Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 5

[bubba hotep]

Looks like DFW will come up one short of the record, based on the current forecast.

 

From FWD:

 

DALLAS/FORT WORTH - MOST FREEZES IN A SEASON THROUGH DECEMBER 31

1 23 2000

   23 1989

3 22 1976

   22 1963

5 21 1985

   21 1983

   21 1964

8 20 2013* (THROUGH DECEMBER 26)

   20 1932

   20 1903

 

Looks like a tie is in the making, DFW busted low last night and hit 32 with the forecast low being 35.  Sunday night and Monday night look like slam dunks with lows forecasted to be well down in the 20s.  We should tie the record at 23, if the low last night comes in officially as a freeze.

[DFWWeather]

As pleasing as December has been, January looks a little worrisome. The outbreak that was slated for this week didn't pan out and the pattern looks to get more progressive as any cold gets quickly shunted off to the east rather than south. I am afraid it will be February before we can get more blocky meridonal pattern. I hope I'm wrong but that's my gut.

 

I wouldn't be so sure of that. I'm currently looking at January 9 through the 12th as a possible Arctic outbreak and fits well with current trends. Gonna say that as long as the warmer than normal water exists in the Gulf of Alaska, the tendency for ridging to push well into the state and build up of Arctic high pressures will be encouraged. Also, blocking may form over Greenland which would tend to funnel colder air into the Central US.

[wxmx]

First generalized snowfall in the Sierra to my south with the strongish s/w along the STJ. Another one is expected the 30th...couldn't make it to the one yesterday because I was in Tampico, and I won't be around in 2 days either...It's a little less than 2 hour trip (less than 50 mi as the crow flies).

[wxmx]

BTW, new severe -EPO might be in the works, with a dump of arctic air in 10 days or so...still outside of obsessive tracking scope.

[ams30721us]

BTW, new severe -EPO might be in the works, with a dump of arctic air in 10 days or so...still outside of obsessive tracking scope.

Yep, day 9-11 setup def. has my attention! Arctic plunge a little deeper than last months along with a phased strong system with trailing upper level energy. Hmmm

[bubba hotep]

Yep, day 9-11 setup def. has my attention! Arctic plunge a little deeper than last months along with a phased strong system with trailing upper level energy. Hmmm

 

Lock it in! However, it seems like we have been fooled a couple of times already this winter with really impressive 9+ day looks.  Weenie University 101: The big ones always show up in the long range

[ams30721us]

The third time is the charm!

[Srain]

I know there is a lot of chatter concerning what we may expect later in the upcoming week into next weekend. The Global ensemble and deterministic guidance continues to struggle with the -WPO/-EPO/-AO telecommunications regime and what the sensible weather will be regard this pattern change. The operational Euro dropped a very deep trough into the Western/Central US yesterday with its 12Z run while the 00Z GFS was depicting a 1065+ mb Arctic High settling into Montana only to loose it with the 06Z output. The 12Z GFS is back to a deep trough pattern with a 1050+ mb Arctic High and a deep Western/Central trough delivering much colder air well south into the Western 2/3rds of the Continental United States. Canada remains very cold, so our source regions are certainly capable of delivering a cold shot into our Region. The New Year appears to start very unsettled with a front arriving Thursday with perhaps a much colder front arriving next weekend. We will see.
 

[Srain]

I am seeing some reports of light freezing drizzle across portions of N Texas. The updated WPC Winter Weather Outlook issued late this afternoon does suggest some potential for very light freezing precip as far S as Central Texas into Monday.

[bubba hotep]

I am seeing some reports of light freezing drizzle across portions of N Texas. The updated WPC Winter Weather Outlook issued late this afternoon does suggest some potential for very light freezing precip as far S as Central Texas into Monday.

Radar is picking up some returns out near Wichita Falls moving to the SE.

 

 

ETA: DFW is reporting 32 and drizzle

[wxmx]

Over 2 feet of snow are very possible in part of the sierra to my SW...too bad I can't make the drive there on time ...

[bubba hotep]

Over 2 feet of snow are very possible in part of the sierra to my SW...too bad I can't make the drive there on time ...

gfs_apcpn_watl_15.png

How common is that type of event down there?  Too bad you won't be able to cash in on it.

[bubba hotep]

FWD starting to beat the drum....

 

 

EXTENDED...A RETURN TO BELOW NORMAL TEMPERATURES IS LIKELY ON
SUNDAY BEHIND THE SATURDAY/SATURDAY NIGHT COLD FRONT. THE MAIN
THING TO PAY ATTENTION TO IN THE EXTENDED FORECAST THOUGH IS THE
EVOLUTION OF A VERY COLD ARCTIC AIR MASS ACROSS NORTH AMERICA
EARLY NEXT WEEK.

BOTH THE 30/00Z GFS AND ECMWF INDICATE AN ARCTIC OUTBREAK FOR
THE SOUTH PLAINS EARLY NEXT WEEK. BOTH MODELS INDICATE THAT A
STRONG POLAR VORTEX WILL MEANDER OVER THE NORTH POLE AND SLIDE
SOUTH OVER NORTHERN CANADA ON THE WESTERN PERIPHERY OF A DEEP
HUDSON BAY UPPER LOW. THIS POLAR VORTEX IS THEN EXPECTED TO MERGE
WITH A STRONG SHORTWAVE TROUGH THAT BOTH MODELS INDICATE IS
CURRENTLY SITTING SOMEWHERE JUST NORTH OF THE KOREAN PENINSULA.
THIS MERGER HELPS TO DEEPEN THE UPPER LEVEL LOW PRESSURE
SYSTEM...RESULTING IN A STRONG SOUTHWARD PUSH OF ARCTIC AIR
THROUGH THE PLAINS. NOW THIS IS STILL ALMOST 200 HOURS OUT IN THE
FORECAST...WITH THE MAIN PLAYERS NOT EVEN OVER OUR CONTINENT AT
THIS TIME...SO A LOT CAN CHANGE BEFORE EARLY NEXT WEEK ARRIVES.
HOWEVER IT IS MENTIONED HERE BECAUSE OF THE VERY GOOD AGREEMENT
BETWEEN THE OPERATIONAL GFS AND ECMWF. WENT WITH TEMPERATURES WELL
BELOW NORMAL FOR EARLY NEXT WEEK AS A RESULT OF THIS ARCTIC AIR
SIGNAL FOR THE REGION.

[wxmx]

How common is that type of event down there?  Too bad you won't be able to cash in on it.

Not very...every year there're several snowfall events down to the valleys (2000-2400m), but they are usually around a few inches, since upper level moisture is uncommon in these latitudes...I have been a follower of Sierra snowfall from a rather short time period, but I think the return period for a foot of snow at valley levels is around once every 5 to 8 years...2+ feet, probably once every 15-20 years.

[bubba hotep]

Lol at the 18z GFS, calls for snow on the ground in all 50 states!

 

[wxmx]

Lol at the 18z GFS, calls for snow on the ground in all 50 states!

 

 

Plus the whole state of Nuevo Leon ... Brownsville didn't have accumulating snow in the 20th century, so if the 18z GFS comes true (not), it would be the second time for the young 21st century 

[Quixotic1]

Lol at the 18z GFS, calls for snow on the ground in all 50 states!

If memory serves me, that happened in '77.

[wxmx]

45cm reported very early today in a community in the Sierra...thats about 1.5 feet...still snowing and it will continue for most of the day today, it will certainly top 2 feet.

[Srain]

There are some significant changes via the 12Z Euro today. That model now suggests the much colder anomalies both in the temperatures expected and the placement of the mean trough axis is further W and S by hour 144.

[Quixotic1]

There are some significant changes via the 12Z Euro today. That model now suggests the much colder anomalies both in the temperatures expected and the placement of the mean trough axis is further W and S by hour 144.

Southeast Ridge beginning to flex?

[DFWWeather]

Overly confident pessimistic view of next week from FWD Forecast Discussion this afternoon in regards to just a weak frontal passage next week. A significant cold air outbreak is still well within the range of possibilities for next week supported by many ensemble runs of both the GFS and ECMWF. 12z operational models look to be trending colder.

[bubba hotep]

Overly confident pessimistic view of next week from FWD Forecast Discussion this afternoon in regards to just a weak frontal passage next week. A significant cold air outbreak is still well within the range of possibilities for next week supported by many ensemble runs of both the GFS and ECMWF. 12z operational models look to be trending colder.

Yeah, they certainly mailed that one in, "meh, glancing blows of cold" now let's get out of here for New Years!

[DFWWeather]

Yeah, they certainly mailed that one in, "meh, glancing blows of cold" now let's get out of here for New Years!

 

Well, seems like they are singing a different tune this morning. BTW, the NWS forecast lows have been too warm lately with each of these cold fronts, so has guidance. I mean this morning was a forecasted low of 34°F and we hit 31°F and yesterday guidance and NWS said a low of 28°F and we hit 24°F (that's quite a bust).

[bubba hotep]

Well, seems like they are singing a different tune this morning. BTW, the NWS forecast lows have been too warm lately with each of these cold fronts, so has guidance. I mean this morning was a forecasted low of 34°F and we hit 31°F and yesterday guidance and NWS said a low of 28°F and we hit 24°F (that's quite a bust).

Yeah, I have been noticing that.  Was the 31 at DFW? If so, then we broke the record for most freezes!

 

Also, the GFS has been sniffing out something in the 1/9 - 1/11 timeframe...

[Srain]

Well the Global ensembles and deterministic guidance did converge on an amplified pattern of that of a very strong Gulf of Alaska Ridge and a deep trough across the Plains and on East. There are still a lot of details to be worked out regarding what the sensible weather will actually be, but we now have agreement that a one/two shot of Arctic air will drop S across our Region and temperatures will turn sharply colder. I do notice a couple of short waves or upper air disturbances riding S from Western Canada and the Pacific NW into Arizona by Tuesday. One short wave/upper low looks rather potent and is depicted on all three of the Global models (Euro/GFS/Canadian). There are already hints of a Coastal trough/low attempting to develop early next week offshore of Brownsville, so we will have to  monitor those finer details as they get a bit closer. It appears the 1050-1060mb Arctic high will deliver very cold air from Western Canada into much of the Eastern 2/3rds of the United States all the way to the Gulf Coast. The Arctic front is expected to drop as far S as the NW Caribbean Sea and Cuba, so it is a very strong cold front.

[DFWWeather]

Well the Global ensembles and deterministic guidance did converge on an amplified pattern of that of a very strong Gulf of Alaska Ridge and a deep trough across the Plains and on East. There are still a lot of details to be worked out regarding what the sensible weather will actually be, but we now have agreement that a one/two shot of Arctic air will drop S across our Region and temperatures will turn sharply colder. I do notice a couple of short waves or upper air disturbances riding S from Western Canada and the Pacific NW into Arizona by Tuesday. One short wave/upper low looks rather potent and is depicted on all three of the Global models (Euro/GFS/Canadian). There are already hints of a Coastal trough/low attempting to develop early next week offshore of Brownsville, so we will have to  monitor those finer details as they get a bit closer. It appears the 1050-1060mb Arctic high will deliver very cold air from Western Canada into much of the Eastern 2/3rds of the United States all the way to the Gulf Coast. The Arctic front is expected to drop as far S as the NW Caribbean Sea and Cuba, so it is a very strong cold front.

 

I agree about a very cold start to next week. I think DFW will be down in the teens for lows Tuesday morning and may not get above freezing on Monday with full insolation. However, there has been no appreciable moisture return in the DFW area before any of these fronts and the Gulf will remain largely cutoff, especially with any coastal low developing. This Arctic airmass may send dewpoints in North Texas below zero, indicative of extremely dry air here. There is just no way appreciable precipitation will fall under those conditions. It will take some time for the atmosphere to recover.

[wxmx]

There's a slight chance of wintry precipitation around here with the aforementioned arctic front around day 6...There's some mid level energy riding the STJ around this latitude...and surface temps are around freezing in both the Euro and GFS, with the former slightly wetter, but no model shows more than light precip for a short period of time, if any.

[DoctorMu]

There's a slight chance of wintry precipitation around here with the aforementioned arctic front around day 6...There's some mid level energy riding the STJ around this latitude...and surface temps are around freezing in both the Euro and GFS, with the former slightly wetter, but no model shows more than light precip for a short period of time, if any.

 

Still lurking on the GFS in near fantasyland

 

http://www.twisterdata.com/index.php?prog=forecast&model=GFS&grid=3&model_yyyy=2013&model_mm=12&model_dd=31&model_init_hh=00&fhour=288&parameter=SNOWIN&level=SURFACE&unit=none&maximize=n&mode=singlemap&sounding=n&output=image&view=large&archive=false

[DFWWeather]

Still lurking on the GFS in near fantasyland

 

http://www.twisterdata.com/index.php?prog=forecast&model=GFS&grid=3&model_yyyy=2013&model_mm=12&model_dd=31&model_init_hh=00&fhour=288&parameter=SNOWIN&level=SURFACE&unit=none&maximize=n&mode=singlemap&sounding=n&output=image&view=large&archive=false

 

I'd be wary of the GFS output as it erodes the cold air much too quickly across North Texas and tries to suggest it will rain by Wednesday after having dewpoints ten below zero. The atmosphere will take longer than that to recover from that dry of air. It is going to be mighty cold here Tuesday morning if those dewpoints verify with clear skies.

[Srain]

Morning Update from Jeff:

 

Widespread freeze ongoing this morning across the area with lows down into the mid 20’s from Conroe to Huntsville and NE toward Lake Livingston. However a much bigger and stronger cold snap is on the way for early next week.

 

Upper level pattern will remain amplified through the period with high pressure ridging over the eastern Pacific into Alaska which will send another shot of very cold arctic air southward this weekend. Models continue to come in colder and colder with this air mass as more of the air mass pours southward down this plains before shifting eastward. This air mass means business and may set low temperature records in the northern plains which for January is very impressive…the forecast high temperature for Fargo, ND early next week is around -20F. Arctic boundary will plow through the region on Sunday with temperatures quickly falling into the 30’s and 40’s during the day. Luckily winds will stay up Sunday night, but still expect a widespread freeze and wind chill values into the 10’s and 20’s over the entire region.

 

Big concern is Monday night into Tuesday morning as arctic high builds overhead and winds go nearly calm under clear skies and very low dewpoints (8-16 degrees over the area). Expect temperatures to fall below freezing shortly after sunset and remain below freezing for up to 12-15 hours. Looks like lows could fall into the upper 10’s across our northern counties with low to mid 20’s along the US 59 corridor and even freezing at the coast. Will likely need a hard freeze warning for most areas for next Monday night as many areas will fall below 25 degrees for more than 2 hours. Tropical plants will need protection along with any exposed outdoor pipes and sprinkler systems. We are still a good bit of time before the event so temperatures could trend upward or downward over the weekend…but residents should take advantage of the “warmer” weather on Saturday to prepare for the upcoming very cold conditions.

 

Large arctic high begins to shift eastward next Wednesday allowing a moderation of temperatures and a return of moisture and possibly some low rain chances to the region.