TX winter wx thread: Spring-like pattern

[Ed Mahmoud]

Snip from NWS FWD AFD

.LONG TERM...
ANOTHER FRONT WILL ARRIVE THURSDAY NIGHT. TEMPS ARE QUITE COLD IN
THE SOURCE REGION OF AIR MASS...GENERALLY -20F TO -40F IN NORTH
CENTRAL CANADA. MAIN ARCTIC HIGH WILL AFFECT THE GREAT LAKES AND
NORTHEAST...BUT ARCTIC AIR WILL GRAZE NORTH TEXAS. MODEL TEMPS
TRENDING COLDER. MORNING TEMPS MAY BE CLOSE TO FREEZING IN NW
ZONES FRIDAY MORNING WITH POTENTIAL FOR PRECIP. A CLOUDY DAY ON
FRIDAY WITH COLD ADVECTION CONTINUOUS THROUGH FRIDAY NIGHT MAY
MEAN AN EVEN COLDER MORNING SATURDAY. EXTENDED MODELS CUT OFF
UPPER LOW OVER DESERT SOUTHWEST...WHICH WOULD MEAN PROLONGED
POSTFRONTAL PRECIP CHANCES. AT THIS TIME...POTENTIAL FOR ANY
FREEZING PRECIPITATION APPEARS TO BE CONFINED TO NORTHERN ZONES
AND HIGHER TERRAIN OF WESTERN ZONES. SINCE THE EVENT IS IN DAYS 6
AND 7 OF THE FORECAST...WILL REFRAIN FROM INTRODUCING ANY WINTRY
PRECIP AT THIS TIME. AT LEAST ONE THING IS CERTAIN...THE
FORTHCOMING WEEKEND WILL BE MUCH MORE LIKE FEBRUARY THAN THE
SPRINGLIKE WEATHER OF THE CURRENT WEEKEND. 25

[Ed Mahmoud]

DGEX still suggests winter precip for Texas toward the weekend...

[Ed Mahmoud]

Hmmm, Northeast winds and precip, but 850 mb line is nowhere to be seen (for Texas)



Gotta find a link for GFS 2 meter temps.

[Ed Mahmoud]

Can't find link, AccuWx PPV GFS raw, about 2ºC in JCT and about 4ºC in AUS, mid 30s and near 40ºF, plenty of precip with 850 mb temps warmer than surface temps. but assuming GFS is correct, on big picture, but poor grid resolution hurts low level temps, ice storm that was progged a little further North could still be on, but shifted a tad to the South.

[Extremeweatherguy]

The 6z GFS is very interesting. It has highs in Houston only in the 40s next Friday afternoon and only in the 30s next Saturday afternoon. Also, it shows a low of 31F at IAH on Saturday morning and 28F on Sunday morning. This cold will be coupled with a cloudy and occasionally wet atmosphere, meaning some icing would not be out of the question either. All in all, this is definitely something we should watch closely considering we are now only 5-6 days out from this possible event.

UPDATE - - The 12z GFS has done a flip-flop. It still shows a strong front, but now it shows less in the way of post-frontal precipitation. The new 12z scenario calls for temperatures falling into the 40s behind the front on Friday morning/afternoon, and then it drops us to freezing by sunrise Saturday, and then we raise into the upper 40s to lower 50s on Saturday with sunny skies, and then we fall into the 30s (but above freezing) on Sunday morning. All in all, this is definitely a warmer and drier scenario than the 6z offered, but still pretty chilly compared to the recent warmth we have experienced.

[MiamiensisWx]

Give it up, Extreme. Wait until next winter...

[Extremeweatherguy]

Give it up, Extreme. Wait until next winter...

Yeah, next winter will definitely be much better. I will be living up in Oklahoma by then, and I am pretty much guaranteed at least a few events each year up there. For a winter weather lover like myself, that should be a great change.

[CajunMama]

Give it up, Extreme. Wait until next winter...

Yeah, next winter will definitely be much better. I will be living up in Oklahoma by then, and I am pretty much guaranteed at least a few events each year up there. For a winter weather lover like myself, that should be a great change.

Nah...it won't be better. You're cursed! Cursed i tell ya!

[Extremeweatherguy]

Hmm... may be there is still some hope left?

The 00z GFS run now shows temperatures both at the surface and at 850mb falling to near or below freezing behind the front with some wrap-around precipitation in parts of the state next Friday and Saturday...

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_120l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_126l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_132l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_138l.gif

We could easily see a snow event into parts of north Texas with a risk of flurries into SE Texas out of a setup like this. That would definitely help to make things interesting! This scenario is probably still a long shot for now, but it is certainly something to watch.

[Extremeweatherguy]

From the Dallas AFD...

THINGS SHOULD GET A LITTLE MORE INTERESTING FRIDAY AND SATURDAY
WITH THE PASSAGE OF A STRONG COLD FRONT...FOLLOWED BY INCREASING
LIFT SUPPLIED BY AN EJECTING CLOSED LOW FROM THE SOUTHWEST. THE
GFS SOLUTION IS INDICATING A WINTER PRECIPITATION OVER A GOOD
CHUNK OF NORTH TEXAS FRIDAY THROUGH SATURDAY MORNING WHILE THE
ECMWF IS MUCH SLOWER AND WARMER AND DOES NOT BRING THE UPPER LOW
ACROSS NORTH TEXAS UNTIL SATURDAY. FOR NOW WILL GO CLOSER TO THE
ECM SOLUTION BASED ON PAST EXPERIENCES WITH THE GFS THIS FAR OUT.
WILL MENTION A CHANCE OF RAIN OR FREEZING RAIN IN THE WEST FRIDAY
NIGHT/SATURDAY MORNING WHERE THE ECM INDICATES SURFACE
TEMPERATURES WILL BE AT OR BELOW FREEZING. THIS SYSTEM WILL BE
MONITORED EXTREMELY CLOSELY IN THE COMING DAYS AS THIS PATTERN CAN
YIELD WINTER STORMS IN NORTH TEXAS IF THE TIMING OF PRECIP AND
COLD TEMPERATURES ARE IN SYNC.

Also - Here is a look at the 6z GFS run...

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_102l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_108l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_114l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_120l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_126l.gif

[Ed Mahmoud]

Relevant snip NSWFO FWD AFD

WEDNESDAY AND THURSDAY WILL BE MOISTURE RECOVERY DAYS AS A
POWERFUL STORM SYSTEM ORGANIZES OVER THE WEST. WIND SPEEDS WILL
ALSO BE ON THE INCREASE MID WEEK AS SURFACE LOW PRESSURE DEEPENS
LEE OF THE ROCKIES.

THINGS SHOULD GET A LITTLE MORE INTERESTING FRIDAY AND SATURDAY
WITH THE PASSAGE OF A STRONG COLD FRONT...FOLLOWED BY INCREASING
LIFT SUPPLIED BY AN EJECTING CLOSED LOW FROM THE SOUTHWEST. THE GFS SOLUTION IS INDICATING A WINTER PRECIPITATION OVER A GOOD CHUNK OF NORTH TEXAS FRIDAY THROUGH SATURDAY MORNING WHILE THE ECMWF IS MUCH SLOWER AND WARMER AND DOES NOT BRING THE UPPER LOW ACROSS NORTH TEXAS UNTIL SATURDAY. FOR NOW WILL GO CLOSER TO THE ECM SOLUTION BASED ON PAST EXPERIENCES WITH THE GFS THIS FAR OUT. WILL MENTION A CHANCE OF RAIN OR FREEZING RAIN IN THE WEST FRIDAY NIGHT/SATURDAY MORNING WHERE THE ECM INDICATES SURFACE
TEMPERATURES WILL BE AT OR BELOW FREEZING. THIS SYSTEM WILL BE
MONITORED EXTREMELY CLOSELY IN THE COMING DAYS AS THIS PATTERN CAN
YIELD WINTER STORMS IN NORTH TEXAS IF THE TIMING OF PRECIP AND
COLD TEMPERATURES ARE IN SYNC.

[Ed Mahmoud]

0Z GFS seems to suggests IP/ZR to plain snow around DFW, as 850 mb temps crash while precip still falls.

6Z GFS still shows some winter precip around DFW.

That would be sleet or snow, based on my secret PPV AccuWx tools. Maybe 3 inches worth.

The 0Z Canadian suggests a very brief interval of sub-freezing surface temps and precip for DFW, ie, probably a minor event.

The morning DGEX is still our wintry friend.

[Portastorm]

I refuse to believe the GFS ... I refuse to believe the GFS ... I refuse to believe the GFS!

[gboudx]

I refuse to believe the GFS ... I refuse to believe the GFS ... I refuse to believe the GFS!

I'm with you. We've seen this before. Models show wintry precip days prior to the event, then either lose it, or it's not as pronounced. Rinse, repeat.

[Ed Mahmoud]

I refuse to believe the GFS ... I refuse to believe the GFS ... I refuse to believe the GFS!

I'm with you. We've seen this before. Models show wintry precip days prior to the event, then either lose it, or it's not as pronounced. Rinse, repeat.

OK, the DGEX uses the GFS initial and boundary conditions, but it shows wintry precip in Texas.


Initial and boundary conditions always brings me back to my Diff EQ and transport phenomena classes back at UT.


Question on the final exam was on cooking vegetables in boiling water, and predicting at what time the center of variously shaped pieces of vegetables would reach a certain temperature.



Brain dumped forever a week after I graduated.

[Texas Snowman]

I agree that the GFS is usually a fast ride to winter weather disappointment in this part of the world.

But...I did notice this morning that Joe B mentioned a freeze at Houston (next week I believe). And he's been talking for some time about an end of February/early March to remember.

His 8-14 day analog year is 1950. Anyone know what happened in N. Texas weatherwise during that analog year.

Finally, I've seen on more than one occasion an end of winter spell or event that just when everyone up here in N. Texas was ready for spring, POW!

Not buying into it yet, but I've still got some firewood to burn, so one last run of winter wouldn't bother me. Then it's time for spring and big bass fishing weather!

Texas Snowman

[Ed Mahmoud]

New 12Z GFS moves the freezing and frozen precip a tad further West than earlier runs, but is still in the general ballpark.

Of course, winter weather isn't that special in Wichita Falls or Childress, but maybe the next run will get it back towards I-35




New Canadian is in same ballpark as GFS

[gboudx]

18z GFS looks to keep it west of DFW as well. Maybe we'll see some more sloshing east and west the next couple days.

[Ed Mahmoud]

18z GFS looks to keep it west of DFW as well. Maybe we'll see some more sloshing east and west the next couple days.

Getting into the range of the NAM.


Some freezing/frozen precip suggested for DFW and poinst North and West on 6Z NAM

6Z GFS isn't quite as encouraging for DFW, but points North & West have a shot.


Doesn't look like anything major (like it did about 3 or 4 days ago), but winter isn't totally over in Texas yet.

[Portastorm]

The 12z NAM appears to be more progressive with the upper low and trough than the other models, swinging it across the state on Saturday.

(pay special attention to hours 60-84):
http://www.nco.ncep.noaa.gov/pmb/nwprod ... /fpc.shtml

Should this verify, the by the time it's cold enough for frozen precip ... the potential for precip is long gone. Sounds pretty typical for this winter.