0z GFS VERY intresting

[Johnny]

AFM,

I sure I am speaking for others here...I sure do appreciate you taking the time to educate all of us simple minded people. I'll tell you what...you've taught me a whole lot over the past couple of years. Especially with winter weather and tropical weather. Thanks bud.

It looks like we MIGHT have something to look at in the near future. I hope that kind of cold does pan out and after it comes and goes, bring on Spring! I just got in from outside tilling up my new garden area. I'm ready for some fresh new potatoes.

[Jim Hughes]

One of these days, I'm hoping to see AFM post something like "am concerned about potential wintry weather in central and southeast Texas." etc, etc, etc. Until then ... I'm going to bang my head against the 540 thickness line.

OK...how's this: I am looking...thinking that a pattern that is favorable for the discharge of arctic air into the southern US is going to set up in about 2-3 weeks. First of all, I am finally starting to see some cold temps in Ak/Yukon. Right now there are some -40F/C temps up there. Looking at the ensembles, by next week (late), it loks as iff the upper pattern becomes more favorable for Siberian air to blled across the poles and into AK and that should reinforce the stuff that is already there. I don't see any big shots coming down before that to empty what is there, so it should build.

Now...the long range GFS does not show any big outbreaks at the end of the period, but I think it's wrong. I think near the end of the period the pattern may be setting up...providing the air up there doesn't get tapped.

The main reason we haven't gotten anything so far is the upper air pattern has sent all the really cold stuff into China and Japan....but in the next couple of weeks...it should start to send it back into our source regions and that could start our setup into an arctic outbreak...maybe like the Feb 1989 outbreak...first week in February....some ice due to overrunning in College Station....lot's of cold...HUGE arctic high slides out of Alaska. Probably not THAT cold as that set a lot of record min max's...but it was chilly.

Anyway...that's my take on it...I think there is a pattern change in a couple of weeks with some building arctic air in Alaska and across the poles (disclaimer: AS LONG AS IT DOESN'T GET TAPPED AND IS ALLOWED TO BUILD).

Happy now?

It usually takes about 2-3 weeks, at this time of the year, for the effects of the stratospheric warming at the North Pole , to propagate down into the troposphere. So the end of this month looks like a sure thing for cold weather. In the Northeast and Midatlantic at least.

Granted the recent warming has only been going on for four days so I would like to see it extended considerably longer. This would increase the chances of an extended cold period.



Jim

[Air Force Met]

AFM,

I sure I am speaking for others here...I sure do appreciate you taking the time to educate all of us simple minded people. I'll tell you what...you've taught me a whole lot over the past couple of years. Especially with winter weather and tropical weather. Thanks bud.

It looks like we MIGHT have something to look at in the near future. I hope that kind of cold does pan out and after it comes and goes, bring on Spring! I just got in from outside tilling up my new garden area. I'm ready for some fresh new potatoes.

Everyone has areas where they can help others...mine is weather...now...ask me to fix your car and I'll tell you to trade it in and get a new one

...and you ought to see my plumbing jobs around the house...just got the insurance check from the last "job" I did. Glad I can forecast. (But that one wasn't really all my fault...)

[Portastorm]

One of these days, I'm hoping to see AFM post something like "am concerned about potential wintry weather in central and southeast Texas." etc, etc, etc. Until then ... I'm going to bang my head against the 540 thickness line.

OK...how's this: I am looking...thinking that a pattern that is favorable for the discharge of arctic air into the southern US is going to set up in about 2-3 weeks. First of all, I am finally starting to see some cold temps in Ak/Yukon. Right now there are some -40F/C temps up there. Looking at the ensembles, by next week (late), it loks as iff the upper pattern becomes more favorable for Siberian air to blled across the poles and into AK and that should reinforce the stuff that is already there. I don't see any big shots coming down before that to empty what is there, so it should build.

Now...the long range GFS does not show any big outbreaks at the end of the period, but I think it's wrong. I think near the end of the period the pattern may be setting up...providing the air up there doesn't get tapped.

The main reason we haven't gotten anything so far is the upper air pattern has sent all the really cold stuff into China and Japan....but in the next couple of weeks...it should start to send it back into our source regions and that could start our setup into an arctic outbreak...maybe like the Feb 1989 outbreak...first week in February....some ice due to overrunning in College Station....lot's of cold...HUGE arctic high slides out of Alaska. Probably not THAT cold as that set a lot of record min max's...but it was chilly.

Anyway...that's my take on it...I think there is a pattern change in a couple of weeks with some building arctic air in Alaska and across the poles (disclaimer: AS LONG AS IT DOESN'T GET TAPPED AND IS ALLOWED TO BUILD).

Happy now?

I stand in awe of your brilliance!

[Portastorm]

I might add the other day I was in disbelief that our (Austin) progged high temps on Tues by NWS was 60. I notice this morning its down to 55 degrees now and I wouldn't be surprised to see it drop a little more ... perhaps the same for many of you other Texans.

If the GFS verifies, this trough coming through this coming week is very, very deep and the thickness lines are quite low. I'm not talking about snow or anything as I have read the debate here with interest and feel more educated than ever, thanks to AFM. I'm just saying: folks it's gonna git cold this week! (at least for 24 hrs or so).

[Air Force Met]

I might add the other day I was in disbelief that our (Austin) progged high temps on Tues by NWS was 60. I notice this morning its down to 55 degrees now and I wouldn't be surprised to see it drop a little more ... perhaps the same for many of you other Texans.

If the GFS verifies, this trough coming through this coming week is very, very deep and the thickness lines are quite low. I'm not talking about snow or anything as I have read the debate here with interest and feel more educated than ever, thanks to AFM. I'm just saying: folks it's gonna git cold this week! (at least for 24 hrs or so).

I think it's gonna be colder on Monday with the rain than our local NWS is saying. They are going for a high of 73 (in Angleton) with a 60% chance of rain. Now...maybe that is early morning...but I think that is too warm...ESPECIALLY if we get more rain. I thinking a cool-cold 50's and rainy day.

I'm just hoping the energy digs down a little more than forecasted so we can get a better shot. IT's been trending more north.

Also...thanks for those kind words.

[Johnny]

I hope Jeff doesn't mind me posting this but this kind of sums up some people's thoughts over here.




Deep upper level torugh will move through TX early next week with very active weather.

High pressure currently over the area will progress eastward today allowing warm air advection to begin. South wind will increase on Sunday pumping a modified tropical air mass northward from the southern Gulf of Mexico. Upper level trough which now appears to eject across TX in pieces instead of one big hooray begins to affect the region early Monday.

Air mass should be moist and unstable enough to support a round of thunderstorms morning to midday Monday as lead short wave ejects across the state. Secondary spoke of energy coupled with the cold front and upper low should move across Monday night into Tuesday with another rough of rainfall.

Severe threat is possible Monday as forecast wind profiles support a damaging wind threat, although instability may be a limiting factor. Widespread 1-2 inches of rainfall is expected with this event with isolated 3-4 inches. This rain should help relieve the high fire danger across the region.

Monday Night/Tuesday:

Upper air cold pocket associated with the deep upper trough is progged to move directly over SE TX. Temp. and thickness profiles fall pretty low during this time frame and one must at least consider the possibility of winter precip. mixing with the rain in a wrap around shield. Temp. profiles still show a substantial warm layer near the surface which should melt most snow grains and ice pellets before they reach the ground, but a few may make it all the way to the surface. This aspect will be watched closely over the next 36 hours.

Feel the NWS highs forecast for Tuesday of 55 is way too warm and is expect steady of even falling temps. during the day. Given thick clouds and precip. falling temps. could easily stay in the 40's.

[Extremeweatherguy]

The NWS has Houston down to 56 on Tuesday, 34 Tuesday night and 59 on Wednesday. I also think that this will be too warm...but since yesterday they have been trending the temps. downward. I also noticed that the storm prediction center has Houston under a slight risk for severe weather on Monday (3-days out). They say that there will be a small to marginal threat of severe weather here, but that there are a few factors that will be keeping the threat of a major high risk outbreak away. Who knows though...with three days anything can change. JB this morning says that the mid-week cold shot will direct it's COLDEST at Texas. Could get interesting...

Also: I know AFM doesn't want to hear this , but the latest GFS has 850mb temps. down to about -5C or below in Houston on Wednesday. Wednesday morning could be cold with near freezing temps. so any remaining precip. could be frozen. Also, thickness values will get down to near 534 (or lower)...the only problem is that most of the precip. will have moved out..but there is still a 5-15% chance though. I hope.. lol

[Air Force Met]

Also: I know AFM doesn't want to hear this , but the latest GFS has 850mb temps. down to about -5C or below in Houston on Wednesday. Wednesday morning could be cold with near freezing temps. so any remaining precip. could be frozen. Also, thickness values will get down to near 534 (or lower)...the only problem is that most of the precip. will have moved out..but there is still a 5-15% chance though. I hope.. lol

Problem is...there won't be any remaining precip according to the GFS. By the time the 850 temps are that cold...1) the sfc/temp spread is 15C...so it's bone dry...anything that might fall (but won't) would evaporate...and 2) the freezing level is STILL at 3000'. Nothing is making it down that far with the freezing level at 3K AGL.

Also...and the real bad news...the latest GFS shows hardly any precip with this...only .03" at IAH...and all of that on the 17th before the temp profile cools down significantly.

Now the NAM is much more moist....thankfully...and that is what I hope pans out....but it is also dry as a bone by 18/00Z....but is much colder during the day on the 17th...but the freezing level is still at about 2500' or so.

Now...if we can get a little more dry air to get some evaporative cooling into the column...that will cool it down a little more and we might see something in the far northern zones near the very end...but I still thikn it is too warm even then.

[Air Force Met]

NOw one thing I don't understand is how they can even mention possible winter scenarios in the AFD and have the highs for Houston on MOnday in the 70's and the lows monday night in the upper 40's.

Talking about covering you collective butts.

[Extremeweatherguy]

well the models continue to look even colder for mid-week, but yet the NWS forecast temps. look even higher...now up to 58 on Tuesday and 65 on Wednesday. Am I missing something or is there no apparent reason behind them raising the temps? Seems like the afternoon shift is always biased warm (compared to the morning guys forecasts).

[Donwx]

Heres a clip from the NWS in Houston looks intresting: TUESDAY IS THE REAL
ENIGMA. THE UPPER LOW IS FORECAST TO BE OVERHEAD WITH 500 MB TEMPS
AROUND -29 C. MSTR IS SPARSE TO SAY THE LEAST. YET FEEL COLD AIR
ALOFT WILL COMPENSATE FOR LACK OF MOISTURE. DECIDED IT WAS BEST TO
LEAVE CHANCE POPS FOR TUESDAY. CONFIDENCE IS NOT HIGH. UNDERCUT
GUIDANCE TEMPS FOR TUES/WED DUE TO THE COLD AIR ALOFT AND
UNSEASONABLY COOL THICKNESS VALUES.[/b]

[Donwx]

Heres even a more intresting dicussion (clip) from the NWS in Jackson,Mississippi:NOW FOR THE REST OF THE STORY...THIS CORE COULD BE THE HIDDEN
SURPRISE WITH THIS WHOLE EVENT AS LARGE SNOWFLAKES MAY OCCUR IN THE
TIME FRAME FROM MIDNIGHT-NOON WEDNESDAY. BEST MEAN RELATIVE
HUMIDITY(65-75%) AXIS MOVES EWD ALONG THE HIGHWAY 82 CORRIDOR AND
COULD BE A QUICK DUSTER IN THE 530-534DM 1000-500MB THICKNESS FIELD.
WILL CONFINE MENTION OF S WORD TO THE DELTA FOR NOW AS TEMPS SHOULD
REMAIN JUST ABOVE FREEZING MOST LOCATIONS.[b]

[Extremeweatherguy]

very interesting..

[jkt21787]

Heres even a more intresting dicussion (clip) from the NWS in Jackson,Mississippi:NOW FOR THE REST OF THE STORY...THIS CORE COULD BE THE HIDDEN
SURPRISE WITH THIS WHOLE EVENT AS LARGE SNOWFLAKES MAY OCCUR IN THE
TIME FRAME FROM MIDNIGHT-NOON WEDNESDAY. BEST MEAN RELATIVE
HUMIDITY(65-75%) AXIS MOVES EWD ALONG THE HIGHWAY 82 CORRIDOR AND
COULD BE A QUICK DUSTER IN THE 530-534DM 1000-500MB THICKNESS FIELD.
WILL CONFINE MENTION OF S WORD TO THE DELTA FOR NOW AS TEMPS SHOULD
REMAIN JUST ABOVE FREEZING MOST LOCATIONS.[b]

Yeah, looking better for snow up in my area as well on the backside of the system late Tuesday. As Jackson hints, not a significant accumulator, but perhaps a quick dusting.

[Extremeweatherguy]

JB Zone forecast this evening is calling for:

-Much colder air to dive into Texas starting Monday.

-snow to reach the highlands of west Texas and the hill country.

-Frost threat all the way to the lower rio grande valley Tues/Wed night.

-Coldest airmass of the season from Houston to Laredo southward...which means that north of that line it will probably not be the coldest, but in comparison with the coldest so far.

-Warm up Thursday, followed by colder air again next weekend.

Looks interesting!

He also says that the threat of much colder air is lurking in the long range. He says that what we will see this week is just a taste of it. He also mentioned that in Japan they have so much snow on the ski slopes that they are almost being closed because of TOO MUCH snow! Wouldn't that be crazy.

[mike815]

hmmm ill believe it when it happ sounds interesting

[EDR1222]

Is a big time arctic outbreak for the deep south on the horizon? Only time will tell. It has been many years since we have had one in our area.

[cctxhurricanewatcher]

JB Zone forecast this evening is calling for:

-Much colder air to dive into Texas starting Monday.

-snow to reach the highlands of west Texas and the hill country.

-Frost threat all the way to the lower rio grande valley Tues/Wed night.

-Coldest airmass of the season from Houston to Laredo southward...which means that north of that line it will probably not be the coldest, but in comparison with the coldest so far.

-Warm up Thursday, followed by colder air again next weekend.

Looks interesting!.

Exactly what he said was going to happen before Christmas about this time last month. I think JB has that forecast in a file and pulls it out about the 14th of each winter month and that would include March.

Hopefully he'll get one month right this winter.

[Extremeweatherguy]

SPC has slight risk threat continuing for SE Texas. They have us under a 5% tornado threat, 15% large hail threat, and 15% damaging wind threat. Those numbers are pretty high for the slight risk category, and are on the edge of moderate. If we can manage to get some sunshine and better instability this morning/afternoon then WATCH OUT, things could get interesting!