Texas winter wx thread (2009-2010)

[wxman57]

Also, it was very similar to last nights 00Z run. There's seems to always be something a little off with a lot of 12z GFS runs lately. It appears to have some sort of warm bias to it. Can anyone verify this or is it just me?

Wxman57 mentioned this that the updated GFS 12z is warm biased.

I just noted that yesterday's 12Z was warmer, I wasn't making a conclusion about model bias. The 06Z run was warmer and drier than the 00Z. Every single run is different (GFS). There are HUGE differences every 6 hours. I wouldn't trust any GFS run as far as I could throw it beyond early next week.

As for Portastorm, let's compare two GFS runs 6 hours apart:

00Z run - ice storm for Austin!


06Z run - most rain occurs with temps near 60 deg:


And I'll bet the 12Z run is completely different again. Use the long-range GFS in this pattern and you'll get burned!

The reason that the 00Z run has an ice storm in Texas is because it has an upper low moving into west Texas near El Paso next Friday. At the same time (168hrs), the Euro has an upper low over northern Minnesota and nothing in Texas. So don't get your hopes up about a central Texas ice event based on the GFS.

Here's a 500mb 168-hr comparison between the GFS and Euro. Note where the Euro has the upper low vs. the GFS's TX ice storm solution:

[srainhoutx]

Just an FYI regarding the GFS. RECON is rather busy in the Pacific and the Atlantic...

000
NOUS42 KNHC 041815
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
0115 PM EST THU 04 FEBRUARY 2010
SUBJECT: WINTER STORM PLAN OF THE DAY (WSPOD)
VALID 05/1100Z TO 06/1100Z FEBRUARY 2010
WSPOD NUMBER.....09-066

I. ATLANTIC REQUIREMENTS
1. FLIGHT ONE - TEAL 76
A. A61/ SAILE/ 06/0100Z
B. AFXXX 05WSA TRACK61
C. 05/2130Z
D. 4 DROPS AS PUBLISHED
E. AS HIGH AS POSSIBLE/ 06/0300Z
F. COUNTERCLOCKWISE

2. SUCCEEDING DAY OUTLOOK.....NEGATIVE.

II. PACIFIC REQUIREMENTS
1. FLIGHT ONE - TEAL 70
A. P27/ 35.5N 156.0W / 06/1200Z
B. AFXXX 17WSC TRACK27
C. 06/0600Z
D. 19 DROPS AS PUBLISHED ON TRACK
E. AS HIGH AS POSSIBLE/ 06/1800Z

FLIGHT TWO - NOAA 49
A. P99/ 44.8N 170.0W/ 06/1200Z
B. NOAA9 18WSW TRACK99
C. 06/0800Z
D. DROPS EVERY 20 MINUTES
E. 39,000 TO 45,000 FT/ 06/1800Z
F. TRACK 36.6N 141.2E, 39.6N 146.3E, 42.3N 152.2E,
44.6N 155.6E, 46.8N 163.7E, 44.8 170.0E, 42.0N
170.2E, 40.6N 166.5E, 42.0N 161.4E, 39.1N 158.0E
AND 36.5N 140.1E

2. OUTLOOK FOR SUCCEEDING DAY:
FLIGHT ONE - NOAA 49
A. TRACK P99/ TBD/ 07/1200Z
JWP

[msstateguy83]

i have to totally agree with wxman57 the gfs in part looks good at times but really is literley all over the
map. its almost like throwing darts at a dart board does not seem much better at this point lol but
clearly i think we are gonna have to wait till later in the weekend to get a better idea on next weeks system.

[jasons2k]

This one always gets me:

COOR WITH SURROUNDING OFFICES AND AGREED TO SPLIT THE TEMP DIFFERENCES AND THROW IN SOME LOWISH
POPS.

In other words...no clue yet.

I understand why they do this, I really do, but sometimes I just wish they would use some of the old school rules, hand analysis, & a little instinct and pick a solution instead of just splitting the model difference.

[Texas Snowman]

Well, I think there are several lessons that I have already learned this winter. And those lessons are still in play.

They are:

1. El Nino doesn't mean that winter takes a holiday in Texas. In fact, strong to blockbuster events can occur (see Christmas Eve blizzard).
2. In such a winter, the trend is the friend.
3. Details of storm track location, intensity, and precip amounts will often remain fuzzy until hours before the event unfolds.

As for next week, the trends have arctic air moving south and an active southern jet in Texas. Where, when, and how much?

Remains to be seen I guess.

Knowing that, I'm tempted to save myself a lot of model waffling grief and just tune back in next Wednesday night!

[Texas Snowman]

This one always gets me:

COOR WITH SURROUNDING OFFICES AND AGREED TO SPLIT THE TEMP DIFFERENCES AND THROW IN SOME LOWISH
POPS.

In other words...no clue yet.

I understand why they do this, I really do, but sometimes I just wish they would use some of the old school rules, hand analysis, & a little instinct and pick a solution instead of just splitting the model difference.

Here, here! I TOTALLY agree with that. It's what guys like Harold Taft, the old-school Brownsville NWS, etc. did - pick a solution after careful analysis and stick with it! As I've opined here before, sometimes I hate the models, especially when they are doing the Fosbury Flop all over the place.

[wxman57]

This one always gets me:

COOR WITH SURROUNDING OFFICES AND AGREED TO SPLIT THE TEMP DIFFERENCES AND THROW IN SOME LOWISH
POPS.

In other words...no clue yet.

I understand why they do this, I really do, but sometimes I just wish they would use some of the old school rules, hand analysis, & a little instinct and pick a solution instead of just splitting the model difference.

NWS does that a lot - split the difference to minimize the error potential. But this almost guarantees the forecast will be wrong.

[goCoogs]

KHOU in Houston showed a chance of sleet wed. and thurs. this morning.

[CaptinCrunch]

Morning AFD NWS FTW

OUR NEXT UPPER TROUGH WILL AFFECT THE AREA SUNDAY THROUGH TUESDAY.
MOISTURE STARTS RETURNING SUNDAY AND A STRONG LLJ WILL BE IN PLACE
SUNDAY NIGHT. A STRONG COLD FRONT WILL SWEPT ACROSS THE CWA ON
MONDAY...BRINGING ANOTHER GOOD SHOT FOR RAIN...AND SOME
THUNDERSTORMS IN THE WARM SECTOR AHEAD OF THE FRONT. ALTHOUGH THE
CORE OF THE COLD AIR WILL STAY TO THE NORTH AND NORTHEAST OF THE
REGION...IT WILL BE COLD ENOUGH FOR ANOTHER HARD FREEZE ACROSS MOST
OF THE CWA WEDNESDAY MORNING.

AFTER WEDNESDAY...WE HAVE LOW CONFIDENCE IN THE FORECAST AS THE
GFS REMAINS WET AND VIGOROUS WHILE THE ECMWF IS DRY AND NOT AS
AMPLIFIED WITH OUR SECOND UPPER SYSTEM NEXT THU-FRI. FOR THIS
REASON...WE/VE COMPROMISED MAX/MIN TEMPS AND LEFT THE FORECAST
DRY FOR NOW. THIS SYSTEM WILL NEED TO BE WATCHED CLOSELY BECAUSE
IF THE GFS IS RIGHT...A WINTRY SITUATION COULD DEVELOP.

This looks like a job for the "Weather Rock" professional forecasting at it's best.......

[Portastorm]

Hey gang, I've really enjoyed the dialogue this morning and there have been a lot of good posts. As always, Wxman57, thank you for your time and expertise!

It strikes me with a bit of irony that as we ebb and flow with each model run, we're not any different than the loopy nutjobs on the Tropical forum who are ready to evacuate Houston for an incoming Cat 5 on every model run! And I use the term "loopy nutjobs" as a term of endearment as I was clearly one yesterday.

IMHO, we know enough about next week to know that we DON'T KNOW about next week yet! But it will be fun this weekend to follow the models. BTW, these are the only models that my wife allows me to follow.

[srainhoutx]

Hey gang, I've really enjoyed the dialogue this morning and there have been a lot of good posts. As always, Wxman57, thank you for your time and expertise!

It strikes me with a bit of irony that as we ebb and flow with each model run, we're not any different than the loopy nutjobs on the Tropical forum who are ready to evacuate Houston for an incoming Cat 5 on every model run! And I use the term "loopy nutjobs" as a term of endearment as I was clearly one yesterday.

IMHO, we know enough about next week to know that we DON'T KNOW about next week yet! But it will be fun this weekend to follow the models. BTW, these are the only models that my wife allows me to follow.

And I didn't even have to talk you down from the ledge. In all seriousness though, things will get a bit clearer as the weekend rolls along and more data ingest from RECON is added to the mix. I suggest folks take a peek at donsutherland1's latest update in the When will the Arctic Air Return Topic by vbhoutex.

[wxman57]

KHOU in Houston showed a chance of sleet wed. and thurs. this morning.

I'd say the chances of that are very slim. And if there is any, it would be just a few minutes of "was that a sleet pellet I saw/heard?".

[somethingfunny]

For those of you wondering how far the GFS can be thrown.....

[WacoWx]

one of the weather men here in Waco mentioned next Fri with a high of 39 and he said that "someone in Texas could be setting up for a wintry situation". I think he's getting his forecasts directly from the NWS. LOTS of ambiguity in that statement, and after reading these last couple of pages, I now understand his indecision. WacoWx needs a blizzard!!!

[wxman57]

For those of you wondering how far the GFS can be thrown.....

http://i.dailymail.co.uk/i/pix/2009/08/ ... 68x316.jpg

Yes, trust the 12Z GFS - when it comes out shortly - just about as much as you can throw it for the 2nd storm system late next week. I think it's ok for today through Monday or Tuesday of next week now. But beyond then, it's having problems.

[Ntxw]

Well as far as I can see, the system on monday has a bit further south shift based on this morning's GFS with more wrap around moisture. Still not expecting anything but to note curiosity. Oklahoma once again could be in for another doozy.

NAM is further north with this system, would be interesting to see how things work out.

[gboudx]

Latest from jeff.

Storm system progressing eastward this morning….better chances for clearing skies.

Weak cold air advection ongoing this morning with patchy breaks in the low overcast over our western counties. Clouds are dropping SSE with clearing noted NW of the region…so will go with more clearing and hold on to hope that Saturday will see clear/sunny conditions. Rapid increase in clouds expected Sunday as next southern stream storm system approaches. Should begin to see rain showers by some time Monday afternoon ahead of the next strong cold front.

Arctic air mass over NW Canada will drop into the plains early next week and reach TX middle to end of next week. Best course of action appears to be to undercut guidance on highs and lows with from Wed-Fri and insertion a mention of cold rain for now. A tad colder and P-type issues will have to be examined.

[wxman22]

For those of you wondering how far the GFS can be thrown.....

http://i.dailymail.co.uk/i/pix/2009/08/ ... 68x316.jpg

Yes, trust the 12Z GFS - when it comes out shortly - just about as much as you can throw it for the 2nd storm system late next week. I think it's ok for today through Monday or Tuesday of next week now. But beyond then, it's having problems.

Wxman57 do you think the GFS is now on crack showing a winterstorm for Texas next week,or is it a chance it could actually be picking up on something legit?

[msstateguy83]

i know one thing this first system needs to be watched closely for oklahoma as far south as say even possibly central, southwest, southcentral portions if that cold air happens to rush down more quickly then expected could be looking at another big mess over the sooner state. however i do think the chances of it impacting dfw with winter precip or any large portion of northern tx is almost slim to none...

[Ntxw]

i know one thing this first system needs to be watched closely for oklahoma as far south as say even possibly central, southwest, southcentral portions if that cold air happens to rush down more quickly then expected could be looking at another big mess over the sooner state, however i think the chances of it impacting dfw with winter precip or any large portion of northern tx is almost slim to none...

I wouldn't quite say none. The 500mb flow has been further south moving of this system through the southwest. Earlier the models moved it through northern Arizona to the four corners into the Texas panhandle. Again not comparing the two storms, but the current energy flow looks similar to the Christmas storm track albeit much weaker.