Texas Summer - 2014

[South Texas Storms]

An awesome discussion from the Austin/San Antonio NWS Office on nighttime core rain events.

"AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
916 AM CDT FRI JUN 20 2014

.UPDATE...
THE MCV RESPONSIBLE FOR THE HEAVY RAIN CONTINUES TO SLOWLY MOVE
NORTH THIS MORNING. THE HEAVIEST RAIN IS CURRENTLY CONFINED TO
NORTHWESTERN VAL VERDE COUNTY NEAR THE CITY OF LANGTRY. HAVE RUN A
QUICK UPDATE TO ACCOUNT FOR CURRENT TRENDS. WITH THE LOCATION OF
THE MCV TO THE NORTHWEST OF THE REST OF THE CWA...THE REST OF THE
AREA WILL BE IN A FAVORABLE POSITION FOR ISOLATED TO SCATTERED
ACTIVITY THIS AFTERNOON WITH DEEP PERSISTENT SOUTHERLY FLOW.

THE SAME MCV WAS ABLE TO GENERATE VERY HEAVY RAINFALL TWO NIGHTS
IN A ROW WITH HEAVY RAIN WEST OF LAREDO 2 NIGHTS AGO. SOME PEOPLE
MAY BE WONDERING WHY THIS OCCURS AND WE WILL TRY TO EXPLAIN THIS.
MCV STANDS FOR MESOSCALE CONVECTIVE VORTEX...OR A SMALL LOW CENTER
THAT IS CREATED FROM PERSISTENT CONVECTION. THE ENVIRONMENT ACROSS
SOUTH CENTRAL TEXAS AND ESPECIALLY NEAR THE RIO GRANDE RIVER WAS
VERY MOIST WITH PRECIPITABLE WATER VALUES NEAR 2 INCHES. LIGHT
WINDS ARE IN PLACE IN THE UPPER LEVELS OF THE ATMOSPHERE WITH A
WEAK LOW-LEVEL JET JUST OFF THE SURFACE. MCVS FORM AFTER
CONVECTION DEVELOPS AND HEAVY RAIN PERSISTS FOR SEVERAL HOURS. WHEN
HEAVY RAIN IS SITTING NEARLY STATIONARY BECAUSE OF THE WEAK UPPER
LEVEL WINDS...THE REPEATED PRODUCTION OF HEAVY RAINFALL LEADS TO
A PROCESS CALLED LATENT HEAT RELEASE. THIS MEANS THAT FOR THE
ATMOSPHERE TO MAKE RAIN IT REQUIRES ENERGY TO CONVERT WATER VAPOR
INTO LIQUID DROPS AND THIS ENERGY CAUSES THE TEMPERATURE OF THE
ATMOSPHERE TO INCREASE IN THE MID AND UPPER LEVELS. THIS WILL
INCREASE THE STATIC STABILITY OF THE ATMOSPHERE WHICH INCREASES
THE VORTICITY WHICH LEADS TO THE SPINNING NATURE OF THESE FEATURES.
THE MCV CAN BE DIFFICULT TO FORECAST BECAUSE THERE ARE A LOT OF
VARIABLES TO DETERMINE HOW LONG THEIR LIFE WILL BE. STRONG WINDS
CAN TEAR THEM APART AND THEY CAN ONLY LIVE IF CONVECTION CONTINUES
TO SUSTAIN THEM. MCVS ARE PARTICULARLY TROUBLESOME AT NIGHT
BECAUSE THE INCREASE IN THE LOW-LEVEL JET FEEDS THE SYSTEM AND THE
INCREASE IN WIND SPEED INCREASES THE LOW-LEVEL LIFT INTO THE
SYSTEM. MCVS ARE WARM-RAIN PRODUCERS DUE TO THE WARMING IN THE
MID-LEVELS AND ARE THEREFORE EFFICIENT IN THE RAIN PRODUCTION AND
CAN LEAD TO VERY HEAVY RAIN IN A SHORT AMOUNT OF TIME LIKE WE SAW
LAST NIGHT ALONG THE RIO GRANDE RIVER.

CURRENT FORECAST SHOWS THE MCV MOVING NORTH OF THE CWA FOR TONIGHT
AND AM NOT EXPECTING A REPEAT ACROSS OUR AREA REGARDLESS IF THE
SYSTEM SURVIVES FOR ANOTHER NIGHT IN ITS CURRENT STATE.

HAMPSHIRE"

[hriverajr]

Yes we finally got off the snide in Del Rio. For awhile I thought the MCV was going to wash out, but it came back with a vengeance. It's interesting that the official amount was around 4 inches. I personally had 5.36 in and I am half a mile away. Other individuals were also having close to or around 5 inches. We had extensive flooding in the city, so I am wondering if perhaps there is an equipment issue there at the airport. We pretty much had non stop heavy rain for over 4 hours. At any rate I am It's about time!

[Portastorm]

Yes we finally got off the snide in Del Rio. For awhile I thought the MCV was going to wash out, but it came back with a vengeance. It's interesting that the official amount was around 4 inches. I personally had 5.36 in and I am half a mile away. Other individuals were also having close to or around 5 inches. We had extensive flooding in the city, so I am wondering if perhaps there is an equipment issue there at the airport. We pretty much had non stop heavy rain for over 4 hours. At any rate I am It's about time!

Feast or famine in Texas ... I'll tell you what.

[TheProfessor]

Ok guys and gals, so on another website someone posted on a doom thread that after seeing the twin tornadoes Nebraska, they had a dream of a place getting hit by triplets. I replied and said that it would be Highly unlikely that triplet tornadoes (not multi vortex) would occur because usually for a Tornadoes to be consider twins one would have to be a cyclonic tornado while the other is an anti-cyclonic tornado right? And if there is a third one then one of the tornadoes would be multi vortex right? Was I right, or am I totally off?

[somethingfunny]

Some impressive wet analogs are showing up within the next few weeks leading up to July 4th holiday. Heat ridge setting up over the east and northeast almost always spells unusual cooler/wetter anomalies for Texas post Solstice (i.e last year in early July). More in depth later.

WSI++ downgrade watch!

This was in last night's AFD from Fort Worth. It's way too early to know, and there will be model fluctuations, and today's AFD didn't mention it (instead saying we should be dry after Wednesday), and it's certainly not likely.... but... what I am saying is.... I'm saying there's a chance

(ISSUED 312 AM CDT FRI JUN 20 2014)

ATMOSPHERE WILL CONTINUE TO DRY AND HAVE LEFT SATURDAY AND SUNDAY
PRECIP FREE AS THE HIGH BUILDS CLOSER TO NORTH TX. BY
MONDAY...WITH HIGH LOCATED IN MEXICO...A SERIES OF TROUGHS WILL
MOVE ACROSS THE SOUTHERN PLAINS AND HAVE THUS CONTINUED WITH THE
LOW POP CHANCES IN THE NORTH MONDAY AND TUESDAY...AND AREA WIDE
WEDNESDAY THROUGH SATURDAY MORNING.

OF INTEREST IN THE EXTENDED...BY WEDNESDAY THE ECMWF BUILDS AN
UPPER TROUGH ORIENTED NORTH/SOUTH ACROSS TEXAS AND KEEPS IT IN
PLACE THROUGH 240 HOURS. IF THIS STATIONARY TROUGH WOULD
MATERIALIZE (THE GFS BUILDS IN A RIDGE WEST AND PUSHES THE TROUGH
EAST) IT WOULD GIVE US PERIODS OF MUCH NEEDED PRECIP OVER A
NUMBER OF DAYS. ECMWF PUSHES PWATS ABOVE 2 INCHES AT DFW
WEDNESDAY AFTERNOON...BUT THE GFS LOOKS MUCH DRIER. ONE ANALOG
THAT COMES TO MIND WOULD BE THE WIDESPREAD RAIN/FLOODING THAT
OCCURRED IN JUNE 2007 WITH A SIMILAR TROUGH. AGAIN...THERE IS NO
CONSENSUS ON THIS OCCURRING SO WE CAN ONLY LOOK FOR MORE
AGREEMENT IN FUTURE GUIDANCE 84.

[Portastorm]

One of the things I wish we saw more of in NWS forecast discussions is continuity. That's been my beef from time to time with EWX is that they'll mention something of interest in one discussion and then you may not see it mentioned again. Furthermore, the actual forecast may take a big swing in momentum and there's no reference to it in the discussion. It would be nice to see something like: "you know that Euro run we talked about Friday morning? Well, it's probably not going to verify due to this-this-and-this" or "as we have been referencing the last few discussions, we're now seeing more support for the Euro scenario next week of a major trough axis ..."

[srainhoutx]

There is increasing very rich and deep tropical moisture streaming N over Mexico and tapping the monsoonal trough as well as Invest 95E which will likely be absorbed into the trough and spread across Texas. The 00Z Euro/Canadian were very wet across Texas while the 00Z GFS was drier. The 12Z GFS has trended much wetter than previous runs and water vapor imagery suggests the potential may increase. The fly in the ointment is an easterly wave crossing the Caribbean. MIMIC does indicate an increase in tropical moisture surging into the Western Gulf next week setting the stage for a potentially wet week into next weekend.

[aggiecutter]

Looks like a wet time ahead for the Eastern 2/3rds of Texas:

[weatherdude1108]

I am very much liking the last two posts about deep tropical Pacific moisture and easterly Caribbean wave.

[weatherdude1108]

:uarrow:

One of the things I wish we saw more of in NWS forecast discussions is continuity. That's been my beef from time to time with EWX is that they'll mention something of interest in one discussion and then you may not see it mentioned again. Furthermore, the actual forecast may take a big swing in momentum and there's no reference to it in the discussion. It would be nice to see something like: "you know that Euro run we talked about Friday morning? Well, it's probably not going to verify due to this-this-and-this" or "as we have been referencing the last few discussions, we're now seeing more support for the Euro scenario next week of a major trough axis ..."

I know exactly what you mean! Very inconsistent. They need to take some pointers from the DFW office.

[Ntxw]

Today is the summer solstice, longest days of the year. It goes downhill from here in terms of sunlight hours. As for summer still 8-10 week hill to climb.

DFW's high today has been 88, cloudy. Who would've guessed that for the solstice given the past 5 solstices have been pushing 100?

[ravyrn]

I'm been loving this summer so far! So is my wallet!

Account Ending In: XXXXXXXXX0363
Payment Amount Due: $40.63
Payment Due Date: 07/07/2014

I live in a very small apartment and watch usage, but have hardly had to turn on the A/C thus far. Mostly just kept the fan on when home.

[JDawg512]

:uarrow:

One of the things I wish we saw more of in NWS forecast discussions is continuity. That's been my beef from time to time with EWX is that they'll mention something of interest in one discussion and then you may not see it mentioned again. Furthermore, the actual forecast may take a big swing in momentum and there's no reference to it in the discussion. It would be nice to see something like: "you know that Euro run we talked about Friday morning? Well, it's probably not going to verify due to this-this-and-this" or "as we have been referencing the last few discussions, we're now seeing more support for the Euro scenario next week of a major trough axis ..."

Thank you for bringing this up, I've been wondering the same thing about EWX and I totally agree witb you. There is a completely different take between the forcasts issued around 3 to 4 a.m. and 3 to 4 p.m.

The forecast updates overnight are much more interesting while the afternoon updates are just blah! There is no consistency at all and like you said whatever is mentioned overnight is almost never brought up in the afternoon updates. Who's in charge of issuing them at EWX anyways?

[somethingfunny]

+1 that Porta, Fort Worth is pretty good but they can be inconsistent too. The 2007 analog certainly hasn't come up again, but we've gotten a pair of CAVANAUGH discussions, this morning and yesterday morning, which have been as enlightening as they always are.

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE FORT WORTH TX
424 AM CDT SUN JUN 22 2014

.DISCUSSION...

EARLY MORNING REGIONAL RADARS SHOWED WIDESPREAD RAIN SHOWER
ACTIVITY ACROSS NORTH AND CENTRAL TEXAS. THE RADAR RETURNS LOOKED
MORE IMPRESSIVE THAN WHAT RAIN GAUGES ACROSS THE AREA RECORDED AS
RAINFALL ACTUALLY REACHING THE GROUND. MOST RAINFALL AMOUNTS
ACROSS THE AREA HAD ONLY RECORDED A TRACE WITH A FEW SITES
PICKING UP A HUNDREDTH OF AN INCH. NO LIGHTNING WAS OBSERVED
ACROSS NORTH OR CENTRAL TEXAS AT THE TIME OF THIS DISCUSSION. THE
00Z FWD RAOB OBSERVED A PRECIPITABLE WATER OF AROUND 1.8
INCHES...OR ABOUT ONE HALF INCH UP FROM 24 HRS AGO. TAKING A LOOK
AT A COMPARISON OF YESTERDAY EVENINGS RAOB AND FRIDAY EVENINGS
RAOB SHOWS THAT THE BULK OF THE INCREASE OF MOISTURE OCCURRED IN
THE MID TO UPPER TROPOSPHERE. THIS MAKES SENSE AS YESTERDAYS WATER
VAPOR SATELLITE IMAGERY SHOWED TROPICAL PLUME OF MOISTURE
STREAMING NORTH FROM MEXICO TOWARDS TEXAS. THE MOUNTAINOUS TERRAIN
OF NORTHERN MEXICO SCOURS OUT ALL OF THE LOWER TO MIDDLE
TROPOSPHERIC MOISTURE...BUT A DEEP SATURATED AIR MASS WAS OBSERVED
ABOVE THE 550 MB LEVEL. WATER VAPOR SATELLITE IMAGERY SHOWS THIS
PLUME OF MOISTURE IN PLACE...STILL CONNECTED TO THE PACIFIC
TROPICAL MOISTURE PLUME NEAR THE BAJA PENINSULA. 00Z UPPER AIR
ANALYSIS SHOWED A WEAK UPPER TROUGH LOCATED OVER NORTHWEST
TEXAS...AND THIS TROUGH WAS LIKELY MOVING VERY SLOWLY TO THE
SOUTHEAST TOWARDS NORTH TEXAS EARLY THIS MORNING.

TODAY AND TONIGHT...ASIDE FROM THE INCREASE IN DEEP LAYER
MOISTURE...THE 00Z FWD RAOB ALSO SHOWED A VERTICAL WIND PROFILE
CHARACTERIZED BY VEERING WINDS WITH HEIGHT THROUGH MOST OF THE
TROPOSPHERE. THIS IS AN IMPORTANT CHANGE FROM PREVIOUS RECENT
RAOBS BECAUSE IT INDICATES THAT BROAD WARM AIR ADVECTION AND LIFT
IS PRESENT OVER THE REGION...SO NO OBVIOUS LAYER OF SUBSIDENCE
PRESENT. THIS MEANS THAT ONGOING SCATTERED TO WIDESPREAD RAIN
SHOWER ACTIVITY IS LIKELY TO CONTINUE THIS MORNING ACROSS MUCH OF
NORTH AND CENTRAL TEXAS. THE INTENSITY OF THE PRECIPITATION MAY
ACTUALLY PICK UP A BIT THIS MORNING AS THE WEAK UPPER TROUGH MOVES
DIRECTLY OVER THE AREA REDUCING STABILITY A BIT AND PROVIDING SOME
ADDITIONAL...ALBEIT WEAK...FORCING FOR ASCENT. DESPITE THE LACK OF
SIGNIFICANT RAINFALL REPORTS EARLY THIS MORNING...THINK THAT MANY
LOCATIONS WILL PICK UP AT LEAST ONE TENTH OF AN INCH OF RAINFALL
BEFORE PRECIPITATION BEGINS TO MOVE EAST THIS AFTERNOON.

THE UPPER TROUGH IS EXPECTED TO BE LOCATED NEAR THE I-35 CORRIDOR
BY EARLY THIS AFTERNOON...MOVING OUR BEST RAIN CHANCES EAST OF
INTERSTATE 35 AND OVER EAST TEXAS BY THIS EVENING. BEHIND THE
UPPER TROUGH...WEAK SUBSIDENCE WILL PROBABLY SHUT OFF RAINFALL AND
MAY EVEN THIN OUT SOME OF THE THICK MID TO UPPER LEVEL CLOUD COVER
THAT HELD TEMPERATURES DOWN IN THE UPPER 80S FOR MOST OF THE CWA
YESTERDAY. THIS WILL PROBABLY NOT OCCUR FAST ENOUGH TODAY TO
RESULT IN SIGNIFICANT SUNSHINE/HEATING THIS AFTERNOON...SO LEFT
HIGHS IN THE MID TO UPPER 80S FOR MOST LOCATIONS.

MOST LOCATIONS SHOULD REMAIN DRY AFTER SUNSET WITH THE WEAK UPPER
TROUGH OFF TO OUR EAST. ATTENTION THEN TURNS TO THE HIGH PLAINS
WHERE THE CONSENSUS OF HIGH RESOLUTION MODEL GUIDANCE INITIATES A
SQUALL LINE JUST BEFORE MIDNIGHT. THIS IS EXPECTED TO OCCUR NEAR
THE TX/OK PANHANDLES IN THE 03 TO 06Z TIME FRAME. ONCE
ORGANIZED...THIS SQUALL LINE IS EXPECTED TO MOVE SOUTHEAST IN
WEAK NORTHWEST FLOW ALOFT. MOST MODELS SHOW THIS SQUALL LINE
WEAKENING...BUT MAINTAINING A SUFFICIENT AMOUNT OF STRUCTURE TO
MAKE IT INTO THE NORTHWESTERN PORTIONS OF THE CWA JUST BEFORE
SUNRISE. THE SQUALL LINE...OR SQUALL LINE REMNANTS...ARE THEN
EXPECTED TO PUSH EAST BEFORE DISSIPATING LATE MONDAY MORNING. MOST
MODELS LEAVE SOME SORT OF CONVECTIVE REMNANTS ORIENTED ALONG THE
INTERSTATE 20 CORRIDOR BY 18Z EARLY MONDAY AFTERNOON. ASSUMING
THAT THIS IS AN OUTFLOW BOUNDARY...THE BEST CHANCES OF NEW
AFTERNOON THUNDERSTORM ACTIVITY SHOULD BE JUST SOUTH OF THIS
BOUNDARY...OVER THE SOUTHERN PORTIONS OF NORTH TEXAS AND INTO
CENTRAL TEXAS.

HAVE HIGHEST POPS IN THE FORECAST NORTH OF INTERSTATE 20 TOMORROW
MORNING...AND THEN SOUTH OF INTERSTATE 20 TOMORROW AFTERNOON WITH
THIS IN MIND. OF COURSE...THE ACTUAL STRENGTH AND POSITION OF THE
SQUALL LINE AND ITS ASSOCIATED OUTFLOW BOUNDARY WILL HAVE A BIG
IMPACT ON MONDAYS FORECAST. CHANGES WILL NEED TO BE MADE TO THE
FORECAST BASED ON WHAT ACTUALLY HAPPENS WITH THIS SQUALL LINE...AS
OPPOSED TO WHAT THE HIGH-RESOLUTION MODELS ARE DOING WITH THIS
FEATURE. IN GENERAL A WEAKER SQUALL LINE WILL LEAD TO LOWER POPS
MONDAY MORNING AND HIGHER POP NORTH OF INTERSTATE 20 MONDAY
AFTERNOON. A STRONGER SQUALL LINE MAY CLEAR OUT POPS COMPLETELY
FOR SOME AREAS ON MONDAY AFTERNOON.

FOR MONDAY NIGHT...MODELS CONTINUE TO INDICATE THAT SOMEWHAT SMALL
SHORTWAVE TROUGHS WILL MOVE THROUGH THE NORTHWEST FLOW ALOFT FROM
MONDAY THROUGH TUESDAY. MODELS ARE FAIRLY CONSISTENT AT SHOWING
ONE OF THESE TROUGHS CAUSING SHOWERS AND THUNDERSTORMS TO
REDEVELOP ACROSS THE REGION MONDAY NIGHT. THE SHORTWAVE TROUGHS
ARE REAL...OBSERVABLE ON WATER VAPOR SATELLITE IMAGERY...SO THE
MAIN QUESTION WILL BE WHAT DOES OUR THERMODYNAMIC ENVIRONMENT LOOK
LIKE AFTER MONDAYS SQUALL LINE AND AFTERNOON THUNDERSTORM
ACTIVITY. ASSUMING OUTFLOW HAS KEPT NORTHERN AREAS SOMEWHAT COOLER
THAN SOUTHERN ZONES...ANTICIPATE THAT AN APPROACHING SHORTWAVE
TROUGH OVERNIGHT WOULD RESULT IN AN ENHANCEMENT TO THE NOCTURNAL
LOW-LEVEL WIND MAXIMA. THIS LOW-LEVEL ENHANCED WIND CORRIDOR OR
JET WOULD THEN INTERACT WITH THE WEAK TEMPERATURE GRADIENT TO
ENHANCE LIFT OVER THE RELATIVELY COOLER AIR OVER THE NORTHERN CWA
MONDAY NIGHT. THE BIGGER THE TEMPERATURE DIFFERENCE...THE STEEPER
THE LOW-LEVEL ISENTROPIC SURFACES WILL BE...ENHANCING LIFT FOR NEW
PRECIPITATION OVERNIGHT. HAVE THE BEST POPS LOCATED NORTH OF
INTERSTATE 20 OVERNIGHT AS A RESULT.

BY TUESDAY...THERE ARE SO MANY MESOSCALE POSSIBILITIES TO CONTEND
WITH THAT THEY MORE OR LESS BLEND INTO NOISE LEVEL FOR FORECAST
PURPOSES. THE LARGE SCALE ENVIRONMENT LOOKS TO REMAIN SUPPORTIVE
OF THE POSSIBILITY OF PRECIPITATION WITH A MORE OR LESS UNCAPPED
THERMODYNAMIC ENVIRONMENT WITH A TROPICAL TYPE MOISTURE PROFILE IN
PLACE. AS A RESULT...JUST WENT WITH BROAD BRUSHED 20 POPS FOR
TUESDAY MORNING...WITH 30 POPS IN THE AFTERNOON AS TROPICAL TYPE
MOISTURE PROFILES USUALLY RESPOND TO DIURNAL HEATING WITH ISOLATED
TO SCATTERED STORMS EACH DAY. HAVE TEMPERATURES AT NEAR SEASONAL
NORMALS.

***WEDNESDAY THROUGH FRIDAY...MODELS ARE REALLY STRUGGLING WITH
ADVERTISING A CONSISTENT SOLUTION FOR THE LARGE SCALE FLOW REGIME
OVER THE REGION FROM MID-WEEK AND BEYOND. IN GENERAL THERE ARE
STILL SOME MODELS THAT SHOW UPPER LEVEL RIDGING TO OUR EAST AND
WEST...RESULTING IN A COL IN THE FLOW FIELD OVER THE CWA. THIS
WOULD ESSENTIALLY TRAP WHATEVER IS HERE...HOLDING IT MORE OR LESS
IN PLACE THROUGH THURSDAY. THE ECMWF...NAM...AND CANADIAN
INDICATE THAT WE WILL HOLD ON TO A TROPICAL TYPE AIRMASS IN THIS
COL...RESULTING IN TUESDAY-LIKE DIURNAL ENHANCEMENTS TO
THUNDERSTORM CHANCES... DISREGARDING MESOSCALE DETAILS FOR NOW.

THE GFS CONTINUES TO PUSH A STRONG UPPER LEVEL TROUGH OVER THE
WESTERN CONUS MID-WEEK...MORE OR LESS LAYING OVER THE WESTERN
RIDGE OVER TEXAS AND CLEARING THE COL ALOFT OFF TO THE EAST. THIS
WOULD RESULT IN A MUCH DRIER AND WARMER FORECAST FOR MID-WEEK AND
BEYOND. AT THIS TIME...IT`S DIFFICULT TO KNOW WHICH SOLUTION IS
LIKELY TO VERIFY...SO HERE`S A FEW THINGS TO WATCH MOVING FORWARD:

1. THE ECMWF IS GENERALLY SLOWER WITH THE BIG WESTERN CONUS UPPER
TROUGH...AND ACTUALLY STALLS A PIECE OF IT OUT OVER NEW MEXICO BY
FRIDAY AND HOLDS IT THERE OVER MOST OF NEXT WEEKEND. THE GFS IS
MUCH MORE PROGRESSIVE. THE MAIN DIFFERENCE BETWEEN THE TWO IS THAT
THE ECMWF ORIGINATES THIS STALLED OUT UPPER TROUGH FROM NORTHERN
JAPAN THIS MORNING. THE GFS SEEMINGLY DOES NOT STALL OUT THIS
UPPER TROUGH BECAUSE IT DOES NOT RESOLVE THIS SHORTWAVE OVER
NORTHERN JAPAN THIS MORNING. LOOKING AT HEMISPHERIC SATELLITE
IMAGERY IS JUST TOO LARGE OF A SCALE TO PICK OUT SOMETHING SO
SMALL...SO I DO NOT KNOW IF THIS FEATURE EXISTS OR NOT. WILL HAVE
TO WATCH IT MOVING FORWARD IF THE ECMWF CONTINUES TO INDICATE THIS
IS IMPORTANT IN FUTURE FORECASTS.

2. THE GFS HAS BEEN MORE CONSISTENT WITH ITS RUN TO RUN SOLUTIONS.
CONSISTENCY DOES NOT EQUAL ACCURACY...BUT PREVIOUS EXPERIENCE HAS
SHOWN THAT THE MORE CONSISTENT MODEL HAS A BETTER TRACK RECORD.
THIS DOES NOT ALWAYS WORK OUT OF COURSE...BUT ITS AT LEAST WORTH
NOTING AS THE ECMWF HAD A RIDGE WHERE IT CURRENTLY HAS A STALLED
OUT UPPER LOW YESTERDAY AT THIS TIME.

3. IF THE COL SETS UP...THAT IS THE ECMWF/NAM/CANADIAN SOLUTION
VERIFIES...WE WILL HAVE TO MONITOR FOR WARM-CORE VORTEX
AMPLIFICATION FROM MID-WEEK AND BEYOND. IF YOU WANT TO SEE WHAT
WARM-CORE VORTEX AMPLIFICATION DOES DYNAMICALLY...JUST LOOK AT THE
21/00Z CANADIAN SOLUTION. IT SHOWS PERSISTENT CONVECTION ALONG THE
GULF COAST WEDNESDAY INTO THURSDAY AND ALLOWS THIS 24-36 HRS OF
QUASI-STATIONARY LATENT HEAT RELEASE RAMP UP A STRONG MID-LEVEL
LOW PRESSURE SYSTEM BY THURSDAY AFTERNOON. THIS "LAND-O-CANE"
LOOKING FEATURE THEN MOVES NORTH ACROSS NORTH TEXAS ON THURSDAY
DUMPING COPIOUS AMOUNTS OF RAIN EAST OF INTERSTATE 35. THIS
PROBABLY WILL NOT HAPPEN...BUT HIGHLIGHTS THE POTENTIAL FOR
LOCALIZED FLOODING RAINFALLS IN UPPER LEVEL COL FLOW REGIMES WITH
A TROPICAL AIRMASS IS IN PLACE. THE CANADIAN SOLUTION IS PROBABLY
WRONG...BUT MATHEMATICALLY/DYNAMICALLY IS SOUND AND REPRESENTS ONE
EXTREME END OF A WIDE SPECTRUM OF POSSIBILITIES.

AT ANY RATE...WILL BE PAYING CLOSE ATTENTION TO THESE FEATURES IN
FUTURE FORECASTS AND MONITORING FOR THE POTENTIAL FOR ANY
LOCALIZED FLOODING EVENT. ASIDE FROM PROPERTY
CONSIDERATIONS...FLOODING MAY BE NEEDED TO REFILL LOCAL AREA
RESERVOIRS. WITHOUT RECEIVING ANY RAINFALL YESTERDAY...DFW AIRPORT
HAS NOW RECORDED ITS 4TH DRIEST START TO THE YEAR THIS YEAR. THE
DETAILS ARE INCLUDED IN A SHORT CLIMATE SECTION BELOW.

CAVANAUGH

(Option 3, the crazy Canadian's "LAND-O-CANE" )

[srainhoutx]

A very complicated and complex weather pattern is developing across our Region this week and could being bouts of very heavy rainfall. The upper pattern places Texas between two weather features in a stagnant summertime flow with a trough/shear axis across the Lone Star State. Typically such a pattern lends to rounds of daily heavy slow moving storms where 1 to 2 inch per hour rainfall rates are common and possibly higher if training storms develop. The area will be trapped between an Upper Ridge to our S and E and a Western trough with embedded short waves crossing Texas with a very tropical air mass planted across the Region. PW's are expected to increase to the 2+ inch mark and no capping. Convective temperatures should be in the low to mid 80's allowing storms to fire about anytime. To further complicate the forecast are mesoscale features that can not be determined beyond 4 to 6 hours as well as old outflow boundaries that could further enhance heavy rainfall.

Abundant deep/rich tropical moisture is streaming across Mexico into Texas in the mid to upper levels awaiting any 'trigger' such as small short wave energy traveling across Northern Mexico into the Southern Plains beneath a stalled out frontal boundary. The concern is that with a very weak N to NW flow aloft that any upper air disturbances will remain somewhat stationary across our Region and there is a potential that daily squall lines will drop S into Texas and focus multiple days of heavy rainfall. Another fly in the ointment is that a couple of upper air lows could take on warm core charactistics and bring heavy nocturnal rain/storm events which could lead to flooding issues.

The pattern is expected to continue into late week and possibly into next weekend. Another issue is a surge of tropical moisture currently in the Western Caribbean Sea will arrive around Tuesday night into Wednesday. The computer models are not much help as the range from very wet (Euro/Canadian/UKMet) to some what progressive and drier (GFS). Our upper pattern can be traced all the back to the Western Pacific near Japan so we will need to watch daily how all the various weather features upstream develop.. That said typically when we see such a long lasting trough pattern anchored across Texas in June, very heavy rainall events can happen and lead to multiple days of very unsettled weather. Stay Tuned!

[Ntxw]

Great discussion guys! I was going to do a post on it to follow up but everyone has done wonderful job laying out the possibilities. Certainly feels very tropical out there. Won't be a boring couple of weeks, there are no major heat waves in sight for Texas. We've already created the feedback late spring with ridges being dampened or shifted away. Clouds and moisture begets less heat, which begets more clouds and moisture. Most of us will hover around 90 for the rest of this month. DFW, Austin, and Houston may not see 100 at all this June.

DFW getting some fun this morning



Edit: FYI looking at DFW records, if I'm not mistaken of the past 10 years only 2004 and 2007 did not feature a June 100 degree day

[Portastorm]

Some really good, insightful posts these last few days. Thanks everyone for your contributions!

It looks like we'll have some real weather to track this week in the Lone Star State. Heh, it's been a few years since we could say that about June weather. Here's hoping we all see a few inches of liquid gold.

[srainhoutx]

Jeff has issued an afternoon Update regarding the potential for heavy rainfall across our Region. It is also noteworthy that over the past several days, the NCEP Tropical Cyclone Genesis Probabilities have been very elevated. The trend continued with the 12Z suite of NCEP guidance with near a 100% probability of some sort of tropical disturbance potentially developing near Veracruz to Tampico.



Jeff's Update just issued...

Period of prolonged high rain chances appear in the offering over the next several days and possibly beyond.

Upper air pattern supportive of past majoring flooding events in TX appears to be shaping up for most of this week across the state. 500-300mb ridging has been unable to gain a strong foothold over the state as in the past several summers and will weaken/break down even more over the next 48 hours. Upper level weakness (trough of low pressure) between an upper level high over the SW US and a second upper level high over the SW Atlantic Ocean will result in a favorable atmospheric profile for widespread showers and thunderstorms Tuesday into next weekend. Tropical tap of mid and high level moisture is seen streaming NNE across MX from the eastern Pacific while a pool of deep tropical moisture over the central Caribbean Sea (PWS at or above 2.0 inches) is moving WNW and will landfall on the TX coast by Tuesday afternoon.

Global models are in fair enough agreement suggesting a trough or shear axis will actually become increasingly better defined along and east of I-35 during the week and begin to interact with the surging Caribbean moisture. Forecasted profiles show the atmosphere becoming saturated with time as the air mass takes on strong tropical characteristics.

First will see an increase in seabreeze generated convection Tuesday as the moisture surges inland and the lack of capping from upper level ridging allows low trigger temperatures (mid 80’s). Extremely tropical air mass will be in place by mid week and threat will then focus on potential overnight/early morning speed convergence near/along the coast to enhance thunderstorms. Rainfall rates will be fairly high in such an air mass and there appears to be little change in the pattern through next weekend so daily shots of heavy rainfall appear at least possible.

Patterns such as this in the past (July 2012 and July 2002) have resulted in significant rainfall amounts and major flooding across portions of TX as weak vort centers tend to focus much like dying tropical systems in such a tropical like air mass and storm motions tend to be on the very slow side. The CMC model was hinting at such a feature developing over SE TX in the Wed-Thurs time period and lifting north into N TX by late week, but it is the only global model showing such a well defined feature at the moment and is likely on the extreme end of the spectrum.

Regardless additional rainfall appears likely helping to reduce drought conditions and hopefully generate some run-off into area lakes.

[dhweather]

time to see what run total precip is for the last two runs of the EURO:






12Z not quite as wet as 0Z, but its still WET. I sure hope this verifies, everybody in the state gets SOMETHING,a few lucky ones get a lot.

[Ntxw]

DFW's high today, 75 degrees. May rise a few more but will be tough to break 80. Is this summer? I'm still dreaming of 1903.

From the WPC