CHANCE FOR ISOLD SMALL HAIL WITH SOME OF THE STRONGER
TSTMS.


...NM/CO...
SMALL AREA OF LOW-TOPPED STORMS MAY DEVELOP AS THE COLD CORE LOW
SPREADS ACROSS THE HIGHER TERRAIN OF NRN NM AND SRN CO THROUGH
TONIGHT.

...FL...
RESIDUAL FRONTAL ZONE AND WEAK INHIBITION WILL LIKELY AID SCATTERED
DIURNAL CONVECTION OVER FL AGAIN TODAY. THE GREATEST CHANCE FOR
STORMS MAY BE DISPLACED SOUTH FROM FRIDAY ACTIVITY AS LATEST VIS
SATL IMAGERY SUGGESTS BEST LOW LEVEL CONVERGENCE MAY DEVELOP NEAR
DIFFERENTIAL HEATING ZONE AND WWD MOVING EAST COAST SEA BREEZE
BOUNDARY...EXPECTED TO BE NEAR AND SW OF LAKE OKEECHOBEE LATER THIS
AFTERNOON. WEAK SHEAR AND LAPSE RATES IN THIS AREA SHOULD PRECLUDE
SEVERE STORMS BUT A ROGUE GUST AND/OR SMALL HAIL CANNOT BE
COMPLETELY RULED OUT.