Southern Plains winter wx thread (2009-2010)

[zaqxsw75050]

Well, FWIW, 12 GFS has the low way up north

[iorange55]

Well, FWIW, 12 GFS has the low way up north

Yeah it's trending that way, but the model is still not showing the full force of the cold air I don't think, and till it does I'm not going to trust it too much. That high is strong, and I don't think the models are giving it enough credit, the low may indeed go that far north, but I think it's underplaying the cold still.

[zaqxsw75050]

I agree. It is weird to see a 1050+ high diving south then all in sudden turned into a zonal flow pattern.

[msstateguy83]

i think these last couple runs are utter hogwash. i dont believe it for one minute
esp the last run that shows temps near 70ish later in the week next week across
n tx into ok.... gfs is quite simply under est the system and the cold air behind it
its hard for me the believe in the pattern we are in and the temps this week that
we are heading in the direction the gfs is showing has anyone looked at the latest
euro run? i havent had time just wondering what its showing, i know i believe yest
or the day before i think it had the very cold air coming down but was holding off
on precip bringing the front in dry.

[iorange55]

i think these last couple runs are utter hogwash. i dont believe it for one minute
esp the last run that shows temps near 70ish later in the week next week across
n tx into ok.... gfs is quite simply under est the system and the cold air behind it
its hard for me the believe in the pattern we are in and the temps this week that
we are heading in the direction the gfs is showing has anyone looked at the latest
euro run? i havent had time just wondering what its showing, i know i believe yest
or the day before i think it had the very cold air coming down but was holding off
on precip bringing the front in dry.

It looks to be a little colder than the GFS, but nothing impressive.

[Extremeweatherguy]

It is worth noting that the gfs mos continues to look colder than the operational model. It still looks like it may be trying to retreat the cold air north too quickly though, but does so in a more believable way than the operational run (a.k.a not as rapidly). The 12z MOS is showing a high of only 36F in OKC next Monday, followed by a high of 45F on Tuesday. These kind of temperatures would still be cold enough to present some sort of minimal winter weather threat, but I continue to fear that they may be too warm. The next 24-72 hours of model runs will be very intersting to monitor. I would not at all be surprised to see a trend back toward colder...ESPECIALLY since we will be dealing with a ~1060mb high coming out of Canada, which is very impressive.

[Ntxw]

1060mb is quite impressive any time of year!

[HockeyTx82]

This is interesting.

http://www.srh.noaa.gov/oun/enhanced.php?map=2

They really are buying into next week of it getting cold around here.

[Extremeweatherguy]

The latest from the Norman NWS...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
245 PM CST FRI DEC 4 2009

.DISCUSSION...
IN THE SHORTER TERM... THE COLD SURFACE HIGH THAT HAS BROUGHT
WINTER BACK TO OKLAHOMA AND NORTH TEXAS WILL CONTINUE TO MOVE
AWAY. THIS WILL BRING WINDS BACK AROUND TO THE SOUTH OVERNIGHT...
BUT CLEAR SKIES AND VERY DRY AIR PROMISE TO ALLOW TEMPERATURES TO
PLUMMET AGAIN... ALTHOUGH PERHAPS NOT QUITE AS FAR AS LAST
NIGHT IN THE WEST.

SOUTH WINDS WILL INCREASE SUBSTANTIALLY TOMORROW... BRINGING
TEMPERATURES BACK UP CLOSER TO SEASONAL AVERAGES... BUT THE WIND
WILL MAKE IT FEEL ALMOST AS COLD AS TODAY.

THERE WILL BE A SLIGHT CHANCE OF LIGHT RAIN OR SNOW AT TIMES FROM
LATE SUNDAY INTO MONDAY... AS A WEAK WAVE AND MEAGER MOISTURE
RETURN AFFECT OUR AREA. FOR SUNDAY NIGHT... IT APPEARS THAT THERE
WILL BE NO SOURCE FOR SNOW DEVELOPMENT... SO FREEZING DRIZZLE
APPEARS MORE LIKELY... IF PRECIPITATION FORMS IN THE FIRST PLACE.

THE NEXT MAJOR EVENT WILL PROBABLY BE TUESDAY... AS A STORM SYSTEM
MOVES OUT OF THE ROCKIES INTO THE SOUTHERN AND CENTRAL PLAINS.
THERE IS STILL A LOT OF UNCERTAINTY REGARDING THE OVERALL
EVOLUTION OF THIS SYSTEM... ESPECIALLY AT THE SURFACE. GIVEN THE
UPPER-LEVEL PATTERN... THE DGEX APPEARS TO HAVE THE MOST
REASONABLE SURFACE SOLUTION... SO THAT IS WHAT WE HAVE FOLLOWED
FOR TUESDAY AND WEDNESDAY.

NO CHANGES WERE MADE TO OUR PREVIOUS FORECAST BEYOND WEDNESDAY... AS
MODEL VARIABILITY IS QUITE WIDE BY THE END OF THE WEEK... BUT THEY
GENERALLY DO NOT STRAY ALL THAT FAR FROM OUR EXISTING FORECAST.

It looks like we will have a good chance of a light winter weather event on Sunday (a.k.a snow flurries and/or freezing drizzle overnight) followed by the still very uncertain storm mid next week which may either bring us precipitation in the form of rain, an icy mix, or snow. Today's models hint at rain or some kind of mix being most likely, but that can still change.

[Ntxw]

Check out the wind chill advisories up in Montana, that's some serious cold

[Extremeweatherguy]

Check out the wind chill advisories up in Montana, that's some serious cold

Yeah, that is pretty cold. There are some forecasted lows in the -10's and -20's up there for this weekend, which is definitely pretty chilly for early December.

[Ntxw]

I was just looking into some blogs and vids by JB of accuweather and points at a cross polar event with that strong high. Could this come into fruition?

[Extremeweatherguy]

It still looks like a borderline weather situation in OKC next week. We continue to not know exactly what precipitation type(s) will fall and exactly how cold it will be at the time. It will all be highly dependent on the speed of the cold air erosion and also the exact track of the low pressure system. Small changes to the placement of the 32F line in all levels of the atmosphere could have HUGE impacts on our weather in the coming days.

As of this evening, here is what the 00z GFS MOS is showing for OKC during the Sunday through Wednesday period...

SUN
Afternoon High - 43F
Morning Low - 32F
Becoming overcast with a 14% chance of precip. (rain/snow)

MON
Afternoon High - 39F
Morning Low - 26F
Variable clouds with a 11% chance of precip. (rain/snow/ice)

TUES
Afternoon High - 45F
Morning Low - 33F
Overcast with a 43% chance of precip. (snow to rain)

WED
Afternoon High - 40F
Morning Low - 27F
Partly cloudy with a 21% chance of precip. (rain/snow to snow)

[Ntxw]

What does it look like for North Texas?

[cheezyWXguy]

If the high, being as strong as it is, digs further south than the model projects, might it influence the track of the low moving across next tuesday to move further south?

[Ntxw]

Im not exactly sure on that, from what i've been taught is that storms generally move along the edges of the cold air where the shifts between warm and cold is battling for ground. Based on that idea, I would believe it should shift southward

[Extremeweatherguy]

What does it look like for North Texas?

It looks even worse (in terms of winter weather) for you guys right now, with warmer conditions than OKC to be expected and mainly a rain event. However, if the low tracks further south and/or the cold air digs deeper/erodes more slowly, then you guys could still potentially get something. We will just have to wait and see what happens next week. Hopefully come Sunday into Monday morning we will have a better idea of where the rain, ice and snow lines will set up across the plains during the Monday afternoon through Wednesday morning time period.

[cheezyWXguy]

What does it look like for North Texas?

It looks even worse (in terms of winter weather) for you guys right now, with warmer conditions than OKC to be expected and mainly a rain event. However, if the low tracks further south and/or the cold air digs deeper/erodes more slowly, then you guys could still potentially get something. We will just have to wait and see what happens next week. Hopefully come Sunday into Monday morning we will have a better idea of where the rain, ice and snow lines will set up across the plains during the Monday afternoon through Wednesday morning time period.

I get a feeling the GFS is still underestimating the cold air. A 1060mb high isnt going to weaken that much that quickly. The model has it only in the 1030's as it reaches the northern US border. Assuming the high is stronger, the cold air would likely push further south. Idk about precip, but if ntxw is right, the low would go further south.

[iorange55]

Where the strong high is about right now I see some temps -20F and -22F I'm not sure how cold that is compared to average around this time of year, but seems pretty cold to me.



The models still are not showing cold cold cold air coming down like you'd think with a high that strong, and they still show the low going north. I'm hoping today is the day they start changing in our favor. Hopefully the next GFS trends more to what it was a few days ago.

[cheezyWXguy]

Where the strong high is about right now I see some temps -20F and -22F I'm not sure how cold that is compared to average around this time of year, but seems pretty cold to me.



The models still are not showing cold cold cold air coming down like you'd think with a high that strong, and they still show the low going north. I'm hoping today is the day they start changing in our favor. Hopefully the next GFS trends more to what it was a few days ago.

yeah, that 12z run 2 days ago was beautiful. Showed quite an event for NTX and OK