Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 6

[ams30721us]

I'm out until the wee hours of the morning, y'all hold it down, this could be winter completing the 80 yd bomb in the 4th qtr with about 7 min to go!  Still time for this to turn into a blow out, don't drop the ball Old Man Winter

 

Ha! Nice enjoy that nap!

[Quixotic1]

Looks convective in spots off to the West.

[bubba hotep]

Looks convective in spots off to the West.

Shhh, I'm trying to sleep!

Returns down I-20 almost to New Mexico

[aggiegeog]

05Z HRRR gives all north of I-20 in North and Northeast Texas 3"+ with some areas of 6"+

[bubba hotep]

We warmed up to 32.9 with rain, maximum fail! but are back down to 32 with some flakes and sleet finally mixing in...

 

 

MESOSCALE DISCUSSION 0095
NWS STORM PREDICTION CENTER NORMAN OK
0332 AM CST WED FEB 25 2015

AREAS AFFECTED...PARTS OF N-CNTRL TX / EXTREME SERN OK AND NWRN LA /
SWRN AR

CONCERNING...WINTER MIXED PRECIPITATION

VALID 250932Z - 251530Z

SUMMARY...MIXED P-TYPE PRIMARILY IN THE FORM OF FREEZING RAIN IS
INITIALLY FORECAST FROM NEAR THE N-CNTRL TX I-35 CORRIDOR EWD INTO
THE ARKLATEX. FREEZING RAIN RATES 0.05-0.15 INCH PER 3 HOURS ARE
POSSIBLE WHERE TEMPS REMAIN AT OR BELOW FREEZING. MODERATE TO HEAVY
SNOW --RATES APPROACHING/AROUND 1 INCH PER HOUR-- IS POSSIBLE
GENERALLY AFTER 11 UTC OVER PARTS OF N-CNTRL TX AND EVENTUALLY
FARTHER ENE INTO SERN OK/SWRN AR THIS MORNING.

DISCUSSION...RADAR MOSAIC SHOWS AN EXPANDING PRECIP SHIELD OVER
N-CNTRL TX INTO NERN TX AHEAD OF A MID-LEVEL LOW/TROUGH LOCATED OVER
FAR W TX. SURFACE ANALYSIS AT 09Z SHOWS TEMPS AROUND 32 FROM THE
N-SIDE OF THE DFW METROPLEX AND INCLUDING AREAS E INTO NERN TX. THE
00Z FWD RAOB SHOWED A SIZABLE LAYER AOA FREEZING /H85-H7/.
MOISTENING AND ASCENT IN THE AFOREMENTIONED LAYER HAS CONSIDERABLY
COOLED THIS LAYER OVERNIGHT. BASED ON SURFACE OBSERVATIONS AND
MODEL FORECAST SOUNDINGS IT APPEARS A FREEZING RAIN THREAT IS
BEGINNING OVER NERN TX. FREEZING RAIN RATES 0.05-0.15 INCH PER 3
HOURS SEEM LIKELY WITH HEAVIER BURSTS 0.10-0.15 INCH PER 1 HOUR
POSSIBLE IN LOCALIZED AREAS BASED ON OBSERVED RATES NEAR DFW.
ADDITIONAL MID-LEVEL COLUMNAR COOLING IS FORECAST AND A EVENTUAL
TRANSITION TO MIX OF FREEZING RAIN/SLEET IS EXPECTED.

AS INCREASING MID-LEVEL ASCENT /DCVA/ ASSOCIATED WITH THE
APPROACHING DISTURBANCE AND STRENGTHENING MID-LEVEL FRONTOGENETIC
FORCING ALONG THE N-SIDE OF THE PRECIP SHIELD OCCURS TOWARDS
MORNING...A CORRIDOR OF MODERATE TO HEAVY SNOWFALL RATES /1 INCH PER
HOUR/ IS FORECAST TO DEVELOP AND SUBSEQUENTLY SPREAD DOWNSTREAM FROM
N-CNTRL TX INTO SWRN AR.

..SMITH.. 02/25/2015


ATTN...WFO...LZK...SHV...FWD...

[bubba hotep]

[bubba hotep]

Everything pretty much showed a warm nose but I guess my biggest surprise is how heavy the rain has been up to this point.  I was really thinking we wouldn't see heavier stuff until later on. 

[bubba hotep]

[aggiegeog]

Models are showing 3-15" of snow in the Metroplex with 3-7" at my place.

[bubba hotep]

Models are showing 3-15" of snow in the Metroplex with 3-7" at my place.

System seems stronger and slower than expected. Really surprised by how heavy the rain has been up to this point.

[bubba hotep]

Sleet mixing in a bit more but there must still be a stout warm nose because we are warming up to 32.2~4 when rates pick up and then back down to 32.0 when it slacks. However, reports of snow in McKinney to my NW.

[cheese007]

Still just rain in Richardson

[bubba hotep]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
415 AM CST WED FEB 25 2015

.SYNOPSIS...

A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR SNOWFALL THIS
MORNING ACROSS MUCH OF NORTH AND CENTRAL TEXAS.

THE ENTIRE FORECAST PACKAGE IS BEING SENT AT THE "LAST MINUTE"
HERE BECAUSE WE HAVE BEEN CLOSELY MONITORING RADAR AND
OBSERVATIONS FOR EVIDENCE OF A CHANGE OVER TO SNOW.

VIRTUALLY ALL HIGH RESOLUTION MODEL GUIDANCE INDICATES THAT A
SWATH OF HEAVY SNOWFALL WILL DEVELOP OVER NORTH TEXAS THIS
MORNING. HIGH RESOLUTION MODELS RANGE FROM 4-10 INCHES OF SNOW
FROM THE DFW AREA TO THE NORTHEAST TO PARIS...AND TO THE EAST
ALONG THE INTERSTATE 20 CORRIDOR TOWARDS TYLER.

THE MAIN PROBLEM IS THAT VIRTUALLY ALL STATIONS ARE REPORTING ALL
RAIN RIGHT NOW. A 09Z KDAL AIRCRAFT SOUNDING SHOWED A WARM NOSE OF
PLUS 5 DEG C AT ABOUT 5,000 FEET ABOVE GROUND LEVEL. THIS WILL
DISAPPEAR ALLOWING PRECIPITATION TO CHANGE OVER TO SNOW AS THE
COLD AIR WITHIN THE UPPER LOW APPROACHES...HOWEVER IT`S VERY
DIFFICULT TO DETERMINE HOW MUCH MODEL QPF EQUALS REALLY COLD RAIN
VERSUS SNOWFALL AT THIS TIME.

IN TERMS OF THE DECISION TO UPGRADE TO A WINTER STORM WARNING OR
NOT...WE DECIDED NOT TO BECAUSE SURFACE TEMPERATURES ARE EXPECTED
TO REMAIN AROUND 32 DEGREES DURING PERIODS OF SNOWFALL...AND
BECAUSE OF THE LATER THAN EXPECTED CHANGE OVER TO SNOW THIS
MORNING. IF THINGS GET REALLY OUT OF CONTROL LATER ON...AN UPGRADE
IS STILL POSSIBLE...HOWEVER THE MOST RELEVANT TIME TO MAKE THAT
DECISION WAS RIGHT NOW AT 4 AM. MOST SCHOOLS...BUSINESSES AND
GOVERNMENT BUILDINGS ARE MAKING CALLS BETWEEN 4-6 AM WHETHER TO
HOLD SCHOOL/BUSINESS TODAY. AS A RESULT...WE MOST LIKELY WILL NOT
BE UPGRADING TO A WINTER STORM WARNING THIS MORNING EVEN AFTER
PRECIPITATION CHANGES OVER TO SNOW BECAUSE IT MAY NOT MAKE MUCH OF
A DIFFERENCE IN TERMS OF SOCIETAL RESPONSE.

HERE`S WHAT WE THINK WILL HAPPEN:

WIDESPREAD VERY COLD RAIN CHANGING OVER TO ALL SNOW AS THE UPPER
LOW CURRENTLY OVER MIDLAND MOVES EAST OVER NORTH CENTRAL TEXAS.
THERE WILL BE PERIODS OF MODERATE TO HEAVY SNOWFALL WHERE
VISIBILITIES WILL BE REDUCED TO ONE HALF TO ONE QUARTER MILE. IF
CONVECTION DEVELOPS...SNOWFALL RATES COULD BRIEFLY PICK UP TO 1 TO
2 INCHES PER HOUR...OF VERY WET...SLUSHY TYPE SNOW. IF A
CONVECTIVE SNOW BAND HAPPENS TO INTERSECT RUSH HOUR
TRAFFIC...IMPACTS COULD BRIEFLY BE VERY HIGH DIRECTLY UNDER THE
BAND.

SNOWFALL AMOUNTS ARE EXPECTED TO RANGE FROM 3-5 INCHES FROM THE
DFW AREA EAST ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR.
FARTHER NORTH AND SOUTH...SNOWFALL AMOUNTS OF 1-3 INCHES ARE MORE
LIKELY. ALL PRECIPITATION IS EXPECTED TO END FROM WEST TO EAST
LATE THIS MORNING THROUGH EARLY THIS AFTERNOON.

TEMPERATURES ARE EXPECTED TO CLIMB ABOVE FREEZING ACROSS THE
REGION THIS AFTERNOON AS CLOUDS CLEAR OUT. HIGHS WILL LIKELY BE IN
THE MID TO UPPER 30S WHEREVER SNOW IS ON THE GROUND...AND HIGHS
WILL CLIMB INTO THE MID TO UPPER 40S ELSEWHERE.

WE WILL PROVIDE UPDATES THROUGHOUT THIS EVENT.

CAVANAUGH

[bubba hotep]

[aggiegeog]

That Cavanaugh discussion seems solid. The Metroplex should start seeing more sleet and then snow mixing in then all snow around sunrise or just after. It could add up to several inches before it moves out by mid morning. Further east I could see the all snow period last longer so slightly higher totals are likely.

[cheese007]

If offices and schools are gonna make a decision based on conditions at the moment good chance they're going to be making a huge mistake

[bubba hotep]

If offices and schools are gonna make a decision based on conditions at the moment good chance they're going to be making a huge mistake

 

This is such a tricky situation but there will be a lot of second guessing if we get 1-2"/hr/rates during rush hour. 

[bubba hotep]

That Cavanaugh discussion seems solid. The Metroplex should start seeing more sleet and then snow mixing in then all snow around sunrise or just after. It could add up to several inches before it moves out by mid morning. Further east I could see the all snow period last longer so slightly higher totals are likely.

 

Yea, I could have done without the mental gymnastics and they could have just said the system won't meet Warning criteria and left it at that. The whole "this could be bad but it won't be bad until after people have to make a decision to close or open.. so it doesn't matter if it is a Warning or not" was a bit odd. 

[aggiegeog]

Yea, I could have done without the mental gymnastics and they could have just said the system won't meet Warning criteria and left it at that. The whole "this could be bad but it won't be bad until after people have to make a decision to close or open.. so it doesn't matter if it is a Warning or not" was a bit odd.

I agree, but that is something we have speculated they take into account so guess it is nice for him to come out and say it.

[bubba hotep]

Sounds like the transition to frozen is finally happening across the northern portions of DFW.

[cheese007]

Still just a heavy rain where I'm at. Starting to wonder if we're gonna bust hardcore. Luckily my only class was canceled so I get to watch all the fun regardless of what happens

[Roy]

Well, not even a school delay here in Keller. Argh. I wanted to at least see the snow when it fell....if it falls. Now I will be in a building. I was getting optimistic due to last night increasing totals. But, since it waited until the precip shield moved off to changeover, think DFW won't see more than 2 inches max except for Collin. Still something though. But, it has to changeoever. Have some sleet, but no snow yet in Keller.

[aggiegeog]

Sounds like the warm nose is finally giving in over the Metroplex. A bit more patience and snow should start piling up there.

[bubba hotep]

Still just a heavy rain where I'm at. Starting to wonder if we're gonna bust hardcore. Luckily my only class was canceled so I get to watch all the fun regardless of what happens

 

Really? You can't be more than 15-20 miles to my SW and we are a mix of sleet/snow/rain right now. 

 

ETA: Just switched over to basically all sleet, 5 min ago car was basically clear

 

[bubba hotep]

You don't say...

 

NWS Fort Worth ‏@NWSFortWorth  2m2 minutes ago

619a-Receiving reports of slick conditions on roads. Snow/sleet will continue this AM. Be cautious, slow down and be smart! #dfwwx #ctxwx

[cheese007]

Yeah as far as I can tell only rain. Just checked with someone downstairs to confirm as well

[bubba hotep]

Now mostly snow with some sleet mixed in!   

 

[ams30721us]

Yes...I was starting to get pretty worried! 

[bubba hotep]

Don't like the look of radar, back edge really pushing west fast now

[jhamps10]

Sounds like only rain to me in SW Ft Worth... maybe some sleet pellets mixed in now... was starting to be concerned that we were busting big time