Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 4

[Srain]

The overnight guidance suggest a bit less chance in the rainfall department today, but as we saw yesterday the computer models do not perform well with subtle meso features and upper trough/lows. The developing 500mb trough/upper low is beginning to wrap up over Central Texas and guidance suggests that feature will slowly drop WSW to the Lower Rio Grande Valley by Sunday. Scattered showers and storms are developing offshore this morning along the Middle/Upper Texas Coast and moving NW. Rain chances look to increase to area wide on Saturday as the upper air disturbance becomes a bit better organized and continues to draw deep tropical moisture inland. PW's near 2.0 and low convection temps in the 80's should produce sufficient conditions for those that are under the stronger storms to pick up a quick inch or two of rain. While it appears areas to the SW of the Houston Metro have the better chance of seeing heavier rainfall totals, I would be cautious as like we saw yesterday the exact placement of those stronger storms cannot be determined and are often modeled incorrectly. The further NE you are from Houston, the lesser the rain chance it would appear.

[DoctorMu]

That she blows! Comin' ashore.

[Srain]

What a difference a year makes. Last year we were under 10 inches for all of 2011 in my locations across SE Texas. As of the first 180 days in Harris County, this is where we stand in the rainfall department.

[icebreaker5221]

Interesting little wave moving onshore. Lots of different storm modes: multi-cell clusters up by Houston, linear MCS down by Brownsville, and a large stratiform rain region just offshore between the two.

How's the lawn Ed?

[DoctorMu]

Interesting little wave moving onshore. Lots of different storm modes: multi-cell clusters up by Houston, linear MCS down by Brownsville, and a large stratiform rain region just offshore between the two.

How's the lawn Ed?

His could be wet.

I ran the sprinklers last night...a virtual guarantee of precipitation today in BCS!

[Srain]

I received almost 2 inches from the first wave this morning in NW Harris County. A second wave is sweeping in from my SE and third wave is nearing Galveston Island...

[Ed Lizard]

Interesting little wave moving onshore. Lots of different storm modes: multi-cell clusters up by Houston, linear MCS down by Brownsville, and a large stratiform rain region just offshore between the two.

How's the lawn Ed?

Solid soaking, sprinkler getting entire weekend off. 88D suggests near half an inch. Which fits the out my window estimate. Someday, a rain gauge.

[Srain]

Scattered showers and storms will be the theme for one more day, although not as widespread as the upper low near Monterrey slowly slides further W and a trough axis near Galveston Bay weakens. The ridge then builds back into the Plains and Mid West allowing for temps to increase to the mid 90's inland and near 90 along the Coast with isolated sea breeze showers/storms that are more typical of a Texas 4th of July Holiday week.

[PottercountyWXobserver]

I'm officially in Houston, and lets just say, I'm pleasantly surprised at the great weather! Oh man, let this pattern stick around for a bit! lovin the onshore flow.

[Ed Lizard]

Just looking at 10 day ensemble heights, the core of the heat ridge should be Northwest of us in 10 days, suggesting seasonal warmth, and the center of the ridge should be far enough away to allow some sea breeze activity, and perhaps the 0Z Day 10 Euro was suggesting as the ridge migrates West, a bit of it pinches off, such that by mid month, a piece of the 500 mb ridge is heading towards Texas from the East, with enhanced rain chances.

Signal for East Pac action, although fishy in nature, on the GFS ensembles.Just looking at 10 day ensemble heights, the core of the heat ridge should be Northwest of us in 10 days, suggesting seasonal warmth, and the center of the ridge should be far enough away to allow some sea breeze activity, and perhaps the 0Z Day 10 Euro was suggesting as the ridge migrates West, a bit of it pinches off, such that by mid month, a piece of the 500 mb ridge trough is heading towards Texas from the East, with enhanced rain chances.

Signal for East Pac action, although fishy in nature, on the GFS ensembles.

^Since I posted this on the KHOU-TV 11 forum run by Steve, new Euro coming in seems to be on same page with 0Z Euro, or a bit of the polar trough maybe getting under the ridge somewhere around Florida. I am, of course, engaged in wishful speculation that a 500 mb low would start retrograding beyond Day 10 towards my lawn. Note also a weaker 500 mb weakness crossing my lawn at Day 10.

[Srain]

Morning e-mail from Jeff:

Wetting rains affect much of the area this past weekend helping to break the dry and hot pattern that had developed the last week of June. A few locations really were dumped on….NW Harris County and around Matagorda Bay.

Upper ridge is slowly building back across the region from the NE this morning with moisture profiles lowering from the extremely tropical levels on Saturday to more marginal levels today. Radar is quite this morning compared to the last 3 days where numerous showers and thunderstorms were already ongoing by this time offshore and along the coast. Drier air mass lurking offshore will spread inland today as upper level low and deep tropical moisture shift westward toward the Rio Grande plains and the area becomes increasingly under the influence of the building upper level high. Still think there will be just enough moisture today for a few seabreeze storms especially over our SW counties, but 20% should cover this.

Ridge builds in to the north of the area for much of the week, but not overhead like last week. E to ESE deep layer flow on the south side of this feature will support at least a slight chance of thunderstorms each day along the seabreeze with better chances possibly coming on Wednesday and then again toward the end of the week/weekend as weak disturbances/tropical waves pass by to our south briefly enhancing moisture. Without the ridge overhead along the the recent wetting rainfall highs will be in the low to mid 90’s instead of the low 100’s for much of the week.

All in all finally a more typical summer type pattern for the area with near/slightly above normal temperatures and a slight chance of daily afternoon thunderstorms.

[DoctorMu]

Not as much rain as hope from the weekend rains (0.4 in) in CLL, but I'll take it compared with a year ago. Clouds and haze will keep temps in the mid 90s (instead off 100°+) with a 20% of a shower w/ the seabreeze and more easterly flow.

[Ed Lizard]

Not as much rain as hope from the weekend rains (0.4 in) in CLL, but I'll take it compared with a year ago. Clouds and haze will keep temps in the mid 90s (instead off 100°+) with a 20% of a shower w/ the seabreeze and more easterly flow.

I got decent rain, but not as much as I wanted. Drying out, but I don't think 2011 type endless heat and dry.

[Ed Lizard]

Not completely boring pattern ahead.

[Srain]

HPC:

A TUTT CELL/UPPER LOW FRACTURED OFF THE TAIL OF THE EASTERN TROUGH

IS EXPECTED RETROGRADE UNDER THE BASE OF THE WARM CORE RIDGE AND

SPREAD MODERATE RAINS FROM THE SOUTHEAST FRIDAY/SATURDAY WESTWARD

ALONG/INLAND OF THE GULF COAST TOWARDS EASTERN TEXAS BY EARLY NEXT

WEEK...WHICH WILL ACT TO SUPPRESS HIGH TEMPERATURES FROM THEIR

RECENT EXTREME VALUES. THE NORTHERN PLAINS SHOULD BE WET AS A

FRONTAL BOUNDARY SLOWLY SAGS SOUTHWARD THROUGH THE

REGION...SPURRING CONVECTIVE COMPLEXES ALONG THE WAY.

[Srain]

Looking ahead to the coming weekend and into next week, the 12Z guidance and ensembles are very suggestive of a rather potent storm system creeping W under the Ridge and rain chance look to increase as PW's near the 2.0 range and very low convective temps become commonplace across the Eastern half of Texas. The GFS and Canadian also suggest a stalling frontal boundary may come into play during the first half of next week providing additional dynamics for producing some widespread rainfall across the region. We will see.

[DoctorMu]

Encouraging signs for next week indeed. Even a few firecracker popcorn variety this afternoon off the seabreeze

[Srain]

I hope everyone had a great 4th of July Holiday. Now attention turns E as an inverted trough/upper air disturbance meanders W under the Ridge along the Northern Gulf Coast. PW's increase to the 2.0+ range this coming weekend as a stronger return flow of Gulf moisture moves inland across the Eastern Half of the Lone Star State. Early next week a slow moving frontal boundary is expected to sag S as a deep East Coast trough develops and the heat ridge shifts towards the West Coast. That slowly sagging boundary appears to be a focal point of healthy rainfall totals as well as a trapped trough across Texas as the upper air pattern becomes very weak. Daily scattered showers/storms should increase in coverage on Saturday and it looks like the upcoming work week will remain unsettled and stormy as well. We will see. One thing for certain, we are not in a pattern like last summer...

[Srain]

Morning e-mail from Jeff:

Large ridge of high pressure over the central US into the eastern US will move slowly into the western US this weekend and this will keep TX on the southern edge of this high pressure dome. SE TX will continue to lie near the edge of the ridge allowing moisture and disturbances to approach and move into the area from the east over the next week.

Daily pattern of seabreeze showers and thunderstorms will continue today and Friday with 20-30% coverage during the afternoon hours. Storms have been really good rainfall producers where they have developed (I picked up 1.95 yesterday, and totaled 4.83 inches since last Thursday). Weak steering winds will yield slow storm motions and good rainfall under the stronger cores…a good example of a few will get a really good dumping while others only miles away remain dry.

Better chances for widespread rains move into the area this weekend into much of next week as several upper level lows look to move westward along the northern Gulf coast into TX. Each feature will bring with it an increase in moisture and a good chance at showers and thunderstorms as a tropical air mass moves back into the region. GFS is showing fairly high rain chances 50-60% each day starting on Saturday into the middle of next week and this seems reasonable given the forecasted favorable thermo profiles and general lack of ridging and subsidence aloft coupled with tropical moisture influx.

Overall not looking at significantly organized storms, just more coverage along the local seabreeze each afternoon and along outflow boundaries. Tropical air mass will continue to provide good rainfall rates, but lack of cell mergers and long lasting/training storms should negate any flooding threat. Increased rainfall and cloud cover will continue to hold temperatures in the lower 90’s for highs with muggy overnights in the mid 70’s (normal for this time of year). Oppressive humidity will continue to make it “feel” warmer than it actually is….but still a for cry from last summer!

[DoctorMu]

GFS, NAM, and euro in agreement on retrograde action at the southern edge of the high pressure ridge. Euro more optimistic about rain persisting through the end of next week. Indeed, a dramatic improvement from last year!

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX

311 PM CDT THU JUL 5 2012

.DISCUSSION...

DESPITE REASONABLE MOISTURE LEVELS AND COOLER 850 MB TEMPS...

CONVECTION HAS BEEN SLOW TO DEVELOP. AN EXPANSIVE 500 MB OVER THE

CENTRAL U.S. WILL SHIFT NORTH OVER THE WEEKEND AND WEST EARLY NEXT

WEEK. THIS WILL ALLOW A SERIES OF WEAK UPPER LEVEL DISTURBANCES TO

PUSH WEST TOMORROW AND AGAIN OVER THE WEEKEND. THE FIRST IMPULSE

APPEARS TO BE SOUTH OF NEW ORLEANS AND THIS SHOULD ARRIVE LATE

FRIDAY MORNING. FCST SOUNDINGS LOOK UNCAPPED AND CONVECTIVE TEMPS

ARE AROUND 90 BUT THE SOUNDINGS DON`T SHOW MUCH IN THE WAY OF A

DEEP SATURATED LAYER SO WILL STAY WITH 20 POPS FOR NOW. THE SAME

HOLDS TRUE ON SAT/SUN. DESPITE PW VALUES INCREASING TO AROUND 2.00

INCHES ON SUNDAY...FCST SOUNDINGS HINT AT SOME DRIER AIR ADVECTING

INTO THE LOW/MID LEVELS. WENT WITH 20/30 POPS WITH THE HIGHER POPS

CLOSER TO THE COAST AND DEEPER MOISTURE. AM NOT EXPECTING A WASH

OUT OVER THE WEEKEND AND FEEL POP FCST IS PERHAPS A BIT GENEROUS.

AS THE UPPER RIDGE SHIFTS WEST...AN UPPER LEVEL TROUGH OVER THE

EAST COAST WILL RETROGRADE WEST. LOWER HEIGHTS COUPLED WITH AN

INCREASE IN MOISTURE SHOULD YIELD HIGHER RAIN CHANCES MON-THU.

BOTH THE GFS AND ECMWF BRING A FRONT INTO TEXAS BUT WEAK PRESSURE

RISES BEHIND THIS FEATURE SHOULD PRECLUDE THE FRONT FROM REACHING

SOUTHEAST TEXAS. FRONT OR NO FRONT...WITH PW VALUES NEAR 2.2

INCHES AND DIVERGENT UPPER LEVEL WINDS...FEEL SHRA/TSRA WILL

INCREASE IN COVERAGE. THE ECMWF ACTUALLY KEEPS THE UPPER TROUGH

AND ASSOCIATED WEAKNESS OVER TEXAS THROUGH NEXT WEEKEND. THIS GETS

SOME SUPPORT FROM THE LONG RANGE CANADIAN. WENT WITH CHANCE POPS

MON-FRI WITH THE BEST CHANCE FOR RAIN TUE-THU. THE WEEK AHEAD

LOOKS MUCH WETTER THAN CLIMO. WENT CLOSE TO MEX GUIDANCE FOR TEMPS

AND FEEL THESE MAY NEED TO BE LOWERED IF PRECIP PANS OUT AS FCST. 43

[PottercountyWXobserver]

Question for all you longtime Houston residents. Is the NE side of town always "wetter" than the SW side of town. Just the last 3 days looking at convective sea breeze t-storms developing during the afternoon,they always tend to develop on the east side of town and head towards IAH before weakening while approaching the station. Obviously this "wetter" scenario will have less meaning in large scale disturbances, but I really noticed this for garden variety storms. Is there something along the gulf shore that causes a local convergence on the eastside of town? Haha I've only been in Houston for 5 days, and I'm already noticing slight nuances in the weather to the area or maybe this is just a coincidence on my part and it has no statistical meaning.

[Srain]

One more day of isolated sea breeze pulse type storm then things are looking wet. What is interesting is the agreement that most of next week will bring a very strong chance of daily showers/storms across much of the Central/SE TX Region and we could some of these totals come close to verifying, then Flood Flooding issues may become a problem as the stalled frontal boundary washes out across the area. Stalled frontal boundaries and moist tropical air with PW's over the 2.2+ range can often lead to a bad mix. We will see.

HPC QPF Forecast updated this morning through day 5...

[Srain]

The overnight guidance has come into rather good agreement with a complicated and complex weather pattern developing from the Southern Rockies on E to the East Coast. The heat ridge that has brought record high temps across the Central and Eastern US will begin to break down and retreat W into the Great Basin and embedded mid/upper air disturbance rotate W under that retreating Ridge along the Gulf Coast. Lowering heights across Texas and increasing deep tropical moisture with PW's in the 2.2 to 2.4 range will become established across the Eastern half of the Lone Star State today and meander W tomorrow. A developing trough over the Great Lakes will activate a slow moving frontal boundary on Monday which will sag S into Central/SE Texas and on E before pulling up stationary. As a weak northerly flow aloft develops N of that boundary, and onshore flow at the surface develops S of that front bringing increasing Gulf and Western Caribbean tropical moisture surging inland and setting the stage for a multi day rainfall event that has some potential to linger into next weekend. The fly in the ointment is the potential for very slow moving high rainfall rate storms to develop and training potential is not out of the question. Folks should be prepared for daily storm chances and copious rainfall rates over the next 5-7 days as the upper air pattern collapses and conditions become stagnant with little or very slow moving tropical downpours. I would not be surprised to see some locations receiving 5-6 inch+ rainfall totals from this upcoming very wet multi day pattern.

HGX:

A WET WEATHER PATTERN MOVING INTO THE REGION TODAY AND WILL REMAIN

THROUGH AT LEAST WEDNESDAY AND MAY WELL STILL BE OVER THE AREA

NEXT WEEKEND. THE RIDGE THAT HAS BEEN BRINGING THE HEAT TO THE

EASTERN U.S. WEAKENING AND LIFTING A LITTLE NORTH WHICH WILL BRING

ABUNDANT MOISTURE (PW 2-2.35") WEST AND ACROSS THE AREA BY SUNDAY

MORNING. DAYTIME HEATING SHOULD DRIVE SHRA/TSRA TODAY WITH

SCATTERED STORMS DEVELOPING BY 2 PM. STORM MOTIONS SHOULD SLOW

DURING THE AFTERNOON AND BRIEF HEAVY DOWNPOURS WILL BE

POSSIBLE...SLOWER SUNDAY. LITTLE IF ANY INHIBITION WILL BE PRESENT

BY NOON WITH THE SEABREEZE MOVING INLAND LATE IN THE AFTERNOON.

S/W OVER LA WILL MOVE INTO THE AREA THIS AFTERNOON SO GIVEN THE

ABOVE HAVE RAISED RAIN CHANCES OVER MOST OF AREA. RAIN CHANCES

REMAIN HIGH THROUGH THE WEEK AS RIDGE SPLITS AND TROUGHING

DEVELOPS DOWN THE MISSISSIPPI AND THEN RETROGRADES OVER THE UPPER

TEXAS COAST. WEAK COLD FRONT SHOULD DROP THROUGH OKLAHOMA MONDAY

AND BE MOVING INTO SETX OR JUST TO THE NORTH OF SETX TUESDAY

AFTERNOON...BECOMING ANOTHER FOCUS FOR RAINFALL. CLOUD COVER WILL

BE MUCH GREATER THIS WEEK AND SO HAVE BEGUN TO DIAL DOWN THE

AFTERNOON HIGHS AND STARTED NUDGING UP THE DEWPOINTS. KEEP THE

UMBRELLAS HANDY THIS WEEK IF YOU DON`T WANT TO GET WET.

[Ed Lizard]

Kind of slow moving, but crude eyeball interpolation gets the Southwest Louisiana activity near my lawn within a few hours past peak heating.

[PottercountyWXobserver]

Anyone know what is wrong with IAH ? The station isn't reporting. I wish I new the current temp, its hot out there!

[DoctorMu]

Kind of slow moving, but crude eyeball interpolation gets the Southwest Louisiana activity near my lawn within a few hours past peak heating.

Sprinklers on Stun. Kirk out.

[bubba hotep]

Wasn't expecting much today and was surprised to see this bad boy when leaving lunch a few minutes ago:

MESOSCALE DISCUSSION 1428

NWS STORM PREDICTION CENTER NORMAN OK

0145 PM CDT SAT JUL 07 2012

AREAS AFFECTED...N-CNTRL TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 071845Z - 072015Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED DAMAGING WIND GUSTS POSSIBLE ACROSS PORTIONS OF

N-CNTRL TX THIS AFTERNOON. WW IS UNLIKELY.

DISCUSSION...VISIBLE SATELLITE AND REGIONAL RADAR IMAGERY SHOW A

CLUSTER OF STORMS LOCATED 25 W OF PRX IN NRN TX...MOVING WSW AT

AROUND 20 KT. AIRMASS AHEAD OF THIS ACTIVITY IS HOT AND DEEPLY

MIXED...WITH TEMPERATURES IN THE UPR 90S. THE HOT TEMPERATURES AND

STEEP LOW-LEVEL LAPSE RATES ARE YIELDING DEWPOINT DEPRESSIONS IN

EXCESS OF 30F. GIVEN THIS ENVIRONMENT...AN ISOLATED DAMAGING WIND

THREAT WILL EXIST AS STORM CLUSTERS MOVE SW ACROSS THE AREA DURING

THE AFTERNOON.

..GARNER/WEISS.. 07/07/2012

ATTN...WFO...FWD...OUN...

[Srain]

The 12Z guidance continues to advertise a wet pattern for the foreseeable future. The only wrinkle is with the mid/upper air disturbance currently to our E over Louisiana and just how much further W that feature meanders. We are sort of in a strange place regarding climo with the forecasted stalling frontal boundary just to our N, and HGX explains this well in their afternoon update. One thing is for certain, we are not in a pattern like the past couple of years when we couldn't buy a rain drop to save our lives...

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX

332 PM CDT SAT JUL 7 2012

.DISCUSSION...

SCATTERED SHOWERS AND THUNDERSTORMS SHOULD DIMINISH IN AREAL

COVERAGE WITH THE LOSS OF HEATING THIS EVENING. IN THE

MEANTIME...SLOW STORM MOVEMENT WILL ALLOW FOR SOME LOCALIZED HEAVY

RAINFALL WITH THE ISOLATED STRONGER CELLS.

MODELS CONTINUE TO SHIFT THE INVERTED TROF THAT HAS SLOWLY BEEN

TRAVELING THE NRN GULF COAST FURTHER WWD INTO THE UPPER TX

COASTAL WATERS TONIGHT & SUN. EXPECT ANOTHER ROUND OF SHRA/TSTMS

TO DEVELOP AFTER MIDNIGHT AND TOWARD MORNING IN THE WATERS AND

NEAR THE COAST. THEN AS YOU ADD DAYTIME HEATING, LOW CONVECTIVE

TEMPS AND DEEP TROPICAL MOISTURE TO THE EQUATION - EXPECT SCT

ACTIVITY TO SPREAD INLAND AND INCREASE IN AREAL COVERAGE THRU THE

LATE MORNING AND AFTERNOON HOURS.

RINSE AND REPEAT QUITE POSSIBLY FOR THE NEXT 6-10 DAYS AS A

TROF/SHEAR AXIS/WEAKNESS IN THE MID LEVEL RIDGE GRADUALLY TAKES

SHAPE BY MIDWEEK AND WAFFLES ABOUT FROM THE GREAT LAKES-MS

VALLEY-S TX AREA.

IN THE SHORT TERM INTO THE EARLY WEEK PERIOD IT APPEARS BEST

MOISTURE WILL BE SITUATED ALONG & NORTH OF I-10. SOME MODELS ARE

STILL TRYING TO BRING A FRONTAL BOUNDARY INTO TX AND STALL IT AS

FAR S AS THE CLL AREA TUE/WED. THIS WOULD ALSO BRING A FOCUS FOR

HEAVIER PRECIP. NOT EXACTLY CLIMATOLOGICALLY FAVORABLE FOR SUCH A

SCENARIO IN JULY - BUT STRANGER THINGS HAVE OCCURRED AND WILL

NEED TO KEEP AN EYE OUT. REGARDLESS...STORM STEERING FLOW REMAINS

FAIRLY WEAK SO ALSO NEED TO WATCH FOR THE SLOWER MOVING STRONGER

CELLS TO PRODUCE LOCALIZED HEAVY RAINFALL.

[Ed Lizard]

Rain not over the lawn, but the radar is looking good, and Euro ensembles still have us in the 500 mb happy place next weekend.

[ticka1]

Rain and thunder here on the west side of Houston near Baytown and Mont Belvieu.