April Weather Discussion.

[srainhoutx]

HGX morning Update...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
913 AM CDT FRI APR 2 2010

.UPDATE...
MORNING DISCUSSION BELOW.

&&

.DISCUSSION...
AT 13Z...LOW PRESSURE WAS LOCATED OVER CENTRAL OKLAHOMA WITH A
WEAK SURFACE TROUGH EXTENDING SOUTHWARD INTO NORTH TEXAS. A DRY
LINE EXTENDED FROM NEAR CHILDRESS TO SAN ANGELO TO WEST OF DEL
RIO. THE DRY LINE WILL PUSH EAST TODAY AND SERVE AS A LOW LEVEL
FOCUS FOR SHOWERS AND THUNDERSTORMS. AT 300 MB...JET STRUCTURE IS
SPLITTING WITH THE MOST PRONOUNCED SPLIT OVER THE NORTHERN ZONES.
12Z SOUNDINGS SHOW A STRONG CAPPING INVERSION IN PLACE. A S-SW LOW
LEVEL JET OF 50 KNOTS IS IN PLACE AND THIS WILL CONTINUE TO DRAW
LOW LEVEL MOISTURE INTO THE REGION. SPC HAS OUTLOOKED MOST OF
SOUTHEAST TEXAS IN SLIGHT RISK TODAY DUE TO ABUNDANT SHEAR. THERE
IS PLENTY OF SHEAR AVAILABLE BUT LIMITED CAPE DUE TO EXTENSIVE
CLOUD COVER AND THE STRONG CAP WILL LIMIT CONVECTIVE POTENTIAL AND
COVERAGE. ADDED SEVERE TO THE ZONES FOR THE NORTHERN ZONES SINCE
THEY ARE CLOSEST TO THE BETTER JET DYNAMICS. WILL LET THE REST OF
THE ZFP RIDE AS IS.

[wxdata]

Dallas/Ft. Worth NWS:

Storms still not impressive on radar, but satellite and radar trends suggest convective inhibition is decreasing as the showers / thunderstorms move east. Still think that the main action will be east of I-35 today.

[srainhoutx]

Austin / San Antonio WFO morning update thinking E of I-35 as well...

NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1034 AM CDT FRI APR 2 2010

.UPDATE...
ATMOSPHERE VERY CAPPED THIS MORNING AND ONLY ISOLATED SHOWERS/PATCHES
OF LIGHT DRIZZLE BENEATH THE INVERSION. WITH LIMITED HEATING DUE
TO CLOUD COVER NOT EXPECTING MUCH CONVECTION UNTIL THE MID AND
LATER AFTERNOON MAINLY ACROSS THE EASTERN CWA...GENERALLY EAST OF I35
WITH THE COLD FRONT. HAVE UPDATED THE RED FLAG WARNING TO START AT
12 NOON AND VALID TO 8 PM BEHIND THE COLD FRONT AS HUMIDITIES WERE
FALLING QUICKER THAN EXPECTED. OTHERWISE EARLY MORNING FORECAST
WAS IN GOOD SHAPE ANY ONLY MINOR CHANGES REQUIRED.

[wxdata]

Front ahead of schedule?

[srainhoutx]

Looks like it. Noticing the showers/storms NW of Austin moving E fairly quickly. A lot of wind damage reports from KS and MO as well.

[wxdata]

Kerrville reports a dew point in the 60's while Junction reports 32°, so there's OUR front- still west of San Antonio.

Showers developing along the I-35 corridor between Dallas and Austin. Still no lightning in those storms yet.

[srainhoutx]

Why is HGX radar still in clear air mode?

[wxdata]

There's nothing to see. All returns are AP caused by the strong inversion. If possible, look at 1.5 elevation- no echoes.

[weatherguy425]

Starting to notice some brighter returns west of Austin, and with the sun out now, maybe storm's will start to take off.

[wxdata]

Weather getting nasty in North Texas. Ft. Worth NWS:

Just received a ham report of pea sized hail...heavy rainfall...and 35-40 mph winds as the cell moved through Gunter.

[wxdata]

A disagreement between the 12z NAM and the 12z GFS-

The NAM brings the warm front through Sunday vs. the GFS which now brings it back on Saturday. That would have an impact on Sunday's forecast of showers vs no showers.

[weatherguy425]

I've got to say, this has got to be one f the most unactive springs in recent memory...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1236 PM CDT FRI APR 2 2010

.DISCUSSION...

SEE AVIATION.

&&

.AVIATION...

BEST CHC FOR TS WILL BE AT CLL AND UTS IN THE 21Z TO 2Z PERIOD.
CAP WILL LIKELY BE TOO STRONG TO OVERCOME FOR IAH TO SEE TS.
MAY SEE SOME SHWR ACTIVITY MID AFT THROUGH MID EVE AT THE TAF
SITES WITH ABUNDANT LOW-LEVEL MOISTURE PRESENT AND SOME HEATING
YET TO COME. PRETTY GOOD CONFIDENCE WE WILL SEE IFR FOG/CEILINGS
NEAR AND SOUTH OF CXO TONIGHT AS THE WEAK BOUNDARY STALLS
OVERNIGHT NEAR THE COAST. TIMING THE ONSET OF THE FOG AND LOW
CEILINGS IS A LITTLE MORE DIFFICULT...BUT TOOK MY BEST SHOT AT IT.

[wxdata]

Line of storms along the I-35 corridor seem to be falling apart...


add: A little more life in the line as of 1:30.

[wxdata]

From D/FW NWS:

"Storms are far from impressive...but we are seeing some redevelopment along the dryline between McKinney and Bonham. Also seeing some development between Hillsboro and Killeen. These have a long way to go to get organized...but with daytime heating...we will continue to monitor for further development."

[wxdata]

skinny girlyman line right on the boundary, and I suspect there is no lightning. Compare to Oklahoma storms.

The 12z NAM may have correct- the model brought rain chances at IAH down below 15%. The model has a higher rain chance on Sunday than today. However as they say, the day is still young...

[srainhoutx]

Dan and I were just discussing how there is better moisture the futher W one goes which matches the thoughts of the NWS of an E of I-35 corridor senario. Beginning to see some cumulus clouds structures to my N and W.

[wxdata]

The front brings.......pollution

AIR QUALITY ALERT MESSAGE
TEXAS COMMISSION ON ENVIRONMENTAL QUALITY
RELAYED BY NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
220 PM CDT FRI APR 2 2010

...OZONE WATCH ON SATURDAY FOR THE HOUSTON AREA...

THE TEXAS COMMISSION ON ENVIRONMENTAL QUALITY...HAS ISSUED AN
OZONE WATCH FOR THE HOUSTON...GALVESTON...AND BRAZORIA AREAS FOR
SATURDAY...APRIL 3RD. ATMOSPHERIC CONDITIONS ARE EXPECTED TO BE
FAVORABLE FOR PRODUCING HIGH LEVELS OF OZONE POLLUTION IN THE
HOUSTON...GALVESTON...AND BRAZORIA AREAS.

[svrwx0503]

Dan and I were just discussing how there is better moisture the futher W one goes which matches the thouhts of the NWS of and E of I-35 corridor senario. Beginning to see some cumulus clouds structures to my N and W.

Yeah, I was just looking over some surface charts and noticed the same thing and interestingly enough there is a pocket of mid to upper 50's dew points across our northern and north central zones this afternoon which is limiting the amount of instability across those regions. Wind shear looks moderate at best at this time with the KHGX VWP showing a little bit of backing in the lower levels over the past hour or so. High res visible sat imagery shows a lot of mid-high level clouds streaming across southeast Texas with some cu streets trying to develop under the strong cap which is most likely the cu structures srain is seeing to his north and west.

Without much forcing along the front not sure if we are going to be able to get much out of this system as it moves through later this evening. The line of storms along the I-35 corridor is just really struggling to hold on as it moves off to the east.

[wxdata]

A small change from the SPC in their early afternoon update- slight risk further north-

"FARTHER S...DESTABILIZATION HAS BEEN QUITE LIMITED -- WHICH HAS THUS
FAR HINDERED STORM EXPANSION/INTENSIFICATION WITHIN THE LARGER-SCALE
BAND. HOWEVER...WITH DEWPOINTS IN THE MID TO UPPER 50S AND SOME
HEATING UNDERWAY FROM E TX/LA NWD INTO THE SERN THIRD OF
MO...ADDITIONAL DESTABILIZATION SHOULD SUPPORT THE POTENTIAL FOR
ISOLATED SEVERE STORM EVOLUTION THIS AFTERNOON/EVENING.
HIGH-RESOLUTION WRF MODEL RUNS CONTINUE TO SUPPORT THIS
SCENARIO...WITH STORMS INCREASING OVER THE NEXT SEVERAL HOURS IN
ADVANCE OF A COMPACT FEATURE OVER W TX NOW ROUNDING THE BASE OF THE
LARGER-SCALE TROUGH. AS THIS FEATURE SHIFTS EWD ACROSS TX/OK AND
INTO MO/AR...ASSOCIATED/EXPECTED CONVECTIVE INCREASE COULD SUPPORT
SOME SEVERE THREAT THROUGH THE END OF THE PERIOD OVER THE OZARKS
VICINITY AND POSSIBLY SWD INTO PARTS OF E TX/LA/MS."

[wxdata]

A little later than forecast, but completely overcast in the Galleria area....