Texas Fall-2015

[TeamPlayersBlue]

I think I-35 will be the target for sure. Somebody will get a foot of rain from this.

[newman22]

Looks like the rain amounts are getting higher towards central and north Texas now. Is this because of the lack of the Gulf of Mexico moisture which was robbed by patricia

[1900hurricane]

Really digging the general setup. It's definitely got shades of some of the bigger ones we've seen in the past.

[Ntxw]

Looks like the rain amounts are getting higher towards central and north Texas now. Is this because of the lack of the Gulf of Mexico moisture which was robbed by patricia

Yeah, formation of an EPAC system is usually the key for inland areas of Texas. As 1900hurricane alluded, that's typically a big ingredient to turn a run of the mill rain event to a blockbuster rain event. Had a storm formed in the gulf, the upper Texas coast would see the most rain but the rest of us in subsidence. Late October luckily doesn't favor western gulf systems (Jerry is a rarity) but rather EPAC recurves.

[1900hurricane]

Looks like the rain amounts are getting higher towards central and north Texas now. Is this because of the lack of the Gulf of Mexico moisture which was robbed by patricia

It actually has more to do with the high pressure location over the east coast. The 12Z GFS has 850 mb trajectories for the coastal areas coming from this deep layer high, which would be a modified continental airmass. Further west, 850 mb trajectories come from more tropical areas.





Also, the 12Z ECMWF is quite a bit more aggressive with coastal rainfall.

[weatherdude1108]

Looks interesting right now for excessive rainfall in the DFW area in a couple days.

[newman22]

OK cool thanks guys. I'm in the Victoria area we should be in a great spot for heavy rain. The models have showed it until really this afternoons run of gfs

[1900hurricane]

If we can get low level trajectories off the Caribbean, that could break this event wide open. The 850 mb ridge to the east would likely have to be centered over the Florida/Georgia area for that to happen. The GFS is trending a little further north, but the ECMWF is fairly close.

[Brent]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
332 PM CDT TUE OCT 20 2015

.DISCUSSION...

...MAJOR RAIN EVENT DEVELOPING LATE WEEK AND INTO THE WEEKEND...

WATER VAPOR LOOPING SHOWS AN UPPER LOW OVER NORTHERN BAJA AND A
TROPICAL FEED OF MID/HIGH LEVEL MOISTURE MOVING NORTHEAST ACROSS
NORTH-CENTRAL MEXICO AND TEXAS THIS AFTERNOON WHICH WILL PLACE AN
IMPORTANT PART IN THE UPCOMING RAIN EVENT.

TONIGHT WILL AGAIN BE SEASONAL WITH SOUTHEAST SURFACE WINDS AS
THE ANTI-CYCLONE OVER THE EASTERN SEASHORE PROVIDES FOR NORTHERN
GULF OF MEXICO AIR TO CURVE INLAND ALONG THE TEXAS COAST AND MOVE
NORTHWARD ACROSS NORTH-CENTRAL TEXAS. THIS MOISTURE TRANSPORT
INTO THE REGION WILL RESULT IN LOW CLOUDS SPREADING ACROSS MUCH OF
THE CWA LATE TONIGHT THROUGH WEDNESDAY MORNING.

THE ABOVE MENTIONED LOW LEVEL WIND PATTERN WILL CONTINUE FOR THE
REST OF THE WEEK AS THE WESTERN UPPER LOW MOVES EAST...OPENS UP
INTO A TROUGH AND MOVES NORTHEAST ON THURSDAY NIGHT. A REPLACEMENT
UPPER TROUGH WILL FOLLOW CLOSELY BEHIND AND SWING THROUGH THE
SOUTHERN ROCKIES ON SATURDAY. THE NET RESULT OF THESE TWO FEATURES
WILL BE A LONG DURATION FETCH OF SOUTHWESTERLY FLOW ALOFT AND
LARGE SCALE FORCING FOR LIFT UNDER THE RIGHT-ENTRANCE REGION OF
THE UPPER JET THURSDAY NIGHT THROUGH FRIDAY AND AGAIN OVER THE
WEEKEND. A SECOND FEATURE THAT WILL HELP PRODUCE WIDESPREAD
RAINFALL IS THE REMNANTS OF TROPICAL SYSTEM SEEDING THE MID AND
UPPER LEVEL WITH SIGNIFICANT MOISTURE. THIS WILL PUSH PWATS ABOVE
2 INCHES FRIDAY THROUGH SATURDAY NIGHT. IN ADDITION...AN INVERTED
SURFACE TROUGH WILL DEVELOP TO OUR WEST AND MOVE SLOWLY ACROSS THE
REGION THIS WEEKEND...AND A COLD FRONT WILL MERGE INTO THIS
INVERTED SURFACE TROUGH SATURDAY NIGHT OR SUNDAY AS BOTH SLOW
ACROSS THE CWA. LASTLY...WE DO NOT SEE ENOUGH FAVORABLE PARAMETERS
FOR SEVERE STORMS WITH THIS EVENT...BUT DO FEEL THAT ISOLATED
FLASH FLOODING IS TO BE EXPECTED DUE TO DRY HARD PACKED SOILS.

CURRENTLY WE FEEL GOOD FORECASTING A WIDESPREAD RAINFALL TOTALS OF
1 TO 2 INCHES WITH ISOLATED HIGHER AMOUNTS UP TO 4 INCHES ACROSS
THE CWA THURSDAY THROUGH SUNDAY. HOWEVER...THIS MORNINGS
GFS...CANADIAN AND ECMWF ARE ALL PRODUCING HIGHER RAINFALL TOTALS
AND WITH MAJOR AMOUNTS FOCUSED FROM COMANCHE TO DFW TO PARIS WHERE
THERE IS A JUXTAPOSITION OF UPPER JET DYNAMICS...DEEP FORCING AND
STRONG LOW TO MID LEVEL THERMODYNAMICS. WE WILL CONTINUE MONITOR
SOLUTION CHANGES FOR THE VARIOUS MODELS AND ADJUST POPS...QPF AND
DURATION ACCORDINGLY...ESPECIALLY AS THE EVENT MOVES INTO THE
TIME RANGE OF THE HIGHER RESOLUTION MODELS.

[Tireman4]

419
FXUS64 KHGX 202038
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
338 PM CDT TUE OCT 20 2015

.DISCUSSION...
HIGH RESOLUTION MODELS HAVE DONE OK SO FAR TODAY WITH THE START
TIME/PLACEMENT/EXTENT OF SHOWERS ACROSS THE AREA. TRAINING ACROSS
PARTS OF GALVESTON ISLAND AND THE BOLIVAR PENINSULA AREA HAS PRODUCED
SOME RAINFALL TOTALS OVER 2 INCHES. LATEST 12Z MODELS POINT TOWARD
LOWISH RAIN CHANCES FOR OUR FORECAST TONIGHT THROUGH TOMORROW NIGHT
FOLLOWED BY GRADUALLY INCREASING CHANCES AS WE HEAD ON INTO THURSDAY
AND FRIDAY. THE LATEST MODEL RUNS HAVE BECOME INCREASING DIVERGENT
IN THEIR FORECAST OF A POSSIBLE WESTERN GULF STORM SYSTEM OVER THE
WEEKEND...AND THIS HAS RESULTED IN MORE UNCERTAINTY IN OUR AREA`S
FORECAST. GENERAL TREND APPEARS TO BE TO DELAY THE GREATEST RISK FOR
LOCALLY HEAVY RAINFALL UNTIL THE SATURDAY THROUGH SATURDAY NIGHT TIME
PERIOD FOLLOWED BY DECREASING RAIN CHANCES AS WE HEAD ON INTO SUNDAY
AFTERNOON AND SUNDAY NIGHT. CURRENT THINKING IS THAT WIDESPREAD 2 TO
5 INCH RAINFALL TOTALS ARE POSSIBLE THROUGH SUNDAY...AND THESE AMOUNTS
WILL LIKELY CHANGE AS THIS EVENT UNFOLDS. 42
&&

.MARINE...
CIRCULATION AROUND BROAD SURFACE HIGH OVER ERN HALF OF US WILL KEEP
PERSISTENT E TO SOUTHEAST FLOW OVER THE NORTHER GULF NEXT SEVERAL
DAYS KEEPING SEAS AND TIDES ELEVATED. WIND SPEEDS CURRENTLY HIGHER
THAN GUIDANCE...WITH 15 TO 20 KNOTS AT BUOY35. SEAS RUNNING
GENERALLY 4 TO 6 FEET. WILL LIKELY KEEP SCEC UP EAST PREDOMINANTLY
FOR WINDS...AND OUTER WATERS WEST FOR THE 6 FOOT SEAS. EXPECT WINDS
AND SEAS TO BUMP OF MORE AS GRADIENT TIGHTENS...AND ONSHROE FLOW
INCREASES ON WEDNESDAY AND THURSDAY. LONGER RANGE WINDS...SEAS AND
TIDES...FOR WEEKEND AND EARLY NEXT WEEK...HIGHLY UNCERTAIN AS MODELS
STRUGGLING TO DEPICT WHAT HAPPENS WITH REMNANTS OF EASTERN PACIFIC
TROPICAL DEPRESSION 20E WHICH MAY BECOME TROPICAL STORM PATRICIA.
SOME MODELS TRY TO BRING IT...OR PERHAPS THE UPPER LEVEL ASSOCIATED
WITH IT...ACROSS MEXICO AND INTO THE GULF. ECMWF HAS CYCLONE OFF
TEXAS COAST ON SUNDAY...GFS MUCH FARTHER SOUTH OVER FAR SW GULF.
ECMWF SOLUTION WOULD MEAN A FURTHER INCREASE IN WINDS...SEAS AND
TIDE LEVELS FOR SUN AND MON...THE GFS WOULD KEEP THOSE IMPACTS WELL
SOUTH. HAVE GONE SORT OF WITH A BLEND OF IDEAS IN THE EXTENDED FOR
NOW WITH CONTINUED MODEST E THEN NE FLOW. 46

&&

.PREV DISCUSSION... /ISSUED 1252 PM CDT TUE OCT 20 2015/

AVIATION...
CHALLENGING TAFS THIS MORNING AS CIGS HAVE ACTUALLY LOWERED AT
MANY OF THE COASTAL SITES GIVEN THE ADVECTION IN OF LOW LEVEL
MOIST AIR AND MIXING UP INTO A 1000 TO 2000 FOOT DECK. ALSO HAVE
HAD PERSISTENT BAND OF SHOWERS OVER GALVESTON BAY IMPACTING MAINLY
GLS. MESOSCALE MODELS SUGGEST THESE SHOWERS WILL CONTINUE TO MAKE
GRADUAL INLAND PROGRESS. HAVE THUS INTRODUCED VCSH FOR INLAND
SITES. HAVE GONE MOSTLY TEMPO FOR HOUSTON AREA AIRPORTS... AND
PREVAILING SHRA FOR GLS BASED ON RADAR TRENDS. SOME TEMPORARY
CLEARING A GOOD BET THIS EVENING...THEN LOWER CIGS AGAIN MOVE IN
OVERNIGHT AND CONTINUE INTO WED MORNING. MOST OF THE SHOWER
ACTIVITY SHOULD SHIFT MORE TO THE SW HOWEVER. 46

[Brent]

Haven't seen a forecast like this in awhile:

Thursday Night
Showers and thunderstorms likely. Mostly cloudy, with a low around 67. South southeast wind around 15 mph, with gusts as high as 20 mph. Chance of precipitation is 60%.
Friday
Showers and thunderstorms. High near 75. South southeast wind 10 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 90%.
Friday Night
Showers and thunderstorms. Low around 67. South wind around 10 mph. Chance of precipitation is 80%.
Saturday
Showers and thunderstorms. High near 73. Southeast wind 5 to 10 mph. Chance of precipitation is 80%.
Saturday Night
Showers and thunderstorms likely. Cloudy, with a low around 61. East wind 5 to 10 mph becoming north northeast after midnight. Chance of precipitation is 60%.

[weatherdude1108]

And for EWX. Looks like the high QPF potential has shifted a tad to the west compared to yesterday's discussion:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
344 PM CDT TUE OCT 20 2015

.LONG TERM (THURSDAY THROUGH TUESDAY)...
AN ACTIVE WEATHER PATTERN CONTINUES TO BE ADVERTISED FOR THE
THURSDAY THROUGH SATURDAY PERIOD. THE MAIN CONCERN WILL BE LOCALLY
HEAVY RAINFALL POSSIBLY LEADING TO FLOODING. FOR NOW...IT LOOKS
LIKE AREAS ALONG AND EAST OF A KERRVILLE TO PEARSALL LINE WILL BE
FAVORED FOR LOCALLY HEAVY RAINFALL.

ON THURSDAY INTO EARLY FRIDAY...A STRONG SHORTWAVE TROUGH WILL LIFT
ACROSS WESTERN TEXAS WHILE THE SUBTROPICAL JET TO THE SOUTH OF
THIS TROUGH STRENGTHENS. RAIN CHANCES WILL BE ON THE INCREASE
ACROSS ALL AREAS GIVEN DEEP LAYER MOISTURE AND INCREASING
DYNAMICS. WE/LL MENTION 60-80% RAIN CHANCES ACROSS ALL AREAS
BASED ON THE CONSISTENCY OF MOS GUIDANCE.

THE ACTIVE PATTERN CONTINUES INTO SATURDAY AS THE REMNANTS
OF TROPICAL SYSTEM TWENTY-E ARE PICKED UP BY THE BROAD TROUGH TO
OUR WEST. WITHIN THIS BROAD TROUGH...ANOTHER SHORTWAVE WILL MOVE
ACROSS TEXAS. THIS SHOULD BRING ANOTHER ROUND OF RAINFALL TO
THE REGION...WITH THE HIGHEST RAINFALL AMOUNTS EXPECTED EAST OF
A KERRVILLE TO PEARSALL LINE. A COLD FRONT IS ALSO EXPECTED TO
MOVE INTO THE REGION ON SATURDAY...PROVIDING AN ADDITIONAL
SURFACE FEATURE FOR CONVECTION. AS THIS FRONT MOVES SOUTH TO NEAR
THE COAST...A SURFACE LOW IS EXPECTED TO DEVELOP. AT THIS
TIME...THIS LOW IS EXPECTED TO REMAIN OFFSHORE. EVENT RAINFALL
TOTALS COULD REACH 3 TO 6 INCHES EAST OF A PEARSALL TO KERRVILLE
LINE...WITH AMOUNTS TAPERING TO AROUND 1" ALONG THE RIO GRANDE.

NORTHERLY WINDS AT THIS SURFACE SHOULD BRING DRIER AIR TO THE
REGION ON SUNDAY. THIS ALONG WITH THE MAIN TROUGH AXIS MOVING
EAST WILL BRING A DECREASE IN RAIN CHANCES TO ALL AREAS SUNDAY AND
MONDAY. A WEAK UPPER TROUGH MAY MOVE INTO NORTHERN TEXAS ON
TUESDAY. WE/LL KEEP THE FORECAST DRY FOR NOW ACROSS SOUTH CENTRAL
TEXAS.

[Brent]

TV station forecasts:

CBS 11 3-6"(the in-house model had widespread 5" totals around DFW)
NBC 5 2-5"(the in-house model had widespread 6" totals around DFW)

[Ntxw]

Still a little early, but based on trends I would think Flash flood watches may be warranted by tomorrow or Thursday for Fri-Sat time frame for much of North, Central, and parts of the Texas coast.

[Ntxw]

For the longer range, all of the guidance generally agrees typhoon Champi is going to undergo bombogenesis (sub 950mb) as it recurves to the Aleutians merging with a deep trough. That then sends cross polar flow and Arctic/Polar high pressure into Alaska and down western and central Canada (-EPO) about a week+ or so from now.



Not sure how cold the air mass in play is yet, but Nuri did a similar thing last year. Near 1040mb high down the rockies

[srainhoutx]

Siberian/Eurasia/Mongolian snow cover is ahead of last year's October levels. Stepping down...

[Brent]

Boat time? Some of this is another round mid week next week:

[gboudx]

I did some prep today and need to try and cut the yard before Thursday. Going get 1/3 cord of firewood tomorrow. Was supposed to go Saturday but doesn't look good for it.

[Brent]

Boat time? Some of this is another round mid week next week:

Meteograms:

Almost 9" at DFW
14" at Paris, TX

[Ntxw]

Here comes the ULL. Don't panic if you only get 1-3 inches from the first round and assume that is it