Southern Plains winter wx thread (2008-2009)

[iorange55]

I think the Noaa Discussion kind of explains what is happening with the heating...unless I am reading this wrong.

RATHER STRONG COLD FRONT JUST BEGINNING TO MOVE INTO NORTHWEST KANSAS
LATE THIS EVENING WITH PRE-FRONTAL TROUGH EXTENDING FROM NC KANSAS
INTO THE OK PANHANDLE. HAVE ADDED LOW LEVEL WIND SHEAR TO MOST TAF
SITES FOR A FEW HOURS BEFORE COLD FRONTAL PASSAGE AS SURFACE WINDS
VEER AND DECREASE. STILL APPEARS MARGINAL MFVR CEILINGS WILL DEVELOP
BEHIND COLD FRONT...ESPECIALLY ACROSS NORTHERN AND CENTRAL OKLAHOMA.
STRONGEST WINDS GUSTS WITH FRONTAL PASSAGE WILL OCCUR ACROSS NORTHWEST
NORTH CENTRAL OK WHERE BEST THERMAL PACKING WILL OCCUR BETWEEN
11-16Z.

[iorange55]

New runs on the GFS show 70's with low's in the 50's and 60's during the time period where it was showing a winter storm.



Crazy GFS.

[Extremeweatherguy]

Still some uncertainty about just how cold it will be in OK next week and whether or not there will be precipitation (or winter precipitation)...

From OKC discussion
ANOTHER WEAK COLD FRONT IS EXPECTED THIS WEEKEND...BUT THAT WILL
NOT PREVENT TEMPS RETURNING TO AT OR ABOVE SEASONAL AVERAGES. MED
RANGE MODELS IN REMARKABLE AGREEMENT UNTIL LATE THIS WEEKEND TO
EARLY NEXT WEEK WHEN THE ECMWF DEPICTS A CUTOFF LOW OFF THE SRN CA
COAST KICKING OUT AND MOVING ACROSS THE SRN PLAINS...WHILE ONLY
ONE OR TWO GFS ENSEMBLE MEMBERS SUPPORT THIS. EARLIER FORECASTS
HAD UP TO CHANCE POPS FOR THE MON/TUE TIME FRAME...AND ADDED THAT CHANCE BACK
DESPITE THE MOST RECENT GFS LOADING IN DRY.


From Tulsa discussion
ANY ATTEMPT AT WARMING WILL BE BRIEF AS ANOTHER SHOT OF CANADIAN
AIR ARRIVES ON SATURDAY WHICH WILL MAINTAIN TEMPERATURES BELOW
NORMAL. GOOD AGREEMENT AMONG EXTENDED MODELS OF A DEEPENING
TROUGH ACROSS THE WESTERN STATES BY THE END OF THE WEEKEND. TIMING
OF THIS WAVE INTO THE CENTRAL U.S. ALONG WITH PLACEMENT OF SURFACE
FEATURES REMAINS MORE UNCERTAIN. HOWEVER THE OVERALL PATTERN WILL
FAVOR INCREASING PRECIP CHANCES FOR EARLY NEXT WEEK WITH MUCH YET
TO BE DETERMINED REGARDING THE EXACT TIMING AND PRECIP TYPE.

[Extremeweatherguy]

The 12z GFS has changed it's tune and is now showing a winter storm impacting Oklahoma early next week! Given the fact that this is less than 7 days out, and has support from the Euro, I am starting to get pretty excited that this may really happen!

[Ed Mahmoud]

The 12z GFS has changed it's tune and is now showing a winter storm impacting Oklahoma early next week! Given the fact that this is less than 7 days out, and has support from the Euro, I am starting to get pretty excited that this may really happen!

As noted in my discussion of the 12Z GFS on the Texas Winter Wx thread, it is a nuisance storm, about half an inch of snow in 12 hours in the DFW area, just over an inch in twelve hours (using standard 10:1 fluff factor) for Oklahoma City.


But, it'll put people in the spirit of Christmas/Chanukkah/Kwa'anza.


ETA- Did you see the 1036 mb high with -20 to -30ºC 1500 meter temps building over the Yukon in a week, with the jet buckling in such a way that while the main path would be a bit East of OK and TX, the density of the cold air itself should insure more than just a parting shot.?.?

ETA2
The GFS does indeed show the cold surface high just glancing the Southern Plains out towards Day 10, but the GFS has issues with shallow and dense cold air masses, so it could be more than just a glancing blow...

[Extremeweatherguy]

What is comical is the fact that right at the GFS shifts to this wintry scenario for next week, the ECMWF shifts away from it. The latest 12z EURO is showing warmer temperatures with no significant precipitation next Monday, Tuesday or Wednesday.

All this run-to-run inconsistency is causing me to hate the models much more than usual this year!

[vbhoutex]

What is comical is the fact that right at the GFS shifts to this wintry scenario for next week, the ECMWF shifts away from it. The latest 12z EURO is showing warmer temperatures with no significant precipitation next Monday, Tuesday or Wednesday.

All this run-to-run inconsistency is causing me to hate the models much more than usual this year!

Are you feeling ? Maybe you're holding your breath too long waiting for some consistency?

[Ed Mahmoud]

What is comical is the fact that right at the GFS shifts to this wintry scenario for next week, the ECMWF shifts away from it. The latest 12z EURO is showing warmer temperatures with no significant precipitation next Monday, Tuesday or Wednesday.

All this run-to-run inconsistency is causing me to hate the models much more than usual this year!

Tie-breakers Canadian and DGEX.

At 144 hours, Canadian has trough sharpening up a tad, bringing a better trajectory to deliver Alaskan cold, with a healthy cold front crossing the Red River.

Don't see anything that would suggest major wintrer precip, although it looks like more vorticity moving onshore may make that trough dig even more.

6Z DGEX- no snow the next week for Texas or Oklahoma.

[Extremeweatherguy]

In the shorter-term, the forecast for OKC tonight through Friday looks downright chilly...

Tonight: Mostly clear, with a low around 24. North wind between 8 and 17 mph, with gusts as high as 24 mph.

Thursday: Mostly sunny, with a high near 41. Northeast wind between 7 and 9 mph.

Thursday Night: Partly cloudy, with a low around 22. East northeast wind around 8 mph.

Friday: Mostly sunny, with a high near 45. East northeast wind 6 to 8 mph becoming south.

Friday Night: Mostly clear, with a low around 28.

This is undoubtedly going to be our coldest 48 hour period we have seen so far this autumn/winter.

[Extremeweatherguy]

Very interesting and informative discussion from the Norman, OK NWS office this afternoon...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
255 PM CST WED DEC 3 2008

.DISCUSSION...
WINDS GRADUALLY DECREASING WITH TIME THROUGH TONIGHT. STILL SEEING
SEVERAL LOCALES HITTING ADVISORY CRITERIAAT 230PM... BUT WITH
CONTINUED DECREASE WE SHOULD BE ABLE TO LET THE WIND ADVISORY
EXPIRE AT 4PM. SFC GRADIENT RELAXES SLOWLY ENOUGH TO SUGGEST THAT
SPEEDS WILL STAY AT MODERATE LEVELS... WITH CONTINUED GUSTS...
WELL INTO THE EVENING/OVERNIGHT HOURS ESPECIALLY S AND E ZONES.
WINDS MOST LIKELY TO DROP OFF TO L/V LATE TONIGHT IN THE FAR NW.
TEMPS COULD PLUMMET GIVEN PROJECTED SFC DEWPOINTS... ESPECIALLY AT
KGAG WHERE WE HAVE SLIGHTLY UNDERCUT EVEN THE LOWEST OF THE
GUIDANCE MINS. WITH ARCTIC AIR MASS CONTINUING TO OVERSPREAD THE
AREA THROUGH THU AND HANGING TOUGH THROUGH MOST OF FRIDAY... WE
HAVE ALSO TRENDED TOWARD OR EVEN LOWER THAN THE LOWER GUIDANCE
TEMPS FOR THESE PERIODS. LIMITED DIURNAL TEMPERATURE RANGES ARE
TYPICAL DURING THESE EARLY PERIODS OF ARCTIC INTRUSIONS. SOME
WARMUP POSSIBLE BY SATURDAY... BUT EVEN THAT LIKELY TO BE THWARTED
BY SOME DEGREE BY A GLANCING BLOW FROM ANOTHER ARCTIC
REINFORCEMENT.

FOR SUNDAY AND BEYOND... PREVAILING LARGE-SCALE PATTERN OF LONG-
FETCH WNW FLOW ACROSS THE CONUS SUGGESTS COOL AND MOSTLY DRY NEXT
WEEK. POPS WE HAVE BEEN CARRYING FOR AROUND MON-TUE WERE BASED
INITIALLY ON EJECTION OF A CLOSED LOW PROGGED TO FORM BY THIS
WEEK`S END OFF THE CA COAST. MODELS LATELY HAVE BEEN TRENDING
TOWARD STRANDING THIS LOW OVER THE PACIFIC OR EVEN RETROGRADING IT
AROUND THE OTHER SIDE OF THE HIGHER-LATITUDE W COAST RIDGE. ECMWF
HAS BEEN AMONG THE LAST TO KICK IT E NEXT WEEK... BUT THE 12Z RUN
HAS COME AROUND TO THE OTHERS AND NOW SHOWS IT AS A NON-FACTOR
HERE AT LEAST THROUGH DAY 7. THIS SOLUTION... WITH ABSENCE OF A
PERSISTENT SPLIT AND ATTENDANT SOUTHERN BRANCH... LEAVES US
DEPENDENT ON THE WNW FLOW AND THE NORTHERN BRANCH FOR ANY PRECIP
CHANCES... AND THOSE CHANCES TYPICALLY ARE SLIM IN THIS PATTERN.
WITH MODEL AND ENSEMBLE CONSENSUS INDICATING A FAIRLY ROBUST AND
DEEPENING WAVE TRAVERSING THE AREA AROUND MONDAY... WE WILL KEEP
SLIGHT-CHANCE POPS IN FOR MONDAY AND MONDAY NIGHT. OTHERWISE A DRY
FORECAST. FURTHER CANADIAN AIR MASS INTRUSIONS WILL BE INEVITIBLE
IN THIS PATTERN... WITH CURRENT TIMING INDICATING ONE SUCH
REINFORCEMENT AROUND NEXT MONDAY AND ANOTHER JUST BEYOND DAY7/WED.

BEYOND DAY 7... THICKNESS IN THE COLDEST POOL OF POLAR AIR HAS BEEN
IN THE LOW 470S OVER SIBERIA... IMPRESSIVE EVEN BY SIBERIAN
STANDARDS. GENERAL TRENDS OF THE GFS/ECMWF ARE TO SHIFT THE
COLDEST AIR MORE TOWARD THE N POLE AND EVENTUALLY TO THIS SIDE OF
IT IN 10 DAYS... WHILE MAINTAINING AN EVER-PRESENT POSITIVE HEIGHT
ANOMALY OVER THE N ATLANTIC AND AN UPSTREAM LONGWAVE TROUGH OVER
CENTRAL/EASTERN N AMERICA. CPC IS LEANING TOWARD RETROGRESSION OF
THE EASTERN TROF MORE TOWARD THE CENTRAL/SW CONUS DURING THE 6-10
AND 8-14 DAY PERIODS... WHICH SHOULD TELECONNECT TO CONTINUED
RIDGING FROM THE E PACIFIC N TOWARD ALASKA. WITH POLAR AIR
CONTINUING TO BUILD UP N... STAGE REMAINS SET TO CAUSE POSSIBLE
SIGNIFICANT AND WIDESPREAD WINTER-TYPE WX TROUBLE IN THE MID-LATE
DEC TIME FRAME... FROM EITHER A BIG-TIME ARCTIC INVASION AND/OR
SIGNIFICANT WINTER STORMS. FIGURING OUT THE DETAILS WILL REMAIN AN
EXERCISE IN FUTILITY AS LONG AS THE MED-RANGE MODELS STRUGGLE
WITH CONTINUITY.

[cctxhurricanewatcher]

Indeed a very interesting discussion from Norman. I hate to give anyone props in OU land, but that was one impressive discussion. Kind of reminds of some of the stuff the old timers back at NWS Brownsville when a week or two out they were warning the area of the 1983 and 1989 arctic blasts.

[double D]

WOW! What a great discussion. It gives me a little more confidence that we will have some good discussions in the coming days over how cold it will acutally get. I don't know about anybody else, but the weather we have been having in Texas (although nice) has been kind of boring.

[Portastorm]

I love it ... CC and Double D posting again!! It must be winter-time in the southern half of Texas. Good to see you guys.

CC, you and I could start our own thread on how we have lost the wisdom of grizzled, ol' forecasters in NWS Brownsville who used to pick out an arctic outbreak without any "stinking models." I miss those guys more every year.

[Extremeweatherguy]

In the shorter term: The 18z GFS continues to look cold for next week. It brings light snow to Oklahoma and far north Texas by Tuesday, with the cold air then continuing to push well south into Texas thereafter. This scenario could mean a freeze for areas as far south as central and SE Texas if it verifies, and perhaps even the first small snow accumulations of the winter season from the red river northward.

[Ed Mahmoud]

Useful Relationships Between 500 mb Features and Major Freeze Events in the Lower Rio Grande Valley of Texas

aka "The McFarland Signature".

[cctxhurricanewatcher]

I love it ... CC and Double D posting again!! It must be winter-time in the southern half of Texas. Good to see you guys.

CC, you and I could start our own thread on how we have lost the wisdom of grizzled, ol' forecasters in NWS Brownsville who used to pick out an arctic outbreak without any "stinking models." I miss those guys more every year.

If only the NWS archived those discussions on the web, the rest on here could see what we are talking about. I recall listening to my little Radio Shack weather radio before the 1989 outbreak and telling people it was going to get seriously cold in a few weeks while the TV Mets were still predicting "shorts weather" for Christmas week.

And hey! I was around here for hurricane season by necessity this time around. Thanks to fine posters like Air Force Met and Wxman 57, I kept calm and cool.

Speaking of Air Force Met? Should he not be putting his two cents into this?

[Ed Mahmoud]

Tragically, this forum seems to attract mostly mets interested in tropical meteorology. Wall Cloud and H Rivera Jr. seem to be exceptions, not the rule.

[southerngale]

In the shorter term: The 18z GFS continues to look cold for next week. It brings light snow to Oklahoma and far north Texas by Tuesday, with the cold air then continuing to push well south into Texas thereafter. This scenario could mean a freeze for areas as far south as central and SE Texas if it verifies, and perhaps even the first small snow accumulations of the winter season from the red river northward.

We had a freeze night before last...blah... show me the white stuff.

[zaqxsw75050]

Actually, wxman57 is on another forum (non s2k) in winter time.

[srainhoutx]

Actually, wxman57 is on another forum (non s2k) in winter time.

Yeah, wxman57 likes to keep it "local" during the winter. We know how much he hates the anything below 85 degrees.