May: IAH Does Not Reach 90 During May. 1970 Mark Achieved

[BlueJay]

May the fourth be with you all.

I hope the rain comes and forces all of those UH graduation parties indoors this weekend!

[srainhoutx]

The 12Z Euro/CMC and UKMet held serve and are much 'wetter' than the operational 12Z GFS. The ensembles appear to be converging on a solution that would make us all a bit happy with a general 1 to 3 inches of rain with some isolated higher totals possible. The GFS was too far offshore with the Coastal disturbance while the other global models are suggesting a slower moving trough and stalling frontal boundary across the Region that may extend into late Sunday/early Monday. Regardless, if the HPC is somewhat correct this would be the best chance of widespread rain we've seen in months around these parts. Keep those fingers crossed...

[wxman57]

Sure was a nice biking weekend. Highs of 88 both days - about perfect. Not too cool, not too warm. The only negative was the wind.

12Z GFS indicates about 1/4" of rain Thursday night/Friday. As has been stated, 12Z Euro is much wetter (1-3" of rain).

[Ptarmigan]

Sure was a nice biking weekend. Highs of 88 both days - about perfect. Not too cool, not too warm. The only negative was the wind.

12Z GFS indicates about 1/4" of rain Thursday night/Friday. As has been stated, 12Z Euro is much wetter (1-3" of rain).

http://home.comcast.net/~cgh57/iahgfs12zmay5.gif

As a compromise, I forecast 1.63 inches of rain.

[srainhoutx]

The evolving pattern continues to advertise more rain chances beyond the late week timeframe. The 00Z Global ensembles are suggesting a general Western trough will remain in place and additional EPAC tropical moisture being tapped into early next week. The MJO appears to continue migrating E across the Pacific until at least mid May to around the 20th. There is also a Kelvin wave assisting with tropical convection across the Eastern Pacific. The longer range guidance suggest another tropical wave may develop later next week as well.

[jasons2k]

Did I read this right? Wouldn't we be EAST of the trough axis?

THE GROUP VELOCITY OF THE MAIN UPPER LEVEL TROUGH IS
FORECASTED TO BE SLOWER THAN THE PHASE VELOCITY OF THE INDIVIDUAL
ENERGY THOUGH WHICH WILL KEEP SOUTHEAST TEXAS WEST OF THE TROUGH
AXIS.

[srainhoutx]

Did I read this right? Wouldn't we be EAST of the trough axis?

THE GROUP VELOCITY OF THE MAIN UPPER LEVEL TROUGH IS
FORECASTED TO BE SLOWER THAN THE PHASE VELOCITY OF THE INDIVIDUAL
ENERGY THOUGH WHICH WILL KEEP SOUTHEAST TEXAS WEST OF THE TROUGH
AXIS.

It appears that is what the guidance is suggesting. What I like is the persistent Western trough with a tap connected to the Eastern Pacific. The convection W of Mexico along the monsoonal trough continues to fire as a broad surface low continues to spin. The GFS suggests yet another surface low developing next week that would keep our PW's rather high (1.8 to near 2.0 and uncapped) and multiple embedded upper air disturbances riding NE across the Southern half of Texas.

The attachment 05062014 1330Z EPAC HPIR.jpg is no longer available

[srainhoutx]

Since this broad area of EPAC tropical disturbed weather will have some influence on our late week rain event, I'll post it here...

SPECIAL TROPICAL WEATHER OUTLOOK...CORRECTED
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM PDT TUE MAY 6 2014

CORRECTED FOR ISSUANCE DATE AND TIME.

FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE.

A LARGE AREA OF DISTURBED WEATHER LOCATED SEVERAL HUNDRED MILES
SOUTH OF MANZANILLO MEXICO IS ASSOCIATED WITH A BROAD AREA OF LOW
PRESSURE. THIS SYSTEM IS EXPECTED TO MOVE GENERALLY NORTHWARD AND
THEN NORTHEASTWARD TOWARD THE COAST OF MEXICO OVER THE NEXT COUPLE
OF DAYS. ENVIRONMENTAL CONDITIONS APPEAR TO BE MARGINALLY
FAVORABLE FOR SOME DEVELOPMENT AT THIS TIME...BUT UPPER-LEVEL WINDS
ARE FORECAST TO BECOME LESS CONDUCIVE WHEN THE DISTURBANCE
APPROACHES THE COAST LATER THIS WEEK. THIS SYSTEM HAS A MEDIUM
CHANCE...30 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT
48 HOURS...AND A MEDIUM CHANCE...30 PERCENT...OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 5 DAYS. REGARDLESS OF DEVELOPMENT...
LOCALLY HEAVY RAINS COULD AFFECT PORTIONS OF SOUTHWEST MEXICO OVER
THE NEXT FEW DAYS.

ANOTHER SPECIAL TROPICAL WEATHER OUTLOOK WILL BE ISSUED BY 8 AM PDT
WEDNESDAY...OR SOONER IF NECESSARY.

$$
FORECASTER PASCH

[unome]

WPC's 7-day looking like lower totals for me now :(

I can't take it if it fizzles...

[jasons2k]

So the HPC shows heavier rains on both sides of us, and we're caught in this wedge of dryness in the middle. What else is new?

[srainhoutx]

There remain a lot of uncertainty regarding the various models and just where the meso features will unfold. The best chance of rain appears to be late Thursday into Friday and likely a decent shot for everyone Friday evening. What is much different in this setup -vs- what we have experienced so far this Spring is no strong front sweeping across the State and uushering in that dreaded NW flow aloft. The trough continues to hang back to our W at least until next Tuesday and that should offer additional chances of rain Sunday into Monday.

Beyond that, there is some indication that moisture begins to build across the Western Caribbean and the Western Gulf as the monsoonal trough takes shape in our Basin. Hopefully before the MJO pulse shifts E around the 20th or so we will see addtional chances of rain. Fingers crossed.

[Katdaddy]

I am also watching Invest 90E in the EPAC which is looking more organized this evening. This may give us some additional moisture boy the weekend.

[unome]

we can dream...

http://earth.nullschool.net/#current/wi ... ,20.04,512

[Ptarmigan]

18Z GFS under two tenths the entire event.

On the bright side, it does have another rain event in 6 days. And what looks like an attempt at developing a subtropical depression for Florida. Hour 132-192 rainfall below. And GFS Florida system that probably doesn't happen.

Salt and grains. But I do tend to trust it in the shorter range, as drier usually verifies better. Euro cut back below an inch at 12Z, I bet it cuts precip even more tonight while I'm sleeping.

http://mag.ncep.noaa.gov/data/gfs/18/gf ... ip_p60.gif

I wonder if the forecast model took into account fot Invest 90E.

[jasons2k]

That rainfall map should be framed or used as the site banner. Look at that donut right over Houston! You can't make this stuff up.

[srainhoutx]

Morning Update from Jeff:

Powerful upper level storm system to affect TX Thursday-Saturday.

Current upper level trough over the western US will slowly progress into the plains today into Thursday. Southerly winds will begin rich moisture advection today with dewpoints and PWS increasing. Eastern Pacific tropical system (90E) located south of the Mexican coast this morning is already starting to spread mid and high level moisture northward into MX and as far north as southern TX.

Factors appear to be attempting to come together for a period of active weather from Thursday afternoon/evening into early Saturday. Trough position on Thursday will be close enough to SE TX to support enough cooling in the mid level to help erode the capping inversion. Dryline feature across central TX should help to develop isolated to scattered strong thunderstorms by the late afternoon hours which will then move eastward toward the area. Unfavorable jet structure will likely limit the amount of development and the eastward movement of any storms. This thinking place our western counties with the greatest rain chances on Thursday.

Friday appears to be setting up to be the day when ingredients peak for thunderstorms and possibly heavy rainfall. A potent short wave rotates through the base of the large scale trough early Friday and will likely develop a band or cluster of thunderstorms over SW TX into WC TX. Downstream air mass over C and SE TX will heat throughout the day and moisten with forecasted PWS values of 1.75 to 2.0 inches and instability of 2500 to 3000 J/kg. Upper level sub-tropical jet begins to split over the area by the afternoon hours yielding greater lift and mid level capping should be a non-factor for the first time in months. Incoming short wave and potential convective cluster/MCS (Mesoscale Convective System) should be able to maintain convection into the area Friday afternoon/evening. Global models have not been handling the placement of the highest QPF (rainfall) with this event well at all and continue to be all over the place. The GFS is drier than the ECMWF mainly due to its placement of the greatest lift and failure to develop a surface trough over the area. While I would like to side with the wetter ECMWF, we are in a drought, and thus far this year the drier model has verified the best. With that said, the potential is certainly there for some heavy rainfall Friday afternoon and evening, but with the mesoscale features taking over it is nearly impossible to predict where the greatest rains will fall. A severe threat will be possible also with the storms that develop on Friday.

Looks like a break in the rainfall potential for the weekend, although could still see some lingering activity Saturday morning. There is some potential for some additional development late in the weekend or early next week, but this is fairly uncertain.

[redneckweather]

I blame the dry weather on Ed with his doom and gloom approach to forecasting. Way to go Ed.

[jasons2k]

That's a bummer, because this really is a make-or-break situation for any remaining green-up or hobbling the trees along until the sea breeze starts (if it does this year at all...).

[BlueJay]

I should go drop into the May thread and mention 0Z EPS control run has right at 1 inch, total, for 16 days through 13 May. And half of that was supposed to fall today, which it won't, or the road goes on forever and the drought will never end.

Until the monumental flood that causes incredible damage and loss of life, but the wild fires will come first. Maybe it'll be the Woodlands.

I am fearful that you could be right, Ed. We were lucky the last time. There is certainly plenty of fire fuel in my area. YIKES! ...

With Ed's prediction and Jasons' observances about the condition of the pines in The Woodlands in mind, we finally invested in a soaker hose this week. I am enjoying using it around the pines and other trees. It claims to drip 1 gallon of water every hour and since it goes directly into the soil at such a slow pace there is no runoff or waste.

[srainhoutx]

The afternoon discussion from NWS San Antonio/Austin offers some insight on the issues regarding QPF and this same issue is likely a problem for SE Texas as well. We often mention that mesoscale feature cannot be accurately determined beyond the 6- 12 hour period and I would caution all the naysayers that with a complex pattern of splitting jet structures, abundant EPAC moisture streaming NE and multiple short waves rotating around the Western trough as well as any convective complexes that develop along I-35 on E. Remember the rainfall is not expected to even start until tomorrow at the earliest around our neck of the woods. The HWP/WPC afternoon QPF update still suggests 1-2 inches possible into early next week and the Dallas/Ft Worth area as well as the eastern areas of Oklahoma have been placed in a slight Rick of excessive rainfall over the next 24 hours.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
326 PM CDT WED MAY 7 2014

.SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...

THERE IS A SLIGHT RISK FOR SEVERE STORMS THIS EVENING AND TONIGHT
ACROSS THE RIO GRANDE PLAINS AND SOUTHERN EDWARDS PLATEAU.

THERE IS A SLIGHT RISK FOR SEVERE STORMS ON THURSDAY ACROSS
EASTERN PORTIONS OF THE REGION INCLUDING BOTH THE SAN ANTONIO AND
AUSTIN METRO AREAS.

AN APPROACHING UPPER LEVEL TROUGH...THE DRYLINE ACROSS WEST CENTRAL
TEXAS...AND A MOIST AIRMASS SPREAD ACROSS SOUTH CENTRAL TEXAS WILL
ALLOW SHOWERS AND THUNDERSTORMS TO DEVELOP THIS AFTERNOON ACROSS
WRN/SWRN PORTIONS OF THE STATE. ADDITIONAL CONVECTIVE DEVELOPMENT
IS EXPECTED (AND ALREADY STARTING) ACROSS THE SERRANIAS DEL BURRO
IN NERN MEXICO. THROUGH THIS AFTERNOON...LITTLE TO NO CONVECTION
IS EXPECTED ACROSS OUR CWA. AS THE EVENING PROGRESSES...SOME OF
THE STORMS ALONG THE DRYLINE AND SOME OF THE STORMS IN NERN MEXICO
WILL PROGRESS EASTWARD INTO THE SOUTHERN EDWARDS PLATEAU AND RIO
GRANDE PLAINS. MODELS CONTINUE TO SUGGEST THAT SOME OF THESE
STORMS WILL BECOME SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS.
PERSISTENT INFLOW COURTESY OF A STRONG LOW LEVEL JET POISED ACROSS
THE REGION SHOULD ALLOW CONVECTION TO CONTINUE OVERNIGHT AND
EXTEND FARTHER EASTWARD.

THE UPPER LEVEL TROUGH WILL MOVE EASTWARD INTO THE CENTRAL PLAINS
ON THURSDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGHOUT THE
DAY ON THURSDAY...WITH THE BEST COVERAGE OF STORMS ACROSS EASTERN
PORTIONS OF THE REGION. UNSTABLE WARM/MOIST SECTOR AHEAD OF THE
UPPER TROUGH AND DAYTIME HEATING WILL LEAD TO A RENEWED POTENTIAL
FOR STORMS TO BECOME STRONG TO SEVERE ACROSS THE HILL COUNTRY AND
THE EASTERN TWO-THIRDS OF THE CWA (GENERALLY EAST OF A LINE FROM
ROCKSPRINGS TO UVALDE TO DILLEY) INCLUDING BOTH THE SAN ANTONIO
AND AUSTIN METRO AREAS. THE PRIMARY THREATS WILL AGAIN BE LARGE
HAIL AND DAMAGING WINDS. HOWEVER...LATEST MODEL GUIDANCE CONTINUES
TO SUGGEST THE POTENTIAL FOR TRAINING/BACK-BUILDING OF STORMS AS
WELL AS A GOOD TAP OF MOISTURE FROM THE AREA OF LOW PRESSURE IN
THE EASTERN PACIFIC...AND THEREFORE THERE IS THE POTENTIAL FOR
HEAVY DOWNPOURS. CONSIDERING WE`RE STILL IN A LONG-TERM
DROUGHT...THE HEAVY RAINFALL WOULD GENERALLY BE WELCOME...BUT THE
CONCERN IS THAT SOILS ARE TOO DRY TO HANDLE INTENSE RAINFALL RATES
AS WELL AS THE POTENTIAL FOR THE HEAVIER RAIN TO OCCUR OVER URBAN
AREAS. A LOT OF UNCERTAINTY REMAINS IN THE QPF FORECAST...WITH THE
POTENTIAL FOR THE SITUATION TO CHANGE OVER THE NEXT 12+ HOURS AS
ADDITIONAL MODEL DATA ARRIVES. THERE IS HIGHER CONFIDENCE IN THE
THREAT FOR HAIL AND DAMAGING WINDS. CHANCES FOR RAIN WILL DECREASE
FROM WEST TO EAST LATE THRS AFTERNOON AND INTO THE EVENING...BUT
AT LEAST A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS WILL LINGER
INTO THURSDAY NIGHT ACROSS MUCH OF THE REGION.