Texas Summer 2016

[aggiecutter]

[weatherdude1108]

Wow! Me Likey!!

Once we get past today and Friday's crazy heat, a change appears in the offing.

000
FXUS64 KEWX 111133
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
633 AM CDT THU AUG 11 2016

.PREV DISCUSSION... /ISSUED 417 AM CDT THU AUG 11 2016/

SHORT TERM (Today through Friday)...
A continued theme of high pressure and hot conditions will prevail
again today. Only difference in the forecast today versus
yesterday is the approach of some cloud cover from the east due to
the westward moving low pressure system over the southern
Mississippi Valley. This probably won`t do much to stop heating
but could delay slightly the mixing out of moisture in the
morning. However, even one or two degrees of dewpoint would push
heat indices well into the 108 range this afternoon as some
isolated spots yesterday were able to reach 112 even. Therefore,
went ahead with another heat advisory for the same area and
duration as yesterday as that seemed to verify quite well. Was
toying with the idea of delaying the advisory onset until 2PM but
kept 1 PM since highs are expected to be a degree or so higher
across the board today and heat indices may also be a bit ahead of
schedule from yesterday.

While Friday temps are expected to still be in the triple digits
across much of the CWA, the difference will be lower dewpoints.
This will keep heat indices right at the advisory threshold for
many locations. At the current time...it does appear another
advisory issuance may be needed Friday afternoon as well, but
possibly more confined to counties east of the 35 corridor and
south of HWY 90.

LONG TERM (Friday Night through Wednesday)...
Over the weekend, the moist H5 trough from the gulf will come
onshore and move northwest into Central Texas by Sunday. Also...a
weak frontal boundary will push into the central part of the state
due to weak H5 troughing in the north-central US. Moisture will be
more than plentiful as PWATs well over 2 inches are being
advertised. The question will be lifting. However...with the
stalled boundary situated across the northern periphery of the
CWA...a decent 20 kt LLJ on the right side of the 850 mb low
center in proximity to the I-35 corridor and instability above
1000 j/kg Sunday afternoon...certainly think that locally heavy
rainfall is a possibility. Precipitation efficiency analysis
highlights an area from Kerrville east and north where heaviest
rain potential would exist, but expect with outflow interactions
focusing lift at isolated spots, locally heavy rain will be a
possibility across much of the CWA Sunday through Monday.

This suite of model runs maintain QPF over the area throughout
the extended period. With the high levels of moisture situated
across the area throughout the week, would expect increased cloud
cover and afternoon convection each day through the week. While
the cloud cover should bring high temps down to more normal
values, RH values may stay up and result in muggy afternoons.

[gboudx]

From jeff:

Streak of high heat index and 100 degree afternoons will be ended by this weekend with onset of much higher rain chances.

Inverted westward moving mid level trough over the central Gulf coast states this morning with some very impressive PWS values of 2.5-2.7 inches will slowly work westward and into eastern TX over the next 48 hours. At the same time an upper level trough will approach from the west and help break down the ridge of high pressure over TX which has been in firm place for the last 5-8 days.

Before the break down of the upper level ridge, the area will suffer through at least one more day of high heat values and 100 or greater temperatures. Morning lows today are running about 4 degrees warmer than yesterday so think 100 will be easily reached today even with increasing cloud cover. May even make 100 again on Friday. Yesterday featured afternoon heat index values of 108-112 over the region or at or above advisory levels so the heat advisory will be in effect for today and maybe again on Friday.

Saturday-mid next week:
Onset of significant deep moisture plume just to our east over Louisiana and weakening effects of upper level ridging aloft point to a rapid increase in rain chances. PWS soar into the 2.2-2.4 inch range by Sunday with convective temperatures falling from the upper 90’s to the lower 90’s. Expect widespread coverage of showers and thunderstorms Sunday-Tuesday along the seabreeze boundary each afternoon. High moisture levels and little to no capping support rain chances really at just about anytime…but think the most active periods will be late morning into the afternoon hours with some surface heating.

Currently not looking a sustained excessive rainfall, but a few of the global models are suggesting some organization to the activity off of a weak frontal boundary Sunday moving southward out of NC TX. Storms will be prodigious rainfall producers with high hourly rainfall totals of 2-3 inches certainly possible in a very tropical air mass. Think 30-40% will work of Saturday and then go up to 60% Sunday-Tuesday. Upper level ridging attempts to build back into the area from the east by the middle of next week…but never looks to really gain a go foothold so will continue with daily rain chances through the end of the week.

Tropics:
Not much to talk about across the Atlantic basin with a lot of dry and sinking air. May see more favorable conditions begin to arrive across the basin by the third week of August.

[ColdFusion]

[Portastorm]

Both the GFS and Euro now on board for weekend rainfall for the Austin area ... anywhere between 1-2". Let's hope we get some relief from the blast furnace.

[Brent]

CBS 11 just had 4"+ for the metroplex and eastward... 2-3" west of there.

[Ntxw]

A lot will depend on the location of the slow/stalled boundary. Along, near it will get the most rain and persistent cooler temperatures. Should sag Ne to Sw across the state.

[Ntxw]

Long range euro is still attempting a crispy air mass late in the run. If real the trof/front could get us into the 60s (lows) if extrapolating. Fall not too far away now

[vbhoutex]

And Houston!! 5th day in a row at or above 100f!! Ugh!! Just dropped from 102F feels like 116F to 100F feels like 113F here at the house in W. Houston. Rain? rain? anybody? anybody? Supposedly our LA friends are sending some rain our way to "celebrate" the weekend.

[Brent]

FWD has multiple paragraphs for the AFD today...

FXUS64 KFWD 112058
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
358 PM CDT THU AUG 11 2016

.DISCUSSION...
We`ve been advertising it for the past few days, and it`s still
coming: a significant pattern shift to cooler and wetter weather
during the weekend, persisting through most of next week. You can
keep the parkas in the closet, but most folks in North and Central
Texas will at least get to use an umbrella and windshield wipers
through early next week.

TONIGHT/FRIDAY: Isolated showers/thunderstorms along the far NW
edge of our county warning area should dissipate by sunset, due
to a lack of sigificant forcing. Friday, we`ll contend with the
final day of major heat, with readings everywhere exceeding the
century mark. Will keep the Heat Advisory going through 7 pm
Friday evening for areas generally along and east of I-35, where
humidities will be higher and Heat Index values will exceed the
106-107 range. For areas north of a Comanche-Sulphur Springs line,
instability, deep layer moisture and upper forcing may be
sufficient to touch off a few showers/t-storms by late afternoon
Friday, so small PoPs will be warranted.

FRIDAY NIGHT THROUGH MONDAY: The long-awaited cold front from the
northlands will be arriving in our Red River counties after
midnight Friday night, eventually pushing (slowly) to near a
Killeen-Athens line by late afternoon Saturday. In addition to the
convergence offered by this boundary, North Central Texas will
also come under the influence of a deep latitude trough extending
from Minnesota to N TX, and the western edge of a sub-tropical low
moving westward from LA into E TX by late Saturday. While this
isn`t your typical synoptic scale pattern, there appears to be
multiple mechanisms for forcing for ascent. When plentiful
moisture (as inferred from precipitable waters in excess of 2
inches) is added to the mix, there is good confidence in the
development of scattered to numerous showers and thunderstorms
across the region.

Initially, the best opportunities for rainfall will be north of
I-20 on Saturday, closer to frontal convergence and
frontogenetical forcing. Indeed, much of Central Texas will have
to endure another day of rugged heat Saturday, though there should
be just enough cloud cover to preclude the need for a Heat
Advisory in these areas. As time progresses Saturday night
through Monday, we`ll likely see one or more axes of convection
develop across the region, generally parallel to the orientation
of the 850 and 700 mb troughs that will reside over the region.
While the general trend is to shift the higher PoPs south and east
through time, there is signficant uncertainty on exactly where the
heaviest convection and QPF is going to set up through Monday.
Current guidance suggests that the best dynamics and moisture will
coincide over much of the area Sunday night and Monday morning, so
we think the threat of heavier rain - and possible isolated urban
flooding - will exist during this timeframe. It`s waaaay too early
to consider a flash flood watch, owing to the timing/location
uncertainties, but folks should be aware that this system`s
moisture content may facilitate some flooding issues for North
and/or Central Texas.

Suffice to say, nearly all of the area SHOULD wind up seeing
rainfall through Monday, and there`s confidence that many areas
will pick up over an inch of welcome rain through Monday.

TUESDAY THROUGH THURSDAY: The wet pattern starts to fade through
this period, but doesn`t dissipate completely. Guidance suggests
that North Texas will remain in a "weak area" between mid-level
ridge centers over the Intermountain West and Southeast. With deep
layer moisture lingering over the area, we`ll continue to see at
least scattered, mainly diurnally-driven convection through
Thursday - and perhaps beyond that. With thicknesses remaining in
check and clouds remaining fairly plentiful, we`ll see daytime
highs recover only into the lower (and possibly middle) 90s by
Thursday. All in all, a nice break from the regimen of heat we`ve
experienced since the beginning of the month.

Bradshaw

[aggiecutter]

Rain, Rain, and more Rain:

[Brent]

The GFS keeps DFW in the 70s on Monday with widespread rain...

and the hottest temperature on the entire run after Saturday is a mere 95. with frequent rain chances throughout.

The Euro doesn't even hit 90 at DFW after the front through 240 hours...

[1900hurricane]

While the heat has been bad, the dewpoints have been ridiculous. HGX even issued an Excessive Heat Warning briefly today, which is the first time I can remember seeing one from them.

[gboudx]

According to an email from Jeff Lindner early this week, there was an Excessive Heat Warning for HGX on 8/9 as well.

"NWS has issued a rare Excessive Heat Warning until 700pm this evening and from 100pm to 700pm Wednesday for Harris, Galveston and Brazoria Counties."

Someone could look through the HGX discussions to verify this.

[TexasBreeze]

There was one 2 days ago issued for 3 counties by the bay, and one today for the southern half of the area. I saw Pearland had a 117 heat index today! The Tuesday evening discussion said not one ex heat warn was issued anytime before from that office!

[Rgv20]

Excessive Heat Watch

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE BROWNSVILLE TX
715 PM CDT THU AUG 11 2016

...DANGEROUS HEAT AND HIGH HEAT INDEX VALUES FRIDAY...

.THE COMBINATION OF NEAR RECORD HIGH TEMPERATURES RANGING FROM
THE UPPER 90S NEAR THE COAST TO WELL ABOVE THE CENTURY MARK
INLAND...ALONG WITH HIGH ELEVATED DEW POINTS AND RELATIVE HUMIDITY
VALUES... WILL RESULT IN DANGEROUSLY HOT...CALID WEATHER AND HIGH
HEAT INDEX READINGS FRIDAY AFTERNOON.

TXZ252-253-121000-
/O.NEW.KBRO.HT.Y.0010.160812T1700Z-160812T1900Z/
/O.NEW.KBRO.HT.Y.0011.160812T2200Z-160812T2300Z/
/O.NEW.KBRO.EH.A.0001.160812T1900Z-160812T2200Z/
STARR-HIDALGO-
INCLUDING THE CITIES OF...RIO GRANDE CITY...ROMA...MCALLEN...
EDINBURG...PHARR...MISSION...WESLACO
715 PM CDT THU AUG 11 2016

...HEAT ADVISORY IN EFFECT FROM NOON TO 2 PM CDT FRIDAY...
...EXCESSIVE HEAT WATCH IN EFFECT FRIDAY AFTERNOON...
...HEAT ADVISORY IN EFFECT FROM 5 PM TO 6 PM CDT FRIDAY...

THE NATIONAL WEATHER SERVICE IN BROWNSVILLE HAS ISSUED A HEAT
ADVISORY...WHICH IS IN EFFECT FROM NOON TO 2 PM CDT FRIDAY. A
HEAT ADVISORY HAS ALSO BEEN ISSUED FROM 5 PM TO 6 PM CDT FRIDAY.
IN ADDITION...AN EXCESSIVE HEAT WATCH HAS BEEN ISSUED. THIS
EXCESSIVE HEAT WATCH IS IN EFFECT FRIDAY AFTERNOON.

* TEMPERATURE...100 TO 110 DEGREES IN THE AFTERNOON. HEAT INDEX
VALUES FROM 111 TO 115 DEGREES. HEAT INDEX VALUES VALUES FROM
116 TO 120 DEGREES OR MORE WILL BE POSSIBLE IN THE EXCESSIVE
HEAT WATCH AREA.

* IMPACTS...PROLONGED OUTDOOR ACTIVITY WITHOUT PROPER REST...
HYDRATION...OR OTHER PRECAUTIONARY ACTIONS MAY RESULT IN HEAT
EXHAUSTION OR EVEN HEAT STROKE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HEAT ADVISORY IS ISSUED WHEN THE HEAT INDEX...A MEASURE OF HOW
IT FEELS WHEN TEMPERATURE AND HUMIDITY ARE COMBINED...EQUALS OR
EXCEEDS 111 FOR 2 HOURS OR MORE DURING THE DAY.

AN EXCESSIVE HEAT WATCH MEANS THAT A PROLONGED PERIOD OF HOT
TEMPERATURES IS EXPECTED. THE COMBINATION OF HOT TEMPERATURES AND
HIGH HUMIDITY WILL COMBINE TO CREATE A DANGEROUS SITUATION IN
WHICH HEAT ILLNESSES ARE POSSIBLE. DRINK PLENTY OF FLUIDS...STAY
IN AN AIR-CONDITIONED ROOM...STAY OUT OF THE SUN...AND CHECK UP
ON RELATIVES AND NEIGHBORS.

&&

$$



Look at this forecast for my neighborhood! I'm used to the heat but 122 is a bit on the high side!

Friday: Sunny and hot, with a high near 110. Heat index values as high as 122. South southeast wind 10 to 14 mph.

[A.V.]

And Houston!! 5th day in a row at or above 100f!! Ugh!! Just dropped from 102F feels like 116F to 100F feels like 113F here at the house in W. Houston. Rain? rain? anybody? anybody? Supposedly our LA friends are sending some rain our way to "celebrate" the weekend.

Bush Airport always seems to reach 100F so readily; it has more 100F days this year than College Station, or anywhere else around it does. Houston Hobby has yet to record a 100F days (quite a few 99Fs, though). Pearland has 2 100F days (but the thermometer may be near some kind of "hot spot" that props up temps abit).

The more this heat goes on, the weirder it gets; the fact that Bush keeps reaching 100F, despite thick cloud cover, and high moisture from the low, is very bizarre.

[TeamPlayersBlue]

I agree its very strange. I think the urban heat island is starting to effect them. Also, just this morning they recorded an all-time record high minimum of 82 degrees. With the gulf being very warm even for this time of year and such a high dewpoint, seems to help. Reaching 100 that many days in a row is odd though. Could be due to the lack of sea breeze all week though.

[South Texas Storms]

Is it hot enough up there in the Dallas area? DFW high temp is up to 107 and still could go higher. Brutal.

[Ntxw]

Could be the last 100 or greater day in 2016 and its going out with a bang...dang.