Texas winter wx thread (2009-2010)

[Ntxw]

No complaints here =P I've had my fair share this winter.

[attallaman]

This is insane ... look at that 850mb 0-degree isotherm halfway into Mexico!

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_pcp_192l.gif

I'm trying to understand these maps, what do those 4 digit numbers in black mean? Barometric pressure or what? I've read the term 850mb a lot. What does that mean?

[Snowman67]

From the Brownsville NWS discussion this afternoon:

THE POSSIBILITY OF
FREEZING TEMPERATURES WITH SOME TYPE OF FROZEN PRECIPITATION IS
NOT OUT OF THE REALM OF POSSIBILITIES LATE THURSDAY INTO FRIDAY
BUT IT IS WAY TOO EARLY TO MENTION THIS WITH ANY CONFIDENCE AT
THIS POINT.

I should have pointed out that this is referring to next Thursday/Friday

[Tireman4]

From the Brownsville NWS discussion this afternoon:

THE POSSIBILITY OF
FREEZING TEMPERATURES WITH SOME TYPE OF FROZEN PRECIPITATION IS
NOT OUT OF THE REALM OF POSSIBILITIES LATE THURSDAY INTO FRIDAY
BUT IT IS WAY TOO EARLY TO MENTION THIS WITH ANY CONFIDENCE AT
THIS POINT.

I should have pointed out that this is referring to next Thursday/Friday

Wow.

[HockeyTx82]

Wow, so lots happened since I last logged in. So is next week really (at this point) looking to get very cold by the end of it? From what I have read and what here is seems to be a possibility. Just wanted to make sure I am reading things right. Also I am going to the Stars game in Dallas tonight. Should I be expecting any problems coming back home after the game? What about on the way down there?

[HockeyTx82]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
250 PM CST THU DEC 31 2009

.DISCUSSION...
LIGHT RAIN CONTINUES TO FALL ACROSS MUCH OF NORTH TEXAS WITH
SURFACE TEMPERATURES REMAINING ABOVE FREEZING. THE SNOW HAS MADE
IT AS FAR SOUTH AS WICHITA FALLS AND THE SNOW SHOULD BEGIN IN OUR
NORTHWESTERN ZONES WITHIN THE NEXT FEW HOURS. THE UPPER LEVEL
TROUGH IS NOW MOVING THROUGH NORTHWEST TEXAS AND SHOULD HELP TO
DRIVE THE COLDER AIR /SURFACE TEMPERATURES IN THE LOWER 30S/ INTO
NORTH TEXAS BY THE LATE AFTERNOON HOURS. WE ARE STILL NOT
EXPECTING ANY SNOW ACCUMULATIONS...BUT SOME LOCATIONS WEST OF A
LINE FROM BRECKENRIDGE TO DENTON TO SHERMAN MAY SEE A DUSTING OF
SNOW ON GRASSY SURFACES. THE COLD FRONT HAS ADVANCED THROUGH ALL
BUT THE FAR SOUTHERN COUNTIES OF NORTH TEXAS AND TEMPERATURES
CONTINUE TO FALL BEHIND THE FRONT.

WITH TEMPERATURES FALLING INTO THE LOWER 20S TO LOWER 30S
AREAWIDE TONIGHT...THIS HAS RAISED SOME CONCERN FOR ICY SPOTS ON
ROADWAYS/BRIDGES/OVERPASSES. HOWEVER...GIVEN THE VERY LIGHT NATURE
OF THE PRECIPITATION AND THE INCREASE IN WIND SPEEDS TONIGHT AS
THE FRONT CONTINUES TO SLIDE THROUGH TEXAS...WE ARE NOT EXPECTING
ICY ROAD CONDITIONS.

THE PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST TONIGHT AS
THE UPPER LEVEL TROUGH SHIFTS INTO EAST TEXAS. NORTHWEST FLOW
ALOFT WILL PERSIST THROUGH THE NEXT WEEK. THE NEXT FRONT WILL
ARRIVE ON SUNDAY FOLLOWED BY A STRONGER FRONT ON WEDNESDAY.
WEDNESDAY/S COLD FRONT WILL BRING ARCTIC AIR TO NORTH TEXAS AND
ANOTHER CHANCE FOR WINTER WEATHER TO NORTH TEXAS. FOR NOW...WILL
KEEP A RAIN/SNOW MIX NORTH OF INTERSTATE 20 ON WEDNESDAY BASED ON
FRONTAL TIMING AND TEMPERATURE TRENDS.

SOME DIFFERENCES BETWEEN THE GFS AND ECMWF HAVE EMERGED ON THE
LATEST MODEL RUNS REGARDING THE ARCTIC AIR OUTBREAK NEXT WEEK. THE
ECMWF DOES NOT DIG THE UPPER LEVEL TROUGH AS FAR SOUTH...KEEPING
THE BASE OF THE TROUGH IN THE CENTRAL PLAINS. THIS PATTERN WOULD
PREVENT THE BITTERLY COLD AIR THAT WAS PREVIOUSLY ADVERTISED FROM
MAKING IT INTO TEXAS. GIVEN THE DIFFERENCES...HAVE KEPT A
PERSISTENCE FORECAST FOR NOW AND BLENDED THE TWO MODELS. IT STILL
LOOKS LIKE COLD ARCTIC AIR WILL ARRIVE IN NORTH TEXAS NEXT WEEK
BUT WE WILL NEED TO MONITOR THE UPPER LEVEL PATTERN TO DETERMINE
JUST HOW COLD IT WILL GET.

[Portastorm]

This is insane ... look at that 850mb 0-degree isotherm halfway into Mexico!

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_pcp_192l.gif

I'm trying to understand these maps, what do those 4 digit numbers in black mean? Barometric pressure or what? I've read the term 850mb a lot. What does that mean?

The black lines are isobars and they reflect certain values of barometric pressure. The 850mb level is about 5,000 feet above the surface and is a good level to look at for moisture, pressure, and temperature. There are certain calculations you can use to get a decent guess at what surface temps will be by looking at the 850mb temps.

[attallaman]

This is insane ... look at that 850mb 0-degree isotherm halfway into Mexico!

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_pcp_192l.gif

I'm trying to understand these maps, what do those 4 digit numbers in black mean? Barometric pressure or what? I've read the term 850mb a lot. What does that mean?

The black lines are isobars and they reflect certain values of barometric pressure. The 850mb level is about 5,000 feet above the surface and is a good level to look at for moisture, pressure, and temperature. There are certain calculations you can use to get a decent guess at what surface temps will be by looking at the 850mb temps.

Thanks.

[srainhoutx]

I know Dodge City, KS is not TX, but an interesting snipet from the afternoon AFD...very telling of how things may play out...

DAYS 3-7...

THE MAJOR ITEM OF INTEREST IN THE EXTENDED WILL BE THE MIDDLE PART
OF NEXT WEEK AT THE END OF THIS FORECAST PERIOD. A SIGNIFICANT
OUTBREAK OF ARCTIC AIR IS ANTICIPATED WITH ALL THE MAJOR GLOBAL
SPECTRAL MODEL SOLUTIONS DEPICTING A VERY COLD SCENARIO...AND
POSSIBLY INCLUDING A WINTER PRECIPITATION EVENT.

ANOTHER MAJOR EXTENDED NORTH PACIFIC JET WILL BE AT PLAY
AGAIN...WITH THE NORTH PACIFIC JET CONTRACTING AND LEADING TO
SIGNIFICANT AMPLIFICATION EVENT AROUND 130-125W. THIS AMPLIFICATION
EVENT WILL MOST LIKELY OCCUR A BIT FARTHER TO THE EAST VERSUS THE
LAST MAJOR AMPLIFICATION EVENT WHICH LED TO THE GREAT PLAINS
CHRISTMAS BLIZZARD. THERE APPEARS TO BE A LOT OF SIMILARITIES TO
THE "LEAD-UP" IN THE MODELS REGARDING THIS AMPLIFICATION EVENT...AND
A MAJOR WINTER EVENT INCLUDING VERY COLD ARCTIC AIR AND A
SUBSTANTIAL WINTER STORM. SINCE THIS IS STILL WELL INTO THE DAY 6-7
PERIOD...THERE IS A LOT OF TIME TO WATCH HOW THIS WILL POTENTIALLY
UNFOLD...BUT USUALLY THE FIRST THING THAT BECOMES CLEAR IS THE
ARCTIC AIR INTRUSION. IF THIS AMPLIFICATION EVENT OCCURS FARTHER TO
THE WEST THAN CURRENTLY ADVERTISED THE THE "MODEL CONSENSUS" THEN
THE GREAT PLAINS WILL BE IN THE MIDST OF ANOTHER MAJOR WINTER STORM
EVENT...PERHAPS INCLUDING SOUTHWEST KANSAS. IN THE GRIDS...HAVE
MADE THE FIRST SUBSTANTIAL CHANGE IN THE FORECAST...WHICH IS
LOWERING TEMPERATURES A GOOD SOLID 8 TO 10 DEGREES ON HIGHS FOR
WEDNESDAY AND THURSDAY OF NEXT WEEK. A BRUTALLY COLD 1045+ MB
SURFACE HIGH NOSING STRAIGHT SOUTH FROM THE WESTERN/CENTRAL CANADIAN
PRAIRIES CERTAINLY ARGUES FOR HIGHS ACROSS MUCH OF THE PLAINS IN THE
SINGLE DIGITS AND TEENS...WITH MID-UPPER TEENS AND TWENTIES FOR
HIGHS ACROSS SOUTHWEST KANSAS.

[gofrogs]

Whats the new gfs saying.

[southerngale]

Thanks, Portastorm.

How cold is "real cold" on the 12z Euro? It's been pretty chilly lately although I see a little warmup for the next several days. A high of 65° for tomorrow! For this winter, that's a massive heat wave. And then 50's for highs most other days (40's on Mon.) - which is definitely warmer overall.

(lows still in the 30's though, except tonight, but with so many freezes lately, including temps dipping into the 20's, 30's are nothing special. lol)

oops.

It's currently 53° and there's no way we're hitting 65° today. Not even close. They recently lowered today's high to 57° from the mid 60's just earlier today. That's EIGHT degrees in a very short time and that's just the predicted high. We haven't hit that either.

It just goes to show what a hard time the models have in just a few hours time... you can imagine how hard it is to get it right, or even close to right, a week+ away!

[southerngale]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
250 PM CST THU DEC 31 2009

SOME DIFFERENCES BETWEEN THE GFS AND ECMWF HAVE EMERGED ON THE
LATEST MODEL RUNS REGARDING THE ARCTIC AIR OUTBREAK NEXT WEEK. THE
ECMWF DOES NOT DIG THE UPPER LEVEL TROUGH AS FAR SOUTH...KEEPING
THE BASE OF THE TROUGH IN THE CENTRAL PLAINS. THIS PATTERN WOULD
PREVENT THE BITTERLY COLD AIR THAT WAS PREVIOUSLY ADVERTISED FROM
MAKING IT INTO TEXAS. GIVEN THE DIFFERENCES...HAVE KEPT A
PERSISTENCE FORECAST FOR NOW AND BLENDED THE TWO MODELS. IT STILL
LOOKS LIKE COLD ARCTIC AIR WILL ARRIVE IN NORTH TEXAS NEXT WEEK
BUT WE WILL NEED TO MONITOR THE UPPER LEVEL PATTERN TO DETERMINE
JUST HOW COLD IT WILL GET.

I just read that the Euro dropped the bitterly cold air straight south to Texas. And now I read this. hmmm... which is it?

[Nederlander]

Whats the new gfs saying.

Edit: I mustve been looking at the wrong map or model cause I just looked again and I see freezing temps at Day 5 for a good portion of Texas.. awfully dry though

[Snowman67]

Those are some cold 850mb temps that are forecasted by the 18z gfs run.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _180.shtml

[vbhoutex]

Long time lurker, first time poster on this board. I think I recognize some of the folks on here from when I was on the KHOU board.

Looks like the shortwave may dig further south than originally anticipated and give our friends in N. Texas another shot at the white stuff.

Happy New Year to all.

Happy New Year to you also and WELCOME TO STORM2K!!

[Ntxw]

Yikes

[Texas2Florida]

Holy crap those model runs look coooollllldd!! Time to use the gift cards to buy long johns..geez! Hope some snow comes with!

[severe]

Holy crap those model runs look coooollllldd!! Time to use the gift cards to buy long johns..geez! Hope some snow comes with!

Keep waiting for someone to say this cold appears to be headed east and not towards us, but that hasn't happened yet.
1983 was a cold snap I'll never forget, but we didn't get one snowflake from that event, just some drizzle.

[txagwxman]

ECMWF 2m temps are near 5F DFW next Friday with 18F Houston. ECMWF has been overdoing the cold.
GFS probably more realistic teens DFW/low 20s Houston this Friday, although I would prefer the milder GEM.

I hope it is more moderate like the GEM suggests, otherwise it maybe a pipe buster.

in 1983, we had 1-3" of snow east side of Houston in some snow burst...

No snow DFW yesterday, boundary layer 950 to 1000 mb were too warm, just drizzle. GFS op was a little too cold.

[srainhoutx]

ECMWF 2m temps are near 5F DFW next Friday with 18F Houston. ECMWF has been overdoing the cold.
GFS probably more realistic teens DFW/low 20s Houston this Friday, although I would prefer the milder GEM.

I hope it is more moderate like the GEM suggests, otherwise it maybe a pipe buster.

in 1983, we had 1-3" of snow east side of Houston in some snow burst...

No snow DFW yesterday, boundary layer 950 to 1000 mb were too warm, just drizzle. GFS op was a little too cold.

In the excitement of watching the guidance that some may feel, we need to remember it's been a long time since our part of the world has seen such an event. If guidance is correct we may have more issues than many have experienced before. Going to be a long and ineresting week. We'll also need to watch how the Upper Air feature exits the Great Basin and where it tracks as well as any STJ activity that might be involved. This situation should be followed closely IMHO.