Wx Infinity Forums

wxman57 wrote:

Snowman wrote:Can someone tell me what may be in store for New Orleans? It won't be as cold as in Houston so are we looking at more ice than snow here? Thanks for any input.

Current models are indicating more snow for New Orleans than Houston, and up to 3-6" for the MS Coast.

Thank you wxman! Will most of the precipitation fall in New Orleans on Tuesday afternoon and night when it's colder?

The 12Z Euro is favorable for developing precip across the Southern half of Texas extending E into Louisiana and the Northern Gulf Coast. There is a good tap of Eastern Pacific moisture associated with the stronger upper low streaming across Texas in the mid and upper levels. There are also indications of embedded upper air features rippling across our Region as well.

What about for the Beaumont area?

Glad y'all are getting to enjoy the winter fun this year. Hoping it's a complete white out this week! Two winter weather events in the south within a week is something you don't see too often. Pretty rare!

Norman has only seen about 3 inches of snow so far this winter, and that was the first part of December. Rest of the events have been sleet and ice storms. It looks like y'all might be ahead of us in snowfall accumulation. Ha!
I just wish we could get some form of precip up this way, even if it was rain. Everything is so starved up here. And the cold arctic weather doesn't help.
Luckily, ridge out west looks to break down by next weekend, and that will be a pattern change itself to give us a chance at storm systems. One can only wait...

Anyway, I'll be watching closely on the weather down there! Expect NWS to issue Winter Storm Watches or warnings within next 24 hours.

Cheers everyone!

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
158 PM EST SUN JAN 26 2014

VALID JAN 26/1200 UTC THRU JAN 30/0000 UTC

...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...

12Z MODEL EVALUATION...INCLUDING FINAL PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NO SIGNIFICANT INITIALIZATION ERRORS WERE SEEN IMPACTING THE SHORT
RANGE FORECAST.


ARCTIC OUTBREAK LED BY LOW PRESSURE CROSSING OVER THE GREAT LAKES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


SOUTHERN STREAM TROUGH/CLOSED LOW REACHING BAJA/MEXICO TUE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 00Z CMC
CONFIDENCE: BELOW AVERAGE

THE CLOSED LOW FORECAST TO REACH BAJA/MEXICO ON TUE IS EXPECTED TO
TRACK EAST INTO THE MIDDLE OF THE WEEK BUT THERE ARE LARGE
DIFFERENCES ON THE TIMING OF THIS BETWEEN THE LATEST MODELS AND IN
THE ENSEMBLES. TODAYS 12Z MODEL SUITE SHOWS NO SIGNIFICANT TREND
BUT RATHER A GREAT DEAL OF RUN TO RUN VOLATILITY BUT THE NAM
APPEARS TOO FAST. OBSERVED ENSEMBLE TRENDS TO BE FASTER ARE
LEANING THE PREFERENCE AWAY FROM THE SLOWER IDEA...BUT FEEL LESS
THAN NORMAL CONFIDENCE GIVEN THE CHANGES SEEN IN EACH MODEL RUN.
GIVEN THE MOST RECENT 12Z GUIDANCE SHOWING A MARKED SPLIT BETWEEN
FASTER AND SLOWER...AND THE RECENT CHANGE IN THE 12Z CMC TO BE
MUCH MORE HELD BACK WITH THE CLOSED LOW...THE OLDER 00Z CMC
APPEARS TO BE A GOOD COMPROMISE WHICH IS CONSISTENT WITH
DOWNSTREAM PREFERENCES ACROSS THE SOUTHEAST.


BROAD SHORTWAVE DIGGING INTO THE SOUTHERN PLAINS/LOWER MS VALLEY
POTENTIAL ICE STORM FOR THE GULF COAST REGION
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z GFS / 00Z CMC BLEND
CONFIDENCE: BELOW AVERAGE

THERE ARE STILL SIGNIFICANT DIFFERENCES REGARDING A BROAD
SHORTWAVE...EXPECTED TO AMPLIFY SOUTHWARD ACROSS THE
CENTRAL/SOUTHERN PLAINS AND MISSISSIPPI VALLEY ON TUE INTO
WED...WITH THE POTENTIAL FOR A MAJOR ICE STORM ALONG THE GULF
COAST INTO THE SOUTHEAST. THE 12Z NAM IS ONE EXTREME OF THE
SPREAD...AS THE SLOWEST AND DEEPEST TO DIG THE TROUGH SOUTH
RESULTING IN WIDESPREAD SN/PL/FZRA FROM THE GULF COAST TO THE
SOUTHEASTERN U.S. COASTLINE. THE 12Z UKMET IS THE OTHER EXTREME
WITH A FLATTER/QUICKER UPPER TROUGH PROGRESSION WHICH VERY LITTLE
WINTER PRECIP FOR THE SOUTH.

TRENDS IN THE ENSEMBLE SPAGHETTI HEIGHT PLOTS SUPPORT A SOLUTION
IN THE MIDDLE WITH THE GFS TRENDING TOWARD THIS MIDDLE
CONSENSUS...ALONG WITH VERY SLOW SHIFTS TOWARD THIS IDEA FROM THE
ECMWF/UKMET AS WELL...INCLUDING THEIR 12Z CYCLES. THE 00Z CMC HAS
A SIMILAR IDEA OF THE 12Z GFS...BUT A BIT LESS SHARP WITH THE
SHORTWAVE TROUGH AS IT MOVES ACROSS THE OHIO VALLEY ON WED. GIVEN
THE FASTER SHIFT IN THE 12Z CMC AND DIFFERENCES ACROSS THE NRN
MEXICO REGION REGARDING THE ABOVE SYSTEM...A BLEND OF THE 12Z GFS
/ 00Z CMC CONTINUES TO BE PREFERRED WITH LIMITED CONFIDENCE DUE TO
THE LARGER THAN AVERAGE SPREAD FOR A DAY 2/3 SYSTEM.



Day 2 Updated QPF:

Winter Storm Watches have already been hoisted for this event in Georgia/South Carolina. Looks to be a major event for the entire south and southeast U.S.

http://www.weather.gov/chs/

Updated WPC Winter Weather Outlook Probabilities:

Snow Freezing Rain/Sleet

Paul Baustista wrote:those maos are wrong srain. very wrong. it shows too much ice and not enough snow. i dont buy those maps.
the airmass will be colder than the previous events airmass. we will get snow and sleet not ice.

Keep us informed, AZ

David Paul posted this on his Facebook page 2 hours ago.... "Winter Storm Watches or Warnings are likely Monday for SE Texas. Here's the latest forecast for more Winter Weather along the gulf coast beginning Tuesday thru Wednesday morning. Stay Tuned to KHOU-11 and expect changes in the evolving Winter Weather event!"

If it snowed this week, this would be a first since February 2010.

I think the difference this time is that they are sending balloons form UH and A&M. Last time we did not.

tireman4 wrote:I think the difference this time is that they are sending balloons form UH and A&M. Last time we did not.

That should give us a better forecast.

Winter Storm Watch is imminent. WSW is now up for parts of the Florida panhandle. As the AFD's are issued this afternoon, watch for the southern US to light up with watches including us in Houston.

Is dry air still a factor?

I'm having deja vu, is this the return of Mr. Bitter cold?

TxJohn wrote:Is dry air still a factor?

Not really and stop thinking negative thoughts

Another thing to keep an eye on is a lot of the global models look to be having trouble with the disturbances moving east across the state. A lot of the higher res models are showing more precip, most likely because they have a better handle on these disturbances.

Paul Baustista wrote:candy cane do you remember feb 2011 and how the models burned us? since you're a pro met i would like your thoughts. i remember you posting on the forum the night of that event. and it became obvious the models had screwed us., remember,no negativity txjohn. lets not even think about dry air

Well it's important to remember that a forecast model is only a tool that is used in weather prediction. However often times we have turned the model into the exact forecast. I think that's the first problem. As we saw last Friday, just because the model indicates something doesn't necessarily means it plays out that way. We saw heavy snow bands set up much further inland than anybody predicted due to the influx of ''dry air.''

It's also important to remember that each winter storm is its own beast and comparing two storms may or may not be a fair comparison. In 2011, our in-house computer model (RPM) at KPRC showed an ice event. Not snow. The microcast models that the other stations were using were indicating snow which clearly wasn't right. Houston in the 2011 event sat in a unique location. The dendritic layer (850 mb--snow making layer) was below 0c at Lake Charles. The sounding at Corpus was above freezing at 850. Intuitively it only made sense that if Lake Charles was below freezing and Corpus was above that the temp at 850 in Houston was probably right at 0c. It wasn't. We had a more pronounced warm nose and therefore we got ice instead of snow.

This event, the air is clearly colder than Friday's event. Therefore almost all precip should fall frozen and not wait on the rain to wet bulb us down to freezing. The second thing is this is a much more pronounced disturbance. When looking at a QPF of .65 inches, that signals to me right away that this could be a pretty significant event. Keep in mind however that a significant event is 2 inches in Houston.

It should be noted though that if IAH were to pick up 4 inches of snow, it would be the heaviest snowfall since the 1950s in Houston and while currently not in the forecast, it wouldn't shock me a bit to see somebody end up with over 4 inches...and that is being conservative.

This is assuming all variables remain as they are now---which clearly they won't. I think it's worth watching and definitely worth issuing a Winter Storm Watch due to the high impacts of winter weather on our area.

Candy Cane wrote:

Paul Baustista wrote:candy cane do you remember feb 2011 and how the models burned us? since you're a pro met i would like your thoughts. i remember you posting on the forum the night of that event. and it became obvious the models had screwed us., remember,no negativity txjohn. lets not even think about dry air

Well it's important to remember that a forecast model is only a tool that is used in weather prediction. However often times we have turned the model into the exact forecast. I think that's the first problem. As we saw last Friday, just because the model indicates something doesn't necessarily means it plays out that way. We saw heavy snow bands set up much further inland than anybody predicted due to the influx of ''dry air.''

It's also important to remember that each winter storm is its own beast and comparing two storms may or may not be a fair comparison. In 2011, our in-house computer model (RPM) at KPRC showed an ice event. Not snow. The microcast models that the other stations were using were indicating snow which clearly wasn't right. Houston in the 2011 event sat in a unique location. The dendritic layer (850 mb--snow making layer) was below 0c at Lake Charles. The sounding at Corpus was above freezing at 850. Intuitively it only made sense that if Lake Charles was below freezing and Corpus was above that the temp at 850 in Houston was probably right at 0c. It wasn't. We had a more pronounced warm nose and therefore we got ice instead of snow.

This event, the air is clearly colder than Friday's event. Therefore almost all precip should fall frozen and not wait on the rain to wet bulb us down to freezing. The second thing is this is a much more pronounced disturbance. When looking at a QPF of .65 inches, that signals to me right away that this could be a pretty significant event. Keep in mind however that a significant event is 2 inches in Houston.

It should be noted though that if IAH were to pick up 4 inches of snow, it would be the heaviest snowfall since the 1950s in Houston and while currently not in the forecast, it wouldn't shock me a bit to see somebody end up with over 4 inches...and that is being conservative.

This is assuming all variables remain as they are now---which clearly they won't. I think it's worth watching and definitely worth issuing a Winter Storm Watch due to the high impacts of winter weather on our area.

Best analysis I have read all day. I totally agree 100%. Some interesting days ahead. Thanks Candy Cane!