SE TX/SW LA weather: Much cooler and WET after Tuesday

[jasons2k]

Morning update from Jeff Lindner:

Small cluster of severe thunderstorms developed over SW Harris and NE Fort Bend counties yesterday evening. While most did not see rains…this area was hard hit with several inches of rainfall, hail, and high winds…see below storm report.

First off will toss the guidance out the window this morning as it is not and has not been handling MCS activity well with intensity or placement in our weak NNW mid to upper level steering flow. See no reason why persistence forecasting is not the best course of action given we are now on Day 3 of this pattern and just like clockwork the next upstream MCS is on its way like the past 2 mornings.

Large MCS currently NW of Fort Worth is weakening per cloud top warming and radar trends out of SW OK and N TX. However large forward moving outflow boundary has been generated moving SE at 45mph and this should reach into our NW counties by early afternoon. Seabreeze has struggled to gain much inland movement the last few days given northerly mid level flow and today will be no different so areas along a line from Winnie to S Houston to Sugar Land should once again be where the seabreeze fires off.

Expect seabreeze and incoming outflow boundary to set things off by mid to late afternoon into the evening hours. Hopefully rainfall will be more widespread today allowing more of us to get wetting rains. Will also expand the chances westward to include our W and SW counties given upstream MCS placement is further west suggesting H5 ridge axis is breaking down and pushing westward. In fact storms yesterday did make it into E Wharton County before weakening…or about 50 miles further west than on Tuesday. Will maintain the pulse severe threat of hail and wind like the past two days and soundings are still inverted V and if temps. reach the mid to upper 90’s pulse severe looks like a good bet.

Upper air pattern remains unchanged through the weekend with disturbances rounding the SW US ridge and US E coast trough backing westward into the lower MS valley…resulting in a continued NNW to NW flow aloft over the southern plains. SE CO and TX panhandle MCS complexes will develop late in the afternoon and move SE into TX overnight. Mid level flow may increase with time increasing the forward movement of these complexes and allowing then to reach our area at their nocturnal peaks in the early morning hours…instead of their leftover outflows in the following day late afternoon. Friday afternoon looks fairly wet given stronger disturbance forecast to top the ridge this evening and set off a large MCS over SE CO and NE NM tonight.

Weekend:

Will continue with higher rain chances Saturday and Sunday as trough approaches the region from the NE with a weak frontal boundary and westward moving tropical wave across the Gulf. Could be active both Saturday and Sunday afternoons…if morning MCS activity does not blow through the area. Other developing concern is greatly weakening wind patterns…which suggest storm motions will collapse to less than 10mph over the weekend increasing the threat of excessive rainfall. While grounds are dry…3-5 inches in an hour or two will result in flooding over urban areas.

Storm Reports for Wednesday:

Houston, Harris: .88 inch hail at Eldridge Pkwy and Briar Forest
Houston, Harris: 1.0 inch diameter hail at Eldridge Pkwy and Briar Forest
Missouri City, Fort Bend: .50 inch diameter hail along FM 1092
Mission Bend, Fort Bend: 1.0 inch diameter hail
Houston, Harris: 1.25 inch diameter hail at Beltway 8 and Westheimer
Houston, Harris: 61mph wind gust recorded by storm spotter at HWY 6 and Westheimer
Sugar Land, Fort Bend: pea size hail reported at the Sugar Land Airport and along Eldridge.
Sugar Land, Fort Bend: Funnel clouds reported by law enforcement at US 59 and HWY 99 over New Territory

[srainhoutx]

Yes, I think today will be our day. Outflow looks great on Central TX Radar and racing this way

Great show last 2 nights here, but not a drop of rain. Here's hoping that the rain can move in without the hail.

[KWT]

Yep now got a severe thunderstorm watch out for the middle chunk of eastern central and parts of southern Texas:


WATCH COUNTY NOTIFICATION FOR WATCH 576
NATIONAL WEATHER SERVICE FORT WORTH TX
806 AM CDT THU JUN 19 2008

TXC001-035-085-113-121-139-145-161-213-217-231-251-257-289-293-
309-349-379-395-397-439-467-191700-
/O.CON.KFWD.SV.A.0576.000000T0000Z-080619T1700Z/

SEVERE THUNDERSTORM WATCH 576 REMAINS VALID UNTIL NOON CDT TODAY
FOR THE FOLLOWING AREAS

IN TEXAS THIS WATCH INCLUDES 22 COUNTIES

IN NORTH CENTRAL TEXAS

BOSQUE COLLIN DALLAS
DENTON ELLIS FALLS
FREESTONE HILL HUNT
JOHNSON KAUFMAN LIMESTONE
MCLENNAN NAVARRO ROCKWALL
TARRANT

IN NORTHEAST TEXAS

ANDERSON HENDERSON LEON
RAINS VAN ZANDT

IN SOUTH CENTRAL TEXAS

ROBERTSON

THIS INCLUDES THE CITIES OF...ARLINGTON...ATHENS...BUFFALO...
BURLESON...CALVERT...CANTON...CENTERVILLE...CLEBURNE...CLIFTON...
COMMERCE...CORSICANA...DALLAS...DENTON...EAST TAWAKONI...
EDGEWOOD...EMORY...ENNIS...FAIRFIELD...FLOWER MOUND...FORNEY...
FORT WORTH...FRANKLIN...GLENN HEIGHTS...GRAND SALINE...
GREENVILLE...GROESBECK...GUN BARREL CITY...HEARNE...HILLSBORO...
JEWETT...KAUFMAN...LEWISVILLE...MARLIN...MERIDIAN...MEXIA...
MIDLOTHIAN...OAKWOOD...PALESTINE...PLANO...POINT...ROCKWALL...
TEAGUE...TERRELL...THE COLONY...VALLEY MILLS...VAN...WACO...
WAXAHACHIE AND WILLS POINT.

$$

[srainhoutx]

New MD for our area...




MESOSCALE DISCUSSION 1469
NWS STORM PREDICTION CENTER NORMAN OK
0932 AM CDT THU JUN 19 2008

AREAS AFFECTED...PARTS OF CNTRL/SE TX

CONCERNING...SEVERE THUNDERSTORM WATCH 576...

VALID 191432Z - 191630Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 576
CONTINUES.

BUT...THE POTENTIAL IS DIMINISHING. AND...THE NEED FOR AN
ADDITIONAL WW IS NOT ANTICIPATED.

WEAKENING TRENDS TO ONGOING CONVECTIVE CLUSTER SPREADING SOUTH
SOUTHEAST OF THE DALLAS/FORT WORTH METROPLEX NOW APPEAR WELL
UNDERWAY. SYSTEM IS STILL ACCOMPANIED BY A DISTINCT SURFACE COLD
POOL AND A 30-40 KT NORTHWESTERLY MID-LEVEL JET STREAK...WITH A
MOIST AND POTENTIALLY UNSTABLE AIR MASS AHEAD /SOUTHEAST/ OF IT INTO
TEXAS COASTAL AREAS. HOWEVER...CURRENT SYSTEM RELATIVE FLOW
CONFIGURATION WITH WEAK/SOUTH SOUTHWESTERLY LOW-LEVEL INFLOW AND
MODEST NORTHWESTERLY HIGH LEVEL FLOW IS ALLOWING CONSIDERABLE ANVIL
BLOW OFF INTO THE DOWNSTREAM ENVIRONMENT...WHICH COULD RESTRICT
SURFACE HEATING. AND...WITH WEAK CONVERGENCE MAXIMIZED ON THE
SOUTHWESTERN FLANK OF THE COLD POOL ...POTENTIAL FOR
RE-INTENSIFICATION OF A SIGNIFICANT FORWARD PROPAGATING MESOSCALE
CONVECTIVE SYSTEM INTO TEXAS COASTAL AREAS APPEARS SMALL.

..KERR.. 06/19/2008


ATTN...WFO...LCH...SHV...HGX...FWD...EWX...

http://www.spc.ncep.noaa.gov/products/md/md1469.html

[jasons2k]

Shot at 2008-06-19

The outflow boundry shows up as a nice arc from Fairfleid to near Salado

[srainhoutx]

[srainhoutx]

Updated HWO from HGX this morning...


HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1008 AM CDT THU JUN 19 2008

TXZ163-164-176>179-195>200-210>214-226-227-235>238-201515-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-COLORADO-FORT BEND-
GALVESTON-GRIMES-HARRIS-HOUSTON-JACKSON-LIBERTY-MADISON-MATAGORDA-
MONTGOMERY-POLK-SAN JACINTO-TRINITY-WALKER-WALLER-WASHINGTON-
WHARTON-
1008 AM CDT THU JUN 19 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...LATE THIS MORING THROUGH TONIGHT

A WEAK STATIONARY FRONT DRAPED ACROSS COASTAL SOUTHEASTERN
TEXAS UP INTO THE HUNTSVILLE REGION WILL INTERACT WITH A COMPLEX
OF THUNDERSTORMS MOVING SOUTH INTO THE REGION. THUNDERSTORMS WILL
LIKELY DEVELOP AS THIS SYSTEM MOVES THROUGH THE NORTHERN PORTIONS
OF THE REGION LATE THIS MORNING AND EARLY THIS AFTERNOON. RAINFALL
OF 1 TO 2 INCHES WILL BE POSSIBLE. THE THUNDERSTORMS WILL BECOME
STRONGER THIS AFTERNOON AND BY MID AFTERNOON STRONG TO SEVERE
THUNDERSTORMS WILL BE POSSIBLE AS THIS COMPLEX OF STORMS COLLIDES
WITH THE SEABREEZE. WITH THIS COLLISION THE POTENTIAL FOR HEAVY
RAINS WILL INCREASE...RAINFALL ACCUMULATIONS ACROSS THE CENTRAL
PORTIONS OF SOUTHEAST TEXAS WILL LIKELY AVERAGE AROUND ONE HALF
INCH WITH ISOLATED TOTALS OF 3 TO 4 INCHES.

IN ADDITION THE POTENTIAL FOR STRONG DAMAGING WINDS AND POSSIBLY
HAIL WILL ACCOMPANY THE STRONGER THUNDERSTORMS THIS AFTERNOON AND
EVENING.


.DAY TWO...FRIDAY

THE DAILY REGENERATION OF LOWER ATMOSPHERIC MOISTURE WITH VICINITY
WIND SHIFT BOUNDARIES CREATED BY LOCAL SEA AND GULF BREEZES...PREVIOUS
DAYS STORMS...AND SOUTHERN-MOVING NORTHERN TEXAS STORM SYSTEMS...WILL
KEEP A CHANCE FOR THUNDERSTORMS IN THE FORECAST. ALTHOUGH MANY
THUNDERSTORMS WILL JUST BRING BENEFICIAL RAINS TO COOL DOWN AFTERNOON
HEAT...A FEW ISOLATED STORMS COULD BRIEFLY BECOME SEVERE IN THE
LATE AFTERNOON TO EARLY EVENING HOURS. THE MAIN THREATS FROM THESE
SEVERE STORMS WILL BE DAMAGING DOWNBURST WINDS AND LOCALLY MINOR
FLOODING FROM HIGH HOURLY RAINFALL RATES.

.DAYS THREE THROUGH FOUR...SATURDAY AND SUNDAY

A NEARING COOL FRONT...BECOMING STATIONARY ALONG OR NEAR THE
LOUISIANA TEXAS COASTLINE...WILL PROVIDE AN ADDITIONAL FOCUS FOR
SOUTHEASTERN TEXAS RAINFALL. IF PRECIPITATION DEVELOPS OFF TO THE
NORTHEAST AND BUILDS BACK ACROSS THE HOUSTON GALVESTON
AREA...THE MAIN THREAT WILL BE HIGH RAIN AMOUNTS. SLOWER STORM
MOTION...OR NEAR EAST TO WEST MOVEMENT OF PRECIPITATION...MAY
CREATE FLOODING CONCERNS PRIMARILY ALONG AND EAST OF INTERSTATE 45
AND GENERALLY SOUTH OF INTERSTATE 10.

DAYS FIVE THROUGH SEVEN...MONDAY THROUGH WEDNESDAY

NO HAZARDOUS WEATHER IS EXPECTED.

.SPOTTER INFORMATION STATEMENT...

AT THIS TIME...SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON FOR
AREAS SOUTH OF A LINE FROM SEALY TO CONROE TO LIVINGSTON.

[KWT]

Thats an impressive meso-scale system there, wouldn't mind to see that in the Atlantic!
Still yep can see that outflow boundary on the radar heading away from the complex and so hopefully it will help to set off storm activity along it.

[srainhoutx]

[vbhoutex]

That is one impressive outflow boundary. Ifyou look at visible imagery for our area you can see other outflow boundaries and the sea breeze starting to move N off the coast a little. My guess is it won't be too long before things begin to fire and when/if they do I believe it will be rapidly.

[Ed Mahmoud]

That is one impressive outflow boundary. Ifyou look at visible imagery for our area you can see other outflow boundaries and the sea breeze starting to move N off the coast a little. My guess is it won't be too long before things begin to fire and when/if they do I believe it will be rapidly.

Radar shows storms refiring up I-45 now on that boundary...

[vbhoutex]

That is one impressive outflow boundary. Ifyou look at visible imagery for our area you can see other outflow boundaries and the sea breeze starting to move N off the coast a little. My guess is it won't be too long before things begin to fire and when/if they do I believe it will be rapidly.

Radar shows storms refiring up I-45 now on that boundary...

I just noticed that few minutes ago. Could get interesting quickly for the whole area or will it bypass us just to the North??? Watch and wait.

[jasons2k]

From Jeff @ 1:08PM

Large outflow boundary noted on visible satellite images and HGX radar from Lufkin to S of Huntsville to N of Hempstead moving SE while seabreeze is starting to move inland. Recently thunderstorms have developed on this outflow boundary from the morning MCS over N TX over Walker and San Jacinto counties back into NW Montgomery County. Visible images show cumulus towers with enhancement over NE Harris County and along the coastal seabreeze boundary from near High Island to Texas City to Freeport. As temps. continue to warm into the mid 90’s feel thunderstorms will become increasingly numerous as boundaries collide over the region in the next 3-4 hours. Given extrapolation trends in radar imagery it appears that areas from Liberty County to Harris County to Fort Bend County should be the area where the outflow boundary and seabreeze collide and this should result in decent development. Will watch storm trends closely as once they fire they should move S to SSW and then SW toward Galveston, Brazoria, and Matagorda counties in steering flow on eastern side of SW US ridge axis.

Too bad it looks like my house will be north of the main show - we need the rain bad!!

[KWT]

Wow srainhoutx the whole MCS just decayed at the same time and created a very large and impressive outflow boundary. Indeed storms are re-firing on the boundary now.

[srainhoutx]

Wow srainhoutx the whole MCS just decayed at the same time and created a very large and impressive outflow boundary. Indeed storms are re-firing on the boundary now.

Not to worry. This has been the case for the last 2 days. As Jason stated, those of us N and NW of Houston Metro have missed out on some impressive rains and even hail. But yet another MD is out in CO/NM/TX Panhandle already, increasing chances for something our way as time goes on...

http://www.spc.ncep.noaa.gov/products/md/md1471.html

FYI, we have a stalled frontal boundry just off the coast that "might" be a focal point as well.
Will also note that for the first time this week, rapidly building cumulus clouds visable to our N and NW at this time.

[jasons2k]

Nice cell is popping-up just NW of my house - I sure hope it can hold together & dump some decent rain!

[KWT]

Some decent cells firing along the boundary now on the SE side of the severe thunderstorm watch area that was issued this morning.

[srainhoutx]

Nice cell is popping-up just NW of my house - I sure hope it can hold together & dump some decent rain!

Watching the sky grow progressively darker on the NW side as well. Maybe I will NOT have to water our new landscaping tonight for a change.

[jasons2k]

Well, it's falling apart *just* as it is reaching my house, with the new development occuring to the south now......I was afraid of that. Now I know what Jen feels like.

[srainhoutx]

MESOSCALE DISCUSSION 1475
NWS STORM PREDICTION CENTER NORMAN OK
0216 PM CDT THU JUN 19 2008

AREAS AFFECTED...PARTS OF SE TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 191916Z - 192045Z

A FEW STORMS CAPABLE OF PRODUCING HAIL/GUSTY WINDS ARE POSSIBLE INTO
THE PEAK HEATING HOURS.

DESPITE WEAK FLOW FIELDS/DEEP LAYER SHEAR AND WEAK CONVERGENCE ALONG
A REMNANT COLD POOL ASSOCIATED WITH A NOW DISSIPATED STORM
CLUSTER...VIGOROUS NEW UPDRAFTS HAVE FORMED IN AN ARC ABOVE/BEHIND
THE LEADING EDGE OF THE OUTFLOW ADVANCING TOWARD SOUTHEAST COASTAL
AREAS. THIS IS BEING PRIMARILY DRIVEN BY MODERATE TO STRONG
DESTABILIZATION OF THE BOUNDARY LAYER WITH DAYTIME HEATING...AND
STORM DEVELOPMENT IS EXPECTED TO CONTINUE INTO THE PEAK HEATING
HOURS. A SIGNIFICANT INTENSIFICATION OF ACTIVITY COULD OCCUR AS THE
OUTFLOW BOUNDARY COLLIDES WITH AN INLAND ADVANCING SEA BREEZE BY
20-21Z. THIS MAY ENHANCE THE SEVERE THREAT ACROSS THE COASTAL
PLAIN...INCLUDING PORTIONS OF THE HOUSTON METRO AREA INTO AREAS JUST
NORTH OF BEAUMONT...BUT THIS PROBABLY WILL BE RELATIVELY
SHORT-LIVED.

..KERR.. 06/19/2008


ATTN...WFO...LCH...HGX...