Jump to content
  • Member Statistics

    17,608
    Total Members
    7,904
    Most Online
    Vesuvius
    Newest Member
    Vesuvius
    Joined

OK / AR / KS / MO Winter 2013-2014


okie333

Recommended Posts

  • Replies 4.9k
  • Created
  • Last Reply

This is why I was watching the satellite imagery earlier. Maybe I'm onto something!

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE SPRINGFIELD MO

927 PM CST MON DEC 24 2012

.UPDATE...

THE 00Z NAM HAS COME IN MUCH FURTHER SOUTH WITH THE LOW PRESSURE

TRACK...BRINGING ONLY LIGHT SNOW ACCUMULATIONS TO FAR SOUTH

CENTRAL MISSOURI. GIVEN THE WATER VAPOR IMAGERY AND NAM

INITIALIZATION...WE BUY THE SOUTHWARD TREND. HOWEVER...WE ARE NOT

SO SURE ABOUT THIS DRASTIC OF A SHIFT TO THE SOUTH. WHILE WE AWAIT

THE GLOBAL MODELS TO FILTER IN...IT DOES APPEAR THAT EXPECTED

ACCUMULATIONS WILL HAVE TO BE LOWERED ACROSS THE MISSOURI OZARKS.

STILL SUSPECT WE WILL SEE ACCUMULATING SNOW ACROSS SOUTH CENTRAL

MISSOURI...WITH EVEN SOME LIGHT SNOW/FLURRIES AS FAR NORTH AS THE

INTERSTATE 44 CORRIDOR. ONCE THE GLOBAL MODELS COME IN...WE`LL

MAKE APPROPRIATE ADJUSTMENTS TO ACCUMULATIONS AND THE HEADLINES.

STAY TUNED...

Link to comment
Share on other sites

Hi guys...Merry Christmas. FYI 'bubba hotpe' posted this AFD from DFW in the TX thread. I thought it was a good read and tells why the trend south may be in the making.

FXUS64 KFWD 250312

AFDFWD

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE FORT WORTH TX

912 PM CST MON DEC 24 2012

.UPDATE...

WE HAVE ANALYZED THE 00Z UPPER AIR DATA AND HAVE WATCHED THE

SURFACE OBS CLOSELY FOR SIGNS OF ANY DISCREPANCIES BETWEEN THEM

AND THE MODEL DATA. THE BIG THING THAT STANDS OUT ARE THAT THE

SURFACE LOW IN NORTHEAST NEW MEXICO AT 6PM WAS ABOUT 80 MILES

FARTHER SOUTH THAN ALL OF THE MODELS HAD FORECAST 24 HOURS AGO.

WHEN DEALING WITH A SWINGING/DIGGING UPPER LEVEL SYSTEM...THE

SURFACE PRESSURE PATTERN AND PRESSURE TENDENCIES OFFER ENORMOUS

CLUES ON THE FUTURE TRACK OF A POTENTIAL VORTICITY ANOMALY BEFORE

IT CLOSES OFF TO BECOME A FULL FLEDGED UPPER LOW. THE 3PM AND 6PM

SURFACE ANALYSIS SHOWED A LARGE REGION OF PRESSURE FALLS ACROSS

NEW MEXICO AND WEST TEXAS IN ADVANCE OF THE SYSTEM. GIVEN THE

ORIENTATION OF THE PRESSURE FALLS AND LOCATION OF THE SURFACE

LOW...IT CAN BE DETERMINED WITHOUT EVEN LOOKING AT A FORECAST

MODEL THAT THE UPPER LOW HAS NOT FINISHED DIGGING SOUTH. THE BIG

QUESTION IS HOW FAR SOUTH WILL THE UPPER LOW MAKE IT BEFORE IT

BEGINS TO SWING BACK TO THE NORTHEAST. AT THIS HOUR PRESSURE FALLS

CONTINUE IN THE REGION FROM LUBBOCK TO MIDLAND...WITH ANOTHER

PRESSURE FALL AREA DEVELOPING IN SOUTHEAST TEXAS. EXTRAPOLATING

SUGGESTS THE UPPER LOW WILL TRACK JUST SOUTH OF LUBBOCK BY SUNRISE

AND TO NEAR WACO BY SUNSET. AS THE LOW APPROACHES WACO...A WARM

FRONT WILL BE ORGANIZING OUT OF THE WEAK STATIONARY FRONT

CURRENTLY ANALYZED FROM SAN ANTONIO TO HOUSTON. BAROCLINIC QG

THEORY SUGGESTS THAT ONCE LOW LEVEL WARM ADVECTION BEGINS IN

EARNEST ACROSS SOUTHEAST TEXAS BY MORNING...IT WILL INDUCE HEIGHT

RISES TO THE SOUTHEAST OF OUR UPPER LOW WHICH WILL CAUSE THE LOW

TO CLOSE OFF AND FINISH DIGGING SOUTH...AND START ITS GRADUAL

TURN TO THE NORTHEAST. TOMORROW EVENING I WOULD EXPECT THE LOW TO

TRACK FROM NEAR WACO TO NEAR SHREVEPORT. IN SUMMARY THE USUAL

MEDIUM RANGE MODELS APPEAR TO BE A LITTLE TOO FAR NORTH WITH THE

TRACK OF THE UPPER LOW. OUR EXPECTATIONS FOR THE TRACK OF THE LOW

ALIGN WELL WITH THE RAP FORECAST WHICH IS TO THE SOUTH OF ALL

OTHER MODELS...SO WE WILL USE THE RAP HEAVILY.

OUR FORECAST HAS BEEN ON THE SOUTHERLY SIDE AND SNOWIER SIDE OF

THE MODEL GUIDANCE. SO ALTHOUGH WE ARE SEEING AN EVEN MORE

SOUTHERLY TRACK COME TO FRUITION...THIS DOES NOT NECESSARILY

MEAN THE FORECAST SNOW AMOUNTS NEED TO BE AMENDED MUCH. THIS IS IN

PART DUE TO THE DIFFICULTY IN GETTING THE COLDER/SUBFREEZING AIR

FARTHER SOUTH BEFORE THE PRECIPITATION ENDS. THE EXCEPTION IS THE

NORTHWEST ZONES WHERE THE MORE SOUTHERLY TRACK SUGGESTS MORE

PRECIP WILL FALL IN SUBFREEZING AIR. DUE TO THE TERRAIN EFFECTS

HERE...COLD AIR HAS AN EASY TIME GETTING INTO OUR NORTHWEST ZONES

WHEN WE HAVE A NORTH/NORTHEAST SURFACE WIND. HAVE EXPANDED THE

SNOW ADVISORY TO INCLUDE YOUNG/JACK/WISE COUNTIES...AND HAVE

INCREASED SNOW TOTALS TO THE 2-4 INCH RANGE FROM BOWIE TO SHERMAN.

THE NORTHEAST ZONES LIKELY WONT SWITCH TO SNOW UNTIL LATE

AFTERNOON...AS COLD AIR WILL HAVE TROUBLE MOVING IN AT THE SURFACE

DUE TO THE LEE SHADOW WARMING EFFECT OF THE OZARK PLATEAU. MOST OF

THE SNOW THAT OCCURS THERE WILL BE AFTER 6 PM AND WILL BE HIGHLY

DEPENDENT ON WHETHER MESOSCALE BANDING CAN SET UP IN THE WAKE OF

THE UPPER LOW. THE NEW NAM HAS FINALLY FORECAST SOME SIGNIFICANT

BANDING TO OCCUR...THUS WILL LEAVE THE ADVISORY ALONE IN THIS

AREA...BUT CONFIDENCE IS A LITTLE LOWER IN THE NORTHEAST ZONES FOR

2+ INCHES OF SNOW.

FARTHER TO THE SOUTH OF THE ADVISORY...FOR THE I-20 CORRIDOR AND

INCLUDING THE METROPLEX...THERE IS NOW HIGH CONFIDENCE THAT SNOW

WILL OCCUR. HOWEVER ALL INDICATIONS ARE THAT IT WILL STILL BE A

BRIEF 1-3 HOUR EVENT WITH NOT ENOUGH TIME TO GET ACCUMULATIONS

OVER AN INCH. IT MUST BE STRESSED THAT WITH TEMPERATURES FALLING

INTO THE 20S BY SUNSET...ANY APPRECIABLE MOISTURE REMAINING ON

BRIDGES...OVERPASSES AND EVEN SURFACE STREETS WILL LIKELY RE-

FREEZE INTO BLACK ICE. ALTHOUGH WE ARE USING 1+ INCH AS CRITERIA

FOR THE COUNTIES IN THE WINTER WEATHER ADVISORY AREA...WE MAY

EXPAND THE ADVISORY SOUTH INTO THE METROPLEX OVERNIGHT DUE SOLELY

TO TRAVEL IMPACTS.

FINALLY CONCERNING THE SEVERE WEATHER TREAT. WITH A MORE SOUTHERLY

TRACK OF THE UPPER LOW...THIS MEANS THERE IS LESS OF A CHANCE OF

THE WARM FRONT MAKING IT INTO THE SOUTHEAST CWA TONIGHT AS IT WILL

LIKELY STAY SOUTHEAST OF THE AREA. ELEVATED THUNDERSTORMS ARE

STILL EXPECTED TO RAPIDLY INCREASE IN COVERAGE AFTER 3 AM...WITH

ELEVATED INSTABILITY HIGH ENOUGH FOR A FEW SEVERE HAIL STORMS

SOUTH OF I-20. HAVE TONED DOWN THE DAMAGING WIND AND TORNADO

THREAT FROM OUR PRODUCTS...BUT WE WILL CONTINUE TO ADVERTISE HAIL

STORMS POSSIBLE LATE TONIGHT AND EARLY TOMORROW MORNING.

Link to comment
Share on other sites

I'm probably beating a dead horse here. But regarding the DFW post above it says they expect the low to track from Waco to Shreveport and that the models are too far north. However, both the GFS and NAM runs have the low tracking south of these locations.

IT WILL INDUCE HEIGHT

RISES TO THE SOUTHEAST OF OUR UPPER LOW WHICH WILL CAUSE THE LOW

TO CLOSE OFF AND FINISH DIGGING SOUTH...AND START ITS GRADUAL

TURN TO THE NORTHEAST. TOMORROW EVENING I WOULD EXPECT THE LOW TO

TRACK FROM NEAR WACO TO NEAR SHREVEPORT. IN SUMMARY THE USUAL

MEDIUM RANGE MODELS APPEAR TO BE A LITTLE TOO FAR NORTH WITH THE

TRACK OF THE UPPER LOW. OUR EXPECTATIONS FOR THE TRACK OF THE LOW

ALIGN WELL WITH THE RAP FORECAST WHICH IS TO THE SOUTH OF ALL

OTHER MODELS...SO WE WILL USE THE RAP HEAVILY.

Link to comment
Share on other sites

Cape Girardeau has a blizzard watch 100% chance of 9-13 inches of snow. I would hate to be falling off that cliff come tomorrow AM, if this south move keeps going.

:lmao: Busting a forecast is never good, but busting the freaking Christmas forecast, ouch.

On the other hand, if you are a kid in Hot Springs, AR or Tunica, MS things are definitely looking up for that once in a childhood white Christmas.

Link to comment
Share on other sites

:lmao: Busting a forecast is never good, but busting the freaking Christmas forecast, ouch.

On the other hand, if you are a kid in Hot Springs, AR or Tunica, MS things are definitely looking up for that once in a childhood white Christmas.

Yep thats what my point was earlier too, especially busting a Christmas storm ouch the guilt on my mind lol. I think the worst would be people that cancel to go see family or something special and then a forecast busts that bad....ooooh Id be pissed I know that lol

Link to comment
Share on other sites

Yeah I remember going to bed as a kid with a 100% chance for snow that night, a winter storm warning with 6+ inches of accumulation, only to wake up to find that it didn't snow at all, and instead it's 35 with drizzle. I also remember the Spring morning I woke up and I was curious why my mom had not woke me up for school. I looked out the window and there was 5" of snow on everything. There was no chance of snow the night before. You win some you lose some.

Edit: But you'd think forecasting would improve in 15+ years. ;)

Link to comment
Share on other sites

I haven't looked long range... any prospects? We are really dry and need moisture. Due to this southward shift issue... we should start looking for storms that are expected to hit around Denver to Minneapolis :)

Some flurries or drizzle on Friday, but later runs will probably take it out completely. After that, boring.

Link to comment
Share on other sites

Yeah I remember going to bed as a kid with a 100% chance for snow that night, a winter storm warning with 6+ inches of accumulation, only to wake up to find that it didn't snow at all, and instead it's 35 with drizzle. I also remember the Spring morning I woke up and I was curious why my mom had not woke me up for school. I looked out the window and there was 5" of snow on everything. There was no chance of snow the night before. You win some you lose some.

Edit: But you'd think forecasting would improve in 15+ years. ;)

Ah...the infamous "Lee George flurries forecast"

Link to comment
Share on other sites

I sliced my forecast amounts for Tulsa and OKC and probably did not slice them enough if the 06Z NAM and the RAP are right now. RAP can have a south/east bias at times but goodness, both places may see nothing if some of these models are correct.

It has been interesting watching this event unfold, I always felt a southern ejection was going to happen, but not to this extreme. Leeside ejections in some type of N-NW upper level jet flows almost always end up farther S due to PV conservation laws associated with terrain interaction. Most models do not have sufficient vertical levels...especially the NAM....which is highly deficient in this area. ECMWF leads the pack, and the new Canadian RGEM is close behind. Both of these numerical models suggested a much farther S ejection through this event. Even then, they did not simulate a far enough S solution, which goes to show how far we still are in terms of vertical resolution.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Guest
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...