November 2015: Ending Cold & Rainy

[srainhoutx]

I,m going to take a stab at issuing some longer range thoughts as November begins. I suspect November will be a wet and active month with additional heavy rainfall potentials as well as several severe episodes particularly as we near Thanksgiving. Temperatures look to remain warm with an occasional cool down, but nothing significant. My biggest concern is an active sub tropical jet with abundant Eastern Pacific moisture being pulled across Mexico into Texas with a rather persistent Western trough allowing for a general unsettled pattern to continue.

One thing I am seeing is the same general pattern continuing into December, but slowly but surely turning colder. I am a bit concerned about a significant pattern change mid to late December with the main storm track dropping out of the Arctic into the front range of the Rockies with a very deep trough developing along and to the East of the lee side of the Rockies to about the Appalachian Mountains. We are already seeing signs of developing Coastal lows, and that tends to favor the pattern we see with El Nino. I will not be surprised to see increasing wintry mischief threats as we move deeper into December and transition into January. Overall I expect an active weather pattern for the next 3 months.

[mckinne63]

I have a question that has been bothering me for a long time. When I go to weather on the KHOU page, the today/tonight forecast never matches the longer range forecast. Example: the box today says a high of 73 low of 63, 90% chance of rain. But when you look at the extended outlook, it says a high of 78 today with a 10% chance of rain. Just curious....

[Texaspirate11]

Just dumped out 7 inches of rain from my gauge at the BAY and its still pouring.
Some forecast....

[srainhoutx]

Getting a bit concerned we may be heading toward another potential heavy rainfall event next weekend. The !2Z guidance suggests another Western trough with a stalling frontal boundary across Central Texas. We probably will get a break in the weather tomorrow and Tuesday, then the Gulf opens back up as well as a SW flow aloft bringing Eastern Pacific moisture back overhead. Strong to possibly severe storms may enter the forecast late in the week possibly extending into next weekend. We will see.

[ticka1]

sunday evening email from Jeff Lindner:

As we begin to recover from one flood, factors appear to be coming together to produce yet another round of heavy rainfall from late Thursday into next weekend. It is too early to talk specific totals, but a slow moving upper level storm system will combine with a stalling frontal boundary over SE TX to produce potentially an extended period of rainfall.

With grounds now fully saturated from between 10-20 inches of rainfall in the last week run-off will be likely with additional rainfall.

Still plenty of time to fine tune the details, timing, and rainfall amounts with this incoming system.

[djjordan]

I'm liking some of the QPF totals I am seeing for parts of California. They need all they can get!!! Unfortunately in an El Nino year they may get way too much of a good thing.

[djjordan]

Dense Fog Advisory in effect this morning for parts of the area. Use the low beams. Be cautious.

AUSTIN-BRAZORIA-BRAZOS-BURLESON-COLORADO-FORT BEND-GRIMES-HARRIS-
HOUSTON-JACKSON-MADISON-MATAGORDA-MONTGOMERY-WALKER-WALLER-
WASHINGTON-WHARTON-
INCLUDING THE CITIES OF...ALVIN...ANGLETON...BAY CITY...
BELLVILLE...BRENHAM...BROOKSHIRE...BRYAN...CALDWELL...
COLLEGE STATION...COLUMBUS...CONROE...CROCKETT...EAGLE LAKE...
EDNA...EL CAMPO...FREEPORT...HEMPSTEAD...HOUSTON...HUMBLE...
HUNTSVILLE...KATY...LAKE JACKSON...LAKE SOMERVILLE...
MADISONVILLE...MISSOURI CITY...NAVASOTA...PALACIOS...PASADENA...
PEARLAND...PIERCE...PRAIRIE VIEW...RICHMOND...ROSENBERG...SEALY...
SUGAR LAND...THE WOODLANDS...TOMBALL...WEIMAR...WHARTON...WILLIS
503 AM CST MON NOV 2 2015

...DENSE FOG ADVISORY IN EFFECT UNTIL 9 AM CST THIS MORNING...

THE NATIONAL WEATHER SERVICE IN HOUSTON/GALVESTON HAS ISSUED A
DENSE FOG ADVISORY...WHICH IS IN EFFECT UNTIL 9 AM CST THIS
MORNING.

* EVENT...DENSE FOG.

* TIMING...THROUGH 9 AM CST.

* IMPACT...VISIBILITIES WITHIN DENSE FOG WILL BE UNDER A MILE...
LOCALLY UNDER A QUARTER OF A MILE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A DENSE FOG ADVISORY MEANS VISIBILITIES WILL FREQUENTLY BE
REDUCED TO LESS THAN ONE QUARTER MILE. IF DRIVING...SLOW DOWN...
USE YOUR HEADLIGHTS...AND LEAVE PLENTY OF DISTANCE AHEAD OF YOU.

[BiggieSmalls]

Already sick and tired of the rain...why cant the cycle at least fall during the work week, and not the weekend?

[Stormrider]

I feel you Biggie on having a weekend rained on. However, if this flood event happened on a weekday, more people would have been on the roads, hence a greater potiential for stranded vehicles and water rescues. Several schools in La Porte were damaged; fortunately, school was out for the weekend. I have a feeling as we get closer to winter, we will see the pattern into the weekday as well.

[srainhoutx]

The November Outlook from the Climate Prediction Center.

[snowman65]

I really wonder about this, given the warm weather we have had so far.

[srainhoutx]

Evening briefing from Jeff:

Another upper level storm system will approach TX late this week with another round of rainfall.

Fairly quite conditions expected Tuesday and Wednesday before another upper level low develops over the SW US and helps to increase onshore flow and Gulf moisture by Thursday. A cold front will surge down the plains ahead of this storm system and arrive into SE TX Friday afternoon and night and likely stall across the region into Saturday. Moisture levels yet again surge to very high numbers for early November of 2.0-2.2 inches which is about equal to this last weekend. SW upper level flow becomes nearly parallel to the incoming boundary which will likely encourage thunderstorm cell training Friday. GFS is faster in trying to clear the region behind the front behind late Saturday while the ECMWF lingers showers into Sunday morning. Will lean toward the slower solution as the GFS was too fast this past weekend with the clearing.

Too soon to be very confident on rainfall totals or severe weather parameters for this event. Some areas of SE TX have seen 20-25 inches of rainfall in the last 10 days…so needless to say the ground is extremely saturated and significant run-off continues into already swollen and flooding rivers. Given lower sun angle, mild temperatures, and lack of growing vegetation, do not expect much drying before the onset of the next rainfall event. Will go ahead and broadbrush a widespread 1-3 inches from late Thursday through late Saturday with isolated totals of 4-5 inches possible. Given moisture levels expected this could be on the low side, but given the already saturated grounds even these lower numbers would likely cause some issues.

Will continue to evaluate model trends over the next few days to see where the heaviest rainfall will align along with any severe potential.

Hydro:

Upstream flood waves are progressing into SE TX from late week and weekend rainfall.

Trinity River:

Upstream flood wave from excessive rainfall south of Dallas a week ago is passing through Lake Livingston and into the lower Trinity Basin. Moderate flooding is expected at Liberty for the next several days with the river holding just below major flood levels.

Brazos River:

Peak of flood wave is at Bryan and will be moving downstream to Hempstead, Richmond, and Rosharon this weekend. No flooding is expected at Hempstead and Richmond, but minor flooding is forecast at Rosharon.

Colorado River:

Flood wave from 12-16 inches of rainfall south of Austin Friday is passing LaGrange and heading for Columbus and Wharton. Minor flooding is expected at both Columbus and Wharton over the next few days.

San Bernard River:

River is below flood stage and not expected to exceed flood stage.

Navasota River:

River is above flood stage at Easterly and forecast to rise above flood stage at Normangee.

Current and Forecast River Levels can be found at the link below:

http://www.srh.noaa.gov/wgrfc/

[srainhoutx]

The 00Z GFS is still a bit too progressive in shifting the upper Western trough and frontal boundary East. The European suggests the Western trough with embedded upper air disturbances as well as the front will be slower and stalling S of the I-35 Corridor. Think the European model has the best handle on the upper pattern at this time. Strong to possibly severe storms should organise Wednesday night into early Thursday to our West and slowly advance S and E into Friday. Meanwhile back across the Great Basin into the higher terrain of the Rockies, the first significant snow fall of the season looks likely. A harbinger of things to come as we move deeper into November.

Forecast Discussion

SPC AC 030651

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1251 AM CST TUE NOV 03 2015

VALID 041200Z - 051200Z

...THERE IS A MRGL RISK OF SVR TSTMS SRN HIGH PLAINS...

...SUMMARY...
WEDNESDAY NIGHT INTO EARLY THURSDAY...ISOLATED SEVERE STORMS ARE
POSSIBLE ACROSS THE SOUTHERN HIGH PLAINS...WHILE A FEW STORMS WITH
SUB-SEVERE HAIL MAY OCCUR OVER WEST-CENTRAL NEBRASKA.

...SYNOPSIS...
AN AMPLIFIED UPPER PATTERN WILL PERSIST WITH A TROUGH WEST AND RIDGE
EAST. A SERIES OF SHORTWAVE IMPULSES EVOLVING ACROSS THE SOUTHWEST
TO NRN GREAT PLAINS WILL YIELD A NET EWD DISPLACEMENT OF THE TROUGH
FROM THE NRN HIGH PLAINS TO FOUR CORNERS AREA BY 12Z/THU. AT THE
SURFACE...A LEAD CYCLONE SHOULD TRACK FROM SD TO NW ONTARIO. A COLD
FRONT WILL EXTEND SW OF THIS LOW TO A LEE CYCLONE OVER NERN CO. THIS
LOW SHOULD REACH S-CNTRL NEB...WITH A PACIFIC COLD FRONT OVERTAKING
THE SRN HIGH PLAINS DRYLINE EARLY THU.

...SRN HIGH PLAINS...
MODIFICATION OF A CONTINENTAL POLAR AIR MASS OVER THE NW GULF INTO
TAMAULIPAS HAS COMMENCED PER GOES PW IMAGERY. POLEWARD MOISTURE
TRANSPORT WILL STRENGTHEN LATE D1 INTO D2...LIKELY YIELDING LOWER
60S SURFACE DEW POINTS INTO NW TX AS A MARITIME TROPICAL AIR MASS
OVERSPREADS MUCH OF S/E TX BY 12Z/THU. INCREASING MID-LEVEL HEIGHT
FALLS IN CONJUNCTION WITH CONVERGENCE ALONG THE COMPOSITE COLD
FRONT/DRYLINE SHOULD RESULT IN ISOLATED TO SCATTERED TSTMS FORMING
WED NIGHT/EARLY THU. MID/UPPER-LEVEL SWLYS WILL BE STRENGTHENING AND
FOSTER A PRIMARY RISK OF MARGINALLY SEVERE HAIL/WIND...IN SPITE OF
MODEST MID-LEVEL LAPSE RATES AND TIME OF DAY. INCREASINGLY VEERED
LOW-LEVEL FLOW MAY LIMIT THE MAGNITUDE OF LOW-LEVEL HODOGRAPHS AND
ATTENDANT TORNADO POTENTIAL.

[texoz]

Does it look like the weather will clear in Central and Southeast Texas by daytime on Saturday?

[srainhoutx]

Does it look like the weather will clear in Central and Southeast Texas by daytime on Saturday?

Still a bit too early to say at this point. As I mentioned the Euro continues to reload the Western Upper trough with embedded disturbances dropping SE from the Pacific NW. If that pattern verifies, then I suspect it will be hard to really clear out Central and SE Texas similar to what we witnessed last weekend. We appear to be stuck in a rather active pattern where storm systems arrive every 3 to 4 days. Looking longer range, the models are trending to a solution that may bring a good shot of cold air into Texas around the 13th with a fairly significant severe weather episode potential across the Plains. We will look more into that as we get into the weekend and next week.

Longer Range:

[sambucol]

Looking longer range, the models are trending to a solution that may bring a good shot of cold air into Texas around the 13th

YES!!!!

[tireman4]

Another interesting set up this weekend. Humm...again, as always folks, stay tuned to the mets here and the local media outlets. They will guide you through this weekend...

[wxman57]

00Z EC & 12Z GFS indicate heaviest rain staying north of Houston this weekend. Less than 1" of rain predicted for Houston by them. Fine with me.

[sambucol]

00Z EC & 12Z GFS indicate heaviest rain staying north of Houston this weekend. Less than 1" of rain predicted for Houston by them. Fine with me.

What about the Liberty area?

[GBinGrimes]

Looks like the opening day of this portion of the deer season will be just a wee bit wet.

Looking forward to the hopeful shot of cold air next week.