OCTOBER: Halloween Storm: Severe Storms/Flash Flood Threat?

[Katdaddy]

Increasing clouds and rain chances this afternoon. Warm front along the coastal areas may lead to heavier rainfall this evening and overnight. Cold front should move off the coast early Saturday morning with slight thunderstorms chances. Skies should begin clearing by early afternoon Saturday with N winds and temps in the upper 70s. Upper 50s Saturday night and mostly sunny skies with mid 70s Sunday.

[srainhoutx]

SPC issues Slight Risk for severe storms for portion of the Permian Basin and Edwards Plateau for later today as a long wave trough and upper air disturbance that has brought snow to the higher elevations near Denver over night sweeps SE and another disturbance rides NE out of Mexico into Texas. The 06Z short range guidance is suggesting showers and storms will develop later tonight into early Saturday and increase rain/storm chances across Central and SE Texas in a very progressive fast moving pattern.



DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0740 AM CDT FRI OCT 18 2013

VALID 181300Z - 191200Z

...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTERNOON/EVENING FOR
PARTS OF THE TX BIG COUNTRY AND EDWARDS PLATEAU...

...TX AREA THROUGH TONIGHT...
AS PART OF A LARGE-SCALE TROUGH OVER MUCH OF NORTH AMERICA...AN
EMBEDDED SHORTWAVE TROUGH OVER CO THIS MORNING WILL PROGRESS TO
KS/OK BY THIS EVENING...AND REACH THE MS VALLEY BY SATURDAY MORNING.
AN ASSOCIATED REINFORCING COLD FRONTAL SURGE WILL MOVE SEWD FROM OK
TO CENTRAL TX BY EARLY TONIGHT...AND TO THE TX COAST BY THE END OF
THE PERIOD. THE COLD FRONT WILL ENCOUNTER A NARROW CORRIDOR OF
RETURN FLOW MOISTURE...WITH PW VALUES AOA 1 INCH AND BOUNDARY LAYER
DEWPOINTS NEAR 60...BY LATE AFTERNOON/EVENING ACROSS THE BIG
COUNTRY/EDWARDS PLATEAU IN TX. THUNDERSTORM DEVELOPMENT WILL BECOME
MORE PROBABLE NEAR OR AFTER 21Z AS SURFACE HEATING IN CLOUD BREAKS
REDUCES CONVECTIVE INHIBITION...AND THE SRN FRINGE OF THE
LARGER-SCALE FORCING FOR ASCENT COINCIDES WITH THE LOW-LEVEL LIFT
ALONG THE SURFACE COLD FRONT.

MLCAPE IS EXPECTED TO INCREASE TO 1000-1500 J/KG WITHIN THE MOISTURE
CORRIDOR BY 21Z...WHERE RELATIVELY STRAIGHT HODOGRAPHS AND SPEED
INCREASES ALOFT WILL CONTRIBUTE TO EFFECTIVE BULK SHEAR OF 40-50 KT.
THESE FACTORS WILL BE SUFFICIENT FOR ORGANIZED LINE SEGMENTS AND
SOME EMBEDDED SUPERCELL STRUCTURES WITH THE INITIAL STORM
DEVELOPMENT THIS EVENING...WHEN THE RISK FOR ISOLATED LARGE HAIL
WILL BE GREATEST. THEREAFTER...THE THREAT WILL BE LIMITED PRIMARILY
TO ISOLATED DAMAGING WINDS WITH CONVECTION THAT ENDS UP BEING
SLIGHTLY UNDERCUT BY THE SURFACE COLD FRONT...WITH THE SEVERE THREAT
DIMINISHING BY 03-06Z IN CENTRAL TX. OTHERWISE...A FEW WEAKLY
ROTATING STORMS WILL BE POSSIBLE NEAR THE MIDDLE AND LOWER TX COAST
TODAY...ALONG A WEAK SURFACE COASTAL TROUGH AND IN ASSOCIATION WITH
A WEAK LEAD SHORTWAVE TROUGH EJECTING ENEWD FROM NE MEXICO THIS
MORNING.

..THOMPSON/GARNER.. 10/18/2013

[srainhoutx]

NWS Dodge City, KS Office this morning shared via Facebook by NWS Amarillo. The weather is transitioning to colder.

[srainhoutx]

That 'Blue Norther' we have been discussing is still suggested by the GFS. It appears the Southern Rockies may see a significant snow storm extending into the front range and as far S as Albuquerque and strong storms sweeping across Texas as that front races S.

[tireman4]

Here is my wonder, will we (IAH) make it to 75? We are sitting at 69. Hummm.....

[Paul Robison]

What do the blue isotherms to the north of us mean, Ed? Will this "blue norther" be anything like the system that literally blasted the area with powerful cold north winds on Feb. 2, 2011?

[srainhoutx]

Paul, it way too soon to know what we may or may not see with that Polar front or even if it actually occurs at all. We are still well over a week+ away from that potential. Meanwhile it is a nasty stormy night with thunderstorms and heavy rain in NW Harris County.

[unome]

Meanwhile it is a nasty stormy night with thunderstorms and heavy rain in NW Harris County.

it sure is ! training raining ! but I'm not complaining

(took out old hotlinks)

[cisa]

It's been raining hard here in Porter for well over an hour. I don't know what it equates to in inches, but it's been pouring. Nice to enjoy from home, but I wouldn't have wanted to be out under the "Friday Night Lights". I've had more than my fair share of getting soaked in the stands. Such is a Fall Friday in Texas.

[Paul Robison]

Have these rain/storms caused damage anywhere in the city?

[unome]

this has to be the wettest week we've had in our little corner of Harris County in years

7-day totals

(removed old hotlink)

[ticka1]

received one inch of rain....didnt even know it rained and it is 59 degrees!

[srainhoutx]

Just emptied 1.83 inches of rain out of the old rain bucket up here in NW Harris County. I see that Cypress and even some locations closer to FM 529 did even better. Breezy and cool with clearing skies. Enjoy the weekend and get ready for some mid 40's tomorrow before more over running showers and storms develop ahead of the next front Monday night. We may actually get to dry out later next week and have some very Chamber of Commerce type weather that October can bring to our Region.

[srainhoutx]

A chilly 44 F up here in NW Harris County this morning is the coldest we have seen since last Spring. Enjoy another gorgeous day before clouds roll in this evening and showers return tomorrow as yet another cold front makes its way across Texas. The heavier rain looks to be confined to our Coastal Counties and offshore tomorrow with lighter amounts inland. The rest of the upcoming week looks cool and clear before another front pushes in next Saturday.



DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1249 AM CDT SUN OCT 20 2013

VALID 211200Z - 221200Z

...NO SVR TSTM AREAS FORECAST...

AN UPPER-LEVEL TROUGH IS FORECAST TO MOVE ACROSS THE SRN PLAINS ON
MONDAY AS A COLD FRONT ADVANCES SEWD ACROSS CNTRL AND NE TX. AHEAD
OF THE FRONT FROM THE TX HILL COUNTRY SEWD TO THE LOWER TX
COAST...SFC DEWPOINTS SHOULD BE IN THE 60S F AND A POCKET OF
MODERATE INSTABILITY MAY DEVELOP BY MONDAY AFTERNOON. THE MODELS
SUGGEST THAT SCATTERED THUNDERSTORMS WILL INITIATE ALONG THE FRONT
AND MOVE SEWD ACROSS THE TX COASTAL PLAINS DURING THE LATE AFTERNOON
AND EARLY EVENING. IN SPITE OF THE MODERATE INSTABILITY...THE
STEEPER MID-LEVEL LAPSE RATES ARE FORECAST TO REMAIN OVER NRN
MEXICO. IN ADDITION...THE STRONGER DEEP LAYER SHEAR IS FORECAST TO
BE OFF THE TX COAST SUGGESTING THAT THE POTENTIAL FOR ORGANIZED
STORMS REMAINS LOW ACROSS CNTRL AND SOUTH TX.

ELSEWHERE...ISOLATED THUNDERSTORM DEVELOPMENT MAY TAKE PLACE ACROSS
SRN AND CNTRL FL MONDAY AFTERNOON. THE COMBINATION OF INSTABILITY
AND SHEAR IS NOT EXPECTED TO SUPPORT SEVERE THUNDERSTORM DEVELOPMENT
IN SRN AND CNTRL FL.

..BROYLES.. 10/20/2013

[srainhoutx]

Taking a look at the medium to longer range forecast, the guidance continues to struggle with a very active Western Pacific where a parade of Typhoons have developed and turned N then NE/ENE and transitioned to large extra tropical cyclones or big lower pressure complexes. These systems have been marching toward the Aleutians and the Bering Sea and buckling the polar jet with each storm system. Super Typhoon Francisco and now Typhoon Lekima are entering the mix. The global models are beginning to suggest that 'Blue Norther' we mentioned last week and the European suite of guidance has joined the GFS and Canadian. The fly in the ointment is EPAC Hurricane Raymond and a persistent cut off upper low that has been meandering N and E of Hawaii. All in all the trends are beginning to signal a fairly significant Polar Cold Front may well arrive a day or two before Halloween bringing the coldest air of the season into the Lone Star State. We will see.

[Rip76]

And where am I headed?

Portland, Texas

[Paul Robison]

2 Questions:

1. What are the prospects for medium to strong thunderstorms tonight when the cold front comes through at 10:00 pm?

2. What will the main threats from the Halloween polar cold front be? NWS describes halloween forcast as "Scarier."

3. WARNING! 18z GFS develops seasons next TC in the southwest gulf, wants to point it north toward Texas! STORM SEASON NOT OVER YET!

[Kludge]

2 Questions:

1. What are the prospects for medium to strong thunderstorms tonight when the cold front comes through at 10:00 pm?

2. What will the main threats from the Halloween polar cold front be? NWS describes halloween forcast as "Scarier."

3. WARNING! 18z GFS develops seasons next TC in the southwest gulf, wants to point it north toward Texas! STORM SEASON NOT OVER YET!

p A ul R ob ISON -a

over before it started.

[Paul Robison]

2 Questions:

1. What are the prospects for medium to strong thunderstorms tonight when the cold front comes through at 10:00 pm?

2. What will the main threats from the Halloween polar cold front be? NWS describes halloween forcast as "Scarier."

3. WARNING! 18z GFS develops seasons next TC in the southwest gulf, wants to point it north toward Texas! STORM SEASON NOT OVER YET!

p A ul R ob ISON -a

over before it started.

Read this HGX disco before you joke:

THE MEDIUM RANGE MODELS DIFFER ON THE WAY THEY HANDLE A WEEKEND
SHORTWAVE TROUGH PASSAGE...THE ECMWF BEING THE AGGRESSOR AND
DIGGING THIS FEATURE A BIT MORE INTO NE`ERN TEXAS SATURDAY INTO
SUNDAY...GENERATING AREAWIDE QPF. THE DRY GFS IS FASTER WITH THIS
WAVE AND QUICKLY DISPLACES IT INTO THE SE U.S. BY SUNDAY AFTERNOON.
HAVE ATTEMPTED TO SPLIT THIS DIFFERENCE IN NWP OPINION AND HAVE
BROAD-BRUSHED SLIGHT CHANCES ACROSS MORE INTERIOR COUNTIES LATE
SATURDAY INTO EARLY SUNDAY. 12Z ENSEMBLE IS IN SLIGHTLY BETTER
AGREEMENT OF THE NEXT COLD FROPA AT MID-WEEK...WITH THE FASTER
GFS (SURPRISE!) PUSHING THE FRONT THROUGH EARLY WEDNESDAY/EURO
ON THURSDAY. BOTH DO PROG A NICE SHOT OF RAIN AHEAD OF A DEEP
INTERMOUNTAIN WEST/DESERT SW TROUGH/CLOSED-OFF LOW. SO...AFTER A
WEEK OF BENIGN WEATHER (WITH THE LONE EXCEPTION BEING OF THAT
POSSIBLE QUICK-PASSING WEEKEND S/W)...HALLOWEEN WEATHER IS FORECAST
TO BE MUCH SCARIER. 31

This is serious business, Houston! Watch this video for an idea of what we might be in for:

http://www.youtube.com/watch?v=ow3IHJL68qs

My apologies if I'm doing y'all a disservice.

[Kludge]

What is it about this forum that draws the caps lock crowd?