December 2014: New Year's Eve Wintry Mix Possible

[srainhoutx]

Current surface analysis shows a 1056mb High dropping S from British Columbia and a 1053mb Ridge building into Western Montana with ridging extending into Western Kansas with a sea level barometric pressure of 1048mb.

[davidiowx]

Srain, Do you see this High Pressure moving further south than the models are predicting or do you think it will shift East and we have no threat of winter weather in the Houston area? Just curious on your opinion. Thanks!

[srainhoutx]

Srain, Do you see this High Pressure moving further south than the models are predicting or do you think it will shift East and we have no threat of winter weather in the Houston area? Just curious on your opinion. Thanks!

It appears the coldest air is in the Plains extending W along and behind that very cold upper trough. Not sure much more than modified cold air will head E. The trough extends from near the Great Lakes WSW into California. This is one of those rare times where our part of the world and into the Great Basin and the Inter Mountain West as getting the strongest shot of cold air from Canada. Rare Winter Storm Warnings are hoisted in San Diego of all places where snow could fall at the airport and the San Diego Zoo into DT and Las Vegas may even see some snow on New Year's Eve/New Year's Day that has not happened since 1974.

[ticka1]

When will we begin to feel the effects of the cold air here in SE Texas? I know most of the time the front passes through - then the cold air slowly starts filtering in and then it gets cold.

[srainhoutx]

When will we begin to feel the effects of the cold air here in SE Texas? I know most of the time the front passes through - then the cold air slowly starts filtering in and then it gets cold.

The dense cold air is seeping S faster than it is to the E. This means locations across the Edwards Plateau into the Rio Grande Valley will get the 'cold' before is oozes E into our area. My friend Paul Kocin just issued the Winter Weather Discussion for the afternoon and we will need to monitor the track of that low moving ESE across Northern Mexico for the New Year's Eve/New Year's Day timeframe.

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
254 PM EST TUE DEC 30 2014

VALID 00Z WED DEC 31 2014 - 00Z SAT JAN 03 2015


DAYS 1-3...

...SOUTHWESTERN U.S....

A POTENT UPPER LEVEL SHORTWAVE TROUGH IS DROPPING SOUTHWARD ALONG
THE SOUTHERN CALIFORNIA COAST AND IS EXPECTED TO CUT OFF AT 500 MB
WHILE CROSSING FROM SOUTHERN CALIFORNIA INTO ARIZONA. WHILE THE
SYSTEM IS ORIGINALLY MOISTURE STARVED...SOME PACIFIC MOISTURE AND
ASCENT OVER THE HIGH TERRAIN WILL SEE SNOW BREAKING OUT THIS
EVENING AND OVERNIGHT AS WEAK LOW PRESSURE DEVELOPS ALONG THE
SAGGING COLD FRONT OVER SOUTHERN CALIFORNIA. SNOW LEVELS WILL FALL
DRAMATICALLY TO NEAR 1500 TO 2000 FEET OVERNIGHT...WITH SNOWFALL
IN HIGH DESERT REGIONS AND SIGNIFICANT ACCUMULATIONS POSSIBLE
ACROSS THE SAN GABRIELS AND ACROSS THE PENINSULA RANGES. FOR DAY 1
ACCUMULATIONS...USED A MULTI MODEL BLEND OF 00Z ECMWF/12Z GFS
PARALLEL/12Z NAM/09Z SREF AND EVEN 00Z UKMET GENERATE THE
FORECAST.

ON WEDNESDAY...SIGNIFICANT MOISTURE TRANSPORT EAST OF THE TROUGH
AXIS OVER ARIZONA INTO SOUTHERN UTAH WILL INCREASE THE LIKELIHOOD
OF HEAVY SNOWFALL AMOUNTS ESPECIALLY ABOVE 3500 TO 5000 FEET. THE
12Z PARALLEL GFS AND 00Z/12Z ECMWF WERE USED FOR THE FORECAST
THOUGH THE ECMWF QPF AMOUNTS ARE OFTEN BIASED ON THE LOW END.
THEREFORE...DAY 1 TO DAY 2 SNOWFALL AMOUNTS ARE EXPECTED TO BE AT
LEAST IN THE RANGE OF 4 TO 8 INCHES ACROSS MUCH OF THE MOGOLLON
RIM AND ACROSS THE COLORADO PLATEAU IN NORTHEAST ARIZONA AND
ACROSS THE MOUNTAINS OF SOUTHERN UTAH. AS COLD AIR CONTINUES TO
SURGE SOUTHWARD ACROSS WESTERN TEXAS...LIGHT SNOW/FREEZING RAIN
AND SLEET WILL LIKELY NOT AMOUNT TO SIGNIFICANT
ACCUMULATIONS...WITH A SMALL POSSIBILITY ACROSS CENTRAL TEXAS ON
DAY 2...BUT WILL STILL RESULT IN TREACHEROUS TRAVELING CONDITIONS
ON DAYS 1, 2 AND INTO DAY 3.

ON THURSDAY/DAY 2...THE UPPER LOW APPEARS TO SPLIT INTO TWO
COMPONENTS...ONE STREAKING AND SHEARING NORTHEASTWARD TOWARD THE
CENTRAL PLAINS WHILE WEAKENING. THE OTHER PORTION REMAINS OVER
THE SOUTHWEST AND BEGINS TO LIFT NORTHEASTWARD ON FRIDAY/DAY 3.
SIGNIFICANT SNOW REMAINS OVER A GOOD PORTION OF THE SOUTHWEST ON
DAY 2...WITH SIGNIFICANT ACCUMULATIONS BEGINNING TO TAPER OFF OVER
NW ARIZONA BUT CONTINUING ACROSS THE HIGHER ELEVATIONS OF EASTERN
ARIZONA INTO WESTERN NEW MEXICO. SIGNIFICANT ACCUMULATIONS ARE
POSSIBLE AS FAR NORTH AS THE SAN JUANS IN SOUTHWEST COLORADO WHILE
LIGHT SNOWFALL ACCUMULATIONS ARE LIKELY EVEN ACROSS HIGH
ELEVATIONS OF SOUTHERN ARIZONA INTO SOUTHERN NEW MEXICO.

BY FRIDAY/DAY 3...THERE IS QUITE A BIT OF SPREAD WITH THE LOCATION
OF THE UPPER LOW OVER THE SOUTHWEST WITH THE 12Z GFS ON THE FAST
SIDE OF THE SPREAD AND THE 12Z UKMET ON THE SLOW SIDE. THE 12Z
ECMWF/GFS PARALLEL AND CANADIAN WERE MORE OR LESS IN LINE AND THE
SNOWFALL FORECAST WAS BASED PRIMARILY ON A BLEND BETWEEN THE ECMWF
AND THE PARALLEL GFS...ESPECIALLY OVER NEW MEXICO...WHERE A LOW TO
MODERATE PROBABILITY OF GREATER THAN 4 INCHES WAS MAINTAINED ON
DAY 3.

...GREAT LAKES...

THE RETURN OF VERY COLD AIR ACROSS THE GREAT LAKES WILL ALSO SEE A
RETURN OF LAKE EFFECT SNOWS ESPECIALLY DOWNWIND OF LAKES
SUPERIOR/HURON AND ONTARIO. CYCLONIC FLOW ALOFT AND THE PASSAGE
OF SEVERAL RELATIVELY WEAK SHORTWAVE TROUGHS WILL OCCUR THROUGHOUT
THE PERIOD...WITH THE UPPER PENINSULA OF MICHIGAN AND THE TUG HILL
PLATEAU IN NEW YORK MAY SEE THE HEAVIEST AMOUNTS.

THE PROBABILITY OF A QUARTER INCH OF ICING IS LESS THAN 10 PERCENT
ON DAYS 1 AND 3. DAYS.

KOCIN

[brooksgarner]

advisories.jpg

Winter storm warnings are up for west Texas, with various icy travel advisories for central sections, up thru the panhandle region...

For Houston, we're still expecting a borderline event, leaning now toward "cold rain" for New Year's day morning. Overall, models seem to be backing off on the amount of precip to fall early in the period, so even if it was cold enough, there doesn't look to be much to work with. (Yes, I know, it only takes a bit of freezing drizzle... but our pavement temps are still too warm.) When before, models were quite bullish on a wet New Year's Eve, now it looks like a few light, isolated showers through New Year's morning only. It's actually not until Friday, now, that models seem to bring the bulk of the moisture into the area. EURO and GFS backing off... only Canadian still brings in heavier rain Wednesday night. This means overall dynamic cooling would theoretically be reduced, allowing the air mass to moderate enough enough before the heavy precip arrives to end any wintry threat.

Getting ready for the 4pm newscast ........ -BG

[jeff]

12Z NAM dewpoints have trended colder along with 12Z GFS, but as mentioned above very little if any QPF in the model guidance. Neither model shows freezing low temperatures Thursday AM and any wet bulb effect (looking unlikely) with lack of QPF appears to go into saturated the low levels instead of decreasing the temperature. QPF onsets in both guidance as dewpoints warm above about 33-36 on Thursday. If the clouds hold in tomorrow the highs on both models are too warm!

Overall liquid for SE TX, exception may be in the Columbus to College Station corridor where a few hours of freezing drizzle could be possible, but even this is looking less likely. Main ice event will be west of I-35.

[Portastorm]

The City of Austin has cancelled its planned New Years Eve celebration due to predicted inclement weather. The fireworks are supposed to be re-scheduled. As it is per the current forecast, it'll be very cold and wet and breezy ... not the best conditions for folks to be outside in.

[srainhoutx]

The latest 18Z RGEM (Canadian meso model) is suggesting a burst of freezing rain and likely some sleet with those bright yellow returns very close to Austin New Year's Eve.

12302014 18Z RGEM rgem_mslp_pcpn_frzn_us_14.png

[Heat Miser]

Ha ha ha, Houston gets what it normally gets, miserable cold with a little rain. Yuck, bring on Spring already.

[nuby3]

I like what I'm seeing, I'm hoping for a little magic this winter. I am very optimistic about the next couple of weeks. I am still watching this scenario unfold with a lot of interest

[Texaspirate11]

CAN anyone tell me if I'll see some frozen stuff in Lufkin over NYE?
I only like it in margaritas

Thanks

[Paul Robison]

Dear Jeff:

I am contemplating a visit to Moody Gardens on Galveston Island Friday. Does the fact that the low you mentioned in your last post is of a coastal nature put Galveston under a greater "elevated thunderstorm" threat than, say, Southwest Houston, where I live?

Reason for post:

"When it roars, stay indoors." That's not drama, that's NOAA talking.

Tell Chita Johnson I said hi.

[jeff]

Dear Jeff:

I am contemplating a visit to Moody Gardens on Galveston Island Friday. Does the fact that the low you mentioned in your last post is of a coastal nature put Galveston under a greater "elevated thunderstorm" threat than, say, Southwest Houston, where I live?

Reason for post:

"When it roars, stay indoors." That's not drama, that's NOAA talking.

Tell Chita Johnson I said hi.

I think there would be equal chances for any elevated thunderstorms on Friday at both GLS and HOU.

[jeff]

CAN anyone tell me if I'll see some frozen stuff in Lufkin over NYE?
I only like it in margaritas

Thanks

It looks unlikely given the cold surface air (freezing or below) will mainly be across central and west TX. This area will see the onset of moisture the latest and not likely until on NYD when temps. warm above freezing...if they even reach freezing in that area NYD morning.

[srainhoutx]

Interesting to see the storm system we mentioned what seems like days ago developing NE of Hawaii rounding the base of the West Coast Ridge now near Baja and Southern California inter acting with the cold upper trough. Could be a weather headliner for areas that typically do not see Winter Weather events on a regular basis.

[harpman]

Interesting to see the storm system we mentioned what seems like days ago developing NE of Hawaii rounding the base of the West Coast Ridge now near Baja and Southern California inter acting with the cold upper trough. Could be a weather headliner for areas that typically do not see Winter Weather events on a regular basis.

Do you mean the southern U.S. or the California area?

[srainhoutx]

Do you mean the southern U.S. or the California area?

Just the whole unusual set up harpman. Seeing an SW/Southern tracking storm system with so much volatility at this range like this has been awhile. Just sayin'...

[harpman]

Just wondering...

[Ptarmigan]

Do you mean the southern U.S. or the California area?

Just the whole unusual set up harpman. Seeing an SW/Southern tracking storm system with so much volatility at this range like this has been awhile. Just sayin'...

Freezes hitting the Western US is not unusual. December 1990 Freeze hit Texas and also Western US. Same goes with February 1989 Freeze.