Winter 2015-16

[John1122]

WPC regarding Wednesday.

 

 

 

MODEST MOISTURE RETURN OVERRUNS TO THE
DECAYING SURFACE RIDGE. THIS SHOULD SPELL A CONTINUATION OF
ACCUMULATIONS ACROSS THE OH/TN VALLEYS INTO THE APPALACHIANS. 

[John1122]

WPC has moved most of us into the 30-50 percent range at day 5 to see more than .25 qpf of snow/sleet. This is for 12z Friday until 12z Saturday.

 

 

[John1122]

06z GFS churned out 2 to 5+ for a good portion of the area with really heavy stuff in Middle/West Tn and NE TN/Mountains. It's moving the heavier bulls eye around as can be expected, but the general idea is for a decent snowfall for a good portion of the Valley from the Miss border working it's way ENE.

 

Might be getting close to thread time since it's getting inside of 5 days for the western half.

 

The last 24 hours seems to really be upping snow totals more in line with some of the individual ensembles.

[weathertree4u]

Talk about eye-candy from the GFS! Would be a historic dumping of snow for Middle TN and blow our snow dome all to you know where!

[jaxjagman]

.DISCUSSION...

SEVERAL PERIODS OF CONTENTION IN THIS MORNING`S FORECAST
PACKAGE...WITH THE BIGGEST QUESTION BEING WEDNESDAY AND WHAT
PRECIPITATION TYPES MIDDLE TENNESSEE WILL EXPERIENCE.  NEEDLESS TO
SAY IT LOOKS LIKE WEDNESDAY MORNING COULD BE A MESS.

LET`S START WITH THE EASY STUFF.  IT`S COLD OUTSIDE.  IT`S GOING TO
REMAIN COLD OUTSIDE FOR THE NEXT COUPLE OF DAYS.  HIGH PRESSURE WILL
DRAG VERY DRY AIR INTO THE STATE OVER THE NEXT 24 HOURS AND ALONG
WITH IT...EVEN COLDER AIR.  HIGHS TODAY...EVEN WITH THE SUNSHINE
EXPECTED...WILL LIKELY TOP OUT IN THE MID TO UPPER 20S.  WITH A BIT
OF A BREEZE...WIND CHILLS IN THE TEENS AND SINGLE DIGITS WILL BE
COMMON.  AS THE SURFACE RIDGE MOVES OVER TOP OF THE MID-STATE
TONIGHT...WINDS WILL CALM...AND WE SHOULD SEE MAXIMUM COOLING.  MID
TO UPPER SINGLE DIGITS WILL BE LIKELY FOR MANY TUESDAY MORNING.

BY DAYBREAK WEDNESDAY THE FUN WILL BEGIN.  WITH ALL OF THE COLD AIR
ALREADY IN PLACE...A LOW PRESSURE SYSTEM WITH PLENTY OF ASSOCIATED
PRECIPITATION WILL BEGIN TO PUSH INTO THE STATE.  AS IT DOES...WE
WILL BE PRESENTED WITH A VERY TRICKY FORECAST.  A NOSE OF WARM AIR
ALOFT WILL NUDGE ITS WAY IN AS THE PRECIPITATION BEGINS.
WHILE THE ONSET OF PRECIPITATION COULD BE SNOW AND ICE PELLETS...THE
WARM NOSE STRENGTHENS AND BY MID-MORNING...A GOOD PORTION OF THE MID-
STATE COULD BE DEALING WITH FREEZING RAIN FOR AT LEAST A COUPLE OF
HOURS.  THIS WILL PRESENT SOME TRAVEL HAZARDS PRIOR TO THE NOON HOUR
BUT BY MID-AFTERNOON...WE SHOULD WARM UP JUST ENOUGH TO CHANGE THE
FREEZING RAIN BACK TO RAIN FOR MOST OF THE MID-STATE AND MELT
ANYTHING THAT ACCUMULATES IN THE MORNING.  HOWEVER...I AM SEEING
FORECAST SOUNDINGS IN SPOTS ON THE CUMBERLAND PLATEAU THAT DO NOT
GET ABOVE FREEZING AND THIS COULD PRESENT A PROLONGED ICE
ACCUMULATION PROBLEM.  WITH THE FACT THAT WE`RE 48 HOURS OUT AND
THERE WILL LIKELY BE CHANGES IN THE MODELS BETWEEN NOW AND
THEN...KEEP A CLOSE EYE ON THE FORECAST OVER THE NEXT COUPLE OF DAYS.

THE FAUCET SHUTS OFF WEDNESDAY EVENING FOR THE MOST PART BEFORE A
SECOND SYSTEM STARTS TO PLAGUE THE STATE.  THIS IS ANOTHER GOOD NEWS-
BAD NEWS SCENARIO.  THE GOOD NEWS...THERE DOES NOT SEEM TO BE A MIX
OF THINGS GOING ON.  RAINS ON THURSDAY CHANGE OVER TO SNOW AS COLD
AIR FILTER BACK INTO THE STATE THURSDAY NIGHT.  THE BAD NEWS...THE
RAIN CHANGES OVER TO SNOW THURSDAY NIGHT.  CURRENT PLACEMENT OF THE
TRACK OF THIS LATE-WEEK SYSTEM IS BAD FOR US.  WRAP AROUND MOISTURE
COUPLED WITH THE TRACK OF THE UPPER LOW COULD SPELL A DECENT AMOUNT
OF SNOW STARTING AROUND DAYBREAK FRIDAY AND LASTING THROUGHOUT THE
DAY.  THE GFS IS VERY BULLISH WITH POTENTIAL SNOW AMOUNTS...A 10 TO
1 SNOW RATIO WITH CURRENT QPFS SHOULD YIELD 2 TO 4 INCHES OF SNOW.
HOWEVER WITH THE RAIN FROM THURSDAY...WE CAN PROBABLY CUT SNOW
ACCUMULATIONS IN HALF COMPARED TO WHAT THEY COULD BE. EITHER
WAY...THERE WOULD BE A LOT OF TRAVEL IMPACTS. AGAIN...FOR NOW...THIS
IS 5 DAYS AWAY AND THE TRACK OF THIS SYSTEM IS GOING TO BE A MAJOR
PLAYER IN WHAT ENDS UP OCCURRING.  MORE TO COME ON THIS.

SOME FLURRIES ARE POSSIBLE FRIDAY NIGHT ON THE BACKSIDE OF THIS
SYSTEM BUT WE SHOULD DRY OUT NEXT WEEKEND AND TEMPERATURES SHOULD
BECOME MUCH MORE SEASONABLE.

http://forecast.weather.gov/product.php?site=OHX&issuedby=OHX&product=AFD&format=CI&version=1&glossary=1

[Freezing Fog]

MRX Morning Discussion

 

.LONG TERM (TUESDAY THROUGH SUNDAY)...

COLD ARCTIC AIR MASS REMAINS ACROSS THE FORECAST AREA TUESDAY WITH
WINDS DECREASING AS SURFACE HIGH MOVES OVERHEAD. TEMPERATURES WILL
STILL BE BELOW FREEZING MOST OF THE DAY. WIND CHILL TEMPERATURES
WILL INCREASE AS WINDS BECOME LIGHT. TUESDAY NIGHT THE HIGH SHIFTS
EAST AND WINDS BECOME LIGHT SOUTHERLY BY EARLY WEDNESDAY. WEATHER
PATTERN BECOMES ACTIVE AS A SYSTEM MOVES INTO THE MID MS VALLEY
TUESDAY NIGHT THEN ACROSS THE TN VALLEY WEDNESDAY AND WEDNESDAY
NIGHT. WIDESPREAD PRECIPITATION WILL DEVELOP WEDNESDAY. AS COLD AIR
REMAINS OVER THE AREA THE PRECIPITATION WILL START AS SLEET OR SNOW
BEFORE TRANSITIONING TO RAIN AS TEMPERATURES WARM. A FEW INCHES OF
SNOW MAY ACCUMULATE BEFORE THE TRANSITION. ALSO WHERE COLD AIR
BECOMES TRAPPED SOME LIGHT FREEZING RAIN MAY FALL WEDNESDAY OR
WEDNESDAY NIGHT BUT AMOUNTS RIGHT NOW ARE EXPECTED TO BE LIGHT AS
THE TRANSITION TIME IS EXPECTED TO BE SHORT.

ANOTHER STRONGER SYSTEM DEVELOPING FARTHER TO THE SW WILL MOVE INTO
THE REGION THURSDAY. WITH WARMER TEMPERATURES THIS SYSTEM WILL
PRODUCE RAIN THURSDAY...THURSDAY NIGHT AND FRIDAY. ON THE BACK SIDE
OF THIS SYSTEM COLD AIR MOVES BACK IN FRIDAY NIGHT AND SATURDAY
CHANGING THE PRECIPITATION BACK TO SNOW WITH SIGNIFICANT SNOWFALL
POSSIBLE IN THE HIGHER ELEVATIONS FRIDAY NIGHT AND SATURDAY. THE
SYSTEM PULLS OUT BY SATURDAY NIGHT WITH HIGHER PRESSURE BUILDING
BACK IN SUNDAY. TEMPERATURES FRIDAY NIGHT WILL DROP BELOW FREEZING
ACROSS THE ENTIRE FORECAST AREA WITH HIGHS SATURDAY ONLY IN THE 30S.
LOWS SUNDAY IN THE 20S WITH HIGHS WARMING INTO THE 40S WITH SUNNY
SKIES AGAIN.

[John1122]

Looks like multiple shots beyond the current two we are tracking. Have a storm in 8 days or so that gets rolling over the Western half of the valley and ends up giving the whole state some snow, with a clipper on it's heels that gives a good portion of us snow. Then another lp tracking south of us in the far extended.

[Carvers Gap]

Looks like multiple shots beyond the current two we are tracking. Have a storm in 8 days or so that gets rolling over the Western half of the valley and ends up giving the whole state some snow, with a clipper on it's heels that gives a good portion of us snow. Then another lp tracking south of us in the far extended.

 

Yes, noticed that on the 12zGFS...Sometimes, it is easy to forget to look at the rest of the model run.  Also, I have to remind myself to be wary of the a storm that follows a storm.  Sometimes that is a red herring.  Think DT always warns against that.  But yes, nice pattern if it verifies.

[John1122]

Yes, noticed that on the 12zGFS...Sometimes, it is easy to forget to look at the rest of the model run.  Also, I have to remind myself to be wary of the a storm that follows a storm.  Sometimes that is a red herring.  Think DT always warns against that.  But yes, nice pattern if it verifies.

 

The 18z looks like it's going to be a Miller A. Will obviously have to see how the next two storms are played out to get a solution on future storms.

[Carvers Gap]

The 18z looks like it's going to be a Miller A. Will obviously have to see how the next two storms are played out to get a solution on future storms.

 

Seems like the -NAO is finally doing its work, even if w/ a bit of a lag.  Nice pattern for sure.

[John1122]

Not very likely to be the exact look at this time, but I'd take it. Decent high in Northern Missouri, storm in the gulf.

 

[John1122]

Man, this is beautiful and all under 240. If true this winter and 1966 will be near mirror images of each other.

 

[JayCee]

Man, this is beautiful and all under 240. If true this winter and 1966 will be near mirror images of each other.

 

 

 

Wow. I'm speechless. 

[John1122]

This is a look I can get behind at 240.

 

[tnweathernut]

This is a look I can get behind at 240.

g]

Most ensemble packages say next weeks storm has a better chance to be a true Miller A.

[Blue Ridge]

This is a look I can get behind at 240.

 

I know I'm jumping way out there, but what becomes of the LP over TX/OK?

[John1122]

GFS just buries us next week.

 

[John1122]

 

 

[Daniel Boone]

The Gfs upgrade is really fouled up for the Cumberland gap are. I have kept records here for nearly 40 years and our seasonal snowfall average is greater than tri cities and Knoxville. If u notice the new gfs 99% of the time forecasts this area lower. Makes u wonder where the data programmed into this came from. Does anyone know ?

[Stovepipe]

The Gfs upgrade is really fouled up for the Cumberland gap are. I have kept records here for nearly 40 years and our seasonal snowfall average is greater than tri cities and Knoxville. If u notice the new gfs 99% of the time forecasts this area lower. Makes u wonder where the data programmed into this came from. Does anyone know ?

 

I'd wager it gets fed the same input data as the other models, probably only the algorithms have changed.  But perhaps a met can chime in and clarify.

[John1122]

The Gfs upgrade is really fouled up for the Cumberland gap are. I have kept records here for nearly 40 years and our seasonal snowfall average is greater than tri cities and Knoxville. If u notice the new gfs 99% of the time forecasts this area lower. Makes u wonder where the data programmed into this came from. Does anyone know ?

All the models have trouble with the microclimates here. Especially the comparatively low res long range models. Out of cities that had a weather station for a number of years, Tazewell had the highest snowfall average in the state at one point with around 20 inches.

[Daniel Boone]

All the models have trouble with the microclimates here. Especially the comparatively low res long range models. Out of cities that had a weather station for a number of years, Tazewell had the highest snowfall average in the state at one point with around 20 inches.

Good points John. You guys back there on the plateau can get walloped sometimes!

Another problem with the models is flawed data from the "so called,official" Airport weather stations. I know for a fact they are not accurate.

K1a6 in Middleborough, Ky was reading about 4 degrees high for several years before anything was done. I contacted jklnwsfo to bring up the problem and they knew and said they had brought it to the ATTN of the Faa, of whom owns/ oversees them, but, nothing was done. A Mr. Toblar from Faa called me, as kjkl had relayed my complaint to them. I explained the problem with him and even provided example of proof. He basically just scoffed it off. Finally, about 2 years later an apparent new sensor was put there.

Also, I was told by a chief nws met. that Faa allowed 4 degrees either way of actual! It's no wonder the models are off.

[John1122]

The GFS went from steady miller A or Apps runner to a frontal passage followed by a clipper for next week. Not sure what happened to the powerful storm it has been advertising for a while.

[John1122]

Next potential threat looks like it's between 156-192 right now.

 

Storm with a favorable position, just no cold to work with on the Euro. Cold on the GGEM but it's a little too far east, but gives North Carolina a winter event.

 

Also plenty of cold on the GFS but weaker and a bit east. 

 

If we could get the Euro's low on the Florida panhandle to combine with the well below freezing 850s of the GFS and GGEM we might have a nice month ending event.

[John1122]

Look at the GFS panels I posted above, now look at tonight's GGEM.

 

[John1122]

All the models have been showing this storm with widely varying tracks. The GFS is way off shore currently with it.

 

This is the NAV from 18z.

 

[John1122]

The 12z Euro from today.

 

[weathertree4u]

The 12z Euro from today.

 

This is an interesting time period, it looks like to me on the 6Z run of the GFS that it tries to develop something off the Southeast Coast at the end of the week; why wouldnt it develop sooner or closer in like the European is indicating?

[John1122]

Still a shot at something next Wednesday/Thursday. GGEM has given at least part of the area a good snow several runs in a row. The GFS brushes the far southern valley areas with a bit of snow with it's suppressed/east solution. Euro gives a pretty good Miller A track but 850s are near the Ohio River because theres a low above the Lakes and HP to our East. The GFS and GGEM  have both those features further west, which allows the cold to be in place.

[Carvers Gap]

Still a shot at something next Wednesday/Thursday. GGEM has given at least part of the area a good snow several runs in a row. The GFS brushes the far southern valley areas with a bit of snow with it's suppressed/east solution. Euro gives a pretty good Miller A track but 850s are near the Ohio River because theres a low above the Lakes and HP to our East. The GFS and GGEM have both those features further west, which allows the cold to be in place.

Lol. GEM 132h 979mb slp just off the NC coast. Formed off a stalled front - a personal favorite scenario of mine. I am always wary of a storm on the models after a big storm. They have a nasty habit of doing that, and then don't verify. But I have to say(and you have been following this) that storm has been on the models every other run. The 0z EPS had it this AM. The 12z GEFS has it on several inividual frames. We need a bit more blocking IMO. But stranger things have happened. Will definitely be following it though!