DEEP SOUTH SNEAUX 1/9/11-1/11/11

[ROLLTIDE]

Good one from Jackson,MS NWS

Quote:LONG TERM...THERE WILL BE TWO MAIN FORECAST ELEMENTS TO FOCUS ON
IN THE LONG TERM. FIRST WILL BE THE SYSTEM FOR EARLY SUN INTO SUN
NIGHT AND THE POTENTIAL FOR SNOW OR LOCALLY HEAVY RAIN. SECOND WILL
BE ON TEMPS AS A SOUTHWARD PUSH OF ARCTIC AIR LOOKS TO ARRIVE BY TUE
AND POTENTIALLY BRING SOME OF THE COLDEST AIR OF THE SEASON. I
MENTION THESE AS THE PRIMARY FOCUS OF THE FORECAST...BUT MUCH
UNCERTAINTY EXISTS FOR ANY OF THIS TO OCCUR...ESPECIALLY THE SNOW.

FOR THE LATE WEEKEND SYSTEM...I WOULD HAVE TO SAY THAT THE GLOBAL
MODEL OUTPUT IS NOT TOO BAD FOR OUR AREA. THE REASON IS THEY ALL
SHOW A SYSTEM MOVING THROUGH AND BRINGING PRECIP TO THE AREA FROM
EARLY SUN-SUN NIGHT. THE DIFFERENCES COME IN THE DETAILS AND THE
TRACK/INTENSITY OF THE UPPER S/WV AND SFC LOW. IN THIS CASE...SMALL
DIFFERENCES IN 50 TO 150 MILES WILL HAVE HUGE IMPACTS ON PRECIP TYPE
AND OVERALL IMPACT TO THE FORECAST AREA. THE RECENT TRENDS FROM THE
GEM/EURO ARE FOR A POTENT UPPER SYSTEM AND FAIRLY STRONG SFC LOW
WITH THE TRACK OF THE SFC LOW FURTHER NORTH NOW AND MORE OF THE CWA
TOO WARM FOR SNOW. THE EXCEPTION WITH THESE MODELS WOULD BE ACROSS
THE FAR NW DELTA WHERE IT REMAINS COLD ENOUGH FOR SNOW OR SOME SORT
OF MIX. AS FOR THE GFS...THE 00Z RUN HAS TRENDED A TAD COLDER...MORE
TOWARD THE PREV EURO...AND OFFERS MORE SNOW/MIX PRECIP POTENTIAL FOR
A GREATER PORTION OF THE CWA. AS YOU CAN SEE...SMALL DIFFERENCES
WILL PLAY A MAJOR ROLE IN PRECIP TYPE AND LOCATION.
ADDITIONALLY...THE S/WV (UPPER LOW) RESPONSIBLE FOR THIS POTENTIAL
IS STILL OFF THE COAST OF SW CA AND LOCATED UNDER A UPPER RIDGE
AXIS. WITH THIS SYSTEM STILL OUT OF THE OBS NETWORK...THERE REMAINS
MULTIPLE SCENARIOS AND MUCH UNCERTAINTY IN JUST HOW THE FEATURE WILL
EVOLVE AS IT MOVES INTO THE WEST AND PUSHES EAST OVER THE NEXT 60-90
HRS.

AN IMPORTANT THING TO MENTION IS HOW ALL THE GUID AT THIS POINT
SHOWS FAIRLY STRONG AGREEMENT ON LIQUID EQUIVALENT TOTALS BETWEEN
1-2 INCHES. THAT IS A DECENT AMOUNT OF RAIN JUST FALLING AS
LIQUID...ESPECIALLY AFTER A GOOD PORTION OF THE CWA RECEIVED 2-4
INCHES LAST WEEKEND. THUS THE POTENTIAL FOR LOCALLY HEAVY RAIN. THE
BIG PROBLEM WILL BE IF SOME OR ALL OF THIS LIQUID WOULD FALL AS SNOW
OR SOME SORT OF MIX. IF SO...THEN A MAJOR WINTER STORM WOULD BE IN
ORDER WITH SNOW TOTALS OF 5-15 INCHES AND SLEET/ICE ACCUMS OF .5 TO
1 INCH. FOR THE WINTRY STUFF TO OCCUR THE COLDER SOLUTIONS WOULD
HAVE TO PAN OUT AND BASED OFF THE MOST RECENT MODEL RUNS...THIS RISK
IS STILL ON THE LOW SIDE BUT DEFINITELY POSSIBLE. HOWEVER...IT WOULD
NOT TAKE MUCH OF A SWING TO THE COLDER SIDE TO MAKE THAT RISK MUCH
HIGHER.

AS FOR NOW...I WILL STAY CONSERVATIVE AND LEAN TO MORE OF THE
CONSENSUS AND STAY WITH THE SLIGHTLY WARMER SOLUTIONS. I WILL
CONTINUE TO MENTION RAIN OR SNOW OR SLEET FOR MOSTLY THE N HALF
WHERE THE POTENTIAL IS A BIT HIGHER FOR WINTRY PRECIP TO BE REALIZED
IN THOSE LOCATIONS. AS FOR POPS...GUID VALUES LOOKED GOOD AND ONLY
SOME SMALL ADJ WERE MADE. THESE NEW POPS ARE A DECENT INCREASE TO
THE PREV FORECAST...ESPECIALLY FOR THE SUN-SUN NIGHT PERIODS. TEMPS
ARE TOUGH AND STAYED PRETTY CLOSE TO GUID. GUID VALUES LOOK GOOD ON
SAT...BUT OPTED TO RAISE SAT NIGHT SOME AND STAY CLOSE TO THE
ENSEMBLE MEAN AS THE MAJORITY OF THE OPS GUID AND ENSEMBLE MEMBERS
FAVORED THE WARMER LOWS. AS FOR SUN HIGHS...GUID VALUES WERE USED
WITH THE EXCEPTION BEING ACROSS THE NW WHERE COOLER READINGS ARE
EXPECTED.

ONE IMPORTANT THING ON DEALING WITH THE FORECAST FOR THIS SYSTEM
IS...EXPECT CHANGES! THE POTENTIAL EXISTS FOR SOME SORT OF BIG
WINTER WEATHER EVENT. HOWEVER...IT IS VERY CLOSE TO BEING JUST RAIN
AND NOT A MAJOR DEAL. FORECASTS SHOULD BE MONITORED OVER THE COMING
DAYS AS I AM SURE CHANGES WILL BE IN STORE.

AS FOR THE SECOND FORECAST ELEMENT OF CONCERN...COLD TEMPS FROM
TUE-THU. THE NICE THING ABOUT THIS IS...MODELS ARE IN DECENT
AGREEMENT ON BUILDING VERY COLD AIR OVER CANADA AND PUSHING IT SOUTH
FOR MID WEEK. JUST HOW MUCH OF THE CORE OF THIS AIRMASS GETS
DELIVERED SOUTH WILL DETERMINE HOW COLD WE WILL ULTIMATELY GET...BUT
INDICATIONS ARE THAT WE WILL BE QUITE CHILLY AND HAVE THE POTENTIAL
TO SEE THE COLDEST CONDITIONS OF THE SEASON. OVERALL...HIGH TEMPS
FOR THIS PERIOD WERE TRIMMED COLDER WITH ONLY SOME SMALL ADJ TO LOWS
FOR WED-THU. AT THIS TIME...DO NOT WANT TO GET TOO AGGRESSIVE AND
WOULD LIKE TO SEE THE MODELS REALLY PUSH THE CORE OF THE COLD INTO
THE REGION BEFORE JUMPING ON THE TEENS FOR LOWS AND STAYING BELOW
FREEZING FOR HIGHS. STAY TUNED FOR WHAT LOOKS TO BE A RETURN TO
WINTER FOR THE SOUTH. /CME/

[ROLLTIDE]

[video=youtube;Jc5P3uxtfV0]http://www.youtube.com/watch?v=Jc5P3uxtfV0&feature=player_embedded[/video]

[Joe-Nathan]

[COLOR="blue"]AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
521 AM CST THU JAN 6 2011[/COLOR]

Quote:OUTLOOK...
THE EUROPEAN MEDIAN RANGE FORECAST MODEL AND THE GFS MODEL ARE IN
BETTER AGREEMENT ON THE 00 UTC CYCLE RUN...DEPICTING THE BIG BEND
LOW EXITING THE MIDDLE TEXAS COASTAL WATERS BY EARLY MORNING SUNDAY.

MUCH COLDER AIR WILL SPILL THROUGH THE FORECAST AREA FOR MONDAY
THROUGH THURSDAY.
[COLOR="blue"]
THE FIRST PROBLEM ENCOUNTERED IS THE POSSIBILITY OF LIGHT FREEZING RAIN
BY EARLY MORNING MONDAY...ACROSS THE PINEY HILLS AND LAKES REGION.
THE GFS DEPICTS NO ACCUMULATION.

THE SECOND PROBLEM ENCOUNTERED IS THE POSSIBILITY OF THE RETURN OF
FREEZING RAIN BY EARLY MORNING THURSDAY...ONCE AGAIN ACROSS THE
PINEY HILLS AND LAKES REGION. THE GFS DEPICTS SOME ICE ACCUMULATION.[/COLOR]

[ROLLTIDE]

...

Quote:AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
1008 AM EST THU JAN 6 2011

.DISCUSSION...
AWIPS PROBLEMS SOLVED AND MRX TAKING BACK FORECASTING FROM OHX AT
THIS TIME. WILL UPDATE MORNING PACKAGE AND TURN ATTENTION TOWARD
WINTER WEATHER POTENTIAL WITH SYSTEM LATE TONIGHT INTO SATURDAY.
MODEL SOUNDINGS LOOK QUITE COLD FOR FRIDAY AND SUPPORT GOOD SNOW
CRYSTAL GROWTH...SO MAY NEED WINTER WEATHER ADVISORIES AS FAR SOUTH
AS CHA AREA...WITH POTENTIAL FOR WARNING AMOUNTS OF SNOW OVER PARTS
OF SW VA AND OUR EASTERN MTNS...AS UPSLOPE SNOW SHOWERS LINGER INTO
SATURDAY.

[ROLLTIDE]

[ROLLTIDE]

12Z GFS run

http://wxcaster.com/gis-gfs-snow-overlay...TIONID=MOB

[Joe-Nathan]

FROM KLFY TV10 Wx BLOG:

Wet Weather This Weekend…

Quote:
We’re tracking a large, spinning area of low pressure in the mid to upper levels of the atmosphere over the Pacific Ocean, off the coast of California. This disturbance will take a track across Northern Mexico, then across the Deep South thru the weekend. As the energy aloft nears the Gulf of Mexico, a surface low pressure system will begin forming over South Texas/Northern Mexico, then really deepen over the Western Gulf. At this point, the actual surface low looks to track over the Gulf waters, keeping a cool northeast wind blowing across South Louisiana as a soaking rainfall begins Saturday night and lasts well into Sunday.



In this scenario, we may only see temps in the 40s Sunday. If the surface low moves inland, then we could jump well into the 60s. We’ll keep tracking this system but bottom line: wet weather looks to be a near certainty for the weekend.

What looks far from certain is getting some wintry precip in the area later next week. The latest couple runs of the GFS model bring the cold air in for the middle of next week, but then produce a low pressure system across the Central US for the end of the week, allowing us to warm up. A second blast of cold air moves into the US for the following weekend, but may stay to the north of us. So, as we’ve been stating, there is much uncertainty regarding the evolution of next week’s Arctic invasion. It’s always fun to think about snow 10 days out when the models are showing such an event, but reality is oftentimes much different. The latest model runs show no chance of snow for us. We’ll keep you posted!

By David Paul, January 5, 2011, 7:03 pm o'clock

[Joe-Nathan]

FROM TwisterData: Monday Morning Jan 10ish

[Joe-Nathan]

LOOK AT THE SNOW COVER FOR THE 12th: hello GA MTN!!!

The south LA duck hunter in me really likes this kind of snow coverage!

[ROLLTIDE]

If you want snow make the drive to Memphis,TN

Quote:LATE SATURDAY NIGHT INTO MONDAY...A DEVELOPING LOW PRESSURE SYSTEM
WILL TRACK SOMEWHERE NEAR THE GULF COAST INTO THE SOUTHEAST UNITED
STATES. MODELS HAVE COME INTO CLOSER AGREEMENT WITH THE TRACK AND
TIMING BUT THERE ARE STILL MINOR DIFFERENCES WHICH COULD PLAY A HUGE
ROLE IN WHERE AND HOW MUCH. THE 00Z GFS IS THE FURTHEST SOUTH WITH
THE SFC LOW OF THE MODELS...TRACKING THE LOW JUST SOUTH OF THE GULF
COAST BUT IS FARTHER NORTH THAN LAST NIGHTS RUN. THE MAJOR
DIFFERENCE BETWEEN THE ECMWF/CANADIAN AND THE GFS IS THAT BOTH THE
00Z ECMWF AND 00Z CANADIAN CLOSE OFF A 500 MB LOW AND TRACK IT
OVER THE MIDSOUTH. THE GFS IS JUST A 500MB WAVE. THE GFS KEEPS BULK OF
THE PRECIPITATION TO THE SOUTH WITH NORTH MISSISSIPPI HAVING THE
BEST CHANCE OF SEEING WINTER WEATHER. HOWEVER IF A 500MB LOW WERE
TO DEVELOP...IT COULD ENHANCE SNOWFALL WHERE IT TRACKS. THE
CANADIAN AND ECMWF SEEM TO BE CONSISTENT WITH A CLOSED 500 MB LOW
DEVELOPING. THE BIG DIFFERENCE BETWEEN THOSE TWO MODELS IS THAT
THE CANADIAN SEEMS TO BE A TAD FARTHER NORTH THAN THE ECMWF WITH
THE SFC LOW TRACK. IF THE CANADIAN IS RIGHT...PRECIP TYPE ISSUES
COULD OCCUR ACROSS THE SOUTHERN PORTIONS OF THE CWA AS SLIGHTLY
WARMER AIR MOVES IN AHEAD OF THE SFC LOW. HOWEVER MOST OF THE CWA
WOULD STAY ENTRENCHED IN THE ARCTIC AIR...KEEPING PRECIP TYPE ALL
SNOW. BOTH MODELS SEEM TO INDICATE THAT SIGNIFICANT SNOWFALL COULD
OCCUR ACROSS THE CWA. A LOT WILL DEPEND WHERE THE DEFORMATION ZONE
SETS UP AND WHERE THE 500 MB LOW TRACKS. LOOKING AT THE LATEST
ECMWF AND CANADIAN...THE MEMPHIS METRO AREA MAY HAVE A BETTER CHANCE AT
SEEING ACCUMULATING SNOW THAN NORTH MISSISSIPPI WHICH THE GFS
SHOWS. WITH THAT BEING SAID...WE ARE STILL A LONG WAY OUT AND
MODELS COULD STILL CHANGE. FOR THIS FORECAST WILL LEAN TOWARD THE
00Z ECMWF AS IT IS THE SOLUTION IN THE MIDDLE. PRECIPITATION
SHOULD BEGIN TO SPREAD IN FROM THE SOUTH LATE SATURDAY NIGHT WITH
THE BULK OF THE PRECIPITATION OCCURRING SUNDAY NIGHT INTO EARLY
MONDAY.

MONDAY NIGHT INTO TUESDAY...A COUPLE OF SHORTWAVES WILL CONTINUE TO
PRODUCE SNOW SHOWERS OVER THE AREA. LITTLE TO NO ACCUMULATIONS ARE
EXPECTED WITH THE SNOW SHOWERS. WITH SNOW COVER ON THE GROUND IN
MANY PLACES...TEMPERATURES WILL BE VERY COLD ON TUESDAY. HIGHS
WILL ONLY BE IN THE UPPER 20S TO MID 30S.

TUESDAY NIGHT INTO WEDNESDAY...ARCTIC HIGH PRESSURE WILL GRADUALLY
BUILD INTO THE MIDSOUTH. THE 00Z GFS IS QUICKER AT MOVING THE HIGH IN
THAN THE ECMWF THUS IF THE ECMWF IS CORRECT FLURRIES COULD
CONTINUE INTO TUESDAY NIGHT POSSIBLY INTO WEDNESDAY.
REGARDLESS...TEMPERATURES WILL REMAIN FRIGID. LOWS WILL NOT BE AS
LOW AS THEY COULD BE THANKS TO CLOUD COVER. READINGS WILL BE IN
THE UPPER TEENS TO MID 20S. HIGHS WILL REMAIN IN THE UPPER 20S TO
LOWER 30S.